DOCUMENT RESUME

ED 296 867 SE 049 158

TITLE Water Treatment Plant Operation Volume 2. A Field

Study Training Program. Revised.
INSTITUTION California State Univ., Sacramento. School of
Engineering.; National Environmental Training
Association, Valparaiso, IN.
SPONS AGENCY California State Dept. of Health Services,
Sacramento. Sanitary Engineering Branch.;
Environmental Protection Agency, Washington, DC.
Office of Drinking Water.
PUB DATE 88
GRANT T-901361-01-0
NOTE 690p.: Some charts and drawings may not reproduce
well. Pages containing final examination and answers
are printed on dark grey paper and maybe
illegible.
AVAILABLE FROM Mr. Ken Kerri, California State
University-Sacramento, 6000 J Street, Sacramento, CA
95819-2654.
PUB TYPE Guides Classroom Use Guides (For Teachers) (052)
Guides Classroom Use Materials (For Learner)
(051) -- Tests/Eveluation Instruments (160)

EDRS PRICE MF04/PC28 Plus Postage.

DESCRIPTORS Chemical Analysis; *Course Content; *Drinking Water;
*Environmental Education; Fluoridation; *Home Study;
Laboratory Procedures; Postsecondary Education;
Safety; Training Methods; *Water Quality; *Water
Treatment

ABSTRACT
The purpose of this water treatment field study
training program is to: (1) develop new qualified water treatment
plant operators; (2) expand the abilities of existing operators,
permitting better service both to employers and public; and (3)
prcpare operators for civil service and certification examinations
(examinations administered by state/professional associations which
operators take to indicate a level of professional competence).
Volume 2 is a continuation of volume 1, in which the emphasis was on
the knowledge and skills needed by operators of conventional surface
water treatment plants. This 12-chapter volume contains information
on: iron and manganese control; fluoridation; softening;
trihalomethanes; demineralization; handling and disposal of processed
wastes; maintenance; instrumentation; safety; advanced laboratory
procedures; drinking water regulations; and administration.
Objectives, glossary, lessons, questions (with suggested answers),
and a test are provided for each chapter. A final examination (with
answers), how to solve water treatment plant arithmetic problems,
water abbreviations, complete glossary, and subject index are
provided in an appendix. Information on objectives, scope, and uses
of this manual and instructions to participants in home-study courses
are found in volume 1. (TW)
 Environmental Protection Agency Review Notice
This training manual has been reviewed by the Office of Drinking Water,
U.S. Environmental r ,*^^tion Agency and the California Department of
Health Services. Both agencies have approved this manual for publication.
Approval does not signify that the contents necessarily reflect the views
and policies of the Environmental Protection Agency nor the California
Department of Health Services. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use by
the Environmental Protection Agency; California Department of Health
Services; California State University, Sacramento; National Environmental
Training Association; authors of the chapters or project reviewers, consul-
tants. and directors.

3
 WATER TREATMENT PLANT OPERATION
Volume II

A Field Study Training Program

prepared by

California State University, Sacramento

School of Engineering
Applied Research and Design Center

in cooperation with the

National Environmental Training Association

***************************************
Kenneth D. Kern, Project Director

***************************************

for the

Caiffornia Department of Health Services

Sanitary Enc:neering Branch
Standard Agreement #80-64652
and
U.S. Environmental Protection Agency
Office of Drinking Water
Grant No. T-901361-01-0

1988

't4
 OPERATOR TRAINING MANUALS

OPERATOR TRAINING MANUALS IN THIS SERIES are available from Ken

Kern, California State University, Sacramento, 6000 J Street, Sacramento, CA
95819-2654, phone (916) 278-6142.
1. WATER TREATMENT PLANT OPERATION, 2 Volumes,
2. SMALL WATER SYSTEM OPERATION AND MAINTENANCE,
3. WATER DISTRIBUTION SYSTEM OPERATION AND MAINTENANCE,
4. OPERATION OF WASTEWATER TREATMENT PLANTS, 2 Volumes,
5. ADVANCED WASTE TREATMENT,
6. INDUSTRIAL WASTE TREATMENT,
7. TREATMENT OF METAL WASTESTREAMS,
8. PRETREATMENT FACILITY INSPECTION, AND
9. OPERATION AND MAINTENANCE OF WASTEWATER COLLECTION
SYSTEMS, 2 Volumes.

NOTICE

This manual is revised and updated before each printing based on comments
from persons using the manual.

First printing, 1983 7,000

Second printing, 1988 5,000

Copyright © 1988 by
Hornet Foundation, Inc
California State University, Sacramento

ii
 PREFACE
VOLUME II

Volume II is a continuation of Volume I. In Volume I, the emphasis was on the knowledge and skills needed by
operators of cor rentional surface water treatment plants. Volume II stresses information needed by those
operators but also includes information on specialized water treatment processes for iron and manganese
control, fluoridation, softening, trihalomethanes, demineralization and the handling and disposal of process
wastes. Topics of importance to the operators of all water treatment plants include maintenance, instrumenta-
tion, safety, advanced laboratory procedures, water quality regulations, administration, and how to solve water
treatment plant arithmetic problems.
You may wish to concentrate your studies on those chapters that apply to your water treatment plant. Upon
successful completion of this entire volume, you will have gained a broad and comprehensive knowledge of the
entire water treatment field.
For information on:
1. Objectives of this manual,
2. Scope of this manual,
3. Uses of this manual,
4. Instructions to participants in the home-study course, and
5. Summary of procedure,
please refer to Volume I.
The Project Director is indebted to the many operators and other persons who contributed to this manual.
Every effort was made to acknowledge material from the many excellent references in the water treatment field.
Reviewers Leonard Ainsworth, Jack Rossum, and Joe Monscvitz deserve special recognition for their extremely
thorough review and helpful suggestions. John Trax, Chet Pauls, and Ken Hay, Office of Drinking Water, U.S. En-
vironmental Protection Agency, and John Gaston, Bill MacPherson, Bert Ellsworth, Clarence Young, Ted Bakker,
and Beverlie Vandre, Sanitary Engineering Branch, California Department of Health Services, a:I performed
outstanding jobs as resource persons, consultants and advisors. Larry Hannah served as Education Consultant.
Illustrations were drawn by Martin Garrity. Charlene Arora helped type the field test and final manuscript for print-
ing. Special thanks are well deserved by the Program Administrator, Gay Kornweibel, who typed, administered
the field test, managed the office, administered the budget, and did everything else that had to be done to com-
plete this project successfully.
KENNETH D. KERRI
PROJECT DIRECTOR

iii
 TECHNICAL CONSULTANTS
John Brady Jim Sequeira
Gerald Davidson Susuma Kawamura
Larry Hannah Mike Young

NATIONAL ENVIRONMENTAL TRAINING ASSOCIATION REVIEWERS

George Kinias, Project Coordinator
E. E. "Skeet" Arasmith Andrew Holtan William Redman
Terry Engelhardt Deborah Horton Kenneth Walimaa
Dempsey Hall Kirk Laflin Anthony Zigment
Jerry Higgins Rich Metcalf

PROJECT REVIEWERS
Leonard Ainsworth Chet Latif David Rexing
Ted Bakker Frank Lewis Jack Rossum
Jo Boyd Perry Libby William Ruff
Dean Chausee D. Mackay Gerald Samuel
Walter Cockrell William Maguire Carl Schwing
Fred Fah len Nancy McTigue David Sorenson
David Fitch Joe Monscvitz Russell Sutphen
Richard Haberman Angela Moore Robert Wentzel
Lee Harry Harold Mowry James Wright
Jerry Hayes Theron Palmer Mike Yee
Ed Henley Eugene Parham Clarence Young
Charles Jeffs Catherine Perman

iv
 COURSE OUTLINE
WATER TREATMENT PLANT OPERATION, VOLUME I
Page Page
1. The Water Treatment Plant Operator 1 9. Taste and Odor Control 373
by Ken Kern by Russ Bowen
2. Water Sources and Treatment 15 10. Plant Operation 413
by Bcrt Ellsworth by Jim Beard
3. Reservoir Management and Intake Structures 39 11. Laboratory Procedures 455
by Dick Barnett by Jim Sequeira
4. Coagulation, and Flocculation 91 Appendix by Ken Kern 527
by Jim Beard
Final Examination 528
5. Sedimentation 143
by Jim Beard How to Solve Water Treatment
Plant Arithmetic Problems 541
6. Filtration 195
by Jim Beard Water Abbreviations 586

7. Disinfection 247 Water Words 587

by Tom Ikesaki Subject Index 633
8. Corrosion Control 333
by Jack Rossum

COURSE OUTLINE
WATER TREATMENT PLANT OPERATION, VOLUME II
Page Page
12. Iron and Manganese Control 1 20. Safety 387
by Jack Rossum by Joe Monscvitz
13. Fluoridation 25 21. Advanced Laboratory Procedures 445
by Harry Tracy by Jim Sequeira
14. Softening 63 22. Drinking Water Regulations 487
by Don Gibson and Marty Reynolds by Tim Gannon
15. Trihalomethanes 115 23. Administration 535
by Mike McGuire by Tim Gannon
16. Demineralization 135 Appendix by Ken Kern 561
by Dave Argo
Final Examination 563
17. Handling and Disposal of Process Wastes 179
by George Uyeno How to Solve Water Treatment 573
Plant Arithmetic Problems
18. Maintenance 207
by Parker Robinson Water Abbreviations 599

19. Instrumentation 331 Water Words 501

by Leonard Ainsworth Subject Index 649

V
 CHAPTER 12

IRON AND MANGANESE CONTROL

by

Jack Rossum

with a special section by

Gerald Davidson

!)
 2 Plant Operation

TABLE OF CONTENTS

Chap`or 12. Iron and Manganese Control

OBJECTIVES 3
GLOSSARY 4
12.0 Need to Control Iron and Manganese 6
12.1 Measurement of Iron and Manganese 6
12.10 Occurrence of Iron and Manganese 6
12.11 Collection of Iron and Manganese Samples 7
12.12 Analysis for Iron and Manganese 7
12.2 Remedial Action 9
1220 Alternate Source 9
12.21 Phosphate Treatment 9
12.22 Removal by Ion Exchange 11

12.23 Oxidation by Aeration 12

12.24 Oxidation with Chlorine 13
12.25 Oxide ion with Permanganate 13
12.26 Operation of Filters 14
12.27 Proprietary Processes by Bill Hoyer 14
12.28 Monitoring of Treated Water 15
12.29 Summary 15
12.3 Operation of an Iron and Manganese Removal Plant
by Gerald Davidson 16
12.30 Description of Process
16
12.31 Description of the Plant 17
12.32 Operation of the Greensand Process 19
12.4 Maintenance of a Chemical Feeder 20
12.5 Troubleshooting Red Water Problems 21
12.6 Arithmetic Assignment 21
12.7 Additional Reading 21

Suggested Answers 22
Objective Test 23

10
 Iron and Many r.ese 3

OBJECTIVES
Chapter 12. IRON AND MANGANESE CONTROL

Following completion of Chapter 12, you shoula be able

to:
1. Identify and describe the various processes used to
control iron and manganese,
2. Collect samples for analysis of iron and manganese,
3. Safely operate and maintain the fallowing iron and man-
ganese control processes:
a. Phosphate treatment,
b. Ion exchange,
c. Oxidation by aeration,
d. Oxidation with chlorine,
e. Oxidation with permanganate,
f. Greensand,
g. Proprietary processes, and
4. Troubleshoot red water problems.

1i
4 Plant Operation

GLOSSARY
Chopter 12. IRON AND MANGANESE CONTROL

ACIDIFIED (uh-SID-uh-FIE-d)
ACIDIFIED
The addition of an acid (usually nitric or sulfuric) to a sample to lower the pH below 2.0. The
purpose of acidification is to "fix" a
sample so it won't change until it ;s analyzed.

AQUIFER (ACK-wi-fer)
AQUIFER
A natural underground layer of porous, water-bearing materials (sand, grave;) usually napable of yielding
supply of water. a large amount or

BACKFLOW
BACKFLOW
A reverse flow condition, created by a difference in water pressures, which causes water to flow back into the
of a potable water supply from any source or sources other than an intended source. Also distribution pipes
see BACKSIPHONAGE.
BACKSIPHONAGE
BACKSIPHONAGE
A form of backflow caused by a negative or below atmospheric pressure within a water system. Also
see BACKFLOW.
BENCH SCALE TESTS
BENCH SCALE TESTS
A method of studying different ways or chemical doses for treating water on a small scale
in a laboratory.
BREAKPOINT CHLORINATION
BREAKPOINT CHLORINATION
Addition of chiorine to water until the chlorine demand has been satisfied. At this point, further additions
of chlorine will result in
a free residual chlorine that is directly proportional to the amount of chlorine added beyond the breakpoint.

CHELATION (key-LAY-shun)
CHELATION
A chemical complexing (forming or joining together) of metallic cations (such as copper) with certain
organic compounds, such
as EDTA (ethylene diamine tetracetic acid). Chelation is used to prevent the precipitation of metals (copper). Also
SEQUESTRATION. see

COLLOIDS (CALL-bids)
COLLOIDS
Very small, finely divided solids (particles that do not dissolve) that remain dispersed in a liquid for
a long time due to their small
size and electrical charge. When most of the particles in water have a negative electrical charge, they tend
to repel each other.
This repulsion prevents the particles from clumping together, becoming heavier, and settling out.

DIVALENT (die-VAY-lent)
DIVALENT
Having a valence of two, such as the ferrous ion, Fe2+. Also called BIVALENT.

GREENSAND
GREENSAND
A sand which looks like ordinary filter sand except that it is green in color. The sand is a natural
ion exchange material which is
capable of softening water and removing iron and manganese.

INSOLUBLE (in-SAWL-you-bull)
INSOLUBLE
Something that cannot be dissolved.

ION EXCHANGE
ION EXCHANGE
A water treatment process involving the reversible interchange (switching) of ions between the
water being treated and the
solid resin. Undesirable ions in the water are switched with acceptable ions on the resin.

ION EXCHANGE RESINS

ION EXCHANGE RESINS
Insoluble polymers, used in water treatment, that are capable of exchanging (switching or giving) acceptable cations
or anions
to the water being treated for less desirable ions.

. 12
 Iron and Manganese 5

RESINS RESINS
See ION EXCHANGE RESINS.

SEQUESTRATION (SEE-kwes-TRAY-shun) SEQUESTRATION

A chemical complexing (forming or joining together) of metallic cations (such zs iron) with certain inorganic compounds, such
as phosphate Sequestration prevents the precipitation of the metals (iron). Also see CHELATION.

ZEOLITE ZEOLITE
A type of ion exchange -naterial used to soften water. Natui at zeolites are siliceous compounds (made of silica) which remove
calcw and m-.gnesiul., m hard water and replace them with sodium. Synthetic or organic zeolites are ion exchange materi-
als % , .-crnc.r.'s calc: JIT1 or magnesium and replace them with either sodium or hydrogen. Manganese zeolites are used to re-
move .cmganese.
 6 Plant Operatior

CHAPTER 12. IRON AND MANGANESE CONTROL

12.0 NEED TO CONTROL IRON AND MANGANESE into a jet black compound called manganese dioxide These
Like the cities of Minneapolis and St. Paul, iron and materials form a loosely adherent coating on the pipe walls.
manganese are referred to as a pair. They are, in fact, two pieces of this coating will break loose from the pipe walls
distinct elements and are often found in water separately when there are changes or reversals of flow in the distribu-
Neither of them has any direct adverse health effects. tion system.
Indeed, both are essential to the growth of many plants and 'roil and manganese in water can be easily detected by
animals, including humans.
observing the color of the inside walls of filters and the filter
However, the iron and manganese found in drinking water media If the raw water is prechlorinated, there will be black
have no nutrient value for humans. Even if they were stains on the walls below the water level and a black coating
available in beneficial amounts, the presence of iron and over the top portion of the sand filter bed. This black colnr
manganese in drinking water would still be objectionable. will usually indicate a high level of manganese in the raw
water while a brownish-black stain indicates the presence of
Clothes laundered in water containing iron and manga- both iron and manganese.
nese above certain levels come out stained. When bleach is
added to remove the stains, they are only intensified and The generally acceptable limit for iron in drinking water is
become fixed so that no amount of further washing with 0.3 mg/L and that for manganese is P n5 mg/L. However, if
iron-free water will remove the stains. They can be removed the water contains more than 0.02 mg/ of manganese, the
by treatment with oxalic acid, but this is rather hard on operator should vitiate an effective flushing program to
.
fabrics or by the use of commercial rust removers. Exces-
avoid complaints. By regularly flushing the water mains, the
sive amounts of iron and manganese are also objectionable
buildup of black manganese dioxide can be prevented.
because they impart stains on plumbing fixtures, bath tubs
and sinks.

Perhaps the most troublesome consequence of iron and

QUESTIONS
manganese in the water is that they promote the growth of a
group of microorganisms known as iron bacteria. These Write your answers in a notebook and then compare your
organisms obtain energy for their growth from the chemical answers with those on page 22.
reaction that spontaneously occurs between iron and man-
ganese and dissolved oxygen. These bacteria form thick 12 OA What problems are caused by iron an manganese in
slimes on the walls of the distribution system mains. Such drinking water9
slimes are rust colored from iron and black from manga-
nese. Variations in flow cause these slimes to come loose 12 OB How can the growth of iron bacteria be controlled'?
which result in dirty water (a big source of consumer
12.0C What are the generally acceptable limits for iron and
complaints). Furthermore, these slimes will cause foul tastes manganese in winking water9
and odors in the water.
The growth of iron bacteria is controlled by chlorination 12.1 MEASUREMENT OF IRON AND MANGANESE
However, when water containir., ron is chlorinated, the iron
is converted into rust particles, and manganese is converted
12.10 Occurrence of Iron and Manganese
'-.
'lel' Ola Because both .ron and manganese react with dissolved
14\
°F.I.n9r oxygen to form INSOLUBLE COMPOUNDS,' they are not
found in high concentrations in waters containing dissolved
oxygen except as COLLOIDAL SUSPENSIONS2 of the
oxides. Accordingly, surface waters are generally free from
both iron and manganes6. One exception to this rule is that
manganese up to one mg/L or higher may be found in
shallow reservoirs and may come and go several times a
year.

1 Insoluble Compounds (in-SAWL-you-bull). Compounds that cannot be dissolved.

2Colloidal Suspensions (CALL-loid-al) Very small, finely divided solids (particles that do not dissolve)
that remain dispersed in a liquid
for a long time due to their small size and electrical charge. When most of the particles in water have a negative electrical charge, they
tend to repel each other This repulsion prevents the particles from clumping together, becoming heavier, and settling out.

14
 iron and Manganese 7

Iron or manganese is most frequently found in water flow rate is su:table for filling the sample bottle. Allow the
systems supplied by wells and springs. Horizontal wells sample water to flew for at least one minute for each 10 feet
under rivers are notoriously prone to produce water contain- (3 m) of sample line before the sample is collected.
ing iron, Bacteria will reduce iron oxides in soil to the
soluble, DIVALENT3 form of Ton (Fe2+) which will produce Samples for iron and manganese should be tested within
groundwater with a high iron content. 48 hours unless they have been acidified. If the sample
contains any clay or if any particles of rust .ire picked up
Iron bacteria can make use of the ferrous ion (Fe2'). These from a steel pipe or fitting, an acidified sampl will dissolve
bacteria will oxidize the iron and use the energy for reducing the iron in these substances and the results will be too high
carbon dioxide to organic forms (s:.mes). The manganous If clay or rust particles are observed in a sample, do not
ion (Mn2') is used in a similar fashion by certain bacteria. acidify and request lab to analyze sample immediately
Very small concentrations of iron and manganese in water Furthermore, many laboratories fail to be sure that iron and
can cause problems, because bacteria obtain the nutrients manganese are in the divalent form (Fe2+ or Mn2') by adding
(iron and manganese) from water in order to grow even enough nitric acid prior to the tests to lower the pH to less
when the concentrations are very low. than two, so laboratory errors may be even greater than
sampling errors.

12.12 Analysis for Iron and Manganese

The preferred method of testing for iron and manganese is

atomic absorption, but for the small plant the equipment is
too expensive. With careful attention to laboratory proce-

Iron bacteria are found nearly everywhere. They are

frequently found in iron water pipes and everywhere else
that a combination of dissolved oxygen and dissolved iron is
usually or frequently present. Only one cell of iron bacteria is
needed to start an infestation of iron bacteria in a well or a
distribution system. Unfortunately it is almost impossible to
drill a well and maintain sterile conditions to prevent the
introduction of iron bacteria.

12.11 Collection of Iron and Manoanese Samples

The best way to determine if there is an iron and manga-
nese problem in a water supply is to look at the plumbing
fixtures in a couple of houses. If the fixtures are stained, dures, colc metric methods (comparing colors of unknowns
then there is a problem. Determination of the concentrations with known standards) can provide sufficient accuracy in
of iron and manganese in water is useful when evaluating most instances. These colorimetric methods use either a
well waters for use and treated waters for effectiveness of spectrophotometer, a filter photometer, or the less satisfac-
treatment processes. tory set of matched Nesslei tubes with standards. Good
results have been obtained by the use of properly calibrated
The results of tests for iron and manganese are wrong colorimeters (Figure 12.1). For detailed procedures on how
more often than they are right. This is because samples for to use a spectrophotometer to measure iron and manga-
these substances are difficult to collect. Both iron and nese, see Chapter 21, "Advanced Laboratory Procedures."
manganese form loosely adherent (not firmly attached)
scales on pipe walls, including the sample lines. When the
sample tap is opened, particles of scale may be dislodged
and enter the sample bottle. If many of these particles enter QUESTIONS
the sample bottle, the error can b "me very large. Further-
more, unless the sample is acidnied (enough nitric acid Write your answers in a notebook and then compare your
added to drop the pH to less than 2), both iron and answers with those on page 22.
manganese tend to form an adherent scale on the walls of
the sample bottle in the few days that sometimes elapse 12.1A How do iron and manganese form insoluble com-
before the analysis is started. When the sample is poured pounds?
from the bottle for testing, most of the iiron and manganese
will then remain inside the sample bottle. 12.1B Why must iron and manganese samples be acidified
when they are collected?
To avoid this situation, samples should be taken from a
plastic sample line located as close to the well or other 12.1C Where sh^uld a sample for iron and manganese
source as possible. Open the sampling tap slowly so that the testing Ix ollected?

3 Divalent (die-VAV-lent). Having a valence of two, such as the ferrous ion, Fe2+. Also called BIVALENT.

15
8 Plant Operation

,...... ,-,11, St14.10,1r

A
L-

HI LO RECOMMENDED
(furnished by customer)
PANEL ALARM
(optional)

R
SSTAMEPAMLE

FLOW METER/ STRAINER SHUT.OFF

CONTROL VALVE (optional) VALVE
(rocommandod)
ALTERNATE
WATER
SUPPLY

RECORDER
CONROLL ER (oplional) ANALYZER
(optional)
POWER
DRAIN
TYPICAL INSTALLATION

Fig. 12.1 Typical continuous on-line pump - colorimeter analyzer

for iron, manganese or permanganate
(Permission of Hach)

16
 Iron and Manganese 9

12.2 REMEDIAL ACTION 1. Treat a series of samples with a standard chlorine

solution to determine the chlorine dose required to pro-
Several methods are available to control iron and manga- duce the desired chlorine residual.
nese in water. This section discusses how to operate the
most common treatment processes. 2. Prepare a standard polyphosphate solution by dissolving
1.0 gram of polyphosphate in a liter of distilled water.
12.20 Alternate Source
3. Treat another series of samples with varying amounts of
The construction of a plant to remove iron and manganese polyphosphate solution. One mL of the standard poly-
will cost as much as or more than a new well so it pays to in- phosphate solution (0.1% solution) in a liter sample is
vestigate the possibility of obtaining an alternate supply of equivalent to 8.34 pounds of polyphosphate per million
water that is free from iron and manganese. This investiga- gallons (see Examples 2 and 3 on pages 15 and 16). Stir
tion should include samples from nearby private wells, to assure tnat the polyphosphate has been well mixed;
and continue stirring while adding the previously deter-
mined chlorine dose so as to minimize the creation of
high concentrations of chlorine.
4. Observe the samples daily against a white backgound,
noting the amount of discoloration. The proper polyphos-
phate dose is the lowest dose that delays noticeable
discoloration for a person of four days.

Samples for the above bench test should be as fresh as

possible and should be kept away from direct sunlight to
discussions with well drillers who have been active in the avoid heating.
locality and discussions with engineers in the state agency
responsible for the regulation of well drilling.

If the water produced by the well contains dissolved

oxygen along with iron and manganese, this is an indication
that water is being drawn from more than one AQUIFER.4
One or more, of the aquifers must be producing water
containing dissolved oxygen but is free of iron and manga-
nese since oxygen reacts with both elements to form insolu-
ble compounds. Furthermore, it is highly probable that the
iron- or manganese-bearing water is from deeper aquifers
so that it may be possible to cure the problem simply by Polyphosphate treatment to control iron and manganese
sealing off these deeper aquifers. is usually most effective when the polyphosphate is added
upstream from the chlorine, but satisfactory results may be
12.21 Phosphate Treatment obtained by feeding them together. The chlorine should
never be fed ahead of the polyphosphate because the
If the water contains manganese up to 0.3 mg/L and less chlorine will oxidize the iron and manganese (cause insolu-
than 0.1 mg/L of iron, an inexpensive and reasonably ble precipitates to form too soon).
effective control can be achieved by feeding the water with
one of the polyphosphates listed below. Chlorine usually If you are able to instal a one-half inch (12 mm) polyethyl-
must oe fed along with the polyphosphate to prevent the ene hose in the well so that it discharges a few inches below
growth cf iron bacteria. The effect of the polyphosphate is to the suction screen, you can construct a very satisfactory
delay the precipitation of ox dized manganese for a few days semi-automatic feed system. Use a gas-feed chlorinator
so that the scale that builds on the pipe walls is greatly whose water suppiy is obtained from the well discharge
reduced. downstream from the check valve (Figure 12.2). In this way,
the chlorinator operates only when the pump is running. The
The chlorine dose for phosphate treatment should be chlorine solution is fed down the polyethylene tube. Poly-
sufficient to produce a free chlorine residual of approximate- phosphate is fed down the same tube by means of a plastic
ly 0.25 mg/L after a five-minute contact time (a higher tee. The phosphate is fed by means of an electrically
chlonne dose may be required with some water to maintain a operated solution feeder so connected as to run when the
free chlorine residual of at least 0.2 mg/L throughout the well pump runs.
distribution system).
The chlorine solution flowing through the polyethylene is
Any of the three polyphosphates (pyrophosphate, tnpoly- extremely corrosive. If the tube does not discharge into
phosphate, and metaphosphate) can be used, but sodium flowing water, the corrosive effect of the solution on a metal
metaphosphate is effective in lower concentrations than the surface can be disastrous. Wells have been destroyed by
others. The proper phosphate dose is determined by labora- corrosion from this cause. The following simple test should
tory BENCH SCALE TESTS5 in the following manner be made at least once every three months.

4 Aquifer (ACK-wi-fer). A natural underground layer of porous, water-bearing materials (sand, gra al) usually capable of yielding a large
...
amount or supply of water.
5 Bench Scale Tests. A method of studying different ways or chemical doses for treating on a small scale in a ,aboratory

17
10 Plant Operaion

POLYPHOSPHATE
SOLUTION FEEDER

GAS-FEED
1C-
CHLORINATOR
CHLORINE
SOLUTION

PLASTIC
WATER
SUPPLY
PUMP

17
ay PUMP
DISCHARGE

At-CHECK VALVE

40-- WATER LEVEL

POLYETHYLENE
HOSE
411.-----SUCTION SCREEN

Fig. 12.2 Polyphosphate and chlorine system

18
 Iron and Manganese 11

EXAMPLE 1 There are some reports in the literature of the successful

use of tetrasodium pyrophosphate on iron-bearing waters,
1. Calculate the time required for water to flow from the but many attempts to control iron have failed. The available
pump suction to the pump discharge.
information is not clear as to whether the process works
a. Record the following information:
only under special conditions or whether the reports of
success are in error.
(1) Length of pump column from suction to discharge
in feet, 324 ft. QUESTIONS
(2) Diameter of pump column in inches, 8 in.
Write your answers in a notebook and then compare your
(3) Discharge rate from pump in gallons per minute, answers with those on page 22.
423 GPM.
12.2A If a well produces water containing dissolved oxygen
b. Calculate the volume of the pump column in inches. as well as iron and manganese, how would you
attempt to solve the iron and manganese problem?
Volume, 12.2B How could you find out if nearby wells produce water
(0.7ts5)(Diameter, in)2(Length, ft)(12 in/ft)
et! in containing iron and manganese?
= (0.785)(8 in)2(324 ft)(12 in/ft)
12.2C What are bench scale tests?
= 195,333 cubic inches
12.2D Why should polyphosphate solutions over 48 hours
old not be used?
c. Convert the pump column volume from cubic inches to
gallons.
12.22 Removal by ION EXCHANGE6
Volume, gal =Volume, cu in
231 cu in/gal
195,333 cu in
231 cu in/gal
= 846 gallons

d. Determine the time required for the water to flow from

the pump suction to the pump discharge.

Time, min = Volume, gallons

Pump Discharge, GPM
846 gallons The actual location of the ION EXCHANGE RESINS' with
423 gal/min respect to other water treatment processes will depend on
the raw water quality and the design engineer. If the water to
= 2.0 minutes be treated contains no oxygen, both iron and manganese
may be removed by ion exchange using the same resins that
2. Turn off the water supply to the chlorinator. Since some are used for water softening. If the water being treated
of the chlorine in the feed line will drain into the well, it contains any dissolved oxygen, the resin becomes fouled
may take several minutes for the chlorine residual to with iron rust or manganese dioxide. The resin can be
disappear. Check to be sure there is no chlorine residual cleaned but this is expensive and the capacity is reduced.
in the water. Well water may contain no oxygen in normal operating
conditions except immediately after the well is first turned
3. Turn the chlorinator back on, noting the exact time. Take on. If this is the case, provisions should be made to run the
samples for chlorine residual every 15 seconds. If the well to waste until the oxygen is no longer present.
chlorine residual has reached its proper value within 30
seconds of the calculated time, you can be sure that the In one Eastern city, an ion exchange plant had operated
polyethylene tube is properly positioned below the suc- for seven years, reducing iron from 52 mg/L to 0.1 mg/L and
tion screen. manganese from 1.3 mg/L to zero. When a pump was
Solutions of polyphosphate containing more than one-half
repaired, a gasket on the suction side of the pump was
pound per gallon (60 gm/L) may be very viscous (thick like improperly installed, allowing air to enter the raw water.
molasses), depending upon which of the polyphosphates is
Within three months the resin was fouled by iron oxide.
used. Do not use a solution much over 48 hours old because The main advantage of ion exchange for iron and manga-
the polyphosphates react slowly with water to form ortho- nese removal is that the plant requires little attention. The
phosphates which are much less effective in preventing disadvantages are the danger of fouling the ion exchange
manganese deposits. resin with oxides and high initial cost.

6 Ion Exchange A water treatment process involving the reversible interchange (switching) of ions between the water being treated and
the solid resin. Undesirable ions in the water are switched with acceptable ions on the resins.
7 Ion Exchange Resins Insoluble polymers, used in water treatment, that are capable of exchanging (switching or giving) acceptable cati-
ons or aniors to the water being treated for less desirable ions.

I9
12 Plant Operation

To operate an ion exchange unit, try to operate as close indicated in Figure 12.3 were determined at 25°C under
as possible to design flows. Monitor the treated water for laboratory conditions. If the water contains any urge=
iron and manganese on a daily basis. When iron and substances, the rates will be significantly lower, reduced
manganese start to appear in the treated water, the unit temperatures will also lower the rates.
must be regenerated. Regeneration is accomplished with a
trine solution that is treated with 0.01 pound of sodium Since pH is increased by the removal of carbon dioxide, it
bisulfate per gallon (1.2 gm/L) of brine to remove oxygen is important that the aeration (which removes carbon diox-
present. After regeneration is complete, the brine must be ide) be as efficient as possible. Lime is sometimes added to
disposed of in an approved manner. the water to aicrease the pH as well a.F remove carbon
dioxide. The higher the pH, the shorter the time required for
See Chapter 14, "Softening," for procedures on how to aeration, as shown in Figure 12.3.
calculate the frequency for regenerating the unit Details are
given in Chapter 17, "Handling and Disposal of Process Operation of the aeration process to remove iron and
Wastes," on how to properly dispose of brine solutions. manganese requires careful control of the flow through the
process. If the flow becomes too great, not enough time will
12.23 Oxidation by Aeration be available for the reactions to occx. Flows are controlled
by the use of variable speed pumps or the selection of the
Iron can be oxidized by aerating the water to form proper number or combinations of pumps. Carefully monitor
insoluble ferric hydroxide. As shown in Figure 12.3, this the iron and manganese content of the treated water. If iron
reaction is accelerated by an increase in pH. The rates is detected, the flows may have to be reduced.

50 100 150 200 250 300 350

TIME, MINUTES

Fig. 12.3 pH vs. time to oxidize 99 percent iron

20
 Iron and Manganese 13

There are several methods of providing aeration. Either After the ferric hydrc .ide is formed, it is removed by
the water being treated is dispersed (scattered) into the air sedimentation or by filtration alone. It only filtration is used,
or air is bubbled through the water. Aeration may be water from the reaction basin is usually pumped to pressure
achieved by the use of compressed air which passes filters for filtration. The water may also be pumped of flow by
through diffusers in the water. These diffusers produce gravity to rapid sand filters. For details on how to operate
many small bubbles which allow the transfer of oxygen in the r.nd maintain filters, see Chapter 5, "Filtration."
air to dissolved oxygen in the water.
The oxidation of manganese by aeration is so slow that
Other aeration techniques include forced draft, multiple this process is not used on waters with high manganese
trays, cascades and sprays These methods may develop concentrations.
slime growths on surfaces or coatings on media. Slime
growths and coatings on media should be controlled to The main advantage of this method is that no chemicals
prevent the development of tastes and odors in the product are required; however, lime may be added to increase the
water and the sloughing off of the slimes. Chlorination may pH The major disadvantage is that small changes in raw
be used to control slime growths and coatings. Regularly surface water quality may affect the pH and soluble organics
inspect aeration equipment for the development of anything level and slow the oxidation rates to a point where the
unusual. capacity of the plant is reduced.

A reaction basin (sometimes called a collection or deten- 12.24 Oxidation with Chlorine
tion basin) follows the aeration process. The purpose of the
reaction basin is to allow time for the oxidation reactions to Chlorine will oxidize manganese to the insoluble manga-
take place. The aerator process should produce sufficient nese dioxide and will oxidize iron to insoluble ferric hydrox-
dissolved oxygen for the iron to be oxidized to insoluble ide which can then be removed by filtration. The higher the
ferric hydroxide. A minimum recommended detention time is chlorine residual, the faster this reaction occurs. Some very
20 minutes with desirable detention times ranging from 30 to compact plants have been constructed by treating the water
60 minutes (see Example 4, page 16). As shown in Figure to a free chlorine residual of 5 to 10 mg/L, filtering, and
12.3, the pH of the water strongly influences the time for the dechlorinating to a residual suitable for domestic use. Do not
reaction to take place. Sometimes chlorine is added before use high doses of chlorine if the water contains a high level
the reaction basin. of organic color because excessive concentrations of total
trihalomethanes (TTHMs) could develop. The water is de-
The reaction basin may be a cylindrically (circular) shaped chlorinated by the use of reducing agents such as sulfur
basin similar to a clarifier. ('ten the basin is baffled to dioxide (SO2), sodium bisuifite (NaHSO3), and sodium sulfite
prevent short-circuiting and the deposition of solids. Since (Na2S03). Bisulfite is commonly used because it is cheaper
there are no provisions for sludge removal, the basin must and more stable than sulfite. When dechlorinating with
be drained and cleaned regularly. If the basins are not reducing agents be very careful not to overdose because
cleaned, slugs of deposits or sludge or also mosquito or fly inadequate disinfection could result (no chlorine residual
larvae (young or any insect) could reach the filters in the next remains) and if the dissolved oxygen level in the water is
process and cause them to plug. depleted, fish kills could occur in home aquariums. Fre-
quently, a reaction basin (as described in Section 12.23,
Operators of reaction basins must always be on the alert "Oxidation by Aeration") is installed between the chlorination
for potential sources of contamination. These basins should processes to allow time for the reactions to occur.
have covers and protective lids to keep out rain, storm water
runoff, rodents and insects. All vents must be properli Chlorine oxidizes iron to insoluble ferric hydroxide which
screened. The outlet to the drain must not be connected is removed by filtration along with the manganese dioxide.
directly to a sewer or storm water drain. There must be an
air gap or some other protective device to prevent contami- 12.25 Oxidation with Permanganate
nation from BACKFLOW.8
Potassium permanganate oxidizes iron and manganese to
insoluble oxides, and can be used to remove these elements
in the same way chlorine is used. The dose of potassium
permanganate must be exact. Bench scale tests are re-
quired to determine the proper dosage. Too small a dose will
not oxidize all the manganese in the water and too large a
dose will allow permanganate to enter the system and may
produce a pink color in the water. Actual observations of the
water being treated will tell you if any adjustments of the
chemical feeder are necessary.
Experience from many water treatment plants has shown
that a regular filter bed (a rapid sand filter or a dual media fil-
ter bed) can remove manganese as long as iron and manga-
nese are both under one milligram per liter. These plants use
either chlorine or permanganate to oxidize the iron and
manganese before the water being treated flows through the
filter bed.

8 Back flow A reverse flow condition, created by a difference in water pressures, which causes water to flow back into the dis nbution
pipes of a potable water supply from any source or sources other than an intended source.

21.
14 Plant Operation

Potassium permanganate is often used with "manganese various sources of raw water are different ana what works
ZEOLITE9" or "manganese GREENSAND.19"Greensand is a for one operator may not work at your water treatment plant.
granular material. After the greensand has been treated with
potassium permanganate it can oxidize both iron and man- Electromedia iron and manganese removal systems are
ganese to their insoluble oxides. The greensand also acts as generally used on aroundwater supplies at individual well
a filter. This mineral is regenerated with potassium perman- sites because of their compactness and simplicity of treat-
ganate after backwashing to remove the insoluble oxides. ment The system uses reaction vessels where chemical
reactions take place and an adsorbtive media that requires
A modification of this procedure called CR (Continuous no regeneration by special chemicals. Chlorine is used as
Regeneration) consists of feet' ng a potassium permangan- the oxidizing chemical because of its cost and efficiency.
ate solution into the water. If ar, excess of permanganate is (Any suitable oxidizing chemical can be used.) Almost 30
fed, the effluent may be colored pink. For more information percent less chlorine, pound for pound, is required to
on this process, see Section 12.3, "Operation of an Iron and perform the same amount of oxidation as potassium per-
Manganese Removal Plant." manganate.

12.26 Operation of Filters After oxidation with chlorine a small dose of sulfur dioxide
When iron and manganese are oxidized to insoluble forms (0 25 to 0 50 mg/L) is introduced prior to the second reaction
by aeration, chlorination or permanganate, the oxidation vessel. This dosage is factory set according to the general
processes are usually followed by filters to remove the mineral analysis of the raw water. Dosage should not ba
trioluble material. In addition to the procedures for operat- altered. The sulfur dioxide is used to accelerate the oxida-
ing and maintaining filters that were outlined in Theater 6, tion of any sulfur compounds in the water to form com-
"Filtration," the procedures discussed in this section apply to pounds having no objectionable taste or odor.
filters used to remove iron and manganese. The water is then sent to a filter operating at a preset rate
Iron tests should be made monthly on the water entering a of up to 15 gallons per minute per square foot (10 liters per
filter to be sure the iron is in the ferric (Fell state. Collect a second per square meter or 10 millimeters per second). In
sample of the water and pass the water through a filter the filter vessel, the iron and manganese are adsorbed on
paper. Run an iron test on the water which has passed the surface of the media until backwashing. The media can
through the filter. If the iron is still in the soluble ferrous withstand a very high backwash rate (20 gallons per minute
(Fe2+) state, there will be iron in the water. If aeration is being per square foot, 13.6 L/sec/sq m or 13.6 mm/sec) and
used to o.adize the iron from the soluble ferrous to the requires only a four-minute backwash to obtain thorough
insoluble ferric state and iron is still present in the soluble cleaning.
state in the water entering the filter, tr.y adding chlorine or The filter effluent can he sampled by a continuously
potassium permanganate. If chlorine or potassium perman- monitoring analyzer that drives a 30-day strip chart recorder.
ganate are being used and soluble iron is in the water The recorder may have a color-coded indicating strip to
entering the filter, try increasing tne chemical dose. If direct the operator in the proper chemical dosage. If the
potassium permanganate is being used, the sand may be recorder trace falls out of the green, the operator increases
replaced by greensand to improve the efficiency of the the chlorine dosage. The dosage is adjusted by turning one
process. knob and can be read immediately. The effect of the change
If oxidation is being accomplished by either aeration o' can be seen on the chart trace in five minutes and will reach
chlorination, a free chlorine residual must be maintained in a steady state within ten minutes. Thus the operator can
the effluent of the filter to prevent the insoluble ferric iron quickly determine the proper dosage. With the chemical
from returning to the soluble ferrous form and passing dosage set properly, a free chlorine residual exists in the
through the filter. filter effluent providing the required disinfection in the distri-
bution system. Variations in water quality are quickly reflect-
Most iron removal treatment plants are designed so that ed in the chart tracing. Since no permanganate is used, there
the filters are backwashed according to head loss. If iron are no "black water" or "pink water" complaints from acci-
breakthrough is a problem, filters should be backwashed dental underdosage or overdosage of chemicals.
when breakthrough occurs or just before breakthrough is
expected. Accurate records can reveal when breakthrough The process uses BREAKPOINT CHLORINATION,11 and
occurs and also when breakthrough can be expected. the very effective adsorbtive qualities of the media. Each
system is provided with an automatic control panel that
12.27 Proprietary Processes by Bill Hoyer permits adjustment of any of the filter cycles simply by
rotating a timer knob. Status of the system is displayed on
There are several patented processes that are available the front panel with pilot lights for easy viewing. The
for iron and manganese control. The best way to learn about automatic control panel operates the manually set chemical
the effectiveness and maintenance requirements of these feed system using gaseous chlorine and gaseous sulfur
processes is to contact someone who has one. Once you dioxide. Backwash is accomplished automatically by using a
are operating one of these processes, the manufacturer is a process signal and filtration timer with a differential pressure
good source of help when troubleshooting. Remember that override.

9 Zeolite A type of ion exchange material used to soften water Natural zeolites are siliceous compounds (made of silica) which remove
calcium and magnesium from hard water and replace them with sodium. Synthetic or organic zeolites are ion exchange materials which
remove calcium or magnesium and replace them with either sodium or hydrogen. Manganese zeolites are used to remove iron and man-
ganese from water.
10 Greensand A sand which looks like ordinary filter sand except that it is green in color. The sand is a natural ion exchange material
which is capable of softening water and removing non and manganese.
II Breakpoint Chlorination. Addition of chlorine to water until the chlorine demand has been satisfied. At this point, further additions of
chlorine will result in a free residual chlorine that is directly proportional to the amount of chlorine added beyond the breakpoint.

22
 Iron and Manganese 15

Maintenance on the system is quite limited. Most systems 12.29 Summary

are built with an automatic standby for the chemicals that will
switch from an empty container to a full container. Table Small iron and manganese water treatment plants can be
12.1 lists the recommended maintenance. very difficult tc operate. If your plant is not operating as
desired, talk to other operators in your area and see if they
have any suggestions. If you have problems, you will have to
Each application for iron and manganese removal is try different chemical doses and procedures. Keep accurate
based on the general mineral analysis of the raw water. The records so you can evaluate the effectiveness of your
required chemical treatment is provided for iron, manganese efforts.
and sulfide treatment. Additional equipment may be pro-
vided where corrosivity and/or chelating compounds are
A lot of "iron complaints" in drinking water are caused by
found to be present. Aeration may precede the process
old steel or cast iron water mains. A possible solution to this
where methane extraction and/or carbon dioxide removal is
problem is to inject polyphosphates directly into the distribu-
required Plant operators are directed to the operation and
tion mains. See Section 12.5, "Troubleshooting Red Water
maintenance instructions provided with the equipment for Problems," for additional ideas on how to solve problems.
additional details.

FORMULAS
TABLE 12.1 RECOMMENDED MAINTENANCE FOR THE A standard po;yphosphate solution is prepared by mixing
ELECTROMEDIA PROCESS and dissolving a known amount of polyphosphate in a
Daily Weekly Monthly container and adding distilled water to the one liter mark. To
determine the settings on polyphosphate chemical feeders:
1. Inspection of chart paper for X
proper chemical dosage 1. Prepare a series of samples and test with polyphosphate,
2. Free chlorine residual test X 2. Select the optimum dosage in mg/L, and
3. Total chlorine residual test X
3. Calculate the chemical feeder setting in pounds of poly-
4. Addition of buffer solution in X phosphate per day.
the analyzer
Stock (Polyphosphate, grams)(1000 mg/gram)
5. Colorimetenc analysis of the X Solution,
(Solution, liter)(1000 ml- /L)
influent and effluent for mg /mL
iron concentration
Dose. =(Stock Solution, mg/mL)(Volume Added, mL)
6. Laboratory tests for analysis of mg/L
Sample Volume, L
influent and effluent for iron
and manganese concentration Dose, (Dose, mg/L)(3.785 L/gal)(1,000,000)
lbs/MG
7. Changing of chart paper (1000 mg/gm)(454 gm/lb)(1 Million)

8. Routine maintenance checks Chemical

= (Flow, MGD)(Dose, mg/L)(8.34 lbs/gal)
associated with valves, pipes Feeder.
and pumps lbs/day

12.28 Monitoring of Treated Water EXAMPLE 2

When controlling iron and manganese by aeration or with A standard polyphosphate solution is prepared by mixing
chemicals, the product water must be monitored closely. If and dissolving 1.0 grams of polyphosphate in a container
lab facilities are available, the treated water can be analyzed and adding distilled water to the one-liter mark. Determine
for iron and manganese to be sure treatment is adequate. A the concentration of the stock solution in milligrams per
quick way to monitor treated water is to collect a sample and milliliter. If 5 milliliters of the stock solution are added to a
add a dose of chlorine. If a brown or rust-colored floc one-liter sample, what is the polyphosphate dose in milli-
develops, then the treatment is inadequate. You will either grams per liter and pounds per million gallons9
have to increase the chemical doses or reduce the flows. If a
pink color appears in the product water when using perman- Known Unknown
ganate, then the dose is too high and must be reduced until
the pink color is no longer visible. Polyphosphate, gm = 1.0 gm 1. Stool< Solution, mg/mL
Solution, L = 1.0 L 2. Dose. mg/L
Stock Solution, mL = 5 mL 3. Dose, lbs/MG
Sample, L = 1L

1. Calculate the concentration of the stock solution in milli-

grams per milliliter.
Stock Solution, (Polyphosphate, gm)(1000 mg/gm)
mg/mL
(Solution, L)(1000 mL /L)
(1.0 gm)(1000 mg/gm)
(1 L)(1000 mL /L)
= 1.0 mg/mL

2 0')
16 Plant Operation

2 Determine the polyphosphate dose in the sample in 2 Convert the basin volume from cubic feet to gallons
milligrams per liter.
Basin Vol , gal = (Basin Vol., cu ft)(7.48 gal/cu ft)
Dose, mg/L = (Stock Solution, mg/mL)(Vol. Added, mL) (565 cu ft)(7.48 gal/cu ft)
Sample Volume, L
= 4226 gal
(1 0 mg/mL)(5 L)
1L 3. Determine the average detention time in minutes for the
reaction basin
= 5.0 mg/L
Detention time, (Basin Vol., gal)(24 hr/day)(60 min/hr)
mm
3 Determine the polyphosphate dose in the sample in Flow, gal/day
pounds of phosphate per million gallons. (4226 gal)(24 hr/day)(60 min/hr)
Dose, lbs/MG = (Dose, mg/L)(3.785 L/gal)(1,000,000) 200,000 gal/day
(1000 mg/gm)(454 gm /Ib)(1 Million) = 30 minutes
(5.0 mg/L)(3.785 L/gal)(1,000.000)
(1000 mg/gm)(454 gm/lb)(1 Million)
QUESTIONS
Write your answers in a notebook and then compare your
= 42 lbs/MG
answers with those on page 23.
EXAMPLE 3 12.2E What happens if water being treated for iron and
manganese by ion exchange contains any dissolved
Determine the chemical feeder setting in pounds of poly- oxygen?
phosphate per day if 0.4 MGD is treated with a dose of 5
mg/L. 12.2F How does the pH of the water influence the rate of
oxidation of iron to insoluble ferric hydroxide?
Known Unknown
12 2G What is the purpose of a reaction basin following the
Flow, MGD = 0.4 MGD Chemical Feeder, lbs/day aeration process?
Dose, mg/L= 5 ng/L
12.2H After chlorine has been added to oxidize iron and
Determine the chemical feeder setting in pounds per day. manganese, how is the water dechlormated?
Chemical Feeder, 12.21 How are greensands regenerated after being used to
= (Flow, MGD)(Dose, mg/L)(8.34 lbs/gal)
lbs/day oxidize iron and manganese?
= (0 4 MGD)(5 mg/L)(8.34 lbs/gal)
= 17 lbs/day

FORMULAS
To calculate the average detention time for a reaction
basin:
1. Determine the dimensions of the basin, and
2. Measure and record the flow of water being treated.
Basin Vol., cu ft = (0.785)(Diameter, ft)2(Depth, ft)
Basin Vol., gal = (Basin Vol., cu ft)(7.48 gal/cu ft)
Detention Time, (Basin Vol. gal)(24 hr/day)(60 min/hr)
min
(Flow, gal/day)

EXAMPLE 4
A reaction basin 12 feet in diameter and 5 feet deep treats 12.3 OPERATION OF AN IRON AND MANGANESE
a flow of 200.000 gallons per day. What is the average REMOVAL PLANT by Gerald Davidson
detention time in minutes?
12.30 Description of Process
Known Unknown
The operation of an iron and manganese removal plant
Diameter. ft = 12 ft Detention Time, min using continuously regenerated manganese greensand in-
Depth, ft = 5 ft volves a number e 'perational procedures which must be
Flow, GPD = 200,000 GPD checked on a daily basis.
1. Calculate the basin volume in cubic feet The very low recommended limits for iron (0.3 mg /L) and
manganese (0.05 mg/L) in water makes these contaminants
Basin Vol., cu ft = (0.785)(Diameter, ft)2(Depth, ft) difficult to treat and sometimes the processes are expen-
= (0.785)(12 ft)2(5 ft) sive. Because of this, operatcrs should know how the
processes work and what to check for when something
= 565 cu ft goes wrong and the limits are exceeded.

24
 Iron and Manganese 17

The filter is the most important piece of treatment equip- solved oxygen to saturation at the water temperature. The
ment. Figure 12.4 illustrates a typical filter consisting of colder the water is, the more oxygen it will hold. During
layers of gravel, filter sand, greensand and anthracite coal. aeration the iron concentration drops from 3 mg/L to 0.15
One inch (25 mm) of filter sand is placed on top of the rng/L which is 95 percent removal in primary clarification
support gravel. This layer helps support the fine greensand.
Differences between greensand filters and conventional
filters are: (1) the greensand is very fine; and (2) the filtration The chlorination and air injection also remove 100 mg/L
rate is slower and should not exceal 3 GPM/sq ft (2 liters carbon dioxide (CO2) and 0.03 mg/L hydrogen sulfide (H2S)
per sec/sq m or 2 mm/sec); the backwash rate is lower and which helps in taste and odor control. This process also
should be less if anthracite coal is used; and, the time of the raises the pH of the raw water from 6.2 to 7.0. The air will
backwash should be increased when using greensand to oxidize most of the manganese to an insoluble precipitate.
insure that the media is clean. After primary clarification, the water goes to the secondary
clarifier, in the secondary treatment, and the water is inject-
12.31 Description of the Plant (Figure 12.5) ed with potassium permanganate (1.22 mg/L) and sodium
hydroxide (30 mg/L).12 The sodium hydroxide is added to
The following is a desorption of an iron and manganese raise the pH for control of corrosion. Detention times are the
removal plant using continuously regenerated manganese same as with primary clarification. After secondary clarifica-
greensand. The treatment plant provides chemical floccula- tion, the water is passed through pressure filters with
tion, sedimentation, pressure filtration (anthracite coal, greensand and the iron and manganese levels are reduced
greensand, and filter sand), and chlorination of raw well to 0.01 mg/L iron and 0.01 mg/L manganese, which is a 99
water that contains three mg/L iron and 0.75 to one mg/L percent removal.

r
manganese.
The potassium permanganate feed system consists of a
The treatment plant in Figure 12.5 has two flocculator/ 50-gallon (100 L) polyethlene solution s ., two' /4 -HP mixers,
clarifiers (solids contact units) 32 feet (10 m) in diameter with liquid level switches, and a metering pump. Provision has
2.0 hours detention time at maximum flow. The clarifiers can been made to add dilution water to the chemical feeder
be operated in series or in parallel. At the present time they pump discharge. The dilution water will prevent the crystali-
are being operated in series. The raw water is being pumped zation of potassium permanganate which could cause fail-
from a 50-foot (15 m) deep well to the i.rst clarifier. The raw ure of the pump discharge piping. The mixers do not have to
water is injected with chlorine at 8.65 mg/L, flash mixed, and run continuously because of the solubility of potassium
flocculated for a period of ten minutes. The water is then permanganate in water. When a batch of potassium oerman-
injected with 60 cfm of air through sixteen f'ne bubble ganate solution is prepared, the potassium permanganate
diffusers. The aeration detention time is 1.9 hours at maxi- chemical is mixed with hot water to help disperse the
mum flows. The raw water changes from zero mg/L dis- chemical in the solution.

WATER TO BE
TREATED
(FROM SECONDARY
FLOCCULATOR
CLARIFIER)

12 INCHES NO. 1 ANTHRACITE COAL

12 INCHES GREEN SAND

1 INCH FILTER SAND

12 INCHES GRADED GRAVEL TREATED

WATER

CONCRETE

Fig. 12.4 Multimedia manganese greensand filter (horizontal)

'2 NOTE. Addition of 30 mg/t. of sodium hydroxide (NaOH) will increase the sodium content of the water by 17 mg/L. If you are trying to
keep the sodium level below 20 mg/L, then the sodium in the raw water must be below 3 mg/L
 J"

ADD KMnO4
AND NaOH
ADD CHLORINE (FLASH MIXING AND
(FLASH MIXING AND FLOCCULATION FOR
FLOCCULATION FOR 10 MINUTES)
10 MINUTES)

GREEN SAND
ADD CHLORINE
PRESSURE
FOR DISINFECTION
CHEMICAL FILTER
RAW WATER AERATION FOR
REACTIONS FOR
1.9 HOURS
(FROM WELL) 1.9 HOURS

1 TREATED WATER
TO CONSUMERS

REMOVES MOST OF
REMAINING IRON
IRON PRECIPITIC. ES AND MANGANESE

TWO FLOCCULATOR/CLARIFIERS
BEING OPERATED IN SERIES

Fig. 12.5 Schmatic of iron and manganese removal plant using green sand

000r 26
 Iron and Manganese 19

12.32 Operation of the Greensand Process Inject the potassium permanganate solution into the water
being treated
Good iron and manganese removal with greensand can
remove 95 percent of both Iron and manganese. However, if The operator of an iron and manganese removal plant
the iron is above 20 mg/L, the efficiency of the greensand using greensand must run jar tests to determine the dosage
drops very quickly. A residual of potassium permanganate of all chemicals used (chlorine, permanganate, and sodium
must be present in the effluent water from the greensand for hydrox.de). In Chapter 3 of this water treatment manual,
the greensand media to be effec / , there is a complete description of how to run jar tests. Iron in
the ferrous form (Fe24) takes about 0.60 mg/L potassium
When using the continuously regenerated manganese permanganate for each mg/L iron (Figure 12.6) and 0.64 mg/
greensand for iron and manganese removal, the greensand L chlorine for each mg/L of iron. The pH of the water has a
must be regenerated or recharged with potassium perman- pronounced effect on iron removal. The oxidation potential
ganate (KMnO4) If the potassium pem nganate charge is of chlorine and potassium permanganate decreases as the
lost in the filter bed (none in the filter effluent), the operator pH increases, although the rate of reaction increases signifi-
must regenerate the greensand. There are two ways to cantly with the increase in pH.
regenerate the bed:
1. Shut down and pour a saturated solution of potassium
permanganate (about 5 percent) into the filters: let the
saturated solution sit for approximately 24 hours. Aft 3r
the saturated solution sits for 24 hours, backwash the
filters at a normal rate to flush out the excess potassium
permanganate; or
2. Recharge the greensand by increasing the potassium
permanganate dosage until pink water flows out of the
greensand media. Then decrease the potassium perman-
ganate until you have a slight pink color before filtration.
There should be no pink water after filtration when the
water is being pumped into the distribution system. If
there is still pink water after filtration, keep decreasing
the potassium permanganate dose until no pink water is
present in the water after filtration. The pink color is the
best indication that the greensand is regenerated or
recharged with potassium permanganate. One problem
with this method is that you might reduce the permangan-
ate level too far and pass water with iron and manganese. NO I NO 2
This could cause red-^olored water in the distribution
NO 1 DOSE 0 95 mg/L
system and stain clothes and/or bathroom fixtures. Be- KMnO4 PER
cause of the importance of the potassium permanganate 1 0 mg/L IRON
in the greensand process, it is highly recommended that
some type of fad-safe system be installed to prevent NO 2 DOSE 0 60 mg/L
KMnO4 PER
filtering water the event the potassium permanganate 1 0 mg/L IRON
solution vat reaches a low level. When a low level is WHEN USING
CHLORINE
reached, the plant should be automatically shut down.
Typical fail-safe systems include low-level alarms in the
vat or an automatic switch over system to another vat
when the level drops too low in the vat in use. 0 2 4 6 8 10 12 14 16 18 20

IRON mgal.
Some operators rind that method No. 1 is more effective.
Since all treatment plants are unique in some respect, one
method or the other or some modification may work best for
your plant. Therefore, procedures and methods should be
developed through actual experience. These methods 30
should be adopted only if they provide the desired results
without eliminating any concepts of design or of good 25 - DOSE 2 mg,I. ICAn04
PER 1 mg, L
operating practice. -a 20 MANGANESE
sn
E
Problems will develop in the iron and manganese removal 64 15
process using greensand if you have too short a detention
time for the chemicals to react. That is, it takes a little time
for the chemicals to start working. If the plant you are
operating does not have sufficient detention time for the
chemical reactions to take place, you should perform exten-
8 10 12 14 16 18 io
sive jar tests to see if a flash mix will improve performance. 6

In some plants the injection of the potassium permanganate MANGANESE. mg'L

solution in the volute of the pump will produce complete
mixing of potassium permanganate.
To prepare a potassium permanganate solution, mix the
potassium permanganate chemical with hot water in a Fig. 12 6 Potassium permanganate demand for oxidation
solution tank to make the chemical disperse completely. of iron awl manganese

2S
 20 Plant Operation

If the filtration system you are using does not have surface 12.3C Why is dilution water added at the discharge of the
washers, it is highly recommended that they be installed. chemical feeder pump9
The benefits of surface washers in plants that treat for iron
and manganese removal are wall recognized. The surface 12 30 Why should a greensand plant be shut down when
washers help prevent mudballs (in any type of plant) and the the permanganate solution level in the vat gets low?
buildup or iron and manganese oxide on the filter h( -1 The
buildup is even greater when anthracite coal is Ube"
Remember that daily tests should also be performed.
These daily tests should include iron, manganese, pH and
chlorine residual. i he iron and manganese test tells the
operator if the treatment plant is working and meeting state
and federal water quality requirements. The pH test is also
very important because of the relationship between pH and
the corrosivity of water. Corrosive waters can cause deterio-
ration of water mains and red water complaints.

FORMULA
To calculate the potassium permanganate dosage, you
need to know the concentration of iron and manganese in
the water being treated at the location in the process where 12.4 MANTENANCE OF A CHEMICAL FEEDER
the permanganate is added. In small water treatment plants that remove iron and
KMn04 Dose, mg/L = 0.6(Iron, mg/L) + 2.0(Manganese, mg/L) manganese, a hypochlorite solution may be used to provide
chlorine instead of using chlorine gas. Commercial sodium
EXAMPLE 5 hypochlorite solutions (such as chlorox) contain an excess
of caustic (sodium hydroxide, NaOH). When the solution is
Calculate the potassium permanganate dose in milligrams diluted with water containing carbonate alkalinity,13 the re-
per liter for a well water with 3 mg/L iron before aeration and sulting solution becomes supersaturated wilh calcium car-
0.2 mg/L after ration. The manganese concentration is 1.0 bonate. This calcium carbonate tends to form a coating on
mg/L both be , and after aeration. the poppet valves in the solution feeder. The coated valves
do not seal properly and the 'er fails to pump the
Known Unknown hypochlorite solution properly.
Iron, mg/L =0.2 mg/L KMn04 Dose, mg/L
Manganese, mg/L =1.0 mg/L

Calculate the potassium permanganate dose in milligrams

per liter.

KMn04 Dose, mg/L = 0 6(Iron, mg/L) + 2.0(Manganese, mg /L)

= 0.6(0 2 mg/L) + 2.0(1 0 mg/L)
= 2.12 mg/L

NOTE: The calculated 2.12 mg/L potassium permanganate

dose is the mioimum dose. This dose assumes
there are no oxidizable compounds in the raw
water. However, typical oxidizable compounds
usually found include organic color, bacteria and
even hydrogen sulfide (H2S). Therefore, the actual This calcium carbonate scale can be removed by using the
dose may be higher. A bench scale test should be following procedure:
performed to determine the required dose 1. Fill a one quart (946 mL) Mason jar half full of tap water.
2. Add one fluid ounce (44 mL) of 30 to 37 percent hydro-
QUESTIONS chloric acid (NCI) to the Mason jar.
Write your answers in a notebook and then compare your 3. Finish filling the jar to the top with tap water.
answers with those on page 23.
4. Place the suction hose of the hypochlorinator in the jar
12.3A What are the accepted limits for iron and manga- and pump the entire contents of the jar through the
nese? system.
12.3B What happens in the two flocculator/clanfiers de- 5. Return the suction hose to the solution tank and resume
scribed in this chapter9 normal operation.

13 See Chapter 14, "Softervng," for a discussion of carbonate alkalinity

29
 Iron and Manganese 21

The hydrochloric acid (HC,,, also called munatic acid, can towards the extremes or most distant points of the distribu-
be obtained from stores selling swimming pool supplies tion system Usually only one portion of the distribution
system is flu ;hed, followed by another portion until the
One way to avoid the formation of calcium carbonate entire system has been flushed.
coatings is to obtain the dilution water for the hypochlonte
from an ordinary home water softener. A common practice is to open a hydrant at the extreme
end of the system at the start of the flushing job to be sure
For additional information on the operation and mainte- the water being flushed will carry the sediment and insoluble
nance of various types of chemical feeders, see Chapter 13, precipitates in the desired direction and out oi the system
"Fluoridation." Flushing is often done late at night when water demands are
QUESTIONS low so facilities won't be overworked and consumers will not
be inconvenienced.
Write your answers in a notebook and then compare your
answers with those on page 23 Valves will have to be opened and closed in the proper
sequences to be sure the desired mains are being flushed
12.4A What problems may develop in a chemical feeder and that no one will be without water Hydrants that are
pumping sodium hypochlonte? opened to allow flushing must be of sufficient size to
2.4B How can the problems caused by calcium carbonate produce flushing velocities (2 5 up to 5 0 ft/sec preferred or
scale on a hypochlonnator's poppet valves be 0 75 to 1 5 m/sec) in the mains. Also the mains providing the
sob/ea? flushing flows must have sufficient capacity to deliver the
12.5 TROUBLESHOOTING RED WATER PROBLEMS desired flows.

The first step when troubleshooting red or dirty water When flushing a system, be sure the pressure in the
con plaints is to be sure tne iron and manganese treatment distribution system does not drop below 20 psi (1 4 kg/sq cm
processes are working properly. If the iron and manganese or 138 kPa). If a four-inch (100 mm) water main is flushed
are being removed by the treatment processes, investigate using a six-inch (150 mm) hydrant, the water pressure in the
the distribution system for sources to the problem. main downstream from the hydrant could become danger-
ously low. When this happens, the distribution system could
Red water or dirty water problems may be caused by be subject to contamination by BACKSIPHONAGE.15 NEV-
corrosive waters or iron bacteria in the distribution system ER ALLOW A BACKSIPHON CONDITION TO DEVELOP IN
When an unstable or corrosive water (see Chapter 8, "Corro- A DISTRIBUTION SYSTEM.
sion Control) is pumped into the distribution system, the In st,mmary, to minimize red water or dirty water problems
water attacks cast iron pipes and/or metal service lines, and complaints, you must provide aoequate treatment to
picks up iron, and causes red water complaints All water control iron and manganese. This is necessary to assure
treatment plants should run a "Marble Test" see page 353 in that the water pumped into the distnbution system contains
Chapter 8) If the test indicates that the water is corrosive, little or no iron and manganese. The water must be stable
the addition of caustic (sodium hydroxide, NaOH) to the (noncorrosive) so that iron will not be picked up in the
water to increase the pH will help When the water becomes distribution system. Corrosion control treatment processes
stable (according to the Marble Test), some of the red water can produce a stable water. If bacterial growths are a
complaints could be eliminated. problem, a free chlorine residual must be maintained in all
The growth of iron bacteria inside water mains causes one water throughout the distribution system If red or dirty water
of the most troublesome and most difficult to eliminate red problems exist in a distribution system. a thorough flushing
water problems These bacteria are not 'harmful. They live program can be very helpful
and accumulate the iron in the water flowing through the 12.6 ARITHMETIC ASSIGNMENT
distribution system. As the bacterial growths increase.
slimes will build up in the mains and eventually slough off Turn to the Appendix at the back of this manual and read
into the water. When these slimes come out a consumer s Section A.30, "Iron and Manganese Control Check all of the
water tap, you can expect complaints of red water and arithmetic in this section using an electronic calculator You
slimes. should be able to get the same answers

Slime growths can be controlled by maintaining a free 12.7 ADDITIONAL READING

chlorine residual throughout the distribution system. Some-
times the residual is very difficult to maintain. If bacterial 1. NEW YORK MANUAL. Chapter 13. "Iron and Manga-
growths have been in the distribution system for a long time nese.'
and are flourishing, it is very difficult to maintain a free 2 TEXAS MANUAL. Chapter 11. "Special Water Treatment
chlorine residual at the extremes or in dead ends of the (Iron and Manganese Removal)
system. Also if the water has a natural high chlorine demand,
your chlorination equipment may not be capable of feeding
enc ugh chlorine to maintain a free chlorine residual. Re- QUESTIONS
member that frequently when zonsumers complain about Write your answers in a notebook and then compare your
chlorine or swimming pool tasting water, the solution is to answers with those on page 23.
add mo, e chlorine in order to get past the breakpoint.
12 5A List the possible causes of red or dirty water com-
One way tc' id a distribution system of iron bacteria is to plaints
develop a flushing program.'4 Flushing should start at the
location where the water enters the distribution system, 12 5B How can slime growths be controlled in water distri-
such as an elevated tank. Flush the water mains by working bution systems?

14 Sea WATER DISTRIBUTION SYSTEM OPERATION AND MAINTENANCE, par,.. 215, Pipe Flushing.
15 Backsipiionage. A form of back flow caused by a negative or below atmo ,,oheric pressure within a water system.
3U
22 Plant Operation

DISCUSSION AND REVIEW QUESTIONS

Chapter 12. IRON AND MANGANESE CONTROL

Please answer these discussion and review questions 7. When should :ron and manganese on exchange units
before continuing. The purpose of these questions is to be regenerated?
indicate to you how well you understand the material in the
lesson. Write the answers to these questions before con- 8. How would you determine whether or not to adjust the
tinuing with the Objective Test on page 23 flows to an oxidation by aeration process to remove
iron',
1 Why should iron and manganese be controlled in drink- 9. Why should reaction basins be drained and cleaned?
ing water?
10. What are the advantages and disadvantages of the
2. Why are accurate results of tests for iron and manga- oxidation by aeration process to remove iron?
nese difficult to obtain?
11. What happens if the dose of potassium permanganate
3. Why is chlorine usually fed with polyphosphates when to remove iron and manganese is not exact?
controlling iron and manganese? 12. What must you do if the potassium permanganate
ch:irge is lost in the filter bed?
4. How do polyphosphates control manganese?
13. '. y should the filtration system for the greensand
5. How is the proper polyphosphate dose determined', process have surface washers?
6. What happens when an ion exchange resin becomes 14. How would you -ittempt to prevent red or dirty water
fouled with iron rust or manganese dioxide? complaints?

SUGGESTED ANSWERS
Chapter 12. IRON AND MANGANESE CONTROL

Answers to questions on page 6. 12.1C Samples for iron and manganese testing should be
12.0A When clothes are washed in water containing iron collected as close to the well or source of water as
possible.
and manganese, they will come out stained. Iron
bacteria will cause thick slimes to form on the walls
of water mains. These slimes are rust colored from
iron and black from manganese. Variations in flow Answers to questions on page 11.
cause these slimes to slough which results in dirty
water. Furthermore, these slimes will impart foul 12.2A If a well produces water containing dissolved oxygen
tastes and odors to th water. a3 well as iron and manganese, the iron and manga-
12.0B The growth of iron bacteria is easdj controlled by nese are probably coming from the lower aquifers.
chlorination. However, when water containing iron is Try to seal off the lower aquifers.
chlorinate°, the iron is converted into rust particles
and manganese is converted into a jet black com- 12 2B To determine if nearby wells contain iron and manga-
pound, manganese dioxide. nese, samples could be collected and analyzed from
nearby private wells. Also, discussions with well
12.0C The generally accepted limit for iron is 0.3 mg/L and drillers who have been active in the locality and with
that for manganese is 0.05 mg/L. engineers with the state agency responsible for the
regulation of well drilling will be helpful.
Answers to questions on page 7.
12.2C Bench scale tests are a method of studying different
12.1A Iron and manganese react with dissolved oxygen or ways Jr chemical doses for treating water on a small
chlorine to form insoluble compounds. scale in a laboratory.
12.1B Iron and manganese samples are acidified when they 12 2D If polyphosphate solutions are much over 48 hours
are collected to prevent the formation of iron and old, they will react slowly with water to form ortho-
manganese scales on the walls of the sample bot- phosphates which are much less effective in prevent-
tles. ing manganese deposits.

*31
 Iron and Manganese 23

Answers to questions on page 16. 12.3C Dilution water is added at the discharge of the
chemical feeder pump to prevent the crystalization of
12 2E If water being treated for iron and manganese by ion potassium permanganate which could cause failure
exchange contains any dissolved oxygen, the resin of the pump discharge piping
becomes fouled with iron rust or insoluble manga-
nese dioxide. 12.3D A greensand plant should be shut down when the
12.2F The higher the pH, the faster the rate of oxidation of permanganate solution level in the vat gets low
iron to insoluble ferric hydroxide. because of the importance of the permanganate ir
the process. Without permanganate the greensand
12.2G The purpose of the reaction basin is to allow time could lose its charge and iron and manganese will
for he oxidation reactions to take place. The aera- enter the distribution system.
tion process should produce sufficient dissolved
oxygen for the iron to be oxidized to insoluble ferric Answers to questions on page 21.
hydroxide.
12.4A When a chemical feeder pumps hypochlonte, cal-
12 2H Water can be dechlonnated by the use of reducing cium carbonate coatings may develop on the poppet
agents such as sulfur dioxide (SO2), sodium bisulfate valves if the dilution water contains carbonate alka-
(NaHSO3), and sodium sulfite (Na2SO3) Bisulfite is linity. Coated valves do not seal properly and the
commonly used because it is cheaper and more feeder fails tc pump the hypochlorite solution prop-
stable than sulfite. erly.
12 21 To oxidize greensands used to oxidize iron and
12.4B The problems caused by calcium carbonate scale on
manianese, backwash the greensands. After back-
a hypochlonnator's poppet valves can be solved in
washing, regenerate with potassium permanganate
two ways:
Answers to questions on page 20. 1. A hydrochloric acid solution can be pumped
12 3A The accepted limits for iron and manganese are 0.3 through the system, or
mg/L for iron and 0.05 mg/L for manganese. 2. The dilution water for the feeder can be obtained
from an ordinary home water softener.
12.3B In the first flocculator/clarifier, chlorine is added with
flash mixing and flocculation for 10 minutes. During Answers to questions on page 21.
the next 1.9 hours, aeration occurs through fine
bubble diffusers. This process removes 95 percent 12.5A Red or dirty water complaints may be caused by:
of the iron. The treated water then flows to the 1. Iron and/or manganese in the water,
second flocculator/clarifier and the water is injected 2. Corrosive waters, and
with potassium permanganate and sodium hydrox- 3. Iron bacteria in the distribution system.
ide. This is followed by flash mixing, 10 minutes of
flocculation and 1.9 hours of settling. After this 12 5B Slime growths in distribution systems can be con-
prccess, the water is passed through filters which trolled by maintaining a free chlorine residual
produce treated waters with 0.01 mg/L of iron and throughout the distribution system and by a distribu-
also 0.01 mg/L oi manganese. tion system flushing program.

OBJECTIVE TEST
Chapter 12. IRON AND MANGANESE CONTROL

Please write your name and mark the correct answer on indication that water is being drawn from only one
the answer sheet as directed at the end of Chapter 1. There aquifer.
may be more than one correct answer to the mulitple choice 1. True
questions. 2. False
True-False
1. Iron and manganese must be removed fro,e water due 5. Chlorine should never be fed ahead of polyphosphate.
to adverse health effects. 1. True
1. True 2. False
2. False
6. If the water to be treated contains dissolved oxygen,
2. Iron and manganese are rarely found in groundwater. both iron and manganese may be removed by ion
1. True exchange using the same resins that are used for water
2. False softening.
1. True
3. Acidified samples for iron may produce high results if 2. False
clay particles are presert.
1. True
7. Oxidation of manganese by aeration is commonly used
2. False
on waters with high manganese concentrations.
4. If the water Produced by a well contains dissolved 1 True
oxygen along with iron and manganese, this is an 2. False

i 4-
32
 24 Plant Operation

8. Chlorine will oxidize manganese to insoluble manga- 3. 24 hours

nese dioxide. 4. 2 days.
1. True 5. 4 days.
2. False
20. Do not use polyphosphate solution much over
9. Chlorine will oxidize iron to insoluble ferric hydroxide hours old.
1. True 1 3
2. False 2. 6
10. Potassium permanganate oxidizes iron and manganese 3. 12
to insoluble oxides in the same way as chlorine. 4. 24
1. True 5 48
2. False
21 The rate of oxidation of iron to form insoluble ferric
11 Greensand is capable of oxidizing both iron and manga- hydroxide is decreased by mei eases in
nese and is also capable of filtration.
1. Carbon dioxide.
1. True
2. Lime dose.
2. False
3. Organic substances
12. The flocculator/clarthers are the most important pro- 4. pH.
cess in the greensand treatment plant. 5. Temperature.
1. True
2. False 22. Chemical doses being added to control iron and manga-
nese are inadequate if
13. The solution mixers in the solution vat must run continu-
ously to keep the potassium permanganate in solution 1. Addition of chlorine to the treated water produces a
1. True brownish floc.
2. False 2. Analysis of treated water contains iron.
3 Consumers complain of black particles.
14. A residual of potassium permanganate must be present 4. Consumers complain of pink water.
in the filter effluent for the greensand media to be 5. Consumers complain of rusty water.
effective.
1. True 23. The differences between greensand filters and conven-
2. False tional filters include the
15. Commercial sodium hypochlorite solutions (such as 1. Backwash rate is higher for greensand filters.
;h1orox) contain an excess of lime 2. Backwash time should be decreased for greensand
1. True filters.
2. False 3. Filtration rate is faster for greensand filters.
4. Greensand is coarser than conventional sand.
5. Greensand removes iron and manganese.
Multiple Choice
24. Determine the setting on a potassium permanganate
16. Problems caused by iron nd manganese in water chemical feeder in pounds per day if the chemical dose
include determined from a jar test is 2.5 mg/L and the flow is
0.45 MGD.
1. Corrosion.
2. Dirty water. 1. 8.4 lbs/day
3. Illness. 2 9.4 lbs/day
4. Stained laundry. 3. 10.4 lbs/day
5. Tastes and odors. 4. 12.9 lbs/day
5. 22.5 lbs/day
17. Iron and manganese react with to form insoluble
compounds. 25. Determine the setting on a potassium permanganate
1. Alum chemical feeder in pounds per million gallons if the
2. Chlorine chemical dose determined from a jar test is 2.5 mg/L.
3. Dissolved oxygen 1. 21 lbs/M Gal
4. Ion exchange resins 2. 32 lbs/M Gal
5. Lime 3. 43 lbs/M Gal
4. 46 lbsi44 Gal
18. Methods or equipment used to test for iron include 5. 50 lbs/M Gal
1. Amperometric.
2. Atomic absorption. 26. A reaction basin 18 feet in diameter and 6 feet deep
3. Nessler tubes. treats a flow of 500,000 gallons per day. What is the
4. Phosphate. average detention time in minutes?
5. Spectrophotometer. 1. 25 minutes
2. 28 minutes
19. The proper polyphosphate dose is the lowest dose the 3. 30 minutes
delays noticeable discoloration for a period of at least 4. 33 minutes
5. 35 minutes
1. 4 hours.
2. 12 hours.
elul. of OVicotive'reA

33
 CHAPTER 13

FLUORIDATION

by

Harry Tracy

I'
el 1
 26 Water Treatment

TABLE OF CONTENTS
Chapter 13. Fluoridation
OBJECTIVES 27
GLOSSARY 28
13.0 Importance of Fluoridation .
29
13.1 Fluondation Programs 29
13.2 Compounds Used to Furnish fluoride Ion 29
13.3 Fluoridation Systems 30
13.30 Chemical Feeders 31
13.31 Saturators 38
13.32 Downflow Saturators 38
13.33 Upflow Saturators 38
13.34 Large Hydrofluosilicic Acid Systems . 42
13.4 Final Checkup of Equipment 42
13.40 Avoid Overfeeding 42
13.41 Review of Designs and Specifications 42
13.5 Chemical Feeder Startup 44
13.6 Chemical Feeder Operation 44
13.60 Fine Tuning 44
13.61 Preparation of Fluoride Solution 45
13.62 Fluoridation Log Sheets 45
13.620 Hydrofluosilicic Acid 45
13.621 Sodium Silicofluonde 48
13.7 Prevention of Overfeeding 48
13.8 Underfeeding 48
13.9 Shutting Down Chemical Systems 52
13.10 Maintenance 52
13.11 Safety in Handling Fluoride Compounds 53
13.110 Avoid Overexposure 53
13.111 Symptoms of Fluoride Poisoning 53
13.112 Basic First Aid 53
13.113 Protecting Yourself and Your Family 54
13.114 Training 54
13.12 Calculating Fluoride Dosages 54
13.13 Arithmetic Assignment 58
13.14 Additional Reading qit
13.15 Acknowledgments 58
Suggested Answers 59
Objective Test 60

:.(3 5
 Fluoridation 27

OBJECTIVES
Chapter 13. FLUORIDATION

Following completion of Chapter 13, you should be able to:

1 Explain the reason for fluoridating drinking water,
2 Describe how fluoridation programs are implementea,
3. List the compounds used to furnish fluoride ion,
4. Review designs and specifications of fluoridation equip-
ment,
5. Inspect fluoridation equipment,
6. Start up a cnemical feeder,
7. Operate and maintain a chemical feeder,
8. Calculate and prepare fluoride solutions,
9. Develop and keep accurate fluoride log sheets,
10. Prevent overfeeding of fluoride,
11. Shut down chemical feed systems, and
12 Safely handle fluoride compounds.

I A

.3
28 Water Treatment

GLOSSARY
Chapter 13. FLUORIDATION

BATCH PROCESS BATCH PROCESS

A treatment process in which a tank or reactor is filled, the water is treated or a chemical solution is prepared, and the tank is
emptied. The tank may then be filled and the process repeated.

DAY TANK DAY TANK

A tank used to store a chemical solution of known concentration for feed to a chemical feeder. A day tank usually stores suffi-
cient chemical solution to properly treat the water being treated for at least one day. Also called an AGE TANK.

ENDEMIC (en-DEM-ick) ENDEMIC

Something peculiar to a particular people or locality, such as a disease which is always present in the population.

FLUORIDATION (FLOOR-uh-DAY-shun) FLUORIDATION

The add.tion of a chemical to increase the concentration of fluoride ions in drinking water to a predetermined optimum limit to
reduce the incidence (number) of dental caries (tooth decay) in children.

GRAVIMETRIC FEEDER GRAVIMETRIC FEEDER

A dry chemical feeder which delivers a measured weight of chemical during a specific time period.

POSITIVE DISPLACEMENT PUMP POSITIVE DISPLACEMENT PUMP

A type of piston, diaphragm, gear or screw pump that delivers a constant volume with each stroke. Positive displacement
pumps are used a7, chemical solution feeders.

SATURATOR (SAT-you-RAY-tore) SATURATOR

A device which produces a fluoride solution for the :luoridation process. The device is usually a cylindrical container with granu-
lar sodium fluoride on the bottom. Water flows either upward or downward through the sodium fluoride to provide the fluoride
solution.

VOLUMETRIC FEEDER VOLUMETRIC FEEDER

A dry chemical feeder which delivers a measured volume of chemical during a specific time period.

37
 Fluoridation 29

CHAPTER 13. FLUORIDATION

13.0 IMPORTANCE OF FLUORIDATION L should be treated to reduce the level to approximately the
one milligram per liter level. The exact point that exceeds the
During the period 1902 to 1931 Dr. Frederick S. McKay, a
drinking water standards depends upon the annual average
dentist practicing in C.Norado Springs, noted what seemed
of the maximum daily air temperatures (Tabel 13.1).
an ENDEMIC' brown stain on the teeth of his patients.
McKay devoted much of his time researching the case of
mottled (brown, chalky deposits) tooth enamel but it was not QUESTIONS
until 1931 that the cause was found to be excessive fluoride
in the water supplies (2 to 13 mg/L). During this penod Write your answers in a notebook and then compare your
McKay had also noted that the mottled teeth seemed to have answers with those on page 59.
fewer dental caries (decay or cavities).
13.0A What happens if a person drinks water with an
The next logical step was to add fluoride to waters that excessive concentration of fluoride?
were deficient in fluoride and to discover if children dnnking
water t:eated with fluoride had fewer cavities. In 1945 13.0B What happens if children drink a recommended dose
controlled fluoridation was started in the cities of Grand of fluoride?
Rapids, Michigan and Newburgh, New York with control
cities of Muskegon and Kingston.
13.1 FLUORIDATION PROGRAMS
Finally in 1955 the results were in and they showed a 60
percent reduction of caries in those children who drank Generally speaking, fluoridation programs start with citi-
fluoridated water compared to those children in the control zens' inquiries about fluoridation of their water supplies and
cities. encouragement of the local dental society. These requests
for the addition of fluoride to prevent dental caries are
The progress of fluoridation did not go smoothly. Anti- passed along to appropriate governing agencies. The gov-
fluoridationists became increasingly vocal and were able to erning body will usually rely upon a vote of the people, or it
stop fluoridation in many cities through action in the political may be forced into a vote by threat of a referendum. If the
arena. decision is made to fluoridate, the water department or
water company will almost always make the final decisions
Although dentists practicing in areas with naturally high
as to types of chemical and feeding equipment to be used.
fluoride waters noted that their patients had remarkably few
cavities, there were still those disfiguring brown stains.
13.2 COMPOUNDS USED TO FURNISH FLUORIDE ION
Mottling of the teeth occurs when the fluoride level exceeds
about 1.5 mg/L. Fluoride concentrations in excess of 1000 The most commonly used compounds to fluoridate water
mg/L have been found in waters from volcanic regions. systems are sodium fluoride, sodium silicofluoride and hy-
Waters with fluoride concentrations more than 1.4 to 2.4 mg/ drofluosilicic acid (Hl-dro-FLEW-oh-suh-lys-ik). There are

TABLE 13.1 INTERIM PRIMARY DRINKING WATER REGULATIONS FOR FLUORIDE AND RECOMMENDED LEVELS

Annual Average Maximum Daily

Temperaturesa Recommended Control Limits
of Fluoride Levels, mg/L Maximum Contamirant Level,
°F °C Lower Optimum Upper mg/L
a. 53.7 8: Below 12.0 & Below 0.9 1.2 1.7 2.4
b. 53.8 to 58.3 12.1 to 14.6 0.8 1.1 1.5 2.2
c. 58.4 to 63.8 14.7 to 17.6 0.8 1.0 1.3 2.0
d. 63.9 to 70.6 17.7 to 21.4 0.7 0.9 1.2 1.8
e. 70.7 to 79.2 21.5 to 26.2 0.7 0.8 1.0 1.6
f. 79.3 to 90.5 26.3 to 32.5 0.6 0.7 0.8 1.4

a Contact your local Weather Service Office to determine the "Annual Average Maximum Daily Air Tempsrature" for your service area.

I Endemic (en-DEM-ick) Something peculiar to a particular people or locality, such as a disease which is always prese it in the
population.

oq uQ
30 Water Treatment

also a few systems using such compounds as hydrofluoric Hydrofluosilicic acid is usually the easiest fluoridation
acid and ammonium silicofluonde All of these chemicals are chemical to feed. However, hydrofluosilicic acid produces
refined from minerals found in nature and they yield fluoride poisonous fumes that must be vented and is very irritating to
ions identical to those found in natural waters Hydrofluosili- your skin Sodium fluoride is easier to feed than the other
cic acid (also called fluonsilicic acid) is the compound most powdered fluoridation chemicals because it is more soluble
commonly used in several states (California, Florida and in water.
Illinois).
Operators can receive instructions from the manufacturer
on how to make up the chemical solutions and how much
solution to meter per million gallons. See Section 13.61,
"Preparation of Fluoride Solution," for calculations and pro-
cedure details.

Prior to fluoridation, the water should be checked for its

natural fluoride level. If there is natural fluoride in the water,
it is only necessary to add enough more to bring the total to
the desired level recommended by the local health authori-
ties.

TABLE 13.2 FLUORIDE COMPOUNDS

Sodium Sodium Hydrofluo-

Silico- Fluoride silicic Acid
fluoride
Na2SiF6 NaF H2Si F6

1 Form Powder Powder or Liquid

Crystal
The compounds most commonly used are covered by 2 Molecular Weight 188 1 42 0 144 1
American Water Works Association Standards. In order for
3 Commercial Purity, % 98-99 95.98 22.30 by
you to be confident of the fluoride compound you are using, Weight
insist that your supplier furnish only compounds meeting the 4 Fluoride Ion, % 60 7 (100%) 45 3 (100%) 79 2 (100%)
appropriate AWWA specifications. (Purity, %) 59 8 (98 5) 43 4 (96) 23 8 (30)
5 Density 55-72 65.90 10 5 (30%)
The plant should have as part of its records several copies lb/cu ft lb/cu ft lb/gal
of the appropriate AWWA standard for reference. Standards 6 Solubility in Water, % 076 405 100a
(gram/100 mL water
can be purchased from the Data Processing Department, at 77°F or 25°C)
American Water Works Association, 6666 W. Quincy Ave- 7 pH of Saturated 3.5 76 12
nue, Denver, Colorado 80235 Solution (1% Solution)

Price a Infinite because we are dealing with a liquid.

Standard Chemical Members Nonmembers Order No.
B701-84 Sodium Fluoride $5.50 $7.00 42701
B702-84 Sodium Silicofluoride $5.50 $700 42702
13703-84 Hydrofluosilicic Acid $5.50 $7.00 42703 QUESTIONS
Write your answers in a notebook and then compare your
Only the fluoride ion in these compounds is of any answers with those on page 59.
importance in the fluoridation of water; therefore, pound-for-
13 1A Who makes the final decisions as to types of fluoride
pound, each compound will provide a different final fluoride
chemicals and feeding equipment to be used9
level. If you switch from one type of fluoride compound to
another, you will have to make separate calculations for 13.2A List the three compounds most commonly used to
each type. Table 13.2 summarizes the important properties fluoridate water.
of fluoride compounds.

When selecting a fluoridation chemical, several important

factors must be considered. The solubility of the chemical in 13.3 FLUORIDATION SYSTEMS
water is very important if we are using the powder or crystal
form of a chemical because we want the chemical to readily Drinking waters may come to contain fluoride ions by
dissolve in water and remain in solution. Operator safety and three different types of situations. First, the raw water
ease of handling must be given serious consideration. source may have adequate or excessive fluoride ions natu-
Storage and feeding requirements as well as costs must rally present. Second, sometimes two water sources are
also be studied when selecting any chemical. blended together to produce an acceptable level of fluoride
ions. This can occur when one source has a higher than
acceptable level of fluoride ions and the other is below the
ag44C, ',A. wicatthare desired level. This chapter is mainly concerned with the third
P0140NOUhat.441014 4. situation in which fluoride ions must be added to the water to
achieve an acceptable level of fluoride ions.

39
 Fluoridation 31

13.30 Chemical Feeders measured on the basis of the weight of chemical to be fed to
the system Fluoride chemical feeders must be very accu-
Fluoride ions are added to water by either chemical rate.
solution feeders or dry feeders. Solution feeders are POSI-
TIVE DISPLACEMENT2 diaphragm pumps (Figure 13 1). Whatever the type of feeding system or chemical used, the
peristaltic pumps (Figure 13.2), or electronic pumps (Figure design should be planned by the engineer experienced in
13 3), that deliver a fixed amount of liquid fluoridation developing feeding systems (Figure 13 7). The design must
chemical with each stroke or pulse. The dry feeders are incorporate means to prevent both overfeeding and back
either VOLUMETRIC3 or GRAVIMETRIC4 types of chemical siphonage along with a means to monitor the amount of
feeders. Volumetric feeders (Figures 13.4 and 13.5) are chemical used It is also desirable to incorporate some
usually simpler, less expensive, less accurate and feed means of feeding fluoride which is adjusted (paced) accord-
smaller amounts of chemicals than gravimetric feeders. ing to the plant flow rate. Also a means to continuously
G7avimetnc feeders (Figure 13.6) are usually more accurate measure the finished water's fluoride ion content with an
than volumetric feeders, however, they are more expensive adjustable "high" fluoride alarm is desirable. Fluoride doses
and require more space for installation. The amount fed is must never be metered against a negative or suction head.

MANUAL STROKE ADJUSTER

ADJUSTING WEDGE
RETURN SPRING
PUSH ROD
BALL BEARING

DRIVING ECCENTRIC
DIAPHRAGM

SILICONE OIL BALL BEARING

.1----TFE DIAPHRAGM INPUT SHAFT

WORM

SUCTION VALVE DIAPHRAGM

OIL PUMP

RETURN SPRING
DISCHARGE
VALVE PUSH ROD
BALL BEARING

DIAPHRAGM ECCENTRIC

BALL BEARING

INPUT SHAFT
& WORM

---- SUCTION
VALVE

Fig. 13.1 Positive displacement diaphragm pumps

(PermiSSion of Wallace & Tiernan Division, Pennwalt Corporation)

2 Positive Displacement Pump A type of piston, diaphragm, gear or screw pump that delivers a constant volume with each strop a. Posi-
tive displacement pumps are used as chemica' -zolution feeders.
3 Volumetric Feeder A dry chemical feeder which delivers a measured volume of chemical during a specific time period.
4 Gravimetric Feeler. A dry chemical feeder which delivers a measured weight of ch,...mical during a specific time period

40
32 Water Treatment

IEND VIEW I
THREE-QUARTER VIEW
E
ROLLER

<-- Out PUMPING

\\\\\WEriN
TUBE

ri\\noliliiiiiimil001111111111011:

DETAIL OF
PLASTIC TUBE
HOUSING

I. SIDE VIEW

....111NIavell11111.11.10,

MECHANICAL PLASTIC
GEAR MOTOR FEED RATE TUBE
CONTROL HOUSING

Fig. 13.2 Peristaltic feeder

(Reproduced from WATER FLUORIDATION. A Training Course Manual for Engineers
and Technicians, by permission of the Dental Disease Prevention Activity,
U S Public Health Service)

41
 Fluoridation 33

RATE-OF-FEED
INDICATOR MEL
11111t . , 1 ' -
1.4111.
a'
SOLENOID 1VL-

DISCHARGE E
I.11 VA
).,k4
r
DIAPHRAGM
ALUMINUM
HOUSING

SUCTION
VALVE

RESERVOIR CHAMBER

RETURN SPRING

Fig 13.3 Electronic feeder

(Reproduced from WATER FLUORIDATION. A Training Course Manual for Engineers
and Technicians, by permission of the Dental Disease Prevention Activity
U S Public Health Service)

40
34 Water Treatment

FLOAT

HOPPER

FLUORIDE
CHEMICAL

GUIDE
VANES MOTOR

FEED
SLIDE

FECO
ROLLS
WATER
SPRAY
INLET
SOLUTION
TANK
WATER LEVEL
LINE

iiiiitlelmliillsa
i
I
DISCHARGE OVERFLOW
LINE LINE & DRAIN

Fig. 13.4 Volumetric feeder, roll-type

(Reproduced from WATER FLUORIDATION. A Training Course Manual for Engineers
and Technicians, by permission of the Dental Disease Prevention Activity.
U S Public Health Service)

43
 Fluoridation 35

FLUORIDE
CHEMICAL
HOPPER

HOPPER
AGITATING
PLATE
MOTOR --0-

GEAR ROTATING
REDUCER ----1". FEEL) SCREW

FEED RATE
REGISTER AND WATER
FEED ADJUSTING INLET
KNOB
......p:
TO WATER
SUPPLY

.0 ET
JET
SOLUTION MIXER
TANK

Fig. 13.5 Volumetric feeder, screw-type

(Reproduced from WATER FLUORIDATION, A Training Course Manual for Engineers
and Technicians. by permission of the Dental Disease Prevention Activity.
U S Public Health Service)
 36 Water Treatment

VERTICAL
GATE
FLUORIDE
CHEMICAL

SMALL SCALES HOPPER

MOTOR

SOLUTION
TANK

WATER IN LE:
CONTROLS

MIXER
I

Fig. 13.6 Gravimetric feeder, belt-type

(Reproduced from WATER FLUORIDAliON A Training Course Manual for Engineers
and Technicians. by permission of the Dental Disease Prevention Activity
U S Public Health Service)

45
 Fluoridation 37

WATER SUPPLY
LOSS OF WEIGHT ANTI SYPHON VALVE RIGID PIPE
RECORDER METERING PUMP ANTI SYPHON
I
VALVE
METERING
PUMP
TRANSFER PUMP ,s

r I

PLATFORM SCALE
ACID TANK

Direct Acid Feed System Diluted Acid Feed System

LOSS OF WEIGHT
RECORDER WATER SUPPLY METERING PUMP
TRANSFER PUMP
MIXER ANTI SYPHON
ALARM
VALVE
VOLUMETRIC
-i FEEDER

WATER SUPPLY
.-1. *.'
SOLUTION TANK PLATFORM SCALE

MIXINI: TANK DAY TANK

Volumetric Feeder Solution Tank System Manual Batch System with Dry Chemicals

Fig. 13.7 Typical fluoridation systems

(Permission of Wallace & Tiernan Division, Pennwalt Corporation)

C,
4 U
 38 Water Treatment

13.31 Saturators The saturator is a special application o: a solution feeder.

Only crystal-grade (20 to 60 mesh) sodium fluoride should small pump delivers a saturated solution of sodium
be fed with a SATURATORS (Figure 13.8). Sodium fluoride fluoride into the water system The principle of a saturator is
has a nearly constant solubility at normal temperature that a saturated solution will result if water is allowed to
ranges and thus produces a fluoride solution of uniform trickle through a bed containing sodium fluoride. Although
strength. Sodium silicofluonde is not recommended to feed saturated solutions of sodium fluoride can be manually
through the saturator because of its very low solubility in prepared, generally the easiest and best way is an automatic
water (see Table 13.2). Maintain a depth of six to ten inches feed device Saturators should be stirred every day to
(150 to 250 mm) in the sodium fluoride bed of the saturator. prevent fluoride solids from building up on the bottom. There
The use of powdered sodium fluoride is not recommended are two kinds of saturators, the upflow saturator and the
because this chemical will clog the saturator. downflow saturator.

Many dry chemical feed systems include a mixer, dissolv-

ing tank and DAY TANK6 (: .gure 13.9). The mixer mixes a 13.32 Downflow Saturators (Figure 13.10)
known amount of chemicals with a measured amount of In the downflow saturator, the solid sodium fluoride is held
water in a dissolving tank or solution chamber. This is a in a plastic drum or barrel and is isolated from the prepared
"batch mixed" process because the chemicals are mixed solution by a plastic cone or a pipe manifold. A filtration
with a specified amount of water, rather than being mixed in
barrier is provided by layers of sand and gravel to prevent
flowing water. The dissolved tank allows the chemicals to particles of undissolved sodium fluoride from infiltrating the
become dissolved in water which is continuously applied to
solution area under the cone or within the pipe manifold. The
the water being treated or is stored in a day tank or storage
feeder pump draws the solution from within the cone or
tank. The day tank usually stores at least enough chemical
manifold at the bottom of the plastic drum. Downflow
solution to properly treat the plant flow for at least one day
saturators require clean gravel and sand. In some systems
The chemical solution is fed from the day tank to the water the gravel and sand must be cleaned every day or two.
being treated by a chemical feeder (feed pump) whose feed
rate continuously adjusts to the flow being treated (flow-
paced). 13.33 Upflow Saturators (Figure 13.11)
When working with fluoridation systems using a sodium In an upflow saturator, undissolved sodium fluoride forms
fluoride solution, the hardness of the water is very important. its own bed below which water is forced upward under
Hard water can produce problems in systems using satura- pressure. No b.Arrier is used since the water comes up
tors and dissolving tanks through the formation of low through the bed of sodium fluoride and the specific gravity of
solubility calcium and magnesium fluoride compounds. If the the solid material keeps it from rising into the area of the
dilution water has a hardness of less than 10 mg/L hardness clear solution above. A spider type water distributor located
as CaCO3, there will be no problem. If the hardness range is at the bottom of the tank contains f:,.ndreds of very small
above 10 mg/L and below 75 mg/L, it is a case of how much slits. Water, forced under pressure through these slits, flows
cleaning and maintenance a particular system wants to put upward through the sodium fluoride bed at a controlled rate
up with. Above a hardness of 75 mg/L, a softened water to assure the desired four percent solution. The feeder
must be used for the water to prepare a fluoride solution in pump intake line floats on top of the solution in order to
order to prevent severe scaling in the equipment. avoid withdrawal of undissolved sodium fluoride. The water
As an alternative to the water softener, polyphosphates pressure requirements are 20 psi (138 kPa) minimum to 125
(at 7 to 15 mg/L) may be used instead of a zeolite softener to psi (862 kPa) maximum and the flow is regulated at 4 GPM
prevent plugging by scale in the feed system. The polyphos- (0 25 L/sec). Since introduction of water to the bottom of the
phates are added to the day tank to prevent scale deposits. saturator constitutes a definite cross-connection, A ME-
If neither a zeolite softener nor polyphosphates are used, CHANICAL SIPHON-BREAKER MUST BE INCORPORAT-
LO INTO THE WATER LINE; or better still, the saturator can
plugging may occur at any point in the feed system. including
valves, saturator bed, and injection point. Remove these be factory modified to include an air-gap and a water feed-
pump.
hardness deposits by flushing the system with vinegar or a
five percent solution of hydrochloric acid (muriatic acid). The
saturator beds also may require the removal of water Figures 13.8 and 13 11 show two configurations of up-
hardness deposits. flow-type saturators which feed and prepare constant
strength fluoride solution from granular sodium fluoride. The
upflow type is the preferred type over the downflow satura-
tor, as it is much easier to clean and maintain. Under normal
conditions, it should need cleaning only once a year; so, we
have discussed its coi..,, action and use in some detail.
To prepare an upflow saturator for use, the following
step, should be taken.
1. With the distributor tubes in place, and the floating
suction device removed, add 200 to 300 pounds (91 to
136 kg) of sodium fluoride directly to the tank. Any type of
sodium fluoride can be used, from coarse crystal to fine
crystal, but fine crystal will dissolve better than coarse
S Saturator (SAT-you-RAY-tore) A device which produces a fluoride solution for the fluoride
process. The device is usually a cylindrical
container with granular sodium fluoride on the bottom Water flows either upward or downward through the sodium fluoride to produce
the fluoride solution.
6 Day Tank A tank used to store a chemical solution of known concentration
for feed to a chemical feeder, A day tank usually stores suf-
ficient chemical solution to properly treat the water being treated for at least one day. Also called an "AGE TANK."

47
 Fluoridation 39

ANTI-SIPHON VALVE METERING PUMP

LEVEL
SWITCH

i
U OVERFLOW
SOLENOID VALVE l%1.j -45-
//....ft 61,... CONNECTION
I I
1 1 FLUORIDE
" SOLUTION FOR SAMPLING
AND
SODIUM CALIBRATION
FLUORIDE
V
- 0 -f
.4.........--. - L.,.
:-. :.,;;,sif4s.iff03:::7O;"e;.;::: ',..

IIDRAIN
WATER SOFTENER WATER METER SATURATOR

Fig. 13.8 Fluoride saturator

(Permission of Wallace & Tiernan Division, Pennwalt Corporation)

4S
40 Water Treatment

MIXING1.0---- OPTIONAL
FUNNEL I
ADD A MEASURED AMOUNT OF :"HEMICAL
WATER METER
4-- MECHANICAL MIXER

MEASURED
AMOUNT OF
WATER DISSOLVING TANK
(BATCH MIXED)

DAY TANK OR
STORAGE TANK
KNOWN
CONCENTRATION
OF SOLUTION CHEMICAL
FEEDER TO WATER
(FLOW- tip BEING
PACED) TREATED

Fig. 13 9 Dry chemical dissolver, day tank and feeder

49
 MAIN WATER Fluoridation 41
LINE

FLUORIDE
INJECTION WATER
POINT SUPPLY
LINE

FLUORIDE
FEEDER

LEVEL CONTROL
FLOAT VALVE

OVERFLOW HIGH WATER

LINE LINE

LOW WATER
LINE

GRANULAR NaF

2" COARSE 4" TO 6" OF

GRAVEL SAND
(1" TO 21 (la. TO 1/4")

FOOT
DRAIN
SATURATED VALVE
SOLUTION NaF

Fig. 13.10 Downflow saturator

(Reproduced from WATER FLUORIDATION. A Training Course Manual for Engineers
and Technicians, by permission of the Dental Disease Prevention Activity.
U S Public Health Service)

TO POINT OF
APPLICATION

FLUORIDE
FEEDER
SOLENOID VALVE
FLOW CONTROL

SIPHON
BREAKER
LIQUID LEVEL
SWITCH

FLOAT VALVE
ASSEMBLY

""main OVERFLOW
WATER LINE
INLET
LINE

50 GALLON .
POLYETHYLENE
SATURATED
TANK
SOLUTION OF
4% FLUORIDE

SODIUM
FLUORIDE

-4-- DRAIN PLUG

DISTRIBUTOR
TUBES

Fig. 13.11 Upflow saturator

(Reproduced from WATER FLUORIDATION, A Training Course Manual for Engineers
and Technicians, by permission of the Dental Disease Prevention Activity.
U S Public Health Service)

50
 42 Water Treatment

material if crystal .s not available for some reason, tanks should be made on two year intervals as some lining
powder can be used, but is not as desirable as a crystal detenoration can be expected over a period of time. Should
form of sodium fluoride. small leaks occur in the PVC piping, repairs should be made
at once as they will only become worse and any acid
2. Connect the solenoid water valve to an electric outlet and
dripping on concrete surfaces will dissolve the surface fairly
turn on the water supply. The water level should be
slightly below the overflow; if it is not, the liquid level quickly.
switch should be adjusted. The use of a closed-loop control system in an unattended
plant utilizing a fluoride analyzer as one of the controls is I of
3. Replace the intake float and connect it to the feeder
intake line. The saturator is now ready to use. recommended. The problem is that if the analyzer goes
haywire and incorrectly indicates low fluoride levels, the
4 By looking through the translucent wall of the saturator system will try to correct itself and increase the addition of
tank, you should be able to see the level of undissolved fluoride chemical. The net result will be to actually over-
sodium fluoride. Whenever the level is low enough, add fluoride the water supply.
another 100 pounds (45 kg) of fluoride.
5. The water distributor slits are supposed to be essentially QUESTIONS
self-cleaning, and the accumulation of insolubles and Write your answers in a notebook and then compare your
precipitates does not constitute as serious a problem as it answers with those on page 59.
does in a down-flow saturator. However, a periodic
cleaning is still required Frequency of cleaning is dictated 13.3A List the three different types of situations whereby
by the seventy of use and the rate of accumulation of drinking waters may contain fluoride ions.
debris.
13.3B List three important design features of fluoridation
6. Because of the thicker bed of sodium fluoride attainable systems.
in an upflow saturator, higher withdrawal rates are possi-
ble. With 300 pounds (136 kg) of sodium fluoride in the 13.3C What problems can be created by hard water in
saturator tank, more than 15 gallons per hour (58 L/hr) of systems using saturators and dissolving tanks?
saturated solution can be fed. This rate is sufficient to 13.3D What is a saturator?
treat about 5,000 gallons per minute (135 L/sec) of water
to a fluoride level of 1.0 mg/L.
13.4 FINAL CHECKUP OF EQUIPMENT
7. The fixed water inlet rate of 4 GPM (0.25 L/sec) should
register satisfactorily on a 5/8-inch (16 mm) meter. 13.40 Avoid Overfeeding
From a financial point of view, many water systems will The operator must be certain that there will be no over-
want to design their fluoridation plants for unattended oper- feed of fluoride ions. A gross overfeed can cause illness and
ation; so there will be designed into the system means for bad public relations. Of all the chemicals used in the water
automatic shut down and alarm. For the sake of the operator
treatment plant, fluoride concentrations are probably the
that has to respond at all hours, alarm lights should be wired most sensitive to correct maximum dosages.
to indicate reasons for plant shutdown.
A few example alarms include low water flow in the main
pipeline; high fluoride flow; high or low fluoride levels, low
injection water pressure, power outage, and running time
meter to indicate "down" time. These warning systems are
partially helpful in large systems.

13.34 Large Hydrofluosilicic Acid Systems (Figure 13.12)

A more complicated system for fluoridation is a closed-
loop control feeding system using hydrofluosilicic acid. This
system finds use in large installations where the hydrofluosi-
licic acid can be delivered by tanker truck of around 4,000
gallons (15,140 L); although of course, smaller amounts can
be purchased. The installation depicted in Figure 13.12 can
treat up to 285 million gallons per day (1,079 ML/day). The
advantages in this system are the elimination of dusting and
also labor requirements are a. a minimum.
The storage tanks are fiberglass filament wound with 13.41 Review of Designs and Specifications
interior lining of Dera Kane 411-45 Resixl with a final barrier
of Nexus Veil which has replaced Dynel. Steel tanks lined When reviewing fluoride feeding system designs and
with at least 3/32 inch (2.34 mm) polyvinyl chloride sheet or specifications, the operator should check the items listed
neoprene sheet secured to the metal surface with adhesive below.
can also be used. Hydrofluosilicic acid storage tanks con- 1. Review the results of pre-design tests to determine the
structed of plastic should be housed in enclosures to protect fluoride rate for both the present and future. The fluori-
the tanks from vandalism. Leaks could be dange, ous to dator should be sized to handle the full range of
passers by and will kill surrounding vegetation. The tanks chemical doses or provisions should be made for future
must be vented to the outsize as the fumes from the acid are expansion.
highly corrosive.
2. Determine if sampling points are provided to measure
Inspection of internal conditions of the hydrofluosilicic chemical feeder output.

51
 -4-- RECEIVER

RECEIVER
/--- ALARMS
AI
iTEGRATOR -91

COUNTER
RECEIVER INTEGRATOR

COUNTER
SQUARE ROOT
CONVERTER

RATIO CRANE
vo '
4- FLOW TO CURRENT
CONVERTER

CONTROLLER DRIVE PACKAGE .4- METERING

1 TRANSMITTER
I
I
I I
SUCTION I
I
CHEM/METER PUMP I
I
POWER SUPPLY
1

I
I
-E- D/P CELL TRANSMITTER

A
1

il DISCHARGE

PRIMARY DEVICE
----6
TRANSMISSION MAIN

52
Fig. 13.12 Large automatic hydrofluosilicic system 53 A
c.)
44 Water Treatment

3. Examine plans for valving to allow flushing the system 2 Confirm that the manfacturer's lubrication and startup
with water before removing from service procedures are being followed Equipment may be
damaged in minutes if it is run without lubrication.
4. Be sure corrosion-resistant drains are provided to pre-
vent chemical leaks from reaching the floor, for exam- 3. Examine all fittings, inspection elates and drains to
ple, drips from pump packing. assure that they will not leak when placed into service.
5 Check that all piping, valves and fittings are made of 4. Determine the proper positions for all valves. A positive
corrosion-resistant materials such as PVC or Stainless displacement pump will damage itself or rupture lines in
Steel Type 316. seconds if allowed to run against a closed valve or
system.
6. Determine the arount of mainhnance required. The
system should require a minimum of maintenance. 5. Be sure that the type of fluoride to be fed is available
Equipment should be standard, with replacement parts and in the hopper or feeder. A progressive cavity pump
readily available. will be damaged in minutes if it is allowed to run dry.
7. Consider the effect of changing head t,onditions (both 6. Inspect all equipment for binding or rubbing.
feeder suction and discharge head conditions) on the
chemical feeder output. Changing head conditions will 7. Confirm that safety guards are in place.
not affect the output if the proper chemical feeder has 8 Examine the operation of all auxiliary equipment includ-
been specified and installed. ing the dust collectors, fans, cooling water, mixing
8. Determine whether locations for monitoring readouts water, and safety equipment.
and dosage controls are convenient to the operation 9. Check the operation of alarms and safety shut-offs. If it
center and easy to read and record. is possible, operate these devices by manually tripping
9. Any switches that throw the equipment from automatic each one. Examples of these devices are alarms and
into a hand or manual mode should be equipped with a shut-offs for high water, low water, high temperature,
red warning light to indicate that the equipment is on high pressure and high chemical levels.
"hand" or "manual." This can easily be accomplished by 10. Be sure that safety equipment such as eyewash, drench
a double-throw, double-pole, toggle switch. Lights with showers, dust masks face shields, gloves and vont
different colors can be used to indicate normal or fans, are in place and functional.
automatic operation as well as on or off in order to avoid
confusion. 11. Record all important nameplate data and place it in the
plant files for future reference.
10. The location where flu..nde is added to the water should
be where there will be the least possible removal o' QUESTIONS
fluoride by other chemicals added to the water (after
filtration and before the clear well) Write your answers in a notebook and then compare your
answers with those on page 59.
11 Be sure the chemical hoppers are located where there
is plenty of room so they can be conveniently and safely 13.4A Why must overfeeding of fluoridation chemicals be
filled with the fluoride chemical. prevented?

12. Dust exhaust systems should be installed wnere sub- 13 4B What should be the capacity or size of the fluoride-
stantial amounts of dry chemicals are handled. tor?
13. In any fluoridation system, except the sodium fluoride 13 5A What items should be considered when inspecting
saturator, scales are necessary for weighing the quanti- the fluonda.ion electncal system?
ty of chemical (including solution) fed per day. 13 5B List the safety equipment that should to available
14. Al,:rms are important to signal and prevent both the loss near a fluoridation system
of feed and overfeeding.
15. Any potable water line connected to a chemical feeder 13.6 CHEMICAL FEEDER OPERATION
unit must be provided with a vacuum breaker or an a.r
gap to prevent a cross-connection. 13.60 Fine Tuning
Once the chemical feed equipment is in operation and the
major "bugs" are worked out, the feeder will need to be "fine
1:..3 CHEMICAL FEEDER STARTUP tuned "To a I in fine tuning and build confidence in the entire
After the chemical feed system has been purchased and chemical feed system, the operator must maintain accurate
installed, carefully chock the sys%:m out before startup records (see Section 13.62, "Fluoridation Log Sheets").
Evan if the contractor who installed the system is responsi-
ble for insuring that the equipment operates as designed,
the operation by plant personnel, the functioning of the
equipment and the results from the process are the respon-
sibility of the chief operator. Therefore, before startup,
check the items listed below.
1. Inspect the electrical syster, for proper voltage; for
properly sized overload protection; for proper operation
of control lights on the control panel; for proper safety
lock-out switches and operation; and for proper equip-
ment rotation.

54 L
 Fluoridation 45

A comment or remarks section should be used to note 4. "% & Sp.Gr Each delivery is accompanied by a ven-
abnormal conditions, such as a feeder plugged for a short dor's laboratory analysis. The specific gravity is not
time, related equipment that malfunctions and other prob- measured until the tank is ready to be placed in service.
lems Daily logs should be summarized into a form that When mixing acids of varying strengths, the end per-
operators can use as a future reference. centage must be calculated and entered in the proper
column. See Example 10 in Section 13.12, "Calculating
Fluoride Dosages."
13.61 Preparation of Fluoride Solution
To learn how to make up a fluoride solution, let's assume 5. For each tank follow the directions give, n Step 4.
a hypothetical case using the following data: 6. "Tank Loss Gals" refers to the amount of feed during the
1. Flow to be treated is 10 million gallons per day, reporting period. In the sample 2930-2600 = 330 gal-
lons. The feeding equipment should be equipped with
2. Hydrofluosilicic Acid 20% is the chemical to be used, an acid totalizer readout.
3. The unfluoridated water contains 0.05 mg/L (ppm) flu- 7. The "ratio" column indicates the feed setting computed
oride ion (F-), and using the acid strength, specific gravity and required
4. The desired fluoride concentration in the treated watei is dosage. The following steps illustrate how to calculate
1.0 mg/L. the feed setting for a specific piece of equipment.

What should the feed rate be? (a) (Sp.Gr.)(lbs/gal water)(% H2SiF6)(% F- (in H2SiF6))
= lbs F-/gal.
See Treatment Chart I, Hydrofluosilicic Acid, located on
the next page. (b) Substituting figures in the above formula.
(c) (1.226)(8.34)(0.229)(0.791) = 1.85 lbs F-/gal.
Locate the 10 MGD flow on the left hand scale of the graph
and follow that line to the right until it intersects the 20 (d) Dosage: 8.34 1.85 = 4.51 gallons acid/M.G.
PERCENT diagonal line. Project this point down vertically to water.
the intersection of bottom line indicating gallons per day (or
gallons per hour) required to produce a one mg/L (ppm) (e) In order to compensate for the .05 mg/L F- in the
dose of fluoride (F). The answer is 50 GALLONS PER DAY raw water supply, the above figure of 4.51 should
or a little less than 2.1 GFH(gallons per hour). Multiply the 50 be reduced by 5% which is the relationship of the
by (1.00-0.05) to give the needed treatment of 47.5 gallons desired level of say 1 mg/L F- to the raw water level
per day or 2 GPH. The 1.00 is the desired dose of 1.00 mg/L of .05 mg/L F-.
and the 0.05 is the actual fluoride concentration of 0.05 mg/L 4.51 (.05 x 4.51) = 4.51 - .23
(f) 4.28.
in the untreated water.
In some cases it might be desirable to use a weaker acid (9) Ratio setting therefore is 4.28 4.80 or 0.89.
solution to avoid feed rates below the minimum capacity of (h) The flow capacity of the pipeline water meter at
the metering pump. Dilution then is in order. The concentra- 100% is 300 MGD.
tion may be reduceo by volumetric proportions, for example
one gallon of 20 percent acid plus one gallon of water results (I) The flow capacity of the acid feed pump is 1440
in two gallons of 10 percent acid. If possible try to avoid gallons of H2SiF6/day.
having to dilute acid because of potential errors and prob-
The ratio of the above two 100% capacities is 1440
lems, especially with hard water. Peristaltic and electronic
- 300 or 4.8 gal/MG.
feeder pumps (Figures 13.2 and 13.3) may be used when the
feed rates are low. Note the difference of the setting of 0.88 and the
See Section 13.12, "Calculating Fluoride Dosages," for calculated figure of 0.89. This adjustment is made in
eleven example problems. order that the fluoride dosage will agree with the
laboratory results. In all instances, the laboratory
results should govern the feed settings.
13.62 Fluoridation Log Sheets
The small difference in calculated setting and actual
You will probably want to design your own log sheets so setting can also result from accumulated errors in
they will be consistent with the installation features at your the control equipment, i.e., flow transmitter,,
plant. Sample log sheets are shown on Figures 13.13, 13.14 extractor, and ratio controller.
and 13.15 (see pages 49, 50 and 51).
8. "H2SiF6 Gals." is the actual amount of acid fed into the
system and is derived as follows:
13.620 Hydrofluosilicic Acid 885005.50 884676.08 = 329.42 gallons
Figure 13.13 shows a typical log sheet from a hydrofluosi- Ths figure should be fairly close to the reading obtained
at Step 6. If it is not, look for c, rors in readings, leaks or
licic acid station. An explanation of the various columns is
given below. equipment malfunctioning.

1. "Date" refers to calendar date when readings were 10. "Water Meter Totalizer" is the cumulative total of the
amount of water being treated measured by a venturi or
logged or the date a shipment of fluoride was received.
some other type of primary water meter.
2. "Time" refers to time event happened.
11. "Vidier M/Gals." is the actual amount of water passir3
3. "Tank" that is supplying the feeder is circled. "Gals." through the water meter for the time period involved and
refers to the gage reading of the amount of acid in the again is derived by simple subtraction:
tank. 268.00 191.01 = 76.99 Million Gallons.
46 Water Treatment

22
1--- -----7 ,
I
1

I I r
1 pprn F. Application with indicated strength
1
1
ei
I
I
of Hydrofluosilicic Acid (H2SiF6)
i { lsoro
1

,0 /11
4-
43
3
::
14

12 /AM
Williiral ilia
....

AlffiallillW.
.
O 10
Is%
L.
II

/00/11elpillail".... le°
CO

01.1.°--
i
c 4 -4110111111.111111111
5%

oll

10 20 30 40 50 60 70
Gallons per day of Hydrofluosilicic Acid
i
0 05 1.0 1.5 2.0 25 3.0 GP

TREATMENT CHART!
Hydrofluosilicic Acid

60 ri
6- 30151°
1 ppm F. Application with indicated strength
lix
1
i
50
of Hydrofluosilicic Acid (H2SiF6) I
o -13 40
,17.

.13 Z 30
4)
a_o
w 20
O0
70 "" 10
0
e
25 50 15 1100
Gallons per day of Hydrofluosilicic Acid
1 125 150 200

I I
3 4 5 6 8 GPH

TREATMENT CHART II
Hydrofluosilicic Acid

Treatment Charts Courtesy of

Wallace & Tiernan Division, Pennwalt Corporation

56
 Fluoridation 47

600
I I

0 1 ppm F. Application with indicated strength

of Sodium Fluoride (NaF) Solution
500

-0
.2 400

2 300

200
to

0
100
0
0
0
I0 20 30 40 50 60 70
Gallons per day of Sodium Fluoride Solution
05 1.0 1.5 2.0 25 3.0 GPH

TREATMENT CHART III

Sodium Fluoride

MGD H i i I 1

4 1 ppm F. Application with indicated strength

of Sodium Fluoride (NaF) Solution
-1-
I I I
4,1 2500
r
I I
1
1

42 2000 I
1

0
I
I per a \ \o
X31
2
I

` 1500 cl vi..treiel
I

0. I 16
10.25 ' "
1000 - . 0.8%1
to
" t I a%)
I

500 .INIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII-.....01.15
0 .1.1111111.1"(

0 25 50 75 100 125 150 175 2C 0

Gallons per day of Sodium Fluoride Solution
I I

0 2 4 5 6 7 8 GPH

TREATMENT CHART IV

Treatment Charts Courtesy of

Wallace & Tiernan Division. Pennwalt Corporation

C.7
.7
It I it
48 Water Treatment

12 "Acid Gal/MG" is the rate of treatment for hydrofluosili- should be equipped with a resettable running time meter
cic acid and is obtained by dividing the figures from Step reading hours and tenths.
9 by the figure from Step 11.
329.42 76.99 = 4.28
13. Figure 13.15 is a typical small plant log used in
plants utilizing sodium silicofluc,ride. This log sheet is
13. "F RESID. PPM" is actual fluoride content in the treated provided through the courtesy of the City of Palo Alto,
water as read by continuous flow fluoride ion analyzer. California.
14. 'Down Time" The equipment should be equipped with a QUESTIONS
ri° ling time meter reading in seconds that begins to
operate any time the plant shuts down. This will give Write your answers in a notebook and then compare your
reasons for low feed as indicated by the readings in answers with those on page 59.
Step 12. The operator should know why this deviation
occurred. 13.6A What should be the feed rate in gallons per day for
treating 6 MGD with hydrofluosilicic acid 20 percent if
15. "OBS.BY" This will be the operator's initials. the desired fluoride ion concentration is 1.2 mg/L?
Assume the raw water does not contain any fluoride
ion.
13.621 Sodium Silicolluoride
13 6B What could be the causes of differences between the
1 Figure 13.14 is a typical log sheet for a gravimetric recorded volume of acid used from a storage tank
feeder feeding powder sodium silicofluoride. and the volume of acid fed into the system as
2. "Date" and "Time" are entered in the first two columns. measured by a flow meter?

3. "Totalizer Reading (lbs.)" This reading indicates a cumu- 13.7 PREVENTION OF OVERFEEDING
lative reading of the amount of silicofluonde that has
been fed by the machine. 1. Operators must be assured that no overfeeding occurs,
because no additional benefits result from overfeeding
4. "Weight Loss per 24 hrs. (lbs )" is the amount of silico- and there is a waste of chemicals and money. Excessive
fluoride actually fed during the time frame and is deter- overfeeding could be harmful to consumers.
mined from the readings observed in Step 3 as follows.
44165.5 43276.9 = 888.6.

5. "Mach. Feed Setting" is the feed rates being used. This

rate may vary from machine to machine depending upon
gear ratios and other devices used to control the rate of
chemical feed. If the laboratory tests indicate low or high
fluoride ion level, the adjustment is made with this
setting on a percentage basis. If the laboratory fluoride
ion level is 10 percent low, then this setting should be
raised 10 percent.
6. "Chem Added to Bin (lbs.)" is the amount of chemical
taken from storage and dumped into the feeder hopper. 2 If the size of the installation warrants, a continuous
7. "Chemical Left in Storage (lbs.)" is the amount of fluoride
fluoride ibn analyser should be installed in the treated
in the bulk storage. This is useful in programming water line located downstream a sufficient distance so
that adequate mixing is assured.
supply orders and in checking the accuracy of the
feeder over a period of time To check accuracy, com- 3. In a large plant involving shift operation, grab samples
pare this amount with the amount indicated in Step 4 can be analyzed for the fluoride level during each shift,
over a six month or one-year period. otherwise, once-a-day checks will suffice.
8. "Pump Operating" is useful if several pumps are avail- 4. If th- plant uses one of the solid fluoride compounds and
able to inject the dissolved sodium silicofluoride into the the operator questions whether there is total solubility,
water main. the fluoride feeder can be shut down and the lack of
fluoride traced out in the distribution system. There
9. "Water Meter Reading (10,000 gals)" is the reading from
the main line water meter. should be a sudden drop to zero fluoride or to the
background level if total solubility is not being achieved
10. "Water Treated (m.g.)" , the amount of water actually (the undissolved solid fluoride compound will settle out).
treated and is derived from Step 9 data as follows:
5. All liquid systems should be checked for positive protec-
39829.73 39762.41 = 67.32. tion against back siphonage from fluoride storage tanks.
11 "Dosage (lbs. per m.g.)" represents the actual dosage of 6. Shut down the plant if there is any significant overfeeding.
fluoride in the water. This figure should 1-,e, constant, Start flushing the affected mains and notify the local and
barring down time; changes in machine feed setting, state health departments. The water department and the
Step 5 or equipment malfunctioning. The value is de- health departments will then decide if public notification
rived from the weight loss (Step 4) divided by the .er should be undertaken.
treated (Step 10) as follows:
888.6 ÷ 67.32 = 13.2. 13.8 UNDERFEEDING
12. "Plant Down Time (Hrs is the period of time fluoride In contrast to the chlorination operation where continuous
was not being fed and the plant was shut down because operation must be assured, fluoridation does not have to be
of power failure or automatic shutdown. The installation continuous. Shutdowns for cleaning, adjustments, or due to

58
 BYPASS TUNNEL FLUORIDE STATION
WEEK ENDING _be6einZe., 1/, 1 9 R
ACID STORAGE
DATE TIME COMM TANK 2 TANK 3 TANK 4
TANK
LOSS RATIO
H2SIF6 H2SIF6 WATER METE WATER ACID RESID DOWN OBS

GALS.
%& GALS %& GALS %& GALS %& GALS
TOTALIZER GALS TOTALIZER M/GALS. AL/MG ppm LIME BY

END O F
PREVIOUS WEEK 0
SP. GR

1.74' MEM SP GR SP GR SP GR

de . 4(. o ' .e, O. 98

IP I I .0 30 . S'OliirS-e e 42- I, __7_4j A. _

co
co
(....,

---1

L
BIF FLOW F&P (REMARKS
METER METER

59
46
Fig. 13.13 Log sheet for bypass tunnel fluoride station
 FLUORIDE STATION REPORT Ut
0
Statim_Sunsel .514,421y_kin_e_ Week End ng_ ..Ae__e_. NJ__L er /l £9 81
Totalizer Weight Mach Chem. Chemical Pump Water Water Dosage Plant Feeder
Date Time Reading Loss per Feed Added Left in Meter Time
24 hrs Set. to Bin Storage ()per. Trea
Treated
te (lbs Down Time %son
Reading per Lapse
(lbs ) (Ills ) Sing (lbs ) (lbs ) acing (m g ) ( Hrs )
(10.000 gal.) mg) (sec )
41 214 9
END OF PREVIOUS WEER
,i,13 1,Zeeo 1A 0 1 n 7.41 13.2
11-1.5" 10:1e A 441Lrf ggg.L 5-2.g 400 -pipe IA 14819.73 47:3X 1,3. ,- 1173s-13,4

o1
'"Q;) 6i Fig. 13.14 Log sheet for fluoride station reports
P?
 City of Palo Alto Water Division

WFEKLY WATER PRODUCTION AND TREATMENT LOG

Week Ending Wed. 19 Station:

FL'JOR IDE WATER ( CCF SAND

fin.1)
Feeder Lbs. Feed Calc Tinier Meter Record
Start Add Final Used Setting mg/Igetting Consumption
Total
Wed
Tues.
Mon.
Fri
Thurs
Previous

Pump A No. motor starts REMARKS

No. running hours
Lead Pump!
No. motor starts
Pump B No. running hours

OTHER METER READINGS

Miter Functios
Present Reading
Previous Reading
Difference
111.
m
1.4
CHLORINE
CU '7 Cy inder, Lbs. OTO
VC
,his ...-
Net Feed lesid.
.-t
>sc Gross Lire J.1 1#2 Used Rate m.:/1
o
Previou,
Thurs.
Fil
Mn.
L.

,.

t..d.
totJ1

MISCELLANEOUS MEASUREMENTS
Well static level, ft.
Well pumping level, ft.
Head against well, pump, psi
?.)
Amp dray reading

6
 52 Water Treatment

safety controls can be tolerated for short time periods. This 13.10 MAINTENANCE
does not mean that sloppy operation and maintenance is
desirable. Every attempt should be made to maintain con- Maintenance should follow the same routine as with any
stant feeding. For example, the installation of standby elec- similar chemical feeder, including regular clean up and
trical generating equipment just to maintain fluoridation painting of the equipment and appurtenant metal piping and
equipment in operation would not be warranted. If the conduits In order to give the plant a fresher look and hold
standby generator had to be purchased for other reasons. down on painting, consider using all plastic piping even
then the emergency circuit may also include the fluoride though it is used only for the water supply. Conduit and
feeding equipment Underfeeding should not be allowed fittings should also be plastic for the same reason. Vacuum
because this results in a very significant reduction of the any gears and other similar parts to remove fluoride dust.
benefits of fluoridation.

Daily inspection of the fluoridation equipment, fluoride

Since fluoride solutions are extremely corrosive, be con-
tests on the treated water, and calculation of the dosage
from water treatment and chemical use data can greatly
stantly on the lookout for drips or leaks and any other
evidence of corrosion. Repair these conditions as quickly as
minimize the possibility of both overfeeding and underfeed-
ing. possible. Also look for the buildup of insoluble deposits in
feedlines and equipment. Schedule the removal of insoluble
deposits on a regular oasis to prevent buildups from creat-
QUESTIONS ing any problems.
Write your answers in a notebook and then compare your All containers of fluoride chemicals must be disposed of in
answers with those on page 59. an acceptable manner. Thoroughly rinse all containers with
13.7A Why should overfeeding be prevented? water to remove all traces of chemicals before allowing
containers to leave your plant. You may burn the containers
13.7B What should be done if significant overfeeding oc- if a nuisance will not be created. Remember that fluoride
curs? fumes can kill vegetation.
13.8A Why might a fluoridation operation be shut down? You don't need to be too concerned about checking the
feed rate by catching a given amount of fluoride over a time
13.9 SHUTTING DOWN CHEMICAL SYSTEMS period. The log will show long-period discrepancies and the
daily laboratory tests will indicate any drifting from the
If the fluoridation equipment is going to be shut down for desired fluonde concentration in he treated water.
an extended length of time, it should be cleaned out to
prevent corrolion and/or the solidifying of the chemical. Either you or the laboratory personnel must analyze the
Lines and equipment could be damaged when restarted if fluoridated water daily. Check the results for any deviations
chemicals left in them solidify. Operators could be seriously from the norm and take corrective action. Hand-held colori-
injured if they open a chemical line that has not been meters are available for measuring fluoride in water. See
properly flushed out. Chapter 21, "Advanced Laboratory Procedures," for details
on how to analyze samples for the fluoride ion.
The following items should be included in your checklist
for shutting down the chemical system: An important part of your maintenance program is the
prevention of any sanitary defects that could adversely
1. Flush out the chemical supply with water, affect the safety or quality of your treated drinking water.
2. Run dry chemicals completely out of the equipment and Sanitary defects that could develop in fluoridation syste.n;
include:
clean equipment by using a vacuum cleaner,
3. Flush out all the solution lines with water until the lines are 1. Lack of or inadequate start-stop controls,
clean, 2. Inadequate feed rate control equipment,
4. Shut off the electrical power, 3. No analyzer to measure fluoride ion levels in treated
5. Shut off the water supply and PROTECT FROM FREEZ- water,
ING, 4. Lack of or inadequate backflow safeguards,
6. Drain and clean the mix and feed tanks, and 5. Fluoridation chemical not meeting AWWA specifications,
7. Padlock (lock out) the main electric switch box to the and
fluoride equipment. 6. Inadequate free chlorine residual in treated water.

65
 Fluoridation 53

13.11 SAFETY IN HANDLING FLUORIDE COMPOUNDS' 13.111 Symptoms of Fluoride Poisoning

From the operators viewpoint, fluoride chemicals have In the event that someone is poisoned, it is vitally impor-
one thing in common with all other chemicals found in tant to recognize the early symptoms.
treatment plants: FLUORIDE CHEMICALS can seriously
injure or kill the careless or untrained operator. Safety Some of the obvious signs of poisoning are vomiting,
should be of special concern to YOU because it is your own stomach cramps, and diarrhea. Usually, the person will
health that is at stake. become very weak, have trouble speaking, be very thirsty,
and have poor color vision. In cases of extreme poisoning,
13.110 Avoid Overexposure there are strong, jerky muscle contractions in the arms and
legs leading to convulsions. If poisoning is not treated
One of the major causes of overexposure is the inhalation immediately, the person may die. Fatal doses range from 4
of fluoride dust This usually occurs while a dry feeder or to 5 gm, or about a tablespoon. This equals about 2,000
saturator is being loaded. Even with the use of dust collector times the amount of fluoride swallowed by a person from a
systems, dust will circulate in the air. Always use approved water supply.
respirators equipped with cartridges for organic dusts and
vapors, protective coveralls and gloves when emptying If a person is poisoned by inhaling fluoride, the first
sacks or cleaning up equipment and plant surfaces. symptoms will be a sharp, biting pain in the nose followed by
a runny nose or nose bleed. It is doubtful that a person could
When loading a saturator, Just will be minimized if crystal- inhale enough fluoride to produce the same effects as
line sodium fluoride is fed instead of powdered sodium encountered from drinking a large amount of fluoride. How-
fluoride. When loading a cry feeder you should wear a ever, the sudden presence of bad stomach cramps and
mask, apron, and rubber gloves to minimize exposure. pains in the nose and eyes should not be igne' ad.

When the protection gear is removed, the remaining small The victim should see a doctor immediately, and the water
traceb of chemical should also be removed from your body. treatment practices should be checked to determine the
Some large water plants have dust-collection systems that source of the fluoride poisoning. It is probably a good idea to
use a partial vacuum to draw dust from your body and vent it check out treatment practices occasionally.
to the outside air after filtering. The importance of quick treatment for fluoride poisoning
cannot be over emphasized. In such cases a doctor should
Care should be taken when emptying bags of chemicals
be called immediately, and if the poisoning is severe, an
into a feeder hopper. TI e bags should be opened carefully
ambulance should be called.
at the top and the contents poured gently to minimize dust.
Care should also be taken during storage of the bags. Bags
13.112 Basic First Aid
should be stored in a dry place, preferably off the floor. If
bags are stacked too high there is the possibility of them Once it is established that it is fluoride poisoning, first aid
falling and breaking open. should be started while waiting for medical help The follow-
ing are recommended first-aid procedures:
If a saturator is used, you should be cautious about
allowing the solution to come in contact with skin and 1. Move the person away from any contact with fluoride and
clothing. If this does happen, the affected area should be keep warm,
washed immediately with water. This also applies to other
fluoride solutions (such as the dissolving water used in a dry 2. Give the person three teaspoons full of table salt in a
glass of warm water,
feeder).
3. If the person is conscious, induce vomiting by rubbing the
If a fluoride acid is being fed, extra precaution must be back of the throat with a spoon or your finger; if available
taken. Fluoride acid is probably the most corrosive chemical use syrup of ipecac,
found in a water plant The pH of fluoride acid is approxi-
mately 1.2 and will eat through glass faster than chlorine. 4. Give the person a glass of milk,
Special care should be taken to keep fumes to a minimum. If
5. Repeat the salt and vomiting several times, and
the acid does come in contact with your skin, you may not be
able to wash it off fast enough to prevent a burn. If this 6. Take the person to the hospital as soon as possible.
happens, standard first aid should be administered as soon
as possible. First aid for a person with a nose bleed from inhaling a
high concentration of fluoride is:
A good pair of safety goggles should be worn at all times
1. Take the person away from the source of the fluoride;
when working around fluoridation equipment where there is
any possibility of splashing fluoride solutions. Be especially 2. Tip the person's head back while placing cotton, cloth, or
cautious around the fluoride acids as the concentrated acid paper towels inside the nostrils (change these often);
can dissolve the whites of one's eyes in addition to the usual
burns associated with acids. Another "must" is a safety 3. Take the person to a doctor if you cannot stop the
shower. This must bu Ircated within easy access to both the bleeding.
unl- 3ding operation £ id points of liquid usage. If common sense and good safety practice are used, the
hazard to the water plant operator should be as small as the
Another safety precaution that should be followed is the
labeling of all feeders and solution tanks. Proper labeling will hazard to the water consumer.
help prevent placement of chemicals in the wrong feeder. If fituviciation ekemica14 are p0i4011D04.
possible, fluoride chemical should be tinted blue to differen-
tiate it from other water tr 'atment chemicals. ko_tatt Wrmif film t1yz4zioxic cligthical.
7 Portions of the material in this section were adopted from "Safety Procedures Necessary During Fluoridation Process," by Ed Hansen
Reproduced from OPFLOW, Volume 9, No. 7, (July 1983) by permission. Copyright 1983, The American Water Works Association.

1G
 54 Water Treatment

13.113 Protecting Yourself and Your Family (Commercial Purity, %)(Fluoride Ion, %)
Portion F
Avoid swallowing fluoridation chemicals. Don't eat, drink (100%)(100%)
nr smoh: in or around chemical storage or feed areas. Do
riot inhale chemical dusts or vapors. Wear a respirator. Be The portion F is the pounds of F per pound of commercial
sure exhaust fans and dust collectors are operating proper- chemical. For exa--21e, 0.6 pounds F per one pound of
ly. Prevent hydrofluosilicic acid from coming in contact with commercial sodiuni silicofluoride.
your skin or eyes because hydrofluosilicic acid is very 5. To calculate the fluoride dosage or any chemical dosage,
corrosive. If any hydrofluosilicic acid touches you, flood the you need to know the pounds of chemical and volume of
contact area with plenty of watoc. If you are acutely poisoned water in million gallons.
by a fluoride chemical, you may he thirsty, vomit and have
stomach cramps, diarrhea, difficulty in speaking and dis- Dosage, mg/L = Chemical, lbs
turbed color vision. If any of these symptoms occur, consult (Water, M Ga(X8.34 lbs/gal)
a physician immediately.
lbs Chemical
When leaving the fluoride plant, wash your hands and
change coveralls so that fluoride dust is not carried home. Million lbs Water
If we substitute milligrams for pounds, we get
13.114 Training
mg Chemical
Special safety training must be given to all operators who
will handle fluoride compounds. Training must include how Million mg Water
to safely receive compounds from supplier, store until One mi!iion milligrams of water occupy a volume of one
needed, prepare solutions, load feeders, and dose water liter.
being treated.
mg Chemical
QUESTIONS Liter of Water
Write your answe,*s in a notebook and then compare your = mg/L
answers with those on page 59.
6. To determine the amount of feed solution in either gallons
13.9A Why should fluoridation equipment be cleaned out or gallons per day to treat a water, you need to know the
if the equipment is going to be shut down for an amount of water to be treated in gallons or gallons per
extended length of time? day, the feed dose in milligrams per liter and the feed
solution in milligrams per liter.
13.10A How can fluoride dust be removed from gears?
Feed Solution, (Flow, gal)(Feed Dose, mg/L)
13.1 .113 How would you determine if your fluoridation equip- gal
ment was providing the desired dosage? Feed Solution, mg/L

13.11A What are the symptoms of acute tluoride poison- NOTE: If the "Feed Solution" is in gallons per day
ing? instead of gallons, then the "Flow" must be in
gallons per day also instead of gallons.
13.12 CALCULATING FLUORIDE DOSAGES 7. When mixing the same two acids or chemicals, but of
FORMULAS different strengths, the volumes or flows of the chemicals
and their strengths must be known.
1. Charts can be used to determine feed rates. The feed rate Mixture (Volume 1. gaIXStrength 1.%)+Nolume 2, gal)(Strength 2.%)
is usually based on a dose of one mg/L; therefore actual Strength.
% Volume 1. gal + Volume 2. gal
feed rates must be adjusted.
(Chart Feed Rate. GPO)(Actual Dose, mg/L)
Actual Feed Rate, GPO NOTE: The "Volumes" may be in gallons or treated as
1 mgl L flows in GPD or MOD. The "Strengths" may be in
2. Feed rates may be calculated on the basis of pounds per percentages or concentrations such as mg/L.
day or gallons per aay. Consideration must be given to 8. When using chemicals for fluoridation, we need to know
the pounds of fluoride ion per pound of commercial the percentage fluoride ion purity. This information will
chemical allow us to convert the pounds of chemical dosage to
Feed Rate. (Flow, MGD)(Dose, mg/L)(8.34 lbs/gal)(100%) pounds of fluoride ion available.
lbs/day Fluoride Ion
Solution, % F (Molecular Weight of Fluoride)(100%)
Purity, %
Or
Feed Rate, = Feed Rate, lbs F/day Molecular Weight of Chemical
lbs/day EXAMPLE 1
lbs F/lb Commercial Chemical

Or
Feed Rate, Feed Rate, lbs/day A flow of 4 MGD is to be treated with a 20 percent solution
gal/day of hydrofluosilicic acid (H2SiF6). The water to be treated
Chemical Solution, lbs/gal
contains no fluoride and the desired fluride concentration is
3. If the water being treated contains some fluoride ion, but 1.8 mg/L. What should be the feed rate of hydrofluosilicic
not sufficient, then a feed dose must be calculated. acid? Use the treatment charts.
Feed Dose, mg/L - Desired Dose, mgIL Actual Concentration, mg/L Known Unknown
4. Commercial chemicals usually are not 100 percent pure. Flow, MGD = 4 MGD 1. Feed Rate, gal/day
Also, the chemical only contains a portion of the ion of Acid Solution, % = 20% 2. Feed Rate, gal/hr
concern (fluoride ion in this chapter). Desired F, mg/L = 1.8 mg /L

6
 Fluoridation 55

1. Use treatment Chart I on paa 46 because we are treating EXAMPLE 3

a relatively small flow (4 MGD).
A flow of 20r .PM is to be ireated with a 2.4 percent (0.2
2. Start on the left side at the 4 MGD value and move lbs/gallon) solution of scdium fluoride (NaF). The water to be
horizontally to the right to the 20 percent diagona: line. treated contains 0.7 mg/L of fluoride ion and the desired
3. At this point drop vertically downward to the bottom lines fluoride ion concentration is 1.6 mg/L. What should be the
and read the teed rates for one mg/L (ppm). feed rate of sodium fluoride? Use the treatment charts.
a. Feed Rate, gallons per day = 19 gal/day
Known Unknown
b. Feed Rate, gallons per hour = 0.8 gal/hr
Flow, MGD = 200 MGD 1. Feed Rate, gal/day
4 Calculate the feed rate to produce the desired fluoride
concentration of 1.8 mg/L. NaF Solution, `)/0 = 2 4% 2. Feed Rate, gal/hr
(Feed Rate, GPD)(Desired F, mg/L) Desired F, mg/L = 1 6 mg/L
2 Feed 'ate. GPD
1 mg/L Actual F, mg/L = 0.7 mg/L
(19 GPDX1.8 mg/L)
1. Use treatment Chart Ill on page 47 because we are
1 mg/L treating 200 GPM.
= 34.2 gallons/day
b. Feed Rate, (Feed Rate, gal/hr)(Desired F, mg/L) 2. Start at the left side at the 200 GPM value and move
gal/hr horizontally to the right to the 2.4 percent diagonal line.
1 mg/L
(0.8 galpir1(1 8 mg/L) 3. At this point drop vertically downward to the bottom lines
1 mg/L and read the feed rates for one mg/L (ppm).
= 1.44 gal/hr a. Feed RaL, gallons per day = 26.5 gal/day
b. Feed Rate, gallons per hour = 1.1 gal/hr
EXAMPLE 2
A flow of 4 MGD is to be aeated with a 20 percent solution 4. Calculate the feed rate to produce the desired fluoride
of hydrofluosilicic acid (H2SiF6). The water to be treated concentration of 1.6 mg/L.
contaii.s no fluoride and the desired fluoride concentration is Feed Dose, mg/L = Desired Dose, mg/L Actual Conc , mg/L
1.8 mg/L. Assume the hydrofluosilicic acid weighs 9.8
pounds per gallon. What should be the feed rate of hydro- = 1.6 rag/L 0 7 mg/L
fluosilicic acid? Calculate the feed rate. = 0.9 mg/L
Known Unknown
Feed Rate, GPD (Feed Rate, GPD,(Feed Dose, mg/L)
Flow, MGD = 4 MGD 1. Feed Rate, gal/day
1 mg/L
Acid Solution, `)/0 = 20% 2. Feed Rate, gal/hr
Acid, ..1.;/gal = 9.8 lbs/gal (26.5 gal/day)(0 9 mg/L)
Desired F, mg/L = 1.8 mg/L 1 mg/L

1. Calculate the hydrofluo- ':cic acid feed rate in pounds per = 23.8 GPD
day. Feed Rate, (Feed Rate, gal/hr)(Feed Dose, mg/L)
Feed Rate, (Flow, MGDXDesired F, mg/LX8.34 lbs/gal)(100°/0) gal/hr
lbs/day 1 mg/L
Acid Solution, %
(1.1 gal/hr)(0.9 mg/L)
(4 MGDX1 8 mg/LX8 34 lbskialX100%)
1 mg/L
20';,
= 300 lbs acid/day = 0.99 gal/hr or 1 gal/hr
2. Determine the feed rate of the acid in gallons per day.
Feed Rate, Feed Rate, '3s/day
gal/day 9.8 lbs/gal EXAMPLE 4
200 lbs ac9/day
A flow of 200 GPM is to be treated with a 2.4 percent (0.2
0.8 lbs -cid/gal acid pounds per gallon) solution of sodium fluoride (NeF). The
= 31 gal acid/day water to be treated contains 0.7 mg/L of fluoride ion and the
desired fluoride ion concentration is 1.6 mg/L. What should
NOTE: We obtained a !..ed rate of 34 gallons of acid per be the feed rate of sodium fluoride? Calculate the feed rate.
day from Treatment Chart I. The differences Assume the sodium fluoride has a fluoride purity of 43.4
result from the problems of drawing and reading percent.
the chart accurately.
Known Unknown
3. Calculate the feed rate in gallons of acid per hour.
Flow, MGD = 200 MGD 1. Feed Rate, gal/day
Feed Rr ,e, gal /day
Feed Rate, gal/hr NaF Solution, `)/0 = 2.4% 2. Feed Rate, gal/hr
24 hr/day
NaF Solution, ibs/gal = 0.2 lbs/gal
31 gal acid/day Desired F, mg/L = 1.6 mg/L
24 hr/day Actual F, mg/L = 0.7 mg/L
= 1.3 c,. : acid/hr Purity, `)/0 = 43.4%

,f
.
 56 Water Treatment

1 Convert flow from gallons per minute to million gallons 1. Calculate the portion of fluoride ion in the commercial
per day. sodium silicofluoride.
Flow, MGD = (Flow, gal/min)(J0 min/hr)(24 hr/day)(1 Million) (Na2SiF6 Purity, %)(Fluoride Ion Purity, %)
Portion F
1,000,000
(100%)(100%)
(200 gal/min)(60 min/hr)(24 hr/day)(1 Million)
(98.5%)(60.7%)
1,000,000
(100%)(100%)
= 0.288 MGD
= 0.598
2 Determine the fluoride feed dose in milligrams per liter. This says that there are 0.598 pounds of fluoride ion in a
pound of commercial sodium silicofluonde.
Feed Dose, mg/L = Cesired Dose, mg/L Actual Conc , mg/L
= 1.6 mg/L
2. Calculate the pounds of fluoride required per day.
0 7 mg/L
Fluoride,
= 0.9 mg/L = (Flow, MGD)(Dose, mg /L)(8.34 lbs/gal)
lbs/day
= (1 MGD)(1.4 mg/L)(8.34 lbs/gal)
3. Calculate the feed rate in pounds of fluoride ion per day
= 11.7 lbs F/day
Feed Rate,
= (Flow, MGD)(Feed Dose, mg/L)(8.34 lbs/gal) 3. Determine the chemical feed rate for the commercial
lbs F/day
sodium silicofluoride in pounds per day.
= (0 288 MGD)(0 9 mg/L)(8 34 lbs/gal)
Feed Rate, Fluoride, lbs/day
= 2.16 lbs F/day lbs/day
Fluoride, lbs/lb Commercial Na2SiF6
4. Convert the feed rate from pounds of fluoride per day to 11.7 lbs F/day
gallons of sodium fluoride solution per day. 0.598 lbs F/lb Commercial Na2SiF6
Feed Rate, (Feed Rate, lbs F /day)(100 %) = 19.5 lbs/day Commercial Na2SiF6
gal/day
(NaF Solution, lbs F/gallon)(Purity, 04)
(2.16 lbs F /day)(100 %)
EXAMPLE 6
(0.2 lbs F /gal)(43.4 %)
= 24.9 gal/day A flow of 1.4 MGD is treated with sodium silicofluonde.
The raw water contains 0.4 mg/L of fluoride ion and the
NOTE: We obtained a feed rate of 23.8 01/day using desired fluoride ion concentration is 1.6 mg/L. What should
be the chemical feed rate in pounds per day? Assume each
the treatment chart. The differences could have
pound of commercial sodium silicofluonde (Na2SiF6) con-
resulte' from accurately preparing and reading tains 0.6 pounds of fluoride ion.
the chart as well as the assumed purity of
fluoride ion in the .odium fluoride. Known Unknown
Flow, MOD = 1.4 MGD Feed Rate, lbs/day
5. Convert the feed rate fror ga per thy to gallons per
hour. Raw Water F, mg/L = 0.4 mg/L
Desired F, mg/L = 1.6 mg/L
Feed Rate, (Feed Rate, g:.I/day) Chemical, lbs F/lb = 0.6 lbs F/lb
gal/hr
24 hr/day
1. Determine the fluoride feed dose in milligrams per liter.
(24.9 gal/day)
Feed Dose, mg/L = Desired Dose, mg/L Actual Conc., mg/L
24 gal/hr
= 1 6 mg/L 0.4 mg/L
= 1.0 gal/hr
= 1.2 mg/L

2. Calculate the fluoride feed rate in pounds per day.

Feed Rate,
lbs F/day = (Flow, MGD)(Feed Dose, mg/L)(8.34 lbs/gal)
EXAMP'.E 5
= (1.4 MGD)(1.2*mg/L)(8.34 lbs/gal)
A flow of 1 MGD is treated with sodium silicofluoride
= 14.0 lbs F/day
(Na2SiF6) to provide a fluoride ion dose of 1.4 mg/L. What is
the feed rate in pounds per day? Commercial sodium 3. Determine the chemical feed rate in pounds of commer-
silicofluoride has a purity of 98.5 percent and the fluoride ion cial sodium silicofluonde per day.
purity as sodium silicofluoride is 60.7 percent.
Feed Rate, Feed Rate, lbs F/day
Known Unknown lbs/day
lbs Fp Commercial Na2SiF6
Flow, MGD = 1 MGD 1. Feed Rate, lbs/day
Dose, mg/L = 1.4 mg/L 14.0 lbs F/day
Na2SiF6 Purity, % = 98.5% 0.6 lbs F/lb Commercial Na2SiF6
Fluoride Ion Purity, % = 60.7% = 23.4 lbs/day Commercial Na2SiF6

-69
 Fluoridation 57

EXAMPLE 7 EXAMPLE 9
The totalizer for a water treatment plant indicated that a The feed solution from a saturator containing 1.8 percent
total of 100,000 gallons of water had been treated with three fluoride ion is used to treat a total flow of 400,000 gallons of
pounds of 98 percent pure sodium fluoride (NaF). The water. The raw water has a fluoride ion content of 0 5 mg/L
fluoride ion purity for sodium fluoride is 45.3 percent. What and the desired fluoride in the finished water is 1.8 mg/L.
was t.*3 added fluoride ion dosage in milligrams per liter') How many gallons of feed solution are needed')
Known Unknown Known Unknown
Water Treated, MG = 0 1 M Gal Fluoride Dosage, mg/L Flow Vol., gal = 400,000 gal Feed Solution, gallons
NaF, lbs = 3 lbs Raw Water F, mg/L= 0.5 mg/L
NaF Purity, % = 98% Desired F, mg/L = 1.8 mg/L
F Ion Purity, % = 45.3% Feed Solution, % F = 1.8% F
1 Calculate the portion of fluoride ion in the commercial 1 Convert the feed solution from a percentage fluoride ion
sodium fluoride. to milligrams fluoride ion per liter of water.
Portion F (NaF Purity, °A)(Fluoride !on Purity, %) 1.0% F = 10,000 mg F/L
(100%)(100%)
Feed Solution, mg/L (Feed Solution, %)(10,000 mg/L)
(98%)(45.3%)
1%
(100%)(100%)
= 0.444 (1 8%)(10,000 mg/L)
1 %
or = 0.444 lbs F/lb commercial NaF
2. Calculate the pounds of fluoride used. = 18,000 mg/L
Fluoride, 2 Determine the fluoride feed dose in milligrams per liter.
= (Commercial NaF, lbs)(0 444 lbs F/lb Comm. NaF)
lbs Raw Water F, mg11.
Feed Dose, mg/L = Desired Dose, mg11.
= (3 lbs Comm. NaF)(0.444 lbs F/lb Comm. NaF)
= 1 8 mg/L 0.5 mg11.
= 1.33 lbs F
= 1 3 mg/L
3. Calculate the fluoride dosage in milligrams per liter
3. Calc :late the gallons of feed solution needed.
Fluoride Fluoride, lbs F
Dosage, (Water Treated, M Gal)(8.34 lbs/gal) Feed Solution, gal = (Flow Vol, Gal)(Feed Dose. mg/L)
mg/L
reed Solution, mg/L
= 1.33 lbs F
(0.1 M Gal)(8.34 lbs/gal) (400,000 gal)(1.3 mg/L)
1.33 lbs F 18,000 mg/L
=
(0.834 Million lbs Water) = 28.9 gallons
= 1 6 lbs F
EXAMPLE 10
1 M lbs Water
A hydrofluosilicic acid (H2SiFG) tank contains 300 gallons
= 1.6 mg/L of acid with a strength of 18 percent. A commercial vendor
EXAMPLE 8 delivers 2000 gallons of acid with a strength of 20 percent to
the tank What is the resulting strength of the mixture as a
Determine the percentage of fluoride ion in the feed percentage/
solutirn from a saturator. The saturator contains 95 percent
pure sodium fluoride, the maximum water solubility for Known Unknown
sodium fluoride is four percent, and sodium fluoride is 45 3 Tank Contents, gal = 300 gal Mixture Strength, %
percent fluoride ion. Tank Strength, % = 18%
Known Unknown Vendor, gal = 2000 gal
Commercial NaF Purity, % = 95°', Solution, % F Vendor Strength, % = 20%
NaF Solubility, % = 4% Calculate the strength of the mixture as a percentage.
F Ion Purity, % =45.3% Mixture (Tank, gal)(Tank, %) + (Vendor, gal)(Vendor, %)
Calculate the percentage of fluoride ion in the feed solution. Strength, % Tank, gal + Vendor, gal

Solution, % F = (NaF Solubility, %) (F Ion Purity, %) (300 gal)(18%1 + (2000 gal)(200/0)

(100%) 300 gal 4 2000 gal
(4%) (45.3%) 5400 + 40,000
(100%) 2300
= 1.8% 45,400
NOTE: In a saturator, the commercial NaF purity of 95 2,300
percent does not enter into the calculations
because the four percent solubility is all NaF. = 19.7%

7o
58 Water Treatment

EXAMPLE 11 2 Calculate the fluoride ion purity as a percentage.

Sodium silicofluoride (Na2SiF6) is used as the chemical to Fluoride Ion (Molecular Weight of Fluoride)(100°/0)
fluoridate a water supply. What is the fluoride ion purity as a Purity, %
percentage? Molecular Weight of Chemical

Known (114 00)(100%)

Unknown
Atomic Weights Fluoride Ion Purity, % 188.07
Na .--- 22 99 60.62%
Si = 28.09
This means that there are 0.6062 pounds of fluoride ion in
F = 19.00 every pound of sodium silicofluoride.

13.13 ARITHMETIC ASSIGNMENT

Tim to the Arithmetic Appendix at the back of this manual.
In Section A.3, "Typical Water Treatment Plant Problems,"
read and work the problems in Section A.31, "Fluoridation."

13.14 ADDITIONAL READING

1. NEW YORK MANUAL, Chapter 16, "Fluoridation."
2 TEXAS MANUAL, Chapter 11, "Special Water Treatment
(Fluoridation)."
3 WATER FLUORIDATION PRINCIPLES AND PRACTICES
(M4). Available from Data Processing Department, Ameri-
can Water Works Association, 6666 W. Quincy Avenue,
Denver, Colorado 80235. Price for members, $13.50;
Non-members, $17.00. Order No. 30004.
4 WATER FLUORIDATION, A Training Course Manual for
Engineers a.id Technicians. Available from Dental Dis-
1 Determine the molecular weight of the fluoridation chemi- ease Prevention Activity, Center ,or Prevention Services,
cal, sodium silicofluoride, Na2S1F6. Centers for Disease Control, U. S. Public Health Service,
Symbol Atlanta, Georgia 30300.
No. Atoms x Atomic Wt.* = Molecular Wt.
Nat 2 x 22 99 = 45.98 13.15 ACKNOWLEDGMENTS
Si 1 ,,, 28.09 = 28 09
F6 6 x 19.00
The author wishes to acknowledge the assistance gra-
= 114 UO
ciously given by Robert A. Hewitt, Assibtant Water Quality
Molecular Wt of Chemical = 188 07 Engineer, San Francisco Water Department, San Francisco,
California, and Tom Reeves, Centers for Disease Control,
Atomic weight values can be obtained from a chemistry Center for Prevention Services, Dental Disease Prevention
book. Activity, Atlanta, Georgia.

DISCUSSION AND REVIEW QUESTIONS

Chapter 13. FLUORIDATION

Please work these discussion and review questions be-

5 What items should be considered when reviewing plans
fore continuing with the Obiective Test on page 60 The
and specifications for the location of fluoride chemical
purpose of these questions is to indicate to you how well yo,1
hoppers'?
understand the material in the chapter. Write the answers to
these questions in your notebook. 6 How can overfeeding be prevented')
1. Why are drinking waters fluoridated') 7. What should be done if significant overfeeding occurs')
2 What factors would you consider when selecting a 8 What shou'd be done when fluoridation equipment is
fluoridation chemical') going to be shut down for an extended length of time?
3 Why should the finished water's fluoride ion content be 9 How would you dispose of fluoride chemical contain-
automatically monitored on a continuous basis') ers
4 How can water be softened prior to use with fluoridation 10 How would you protect yourself from the dusts of dry
equipment? Vuoride compounds')

71.
 Fluoridation 59

SUGGESTED ANSWERS
Chapter 13. FLUORIDATION

Answers to questions on page 29. showers, dust masks, face shields, gloves and vent
13.0A If a person drinks water with an excessive amt int of fans.
fluoride, the teeth become mottled (brown, chalky
deposits). Answers to questions on page 48
13.0B Children who drink a recommended dose of fluoride 13.6A Known Unknown
have fewer dental caries (decay or cavities). Flow. MGD = 6 MGD Feed Rate, gal/day
Conc Fluoride. mg/L = 1.2 mg/L
Answers to questions on page 30. Hydrofluostlicic acid = 20%
13 1A The water department or water company makes the 1. Use Treatment Chart I, Hydrofluosilicic Acid. Start
final decisions as to types of fluoride chemicals and at the left side with 6 MGD and move horizontally
feeding equipment to be used. to the right to the intersection of the 20% diagonal
13.2A The three compounds most commonly used to fluori- line.
date water are hydrofluosilicic acid, sodium fluoride 2. Drop down vertically to the chemical feed rate of
and sodium silicofluonde. 30 GALLONS PER DAY, for 1 mg/L fluoride appli-
cation.
Answers to questions on page 42.
3. Adjust the flow rate for a dose of 1.2 mg/L.
13.3A Drinking waters may contain fluoride ions by three Flow Rate. (Row Rate from Cnart. gal /dayXDeslred Dose. mg /L)
different types of situations: gal/day
1 mg /L
1. Raw water source may have adequate or exces- ,(30 gal/day)(1 2 mg/L)
sive fluoride ions naturally present, 1 mg/L

2. Two water sources may be blended together (one 36 ga./day

higher and one lower than acceptable level) to 13.6B Differences between the volume of acid used from a
produce an acceptable level, and storage tank and the volume actually fed into the
3. Fluoride ions must be added to the water to system could be caused by errors in readings, leaks
achieve an acceptable level or equipment malfunctions.
13.3B Fluoridation systems must incorporate means to Answers to questions on page 52.
prevent both overfeeding and backsiphonage along
with means to monitor the amount of chemical used. 13.7A Overfeeding shcdld be prevented because no addi-
tional benefits result from overfeeding and there is a
13.3C Hard water can produce problems in systems using waste of chemicals and money. Excessive overfeed-
saturators and dissolving tanks through the forma- ing could be harmful to consumers.
tion of low solubility (deposits of) calcium and mag-
nesium fluoride compounds. 13.7B If significant overfeeding occurs, the plan; should be
shut down. The affected mains should be flushed
13.3D A saturator is a device which produces a ';uoride and the local and state health departments notified.
solution for the fluoridation process. The device is
usually a cylindrical container with granular sodium 13.8A A fluoridation operation could be shut down for
fluoride on the bottom. Water flows either upward or cleaning, adjustments or due to safety controls.
downward through the sodium fluoride to produce
the fluoride solution. Answers to questions on page 54.
Answers to questions on page 44. 13.9A If fluoridation equipment is going to be shut down
for an extended length of tine, it should be cleaned
13.4A Overfeeding of fluoridation chemicals must be pre- out to prevent corrosion and/or the solidifying of
vented to avoid illness and bad public relations. the chemical. Lines and equipment could be da-
13.4B The fluoridator should be sized to handle the full maged when started if chemicals left in them solidi-
range of both present and future doses or provisions fy.
should t a made for future expansion. 13.10A Fluoride dust can be removed from gears by the
13.5A When inspecting the fluoridation electrical system, use of a vacuum cleaner.
inspect the system for (1) proper voltage; (2) properly 13.10B To determine if the fluoridation equipment is provid-
sized overload protection; (3) proper operation of ing the desired dosage, monitor the fluoride ion
control lights on control panel; (4) proper safety lock- concentration in the treated water.
out switches and operation; and (5) proper equip- 13.11A If you are acutely poisoned by a fluoride chemical,
ment rotation.
you may be thirsty, vomit and have stomach
13.5B Safety equipment that should be available near a cramps, diarrhea, difficulty in speaking and dis-
fluoridation system include an eyewash, drench turbed color vision.

7°
60 Water Treatment

OBJECTIVE TEST
Chapter 13. FLUORIDATION

Please write your name and mark the correct answers on 11. Hydrofluosilicic acid solutions can irritate your skin.
the answer sheet as directed at the end of Chapter 1. There
1. True
may be more than one correct answer to the multiple choice
2. False
questions.

True-False 12 Never eat, drink or smoke in or around fluoridation

chemical storage o feed areas.
1. Governing bodies usually rely upon a vote of the people
1. True
to decide the types of fluoride chemicals and feeding
2. False
equipment to be used.
1. True 13. Sanitary defects may develop in fluoridation systems.
2. False
1. True
2. False
2. Water should be analyzed for its natural fluoride level
before fluoridation.
14. Hydrofluosilicic acid must be washed off your skin
. True immediately.
2 False
1. True
2. False
3. Fluoridation chemicals are harmful to consumers at high
levels.
15. Special safety training must be given to all operators
1. True who must handle fluoride compounds.
2. False
1. True
4. Scale formation in chemical feed systems may be 2. False
prevented by ti.s. use of polyphosphates instead of a
zeolite softener Multiple Choice
1. True 16. The Maximum Contaminant Level (MCL) for fluoride in
2. False drinking water ranges from mg/L, depending
on the annual average s 'mum daily air temperatures.
5. A day tank usually stores sufficient chemical solution to
treat water for at least one day. 1. 0.4 to 0.8
2. 0.9 to 1.3
1. True 3. 1.4 to 2.4
2. False 4. 2.5 to 3.5
5. 3.6 to 5.0
6. Chemical feed systems should allow the chemical feed
to vary with changing head condi' ins. 17. The compounds most commonly used to fluoridate
1. True water include
2. False 1. Ammcnium silicofluonde.
2. Calcium fluoride.
7. Equipment may be damaged in minutes if it is run 3. Hydrofluosilicic.
without lubrication. 4. Silicofluonde.
1. True 5. Sodium fluoride.
2. False
18. Which o' the following items must be considered when
8. A positive displacement pump will damage itself or selecting a fluoridation chemical?
rupture lines in seconds if allowed to run against a 1. Costs
closld valve or system. 2. Ease of handling
1. True 3. Operator safety
2. False 4. Solubility of chemical in water
5. Storage requirements
9. Fluoridation must be a continuous operation.
19. Water with a hardness above mg/L must be
1. True
softened to prevent severe scaling of fluoridation equip-
2. False
ment.
1. 10
10. Operators could be seriously injured if they open a
2. 25
chemical line that has not been properly flushed out.
3. 40
1. True 4. 55
2. False
73 5. 75
 Fluoridation 61

20. Fluoridation chemicals that may be fed with a saturator 3. 30 GPD

include 4. 110 GPD
1. Granular calcium fluoride. 5. 300 GPD
2. Granular sodium fluoride.
3. Hydrofluosilicic acid. 25 A flow of 250 GPM is to be treated with a 2.4 percent
4. Powdered calcium fluoride. (0.2 pounds per gallon) solution of sodium fluoride
5. Powdered sodium fluoride. (NaF). The water to be treated contains 0.3 mg/L of
fluoride ion and the desired fluoride ion concentration is
21. The responsibility of the chief operator regarding fluori- 1.4 mg/L. Calculate the sodium fluoride feed rate in
dation equipment includes gallons per day. Assume the sodium fluoride has a
1. Design. fluoride purity of 43.4 percent. Select the closest an-
2. Functioning of equipment. swer.
3. Maintenance. 1. 1.1 gal/day
4. Operation by plant personnel 2. 2.2 gal/day
5. Results from the process. 3. 3.3 gal/day
4. 25 gal/day
22. Fluoridation operations may be temporarily shut down 5. 38 gal/day
due to
1. Adjustments. 26. A flow of 0.8 MGD is treated with sodium silicofluoride
2. Calculating dosages. (Na2SiF6) to provide a fluoride ion dose of 1.2 mg/L.
3. Cleaning. What is the feed rate in pounds per day? Commercial
4. Maintaining storage area sodium fluoride has a purity of 98.5 percent and the
5. Safety controls. fluoride ion purity of sodium silicofluoride is 60.7 per-
cent. Select the closest answer.
23 Which of the following items should be included in your
checklist for shutting down a fluoridation chemical sys- 1. 6.0 lbs/day
tem? 2. 8.0 lbs/day
3. 11.7 lbs/day
1. Clean the mix and feed tanks. 4. 13.4 lbs/day
2. Drain the mix and feed tanks. 5. 19.5 lbs/day
3. Fill the chemical hoppers.
4. Flush out all the solution lines.
5. Turn on the electrical power. 27. The feed solution from a saturator containing 1.8 per-
cent fluoride ion is used to treat a flow of 500,000
24. A flow of 2 MGD is to be treated with an 18 percent gallons per day. The desired dose is 1.2 mg/L of fluoride
solution of hydrofluosilicic acid H2SiF6). The water to be ion and the raw water does not have any fluoride.
treated contains no fluoride and the desired fluoride Calculate the feed rate in gallons per day of the satura-
concentration is 1.2 mg/L. Assume the hydrofluosilicic tor solution. Select the closest answer.
acid weighs 9 6 pounds per gallon. Calculate the hydro-
1. 18.0 gal/day
fluosilicic acid feed rate in gallons per day. Se le ,t the 2. 19.5 gal/day
closest answer.
3. 26.6 gal/day
1. 12 GPD 4. 28.9 gal/day
2. 15 GPD 5. 33.3 gal/day

fact of Oloicai tie Ta÷t

CHAPTER 14

SOFTENING

by

Don Gibson

and

Marty Reynolds
64 Water Treatment

TABLE OF CONTENTS
Chapter 14. Softening

Page
OBJECTIVES 66
GLOSSARY 67

LIME-SODA ASH SOFTENING by Don Gibson

Lesson 1

14.0 What Makes Water Hard? 70

14.1 Why Soften Water' 71
14.2 Chemistry of Softening 72
14.20 Hardness 72
14.21 pH 73
14.22 Alkalinity 73
14.3 How Water Is Softened 75
14.30 Basic Methods of Softening 75
14.31 Chemical Reactions 75
14.310 Lime 76
14.311 Removal of Carbon Dioxide 76
14.312 Removal of Carbonate Hardness 76
14.313 Removal of Noncarbonate Hardness 76
14.314 Stability 76
14.315 Caustic Soda Softening 77
14.316 Calculation of Chemical Dosages 77
14.32 Lime Softening 78
14.33 Split Treatment 78
14.34 Lime-Soda Ash So' ling 81

14.35 Caustic Soda Softening 81

14.36 Handling, Application and Storage of Lime 82

14.4 Interactions with Coag lants 82
14.5 Stability 83
14.6 Safety 84
14.7 Sludge Recirculation and Disposal 85
14.8 Records 85

76
 Softening 65

14.9 Jar Tests 85

14.90 Typical Procedures 85

14 91 Examples 86

;4.92 Calculation of Chemical Feeder Settings 86

ION EXCHANGE SOFTENING by Mai Mynolds

Lesson 2
14.10 Description of Ion Exchange Softening Process 91

14.11 Operations . 95

14.110 Service 95

14.111 Backwash 95

14.112 Brine 97

14.113 Rinse 97

14.12 Control Testing of Ion Exchange Softeners 97

14.13 Limitations Caused by Iron and Manganese 98

14.14 Disposal of Spent Brine 98

14.15 Maintenance 99

14.1E Troubleshooting 100

14.160 Test Units 100

14.161 Service Stage 100

14.162 Backwash Stage 100

14.163 Rinse Stage 100

14.164 Brine Injection Stage 100

14.17 Startup and Shutdown of Unit 101

14.18 Ion Exchange Arithmetic 101

14.19 Blending 105

14.20 Recordkeeping 106

14.21 Arithmetic Assignment 106

14.22 Additional Reading 106

14.23 Acknowledgments 107

Suggested Answers 107

Objective Test 111

.. i
7
66 Water Treatment

OBJECTIVES
Chapter 14. SOFTENING

Following completion of Chapter 14, you should be able

to:
1. Explain what makes water hard and the advantages of
softening,
2. Describe the processes used to soften water,
3. Prepare chemical doses to soften water with consider-
ations given to coagulants and stability,
4. Safely handle softening chemicals,
5. Dispose of process sludges and brines,
6. Keep neat and accurate softening records,
7. Perform jar tests and apply results,
8. Operate and maintain chemical precipitation and ion
exchange softening processes,
9. Start up anG shut down water softening units, and
10. Blend softened waters with unsoftened waters (split
treatment) for delivery to consumers.

78
 Softening 67

GLOSSARY
Chapter 14. SOFTENING

ALKALINITY (AL-ka-LIN-it-tee) ALKALINITY

The capacity of water to neutralize acids. This capacity is caused by the water's content of carbonate, bicarbonate, hydroxide,
and occasionally borate, silicate, and phosphate. Alkalinity is expressed in milligrams per liter of equivalent calcium carbonate
Alkalinity is a measure of how much acid can be added to a liquid without causing a great change in pH.

ANION SAN-EYE-on) ANION

A negatively charged ion in an electrolyte solution, attracted to the anode under the influence of a difference in electrical poten-
tial. Chloride (CI-) is an anion.

CALCIUM CARBONATE EQUILIBRIUM CALCIUM CARBONATE EQUILIBRIUM

A water is considered stable when it is just saturated with calcium carbonate. In this condition the water will neither dissolve nor
deposit calcium carbonate. Thus, in this water the calcium carbonate is in equilibrium with the hydrogen ion concentration

CALCIUM CARBONATE (CaCO3) EQUIVALENT CALCIUM CARBONATE (CaCO3) Ek..IUIVALENT

An expression of the concentration of specified constituents in water in tern is of their equivalent value to calcium carbonate.
For example, the hardness in water which is caused by calcium, magnesium and other ions is usually described as calcium car-
bonate equivalent.

CATION (CAT-EYE-on) CATION

A positively charged ion in an electrolyte solution, attracted to the cathode under the influence of a difference in electrical poten-
tial. Sodium ion (Nat) is a cation.

DIVALENT (die-VAY-lent) DIVALENT

Having a valence of two, such as the ferrous ion, Fe2*.

EQUIVALENT WEIGHT EQUIVALENT WEIGHT

That weight which will react with, displace or is equivalent to one gram atom of hydrogen.

GREENSAND GREENSAND
A sand which looks like ordinary filter sand except that it is green in color This sand is a natural ion exchange mineral which is
capable of softening water and removing iron and manganese.

HARD WATER HARD WATER

Water having a high concentration of calcium and magnesium ions. A water may be considered hard if it has a hardness greater
than the typical hardness of water from the region. Some textbooks define hard water as water with a hardness of more than
100 mg/L as calcium carbonate.

HARDNESS, WATER HARDNESS, WATER

A characteristic of water caused mainly by the salts of calcium and magnesium, such as bicarbonate, carbonate, sulfate, chlo-
ride and nitrate. Excessive hardness in water is undesirable because it causes the formation of soap curds, increased use of
soap, deposition of scale in boilers, damage in some industrial processes, and sometimes pauses objectionable tastes in drink-
ing water.

HYDRATED LIME HYDRATED LIME

Limestone that has been "burned" and treated with water under controlled conditions until the calcium oxide portion has been
converted to calcium hydroxide (Ca(OH)2). Hydrated lime is quicklime combined with water. CaO + H2O Ca(OH)2. Also see
QUICKLIME.

INSOLUBLE (in-SAWL-you-bull) INSOLUBLE

Someining that cannot be dissolved.

79
 68 Water Treatment

ION
ION
An electrically charged atom, radical (such as S042 ), or molecule formed by the loss or gain of one or more electrons

ION EXCHANGE ION EXCHANGE

A water treatment process involving the reversible interchange (switching) of ions between the water being treated and the
solid resin. Undesirable ions in the water are switched with acceptable ions in the resin.

ION EXCHANGE RESIN ION EXCHANGE RESIN

Insoluble polymers, used in water treatment, that are capable of exchanging (switching or giving) acceptable cations or anions
to the water being treated for less desirable ions

METHYL ORANGE ALKALINITY METHYL ORANGE ALKALINITY

A measure of the total alkalinity ,n a water sample The alkalinity is measured by the amount of standard sulfuric acid required
to lower the pH of the water to a pH level of 4.5, as indicated by the change in color of methyl orange from orange to pink.
Methyl orange alkalinity is expressed as milligrams per liter equivalent calcium carbonate.

NPDES PERMIT
NPDES PERMIT
National Pollutant Discharge Elimination System permit is the regulatory a_incy document designed to control all discharges of
pollutants from point sources in U.S. waterways. NPDES permits regulate discharges into navigable waters from all point
sources of pollution, including industries, municipal treatment plants, large agricultural feed lots and return irrigation flows.

PHENOLPHTHALEIN ALKALINITY (FEE- nol -THAY -teen) PHENOLPHTHALEIN ALKALINITY

The alkalinity in a water sample measured by the amount of standard acid required to lower the pH to a level of 8.3, as indicated
by the change in color of phenolphthalein from pink to clear. Phenolphthalein alkalinity is expressed as milligrams per liter
equivalent calcium carbonate.

PRECIPITATE (pre-SIP-uh-TATE) PRECIPITATE

(1) An insoluble, finely divided substance which is a product of a chemical reaction woe' in a liquid.
(2) The separation from solution of an insoluble substance.

QUICKLIME
QUICKLIME
A material that is mostly calcium oxide (CaO) or calcium oxide in natural association with a lesser amount of magnesium oxide.
Quicklime is capable of combining with water to form hydrated lime. Also see HYDRATED LIME.

RECARBONATION (re-CAR-bun-NAY-shun) RECARBONATION

A process in which carbon dioxide is bubbled into the water being treated to lower the pH. The pH may also be lowered by the
addition of acid Pecarbonation is the final stage in the lime-soda ash softening process. This process converts carbonate ions
to bicarbonate ions and stabilizes the solution against the precipitation of carbonate compounds.

RESINS RESINS
See ION EXCHANGE RESINS.

SATURATION SATURATION
The condition of a liquid (water) when it has taken into solution the maximum possible quantity of a given substance at a given
temperature and pressure.

SLAKE SLAKE
To mix with water with a true chemical combination (hydrolysis) taking place, such as in the slaking of lime.

80
 Softening 69

SLAKED LIME SLAKED LIME

See HYDRATED LIME.

SUPERSATURATED SUPERSATURATED
An unstable condition of a solution (water) in which the solution contains a substance at a concentration greater than the satu-
ration concentration for the substance.

TITRATE (TIE-trate) TITRATE

To TITRATE a sample, a chemical solution of known strength is added on a drop-by-drop basis until a certain color change,
precipitate, or p Li change in the sample is observed (end point). Titration is the process of ad ling the chemical reagent in incre-
ments until completion of the reaction as signaled by the end point.
 70 Water Treatment

CHAPTER '14 SOFTENING

.ime-Soda ;,sh Softening by Don Gibson
(Lesson 1 of 2 Lessons)

14.0 WHAT MAKES WATER HARD?' Cainium and magnesium are usually the only cations that are
present ir, significant concentrations. Therefore, "ardness is
generally coi,sidered to be an expression of the total con-
centration of the calcium and magnesium ions that are
present in the water. However, if any of the other cations
listed are present in significant amounts, they should be
included in the hardness determination.
Table 14.1 describes various levels of hardness. Different
textbooks will use s,milar classifications. Hardness levels in
source waters, local conditions, and local usage will influ-
ence consumers' attitudes towards the hardness of theii.
water.

TABLE 14.1 DESCRIPTION OF VARIOUS LEVELS OF

HARDNESS3
Description Hardness in Terms of
:NIL as Calcium
Carbonate
1. Extremely soft to soft 0-45
Water hardness is a measure of the soap or detergent 2. Soft to moderately hard 46-90
consuming power of water. Technically hardness is caused 3. Moderately hard to hard 91-130
by DIVALENT2 metallic cations which are capable of reac'- 4. Hard to very hard 131-170
ing (1) with soap (detergent) to form precipitates and (2) %vim 5. Very hard to excessively 171-250
certain anions present in water to form scale. hard
6. Too hard for ordnary domestic OVER 250
use
Cations Causing Most Common Anions
Hero. is
Calcium, Ca2+ Bicarbonate, HCO3-
Magnesium, Mg2+ Sulfate, S042-
Strontium, Sr2+ Chloride, CI-
Icon, Fe2+ Nitrate, NO3-
Manganese, Mn2+ bi;.cate, Si032-

., A4 'NE CATION4 &O ROIAMO A 1.0,001

1. 4:),

To help you understand this chapter on water softening,

some of the terms used are defirfed below.
HARD WATER is a water having a high concentration of
ralcium and magnesiL.n ions. A water ma: be considered
h ird if .. has a hardness greater than the typical hardness of
water from the region. Some textbooks define hard water as
a water with a hardness of more than 100 mg/L as ce'ci m
carbonate.

Portion of the material covered in the first three sections of this chapter were provided by Don Gibbon, Marty Reynolds, Susumu Kaa-
mura, Teriy Engelhardt, Jack Rossum and Mike Curry.
2 Divalent (die -VAV-lent). Having a valence of two, such as ferrous ion, Fe2+.
3 Lipe, L.A. and M.D. C irry "Ion Exchange-1 Water Softening," a discussion for water treatment plant operators, 1974-75 seminar sear
sponsored by Illinois Envii..nmental Protection Agency.

82
 Softenitig 71

HARDNESS is a characteristic of water caused mainly by water used. Industrial plants usinr- boilers for processing
the salts of calcium and magnesium, such as bicarbonate, steam or heat must remove the r less from their make-
carbonate, sulfa..., chloride and nitrate. Excessive hardness up water, even beyond what a water treatment plant would
in water is undesirable because it causes the formation of do. The reason for this is that the minerals will plate out on
soap curds, increased use of soap, deposition of scale in the boiler tubes and foal.' a scale. This scale forms an
boilers, damage in some industrial processes, and some- insulation baffle' which prevents proper heat transfer, thus
t:mes may cause objectionable tastes in drinking water. causing excessive energy requirements to fire the bode s.
The problems associated with process water softening are
CALCIUM HARDNESS is 3used by calcium ions (Ca2+). too numerous to go into; however, everything from food
MAGNESIUM HARDNESS is caused by magnesium ions processing to intricate manufacturing processes is affected
(mg2+). by the hardness of water
TOTAL HARDNESS is the sum of the hardness caused by In addition to the removal of hardness from water, some
both calcium and magnesium ions. other benefits of softening include:
CARBONATE HARDNESS is caused by the alkalinity 1. Removal of iron and manganese,
present in water up to the total hardness. This value is 2. Control of corrosion when proper stabilization of water is
usually less than the total hardness. achieved,
NONCARBONATE -MADNESS is that portion of the total 3. Disinfection due to high pH values when using lime
hart '955 in excess of the alkalinity. (especially the excess lime softening process),
ALKALINITY (AL-ka-LIN-it-tee) is the capacity o' water to 4. Sometimes a reds ctit..,1 in tastes and odors,
neutralize a,;ids. This capacity is caused by the water's
content e carbonate, bicarbonate, hydroxide, and occasion- 5. Reduction of some total solids content by the lime treat-
ally borate, silicate, and phosphate. Alkalinity is expressed in ment process, and
milligrams per liter of equivalent calcium carbonate. Alkalin-
ity is a measure cf how much acid can be added to a water 6. Removal of radioactivity.
without causing a great change in pH. Possible limitations of softening might include:
CALCIUM CARBONATE (CaCO3) EQUIVALENT is an 1. Free chlorine residual is predominantly ilypochonte at pH
tpression of the concentration of specified constituents in levels above 7.5 and is a less powerful disinfectant.
wester in terms of their equivalent value to calcium carbonate.
For example, the hardness in water which is caused by 2. Costs and benefits must be carefully weighed to justify
calcium, magnesium and other ions is usually described as softening.
calcium carbonate equivalent.
3. Ultimate disposal of process wastes.
14.1 WHY SOFTEN WATER? 4. At the pH levels associated with softening chemical
precipitation, the tr: lomethane fraction in the treated
The dissolved minerals (calcium and magnesium ions) in
water may increase (depends on several other factors).
water cause difficulties in doing the laundry and in dishwash-
ing in the household. These ions also cause a coating to 5. Producing an "aggressive" water which would tend to
form inside the hot water heater similar to that in a tea kettle corrode metal ions from the distribution system piping.
after repeated use. Hard waters usually do not corrode pipe. However,
excessively hard water can cause scaling on the inside of
pipes and thereby restrict flow.
In many cases, the decision to soften the water is left up to
each community as softening is done mostly as a customer
service. Hard water does not have an adverse effect on
health, but can create several unwanted side affects, some
of which are:
1. Over a periou of time, the detergent-consuming power of
hard water can be very costly,
2. Scale problems on fixtures will be more noticeable, and
3. The life cycle of several types of clothing will be reduced
with repeated washing in hard water. Also, a residue can
be left in clothing, creating a dirty appearance.
Once the decision is made to soften, a method must be
Hardness, in addition to inhibiting the cleaning action of selected. The two mist common methods used to soften
soaps, will tend to shorten the life of fabrics that are washed water are chemical precipitaticn (lime-soda ash) and ION
in hard water. The scum or curds may become lodged in the EXCHANGE.. Ion exchange softening can best be applied to
fibers of the fabric and cause them to lose their softness and waters high in noncarbonate hardness and where the total
elasticity. hardness does not exceed 360 mgjL. This method of
softening can produce a water of zero hardness, as op-
In industry hardness can cause even nreater problems. posed to lime softening where zero hardness cannot be
Many processes are affected by the hardness content of the reached.

4 Ion Exchange. A water treatment '9ss invoicing the reversible interchange (switching) of ions between the water being treated and
the solid resin. Undesirable ions in the water are switched with acceptable ions in the resin.
72 Water Treatment

Ion exchange softening will also remove ncncarbonate Calcium Hardness Equivalent Weight of CaCO3
hardness without the addition of soda ash whicn is required mg/L as CaCO3 (Calcium mg/L) (Equivalent
Weight of Calcium)
with lime softening. Ion exchange is a nonselective method
of softening. This means it will remove total hardness (the = (Ca, mq /L) (__50 )

sum of carbo. ate and noncarbonate hardness) making it a 20

very desirable means of water softening. = 2 50(Ca. mg/L)
Limitations of the ion exchange softening process include This equation indicates that if the ca'.c,im concentration in
an increase in the sodium content of the softened water if milligrams per liter is multiplied by 2.50, the result is the
the ion exchanger is regenerated with sodium hydroxide calcium hardness in milligrams per liter as calcium carbon-
The sodium level should not exceed 20 mg/L in treated ate. The EQUIVALENT WEIGHTS of most elements or
water because of the potentially harmful effect on persons chemical radicals (S042 is a radical) can be obtained by
susceptible to hypertension. Also the ultimate disposal of dividing the molecular weight by the valence.
spent brine and rinse waters from softeners can be a major
problem for many installations.
Equivalent Weight Atomic Weight
QUESTIONS of Calci' i Valence
Write your answers in a notebook and then compare your 40
answers with those on page 107.
2
14.0A What causes hardness in watt
= 20
14 1A Why is excessive hardness unuesirable in a domestic
water supply'? To express the magnesium hardness of water as calcium
carbonate equivalent use the following formula.
14.1B What are some of the limitations of the ion exchange
magnesium Hardness. Equivalent Weight m CaCO3
softening process? mg,q_ as CaCO3 . /Magnesium mg/L)(Equivaunt Weight oi Mignuaiuni

50
14.2 CHEMISTRY CF SOFTENING
("g. mg"-12 15
To understand how water hardness is described and also = 4 12 (Mg, mg/L)
how hardness is removed from water by softening proc-
esses, operators need to have an idea of the chemical
reactions that take place in water. In this section hardness,
The total hardness of water is the sum of the calcium and
magnesium hardness as CaCO3.
pH, and alkalinity reactions in water will be discussed.
Total Hardness, Calcium Hardness,+ Magnesium Hardness,
14.es, Hardness mg/L as CaCO3 mg/L as CaCO3 mg11. as CaCO3

Hardness is due to the presence of divalent metallic

cations in water, but the Fifteenth Edition of STANDARD EXAMPLE 1
METHODS5 identifies only calcium and magnesium as hard- Determine the total hardness as CaCO3 for a sample of
ness constituents. Hardness is commonly measured by water with a calcium content of 30 mg/L and a magnesium
TITRATION9 as described in Volume I on page 513. Individ- content of 20 mg/L.
ual divalent cations may be measured in the laboratory using
an atomic adsorption (AA) spectrophotometer for ye:1y accu- Known Unknown
rate work.
Calcium, mg/L = 30 mg/L Total Hardness,
Hardness is usually reported as CALCIUM CARBONATE Magnesium, mg/L = 20 mg/L mg/L as CaCO3
(CaCO3) EQUIVALENT.' This procedure allows us to com-
bine or add up the hardness caused by both calcium and Calculate the total hardness as milligrams per liter of
magnesium and report the results as total hardness. calcium carbonate equivalent.

5 STANDARD METrIODS FOR THE EXAMINATION OF WATER AND WASTEWATER, 16th Edition, 1985. Order No. 10035. Available from
Data Processing Department, American Water Works Association, 6666 W. Quincy Avenue, Denver, Coloratfo 80235. Pric9 to members
$72.00; nonmembers $90.00.
6 Titrate (TIE-trate) To TITRATE a sample, a chemical solution of known strength is added on a drop-by-drop basis until a certain color
change, precipitate, or pH change in the sample is observed (end point). Titration is the process of adding the chemical reagent in incre-
ments until completion of the reaction, as signaled by the end point
7 Ca:,;ium Carbonate (CaCO3) Equivalent An expression of the concentration of specified constituents in water in terms of their
equivalent value to calcium carbonate For example, the hardness in water whicn is caused by cal "ium, magnesium and other ions is
usually described as calcium carbonate equivalent.
8 Equivalent Weight. That weight which will react with, displace or is equivalent to one gram atom of hydrogen. The equivalen weight of
an ,dement (such as Ca2+) is equal to the atomic weight divided by the valence.
Molecular Weight
Equivalent Weight of CaCO3 =
Number of Equivalents
100

= 50 84
 Softening 73

Total Hardness, Calcium Hardness,+ Magnesium Hardness, When treating waters th,?, pH is very important The pH of
mg /Las CaCO3 rrigIL as CaCO3 mg/L as CaCO3 water may be increased cr decreased by the auJition of
certain chemicals used to treat water (Table 14.3). In many
= 2 50(Ca, mg/L) + 4 12 (Mg, mg/L)
instances, the effect on pH of adding one chemical is
= 2 50(30 mg/L) + 4.12(20 mg/L) neutralized by the addition of another chemical When soft-
ening water by chemical precipitation processes (lime-soda
= 75 mg/L + 82 4 mg/L
softening for example), the pH must be raised to 11 for the
= 157.4 mg/L as CaCO3 desired chemical reactions to occur The levels of carbon
dioxtle, bicarbonate ior and carbonate ion in waters are
Total hardness is also described as the sum of the very sensitive to pH
carbonate hardness (temporary hardness) and noncarbon-
ate hardness (permanent hardness).
Total Hardness, Carbonate Hardness.+ Noncarbonate Hardness,
mg/L as CaCO3 mg/L as CaCO3 mg/L as CaCO3

The amount of carbonate and noncarbonate hardness

depends on the alkalinity of the water. This relationship can
be described as follows:
1. When the alkalinity (expressed as calcium carbonate
equivalent) is greater than the total hardness, all the
hardness is in the carbonate form.
Carbonate Hardness, Total Hardness,
mg/L as CaCO3 mg/L as CaCO3
2. When the total hardn....3 is greater than the alkalinity, the
alkalinity is carbonatc hardness and noncarbonate hard-
ness is the difference between total hardness and alkalin-
ity.
i ABLE 14.3 INFLUENCE OF WATER TREATMENT
Carbonate Hardness, Alkalinity.
mg/L as CaCO3 mg/L as CaCO3
CHEMICALS ON pH

Noncarbonate Hardness,_ Total Hardness, Alkalinity.

mg/L as CaCO3 mg/L as CaCO3 mg/L as CaCO3
Lowers pH !:,creases pH
Aluminum Sulfate (Alum), Calcium Hypochlorite,
Al2(504)318H20 Ca(0C1)2
Carbon Dioxide, CO2 Caustic Soda, NaOH
14.21 pH
Chlorine, Cl2 Hydrated Lime, Ca(OH)2
pH is an expression of the intensity of the basic or add Ferric Chloride, FeCI3 Soda Ash, Na2CO3
condition of a liquid. Mathematically, pH is the logarithm Hydrofluosilicic Acid, H2SiF6 Sodium Aluminate, NaA102
(base 10) of the reciprocal of the hydrogen ion activity. Sulfuric Acid, H2504 Sodium Hydrochlorite,
NaOCI
1
ci-i = Log
(Hi) The stability of treated water is determined by measuring
The pH may range from 0 to 14, where zero is most acid, 14 the pH and calculating the Langelier Index (see Chapter 8,
most basic, and 7 neutral. Natural waters usually have a pH "Corrosion Control," pages 357 to 360). This index reflects
between 6.5 and 8.5. Table 14.2 shows the relationship the equilibrium pH of a water with respect to calcium and
alkalinity.
between pH and hydrogen and hydroxide ions.
Larigelier Index (L.L) = pH pHs
where
TABLE 14.2 RELATIONSHIP BETWEEN pH AND pH = actual pH of water, and
HYDROGEN AND HYDROXIDF IONS pHs = pH at which water having the same
alkalinity and calcium content is
pH Hydrogen Ion (H+), Hydroxide Ion (OH), just saturated with calcium carbon-
Moles/Liter Moles/Liter ate
0 1.0 0.000 000 000 000 01
A negative Langelit. Index indicates that the water is corro-
1 0.1 0.000 000 000 000 1
sive and a positive index indicates that the water is scale
2 0.01 0.000 000 000 001 forming. After water has been softened, the treated water
3 0.001 0.000 000 000 01 distributed to consumers must be stable (neither corrosive
4 0.000 1 0.000 000 000 1 nor scale forming).
5 0.000 01 0.000 000 001
6 0.000 001 0.000 000 01 14.22 Alkalinity
7 0.000 000 1 0.000 000 1

8 0.000 000 01 0.000 001 Alkalinity is the capacity of water to neutralize acids. This
9 0.000 000 001 0.000 01 capacity is caused by the water's content of carbonate,
0 C 000 000 000 1 0.000 1 bicarbonate, hydroxide, and occasionally borate, silicate,
11 0.000 000 000 01 0.001 and phosphate. Alkalinity is expressed in milligrams per liter
12 0.000 000 000 001 0.01 of equivalent calcium carbonate. Alkalinity is measure of
13 0.000 000 000 000 1 0.1 how much acid can be added to a liquid without causing a
14 0.000 000 000 000 01 1.0 great change in pH.
 74 Water Treatment

Alkalinity is measured in the laboratory by t le addit.. n of Total alkalinity is the sum of the bicarbonate, carbonate
color indicator solutions and the alkalinity is then determined and hydroxide. Each of these values can be determined by
by the amount of acid required to reach a titration acid point measuring the P and T alkalinity in the laboratory and
(specific color change) (see Chapter 11, "Laboratory Proce- referring to Table 14.4. Alkalinity is expressed in milligrams
dures," pages 491 to 493). The P (phenolphthalein) end point per liter as calcit.m carbonate equivalence. Alkalinity is
is at pH 8.3. When the pH is below 8.3, there is no P alkalinity influenced by chemicals used to treat water as shown in
present. When the pH is above 8.3, P alkalinity is present. No Table 14.5.
carbon dioxide is present when the pH is above 8.3, so there
is no carbon dioxide in the water when P alkalinity is present.
Also, hydroxide and carbonate alkalinity are not present
when pH is below 8.3. TABLE 14.5 INFLUENCE OF WATER TREATMENT
CHEMICALS ON ALKALINITY
The relationship between the various alkalinity constitu-
ents (bicarbonate (HCO3--), carbonate (C032-) and hydroxide
..nwers Alkalinity Increases Alkalinity
(OH-)) can be based on the P (phenolphthalein and T (total or Aluminum Sulfate (Alum), Calcium Hypochlonte,
methyl orange' alkalinity as shown in Table 14.4 and Figure Al2(SO4)3.18H20 Ca(0C1)2
14.1. Carbon Dioxide, CO2 Caustic Soda, NaOH
Chlorine Gas, Cl2 Hydrated Lime, Ca(OH)2
Ferric Chloride, FeCl3 Soda Ash, Na2CO3
TABLE 14.4 ALKALINITY CONSTITUENTS Ferric Sulfate, Fe2(SO4)3 Sodium Aluminate, NaAl02
Sulfuric Acid, H2SO4
Alkalinity, mg/L as CaCO3
Titration Result Bicarbonate Carbonate Hydroxide EXAMPLE 2
P=0 T 0 0 Results from alkalinity titrations on a raw water sample
P is less than '/2T T-2P 2P 0
were as follows:
P = ' /2T 0 2P 0 Known
P is greater than '/2T 0 2T-2P 2P-T Sample size, mL = 100 mi.
P =T 0 0 T mL titrant used to pH 8.3, A = 3 mi.
where P = phenolphthalein alkalinity Total mL of titrant used, B = 8.2 mL
Acid normality, N = 0.02 N H 2 SO4
T = total alkalinity
Unknown
1. Total Alkalinity, mg/L as CaCO3
When the pH is less than 8.3, all alkalinity is in the 2. Bicarbonate Alkalinity, mg /L as CaCO3
carbonate form and is commonly referred to as natural 3. Carbonate Alkalinity, mg /L as CaCO3
alkalinity. When the pH is above 8.3, the alkalinity may 4. Hydroxide Alkalinity, mg /L as CaCO3
consist of bicarbonate, ..:arbonate and hydroxide. As the pH
'ncreases, the alkalinity progressively shifts to carbonate See Chapter 11, "Lab Procedures," pages 491-493 for
and hydroxide forms. 'retails and formulas.

1000/0 1.......M.

CARBONATE, C032'
AND
HYDROXIDE, OH'
BICARBONATE, HCO3"

CARL,ON DIOXIDE, CO2

0%
4.5 8.3 11.3

Fig. 14 1 Relationship between pH and alkalinity constituents (HCO3 , C032- and OH-)

86
 Softening 75

1 Calculate the phenolphthalein alkalinity in mg/l. as Hardness is not completely removed by the chemical
CaCO3. precipitation methods used in water treatment plants. That
is. hardness is not reduced to zero. Water having a hardness
Phenolphthalein A N 50,000 of 150 mg/L as CaCO3 or more is usually treated to reduce
Alkalinity,
mL of sample the hardness to 80 to 90 .ng/L when softening is chosen as a
mg/L as CaCO3
treatment option
(0 mL) y (0 02 N) (50,000)
The minimum hardness that can be achieved by the lime-
100 mL soda ath process is around 30 to 40 mg/L as CaCO3. The
effluent from an ion exchange softener could contain almost
= 0 mg/L
zero hardness. Regardless of the method used to soften
water, consumers usually receive a blended water with a
2 Calculate the total alkalinity iri mg/L as CaCO3. hardness of around 80 to 90 mg/L as CaCO3 when softening
is used in water treatment plants.
Total Alkalinity, B r. N y 50,000
mg/L as CaCO3 mL of sample Lime-soda softening may produce benefits in addition to
the softening of water. These advantages include:
(8.2 mL) x (0.02 N) x (50,000)
1 Removal of iron and manganese,
100 mL
2. Reduction of solids,
= 82 mg/L
3. Removal and inactivation of bacteria and virus due to high
pH,
3. Refer to Table 14 3 for alkalinity constituents. The first
row indicates that since P = 0, the total alkalinity is equal 4 Control of corrosion and scale formation with proper
to the bicarbonate alkalinity. stabilization of treated water, and

Bicarbonate Alkalinity, Total Alkalinity. 5 Removal of excess fluoride.

mg/L as CaCO3 mg/L as CaCO3
Limitations of the lime-soda softening process include:
= 82 mg/L
1 Unable to remove all hardness,
The first row also ,ndicates that since P = 0, the carbon-
ate and hydroxide alkalinities are also zero. 2. A high degree of operator control must be exercised for
maximum efficiency in cost, hardness removal and water
Carbonate Alkalinity, 0
stability,
mg/L as CaCO3
Hydroxide Alkalinity, 0 3. Color removal may be complicated by the softening
mg/L as CaCO3 process due to high pH levels, and
4. Large quantities of sludge are created which must be
QUESTIONS handled and disposed of in an acceptable manner.
Write your answers in a notebook and then compare your
answers with those on page 107. QUESTIONS
14 2A What laboratory procedures are used to measure Write your answers in a notebook and then compare your
hardness? answers with those on page 108.
14 2B Determine the total hardness of CaCO3 for a sample 14.3A What is the minimum hardness that can be achieved
of water with a calcium content of 25 mg/L and a by the lime-soda ash process?
magnesium content of 14 mg/L.
14.3B List some of the benefits that could result from the
14 2C Which water treatment chemicals lower the pH when lime-soda softening process in addition to softening
added to water? the water.
14.2D Results from alkalinity titrations on a sample of water
were as follows: sample size, 100 mL; mL titrant 14.31 Chemical Reactions
used to pH 8.3, 1.2 mL; total mL of titrant used, 5.6
ml., and the acid normality was 0.02 N H2SO4. In the chemical precipitation process, the hardness caus-
Ca ,ulate the total, bicarbonate, carbonate and hy- ing ions are converted from soluble to insoluble forms.
droxide alkalinity as CaCO3. Calcium and magnesium become less soluble as the pH
increases. Therefore, calcium and magnesium can be re-
med from water as insoluble precipitates at high pH
14.3 HOW WATER IS SOFTENED levels.

14.30 Basic Methods of Softening Addition of time to water increases the hydroxide concen-
trations, thus increasing the pH. Addition of lime to water
The two basic methods of softening a municipal water also converts alkalinity from the bicarbonate form to the
supply are chemical precipitation and ion exci.ange. Ion carbonate form which causes the calcium to be precipitated
exchange will be discussed in the second portion of this as .alcium carbonate (CaCO3). As additional lime is added to
chapter in Sections 14.10 through 14 21. Well begin here the water, th, nhenolphthaleir. (P) Mkalinity increases to a
with the chemical precipitation methoos, mainly lime-soda level where hydroxide becomes present (excess causticity)
ash softening and variations of this process. allowing magnesium to precipitate as magnesium hydroxide.

87
 76 Water Treatment

Following the chemical softening process, the pH is high When lime is added to water, any carbon dioxide present is
and the water is SUPERSATURATED9 with excess caustic converted to calcium carbonate if enough lime is added
alkalinity in either the hydroxide or carbonate form. Carbon (Equation 1). With the addition of more lime the calcium
dioxide can be used to decrease the causticity and scale bicarbonate will be precipitated as calcium carbonate. To
forming tendencies of the water prior to filtration. remove both the calcium and magnesium bicarbonate. an
excess of lime must be used.
The chemical reactions which take olace in water during
the cilamical precipitation process a e described in the 14.313 Removal of Noncarbonate Hardness
remainder of this section. The procedures for softening
water des and on whether the l ardness to be removed is Magnesium noncarbonate hardness requires the addition
carbona: or noncarbonate hardness. Carbonate hardness of both lime and soda ash (sodium carbonate, Na2CO3).
(also called "temporary hardness") can be removed by the (5) agneeerm Sulfate + Lime Magnosium Hydroxide! ( Icsum Sulfate
use of lime only. Removal of noncarbonat' ardness (also MgSO4 + Ca(011)2 Mg(OH)2 + CaSO4
called "permanent hardness") requires both lime and soda.
(6) Caic um Sulfate + Soda Ash Calcium Carbonate( + Sodium Sulfate
CaSO4 + Na2CO3 CaC031 + Na2SO4
14.310 Lime
Equation (6) is also one of the equations .or the removal of
The lime used in the chemical precipitation softening calcium noncarbonate hardness. Similar equations can be
process may be from either HYDRATED LIME") (Ca(Cri)2), written for the removal of noncarbonate hardness caused by
calcium hydroxide, or "slaked" lime) or calcium oxide (CaO, calcium and magnesium chloride.
QUICKLIME" or "unslaked" lime). The hydrated lime may be
used directly. The calcium oxide or quicklime must first be 14.314 Stability
SLAKED.12 This involves adding the calcium oxide (CaO)
pellets to water and heating to cause "slaking" (the formation The main chemical reaction products from the lime-soda
of calcium hydroxide (Ca(OH)2)) before use. Small facihhties softening process are CaC031 and Mg(OH)2j. The water thus
commonly use hydrated lime (Ca(OH)2). Large facilities may treated has been chemically changed and is no longer stable
find it more economical to use quicklime (CaO) and slake it because of pH and alkalinity changes. Limc soda softened
on site. water is usually supersaturated with calcium carbonate
(CaCO3). The degree of instability and excess calcium car-
14.311 Removal of Carbon Dioxide bonate depends on the degree to which the water is sof-
tened. Calcium carbonate hardness is removed at a lower
The application of lime for the removal of carbonate pH than magnesium carbonate hardness. If maximum car-
hardness also removes carbon dioxide. Carbon dioxide bonate hardness removal is practiced (thus requiring a high
dnes not contribute to hardness and therefore does not pH to remove the magnesium carbonate hardness), the
eed to be removed. However, carbon dioxide will consume water will be supersaturated with calcium carbonate and
a portion of the lime to be used and therefore must be magnesium hydroxide. Under these conditions deposition of
considered. Equation (1) describes the reaction of carbon precipitates will occur in filters and pipelines.
dioxide with lime.
Excess lime addition to remove magnesium carbonate
(1) Carbon Dioxide Lime Calcium Carbonate' + Water hardness results in supersaturated conditions and a residual
CO2 + Ca(OH)2 CaCO3: 4 H2O of lime which will produce a pH of about 10.9. The excess
lime is called caustic alkalinity since it has the effect of
raising the pH. If the pH is then lowered, better precipitation
14.312 Removal of Carbonate Hardness of calcium carbonate and magnesium hydroxide will occur.
The equations be!' describe the removal of carbonate Alkalinity will be lowerc... also. This is usually accomplished
hardness. by pumping carbon dioxide (CO2) gas into the water. This
addition of carbon dioxide to the treated water is called
(2) Calcium Bicarbonate + Lime Calcium Carbonate! + Water RECARBONATION.13
Ca(HCO3%2 Ca(011)2 2 CaC031 + 2 H2O
Recarbonation may be carried out in two steps. The first
(3) Magnesium Calcium Magnesium addition of carbon dio) ide would follow excess lime addition
Bicarbonate + Lime Carbonate( + Carbonate + Water to lower the pH to about 10.4 and encourage the precipita-
Mg(HCO3)2 Ca(01-42 CaCO3 : 4 MgCO3 + 2 H2O tion of calcium carbonate and magnesium hydroxioe. A
(4) Magnesium Calcium
second addition of carbon dioxide would be after treatment
Magnesium
Carbonate + Lime Carbonate) + Hydroxide' to remove noncarbonate hardness. This would again lower
MgCO3 + Ca(011)2 CaC031 + mg(OH)21 the pH to about 9.8 and would encourage precipitation. By

9 Supersaturated. An unstable condition of a solution (water) in which the solution contains a substance at a concentra in greater than
the saturation concentration for the substance.
10 Hydrated Lime. Limestone that has been "burned" and treated with water under controlled conditions until the calcium oxide portion
has been converted to calcium hydroxide (Ca(OH)2). Hydrated lime is quicklime combined with water. Ca0 + H2O Ca(OH)2. Also
called slaked limo.
n Quicklime. A material that Inntly calcium oxide (Ca0) or calciun: oxide in natural association with a lesser amount of magnesium
oxide. Quicklime is capable of combining with water to form hydrated lime.
12 Slake. To mix with water with a true chemical combination (hydrolysis) taking place, such as in the slaking of lime.
13 Recarbonation (re-CAR-bun-NAY-shun). A process in which carbon dioxide is bubbled into the water being treated to lower the pH.
The pH may also be lowered by the addition of acid. Recarbonation is the final stage in the lime-soda ash softening process. This proc-
ess converts carbonate ions to bicarbonate ions and stabilizos the solution against the 'recipitation of carbonate compounds.

88
 Softening 77

carrying out recarbonation prior to filtration, the build up of 14 3D Why is the pH increased during the lime-soda soften-
excess lime and also calcium carbonate and magnesium ing process')
hydroxide precipitates in the filters will be prevented or
minimized. The recarbonation reaction for excess lime re- 14 3E How are the scale forniing tendencies reduced in
moval is shown below. water after the chemical softening process')

(7) Calcium Hydroxide + Carbon Dioxide -. Calcium Carbonate( + Water 14 3F Under what conditions might caustic soda softening
Ca(OH)2 + CO2 CaC031 + H2O be used')
Care must be exercised when using recarbonation Feed-
ing excess carbon dioxide may result in no lowering of the 14.316 Calculation of Chemical Dosages
hardness by causing calcium carbonate precipitates to go
back into solution and cause carbonate hardness. There are several dif,arent approaches to calculating
chemical doses for the lime-soda softening process. This
(8) Calcium Carbonate r Carbon Dioxide + Water Calcium Bicarbonate section illustrates one step-by-step procedure. To use this
CaCO3 . CO2 + H2O Ca(HCO3)2 procedure you need to obtain a chemical analysis of the
water you are softening. From this analysis obtain the
known values for your water similar to the "Knowns" listed in
14.315 Caustic Soda Softening EXAMPLE 2. Then calculate the dosages of chemicals for
An alternate method in the lime-soda softening process is your water by following the steps in the example.
the use of sodium hydroxide (NaOH, often called caustic To help you understand where some of the numbers come
soda) place of soda ash. The chemical reactions of from in the formulas, we have listed the molecular weights of
sodium .idroxide with carbonate and non-carbonate hard- the major chemical components involved in the chemical
ness are listed below. precipitation softening process.
(9) Carbon Dioxide + Sodium Hydroxide Sodium Carbonate + Water Quicklime, CaO = 56
CO2 + 2NaOH Na2CO3 + H2O
Hydrated Lime, Ca(OH)2 = 74
(10) Calcium Sodium Calcium Sodium Magnesium, Mg2' = 24.3
Bicarbonate Hydroxide Carbonate! + Carbonate + Water
Carbon Dioxide, CO2 = 44
Ca(HCO3)2 + 2 NaOH CaC031 + Na2CO3 + 2 H2O
Magnesium Hydroxide, Mg(OH)2 = 58.3
(11) Magnesium Sodium Magnesium Sodium Soda Ash, Na2CO3 = 106
Bicarbonate + Hydroxide
Hydroxide! + Carbonate + Water
Alkalinity, as CaCO3 = 100
Mg(HCO3)2 + 4 NaOH Mg(OH)21 + 2 Na2CO3 + 2 H2O
Hardness, as CaCO3 = 100
(12) Magnesium Sodium Magnesium Sodium
Sulfate Hydroxide Hydroxide! Sulfate
MgSO4 + 2 NaOH Mg(OH)2 + Na2SO4
FORMULAS
These chemical reactions show that in removing carbon
1 The lime dosage for softening can be estimated by using
dioxide and carbonate hardness, sodium carbonate the following formula:
(Na2CO3, soda ash) is formed which will react to remove the
noncarbonate hardness. Not only will sodium hydroxide Quicklime (CaO) (A + B + C + D)1.15
substitute for soda ash, but it may replace all or part of the Feed, mg/L
Purity of Lime, as a decimal
lime (Ca(OH)2) requirement for removal of the carbonate
hardness. The use of caustic soda (usually as a 5C percent Where A = CO2 in source water
solution) may have several :advantages: (mg/L as CO2)(56/44)

1. Stability in storage, B = Bicarbonate alkalinity removed in softening

(mg/L as CaCO3X56/100)
2. Less sludge is formed, and
C = Hydroxide alkalinity in softener effluer.
3. Ease of handling and storage. (mg/L as CaCO3(56 /100)

Safe handling procedures for caustic soda must be used D = Magnesium removed in softening
1g/L as Mg2+)(56/24.3)
at all times. A 50 percent caustic solution is very dangerous.
Caustic soda is a strong base and will attack fabrics and 1.15 = Exr:ess lime dosage
leather and cause severe burns to the skin. Rubber gloves, (using a 15 percent excess)
respirator, safety goggles and a rubber apron must be worn
when handling caustic soda. A safety shower and an emer- NOTE If hydrated lime (Ca(OH)2) is used instead of quick-
gency eye wash must be readily available at all times. lime substitute 74 for 56 in A, B, C and D.
The decision to use caustic soda rather than soda ash
depends on the quality of the source water ano tne delivered 2 The soda ash dosage to remove noncarbonate hardness
costs of the various chemicals. can to estimated by using the formula below.
Soda Ash (Na2CO3).
,,(Nuncarbonate Ha-lness. mg/L as CaCO3X106/100)
Feed. mgIL
QUESTIONS
Write your answers in a notebook and then compare your 3 The dosage of carbon dioxide required for recarbonation
answers wit those on page 108. can be estimated using the formula below.

14.3C What causes the pH to increase during the lime-soda

Total CO2 = (Cat0H)2 excess, mg/L)(44/74)
Feed, mg/L -t- (Mg(OH)2 residual, mg/L)(44/58.3)
softening process?

t
89
78 Water Treatment

EXAMPLE 3 Total CO2 =(Ca(OH)2 excess, mg/L)(44/74)

Feed, mg/L + (Mg2' residual, mg/L)(44/24.3)
Calculate the hydrated lime (Ca(OH)2) with 90 percent
purity, soda ash, and carbon dioxide dose requirements in
milligrams per liter for the water shown below. = (30 mg/L)(44/74) + (3 mg/L)(44/24.3)

Known = 18 mg/L + 6 mg/L

Softened Water = 24 mg/L
After Recarbonation
Constituents Source Water and Filtration QUESTIONS
CO2. mg /L = 6 mg/L = a mg /L
Total Alkalinity, mg /L = 170 mg /L as CaCO3= 30 mg/L as CaCO3 Write your answers in a notebook and then compare your
Total Hardness, mgIL=
answers with those on page 108.
280 mg /L as CaCO3= 70 mg/L as CaCO3
mg2+, mg/L = 21 mg /L = 3 mg /L 14.3G Calculate the hydrated lime (Og0H)2) with 90 percent
pH 7.5 = 8.8 purity. soda ash, and carbon oloxide dose require-
Lime Purity, 010 = 90% ments in milligrams per liter for the water shown
below.
Unknown
1. Hydrated Lime, mg/L
Softened Water
After Recarbonation
2. Soda Ash. mg/L Constituents Source Water and Filtration
3. Carbon Dioxide, mg/L CO2, mg/L = 5 mg /L = 3 mg /L
1. Calculate the hydrated lime (Ca(OH)2) required in milli- Total Alkalinity. mg /L = 150 mg /L as CaCO = 20 mg /L as CaCO
grams per liter. Total Hardness, mg /L = 240 mg /L as CaCO = 50 mg /L as CaCO
Mg2+. mg/L = 16 mg /L = 2 mg /L
A = (CO2, mg/L)(74/44) pH = 7.4 = 8.8
= (6 mg/LX74/44) Lime Pu-ity, % = 90%
= 10 mg/L
B = (AlkCinity, mg/LX74/100)
14.32 Lime Softening (Figure 14.2)
= (170 mg/LX741 V)
= 126 mg/L Water having hardness caused by calcium and magne-
sium bicarbonate (carbonate hardness) can usually be sof-
C=0 tened to an acceptable level using only lime. The lime reacts
D = (Mg2+, mg/L)(74/24.3) with the bicarbonate to form calcium carborate which will
precipitate and settle out (convert from soluble to insoluble
= (21 mg/L)(74/24.3) form) at a pH above 10 and magnesium carbonate which will
= 64 mg/L remain in solution. The magnesium carbonate reacts with
liydrated Lime additional lime at a pH above 11 to form magnesium
(Ca(OH)2) Feed, (A + B + C + D)1.15 hydroxide which will precipitate.
mg/L
Purity of Lime, as a decimal In practice, if enough hardness can be removed by react-
=10 mg /L + 126 mg/L + 0 + 64 mg/L)1.15
ing lime with the calcium bicarbonate, softening can be
accomplished at less expense. This procedure is sometimes
0.90 called partial lime softening (no magnvit.. removal). On the
(200 mg/L)(1.15) other hand, if some of the magnesium is to be removed,
additional lime will be required.
0.90
= 256 mg/L
Figure 14.2 is a flow diagram of a typical straight lime
softening treatment plant. Settling should be provided after
the addition of carbon dioxide (recarbonation) to ease the
2. Calculate toe soda ash required in milligrams per liter. load on the filters. Recarbonation is used to lower the pH of
Noncarbonate Hardness. =Total Hardness. _Carbonate Hardnc. the water. When properly recarbonated the water is still
mg/L as CaCO3 mg/L as CaCO3 mg/L as CaCO3 supersaturated with calcium carbonate (CaCO3). If the pH is
= 280 mg/L 170 mg/L much above 9, the water will usually cause scale to form. By
recarbonation the pH can be lowered to a range between 8.8
= 110 mg/L as CaCO3 and 8.4 and the Langelier Index will still be positive; there-
Soda Ash (Na2CO3) =, Noncarbonate Hardness, ) (106/100) fore there will be little or no corrosion. A polyphosphate is
Feed, mg /L ' mg /L as CaCO3 sometimes added to the water to prevent excessively heavy
calcium carbonate scale deposits from forming. A polyphos-
= (110 mg/L)(106/100) phate may not be necessary if recarbonation is properly
- 117 mg/L controlled. Addition of acid will NOT accomplish the sante
things as recarbonation and the addition of a polyphos-
3. Calculate the dosage of carbon dioxide required for phate.
recarbonation.
Excess Lime. mg/L - (A + B + C + DX0.15) 14.33 Split Treatment
= (10 mg/L + 126 mg/L + 0 + 64 mg/L)(O 15) The amount of calcium and magnesium in source waters
- (200 mg /LXO.15)
may vary. When the water contains a high level of magne-
sium, a method known as split treatment may be u:ed
- 30 mg/L (Figure 14.3). Split treatment can be used in lime treatment

90
 Softening 79

only or lime-soda ash treatment. In split treatment a portion carbon dioxide dose of 145 mg/L as CaCO3 to produce a
of the water (say 90 percent) is treated with an excess water having a hardness of 61 mg/L as CaCO3 and a pH of
amount of lime to remove the magnesium at a pH of over 11. 8.63.
Then source water (the other 20 percent) is added in the next
basin to neuti-ali7e (lower the pH) the excess - lime - treated While split treatment may be used in the lime-soda proc-
portion. The percentages will vary depending upon the water ess. it is often aovantageous to use a lime-ion exchange
hardness, treatment layout, and desired results. process (see Section 14.10). The salt used to remove
noncarbonate hardness in the ion exchange process is
much less expensive than the soda ash required in the lime-
Split treatment softening can eliminate the need for recar- soda ash process.
bonation as well as offer a significant savings in lime feed.
Since the fraction of the water that is treated has a high lime The curves shown in Figure 14.4 assume that carbonate
dose, magnesium is almost completely removed from this equilibrium has been achieved. In practice, it is not possible
portion. When this water is mixed with the unsoftened water, to attain equilibrium, but if the reactions take place in solids-
the carbon dioxide and bicarbonate in the unsoftened trac- contact units the results are very close to carbonate equilib-
tion of the water tend to recarbonate in the final blend or mix rium.
of the treated water (effluent). The proper fraction of water to bypass is rather critically
dependent on the lime dose and chemical composition of the
If the water shown in Figure 14.4 was treated by conven- unsoftened water. The p:oper fraction may be calculated,
tional treatment (not split treatment), it would require a lime but the calculations are very complex. An experienced water
dose of 400 mg/L as CaCO3 which is 25 percent higher and a chemist can perform the calculations.

COAGULANT
LIME
4
[SOURCE MIX

Fig. 14.2 Straight lime treatment

LIME
CO2
4 FILTERS
ISOURCE MIX SETTLE MIX SETTLE / 11
MINIM=
;LEAR
WELL
St
BYPASS PO4 PO4
(OPTIONAL)
COAGULANT

Fig, 14,3 Split lime treatment

91
: I

II

"VOWS
OOOO
as asiip
n pew ; ;v__ ;CM
...a:
...-
MOS. 4MM" 22.0SWO.S 22.. ilairgingigne
....askii;

MISES 22 ......." .. 0.22 RV

;rn seam mem ......... sow makit ems UM patiquelittritr.tmlikra tt-ktudhporgirs
:- ........
..40.
........ 2::::;12!:;111:1111:dri:21.
mamprna alma
.....
triFisin
s

bettirtima
pporni.-..mumm. :::::::::::::::
............ sense ............... piMIE:i
..
F..0
mi. mann

Fdlillandllii"
WI
::::::0

som
isw...es
...... p ..... p
1.
:Lamp:
.......
un
............ assaults:
t...
WO

: .........
0.00....
ri
............. 212. g:
Eirdi giEwirdniamm-33
.....::::....::: ..11:-... Entliiiriknrmam
.".10.:::::::
OS :2:: .... ......
MO OS. RM. LEE gum
dad ritrtral
germ
.0.0

EEO ME
WO

11
h illamet:
muirtir Fiseilljumarawalli
ME IN
:um:mutts Affil
mo
:11:11.4":".... Pin EfilifEMBEI
:1 :Liitunutuumens ;61
1RE:nuto
:::2,,:::. ... .... S.: .... WW.:2.0CWV.
::::..............finmiiiir:F:F.9m
.,
::::::am....
2:22:22

,
8.0..
S.M.
'Ir...aillitrrat
:WS00:1f:01::::i2:!!
:2::: .E I.'...;1:411 1"1011.:iil
UMS.::122 ..:'
WO:MS: i 2***::::;:if
.......0....., .............. male. 41111...11rUS ..... --Y1:1 --Ir
11111.111r11 611=1.11111.1.1111,11014::::::::=WAng:
,.....: Ireara5Mila
r:::
.: ::::1".-
:::......:::.....
ig:
11:31141$11112111:arlisa
Ai: 11,11:iiiiiiii::1 .
rill: .......... gi..:::...:::::'-. J :..
flail. ...12:08.
re.. um
:1:146.671. ::i21:211:11:iiiii!!!7:0:
211::!!30:7.1i:..... 212::11.1!!!!!ii!!!!;;!ii;:iii.:1

!nil.... 22lids.p.P.2:11.111,41:1111:4rip:::::11:2!
.......-.....sea sew _
OM. SOW
us VMS .
11;;;;;P:a."'IMPEETI::"
0 Se.
S O OSSEO.. OM
"1
pp
SWUM NOVI 2.. ?a Ii
..... ::::::ust :::::::::::::2lltinttkir
1::::!!
Urn .....41221p22221H2Ornidlin
:mien:mire PailiillitinstakiiHitlii
Aff:#11-1111:10119.
J.44 111
11- E INELmisallElerninsseasss....
.1 11
 Softening 81

QUESTIONS The reactions of caustic soda with the carbonate and

noncarbonate hardness are given iri Section 14.315. Recall
Write your answers in a notebook and then compare your that caustic soda reacts with the carbonate hardness to form
answers with those on page 109. soda ash (sodium carbonate) which will react with calcium
sulfate to form calcium carbonate (CaCO3j) as shown pre-
14 3H What compounds are formed when calcium and
viously.
magnesium are pi ecipitated out of water in the lime
softening process?
14.31 What hardness is removed by partial lime softening
(no magnesium removal)?
14 3J What is split lime treatment?
14.3K What is recarbonation9

14.34 Lime-Soda Ash Softening

Let's look now at hardness requiring lime-soda ash treat-
ment for removal (Figure 14.5).
When water cannot be softened to the desired level with
lime only, it no c' .abt contains noncarbonate hardness.
Noncarbonate hardness requires the addition of a com-
pound which increases carbonate concentration, usually
soda ash (sodium carborate).
A water could contain only calcium hardness, yet require
both lime and soda ash treatment. This would occur if the
hardness were only calcium bicarbonate, sulfate and/or The advantages of using liquid caustic soda include ease
chloride. In other words, all of the hardness is calcium of handling and feeding, lack of deterioration in storage, and
carbonate and calcium noncarbonate hardness. This would less calcium carbonate sludge to handle and dispuse of.
not require split treatmen (Figure 14.6). Caustic soda is capable of removing both carbonate and
noncarbonate hardness. Therefore, caustic soda may be
used instead OT soda ash, but also in place of part or all of
14.35 Caustic Sods Softening
the lime requirement. The use of caustic soda depends on a
An alternative to the lime-soda ash process is the use of comparison of the costs of caustic soda, lime and soda ash
caustic soda (sodium hydroxide, NaOH) instead of soda ash. and the characteristics of the source water.

LIME CO2
SODA ASH FILTERS

SETTLE SETTLE
MIN I CLEAR
WELL

COAGULANT PO4
(OPTIONAL)

Fig. 14.5 Lime-soda ash treatment

LIME
SODA ASH
CO2
1 v 80%
[SOURCE MIX SETTLE MIX -14 SETTLE -II SETTLE

20%
Iv A
t
COAGULANT

Fig. 14.6 Lime soda ash split treatment

3
.1(...c,...,.. .
82 Water Treatment

Two points to observe are that sodium does not contribute If lime comes in contact with your skin or eyes, immediate-
to hardness, thus all the reactions having sodium com- ly flush the affected areas with water and consult a physician
pounds as an end product are non-hardness-producing if necessary. Do not rub your eyes if they are irritated with
compounds However, sodium levels in drinking water lime dust because rubbing will make the irritation worse.
should be less than 20 mg /L The second point is that the Keep any lime burns covered with a bandage during healing
precipitated compounds, CaCO3j and Mg(OH)2j are the to prevent infection.
desired end products whether lime or lime-soda ash or
caustic soda treatment is used. After handling lime, you should take a shower. If your
clothes are covered with dust, or splattered with a lime
slurry, take them off and have them washed. If possible,
wear clean clothes on every shift.
QUESTIONS
Write your answers in a notebook and then compare your For additional information regarding hme, contact the
answers with those on page 109. National Lime Asr.,ociation, Washington, D.C. 20016, and
request a copy of their publication, LIME HANDLING, AP-
14.3L Under what conditions would lime-soda ash soften- PLICATION, AND STORAGE IN TREATMENT PROC-
ing be used9 ESSES. Lime, as well other water treatment chemicals,
should comply with the Standards of the American Water
14.3M What chemical is used to remove noncarbonate Works Association.
hardness in the chemical precipitation softening pro-
cess?

14.36 Handling, Application and Storage of Lime QUESTIONS

Where the daily requirements for lime are small, lime is Write your answers in a notebook and then compare your
usually delivered to the water treatment plant in bags. At answers with those on page 109.
larger treatment plants either quick (Ca0) or hydrated
(Ca(OH)2) lime is delivered in bulk quantities. Truck loads of 14 3N How is lime delivered to plants where the daily
lime are commonly transferred to weather-tight bins or silos requirements are small?
by mechanical or pneumatic conveying systems.
14.30 Why should quicklime be kept dry9
Storage areas for bagged lime must be covered to prevent
rain from wetting the bags. Bagged quicklime (Ca0 or 14 3P What types of chemical feeders are used to apply dry
lime?
calcium oxide) should never be stored close to combustible
materials because considerable heat will be generated if the
lime accidentally gets wet. Quicklime may be stored as long
as six months, but in general should not be stored over three
14.4 INTERACTIONS WITH COAGULANTS
months. Hydrated lime should not be stored for more than
three months before using. Coagulation is discussed in detail in Chapter 4, "Coagula-
Lime may be applied by dry feeding techniques using tion and Flocculation." However, the interactions of lime and
volumetric or gravimetnc feeders. Lime is too insoluble to soda ash with metallic coagulants such as alum, iron salts
make "solution feeding" by pump feeders practical because (ferric chloride, ferric sulfate and ferrous sulfate), sodium
of the accumulation of carbonate precipitation. See Chapter aluminate, and many polymers are important.
13, "Fluoridation," for additional details and pictures of the Alum and iron salts are acidic and react with the alkalinity
various types of chemical feeders. in water to cause a demand the same way that flee carbon
Operator safety must be considered before attempting to a,oxide will. Therefore, this acidic condition must be met
work with lime. A properly designed lime feeding system can before softening can occur. In other words, extra lime will be
minimize or eliminate hme dust problems. If lime dust is a required as the alum or iron feed rate goes up and therefore,
problem, operators must wear protective clothing to avoid less lime will be required as the alum or iron feed rate is
burns from contact with lime. Protective clothing includes reduced. Cationic polymers are not very pH sensitive and
long-sleeved shirt with sleeves and collar buttoned, trousers are often used as coagulant aids in softening plants rather
with legs down over tops of shoes or boots, head protection, than alum or iron salts.
and gloves. Clothing should not fit too tightly around your On the other hand, when sodium aluminate (a basic rather
neck, wrists or ankles, P protective cream should be applied than an acidic compound) is the coagulant, the lime required
to exposed parts of the body, especially your neck, face and to achieve a specific hardness reduction will be less, and will
wrists. You should wear a light-weight filter mask and tight- vary the opposite of alum or iron salts.
fitting safety glasses with side shield to protect yourself from
the time dust. The proportion of lime required in either instance is
directly related to the coagulant dosage as well as the
hardness removal desired. Approximate relationships can
be calculated; however, experimentation is in order since
plant equipment and source water variations are primary
factors in the efficiencies of each waterworks. Jar tests are
discussed later in Section 14.9.
If you are treating. highly colored waters, these waters
must be coagulated for color removal at low pH values. Aium
is a good coagulant under these conditions. Ozone, perman-
ganate and chlorine may be tried along with alum to oxidize
color. The high pH values required during softening tend to
"set" the color which then becomes very difficult to remove.

94
 Softening 83

QUESTIONS 2. To an identical sample, add one gram of powdered

calcium carbonate. Mix and let stand for an hour or so.
Write your answers in a notebook and then compare your
answers with those on page 109. 3 Filter both samples (so they are both exposed to the
same conditions).
14.4A What happens to the lime dose when the alum doco
is increased for coagulation'? 4. Run pH and alkalinity tests on both samples.

14.4B How can color be removed from water? 5. The goal is to have the sample of softened tap water as
nearly matched to the softened sample treated with
14.5 STABILITY calcium carbonate as possible. Then stability is near. The
plant treatment must be controlled to permit this condi-
In nature, most waters are more or less stable. That is, tion to exist. If the pH and alkalinity in the softened
they are in chemical balance. When lime is added, the sample are higher than in the softened sample treated
chemical balance is changed. The calcium carbonate with calcium carbonate, ycu are probably over-treating
(CaCO3) formed in lime treatment is scale forming unless the your supply and have scale-forming water. But, if the pH
exact chemical balance is achieved, which is seldom the and alkalinity in your untreated softened sample are
case. lower than in the treated one (calcium carbonate added),
you are undertreating your supply. If they are similar, then
Under most conditions, a slight excess of lime is fed to
stability is near.
cause a caustic condition to insure complete reactions and
achieve the desired results In order to prevent scale forma- Another way to check your water is to suspend a couple of
tion on the filter sand, di i+ribution mains, and household nails on strings in your filter. Observe the nails occasionally
plurruing, the excess caustic and unprecipitated carbonate to F.- a if they are rusting or scaling up. re further protect the
ions (pin floc) must be converted to soluble forms. Recar- distribution system as well as prevent scale formation in the
bonation is the monk common way to do this Again, as with filter bed, 0.7 to 1.0 mg/L polyphosphate could be fed ahead
all chemical treatment, recarbonation must be controlled to of the filters at such a estance to allow mixing before it goes
achieve the desired results. on to the filters. Addition of polyphosphate can PREVENT
THE FORMATION OF SCALE on filter media and in distribu-
Recarbonation lowers the pH to about 8.8 and thus tion system mains, but polyphosphate does NOT prevent
converts some of the carbonate (C032-) back to the original
corrosion. The Langelier Index (see pages 357 to 360 in
bicarbonate (HCO3-) that existed in the source water. Recar-
Volume I) is another approach to determining the corrosivity
bonation can be accomplished, to a degree, by using the
of water.
source water in the split treatment mode discussed earlier.
Usually this is not adequate so further recarbonation is
required. One reason for using source water as a neutraliz-
ing agent is that the recarbonation process is much less
costly than if a high caustic water (high pH) is neutralized by
chemical addition.
Use of carbon dioxide gas is the most common method of
recarbonation. The reactions are:
1. Ca(OH)2 + CO2 + H2O Ca(HCO3)2 arid

2. CaCO3 + CO2 + H2O Ca(HCO3)2.

These reactions may be looked at as June softening in

r verse and will increase the hardness slightly. In these
reactions you are producing bicarbonate ions which were
removed in softening as carbonate hardness. This process
tends to move the water back toward its original state, thus
rendering it more stable.
The use of acids such as sulfuric or hydrochloric instead
of recarbonation with carbon dioxide (CO2) does nci pro-
duce the same results. When carbon dioxide is added to a
water containing calcium ions (Ca2+) and hydroxide ions
(OH-), a calcium carbonate (CaCO3) precipitate will firm and
the water will be saturated (or supersaturated) with calcium
carbonate. If a strong acid is added to neutralize the
softened water which is highly basic, these reactions will not Caution should be exercised when using polyphosphate
take place. compounds. If they are converted to the orthophosphate
form, they will lose their effectiveness. With the addition of
The marble test is the simplest method of measuring phosphorous to water, there could be an increase in bacte-
stability in the laboratory. Run the marble test" as outlined i ial growths in the distribution system. Also some
below: wastewater treatment plants have phosphorous discharge
limitations and polyphosphates added to drinking water can
1. Collect a sample of tap water that has been softened and cause wastewater treatment plants to violate their discharge
stopper the sample bottle (avoid splashing into the flask). requirements.

14 For additional information on the marble test, see Chapter 21, "Advanced Laboratory Procedures," Test Procedure 9, Marble Test.
84 Water Treatment

QUESTIONS tocis on any slaker in operation. A metal tool will damage the
slaker and could even injure the operator if dropped by
Write your answers in a notebook and then compare your accident However, a wooden paddle is less likely to damage
answers with those on page 109. the equipment or the operator.
14.5A What problems are sometimes created when a slight Types of equipment vary greatly. Usually the operator has
excess of lime is fed during softening to cause a little or no input in this area. Engineers usually design a plant
caustic condition to insure complete reactions? and specify the type of chemical feed equipment.
14.5B How can excess caustic and unprecipitated carbon- Equipment suppliers are usually quite cooperative in ad-
ate ions (pin floc) be removed from softened water? vising any operator in the use and care of their equipment in
14.5C What test is used to determine if a water is stable? your treatment plant.

14.5D How can nails be used to determine if a water is Detailed startup and shutdown and maintenance proce-
stable? dures are available in the equipment manuals.
Another important safety precaution is to avoid using the
same conveyor or LAn for alternately handling both quicklime
14.6 SAFETY and one of the coagulants containing water, such as alum,
ferric sulfate or copperas. This water may be withdrawn by
When quicklime reacts with water in the slaking process the quicklime and could generate enough heat to cause a
(Figure 14.7), it gets hot enough to cause serious burns. fire Explosions have been reported to have been caused by
Also, being caustic in nature, it can harm your eyes and skin. lime-alum mixtures in enclosed bins. Therefore, always
ALWAYS wear goggles or a face shield when working with clean facilities before switching from one chemical to an-
lime that has been or is in the process of slaking. Flush with other
water if exposed to lime. Seek medical attention if it gets in
your eyes. As for hands or face burns, immediately wash the
affected areas and consult a physician if the burns appear
QUESTIONS
serious. Write your answers in a notebook and then compare your
answers with those on page 109.
Feeding equipment has moving parts. All moving machin-
ery is a potential safety hazard. A paste-type slaker is 14 6A Why should wooden paddles be used as cleaning
particularly dangerous. This type of slaker will "eat you tools on any slaker in operation?
alive Never put your hand in or near the slaker paddles 14.6B Where would you look for information on how to
while the slaker is running. Use wooden paddles as cleaning safely maintain equipment?

QUICKLIME
, &LI:-
1-"' TORQUE CONTROLLED WATER VALVE

DUST SHIELD

SLAKING WATER WATER SPRAY

RAKES

:'........"GRIT DISCHARGE

LIQUID LEVEL

PADDLES DILUTION CHAMBER

WEIR
WATER FOR GRIT WASHING
SLAKING COMPARTMENT SLURRY DISCHARGE SECTION
DISCHARGE PORT

CLASSIFIG GRIT ELEVATOR

Fig. 14.7 Lime-slaking system

(Permission of Wallace & T:ernan Division. Pennwalt Corporation)

96
 Softening 85

14.7 SLUDGE RECIRCULATION AND DISPOSAL Again. every plant is different. However, records will help
a good operator be a better operator

QUESTIONS
Write your answers in a notebook and then compare your
answers with those on page 109.
14.7A What is a disadvantage of recirculating sludge back
to the primary mix area9
14.7B How could you determine if sludge recirculation will
serve a useful purpose in your plant9
14.8A What types of records should be kept regarding
treatment plant chemicals?

14.9 JAR TESTS

14.90 Typical Procedures

Approximate amounts of chemicals required can be calcu-
Considerable sludge may be produced by the lime and lated (see Section 14.316, "Calculation of Chemical Dos-
lime-soda softening processes. When calcium and magne- ages"), however, the best method of determining the proper
sium hardness are converted from soluble iorms to insolu- dosages is by the use of the jar test. See Chapter 11,
ble precipitates (calcium carbonate and magnesium hydrox- "Laboratory Procedures," for details on the equipment and
ide), these precipitates form sludge. This sludge is removed procedures required to run jar tests.
from the bottom of settling basins and may be recirculated
Cnernical reagents may be made up by adding one gram
or must be disposed of by an acceptable procedure.
of reagent to a liter of water.15 This will produce a 0.1
In some instances, sludge is recirculated back into the percent chemical solution. When 1.0 gram/liter of lime, soda
primary mix area of conventional plants to help "seed" the ash or coagulant is made up as the stock solution, one mL of
process. The advantages are (1) recirculation speeds up the the stock solution in a one liter sample of water equals one
precipitation process and (2) some reduction of chemical mg/L dosage. If large doses of lime are required, add 10
requirements may result. One disadvantage is that an in- grams of lime per liter. With this stock solution, one mL of
crease in magnesium could result. Only trial and error will stock solution in a one liter sample of water equals ten mg/L
really determine if sludge recirculation will serve a useful dosage
purpose in your plant.
Set up 6 samples and estimate the dosage required by
Sludge disposal is a problem everywhere. Perhaps the adding varying amounts to each sample. Trial and error will
most common method is landfill disposal. This is accom- put you in the "ball park." To refine the dosage, pick the best
plished by dewatering the sludge ;drying beds or mechanical looking sample from the settling properties of the floc to
means) and then hauling the sludge to 'anthill sites devel- establish the optimum lime dose. Then do the same with
oped solely for sludge disposal or sanitary landfills. General- varying amounts of soda ash, leavin the lime dosage
ly. a sludge with a Ca Mg ratio of less than 2.1 will be difficult constant. By running pH, alkalinity, and hardness tests you
to dewater, whereas r. sludge with a Ca Mg ratio of greater can find the optimum dosages that give the desired softened
than 5:1 will dewater relatively easily. The less water in the water results.
sludge. the less volume to transport to the disposal site and
the less space required in the landfill. The exact procedures used to soften water by chemical
precipitation using the lime-soda ash process depend on the
To a lesser degree, sanitary sewer disposal is sometimes hardness and other chemical characteristics of the water
used. This only moves the sludge to another location for being treated. A series of jar tests are commonly used to
someone else to deal with. Some work has also been done determine optimum dosages. In many cases, the feed rates
with land application as a substitute for agriculture lime to determined by jar tests do not produce the exact same
increase the pH of highly acid soils. The lime sludge is results in an actual plant. This is because of differences in
applied at a rasa which will produce the ^ptimum soil pH for water temperature, size and shape of jar as compared with
the crops to be planted. For additional information on sludge plant basins, mixing equipment, and influence of coagulant
disposal, see Chapter 17, "Handling and Disposal of Proc- (a heavy alum feed will neutralize more of the lime). You
ess Wastes." must remember that jar test results are a starting point. You
may have to make additional adjustments to the chemical
14.8 RECORDS feeders in your plant based on actual analyses of the treated
water.
Records should be kept on the amounts of chemicals
ordered and the amounts fed Laboratory results should be Convert the jar tet,t results to plant feed rates Always feed
recorded in a permanent lab book. See Chapter 18, "Mainte- enough chemical to achieve the desired results, but don't
nance," for detail:, on how to keep equipment maintenance overfeed. Over . ..z: ..ng is a waste of money and quality
schedules and records. control will suffer.

15 Some operators add 10 grams of reagent to a ,'itei f water. i'his wii produce a one percent solution. One ml of the stock solution in one
liter will produce a ten mg/L dosage.

9"7
 86 Water Treatment

14.91 Examples 3 Try slightly increasing the actual lime dose in your plant to
Let's set up some jar tests to determine the optimum see if there is any decrease in the remaining hardness. Is
dosages for lime or lime-soda treatment to remove hardness the decrease in hardness worth the increase in lime
from a municipal water supply. To get started, add 10.0 costs?
grams of hydrated lime to a one-liter graduated cylinder or 4. Try slightly increasing and decreasing both lime and soda
flask and fill to the one-liter mark with tap water. Thoroughly ash dosages at your plant one at a time, and evaluate the
mix this stock solution in Crder to thoroughly suspend all of results.
the lime. One mL of this solution (which has been thoroughly
mixed) in a liter of water is the same as a !ime dose of ten 5. If you are treating well water or a water of constant
mg/L, or 0.5 mL in 500 mL is still the same as a ten mg/L lime quality, all you have to do to maintain proper treatment is
dose. to make minor adjustments to keep the system fine
tuned.
Set up a series of hardness tests by adding 5.0 mL, 10.0
mL, 15.0 mL, 20.0 mL, 25.0 mL, 30.0 mL, 35.0 mL and 40.0 6. If you are treating water from a lake or a river and the
mL to one-liter (1000 mL) beakers or jars. r all the beakers to water quality (including temperature) changes, you'll have
the 1000 mL mark with the water being tested. Mix thor- to repeat these procedures whenever the raw water
oughly for as long as normal mixing will occur in your plant. quality changes. Water quality changes of concern in-
Allow the precipitate to settle (20 minutes if this is the settling clude raw water hardness, alkalinity, pH, turbidity and
time in your plant) and measure the hardness remaining in temperature.
the water above the precipitate. A plot of the hardness 7. REMEMBER, you do not want to produce water of zero
remaining against the lime dosage will reveal the optimum hardness. If you can get the hardness down to around 80
dosage. Examination of Figures 14.8, 14.9 and 14.1016 to 90 mg/L, that usually will be low enough for most
reveals that the water of all three cities responded differently
domestic consumers. When selecting a target hardness
to the increasing lime dosage. City 1 (Figure 14.8) should be
level for your plant, consider the uses of your softened
providing a lime dose of 100 mg/L. The cost of increasing water and the cost of softening.
the dosage to 150 mg/L is not worth the slight reduction in
hardness from 110 to 100 mg/L as CaCO3. Note that an
overfeed of lime will actually increase the hardness. QUESTIONS
Write your answers in a notebook and then compare your
City 2 (Figure 14.9) should be providing a lime dose of 200 answers with those on page 109.
mg/L. A dose of 300 mg /L will reduce hardness, but th3
increase in lime costs is too great. City 3 (Figure 14.10) 14 9A What items should be considered when determining
should be dosing lime between 200 and 250 mg /L. Note that the hardness of the treated water from a water
the greater the lime dose, the less the hardness, but the softening plant?
greater the quantities of sludge that must be handled and
disposed of. 14.9B If lime added to water does not reduce the hardness
of a water sufficiently, what would you do?
If lime added to the water does not remove sufficient
hardness, select the optimum lime dose and then add
varying amounts of soda ash. From Figure 14.9 we found
that the optimum lime dose was 200 mg/L (300 mg /L would
have reduced the hardness slightly). Let's take six one-liter
containers and add 20 mL of our lime stock solution (a
dosage of 200 mg/L). Prepare a stock solution of soda ash
similar to our lime solution by adding 10 grams of soda ash
to a one-liter container, fill with distilled water and mix
thoroughly. Add zero, 2.5 mL (25 mg/L dose), 5 mL, 7.5 mL,
10 mL and 12.5 mL to the one-liter containers. Mix thorough-
ly, allow the precipitate to settle and measure the hardness
remaining in the water above the precipitate. A plot of
hardness remaining against the soda ash dosage will reveal
the desired dosage. We would like the final hardnes:. to be in 14.92 Calculation of Chemical Feeder Settings
the 80 to 90 mg/L as CaCO3 range in this example. After chemical doses have been calculated or determined
To select the optimum doses of lime and soda ash, from jar tests, convert the results to plant chemical feed
consider the items discussed below. rates. Depending on the type of chemical feeder, you may
have to calculate the feed rates in pounds per day, pounds
1 Optimum dosage of lime was based on increments of 50 per hour or pounds per m nute. Always feed enough chemi-
mg/L. You should refine this test by trying at least two-10 cal to achieve the desired results, but don't over feed Over
mg/L increments above and below the optimum dose. treating is a waste of money and quality control will suffer.
From Figure 14.8 we found that 100 mg /L was the
optimum dose. Try lime doses of 80, 90, 100, 110 and 120 EXAMPLE 4
mg /L.
The optimum lime dosage from the jar tests is 230 mg/L. If
2 Optimum dosage of soda ash can be refined by trying the flow to be treated is 6 MGD, what is the feeder setting in
smaller increments also. pounds per day and the feed rate in pounds per minute?

16 These figures were adapted from an article titled, Use of Softening Curve for Lime Dosage Control," by Michael D. Curry, °. E., v inch
appeared in THE DIGESTER /AVER THE SPILLWAY, published by the Illinois Environmental Protection Agency.

98
250
I
HARDNESS REMAINING

20e 1

150

100

50

Ii
50 100 150 200 250 300 350 400

LIME DOSAGE, nig/L

Fig. 14.8 Softening curve for City 1 1 CO

 250

HARDNESS REMAINING

200
0
0w
0
,,,
4,
..4
-En 150
E

U)
cn
tu
z
atc
4
x 100

50

50 100 150 200 250 300 350 400

LIME DOSAGE, mg/L

Fig. 14.9 Softening curve for City 2

250

HARDNESS REMAINING

200

150

100

50

50 100 150 200 250 300 350 400

LIME DOSAGE, mg/L

Fig. 14.10 Softening curve for City 3

90 Water Tmatment

Known Unknown Known Unkrown

Lime Dose. mg/L = 230 mg/L 1. Feeder Setting, lbs/day Noncarbonate Hardness 1 Feeder Setting. lbs/
Flow. MGD - 6 MGD 2. Feed Rate. lbs/min Removed. mg/L as CaCO3 day
Flow. MGD - 6 MGD 2 Feed Rate. lbs/min
1. Calculate the feeder setting in pounds per day 1 Calculate the soda ash dose in milligrams per liter. See
Feeder Setting. Section 14 316. "Calculation of Chemical Dosages" for
(Flow, MGD)(Lirne. mg/L)(8.34 lbs/gal) the following formula.
lbs/day
= (6 MGD)(230 mg/L)(8.34 ibs/gal) Soda Ash, , Noncarbonate Hardness, )(106/100)
t
= 11.509 lbs/day mg/L mg/L as CaCO3

2. Calculate the feed rate in pounds per minute. = (50 mg/L)(106/100)

Feed Rate. Feeder Setting. lbs/day = 53 mg/L

lbs/min 2. Determine the feeder setting in pounds per day.
(6u min/hr)(24 hr /day)
11.509 lbs/day Feeder Setting.
(Flow. MGO)(Soda Ash, mg/L)(8.3d lbsjgal)
lbs/day
(60 min/hr)(24 hr/day) = (6 MGD).53 mg/L)(8.34 lbs/gal)
= 8.0 lbs/min = 2652 lbs/day

When the calculated feed rate of eight pounds of lime per 3 Calculate the soda ash feed rate in pounds per minute.
minute is put into the plant process, observations and tests Feed Rate. Feeder Setting, lbs/day
will determine if optimum levels are met. In many instances, lbs/min
jar tests and actual plant feed rates do not agree exactly. (60 min/hr)(24 hr/day)
This is because of temperature, size and shape of jars vs. 2652 lbs/day
=
size and shape of plant facilities, mixing time, and influence
of the coagulant (a heavy alum feed would neutralize more (60 min/hr)(24 hr/day)
of the lime). Jar tests are merely indicators or a point of = 1.8 lbs/min
beginning.

If underfeeding results, reactions will not be complete and After you determine the proper feed rates and implement
the results will be undertreatei water having a hardness them. if you are treating well water or other water of
higher than that desired. constant quality, all you have to do to maintain proper
treatment is make minor adjustments to keep the system
If overfeeding results, chemicals are being wasted. Also, it fine tuned.
is quite possible to have excessive calcium in the water This
results in unstable conditions which cause buildup on the On the other hand, if you treat a river or lake supply
sand grains and the interior of the water mains. This is subject to constant and frequent changes in water quality,
where the stability test enters the p.zture (refer to Section it's an entirely different set of circumstances. Until you learn
14.5. "Stability"). from experience to judge the chemical changes necessary
by the fluctuations in raw water hardness, alkalinity and
The above discussion has oealt with establishing the tui b.dity. you almost nave to check yourself daily by the jar
proper lime feed. The same process would be used to test method.
determine the soda ash requirements if you are removing
noncarbonate hardness Set up the lime feeds as discussed. When your treatment process does not work properly, the
Pick the optimum dosage. Then set up another series of jars first thing to check is whether or not the feeder is feeding
using the same lime feed rate in all jars. Now, vary the soda properly If it is. the next step is to check your source water
ash feed rate. quality Generally, one of these two will be the cause of your
problem
EXAMPLE 5
How much soda ash is required (pounds per day and QUESTIONS
pounds per minute) to remove 50 mg/L noncarbonate haro- Write your answers in s notebook and then compare your
ness as CaCO3 from a flow of 6 MGD answers with those on page 109.
14 9C Why should the overfeeding of chemicals Lie avoid-
ed
14 9D What should be the lime feeder setting in pounds per
day to treat a flow of 2 MGD when the optimum lime
dose is 160 mg / L''
14 9E How much soda ash is required in pounds per day to
remove 40 mg/L of noncarbonate hardness from a
flow of 2 MGDo

eh& of Les5ok 1 of f 1(244014,4

4orremiNe
1n5
 Softening 91

DISCUSSION AND REVIEW QUESTIONS

Chapter 14. SOFTENIKi
(Lesson 1 of 2 Lessors)

At the eno of each lesson in this chapter you will find some for alternately handling both quicklime and one of the
discussion and review questions that you would work coagulants containing water, such as &um?
before continuing. The purpose of these questions is to
indicate to you how veil you understand the material in the 10 Why is sludge sometimes recirculated back into the
lesson. Write the answers t-) these questions in your rote - primary mix area of conventional plants?
book before continuing 11 When running jar tests, how would you determine the
1. Why should water be softened? optimum dosage for a coagulant, lime and soda ash?

2. What are the benefits of softening water in addition to 12 When your lime-soda ash softening plant does not
hardness removal? perform properly, what is the first thing you should
check?
3 Why is settlea water recarbonated after the precipitation
of calcium carbonate?
4 What are the advantages of using liquid caustic to
soften water?
Why should quicklime never be stored close to combus-
tible material?
6. How can operators protect themselves from lime?
7. Why is the stability of a water important?
8. Why is a paste-type slaker dangerous?
9. Why should you avoid using the same conveyor or bin

CHAPTER 14. SOFTENING

Ion Exchange Softening by Marty Reynolds

(Lesson 2 of 2 Lessons)

14.10 DESCRIPTION OF ION EXCHANGE SOFTENING The treatment plant operator should be aware of the three
PROCESS basic types of softeners on the market.
The term "Zeolite" is most often associ ited with sodium 1 An upflow unit in which the water enters from the bottom
on exchangers and snould be considered to mean the same and flows up through the ion exchange bed ar.t.i out the
as the term ion exchange. Most ion exchange units in use top
today use sulfonated polystyrene resins as the exchange
media. Ion exchange softening can be defined as exchang- 2 A unit which is constructed and operated like a grevity
ing hardness-causing ions (calcium and magnesium) for the rapid sand filter The water enters the top, flows down
sodium ions that are attached to the ion exchange resins to through the ion exchange bed and out the bottom.
create a soft water. 3. The pressure downflow ion exchange softener, which is
the most common will be covered by this chapter. See
Figures 14 11 and 14.12. Pressure filters mu/ be either
horizontal or vertical units. Vertical units are preferred
because there is less chance of short-circuiting.
To help explain the construction and activity that occurs in
an ion exchanger, let's compare it to a pressure filter. The
water enters the unit through an inlet distributor located in
the top; it is forced (usually pumped) down through a bed of
some type of media into an underdrain structure. From the
underdrain structure, the treated water flows out of the unit
and into storage or into the distribution system.
The flow pattern through a filter and r ,ftener are similar,
the key difference being the action that takes place in the
media or bed of each unit. The filter bed may be considered
1rG
92 Water Treatment

RELEASE LINE

VERTICAL SOFTENER TANK

BAFFLE
" DIAMETER
" SIDE SHELL HEIGHT
P.S.I. WP FREEBOARD

" ZEOLI TE =
CU. FT.

" FILTER SAND, SIZETOMM.

GRADED GRAVEL, SIZE 1/4"0.10_
" GRADED GRAVEL, SIZE I/2"x 1/4- gg`6g,44034,(41.4e,ZI,,g GRAVEL BED
" GRADED GRAVEL, SIZE 3/4" x I/2" gfgogogefvo'c',eb°40E'llof
u GRADED GRAVEL, SIZE I I/2" x3/4 a 00dod--- 0 - 0 a, ,,,,,a,ge.00,9

UK^ERDRAIN

STANDARD SOFTENER

UNDERDRAIN:-
RIGIDLY SUPPORTED PLATE OVER IC3 %
FILTER AREA WITH STAINLESS STEEL
BAFFLE ASSEMBLIES.

ZEOLITE: CUBIC FEET.

STAINLESS STEEL
SUPPORTING GRAVEL- "GRADED. BAFFLE ASSEMBLY

Figure 14.11 Pressure down flow ion exchange softener

(Permission of General Filter Company)

107
 1 POWER SUPPLY
i 110 VOLT 60 CYCLE
ii I-PHASE SERVICE
4
01
II 1:

,1

ii 0) ,
1,
1,

ii
ii

111

PILOT PAN EL--

LOCAT I ON--
VENT- ON SOFTENER

CONTROL PANEL
BRINE EJECTOR----
CYCLE TIMERS
INTERLOCK
BRINE CONTROL

DIAPHRAGM VALVE
BRINE BRINE OUTLET CiA CONTROL LINES
LEVEL MEASURING
ELECTRODES TANK METER II METER

"IL" BUTTERFLY
CONTROL
1i% nl --VALVES
I

WEIR B'IARD-1;;

Figure 14.12 Semi-automatic controls for ion exchanger

(Permission of General Filter Company)
19
94 Water Treatment

an adsorption and mechanical straining dev,ce used to Once a softener has exchanged all of its sodium ions and
remove suspended solids from the water. The `red usually the resins is saturated with calcium c.nd magnesium, it will no
consists of sand, anthra' ;ite (crushed coal) or a combination longer produce saft water. At this time the unit must be
of both. Once the bed becomes saturated with the. insoluble taken out of service, the calcium and magnesium removed
material (usually clay, suspended solids and iron manga- tror,i the resin by exchange with sodium ions. This process
nese hydroxide), the filter is taken out of service, back- is referred to as a regeneration cycle.
washed and returned to service. This pressure filter will
continue to operate until the condition reoccurs and the In a regeneration cycle, the calcium and magnesium ions
procedure is repeated. that have been retained by the resin must be removed and
the sodium ions restored. In order for the exchange to take
The bed, media or resin in an ion exchange softener, place, the resin must hold all ions loosely. If the calcium and
however, is much more complex. This resin serves as a magnesium ions cannot be removed, the resin will not
medium in which an ion exchange takes place. As hard accept the addition of new sodium ions that are necessary
water is oassed through the resin, the sodium ions on the for additional softening
resin are exchanged for the calcium and magnesium ions (in
the case of sodium exchange reqins. The sodium ions are Salt in the form of a concentrated brine solution is used to
released from the exchange resin and remain in the water regenerate (recharge) the ion exchange resin. When salt is
which flows out of the softener. The calcium and magnesium added to water it chan6 is into or ionizes to form sodium
ions, however, are retained by the resin. The softener cation (Na+) and chloride anions (Cll. Wher the brine
effluent is free from calcium and magnesium ions and solution is fed into the resin, the sodium cations are ex-
therefore is softened (Figure 14.13). changed for calcium and magnesium cations. As the brine

PLUG FLOW - PISTON EFFECT

HARDNESS APPLIED
Ca++ Mg++

1 1 1 1 1

Na+ Na+ Na+ Ca++ Mg++ Ca++

Na+ Na+ Na+ Na+ Na+ Na+
Na+ Na+ Na+ Na+ Na+ Na+
Na+ Na+ Na+ Na+ Na+ Na+
Na+ Na+ Na+ Na+ Na+ Na+

1 1 1 1
[1]
EXCHANGE RESIN [2]
PRIOR TO SOFTENING Na+ AND SOFT WATER EXCHANGE
(AFTER REGENERATION) RESIN AFTER START OF SOFTENING CYCLE

PLUG FLOW - PISTON EFFECT

HARDNESS APPLIED
Ca' Mg++

1 1 1 I 1

Ca++ mg++ Ca++

Ca++ Mg++ Ca++
Ca++ Ca++ mg++
Ca++ Ca++ Mg++
mg++ Ca++ Ca++
Mg++ Ca++ Ca++
Ca++ Na+ Ca++
Ca++ Mg++ Mg++
Na+ Na+ Na+
Ca++ Ca++ Mg++
1 1 1 1 1 1

[4]
[3]
Na+ AND SOFT WATER EXCHANGE EXCHANkiE RESIN EXHAUSTED
RESIN DURING SOFTENING CYCLE (ALL SOFTENING CAPACITY LOST-
READY TO REGENERATE, SEE [1])

Fig. 14.13 Ion exchange resin condition during softening cycle

110
 Softening 95

solution travels down through the resin, the sodium cations The length of each service stage is dependent on several
are attached to the resin while the calcium, magnesium and factors, source water hardness is a main consideration. The
chloride (from the salt) ions flows to waste After the harder the water, the more calcium and magnesium must be
regeneration has taken place, the bed it ready to be placed removed to reach a level of zero hardness. Simply stated,
in service again to remove calcium and magnesium by 'on the harder the water, the less water you can treat before the
exchange. resin becomes exhausted. As long as the design flow for the
on exchange unit is not exceeded, changes in the hardness
of the source water may be automatically adjusted for in the
ion exchange unit. The effluent from the unit usually will have
zero hardness until the unit needs regeneration. If the total
dissolved solids (TDS) in the water supply is fairly high
(above 500 mg/L), there may be some leakage. If a high TDS
water has a high sodium content, the sodium may hinder the
process by causing a local exchange on the media of
calcium and magnesium (hardness leakage) for some of the
sodium The amount of hardness leakage depends on the
TDS and the salt dosage (percent salt) used for regenera-
tion.
Other factors involved are the size of the softener and the
exchange capacity of the resin Softeners can vary in size
from a few cubic feet to several hundred cubic feet. The size
of the unit will generally be consistent with regard to the
overall treatment plant design. In other words, the softener
QUESTIONS should be capable of producing enough softened water so
Write your answers in a notebook and then co:npare your that the mix or blend of softened and ursoftened water will
answer s with those on page 110. produce a treated water with the desired level of hardness.

14.10A List the three basic types of softeners on the The exchange resin will also vary in its removal capacity.
market. There are many types of strong acid cation exchange resins
on the market today. Most will range in capacity from 20,000
14 10B What happens during the regeneration cycle of an to 30,000 grains of hardness removal per cubic foot (0.011 to
ion exchange softener? 0.016 kg/cu m) resin. The removal ability of the resin is
usually expressed in grains of hardness removal per cubic
foot of material or resin.
14.11 OPERATIONS
The source water hardness, size and the removal capacity
Many factors influence the procedures uses to operate an of the resin will determine the amount of water that can be
ion exchange unit and the efficiency of the softening proc- treated before the softener must be regenerated. With a few
ess. These factors include* simple calculations, an operator can determine the softening
1. Characteristics of the on exchange resin, capacity of the units. Calculations and examples will be
given at the end of the chapter. See Example 8 in Section
2. Quality of the source water, 14 18, "Ion Exchange Arithmetic."
3. Rate of flow applied to the softener, 14.111 Backwash
4. Salt dosage during regeneration, The second stage of the ion exchange softener process is
5. Brine concentration, and the backwash. In this stage, the unit is taken out of service
and the flow pattern through the unit is reversed. The
6. Brine contact time. purpose of this is to expand and clean the resin particles and
Each ion exchange softener, regardless of manufacturer,
also to free any material such as iron, manganese and
will have at least four common stages of operation. These particulates that might have been rem wed during the sof t-
stages are listed below and will be explained as each occurs
ening stage. The backwash water entering the softener at
in the softener operation (see Figure 14.14). the beginning of this stage should be applied at a slow
steady rate If the water enters the unit too quickly, it could
1. Service, create a surge in the resin and wash it out of the unit with the
water going to waste.
2. Backwash,
Ideal bed expansion during the softener backwash snould
3. Brine, and be 75 to 100 percent. In other words, when the unit is
4. Rinse. backwashed, the resin should expand to occupy a volume
from 75 to 100 percent greater than when in normal service.
An example of this would be an ion exchange softener with
14.110 Service 24 inches (60 cm) of resin while in service. When the unit is
backwashed, the resin should expand to 48 inches (120 cm)
The service stage of each unit is where the actual soften-
for a 100 percent expansion of the bed. As the bed expands
ing of the water occurs. Hard water is forced into the top of
a shearing action due to the backwash water and some
the unit and allowed to flow down through the exchange scrubbing action will free any material that might have
resin. As this takes pla.;e, the calcium and magnesium ions
formed on the resin particles during the softening stage.
exchange with sodium on the re..in. The sodium ions are
released into the water and the exchange capacity of the unit During the backwash a small amount of resin could be
is slowly exhausted. lost. This amount, however, should be minimal and you

*4* L1
96 Water Treatment

TREATED WATER -4---

METER

] SUMP

U DRAIN

VALVE NUMBER
OPERATION
1 2 3 4 5 6 7

SERVICE OPEN CLOSE CLOSE OPEN CLOSE CLOSE CLOSE

BACK WASH CLOSE OPEN CLOSE CLOSE OPEN CLOSE CLOSE
BRINE CLOSE CLOSE OPEN CLOSE CLOSE OPEN CLOSE
RINSE OPEN CLOSE 'CLOSE I CLOSE CLOSE CLOSE OPEN

Fig. 14.14 Valve positions for each stage

of ion exchange softener operation
(Permission of General Filter Company)

112
 Softening 97

should check the backwash effluent at different intervals to 14.113 Rinse

insure that the resin is not being lost. A glass beaker can be
used to catch a sample of tile effluent while the unit is The fourth and final stage of softener operations is the
backwashing A trace amount of resin should cause no rinse stage After adequate contact time has been allowed
alarm, but a steady loss of resin could indicate a prohl Am in between the brine solution and resin, a clear rinse is applied
the unit and the cause should be located and corrected as from the top of the unit to remove the waste products and
soon as possible. Too much loss of resin may be caused by excess brine solution from the softener. The flow pattern is
an improper freeboard on the tank or wash troughs. very similar to the service stage except that the softener
effluent goes to waste instead of storage. The waste dis-
The backwash duration and flow rate will vary depending charge contains high concentrations of calcium and magne-
on the manufacturer and the type ar J size of resin used and sium chloride Most rinse stages will last between 20 and 40
the water temperature minutes, depending on the size of the unit and the manufac-
ture See Section 14.14, "Disposal of Spent Brine," for
14.112 Brine procedures on how to oispose of the waste discharge.
The third stage is most often termed the regeneration or Again. the operator should pay close attention to the
brine stage At this point, the sodium ion concentration of the softener while it rinses The rinse must be long enough to
resin is recharged by pumping a concentrated brine solution remove the heavy concentration of waste from the unit. If the
onto the resin. The solution is allowed to circulate through rinse is not of the correct length and the unit returns to
the unit and displace all water from the resin in order to service. a salty taste will be very noticeable in the softener
provide full contact between the brine solution and the resin. effluent Taste the waste effluent near the end of the rinse
stage to determine if the majority of chloride ions have been
Most treatment plants use a brine solution to regenerate removed. The chloride ion concentration may also be meas-
their softening units. The optimum brine concentration com- ured by titration as outlined in Chapter 21, "Advanced
ing in contact with the on exchange resin is around 10 to 14 Laboratory Procedures or by measuring the conductivity of
percent sodium chloride solution Concentrated brine is only the water If the water still has a strong salty taste or
used when the water v 'thin the softener tank serves as the excessive chloride ions are present, check the rinse rate and
dilution water A 26 percent brine solution (fully concentrated timer settings. The unit may need adjustment to increase the
or saturated) causes too great of an osmotic shock on the duration of the rinse stage
on exchange resin and can cause it to break up. The salt
dosage used to prepare the brine solution is one of the most
important factors affecting the ion exchange capacity and QUESTIONS
ranges nom 5 to 15 pounds of salt per cubic foot (80 to 240
Write your answers in a notebook and then compare your
kg/cu m) of resin. See EXAMPLE 10 on page 104 for
procedures on how to calculate the salt dosage and gallons answers with those on page 11n.
of brine solution required. Brine concentrations less than 14 11A What is the main consideration in determining the
saturated require longer contact time and more solution length of the service stage of an ion exchange
must be applied to the unit to achieve a successful regenera- softener?
tion.
14 11B What is the purpose of the backwash stage of an
The regeneration stage of the softener is very important ion exchange softener?
and the operator should be certain it is properly carried out.
In the regeneration stage, the sodium ions present in the 14 11C How are on exchange softeners regenerated?
brine solution are exchanged with the calcium and magne- 14 11D Where does the softener effluent go during the
sium ,ons on the resin. The ions on the resin were ex- rinse stage?
changed during the service or softening stage. The regen-
eration rate is usually one to two GPM per cubic foot (2.2 to
4 4 liters per second per cubic meter) of resin for the first 53 14.12 CONTROL TESTING OF ION EXCHANGE
minutes and then three to five GPM per cubic foot (6.6 to 11 SOFTENERS
liters per second per cubic meter) for the last five minutes of
fast drain. If the regeneration process is performed correct- In most small treatment plants, the operator has to per-
ly. the result is a oed that is completely recharged with form many jobs and may not always have time to monitor the
sodium ions and will again soften water when the unit is softening units as they should be monitored. If a few simple
returned to service test procedures are learned and carried out on a regular
basis the operator can reel confident the ion exchange units
are operating properly. Control tests the operator should
perform are listed it this section.
1. Softener Influent
Be aware of the iron and manganese levels entering
the softener. These levels should be kept to a minimum to
prevent fouling of the media bed as the unit will remove a
certain amount of iron and manganese before becoming
plugged. Insoluble particles of iron and manganese will
plug the filter media. Soluble ionic iron (Fe2+) and manga-
nese (Mn24) will exchange onto the media and will not be
fully removed by regeneration. If the source water enter-
ing the plant is high in iron and manganese, proper
oxidation and filtration of the water BEFORE the softener
should reduce the levels and prevent problems from
developing in the softeners.

113
98 Water Treatment

Monitor source water hardness on a routine basis. 14.14 DISPOSAL OF SPEW' BRINE
Generally, hardness will not vary, but if it changes, you
will need to adjust the amount of water treated by each One of the largest problems associated with the design
softener before the media becomes exhauster' and the and operation of ion exchange softening plants is the
unit must be regenerated disposal of the softener waste.

2. Softener Effluent
At the end of a regeneration stage, as the unit goes
back into service, check the effluent for hardness This
one test will tell you if the regeneration of the softener has
been properly conducted. Allow a few minutes to ensure
that all of the rinse %ater in the unit has been purged
(removed). Run a hardness test on the effluent side of the
unit. The results should indicate a water of zero hard-
ness. Several test kits are available on the market today
that are fairly quick ar.-1 simple to use to measure water
hardness.

14.13 LIMITATIONS CAUSED BY IRON AND

MANGANESE
Ion exchange units are very versatile. The primary pur-
pose of the unit is to remove calcium and magnesium from
the water thus making the water soft. Ion exchange soften-
ers, however, will also remove iron and manganese in either
the soluble or precipitated form. If this occurs, the iron and The waste discharge from softeners conwsts mostly of
manganese will seriously affect the life of the exchange calcium. magnesium and sodium chlorides. These by-prod-
capacity of the resin. If water high in iron and manganese is ucts are corrosive to material they contact and possess
applied to the ion exchange resin for very long, iron fouling varying toxic levels in relationship to the environment.
or the loss of exchange capacity will result.
Many water treatment plants discharge spent brine into
When the softeners remove iron in the ferrous (soluble) or nearby sewers This procedure may be approved if the
ferric (solid) form, the two problems discussed below could downstream wastewater treatment plant and receiving wa-
result ters can handle the brine. Usually the water treatment plant
must have some type of holding tank to store the spent
1 If water with iron in the ferrous form is applied to the brine The brine is slowly discharged into the sewer at a rate
softener, the resin will remove the iron from the water. which will not upset (or be toxic to) the biological treatment
The iron can be retained on the surface of the resin or is processes at the wastewater treatment plant Also the salt
sometimes captured deep inside the resin itself. As this level in the effluent from the wastewater treatment plant
happens, the resin or bed will develop an orange or rusty
must not adversely impact the aquatic life in the receiving
appearance. I: the resin becomes iron coated, the effi- waters nor cause a violation of the wastewater treatment
ciency of the softener will by reduced greatly. plant's NPDES PERMIT.17
2. The second problem associated with high iron levels is a
plugging or clogging of the resin bed. When water con- Some water treatment plants may be issued an NPDES
Permit to discharge spent brine into receiving waters. This
taining iron in the ferric form (solid) is applied to the unit, it
will act like a filter and strain the iron from the water, could happen only if the flow in the receiving waters was
leaving the iron trapped in the bed. If high iron loadings very high (plenty of dilution) and the flow of spent brine was
very low A holding tank would be needed for the spent brine
continue, the upper layer of the bed could become
and the brine could be discharged very slowly. The receiving
plugged, forcing the water to channel or short-circuit
through the bed. The result is incomplete contact be- waters would have to be monitored to be sure that the
discharge of brine will not cause a significant increase in the
tween the water and media thus creating hardness leak-
level of brine
age and loss of softening efficiency.
IRON AND MANGANESE MUST BE REDUCED TO Sanitary landfills also may be an acceptable means of
THEIR LOWEST POSSIBLE LIMITS BEFORE APPLYING
disposing of spent brine See Chapter 17, "Handling and
Disposal of Process Wastes," for additional information.
WATER TO THE SOFTENER. Oxidation of iron and
manganese (see Chapter 12, "Iron and Manganese Con- Each ion exchange treatment plant probably has only one
trol") BEFORE applying water to ion exchange units is approved method of waste disposal. Very few options are
very helpful. You should also be aware of the chlorine available to plants discharging this type of waste. Alternate
levels applied to the softening units Normal chlorine waste disposal methods available for spent brine are cov-
dosages will not present a problem, but high residuals ered in Chapter 17, "Handling and Disposal of Process
Could damage the resin and reduce its life span. Wastes

/7 NPDES Permit. National Pollutant Discharge Elimination System permit is the regulatory agency document issued by either a federal or
state agency which is designed to control all discharges of pollutants from point sources in U.S. waterways. NPDES permits regulate
discharges into navigable waters from all point sources of pollution, including industries, municipal treatment plants, large agricultural
feed lots and return irrigation flows.

114
 Softening 99

The operator needs to aware of the seriousness pump The combination of sand and mechanical seals will
involved with softener waste. If a problem develops at the must often result in high repair and maintenance costs
treatment plant. the operator should be working with the Packing is ,,heaper and easier to install and maintain than
agency in the area that governs waste disposal as several mechanical seals and packing will usually outlast mechani-
considerations must be studied when changing a disposal cal seals in this type of installation
method The brine pump motor should have a "heavy duty" rat,ng
and a body made of cast iron is preferable. Aluminum or mild
QUESTIONS steel motor housings do not hold up as well as cast iron
when subjected to the corrosive environment around the
Write your answers in a notebook and then compare your brine pumping station.
answers with those on page 110.
An .rea most often neglected until problems arise is the
14 12A Which water quality indicators should be monitored bulk brine storage area of the treatment plant. Most storage
in the effluent of an ion exchange softener'? areas are underground pits equipped with rock or gravel
strainers above some type of underdrain collection system.
14 13A What happens when high chlorine residual levels Over a period of time, the strainers will sit in with sand and
are applied to the softening units'? impurities received with salt deliveries. The best way to
14.14A Why is the disposal of spent brine a problem'? prevent this from occurring is to regularly shut down, drain
and replace the strainer systems in the pit. This is a great
deal of work, but it is a necessity if the brine system is to stay
14.15 MAINTENANCE in operation.
Most of the ion exchange water softening equipment on Some brine storage areas have become so clogged that
the market today is fully automated (Figure 14.12). The the brine solution could not penetrate the strainer media and
reason for most of this automation is to reduce the time an reach the underdrain system. Like the head loss on a filter,
operator must spend with each unit. Automation is fine for the strainers can become so clogged that the solution
operational control, but it does not mean a unit is mainte-
cannot seep through to the underdrain system. If this
nance free. Systems like this have a tendency to lead happens and the system cannot be shut down for cleaning, a
operators astray. A small routine maintenance item can go pipe can be driven down through the sand and impurities
unnoticed until it becomes a full scale problem if the opera- into the gravel layers. If enough holes are driven through the
toi does not run a regular maintenance schedule on the zones of impurities. the solution will eventually seep into the
equipment. For example, most valves on ion exchange units underdrains and can be pumped into the softeners. This is a
are pneumatic or are equipped wan some type of self- temporary repair measure only and II), storage area should
operating device (valve actuators). This does not mean,
be cleaned as soon as possitle.
however, the valve will operate each time it is required to do
so w,thout a regular examination and overhaul. The operator Inspect the brine solution make-up water line while the
must check the equipment to insure it is always in proper storage area is shut down. This line must be kept in good
working order One valve that fads to open or to close during working order because it provides potable water to the salt
a regeneration stage could mean trouble (a storage tank full supply This water makes the saturated brine solution that is
of salty water or no brine at all,. used to regenerate the softener PVC pipe would provide
excellent service in a corrosive environment such as a
The components of an ion exchange softening system
storage area.
that should receive constant attention are the brine pumps
and piping. A saturated brine solution is very corrosive and
will attack any unprotected metallic surface it comes di
contact with. Try to keep the system as tight as possible. An
uncontained brine leak will only get worse.
If you must change the pipe work in the brine system, give
serious consideration to installing PVC pipe. The material is
much cheaper than bronze and will outlast steel or galva-
nized pipe when properly installed and supported. Future
repairs are also much easier to make if PVC pipe is used.
The pump on the brine system is most often made of
brass which offers some additional protection from the brine
solution. The impeller should be bronze and the shaft
stainless steel. A strainer or screen cevice should be in-
stalled ahead of the pump on the suction side.

Most treatment plants buy salt to make their brine solution

in bulk form. Regardless of the salt supplier, a certain
amount of insoluble material will accompany each bulk Wet salt storage brine tanks are another location at a
delivery This insoluble material will consist of rocks, coal.
water treatment plant where sanitary defects may develop.
sand and other particles that can clog or destroy an impeller
The make-up water line must have a free fall or air gap
if they reach the pump. Check the strainer assembly on the
someplace in the system to prevent the backflow of a brine
brine pumps quite often and keep spare parts on hand in
solution into the potable water supply. The brine tanks must
case replacement is required.
be protected from contamination just like any other water
The use of packing on the pumps is recommended over storage facility. The cover and access hatches must be of
mechanical seals. Regardless of how well the strainers the raised-lip, overlapping-cover type. All vents must be
perform, a small amount of sand will usually end up in the properly screened to keep out insects, birds, and rodents.
 100 Water Treatment

All areas of maintenance in an ion exchange softening the particulate matter from t` ) resin as possible. A means of
plant cannot be covered here because each plant will differ surface washing the resin must be provided for this proce-
with the type of equipment used and its method of operation dure to be effective Avoid exceeding recommended manu-
Set up a maintenance routine that is characteristic of your facturer s flow rates to prevent washing resin from the unit
treatment plant The objective of the maintenance routine
must be to keep the plant operating and hold repair costs to A chemical cleaner can be used to remove heavy iron
a minimum coatings from the resin itself. These cleaners are mostly
sodium bisulfite and can be mixed in solution form and
QUESTIONS poured into the softener. The bisulfite could also be added to
the resin during the regeneration stage by dumping a
Write your answers in a notebook and then compare your concentrated powder form in with the brine solution. Consult
answers with those on page 110. the resin supplier or manufacturer before using any cleaner
on the resin
14 15A What could happen if a valve fails to open or close
during a regeneration stage'?
14 15B Why should the brit ie pumps and piping receive
constant aiteist.nn9
14 15C Why is packing on brine pumps recommended over
mechanical seals'?

14.16 TROUBLESHOOTING

14.160 Test Units

Ion exchange softeners. if properly operated and main-
tained. will usugy provide years of trouble-free service. If
problems arise, however, the operator should be able to
identify and correct the situation without a great deal of
difficulty.
The best way to insure that a softener will continue to
operate properly is to occasionally test the unit during
various stages of operation Learn to recognize minor
problems as they develop and make the necessary repairs
before a full scale problem exists
Items an operator shc..ild check on in each stage are
discussed in this section 14.163 Rinse Stage
14.161 Service Stage The rinse stage of the softener should be checked when
tests indicate problemc are developing. The rinse rate is a
In the service stage, while the unit is producing soft water, key factor in keeping thy, softorer functioning properly. If the
hardness tests shoule be r.in on the softener effluent to rinse starts too soon. the brine solution could be forced out
insure the water has a hardness of zero. One grain hardness of the unit before adequate contact time has elapsed. If the
per gallon of water (17 1 mg/L) showing up in the effluent rinse rate is too low. all the waste material might not be
should not cause alarm, but concentrations of hardness removed from the unit before it goes into the service stage.
higher than one grain hardness per gallon signal the need to
investigate the softener s operation more closely. The rate settings on the unit should be compared, on all
stages. against the actual manufacturer's recommended
14.162 Backwash Stage settings As equipment ages. it wears. Over a period of time,
valves might need adjustment to keep the unit operating
Check the backwash stage for adequate flow rates and within the manufacturer's guidelines.
full extent of the time required to complete the stage Unless
the rate is high enough to remove trapped turbidity particles 14.164 Brine Infection Stage
and other insoluble material that is trapped in the resin, a
loss of softener efficiency could result The brine injection stage of the softener sequence must
be correctly applied or the unit will not perform satisfactorily
Check the timer on the backwash star ; to make sure the when it returns to service. If the resin is not regenerated
unit is washed for the required length of time. during this stage, there will be no sodium ions to exchange
If high iron concentrations have been applied to the with the hardness ions in the water when the water is applied
softener, check the condition of the resin by visually inspect- to the unit
ing the top layer of the bed Color is a key factor to watch for The brine storage area should always contain enough salt
in units beginning to show signs of an iron-fouled resin. The to provide a brine so'ution when make-up water is added.
resin will be an orange, rusty color, while the backwash
effluent will appear a light orange at the end of the backwash Also check the amount of salt solution that is pumped into
stage Also, the head loss on the unit will run higher than the softener This is usually done with a meter that is preset
normal as the bed becomes plugged with iron. to deliver the exact amount of brine solution required to
regenerate the softener. If a brine solution is less than
If iron fouling appears to be a problem, the length of the saturated, longer contact time is required between the
backwash stage should be increased to wash as much of media and the solution

i
116
 Softening 101

The required amount of solution must be delivered consis- evenly to the top of the resin bed If the pipe work is
tently to achieve a successful regeneration of the unit. If deteriorating from the brine solution, PVC pipe should be
hardness leakage appears early in the service or softening used as a replacement.
stage, check the amount and saturation of brine solution in
the brine system since these are the main reasons for If the resin and gravel support material is removed from
hardness leakage. the softener. check the underdrain structures in the unit and
repair any problems you discover. In filling the unit with
If hardness leakage is excessive immediately following a gravel and resin, each zone of the bed should be leveled and
regeneration stage, shut the unit down and check the media sized according to manufacturer's specifications.
level. The bed could bP disrupted from excessive backwash
or rinse rates. Iron fouling could also cause a channeling The procedure for filling a unit with water after a total
condition to occur and cause the water to short-circuit shutdown is very important. The flow into the unit should be
through the media without contacting the complete bed from the bottom at a slow, controlled rate. This is done by
volume. putting the unit in 'he backwash position, running water into
the unit from the bottom and out the backwash effluent
valve. The purpose of this procedure is to fill tie unit with
QUESTIONS water and purge the air that was trapped in the resin and
Write your answers in a notebook and then compare your softener during the replacement process.
answers with those on page 110. filled the backwash rate should be
After the unit is
14.16A What is the maximum hardness level expected in increased to normal and continued until the effluent is clear.
the effluent of a properly operating ion exchange Again, care should be taken when banging the rates up to
softener before the operator should investigate the the manufacturer's recommendations, to prevent disrupting
operation? or displacing resin from the bed.
14.16B What is the purpose of the backwash stage of an Once the unit has been satisfactorily backwashed, the bed
ion exchange softener operation? should be regenerated. This can be accomplished by run-
ning the softener through a normal brine and rinse proce-
14.16C What problems may occur 4 the rinse rate starts too dure before it is returned to service. Run a hardness test on
soon or is too slow? the effluent to insure all stages have performed correctly
14 16D What would you do if hardness leakage is exces- and the unit is softening water.
sive immediately following a regeneration stage?
QUESTIONS
Write your answers i:i a notebook and then compare your
answers with those on page 110.
14.17A Why must ion exchange softeners be drained and
filled slowly during startup and shutdown?
14.17B What should be done if the pipe work in an ion
exchange softener is deteriorating from the brine
solution?

14.18 ION EXCHANGE ARITHMETIC

14.17 STARTUP AND SHUTDOWN OF UNIT Hardness is usually expressed as mg/L of CaCO3. In ion
At times it becomes necessary to shut a unit down and exchange softening, however, hardness is most often ex-
take it out of service for repairs or inspection. If the operator pressed in terms of grains per gallon or grains of hardness
will follow common sense guidelines, no problems should removed from the water being treated.
arise from unit shutdowns.
When dealing with these units, drain and fill them slowly.
This will prevent surging of the media which will either wash
it out of the unit or disrupt it. thus making the media uneven
and creating channeling problems. If you suspect problems
with a unit, the last thing you want to do is make the situation
worse by rapidly backfilling or backwashing the softener.
Most units are equipped with automatic air release valves
(Figure 14.15). Be certain these valves are operating proper-
ly, because the venting of trapped air is an important step in
filling a unit after it has been shut down.
During unit shutdown, make a complete visual inspection.
Now is the time to detect and correct minor problems that
might otherwise develop into bigger ones. Check the brine
inlet distributors while the unit is down. They should be
visible from the top hatch on most softeners.
Make sure the pipe work is leve; and the nozzles or The exchange capacity of most softeners is expressed as
openings are not clogged. The distributors play an important kilograms (1000 grains) of hardness removed per each cubic
role in the regeneration stage by applying the brine solution foot of resin.

117
102 Water Treatment

AIR RELEASE ASSEMBLY

AIR DISCHARGE AIR PLU

AIR RELEASE VALVE VALVE 3

//
//
SUMP

///////////
Pressure aeration and pressure filtration type filter plants require an automatic air release
assembly to prevent accumulation of an excessive volume of air in the pressure filter tanks.
This air release assembly consists of an automatic air release valve, and necessary pipe,
valves and fittings to install on filter tank. The air release valve is a float operated type and
must be installeJ with center !me of valve level with or above top oa filter tank,. Air from top
of filter enters air release valve at top connection and water from filter inlet pipe enters
valve at bottom connection. Excessive air from filter fills valve body with air forcing water
level down and thereby allowing float to drop. Downward movement of float allows excessive
air to escape through the needle valve until an air-water pressure balance is restored.
In normal operation valves I and 3 are open and valve 2 is closed. To flush air release valve
close valve I and open valve 2 which allows water from top of filter to flush down through the
valve to the drain. Valve 3 is left open at all times unless it is necessary to remove air re-
lease valve.

Figure. 14.15 Air release assembly

Oermission of General Filter Company)

118
 Softening 103

Salt in solution form is u sed to regenerate ion exchange Exchange Capacity = (Removal Capacity. grams /cu ft) (Media Vol. cu ft)
grains
softeners. The the oretical s alt requirement is 0.17 pounds of
salt for 1000 grains of ha rdness removed. Most regenera- Water Treated Exchange Capacity, grains
tions, however, require 0.3 to 0.5 pounds of salt per 1000 gal Hardness Removed. grains/gal
grains of hardness remo val,
Operating Time. hr (water Treated. gal) (24 hr/day)
In this section you will learn how to calculate the volume of (At a Given Row
Ave Daily Flow. gal/day
Rate Before Re-
the brine solution requi ed to regenerate the softening unit generation)
as well as the pounds of salt required for regeneration. The
concentration of brine solution used at each treatment plant To determine the amount of salt required for regeneration,
may vary. Table 14.6 lists the pounds of salt present in the you need to know the pounds of salt per 1000 grains
percentage of brine s olution being used. required for regeneration. To calculate the gallons of brine
required for regeneration, you need to know the percent
FORMULAS AND CONVERSION FACTORS brine solution or the pounds of salt per gallon of brine.
Hardness is usua liy expressed as milligrams of hardness Salt Needed _ (Salt Required. lbs/1000 gr) (Hardness Removed. gr)
lbs
per liter of water a s CaCO3.
Brine, Salt Needed, lbs
Treatment for hardness is often discussed as grains of gallons Salt Solution. lbs salt/gallon of brine
hardness per gall on of water.
1 grain per gallon = 17.1 milligrams per liter EXAMPLE 6
Of 1 gpg = 17.1 mg/L How many milligrams of hardness per liter are there in a
7000 grains = 1 pound water with 16 grains of hardness per gallon of water?

To convert gr ains per gallon to milligrams per liter, Known Unknown

(Hardness, grains/gallon)(17.1 mg/L) Hardness, gpg = 16 gpg Hardness, mg/L

Hardness, m
1 gpg 1 Calculate the hardness of the water in milligrams per liter.

To convert milligrams per liter to grains per gallon, (Hardness, grains/gallon) (17.1 mg/L)
Hardness, mg/L-
1 grain/gallon
Hardness. (Hardness, mg/L)(1 gpg)
grains/o allon 16 grains/gallon) (17 1 mg/L)
17.1 mg/L
1 grain /gallon
To find the exchange capacity of a softener, you need te
know th e removal capacity of the softener in grains per cubic - 2-/ 4 mg/L
foot of esin or in kilograins per cubic foot of resin and the
volume of the resin in cubic feet. EXAMPLE 7
Convert the hardness of a water at 290 mg/L to grains per
TABLE 14.6 SALT SOLUTION CHARACTERISTICS gallon
Known Unknown
Percent NaCI
or grams per Lbs NaCI Lbs NaCI Hardness, mg/L = 290 mg/L Hardness, grains/gallon
100 grams of Specific Gravity Salameter per per
solution at 15°C or 59°F Degree U.S. gal Cu Ft 1. Convert the hardness from milligrams per liter to grains
per gallon
1.0 1.0073 4 0.084 0.63
20 1.0145 8 0.169 1.27
Hardness, (Hardness mg/L) (1 grain/gallon)
3.0 1 0217 11 0.255 1.91
4.0 1.0290 15 0 343 2.57 grains/gallon 17.1 mg/L
5.0 1 0362 19 0 432 3.23
6.0 1.0437 23 0.522 3.90 (290 mg/L) (1 grain/gallon)
70 1.0511 27 0.612 4.59 17.1 mg/L
8.0 1.0585 30 0.705 5.28
90 1.0659 34 0.799 5.98 = 17 grains/gallon
10 0 1.0734 38 0.874 6.69
11.0 1.0810 42 0.990 7.41
EXAMPLE 8
12 0 1 0885 45 1.09 8.14
13.0 1.0962 49 1.19 8.83 An ion exchange softener contains 50 cubic feet of resin
14.0 1.1038 53 1 29 9.63 with a hardness removal capacity of 20 kilograins per cubic
15.0 1.1115 67 1.39 10.4 foot of resin. The water being treated has a hardness of 300
16.0 1.1194 60 1 49 11.2
mg/L as CaCO3. How many gallons of water can be softened
17 0 1.1273 65 1.60 12.0
18.0 1.1352 68 1.70 12.7 before the softener will require regeneration?
19.0 1.1432 72 1.81 13.5 Known Unknown
20.0 1.1511 76 1.92 14.4
21.0 1.1593 80 2.03 15.2 Resin Volume, = 50 cu ft Water Treated, gal
22.0 1.1676 84 2.14 16.0 cu ft
23 0 1 1758 87 2.25 16.9
24.0 1.1840 91 2.37 17.7 Removal Capacity, = 20,000 grains/cu ft
25.0 1.1923 95 2.48 18.6 gr/cu ft
26.0 1.2010 99 2.60 19.5
26.4 1.2040 100 2.65 19.8 Hardness. mg/L = 300 mg/L

119
104 Water Treatment

1 Convert the hardness from mg/L to grains per gallon 4. 7ind the length of time the softeners can run before
Hardness. (Hardness mg/L) (1 grain/gallon) requiring regeneration.
grains/gallon 17.1 mg/L Operating Time, (Water Treated, gal)
hr
(300 mg/L) (1 grain/gallon) (Ave Daily Flow. gal/min)(60 Minihr)

17.1 mg/L (861.429 gal)

17 5 grains/gallon (500 gal/min)(60 min /hr)

= 28 7 hours of operation before regeneration
2 Calculate the exchange capacity of the softener in grains is required
L. change (Resin Vol cu ft) (Removal Capacity grains/cu ft)
Capacity
grains (50 cu it) (20 000 grams /cu ft)
1,000 000 grains of removal capacity

3 Calculate the volume of water in gallons that may be

treated before regeneration
Exchange Capacity, grains
Water Treated. gal
Hardness. grains/gallon
1.000,000 grains
17.5 grains/gallon
57.143 gallons
Therefore. 57.000 gallons of water with 17.5 grains of
hardness per gallon of water can be treated before the resin
becomes exhausted
EXAMPLE 9
An ion exchange softening plant has two softeners that
are eight feet in diameter and the units have a resin depth of
six feet. The resin has a 20 kilogram removal ability. How
many gallons of water can be treated if the hardness is 14
grains per gallon? If the flow rate to the softeners is 500
gallons per minute, how long will they operate before
regeneration is required?
Known EXAMPLE 10
Unknown
Whitler of Softeners = 2 Softeners 1. Water An ion exchange softener will remove 1,000,000 grains of
Diameter, ft = 8 ft Treated, gal hardness before the resin becomes exhausted. If 0.3
Resin Depth, ft 2. Operating pounds of salt are required per 1000 grains of hardness,
= 6 ft
Time, hr how many pounds of salt are needed? If a 15 percent salt
Exchange Capacity, = 20,000 grains/cu ft solution is used to regenerate the unit, how many gallons of
gr/cu ft brine are required? Table 14.6 indicates that 1.39 pounds of
Hardness, = 14 grains/gallon salt is present in each gallon of 15 percent brine solution.
grain/gallon
Known Unknown
Flow, gallons/min = 500 gallons/min
Hardness Removal, = 1,000,u00 grains 1 Salt Needed, lbs
1. Calculate the total volume of softener media grains
2 Brine, gal
Resin Vol, = (0.7b5)(Diameter, ft)2(Depth, ft)(No. Softeners) Salt Required, = C.3 lbs/1000 gr
cu ft lbs/1000 gr
= (0.785)(8 ft)2(6 ft)(2 Softeners) Salt Solution, = 1.39 lbs/gal
= 603 cu ft lbs/gal

2. Calculate the total exchange capacity of the two soften- 1 Determine the pounds of salt needed for regeneration.
ers in grains. Salt Needed. = (Salt Required, lbs/1000 gr)(Hardness Removed, gr)
Exchange = (Resin Vol, cu ft)(Removal Capacity, grains/cu ft) lbs
Capacity,
= (603 cu ft)(20,000 grains/cu ft) (0 3 lbs Salt)(1,000,000 grains)
grains
(1000 grains)
= 12,060,000 grains, removal capacity of the beds
= 300 lbs of salt
3. Calculate the volume of water in gallons that may be
treated before the resin is exhausted. 2. Find the gallons of brine solution required.
Water Treated, Exchange Capacity, grains Salt Needed, lbs
gal Brine, gal =
Hardness, grains/gallon Salt Solution, lbs/gallon of brine
12,060,000 grains 300 lbs of Salt
=
14 grains/gallon 1.39 lbs of salt /gallon of brine
= 861,429 gallons can be treated before = 216 gallons of brine
resin is exhausted (15 percent salt solution)

120
 Softening 105

EXAMPLE 11 14 18B An ion exchange softener contains 60 cubic feet of

resin with a hardness removal capacity of 25 kilo -
Use the same information as in Example 10, except use a grains per cubic foot of resin. The water being
12 percent brine solution. Table 14.6 indicates that 1.09 treated has a hardness of 250 mg/L as CaCO3. How
pounds of salt ale present in each gallon of 12 percent brine many gallons of water can be softened before the
solution. Three hundred pounds of salt are needed for softener will require regeneration')
regeneration. How many gallons of 12 percent brine solution
is required') 14.19 BLENDING
Known Unknown Ion exchange softeners wilt produce a water with zero
Salt Needed, = 300 lbs Brine, gal hardness Water with zero hardness must not be sent into a
lbs distribution system. Water with zero hardness is very corro-
Salt Solution, = 1.09 lbs/gal sive and ov Jr a period of time will attack steel pipes in the
lbs/gal system and create red water problems. Also, to provide a
water supply with zero hardness water would be very
1. Find the gallons of brine solution required. expensive.

Brine, gal = Salt Needed, lbs At most softening plants, the zero hardness effluent from
Salt Solution, lbs/gallon of brine the softeners is mixed with filtered water having a known
hardness concentration. In other words, a certain amount of
300 lbs water the treatment plant produces will bypass the softening
1.09 lbs/gal units (spit treatment). This water has a known hardness
concentration and is mixed in various proportions with the
= 275 gallons of 12 percent brine solution softener effluent to arrive at a desired level of hardness in
the finished water (Figure 14.16).
NOTE: More gallons of brine solution are required when
using a 12 percent brine solution than when using a An example would be a treatment plant that has a filtered
15 percent soidtion. The weaker concentration re- water hardness of 16 grains/gallon. If the desired plant
quires more gallons to achieve the same results. effluent hardness is 8 grains/gallon, fifty percent of the plant
influent must be softened and tne other fifty percent would
be filtered water mixed together with the softener effluent.
QUESTIONS The result would be water that has a hardness of 8 grains
per gal' 3n.
Write your answers in a notebook and then compare your
answers with those on page 110.
The blending of water is very simple and is usually
controlled by a valve and meter. The operator adjusts the
14.18A A source water has a hardness of 150 mg/L as exact gallons per minute bypassing the softener to produce
CaCO 3' What is the hardness in grains per gallon') the desired hardness

UNSOFTENED WATER

FLOW CONTROLLER

BY PASS ADJUSTABLE
WATER ORIFICE
?Is
SOFTENER
)11n
to:g,
>01:
BY PASS METER
OPTIONAL

L CONTROL
LINE
BLENDED WATER

TREATED
FIXED WATER
ORIFICE
Fig. 14.16 Automatic softener bypass
(Permission of General Filter Company)
 106 Water Treatment

FORMULAS 2 Determine the total flow produced by the plant per

To calculate the bypass flow in gallons per day to blend regeneration.
water, determine the total flow, the filtered water hardness Total Flow, gal = Softener Capacity, gal 4 Bypass Water, gal
and the desired effluent hardness.
= 105,000 gal + 52,500 gal
The softener capacity iii gallons and both the softener and
= 157,500 gallons
bypass flows in gallons per day are needed to determine the
volume of bypass water.
14.20 RECORDKEEPING
The total flow produced by the plant before egeneration
Keeping correct and up-to-date records is as important as
is the sum of the flows through the softener and the bypass
flow. performing scheduled maintenance on a regular routine. The
recordkeeping system should be set up to record data on a
Bypass Flow, GPD= (Total Flow, GPD)(Plant Effl Hardness, gpg) daily basis. Record the total flow through the softener each
Filtered Hardness, gpg day, along with the blend rates and gallons that have
bypassed the unit. The total gallons of brine used each day,
Bypass Water, gal = (Softener Capacity, gal)(Bypass Flow, GPD) along with the pounds of salt used to keep the ion exchange
Softener Flow, GPD softener in good working order should be recorded. Records
of the tests performed on the softeners should be kept up-
Total Flow, gal = Softene Capacity, gal + Bypass Water, gal
to-date in order to warn the operator of any problems that
might be developing with the softening unit. Good records
EXAMPLE 12
are an impc-tant part of a successful treatment plant oper-
A softener plant treats 120,000 gallons per day. The ation Many problems can be avoided or solved with an
filtered water has a hardness of .5 grains per gallon (256 adequate recordkeeping system if you review your daily
mg/L) and the desired hardness in the plant effluent is 5 records and compare them with the normal records to
grains per gallon (86 mg/L) How much water in gallons per determine operating problems.
day must bypass the softener to produce the desired level of
hardness'
QUESTIONS
Known Unknown Write your answers in a notebook and then compare your
answers with those on page 111.
Total Flow, GPD = 120,000 GPD Bypass Flow,
Filtered Hardness, gpg = 15 gpg GPD 14.19A Why is source water blended with the effluent from
Effl Hardness, gpg = 5 gpg an ion exchange softener'
1. Calculate tie bypass flow in gallons per day. 14.20A What records should be kept by the operator of an
ion exchange softening plant'
GPD
(Total Flow. GPD)(Plant Effl Hardness, gpg)
Filtered Hardness. gpg 14.21 ARITHMETIC ASSIGNMENT
(120,000 GPD)(5 gpg) Turn to the Appendix at the back of this manual on "How
(15 gpg) to Solve Water Treatment Plant Arithmetic Problems." In
= 40,000 GPD Section A.52, "Softening," read the material, work the exam-
ple problems and check the arithmetic using your calculator.

EXAMPLE 13 14.22 ADDITIONAL READING

Using the information in Example 12, how many gallons of 1 NEW YORK MANUAL, Chapter 11, "Softening."
water will be bypassed before the softener requires regen-
2 TEXAS MANUAL, Chapter 11, Special Water Treatment
eration? The softener has the capacity to treat 105,000 (Softening and Ion Exchange).
gallons. From Example 12 the bypass flow is 40,000 GPD
and the total flow is 120,000 GPD. Therefore the softener 3 NOTES ON WATER CHEMISTRY, prepared for "Ad-
flow is 80,000 GPD (120,000 GPD 40,000 GPD). What is vanced Water Works Operations," by Michael D. Curry,
the total flow produced by the plant per regeneration? P E , President Curry and Associate Engineers, Inc., P.O.
Box 246, Nashville, Illinois 62263.
Known Unknown
Softener Capacity, = 105,000 gal 1. Bypass Water, gal
gal
2. Total Flow, gal
Softener Flow, GPD = 80,000 GPD
Oypass Flow, GPD = 40,000 GPD
1, Calculate the gallons of water that will be bypassed
before the softener requires regeneration.
Bypass Water, (Softener Capacity, gal) (Bypass Flow, GPD)
gal (Softener Flow, GPD)
(105,01 gal) (40,000 GPO)
80,000 GPD
= 52.500 gallons

1Z2
 Softening 107

14.23 ACKNOWLEDGMENTS 1974-75 seminar series sponsored by Illinois Environ-

mental Protection Agency, and
Portions of the material discussed on ion exchange soft-
ening came from the sources listed below. 3. Riehl, Merrill L., WATER SUPPLY AND TREATMENT,
National Lime Associaiion, 3601 North Fairfax Drive,
1. Bowers, Eugene, "Ion Exchange Softening" in WATER Arlington, Virginia 22201. Price, $10.00.
QUALITY AND TREATMENT, 3rd Ed., American Water
Works Association, Computer Services, 6666 W. Quincy
Ave., Denver, Colorado 80235. Order No. 10008. Price,
members, $41.00; nonmembers, $51.00 eta of Lessoft2cie f 1.42440/44
2. Lipe, L.A. and M.D. Curry, "Ion Exchange Water Soften-
ing," a discussion for v :ter treatment plant operators, 40FITN I NO

DISCUSSION AND REVIEW QUESTIONS

Chapter 14. SOFTENING

(Lesson 2 of 2 Lessons)

Write the answers to these questions in your notebook 17. What types of insoluble material may be found in salt?
before continuing with the Objective Test on page 111. The What problems can be caused by this me 'enal and how
problem numbering continues from Lesson 1. can these problems be prevented?
18. How would you prevent the strainers under the bulk
13. What happens in the resin or media in an ion exchange brine stu-age area from silting in with sand and impuri-
softener during the softening stage? ties?
14. How would you insure that large amounts of resin are 19. How would you determine if iron has fouled the resin of
not being lost during the backwash stage? an ion exchange softener?
15. How would you determine if an ion exchange softener 20. How are ion exchange units filled with water after total
rinse stage has been successful? shutdown?
16. What happens if an ion exchange softener removes iron 21 Why is water with zero hardness not delivered to
.n the ferrous (soluble) or ferric (solid) form? consumers?

SUGGESTED ANSWERS
Chapter 14. SOFTENING

ANSWERS TO QUESTIONS IN LESSON 1 14 2B Determine the total hardness as CaCO3 for a sample
of water with a calcium content of 25 mg/L and a
Answers to questions on page 72. magnesium content of 14 mg/L
14 OA Hardness is caused mainly by the calcium and mag- Known Unknown
nesium ions in water. Calcium, mg/L = 25 mg/L Total Hardness,
141A Excessive hardness is undesirable because it Magnesium, mg/L = 14 mg/L mg/L as CaCO3
causes the formation of soap curds, increased use of Calculate the total hardness as milligrams per liter of
soap, deposition of scale in boilers, damage in some calcium carbonate equivalent.
industrial processes, and sometimes may cause ob- Total Hardness. Calcium Hardness. Magnesium Hardness,
jectionable tastes in drinking water. mg/L as CaCO3 mg/L as CaCO3 mg/L as CaCO3
14.1.i Limitations of the ion exchange softening process - 2 50 (Ca, mg/L) 4- 4 12 (Mg. mg/L)
include (1) an increase in the sodium content of the = 2 50 (25 mg/L) + 4 12 (14 mg/L)
softened water and (2) ultimate disposal of spent = 62.5 mg/L + 57.7 mg/L
brine and rinse waters. = 120 2 mg/L as CaCO3

Answers to questions on page 75. 14.2C Water treatment chemicals which lower the pH when
14.2A Hardness is commonly measured by titration. Individ- added to water include alum, carbon dioxide, chlo-
ual divalent cations may be measured by using an rine (Cl2), ferric chloride, hydrofluosilicic acid and
atomic adsorption (AA) spectrophotometer. sulfuric acid.

12
108 Water Treatment

14.2D Results from alkalinity titrations on a sample of water 14.3D The pH is increased because calcium and magne-
were as follows: sium become less soluble as the pH increases.
Known Therefore, calcium and magnesium can be removed
Sample Size, mL = 100 mL from water as insoluble precipitates at high pH
mL titrant used to pH 8 3, A = 1.2 mL levels.
Total mL of titrant used, B = 5 6 mL 14 3E After the chemical softening process, the scale form-
Acid normality, N = 0.02 N H2SO4 ing tendencies of water are reduced by bubbling
Unknown carbon dioxide (recarbonation) through the water.
1. Total Alkalinity, mg/L as CaCO 3 14 3F Caustic soda softening might be used in place of
2. Bicarbonate Alkalinity, mg/L as CaCO3 soda ash The decision to use caustic soda rather
3 Carbonate Alkalinity, mg/L ac. CaCO3 than soda ash depends on the quality of the source
4. Hydroxide Alkalinity, mg/L as ..;aCO3 water and the delivered costs of various chemicals.

1. Calculate the phenolphthalein alkalinity In mg/L as Answers to questions on page 78.

CaCO3.
14.3G Calculate the .,ydrated lime (Ca(OH)2) with 90 percent
Phenolphthalein A x N x 50.000 purity soda ash, and carbon dioxide dose require-
Alkalinity.
mg/L as CaCO3 rriL of sample ments in milligrams per liter for the water shown
(1 2 mL) x (0 02 N) x 50.000 below.
100 mL Known Softened Water
- 12 mg/L as CaCO3 After Recarbonation
Constituents Source Water and Filtration
CO2. mg/L - 5 mg/L = 0 mg/L
2. Calculate the total alkalinity in mg/L as CaCO3. Total Alkalinity, mg/L = 150 mg/L as CaCO3 = 20 mg/L as CaCO3
Total Hardness, mg/L 240 mg/L as CaCO3 - 50 mg/L as CaCO3
Total Alkalinity, B x N x 50,000 mg2+. mg/L
mg/L as CaCO3 mL of sample - 16 mg/L = 2 mg/L
pH -74 =88
(5 6 mL) x (0 02N) x (50.000) Lime Purity. % = 90%
100 mL
= 56 mg/L as CaCO3 Unknown
Hydrated Lime. mg/L
3. Refer to Table 14.3 for alkalinity constituents. Soda Ash, mg/L
Carbon Dioxide, mg/L
From Table 14.3 we want the second row because
P = 12 mg/L which is less than 1/2T[(1/2) (56 mg/L)
= 28 mg/L]. 1 Calculate the hydrated lime (Ca(OH)2) required in
milligrams per liter.
Therefore,
A = (CO2 mg/L) (74/44)
a. Bicarbonate Alkalinity = T 2P = (5 mg/L) (74/44)
= 56 mg/L 2 (12 mg/L) = 8 mg/L

-- 32 mg/L as CaCO3 B = (Alkalinity, mg/L) (74/100)

= (150 mg/L) (74/100)
b. Carbonate Alkalinity = 2P - 111 mg/L
= 2 (12 mg/L) C=0 Hydroxide Alkalinity = 0
= 24 mg/L as CaCO3 D = (Mg2+ mg/L) (74/24 3)
- (16 mg/L) (74/24 3)
c. Hydroxide Alkalinity = 0 mg/L as CaCO3 = 49 mg/L
Hydrated Lime (A + B + C + D) 1 15
(Ca(OH)2) Feed.-
Answers to questions on page 75. mg/L Purity of Lime, as a decimal

14.3A The minimum hardness that can be achieved by the (8 mg/L + 111 mg/L + 0 + 49 mg/L) 1
lime-soda ash process is around 30 to 40 mg/L as 0 90
CaCO3. (168 mg/L) (1 15)
14.3B Benefits that could result from the lime-soda soften- 0 90
ing process in addition to softening include: = 215 mg/L
1. Removal of iron and manganese,
2. Reduction of solids, 2 Calculate the soda ash required in milligrams per
3. Removal and inactivation of bacteria and virus liter.
due to high pH,
Noncarbonate Total Hardness. Carbonate Hardness,
4. Control of corrosion and scale formation with Hardness, = mg/L as CaCO3 mg/L as CaCO3
proper stabilization of treated water, and mg/L as CaCO3
5. Removal of excess fluoride. = 240 mg/L - 150 mg/L
= 90 mg/L as CaCO3
Soda Ash
Noncarbonate Hardness.
(Na2CO3) =( ) (106/100)
Answers to questions on page 77. Feed. mg/L
mg /L as CaCO3
14.3C The addition of lime to water increases the hydroxide = (90 mg/L) (106/100)
concentration, thus increasing the pH. = 95 mg/L

124
 Softening 109

3. Caculate the dosage of carbon dioxide required 14.5B Excess caustic and unprecipitated carbonate ions
for recarbonation. (pin floc) can be removed from softened water by
Excess Lime,= (A + B + C + D) (0 15) recarbonation. Recarbonation is the bubbling of car-
mg/L bon dioxide through the water being treated to lower
= (8 mg/L + 111 mg/L + 0 + 49 mg/L) (0 15)
the pH. Recarbonation can be accomplished, to a
= (168 mg/L) (0 15) degree, by using source water in the split treatment
= 25 mg/L mode.
Total CO2 (Ca(OH)2 excess, mg/L) (44/74) 14.5C The marble test is used to determine if a water is
Feed, mg/L + (MT.-2 residual, mg/L) (44/24 3)
stable. The Langelier Index is also used to determine
= (25 mg/L) (44/74) + (2 mg/L) (44/24 3) the corrosivity of water.
= 15 mg/L + 4 mg/L
14 5D Suspending a couple of nails on strings in a filter can
= 19 mg/L indicate if the water is stable. If the nails are rusting,
the water is corrosive. If a scale forms on the nails,
then scale is forming on your filter media and in your
Answers to questions on page 81. distribution system.
14.3H In the lime softening process, calcium is precipitated
out as calcium carbonate and magnesium hydroxide.
Answers to questions on page 84.
14.31 Partial lime softening (no magnesium removal) re-
moves hardness caused by calcium ions. This may 14.6A Wooden paddles should be used as cleaning tools on
be referred to as calcium hardness. any slaker in operation. A metal tool will damage the
slaker and could even injure the operator if dropped
14.3J In split lime treatment, a portion of the water is by accident. However, a wooden paddle will likely be
treated with excess lime to remove the magnesium at broken up with no damage to the equipmert or
a high pH. Tne source water (the remaining portion) operator.
is added in the next basin to neutralize (lower the pH)
the excess-lime-treated portion. 14.6B Information on how to safely maintain equipment
may be found in equipment manuals provided by
14.3K Recarbonation is a process in which carbon dioxide equipment suppliers and manufacturers.
is bubbled into the water being treated to convert
carbonate ions to bicarbonate ions to stabilize the
llution against the precipitaticn of carbonate com- Answers to questions on "age 85.
pound;. The pH may also be lowered by the addition
of acid. 14.7A A disadvantage recirculating sludge back to the
primary mix area is that an increase in magnesium
could result.
Answers to questions on page 82. 14.7B Only trial and error will really determine if sludge
14.3L Lime-soda ash softening is used when lime alone will recirculation will serve a useful purpose in your plant.
not remov-3 enough hardness. 14.8A Records should be kept on the amounts of treatment
14.3M Noncarbonate hardness is removed by the addition plant chemicals ordered and the amounts fed.
of soda ash in the chemical precipitation softening
process.
Answers to questions on page 86.
14.9A When selecting the target hardness for a water
Answers to questions on page 82. softening plant, consider the uses of the softened
14 3N Where the daily requirements 'tor lime are small, lime water and the cost of softening.
is usual'y delivered to the water treatment plant in 14.9B If lime added to water does not reduce the hardness
bags. of a water sufficiently, use the optimum lime doc'd
14.30 Considerahle heat is generated if quicklime acciden- and run jar tests with varying soda ash doses. Se!ect
tally gets wet. the soda ash dose that will produce a water with a
softness of around 80 to 90 mg/L.
14.3P Lime may be applied by dry feeding techniques using
volumetric or gravimetric feeders.
Ar vers to questions on page 90.
Answers to questions on page 83. 14.9C The overfeeding of chemicals is a waste of money
and quality control will suffer.
14.4A When the alum dose increases for coagulation, the
lime dose must be increased also. 14.9D What should be the lime feeder setting in pounds per
day to treat a flow of 2 MGD when the optimum rine
14.4B Color can be removed from water by coagulation dose is 160 mg/L9
with alum at low pH values. The high pH values
required during softening tend to "set" the color Known Unknown
which then becomes very difficult to remove. Flow, MGD = 2 MGD Feeder Setting,
Lime Dose, mg11.. = 160 mg11.. lbs/day
Calculate the lime feeder setting in pounds per day.
Answers to questions on page 84. Feeder Setting,_
lbs/day (Flow, MGD) (Lime, mg /L) (8.34 lbs/gal)
14.5A A slight excess of lime can cause a scale to form on
the filter sand, distribution mains, and household = (2 MGD) (160 mg /L) (8.34 lbs/gal)
plumbing. = 2669 lbs/day
110 Water Treatment

14 9E How much soda ash s required in pounds per day to 14.14A The disposal of spent brine is a problem because
remove 40 mg/L hardness from a flow of 2 MGD'' the brine is very corrosive and toxic to many living
Known Unknown things in the environment.
Flow. MGD = 2 MGD Feeder Setting.
Hardness Removed. mg/L = 40 mg/L lbs/day
Answers to questions on page 100.
1 Calculate the soda ash dose in milligrams per liter.
14.15A One valve that fails to open or close during a
Soda Ash, mg/L = (1.1) (Hardness Removed, mg/L) regeneration stage could mean a storage tank full
= (1 1) (40 rng /L) of salty water or no brine.
= 44 mg/L 14 15B Brine pumps and piping must receive cor,stant
2 Determine the soda ash feeder setting in pounds attention because a saturated brine solution is very
per day. corrosive. An uncontained brine leak will only get
worse.
Feeder Setting._ (Flow,
MGD) (Soda Ash. mg/L) (8 34 lbs/gal)
lbs/day 14.15C Packing is recommended over mechanical seals on
(2 MGD) (44 mg /L) (8 34 lbs/gal) brine pumps because sand in mechanical seals will
- 734 lbs/day result in high repair and maintenance costs.

Answers to questions on page 101.

14.16A The maximum expected hardness level in the efflu-
ANSWERS TO QUESTIONS IN LESSON 2 ent from an ion exchange softener should not
exceed one grain hardness per gallon (17.1 mg/L).
Answers to questions on page 95.
14.16B The purpose of the backwash stage is to remove
14 10A The three basic types of softeners on the market trapped turbidity particles and other insoluble mate-
are: rial that is trapped in the resin.
1. An upflow unit, 14.16C If the rinse rate starts too soon, the brine solution
2 A gravity flow unit, and could be forced out of the unit before adequate
3 A pressure downflow unit (the most common). contact time has elapsed. If the rinse rate is too low,
14.10B During the regeneration cycle the softener is taken all the waste material might not be removed from
out of service. Salt in the form of a concentrated the unit before it goes into the service stage.
brine solution is used to regenerate (recharge) the 14.16D If hardness leakage is excessive immediately fol-
ion exchange media. When the brine solution is fed lowing a regeneration stage, shut the unit down and
into the media, the sodium cations are exchanged check the media level. The bed could be disrupted
for calcium and magnesium cations As the brine from excessive backwash or rinse rates. Iron foul-
solution travels down through the media, the sodi- ing could also cause a channeling condition to
um cations are attached to the media while the occur and cause the water to short-circuit through
calcium, magnesium and chloride (from the salt) the media without contacting the complete bed
ions flow to waste. After the regeneration has taken area.
place. the bed is ready to be placed in service again
to remove calcium and magnesium, by ion ex-
change. Answers to questions on page 101.
14.17A Ion exchange softeners must be drained and filled
slowly during startup and shutdown to prevent
Answers to questions on page 97. surging of the media which will either wash it out of
14.11A The source water hardness is the main consider- the unit or disrupt it, thus making the media uneven
ation in determining the length of the service stage and creating a channeling problem.
of an ion erlhange softener. 14.17B If the pipe work is deteriorating from the brine
14.11B The purpose of the backwash stage is to expand solution, PVC pipe should be used as a replace-
and clean the media or resin particles and also to ment.
free any material such as iron and manganese that
might have been removed during the softening
stage. Answers to questions on page 105.
14.11C Ion excnange solteners are regenerated by the use 14 18A A source water has a hardness of 150 mg/L as
of a saturated brine solution CaCO3. What is the hardness in grains per gallon?
14.11D During the rinse stage the softener effluent goes to Known Unknown
waste. Hardness, mg/L = 150 rng/L Hardness, grains/yallon
Calculate the source water hardness in grains per
gallon.
Answers to questions on page 99. (Hardness, mg/L) (1 gpg)
Hardness,
14.12A Hardness should be monitored in the effluent from grains/gallon 17.1 mg/L
an ion exchange softener.
(150 mg/L) (1 gpg)
14.13A High chlorine residual levels applied to softening
units could damage the resin and reduce its life 17.1 mg/L
span. = 8.8 grains/gallon

126
 Softening 111

14.18B An ion exchange softener contains 60 cubic feet of 3 Calculate the volume of water .n gallons that
resin with a hardness removal capacity of 25 kilo- may be treated before regeneration
grains per cubic foot of media. The water being Exchange Capacity, grains
treated has a hardness of 250 mg/L as CaCO3. How Water Treated,
many gallons of water can be softened before the gal Hardness, grams /gallon
softener will require regeneration9 1,500,000 grams
14 6 grains/gallon
Kno. n Unknown
Resin Vol, cu ft = 60 cu ft Water Treated. gal = 102,700 gallons
Removal Capacity, = 25,000 gr/cu ft
gr/cu ft Therefore, 102,700 gallons of water with 14.6
Hardness. mg /L = 250 mg /L grains of hardness per gallon of water can be
treated before the resin becomes exhausted.
1. Convert the ardness from mg/L to grains per Answers to questions on page 106.
gallon.
14 19A Source water is blended with the effluent from an
Hardness, (Hardness, mg/L) (1 grain/gallon)
ion exchange softener so the consumers will re-
grains/gallon 17.1 mg/L ceive water with an acceptable hardness. Deliver-
t250 mg/L) (1 grain/gallon) ing water with zero hardness is very expensive and
_ the water is very corrosive.
17.1 mg/L
= 14.6 grains/gallon 14 20A Records that should be kept by the operator of an
ion exchange softening plant include:
1 T ital daily flow through unit,
2. Calculate the exchange capacity of the softener 2. Blend rates,
in grains. 3 Total daily gallons that have bypassed unit,
Exchange 4 Gallons of brine used each day,
Capacity.- (Resin Vol. cu ft) (Removal Capacity. gr/cu ft)
5. Pounds of salt used each day, and
grains (60 cu ft) (25.000 grains/cu ft) 6. Results of tests performed on source water,
1.500.000 grains of hardness removal capacity softener effluent and blended water

OBJECTIVE TEST
Chapter 14. SOFTENING

Please write your name and mark the correct answers on 5 Recarbonation is a process which causes the precipita-
the answer sheet as directed at the end of Chapter 1. There tion of calcium carbonate
may be more than one correct answer to the multiple choice 1 True
questions.
2. False
TRUE-FALSE
1 Most of the hardness in water is caused by iron. 6 Water which cannot be softened by lime contains car-
bonate hardness
1 True
1 True
2. False
2. False
2 Some industrial processes require softer water than is
produced by municipal water treatment plants which 7 Noncarbonate hardness requires the addition of a com-
soften water pound containing carbonate to soften the water.
1. True 1. True
2. False 2. False

3 The lime-soda ash softening process produces water

with zero hardness. 8 The addition of caustic soda to water can remove both
carbonate and noncarbonate hardness.
1. True
2. False 1 True
2. False
4. Water having a hardness caused by calcium and mag-
nesium bicarbonate ion can usually be softened to an 9. Carbonate hardness is caused by the presence of
acceptable level using lime only. sulfate and chloride ions.
1. True 1. True
2. False EzIse
1 "g.",
112 Water Treatment

10 All three forms of alkalinity can exist at once in a sample 23. The on exchange softener regeneration and brine
of water stages are two different stages.
1 True 1 True
2. False 2. False

11 Quicklime should never be stored close to combustible 24. During the rinse stage the softener effluent goes to
materials. storage.
1. True 1 True
2. False 2. False

12 Do not rub your eyes if they become irritated with lime 25 on exchange softening will remove iron and manga-
dust. nese in either the soluble or precipitate:; form.
1. True 1 True
2. False 2. False
13 When the alum dose is decreased for coagulation, the 25 A .aturated brine solution will attack any unprotected
lime dose for softening can be
metallic surface it comes in contact with.
1. Decreased 1. True
2. Increased.
2 False
14 Recarbonation will actually increase the hardness of the
water slightly. 27 The use of mechanical seals on brine pumps is recom-
mended over packing.
1. True
2. False 1. True
2 False
15. Always wear goggles or a face shield when working
with lime that has been or is in the process of slaking. 28 The brine tanks must be protected from contamination
1. True just like any other water storage facility.
2. False 1. True
2. False
16 Records will help a good operator to be a better
operator 29. If iron fouling appears to be a problem with an ion
1. True exchange softener, the duration of the backwash stage
2. False should be decreased.
1. True
17. An overfeed of lime to some waters will actually in- 2. False
crease the hardness.
1 True 30. If the rinse rate of an ion exchange softener is too low,
2. False all of the waste material might not be removed from the
unit before it goes into the service stage.
18. Ion exchange water softening is a process in which the 1. True
hardness-causing sodium ions are replaced by calcium 2. False
and magnesium ions.
1. True
2. False

19 Hard water has an adverse effect on health.

1. True
2. False MULTIPLE CHOICE

20. Lime softening will remove noncarbonate hardness. 31. Carbonate hardness is caused by
1 True 1. Calcium chloride.
2. False 2. Calcium sulfate.
3. Magnesium bicarbonate.
4. Magnesium chloride.
21. Changes in the hardness of the source water are 5. Magnesium sulfate.
witomatically treated by an ion exchange unit.
1. True 32. The two basic methods of softening a municipal water
2. False supply are
1. Ion exchange and chemical precipitation.
22. At the beginning of the backwash stage, the backwash
2. Ion exchange and lime.
water should be applied at a slow steady rate.
3. Ion exchange and excess lime.
1. True 4. Lime and soda ash.
2. False 5. Lime-soda ash and caustic soda.

128
 Softening 113

33. Regardless of the method used to soften water, con- 41 The chemical feed rates produced by jar tests may not
sumers usually receive a softened water with a hard- produce the exact same results in an actual plant
ness of around because of differences in
1. 30 to 40 mg/L. 1 Coagulant feed
2. 50 to 60 mg/L. 2 Mixing equipment.
3. 80 to 90 mg/L. 3 Sizes and shapes of jars and basins.
4. 140 to 150 mg/L. 4 Water quality.
5. 150 to 200 mg/L. 5 Water temperature.

34. Removal of noncarbonate hardness by chemical pre- 42. Source water quality changes of concern to the opera-
cipitation requires the addition of a compound contain- tor of a lime-soda ash softening plant include changes in
ing
1. Alkalinity
1. Bicarbonate 2. Hardness.
2. Calcium. 3. pH.
3. Carbonate. 4 Temperature.
4. Chloride. 5 Turbidity.
5. Sulfate.
43. A soft to moderately hard water will have a haroness of
35. Items to be considered when deciding whether to Lse mg/L as calcium carbonate.
caustic soda or tne lime-soda ash process to soften
water include 1. 0 to 45
2. 46 to 90
1. Amounts of sludge produced. 3. 91 to 130
2. Costs. 4. 131 to 170
3. Disposal of sludge. 5. 171 to 250
4. Handling and feeding of chemicals.
5. Source water characteristics.
44. The common stages of operation of an ion exchange
softener include
36. Alkalinity exists as
1. Backwash
1. Bicarbonate. 2 Brine.
2. Carbonate. 3 Recarbonation.
3. Hydroxide. 4. Rinse.
4. pH.
5. Service
5. Sulfate.

37. How frequently should alkalinity be measured if the 45. Most ion exchange resins on the market will rei ice ;n
source water for a lime-soda ash process is subject to exchange capacity from grains of hardress
change? Every removed per cubic foot of resin.
. 100 to 500
1. 2 hours.
2. 4 hours. 2. 500 to 1000
3. 8 hours. 3. 1000 to 5000
4. 16 hours. 4. 5000 to 20,000
5. 24 hours. 5. 20,000 to 30,000

38. Which of the following protective devices could be used 46 The backwash duration and flow rate of an ion ex-
to protect you from lime? change softener will vary depending on the
1. Filter mask 1. Amount of alkalinity being removed.
2. Gloves 2. Amount of hardness being removed.
3 Long-sleeved shirt 3. Manufacturer.
4. Safety glasses 4. Temperature of the water.
5. Skin cream 5. Type of resin used.

39. How can the pH of softened water be lowered after lime 47 Which water quality indicators should be monitored in
softening? By the use of the influent to an ion exchange softener?
1. Carbon dioxide gas. 1 Alkalinity
2. Caustic soda. 2 Hardness
3. Hydrochloric acid. 3 Iron and manganese
4. Source water. 4. pH
5. Sulfuric acid. 5. Temperature

40. The most common method of sludge dispusal is 48 Whai type of pipe ma,,nal should be used in a brine
disposal. system/
1. Drying bed 1. Boron
2. Land application 2. Galvanized
3. Landfill 3. Iron
4. Sewer 4. PVC
5. Sludge recirculation 5. Steel

I "
114 Water Treatment

49 What can the operator do if iron fouling appears to be a 51 How many gallons of water v.ith a hardness of 14 grains
problem on an ion exchange softener'? per gallon may be treated by an ion exchange softener
1. Apply a chemical cleaner such as sodium bisulfate with an exchange capacity of 20.000 kilograms'?
2. Decrease the strength of the brine used in the 1 0.70 M Gal
regeneration stage 2 1 07 M Gal
3. Increase backwash flow rates 3. 1 24 M Gal
4. Increase duration of backwash stage 4 1.43 M Gal
5. Increase duration of service stage 5 1.67 M Gal

50 Hardness may be expressed as

52. How many hours will an ion exchange softening unit
operate when treating an average flow of 500 GPM'?
1. Grains per gallon. The unit is capable of softening 1.500,000 gallons of
2. Milligrams per liter water before requiring regeneration
3. Milliliters per liter. 1 25 hours
4. Pounds per day.
2. 30 hours
5. Pounds per million gallons
3. 35 hours
4. 40 hours
5, 50 hours

eta a atieztive fc4t

130
 CHAPTER 15

TRIHALOMETHANES

by

Mike McGuire

131
116 Water Treatment

TABLE OF CONTENTS
Chapter 15. Tnhalomethanes

Page
OBJECTIVES
117
GLOSSARY
118
15.0 The Trihalomethane (THM) Problem
119
15.1 Feasibility Analysis Process
121
15.2 Problem Definition
121
15.20 Sampling
121
15.21 THM Calculations
122
15.22 Chemistry of THM Formation
123
15.3 Control Strategies
124
15.4 Existing Treatment Processes
124
15.5 Treatment Process Research Study Results
124
15.50 Consider Options
124
15.51 Remove THMs After They Are Formed
125
15.52 Remove THM Precursors
126
15.53 Alternate Disinfectants
128
15.6 Selection and Implementation of a Cost-Effective Alternative
128
15.7 Regulatory Update
129
15.8 Summary and Conclusions
129
15.9 Arithmetic Assignment
130
15.10 Additional Reading
130
Suggested Answers
131
Objective Test
132

132
 Trihalomethanes 117

OBJECTIVES
Chapter 15. TRIHALOMETHANES

Following completion of Chapter 15, you should be able

to:
1. Describe how trihalomethanes are formed,
2. Explain why trihalomethanes are a problem in drinking
water,
3. Collect samples for trihalomethane analysis,
4. Identify control strategies for trihalomethanes,
5. Describe treatment processes capable of controlling tri-
halomethanes, and
6. Select and implement a cost-effective means of control-
ling trihalomethanes.

1040;19.44e14I-1 astis
118 Water Treatment

GLOSSARY
Chapter 15. TRIHALOMETHANES

CARCINOGEN (car-SIN -o-den)

CARCINOGEN
Any substance which tends to produce a cancer in an organism.

MAXIMUM CONTAMINANT LEVEL (MCL) MAXIMUM CONTAMINANT LEVEL

The largest allowable amount. MCLs for various water quality indicators are specified in the National Interim Primary Drinking
Water Regulations (NIPDWR).

PRECURSOR, THM (pre-CURSE-or)

PRECURSOR, THM
Natural organic compounds found in all surface and groundwaters. These compounds MAY react with halogens (such as chlo-
rine) to form tnhalomethanes (try-HAL-o-METH-hanes) (THMs), they MUST be present in order for THMs to form.

REPRESENTATIVE SAMPLE REPRESENTATIVE SAMPLE

A portion of material or water that is as nearly identical in content and consistency as possible to that in the larger body of
material or water being sampled.

TRIHALOMETHANES (tri-HAL-o-METH-hanes) TRIHALUMETHAN73

Derivatives of methane, CH,, in which three halogen atoms (chlorine or bromine) are substituted for three of the hydrogen
atoms Often formed during chlorination by reactions with natural organic materials in the water. The resultant compounds
(THMs) are suspected of causing cancer.

VOLATILE (VOL-uh-tull)
VOLATILE
A substance that is capable of being evaporated or easily changed to a vapor at relatively low temperatures. For example, gas-
oline is a highly volatile liquid
 Trihalomethanes 119

CHAPTER 15. TRIHALOMETHANES

15.0 THE TRIHALOMETHANE (THM) PROBLEM EQUATION 1

For the past few decades water utilities have been con- Natural Other
Free
cerned about the presence of organic compounds in drink- + Organics + Bromide THMs +
Chlorine Products
ing water. The analytical methods for detecting inorganic (precursor)
compounds such as calcium, magnesium, and iron have
Free chlorine is added to drinking water as a disinfectant.
been known for many decades. However, the ability to The naturally occurring organics get into water when the
analyze for organic compounds in water has been devel-
water partially dissolves organic materials from algae,
oped only recently. What are organic compounds9 Organic
leaves, bark, wood, soil and other similar materials. This
compounds are defined as those compounds that contain a
dissolved action is similar to what happens when a teabag is
carbon atom. Carbon is one of the ba,:qc chemical elements.
placed in hot water; the water dissolves those parts of the
Examples of organic compounds include: proteins, carbohy-
tea leaves which are soluble organic and inorganic com-
drates, fats, vitamins, and a wide variety of compounds that
pounds. While it is possible to form THMs by reactions
modern technology has created.
between chlorine and industrial organic chemicals, the over-
whelming bulk of THM precursors in water are from natural
organic compounds
One source of bromide is sea water. Water agencies
whose supplies are subject to sea water intrusion can
expect THMs in their treated water to have high levels of
bromide. Bromide reaction products can be found in most
surface waters, even where bromide concentrations are low.
The "other products" formed in this reaction are very poorly
understood and are not regulated at this time.
After THMs were discovered in drinking waters around the
country, several studies were made of the possible health
effects of THMs in general and chloroform (a THM) in
particular. The results of these tests indicated that chloro-
form caused cancer in laboratory animals (rats and mice)
and was suspected of causing cancer in humans. Further
studies comparing people who used different sources of
drinking water suggested that there may be a link between
the presence of man-made organic compounds like THMs
and increased levels of cancer. Animal feeding experiments
and population studies are not definite proof that THMs in
In 1974, researchers with the U.S. Environmental Protec-
drinking water cause cancer. Under the Safe Drinking Water
tion Agency (EPA) and in the Netherlands published their
Act, EPA may pass a regulation for any contaminant which
findings that tnhalomethanes are formed in drinking water
MAY HAVE any adverse health fect.
when free chlorine comes in contact with naturally occurring
organic compounds (THM PRECURSORS'). Trihalometh- On November 29, 1979, the THM regulations were pub-
anes are a class of organic compounds where there has lished in the FEDERAL REGISTER. These regulations wr re
been a replacement of three hydrogen atoms in the methane amended on February 28, 1983 (see Section 15.7, "Regula-
molecule with three halogen atoms (chlorine or bromine) tory Update"). The details of the regulation are covered in
The four most commonly found THMs are chloroform, Chapter 22, "Drinking Water Regulations," and general as-
bromodichloromethane, dibromochloromethane, and bro- pects of the regulation are outlined below:
moform (Figure 15.1). While it is theoretically possible to
form iodine-substituted THMs, they are rarely found in MAXIMUM CONTAMINANT LEVEL: 0.10 mg/L total triha-
treated water and they are not regulated at this time. In lomethanes (TTHMs) sum of the concentrations of
general, methane is not involved in the THM reaction. The chloroform, bromodichloromethane, dibromochloro-
production of THMs can generally be shown as: methane, and bromoform.

1 Precursors, THM (pre-CURSE-ors). Natural organic compounds found in all surface and groundwaters These compourls MAY react
with halogens (such as chlorine) to form tnhalomethanes (try- HAL -o- METH -anes) (THMs) they MUST be present in order for THMs to
form.

I
120 Water Treatment

H H

I
H C H Cl- CI Cl

I
H CI
Methane, CH, Chloroform, CHCI3

Br C Br

Br

Bromoform, CHBr3

H H

Ci C Br CI C Br
t

I
Cl Br

Bromodichloromethane, CHBrCl2 Dibromochloromethane, CHBr2CI

Fig. 15.1 Methane and THMs

1.1G
 Trihalomethanes 121

APPLIES TO All community water systems that add a

TABLE 15.1 FEASIBILITY ANALYSIS PROCESS
disinfectant to their water supply which serve a popula-
tion greater than 10,000 persons. 1 Determine extent of THM problem
MONITORING REQUIREMENTS: Monitoring compliance a Monitor THM levels
based on an annual running TTHM (total trihalometh-
ane) average of four quarters of data. Schedule, loca- b THM chemistry (time of formation)
tions, and numbers of samples depends on system size 2. Evaluate control strategies
and to be worked out with State or EPA.
a Change sources of supply
ENSURINC MICROBIOLOGICAL QUALITY: State or EPA
must be notified of significant modifications to treatment b Treatment options
processes to remove TTHMs in order to ensure micro-
(1) Remove THMs
biological quality of the treated water.
(2) Remove precursors
The MCL for TTHMs was not established on the basis of
the health effects data, but was set as a feasible level for (3) Adjust or modify the chlorine application points
compliance. The supporting material for the regulation
states very clearly that the MCL may be lowered in the future (4) Use alternate disinfectants
to 0.025 mg/L perhaps as low as 0.010 mg/L 3 Evaluate existing treatment processes
The rest of this chapter is devoted to a discussion of how 4. Examine studiez of proposed treatment processes
to collect samples for THM analysis and how a utility can (Bench-, pilot- and full-scale)
evaluate the many alternatives available to control THMs in
its system. This discussion is presented in outline form. A 5 Select a cost-effective option
much more detailed treatment of control techniques for
6 Implement the coosen option
THMs is presented in an EPA publication entitled TREAT-
MENT TECHNIQUES FOR CONTROLLING TRIHALO-
METHANES IN DRINKING WATER, by J.M. Symons, et , 15.2 PROW.EM DEFINITION
September 1981.2 A large part of this chapter is a summary
of material from that source. In order to determine the extent of a THM problem in a
system, a reliable analytical technique must be used THM
analytical services may be developed by the utility or may be
QUESTIONS purchased from a contract laboratory. A discussion of the
THM analytical methods will not be made here; rather, the
Write your answers in a notebook and then compare your reader is referred to the FEDERAL REGISTER publication of
answers with those on page 131. the regulation or to the EPA document prepared by J.M.
15 OA What are THM precursors') Symons which was previously discussed

15 OB Why is free chlorine added to drinking water') 15.20 Sampling

15 OC What is one source for bromide in drinking water, To determine the extent of the THM problem, collect
15.01) How are tnhalomethanes formed') REPRESENTATIVE SAMPLES3 from the distribution sys-
tem of the water utility and analyze them according to an
15.1 FEASIBILITY ANALYSIS PROCESS approved method to determine if the utility is in compliance
with the THM regulation. Of course, four quarters of data are
In any problem solving process, it is useful to follow a needed to make a definite judgment on the MCL. However,
series of prescribed steps that will lead you to the most cost- even one quarter of data can show how close the system will
effective solution. Table 15 1 lists the stages of a feasibility be to complying with the MCL. See Section 15.21, "THM
analysis process that has been used to solve a water utility's Calculations," Exarples 1 and 2 for procedures on how to
THM problem. However, the process outlined in Table 15 1 calculate quarterly average TTHM levels and annual TTHM
is very general and can also be applied to solving other running averages.
treatment or operational problems.
To collect samples to determine THM levels, use the
following procedures.
1 A minimum of four samples per quarter (every three
months) must be taker, on the same day for each treat-
ment plant in the distribution system.
2. Twenty-five percent of these samples must be collected
from the extremities of the distribution system (the points
efffiN, farthest from each treatment plant), and
114 imam, / 0111111111
loam =MAO
3 Seventy-five percent of the five samples must be repre-
2.7;#00e04TEPFEZNt ACke\Ok4 sentative of the population served by the distribution
system.

2 Available from Computer Services, AWWA, 6666 West Quincy Avenue, Denver, Colorado 80235. Catalog Number 20221. Pride to
members, $16.00; nonmembers, $20.00.
3 Representative Sample A portion of material or water that is as nearly identical in content and consistency as possible to that in the
larger body of material or water being sampled.

13/
 122 Water Treatment

Do not collect samples from swivel faucets, faucets with ments, sum up the measurements and divide the total by the
aerators, or faucets with hoses because of the possibility of number of measurements.
contaminating the sample or loss of THMs
Sum of Measurements
To collect samples for THM analysis, use a narrow-mouth Average
screw-cap glass sample bottle that can hold at least 25 mL Number of Measurement,
of water Use a polytetrafluorethylene (PTFE)-f aced silicon- To calculate the running annual average, sum up the
septia bottle-cap liner to provide an airtight seal over the average measurements for each quarter and divide the total
sample bottle. The bottle cap must screw tightly on the by the number of quarters.
sample bottles
Sum of Averages for Each Quarter
Some sample bottles will contain a small amount of a Running Average =
Number of Quarters
chemical reducing agent (usually sodium thsosulfate or soo,
urn sulfite). The reducing agent will stop the chemical Whenever data for a new quarter becomes available, the
reaction that occurs between chlorine and the THM precur- newest quarterly average replaces the oldest quarterly aver-
sors (humic and fluvic acids). By stopping this chemical age and the running annual average is recalculated.
reaction, THMs will not continue to form in the sample after it
has been collected from the distribution system. When using EXAMPLE 1
sample bottles that contain a reducing agent, do not rinse
out the reducing agent before collecting the sample. A water utility collected and analyzed eight samples from a
water distribution system on me same day for TTHMs. The
Some sample bottles will not contain a reducing agent. results are shown below.
Water samples from these bottles will be tested for the
Sample No. 1 2 3 4 5 6 7 8
maximum -oncentration of TTHMs that can form over an
TTHM, mg/L 80 50 70 110 90 120 80 90
extended period of time. These tests cannot be performed if
a reducing agent has been added to the sample. When using What was the average TTHM for the day?
sample bottles that do not contain a reducing 'gent, do not
add any chemicals to the bottles. Known Unknown
When collecting water samples for THM aralysis, use the Results from analysis of Average TTHM level for the
following procedures. 8 TTHM samples day.

1. Turn on the sampling tap, Calculate the average TTHM level in micrograms per liter.
Ave TTHM. Sum of Measurements. pg /L
2. Allow sufficient time (about five minutes) for .he water
temperature to become constant. PgIL Number of Measurements
80 pg/L + 50 pg/L 4- 70 pg /L 1 110;494 + 90 pg/L
3. Fill the sample bottle until a begins to overflow, + 120 pg/L - 80 pg /L -4- 90 pg/L
4. Set the bottle on a level surface and place the bottle-cap 8 measurements
liner on top of the bottle, 690 pg/L
5. Screw the bottle cap tightly on the bottle and turn the 8
bottle upside down, - 86 p94
6. The sample is properly sealed if no air bubbles are
present, and EXAMPLE 2

7. If air bubbles are present, remove the bottle cap and The results of the quarterly average TTHM measurements
bottle-cap liner, turn on the sampling tap and add a small for two years are given below Calculate the running annual
amount of water to the sample in the bottle, and repeat average of the four quarterly measurements in micrograms
steps 4 through 6. per liter.

A good practice is to collect two samples at each location. Quarter 1 2 3 4 1 2 3 4

This procedure allows the laboratory to double check test Ave Quarterly 87 72 99 82 62 111 138 89
results and if a sample bottle is broken, there will be another TTHM, pg/L
sample available for testing.
Known Unknown
Each sample bottle must include a label on which impor- Results from analysis of Running annual average
tant information is recorded. Be sure to write on the label the 2 years of TTHM samples of quarterly TTHM
sample location, date, and name of person collecting the
measurements
sample. Samples should be sent to the laboratory immedi-
ately after they are collected and should be analyzed within Calculate the running annual average of the quarterly TTHM
14 days. When sending samples to the lab, be sure to measurements.
include the complete name and address of the person to
Annual Running TTHM Sum of Ave TTHM for Four Quarters
whom the test results are to be returned. Samples do not
Average, pg/L Number of Quarters
have to be refrigerated during storage. Do not use dry ice
when shipping or storing samples because the water in the Quarters 1, 2, 3, and 4
bottles may freeze and break the sample bottles.
Annual Running TTHM 87 pg/L + 72 ;194 4 99 pg/L + 82 pg/L
15.21 THM Calculations Average. jpgIL 4

340 pg/L
FORMULAS
4

In order to calculate the average of a group of measure- = 85 ;AWL

133
 Trihalomethanes 123

Quarters 2. 3, 4, and 1 may not be the only controlling factor, however; higher levels
Annual Running TTHM 72 ug/L 99 mg/L. - 82 pg/L + 62 mg/L may show up in the winter, as they have in California.
Average. mg/L 4 The higher the pH of the water, the faster the production
315 mg/L of THMs For most water utilities this will not be a concern;
4
however, utilities raising the pH of treated water by caustic
soda or by lime for corrosion control (Langelier Index) or
79 mcl/L using lime softening should he aware that free chlorine in
Quarters 3, 4, 1 and 2 contact with natural organics at a pH of 10.5 or higher will
produce THMs much faster than if the pH were near 7.0.
Annual Runn,ng TTHM 99 yg/L + 82 mg/L + 62 mg/L 111 mg/L
Average, ug /L 4
The higher the concentrations of free chlorine and natural
organics in the water, the more THMs will be produced. In
354 mg/L the past, the amount of tee chlorine that utilities used was
4 only limited by economics and possible taste and odor
= 89 mg/L
complaints from consumers. Careful use of chlorine may
help a utility to lower the THMs in its system. However,
Quarters 4. 1, 2 and 3 because of the danger of using too little chlorine (inadequate
disinfection) in a system, the THM regulation specifically
Annual Running TTHM 82 mg/L 62 mg/L + 111 ug /L - 138 mg/L
Average. ug /L
requires State or EPA approval of major treatment changes
4 to meet the regulation.
393 mg/L
The concentration of precursors in water is as important
4
as the type of precursors that are found in water. Some
= 98 mg/L naturally occurring organic compounds can produce 10 or
100 times the THMs on an equivalent basis as organics from
Quarters 1, 2, 3, and 4 another source. Also, some types of precursors will produce
Annual Running TTHM 62 mg/L + 111 mg/L + 138 ,Ag/L + 89 mg/L THMs faster than others. For this reason it is important to
Average. ug /L 4 evaluate the TTHMFP of each source of supply as a possible
THM control measure.
400 mg/t.
4

= 100 mg/L

SUMMARY OF RESULTS
Quarter 1 2 3 4 1 2 3 4
Ave. Quarterly
TTHM, mg/L 87 72 99 82 62 111 138 89
Annual Running
TTHM Ave., mg/L 85 79 89 98 100

15.22 Chemistry of THM Formation

An understanding of the chemistry of THM formation is
crucial if a water utility is to solve a THM sroblem. Equation 1
shown in Section 15.0, "The Tnhalomethane (THM) Prob- The effect of higher bromide concentrations on THM
lem," describes the overall mechanism. Very Ittle is known production is not as clear as the effects of temperature and
about the specific reactions that free :hlo, ine and natural pH The more bromide present, the more bromide-contain-
organics (precursors) undergo. In general, the effects of ing THMs will be formed. . ree chlorine selectively attacks
time, temperature, pH and concentrations of the chemicals the bromide ion and changes it to brcmine, which reacts
on the production of THIAs have been :- idied by various quickly with precursors to form bromoform, dibromochloro-
investigators and are fairly well understood. methane, and bromodichloromethane. The usual result of
high bromide levels is higher THM levels because the higher
Depending on the type of natural organics present in the molecular weights of these compounds mean more mole-
water, the time it takes for 0.10 mg/L (100 mg/L) of THMs to cules are available for these chemical reactions.
form may range from minutes to days. Set up a THM
monitoring program on the source water(s) of the utility to Now that some of the basics of THM chemistry are
measure the production of THMs over an appropriate time understood and a THM problem can be propsrly defined, it is
period (time from when chlorine is first added to water until time to look at some of the possible control strategies.
water is consumed). A plot of the THMs produced against
time will giv 3 you an idea of the TTHM (Total TriHaloMeth- QUESTIONS
anes) formation potential (TTHMFP) of each source water.
For many systems, a large par, of the production of THMs Write your answers in a notebook and then compare your
will take place after the water leaves the treatment plant. answers with those on page 131.

The higher the temperature, the faster the THMs will be 15 1A List the major steps that a water utility could take to
solve a THM problem.
produced. As might be expected, a dependence on tempera-
ture will probably show up as a seasonal effect higher 15.1B List the possible control strategies that could be
THM levels in the summer than in the winter. Temperature evaluated to control a THM problem.

139
124 Water Treatment

15 2A What important factors influence the production of Using a disinfectant other than free chlorine has a number
trihalomethanes? of advantages and disadvantages that must be evaluated on
a case-by-case basis. Abandoning tree chlorine is a serious
15 2B How does lime used for softening influence the move in view of its superior performance as a disinfectant.
production of THMs?
However, if the alternate disinfectants are the lowest cost
alternative, they must be given careful consideration.

15.4 EXISTING TREATMENT PROCESSES

Before beginning a complex, expensive research pro-
gram, it is valuable to examine how well existing treatment
processes can control the formation of THMs. The following
sections cover the potential of individual processes for THM
control; however, some generalizations can be made with
regard to existing unit processes. Aeration-unit processes
are sometimes available in water treatment plants to control
tastes and odors. The same process may show measurable
removals of THMs after they are formed. Oxidation of tastes
and odors with chlorine dioxide (CI02) and potassium per-
manganate are common unit processes available in water
15.3 CONTROL STRATEGIES
treatment plants. Chlorine dioxide does not form THMs.
Permanganate sometimes can be used to oxidize THM
Assuming that a utility discovers a THM problem in its precursors if they are affected by this kind of treatment.
system, there are two ways to control it change the source
of supply or provide some type of treatment. Changing the Coagulation/sedimentation/filtration and softening pro-
cesses can remove THM precursors depending on the types
source of supply can consist of an entire range of alterna-
tives such as shifting between wells of different quality, that are present in the water supply. Studies at many water
treatment plants have revealed that a significant reduction of
drawing water from different levels in a reservoir, or aban-
doning a surface supply altogether during part of the year.
total organic carbon (TOC) in source water by chemical
Since most utilities do not have the flexibility to abandon a
coagulation often shows very little effect on total trihalo-
source of supply, this alternative will have limited applica- methane (TTHM) formation (which is a disappointment).
tion.
Powdered activated carbon and granular activated carbon
used for taste and odor control can have a limited impact on
The three treatment options available to control THMs are the removal of both THMs and THM precursors.
as follows:
1. Remove THMs after they are formed, QUESTIONS
2. Remove THM precursors before chlorine is added, and Write your answers in a notebook and then compare your
answers with the on page 131.
3. Use a disinfectant other than free chlorine.
15.3A If a utility discovers a THM problem, what are two
A later section will examine each of these options and the ways to control the problem?
processes associated with them. At this point it is useful to
discuss overcli treatment strategies. The general equation 15.3B Why is abandoning the use of free chlorine consid-
for forming THMs MI strates how each of the three options ered a serious move?
can work. 15.4A List the water treatment processes that can be used
to control THMs.
EQUATION 1
Natural
Free Other
+ Organics + Bromide THMs + 15.5 TREATMENT PROCESS RESEARCH STUDY
Chlorine Products
(precursor) RESULTS
Removing THMs after they are formed is generally not the 15.50 Consider Options
strategy of choice unless there is a particular circumstance
at the utility that warrants its evaluation. Since precursors There is a long list of treatment options that can be
are not necessarily removed when THMs are removed, there investigated for the control of THMs. Since a large number
is the problem of continued THM formation, especially in the of them have already been studied and reported on, it is not
distribution system. necessary for every utility to repeat this work. A careful
evaluation of the results published by the U.S. EPA will help
Removing precursors before free chlorine is added has a utility focus on the treatment processes that should be
some major advantages, particularly if the precursors can be looked at on a bench-, pilot-, or full-scale basis.
removed by a fairly inexpensive process. Also, removing
precursors allows the continued use of free chlorine as a Most feasible treatment options include the removal of
disinfectant, which has been proven to be an effective precursor materials prior to the formation of a THM; the
barrier against disease for many decades. As the above avoidance of generation of a THM by use of an alternate
equation shows, fewer precursors also means the formation disinfectant; or the actual removal of a THM via aeration or
of fewer "other products." These other products consist of carbon adsorption. Also the geographic and climatological
high-molecular-weight organic compounds that contain conditions can have a very important influence on the choice
chlorine and bromine,. The health significance of these other of the most desirable process. For example, aeration is not a
products is not known, but concern has been ra;sed by desirable method of treatment where severe cold weather is
regulatory agencies. common.

140
 Trihalomethanes 125

15.51 Remove THMs After They Are Formed water treatment plants currently have an aeration process of
some kind to help control tastes and odors in the source
There are three treatment processes available to remove water The efficiencies of these existii It" processes would
THMs after they have been formed: not be expected to be very great for THM removal.
1. Oxidation
Operators should realize that aeration of treated water
a. Ozone can cause a significant amount of contamination. Air in many
areas may contain large amounts of dust, dirt, bacteria and
b. Chlorine dioxide other contaminants which can contaminate treated water
c Ozone /ultraviolet light and also lead to operation and maintenance problems.

2. Aeration In the research results that are currently available,

counter-current tower aeration (Figure 15.2) has produced
a. Open storage tne highest removals of THMs with air-to-water ratios (the
ratio of the volume of air added to the volun-ie of water
b. Diffused air
treated) in the 20 to 1 to 50 to 1 range. Treatment efficiencies
c. Towers greater than 90 percent removal have been demonstrated
with some aeration towers on some types of wager. Counter-
current aeration towers are designed so that the water and
air pass over a packing material countercurrent to each
other (in opposite directions). A significant amount of theo-
retical work has been done on the possible tower designs
for any given set of treatment condition.. Pilot-scale testing
is usually recommended before a full-scale plant is con-
structed. Aeration is most effective on the more volatile
chemicals. Chlorofc-m is the most volatile of the THMs and
is generally the most easily removed by aeration. Bromo-
form, on the other hand, is the least volatile THM and
consequently is the hardest to remove by aeration. If the
TTHM content of the water contains significant amounts of
bromoform, aeration may not be the most desirable tech-
nique to investigate.

ADSORPTION. THMs can be removed by a wide variety of

activated carbons and synthetic resins. The adsorption
process involves the individual THM compounds leaving the
water and becoming attached to the surface of the carbon or
resin. THMs are generally considered difficult to adsorb on
any surface. The efficiency by adsorption from easiest to
3. Adsorption most difficult is bromoform, dibromochloromethane, bromo-
a. Powdered activated carbon dichloromethane, and chloro'orm.

b. Synthetic resins Powdered activated carbon (PAC) is usually added as a

treatment chemical in the rapid-mix process or in the sedi-
OXIDATION. Oxidation of THMs using aro; one of the mentation basin effluent. PAC is normally used in water
three oxidants listed above has not been very successful. treatment for taste and odor control at dosages of less than
The combination of ozone/ultraviolet light showed some 20 mg/L Studies have shown that PAC dosages of 100 mg/
promise, however, the cost-effectiveness of the process has L or more are necessary to get significant removals of
yet to be demonstrated. THMs Chloroform is particularly difficult to remove w,..1
PAC.
AERATION. In contrast, aeration is an effective process
for removing THMs from water, although the individual
THMs are removed at different efficiencies. THM removal
efficiencies by aeration, ranging from the easiest to most
difficult, are from chloroform to bromodichloromethane to
dibromochloromethane and to bromoform. Allowing water
containing THMs to stand uncovered will ultimately result in
the THMs leaving the water, since they a:e VOLATII E°
.1tompounds that are poorly soluble in water. In other words,
THMs have a natural tendency to migrate from water ;nto the
atmosphere if given the chance. Because of this tendency,
ThM reductions may be noticeable in effluents fmm open,
finished water reservoirs after a significant detention time
(days).

More efficient removal of THMs can be accomplished if

energy is put into the aeration process. A convenient way to
put energy into aeration is by bubbling air into water. Many

4 Volatile (VOL-uh-tull) A substance that is capable of being evaporated or easily changed to a vapor at relatively low temperatures. For
example, gasoline is a highly volatile liquid.

14
126 Water Treatment

Synthetic resins such as XE-340 have been demonstrated In the Southeastern United States in the warmer and
to be effective in removing THMs from water, however, highly organic waters, controlled oxidation levels with small
economics must be taken into consicaration, since the cost doses of ozone can actually coagulate organic material and
of the resins is high in comparison w:th other alternatives make it more efficient for conventional sedimentation. Too
Regeneration of the resins has not been worked out satis- much ozont crri break the organics down to be more
factorily Pilot-scale studies show some promise. but full- reactive with chlorine. However, small controlled doses of
scale applications are not available. ozone may be a,i effective microflocculant and may be
added to conventional water treatment plants to improve the
physical removal of THM precursors to the point that pre-
QUESTIONS chlorination disinfection is possible.

Write your answers in a notebook and then compare your CLARIFICATION The clarification process used in water
answers with those on page 131. treatment plants has the potential for removing significant
amounts of THM precursors. Dozens of studies by the U S.
15 5A Which is the better process for removing THMs after EPA have demonstrated widely varying removal efficiencies
they are formed, oxidation or aeration? (0 to i00 percent) because of the highly variable nature of
15 5B How does the storage of water in uncovered reser- THM precursors from place to place. The use of this process
voirs affect THM levels? to remove THM precursors, which is available in most water
treatment plants, holds great promise for an economical
15 5C How does the adsorption process work? solution to any THM problem. Moving the addition of free
chlorine to a point following the clarification process is the
key to success for this approacn. Many water utilities have
15.52 Remove THM Precursors adopted this approach to solve their problem.
A variety of treatment processes have been investigated ADSORPTION. The use of PAC and GAC are effective in
to remove THM precursors before they come in contact with removing THM precursors; however, the economics of
chlorine. These include: these processes must be carefully evaluated. Dozens of
1. Aeration studies have reported a wide variety of THM precursor
removal efficiencies. Because of the high cost of PAC and
2. Oxidation GAC, their use as THM control methods will be restricted to
those cases where no other alternatives are available.
a Ozone Synthetic resins showed limited removal potential for THM
b. Chlorine dioxide precursors. Effective regeneration of the resins for addition-
al precursor removal has not been demonstra 1.
c. Permanganate
ION EXCHANGE. Anion exchange resins can be effective
d Ozone/ultraviolet light for removing THM precursors which generally have a nega-
c Hydrogen peroxide tive charge. Both strong-base and weak-base anion ex-
change resins have been investigated. As with the activated
3. Clarification carbons discussed above, anion exchange resins will only
find a role in controlling THMs if the economics of the
a Coagulation/sedimentation/filtration treatment process for a particular site are favorable. Dispos-
b. Softening al of the spent regenerant liquid may be a problem.
4. Adsorption
a. Powdered activated carbon
b. Granular activated carbon
c. Synthetic resins
5. Ion Exchange
AERATION. Since THM precursors are not volatile com-
pounds, it is not surprising that aeration is ineffective in
removing them from water.
OXIDATION. All of the oxidants listed above have some
effect on removing or modifying THM precursors. Since
THM precursors vary so much between locations, it is
difficult to generalize on the effectiveness of any of the
oxidants. In fact, some studies have demonstrated that the QUESTIONS
formation potential for THMs can INCREASE with the appli-
cation of certain dosages of ozone and potassium perman- Write your answers in a notebook and then compare your
ganate. In general, it is necessary for bench- and/or pilot- answers with those on page 131.
scale studies to be performed on the water in question
15.5D List the major treatment processes that have been
before the usefulness of any of these oxidants can be investigated to remove THM precursors before they
considered. The U.S. EPA is also concerned with the pro-
come in contact with chlorine.
duction of potentially harmful byproducts that could result
from the use of any of these oxidants. Once again, studies 15.5E What is the key to the success cf using clarification
on the water to be treated are necessary to determine to remove THM precursors from tne water being
whether or not this is a problem. treated?

142
 Trihalomethanes 127

INFLUENT

4.2....13 AIRY
-lib EFFLUENT

Fig. 15.2 Countercurrent aeration tower

143
128 Water Treatment

15.53 Alternate Disinfectants and after a disinfectant change must be provided by the
Removing free chlorine from the chlorine/bromide/precur- utility The THM regulation specifies guidelines that the
sor reaction will stop the formation of any signikant states must use in establishing such a monitoring program.
amounts of THMs. however, free chlorine has been an Guidelines describing conforms, standard plate count. Lir-
bidity, and nutrients are included in the suggested montor-
effective barrier between people and disease-causing bacte-
ria since the beginning of this century, and abandoning its ing list With "before and after" monitoring by the water utility,
use is a very serious step There are other disinfectants Mat it will be possible to determine if there is any significant
can be used instead of free chlorine, but the advantages degradation of the bacteriological quality in the distribution
and disadvantages of each alternative must be carefully system Control of THMs rmist not be accomplished at the
evaluated expense of a higher risk of 21r.tenal and viral diseases
among the population that is being served. Therefore, a
The most commonly considered alternate disinfectants decision to use a disinfectant other than free chlorine must
are ozone, chlorine dioxide, and chloramines. Ozone is a be based on a carefully considered plan A utility that rushes
gas that is produced by passing oxygen through an electri- into the use of an alternate disinfectant without the required
cal discharge While ozone is a highly effective disinfectant, studies is likely to experience many problems that are easily
it is very expensive, it must be generated on site, and it does avoided with proper planning
not leave a residual in the treated water. Chlorine dioxide is a
gas produced by the reaction of free chlorine and sodium
chlorite. Chlorine dioxide is a very effective disinfectant QUESTIONS
which does leave a residual in the treated water: however,
there are some concerns regarding the health implications Write your answers in a notebook and then compare your
of the inorganic breakdown products, chlorite and chlorate. answers with those on page 131.
The THM regulation recommended a 0.5 mg/L limit for the 15.5F What items must be considerea before an alternate
total concentration of chlorine dioxide, chlorite, and chlorate disinfectant is applied to any system?
in water after chlorine-dioxide treatment
15 5G What type of distribution system monitoring must be
Chloramines are produced in water by the reaction be- provided by a utility before and after a disinfectant
tween free chlorine and ammonia. Chloramines are weaker change9
disinfectants than free chlorine, ozone, or colorine dio) ,de,
bu the residuals remain much longer than fme chlorine and 15 5H What water quality indicators should be monitored
they have been used successfully by dozens of water before and after a disinfectant change?
utilities for many years. The effectiveness of monochlora-
mines as a disinfectant depends on water temperature, pH, 15.6 SELECTION AND IMPLEMENTATION OF A
and biological quality, as well as the proper ratio of ammonia COST-EFFECTIVE ALTERNATIVE
to chlorine. For example, the City of Denver has used
chloramines for many years. The use of chloramines can A detailed evaluation of the comparative economics of the
also cause problems in a utility's system unless proper many treatment processes described above is outside the
precautions are taken. Chloramines must be removed from scope of this chapter In many cases, a utility will commis-
the water before it is used in kidney dialysis machines. sion a special cost-effectiveness study that will be accom-
Chloramines in water can pass through kidney dialysis plished in house or by an outside consultant. The U.S. EPA
machines and into a patient's blood where the ammonia will THM treatment manual presents a detailed look at cost
decrease the oxygen carrying capacity of the blood. In estimates for various alternatives with equivalent THM con-
addition, chloramines are toxic to fish in home aquariums, trol levels F.owever, this data is not current and should be
and they must be removed from water before it comes in updated to reflect current economic conditions whenever
contact with them. Dechlorination of water with activated cost studies are conducted.
carbon, ascorbic acid, or sodium thiosulfate will prevent any
If existing processes are not capable of solving a utility's
of these problems if the removal of chloramines is properly
THM problem, the least-cost solution will probably be an
co rolled. Any oxidants that are present in drinking water alternate disinfectant. While no statistics are currently avail-
can cause problems with kidney dialysis machines and fish
able, evidence from discussions with consultants and utility
in home aquariums. However, chloramines are somewhat
managers suggests that alternate disinfectants, especially
more difficult to remove than the other alternate disinfec- chloramines, are the overwhelming least-cost solution for
tants.
water utilities with a THM problem. However, the use of
Before an alternate disinfectant is applied to any system. chloramines may cause problems for persons using kidney
the source of the water supply, water quality and treatment dialysis machines.
effectiveness for bacteriological control must be evaluated.
For example, the use of a weaker disinfectant such as Implementation of a THM control strategy requires a
number Df well defined steps.
chloramines may not be appropriate for a surface water
supply that is highly contaminated with discharges from 1. Full-scale design,
municipal and industnal wastewater treatment plants unless
an extra high dosage and a Ion!! contact time are provided. 2 Construction,
Also, many of the conventional water treatment processes 3 Startup, and
are capable of removing bacteria, viruses and protozoa from
the water (for example, softening and coagulation/sedimen- 4 Operation.
tation/filtration). These conventional processes may help to
provide the required disinfection barrier between a contami- The length of time required to complete these steps will
nated supply and the population served, which could allow depend on the comolexity of the control strategy chosen and
the use of a less potent disinfectant in the distribution the availability of eligineenng services to complete the
system. assigned tasks. Throughout the implementation phase, it is
important that the bench-, pilot-, and full -sc'le tests initiated
Upgraded monitoring of the distribution system before in the feasibility-analysis phase be continued so that the

144
 Trihalomethanes 129

chosen strategy can be refined and optimized. For example, The rule also allows the regulator to require the study of
a pilot plant can be used to train treatment plant operators to Group 2 technologies by water systems where Group 1
use the new technology that will soon be on-line. technologies are not appropriate or sufficient in meeting the
MCL. If a Group 2 technology indicates that it would be
technically feasible and economically reasonable and result
in significant TTHM reductions in line with the cost of
treatment, then The regulator can re:pire the use of a Group
2 technology
The listed Group 2 technologies are introduction of off-line
water storage, aeration, introduction of clarification, alterna-
tive sources of raw water, and the use of ozone as an
alternative or supplement to chlorine for disinfection or
oxidation.
The February 28, 1983, amendment to the THM regula-
tions does not mention granular activated carbon (GAC) or
biological activated carbon (BAC) as treatment alternatives
that must be considered. These two treatment methods
were judged to be too expensive and to not have sufficient
US experience to warrant their evaluation for THM control.
In general, the amendment is designed to reduce the eco-
nomic impact of the THM regulation on those utilities that
have THM problems and limited resources to drastically
QUESTIONS modify their treatment procedures.
Write your answers in a notebook and then compare your Utilities that may be affected by THM regulations are
answers with those on page 131. advised to follow future developments in the FEDERAL
REGISTER.
15.6A If existing water treatment processes are not capa-
ble of solving a THM problem, what is the most likely
least-cost solution?
15.6B What appears to be the most popular alternate
disinfectant?

15.7 REGULATORY UPDATE

On February 28, 1983, the U.S. EPA published in the
FEDERAL REGISTER (page 8406) an amendment to the
THM regulation originally published on November 29, 1979.
The amendment specifies the treatment alternatives that a
utility must consider or investigate in detail before it can
apply for and receive a variance from meeting the MCL as
defined under the regulation. The U.S. Environmental Pro-
tection Agency or the state may require a community water
system to use a "generally available" technology before 15.8 SUMMARY AND CONCLUSIONS
granting a variance. "Generally available" or Group 1 treat-
ment techniques are: 1 Tnhalomethanes are produced wh'n free chlorine, which
is added as a disinfectant, reacts with naturally occurring
1. Use of chloramines or chlorine dioxide as an alternative bromide and organic compounds.
or supplement to chlorine for oxidation and disinfection,
2. A tnhalomethane regulation is now in effect which has
2. Use of chloramines, chlorine dioxide, or potassium per- established a 0.10 mg/L maximum contaminant level and
manganate as an alternative to chlorine for preoxidaticn, monitoring requirements.
3. Moving the point of chlorination in order to reduce THM 3. A feasibility-analysis process is a series of logical steps
formation, to arrive at a cost-effective solution to a THM problem:
4. Improvement of existing clarification, and 1. Determine the extent of THM problem
5. Use of powdered activated carbon (PAC), intermittently a. Monitor
as necessary, to reduce TTHM or THM precursors. The
dosage of PAC is not to exceed an annual average of 10 b. THM chemistry
mg/L.
2. Evaluate control strategies
Any of these technologies may be required in the variance
unless the regulatory agency, USEPA or the state, deter- a. Change sources of supply
mine that such treatment method ... is not available and b. Treatment options
effective for TTHM control for the system." The rule allows
exemption from the use of a technique if the method would (1) Remove THMs
not be technically appropriate and technically feasible for the (2) Remove precursors
system or if the method would result in only a marginal
reduction in TTHM. (3) Use alternate disinfectants

145
130 Water Treatment

3 Evaluate existing treatment processes 15.7B If treatment processes are not technically feasible
nor economically reasonable, then what should utili-
4 Research studies of treatment processes
ties consider?
a. Bench-, pilot-, and full-scale
15.9 ARITHMETIC ASSIGNMENT
5. Select a cost-effective option
Turn to the Appendix at the back of this manual and read
6. Implement chosen option Section A 33, "Tnhalomethanes Work all of the problems
on your pocket calculator. You should be able to get the
4 There are three treatment options available to control same answers.
THMs:
15.10 ADDITIONAL READING
1. Remove THMs after they are formed,
1. TREATMENT TECHNIQUES FOR CONTROLLING TRI-
2 Remove THM precursors before chlorine is added, HALOMETHANES IN DRINKING WATER by James. M.
and Symons, Alan S. Stevens, Robert M. Clark, Edwin E.
3. Use a disinfectant other than free chlorine. Geldreich, 0. Thomas Love, Jr., and Jack DeMarco.
Drinking Water Research Division, Municipal Environ-
5 A water utility must not create a possible health problem mental Research Laboratory, Office of Research and
by ignoring bacteriological safeauards in an attempt to Development, U.S. Environmental Protection Agency,
solve a THM problem Cincinnati, Ohio 45268. EPA-600/2-81-156, September
6. An amendment to the THM regulation specifies treatment 1981. Available from Data Processing Department,
techniques that must be evaluated before a utility may AWWA, 6666 West Quincy Avenue, Denver, Colorado
receive a variance Since this amendment affects a utili- 80235. Catalog Number 20221. Price to members,
$16.00; nonmembers, $20.00
ty's feasibility analysis procedure, the steps outlined in
the amendment should be followed. 2. CHLORAMINATION FOR THM CONTROL: PRINCIPLES
AND PRACTICES. AWWA Computer Services, 6666 W.
QUESTIONS Quincy Ave., Denver, Colorado 80235. Order No. 20181.
Price, members, $12.50; nonmembers, $15.50.
Write your answers in a notebook and then compare your
answers with those on page 131. 3. STRATEGIES FOR THE CONTROL OF TRIHALOMETH-
ANES. AWWA Computer Services, 6666 W. Quincy Ave.,
15 7A What treatment processes must utilities evaluate Denver, Colorado 80235. Order No. 20174. Price, mem-
before applying for and receiving a variance? bers, $12.50; nonmembers, $15.50.

DISCUSSION AND REVIEW QUESTIONS

Chapter 15. TRIHALOMETHANES

Work these discussion and review questions before con- 5 What are the advantages of removing precursors before
tinuing with the Objective ", est on page 132 The purpose of free chlorine is added?
these questions is to indicate to you how well you under-
stand the material in this chapter. Write the answers to these 6 Why might ozone be used prior to clarification and
questions in your notebook. filtration?
1. How are trihalomethanes formed in thinking water?
7 List the three alternative disinfectants to free chlorine and
2. On what basis was the Maximum Contaminant Level the advantages and limitations to each one.
(MCL) for total trihalomethanes (TTHMs) established?
3. What is the influenc.3 of higher temperatures an 1 pH on 8 What items must be considered before an alternate
the production of trihalormtnanes (THMs)? disinfectant is applied to any system?

4. What are some of the options if a water utility decides to 9 What are the advantages of using a p.lot plant in the
investigate changing the source of the water supply? implementation of a THM control strategy?

146
 7 rinalomethanes 131

SUGGESTED ANSWERS
Chapter 15. TRIHALOMETHANES

Answers to questions on page 121. 15.5B THM concentrations should be reduced in waters
15.0A THM precursors are defined as natural organic com-
which have been stored in uncovered reservoirs
because of loss to the atmosphere.
pounds found in all surface and groundwaters The
THM precursors react with halogens (such as chlo- 15 5C The adsorption process involves the individual THM
rine) to form trihalomethanes (THMs); they must be compounds leaving the water and becoming at-
present in order for THMs to form. tached to the surface of the carbon or resin.
15.0B Free chlorine is added to drinking water as a disin-
fectant. Answers to ques*.ons on page 126.
15.0C One source of bromide is sea water. 15 5D The major treatment processes that have been in-
15.0D Trihalomethanes are formed by the reactions of vestigated to remove THM precursors before they
natural organic compounds with halogens (such as come in contact with chlorine include:
chlorine). 1. Aeration,
Answers to questions on page 123. 2 Oxidation (including ozone oxidation prior to co-
agulation and clarification).
15.1A The major steps that a water utility could take to
3. Clarification,
solve a THM problem include
4 Adsorption, and
1. Determine extent of THM problem. 5. Ion exchange.
2. Evaluate control strategies,
15.5E Moving the addition of free chlorine to a point follow-
3. Evaluate existing treatment processes, ing the clanfication process is the key to success
4. Examine research studies of treatment proc- when using clarification to remove THM precursors.
esses,
5. Select most cost-effective option, and
6. Implement selected option. Answers to questions on page 128.
15 1B Control strategies that could be evaluated to control 15.5F Before an alternate disinfectant is applied to any
a THM problem include: system, the source of the water supply, water quality
1. Change sources of supply, and and treatment effectiveness for bacteriological con-
2. Treatment options trol must be evaluated.
(a) Remove THMs, 15.5G Upgraded monitoring (more samples and tests) of
(b) Remove precursors, and the distribution system before and after a disinfec-
(c) Use alternate disinfectants tant change must be provided by a utility.
15 2A Important factors that influence the production of 15.5H Before and after a disinfectant change, the distribu-
trihalomethanes include the effects of time, tempera- tion system monitoring program should include coli-
ture, pH and the types and concentrations of chemi- forms, standard plate count, turbidity and nutrients.
cals.
15.2B Those utilities that use lime softening should be
aware that free chlorine in contact with natural or- Answers to questions on page 129.
ganics at a pH of 10.5 or higher will produce THMs 15 6A If existing water treatment processes are not capa-
faster than if the pH were near 7.0. ble of solving a THM problem, the least cost solution
will probably be an alternate disinfectant.
Answers to questions on page 124. 15 6B Apparently the most popular alternate disinfectant is
15.3A The two types of controlling a THM problem are (1) chloramine3.
change the source of supply or (2) provide some type
of treatment.
Answers to questions on page 130.
15.3B Abandoning the use of free chlorine is a serious
move in view of its superior performance as a 15.7A Treatment processes which utilities must evaluate
before applying for and receiving a variance include:
disinfectant.
15.4A Water treatment processes that can be used to 1. Use of chloramines or chlonne dioxide as an
control THMs include: alternative or supplement to chlorine for oxidation
and disinfection,
1. Aeration, 2. Use of chloramines, chlorine dioxide, or potas-
2. Oxidation with potassium permanganate, sium permanganate as an alternative to chlorine
3. Coagulation, flocculation and filtration, for preoxidation,
4. Softening processes, and 3. Moving the point of chlorination in order to reduce
5. Powdered activated carbon applications. THM formation,
4. Improvement of existing clarification, and
Answers to questions on page 126. 5. Use of powdered activated carbon (PAC), inter-
15.5A Aeration is a much more effective process than mittently as necessary to reduce TTHM or THM
oxidation for removing THMs after they have been precursors. The dosage of PAC is not to exceed
formed. an annual average of 10 mg/L.

147
 132 Water Treatment

15 76 If treatment processes are not technically feasible 3 Introduction of clarification where not practiced,
nor economically reasonable, then utilities must con- 4 Alternative sources of raw water, and
sider. 5 Use cf ozone as an alternative or supplement to
1. Off-line storage for precursor reduction, chlorine for disinfection or oxidation
2. Aeration where appropriate,

OBJECTIVE TEST
Chapter 15. TRIHALOMETHANES

Please write tour name and mark the correct answers on 8. Removal of THMs after they are formed using oxidants
the answer sheet as directed at the end of Chapter 1. There has been very successful.
no-.1y be more than one correct answer to the multiple choice
questions . 1. True
2 False
TRUE-FALSE
1. Trihalomethanes are formed in drinking water when free 9 Aeration is an effective process for removing THMs
chlorine comes in contact with naturally occurring or- from water.
ganic compounds. 1. True
1. True 2 False
2. False

2 The tnhalomethane regulations apply to all community 10 Aeration is an effective means for removing THM pre-
water systems that add a disinfectant to their water cursors
supply. 1 True
1. Tru° 2. False
2. False
11. THM precursors vary considerably between locations.
3. The Maximum Contaminant Level (MCL) for total tn- 1 True
halomethanes (TTHMs) was established solely on the 2. False
basis of health-effects data
1. True
2. False 12. Removing free chlorine from the chlorine/bromide/pre-
cursor reaction will stop the formation of any significant
4. Depending on the type of natural organics present in the amounts of THMs
water, the time it takes for 0.10 mg/L of THMs to form 1. True
may range from minutes to days. 2 False
1. True
2. False 13. A chemical reducing agent is added to THM sample
bottles to stop the chemical reaction between chlorine
5. ',lost THM precursors enter source waters from indus- and the THM precursors.
trial organic chemicals. 1. True
1. True 2 False
2. False

6. The concentration of precursors in water is as important 14 Tnhalomethanes are produced when free chlorine
as the types of precursors that are found in water for the reacts with naturally occurring bromide and organic
production of THMs. compounds.
1 True
1. True
2. False
2. False

7. All types of precursors will produce THMs at the same 15. A water utility may apply for a variance from the THM
rate. regulations.
1. True 1. True
2. False 2. False

I
148
 Trihalomethanes 133

MULTIPLE CHOICE 24 Uxidation treatment processes include

16 Examples of organic compounds include 1 Chlorine dioxide.
1. Calcium. 2. Granular activated carbon
2 Carbohydrates.
3. Ozone.
3. Fats. 4 Powdered activated carbon
5 Synthetic resins
4. Trihalomethanes
5. Vitamins
25. The most commonly considered alternate disinfectants
17. Naturally occurring organics get into water when the to free chlorine are
water partially dissolves organic materials from 1. Chloramines
1. Algae. 2. Chlorine dioxide.
3. Hydrochloric acid
2. Leaves
4 Hypochlonte.
3. Rocks.
4. Salts. 5 Ozone
5. Soils.
26. Dechlonnation of water containing chloramines can be
18. The total tnhalomethanes in water are the sum of the accomplished by the use of
concentrations of 1. Activated carbon.
1. Bromodichloromethane. 2. Ammonia.
2. Bromoform 3 Ascorbic acid.
3 Chloroform. 4. Hypochlonte.
4. Dibromochloromethane. 5 Sodium thiosulfate.
5. Methane.
27. Water quality indicators which should be monitored in
19. The Maximum Contaminant Level (MCL) for total trihat- the distribution system before and after a disinfectant
omethanes (TTHMs) is change include

1. 0.01 mg/L. 1. Chloride.

2. 0 03 mg/L 2. Conforms.
3 0.05 mg/L. 3. Nutrients.
4. 0.10 mg/L 4. Standard plate count
5 Turbidity.
5. 0.20 mg/L.

20. Important factors that influence the production of tribal- 28 The results of the quarterly average TTHM measure-
omethanes include ments for one year are given below. Calculate the
running annual average for the fourth quarter.
1. Concentration of chemicals.
2. Location of chlorine application. Quarter 1 2 3 4

3. pH. Ave Quarterly TTHM, pg /L 63 89 121 72

4. Temperature. 1 43 ug/L
5. Time. 2 68 ug/L
3. 86 ug/L
21. Treatment techniques available to control THMs include 4 93 ug/L
1 Drawing water from different levels in a reservoir. 5 95 pg /L
2. Removing THM precursors before chlorine is added
3. Removing THMs after they are formed.
4. Shifting to a different source.
5. Using a disinfectant other than free chlorine.

22 Which of the following treatment processes are effec-

tive in removing THM precursors?
1. Aeration
2. Coagulation, flocculation and filtration
3. Open storage
4. Potassium permanganate
5. Softening processes

23 Which of the following treatment processes are effec-

tive in removing THMs after they have been formed?
1. Adsorption
2. Aeration
3. Coagulation, flocculation and filtration
4. Oxidation
5. Softening processes end. ii Orieetive're

14J
136 Water Treatment

TABLE OF CONTENTS
Chapter 16 Demineralization
(Removal of Dissolved Minerals by Membrane Processes)

Page
OBJECTIVES . .. 138
GLOSSARY .. .. 139

LESSON 1

16.0 Sources of Mineralized Waters 141

16.1 Demineralizing Processes 142

16.2 Reverse Osmosis 142
16.20 What is Reverse Osmosis? 142
16.21 Reverse Osmosis Membrane Structure and Composition 145
16.22 Membrane Performance and Properties 145
16.23 Def,nition of Flux 146
16.24 Mineral Rejection 146
16 25 Effects of Feedwater Temperature and pH on Membrane Performance 147
16 25 r.ecovary 151

LESSON 2

16.3 Different Types of Reverse Osmosis Plants 153

16.4 Operation 156
16.40 Pretreatment 156
16.41 Removal of Turbidity and Suspended Solids 156
16.42 pH and Temperature Control 156
16.43 Other Potential Scalants 156
16.44 Microbiological Organisms 157
16.45 RO Plant Operation 157
16.46 TypicPI RO Plant Operations Checklist 157
16.47 Membrane Clearing 161
16.48 Safety 162
16.480 Use of Proper Procedures 162
16.481 Chemicals 162
16.482 Hydraulic Safety 162
16.483 Electrical Safety
162

15.E
 Demineralization 137

LESSON 3

16.5 Electrodialysis 163

16.6 Principles of Electrodialysis .. 165

16.60 Anions and Cations in Water .... .. 165

16.61 Effects of Direct Current (D.C.) Potential on Ions ... 165

16.62 Ahion and Cation Membranes and Three-Cell Unit 165

16.63 Multi-compartment Unit . ..... 165

16.7 Parts of an Electrodialysis Unit .. ..... .. 168

16.70 Flow Diagram .. . .... ..... 168

16 71 Pretreatment ... .. . . .. 168

16.72 Pumping Equipment and Piping 168

16.73 D.0 Power Supply . 168

16 74 Membrane Stack 168

16.75 Chemical Flush System 168

16.8 Routine Operating Procedures ... 168

16.80 Design Specifications for Feedwater . . 168

16.81 Detailed Operating Procedures 171

16.9 Safety Precautions 171

16.10 Arithmetic Assignment 173

16.11 Additional Reading 173

Suggested Answers 174

Objective Test .... . ...... . ...... . 176

t- -1
i O.
1
138 Water Treatment

OBJECTIVES
Chapter 16. DEMINERALIZATION

Following completion of Chapter 16, you should be able

to
1 Describe the various demineralizing processes,
2 Explain how the reverse osmosis process works,
3. Operate and maintain a reverse osmosis demineraliza-
tion plant,
4 Explain the principles of electrodialysis,
5. Identify and describe the parts of an electrodialysis plant,
6. Operate and maintain an electrodialysis plant, and
7. Safoly perform your duties around reverse osmosis and
electrodialysis plants.

de-MIN-er- NA*
 Demineralization 139

GLOSSARY
Chapter 16. DEMINERALIZATION

ANGSTROM (ANG-strem) ANGSTROM

A unit of length equal to one tenth of a nanometer or one ten-billionth of a meter (1 Ai ,strom = 0.000 000 000 1 meter). One
Angstrom is the approximate diameter of an atom.

CHELATION (key-LAY-shun) CHELATION

A chemical complexing (forming or joining together) o, Aallic cations (such as copper) with certain organic compounds, such
as EDTA (ethylene diamine tetracetic acid). Chelation is used to prevent the precipitation of metals (copper). Also see
SEQUESTRATION.

COLLOIDS (CALL-bolds) COLLOIDS

Very small, finely divided solids (particles that do not dissolve) that remain dispersed in a liquid for a long time due to their small
size and electrical charge When most of the particles in water have a negative electrical charge, they tend to repel each other.
This repulsion prevents the particles from clumping together, becoming heavier and settling out.

CONCENTRATION POLARIZATION CONCENTRATION POLARIZATION

The ratio of the salt concentration in the membrane boundary layer to tho salt concentration in the water being treated. The
most common and serious problem resulting from concentration polarization is the increasing tendency for precipitation of
sparingly soluble salts and the deposition of particulate matter on the membrane surface.
DEMINERALIZATION (DEE-MIN-er-al-uh-ZAY-shun) DEMINERALIZATION
A treatment process which removes dissolved minerals (salts) from water.

ENZYMES (EN-zimes) ENZYMES

Organic substances (produced by living organisms) which cause or speed up chemical reactions. Organic catalysts and/or bio-
chemical catalysts.

ESTER (ESS-ter) ESTER

A compound formed by the reaction between an acid and an alcohol with the elimination of a molecule of water.

FEEDWATER FE EDWATER
The water that is fed to a treatment process; the water that is going to be treated.

FLUX FLUX
A flowing or flow.

HYDROLYSIS (hi-DROLL-uh-sis) HYDROLYSIS

Chemical reaction in which a compound is converted into another compound by taking up water.

OSMOSIS (oz-MOE-sis) OSMOSIS

The passage of a liquid from a weak solution to a more concentrated solution across a semipermeable membrane. The mem-
brane allows the passage of the water (solvent) but not the dissolved solids (solutes). This process tends to equalize the condi-
tions on either side of the membrane.

PERMEATE (PURR-me-ate) PERMEATE

The demineralized water.

REVERSE OSMOSIS (oz-MOE-sis) REVERSE OSMOSIS

The application of p,-:.*csure to a concentrated solution which causes the passage of a liquid from the concentrated solution to a
weaker solution across a semipermeable membrane. The membrane allows the passage of the water (solvent) but not the dis-
olved solids (solutes). The liquid produced is a demineralized water. Also see OSMOSIS.

15,4
140 Water Treatment

SALINITY SALINITY
(1) The relative concentration of dissolved salts, usually sodium chloride, in a given water.
(2) A measure of the concentration of dissolved mineral substances in water.

SEQUESTRATION (SEE-kwes-TRAY-shun) SEQUESTRATION

A chemical complexing (forming or Joining together) of metallic cations (such as iron) with certain inorganic compounds, such
as phosphate. Sequestration prevents the precipitation of the metals (iron). Also see CHELATION.

SPECIFIC CONDUCTANCE SPECIFIC CONDUCTAW:E

A rapid method of estimating the dissolved-solids content of a water supply. The measurement indicates the capacity of a sam-
ple of water to carry an electrical current, which is related to the concentration of ionized substances in the wate Also called
CONDUCTANCE.

TOTAL DISSOLVED SOLIDS (TDS) TOTAL DISSOLVED SOLIDS (TDS)

All of the dissolved solids in a water. TDS is measured on a sample of water that has passed through a very fine mesh filter to
remove suspended solids. The water passing through the filter is evaporated and the residue represents the dissolved solids.
Also see SPECIFIC CONDUCTANCE.

15,5
 Demineralization 141

Chapter 16. DEMINERALIZATION

(Removal of Dissolved Minerals by Membrane Processes)

(Lesson 1 of 3 Lessons)

16.0 SOURCES OF MINERALIZED WATERS sodium) bonded to negative ions (such as chloride, sulfate,
carbonate) Many of these compounds are soluble in water
As our country's population continues to grow, so does
our demand for more water resources. Traditionally, water
and come from the weathering and erosion of the earth's
surface.
suppes have been obtained from "fresh water" sources.
This -onstantly increasing need for water has started to Fresh water supplies, which have been the major sources
deplete the available fresh water supplies in some areas of of water developed in the past, usually contain less than
the country.
1000 mg/L of total dissolved solids. Secondary drinking
Faced with potential shortages, water planners must now water standards recommend 500 mg/L TDS as the limit
consider new treatment technologies which until recently Waters containing slightly higher concentrations can bf;
were not considered tc economically feasible. Since most used without adverse effects.
of the earth's water supplies are saline (the ocean is high in
dissolved minerals) rather than fresh, these impurities must Brackish water contains from 1000 to 10,000 mg/L IDS
be removed. One process receiving considerable attention (sea water has 35,000 mg/L TDS). Most brackish water is
is demineralization. Demineralization is the process which found in groundwater. Figure 16.1 shows that over one half
removes dissolved minerals (salts) from water. of the United States overlays groundwater containing TDS
levels ranging from 1000 to 3000 mg/L. To date, brackish
AU available water supplies can be classified according to water has not been widely used for municipal drinking water
their mineral quality. All waters contain various amounts of supplies because of its highly mineralized taste and associ-
TOTAL DISSOLVED SOLIDS (TDS)1, including fresh water. ated problems such as scaling in pipes. With the advent of
A majority of the dissolved materials are inorganic minerals new treatment technologies, however, demineralization of
(salts) Minerals are con .)unds commonly found in nature brackish waters (including reuse of wastewater) has great
which consist of positive itetallic ions (such as calcium, potential for further development.

Groundwater containing WOO ppm

or more of minerals

Monerolized woter of depths

ti of more than 500 ft
Fig. 16.1 Map of the conterminous United States showing
depth to and quality of shallowest groundwater containing
more than 1,000 mg/L dissolved solids
from paper by Bill Katz. 'Treating Brackish Water for Community Supplies. published
in Proceedings in "Role of Desalting Technology,' a series of Technology Transfer
Workshops presented by the Office of Water Research and Technology)

1 Total Dissolved Solids (TDS) All of the dissolved solids in a water_ TDS is measured on a sample of water that has passeo through a
very fine mesh filter to remove suspended solids. The water passing through the filter is evaporated and the residue represents the dis-
solved solids. Also see SPECIFIC CONDUCTANCE.

156
142 Water Treatment

1. Mineral concentration in FEEDWATER3 (brackish water

supply),
2 Product water quality required,
3. Brine disposal facilities,
4 Pretreatment required,
5. Need to remove other material such as bacteria and virus,
and
6. Availability of energy and chemicals required for the
The largest available source of water in terms of qualii:, is process.
classified as sea water, which usually contains more than
35,000 mg /L TDS. While sea water may be an important The basic system is similar for all demineralizing pro-
future water resource because of its seemingly unlimited cesses and includes the processes shown in Figure 16.3.
availability in coastal areas, it is more expensive to treat than Since freezing and distillation apply primarily to sea water
brackish water because of its greater TDS concentration. demineralizing and their widespread use seems unlikely,
The purpose of this chapter is to introduce and familiarize these processes will not be discussed. Neither will ion
the water treatment plant operator with the newer treatment exchange because of its limited use for brackish water (1000
processes which have beer. developed to remove the dis- to 3000 mg/L TDS). Currently, activity within the water
solved minerals (TDS) from water. The development of the industry is focused primarily on the membrane demineraliz-
membrane demineralization processes have significantly ing processes, known as reverse osmosis and electrodialy-
reduced the cost of demineralization. This savings, com- sis.
bined with diminished fresh water supplies, will increase the
use of demineralization treatment processes. The large QUESTIONS
quantities of mineralized groundwater and the increased
Write your answers in a notebook and then compare your
SALINITY2 of many rivers and lakes due to waste dis- answers with those on page 174.
charges, agricultural runoff and other uses will increase the
need for demineralization. 16 1 A List the two classes of methods of removing minerals
from water.
Some areas of the United States, such as the Florida Gulf
Coast, are already turning to demineralization. A report by 16.1B List the common membrane demsneralizing pro-
the Office of Water Research and Technology indicates the cesses.
worldwide capacity of brackish water demineralization
plants has increased from zero in 1962 to over 100 MGD 16.2 REVERSE OSMOSIS
(380 MLD or megaliters per day) by 1977. Thus, it is
important that the water treatment plant operator become 16.20 What is Reverse Osmosis?
more knowledgeable concerning the methods used to de-
mineralize water. Osmosis can be defined as the passage of a liquid from a
weak solution to a more concentrated solution across a
QUESTIONS semipermeable membrane. The membrane allows the Pas-
Write your ansr'ers in a notebook and then compare your sage of the water (solvent) but not the dissolved solids
answers with those on page 174. (solutes).

16.0A What is demineralization? Osmosis plays a vital role in many biological processes.
Nutrient and waste minerals are transported by osmosis
16.0B Why is sea water more expensive to treat than through the cells of animal tissues, which show varying
brackish water? degrees of permeability to different dissolved solids. A
striking example of a natural osmotic process is the behav-
16.1 DEMINERALIZING PROCESSES ior of blood cells placed in pure water. Water passes through
Methods of removing minerals from water can be divided the cell walls to dilute the solution inside the cell. The cell
into two classes: (1) those that use a phase change such as swells and eventually bursts, releasing its red pigment. If the
freezing or distillation, and (2) non-phase change methods blood cells are placed in a concentrated sugar solution, the
such as reverse osmosis, electrodialysis and ion exchange. reverse process occurs; the cells shrink and shrivel up as
water moves out into the sugar solution.
Demineralizing processes have primarily been used to
remove dissolved inorganic material (TDS) from industrial
water and wastewater, municipal water and wastewater, and
sea water. However, some processes will also remove
suspended material, organic material, bacteria and viruses.
Application of the various demineralizing processes is par-
tially dependent upon the total dissolved solids (TDS) con-
centration of the water to be treated. Figure 16.2 illustrates
the approximate DS range for use of two phase change
processes (distillation and freezing) and three non-phase
change processes (reverse osmosis, electrodialysis and ion
exchange). The bottom half of Figure 16.4 illustrates osmosis. The
transfer of the water (solvent) from the fresh side of the
The selection of a demineralizing process for a particular membrane continues until the level (shown in shaded area)
application depends upon several factors including: r ses, and the head or pressure is large enough to prevent
2 Salinity (1) The relative concentration of dissolved salts, usually soilium chloride, in a given water. (2) A measure of the concentration
of dissolved mineral substEnces in water.
3 Feedwater. Tne water that is fed to a treatment process; the water that is going to be treated.

157
 Demineralization 143

I
ION EXCHANGE

1
ELECTRODIALYSIS
-1
I
REVERSE OSMOSIS
1
J

FREEZING

DISTILLATION

10 100 1000 10,000 100,000

TDS CONCENTRATION, mg/ L

NOTE: The dashed lines indicate a feasible range of oper-

ation, but not typical range.

Fig. 16.2 Demineralization processes versus

feedwater TDS concentrations

DESALTING PRODUCT...
BRACKISH PROCESS WATER
PRETREATMENT PUMP
WATER SUPPLY 1

BRINE TO WASTE

Fig. 16.3 Basic system for demineralizing processes

144 Water Treatment

REVERSE OSMOSIS-FLOW REVERSED BY APPLICATION OF

PRESSURE TO HIGH CONCENTRATION SOLUTION

PRESSURE

SEMIPERMEABLE
MEMBRANE

CONCENTRATED
)II FRESH WATER
SOLUTION

OSMOSIS-NORMAL FLOW FROM LOW TO HIGH

CONCENTRATION

OSMOTIC
PRESSURE

SEMIPERMEABLE
MEMBRANE

CONCENTRATED
SOLUTION FRESH WATER

Fig. 16.4 Flows through a semipermeable membrane

 Demineralization 145

any net transfer of the solvent (water) to the .nore concen- The modified cellulose acetate membrane in general use
trated solution. At equilibnum, the quantity of water passing today is approximately 100 it thick (that is, 100 microns or
in either direction is equal, the difference in water level 0 ON in.). The membrane is asymmetric (one side different
between the two sides of the membrane is defined as the from the other), having on one surface a relatively dense
osmotic prt.ssure of the solution. layer approximately 2000 A (1 cm = 1 x 108 A or 100 million
Angstroms) or 0.2 micron thick which serves as the rejecting
If a piston is placed on the more-concentrated solution
side of the semipermeable membrane (Figure 16.4) and a
surface. The remainder of the film is a relatively spongy
pressure, P, is applied which is greater than the osmotic porous mass, the membrane currently in use contains
pressure, water flows from the more concentrated solution
approximately two-thirds water by weight, and generally
to the "fresh" water side of the membrane. This condition must be maintained wet at all times.
illustrates the process of reverse osmosis. In recent years, progress in developing new polymeric
materials superior to cellulose acetate membrane have
16.21 Reverse Osmosis Membrane Structure and produced a family of new materials consisting of aromatic
Composition polyamids and polyimides. Although not widely available on
Many matenals have been studied and characterized for
a commercial scale yet, these thin-film composite mem-
possible value as membranes for water purification The branes appaar to have several advantages over the old
cellulose type and are considered to be the membrane of the
best general-purpose membrane developed to date is sim-
ply described as a modified cellulose acetate film. The future
techniques for preparing these membranes were discovered
by Loeb and Sounrajan at UCLA. Table 16.1 lists the 16.22 Membrane Performance and Properties
important characteristics of the common types of mem-
branes. The bz..:,ic behavior of semipermeable cellulose acetate
reverse osmosis membranes can be described by two
equations. The product water flow through a semipermeable
TABLE 16.1 CHARACTERISTICS OF MEMBRANE TYPES membrane can be expressed as shown in Equation 1.
A. CELLULOSE ACETATE CLASS
(cellulose diacetate, cellulose triacetate and blended cel-
lulose diacetate/triacetate) EQUATION 1
1. Membrane must be wetted in storage. I, = A(AP Az)
2. Membrane is susceptible to hydrolysis at high and low Where
pH.
Fw = Water FLUX° (gm/sq cm sec).
3. Membrane is susceptible to deterioration in the pres-
A = Water permeability constant (gm/sq cm sec atm5),
ence of microorganisms capable of cellulose enzyme
production. AP = Pressure differential applied across the membrane
(atm).
4. Membrane is subject to compaction and loss of pro-
ductivity with time. Az = Osmotic pressure differential across the membrane
(atm)
5. Membrane can withstand prolonged maximum oxidant
concentration of one milligram per liter.

B. POLYAMIDE , .EMBRANE Note that the water flux is the flow of water in grams per
second through a membrane area of one square centimeter.
1. Membrane is not subject to biological degradation. Think of this as similar to the flow through a rapid sand filter
2. Membrane is extremely sensitive to oxidants. in gallons per minute through a filter area of one square foot
(GPM/sq ft).
3. Membrane can operate in a pH range of 4 to 11
without hydrolysis. The mineral (salt) flux (mineral passage) through the
4. Membrane can operate at higher temperatures with- membrane can be expressed as shown in Equation 2.
out degradation.

C THIN FILM COMPOSITE EQUATION 2

1. Membrane is wet-dry stable. Fs = B(Ci C2)
2. Membrane has a thin semipermeable barrier which Where
results in a high flux.
Fs = Mineral flux (gm/sq cm sec),
3. Membrane has a high selectivity.
B = Mineral permeability constant (cm/sec),
4. Membrane has an improved resistance to compaction
and bacterial attack. C1 C2 = Concentration gradient across the membrane
(gm/cu cm).
5. Membrane has improved stability at high tempera-
tures.
6. Membrane is stable in acidic (jr' 12) and caustic feed The water permeability (A) and mineral permeability (B)
(pH 12). constants are characteristics of the particular membrane
7. Membrane is sensitive to oxidants. which is used and the processing which it has received.

4 Flux. A flowing or flow.

5 atm. The abbreviatiois foi atmosphere. One atmosphere is equal to a pressure of 14.7 psi or 101 kPa

160
 146 Water Treatment

An examination of Equations (1) and (2) shows that the

water flux (the rate of water flow through the membrane) is
QUESTIONS
dependent upon the applied pressure, WHILE THE MINER- Write your answers in a notebook and then compare your
AL FLUX IS NOT DEPENDENT ON PRESSURE. As the answers with those on page 174.
pressure of the feedwater is increased, the flow of water
through the membrane increases while the flow of minerals 16 2A What is the osmotic pressure of a solution?
remains essentially constant. Therefore, both the quantity 16.26 What type of semipermeable membrane is commonly
and the quality of the purified product should increase with used today?
increased pressure. This occurs because there is more
water to dilute the same amount of mineral. 16.2C What is the meaning of water flux and of mineral
flux? What units are us9d to express measurement
The water flux DECREASES (Fw) as the mineral content of of these quantities?
the feed increases because the osmotic pressure contribu-
tion increases (Aar) with increasing mineral content. In other 16 2D When additional pressure is applied to the side of a
words, since Lar increases, the term (AP oar) decreases membrane with a concentrated solution, what hap-
which results in a decrease in Fw, the water flux. Further, as pens?
more and more feed water passes through the membrane,
16.2E When higher mineral concentrations occur in the
the mineral content of the feedwater becomes higher and
feedwater, what happens to the product water?
higher (more concentrated). The osrotic pressure contribu-
tion (Aar) of the concentrate increases, resulting in a tower 16.23 Definition of Flux
water flux.
The term flux is the expression used to describe the rate
Finally, since the membrane rejects a constant percentage
of water flow through the semipermeable membrane. Flux is
of mineral, product water quality decreases with increased
usually expressed in gallons per day per square foot of
feedwater concentration. Also note that Equation 2 reveals membrane surface or in grams per second per square
that the greater the concentration gradient (C1 C2) across centimeter.
the membrane, the greater the mineral flux (miner i flow).
Therefore, the greater the feed concentration, the greater Even under ideal conditions (pure feedwater and no
the mineral flux and also mineral concentration in the fouling of the membrane surface), there is a decline in water
product water. flux with time. This decrease in flux is due to membrane
compaction. This phenomenon is considered comparable to
Water treatment plant operators must have a basic under- "creep" observed in other plastics or even metals when
standing of these mathematical relationships which describe
subjected to compressing stresses (pressure).
RO (reverse osmosis) membrane perform..-2. To help
develop a better understanding of the interrelationships of The term "flux decline" is used to lescribe the loss of
flux, rejection, time, temperature, pH, and recovery, further water flow through the membrane due to compaction plus
explanation of these variables continues in the next section. fouling. In the real world, feedwaters are never "pure" and
contain suspended solids, dissolved organics and inorgan-
ics, bacteria, and other potential foulants. These impurities
can be deposited or grow on the membrane surface, thus
hindering the flow of water through the membrane.

EXAMPLE 1
Convert a water flux of 5 x 10-4 gm/sq cm sec to
gallons per day per square foot.
Known Unknown
Water Flux, Flow, GPD/sq ft
= 5 x 10- 4 gm/cm-sec6
gm/sq cm-sec
16.24 Mineral Rejection
Convert the water flux from gm/sq cm sec to flow in GPD/
sq ft. The purpose of demineralization is to separate minerals
Water Flux, from water and the ability of the membrane to reject minerals
Flow. (gmlsq cm-sec)(1 liter) (1 Gal) (100 cm)2 (3600 sec) (24 hr) is called the mineral rejection. Mineral rejection is defined as:
GPD/sq ft" (1000 gm) (3.785 1) (3 28 ft)2 (1 hr) (1 day)

(0 0005 gmjsq cm-sec) (1 Liter) (1 Gal) (100 cm)2 (3600 sec) l24 hr) EQUATION 3
(1000 gm) (3 7851) (3 2811)2 (1 hr) (1 day) Product Concentration
10 6 GPDIsq it
Rejer:oton, % = (1 ) x 100%
Feedwater Concentration

6 5 x 10-4 is the same as 0.0005.

16-
 Demineralization 147

Mineral rejections can be determined by measuring the TDS Known Unknown

and using the above equatioh. Rejections also may be Feedwater TDS, mg/L = 1500 mg/L Mineral Rejection, %
calculated for individual constituents in the solution by using Product Water TDS, = 150 mg/L
their concentrations. mg/L
The basic equations which describe the performance of a Calculate the mineral rejection as a percent.
reverse osmosis membrane indicate that rejection de-
creases as feedwater mineral concentration increases. Re- Product TDS, mg/L%)
Mineral Rejection, % = ( 1 )(100
member, this is because the higher mineral concentration Feed TDS, mg/L
increases the osmotic pressure. Figure 16.5 illustrates the
rejection performance for a typical RO (reverse osmosis) 150 mg/L)(100°/0)
=(1
membrane operating on three different feedwater solutions 1500 mq/L
This figure shows that as feed mineral concentration in-
creases (TDS in mg/L), rejection decreases at a given feed =(1 0.1)(100%)
pressure. Notice also that rejection improves as feed pres-
sure increases. = 90%
Typical rejection for most commonly encountered dis-
solved inorganics is usually between 92 to 95 percent.
Divalent ions like calcium and sulfate are better rejected than
QUESTIONS
monovalent ions such as sodium or cnloride. Table 16.2 lists Write your answers in a notebook and then compare your
the typical rejection of an RO membrane operating on a answers with those on page 174.
brackish feedwater.
16.2F Water flux is usually expressed in what units?
16.2G What is "flux decline"?
TABLE 16.2 TYPICAL REVERSE OSMOSIS REJECTIONS
OF COMMON CONSTITUENTS FOUND IN BRACKISH 16.2H How is mineral rejection measured?
WATER

Contamination Units Feedwater Percent

Concentration Remova. 16.25 Effects of Feedwater Temperature and pH on
pmhoS 1400 92 Membrane Performance
ECa
TDSa mg/L 900 92 In reverse osmosis operation, feedwater temperature has
Calcium mg/L 100 99 a significant effect on membrane performance and must
Chloride mg/L 120 92 therefore be taken into account in system design and
Sulfate mg/L 338 99 operation. Essentially, the value of the water permeation
Sodium mg/L 158 92 constant is only constant for a given temperature. As the
Ammonia mg/L 22.5 94 temperature of the feedwater increases, flux increases.
Nitrate mg/L 2.9 55 Usually, flux is reported at some standard temperature
CODS mg/L 12.5 95 reference condition, such as 25°C. Figure 16.6 illustrates the
TOCa mg/L 6.0 88 increase in flux for a standard RO module over a range of
Silver
Arsenic
Aluminum
pg/L
pg/L
pg/L
1.2
<5.0
71.0
-
88

93
operating temperatures when 400 psi (2758 kPa or 28 kg/sq
cm) net operating pressure is applied.
You must remember that the membrane is an ESTER' and
Barium
Beryllium
Cadmium
pg/L
I.g/L
pg/L
24.0
<1.0
3.4
-96

98
therefore sub;Jct to long-term HYDROLYSIS8. Hydrolysis
results in a lessening of mineral rejection capability. The rate
Cobalt pg/L 4.6 >90 of hydrolysis is accelerated by increased temperature, and
Chromium pg/L 3.6 80 is also a function of feed pH (Figure 16.7). Slightly acidic pH
Copper mg/I- 12.7 63 values (5 to 6) insure a lower hydrolysis rate, as do cooler
Iron pg/L 24.0 91 temperatures. Therefore, to insure the longest possible
Mercury pg/L 0.8 41 lifetime of the membrane and to slov. hydrolysis, acid is
Manganese pg/L 1.0 85 added as a pretreatment step before demineralization. Table
16.3 indicates the relative time for mineral passage to
Nickel
Lead
pg/L
pg/L
2.5
<1.0 --
88
increase 200 percent at different feedwater pH levels.
Selenium
Zinc
pg/L
pg/L
<5.0
<100.0 -
a EC, Electrical Conductivity; TDS, Total Dissolved Solids, COD, TABLE 16.3 TIME REQUIRED TO ACHIEVE A 200
Chemical Oxygen Demand, and TOC, Total Organic Carbon PERCENT INCREASE IN MINERAL PASSAGE AT 23°C
AT VARIOUS pH LEVELS

EAAMPLE 2 pH 5.0 6 years

Estimate the ability of a reverse osmosis plant to reject 6.0 3.8 years
minerals by calculating the mineral rejection as a percent. 7.0 1 year
The feedwater contains 1500 mg/L TDS and the product 8.0 0.14 year = 51 days
water TDS is 150 mg/L. 9.0 0.01 year = 3.6 days

7 Ester (ESS-ter). A compound formed by the reaction between an acid and an alcohol with the elimination of a molecule of water
8 Hydrolysis (hi-DROLL-uh-sis). Chemical reaction in which a compound is converted into another compound by taking up water

) .

Po
148 Water Treatment

100

98

1000
5000
10,000
96

94

92 A

90 Id
88

86
SODIUM CHLORIDE REJECTION
VS
APPLIED PRESSURE
STANDARD FLUX MODULE
84

62

80
200 400 600 800 1200 1400

FEED PRESSURE, psi

Fig. 16.5 Typical RO rejection for three different feedwater concentrations of TDS in mg/L
(Source REVERSE OSMOSIS PRINCIPLES AND APPLICATIONS by %ids Systems. Division of tIOP. October 1970)

163
 1:erainereiiiaiion 14?

14.0

50 60 70 80 SO

FEEDWATER TEMP. F°

Fig. 16.6 Effect of temperature on water flux rate, cellulose acetate

membrane operating pressure at 400 psi (2758 kPa or 28 kg/sq cm) net
(Source REVERSE OSMOSIS PRINCIPLES AND APPLICATIONS by Fluids Systems, Division of UOP, October 1970

16i
150 Water Treatment

5
PH
Fig. 16.7 Effect of temperature and pH on hydrolysis rate

165
 Demineralization 151

16.26 Recovery units - 1 unit (85 percent recovery) or 2 units 1 unit (75
percent recovery) are used most often (Figure 16.8).
Recovery is defined as the percentage of feed flow which
is recovered as product water. Expressed mathematically, These configurations consist of feeding water to a series
recovery can be determined by Equation 4 of pressure vessels in parallel where about 50 percent of the
water is separated by the membrane as product water and
EnUATION 4 50 percent of the water is rejected The reject is then fed to
Product Flow half as many vessels in parallel where again about 50
Reco% ary, %, (100%) percent is product water and 50 percent rejected. This reject
Feed Flow becomes the feed for the next set of vessels. By arranging
The recovery rate is usually determined or limited by two the pressure vessels in the 4-2-1 arrangement, it is possible
considerations. The first is the desired product water quality. to recover over 85 percent of the feedwater as product
Since the amount of mineral passing through the membrane water and to maintain adequate flow rates across the
is influenced by the concentration differential between the membrane surface to minimize polarization. For example, a
brine and product, there is a possibility of exceeding product system consisting of a total of 35 vessel:; would have a
quality criteria with excessive recovery. The second consid- configuration of 20-10-5 pressure vessel arrangement for an
eration concerns the solubility limits of minerals in the brine. 85 percent recovery.
One should not concentrate the brine to a degree that would
precipitate minerals on the membrane. This effect is com-
monly referred to as concentration polarization. EXAMPLE 3
THE MOST COMMON AND SERIOUS PROBLEM RE- Estimate the percent recovery of a reverse osmosis unit
SULTING FROM CONCENTRATION POLARIZATION IS with a 4-2-1 arrangement if the feed flow is 5.88 MGD and
THE INCflEASING TENDENCY FOR PRECIPITATION OF the product flow is 5.0 MGD.
SPARINGLY SOLUBLE SALTS AND THE DEPOSITION OF
PARTICULATE MATTER ON THE MEMBRANE SURFACE. Known Unknown

In any flowing hydraulic system, the fluid near a solid Product Flow, MGD = 5.0 MGD Recovery, %
surface travels more slowly than the main stream of the fluid. Feed Flow, MGD = 5.88 MGD
In other words, there is a liquid boundary layer at the solid
surface. This is ail° true at the su, face of the membrane in a Calculate the recovery as a percent
spiral wound eleme .t or in any other membrane packaging
(Product Flow, MGD) (100%)
configuration. Since water is transmitted through the mem- Recovery, %
brane at a much more rapid rate than minerals, the conc9n- (Feed Flow, MGD)
tration of ...,e minerals builds up in the boundary layer and it
(5.0 MGD) (100%)
is necessary for the minerals to diffuse back into the flowing
stream. The ratio of the mineral concentration in the bound- (5.88 MUD)
ary layer (layer of water next to membrane) to the mineral = 85%
concentration in the flowing water is defined as concentra-
tion polarization. Polarization will reduce both the flux and
rejection of a reverse osmosis system. Since it is impractical
to totally eliminate the polarization effect, it is necessary to
minimize it by good design and operation. QUESTIONS
The boundary layer effect can be minimized by increased Write your answer? .n a notebook and then compare your
water flow velocity and by promoting turbulence within the answers with those on page 174
RO elements. Brine flow rates can be kept high as product 16.21 How will an increase in feedwater temperature influ-
water is removed by staging (reducing) the module pressure ence the water flux?
vessels. This is popularly referred to as a "Christmas Tree"
:.-...rangement. Typical flow arrangements such as 4 units - 2 16.2J How does hydrolysis influence the mineral rejection
capability of a membrane?
16.2K How is recovery defined?
16.2L Recovery rate is usually limited by what two consid-
erations?
16 2M Define concentration polarization.

Cul of Le440111 of 5 L244.11t4

NEFALIZATION

16
152 Water Treatment

FOUR TWO ONE

PRESSURE PRESSURE PRESSURE
VESSELS VESSELS VESSEL

FEED WATER
41- BRINE TO
WASTE

I-
[
".
1
NOTES: 1. BRINE FLOWS OUT OF PRESSURE
VESSELS TO NEXT VESSEL.
2. PRODUCT WATER IS NOT SHOWN.
PRODUCT WATER FLOWS OUT OF EACH
VESSEL INTO A COMMON HEADER.

Fig, 16,8 Typical 4-2-1 "Christmas Tree" arrangement

 Demineralization 153

DISCUSSION AND REVIEW QUESTIONS

Chapter 16. DEMINEFIALIZATION
(Lesson 1 of 3 Less '5)

At the end of each lesson in this chapter you will f...d some 2. Osmotic pressure differential across the membrane
discussion and review questions that you should work (..170 increases, and
before continuing. H-.0 purpose of these questions is to 3 Concentration gradient across the membrane (C,
Indicate to you how well )-2._1 understand the material in the C2) increases.
lesson. Write the answers to these questions in your note-
4. What usually happens to water flux with time and why?
book before continuing.
1. Why has brackish water not been widely used for 5 How does fouling develop on membranes?
municipal drinking water supplies? 6. What factors influence the rate of hydrolysis of a mem-
brane and how?
2. What is reverse osmosis?
7. What is the most common and serious problem result-
3. Indicate what will happen to both the water flux and
ing from concentration polarization?
mineral flux when:
1. Pressure differential applied across the niembrane 8. Why do demineralization plants use a pressure vessel
(AP) increases, Christmas tree configuration's

CHAPTER 16. DEMINERALIZATION

(Lesson 2 of 3 Lessons)

16.3 DIFFERENT TYPES OF REVERSE OSMOSIS system include the brackish water demineraiizing plants at
PLANTS Key Largo, Florida and Kashima, Japan; the wastewater
demineraIizing plants in California; and the sea water demin-
Operating plants use the RO principle in several different eralizing plant at Jeddah in Saudi Arabia.
process designs and membrane configurations. 'there are
three types of commercially available membrane systems The hollow fiber type of membrane was developed by
which have been used in operating plants: DuPont and Dow Chemical. The membranes manufactured
by DuPont are made of aromatic polyamide fibers about the
1. Spiral wound, size of a human hair with an inside diameter of about 0.0016
2. Hollow fine fiber, and inch (0.04 mm). In th::::3e very small diameters, fibers can
withstand high pressures. In an operating process the fibers
3. Tubular. are placed in a pressure vessel; one end of each fiber is
sealed and the other end protrudes outside the vessel. The
brackish water is under pressure on the outside of the fibers
The spiral-wound RO module was developed by Gulf Envi- and product water flows inside of the fiber to the open end. A
ronmental Systems Company (now Fluid Systems Division, DuPont module is illustrated in Figure 16.10. For operating
UOP) under contract to f'se U.S. Office of Saline Water. This plants, the membrane modules are assembled in a config-
RO unit was conceived as a method of obtaining a relatively uration similar to the spiral wound unit. Municipal demineral-
high ratio of 'nembrane area to pressure vessel volume. The izing plants (manufactured by DuPont) in Greenfield, Iowa
membrane is supported on both sides of a backing material and in clonda and sea water demineralizing plants in the
and sealed with glue on 3 of the 4 edges of the laminate. The Middle East use this type of membrane.
laminate is also sealed to a central tube which has been
drilled to allow the demineralized water to enter. The mem- Tubular membrane processes operate on much the same
brane surfaces are separated by a screen material which principle as the hollow fine fiber except that the tubes are
acts as a brine spacer. The entire package is then rolled into much larger in diameter, on the order of 0.5 inch (12 mm).
a spiral configuration and wrapped in a cylindrical form. The Use of this type of membrane system is usually limited to
membrane modules are lueded, end to end, into a pressure special situations such as for wastewater with high sus-
vessel as shown in Figure 16.9. Feed flow is parallel to the pended solids concentration. The tubular memt ane proc-
central tube while PERMEATES flows through the mem- ess is not economically competitive with other available
brane toward the central tube. Plants using this type of systems for treatment of most waters.

9 Permeate (PURR-me-ate). The desalted water. This is the water that has passed through the membrane.

168
154 Water Treatment

ROLL TO
ASSEMBLE

FEED SIDE
SPACER FEED FLOW

PERMEATE
OUT

PERMEATE FLOW
PERMEATE SIDE BACKING (AFTER PASSAGE
(MATERIAL WITH MEMBRANE ON THROUGH MEMBRANE)
EACH SIDE AND GLUED AROUND
EDGES AND TO CENTER TUBE)

SPIRAL-WOUND REVERSE OSMOSIS MODULE

PRODUCT WATER
OUTLET FEED CONNECTION

CONCENTRATE HYDRAULIC \--SEAL MODULE

OUTLET TUBE

PRESSURE VESSEL ASSEMBLY

Fig. 16.9 Spiral-wound reverse osmosis module (as manufactured by UOP)

(From paper by Mack Wesner. "Desatting Process and Pretreatment: pirblishecf in Proceedings on 'Role of Desalting Technology.'
a series of Technology I ransfer Workshops presented by the Office of Water Research and Technology)

169
 Demineralization 155

FIBER CROSS SECTION

OPEN ENDS
85 14. OF FIBERS
(0 0033 inch)

POROUS
THIN SKIN
0.1-1 II THICK

SNAP RING CONCENTRATE POROUS

OUTLET BACK-UP DISC

RING FLOW SCREEN EPDXY

SEAL TUBE SHEET

FEED PERMEATE

.......... "

SHELL END PLATE

END PLATE FIBER

FIBER '0 RING SEAL/

SNAP RING

POROUS FEED
DISTRIBUTION TUBE

Fig. 16.10 Hollow fiber reverse osmosis module (as manufactured by DuPont)
(From paper by Mack Washer. 'Desalting Process and Pretreatment: published in Proceedings on 'Role of Desalting Technology:
a series of Tech 'fogy Transfer Workshops presented by the Off.ce of Water Research and Technology)

170
156 Water Treatment

QUESTiONS source water pH and temperature. As the membrane hydro-

lyzes, both the amount of water and the amount of solute
Write your answers in a notebook and then compare your which permeate the membrane increase and the quality of
answers with those on page 175. the product water deteriorates. The rate of hydrolysis is at a
16.3A List the three types of commercially available mem- minimum at a pH of about 4.7, and it increases with both
brane systems which have been used in operating increasing and decreasing pH. Thus it is standard practice to
plants. inject acid, usually sulfuric acid, to adjust feedwater pH to
5.5 Not only does pH adjustment minimize 'he effect of
16 3B What type of membrane process is used to treat hydrolysis, but it is also essential in controlling precipitation
wastewater with a high suspended solids concentra- of scale-forming or membrane - fouling minerals.
tion?
Calcium carbonate and calcium sulfate are probably the
most common scaling salts encountered in natural waters
16.4 OPERATION and are certainly the most common cause of scale in reverse
osmosis systems. The addition of a small amount of acid can
16.40 Pretreatment reduce the pH to a point where the alkalinity is reduced; this
Water to be demineralized always contains impurities shifts the equilibrium to the point where calcium bicarbon-
which should be removed by pretreatment to protect the ate, which is much more soluble, is present at all points
membrane and to assure maximum efficiency of the reverse within the reverse osmosis loop. Neutralization of 75 percent
osmosis process. Depending on the water to be demineral- of the total alkalinity usually provides sufficient pH adjust-
ized, it is usually necessary to treat the feedwater to remove ment to achieve calcium carbonate scale control and bring
materials and conditions potentially harmful to the RO proc- the membrane into a reasonable part of the hydrolysis curve.
ess such as: The pH reached by 75 percent neutralization is about 5.7.
Calcium carbonate precipitation is also inhibited by the
1. Remove turbidity/suspended solids, control procedi ire used for calcium sulfate.
2. Adjust pH and temperatures, Calcium sulfate is relatively soluble in water in comparison
to calcium carbonate. Again, however, as "pure" or product
3. Remove materials to prevent scaling or fouling, and
water is removed from a feed solution containing calcium
4. Disinfect to prevent biolcgical growth. and sulfate, these chemicals become further concentrated in
the feed water. When the limits of saturation are eventually
16.41 Removal of Turbidity and Suspended Solids exceeded, precipitation of calcium sulfate will occur. Since
calcium sulfate solubility occurs over a wide pH range, the
In general, the feedwater should be filtered to protect the scale control method used to inhibit calcium sulfate precipi-
reverse osmosis system and its accessory equipment. tation is a threshold treatment" with sodium hexametapi Kip-
When the water source is a groundwater or previously phate (SHMP). This precipitation inhibitor represses both
treated municipal or industrial -apply, this may be accom- calcium carbonate and calcium sulfate by interfering with the
plished by a simple screening procedure. However, such a crystal formation process. Other polyphosphates may also
procedure may not be adequate when the source is an be used but are not as effective as the hexametaphosphate.
untreated surface water. The amount of suspended matter Generally 2 to 5 mg/L of SHMP are added to the feedwater
in surface waters may vary by several orders of magnitude to decrease precipitation of calcium sulfate.
and may change radically in character and composition in a
very short time. In such cases, in addition to the mechanical
action of the filter, the operator may have to introduce
chemicals for coagulation and flocculation and use filtration
equipment in which the media can be washed or renewed at
low cost. Pressure and gravity sand filters and diatoma-
ceous earth filters may be required, particularly for large
installations. Where the particulates approach or are COL-
LOIDAL,10 chemical treatment and filtration are almost
essential.
Cartridge filters function as a particle safeguard and not
as a primary particle removal device. In general, the influent
turbidity to a cartridge filter should be less than one TU.
Typical cartridge filter sizes range from 5 to 20 microns and
loading rates vary from 2 to 4 GPM sq ft (1.4 to 2.8 mm/sec). 16.43 Other Potential Scalants
The oxides or hydroxides most commonly found in water
16.42 pH and Temperature Control are those of iron, manganese, and silica. The oxidized and
precipitated forms of iron, manganese and silica can be a
As previously discussed, an important limiting factor in the serious problem to any demineralization scheme because
life of cellulose acetate membranes in reverse osmosis is they can coat the reverse osmosis membrane with a tena-
the rate of membrane hydrolysis. Cellulose acetate will cious (difficult to remove) film which will affect performance.
break down (hydrolyze) to cellulose and acetic acid. The rate The scale inhibitor most frequently used is sodium hexame-
at which this hydrolysis occurs is a function of feedwater or taphosphate.

10 Colloids (CALL-Ioids). Very small, finely divided solids (particles that do not dissolve) that remain dispersed in a liquid for a long time
due to their small size and electrical charge. When most of the particles in water have a negative electrical charge, they tend to repel
each other. This repulsion prevents the particles from clumping together, becoming heavier, and settling out.
11 Threshold treatment refers to the practice of using the least amount of chemical to produce the desired effect.

171
 Demineralization 157

16.44 Microbiological Organisms The operator must properly maintain and control all flows
and recovery rates to avoid possible damage to the mem-
Reverse osmosis modules provide a large surface area branes from scaling.
or the attachment and growth of bacterial slimes and molds.
These organisms may cause membrane fouling or even You must remember that the
module pluging. There is also some evidence that occasion-
ally the enzyme systems of some organisms will attack the
cellulose acetate membrane. The continuous application of WI NP PLOW VALV_E4 AR'
chlorine to produce a 1 2 mg/L chlorine residual will help
inhibit or retard the growth of most of the organisms
encountered. However, caution must be exercised since
weverzw POW? yea
continuous exposure of the membrane to nigher chlorine Should they be accidentally closed during operation, 100
residuals will impair membrane efficiency. Shock concentra- percent recovery will result in almost certain damage to the
tions of up to 10 mg/L of chlorine are applied from time to membranes due to precipitation of inorganic salts (CaSO4).
time. When an oxidant intolerant polyamide type membrane Product or permeate flow is not regulated and varies as
is used, cholonnation must be followed with dechlorination. feedwater pressure and temperature change as previously
One of the dechlonnation agents, sodium bisulfite is also discussed.
known to be a disinfectant. Another disinfection option is the Most RO systems are designed to operate automatically
use of ultraviolet disinfection which leaves no oxidant resid- and require a minimum of operator attention. However, the
ual in the water. continuous monitoring of system performance is an impor-
tant aspect of operation. An example of a typical operation
log for monitoring the Orange County Water District's 5
QUESTIONS MGD (19 MLD) RO plant is given in Table 16.4.
Write your answers in a notebook and then compare your
answers with those on page 175. QUESTIONS
16.4A How are tu idity and suspended solids removed Write your answers in a notebook and then compare your
from feedwater to the reverse osmosis system? answers with those on page 175.
16.4B How are colloidal particulates removed from feed- 16.4F How is the operating pressure on a reverse osmosis
water to the reverse osmosis system? unit regulated?
16.4C What happens to the product water as an acetate 16.4G The demineralized water is usually called the
membrane hydrolyzes? reject
16.4D How is the precipitation of calcium sulfate prevent- 16.4H How does the product or permeate flow vary or
ed? change?
16.4E How is biological fouling on membranes controlled?
16.46 Typical RO Plant Operations Checklist
1. Check cartridge filters. Properly installed filters insure
additional removal of suspended solids that could dam-
age either the high pressure feed pumps or foul the
membrane elements. Cartridge filters should be replaced
whenever head loss exceeds manufacturer's recommen-
dations or effluent turbidity exceeds one TU.
2. Start up and check scale inhibitor feeding equipment and
adjust feed rate to desired dose (2 to 5 mg/L). Most RO
systems should not be operated without the addition of a
scale inhibitor to protect membranes from precipitation of
calcium sulfate or other inorganics. The scale inhibitor
most frequently used is sodium hexametaphosphate.
3. If chlorine is used to prevent biological fouling, start
16.45 RO Plant Operation
chlorine feed and adjust dose to produce a chlorine
Following proper pretreatment, the water to be demineral- residual of between 1 and 2 mg/L.
ized is pressurized by high pressure feed pumps and 4. Start up and adjust acid feed system to correct feedwater
delivered to the RO pressures 'asset membrane assemblies.
pH to a level between 5.0 and 6.0 to protect membranes
An example of a typical RC ant layout is given in Figure
from possible damage due to hydrolysis. Note, feedwater
16.11. The membrane assemblies consist of a series of should always be bypassed until the pH is properly
pressure vessels (usually fiberglass-reinforced plastic) ar- adjusted.
ranged it the 'Christmas Tree layout" depending on the
desired recovery. Typical operating pressure for brackish 5. Most RO systems are designed with automatic controls
water demineralizing varies from 400 to 500 "si (2760 to and various shutdown alarms. These alarms prevent
3450 kPa or 28 to 35 kg/sq cm). A control valve on the startup or running of the unit until proper operating
influent manifold regulates the operating pressure. The conditions are reached. After satisfying these conditions,
volumes of feed flow and of product water are also moni- high pressure feed pumps can be started and water
tored. The demineralized water is usually called permeate, delivered to the RO units. A control valve is used to
and the reject, brine. The recovery rate is controlled by regulate feedwater pressure. Typical operating pres-
increasing teed flow (increase operating pressure) and con- s ires vary from 350 to 500 psi (2400 to 3400 kPa or 25 to
trolling the brine or reject with a preset brine control valve. 33 kg/sq cm).
172
 CLEANING
TANK FLUSH
SCALE (---,, TANK
INHIBITOR CHLORINATOR
FEEDER FLUSH
...}

\ / Cl2
PUMPS

U
CLEANING
CARTRIDGE PUMPS BLOWER
FILTERS DECARBONATOR

g
PRETREATMENT
triMEMBRANE PRODUCT
Y Y ASSEMBLIES WATER
PRETREATMENT HIGH PRESSURE PRODUCT
TRANSFER PUMPS FEED PUMPS PUMPS

ACID ACID ACID ACID

a
ACID
STORAGE TRANSFER DAY INJECTION DILUTION
TANK PUMPS TANK PUMPS PUMPS

17 .1
173
Fig. 16.11 RO flow diagram
 Pr et r eat Ment

Cartridge F rite' s Pump 2 Disci)

Cl
1:i ..: :..: ir .
Turb A
TIME mg/1,
0S1C1 Sl S1 NTU
Temp
of
Feed Cond
prnhos /cm pH ;nig
B
psig
C
pug

0400

1200
2000

RO Unit 1 RO Und 2 Total Brine Total Pro luct 0

co
Feed Feed Flow Product Feed teed How Product Flow Conductivity KWH Conductivity Flow
>
w
TIME psig 1,1GD Cond tul psig MGD Cond. WI PH .bumlios/cm Ton pH Pmhos/cm
MGD MGD 17,

cn
0400 O
3
120.1. 00
0>
2000 .1D
c7)
3
rmx
0m
21 I
m0
RO Unit 1 <
m
Z
Section 1A-Product EC Section 1C-Product EC w0
Section 1R-Product EQ mm
AP Product Brine Feed :...P Product Brine Feed
ini P
Prod.zt
-I
Brine 00
Feed w0
TIME Psig 1st 2nd 3rd dm 2.1GD psrt 1st 2nd 3rd M MGD
pstg 1st 2nd 3rd M MGD 3c
0400
co
co
1200 co
>
-gym
2000 moo
3

RO Unit 2

Section 2A-Product EC Section 2B- Product EC Section 2C-Product rc

TIME
Feed
100., AP Product Brine Feed LP Product] Brine Feed tli P Product 13""P
Psig 2nd 3rd gpm
L_1st MGD wag 1st 2nd 3rd gpm 11GD Ps") 1st 2m1 3rd NGD
0400
1200

2000
 160 Water Treatment
TABLE 16.4 (Continued) DATA SHEET ORANGE COUNTY
WATER DISTRICT 5.0 MGD (19 MLD) REVERSE OSMOSIS
SYSTEM
Shift Operator
Da te

24 Hour Totalizer
a
Feed Flow Bypass Flow Total Product Total Brine
TIME
MGD MGD MGD MGD
(A)2400(Iii

181240011)

ci i SHMP ACID ELAPSED TIME POWER

2400 (11) RO #1 RO #2 24 00 (11)

2400 (1) lbs gal 2400 (1)

REMARKS:

1 7 '7
 Demineralization 161

6. Aojast feed and brine flow to estGolish the desired manner similar to feedwater Typically, cleaning solutions
recovery cate are passed through the pressure vessels at low pressure
and at flow rates where the AP does not exceed 60 psi (414
7. Once flow has beon established, check P. dfferential kFa or 4.2 kg/sq cm) to avoid damaging the elements. The
pressure (AP) across the RO unit wh'ch is iy indicat- cleaning solutions are returned to clean tanks at the end of a
ed by a meter and recorded. The impol (ice of AP cleaning cycle which usually lasts about one hour. Different
relates to cleaning. When the elements become fouled, cleaning solutions are available for use depending upon the
AP usually increases, thus indicating the nee: for clean- type of fouling. Membranes are typically cleaned for ap-
ing. The AP should not exceed 70 to 100 psi (483 to 690 proximately 45 minutes after which the cleaning solution is
kPa or 5 to 7 kg/sq cm) because of possible damage to spent.
the RO modules.
8. With the system on-line, monitcr the performance. Rely
on flow measurements, product water quality, and var-
ious pressure indications. A sample of a typical log sheet
is shown :n Table 16.4.

16.47 Membrane Cleaning

Periodically the performance of the RO system will de-
cline. This is usually observed when either the product water
flow rate (flux) decreases, or salt removal (rejection) de-
creases. Table 16.5 summarizes common causes of mem-
brane damage or loss of performance. Note that in Cases III
and IV the corrective action requires esaning of the element.
Provisions for the periodic cleaning of the reverse osmosis
elements are usually included in the system design. This
makes it possible to clean impurites off the membrane
surface and restore :.ormal flow rates without removing the To remove inorganic precictates, use an acid flush of
elements from the pressure vessels. Element cleaning Citric acid. For biological or organic fouling, various solutions
should be performed at regular intervals to assure as low an of detergents, sequest -ants, chelating agents, bactericides,
operating pressure as practical. The elements should be and enzymes are available. Examples include sodium ti-
cleaned when the pressure required to maintain the rated polyphosphate, B13, Tr;ton X-100, and EDTA.
capacity has either been increased by 15 percent (or a 15
percent decrease in product water flow has occurred at To improve the long-term performance of an RO system,
constant pressure), or a rise of 15 percent in the system the membranes should be flushed with flush water during
differential pressure has been observed. periods of shutdown to remove raw feed water and concen-
trate. If raw water is allowed to remain in the unit, precipita-
Most RO systems are provided with in-place cleaning don may occur. Flushing is also done after cleaning to
systems. This includes tanks, pumps, valves arv, piping for remove the cleaning solution prior to system startup. In
mixing and pumping cleaning solutions through the mem- some cases, where the system is shutdo. n for long periods
brane elements. For cleaning, the unit is shut down and of time, formaldehyde may be added to the flush water to
cleaning sclutions are pumped through the vessels in a inhibit bioiogical growth.

TABLE 16.5 SUMMARY OF COMMON CAUSES OF MEMBRAk!.S. DAMAGE

Symptoms C-use Restoration Procedures
Case I 1. Lower product water flow rate Membrane compaction a accelerated None. Requires element replacement
2. Higher salt rejection by operating pressure greater than when product water flow rate reaches
500 psi (3450 kPa or 35 kg/sq cm). an unacceptable level.

Case II 1. Higher product level Membrane hydrolysis Injection of colloid 189 (size) or
flow rate 1. pH outside operating limits element replacement.
2. Lower salt rejection 2. Bacteria degradation
3. Temperature outside
operating limits.

Case III 1. Low' r product water Membrane fo' ling. Elehant clerning.
flow rate
2. Lower salt rejection

Case IV 1. Lower product water Membrane fouling. Element cleaning.

flow rate
2. High AP
3. High operating pressure

8 Membranc Ccoaction. Prnduci water flow rate declines with operational time in addition to fouling of the membrane surface due to
othe factors. 4.ater flow rate plotted versus time on log-log paper will yield a straight line (flow rate decline).

17R
 162 Water Treatment

QUESTIONS 16.492 Hydraulic Safety

Write your answers in a notebook and then compare your For the reverse osmosis proce._, ,0 function properly,
answers i.n'ith those on page 175. hydraulic pressure in excess of the solution's average
16 41 osmotic pressure (r) is required. Within the plant, therefore,
Why is chlorine added to the feedwater to a reverse most of the pipes, tubing, ve3sels, and their associated
Osmosis unit'
equipment, along with the substances inside these items
16 4.1 Why must the operator chack the differential pres- operate under varying levels of hydraulic pressure (200 to
sure (AP) across the r 7 unit' 500 psi, 1380 to 3450 kPa, or 14 to 35 kg/sq cm). Therefore,
prior to ANY repairs, modifications, or work of any kind, NO
16 4K When should the reverse osmosis elements be MATTER HOW MINOR, know the substances contained,
deaned/ isolate the piece of equipment and equalize pressure levels
to atmospht,(ic pressure.
16.48 Safety
After being repaired, any piece of equipment should be
Purged of ALL foreign substances BL,-ORE being restarted.
16.480 Use Proper Procedures v'Vhen bringing a piece(s) of equipment on-line, increase the
As in any water treatment plant, there are forces and hydraulic pressures slowly. Keep all personnel in a safe area
chemicals used in a reverse osmosis plant which must be to maximize their personal safety.
handled properly to insure the safety and protection of
persc "el. Safety necds for demineralization plants can be 16,483 Electrical Safety
divided into three general groups consisting of chemicals, An RO plant consists cf a series of electrically powered
ele;Ariccl, and hydraulics.
pumps and mechanicel equipment. Electric shocks due to
the use cf electrical equipment occur without warning and
16.481 Chemicals are usually serious. The average individual thinks of the
Operation of an RO plant requires the use of a wide variety hazards of electric shock in terms of high voltage and does
of chemicals. Whenever you must handle chemicals, follow not always realize that it is primarily the current that kills, not
the proper procedures for each chemical. Manufacturer's the voltage. Consequently, persons who work around low-
recommendations for use of each chemical must be ob- voltage equipment do not always have the same healthy
se ved. A list of the commonly used chemicals requiring respect for current as they do for high voltage. Whenever
spa ial handling found in an RO plant operation include: working around electrically operated equipment, strictly ob-
serve all applicable rules of the National Electrical Safety
1. Acid, Code.12
2. Chlorine,
3. Sodium hexametaphosphate, QUESTIONS
4. Formaldehyde, Write your ansv:ers in L 3tebook and then compare your
answers with those on page 175.
5. Citric acid, and
16.4L List the three general groups of safety needs for a
6. Numerous cleaning agents. demineralization plant.
See Chapter 20, "Safety;' for more detailed procedures on 16.4M What type of electrical equipment is used around
the safe use of hazardous chemicals. reverse osmosis plants?

fiat of Lefr4oixfpf 5 La4oli4

PEMONEIZAUZATION

12 NATIONAL ELECTRICAL SAFETY ( -"E. Available from Institute of Electrical and Electronic Engineers, Inc., IEEE Service Center,
PO Box 1331, 445 Hoes Lane, Piscts,.. .4y, NJ 08855-1331.
 Demineralization 163

DISCUSSION AND REVIEW QUESTIONS

Chapter 16. DEMINERALIZATION
(Lesson 2 of 3 Lessons)

Write the answers to tnese questions in your notebook possible damage to the membrane from scaling?
before continuing The problem numbering continues from
12. What will happen in a reverse osmosis plant if the brine
Lesson 1
flow valves are accidentally closed during operation?
S. Why does water to be demineralized require pretreat-
13. What is the purpose of cartridge filters and when should
ment?
they be replaced?
10. What problems are created for demineralization pro-
14. How can the operator determine if the performance of
cesses by the oxidized and precipitated fcrms of iron,
ie RO system is declining?
manganese and silica?
15. What does hydraulic safety consist of around a everse
11. How does the operator of a reverse osmosis plant avoid osmosis process?

CHAPTER 16. DEMINERALIZATION

(Lesson 3 of 3 Lessons)

each 100 rhg/L dissolved solids removed, plus 2 to 3 kWh/

16.5 ELECTRODIALYSIS
1000 gal for pumping feedwater and brine. Advantages of
Electrodiaiysis (ED) is a weal developed process with a the ED process include: (1) well developed technology,
history of many years of operation on brackish well water including equipment and membranes; (2) efficient removal of
supplies. A 650,000 GPD (2.5 MLD) ED plant, manufactured most inorganic constituents; and (3) waste brine contains
by Ionics, Inc., Watertown, Massachusetts, began operation only salt... -emoved plus a small amount of acid used for pH
on well water at Buckeye, Arizona in September 1972 and control in some ED applications.
has been in continuous operation to date. ED plants are also
in operation demineralizing municipal water supplies in in the ED process brackish water flows between alterhat-
Siesta Key, Florida; Sanibel Island, Florida; Sorrento ing cation-permeable and anion-permeable membranes r
illustrated in Figure 16.12. A direct electric current provides
Shores, Florida and at the Foss Reservoir in Oklahoma. The
the motive force cause ions to migrate through the
process is also used for industrial water demineralizing.
membranes. Many alternating cation and anion membranes,
Typical removals of inorganic salts from brackish water by each separated by a plastic spacer, are assembled into
ED range from 25 to 40 percent of dissolved solids per stage membrane stacks. 1 i;9 spacers (about 0.34 inches or one
of treatment. Higher removals require treatment by multiple mm thick) contain the water streams within the stack and
stages in series. Less than 20 percent of the organics direct the flow of water through a tortuous path across the
re aining in activated carbon treated seam 'ary effluent are exposed faces of the membranes. Membrane thicknesses
.oved by electrodialysis. Energy required for ED is about generally range between 0.005 and 0.025 inches or 0.125 to
v.2 to 0.4 kilowatt-hours per 1000 gvIlons (kWh/1000 gal) for 0.625 mm.

ISO
 164 Water Treatment

C CATION-PERMEABLE MEMBRANE
A ANION-PERMEABLE MEMBRANE

-0,
FEEDWATER IN

TO NEGATIVE TO POSITIVE
POLE OF POLE OF
ELECTRICAL
SUPPLY
ELECTRICAL
SUPPLY

CATHODE
+
ANODE

4-
CON NTRATED
BRINE WATER

FRESH PRODUCT WATER

Fig. 16.12 Electrodialysis aemineralization process

(From STANDARD OPERATION INSTRUCTION PLAN FOR ELECTRODIALYSIS, prepared by IONICS, Inc.)

Physically, the equipment takes the form of a plate -and- and the removal efficiency increases with increasing tem-
frame assembly similar tc, that of a filter press. The spacers perature. Ion - selective membranes in commercial electro-
determine the thickness of the solution compartments and dialysis equipment are commonly guaranteed for as long as
also define the flow paths of the water over the reiembrane 5 years and experience has demonstrated an effective life of
surface. Several hundred membranes and their separating over 10 years.
spacers are usually assembled between a single set of
electrodes to form a membrane stack. End plates and tie The most commonly encountered problem in ED oper-
rods complete the assembly. When a membrane is placed ation is scaling (or fouling) of the membranes by both
between two salt solutions and subjected to the passage of organic and inorganic materials. Alkaline scales are trouble-
a direct electric current, most of the currant will be carried some ;n the concentrating compartments when the diffusion
through the membrane by ions, hence the membrane is said of ions to the surface of the anion membrane in the diluting
to be ion selective. Typical selectivities ar: greater than 90 cell is insufficient to carry the current. Water is then electro-
percent. When the passage of current is continued for a lyzed and hydroxide ions pass through the membrane and
sufficient length of time, the solution on the side of the raise the pH in the cell. This increase is often sufficient to
membrane that is furnishing the ions becomes partially cause precipitation .Nf materials such as magnesium hydrox-
desalted, and the solution adjacent to the other side Df the ide or calcium can -late. The accumulation of particulate
membrane becomes more concentrated. These desalting matter increases the electrical resistance of the membrane;
and concentrating phenomena occur in thin layers of solu- this may damage or destroy the membranes. This condition
tion immediately adjacent fc the membrane resulting in the can be offset by feeding acid to the concentrate water
desalting of the bulk of me solution. stream to maintain a negative Langelier Index to assure
scale-free operation.
Passage of water between the membranes of a single
stack, or stage, usually requires 10 to 20 seconds, during Ionics, Inc., has developed a type of ED unit which does
which time the entering minerals in the feedwater are not requ;re the addition of acid or other chemicals for scale
removed. The actual percentage removal that is achieved control. This system reverses the DC current direction and
varies with water temperatures type and amounts of is is the flow path of the dilution and concentrating streams every
present, flow rate of the water and stack design. Typical 15 minutes. Tile electrodes reverse by switching the polarity
removals per stage range from 25 to 40 percent and of the cathodes and anodes. The stream flo, paths also
systems use one to six stages. An ED system will operate at exchange their source every 15 minutes. Motor-operated
temperatures up to 110 degrees Fahrenheit (110°F or 43"C) valves controlled by timers switch the streams so that the

181
 Demin -ralization 165

flow path that was previously the dila, ig strevi becomes (positively c;-,arged ions); and
the concentrating stream and the flow path tnat was pre- Permit only the passage of anions
2. Anion Membranes
viously the concentrating stream becomes the diluting (negatively charged ions).
stream. This reversing polarity system is commonly referred
to as electrodialysis polarity reversal (EDR). Introduction of a cation membrane and anion membrane
into a salt solution to form three water-tight compartments
QUESTIONS (Figure 16.13 (C)) followed by a direct electric current into the
water (Figure 16.13 (D)) will result in the demineralization of
Write your answers in a notebook and then compare your the central compartment.
answers with those on page 175.
In the three-cell unit shown in Figure 16.13 (C) and (D), "1"
16.5A What are the typica! removals of inorganic salts from is the anode (positive electrode), "2" is the anion membrane,
brackish water by eiectrodialysis (ED) per stage of "3" is i!,e cation membrane, and "4" is the cathode (negative
treatment? Electrode). In Figure 16.13 (C) there is no electric flow so the
ions move at random in their respective compartments. In
16.5B What is a membrane stack in an electrodialysis unit? Figure 16.13 (1 the ...troduction of a D.C. potential gives
16.5C that is the most commonly encourtered problem in these ions direction: the cations (Nat) move toward the
ED operation? cathode and the anions (CI-) toward the anode. The follow-
ing occurs:
16.6 PRINCIPLES OF ELECTRODIALYSIS 1. Na+ from compartment A cannot pass through anion
membrane (2) into compartment B,
16.60 Anions and Cations in Water
2. Cl- from compartment A reacts at the anode (1) to give off
When most common salts, minerals, acids, and alkalis are chlorine gas,
dissolved in water, each molecule splits into two oppositely
charged particles called "ions." All positively charged ions 3. Na+ from compartment B passes through cation mem-
are known as "cations" and all negatively charged ions, as brane (3) into compartment C,
"anions." For instance, when common table salt (sodium
chloride or NaCI) is dissolved in water, it separates into 4. CI- from compartment B passes through anion mem-
positive sodium ions (Nat) and negative chloride ions (Cll. brane (2) into compartment A,
The following ions are in sea water or brackish water in 5. Na+ from compartment C reacts at the cathode to give off
appreciable quantities. hydrogen gas and hydroxyl ions (OH-), and
6. Cl- from compartment C cannot pass through cation
membrane (3) into compartment B.
This description indicates how the overall effect has
produced a demineralization of the central compartment.

16.63 Multi-compartment Unit

Figure 16.14 presents a multi-compartment unit similar in
principle to a stack. Letter "A" designates the anion mem-
branes; letter "C" the cation membranes; the "+" sign the
anode; the "" sign the cathode. A salt solution of Na+ and
CI-ions flows between the membrane. On application of the
'bons Anions D.C. potential, the overall effect will be as shown, a move-
Chloride Cl- ment of ions from the compartments bounded by an anion
Sodium Na+
Bicarbonate HCO3 membrane on the left and a cation membrane on the right
Calcium Ca2+
Sulfate 5042- into the adjacent compartments. The compartments losing
Magnesium Mgt`
salt are labeled "dilute" and those receiving the transferred
16.61 Effect of Direct Current (D.C.) Potential on Ions salt, "brine." Two electrode compartments are also found in
If a D.C. potential is applied across a solution of salt in the drawing. Each is bordered by a cation membrane and the
water by means of insertion of two electrodes in the solution, electrode. At the anode, a reaction takes place evolving
the cations will move towards a negative electrode, which is chlorine and oxygen gases; at the cathode, hydrogen gas is
known as the "cathode," arid the anions will move towards produced and hydroxyl ions (OW) are left in the solution.
the positive electrode, which is known as the "anode." In Hydroxyl ions are alkaline.
Figure 16.13 (A) we have a solution of sodium chloride in QUESTIONS
water. The ca..ons (Nat) and anions (CI-) are moving about
at random. In Figure 16.13 (B) a D.C. potential has been Write your answers in a notebook and then compare your
introduced in the solution and the anions move toward the answers with those on page 175.
positive electrode and the cations move toward the negative
16.6A What happens if a D.C. potential is app!ied across a
electrode.
solution of salt in water by means of insertion of two
16.62 Anion and Cation Membranes and Three-Cell Unit electrodes in the solution?
Advantage could be taken of this movement of ions if 16.6B What type of ions can pass through cation mem-
proper barriers were available to isolate the purified zone in branes?
Figure 16.3 (B) so as to prevent remixing. There are two 16.6C In a multi-compartment ED unit, the compartments
types of membranes which can be used as such barriers: and those receiving
losing salt are labeled
1. Cation Membranes Permit only the passage of cations the transferred salt,

182
166 Water Treatment

e...----...s-.....,,,_,-.,..,-,,a,.....-.1 -I ® 0
Na+ CI CP'(3 15'
?G
Na+ _I
Na-1-
CI- Na

CI 0\A

Na+
cl- CI_ CI- Na+

A B

8
+
................................v...
- +
7
esell
CI
GAS
2
+
+ H2
e
GAS
1............

+ , iNa+
e-,, ...-
-1 .
+
a
CI- ,-, + Na
1 %
I +
CI e
CI +

A 4-

A B.
+
2 3 4 1 2 3 4

C (NO CURRENT FLOW) 0 (CURRENT FLOW)

Fig. 16 13 Influence of current flow

(From STANDARD OPERATION INSTRUCTION PLAN FCR ELECIPODIALYSS, prepared by IONICS. InC)

183
 NoCI SOLUTION

Cl2 GAS H2 GAS

0 C A C A A C C
0

No+ No+ Na+ No+ No+ No+ No+ No+

(OH)

CI" CI" CI" Cl" Cr CI' E cr cr

( (

ELECTRODE DILUTC DILUTE C.A_UTE DILUTE DILUTE

BRINE BRINE BRINE BRINE BRINE ELECTRODE

18
,1

LI
Fig. 16.14 Multi-compartment ED stack
(From STANDARD INSTRUCTION PLAN FOR ELECTRODIALYSIS, prepared by IONICS, Inc.)
185
 168 Water Treatment

16.7 PARTS OF AN ELECTRODIALYSIS UNIT 16.74 Membrane Stack

16.70 Flow Diagram The merr Irene "stack" is so called because it is composed
of a large number of stacked pieces, like a deck of cards.
The basic electrodialysis unit consists of: Half of these pieces are spacers and half are membranes
1. Pretreatment equipment, which alternate from the bottom to the top of the stack. In
other words, if one examines any portion of the stack, you
2. Pumping equipment (feed, brine and recirculation) will find a membrane above and below every spacer (except
3. D.C. power supply. at the electrodes) and a spacer above and below every
membrane. Two membranes or two spacers should never
4. Membrane and electrodes, and occur together.
5. In-place cleaning system. Each membrane stack constitutes one stage of deminer-
alization and is a separate hydraulic and electrical stage.
Figure 16.15 shows a typical flow diagram and Figure The total number of stacks in the unit will be arranged in
16.16 a photo of an electrodialysis unit. either one line or two lines running in parallel (each with an
equal number of stacks). Since all the stacks in a line are
16.71 Pretreatment connected in a series, the number of stacks per line will
equal the number of stages of demineralization.
A certain degree of pretreatment of the feedwater supply
is necessary in order to prepare it for demineralization in the The membranes and spacers in the main section of the
stacks. Pretreatment depends on the specific water being stack make up the number of cell pairs rioted in the stack
treated, but it usually includes the removal of suspended or specifications. A cell pair consists of one anion membrane,
dissolved solids which could adversely affect the surface of one cation membrane and two inter-membrane spacers and
the membranes or mechanically block the narrow passage- is the basic demineralizing element. The metal electrodes
ways in the individual celis. Cartridge filters are used as a located at the ends of the stack apply the D.C. electrical
particle safeguard before the ED unit. Before development power required for demineralization.
of the electrodialysis polarky reversal (EDR) unit. acid addi-
tion to prevent carbonate scaling was always practiced. With 16.75 Chemical Flush System
the electrodialysis reversal process, the requirement for acid
addition is reduced or eliminated. Removal of specific mate- ED units are equipped with a Clean -In -Place (CIP) flush
rials such as iron, n. .ganese, or chlorine residual if re- system to allow periodic flushing of the membrane stacks
quired is included in pretreatment. and associated piping with acid solutions down to pH 1 or
with brine solutions up to 10 percent sodium chloride.
16.72 Pumping Equipment and Piping The two chemical solutions which are used most often for
In the electrodialysis process the water pump(s) is used stack cleaning are a five percent solution of hydrochloric
only for circulation of the water through the stack. The heed acid (for removal of scale and normal cleaning), and a five
loss for this circulation varies with the construction of the percent salt solution which has caustic soda added to adjust
stacks, number of stages, stacks, and piping, but generally a the pH to between 12 and 13 (for amoval of organic fouling
pumping pressure of only about 50 to 75 psi (345 to 517 kPa or slime).
or 2.5 to 5.3 kg/sq cm) is needed.
Since only low operating pressures compared to RO are
QUESTIONS
required. ED systems are constructed with common materi- Write your answers in a notebook and then compare your
als found in most water treatment applications. This has answers with those on page 175.
allowed the use of a great deal of standard plastic pipe and
fittings. The use of plastic pipe produces benefits regarding 16.7A What must be removed by pretreatment of the feed-
lower cost ( compared to stainless steel), high resistance to water supply to the electrodialysis unit?
corrosion in a r,aline environment, and ease of construction. 16.7B What is the purpose of the rectifier in an electrodialy-
sis unit?
16.73 D.C. Power Supply
16.8 ROUTINE OPERATING PROCEDURES
The rectifier provides the D.C. power to the membrane
stack assembly. The input (alternating current, A.C.) is
converted by the rectifier to direct current which is applied to 16.80 Desigi; Specifications for Feedwater
the electrodes on each side of the membrane stack to The electrodialysis desalting unit will produce demineral-
remove the ions from the feed stream. This equipment also ized water at a rate dependent on water temperature and
includes a control module for periodic reversal of the current mineral composition of feedwater. The quality of the feed-
every 15 to 30 minutes on all new electrodialysis polarity water, and its ionic composition is extremely important and
reversal (EDR) models. the design of the ED unit is based on these conditions.

'I
186
 CLEANING TANK

CLEANING PUMP MEMBRANE

STACK PRODUCT
WATER
I

ELECTRODE I
RAW FEEDWATER

CARTRIDGE
FILTER
A
I
I

SPECIAL LOW- I
PRETREATMENT PRESSURE I ELECTRODE
(IF REQUIRED) CIRCULATION
PUMP
---1
I

DC POWER
1 BRINE
RECIRCULATION
PUMP I
CONCENTRATE
AC POWER Cm._ DISCHARGE
SUPPLY
SOURCE TO
(RECTIFIER)
1 1
WASTE

Fig. 16.15 Typical flow diagram

, 187 18
 HYDRAULIC ELECTRICAL MEMBRANE
CONTROL PANELS PANEL STACKS

*
4iss, 41111111101mer.----

mss`

PRETREATMENT CIRCULATION DC POWER ELECTRODES

(FEEDWATER FILTERS) PUMP SUPPLY
(RECTIFIER)

Fig. 16.16 Basic parts of an electrodialysis unit

(Courtesy cat IONICS INCORPORATED)
 Demineralization 171

The ions most often encountered in feedwater are: 4. Check the pressure drop across the cartridge filter and
Cations
change the cartridges whenever the pressure drop
Anions
reaches 10 psi (69 kPa or 0.7 kg/sq cm).
1. Calcium 1. Bicarbonate
2. Iron 2. Chloride Weekly
3. Magnesium 3. Sulfate 1. Voltage probe the membrane stacks,
4. Silica 2. Check the oil level on pumps fitted with automatic oilers,
5. Sodium 3. Inspect all piping and skid components for leaks, and
4. Twice per week, measure all electrode waste flows.
An excessive concentration of any of these constituents
could lead to chemical fouling due to scaling. Iron in the
feedwater will cause certain process problems; above 0.1 QUESTIONS
mg/L certain precautions have to be taken. One of the
effects of excess iron in feedwater is the deposit of an Write your answers in a notebook and then compare your
orange film onto the membrane surface which increases the answers with those on page 175.
electrical resistance of thn membrane stack. Concentrations
of iron in excess of J.3 mg/L should be removed by 16.8A List the ions most often encountered in the feedwater
pretreatment. to an electrodialysis unit.

There are other important considerations regarding feed- 16.8B What items must be considered to prevent biological
water quality. These include pH, biological, and bacteriolog- fouling of the cation and anion membranes?
ical quality of the feed. To prevent biological fouling of the 16.8C Generally the electrodialysis unit should NOT be
cation and anion membranes, the feedwater should be free operated when the feed water contains (list the
of bacteria. Proper control of feedwater pH is also important, appropriate water quality constituents).
particularly in terms of corrosion control in piping and
plumbing equipment. Because chlorine attacks the ED mem- 16.8D List the recommended daily activities for the operator
brane, the feedwater cannot contain any chlorine residual. of an electrodialysis unit.
If prechlorination is practiced, the feedwater must be de-
chlorinated before entering the ED unit. Generally the unit
16.9 SAFETY PRECAUTIONS
should NOT be operated when the feedwater contains any
of the following: 1. Grounding. The entire unit, including the stacks, must
1. Chlorine residual of any concentration, be connected to an electrical ground of each potential.
AT THE TIME OF INSTALLATION IT IS NECESSARY
2. Hydrogen sulfide of any concentration, TO GROUND THE SKID OR THE CONTROL PANEL
CABINET, EITHER BY A METAL CONDUIT OR A SEPA-
3. Calgon or other hexametaphosphates in excess of 10 RATE GROUNDING WIRE.
mg/L,
Each time the unit is moved or dismantled, check the
4. Manganese in excess of 0.1 mg/L, and ground connections before turning on the power. The
5. Iron in excess of 0.3 mg/L. skid, power supply cabinet, and stack(s) must always be
firmly connected to the building ground cr other suitable
16.81 Detailed Operating Procedures ground.

Detailed operating procedures vary from one system to 2. Check the ELECTRODE TAB connecting bolts and be
the next. Most ED or EDR units come designed with fully sure these are tight and there is no corrosion. Loos°
automatic control systems. A typical operating log used to connections at these points will cause overheating
monitor an ED system is given in Table 16.6. which could result in serious damage to the membrane
stack.
The detailed specifications for any plant will give the 3. Do not touch wet stack sides or electrode tabs when the
proper setting for the various controls on the unit. These
D.C. power is on.
control settings shr,uld be checked and recoraed at least
once every 24 hours using the sample log sheet given in 4. Always wear rubber gloves when voltage probing the
Table 16.6. Any action needed to keep the plant running membrane stack.
according to the specifications should be taken immediately.
5. When washing down the area, never direct a hose on
In addition to checking the specifications, the routine the membrane stack wnen the D.C. power is on.
maintenance schedule outlined below should be followed
closely in order to reduce the risk of lengthy and expensive 6. Never operate a dry centrifugal pump, even when
down times. Any process problems discovered must be checking rotation.
acted upon immediately. 7. Never apply D.C. voltage to the membrane stack with-
out water flowing through the stack.
Daily
8. Expect the D.C. amperage to DROP when the feed
1. Fill out log sheet, water temperature DROPS. Never increase the D.C.
2. Verify that electrodes are bumping and flowing properly, stack volta 3e as the water temperature drops in an
attempt to raise currents to those recorded at the higher
3. Inspect stacks for excess external leakage (greater than temperatures unless you have received specific instruc-
10 gallons per hour or 38 liters per hour per stack), and tions to do so from the manufacturer.

190
172 Water Treatment
TABLE 16.6 TYPICAL OPERATING LOG SHEET FOR ED UNIT

Date

Polarity

Feed Temp (°F)

Feed TDS (mg/L)

Product TDS (mg/L)

Product Conductivity
Dilute Flowrate (GPM)
Brine Make-up (GPM)
Stack Inlet
Stack Outlet
co
trw Differential In
D
N
(I) Differential Out
w
cr
a.
Before Filter
After Filter
Electrode Inlet

Line 1
Stage 1 Volts
Line 2

Line 1
Stage 1 Amps
Line 2

Line 1
Stage 2 Volts
Line 2

Line 1
Stage 2 Amps
Line 2

Line 1
Stage 3 Volts
Line 2

Line 1
Stage 2 Amps
Line 2

Line 1
Stage 4 Volts
Line 2

Line 1
Stage 4 Amps
Line 2

Line 1
Stage 5 Volts
Line 2

Line 1
Stage 5 Amps
Line 2

Line 1
Stage 6 Volts
Line 2

Line 1
Stage 6 Amps
Line 2

1 9 .1
 Demineralization 173

9. Expect the D.C. amperage to RISE when the feedwater 18. When the plant is on automatic, the plant is controlled by
temperature RISES. As this happens, the D.C. stack the product water tank's level switch. Therefore, when
voltages must be lowered until the D.C. amperage working on the equipment, the plant should be switched
returns to the normal setting. This conserves power and to manual operation and locked out, thus avoiding the
prevents damage to the stack. possibility of an unexpected startup.
10. Never allow oil, organic solutions, solvents, detergents, 19. Use of the "STOP" switch or "STOP/START" switch
wastewater, chlorine, nitric acid, strong bleach or other activates an automatic flushing cycle and therefore
oxidizing agents to come in contact with the membranes does NOT immediately stop operation of all compo-
and spacers unless directed to do so by the manufactur- nents of the unit. If the operation of the entire unit must
er. Membranes can be damaged by a feedwater con- be stopped immediately, the MAIN BREAKER should be
taining even 0.1 mg/L free chlorine. switched off.
11. Always keep the membranes wet. Store in the mem-
brane tube supplied or in the original plastic bags
provided the seals are not broken.
12. Do not smoke or use exposed flames or sparks in the
gas separator tank area due to the presence of poten-
tially explosive gases.
13. Do not service the gas separator tank when the unit is in
operation. Especially avoid the vent lines where toxic
and explosive gases can be present. If it is necessary to
service the tank, operate the unit for 30 minutes without
D.C. power, then wait an additional hour before begin-
ning work or ventilate with fans to ensure complete QUESTIONS
dispersion of dangerous gases.
Write your answers in a notebook and then compare your
14. If it is necessary to troubleshoot any of the electric answers with those on page 176.
panels, be extremely careful of the live panel voltages.
This maintenance should be done only by someone 16 9A What problems can be created by loose connections
familiar with the circuits and wiring. The unit should at the electrode tab connecting bolts9
never be operated with the panel doors open, except for 16.9B What happens to the D.C. amperage when the feed
maintenance purposes, and only by experienced per- water temperature drops?
sonnel.
16 9C How can shorting be prevented from the metal end
15. Should shorting occur from a metal end plate across the plate across the plastic end block to the electrode?
plastic end block to the electrode, IMMEDIATELY turn
off the rectifier. Try to eliminate the cause of the 16.9D How can the operation or the entire electrodialysis
shorting by wiping excess moisture off the block. Also unit be stopped immediately?
be sure to completely remove the black carbon that has
formed at the point of shorting. If this is not effectively 16.10 ARITHMETIC ASSIGNMENT
done, the shorting will recur when the rectifier is turned
back on. Turn to the Appendix at the back of this manual. Read and
work the problems in Section A.34, "Demineralization." You
16. Feedwater containing Calgon or other hexametaphos- should be able to get the same answers en your pocket
phates will cause high membrane stack resistance. calculator.
Avoid operation when these are present.
16.11 ADDITIONAL READING
17. Red warning lamps are mounted on the wire way for the
stack power connections. The lamps are ht when the 1. TEXAS MANUAL, Chapter 11, "Special Water Treatment
D.C. power is applied to the stacks. (Desalting)."

attet of 1.0444oloi 3 La4010

PeMiNECALIZATION

199
174 Water Treatment

DISCUSSION AND REVIEW QUESTIONS

Chapter 16. DEMINERALIZATION
(Lesson 3 of 3 Lessons)

Write the answers to these questions in your notebook 21. When should you check to be sure that an electrodialy-
before continuing with the Objective Test on page 176. The sis unit is properly grounded?
problem numbering continues from Lesson 2.
16. How does an electrodialysis unit demineralize brackish
water?
17. What are the basic parts of an electrodialysis unit?
18. What are the benefits of using plastic pipe in an electro-
dialysis plant?
19. What is the purpose of the chemical flush system in an
electrodialysis unit?
20. An excessive concentration of any specific ion in the
feedwater to an electrodialysis unit can cause what
problem?

SUGGESTED ANSWERS
Chapter 16. DEMINERALIZATION

ANSWERS TO QUESTIONS IN LESSON 1 16 2D When additional pressure is applied to the side of a

membrane with a concentrated solution, the water
Answers to questions on page 142. flux (rate of water flow through the membrane) will
16.0A Demineralization is the process which removes dis- increase, but the mineral flux (rate of flow of miner-
solved minerals (3alts) from water. als) will remain constant.
16.0B Sea water is more expensive to treat than brackish 16 2E When higher mineral concentrations occur in the
water becauses of its much higher TDS concentra- feedwater, the mineral concentrations will increase in
tion. the product water.

Answers to questions on page 142. Answers to questions on page 147.

16.1A Methods of removing minerals from water can be 16 2F Water flux is usually expressed in gallons per day per
divided into two classes: square foot (or grams per second per square centi-
meter) of membrane surface.
1. Those that use a phase change such as freezing
and distillation, and 16.2G The term "flux decline" is used to describe the loss of
water flow through the membrane due to compaction
2. Non-phase change methods such as reverse os- plus fouling.
mosis, electrodialysis and ion exchange.
16.1B The common membrane demineralizing processes
are reverse osmosis and electrodialysis. 16.2H Mineral rejection is defined as
Product Concentration
Rejection, % = (1 ) (100%)
Answers to questions on page 146. Feedwater Concentration
16.2A The osmotic pressure of a solution is the difference Mineral rejection can be determined by measuring
in water level on both sides of a membrane. the TDS and using the above equation. Rejections
16.2B The modified cellulose acetate membrane is com- also may be calculated for individual constituents in
monly used today. the solution by using their concentrations.
16.2C The water flux is the flow of water in grams per Answers to questions on page 151.
second through a membrane area of one square
centimeter (or gallons per day per square foot) while 16 21 An increase in feedwater temperature will increase
the mineral flux is the flow of minerals in grams per the wate. flux.
second through a membrane area of one square 16.2J Hydrolysis of a membrane resufts in a lessening of
centimeter. mineral rejection capability.

193
 Demineralization 175

16.2K Recovery is defined as the percentage feed flow 16.4K The reverse osmosis elements should be cleaned
which is recovered as product water when the operator observes (1) lower product w...-..r
(Product Flow) (100%) flow rate, (2) lower salt rejection, (3) higher differen-
Recovery, % = tial pressure (AP), and (4) higher operating pressure.
Feed Flow
16.2L Recovery rate is usually limited by (1) desired prod- Answers to questions on page 162.
uct water quality and (2) the solubility limits of miner- 16 4L Safety needs for demineralization plants can be
als in the brine. divided into three general groups consisting of
16.2M Concentration pdtrization is the ratio of the mineral chemicals, electrical and hydraulics.
concentration in the, membrane boundary layer to the 16.4M Electrical equipment used around reverse osmosis
mineral concentration in the flow stream. plants consists of a series of electrically powered
pumps.
ANSWERS TO QUESTIONS IN LESSON ANSWERS TO QUESTIONS IN LESSON 3
Answers to questions on page 156. Answers to questions on oage 165.
16.3A The three types of commercially available membrane 16.5A Typical removals of inorganic salts from brackish
systems which have been used in operating plants water by ED range from 25 to 40 percent of dissolved
are (1) spiral wound, (2) hollow fine fiber, and (3) solids per stage of treatment.
tubular.
16.5B A membrane stack in an electrodialysis unit consists
16.3B The tubular membrane process is used to treat of several hundred membranes and their separating
wastewater with a high suspended solids concentra- spacers assembled between a single set of elec-
tion.
trodes. End plates and tie rods complete the assem-
bly.
Answers to questions on page 157. 16.5C The most commonly encountered problem in ED
16.4A To protect the reverse osmosis system and its ac- operation is sealing (or fouling) of the membranes by
cessory equipment, the feedwater should be filleted. both organic and inorganic materials. Alkaline scales
When the water source is a groundwater or a pre- are troublesome in the concentrating compartments
viously treated municipal or industrial supply, filtra- when the diffusion of ions to the surface of the anion
tion may be accomplished by a simple screening membrane in the diluting cell is insufficient to carry
procedure. An untreated surface water will probably the current.
require coagulation, flocculation, sedimentation and
filtration. Answers to questions on page 165.
16.4B Colloidal particulates are removed from feedwater by 16.6A If a D.C. potential is applied across a solution of salt
chemical treatment and filtration. in water by means of insertion of two electrodes in
the solution, the cations will move towards a negative
16.4C As an acetate membrane hydrolyzes, both the electrode, which is known as the "cathode", and the
amount of water and the amount of solute which anions will move towards the positive electrode,
permeate the membrane increase and the quality of which is known as the "anode."
the product water deteriorates.
16.6B Only cations (positively charged ions) can pass
16.4D The scale control method which is used to inhibit through cation membranes.
calcium sulfate precipitation is a threshold treatment
with 2 to 5 mg/L of sodium hexametaphosphate 16.6C In a multi-compartment ED unit, the compartments
(SHMP). losing salt are labeled "dilute" and those receiving the
transferred salt, "brine."
16.4E A 1 to 2 mg/L chlorine residual is maintained to
control biological fouling. Answers to questions on page 168.
16.7A Iron, manganese and chlorine residual must be re-
Answers to questions on page 157. moved from the feedwater supply to the electrodialy-
16.4F Operating pressure on a reverse osmosis unit is sis unit.
regulated by a control valve on the influent manifold. 16.7B The rectifier provides the D.C. power to the mem-
16.4G The demineralized water is usually called PERME- brane stack assembly. The input (alternating current,
ATE, the reject BRINE. A.C.) is converted by the rectifies to D.C. which is
applied to the electrodes on each side of the mem-
16.4H Product or permeate flow is not regulated and varies brane stack to remove the ions from the feed stream.
as feedwater pressure and temperature change.
Answers to questions on page 171.
Answers to questions on page 162. 16.8A The ions most often encountered in the feedwater to
an electrodialysis unit include:
16.41 Chlorine is added to the feedwater to prevent biologi-
cal fouling. Cations Anions
16.4J The operator must check the differential pressure 1. Calcium 1. Bicarbonate
across the RO unit to know when to clean the 2. Iron 2. Chloride
elements. When the elements become fouled, AP 3. Magnesium 3. Sulfate
usually increases, thus indicEting the need for clean- 4. Silica
ing. 5. Sodium
a
1 C... ' 4.
-
,
176 Water Treatment

16 8B To prevent biological fouling of the cation and anion 3. Inspect stacks for excess external leakage, and
membranes, the operator must control feed, pH, 4. Check the pressure drop across the cartridge
biological and bacteriological quality.
filter and change the cartridges whenever the
pressure drop re- _hes 10 psi.
16.8C Generally the electrodialysis int should NOT be
operated when the feedwater contains any of the Answers to questions on page 173.
following:
16.9A Loose connections at the electrode tab connecting
1. Chlorine residual in any concentration,
bolt' will cause overheating which could result in
2. Hydrogen sulfide of any concentration, serious damage to the membrane stack.
3. Calgon or other hex:imetaphosphates in excess 16.9B Expect the D.C. amperage to DROP when the feed-
of 10 mg/L, water temperature DROPS.
4. Manganese in excess of 0.1 mg/L, and 16.9C Should shorting occur from a metal end plate across
5. Iron in excess of 0.3 mg/L. the plastic end block to the electrode, IMMEDIATELY
turn off the rectifier. Try to eliminate the cause of the
16.8D The recommended daily activities for the operator of
shorting by wiping excess moisture off the block.
Also, be sure to completely remove the black carbon
an electrodialysis unit include.
that has formed at the point of shorting.
1. Fill out log sheet,
16.9D If the operation of the Pntire unit must be stopped
2. Verify that electrodes are bumping and flowing immediately, the W i BREAKER should be
properly, switched off.

OBJECTIVE TEST
Chapter 16. DEMINERALIZATION

Please write your name and mark the correct answers on 7. Water flux throuah a membrane over time tends to
the answer sheet as directed at the end of Chapter 1. There increase because Jf membrane erosion.
may be more than one correct answer to the multiple choice
answers. 1. True
2. False

8. Mineral rejection by a reverse osmosis membrane in-

TRUE-FALSE creases as feedwater mineral concentration increases.
1. True
1. Most of the earth's water supplies are fresh water
2. False
1. True
2. False 9. The value of the water permeation constant is only
constant for a given temperature.
2. All fresh waters contain totai dissolved solids (TDS).
1. True
1. True 2. False
2. False
10. Minerals are transmitted through the membrane at a
3. The development of the membrane demineralizing much more rapid rate than water.
processes has significantly increased the cost of demin-
eralizing water. 1. True
2. False
1. True
2. False 11. Water to be demineralized always contains impurities
which must be removed by pretreatment.
4. Osmosis is the passage of a liquid from a concentrated
1. True
to a dilute solution across a semipermeable membrane.
2. False
1. True
2. False 12. The rate of acetate membrane hydrolysis is at its
minimum at about a pH of 4.7, and the rate increases
5. Semipermeable RO membranes generally must oe with both increasing and decreasing pH.
maintained wet at all times.
1. True
1. True 2. False
2. False
13. Reverse osmosis modules provide a large surface area
6. When the pressure differential applied across the mem- for the attachment and growth of bacterial slimes and
brane increases, the salt flux will increase. molds.
1. True 1. True
2. False 2. False

19 ",;
 Demineralization 177

14. The operator of a reverse osmosis plant must properly 26. A,ways wear rubber gloves when voltage probing the
maintain and control all flows and recovery rates to membrane stack of an electrodialysis unit.
avoid possible damage to the membranes from scaling. 1. True
1. True 2. False
2. False
27. Always keep the electrodialysis membranes dry when
15. The brine flo: valves in a reverse osmosis plant must not in use.
never be fully closed. 1. True
1. True 2. False
2. False
28. The gas separator tank on electrodialysis units should
16. To properly operate a reverse osmosis plant, the prod- be serviced when the unit is in operation.
uct or permeate flow must be regulated. 1. True
1. True 2. False
2. False
29. Fee1water containing Calgon or other hexametaphos-
17. Most RO systems should be operated with the addition phates will lower membrane stack resistance.
of a scale inhibitor to protect membranes from precipita- 1. True
tion of calcium sulfate or other inorganics. 2. False
1. True
2. False 30. When an electrodialysis plant is operating on automatic
controls, the plant is controlled by the product water
18. When starting up a reverse osmosis unit, the feedwater tank's level switch.
should always be bypassed until the ph ;s properly 1. True
adjusted. 2. False
1. True
2. False

19. To clean the elements of a reverse osmosis unit, the

elements must be removed from the pressure vessel.
1. True
2. False
MULTIPLE CHOICE
20. When working around electrical equipment, shut off and
lock out electrical circuits if you are not a qualified 31. The need for demineralizing treatment processes is
electrician. increasing due to
1. True 1. A.oricultural runoff into rivers.
2. False 2. Increased demands for water.
3. Increased mineral content of many rivers.
21. The removal efficiency of ED units increases with de- 4. Large quantities of mineralized groundwater.
creasing temperature. 5. Weather modification programs.
1. True 32. Demineralizing processes include
2. False
1. Distillation.
22. If a D.C. potential is applied across a solution of salt 2. Electrodialysis.
water, the cations will move towards a negative elec- 3. Ion exchange.
trode. 4. Mineralization.
5. Reverse osmosis.
1. Trut,
2. False 33. Matemls that can be removed by some demineralizing
processes include
23. The negative electrode is known as the anode.
1, Bacteria.
1. True 2. Organic material.
2. False 3. pH.
4. Suspended solids.
24. Electrodialysis requires much higher operating pres- 5. Viruses.
sures than reverse osmosis.
1. True 34. The selection of a demineralization process for a par-
2. False ticular application depends on
1. Availability of energy and chemicals.
25. The quality of the feedwater to an electrodialysis unit 2. Brine disposal facilities.
and its ionic composition are extremely important. 3. Mineral concentration in feedwater.
1. True 4. Pretreatment required.
2. False 5. Product water quality required.

1 9 t3
 178 Water Treatment

35. What happens when the osmotic pressure differential 1. 20 to 4G psi

across a membrane decreases? 2. 70 to 100 psi
1. Mineral flux does not change. 3. 100 to 250 psi
2. Mineral flux will decrease. 4. 150 to 500 psi
3. Water flux decreases. 5. 1000 to 2000 psi
4. Water flux does not change.
5. Water flux increases.
44. What types of cleaning srJutions we used to remove
biological or organic fouling from an RO membrane?
36. Fouling on RO membranes can be caused by 1. Bactericides
2. Chelating agents
1. Bacteria. 3. Citric acid
2. Dissolved inorganics.
4. Detergents
3. Dissolved organics.
5. Sequestrants
4. Growths on membrane surfaces.
5. Suspended solids. 45. Advantages of the electrodialysis process include
37. To insure the longest possible lifetime of a membrane 1. Efficient removal of most inorganic constituents.
and to slow hydrolysis 2. Low costs.
is added as a pretreat- 3. Low energy requirements.
ment step before demineralization.
4. Waste brine contains only salts removed from feed-
1. Acia water.
2. Alkalinity 5. Well developed technology.
3. Caustic
4. Lime 46. The actual percentage removal of mine.als by an ED
5. Polymer unit varies with
1. Flow rate of the water.
38. Feedwater should be pretreated to remove materials 2. pH.
and change conditions potentially harmful to the RO 3. Stack design.
process such as 4. Types and amounts of ions present.
1. Adjust pH. 5. Water temperature.
2. Adjust temperature.
3. Disinfect to prevent biological growth 47. Which of the following ions must be lowered or removed
4. Remove or prevent scaling or fouling. Ly pretreatment of the feedwater supply to the eiectro-
5. Remove turbidity/suspended solids. dialysis unit?
1. Chlorine residual
39. Why is sulfuric acid usually added to the feedwater? 2. Hydrogen
1. To control precipitation of membrane fouling materi- 3. Hydroxyl
als. 4. Iron
2. To control precipitation of scale-forming minerals. 5. Manganese
3. To improve the alkalinity of the feedwater.
4. To increase pH. 48. Which of the following tasks should be performed daily
5. To prevent corrosion. by the operator on an electrodialysis unit?
1. Check the oil level on pumps fitted with automatic
40. What problems may be caused in the reverse osmosis oilers.
process by microbiological organisms? 2. Fill out log sheet.
1. Deterioration of cellulose acetate membrane 3. Inspect stacks for excess external leakage.
2. Increase in coliforms in product water 4. Verify that electrodes are bump;ng and flowing prop-
3. Membrane fouling erly.
4. Module plugging 5. Voltage probe the membrane stacks.
5. Reduction of organic matter
45. Estimat' the ability of a reverse osmosis plant to reject
41. Typical operating pressures for brackish water demin- minerals by calcuiating the mineral rejection as a per-
eralizing reverse osmosis processes vary from cent. The teedwater contains 1700 mg /L TDS and the
1. 20 to 40 psi. product water is 140 mg /L.
2. 70 to 100 osi. 1. 85%
3. 150 to 350 psi. 2. 87%
4. 400 to 500 psi. 3. 90%
5. 1000 to 2000 psi. 4. 92%
5. 9510
42. Which of the following chemicals are used in the ope--
ation of a reverse osmosis unit? 50. Estimate the percent recovery or a reverse osmosis unit
1. Caustic with a 4-2-1 arrangement if the feed flow is 4.5 MGD and
the product glow is 3.9 MGD.
2. Chlorine
3. Lime 1. 85%
4. Sodium hexametaphosphate 2. 87%
5. Sulfuric acid 3. 90%
4. L 0%
43. The differential pressure (LIP) across the RO unit should 5. 95%
not exceed because of possible damage to the
RO modules.
ent000leetivevA
19 'i
 CHAPTER 17

HANDLING AND DISPOSAL OF PROCESS WASTES

by

George Uyeno

1CI )
.1. 2
180 Water Treatment

TABLE OF CONTENTS
Chapter 17. Handling and Disposal of Process Wastes

Page
OBJECTIVES
181
GLOSSARY
182
17.0 Need for Handling and Disposing of Process Wastes
183
17.1 Sources of Treatment Process Wastes
1e3
17.2 Process Sludge Volumes
184
17.3 Methods of Handling and Disposing of Process Wastes
185
17.4 Draining and Cleaning of Tanks
185
17.5 Backwash Recovery Ponds (Solar Lagoons)
187
17.6 Sludge Dewatering Processes
190
17.60 Solar Drying Lagoons
190
17.61 Sand Drying Beds
190
17.62 Belt Filter Presses
191
17.63 Centrifuges
191
17.64 Filter Presses
195
17.65 Vacuum Filters
195
17.7 Discharge Into Collection Systems (Sewers)
195
17.8 Disposal of Sludge
195
17.9 Equipment .
200
17.90 Vacuum Trucks
200
17.91 Sludge Pumps
202
17.10 Plant Drainage Waters
202
17.11 Monitoring and Reporting
202
17.12 Additional Reading
202
Suggested Answers
203
Objectiva Test
204
 Process Wastes 181

OBJECTIVES
Chapter 17. HANDLING AND DISPOSAL OF PROCESS WASTES

Following completion of Chapter 17. you shou;d be able

to:
1. Outline the need for handling and disposal of process
wastes,
2. Identify the sources of water treatment plant wastes,
3. Drain and clean sedimentation tanks,
4. Discharge process wastes to collection systems (sew-
ers),
5. Operate and maintain backwash recovery ponds (la-
goons) and sludge drying beds.
6. Dispose of process wastes,
7. Safely operate and maintain sludge handling and dispos-
al equipment. and
8. Monitor and report on the disposal of process wastes.

209
182 Water Treatment

GLOSSARY
Chapter 17. HANDLING AND DISPOSAL OF PROCESS WASTES

CENTRIFUGE
CENTRIFUGE
A mechanical device that uses centrifugal or rotational forces to separate solids from liquids.

CONDITIONING
CONDITIONING
Pretreatment of sludge to facilitate removal of water in subsequent treatment processes.

DECANT
DECANT
To draw off the upper layer of liquid (water) after the heavier material (a solid er another liquid) has settled.

DEWATER
DEWATER
To remove or separate a portion of the water present in a sludge or s!urry. To dry sludge so it can be handled and disposed of.

SLUDGE (sluj)
SLUDGE
The settleable solids separated from water during processing.

SUPERNATANT (sue-per-NAY-tent) SUPERNATANT

Liquid removed from settled sludge. Supernatant commonly refers to the liquid between the sludge on the bottom and the water
surface of a basin or container.

THICKENING THICKENING
Treatment to remove water from the sludge mass to reduce the volume that must be handled.

6ttelle cittaitt

20;
 Process Wastes 183

CHAPTER 17. HANDLING AND DISPOSAL OF PROCESS WASTES

17.0 NEED FOR HANDLING AND DISPOSAL OF the proper authorities and must conform to their rigid
PROCESS WASTES standards. For these reasons, it is absolutely necessary to
make provisions for facilities to handle these wastes on a
The need for handling and disposal of potable water routine basis. While the most important part of an operator's
treatment plant wastes is a problem that must be faced by all job is still the end product, good potable water, an opera-
plant cperators. Many articles and books have been pub- tor's duties are not complete until all by-products and
lished on potable water treatment processes. Their empha- wastes are disposed of in an acceptable and documented
sis is usually on producing wholesome and pure water for manner.
human consumption in compliance with EPA, state and local
health department regulations, but very few mention sludge
handlinc and disposal in any great detail. In response to a QUESTIONS
growing population and increasing concern about pollution Write your answers in a notebook and then compare your
of natural water sources, pollution control agencies, health answers with those on page 203.
departments, and fish and game departments established
programs to enforce rules to prevent any waste discharge 17.0A Wh, are strict laws neederf regarding the disposal of
that would tend to discolor, pollute or generally be harmful to process wastes?
aquatic or plant life or the environment.
17.0B If a discharge results from the disposal of process
The law which restricts or p:ohibits the discharge of wastes, what water quality irdicators may require
process wastes from water treatment plants is Public Law monitoring?
92-500, the Water Pollution Control Act Amendments of
1972. This Act clearly includes treatment plant wastes such 17.1 SOURCES OF TREATMENT PROCESS WASTES
as sludge from a water treatment plant These wastes are
considered an industrial waste which requires compliance Although there are many types of water treatment plants
with the provisions of the Act. Under the National Pollutant and methods for treating water, most of them probably
Discharge Elimination System (NPDES) provisions, a permit operate in the following general manner. Alum or polymers
must be obtainea in order to discharge wastes from a water are applied to the water in a rapid mix chamber, agitated by
treatment plant. Water treatment plants are classified into mechanical means or through a cylinder designed for hy-
three categories. draulic flash mixing for coagulation. Following this, the water
passes through mechanical flocculators or a series of baf-
Category 1 Plants that use one of the fo!lowing three pro- fles for flocculation. The water then moves into the sedimen-
cesses: (1) coagulation, (2) oxidative iron and tation tank where the floc is allowed to settle out before the
manganese removal, or (3) direct filtration. water moves to the filters. The sedimentation tanks may be
of various shapes and depths; however, they are most
Category 2 Plants that use only chemical softening pro- commonly rectangular or circular. Many large plants are
cesses. equipped with either mechanical rakes or scrapers which
Category 3 Plants that use combinations of coagulation and periodically rcrnOve sludge from a hopper or with a vacuum-
chemical sottening, or oxidative iron-manga- type sludge removal device. The sludge is continuously
nese removal and chemical softening. scraped into the hopper. The hopper is emptied from one to
three times per day for 20 to 30 minutes each time depend-
Enforcement of PL 92-500 is the responsibility of each ing on the size of the hopper and the density of the sludge.
state. Many NPDES permits have been issued by the states
to water treatment plants using state standards applicable to
the local conditions at the time the permits were issued.
Water quality indicators for which waste discharge lirr a-
tions have been issued include pH, total suspended solids,
settleable solids, total iron and manganese, flow rate, total
dissolved solids (TDS), BOD, turbidity, total residual chlo-
rine, temperature, floating solids and visible forms of waste.
Water treatment plants can no longer simply discharge
dirty backwash water or settled sludge into lakes, rivers,
streams or tributaries as was done in the past. Current
.......)1/4.....
regulations require daily monitoring of any discharge and __---''.-----
analysis of such water quality indicators as pH, turbidity,
TDS, settleable solids or ether harmful materials. The results Sludge is then usually moved to drying beds. The smaller
of the analyses must be logged and reported frequently to and older plants may not have these sludge handling facili-

202
 184 Water Treatment

ties available. Many new water treatment plants are

equipped with sludge collection headers with squeegees. QUESTIONS
This system does not need any sludge hoppers. The collec- Write your answers in a notebook and then compare your
tion headers are supported by a travelling bridge or floats. answers with those on page 203.
The sludge is pumped out of the bottom of the basin and into
a sludge channel on the walkway level. This system is 17.1A How is sludge removed from sedimentation tanks?
described in Chapter 5, "Sedimentation."
17.1B How is sludge removed from an upflow solids-con-
tact type of unit?
Another type of plant similar to the one above contains an
upflow solids-contact unit with clarifiers. The clarifiers are
usually circular in shape and have sludge draw-off levels
which must be monitored; the solids are then drawn off 17.2 PROCESS SLUDGE VOLUMES
periodically as sludge.
All of the different methods of sludge collection require
For small plants and in areas where water must be some type of facilities for handling processed waste. The
pumped, pressure filters may be used and the coagulant is possibilities here include sedimentation tanks, backwash
applied directly to the filter. Sedimentation tanks or clarifiers recovery ponds, drying beds, lagoons, ponds, holding tanks,
may occasionally accompany the use of pressure filters but adequate land, access to sewer systems or vacuum trucks
this is not usuall., the case if the quality of the source water or £.milar equipment for removal and disposal of the waste
is good. material.
In another type of plant layout (not too commonly used), The amount of sludge accumulation depends on the type
the sedimentation tank also functions as the backwash and amount of suspended matter in the source water being
recovery area. In this case the backwash wastewater is treated as well as on the level of dosage and the tuns of
pumped back to the head of the plant. Most of the solids will coagulant used. As an example, let's examine sludge pro-
settle out when the water flows through the sedimentation duction at two 5 MGD (19 MLD) plants. The annual water
basin. This method does eliminate the need for backwash production at each was 800 to 900 million gallons (3000 to
recovery ponds or lagoons. 3400 megaliters). Plant One had no source water stabilizing
Diatomaceous earth filtration is different from all other reservoir and the raw water turbidity ranged from 3 units
types of filtration in its method of operation. There is usually during the summer months to over 100 units during the
no pretreatment of the water. Disposal of backwash wastes winter, with an annual average alum dosage of 11 mg/L.
is still a problem. Table 17.1 summarizes the various Yearly sludge accumulation was approximately 500,000
sources of treatment process wastes and the methods of gallons (1.9 megaliters). Plant Two with a 15 million gallon
collecting, handling and disposal of these wastes. (56.8 megaliters) source water stabilizing reservoir treated
raw -ater which never exceeded 20 turbidity units at the
intake with an average alum dosage of 8 mg/L. The annual
TABLE 17.1 COLLECTON, HANDLING AND DISPOSAL sludge accumulation was approximately 300,000 gallons
OF PROCESS WASTES (1.14 megaliters). In both cases, non-ionic polymer was used
for filte aid at approximately 15 ppb. The scurce water
SOURCES OF WASTES stabilizing reservoir provided water to be treated with a
reduced turbidity level with a more constant quality of water
1. Trash racks
which required less alum and produced less sludge.
2. Grit basins
3. Alum, ferric hydroxide or polymer sludges from sedimen- Organic polymers may be used instead of alum to reduce
tation basins the quantity of sludge produced. Polymer sludges are rela-
4. Filter backwash tively denser and easier to dewater for subsequent handling
5. Lime-soda softening and disposal. Not all waters can be treated by polymers
6. Ion exchange brine instead of using alum.

COLLECTION OF SLUDGES For plants without sludge collection devices, the volume of
sludge produced and the frequency of cleaning the sedimen-
1. Mechanical scrapers or vacuum devices tation tank is affected by several factors. Items to consider
2. Manual (hoses and squeegees) include:
3. Pumps (into tank trucks or dewatering facilities)
1. Water demand,
DEWATERING OF SLUDGES 2. Suspended solias loads and when peak demands occur,
1. Solar drying lagoons 3. Water temperature (as the temperature of the water
2. Sand drying beds increases, the settling rate of the solids will increase),
3. Centrifuges°
4. Belt presses 4. Detention time (23 the detention time increases, the
5. Filter presses amount of solids that settle out will increase),
6. Vacuum filters
5. Volume of sludge deposited in basin (as the volume of
sludge increases, the detention time decreases as well as
DISPOSAL OF SLUDGES AND BRINES the efficiency of the basin),
1. Wastewater collection systems (sewers)
2. Landfills (usually dewatered sludges)
6. Volume of treated water storage for the system (the
greater the volume of treated water storage. the more
S. spread on land time is available for sludge removal),
Mechanical devices that use centrifugal or rotational forces to 7. Time required to clean and make any necessary repairs
separate solids from liquids (sludge from water). during the shutdown. and

203
 Process Wastes 185

8. Availability of adequate drying beds, lagoons, landfill, a or hauled off to a disposal site. Lime softening sludges may
vacuum tank truck, pumps or equipment, and adequate be applied to agricultural lands to achieve the best soil pH
help with all necessary safety equipment and procedures. for optimum crop yields.
Sedimentation tanks should be drained and cleaned at Larger plants or plants that produce large volumes of
least twice a year and more often if the sludge buildup sludge may use THICKENING,' CONDITIONING2 and
interferes with the treatment processes (filtration and disin- DEWATERING3 pro,:esses to reduce the volume of sludge
fection). Alum or polymer sludge solids content is only 0.5 to that must be handled and ultimately disposed of. Sometimes
1 percent for continuous sludge removal and 2 to 4 percent polymers are added to sludges for conditioning prior to
when the sludge is illowed to accumulate and compact. dewatenng. Belt filter presses, centrifuges, solar lagoons
Therefore, the sludge' can f' -'w readily in pipes or be and drying beds are some of the processes used to dewater
pumped, espr-ially win waste.. 3r-type pumps. sludges.

Ultimately process wastes such as trash, grit, sludge and

QUESTIONS brine must be disposed of in a manner that will not harm the
Write your answers in a notebook r d then compare your environment. Trash and grit may be disposed of in landfills.
answers with those on page 203. Sometimes sludge and brine are discharged into wastewater
collection systems (sewers. however, this procedure may
17.2A How can a Source water stabilizing reservoir reduce cause operational problems tor the wastewater treatment
the volume of sludge handled') plant operator. To avoid upsetting wastewater treatment
17.2B If a plant does not have sludge drying beds or plants, discharges to sewers must be made very slowly to
lagoons, how is the raw or wet sludge handled') take advantage of the dilution provided by the wastewater.
Sludges are commonly disposed of by spreading o- 'and or
dumping in landfills. The method used will der.mo on the
volume of the sludge, sludge moisture content, land avail-
able, and distance from the plant to the ultimate disposal
site.
"he remainder of , s chapter will discuss the detailed
operational procedures that an operator must consider
when handling and disposing of process wastes. Sections
are also provided on equipment operation and maintenance
as well as on monitoring and reporting.

QUESTIONS
Write your answers in a notebook and then compare your
17.3 METHODS OF HANDLING AND DISPOSING OF answers with those on page 203.
PROCESS WASTES (Figure 17.1)
17.3A List the methods that may be used to dewater
Various methods are used to handle and dispose of sludge.
process wastes. The facilities at your plant will depend on
17.3B Who., should sedimentation tanks be inspected and
when the plant was built, tht region where the plant is repaired?
located (topography and climate), the sources of sludge and
the methods of ultimate disposal.
17.4 DRAINING AND CLEANING OF TANKS
An effective method of handling sludge is to regularly
Plants without mechanical sludge collectors will require
during the day remove sludge from sedimentation tanks to a
the use of manual labor to remove the sludge once or twice a
drying bed. When one drying bed is full of sludge, the sludge
year. When two or more sedimentation tanks are designed
is allowed to dry while the other drying beds are being filled.
into a plant, the job of cleaning is made easier. While one
A key to speedy drying is the regular removal of the water on
sedimentation tank s down, the other(s) can remain in
top of the sludge. ,----
Some plants require that portions of the facilities be shut
down twice a year, the tanks drained and the sludge
removed. This is an excellent time to inspect the tanks and
equipment and perform any necessary maintenance and
repairs.
Backwash recovery ponds or lagoons are used to sepa-
rate the water from the solias after the filters have been
backwashed. The water is usually returned or recycled to
the plant headworks for treatment with the source water.
These ponds also may be used to concentrate or thicken
)
sludges from sedimentation tanks. Sludges from the lime- -."/ \_
soda softening process are usually stored in lagoons. The
drainage water is removed and the sludge may be covered adir.391C16-41

1 Thickening. Treatment to remove water from the sludge mass to reduce the volume that must be handled.
2 Conditioning. Pretreatment of sludge to facilitate removal of water in subsequent treatment processes.
3 Dewatering. Treatment which removes or separates a portion of the water present in a sludgt, or slurry. To dry sludge so It can be han-
dled and disposed of.
SLUDGE SOURCE:
SEDIMENTATION FILTRATICN

SANITARY
SEWER

CONCENTRATION: WASH WATER RECLAMATION

THICKENER
TREATMENT PLANT BASIN

DEWATERING:

J
BELT PRESS FILTER PRESS
VACUUM SOLAR
CENTRIFUGE SAND BED
FILTER LAGOON

ULTIMATE LANDFILL ON-SITE

DISPOSAL:

20

Fig. 17.1 Sludge processing alternatives

 Process Wastes 187

operation. The cleaning of sedimentation tanks should be Caution must be exercised whenever operators are in any
done prior to and/or after peak demand months. Generally, closed tark (confined space):
early spring and. the fail of the year are the better times to
take some facilities out of service for cleaning. 1. Do not operate gasoline engines in the tank,

Before draining any tank, always determine the level of the 2. Provide adequate ventilation of clean air at all times,
water table. If the water table is high, an empty tank could 3 Provide a source of water to clean off boots and tools
float like a cork on the water surface and cause considerable where the operators come out of the tank, and
damage to the tank and piping. A properly designed tank will
ha..e provisions to drain high water tables or will contain 4 Use the buddy system. Someone must be outside the
other protective features (bottom pressure-relief discs to !et tank and watching anyone inside the tank.
groundwater into tank to prevent damage).
Before filling the tank, thoroughly inspect and repair all
After any necessary intake valve(s) o, gate(s) changes are equipment and valves. Wash everything down with clean
made, drain the water down to the sludge blanket by partially water or a solution of 200 mg//. chlorine to disinfect the
opening the drain valve from the sedimentation tank into tne basin If a chlorine wash solution is not used, fill the tank 10
lagoon or drying bed. After the first few minutes (if the salve percent full with a 50 mg/L chlorine solution and then finish
is not wide open), the water will become clear. This portion filling it with clean water from the plant. The final free
of the water can 5e diverted from the lagoon or drying bed, if chlorine residual should not be so high that water with a free
proper plumbing is available, and returned to the source to chlorine residual greater than 0.5 mg/L reaches the consum-
be reprocessed. Most drying beefs will not handle this great ers.
a volume of water unless this draining process is extended
Although manually draining and cleaning tanks requires
over a period of a few days. Pump(s) can be used tr transfer
more operator hours and plant down time than mechanical
the settled water to another sedimentation tank that is still in
operation. sludge removal, it does have its advantages. A more sani-
tary condition in the tank is obtained by cleaning up algae
As the water gets down to the sludge, fully open the drain buildups or other deposits that are not picked up by me-
valve into the drying bed(s). A large quantity of the sludge chanical collectors and regular inspection of equipment can
will drain by itself. As shown in Figure 17.2, the tank wall is eliminate many potential breakdown conditions. Even basins
10 feet (3 m) high with the sludge level showing about five with continuous sludge collection systems should be
feet (1.5 m) from the top. When the level drops down to drained once a year for inspection and maintenance.
about two feet (0.6 m) of depth by the drain opening, the
sludge will have to be assisted by an operator with a QUESTIONS
squeegee (Figure 17.3).
Write your answers in a notebook and then compare your
During the draining stages, the walls and all the equipment answers with those on page 203.
should be completely hosed down and inspected for dam-
age. All necessary repairs should be made at this time. Once 17.4A How can sludge be removed from tanks without
sludge dries on any coated surface, it is difficult to remove mechanical or iacuum-type sludge collectors?
so it is important to hose everything down during the 17.4B When draining a sedimentation tank, what should be
process of draining and while the sludge is still wet. All done with the settled water above the sludge?
gears, sprockets, and moving parts should be lubricated
immediately after hosing down to prevent "freeze up" result- 17 4C What precautions must be exercised whenever an
ing from exposure to the air during inspection and repair. By operator enters a closed tank (confined space)?
using drying beds and drying bed DECANT' pumps, ample
amounts of water may be used for cleaning and assisting 17.5 BACKWASH RECOVERY PONDS (SOLAR
draining of the sludge. Under these conditions, two to three LAGOONS)
operators can clean cut one sedimentation tank for a plant Because of water pollution control legislation enacted
of 5 to 10 MGD (19 to 38 MLD) in one day. Additional time is since the 1960s, many recently constructed water treatment
required for initial draw down, gathering up c.,` tools and plants now have backwash recovery ponds (Figure 17.5). In
equipment, final cleanup and any repairs that may be many instances these ponds can serve a dual purpose. In
needed. addition to their primary function as backwash recovery
Sludge that settles out near the entrance to the sedimen- ponds, they can also be used to collect the sludge from
tation tank is more dense, especially when a polymer is used sedimentation tanks and clarifiers with a few modifications.
for flocculation aid. Therefore, the drain should be located in While these modified ponds are capable of performing both
the headworks area. Once the sludge ceases to flow freely, functions at the same time, it would be preferable to pay
even with the dilution water, then operators will have to push Particular attention to timing these operations so that they
it towards the drain with squeegees (Figure 17.4). do not overlap. Water for hosing down the sedimentation
basin and assisting the flow of sludge should be used
The volume of sludge can vary with the size of the basin or f oaringly. Also, the backwash recovery pump suction pipe
clarifier, the quality of the source water being treated, the should be floated near the surface, by use of a flexible hose
use of alum, polymer or combinations of both, and the and tire tube or any similar float, so that any excess water
frequency of cleaning. This volume may range from 100,000 can be recycled without also drawing out sludge. This will be
to 200,000 gallons (0.38 to 0.76 ML), depending on the size very important if the filters must be backwashed at the same
of the basin and how long the sludge has accumulated in the time sludge is being cleaned out of the backwash recovery
basin. ponds.

Decant. To draw off the upper layer of liquid (water) after the heavier material (a solid or another liquid) has settled.

207
188 Water Treatment

*MAA,,Y4

Fig. 17.2 Sludge being drained from a clarifier

44.1$

Tp1

Fig. 17.3 Operator with a squeegee assisting s.Jdge out of clarifier

208
 Process Wastes 189

.74 gal

0
Ali
404
.4431,z

Fig. 17.4 Operators pushing sludge towards drain with squeegees and vacuum truck removing sludge

Fig. 17.5 Backwash recovery pond

209
190 Water Treatment

A vacuum tank truck will be needed to move the wet 17.6 SLUDGE DEWATERING PROCESSES5
sludge (a vacuum tank truck is shown in Figure 17.4). The
capacity of the vacuum truck's tank in the picture is 5000 17.60 Solar Drying Lagoons
gallons (19 cu m) and it has a 6-inch (150 mm) suction hose.
About 15 minutes are required to fill up the tank if sludge is Solar drying lagoons are shallow, small-volume storage
fed to the suction end constantly without breaking the ponds in which treatment process sludge (sometimes con-
vacuum. A lift of 12 feet (3.6 m) can be obtained without too centrated) is stored for extended time periods. Sludge solids
much difficulty. settle to the bottom of the lagoon by plain sedimentation
(gravity settling) and the clear SUPERNATANT water is
Sludge is sometimes applied to land as a sod conditioner. skimmed off the top with the aid of an outlet structure that
Polymer sludges are suitable as a sod conditioner. Sludges drains the clear surface waters. Evaporation removes addi-
produced by direct filtration, without coagulants, usually tional water and the solar drying process proceeds until the
make excellent soil conditioners both with and without sludge reaches a concentration of from 30 to 50 percent
polymers. The sludge may be applied either wet or dry. solids. At this point, the sludge can be disposed of on-site or
Because commercial soil conditioner is becoming more at a sanitary landfill. Obviously, the solar drying process is
expensive, sale of sludge as a sod conditioner can help to dependent on environmental conditions (weather) and may
offset sludge handling and disposal costs. take many months to complete. For this reason, several
lagoons should be provided (a minimum of three) so that
sludge loading and drying can be rotated from one lagoon to
another.
17.61 Sand crying Beds

Most plants that use the lime-soda ash softening process

collect the sludge and dewater the sludge in a lagoon. A
variable length riser or discharge pipe is used to draw off the
water that is separated from the sludge. When the lagoon is
full and the sludge is dried, the surface may be covered with
soil as in a landfill operation. In some plants where space is
scarce, the dried sludge is hauled off to a landfill and the Sand drying beds have been used extensively in municipal
lagoon refilled. Lime softening sludges also can be disposed wastewater treatment where high solids volumes are han-
of by application to agricultural soils to ad,ust the pH for dled. Sand drying beds are similar in construction to a sand
optimum crop yields. filter, and consist of a layer of sand, a support gravel layer,
an underdrain system, and some means for manual or
Discharge of lime-soda sludges to the waterwater collec- mechanical removal of the sludge (see Figures 17.6, 17.7
tion system (sewers) is a poor practice because (1) the and 17.8). They are built with underdrains covered with
sewers could become plugged regularly, and (2) the opera- gradations of aggregate and sand. The drair,s discharge into
tor at the wastewater treatment plant will have to handle and a sump where recovery pumps can return the water drained
dispose of the sludge. However, the lime-soda sludge may from the sludge back to the plant to be reprocessed.
help the wastewater treatment plant operator by (1) adjust- Frequently, three beds are used so one can be dried out
ing the pH, or (2) serving as a coagulant aid in treating the in- while one is being filled from the draw-down of wet sludge
coming wastewater. from the sedimentation tanks. The third bed contains dried
sludge which is being hauled out.

QUESTIONS The efficiency of the sand drying bed dewatering process

can be greatly improved by preconditioning the process
Write your answers in a notebook and then compare your sludge with chemical coagulants. The drying time can vary
answers with those on page 204. from days to weeks, depending on weather conditions and
17.5A Why is timing critical if backwash recovery ponds are the degree of preconditioning of the sludge. The frequency
used to handle sludge from sedimentation basins9 of removal of dried sludge will vary with different plants
depending on the volume of sludge produced, size of drying
17.5B Why must the suction pipe for the backwash recov- beds, and drying conditions (weather).
ery pump be floated near the surface of the pond?
Sludge has a unique c!laracteristic about it that once it has
17.5C How can lime-soda softening sludge be disposed of even partially dried, it will not expand, therefore, layer after
ultimately? layer of wet sludge can be added over a period of time. This

5 Portions of this section were prepared by Jim Beard.

6 Supernatant (sue-per-NAY-tent) Liquid removed Iron. settled sludge Supernatant commonly refers to the liquid between the sludge
on the bottom and the wdter surface of a basin or container.

210
 Process Wastes 191

17.6 Photo of sludge drying beds

17.6B Describe a typical sludge drying bed.

17.6C When is the proper time to remove dried sludge from
the drying bed?
17.6D What precautions must be exercised when operating
a front-end loader to remove sludge from a drying
bed?

17.62 deft Filter Presses

Continuous-belt filter presses are popular because of their
relative ease of operation, low energy consumption, small
land requirements, and their ability to produce a relatively
dry filter cake (material removed from the filter press has
about 35 to 40 percent solids). There are two primary
procedure will work as long as the solids content of the mechanisms by which free water is separated from the
applied sludge is at least 2 to 3 percent. When drying this sludge solids in a belt press:
type of sludge, large cracks and checks will develop on the
surface and extend down through the sludge to the sand. 1. Gravity drainage, and
The proper time to remove this dried sludge is when no more 2. Pressure dewatenng.
than one foot (0.3 m) has accumulated and dried into a
checkered pattern A piece of dry sludge can then be picked Sludge is conveyed and dewatered between two endless
up off the sand. The dried sludge can easily be removed with belts (Figure 17.9) After the sludge is initially mixed w,th a
a front-end loader onto a dump truck and be hauled off to a polymer in a rotary drum conditioner, it is dewatered in three
landfill. However, the operator must exercise extreme cau- distinct zones:
tion so that only the dried sludge is picked up with the 1. A horizontal zone for gravity drainage,
minimum possible disturbance to the sand and aggregate.
The loader bucket should be operated carefully since there 2 A vertical sandwich draining zone, and
may be only about ten inches (36 cm) of sand cover over the 3 A final dewatenng zone containing an arrangement of
underdrains. The loader bucket capacity should be limited to staggered rollers which produce a multiple-shear force
one or two cubic yards of sludge. Concrete tracks should be
action which squeezes out the remaining free water.
provided for larger equipment to collect the dried sludge.
Each belt is washed with a high pressure/low volume
QUESTIONS water spray.

Write your answers in a notebook and then compare your 17.63 Centrifuges
answers with those on page 204.
Centrifuges have been used to dewater municipal sludges
17.6A What is the minimum recommended number of solar for some time. Problems with the earlier units included
drying beds? erosion of surf aces hit by high speed particles, and poor

211
 NO..00 X NO. 4 SAND
TOP OF SAND AGGREGATE
ELEV. 825.5

U
10 FT.
r -47r7u r ahRaia§ --T 4 IN. 1/8 IN. X 3/8 IN. GRADED
1

s = °zoo10y
t AGGREGATE
10
I f_FT.../
3/8 IN. X 3/4 IN. GRADED
I
AGGREGATED
1 T'
J 10 FT.
4 ._._t_ BOTTOM
6 FT. ELEV. 824.0

L
NOTE:
DIMENSIONS AND
ELEVATIONS ARE
TYPICAL FOR BOTH
SLUDGE BEDS
96 FT.-

21:). 2 13

Fig. 17.7 Sludge drying beds

194 Water Treatment

ROTARY DRUM
CONDITIONER REAGENT

HORIZONTAL
DRAINAGE FEED
SECTION

VERTICAL
DRAINAGE
SECTION
FINAL
DEWATERING
SECTION

,/

DISCHARGE

BAND
WASH

Fig. 17.9 Flow diagram of Winklepress

(Permission of Ashbrook-SimonHartley)

215
 PrDcess Wastes 195

performance capacity Design improvements and the use of QUESTIONS

polymers have generally eliminated these problems. The
principal advantage of this dewatenng technique is that the Write your answers in a notebook and then compare your
density of the sludge cake can be varied from a thickened answers with those on page 204.
liquid slurry to a dry cake. The major limitation of using 17.6E List the methods available for dewatenng sludges.
centrifuges is high energy consumption.
17.6F List the major advantages and limitations of using
There are two basic types of centrifuges, he scroll type centrifuges to dewater sludges.
and the basket type. The scroll centrifuge operates continu-
ously, while the basket centrifuge is a batch type unit Solids 17.6C When is a precoat of diatomaceous earth required on
captt .e is generally greater with the basket centrifuge. vacuum filters?

In the scroll centrifuge (Figure 17.10), solids are intro- 17.7. DISCHARGE INTO COLLECTION SYSTEMS
duced horizontally into the center of the unit. The spinning (SEWERS)
action forces the solids against the outer wall of the bowl, The easiest method of sludge disposal would be to send
where they are transported to the discharge end by a the s''.idge down the wastewater collection (sewer) system.
rotating screw conveyor. Clear supernatant liquid is dis- This does create some complications even if the wastewater
charged over an adjustable weir on the opposite end of the
treatment plant has the capacity to handle the load. The fees
unit. charged by the wastewater treatment plant could be prohibi-
In the basket centriicrie (Figure 17.11), sludge is intro- tive. The charges are usually based upon annual fow,
chemical or biochemical oxygen demand, suspended solids,
duced vertically into the bottom of the bowl and the superna-
and peak and average discharge. There are also increased
tant is discharged over a weir at the top of the bowl. When
monitoring requirements and costs associated dith a sewer
the solids concentration in the supernatant becomes too
discharge. The water treatment plant must have a holding
high, the operation is stopped and the dense solids cake is
tank so that the sludge can be released at a uniform rate
removed by a knife unloader.
throughout the day or released only during the wastewater
treatment plant's low-flow period.
17.64 Filter Presses
Filter presses have been successailly used to process Brine from ion exchange units may be discharged into
difficult-to-dewater sludges (alum sludges). These machines
wastewater collection systems. Usually the brine is dis-
charged during the day to take advantage of high flows fc.
are best suited for sludges with a high specific resistance
dilution. When you plan such a discharge, notify the operator
(the internal resistance of a sludge cake to the passage of
of the downstream wastewater treatment plant to be sure
water). Filter presses produce very dry cakes, a clear filtrate,
you won't create any unnecessary problems.
and have a very high solids capture.

A filter press consists of a series of verticai plates covered QUESTIONS

with cloth which supports and retains the filter cake (Figure
Write your answers in a notebook and then compare your
17.12). These plates are rigidly held in a frame. Sludge is fed
answers with those on page 204.
into the press at increasing pressures for about half an hour.
The plates are then pressed together for one to four hours at 17.7A What are the complications of discharging sludge to
pressures as high as 225 psi (15.8 kg/sq cm or 1,551 sewers?
kiloPascals). Water passes through the cloth while the solids
are retained, forming a cake which is removed when the 17.7B When is brine from ion exchange units usually dis-
press is depressurized. charged into wastewater collection systems?

17.65 Vacuum Filters 17.8 DISPOSAL OF SLUDL.E7

Vacuum filtration was once the main chemical sludge Sludge is commonly disposed of in sanitary landfills. Other
dewatering process. However, its use has declined due to methods of ultimate disposal include land application and
development of devices such as the belt press which con- sanitary sewers. The method of disposal depends or the
sumes less energy, is less sensitive to polymer dosage, and source and type of sludge, as well as economic and environ-
does not require use of a precoat (a substance applied to the mental considerations.
filter before applying stud 4e for dewatering).

A vacuum filter consists of a cylindrical drum which

rotates partially submerged in a tank of chemically condition-
ed sludge ( Figure 17.13). As the drum slowly rotates, a
vacuum is applied under the filter medium (belt) to form a
cake on the surface. As the belt rotates suction is main-
tained to promote additional dewatering. As the belt passes
the top of the drum, it separates from the drum and passes
over a small-diameter roller for discharge of the cake. The
belt is then washed before it re-enters the vat. A precoat of
diatomaceous earth is required to dewater gelatinous alum
sludge.

7 Portions of this section were obtained from ILLINOIS EPA SLUDGE REGULATION GUIDANCE DOCUMENT, Illinois Environmental
Protection Agency. 2220 Churchill Road, Spring filed, Illinois 62706.

21(3
196 Water Treatment

,i 1-1
I ..--,
I I

Isswwilmadrisawr I
1 r
1t
1 1

PA I I if ild
.,41.....,:v.
a
.n77.7:0,7,7:0
,-,32,,Xyzz'S.-

'ICAO 7411(11.
,

Stuff,. in

Solids "I
dist harp:

Fig. 17.10 Solid-bowl scroll centrifuge

(Permission of Snarples-Stokes Division, Pennwalt Corporation)

217
 Process Wastes 197

Slurry
influent

Access door

Knife cake unloader

Feed pipe

Skimmer for
slurry discharge

Feed accelerator

Drive assembly

Centrate effluent

Discharge of
dense cake

Sludge
influent Rotation
Rots non Plastic
entrate Lake

Knife

Feed cycle

Discharge cycle

Fig. 17.11 lmperfcrate basket centrifuge

(Permission of Sharpies- Stokes Division. Pe inwalt Division)

216
198 Water Treatment

Fig. 17.12 Filter press

(Permission of Shrive, Division. Eimco Process Equipment Co.)

219
 Process Wastes ;99

Fig. 17.13 Operating zones of a vacuum filter

(Permission of Metropolitan Water District of Southern Californ 3)

220
 200 Water Treatment

Water treatment plant lime sludge is an excellent liming Sometimes individuals will request the sludge for fill and
agent for agricultural purposes. Lime sludge must be ap- some contractors have used the sludge to mix with decom-
plied at a rate to achieve the best soil pH for optimum crop posed granite (DG) (a type of rock found in some regions) for
yield. Optimum levels of nitrogen and phosphorus are also fill purposes.
important to achieve high crop yields.
Sludge drying beds for sedimentation tank wastes also
The application of nitrogen fertilizers cause a reduction in can be used to dry sludge from nearby backwash recovery
soil pH. If optimum soil pH conditions do not exist, crop ponds, but this requires the sludge to be handled for a
yields will be reduced. Therefore, sufient quantities of lime second time. An open field spray bar application is o. ie
must be applied as a means of counteracting the fertilizer method for disposing of backwash recovery sludges be-
applications. cause after a few weeks, the residual is hardly noticeable.
PVC pipe may be used to dispose of backwash recovery
Lime softening sludges can also aid in the reclamation of sludges instead of using a spray bar.
spoiled lands by neutralizing acid soils. Disposal of lime
softening sludge on strip mine land will help minimize the Where sludge is repeatedly spread in a single landfill site,
be prepared to disc the sludge in with the native soil because
discl-iarge of acidic compounds and low pH drainage waters.
it :s unsightly. Obviously a location as close to the plant as
Although must lime softening sludges are an excellent possible would be the most cost-effective solution.
liming agent for agricultural and land reclamation purposes, In plants with a size range from 5 to 10 MGD (19 to 38
some lime softening sludges must be disposed of in a MLD), it will take four operators approximately two days to
sanitary landfill due to the lack of availability of agricultural complete the job of draining and cleaning a sedimentation
land or excessive costs. Landfilling of lime softening sludge tank or a backwash recovery pond and disposing of the
is a practical alternative where this method is cost-effective sludge
(minimum cost of disposal).
In plants where a backwash pond is not available, the
Alum sludge has a tendency to cause soils to harden and sludge can be moved to a sump. A smaller suction hose
does not provide any beneficial value. For this reason water must be used to empty small sumps; instead of the 6 inch
treatment plant alum sludge must not be applied to agricul- (150 mm) hose, use either a 3 or 4 inch (75 or 100 mm) hose.
tural land. The sludge may be applied to a dedecated land With a smaller suction hose, it will take 25 minutes or more
disposal site. The sludge is applied to the land and disked to fill the vacuum tank. Five or six operators will be needed
into the soil. Landfilling is another method of ultimate dis- to keep the sump filled. Of course, during the time that the
posal of alum sludge truck is on the road to the dump site and back again, the
Some water treatment plants use a slow sand filter or operators are standing by and the sludge cannot be moved.
If two trucks were used, this disadvante could be over-
settling pond for the treatment of iron filter backwash
wastewater. The slow sand filter must be cleaned occasion- come, but the cost may also increase. Obviously, the larger
ally by removing the top 2 to 3 inches (50 to 75 mm) of sand the sump and the truck's tank, the cheaper the operation
and iron sludge. The material removed must be disposed of from the standpoint of labor costs.
in a sanitary landfill. Plants of one MGD (3.8 MLD) capacity may be able to use
some of the local septic tank pumpers or vacuum trucks to
Water treatment plants which soften water by the ion an advantage. Such companies usually have made arrange-
exchange (zeolite) softening method produce a waste% vater ments for the use of dump sites that may be used to dispose
which has high concentrations of total dissolved solids and of the sludge they pump.
chloride compounds. Ion exchange softening wastes should
not be discharged untreated into low flow streams. The
wastewater treatment processes capable of reducing the QUESTIONS
total dissolved solids and chloride concentrations to accept- Write your answers in a notebook and then compare your
able levels are very energy consumptive and expensive. Ion answers with those on page 204.
exchange softener regeneration wastewater may be very
carefully and slowly discharged into a sanitary sewer sys- 17.8A List the methods of ultimate sludge disposal.
tem. The operator at the wastewater treatment plant must 17.8B Why should sludge be disposed of as close as
be notified in advance.
possible to the water treatment plant?
If a sanitary sewer system is not available for the disposal
of ion exchange softening wastes, holding tanks should be
installed to store the liquid from the regeneration and rinse
cycles. This liquid should be ultimately disposed of in a
sanitary landfill.
Filter backwash wastewater may be recycled through the
water treatment plant, placed in wastewater storage ponds
for additional treatment and disposal or discharged into a
sanitary sewer. The remainder of this section discusses
some of the procedures used by operators to dispose of
sludges.

Wet sludge can be disposed of in an open field by use of

spray bars or dumped out for landfill (Figure 17.14). When 17.9 EQUIPMENT
releasing the wet sludge at one spot, the back of the trmk
should face downhill so it will drain faster and be emptied out 17.90 Vacuum Trucks
completely (Figure 17.15). This practice will also reduce the The use of a vacuum truck is highly recommended be-
chances of the truck getting stuck in the sludge. Usually it cause these trucks develop the fewest problems with clog-
takes about 10 minutes to empty a truck. ging. The larger the suction pipe the better. Any object

22 .._
 Process Wastes 201

Fig. 17.14 Use of sludge for a landfill

WOW'

Fig. 17.15 Emptying sludge from a truck

2.0 --1
...,
 202 Water Treatment

smaller than the hose size can be readily sucked through 17.10 PLANT DRAINAGE WATERS
unless there are too many objects in the sludge. Wedging of
several rocks or sticks can occur, slowing up the process of There are several sources of drainage waters in a water
sludge removal Otriously any object that is sighted should treatment plant which must be properly handled and dis-
be removed by hand picking and tossed out. Any well posed of These sources incLide the laboratory, shops ana
operated plant should oe void of these solids, but they are plant drainage water from leaks and spills. If continuous
sometimes accidentally dropped in or thrown in by vandals. sampling pumps provide the lab with continuous flowing
Leaves and other small objects that nay get by the plant water from various plant processes, this water could be
inlet screens are not too much of a problem unless an discharged to a sewer. Any reagents, toxics or potentially
excessive amount exists. Under these conditions, the heav- pathogenic wastes from the lab must be properly treated
ily accumulated portions should be scooped out to prevent and packaged before ultimate disposal in landfills. Drainage
any clogging of drain pipes or suction hoses. waters from leaks and other sources in the plant may be
discharged to sewers. These drainage waters may be recy-
cled through the plant; however, extreme caution must be
17.91 Sludge Pumps
exercised at all times to avoid contributing to taste, odor, or
Many small treatment plants exist, especially in rural health hazards as well as operational problems.
areas, where disposal of sludge would appear less trouble-
some. A couple of thousand gallons of sludge can be moved 17.11 MONITORING AND REPORTING
by gravity or pumped out to an open field and disked. Even a The location of the water treatment plant and the methods
quarter of an acre can handle many years of dried sludge used to ultimately dispose of the process wastes will dictate
from a small plant. Unfortunately, most of these plants do the monitoring and reporting requirements. These reporting
not have the land available, so the sludge in its wet form requirements may be established by local or state health or
must be hauled out to a disposal site or a small lagoon or pollution control agencies. Monitoring and reporting will
pond must be excavated for sludge collection If sludge must usually involve measuring and recording volumes of sludges
be moved wet, use a sludge pump8 to pump it into a tank or or brines, percent solids and other measurements which will
hire a septic tank pumper. Septic tank pumps, especially the
prove that these processes are not creating any adverse
suction hose, must be thoroughly rinsed and disinfected environmental impacts.
before use in any water treatment plant facilities. This
applies also to all tools and equipment used. 17.12 ADDITIONAL READING
A sludge pump can be an advantage over a self-priming 1. PROCESSINGWTER TREATMENT PLANT SLUDGES.
centrifugal pump because of its :grge suction and discharge AWWA Computer Services, 6666 W. Quincy Ave., Den-
hose (usually three inches (75 I.:n-) in diameter). These ver, Colorado 80235. Order No. 20108. Price, members,
pumps are rated at about 60 GPM (3.8 L/sec) and can handle $10.50; nonmembers, $13.00.
more solids. However, there are also self-priming types of
wastewater pumps available that are designed so that solids
do not actually pass through the impellers. These pumps QUESTIONS
may be used to pump sludges from water treatment plants.
In either case, an excessive amount of foreign solids other Write your answers in a notebook and then compare your
than sludge itself can cause some pumping probi3ms. answers with those on page 204
17.9A How do objects that plug sludge suction hoses get
Wet sludge from a sedimentation tank will flow through
into water treatment plants?
pipes by gravity even if there are some ups and downs in the
line provided the sludge is under some head. If difficulty 17.9B What type of pump can be used to pump sludge into
arises, add some water for dilution or raise the end of the a tank on a truck?
suction hose cioser to the surface of the sump where the
sludge is more diluted. 17.10A List the sources of plant drainage waters.

17.11A What factors will dictate your monitoring and re-

Because of the differences in volume between wet and porting requirements for your sludge disposal pro-
dried sludge, it is always preferable to contain the wet gram?
sludge a' the plant for drying. If the )Iant water source is a
canal or reservoir close to the site, ..onstruct a small pond
parallel to it and return the supematant to tha source for
recycling by removing baffle boards. Only fresh backwash
wastewater should be recycled. Water separated or drained
from old sludge can cause serious problems if recycled. This
water is likely to be septic and could cause taste and odor
problems. Also this water will contain millions of bacteria
and microorganism:, which should not be recycled through a
water treatment plant.

If necessary, semi-dry or dried sludge can be hauled out

of the pond.

8 Types of sludge pumps include types of diaphragm, nonclog,

and progressive cavity pumps.

223
 Process Wastes 203

DISCUSSION AND REVIEW QUESTIONS

Chapter 17. HANDLING AND DISPOSAL OF PROCESS WASTES

Work these discussion and review questions before con- 5. What precautions must be taken before draining a tank?
tinuing with the Objective Test on page 204. The purpose of
these questions is to indicate to you how well you under- 6. What duties should be performed by operators as the
stand the material in the chapter. Write the answers to these sludge is being drained from a sedimentation tank?
questions in your notebook. 7. How would you fill a sedimentation tank after the tank
1. The amount of sludge produced by a conventional water has been emptied, inspected and the necessary repairs
filtration plant depends on what factors? completed?

2. What items should be considered when determining the 8. How is sludge from the lime-soda softening process
frequency of cleaning a sedimentation basin? dewatered?

3. What happens to the water separated from sludges in 9. Why should the back of tie sludge truck face downhill
backwash recovery ponds or lagoons? when releasing wet sludge at one point?
4. Why are at least three sludge drying beds installed at 10 What is the purpose of monitoring and reporting for a
water treatment plants? sludge disposal program?

SUGGESTED ANSWERS
Chapter 17. HANDLING AND DISPOSAL OF PROCESS WASTES

Answers to questions on page 183. Answers to questions on page 185.

17 OA Strict laws are needed regarding the disposal of 17.3A Sludge may be dewatered by the use of belt presses,
process wastes to prevent rivers and streams from centrifuges, filter presses, vacuum filters, solar la-
becoming more polluted. These laws are designed to goons and sand drying beds.
prevent any waste discharge that could discolor,
pollute or generally be harmful to aquatic or plant life 17 3B Sedimemation tanks should be inspected and re-
or the environment. paired (if necessary) when the tanks are drained and
cleaned.
17.0B If a discharge results from the disposal of process
wastes, such water quality indicators as pH, turbidity,
TDS, settleable solids and any other harmful materi- Answers to questions on page 187.
als may require monitoring.
17.4A Sludge must be removed manually from tanks with-
Answers to questions on page 184. out mechanical or vacuum-type sludge collectors.
The tanks must b: drained and then..;perators must
17.1A Sludge is removed from sedimentation tanks by push the sludge to the drain lines with queegees or
mechanical rakes or scrapers wh ch periodically the sludge must be pumped out into tank trucks.
draw out sludge from a hopper or a vacuum-b,ne
sludge removal device may be used. 17.4B When draining a sedimentation tank, do not drain the
17.1B Sludge is removed from upflow solids-contact units settled water above the sludge to the lagoons or
through sludge drawoff lines which must be moni- sludge drying beds. Divert or pump this water to
tored. sedimentation tanks that are in operation, to tne
headworks for reprocessing, or return the water to
Answers to questions on page 185. the source.
17.2A A source water stabilizing reservoir can reduce the 17 4C Whenever an operator enters a closed tank (confined
volume of sludge handled by reducing the turbidity in space), be sure that:
the wet:: being treated. Lower turbidities reduce the
amount of alum required and thus the volume of 1. No gasoline engines are operated in the tank,
sludge that settles out. 2. Adequate ventilation of clean air is provided at 111
17.2B If a plant does not have sludge drying beds or times.
lagoons, the raw or wet sludge can be pumped into a 3. Clean running water is available to wash down
vacuum tank truck and hauled to a site where the boots and equipment when leaving the tank, and
sludge can be spread out on land to dry or dumped in 4. Use the buddy system Someor 7. must be outside
a landfill. the tank and watching anyone inside the tank.

2 2,i
204 Water Treatment

Answers to questions on page 190. dry cake. The major limitation of using centrifuges is
17.5A Time is critical if backwash recovery ponds are used high energy consumption.
to handle sludge from sedimentation basins, be- 17.6G A precoat of diatomaceous earth is required to
cause you want to avoid having to backwash the dewater gelatinous alum sludge.
filters while you are draining a sedimentation tank.
17.5B The suction pipe for the backwash recovery pump Answers to questions on page 195.
must be floated near the surface of the pond so that
17 7A The complications of discharging sludge to sewers
any excess water can be recycled, but the sludge will include:
not be pumped out of the pond.
17.5C Lime-soda softening sludge can be disposed of 1. Fees charged by wastewater treatment plants
ultimately by
could be very high,
2. Increased monitoring requirements and costs,
1. Covering the lagoon with soil, 3. A holding tank may be necessary so the sludge is
2. Hauling the dried sludge to a landfill, or released at a uniform rate.
3. Spreading on agricultural soils to adjust the pH for 4. Possibility of causing a sewer blockage, and
optimum crop yields. 5. Wastewater treatment plant will have to handle
and dispose of sludge.
Answers to questions on page 191.
17 7B Brine from ion exchange units is usually discharged
17 GA The minimum recommended number of solar drying into wastewater collections during the day to take
lagoons is three. advantage of high flows for dilution.
17.6B Sludge drying beds are made with underdrains cov-
ered with gradations of aggregate and sand. The Answers to questions on page 200.
drains terminate into a sump where recovery pumps
17 8A Methods of ultimate sludge disposal include:
can return the water drained from the sludge back to
the plant to be reprocessed. 1. Wet sludge can be disposed of on open fields,
2. Wet or dry sludge can he dumped in landfills, and
17.6C The proper time to remove sludge from the drying 3 Lime softening sludges may be sold to improve
bed is when one foot of sludge has accumulated and the pH of agricultural soils
a checkered-shaped piece of dry sludge can be 17.8B Sludge should be disposed of as close as possible to
picked up off the sand. the water treatment plant to reduce hauling costs.
17.6D When operating a front-end loader to remove sludge
from a drying bed, be careful so only the dried sludge Answers to questions on page 202.
is picked up with a minimum of disturbance to the
sand and aggregate. The loader oucket capacity 17 9A Objects that plug sludge suction hoses get into
should be limited to one or two cubic yards of sludge water treatment plants by heing accidentally
because there may be only about 14 inches of sand dropped in or thrown in by vandals.
cover over the underdrains. 17.9B A diaphragm pump can be used to pump sludge
into a tank on a truck.
Answers to questions on page 195.
17.10A Sources of plant drainage waters include the labo-
17.6E Sludges may be dewatered using: (1) solar lagoons, ratory, shops and plant drainage water from leals
(2) sand drying beds, (3) belt presses, (4) centrifuges, and spills.
(5) filter presses, and (6) VP .:uum filters.
17.11A Monitoring and reporting requirements for a sludge
17.6F The principal advantage of using centrifuges to disposal program are d;ctated by the location of
dewater sludges is that the density of the sludge your water treatment plant and the methods used to
cake can be varied from a thickened liquid slurry to a ultimately dispose of your process wastes.

OBJECTIVE TEST
Chapter 17. HANDLING AND DISPOSAL OF PROCESS WASTES

Please write your name and mark the correct answers on 2 Frequently water treatment plants will use a sethmenta-
the answer sheet as directed at the end of Chapter 1. There tion tank as a backwash recovery area
may be more than one correct answer to the multiple choice
1. True
questions.
2 False
TRUE-FALSE

1. Many articles and books have been written on sludge 3 Ultimately process wastes must be disposed of in a
handling and disposal. manner that will not harm the environment.
1. True 1 True
2. False 2 False

2k)
 Process Wastes 205

4 Wet sludge can easily be removed from drying beds by 14 The frequency of draining and cleaning a sedimentation
a front-end loader. tank will depend on
1. True 1. Backwash rate of rapid sand filters.
2. False 2. Detention time in sand filters.
3. Time required to drain and clean tank.
5. After draining a sedimentation tank, allow the sludge to 4. Volume of sludge in tank.
dry on the equipment so the sludge can be easily 5 Volume of treated water in distribution system pipes.
removed.
1. True 15 How freqently are sedimentation tanks usually drained
2. False and cleaned'',
1. Weekly
6. Sludge that settles out near the entrance to the sedi- 2. Monthly
mentation tank is more dense than the rest of the 3. Quarterly
sludge. 4. Semi-annually
1 True 5. Annually
2. False
16. Treatment processes used in water treatment plants to
7. The sale of lime sludge as an agricultural liming agent reduce the volume of sludge that must be handled and
can help offset sludge handling and disposal costs. ultimately disposed of include
1. True 1. Conditioning.
2 False 2. Dewatering.
3. Digesting.
8. Brine from ion exchange units is usually discharged into 4. Flocculating.
sewers at night during low flow periods. 5. Thickening.
1. True 17. Methods of ultimate sludge disposal will depend on
2. False
1. Distance to disposal site.
9 Wet sludge from a sedimentation tank can flow through 2. Land available.
pipes by gravity. 3. Quality of product water.
4. Sludge moisture content
1. True 5. Volume of sludge.
2. False
18. The frequency of removal of dried sludge will depend on
10. Wet sludge should be dewatered or dried at the plant
before being hauled away. 1. Drying conditions (weather).
2. Number of operators at the plant.
1. True 3. Size of drying beds.
2 False 4. Time available for operators to do job.
5. Volume of sludge produced.

19. When draining a sedimentation tank, the settled water

MULTIPLE CHOICE above the sludge should be
1. Diverted to the clear well.
11. Sources "f process wastes include 2 Diverted to the headworks for reprocessing.
1. Disinf action. 3 Emptied onto the sludge drying beds.
2. Filter backwash. 4. Pumped to a sedimentation tank in operation.
3. Grit basins 5 Recycled to the solar drying ponds.
4. Ion exchange softening.
5 Lime-soda softening. 20. The easiest way to dispose of sludge from a sedimenta-
tion tank is to
12. Sludges may be dewater7:: by
1. Discharge sludge to the sewer.
1. Centrifuging. 2 Divert sludge to backwash recovery ponds.
2. Drying. 3. Haul sludge to landfill.
3. Filter pressng. 4. Pump sludge to drying beds.
4. Flocculating. 5. Spread sludge over land.
5. Lagooning.
21. When releasing wet sludge at one point, the back of the
13. Sludges and brines may be ultimately disposed of in sludge truck should face downhill so the
1. Lakes. 1. Spray bars will not become plugged.
2 Landfills. 2. Tank will empty completely.
3. Rivers. 3. Tank will empty faster.
4. Streams. 4. Truck will not become stuck in the sludge.
5. Wastewater collection systems. 5. Water will flow out before the sludge.

fttot of able/44w Ta4i.-

 CHAPTER 18

MAINTENANCE

by

Parker Robinson

2 `;'
., I
208 Water Treatment

TABLE OF CONTENTS
Chapter 18 Maintenance

Page
OBJECTIVES 213
GLOSSARY 214
LESSON 1

18.0 Treatment Plant Maintenance General Program 218

18.00 Preventive Maintenance Records 218
18.01 Library of Manufacturers' Operation and Parts Manuals 218
18.02 Emergencies 220
18.1 Electrical Equipment 220
18.10 Beware of Electricity 220
18.100 Attention 220
18.101 Recognize Your Limitations 221
18.11 Electrical Fundamentals 221
18.110 Introduction 221
18.111 Volts 221
18.112 Direct Current (D.C.) 223
18.113 Alternating Current (A.C.) 223
18.114 Amps 224
18.115 Watts 224
18.116 Power Requirements 225
18.117 Conductors and Insulators 225
18.12 Tools, Meters and Testers 225
18.120 Voltage Testing 225
18.121 Ammeter 227
18.122 Megger 229
18.123 Ohm Meters 230
18.13 Switch Gear 230
18.130 Equipment Protective Devices 230
18.131 Fuses 230
18.132 Circuit Breakers 230
18.133 Overload Relays 231
18.134 Motor Starters 231

228
 Maintenance 209

18 14 Electric Motors 234

18 140 Classifications 234

18.141 Troubleshooting 236

18.142 Recordkeeping 236

18.15 Auxiliary Electrical Power 244

18.150 Safety First 244

18.151 Stanc ,y Power Generation 244

18.152 Emergency Lighting 245

18.153 Batteries 245

18.16 High Voltage 246

18.160 Transmission 246

18.161 Switch Gear 246

18.162 Power Distribution Transformers 247

18.17 Electrical Safety Check List 247

18.18 Additional Reading 247

LESSON 2

18.2 Mechanical Equipment 249

18.20 Repair Shop 249

18.21 Pumps 249

18.210 Centrifugal Pumps 249

18.211 Let's Build a Pump 249

18.212 Horizontal Centrifugal Pumps 257

18.213 Vertical Centrifugal Pumps 257

18.214 Reciprocating or Piston Pumps 257

18.215 Progressive Cavity (Screw-Flow) Pumps 257

18.216 Chemical Metering Pumps 258

18.22 Lubrication 262

18.220 Purpose of Lubrication 262

18.221 Properties of Lubricants 252

18.222 Lubrication Schedule 262

18.223 Precautions 263

18.224 Pump Lubrication .... 263

18.225 Equipment Lubrication 263

LESSON 3

18.23 Pump Maintenance 265

18.230 Section Format 265

18 231 Preventive Maintenance 265

1. Pumps, General 265

2. Reciprocating Pumps, General 272

22
210 Water Treatment

3. Propeller Pumps, General ... 273

4. Progressive Cavity Pumps, General 273
5 Pump Controls 273
6. Electric Motors 274
7 Belt Drives . .
274
8 Chain Drives ....... .. .. . ..... . 277
9. Variable Speed Belt Drives 278
10 Couplings 278
11. Shear Pins 280
18.24 Pump Operation . ..... .. . ..................... .. ..... . . 282
18.240 Starting a New Pump .
282
18.241 Pump Shutdown 282
18 242 Pump-Driving Equipment 282
18.243 Electrical Controls
282
18.244 Operating Troubles 283
18.245 Starting and Stopping Pumps 284
18.2450 Centrifugal Pumps 284
18.2451 Positive Displacement Pumps 286

LESSON 4

18 25 Compressors
287
18.26 Valves .
289
18.260 Uses of Valves 289
18.261 Gate Valves 289
18.262 Maintenance of Gate Valves 291
12. Gate Valves 291
18 263 Globe Valves
292

18.264 Eccentric Valves 292

18.265 Butterfly Valves . 292
18.266 Check Valves 296
18.267 Maintenance of Check Valves 305
13. Check Valves 305
18.268 Automatic Valves 305

LESSON 5

18.3 Internal Combustion Engines 307

18.30 Gasoline Engines
307
18.300 Need to Maintain Gasoline Engines 307
18.301 Maintenance 307
18.302 Starting Problems 307

23 i 0
 Maintenance 211

18.303 Running Problems .. .... . . ....... 307

18.304 How to Start a Gasoline Engine ..... .. 308

18.3040 Small Engines . . 308

18.3041 Large Engines . . 308

18.31 Diesel Engines .. 309

18 310 How Diesel Engines Work 309

18.311 Operation 309

18 312 Fuel System . ...... . 311

18 313 Water-cooled Diesel Engines . 311

18.314 Air-cooled Diesel Engines . 311

18.315 How to Start Diesel Engines 311

18 316 Maintenance and Troubleshooting 311

18 32 Cooling Systems 313

18 33 Fuel Storage 315

18.330 Code Requirements 315

18.331 Diesel 315

18.332 Gasoline 315

18.333 Liquified Petroleum Gas (LPG) 316

18 334 Natural Gas . 316

18.34 Standby Engines 316

18.4 Chemical Storage and Feeders 316

18.40 Chemical Storage 316

18.41 Drainage from Chemical Storage and Feeders ..... 317

18.42 Use of Feeder Manufacturer's Manual . 317

18.43 Solid Feeders 317

18.44 Liquid Feeders ....... 317

18.45 Gas Feeders 317

18.46 Calibration of Chemical Feeders 317

18.460 Large-Volume Metering Pumps 317

18 461 Small-Volume Metering Pumps 317

18 462 Dry-Chemical Systems 317

18.47 Chlorinators 320

18.5 Tanks and Reservoirs 321

18.50 Scheduling Inspections 321

18.51 Steel Tanks 321

18.52 Cathodic Protection 321

18.53 Concrete Tanks 321

18.6 Building Maintenance 321

231
 12 Water Treatment

18.7 Arithmetic Assignment

18.8 Additional Reading
18.9 Acknowledgments .

Suggested Answers
Objective Test

23
 Maintenance 213

OBJECTIVES
Chapter 18. MAINTENANCE

Following completion of Chapter 18, you should be able

to:
1 Develop a maintenance program for your plant, includ-
ing equipment, buildings, grounds, channels, and tanks;
2. Start a maintenance recordkeeping system that will
provide you with information to protect equipment war-
ranties, to prepare budgets, and to satisfy regulatory
agencies;
3. Schedule maintenance of equipment at proper time
intervals;
4. Perform maintenance as dirc:ted by manufacturers;
5. Recognize symptoms that indicate equipment is not
performing properly, identify the source of the problem,
and take corrective action;
6. Recognize the serious consequences that could occur
when inexperienced, unqualified or unauthorized per-
sons attempt to troubleshoot or repair electrical panels,
controls, circuits, wiring or equipment;
7. Communicate with electricians by indicating possible
causes of problems in electrical panels, controls, cir-
cuits, wiring, and motors;
8 Properly select and use the faowing pieces of equip-
ment (if qualified and authorized):
a. Voltage tester,
b. Ammeter,
c. Megger, and
d. Ohm meter;
9. Safely operate and maintain auxiliary electrical equip-
ment, including during standby and emergency situa-
tions;
10. Describe how a pump is put together;
11. Discuss the application or use of different types of
pumps;
12. Star' and stop pumps;
13. Maintain the various types of pumps;
14. Operate and maintain a compressor;
15. Develop and conduct an equipment lubrication pro-
gram; and
16. Start up, operate, maintain and shut down gasoline
engine3, diesel engines, heating, ventilating and air
conditioning systems.
NOTE: Special maintenance information is given in the pre-
vious chapters on treatment processes where appro-
priate.

233
 214 Water Treatment

GLOSSARY
Chapter 18. MAINTENANCE

AIR GAP DRINKING

WATER AIR GAP
An open vertical drop, or vertical empty space, that sepa- --41.
rates a drinking (potable) water supply to be protected from
another system in a water treatment plant or other location.
This open gap prevents the contamination of drinking water
by backsiphonage or backflow because there is no way raw
water or any other water can reach the drinking water.

ALTERNATING CURRENT (A.C.) ALTERNATING CURRENT (A.C.)

An electric current that reverses its direction (positive/negative values) at regular intervals.

AMPERAGE (AM-purr-age)
AMPERAGE
The strength of an electric current measured in amperes. The amount of electric, current flow, similar to the flow of water in gal-
lons per minute.

AMPERE (AM-peer)
AMPERE
The unit useo to measure current strength The current produced by an electromotive force of one volt acting through a resis-
tance of one ohm.

AMPLITUDE
AMPLITUDE
The maximum strength of an alternating curren. during its cycle, as distinguished from the mean or effective strength.

AXIAL TO 'MPELLER
AXIAL TO IMPELLER
The direct-in in which materiai being pumped flows around the impeller or parallel to the impeller shaft.

AXIS OF IMPELLER
AXIS OF IMPELLER
An imaginary line running along the center of a shaft (such as an impeller shaft).

BRINELLING (bruh-NEL-ing)
BRINELLING
Tiny indentations (dents) high on the shoulder of the bearing race or bearing. A type of bearing failure.

CATHODIC PROTECTION (ca-THOD-ick)

CATHODIC PROTECTION
An electrical system ior prevention of rust, corrosion, and pitting of metal surfaces which are in contact with water or soil. A
low-voltage current is made to flow through a liquid (water) or a soil in contact with the metal in such a manner that the external
electromotive force renders the metal structure cathodic. This concentrates corrosion on auxiliary anodic parts which are delib-
erately allowed to corrode instead of letting the structure corrode.

CAV; CATION (CAV-uh-TAY-shun)

CAVITATION
The formation and collapse of a gas pocket or bubble on the blade of an impeller or the gate of a valve. The collapse of this gas
pocket or bubble drives water into the impeller or gate with a terrific force that can cause pitting on the impeller or gate surface.
Cavitation is accompanied by loud noises that sound like someone is pounding on the impeller or gate with a hammer.

CIRCUIT
CIRCUIT
The complete path of an electric current, including the generating apparatus or other source, or, a specific segment or section
of the complete path.

a" j
 Maintenance 215

CIRCUIT BREAKER CIRCUIT BREAKER

A safety device in an electrical circuit that automatically shuts off the circuit when it becomes overloaded. The device can be
manually reset.

CONDUCTOR CONDUCTOR
A substance, body, device or wire that readily conducts or carries elect-ical current.

COULOMB (COO-lahm) COULOMB

A measurement of the amount of electrical charge conveyed by an electric current of one ampere in one second. One coulomb
equals about 6.25 x 1018 electrons (6,250,000,000,000,000,000 electrons).

CROSS-CONNECTION CROSS-CONNECTION
A connection between a drinking (potable) water system and an unapprovea water supply. For example, if you have a pump
moving non-potable water and hook into the drinking water system to supply water for the pump seal, a cross-connection or
mixing between the two water systems can occur. This mixing may lead to contamination of the drinking water.

CURRENT CURRENT
A movement or flow of electricity. Water flowing in a pipe is measured in gallons per second past a certain point, not by the
number of water mclecules going past a point. Electric current is measured by the number of coulombs per second flowing past
a certain point in a conductor. A coulomb is equal to about 6.25 x 1018 electrons (6,250,000,000,000,000,000 electrons). A flow
of one coulomb per second is called one ampere, the unit of the rate of flow of current.

CYCLE CYCLE
A complete alternation of voltage and/or current in an alternating current (A.C.) circuit.

DATECMETER (day-TOM-uh-ter) DATEOM ETER

A small calendar disc attached to motors and equipment to indicate the year in which the last maintenance service was per-
formed.

DIRECT CURRENT (D.C.) DIRECT CURRENT (D.C.)

Electrical current flowing in one direction only a7d essentially free from pulsation.

ELECTROLYTE (ee-LECK-tro-LIGHT) ELECTRL (TE

A substance which dissociates (separates) into two or more ions when it is dissolved in water.

ELECTROMOTIVE FORCE (E.M.F.) ELECTROMOTIVE FORCE (E.M.F.)

The electrical pressure available to cause a flow of current (amperage) when an electrical circuit is closed. See VOLTAGE.

ELECTRON ELECTRON
An extremely small, negatively-charged particle, the part of an atom that determines its chemical properties.

END BELLS END BELLS

Devices used to hold the rotor and stator of a motor in Position.

FUSE FUSE
A protective device having a strip or wire of fus.bie metal which, when placed in a circuit, will melt and break the electrical circuit
if heated too much. High temperatures vill develop ii, .rte fuse when a current flows through the fuse in excess of that which the
current will carry safely.

GROUND GROUND
An expression representing an electrical connection to earth or a large conductor which is at the earth's potential or neutral
voltage.

HERTZ (H UR TS) HERTZ

The number of complete electromagnetic cycles or waves in one second of an electrical or electronic circuit. Also called the fre-
quency of the current. Abbreviated Hz.

HYGROSCOPIC (HI-grow-SKOP-ick) HYGROSCOPIC

Absorbing or attracting moisture from the air.

JOGGING JOGGING
The frequent starting and stopping of an electric motor.

23 0
216 Water Treatment

LEAD (LEE-d) LEAD

A wire 0. conductor that can carry electricity.

MANDREL (MAN-drill) MANDREL

A special tool used to push bearings in or to pull sleeves out.

MEG MEG
A procedure used for checking the insulation resistance on motors, feeders, buss bar systems, grounds, and branch circuit wir-
ing. Also see MEGGER.

MEGGER (from megohm) MEGGER

An instrument used for checking the insulation resistance on motors, feeders, buss bar systems, ground, and branch circuit
wiring. Also see MEG

MEGOHM MEGOHM
Meg means one million, so 5 megohms means 5 million ohms. A megger reads in millions of ohms.

MULTI-STAGE PUMP MULTI-STAGE PUMP

A pump that has more than one impeller. A single-stage pump has one impeller.

OHM OHM
The unit of electrical resistance The resistance of a conductor in which one volt produces a current of one ampere.

POLE SHADER POLE SHADER

A copper bar circling the laminated iron core inside the coil of a magnetic starter.

POWER FACTOR POWER FACTOR

The ratio of the true power passing through an electric circuit to the product of the voltage and amperage in the circuit. This is a
measure of the lag or load of the current with respect to the voltage. In alternating current the voltage and ampere- are not
always in phase; therefore, the true power may be slightly less than that determined by the direct product.

PRUSSIAN BLUE PRUSSIAN BLUE

A blue paste or liquia (often on a paper like cart on paper) used to show a contact area. Used to determine if gate valve seats fit
properly.

RADIAL TO IMPELLER RADIAL TO IMPELLER

Perpendicular to the impeller shaft. Material being pumped flows at right angle to the impeller.

RESISTANCE RESISTANCE
That propezty of a conductor or wire that opposes the passage of a current, thus causing electrical energy to be transformed
into heat.

ROTOR ROTOR
The rotating part of a machine. The rotor is surrounded by the stationary (non-moving) parts (stator) of the machine.

SEIZE UP SEIZE UP
Seize up occurs when an engine overheats and a part expands to lie point where the engine will not run. Also called "freezing."

SHEAVE (SHE-v) SHEAVE

V-belt drive pulley which is commonly made of cast iron or steel.

SHIM SHIM
Thin metal sheets wnich are inserted between two surfaces to align or space the surfaces correctly. Shims can be used any-
where a spacer is needed. Usually shims are 0.001 to 0.020 inches tnick.

SINGLE-STAGE PUMP SINGLE-STAGE PUMP

A pump that has only one impeller. A multi-stage pump has more than one impeller.

STATOR STATOR
That portion of a machine which contains the stationary (non-moving) parts that surround the moving parts (rotor).

23,3
 Maintenance 217

STETHOSCOPE STETHOSCOPE
An instrument used to magnify sounds and convey them to the ear.

VOLTAGE VOLTAGE
The electrical pressure available to cause a flow of current (amperage) when an electrical circuit is closed. See ELECTROMO-
TIVE FORCE (E.M.F.).

WATER HAMMER WATER HAMMER

The sound like someone hammering on a pipe that occurs when a valve is opened or closed very rapidly When a valve position
is changed quickly, the water pressure in a pipe will increase and decrease back and forth very quickly. This rise and fall in
pressure can do serious damage to the system.

23 */
,
 218 Water Treatment

CHAPTER 18. MAINTENANCE

(Lesson 1 of 5 Lessons)

18.0 TREATMENT PLANT MAINTENANCE GENERAL

PROGRAM
A water treatment plant operator has many duties. Most of
them have to do with the efficient operation of the plan. An
operator has the responsibility to produce a water that will
meet all the requ -ements established for the plant. By doing
this, the operator develops a good working relationship with
the regulatory agencies, water users, and plant neighbors.
Another duty an operator has is that of PLANT MAINTE-
NANCE. A good maintenance program is a must in order to
maintain successful operation of the plant. A successful
maintenance program will cover everything from mechanical
equipment to the care of the plant grounds, buildings, and
structures. An EQUIPMENT SERVICE CARD (master card) should be
filled out for each piece of equipment in the plant. Each card
Mechanical maintenance is of prime importance as the should have the equipment name on it, such as Raw Water
equipment must be kept in good operating ccr.Jition in order Intake Pump No. 1
for the plant to maintain peak performance. Manufacturers
provide information on the mechanical maintenance of their 1 List each required maintenance service with an item
equipment. You should thoroughly read their literature on number.
your plant equipment and UNDERSTAND the procedures.
Contact the mar afacturer or the local representative if you 2 List maintenance services in order of frequency of per-
have any questions Follow the instructions very carefully formance. For instance, show daily service as items 1, 2,
and 3 on the card; weekly items as 4 and 5; mop Mthly items
when performing maintenance on equipment. You also must
as 6, 7, 8, and 9; and so on.
recognize tasks that may be beyond your capabilities or
repair facilities, and you should request assistance when Describe each type of service under work to be done.
needed.
Make sure all necessary inspections and services are
For a successful maintenance program, your supervisors shown. For reference data, list paragraph or section num-
must understand the need for and benefits from equipment bers as shown in the pump maintenance section of this
that operates continuously as intended Disabled or improp- lesson (Section 18.23, p. 265) Also list frequency of service
erly working equipment is a threat to the quality of the plant as shown in the time schedule columns of tI -I same section.
output, and repair costs for poorly maintained equipment Under time, enter day or month service is due. Service card
usually exceed the cost of maintenance. information may be changed to fit the needs of your plant or
particular equipmen' as recommended by the equipment
18.00 Preventive Maintenance Record manufacturer. Be sure the information or. the cards is
Preventive programs help operating personnel keep complete and correct.
equipment in satisfactory operating condition and aid in The SERVICE RECORD CARD should have the date and
detecting and correcting malfunctions before they develop work done, listed by item number and signed by the operator
into major problems. who performed the service. Some operators prefer to keep
A frequent occurrence in a preventive maintenance pro- both cards clipped together,-while otners place the service
gram is the failure of the operator to record the work after it record card near the equipment..
is completed. When this happens the operator must rely on When the service record is filled, it should be filed for
memory to know when to perform each preventive mainte- future reference and a new card attached to the master card.
nance function. As days pass into weeks and months, the The EQUIPMENT SERVICE CARD tells what should be done
preventive maintenance program is lost in the turmoil of and when, while the SERVICE RECORD CARD is a record of
everyday operation. what you did and when you did it.
The only way an operator can keep track of a preventive
18.01 Library of Manufacturers' Operation and Parts
mair.tenance program is by GOOD RECORDKEEPING.
Wh; over record system is used, it should be kept up to date Manuals
on ally basis and not left to memory for some other time. A plant library can contain helpful information to assist in
Equipment service record cards (Figure 18.1) are easy to set plant operation. Material in the library should be cataloged
up and require little time to keep up to date. and filed for easy use. Items in the library should include:

23
 Maintenance 219

EQUIPMENT SERVICE CARD

EQUIPMENT. #1 Raw Water Intake Pump
Item No. Work to be Done Reference Frequency Time
1 Check water seal and packing gland Par. 1 Daily
2 Listen for u Jsual noises Par. 6 Daily
3 Operate pump alternately Par. 1 Weekly Monday
4 Inspect pump assembly Par. 1 Weekly Wednesday
5 Inspect and lube bearings Per. 1 Quarterly 1-4-7-10b
6 Check operating temperature of bearings Par. 1 Quarterly 1-4-7-10b
7 Check alignment of pump and motor Par. 1 Semi-Ann. 4 & 10
8 Inspect and service pumps Par. 1 Semi-Ann. 4 & 10
9 Drain pump before shutdown Par. 1

SERVICE RECORD CARD

EQUIPMENT: #1 Raw Water Intake Pump

Work Done Work Done

Date (Item No.) Signed Date (stem No.) Signed

1-5-84 1-2-3 J.B.

1-6-84 1-2 J.B.

1-7-84 1-2-4-5-6 R.W.

a Par. 1 refers to Paragraph 1 in Section 18.23 of this manual Par. 6 is also in Section 18.23.
b 1-4-7-10 represent the months of the year when the equipment should be serviced 1-January, 4-April, 7-July, and 10-October.

Fig. 18.1 Equipment service card and service record card

2i3
220 Water Treatment

1. Plant operation and maintenance instruction manuals, be carefully evaluated and any errors or weaknesses
corrected
2. Plant plans and specifications,
3. Manufacturers' instructions,
4. Reference books on water treatment,
5. Professional Journals and publications,
6. First-aid book,
7. Reports from other plants, and
8. A dictionary.

18.02 Emergencies
If your plant has not developed procedures for handling
potential emergencies, do it NOW. Emergency procedures
must be established for operators to follow when emergen-
cies are caused by the release of chlorine, hazardous or
toxic chemicals into the raw water supply, power outages or
broken transmission lines or distribution mains. These pro- 5 Emergency team performance must be reviewed annually
cedures should include a list of emergency phone numbers on a specified d ate. Review must include:
located near a telephone that is unlikely to be affected by the a. Training program,
emergency.
b. Response to actual emergencies, and
1. Police c. Team physical and mental examinations.
2. Fire WARNING. One person should never be permitted to at-
3. Hospital and/or Physician tempt an emergency repair alone. Always wait
for trained assistance. Valuable time could be
4. Responsible Plant Officials lost rescuing a foolish individual rather than
repairing or correcting a serious emergency.
5. Local Emergency Disaster Office
For additional information on emergencies, see Chapter 7,
6. CHEMTREC (800) 424-9300
Disinfection, Section 7.52, "Chlorine Leaks," Chapter 10,
7. Emergency Team (if your plant has one) Plant Operation, Section 10.9, "Emergency Conditions and
Procedures," and Chapter 23, Administration, Section 23 3,
The CHEMTREC toll-free number may be called at any "Contingency Planning for Emergencies." Chapter 23 con-
time. Personnel at this number will give information on how tains information on what to do if a toxic substance gets into
to handle emergencies created by hazardous materials and your water supply.
will notify appropriate emergency personnel.
An emergency team for your plant may be trained and QUESTIONS
assigned the task of responding to SPECIFIC EMERGEN-
CIES such as chlorine leaks. This emergency team must Write your answers in a notebook and then compare your
meet the following strict specifications at all times. answers with those on page 323.

1. Team personnel must be physically and mentally quali- 18.0A Why should you plan a god maintenance program
fied. for your treatment plant?

2. Proper equipment must be available at all times, includ- 18.08 What general items would you include in your mainte-
ing: nance program?

a. Protective equipment, including self-contained breath 18,0D Why should you have a good recordkeeping system
ing apparatus, for your maintenance program'?

b. Repair kits, and 18.0D What is the difference between an EQUIPMENT

SERVICE CARD and SERVICE RECORD CARD?
c. Repair tools.
18 OE Prepare a list :1 emergency phone numbers for your
3. Proper training must take place on a regular basis and treatment plant.
include instruction about:
18 OF What items should be included in the training pro-
a. Properties and detection of hazardous chemicals, gram for an emergency team?
b. Safe procedures for handling and storage of chemi- 18.1 ELECTRICAL EQUIPMENT
cals,
c. Types of containers, safe procedures for shipping 18.10 Beware of Electricity
containers, and container safety deices, and
18.100 Attention
d. Installation of repair devices.
4. Team members must be exposed regularly to simulated A. DO NOT ATTEMPT TO INSTALL, TROUBLESHOOT,
field emergencies or practice dulls. Team response must MAINTAIN, REPAIR OR REPLACE ELECTRICAL EQUIP-

24 0
 Maintenance 221

MENT, PANELS, CONTROLS, WIRING OR CIRCUITS Most municipalities employ electricians or contract with a
UNLESS YOU commercial electrical company that they call when major
1 KNOW WHAT YOU ARE DOING, problems occur. However, the maintenance operator should
be able to EXPLAIN HOW THE EQUIPMENT IS SUPPOSED
2. ARE QUALIFIED, AND TO WORK AND WHAT IT IS DOING OR IS NOT DOING
WHEN IT FAILS. After studying this section, you should be
3. ARE AUTHORIZED. able to tell an electrician what appears to be the problem
Sect.Jr1 1811, Electrical Fundamentals, is presented to with electrical panels, controls, circuits and equipment.
provide you with an understanding and awareness of The need for safety should be apparent. If proper safe
electricity. THE PURPOE E OF THE SECTION IS TO procedures are not followed in operating and maintaining
HELP YOU PROVIDE ELECTRICIANS WITH THE INFOR- the venous electrical equipment used in water treatment
MATION THEY WILL NEED WHEN YOU CONTACT facilities, accidents can happen that cause injuries, perma-
THEM AND REQUEST THEIR ASSISTANCE. YOU MUST nent disability, or loss of life. Some of the senous accidents
BE EXTREMELY FAMILIAR WITH ELECTRICITY BE- that have happened and could have been avoided occurred
FORE ATTEMPTING ANY MAJOR REPAIRS. when machinery was not shut off, locked out, and tagged
B. Due to the wide variety of equipment and manufacturers properly (Figure 18.2) Possible accidents include:
in the water treatment field, detailed procedures for the
1. Maintenance operator could be cleaning pump and have
maintenance of some types of equipment were very it start, thus losing an arm, hand, or finger,
difficult to include in this chapter. Also manufacturers are
continually improving their products and some details 2 Electrical motors or controls not properly grounded could
would soon be out of date FOR DETAILS CONCERNING lead to possible severe shock, paralysis, or death, and
THE OPERATION, MAINTENANCE AND REPAIR OF A
PARTICULAR PIECE OF EQUIPMENT, REFER TO THE 3 Improper circuits such as a wrong connection, safety
0 & A^ INSTRUCTIONS MANUAL OR CONTACT THE devices jumped, wrong fuses, or improper wiring can
MANUFACTURER. cause fires or injuries due to incorrect operation of
machinery
C Effective equipment maintenance is the key to successful
system performance. The better your maintenance, the Another consideration for having a basic working knowl-
better your facilities will perform. Abuse your equipment edge of electricity is to prevent financial losses resulting
and facilities and they will abuse you Everyone must from motors burning out and from damage to equipment,
realize that if the equipment can't work, no one can work machinery and control circuits. Additional costs result when
damages have to be repaired, including payments for out-
18.101 Recognize Your Limitations side labor
WARNING
In the water departments of all cities, there is a need for
maintenance operators to know something about electricity. NO 1-Ot.tC1.4 EaulOmeNrr
Duties could range from repairing a tail light on a trviler or PAss,..4,coNVOL.s, csac,th-r4, WIRIN1CvOR
vehicle to repairing complex pump controls and motors. czi.) OMEN?' LANL.E,4; Q0c4ARE OLAAL I FIEP
VERY FEW MAINTENANCE OPERATORS DO THE ACTU- Aro,' AUTHORIZE-p. 1341 THE nitAg-rzr'OLA
AL ELECTRICAL REPAIRS OR TROUBLESHOOTING BE- FIND OLAT WHAT 44)0 DON? 14140W AE3AAT
CAUSE THIS iS A HIGHLY SPECIALIZED FIELD AND et,EGIVICITV, QDLiCaAL.0 FIND Qactret...F
UNQUALIFIED PEOPLE CAN SERIOUSLY INJURE THEM- ..roo coAr, i2 LAS- 1.4NOLvt-er.
SELVES AND DAMAGE COSTLY EQUIPMENT. For these
reasons, you must be familiar with electricity, ,(NOW THE
HAZARDS, and RECOGNIZE YOUR OWN LIMITATIONS QUESTIONS
when you must work with electrical equipment. Write your answers in a notebook and then cc-,'pare your
answers with those on page 323
18.10A Why must unqualified or inexperienced people be
extremely careful when attempting to troubleshoot
or repair electrical equipment'?
18.10B What could happen when machinery is not shut off,
locked out, and tagged properly?

18.11 Electrical Fundamentals

18.110 Introduction
This section contains a basic introduction to electrical
terms and information plus directions on how to trouble-
shoot problems with electrical equipment.
Most electrical equipment used in water treatment plants
is labeled with name plate information indicating the proper
voltage and allowable current in amps.

18.111 Volts
Voltage (E) is also known as Electromotive Force (E.M.F.),
and is the electrical pressure available to cause a flow of

241_
222 Water Treatment

MAN
WORKING
ON LINE
DO NOT CLOSE THIS
SWITCH WHILE THIS
TAG IS IMPLAYED

SIGNATURE
This is the ONLY person authorized to remove this tag

Note: Tag also should Include: TIME OFF

DATE

Fig. 18.2 Typical warning tag

(Source Industrial Indemnity/Industrial Underwriters/Insurance Cos )

24""
 Maintenance 223

current (amperage) when an electrical circuit is closed.' This Single-phase power is found in lighting systems, small
pressure can be compared with the pressure or force that pump motors, various portable tools and throughout our
causes water to flow in a pipe Some pressure in a water homes This power is usually 120 volts and sometimes 240
pipe is required to make the water move The same is true of volts Single phase means that only one phase of power is
electricity. A force is necessary to push electricity or electric supplied to the main electrical panel at 240 volts and has
current through a wire This force is called voltage. There three wires or leads. Two of these leads have 120 volts
are two types of current Direct Current (D C) and Alternat- each, the other lead is neutral and usually is coded white.
ing Current (A.C.). The neutral lead is grounded. Many appliances and power
tools have an extra ground (commonly a green wire) on the
18.112 Direct Current (D.C.) case for additional protection.
Direct Current (D.C) flows in one direction only and is Thiee-phase power is generally used with motors and
essentially free from pulsation. Direct current is seldom used transformers found in water treatment plants, and usually is
in water treatment plants except in electronic equipment, 208, 220, 240 volts, or 440, 460, 480 and 550 volts. Higher
some control components of pump drives and stand-by voltages are used in sone pump stations. TI ree phase is
lighting Direct current is used exclusively 1 automotive used when higher power requirements or larger motors are
equipment, certain types of welding equipment, and a vari- used because efficiency is usually higher and motors require
ety of portable equipment. Direct current is found in various less maintenance. Generally speaking, all motors above two
voltages such as 6 volts, 12 volts, 24 volts, 48 volts, and 110 horsepower are three phase unless there is a problem with
volts All batteries are direct current. D.C. voltage can be the power company getting three phase to the installations.
measured by holding the positive and negative leads of a Three-phase power usually is brought in to the point of use
D C voltmeter on the corresponding terminals of the D.C. with three leads. There is power on all three leads and the
device such as a battery. Direct current usually is not found fuse switches will generally appear as shown in Figure 18.3.
in higher voltages (over 24 volts) around plants except in
motor-generator sets. Care must be taken when installing
battery cables and wiring that Positive (+) and Negative ()
poles are connected properly to wires marked (+) and (). If
not properly connected, you could get an arc of electricity
across the unit that could cause an explosion

18.113 Alternating Current (A.C.)

An alternating current circuit is one in which the voltage
and current periodically change direction and AMPLITUDE.2
In other words, the current goes from zero to maximum
strength, back to zero and to the same strength in the
opposite direction. Most A.C. circuiis have a frequency of 60
CYCLES3 per second. "Hertz" is the term we use to describe
the frequency of cycles completed per second so our P.C.
voltage would be 60 Hertz (Hz). n _____11

1.
Alternating current is classified as:
a. Single phase,
b. Two phase. and
c Three phase, or polyphase.
The most common of these are single phase and three
phase. The various voltages you probably will find on your
job are 110 volts, 120 volts, 208 volts, 220 volts, 240 volts,
277 volts, 440 volts, 480 volts, 2400 volts and 4160 volts. Fig. 18.3 Fuse switches
(Courtesy of Consolidated Electrical Distributors. Inc )

When making voltage measurements on three-phase

power circuits, take three readings: (1) between lead 1 and
lead 2, (2) between 1 and 3, and (3) between 2 and 3. The im-
balance between readings should not exceed five percent of
the average of the three readings and the average should
not be below the nominal voltage (20P 220, 240, 460) nor
should it exceed the nominal voltage by more than five
percent. Voltages that do not meet these limits will place
undue stress on electrical equipment, especially motors.

' Electricians often talk about _.'osng an electrical circuit. This means they are closing a switch that actually connects circuits together so
electricity can flow through the circuit. Closing an electrical circuit is like opening a valve on a water pipe.
2 Amplitude The maximum strength of an alternating current during its cycle, as distinguished from the mean or effective strength.
3 Cycle. A complete alternation of voltage and/or current in an alternating current (A.C.) circuit.

243
224 Water Treatment

When there is power in three leads and a fourth lead is These equations are used by electrical engineers for
brought in, it is a neutral lead Incoming power goes through calculating circuit characteristics If you memorize the fol-
a meter and then some type of disconnecting switch This lowing relationship, you can always figure out the correct
switch could be a fuse switch or a circuit breaker The formula
purpose of the disconnect switch is to open whenever a
short or fault occurs and thus protect both the electrical
circuits and electrical equipment.
Circuit breakers (Figure 18.4) are used to protect electrical
circuits from overloads. Most circuit breakers are metal
conductors that de-energize the main circuit when excess
current passes through a metal strip causing it to overheat
and open the main circuit.

To use the above triangle you cover up the term you don't
know or are trying to find out with your finger. The relation-
ship between the other two known terms will indicate how to
calculate the unknown. For example, if you r d trying to
calculate the current, cover up I. The two knowns (E and R)
are shown in the triangle as E/R. Therefore, I = E/R. The
Fig. 18.4 Circuit breakers same procedure can be used to find E when I and R are
(Courtesy of Consolidated Eiectrical Distributors Inc ) known or to find R when E and I are known.

18.115 Watts
Two-phase systems will not be discusses. oecause they
are seldom found in water treatment facilities. Watts (W) and kilowatts (kW) are the units of measurement
of the rate at which power is being used or generated. In
18.114 Amps D.C. circuits, watts (W) equal the voltage (E) multiplied by the
current (I).
An Ampere (I) is the practical unit of electric current. This
is the current produced by a pressure of one volt in a circuit Power, watts = (Current, amps) (Electromotive Force, volts)
having a resistance of one ohm. Amperage is the measure- or P, watts = (I, amps) (E, volts)
ment of current or electron flow and is an indication of work
being done or "how hard the electricity is working." In A C polyphase circuits the formula becomes more
complicated because of the inclusion of two additional
In order to understand amperage, one more term must be factors. First, there is the square root of 3, for three-phase
explained. The OHM is the practical unit of electrical resis- circuits which is equal to 1.73. Secondly, there is the power
tance (R). "Ohm's Law" states that in a given electrical circuit factor which is the ratio of the true or actual power passing
the amount of current (I) in amperes is equal to the pressure through an electrical circuit to the product of the voltage
in volts (E) divided by the resistance (R) in ohms. The times the amperage in the circuit. For standard three-phase
following three formulas are given to provide you with an induction motors the power factor will be somewhere near
indication of the relationships among current, resistance and 0.9. The formula for power input to a three-phase motor is:
EMF (electromotive force).
(E volts) (I, amps) (Power Factor) (1 73)
Power, kilowatts
EMF, Volts 1000 watts/kilowatt
Current, amps=
Resistance, ohms
Since 0 746 kilowatts equal 1.0 horsepower, then the power
EMF, Volts = (Current, amps) (Resistance, ohms) output of a motor is
Resistance, EMF, Volts Power Output = (Power Input, kilowatts) (Efficiency, %)
=
ohms horsepower
Current, amps (0.746 kilowatts/horsepower) (100%)

24 4
 Maintenance 225

18.116 Power Requirements Be sure the voltage tester that you are using has sufficient
range to measure the voltage you would expect to find. In
Power requirements (Pr) are expressed in kilowatt hours other words do not use a tester with a limit of 600 volts on a
500 watts for two hours or one watt for 1000 hours equals circuit that normally is energized at 2300 volts. With the
one kilowatt hour The power company charges so many voltage tester you can tell if the current is A.C. or D.C. and
cents per kilowatt hour. the intensity or voltage which will probably be one of the
Power req., kW-hr = (Power, kilowatts) (Time, hours) following: 120, 207, 230, 460, 2400, or 4160.

P;, kW-hr (P, kW) (T, hr) Do not work on any electr!ca! c!rcu!ts un!ess you are
qualified and authorized. Use a voltage tester and other
18.117 Conductors and Insulators circuit testers to determine if a circuit is energized, or if all
voltage is off. This should be done after the main switch is
turned off to make sure it is safe to work inside the electrical
pa.iel. Always be aware of the possibility that even if the
disconnect to the unit you are working on is off, the control
circuit may still be energized if the circuit originates at a
different distribution panel. Also a capacitor in the unit may
have sufficient energy stored to cause considerable harm to
an operator, such as a power factor correction capacitor on
a motor. Test for voltage both before and during the time the
switch is pulled off to have a double check. This procedure
ensures that the voltage tester is working and that you have
good continuity to your tester. Use circuit testers to measure
voltage or current characteristics to a given piece of equip-
ment and to make sure that you have or do not have a "live"
circuit.

A material, like copper, which permits the flow of electrical Besides using the voltage tester for checking power, it can
current is called a conductor. Material which will not permit be used to test for open circuits, blown fuses, single phasing
the flow of electricity, like rubber, is called an insulator. Such c' Mors, grounds, and many other uses. Some examples
material when wrapped or cast around a wire is called are illustrated in the following paragraphs.
insulation. Insulation is commonly used to prevent the loss In the circuit shown below (Figure 18.5), test for power by
of electrical flow by two conductors coming into contact with holding one lead of the tester on point "A," and the other at
each other. point "B." If no power is indicated, the switch is open or
faulty. Sketch shows switch in "open" position.
QUESTIONS
Write your answers in a notebook and then compare your
answers with those on page 323.
Light
18.11A What are two types of current? Switch
18.11B Amperage is a measurement of what? eil
A
C) 13
18.11C How can you determine the proper voltage and
allowable current in amps for a piece of equipment9 Ground

18.12 Tools, Meters and Testers Fig. 18.5 Single-phase circuit (switch in open position)
WARNING'

NeVEC2 s-tsrea AN Et-eC,TRICAL, PANEL,

OR ATTEMPT To -roaiii3t-E-Naol" Oa To test for power at Point "A" and Point "B" in Figure 18.6,
open the switch as shown. Using a volt meter or voitage
CIEPAIR ANQ Plea OF ei-EaralcAL. tester, connect a lead on Line 1 and a lead on Line 2, at
eziPMaNTDcl MP age.,12 ICA. Clr2ear points A and B, between the fuses and the load. Bring the
Litsit-vic, Oa APE QUAL-1'5i D AN17 voltage tester and leads out of the panel and dose the panel
AUTHORI7ED. door as far as possible without cutting or damaging the
meter leads. Some switches cannot be closed if the panel
door is open. The panel door is closed when testing because
hot copper sparks could seriously injure you when the circuit
18.120 Voltage Testing is energized and the voltage is high. Close the switch.
In order to maintain, repair, and troubleshoot electrical 1. Voltage tester should register at 220 volts. If there is no
equipment and circuits, the proper tools are required. You reading at points "A" and "B," the fuse or fuses could be
will need a VOLTAGE TESTER to check for voltage. There blown.
are several types on the market and all of them work. They
are designed to be used on energized circuits and care must 2. Move voltage tester to L1 and L2. If there is still no
be exercised when testing. By holding one lead on ground reading on the voltage tester, check for an open switch in
and the other on a power lead, you can determine if the another location, or call the power company to find out if
circuit is energized. power is out.

24: i
 226 Water Treatment

LINE

L1 NEUTRAL L2
INCOMING
SINGLE PHASE 220 VOLT
(110 VOLTS FROM N TO L1 AND
110 VOLTS FROM N TO L2
220 VOLTS FROM L1 TO L2
OR A TO B)

LOAD

Fig. 18.6 Single-phase, three lead circuit

3. If a 220 volt reading is registered at L1 and L2, clove the switch or a power company problem. Assuming normal
test leads to point "A," and the "neutral" lead If a reading readings were found at A3, B3, and C3, repeat the three
of 110 volts is observed, the fuse on line "A" is okay. If readings at points A2, B2, and C2 with the switch closed.
there isn't a voltage reading, the fuse on line "A" could be Any zero voltage readings are an indication of a defective
"blown." Move the lead from iine "A" to line "B." Observe
the reading. If 110 volt power is not observed, the fuse on
line "B" 'ould be "blown." Another possibility to consider
is that the neutral line could be bra an. Under these
conditions, if there is voltage on line "A" and the fuse on
line "B" is blown, voltage may appear on line "B."

WARNING
TURN OFF POWER AND BE SURE THAT THERE IS
NO VLT.AGE IN EITHER POWER LINE BEFORE
CHANGINJ FUSES. Use a FUSE PULLER. Test circuit
again in the same manner to make sure fuses or circuit
breakers are okay. 220 volts power or voltage should
be present between points "A" and "B." If fuse or circuit
breaker trips again, shut off and determine the source
of the problem.

Referring to Figure 18.7, test for voltage in three-phase

circuits as follows with the switch closed and the load
disconnected, check for voltage (probably either 220 or 440)
between points A3-B3, A3-C3, and between B3-C3. A zero
voltage reading on any or all of the three tests indicates a
problem ahead of this location that could be at another

246
 Maintenance 227

LINE
INCOMING
3 PHASE ---01"
220 VOLTS

82 1 C2

NIININI

FUSES

Al 131 Cl

Ll L2 L3

LOAD

Fig. 18.7 Three-phase circuit, 220 volts

switch. Assuming normal readings were found at A2, B2, AGE IS UNKNOWN AND THE METER HAS DIFFERENT
and C2, repeat the three readings at points Al, B1, and C1 SCALES THAT ARE MANUALLY SET, ALWAYS START
with the switch closed. If any two voltage readings are zero, WITH THE HIGHEST VOLTAGE RANGE AND WORK
one fuse is blown and it will be the one in the line that was DOWN. Otherwise the voltmeter could be damaged. Look at
common to the two zero readings. If all three voltage the equipment instruction manual or name plate for the
readings are zero, either two or three fuses are blown. To expected voltage. Actual voltage should not be much higher
determine which fuses are blown, refer to Table 18.1. Note than given unless someone goofed when the equipment was
that a zero voltage reading indicates a blown fuse. wired and inspected.

18.121 Ammeter
TABLE 18.1 LOCATING A BLOWN FUSE
Another meter used in electrical maintenance and testing
Blown Fuse In Line Use Either Test is the AMMETER. The ammeter records the current or
L1 Al -B2 or Al -C2 "arms" flowing in the circuit. There are several types of
ammeters, but only two will be discussed in this section. The
L2 B1 -A2 or B1 -C2 ammbt °r generally used for testing is called a "clamp on"
type. The term "clamp on" means that it can be clamped
L3 C1-A2 or C1-B2 around a wire supplying a motor, and no direct electrical
connection need be made. Each "leg" or lead on a three-
Another way of checking the fuses with the load connect- phase motor must be individually checked.
ed on this three-phase circuit would be to take your voltage
tester and place one lead on the bottom and one lead on the The first step should be to read the motor name. plate data
top of each fuse. You should NOT get a voltage reading on and find what the amperage reading should be for the
the voltmeter. This is because electricity takes the path of particular motor or device you are testing. After you have
least resistance. If you get a reading across any of the fuses this information, set the ammeter to the proper scale. Set it
(top to bottom), that fuse is bad. on a higher scale than necessary if the expected reading is
close to the top of the meter scale. Place the clamp around
ALWAYS MAKE SURE THAT WHEN YOU USE A VOLT- one lead at a time. Record each reading and compare with
METER IT IS SET FOR THE PROPER VOLTAGE. IF VOLT- the name plate rating. If the readings are not similar to the

24
228 Water Treatment

name plate rating, find the cause, such as low voltage, bad If the current on Lines L1, L2, and L3 are about the same
bearings, poor connections or excessive load. If the amme- both before and after the wiring change, this is an indication
ter readings are higher than expected, the high current could that the imbalance is being caused by the power company
produce overheating and damage the equipment. Try to find and they should be asked to make adjustments to correct
the problem and correct it. the condition. However, if the current reading followed the
Current imbalance is undesirable because it causes un- motor terminal (T) numbers rzther than the power line (L)
even heating in a motor that can shorten the life expectancy numbers, the problem is within the motor and there isn't
of the insulation. However, a small amount of current much that can be done except contact the motor manufac-
imbalance is to be expected in the leads to a three-phase turer for a possible exchange.
motor. This imbalance can be caused by either peculiarities When using a clamp on ammeter, be sure to set the meter
in the motor or by a power company imbalance. To isolate on a high enough range or scale for the starting current if
the cause, make the following test. Note that this test should you are testing during startup. Starting currents range from
be done by a qualified electrician. Refer to Figure 18.8. 500 to 700 percent higher than running currents and using

LINE

MOTOR
STARTER

Fig. 18.8 Determination of current imbalance

1. With the motor wired to its starter, L1 to T1, L2 to T2 and
L3 to 13, measure and record the amperage on L1, L2
and L3.
2. De-energize the circuit and reconnect the motor as fol-
lows: L1-T3, L2-T1, L3-T2. This wiring change will not
change the direction of the rotation of the motor.
3. Start up the motor and again measure and record the
amperage on L1, L2, L3.

2.4.-3
 Maintenance 229

too low a range can ruin an expensive and delicate instru- The test is an indication of cleanliness and good housekeep-
ment Newer clamp on ammeters automatically adjust to the ing as well as a detector of deterioration and impending
proper range and can measure both starting or peak current trouble
and normal running current.
Several criferia for "minimum values" of insulation resis-
Another type of ammeter is one that is connected in line tance have been developed. These values should be pro-
with the power lead or leads Generally they are not portable vided by the equipment manufacturer and should serve as a
and are usually installed in a panel or piece of equipment guide for equipment in service. However, periodic tests on
They require physical connections to put them in series with equipment in service will usually reveal readings consider-
the motor or apparatus being tested Current transformers ably high .r than the suggested minimum safe values Rec-
(CT) are commonly used with this type of ammeter so that ords of periodic tests must be kept, because persistent
the metar does rot have to conduct the full motor current downward trends in insulation resistance usually give fair
These ammeters are usually more accurate tha-. the clamp warning of impending trouble, even though the actual values
on type and are used in motor control centers and pump may be HIGHER than the suggested minimum safe values.
panels
Also. allowances must be made for equipment in service
18.122 Megger showing periodic test values LOWER than the suggested
minimum safe values, so long as the values remain stable or
A MEGGER is a crevice used for checking the insulation consistent In such cases, after due consideration has been
resistance on motors. feeders, buss bar systems, grounds. given to temperature and humidity conditions at the time of
and branch circuit wiring. the test, there may be no need for concern. THIS CONDI-
TION MAY BE CAUSED 3Y UNIFORMLY DISTRIBUTED
LEAKAGES OF A HARMLESS NATURE, AND MAY NOT BE
---YAlth117a1 THE RESULT OF A DANGEROUS LOCALIZED WEAK-
UE MEC.15-12 ONI.? ON 0E-EN5C2bIZa7 NESS Here again, records of insulation resistance tests
AA017, over a period of time reveal changes which may justify
CIRCO
investigation. The "trend of the curve" may be more signifi-
cant than the numerical values themselves
There are three general types of meggers crank operat- For many years ONE MEGOHM4 has been widely used as
ed. battery operated. and instrument There are two leads to a fair allowable lower limit for insulation resistance of
connect One lead is clamped to a ground leac Ind the other ordinary industrial electrical equipment rated up to 1000
to the lead you are testing The readings on t, megger will volts. This value is still recommended for those who may not
range from "0" (ground) to Infinity (perfect). depending on the be too familiar with insulation resistance testing practices, or
condition of your circuit. who may not wish to approach the problem from a more
The megger is usually connected to a motor terminal at technical point of view
the starter. and the other lead to the ground lead. Results of For equipment rated above 1000 volts, the one megohm"
this test indicate if the insulation is deteriorating or cut rule is usually stated. "A minimum of one megohm per
Insulation resistance of electrical equipment is affected by thousand volts Although this rule is somewhat arbitrary,
many variables such as the equipment design, the type of
insulating material used, including binders and impregnating
compounds. the thickness of the insulation and its area. GAOhttoJi4A-1
cleanliness (or uncleanliness), moisture, and temperature ARgprra"±i2g aui-E
For insulation resistance measurements to be conclusive in
analyzing the condition of equipment being tested. these MINIMUM oF Ma4401,04
variables must be taken into consideration.
V.i)LA,;;At4f7 vouP,"
Such factors as the design of the equipment, the kind of
insulating material used, and its thickness and area cease to
be variables after the equipment has been put into service,
and minimum insulation resistance values can be estab- As.
lished within reasonable tolerances. The variables that must
be considered after the equipment has been put into service.
and at the time that the irsulation resistance measurements
are being made, are uncleanliness, moisture, temperature. and may be criticized as iing an engineering foundation,
and damage such as fractures it has stood the test of a good many year.; of practical
experience. This rule gives some assurance that equipment
The most important requirements in the reliable operation is not too wet or not too dry and has saved many an
of electrical equipment are cleanliness and the elimination of unnecessary breakdown.
mor:t.tre penetration into the insulation. This is merely good
housekeeping but it is essential in the maintenance of all More recent studies of the problem, however, have result-
types of electrical equipment. The very fact that insulation ed in formulas for minimum values of insulation resistance
resistance is affected by moisture and dirt, with due that are based on the kind of insulating material used and
allowances for temperature, makes the "megger" insulation the electrical and physical dimensions of the types of
test the valuable tool which it is in electrical maintenance. equipment under consideration

4 Megohm Meg means one million, so 5 megohms means 5 million ohms A megger reads in millions of ohms
5 Portions of the preceding paragraphs were taken from INSTRUCTION MANUAL FOR MEGGER INSULATION TESTERS, No
pages 42 and 43, published by Biddle Instruments, go Advertising Department, 510 Township Line Road, Blue Bell, Pennsylvania
19422. For additional information see Biddle's publication, A STITCH IN TIME, price $2.00

24
 230 Water Treatment

Motors and wirings should be megged at least once a where the power enters. This protection is provided by
year. and twice a year if possible. The readings taken should either fuses or a circuit breaker
be recorded and plotted in some manner so that you can
determine when insulation is creaking down. Meg motors 18.131 Fuses
and wirings after a pump station has been flooded. If
insulation is wet, excessive current could be drawn and Let s start with fuses The power company has installed
cause pump motors to "kick out fuses on their power noles to protect their equipment from
damage We also must install something to protect the main
18.123 Ohm Meters control panel and wiring from damage due to excessive
voltage or amperage
OHM MET ERS, sometimes called circuit testers, are valu-
able tools used for checking electrical circuits. An ohm meter A FUSE is a protective device having a strip or wire of
is used only when the electrical circuit is OFF, or de- fusible metal which, when placed in a circuit, will melt and
energized The ohm meter supplies its own r-wer by using break the electrical circuit when subjected to an excessive
batter es An ohm meter is used to measure the resistance temperature This temperature will develop in the fuse when
(ohms) in a circuit These are most often used in testing the a current flows through the fuse in excess of what the circuit
control circuit components such as coils, fuses, relays, will carry safely This means that the fuse must be capable of
resistors, and switches. They are used also to check for de-energizing the circuit before any damage is done to the
continuity An ohm meter has several scales which can be wiring it is safely protecting. Fuses are used to protect
used Typical scales are: R x 1, R x 10, R x 1,000, and R x operators, main circuits, branch circuits, heaters, motors,
10,000. Each scale has a level of sensitivity for measuring an'' 'anous other electrical equipment.
different resistances. To use an ohm meter, set the scale. I ei e are several types of fuses, each being used for a
start at the low point (R x 1), and put the two leads across
certain type of protection. Some of these are:
the part of the circuit to be tested such as a coil or resistor
and read the resistance in ohms. A reading of infinity would 1 CURRENT-LIMITING FUSES. These fuses open so
indicate an L, pen circuit, and a "0" would read no resistance. quickly while clearing a short-circuit current that the
These usually would be used only by skilled technicians potential fault current is not allowed to reach its peak.
because they are very delicate instruments. They are used to protect power distribution circuits.
All meters should be kept in good working order and 2 DUAL-ELEMENT FUSES: These fuses provide a time
calibrated periodically They are very delicate, susceptible to delay in the low overload range and a fast acting element
damage, and should be well protected during transportation. for short-circuit protection. These fuses are used for
When readings are taken, they should always be recorded motor protection arc Jits.
on a machinery history card for future reference. Meters are
a good way to determine pump and equipment perform- There are many other types of fuses used for special
ance. NEVER USE A METER UNLESS QUALIFIED AND application. but the above are the most common.
AUTHORIZED. A fuse must NEVER be by-passed or jumped. This is the
only protection the circuit has; without it, serious damage to
QUESTIONS equipment and possible injury to operators can occur. Make
Write your answers in a notebook and then compare your sure that all fuses are replaced with the proper size and type
answers with those on page 323. indicated for that circuit. If you have any doubt, check the
electrical prints or contact your electrical engineer.
18 12A How can you determine if there is voltage in a
circuit'
18.12B What are some of the uses of a voltage tester9
18.12C What precautions should be aken before attempt-
ing to change fuses9
18.12D How do you test for voltage with a voltmeter when
the voltage is unknown?
18.12E What could be the cause of amp readings different
from the name plate rating?
p
18.12F How often should motors and wirings be megged'
18 12G An ohm meter is used to check the ohms of
resistance in what control circuit components?

18.132 Circuit Breakers

18.13 Switch Gear
The CIRCUIT BREAKER (Figure 18.4) is another safety
18.130 Equipment Protective Devices device and is used in the same place as a fuse. Most circuit
breakers consist of a switch that opens automatically when
Electricity needs safety devices to protect operators and the current or the voltage exceeds or falls below a certain
equipment Water systems have pressure valves, pop offs limit. Unlike a fuse that has to be replaced each time it
and different safety equipment to protect the pipes ant- "blows," a circuit breaker can be reset after a short delay to
equipment. So must electricity have safety devices to con- allow time for cooling. This is done by moving the handle to
tain the voltage and amperage that Npmes in contact with the the "off" position or slightly past, and then moving it back to
wiring and equipment. The first piece ,:f equipment which the "on" position. Also, unlike a fuse, a circuit breaker can be
must be protected is the main electrical panel or control unit visually inspected to find out if it has been tripped. The

23 ti
 Maintenance 231

handle will be at the mid position between "on" and "off.' action This starter has contractors and titey operate by
Several different types of circuit breakers are being used energizing a coil which closes the contact, thus starting the
today and each one is selected for a F icial protective motor The circuit which energizes the starter is called the
purpose. control circuit and it may operate on a lower voltage (115
volts) than the motor. Whenever a starter is used as a pert of
18.133 Overload Relays an integrated circuit (such as for flow, pressure or tempera-
ture control), a magnetic starter or controller is necessary.
Three-phase motors are usually protected by OVERLOAD
relays. This is accomplished by having heater strips, bimetal, Magnetic starters are sized for their voltage and horse-
or solder pots which open on current rise (overheating), and power ratings These are divided into classes The most
open the control circuit. This in turn opens the power control conmon starter is Class "A." A Class "A" starter is an
circuit, which de-energizes the starter and stops power to 'Alternating Current air-break and oil immersed mania!, or
the motor. Such relays are also known as heaters or magnetic controller for service on 600 volts or less. It is
thermal overloads. Sizing of these overloads is very critical capable of interrupting operating overloads up to and ,nolud-
and should coincide with the name plate rating on the motor. ing 10 times their normal motor rating, but not short circuits
Sizing depends on the servic,? factor of the electnc motor. or faults beyond operating overloads."
Usually they range from 100 to 110 percent of the motor
Additional class information can be found in electrical
name plate ratings and should never exceed 125 percent
catalogs, manuals and manufacturers' brochures.
(isually 115 percent) of the motor rating. For example, if the
motor is rated for 10 amps, the overloads should be sized There are a number of different types of three-phase
from 10 to 11 amps. magnetic motor starters available. The simplest and most
Again, NEVER INCREASE 7-1E RATING OF THE OVER-
common is the "across-the-line" full voltage starter. This
LOAD HEATERS BECAUSE OF TRIPPING. YOU SHOULD
starter consists of three contacts, a magnetic actuating
device, and overload detection. This starter subjects the
FIND THE PROBLEM AND REPAIR IT. There are many
other protective devices for electricity such as motor wind- power system to the full surge current on startup and may
cause the lights in the treatment plant to dim momentarily.
ing thermostats, phase protectors, low voltage protectors,
and ground fault protectors. Each has its own special To reduce the in-rush current when starting polyphase
applications and should never be tampered with or jammed. motors, a number of other types of starters are available.
GROUND is an expression representing an electrical 1. Auto-Transformer Type Reduced Voltage Starters. These
connection to earth or a large conductor which is at the begin the motor start sequence by applying a reduced
earth's potential or neutral voltage. Motor frames and all voltage to the motor for a few seconds. The voltage is
electrical tools and equipment enclosures should be con- controlled by a time delay relay within the starter. The
nected to ground. This is generally referred to simply as reduced voltage is obtained from transformers that are a
grounding, or equipment ground. part of the starter. These transformers are designed to
operate for only a few seconds at a time and can easily be
The third prong on cords from electric hand tools is the burned out if the motor is started too frequently.
equipment ground and must never be removed. When an
adapter is used with a two-prong receptacle, the green wire 2 Solid State Reduced Voltage Starters. These starters do
on the adapter should be connected udder the center screw the same job as the auto-transformer type reduced
on the receptacle cover plate. Many times equipment voltage starters but they do not need transformers be-
grounding, especially at home, is achieved by connecting cause the voltage and current are Llectncally controlled.
onto a water pipe or drain rather than a rod driven into the
ground. This practice generally is not recommended when 3 Part Winding Starters. These starters are used with
plastic pipes and other non-conducting pipe materials are special motors that have two separate sets of windings
used unless it is known that the piping is all metal and not in- on the same motor frame. By energizing the windings
terrupted. Also corrosion can be accelerated pipes of about one second apart, the in-rush current is limited to
different metals are used. A rod driven into dry ground isn't about half that of a normal motor with a full voltage
very effective as F around. starter.
4. Wye-Delta Starters. These starters are used with motors
18.134 Motor Starters that have all leads brought out to the terminal box. The
A motor starter is a device or group of devices which are
motor is first started with wye connected coils and
switched over to a aelta connection for running. The
used to connect the electrical power to a motor. These result is the same as if you used a reduced voltage
starters can be either manually or automatically controlled.
starter.
Manual and magnetic starters range in complexity from a
single "on-off" switch, to a sophisticated automatic device
QUESTIONS
using timers and coils. The simplest motor starter is used on Write your answers in a notebook and then compare your
single-phase motors where a circuit breaker is turned on answers with those on page 323.
and the motor starts. This type of starter also is used on
three-phase motors of smaller horsepower. These are used 18 13A What are two types of safety devices found in main
on fan motors, machinery motors, and several others where electrical panels or control units9
it isn't necessary to have automatic control. 18.13B What are fuses used to protect?
MAGNETIC STARTERS (Figures 18.9 and 18.10) are 18.13C Why must a fuse never be by-passed or jumped?
commonly used to start pumps, compressors, blowers, and
anything where automatic or remote control is desired. They 18.13D How does a circuit breaker work?
permit low power circuits to energize the starter of equip- 18.13E How are motor starters controlled?
ment at a remote location or to start larger starters (Figure
18.11). A magnetic starter is operated by electromagnetic 18.13F When are magnetic starters used?

25
232 Water Treatment

FURNAS
Heater Overloads

., r
-Mi

Fig. 18.9 Three-phase magnetic starter

(Courtesy of Furnas Electric Company)
 Maintenance 233

Start Stop
Button Button

Fuses

Hold In
Control

Contacts
Coil

Overload Overloads
Contacts (Sometimes two but
preferably three)

T1- T3

Fig. 18.10 Wiring diagram of three-phase magnetic starter

ELECTRICAL
CONTROL CENTER
LOW VOLTAGE
CONTROL CIRCUIT

STOP RELA MAGNETIC

START REMOTE STARTER
SWITCH HIGH VOLTAGE

Fig. 18.11 Application of magnetic starter

 234 Water Treatment

18.14 Electric Motors

QUESTIONS
18.140 Classification Write your answers in a notebook and then compare your
answers with those on page 324.
Electric motors are the machines most commonly used to
convert electrical energy into mechanical energy. A motor 18 14A How is electrical energy converted into mechanical
usually consists of a STATOR,8 ROTOR,' END BELLS,8 and energy?
Windings. The rotor has an extending shaft which allows a
machine to be coupled to it. 18.148 What are the important parts of an electric motor?
Motors are of many different types (Figure 18.12), such as, 18 14C How can motors be kept trouble free?
squirrel cage induction motors, wound rotor motors, syn- 18.14D What should be done with motor name plate data
chronous motors and many others. The most common of
these is the squirrel cage induction motor. Some pumping
stations use wound rotor induction motors when speed 18.141 Troubleshooting
control is needed
Practical stop-by-step procedures combined with a com-
Three-phase electric motors are used for operating mon sense approach is the key to effective troubleshooting.
pumps, compressors, fans and other machinery. Motors are
generally trouble free and, when lubncated properly, cause
very few problems The amperage and voltage readings on
motors should be taken periodically to insure proper oper-
°KW? 01/6 mil f1.110 FOR 6Aiviee
ation
A. Gather preliminary information. The first step in trouble-
Motors are classified by NEMA (National Electrical Manu- shooting any motor control which has developed trouble
facturers Association) with code letters from A through V is to understand the circuit operation and other related
with "A" having the lowest starting torque and in-rush current functions. In other words, what is supposed to happen,
and "V" having the highest starting torque and in-rush operate, and so forth when it's working right? Also, what
current The most commonly available motors have cod, is it doing now? The qualified maintenance operator
letters from "F" through "L" which have in-rush currents on should be able to do the following:
start of from 500 to 1000 percent of full load.
1. KNOW WHAT SHOULD HAPPEN WHEN A SWITCH IS
Another important consideration in selecting a motor is PUSHED: When switches are pushed or tripped, know
the class of insulation. This determines how hot a motor may what coils go in, contacts close, relays operate, and
operate and is listed as degree rise on the motor nameplate motors run.
(Figure 18.13).
2. EXAMINE ALL OTHER FACTORS: What other unusual
Motor insulation classes are as follows: things are happening in the plant now that this circuit
Class Temperaturing Rating doesn't work properly? Lights dimmed, other pumps
A 105°C (221°F)
B 130°C (266°F)
F 155°C (311°F)
H 180°C (356°F)
At present most motors are Class B insulated. Try to keep
the actual operating temperature below the temperature
rating or limit in order to prolong the life of the insulation.
All of this information can be found on the motor name
plate and should be taken into consideration when evaluat-
ing a motor. Most of the trouble encountered with electrical
motors results from bad bearings, shorted windings due to stor ed, lights went out when it broke, everything was
insulation breakdown or excessive moisture. flooded, operators were hosing down area, and many
other possible factors.
All of the information on the motor name plate (Figure
18.13) should be recorded and placed in n file for future 3. ANALYZE WHAT YOU KNOW: What part of it is
reference. Many times the name plate is painted, corroded working correctly? Is switch arm tripped? Is it a
or missing from the unit when the information is needed to mechanical failure or an electrical problem caused by
repair the motor or replace parts. Also record the date of a mechanical failure?
installation and service startup. See Section 18.142, "Rec-
ordkeeping," for a typical data sheet for recording the 4. SELECT SIMPLE PROCEDURES: To localize the
essential information. This information also should be on the problem, select logical ways that can be simply and
manufacturer's data sheet and in the instruction manual. quickly accomplished.
Compare the information for consistency and file in an 5. MAKE A VISUAL INSPECTION: Look for burned
appropriate location. Be sure you have the correct serial wires, loose wires, area full of water, coil burned,
and/or model numbers. contacts loose, or strange smells.
6 Stator That portion of a machine which contains the stationary (non-moving) parts that surround the moving parts (rotor).
7 Rotor The rotating part of a machine. The rotor is surrounded by the stationary
(non-moving) parts (stator) of the machine,
8 End Bells. Devices used to hold the rotor and stator of a motor in position.
 Maintenance 235

DRIP PROOF

ITEM
NO.
PART NAME

1 Wound Stator w/ Frame

2 Rotor Assembly
3 Rotor Core 1
4 Shaft to*
5 Bracket
6 Bearing Cap
7
7 Bearings
8 Seal, Labyrinth
9 Thru Bolts/Caps
10 Seal, Lead Wire
11 Terminal Box
12 Terminal Box Cover
13 Fan
1 14 Deflec:-or
15 Lifting Lug Itv-e-""

TOTALLY ENCLOSED FAN COOLED

ITEM 17

NO.
PART NAME

4
1
2
3
Wound Stator w/ F:,ama
Rotor Assembly
Rotor Core
Shaft
15

,0 I/ 5

Palley Lad

7
5 Brackets 1S

6 Bearings.
7 Seal, Labyrinth
8 Thru Bolts/Caps
9 Seal, Lead Wire
10 Terminal Box 111

11 Terminal Box Cover

12 Fan, inside
13 Fan, Outside
_4 Fan Grill
13
15 Fan Cover
16 Fan Cover Bolts
17 Lifting Lug

Fig. 18.12 Typical rr.s.fors

:ourtesy of Starting Power Systems. Inc
236 Water Treatment

St din VARIABLE SPEED

SERIAL NO. B-9610283
H.P. S !DESIGN Ame 55 ABFK TYPE

FRAME 215 CLASS

40 R TING
INSUL.
DUTY Continuous
EPDXY ENCAPSULATED
T
MOTOR MIN.
R.P.M. 1750 1200 900
R.P.M. R.P.M.
PHASE 3 ICYCLE 60 I CLASS 'CODE

nnn 440 I 220

F

MMINIMNIO
L

7.6 nia.6. 15,2

000 I 1'
0
NOTE 1. The motor for this unit is rated at 1750 RPM and
the maximum speed for the variable drive unit is
1200 RPM.
2. The 40°C rating is t'le allowable operating tem-
perature above ambient tempera'ure.

Fig. 18.13 Typical nameplate

(Courtesy of Sterlsng Power Systems. Inc.)

6 CONVERGE ON SOURCE OF TROUBLE: Mechanical 18.142 Recordkeeping

or electrical. Motor or control, whatever it might be
Electrical problems result from some type of mechani- Records are a very important part of electrical mainte-
cal failure. nance They must be accurate and complete. Whenever
something is changed, repaired. or tested, it should be
7 PINPOINT THE PROBLEM. Exactly where is the prob- recorded on a material history cz 'd of some type. Pages 242
lem and what do you need for repair? and 243 are examples gt typical record sheets
8. FIND THE CAUSE. What caused the problem9 Mois-
ture, wear, poor design, voltage, or overloading.
QUESTIONS
9. REPAIR THE PROBLEM AND ELIMINATE THE
CAUSE IF POSSIBLE. If the problem is inside switch Write your answers in a notebook and then compare your
gear or motors, call an electrician. Give the electrician answers with those on page 324.
the information you have regarding the equipment. Do
18 14E What is the key to effective troubleshooting9
not attempt electrical repairs unless qualified and
authorized, otherwise you could cause excessive 18.14F What are some of the steps that should be taken
damage to yourself and to the equipment. when troubleshooting electrical equipment?
B Some of the things to look for when troubleshooting are 18 14G What kind of information should be recorded re-
given in the remainder of this section, garding electrical equipment?

2 Fic
 Maintenance 237

ELECTRIC MOTOR TROUBLESHOOTING

1. Contacts
Trouble Possible Causes Remedy
Contact chatter 1. Broken POLE SHADER 9 1. Replace
2. Poor contact in cc,ntro! circuit. 2. Improve contact or use holding circuit
interlock
3. Low voltage 3. Correct voltage condition. Check mo-
mentary voltage dip.
Welding or freezing 1. Abnormal surge of current. 1. Use larger contactor and check for
grounds, shorts, or excessive motor
load current.
2. Frequent JOGGING.1° 2. Install larger device rated for jogging
service or caution operator.
3. Insufficient contact pressure. 3. Replace contact spring; check contact
carrier for damage.
4. Contacts not positioning properly. 4. Check for voltage dip during startup.
5. Foreign matter preventing magnet 5. Clean contacts.
from seating.
6. Short cir,,Jit 6. Remove short fault and check that
fuse or breaker are right.
Short contact life or overheating 1. Contacts poorly aligned, spaced or 1. Do not file silver-faced contacts.
of tips damaged. Rough spots or discoloration will not
harm contacts.
2. E.,z-Qively high currents. 2. Install larger device. Check for
grounds, shorts, r excessive motor
currents.
3. Excessive starting and stopping of 3. Caution operators. Check operating
motor. controls.
4. Weak contact pressure. 4. Adjust or replace contact springs.
5. Dirty contacts. 5. Clean with approved solvent.
6. Loose connections. 6. Check terminals and tighten.
Coil. overheated 1. Starting coil may not kick out 1. Repair coil.
2. Overload won't let motor reach mini- 2. Remove overload.
mum speed.
3. Over voltage or high ambient tem- 3. Check application and circuit.
perature.
4. Incorrect CO( 4. Check rating and if incorrect, replace
with proper coil.
5. Shorted turns caused by mechanical 5. Replace coil.
damage or corrosion.
6. Undervoltage, failure of magnet to 6. Correct system voltage.
seal it.
7. Dirt or rust on pole faces increasing 7. Clean pole faces
air gap.

9 Pole Shader. A copper bar circling the laminated iron core inside the coil of a magnetic starter.
10 Jogging. The frequent starting and stopping of an electric motor.
238 Water Treatment

ELECTRIC MOTOR TROUBLESHOOTING ,:lontinued)

Trouble Possible Causes Remedy
Overload relays tripping 1 Sustained overload 1. Check for grounds, shorts or exces-
sive motor currents Mechanical over-
load
2. Loose connection on all or any load 2 Check, clean, and tighten.
wires.
3 Incorrect heater 3. Replace with correct size heater unit.
4. Fatigued heater blocks. 4. Inspect and replace
Failure to trip overload relay 1. Mechanical binding, dirt, or corrosion. 1 Clean or replace.
2. Wrong heater, or heaters omitted and 2. Check ratings Apply heaters of prop-
jumper wires used er rating.
3. Motor and relay in different tempera- 3. Adjust relay rating accordingly, or in-
tui e :.= stall temperature compensating re-
lays.
2. Magnetic and Mechanical Parts
Noisy magnet (humming) 1 Broken shading cod. 1. Replacing shading coil.
2. Magnet faces not mating. 2. Replace magnet assembly or realign
3. Dirt or rust on magnet faces. 3 Clean and realign.
4. Low voltage. 4. Inspect system voltage and voltage
dips during starting.
Failure to pick up and seal 1. Low voltage 1 Inspect system voltage and correct.
2. Coil open or shorted. 2. Replace.
3. Wrong coil. 3. Check coil number and voltage rating.
4. Mechanical obstruction 4. With power off, check for free move-
ment of contact and armature assem-
bly. Repair.
Failure to drop out 1. Gummy substance on pole 1. Clean with solvent.
2. Voltage not removed from coil. 2. Check coil circuit.
3. Worn or rusted parts caus:ng binding. 3. Replace or clean parts as necessary.
4. Residual magnetism due to lack of air 4. Replace worn magnet parts or align if
gap in magnet path. possible.
5 Welded contacts. 5 Replace contacts.

2F3
 Maintenance 239

TROUBLESHOOTING GUIDE FOR ELECTRIC MOTORS

Symptoms Cause Result* Remedy
=
*. Motor :loes not a Incorrectly connected. a Burnout. a Connect correctly per diagram
start. (Switch is on on motor
and not defective )
b. Incorrect power supply. b Burnout b Use only with correctly rated
power supply.
c. Fuse out. loose or open con- c Burnout c Correct open circuit condition.
nection.
d Rotating parts of motor may d. Burnout d. Check and correct:
be jammed mechanically 1. Bent shaft.
2. Broken housing.
3. Damaged bearing.
4. Foreign material in motor.
e. Driven machine may be e. Burnout e Correct jammed condition.
jammed.
f. No power supply. f. None. f Check for voltage at motor and
work back to power supply.
g. Internal circuitry open. g Burnout. g. Correct open circuit condition.
2 Motor starts but a. Same as 1-a, b, c above. a. Burnout. a. Same as 1-a, b, c above.
ooes not come up
to speed b Overload. b. Burnout. b. Reduce load to bring current to
rated limit. Use proper fuses
and overload protection.
c. One or more phases out on c. Burnout. c. Look for open circuits.
a 3 phase motor.
3 Motor noisy electri- a. Same as 1-a, b, c above. a. Burnout a. Same as 1-a, b, c above.
cally.
r
4. Motor runs hot (ex- I a. Same as 1-a, b, c above. a. Burnout. a. Same as 1-a, b, c above.
ceeds rating). b. Reduce load.
b. Overload. b. Burnout.
c. Impaired ventilation. c. Burnout. c Remove obstruction.
d. Frequent start or stop d. Burnout d. 1. Reduce number of starts or
reversals.
2. Secure proper motor for this
duty.
e. Misalignment between rotor e. Burnout e. Realign.
and ztator laminations.
5 Noisy a. Misalignment of coupling or a. Bearing failure, a. Correct misalignment.
(mechanically) sprocket. broken shaft, stator
burnout due to motor
drag.
b. Mechanical unbalance of ro- b. Same as 5-a. b. Find unbalanced part, then bal-
tating parts. ance.
c. Lack or imprope' lubricant. c. Bearing failure c. Use correct lubricant, replace
parts as necessary.
d. Foreign material in lubricant. d. Same as 5-c. d. Clean out and replace bear-
ings.
e. Overload. e. Same as 5-c. e. Remove overload condition.
Replace damaged parts.
f. Shock loading. f. Same as 5-c. f. Correct causes and replace
damaged parts.
g. Mounting acts as amplifier g. Annoying. g. Isolate motor from base.
of normal noise.
h. Rotor dragging due to worn h. Burnout. h. Replacing bearings, shaft or
bearings, shaft or bracket. bracket as needed.
6 Bearing failure a. Same as 5-a, b, c, d, e. a. Burnout, damaged a. Replace bearings and follow 5-
shaft, damaged hous- a, b, c, d, e.
ing.
b. Entry of water or foreign ma- b. Same as 6-a. b. Replace bee rings and seals
tenal into bearing housing. and shield against entry of for-
eign material (water, dust, etc.).
Use proper motor.
Many of these conditions should trip protective devices rather than burn out motors.

259
240 Water Treatment

TROUBLESHOOTING GUIDE FOR ELECTF MOTORS (continued)

Symptom Caused By I A, pearance
1 Shorted motor winding a Moisture, chemicals, foreign material in a. Black or burned with remainder of winding
motor, damaged winding. good.
2 All windings completely a. Overload. a. Burned equally all around winding
burned
b. Stalled. b. Burned equally all around winding.
c. Impaired ventilation. c. Burned equally all around winding
d. Frequent reversal or starting d Burned equally all around winding.
e. Incorrect power. e. Burned equally all around winding.
3 Single phase cond ,,n a Open circuit in one line. The most common a. If 1800 RPM motor four equally burned
causes are loose connectior, one fuse groups at 90° intervals.
out, loose contact in switch.
b. If 1200 RPM motor six equally burned
groups at 60° intervals
c. If 3600 RPM motor two equally burned
groups at 180°.
NOTE: If Y-connected each burned group
will consist of two adjacent phase groups.
If delta-connected each burned group will
consist of one phase group.
4 tither a. Improper connection a Irregularly burned groups or spot burns.
b Ground.
Many burnouts occur within a short period c, time after motor is started up This does not necessarily indicate that the motor was defec-
tive, but usually is due to one or more of the above mentioned causes The most common of these are improper connections, open circuits
in one line, incorrect r, wer supply or overload

2 G0
 Maintenance 241

TROUBLE-REMEDY CHART FOR INDUCTION MOTORS

A. Motor will riot start. 4. Incorrect voltage and frequency: check name plate
values with power supply. Also check voltage at
Overload control tripped. Wm( for overload to cool, then motor terminals with motor under full load.
try to start again. If motor still does not start, check for the
5. Motor stalled by driven tight bearings: remove power
causes outlined below.
from motor. Check machine for cause of stalling.
1. Open fuses: test fuses. 6. Stator winding shorted or grounded: test windings by
2. Low voltage check name plate values against power standard method.
supply characteristics. Also check voltage at motor 7. Rotor winding with loose connection: tighten, if pos-
terminals when starting mot r under load to check sible, or replace with another rotor.
for allowable voltage drop. 8. Belt too tight: remove excessive pressure on bear-
3. Wrong control connections: check connections with ings.
control wiring diagram. 9. Motor used for rapid reversing service. replace with
motor designed for this service.
4. Loose terminal-lead connection: turn power off and
tighten connections. D. Bearings hot.
1. End shields loose or not replaced properly: make
5. Drive machine locked: disconnect motor from load. If
sure end shields fit squarely and are properly tight-
motor starts satisfactorily, check driven machine.
ened.
6. Open circuit in stator or rotor winding: check for open 2. Excessive belt tension or excessive gear side thrust:
circuits. reduce belt tension or gear pressure and realign
7. Short circuit in stator winding: check for short. shafts. See that thrust is not being transferred to
motor bearing.
8. Winding grounded: test for grounded wiring 3. Bent shaft: straighten shaft or send to motor repair
9. Bearing stiff: free bearing or replace. shop.

10. Overload: reduce bad.

6 Motoi noisy.
":Iiree-phase motor running on single phase. stop
motor, then try to start. It will not start on single
phase. Check for open circuit in one of + ..1 lines.
2. Electrical load unbalanced: check current balance.
3. Shaft bumping (sleeve-bearing motor): check align- E. Sleeve baarings.
ment and conditions of belt. On pedestal-mounted 1. Insufficient oil: add oil - if supply is very low, drain,
bearing check cord play and axial centering of rotor. flush,and refill.
4. Vibration: driven machine may tha unbalanced. Re- 2. Foreign material in oil or poor grade of oil: drain oil,
move motor from load If motor is still noisy, re- flush, and relubncate using industrial lubricant rec-
omm- ..ded by a reliable oil manufacturer.
balance.
3. Oil rings rotating slowly or not rotating at all: oil too
5. Air gap not uniform: ceilter tt . rotor arid if necessary heavy; drain and replace. If oil ring has worn spot,
replace bearings. replace with new ring.
6 Noisy ball bearing: check lubrication. Replace bear- 4. Motor tilted too far: level motor or reduce tilt and
ings if noise is excessive and persistent. realign if necessary.
7. Rotor rubbing on stator: center the rotor and replace 5. Rings bent or otherwise damaged in reassembling:
bearings if necessary. replace rings.

8. Motor loose on foundation: tighten hold-down bolts. 6. Rings out of slot (oil-ring retaining clip out of place):
Motor may possibly have to be realigned. adjust or replace retaining clip.
7. 'Jefective bearings or rough shaft: replace bearings.
9. Coupling loose: insert feelers at four places in cou- Resurface shaft
pling joint before pulling up bolts to check alignment.
Tighten coupling bolts securely. F. Ball bearings.
1. Too much grease: remove relief plug and let motor
C. Motor at higher than normal temperature or smoking. run. If excess grease does not come out, flush and
(Measure temperature with thermometer or thermister
relubncate.
and compare with name plate value.)
2. Wrong grade of grease: flush bearing and relubncate
1. Overload: measure motor loading with ammeter. with correct amount of proper grease.
Reduce load.
3. Insufficient grease: remove relief plug and grease
2. Electrical load unbalance: check for voltage unbal- bearing.
ance or single-phasing. 4. Foreign material n grease: flush bearing, relubricate;
3. Restricted ventilation, clean air passage and wind- make sure grease supply is clean (keep can covered
ings. when not in use).

261
242 Water Treatment

PUMP RECORD CARD

NAME MAKE MODEL

TYPE SIZE SERIAL #
ORDER NUMBER SUPPLIER DATE PURCHASED
DATE INSTALLED APPLICATION PLANT #

Name Plate Data and Pump Info Stuffing Box Data Motor Data
GPM Diameter Depth Name Serial #
TOH Pack. Size Type H.P. Speed
RPM Length No. Rings Ambient°

Gage Press Disc Lantern Ring Flushed RPM Frame

Gage Press Suc Mech. Seal Name Size Volts Amps

Shut off Press Type Phase Cycle

Suction Head
Shaft Size Key
Pump Materials
Rotation Coing
Bearing Front
Impeller Type Shaft
Rear
Impeller Dia. Wearing Rings Casing Code Typt

Impeller Clear Wearing Rings Impeller Amps @ Max, Speed

Coupl Type & Size Shaft Sleeve Amps @ Shut Off

Front Brg # Slinger Control Data Info

Rear Brg # Shims Starter

Lub Interval Gaskets MENA Size
Lubricant "0" Rings Cat. #

Wearing Rings Brg: Seals Front Heater Size

Shaft Sleeve Size Rear Rated @

Pump Shaft Size ^asing Wear Ring Size ID Control Voltage

Pump Keyway OD Variable Speed

Type
Width Speed Max
Other Related Information:
Impeller Wear Ring ID Speed Min

OD
 Maintenance 243

MOTOR STARTERS Number

Title:

Mfg.: Address

Style: Class Si :e

Type:

O.L. HEATERS O.L. TRIP UNITS

Style Code Mfg: Style:

Amps Type:

Amps Range:_

CIRCUIT 'BREAKER

Mfg: Address

Style: Frame: Volts Amps Setting

Cat. No.

MOTOR Number

TITLE

Mfg: Address

HP: Volts: Ser. No. Duty:

Phase: Amps: Frame: Temp:

Cycles: RPM: Type Class:

Code: S.F.: Model Spec.:

SO# S# Style: CSA App:

Form Spec. Shft. Brg. Rear Brg.

50 Cycle Data

Suitable for 208V Network: Connection Diagram

(6) (5) (4) (6) (5) (4)

Additional data

(7) (8) (9) (7) (8) (9)

(1) (2) (3) (1) (2) (3)

2
 244 Water Treatment

18.15 Auxiliary Electrical Power

18.150 Safety First

Always remember that a QUALIFIED ELECTRICIAN
should perform most of the necessary maintenance and
repair of electrical equipment. If you don't know the how,
why, and when of the job, don't do it. You could endanger
your life as well as your fellow operators. Never attempt
work that you are not qualified to do or are not authorized to
perform.

18.151 Standby Power Generation

Where do you begin? You have to consider whether you
There are three ways of providing standby power. One is would like to have all of your facility operating or whether
by providing the treatment plant with an engine driven just the vital or key equipment would be sufficient. Since the
generator set. The limit of how much power can be produced characteristics and operating conditions of ever; p.ant are
is determined only by the size of the generator. The second different, it is extremely difficult to make specific sugges-
possibility for standby power is batteries. Batteries should tions.
only be considered for low power consumption uses such as
emergency lighting, communication, and possibly some con- For the sake of illustration, let us pose a hypothetical
trol and instrumentation functions. The other possibility for situation. Consider a 10 MGD (38 MLD) capacity plant with
standby power is a connection to an alternate power source, an average flow rate of 6 MGD (23 MLD). Prepare a list of
such as a different substation or another power company. needs that must be met to insure minimal operation:
1. Raw water pumping,
Because the treatment of water is considered a critical 2. Clarification,
service, it is important to be able to provide drinking water
even with the loss of commercial power. A power outage of 3. Clear water pumping,
a short duration probably will not have adverse effects on
4. Chlorination, and
plant operation. The question you must ask yourself is, "Can
my plant meet the needs of the public if a 'brown out' or 5. Minimal lighting.
catastrophic event eliminates commercial power for an
extended length of time?" If the answer is "no," then perhaps Calculate the maximum horsepower or total kilowatts
a form of standby power generation should be cc idered. necessary to maintain the limited operation:
1. Raw Water Pump 75 horsepower 56.00 kW
The following six conditions must be analyzed to deter- 2. Clarification 21/2 horsepower 2.24 kW
mine the need for and size of standby power generation.
3. Clear Water Pump 40 horsepower 30.00 kW
1. Frequency of power outages in last 10 to 15 years.
4 Chlorination 15 horsepower 11.20 kW
2. Duration of the power outage it each occurrence.
5. Lighting 5.00 kW
3. Availability of additional source of power supply from a
different substation in the vicinity. 104.44 kW

4. Method by which raw water reaches plant (is flow by The minimum power required is 104.44 kW. When sizing a
gravity or by a raw water pumping station"). generator for emergency power, you have to make sure that
the operator will be able to start the needed motors. Since
5. Total storage capacity of reservoirs in the distribution the locked rotor current of the 75 horsepower induction
system. motor on the raw water pump is approximately four times
running current, then the generator must be able to handle
6. Possibility of obtaining a potable water supply from 224 kW at that instant. Size the generator not only by total
adjacent cities (is there a reasonably sized pipe connec-
load. but also for the highest horsepower motor being
tion between your system and the distribution system of started. Consider the sequence in which motors will be
an adjacent city?).
started. The starting of all the motors simultaneously (with-
out sequence starting) would be nearly impossible. Consult
If the frequency of power outages is once or twice a year experts in power generation for answers to your specific
with a 10 to 30 minute duration, the capacity of a standby questions regarding your plant because each plant has
power generator can be relatively small. The minimum size different needs If you are considering standby power, shop
of a standby power generator may require sufficient capac- around and get ideas from the equipment manufacturers.
ity to operate essential equipment such as: You may be able to reduce the size of the generator by using
reduced voltage starters on the larger motors.
1. Coagulant and chlorine feeders,
After you have determined the size or generator needed,
2. One-third of flocculators, you must be able to connect it to yea power distribution
3. Major electric valve operators and plant control system, system. Tnis may require some sophisticated switch gear.
Besides the mechanical functions necessary in connecting
4. One-third of pumping capacity (if necessary). and the emergency power with your normal system, it is impor-
tant that the two systems cannot be electrically coupled.
5. Minimum lighting.
(Two electrical systems must be "in phase" with each other

264
 Maintenance 245

before parallel coupling.) For this reason, mechanical inter- ies. In earlier designed units, a trickle charger was used
locks are used to insure that one circuit is always open. A This constant charging resulted in inoperative batteries in a
"kirk-key" system, where one key is used for two locks, short time because of overcharging
locking one sw:tch open before the other can be closed, is
The lamps used are normally 6 to 12 volt sealed-beam 25-
sometimes used. The manufacturers of most packaged
motor-generator systems can provide automatic transfer watt lamps The light pattern provided is most effective when
illuminating a work area. A rule of thumb is that one lamp will
switches that will automatically start the generator when a
power failure occurs and connect the generated power into be sufficient for about 1.000 square feet, providing that the
full light pattern can be used. Consult emergency light level
the plant power oistribution wiring.
codes (Table 18.2) for your particular application.
Looking back at the plant described, a generator of 125
kW with intermittent overload capabilities should handle the When selecting an emergency lighting system, check it
load. (Note: This is an assumption. Actual calculation may very thoroughly to insure that it will give you the protection
indicate a different size.) An engine-generation system of needed. If it fails to work _Then the chips are down and the
this size could handle your minimal power needs. If your mai, cower is out, you've wasted your money.
water distribution system has ample ^apacity, it may be
possible to cut the plant production rate to reduce power 18.)53 Batteries
requirements to what can be handled with a smaller capacity This section will discuss wet storage batteries since they
generator. are the most prevalent. Automotive and equipment batteries
If you do not have standby power generation at your are usually of the lead-acid type. This indicates that the
facility, talk to others in the water treatment field who do and
dissimilar plates are made of two types of lead and the
obtain ideas and information. After due consideration, take
electrolyte is sulfuric acid. Wet-type batteries can also be
nickel cadmium or nickel iron.
the neces3ary steps to insure yourself against interrupted
power. Most batteries are a series of cells enclosed in a common
Standby power generators should be operated on a case. Each of these cells develops a potential (voltage) of
regular basis (once a week) to be sure they will operate 2 3 volts per cell when fully charged. Hence, a six-volt
properly when needed. Be sure to operate your generator at battery contains three cells and a 12-volt battery has six
full load for at least an hour. Commercial power into your cells. The voltage output of a 12-volt battery is 13.8 volts
plant must be shut off to operate standby power at full load. when fully charged. Once a lead-acid battery has been
placed in service, the addition of sulfuric acid is not neces-
18.152 Emergency Lighting sary. The water portion of the electrolyte solution evapo-
rates as the battery is charged and discharged. Lost water
The most practical form of emergency lighting in most must be replaced. Deionized or distilled water should be
instances is that provided by battery-powered lighting units. used. Tap water contains impurities that shorten the life
Because they are uscd primarily for exit lighting, they are span of a battery if used to replace lost water. These minute
more ecoromical than engine-driven power sources. If you particles become attached to the lead plates and Co not
have a niomentary power outage, the system responds allow the battery to retuvena, self fully when charged.
without an engine-generator start-up. All emergency lighting
unit equipment is basically the same and consists of a When batteries are placed on charge, remove the cell
rechargeable battery, a battery charger, low voltage flood covers to allow the gas (hydrogen) caused by charging to
lights, and test monitoring and control accessories. Proper escape and not to build excessive pressure in the battery. A
selection of a unit for a particular location requires careful battery on charge is as lethal as a small bomb if you ignite
consideration of the following itens: the gas. Do not smoke or cause electrical arcing near the
battery. Do not breath the gas and make sure that the area
1. Initial cost, where a battery is being charged is well ventilated.
2. Types of batteries, The keys to prolonged life of a battery are to '<eep the
electrolyte level above the cell plates, to keep the battery
3. Maintenance requirements, and fully charged, and above all, to keep the terminals and top
4. Lighting requirements. clean. When dirt and residue accumulate on the top of a
battery, it forms a path for current to flow between the
The three types of batteries most commonly used are: negative and positive posts. Take a multimetei, connect one
lead acid, lead calcium, and nickel cadmium Because poor lead to the proper post (it will cause up-scale deflection) and
battery maintenance is quite common in emergency lighting slowly slide tte other lead across the top of the battery
systems, "maintenance free" batteries are becoming in- toward the other post. If the top is dirty, the meter will deflect
creasingly popular. These batteries can have a gelatin or mo" as you proceed across the top.
acid (wet) ELECTROLYTE." The gelatin type is completely
spillproof and can be handled safely without the dangers of
acid spills. These batteries have a shorter life span than the
wet type. Since all batteries undergo evaporation, the gelatin
electrolyte wid be exhausted before that of a battery contain-
ing liquid. Wet-type maintenance free batteries require no
refilling and, when handled properly, acid spillage is minimal.
In terms of cost, the maintenance-free battery is more
expensive: but when you consider the human factor, they
may be more reliable and cheaper in the long run. Most
systems use a battery charger that monitors the battery
voltage. When required, the charger then charges the batter-
" Electrolyte (ee-LECK-tro-LIGHT). A substance which dissociates (separates) into two or more ions when it is dissolve in water

26;
 246 Water Treatment

TABLE 18.2 IES RECOMMENDED EMERGENCY LIGHT LEVELSa

Hazard requiring visual Slight High
detection
NORMAL
ACTIVITY
LEVEL* LOW HIGH LOW HIGH
Areas Conference rooms Lobbies Elevators (freight) Elevators
Reception rooms Corridors File rooms Escalators
Exterior floodlighting Concourse Mail rooms Computer rooms
Closets Restrooms, washrooms Offices Drafting rooms
Telephone switchboard Stairways Offices
rooms Stockrooms Stairways
Exterior entrance Exterior entrance with Transformer vaults
Exterior floodlighting stairs Engine rooms
Elect.cal, mechanical,
plumbing rooms
Footcandles 0.5 1.0 2.0 5.0
Dekalux 0.54 1.1 2.2 2.2
Minimum illumination for safety of personnel, absolute minimum at any time and at any location on any plane where safety is related to
seeing conditions.
Special conditions may require different levels of illumination. In some cases higher levels may be required as for example where securi-
ty is a factor In some other cases greatly reduced levels of illumination, including total darkness, may be necessary, specifically in situa-
tions involving manufacturing, handling, use, or processing of light-sensitive materials (notably in connection with photographic
products). In these situations alternate methods of insuring safe operation must be relied upon.
EMERGENCY LIGHT LEVEL codes and standards vary widely throughout the country Recommended minimum lighting levels of the Illu-
minating Engineering Society are being considered as a possible standard by ANSI and the Life Safety Code. These are minimum lighting
levels recommended for safety of personnel.
a Reprinted from December 1978 issue Electrical Construction and Maintenance. Copyright 1978 McGraw-Hill. Inc All rights reserved.

To clean the battery. use a stiff-bristled brush (not a wire reaches tI e plant. it is transformed down to a useable
brush) and remove the heavy material, Then wash with a voltage ( ,0 to 480 volts) either through utility-owned or
solution of baking soda and water (four teaspoons of baking customer-owned transformers. The NEC (National Electrical
soda to one quart of water). This will remove the acid film Code) denotes high voltages as those over 600 volts.
from the top and neutralize corrosion on the battery termi-
nals. Rinse with fresh water and dry the top with a dry, Why have high voltage? Since current (amperes) varies
Tintless cloth. Remove cell caps and wipe between them, inversely with voltage, a load of 500 amps on the low voltage
then replace. At this time check to be sure that the battery side of the transformer would create a 20 amp load on the
terminals are clean and tight. If a battery is charged, but the high voltage side of a 12,000 volts/480 volt transformer.
terminals are loose. proper voltage and current cannot be Transmission lines would have to be enormous in order to
delivered. carry the load if a lower voltage were used. Where high
voltage cables terminate at a transformer or switch gear,
QUESTIONS certain conditions must be adhered to. If outdoor transform-
Write your answers in a notebook and then compare your ers are used that have high voltage wires exposed, an eight-
answers with those on page 324. foot (2.4 m) high fence is required to prevent accessibility by
unqualified or unauthorized persons. Signs attached to the
18 15A Why should a qualified electrician perform most of fence must indicate "High Voltage." Specifications for clear-
the necessary maintenance and repair of electrical ances. grounding, access, and enclosures vary with installa-
equipment? tions. Any modification or repair work must be completed by
18.15B What is the purpose of a "kirk-key" system? qualified people only.

18 15C Why are battery-powered lighting units considered

18.161 Switch Gear
better than engine-driven power sources?
When we see the term "switch gear," it is usually associat-
1 8.15D Why should the water lost from a lead-acid battery
ed with the equipment used in the interruption, transfer, or
be replaced with deionized or distilled water?
disconnecting of voltages over 600 dolts. The enclosure is
designed and manufactured to safely control high-voltage
18.16 High Voltage switching. Most distribution systems have a load-interrupt-
ing switch that is capable of disconnecting high voltage lines
18.160 Transmisz;on that are unde. load. Because of the arc that is caused in
breaking the circuit. special "arc shoes" (arc-suppressant
In general terms, high voltage is the voltage transmitted to devices) are used to ensure that the contact points are not
the plant site by the utility company. The voltage level can p tted. A keyed lock system is used to prevent opening of the
vary, but 12,000 volts is quite common. After the power enclosure in the enei gized state.

2 66
 Maintenance 247

Probably the best preventive maintenance that a treat- 18 16A Why is electricity transmitted at hgh voltage/
ment plant operator can provide for switch gear is to keep
18 16B What precautions must be taken if outdoor trans-
the exterior and its surroundings clean If you encounter
formers have exposed high voltage wires/
difficulties in the course of operating the switches, please
obtain qualified help to do the inspection or lepairs needed 16 16C Vv'ilat kind of n-laintenance should a treatment plant
Check with your particular manufacturer to determine what operator perform on switch gear')
is needed and when this has to be done to keep your system
functioning as designed. If your equipment is in a corrosive 18 16D What symptoms indicate that a power distrit ution
atmosphere. it may be necessary to remove it from service transformer may be in need of maintenance or
and expoxy paint the internal buses. All pivoting points repair')
should be lubricated with a lubricant specified by the manu- 18.17 Electrical Safety Check List
facturer.
Throughout this manual and throughout this cnapter the
18.162 Power Distribution Transformers need for electrical safety is always being stressed. This
section contains an electrical safety check list which is
If the high voltage transformers are caned by the utility. provided to help you ensure that you have minimized electri-
the inspection and maintenance is carried out by the utility. cal hazards in your plant. This list is provided to make you
Any peculiar changes. smells. or noises should be reported ay.,are of potential electrical hazards. You should add to the
to the utility. When transformers are customer owned. a list additional electrical hazards that could injure someone at
regular inspection program should be established. your water treatment plant.
Most transformers use an oil to insulate as well as to cool 1 Are there any conduits rusted to the point where they
the windings. As heat is generated in the windings. it is might have lost their explosion proof integrity)
transferred to the oil. The oil is then cooled by air passing the
cooling fins of the transformer. The primary requirements 2. Are there any electrical conduit hangers that are rusted
of the oil are: so bad that they are allowing the conduit to sag?

1. High dielectric strength; 3 Are there any fasteners on the conduit hangers that are
rusted and allowing the conduit to hang by the wires?
2. Freedom from inorganic acid. alkali. and sulfur to prevent
injury to insulation and conductors; 4 Do all of the extension cords and power tools meet code
requirements for use in wet areas?
3. Low viscosity to provide good heat transfer: and
5. Does the age;icy or utility have a policy covering the
4. Freedom from sludging under normal operation condi- proper placement of portable ventilation equipment whcr,
tions. operators work inside enclosed tanks. vaults and other
confined spaces/
The principal causes of deterioratio.. of insulating oil are
water and oxidation. The oil may be exposed to moisture 6. Does the agency use proper grounding units (ground
through condensation of moist air due to "breathing" of the fault interruptor3) when working in wet areas?
transformer. especially when the transformer is not continu-
ously in service. The moist air condenses on the surface of 7. Is the grounding of electrical equipment and systems
the oil and on the inside of the tank. Oxidation causes inspected regularly?
sludging. The amount of sludge formed in a given oil 8 Are electrical breakers and controls clearly marked/
depends upon the temperature and the time of exposure of
the oil to the air. Excessive operating temperatures may 9 Is there a formal program for locking out, tagging and
cause sludging of any transformer oil. Check with the blockout of electrical devices?
manufacturer to determine how often the oil should oe If you can answer these questions properly. you are
tested. Oil can be revitalized by a cleaning procedure that is working in the right direction to minimize electrical hazards
accomplished at the transformer site. in your water treatment plant.
Any symptoms such as unusual noises. high or low oil
levels. oil leaks. or high operating temperatures should be QUESTIONS
investigated at once. If your transformer has a thermometer. Write your answers in a notebook and then comp e your
it is of the alcohol type and should be replaced with that type answers with those on page 324.
only. A mercury-type thermometer could cause insulation
failures by reason of proximity of a metallic substance. 18.17A Why are rusted conduits of concern to a water
regardless of whether it is intact or broken. treatment plant operator/
The tank of every power transformer should be grounded 18.17B What is the purpose of an electrical safety check
to eliminate the possibility of obtaining static shocks from it list/
or from being injured by accidental grounding of the winding
18.18 Additional Reading.
to the case.
1. BASIC ELECTRICITY by Van Valkenburgn, Nooger &
If repairs are indicated, uze the expertise of a qualified
Neville, inc. Obtain from The Brolet Press, 33 Gold Street,
person to ensure that the repairs are made safely as well as
New York, N.Y. 10038. $39.95 for combined Edition of all
correctly. Your life and the lives of others may depend on the
five volumes.
use of qualifies people.
a. Volume 1. Price $10.50.
Where Electricity Comes From
QUESTIONS Electricity in Action
Write your answers in a notebook and then compare your Current Flow, Voltage, Resistance
answers with those on page 324. Magnetism. DC Meters

26' i
IM,
 248 Water Treatment

b. Volume 2. Price $10.50 4 ELECTRICITY PRINCIPLES AND PRACTICES by Ad-

Direct Current ams. McGraw-Hill Book Company 8171 Redwood High-
Ohm's and Kirchoff's Law way Novato. CA 94547 Price $24.95.
Electric Power
5. "Electrical and Automation," Chapter XII in WATER DIS-
c. Volume 3. Price $10.50. TRIBUTION OPERATOR TRAINING HANDBOOK, by I.E.
Alternating Current Nichols and B.W. Jex. Obtain from American Water
Resistance. Inductance. Capacitance in AC Works Association, 6666 W. Quincy Ave., Denver, Colo-
reactance rado 80235. Order No. 20103. Price $14.50 for members
AC Meters of AWWA, $17.50 for others.
d. Volume 4. Price $10.50. 6. MAINTENANCE ENGINEERING HANDBOOK by Higgins,
Impedance. McGraw-Hill Book Company, PO Box 402, Highstown,
Alternating Current Circuits New Jersey 08520. Price $79.50.
Series and Parallel Resonance
Transformers 7. ELECTRICITY FOR WATER AND WASTEWATER
TREATMENT PLANT OPERATORS. Available from Na-
e. Volume 5. Price $10.50. tional Environmental Training Association, 8687 Via de
DC Generators and Motors Ventura, Suite 214, Scottsdale, AZ 85258. Price $181.50.
Alternators and AC Motors
Power Control Devices 8. MECHANICAL MAINTENANCE FOR WATER AND
WASTEWATER TREATMENT PLANT OPERATORS.
NOTE- For an additional $2 00 per volume. you can Available from National Environmental Training Associ-
obtain an "Interactive Self-Learning Package: ation, 8687 Via de Ventura, Suite 214, Scottsdale, AZ
f Other Training Programs 85258. Price $156.50.
Basic Electronics. 6 Volumes
Basic Industrial Electricity. 2 Volumes
2 "Maintenance" by Stan Wciton. Volume II. Chapter 15, in
OPERATION OF WASTEWATER TREATMENT PLANTS. end of t-ervtz1 of 5 Li244410
Kenneth D. Kern. California State University, Sacramen-
to. 6006 J Street. Sacramento. CA 95819. Price for
Volume It. $25.00. MAI NTENANde
3. "Instrumentation" by George Ohara, Chapter 8, in AD-
VANCED WASTE TREATMENT, Kenneth D. Kerri, Cali-
fornia State University, Sacramento, 6000 J Street, Sac- Please answer the discussion and n. view questions be-
ramento, CA 95819. Price, $20.00. fore continuing with Lesson 2.

DISCUSSION AND REVIEW QUESTIONS

Chapter 18. MAINTENANCE
(Lesson 1 of 5 Lessons)

At the end of each lesson in this chapter you will find some 6 Why should one person never be permitted to repair a
discussion and review questions that you should work chlorine leak alone/
before continuing. Thf. purpose of these questions is to
indicate to you how well you understand the material in the 7 Why should inexperienced. unqualified or unauthorized
lesson. persons and even qualified and authorized persons be
extremely careful around electrical panels. circuits. wir-
Write the answers to these questic in your notebook. ing and equipment/
1 Why should operators thoroughly i cad and understand
8 What protective or safety devices are used to protect
manufacturers' literature before attempting to maintain operators and equipment from being harmed by elec-
plant equipment/ tric ji
2 Why must administrators or supervisors be made aware 9 Why must motor name mote data be recorded and filed?
of the need for an adequate maintenance program/
10 What might be the cause of a pump motor failing to
3. What is the purpose of a maintenance recordkeeping start?
program?
11 Why should a water treatment plant have standby
4. What items should be included in a plant library/ power/
5. Why should your plant have an emergency team to 12 How would you determine the capacity of standby
repair chlorine leaks/ generation equipment/

26d
 Maintenance 249

CHAPTER 18. MAINTENANCE

(Lesson 2 of 5 Lessons)

18.2 MECHANICAL EQUIPMENT ration, Milwaukee, Wisconsin, Industrial Pump Division, Nor-
wood, Ohio. Originally, the material was printed in Allis-
Mechantal equipment commonly used in water treatment Chalmers Bullet. OBX62568.
plants is describer; and d 3c...issea .n this section. Equipment
used with specific treatment processes such as flocculation
and filtration is not discLssed. You must be familiar with 18.211 Let's Budd a Pump!
equipment and understand what it is intended to do before A student of medicine spends long years learning exactly
developing a preventive maintenance program and main- how the human body is built before attempting to prescribe
taining equipment. for its care. Knowledge of PUMP anatomy is equally basic in
caring for centrifugal pumps!
18.20 Repair Shop But whereas the medical student must take a body apart
Many large plants have fully equipped machine shops to learn its secrets, it will be far more instructive to us if we
staffed with competent mechanics. But for smaller plants, put a pump TOGETHER (on paper, of course). Then we can
adequate muffle shop facilities often can be found in the start at the beginning adding each new part as we need it
community. In addition, most pump manufacturers maintain in logical sequence.
pump repair departments where pumps can be fully recondi-
As we see WHAT each part does, HOW it does it ... well
tioned.
see how it must be CARED FOR!
The pump repair shop it a large plant commonly includes Another analogy between medicine and maintenance:
such items as welding equipment, lathes, drill press and
there are various types of human bodies, but if you know
drills, power hacksaw, flame-cutting equipment, microme- basic anatomy, you understand them all. The same is true of
ters, calipers, gates, portable electric tools, grinders, a centrifugal pumps. In building one basic type, well learn
forcing press, metal-spray equipment, and sand-blasting
about ALL types.
equipment. "ou must determine what repair work you can
ane should do and when you need to request assistance Part of this will be elementary to some maintenance
from an expert. people . .. but they will find it a valuable "refresher" course,
and, after all, maintenance Just can't be too good.
Some agencies have their own repair shops or local
machine shops rebuild parts rather than buying direct from So, with a glance at the centrifugal principle on page 252,
manufacturers. Many agencies try to select equipment on let's get on with building our pump ...
the basis of the reputations of distributors for supplying
repair parts when needed. A parts inventory is essential for FIRST WE REQUIRE A DEVICE TO SPIN LIQUID AT HIGH
key pieces c .quipment. SPEED ...
That paddle-wheel device is called the Impeller" ... and
18.21 Pumps it's the heart of our pump.
Pumps serve many purposes in water treatment plants. Note that the blades curve out from its hub. As the impeller
They may be classified by the character of the material spins, liquid between the blades is impelled outward by
handled, such as raw or filtered water. Or, they may relate to centrifugal force.
the conditions of pumping: high lift, low lift, or high capacity.
They may be further classified by principle of operation,
such as centrifugal, propeller, reciprocating, and turbine
(Figure 18.14).
The type of material to be handled and the function or
required performance of the pump vary so widely that the
designing engineer must use great care in preparing specifi-
cations for the pump and its controls. Similarly, the operator
must conduct a maintenance and management program
adapted to the peculiar characteristics of the equipmert.

18.210 Centrifugal Pumps

A centrifugal pump is basically a very simple device: an
imprler rotating in a casino. The impeller is supported on a alommanol

shaft which is, in turn, supported by bearings. Liquid coming

in at the center (eye of the impeller (Fiouire 18.15)) is picked
up by the vanes and by the rotation of me impeller and then
is thrown out by centrifugal force 'nto the discharge.
toa ou
To help you understand how pumps work and the 7urpose th
ir--S1j.
of the various parts, a section titled "Let's Build a Pump" has
been included cr. the following pages. This material has 1ST. u$ Ofinow1DIFFINsi
been reprtned with the permission of Allis-Chalmers Corpo- wxrilt GAItICANG SuCKSATC:

2''
 F-PUP.S-1
1

ri DISPLACEMENT DYNAMIC 1
. J

I
i PUMPS
-I RECIPROCATING

DYNAMIC -+ DISPLACEMENT 1,
H PISTON,
PLUNGER

-I CENTRIFUGAL SIMPLEX
STEAM-DOUBLE ACTING
DUPLEX

--I AXIAL FLOW

- SIMPLEX
...4- SINGLE ACTING --L- DUPLEX
1.[ SINGLE STAGE-Li- CLOSED IMPELLER
- POWER
L DOUBLE ACTING --I - TRIPLEX
MULTiSTAGE -H- OPEN IMPELLER { FIXED PITCH

VARIABLE PITCH MULTIPLEX

_.1 MIXED FLOW.

(RADIAL FLOW -4 DIAPHRAGM I

- OPEN
j--
SINGLE

-
SUCTION -- NONPRIMING
,.._ DO9BLE
SELF-PRIMING -

- SINGLE STAGE -
-
IMPELLER
SEMI-OPEN
IMPELLER
SIMPLEX

L MULTIPLEX I L
- FLUID OPERATED

MECHANICALLY OPERATED
SUCTION
.-- MULTISTAGE - _ CLOSED
IMPELLER ROTARY i

- VANE
--[PERIPHE:ZAL I
- PISTON

HSINGLE ROTOR FLEXIBLE MEMBER

LESINGLE STAGETTSELF -PRIMING
MULTISTAGE -I L NONPRIMING SCREW

- PERISTALTIC
- JET (EDUCTORI r- GEAR

- GAS LIFT - LOBE

'- {SPECIAL EFFECT ---IMULTIPLE ROTOR
- HYDRAULIC RAM
- CIRCUMFERENTIAL PISTON
- ELECTROMAGNETIC
- SCREW

Dynamic types of pumps 4s .

Displacement types of pumps
Fig. 18.14 Classification of pumps
 Maintenance 251

Discharge

Suction

Impeller -
eye
Refer to Fig. 18.18, pages 258 and 259, for location of impeller in pump

Fig. 18.15 Diagram showing details of centrifugal pump impeller

(Source CENTRIFUGAL PUMPS by Karassik and Carter of Worthington Corporation)

Note, too, that our impeller is open at the center the

"eye." As liquid in the impeller moves outward, it will suck
more liquid in behind it through this eye . . . PROVIDED IT'S
NOT CLOGGED!

That brings up Maintenance Rule No. 1: if there's any

danger that foreign matter (sticks, refuse, etc.) may be
sucked into the pump clogging or wearing the impeller
unduly PROVIDE THE INTAKE END OF ThE SUCTION
PIPING WITH A SUITABLE SCREEN.

NOW WE NEED A SHAFT TO SUPPORT AND TURN THE

IMPELLER ...
Our shaft looks heavy and it IS. It must maintain the
impeller in precisely the right place.

ilicSa
But that ruggedness does NOT protect the shaft from the gizmo
corrosive or abrasive effects of the liquid pumped ... so we wiu
must protect it with sleeves slid on from either end. MarECr Tiit SW4FT

27 j.
252 Water Treatment

matiroveAL FoRcr Acriew.,

ALL MOVING Waits IVO TRAAILIN ASIRMINT
UNE *WHIN FORM TO TRAWL IN &CURIA 'THEY
CONSTANTLY TRY TO TRAVEL ON TANGNIf..

__,.......--
II

'V 11
11ORMANE
eiDElsisc\
Ci.11:mV

Centtifugal force pusbes dummy planes swung

& circle away from center of rotatior..
m4

4.1-=

Centrifugal force teat to rah raiding water

outward forming vortexin eater.
 Maintenance 253

What these sleeves and the impeller, too are made

of depends on the nature of the liquid were to pump.
Generally they're bronze, but various other alloys, ceramics,
glass, or even rubber-coating are sometimes required.

Maintenance Rule No. 2: NEVER PUMP A LIQUID FOR

WHICH THE PUMP WAS NOT DESIGNED.

Whenever a change in pump application is contemplated

and there's any doubt as to the pump's ability to resist the
different liquid, CHECK WITH YOUR PUIVP MANUFAC-
TURER!

WE MOUNT THE SHAFT ON SLEEVE, BALL OR ROLLER

BEARINGS ...
As well see later, clearances between moving parts of our
pump are QUITE SMALL.

If bearings supporting the turning shaft and impeller are

allowed to wear evressively and lower the turning units via *IRt7C GMGIS1tTwisn flfdlaft,
within a pump's closely-fitted mechanism, the life and effi- A 611AuStor-Mc At3PoSs Ton AND SID113.
ciency of that pump will be seriously threatener

Maintenance Rule No. 4: SEE THAT PUMP AND MOTOR

FLANGES ARE PARALLEL VERTICALLY AND AXIALLY . . .
AND THAT THEY'RE KEPT THAT WAY!

If shafts are eccentric or meet at an angle, every revolution

throws tremendous extra load on bearings of both pump and
motor. Flexible couplings will NOT correct this condition if
excessive.

Checking alignment should be regular procedure in pump

maintenance. Foundations can settle unevenly, piping can
change pump position, bolts can loosen. Misalignment is a
MAJOR cause of pump and coupling wear.

NOW WE NEED A "STRAW" THROUGH WHICH LIQUID

CAN BE SUCKED ...
Maintenance Rule No. 3: KEEP THE RIGHT AMOUNT OF Notice two things about the suction piping: 1) the horizon-
THE RIGHT LUBRICANT IN BEARINGS AT ALL TIMES. tal piping slopes UPWARD toward the pump; 2) any reducer
FOLLOW YOUR PUMP MANUFACTURER'S LUBRICATION which connects between the pipe and pump intake nozzle
INSTRUCTIONS TO THE LETTER. should be horizontal at the top (ECCENTRIC, not concen-
tric).
Main points to keep in mind are ...
1. Although too much oil won't harm sleeve bearings, too
much grease in antifriction type bearings (ball or roller)
will PROMOTE friction and heat. Main job of grease in
antifriction bearings is to protect steel elements against
corrosion, not friction.
2. Operating conditions vary so widely that no one rule as to
frequency of changing lubricant will fit all pumps. So play
safe: if anything, change lubricant BEFORE it's too worn
or too dirty.

TO CONNECT WITH THE MOTOR, WE ADD A COUPLING

FLANGE ...
Some pumps are built with pump and motor on one shaft,
of course, and offer no alignment problem. Alit POCKET

But our pump is to be driven by a separate motor . .. and rirremrom..*kt-

we attach a flange to one end of the shaft through which
bolts will connect with the motor flange. AIL OWED BY ',,OWNStO. I NO,PrPi ALLOWED BY TAPERED REDUCER

2
 254 Water Treatirent

This up-sloping prevents air pocketing in the top or the Our pump happens to be a "double suctior" pump, which
pipe which air might be d awn into the primp and cause means thPt water flow is divided inside the pump casing ...
loss of suction. reaching t! eye of the impeller from either side
Maintenance Rule No. 5: ANY DOlNSLOPING TOWARD
THE PUMP IN SUCTION PIPING (AS EXAGGERATED IN Ct_
LegulD 6C4S IN HERE
THE DIAGRAMS ABOVE) SHOULD BE CORRECTED. 61,i0ER i(KPW) f%kt
WV AND rr COMES OUT
This rule is VERY important. Loss of suction greatly HeRE(.44e.ektssidt)
endangers a pump . . as we'll see shortly.

'VO
WE CONTAIN AND DIRECT THE SPINNING LIQUID WITH A
CASING ... =MK
T
V

We got a little ahead of our story in the previous para-

graphs ... because we didn t yet have the casing to which
the suction piping bolts. And the manner in which it is
attached is of great importance.
BuTSOME Of IT LEAKS
Maintenance Rule No. 6: SEE THAT PIPING PUTS ABSO-
LUTELY NO STRAIN ON THE PUMP CASING.
As water is sucked into the spinning impeller, centrifugal
force causes it to flow outward ... building up high pressure
at the outside of the pump (which will force water OUT) and
creating low pressure at the center of the pump (which will
suck water IN.) This situadon is diagrammed in the upper
half of the pump, above.
So tar so good ... except that water ter, to be sucked
back from pressure to suction through the st.. ice between
impeller and casing as diagrammed in the lower half of
the pump, above and our next step must be to plug this
leak, if our pump is to be very efficient!

SO WE ADD WEARING RINGS TO PLUG INTERNAL LIQUID

LEAKAGE ...
You might ask why we didn't build our parts closer fitting
in the first place instead of narrowing the gap between
them by inserting wearing rings.

TOE WEt6i4TOFT,MING CAN

EA$1 Lf RtilB A 'PUMP

When thr original installation is made, all piping should be

in place arid self-supporting before connection. Openings
should meet with no force. Otherwise tne casing is apt to be The answer is that those rings are removable znd RE-
c ticked ... or sprung enough to allow closely - fitter Dump PLACEABLE . . when wear enlarges the tiny gap between
ports to rut. them and the impeller. (Sometimes rings are attached to
impeller rather than casing or rings are attached to BOTH
It's good practice to cheek the piping supports regularly to so they face each other.)
see that loosening, or settling ,)f the building, hasn't put
strains on the casing.

NOW OUR PUMP IS ALMOST COMPLETE, BUT IT WOULD

LEAK "YE A SIEVE ... )

Wert far enough along now to trace the flow of water

through our pump. laeSritiociivE A LOT DEPENDS ON
not easy to show suction piping in the FRICTIOV AND
cross-section view above, so imagine it stretching fr..,m your *PONTA iNIN PRIME!
eye to the lower center of the p.. ,gyp.

274
 Maintenance 255

Maintenance Rule No. 7. NEVER ALLOW A PUMP TO TO MAKE PACKING MORE AIR-TIGHT, WE ADD WATER
RUN DRY (either through lack of proper priming when SEAL PIPING ...
starting or throuO loss ,. f suction when operating). Water is
a LJBRICANT between rings and impeller. In the center of each stuffing box is a "seal cage." By
connecting it with piping to a point near the impeller rim, we
Maintenance Rule No. 8. EXAMINE WEARING RINGS AT bring liquid UNDER PRESSURE to tha stuffing box.
REGULAR INTERVALS. When seriously worn, their replace-
ment will greatly improve pump efficiency. This liquid acts both to block out air intake and to lubricate
the packing. It makes both packing and shaft sleeves wear
longer . . . PROVIDING ITS CLEAN LIQUID!
TO KEEP AIR FROM BEING SUCKED IN, WE USE STUFF-
ING BOXES ...
We havc two good reasons for wanting to keep air out of
our bump: 1) we want to pump water, not air; 2) air leakage is
apt to cause our pump to lose suction.
Each stuffing box we use misists of a casing, rings of
packing and a gland at the ou,side end.

Maintenance Rule No. 9: PACKING SHOULD BE RE-

PLACED PERIODICALLY DEPENDING ON CONDITIONS WATER, IS A LUBRICANT
USING THE PACKING RECOMMENDED BY YOUR
PUMP MANUFACTURER. Forcing in a ring or two of new
packing instead of replacing worn packing is BAD PRAC- Maintenance Rule No. 12: IF THE LIQUID BEING
TICE. It's apt to displace the seal cage (see next column). PUMPED CONTAINS GRIT, A SEPARATE SOURCE OF
Put each ring of packing in separately, seating it firmly STALING LIQUID SHOULD BE OBTAINED (e.g., it may be
;fore adding the next. Stagger adjacent rings so the points possible to direct some of the pumped liquid into a container
where their ends meet do not coincide. and settle the grit out).

Maintenance Rule No. 10: NEVER TIGHTEN A GLAND To control liquid flow, draw up the gland just tight enough
MORE THAN NECESSARY . . . as excessive pressure will so a THIN stream flows from the stuffing box during pump
wear shaft sleeves unduly. operation.

Maintenance Rule No. 11: IF SHAFT SLEEVES ARE DISCHARGE PIPING CJMPLETES THE PUMP INS TALLA-
BADLY SCORED, REPLACE 01-7 REPAIR THEM IMMEDI- TION AND NOW WE CAN ANALYZE THE VARIOUS
ATELY . . or packing life will be entirely too short.
. tORCES WE'RE DEALING WITH ...

275
256 Water Treatment

SUCTION At least 75% of centrifugal pump troubles trace PUMP CAPACITY generally is measured in gallons per
to the suction side. To minimize them . .
minute A new pump is guaranteed to deliver its rating in
1. Total suction lift (distance between center line of pump capacity and head.
and liquid level whr pumping, plus friction losses) gen-
erally should not exeed 15 feet. But whether a pump RETAINS its actual capacity depends
to a great extent on its maintenance.
2. Piping should be at least a size larger than pump suction
nozzle. Wearing rings must be replaced when necessary to
3. Friction in piping should be minimized . . use as few and keep internal leakage losses down.
as easy bends as possible ... avoid scaled or corroded
pipe. Friction must be minimized in bearings and stuffing boxes
by proper lubrication . .. and misalignment must not be
DISCHARGE lift, plus suction lift, plus friction in the piping allowed to force scraping between closely-fitted pump parts.
from the point where liquid enters the suction piping to the
end of the discharge piping equals total head. POWER of the driving motor, like capacity of the pump,
will not remain at constant level without proper mainte-
PUMPS SHOULD BE OPERATED NEAR THEIR RATED nance. ',If you us electric motors, by all means send for
HEADS.
Allis-Chalmers free "Guide to Care of Electric Motors!")
Otherwise, pump is apt to operate under unsatisfactory
and unstable conditions which reduce efficienc, and operat- Starting load on motors can be reduced by throttling or
ing life of the unit. closing the pump discharge valve (NEVER the suction valve!)
.. but the pump must not be operated for lon$.., with the
Note the description of "cavitation" below and direc- discharge valve closed. Power then is converted into friction
tions for figuring the head your pumps are working against. overheating the water with serious consequences.

HAVE A WEALTHY RESPECT FOR CAVIT-47/00W

IF PUMP cATACiir, SitEDMEAD, AND SUCTION LIFT
AREN'T FIGURED PROPERLY, CAVITATI, 141 CAN. SATAN
IMPELLER AWAY MST/ A LABORATDRY WATER.
HAMMER INDICATES IT/S EROSIVE FORCE,,.

1 ye SSEL i1LLeA momorrum porrit PMESSURI CL VAS

WATEMInkrPED 4wEion. mouctcAvire CAVITY-WATIR 'Mae
Tolorrom of vuoc SOWN tioonweom Tun MOLE MO albMS hale!

1 MT MOVIEMIwt 2 "novas cmar 3 Low. taisseis

or ves(tallt Bun Ilisoto1hol* issdion POMO MUM
TimItouoti WS atm vow TOWN
MU!.
MORAL t VE SURF 10414 MAO 4CRIerilneMitxMPAIRI

276
 Maintenance 257

Cavitation is a condition that can cause a drop in pump

efficiency, vibration, noise and rapid damage to the impeller
of a pump. Cavitation occurs due to unusually low pressures
Adjusting Nut
within a pump. These low pressures can develop when
pump inlet pressures drop below the design Inlet pressures Drive Key

or when the pump is operated at flow rates considerably

higher than design flows. When the pressure within the
Vertical Hollow
flowing water drops very low, the water starts to boil and Shaft Motor
vapor bubbles form. These bubbles then collapse with great
force which knocks metal particles off the pump impeller. Top Shaft
This same action can and does occur on pressure reducing
Deflector Ring
valves and partially closed gate and butterfly valves.
Packing Gland
18.212 Horizontal Centrifugal Pumps Packing

Horizontal centrifugal pumps, like the one we just con- Lantern Ping
structed on paper in the last section, are available in a Packing Box
number of configurations. The one we built is best described
Discharge Head
as a single-stage, horizont, double-suction, split-case cen-
trifugal pump. The pump is a single-stage pump because it Packing Box Bushing
has only one impeller. Some horizontal pumps have two Drain Line
impellers that are working in series to create higher heads
Top Column Flange
than can readily be obtained with only one impeller. Our
paper pump was double suction in that water entered the Shaft Coupling
impeller from both sides. The advantage of this design is Column ripe
that the longitudinal thrust frolu the water entering the Bowl Shaft
impeller is balanced. This grey reduces the thrust load
that the pump's bearings must carry. The split case designa- Discharge Case Cap
tion indicates that the pump case is made in two halves. Discharge Case Coupling
Some centrifugal pumps have a single suction in line with the
Discharge Case
shaft. These are described as single stage end suction
centrifugal pumps. Discharge Casa Bearing

Impelici
18.213 Vertical Centrifugal Pumps (Figures 18.16,18.17
Intermediate Bowl
and 18.18)
Impeller Lock Collet
Another common configuration for centrifugal pumps is
Intermediate Bowl Bearing
t vertical suction cased centrifugal pump. This is an
adaptation of the deep well turbine pump for booster pump Bowl Wear Ring
service. They are very flexible in design as the engineers can
specify either single or multi-stage in a wide variety of sizes
and characteristics. --- Suction Case Bearing
Besides the usual lubrication ur the electric motor, the only
routine maintenance required is to adjust and repair, as Suction Flange
needed, the single packing gland.

18.214 Reciprocating or Piston Pumps Fig. 18.16 Vertical centrifugal pump (multistage)
(Permission of Aurora Pump Company)
The word "reciprocating" means moving back and forth,
so a reciprocating pump is one that moves a liquid by a
piston that moves back and forth. A simple reciprocating
pump is shown in Figure 18.19. If the piston is pulled to the
left, Check Valve A will be open and the liquid will enter the
pump and fill the casing. When the piston reacnes the end of
its travel to the left and is pushed back to the right, Check
Valve A will close, Check Valve B will open, and the liquid will
be forced out the exit line.
A piston pump is a positive-displacement pump. Never
operate it against a closed discharge valve or the pump,
valve, and/or pipe could be damaged by excessive pres-
sures. Also, the suction valve. should be open when the
pump is started. Otherwise an excessive suction or vacuerm
could develop and cause problems.

18.215 Progressive Cavity (Screw-Flow) Pumps

(Figure 18.20)
The progressive cavity pump consists of a screw-shaped
rotor snugly enclosed in a non-moving stator or housing
(Figure 18.2 i). The threads of the screw-like rotor (common- Fig. 18.17 Vertical centrifugal pump (single sta,
ly manufactured of chromed steel) make contact along the (Permission of Aurora Pump Company)

27
 258 Water Treatment

walls of the stator (usually made of synthetic rubber). i ne 18.216 Chemical Metering Pumps
gaps between the rotor threads are called "cavities." When
water is pumped through an inlet valve, it enters the cavity Many chemical metering pumps are a type of positive
As the rotor turns, the material is moved along until it leaves displacement pump Fa information on chemical metering
the conveyor (rotor) at the discharge end of the pump. The pumps, see Chapter 13, Fluoridation, Section 13.30, "Chemi-
size of the cavities along the rotor determines the capacity of cal Feeders," and Section 18.4, "Chemical Feeders," in this
the pump. Chapter.

QUESTIONS
All progressive cavity pumps operate on the basic princi-
ple described above. To further increase capacity, some Write your answers in a notebook and then compare your
models have a shaped inside surface of the stator (housing) answers with those on page 324.
with a similarly shaped rotor. In addition, some models use a 18.20A List tint pieces of equipment and special tools
rotor that moves up and down inside the stator as well as commonly found in a pump renew shop.
turning on its axis (Figure 18.21). This allows a further
increase in the capacity of the pump. 18.21A What is the purpose of a pump impeller?
18.21B Why should the intake end of suction piping have a
suitable screen?
Progressive cavity pumps are recommended for materials
which contain higher concentrations of suspended solids. 18.21C Why must suction piping always be up-sloping?
They are commonly used to pump sludges. Progressive
cavity pumps should NEVER be operated dry (without liquid 18.21D What is cavitation':
in the cavities), nor should they be run against a closed 18.21E What is an advantage of having a DOUBLE-SUC-
discharge valve. TION pump over a SINGLE-SUCTION pump?

1
6

taj

sf
10--

12

17

18

1. Motor frame 7. Shaft sleeve 13. Shaft sleeve

2. Impeller 6. Back pull-out 14. Close coupled motor support
3. Oil seal 9. Lubrication fittings 15. Impeller
4. Mechanical seal 10. Shaft 16. Wearing ring
5. Frame 11. Impeller 17. Oil reservoir
G. Casing 12. Bearings 18. Rear support foot

Fig. 18,18 Centrifugal pump parts

(Permission of Aurora Pump Company)

278
 Maintenance 259

4 7

=
2

F
11

7,*
16
13 14 15

1. Motor frame 7. Shaft sleeve 13. Shaft sleeve

2. Impeller 8. Back pull-out 14. Close coupled motor support
3. Oil seal 9. Lubrication fittings 15. Impeller
4. Mechanical sez..1 10. Shaft 16. Wearing ring
5. Frame 11. Impeller 17. Oil reservoir
6. Casing 12. Bearings 18. Rear support foot

Fig. 18.18 Centrifugal pump parts (contii .d)

Fig. 18.19 S.mple reciprocating pump

27
28u Fig. 18.20 Progressive cavity (screw-flow) pump 26 i
(Permission of Moyno Pump Division, Robbins & Meyer. Inc )
 Maintenance 261

Pumping principle
00

--;.:::::::::::::::::::"..:::::

45°

90°

135°
...-- -

180°

Fig. 18.21 Pumping principle of a progressive cavity pump

(Permission of /Winder Pumpi. Inc )

28:e,
 262 Water Treatment

18.22 Lubrication
Viscosity in the United States is the number of seconds it
takes 60 cubic centimeters (cc) of an oil to flow through the
18.220 Purpose of Lubrication standard orifice of a Saybolt Universal Viscometer at 100,
Lubrication of equipment is probably one of the most 130, or 210 degrees Fahrenheit. A 300 SSU12 @ 130 oil
important phases of a maintenance operator's Job. Without means that it took 300 seconds for 60 cc to flow through a
proper lubrication, the tools and equipment used for operat- Saybolt Universal Viscometer at 130 degrees Fahrenheit.
ing and maintaining water treatment plants would fail. Prop- Viscosity decreases with temperature rise because oil be-
er lubrication of tools and equipment is probably one of the comes thinner The specific gravity of an oil is measured by
maintenance operator's easiest jobs, but often :, is the most comparing the weight of oil with an equal volume of water,
neglected. both at 60 degrees Fahrenheit.

Some other important information to know about lubri-

cants is the:r "Pour Point." "Flash Point," and "Fire Point."
"Pour Point" is the temperature at which a lubricant refuses
to run. This is important in low temperature work. "Flash
Point" is the temperature at which oil vaporizes enough to
ignite momentarily when near a flame. A low flash point
means that oil evaporates more readily in service. "Fire
Point" is the temperatui a at which oil vaporizes enough to
keep on burning. Oils in service tend to become acid and
may cause corrosion, deposits, sludging and other prob-
lems. This condition may not be visible when you look at the
oil. Therefore, do not extend the time for an oil change
because the oil looks clean.
To detect acid conditions in oils, the neutralization number
of an oil is used. The neutralization number is the weight in
milligrams of potassium hydroxide required to nei. alize
one gram of oil. This is used by laboratories which teat the
oil on large engines, turbines, compressors, and other
equipment which have large volume oil reservoirs to deter-
The purpose of lubrication is to reduce friction between mine when cil changes or additives are needed.
two surfaces. I I.:or:cation also removes heat that is caused
by friction. Solid fr.ction of two dry surfaces in contact is Most lubricants in gel eral use are fluid at room tempera-
changed to a fluid friction of a separating layer of liquid or ture. Mostly, these are petroleum base, but others are used.
liquid lubricant. Actually, water is a lubricant, although not a Greases are mixtures of petroleum products with soaps
good lubricant. such as lime, soda, aluminum, and metallic. Metallic soaps,
forms of calcium, sodium, potassium, and lithium, have good
18.221 Properties of !ubricants retention in bearings and can withstand high temperatures
and pressures. A sodium base grease has sodium as the
A good lubricant must have the following properties: soap mixed with the petroleum.
1. Form a slippery coating on contacting surfaces so they Solid materials such as graphite, finely ground mica, and
can slide freely past each other, and yarn are sometimes used as lubricants. Some recently
2. Exert sufficient pressure to keep the surfaces apart when developed silicon compounds (silicones) work very well
running. uncier heavy loads and widely varying temperatures.
There are many oil additives on the market today and they
are worth investigating. Oil additives are chemical com-
pounds added to an oil to improve certain chemical or
physical properties such as stability, lubricity and foaming.
They are used to prevent rust or deposits and many other
items that could cause problems.

18.222 Lubrication Schedule

Tc be a good lubricant for a particular job, the lubricant To have proper lubrication you must first set up a lubrica-
used mast have the following qualities: tv,,n schedule. This can be a sii,:ple check-off st-et or card
1. Thickness of the lubricant layer must be sufficient to keep system or an elaborate computer system. The first thing to
do is make a list of everything that needs lubrication down to
the roughness of the metal parts from touching.
the smallest item including chains, rollers, and sprockets.
2. Lubricity (slipperiness) must be sufficient to allow mole- After you have listed every item on paper, go through the
cules to slide freely past each other, and manufacturer's instruction books to determine the frequen-
cy and type of lubrication required. Is the frequency daily,
3. Viscosity (resistance to flow) must be sufficient to bu,id weekly, monthly, semi-annual, or annually? The manufactur-
up a pressure necessary to keep the surfaces apart. If er's literature usually lists several different name brands of
viscosity alone cannot provide enough pressure, an ex- lubricants which are equal. If you need help determining the
ternal pressure must be supplied by a pump. type of lubricant or cross-referencing it to your particular
brand, contact your supplier. Most oil distributors have a
service representative who will come to your facility and go
12 SSU. Star,dard Saybolt Units.
over the individual equipment and specify which lubricants

283
 Maintenance 263

you should use. Next, determine the amount of each lubri- bearings will pick up and retain a considerable amount of oil
cant required. This is achieves by counting the number of When the unit comes to rest, an overflow of oil around the
grease fittings Determine the locations of fill plugs, drain shaft or out of the oil cup will result.
pl'igs, oil levels, sight glasses, dip sticks and other important
Greased bearings should be lubricated as follows:
items. To find these locations, physically inspect each piece
of equipment thoroughly and look for all lubncation points. 1. Shut off the unit if moving parts that might be a safety
Also the manufacturer's maintenance manual should show hazard are close to the grease fitting oi drain plugs.
the lubrication points for each piece of equipmf-mt.
2. Remove the drain plug from the bearing housing.
When you have gathered all this information, transfer it to
the equipment history cards for future reference. From this 3 Remove the grease fitting protective cap and wipe off the
information you can make up a lubrication chart or form. grease fitting. Be sure that you do not force dirt into the
bearing housing along with the clean grease.
As stated earlier, use whatever type of lubrication form
you prepare, but follow it. Always record each lubrication job 4 Pump in clean grease until the grease coming out of the
when completed and have the operator who did the job initial drain hole is clean. Don't pump grease into a bearing with
the record card. Always keep your lubrication schedules up the drain plug in place. This could easily build up enough
to date. If there are failures due to the wrong or insufficient pressure to blow out the seals.
lubricant, change or increase the lubrication frequency on 5. Put the protective cap back on the grease fitting.
the schedule. Also, new equipment must be added and
discarded equipment removed from the schedule. Someone 6. With the drain plug still removed, put the unit back in
must be assigned to take care of the lubrication and records. service. As the bearing warms up, excess grease will be
Assign more than one operator or rotate this job so if an expelled from the drain hole. After the unit has been
individual is off work or leaves the crew, there is a continuity running for a few hours, the drain plug may be put back in
in the lubrication schedule. place. Special drain plugs with spring loaded check
valves are recommended because they will protect
18.223 Precautions against further buildup.
When handling or storing oils and greases, some special 7 Unless you intend to be very careful, we recommend that
precautions must be followed. Make sure the storage area bearing grease be p -chased in cartridge form to mini-
does not create a fire hazard. Most al lubricants are highly mize the chance of getting dirt into the lubricant.
flammable and shouldn't be stored wr.,re there is an open
flame. "NO SMOKING" signs must be posted outside the QUESTIONS
building. Be sure to Keep any spills wiped up and make sure
that all the lids are tight on their containers. Write your answers in a notebook and then compare your
answers with those on page 324.
18.22A What is the purpose of lubrication?
18.22B What happens to oils in service/
18.22C What should be done to insure proper lubrication of
equipment?

18.225 Equipment Lubrication

Different authorities may make conflicting lube recom-
mendations for essentially the same item; however, general
reference material is available to help select the correct
luhncant for a specific application.
Grease is graded on a number scale, or viscosity index, by
the National Lubricating Grease Institute. For example, No. 0
is very soft.; No. 6 is quite stiff. A typical grease for most
treatment plant applications might be a N.., 2 lithium or
sodium compound grease. which is used for operating
temperatures up to 250°F (120°C).
Generally, the time between flushing and repacking for
greased bearings should be divided by 2 for every 25°F
Keep materials and containers clean. Sand, grit, and other (15°C) above 150°F (65°C) operating temperature. Also,
substances can contaminate lube supplies and create an generally, the time between lubrications should not be
equipment failure that lubrication maintenance is intended to allowed to exceed 48 months, since lube component sepa-
prevent. Another good idea is to direct the first shot of ration and oxidation can become sionificant after this period
grease from a gun into a waste can. of time, regardless of amount of use.
Another point worth noting is that grease is normally not
18.224 Pump Lubrication suitable for moving elements with speeds exceeding 12 000
Pumps, motors, and drives should be oiled and greased in in./min (5 m/s). Usually, oil-lubricating systems are used for
strict accordance with the recommendations of the manu higher speeds, Lighter viscosity oils are recommended for
facturer. Cheap lubricants may often be the most expensive high speeds, and, within the same speed and temperature
in the end. Oil should not be put in the housing while the range, a roller bearing will normally require one grade
pump shaft is rotating because the rotary action of the ball heavier viscosity than a ball bearing.

c
284
 264 Water Treatment

A good rule of thumb is to change and flush oil completely

at the end of 600 hours of operation or 3 months, whichever for lubricants, conflicting advice can be obtained A file
containing data on general properties of materials used can
occurs first. More specific procedures for flushing and help in the choice of lubricant.
changing lubricants are outlined by most equipment manu-
facturers.
QUESTIONS
Every operator should be aware of the dangers of overfill-
ing with either grease or oil. Overfilling can result in high Write your answers in a notebook and then compare your
pressures and temperatures, and ruined seals or other answers with those on page 324.
components. It has been observed that more antifriction 18 22D Does a soft grease have a high or low viscosity
bearings are ruined by over-greasing than by neglect.
index as compa-ed with a hard grease?
A thermometer can tell a great deal about the condition of 18.22E Is oil or grease used with higher speeds?
a bearing. Ball bearings are generally in trouble above 180°F
(80°C). Grease-packed bearings typically run 10 to 50 de- 18.22F What problems can result from overfilling with oil or
grees above ambient. grease?
For clarifier drive units, which are almost always located
outdoors, condensation presents a dangerous problem for
the lubrication system. Most units of current design have a
condensate bailing system to remove water from the gear
esci of ief-,40,tior SW440;44
housing by displacement. These units should be checked
often for proper operation, particularly during seasons of
wide air temperature fluctuation. MAINTENANa
Pumps incornorate many types of seals and gaskets Please answer the discussion and review questions be-
constructed of combinations of elastomers and metals. As fore continuing with Lesson 3.

DISCUSSION AND REVIEW QUESTIONS

Chapter 18. MAINTENANCE
(Lesson 2 of 5 Lessons)

Write your answers to these questions in your notebook

15. Why should a pump never be allowed to run dry?
before continuing The question numbering continues from
Lesson 1. 16. How would you develop a lubrication schedule for a
pump?
13. What is the purpose of a pump shaft?
14. What is the purpose of pump sleeves? 17. Why is cleanliness important in the storing and use of
lubricants?

28 `-;
 Maintenance 265

CHAPTER 18. MAINTENANCE

(Lesson 3 of 5 Lessons)

18.23 Pump Maintenance NOTE: If you need to shut a unit down, make sure it is also
locked out and tagged properly. (Figure 18.22)
18.230 Section Format
The format of this section differs from the other chapters.
This format was designed specifically to assrzt you in
planning an effective preventive maintenance program. The CO 17E-
paragraphs are numbered for easy reference when ycu use 17 MEAN 5 RAIL W; W, WeOKLY; M,MON1-1-41.-Y;
the Equipment Service Cards and Service Record Cards Q, QUA21 1.-Y; 5, 5EMIANKEJA LW; A, ANNUALLY
mentioned in Section 18.00, page 219, and shown in Figure
18.1.
405Wirei
An entire book could be w itten on the topics covered in
Paragraph 1: Pumps, General
this section. Step-by-step r' :tails for maintaining equipment
are not provided because manufacturers are continually This paragraph lists some general preventive mainte-
improving their products and these details could soon be out nance services and indicates frequency of performance.
of date. You are assumed to have some familiarity with the Typical centrifugal pump sections are shown in Figure 18.18.
equipment being discussed. FOR DETAILS CONCERNING
A PARTICULAR PIECE OF EQUIPMENT, YOU SHOULD Frequency
CONTACT THE MANUFACTURER. This section indicates to of
you the kinds of maintenance you should include in your Service
program and how you could schedule your work. Carefully
read the manufacturer's instructions and be sure you clearly D 1. CHECK WATER-SEAL PACKING GLANDS
understand the material before attempting to maintain and FOR LEAKAGE. See that the packing box is
repair equipment. If you have any questions or need any protected with a clear-water supply from an
help, do not hesitate to contact the manufacturer or your outside source, make sure that water seal
local representative. pressure is at least 5 psi (35 kPa or 0.35 kg/
sq cm) greater than maximum pump suction
A glossary is not provided in this section because of the pressure. See that there are no CROSS-
large number of technical word; that require familiarization CONNECTIONS.13 Check packing glands
with the equipment being discussed. The best way to learn for leakage during operation. Allow a slight
the meaning of these new words is from manufacturers' seal leakage when pumps are running to
literature or from their representatives. Some new words are keep packing cool and in good condition.
described in the lessons where necessary. The proper amount of leakage depends on
equipment and operating conditions. Sixty
drops of water per minute is a good rule-of-
thumb. If excessive leakage is found, HAND
TIGHTEN glands' nuts evenly, but not too
tight. After adjusting packing glands, be
sure shaft turns freely by hand. If serious
leakage continues, renew packing, shaft, or
shaft sleeve.
D 2. CHECK GREASE-SEALED PACKING
GLANDS. When grease is uzied as a packing
gland seal, maintain constant grease pres-
sure on packing during operation. When a
spring-loaded grease cup is used, keep it
loaded with grease. Force grease through
18.231 Preventive Maintenance packing at a rate of about one ounce (30 gm)
per day. When water is used, adjust seal
The following paragraphs list some general preventive pressure to 5 pal (35 kPa or 0.35 kg/sq cm)
maintenance services and indicate frequency of perform- above maximum pump suction pressure.
ance. There are many makes and types of equipment and Never allow the seal to run dry.
the wide variation of functions cannot be included; therefore,
you will have to use some judgment as to whether the W 3. OPERATE PUMPS ALTERNATELY. If two
services and frequencies will apply to your equipment. If or more pumps of the same size are in-
something goes wrong or breaks in your plant, you may stalled, alternate their use to equalize weal,
have to disregard your maintenance schedule and fix the keep motor windings dry, and distribute
problem now. lubricant in bearings.

13 Cross-Connection. A connection between a drinking (potable) water system and an unapproved water supply For example, if you
have a pump moving non potable water and hook into the e!rinking water system to supply water for the pump seal, a cross-connection
or mixing between the two water systems can occur. This mixing may lead to contamination of the drinking water.
266 Water Treatment

AN_ ER

MAN
WORKING
ON LINE
DO NOT CLOSE THIS
SWITCH WHILE THIS
TAG IS DISPLAYED

SIGNATURE
This is the ONLY person authorized to remove this tag

NOTE: Tag also should Include: TIME OFF

DATE

Fig. 18.22 Typical warning tag

(Source Industrial Indemnity/Industrial Ui.derwriters(uisuiance Cos )

287
 Maintenance 267

Frequency repair grooved or scored shaft sleeve be-

of cause packing cannot be held in stuffing
Service box with roughened shaft or shaft sleeve.
Replace the packing a strip at a time, tamp-
W 4. INSPECT PUMP CONTROL. Inspect the ing each strip thoroughly and staggering
pump controls to see that the pump re- joints. (See Fig. 18.23.) Position lantern ring
sponds properly to changes in tne control- (water-seal ring) properly. If grease sealing
ling variable. This variable may be either a is used, completely fill lantern ring with
pressure or a water level. This check could grease before putting remaining rings of
be done physically or by analyzing recording packing in place. The type of packing used
gage records. (Fig. 18.24) is less important than the man-
D 5. CHECK MOTOR CONDITION. See Para- ner in which packing is placed. Never use a
graph 6: Electric Motors. continuous strip of packing. This type of
packing wraps around and scores the shaft
W E CHECK PACKING GLAND ASSEMBLY. sleeve or is thrown out against outer wall of
Check packing gland, the unit's most stuffing box, allowing water to leak through
abused and troublesome part. If stuffing and score the shaft. The proper size of
box leaks excessively when gland is pulled packing should be available in your plant's
up with mai pressure, remove packing and equipment files. See Fig. 18.25 for illustrat-
examine shaft sleeve carefully. Replace or ed steps on how to pack a pump.

WATER-SEAL SUPPLY

WATER-SEAL RING (LANTERN RING)

PACKING
GLAND

MIEECOLII

iallata..N.NE111114101b11111411abltc.
.WEEISINEGENI SHAFT

PACKING

Fig. 18.23 Method of packing shaft

(Source War Department TochnIcal Manual TM5.666)
0
268 Water Treatment

#1' --..."'....77-111111111.61...

r.4,44

.- . 4

Teflon Packing

Graphite Packing

Fig. 1824 Packing

(Courtesy A W Chesteron Co )

2
 Maintenance 269

Remove ail old packing. Aim pocking for bent rod, grooves or shou
shout- 01 Revolve rotary shaft. If the Indicator
I hook at bore of the box is keep from L d-rs. If the neck bushing clearance runs out over 0.003-In., straighten
scratching the shaft. Clean box thor- in bottom of box is great, use stiffer shaft, r check bearings, or balance
oughly so the new pocking won't hong up bottom ring or replace the neck bushing rotor. Gyrating shaft beats out pocking

PIN Wrong

g Cutting off rings while packing Is If you cut pocking while stretched out straight, the ends will be at an angle.
U wrapped around shaft will give you 1 With gap at angle, packing on either side squeezes into top of gap and ring,
rings with parallel ends. This is very cannot close. This brings up the question stout gap for expansion. Mos pockings
important if pocking is to do job need none. Channel-type pocking with lead core may need slight gap for expansion

HOW Install
Open ring joint sidewise, especially Use split wooden bushing.

TO PACK 11
lead-filled and metallic types. This
prevents distorting molded circumfer-
encebreaking the ring opposite gap
12 first turn of pocking, then farce
into bottom of box by tightening gland
ogainst bushing. Seat each turn this way

A PUMP
(Editor's Note:This step-by-step il-
lustration of a basic maintenance
duty was brought to our attention
by Anthony J. Zigment, Director,
Municipal Training Division, De-
partment of Community Affairs.) Sectional Diagonal
Cross expansion

Always install cross - expansion pocking so plies slope toward the fluid pres-
15
IU sure from housing. Place sectional rings so slope between inside and outside
ring Is toward the pressure. Diagonal rings must clso have slope toward the fluid
pressure. Watch these details for best results when installing new pocking In a box

Fig. 18.25 How to pack a pump

(Source Water Pollution Control Association of Pennsylvania Magazine. January-February. 1976)
2
270 Water Treatment

A To find the right size of packing to Wind packing, needed for filling stuffing box, snugly around rod (for SCUM size
install, measure stuffing-box bore and U shaft held in vise) and cut through each turn while coiled, as shown. If the
subtract rod diameter, divide by 2. pocking is slightly too large, never flatten with a hammer. Place each turn on
Packing is too critical for guenwark. a clean newspaper and then roll out with pipe os you would v ith a rolling pin

,Neck bushing

Li

Q Install foil-wrapped packing so edges Q Neck bushing slides into stuffing in Swabbing new metallic pockings with
1.1 on inside will face direction of shaft 0 box. Quick way to make it is to pour 1U lubricant supplied by pocking maker
rotation. This is o must; otherwise, thin soft bearing metal into tin con, turn is OK. These include foil types, lead-
edges flake off, reduce pocking life and bore for sliding fit into place core, etc. If the rod is oily, don't swab it

Lonsern ring. Clone/

111117.11111

Yd

11 Stagger joints 180 degrees if only iA Install pocking so lantern ring lines up with cooling-liquid opening. Also, remem
IU two rings ore in stuffing box. Space ber that this ring moves bock into box as pocking is compressed. Leave space
at 120 degrees for three rings, or 90 for gland to enter as shown. Tighten gland with wrenchbock off finger-tight.
degrees if four rings or more ore in set Allow the pocking to leak until it seats itself, then ollow a slight operoong leakage

Hydraulic-packing pointers
First, clean stuffing box, examine ram or rod. Next, measure stuffing-box
depth and packing setfind difference. Place 1/2-in. washers over gland
studs as shown. Lubricate ram and packing set (if for water). If you
can use them, endless rings give about 17% more wear than cut rings.
Place male adapter in bottom, then carefully elide each packing turn
homedon't harm lips. Stagger joints for cut rings. Measure from top
of packing to top of washers, then compare with gland. Never tighten
down new packing set until all air has chance to work out. As packing
wears, remove one set of washers, after more wear, remove other washer.

Fig. 18.25 How to pack a pump (continued)

2
 Maintenance 271

Frequency however, if solid L',:lafting is used, align

of exactly. If beams carrying intermediate
Service bearings are too light or are subject to
contraction or expansion, replace beams
If a bronze shaft sleeve is not too badly and realign intermediate bearings carefully.
scored, the shaft sleeve can be restored to S 11 INSPECT AND SERVICE PUMPS.
service. The repair procedure consists of
turning the sleeve down to a uniform diame- a Remove rotating element of pump and
ter with a rough cut. Then spray the sleeve inspect thoroughly for wear. Order re-
with stainless steel to a slightly oversized placement parts where necessary.
outside diameter foilowed by machining and Check impeller clearance between vo-
polishing to bring the sleeve back to its lute
original diameter. You will probably find that
b. Remove any deposit or scaling. Clean
these reworked sleeves will outlast the out water-seal piping.
originals.
c. Determine pump capacity by pumping
W 7. CHECK MECHANICAL SEALS. Mechanical into empty tank of known size or by
seals usually consist of two sub-assem- timing the draining of pit or sump.
blies: (1) a rotating ring assembly, and (2) a
stationary assembly. Volume. gallons
Pump Capacity. GPM
Inspect seal for leakage and excessive heat. Time, minutes
If any part of the seal needs replacing, Or
replace the entire seal (both sub-assem- liters Volume. liters
Pump Capacity.
blies) with a new seal that has been pro- sec Time, seconds
vided by the manufacturer. Before installing
a new seal, be sure that there are no chips See EXAMPLE 1 for procedures on how
or cracks on the carbide sealing surface. to calculate pump capacity.
Keep a new mechanical seal clean at all
times d. Test pump efficiency. Refer to pump
manufacturer's instructions on how to
Always be sure that a mechanical seal is collect data and perform calculations.
surrounded with water before starting and Also see pages 147 and 148 in SMALL
running the pump. W ITER SYSTEM OPERATION AND
MAINTENANCE of this series of man-
Q 8. INSPECT AND LUBRICATE BEARINGS. uals.
Unless otherwise specifically directed for a
particular pump model, lubricate according e. Measure total dynamic suction head or
to the procedures covered in Section lift and discharge head to test pump and
18.224. page 263. Check sleeve bearings to pipe condition. Record figures for com-
see that oil rings turn freely with the shaft. parison with later tests.
Repair or replace if defective.
f. Inspect foot and check valves, paying
Measure sleeve bearings and replace those particular attention to check valves,
worn excessively. Generally. allow clear- which can cause water hammer when
ance of 0.002 inch plus 0.001 inch for each pump stops. (See Paragraph 13: Check
inch or fraction of inch of shaft-journal diam- Valves also.) Foot valves are a type of
eter. check valve which are used when pump-
ing raw water.
Q 9. CHECK OPERATING TEMPERATURE OF
BEARINGS. Check bearing temperature g. Examine wearing rings. Replace serious-
with thermometer, not by hand. If antifriction ly worn wearing rings to improve efficien-
bearings are running hot, check for over- cy. Check wearing ring clearances which
lubrication and relieve if necessary If sleeve generally should be no more than 0.003
bearings run too hot, check for lack of inch per inch of wearing diameter.
lubricant. If proper lubrication does not cor-
rect condition, disassemble and inspect CAUTION: To protect rings and castings,
bearing. Check alignment of pump and mo- never allow pump to run dry through lack
tor if high temperatures continue. of proper priming when starting or loss of
suction when operating.
S 10. CHECK ALIGNMENT OF PUMP AND MO-
TOR. For method of aligning pu.-np and A 12. DRAIN PUMP FOR LONG-TERM SHUT-
motor, see Paragraph 10: Couplings. If mis- DOWN. When shutting down pump for a
alignment recurs frequently, inspect entire long period, open motor disconnect switch;
piping system. Unbolt piping at suction and and if so equipped, turn on the electric
discharge nozzles to see if it springs away. motor winding heaters. Shut all valves on
indicating strain on casing. Check all piping suction, discharge, water-seal, and priming
supports for soundness and effective sup- lines; drain pump completely by removing
port of load. vent and drain plugs. This procedure pro-
tects pump against corrosion, sedimenta-
Vertical pumps usually have flexible shafting tion, and freezing. Inspect pump and bear-
which permits slight angular misalignment; ings thoroughly and perform all necessary

.2 ,9 '),
 272 Water Treatment

Frequency
of QUESTIONS
Service Write your answers in a notebook and then compare your
answers with those on page 325.
servicing. Drain bearing housings and re- 18 23A What is a cross-connection9
plenish with fresh oil, purge old grease and
replace. When a pump is out of service, run 18.23B Is a slight water-seal leakage desirable when a
it monthly to warm it up and to distribute pump is running? If so, why?
lubrication so the packing will not "freeze" to
18.23C How would you measure the capacity of a pump?
the shaft. Resume periodic checks after
pump is put back in service. 18.23D Estimate the capacity of a pump (in GPM) if it
lowers the water in a 10-foot wide by 15-foot long
wet well 1.7 feet in five minutes.
FORMULAS
18.23E What should be done to a pump before A is shut
To find the volumes of a rectangle in cubic feet, multiple down for a long time, and why?
the length times width times depth.
Paragraph 2: Reciprocating Pumps, General
Volume, cu ft = (Length, ft) (Width, ft) (Depth, ft)
To find the volume of a cylinder in cubic feet, multiply The general procedures in this paragraph apply to all
reciprocating pumps described in this section.
0.785 times the diameter squared times the depth.
Frequency
Volume, cu ft - (0.785) (Diameter, ft12 (Depth, ft) of
To convert a volume from cubic feet to gallons, multiply Service
the volume in cubic feet times 7.48 gallons per cubic foot.
W 1. CHECK SHEAR PIN ADJUSTMENT. Set ec-
Volume, gal = (Volume, cu ft) (7.48 gal/cu ft) centric by placing shear pin through proper
To calculate the output or capacity of a pump in gallons hole in eccentric flanges to give required
stroke. Tighten the two 5/9- or 1/8 -inch hexag-
per minute, divide the volume pumped in gallons by the
pumping time in minutes. onal nuts on connecting rods just enough to
take spring out of lock washers. (See Para-
Volume Pumped, gallons graph 11: Shear Pins). When a shear pin
Pump Capacity, GPM = fails, eccentric moves toward neutral posi-
Pumping Time, minutes
tion, preventing damage to the pump. Re-
move cause of obstruction and insert new
EXAMPLE 1 shear pin. Shear pins fail because of one of
three common causes:
A pump's capacity is measured by recording the time in
minutes for water to rise 3 feet in an 8-foot diameter tank. (1) Solid object lodged under piston,
What is the pumping rate or capacity in gallons per minute (2) Clogged discharge line, and
when the pumping time is 9 minutes?
(3) Stuck or wedged valve.
Known Unknown
D 2. CHECK PACKING ADJUSTMENT. Give
Diameter, ft = 8 ft Pump Capacity, GPM special attention to packing adjustment. If
Depth, ft = 3 ft packing is too tight, it reduces efficiency and
scores piston walls. Keep packing just tight
Time, min = 9 min enough to keep s'udge from leaking through
gland. Before pump is installed or after it
Calculate the tank volume in cubic feet.
has been idle for a time, loosen all nuts on
Volume, cu ft = (0.785) (Diameter, ft)2 (Depth. ft) packing gland. Run pump with sludge suc-
tion line closed and valve covers open for a
= (0.785) (8 ft)2 (3 ft) few minutes to break in the packing. Turn
= 151 cu ft down gland nuts no more than necessary to
prevfnt sludge from getting past packing.
Convert the tank volume from cubic feet to gallons. Tighten all packing nuts uniformly.
Volume, gal = (Volume, cu ft) (7.48 gal /cu ft) When packing gland bolts cannot be taken
up farther, remove packing. Remove old
= (151 cu ft) (7 48 gal/cu ft)
packing and thoroughly clean cylinder and
= 1129 gallons piston walls. Place new packing into cylin-
der, staggering packing-ring joints, and
Calculate the pump capacity in gallons per minute. tamp each ring into place. Break in and
Volume Pumped, gal adjust packing as explained above. When
Pump Capacity, GPM chevron type jr..i.ing is used, tighten gland
Pumping Time, min nuts only finger tight because excessive
1129 gallons pressure ruins packing and scores plunger.
9 min 0 3. CHECK BALL VALVES. When va've balls
are so worn that diameter is 5/6 inch (1.5 cm)
= 125 GPM smaller than original size, they may jam into

2 93
 Maintenance 273

Frequency W 3. INSPECT PUMP ASSEMBLY. See Para-

of graph 1.4.
Service 4. LUBE LINE SHAFT AND DISCHARGE
W
BOWL BEARING. Maintain oil in oiler at all
guides in valve chamber. Check size of
valve balls and replace if badly worn. times. Adjust feed rate to approximately
four drops per minute.
O 4. CHECK VALVE-CHAMBER GASKETS.
Valve-chamber gaskets on most pumps W 5. LUBE SUCTION BOWL BEARING. Lube
serve as a safety device and blow out under through pressure fitting. Usually three or
excessive pressure. Check gaskets and re- four strokes of gun are enough.
place if necessary. Keep additional gaskets W 6. OPERATE PUMPS ALTERNATEL". See
on hand for replacement. Paragraph 1.3.
A 5. CHECK ECCENTRIC ADJUSTMENT. To A 7. LUBE MOTOR BEARINGS. See Paragraph
take up babbitt bearing, remove brass 6.3.
shims provided on connecting rod. After
removing shims, operate pump for at least
one hour and check to see that eccentric Paragraph 4: Progressive Cavity Pumps, General
does not run hot. !Fig. 18.20, page 260).
D 6. NOTE UNUSUAL NOISES. Check for no- Cl 1 CHECK MOTOR CONDITION. See Para-
ticeable water hammer when pump is oper- graphs 6.1 and 6.2.
ating. This noise is most pronounced when
pumping water or very thin sludge; it de- D 2. CHECK PACKING GLAND ASSEMBLY. See
creases or disappears when pumping heavy Paragraph 1.6.
sludge. Eliminate noise by opening the 1/4- D 3. CHECK DISCHARGE PRESSURE. A higher
inch (0.6 cm) petcock on pump body slightly; than normal discharge pressure may indi-
this draws in a small amount of air, keeping cate a line blockage or a closed valve down-
discharge air chamber full at all times. stream. An abnormally low discharge pres-
D 7. CHECK CONTROL VALVE POSITIONS. Be- sure can mean reduced rate of discharge.
(ause any plunger pump may be damaged if S 4. !NSPECT AND LUBRICATE BEARINGS -
operated against closed valves in the pipe- GREASE. If possible, remove bearing cover
line, especially the discharge line, make all and visually inspect grease. When greasing,
valve setting changes with pump shut down; remove relief plug and cautiously add 5 or 6
otherwise pumps which are installed to strokes of the grease gun. Afterwards,
pump from two sources or to deliver to check bearing temperature with thermom-
separate tanks at different times may be eter. If over 220°F (104°C), remove some
broken if all discharge line valves are closed grease.
simultaneously for a few seconds or dis-
charge valve directly above pump is closed. S 5. LUBEFLUSH MOTOR BEARINGS. See
Paragraph 6.3.
W 8. GEAR REDUCER. Check oil level by remov-
ing plug on the side of the gear case Unit S 6. CHECK PUMP OUTPUT Check how long it
should not be in operation. takes to fill a vessel of known volume or
quantity; or check performance against a
O 9. CHANGE OIL AND CLEAN MAGNETIC meter, if available. See Paragraph 1.11.c.
DRAIN PLUG.
A 7. SCOPE MOTOR BEARINGS. See Para-
W 10. CONNECTING RODS. Set oilers to disperse graph 6.4.
two drops per minute.
A 8. SCOPE PUMP BEARINGS. See Paragraph
W 11. PLUNGER CROSSHEAD. Fill plunger as re- 6.4.
quired to half cover the wrist pin with oil.
D 12. PLUNGER TRJUGH. Keep small quantity of
oil in trouph to lubricate the plunger. Paragraph 5: Pump Controls

M 13 MAIN SHAFT BEARING. Grease bearings To ensure the best operation of the pump, a systematic
monthly. Pump should be in operation when inspection of the controls should be made at least once a
lubricating to avoid excessive pressure on week.
seals.
W 1. CHECK CONTROLS. Controls respond to
14. CHECK ELECTRIC MOTOR. See Para- the control variable.
graph 5: Electric Motors.
W 2. STARTUP. The unit starts when the control
system makes contact, and the pump stops
Paragraph 3: Propeller Pumps, General at the prescribed control setting.

D 1. CHECK MOTOR CONDITION. See Para- W 3. MOTOR SPEED. The motor comes up to
graphs 6.1 and 6.2. speed quickly and is maintained.
D 2. CHECK PACKING GLAND ASSEMBLY. See W 4. SPARKING. A brush-type motor does not
Paragraph 1.6. spark profusely in starting or running.

2 L4 /4
 274 Water Treatment

Frequency Frequency
of of
Service Service
W 5. INTERFERENCE WITH CONTROLS. k. Brush chatter.
Gr se and dirt are not interfering with
corm ols. I. Vibration.
W 6. ADJUSTMENTS. Any necessary adjust- m. Hot commutator.
ments are properly completed. A 3 LUBRICATE BEARINGS (Fig. 18.27). Check
grease in ball bearing and relubricate when
QUESTIONS necessary.
Write your answers in a notebook and then compare your Follow instructions in Section 18.224, Pump
answers with those on page 325. Lubrication, when lubricating greased bear-
ings.
18.23F What are some of the common causes of shear pin
failure in reciprocating pumps? A 4. USING A STETHOSCOPE," CHECK BOTH
BEARINGS. Listen for whines, gratings, or
18.23G What may happen when water or a thin sludge is uneven noises. Listen all around the bearing
being pumped by a reciprocating pump? and as near as possible to the bearing.
18.23H What could be the causes of a higher than normal Listen while the motor is being started and
discharge pressure in a progressive cavity pump? shut off. If unusual noises are heard, pin-
point the location.

Paragraph 6: Electric Motors (Fig. 18.26) 5. IF YOU THINK THE MOTOR is running
unusually hot, check with a thermometer.
In order to ensure the proper and continuous function of Place the thermometer on the casing near
eiectric motors, the items listed in this paragraph must be the bearing, holding it there with putty or
performed at the designated intervals. If operational checks clay. Check the current on each leg to
indicate a motor is not functioning properly, these items will determine if the currents are balanced and
have to be checked to locate the problem. within the motor name plate limits.
A 6. DATEOMETER.15 If there is a dateome er
D 1. CHECK MOTOR CONDITIONS.
on the motor, after changing the oil in the
a. Keep motors free from dirt, &at and motor, loosen the dateometer screw and set
moisture. to the corresponding year.
b. Keep operating space free from articles QUESTIONS
which may obstruct air circulaton.
Write your answers in a notebook and then compare your
c. Check for excessive grease leakage answers with those on page 325.
from bearings.
18.231 What are the major items you would include when
D 2. NOTE ALL UNUSUAL CONDITIONS. checking an electric motor?
a. Unusual noises in operation. 18.23J What is the purpose of a stethoscope?
b. Motor failing to start or come to speed
normally, sluggish operation. Paragraph 7: Belt Drives
c. Motor or bearings which feel or smell Frequency
hot. of
Service
d. Continuous or excessive sparking com-
mutator or brushes. Blackened commu- 1. GENERAL. Maintai: ing a proper tension
tator. and alignment of belt drives ensures long
e. Intermittent sparking at brushes. life of belts and sheaves. Incorrect align-
ment causes poor operation and excessive
f. Fine dust under coupling having rubber belt wear. Inadequate tension reduces the
buffers or pins. belt grip, causes high belt loads, snapping,
and unusual wear.
g. Smoke, charred insulation, or solder
whiskers extending from armature. a. Cleaning belts. Keep belts and sheaves
clean and free of oil, which causes belts
h. Excessive humming.
to deteriorate. To rem 3ve oil, take belts
i. Regular clicking. off sheaves and wipe belts and sheaves
with a rag moistened in a non-oil base
j. Rapid knocking. solvent. Carbon tetrachloride is NOT rec-

14 Stethoscope. An instrument used to magnify sounds and convey them to the ear.
15 Dateometer (day-TOM-ut-ter). A small calendar disc attached to motors and equipment to indicate the
maintenance service was performed. year in which the last

296
 Mairtenance 275

DRIP PROOF

ITEM
PART NAME
NO.
1 Wound Stator w/ Frame
2 Rotor Assembly
3 Rotor Core
4 Shaft
5 Bracket
6 Bearing Cap
7 Bearings
8 Seal, Labyrinth
9 Thru Bolts/Caps
10 Seal, Lead Wire
11 Terminal Box
12 Terminal Box Cover
13 Fan
14 Deflector
15 Lifting Lug

TOTALLY ENCLOSED FAN COOLED

ITEM
PART NAME
NO.

Wound Stator w/ Frame

2 Rotor Assembly
3 Rotor Core
4 Shaft
5 Brackets
6 Bearings
7 Seal, Labyrinth
8 Thru Bolts/Caps
9 Seal, Leai Wire
111
10 Terminal Box
11 Terminal Box Cover
12 Fan, Inside
13 "an, Outside
14 Fan Grill 13

15 Fan Cover
11
16 Fan Cover Bolts
17 Liftin Lu

Fig. 18.26 Typical motors

(c,atesy of Sterling Power Systems. Inc

2(w
276 Water Treatment

ELECTRIC MOTOR

MOTOR LUBRICATION

FILL

LUBE FITTING / 1

DRAIN

1 FRONT BEARING BRACKET

2 FRONT AIR DEFLECTOR 8 SCREENS
3 FAN 9 CONDUIT BOX
4 ROTOR
10 BACK AIR DEFLECTOR
5 FRONT BEARING 11 BACK BEARING
6 END COVER 12 BACK BEARING BRACKET
7 STATOR 13 OIL LUBRICATION CAP

Fig. 18.27 Electric motor lubrication

297
 Maintenance 277

Frequency being aligned. Be especially careful in

of aligning drives with more than one V-belt
Service on a sheave, as misalignment can cause
unequal tension
ommended because exposure to its
fumes has many toxic effects on hu- Paragraph 8: Chain Drives
mans. Carbon tetrachloride also is ab-
1. GENERAL. Chain drives may be desigr.ated
sorbed into the skin on contact and its for slow, medium, or high speeds.
effects become stronger with each con-
tact. a. Slow-speed drives. Because slow-speed
drives are usually enclosed, adequate
b. Installing belts. Before installing belts, lubrication is difficult. Heavy oil applied to
replace worn or damaged sheaves, ien
the outside of the chain seldom reaches
slack off on adjustments. Do not try to
the working parts; in addition, the oil
force belts into position. Never use a catches dirt and grit and becomes abra-
screwdriver or similar lever to get belts
sive. For lubricating and cleaning meth-
onto sheaves. After belts are installed,
ods, see 5 and 6 below.
adjust tension; recheck tension after
eight hours of operation. (See Table b. Medium- and high-speed drives. Medi-
18.3). um-speed drives should be continuously
lubricated with a device similar to a sight-
c. Replacing belts. Replace belts as soon feed oiler. Highspeed drives should be
as they become frayed, worn, or completely enclosed in an oil-tight case
cracked. NEVER REPLACE ONLY ONE
and the oil maintained at proper level.
V-BELT ON A MULTIPLE DRIVE. Re-
place the complete set with a set of D 2. CHECK OPERATION. Check general oper-
matched belts, whit h can be obtained ating condition during regular tours of duty.
from any 3upplier. All belts in a matched
set are machine-checked to insure equal O 3. CHECK CHAIN SLACK. The correct amount
size and tension. of slack is essential to proper oneration of
chain drives. Unlike other belts, chain belts
d. Storing spare belts. Store spare belts in a
should not be tight around the sprocket;
cool, dark place. Tag all belts in storage when chains are tight, working parts carry a
to identify them with the equipment on much heavier load than necessary. Too
which they can be used.
much slack is also harmful; on long centers
2. V-BELTS. A properly adjusted V-belt has a particularly, too much slack causes vibra-
slight bow in the slack side when running; tions and chain whip, reducing life of both
when idle it has an alive springiness when chain and sprocket. A properly installed
thumped with the hand. An improperly tigh..- chain has a slight sag or looseness on the
ened heft feels dead when thumped. return run.
If the slack side of the drive is less than 45° S 4. CHECK ALIGNMENT. If sprockets are not in
from the horizontal, vertical sag at the cen- line or if shafts are not parallel, excessive
ter of the span may be adjusted in accor- sprocket and chain wear and early chain
dance with Table 18.3 below: failure result. Wear on inside of chain, side
walls, and sides of sprocket teeth are signs
TABLE 18.3 HORIZONTAL BELT TENSION of misalignment. To check alignment, re-
Span
10 20 50 100 150 200
move chain and place a straight edge
(inches)
against sides of sprocket teeth.
Vertical
Sag From 01 03 20 80 1 80 3 30
(inches) S 5. CLEAN. On enclosed types, flush chain and
To 03 09 58 2 30 4 90 8 60
enclosure with a petroleum solvent (kero-
Span sene). On exposed types, remove chain and
(millimeters) 250 500 1250 2500 3750 5000
soak and wash it in solvent. Clean sprock-
Vertical
Sag From 0 25 0 75 5 00 20 0 45 0 82 5 ets, install chain, and adjust tension.
(millimeters) To 075 225 14 50 575 122 5 215 0
S 6. CHECK LUBRICATION. Soak exposed-type
chains in oil to restc.e lubricating film. Re-
M a. Check tension. If tightening belt to proper move excess lubricant by flanging chains up
tension does not cc ect slipping, check to drain.
for overload, oil on belts, or other possi-
ble causes. Never use belt dressing to Do not lubricate underwater chains which
stop belt slippage. Rubber weavings near operate in contact with considerable grit. If
the drive are a sign of improper tension, water is clean, lubricate by applying water-
incorrect alignment, or damaged proof grease with brush while chain is run-
sheaves. ning.

M b. Check sheave (pulley) alignment. Lay a Do not lubricate chains on elevators or on

long straight edge or string across out- conveyors of feeders which handle dirty or
side faces of pulley, and allow for differ- gritty materials. Dust and grit combine with
ences in dimensions from center lines of lubricants to form a cutting compound which
grooves to outside faces of the pulleys reduces chain life.

2 L4 d
 278 Water Treatment

Frequency Frequency
of of
Serv;ce Service

S 7. CHANGE OIL. On enclosed types only, drain belt in opposite direction from that in which
oil and refill case to proper level. it formerly ran.
S 8. INSPECT. Note and correct abnormal condi- M If drive is not operated for 30 days or more,
tions before serious damage results. Do not shift unit to minimum speed position, plac-
put a new chain oil worn sprockets. Always ing spring on variable -speed shaft at mini-
replace worn sprockets when replacing a mum tension and relieving belt of excessive
chain because out-of-pitch sprockets cause pressure.
as much chain wear in a few hours as years
of normal operation. 4 LUBRICATE DRIVE. Make sure to apply
lubricant at all the six force-feed lubrication
9. TROUBLESHOOTING. Some common fittings (Fig. 18.28: A, B, D, E, G and H) and
symptoms of improper chain-drive oper- the one cup type fitting (C).
ation and their remedies follow:
NOTE: If the drive is used with a reducer,
a. Excessive noise. Correct alignment, if fitting E is not provided.
misaligned. Adjust centers for proper
chain slack. Lubricate in accordance with W a. Once every ten days to two weeks, use
aforementioned methods. Be sure all two or three strokes of a grease gun
bolts are tight. If chain or sprockets are through fittings A and B at ends of shift-
worn, reverse or renew if necessary. ing screw and variable-speed shaft, re-
b. Wear on chain, side walls, and sides of spectively, to lubricate bearings of mov-
teeth. Remove chain and correct align- able discs. Then, with unit running, shift
ment. drive from one extreme speed position to
the other to ensure thorough distribution
c. Chain climbs sprockets. Check for poorly of lubricant over disc-hub bearings.
fitting sprockets and replace if neces- Q b. Add two or three shots of grease through
sary. Make sure tightener is installed on
drive chain. fittings 0 and E to lubricate frame bearing
on variable-speed shaft.
d. Broken pins and rollers. Check fo- chain Q
speed which may be too high ior the c Every 90 days, add two or three cupfulls
pitch, and substitute chain and sprockets of grease to CUD C which lubricates
with shorter pitch if necessary. Breakage thrust bearing on constant-speed shaft.
al3o may be caused by shock loads. Q d. Every 90 days, use two or three strokes
e. Chain clings to sprockets Check for in- of grease gun through fittings G and H to
correct or worn sprockets or heavy, lubricate motorframe bearings.
tacky lubricants. Replace sprockets or CAUTION: Be sure to follow manufactur-
lubricants it necessary. er's recommendation on type of grease.
f. Chain whip. Check for too-long centers After lubricating, wipe excessive grease
from sheaves and belt.
or high, pulsating loads and correct
cause.
g. Chains get stiff. Check for misalignment,
QUESTIONS
improper lubrication, or excessive over- Write your answers in a notebook and then compare your
loads. Make necessary corrections or answers with those on page 325.
adjustments.
18 23K How can you tell if a belt on belt-drive equipment
Paragraph 9: Variable Speed Belt Drives (See Fig 18.28) has proper tension and alignment/

D 1. Cl_EAN DISCS. Remove grease, acid, and 18 23L Why should sprockets be replaced when replacing
water from disc faces. a chain in a chain-drive unit/

D 2. CHECK SPEED-CHANGE MECHANISM. Paragraph 10: Couplings

Shift drive through entire speed range to
make sure shafts and bearings are lubricat- 1 GENERAL. Unless couplings between the
ed and discs move freely in lateral direction driving and driven elements of a pump or
on shafts. any other piece of equipment are kept in
W
proper alignment, breaking and excessive
3. CHECK V-BELT. Make sure it runs level and weal results in either or both the driven
true. If one side rides high, a disc is sticking machinery and the driver. Burned-out bear-
on shaft because of insufficient lubrication ings, sprung or broken shaft, and exces-
or wrong lubricant. In this case, stop the sively worn or ruined gears are some of the
drive at once, remove V-belt, and clean disc damages caused by misalignment. To pre-
hub and shaft thoroughly with petroleum vent outages and the expense of installing
solvent until disc moves freely. Relubricate replacement parts, check the alignment of
with soft ball-bearing grease and replace V- all equipment before damage occurs.

29j
 Maintenance 279

MOTOR
REDUCER

BELT

MOTOR DISCS

I
SPEED
CHANGE
MECHANISM

NOTE A, B, D. E, G and H are force-feed lubrication fittings.

C is a cup type lubrication fitting

Fig 18.28 Reeves laridnve

(Source War Department Technical Manual TM5.666)

Frequency necessary (Fig 18 29) using a straight edge

of and thickness gage or wedge. To ensure
Service satisfactory operation, level up to within
0.005 inch (0.13 mm) as follows:
a. Improper original installation of the a. Remove coupling pins.
equipment may not necessarily be the
b. Rigidly tighten driven equipment; slightly
cause of the trouble. Settling of founda- tighten bolts holding drive.
tions, heavy floor loadings, warping of
bases, excessive bearing wear, and c To correct horizontal and vertical misa-
many other factors cause misalignment. lignment, shift cr shim drive to bring
A rigid base is not always security coupling halves into position so no light
against misalignment. The base may can be seen under a straight edge laid
have been mounted off level, which could across them. Place straight edge in four
cause it to warp. positions, holding a light in back of
b. Flexible couplings permit easy assembly straight edge to help ensure accuracy.
of equipment, but they must be aligned d. Check for angular misalignment with a
as exactly as flanged couplings if mainte- thickness or feeler gage inserted at four
nance and rapair are to be kept t. places to make certain space between
minimum. Rubber-bushed types cannot coupling halves is equal.
function properly if the bolts cannot
move in their bushings. e. If proper alignment has been secured,
coupling pins can be put in place easily
2. CHECK COUPLING ALIGNMENT (straight using only finger pressure. Never ham-
edge method). Excessive bearing and motor mer pins into place.
temperatures caused by overload, notice-
able vibration, or unusual noises may all be f. If equipment is still out of alignment,
warnings of misalignment. Realign when repeat the procedure.
 280 Water Treatment

STRAIGHT EDGE.

PARALLEL MISALIGNMENT
STRAIGHT EDGE

FEELER GAGE FEELER GAGE

ANGULAR MISALIGNMENT PEPCECT ALIGNMENT

Fig. 18.29 Testing alignment, straight edge

(Source Unknown)

Frequency so solidly that an overload fails to break them.

of
Service ME lufacturers' drawings for particular installations usual-
ly specify shear pin material and size. If this information is
S 3 CHECK COUPLING ALIGNMENT (dial indi- not available, obtain the information from the manufacturer,
giving the model, serial number, and load conditions of unit.
cator method). Dial indicators also are used
to measure coupling alignment. This meth- When necessary to determine shear pin size, select the
od produces better results than the straight lowest strength which does not break under the unit's usual
edge method. The dial indicates very small
loads. When proper size is determined, never use a pin of
greater strength, such as a bolt or a nail.
movements or distances which are meas-
ured in mils (one mil equals 1/1000 of an If necked pins are used, be sure the necked-down portion
inch). The indicator consists of a dial with a is properly positioned with respect to shearing surfaces.
graduated face (with "plus" and "minus" When a shear pin breaks, determine and remedy the cause
readings, a pedestal, and a rigid indicator of failure before inserting new pin anti starting drive in
bar (or "fixture) as shown in Figure 18.30). operation.
The dial indicator is attached to one cou-
pling via the fixture and adjusted to the zero Frequency
position or reading. When the shaft of the of
machine is rotated, misalignment will cause Service
the pedestal to compress (a "plus" reading),
or extend (a "minus" reading). Literature
M 1 GREASE SHEARING SURFACES
; ovided by the manufacturer of machinery
usually wi!I indicate maximum allowable tol- 0 2. REMOVE SHEAR PIN. Operate motor for a
erances or movement. short time to smooth out any corroded
Carefully study the manufacturer's literature spots.
provided with your dial indicator before at- A 3. CHECK SPARE INVENTORY. Make sure an
te.npting to use the device. adequate supply is on hand, properly identi-
A 4. CHANGE OIL IN FAST COUPLINGS. Drain fied and with record of proper pin size,
out old oil and add oil to proper level. necked diameter, and longitudinal dimen-
Correct quantity is given on instruction card sions.
supplied with each coupling.
QUESTIONS
Paragraph 11: Shear Pins
Write your answers in a notebook and then compare your
Some water treatment units use shear pins as protective answers with those on page 325.
devices to prevent damage in case of sudden overloads. To
serve this purpose, these devices must be in operational 18,23M What factors could cause couplings to become out
condition at all times. Under some operating conditions, of alignment?
shearing surfaces of a shear pin device may freeze together 18.23N What is the purpose of shear pins') ...

30 i
 Maintenance 281

DIAL

PEDESTAL

DIAL
INDICATORS
25 MILS 25 MILS

INDICATOR BAR -NP.

(FIXTURE)

f
REVERSE 20 MILS
DIALING
PARALLEL
MISALIGNMENT

20 MILS

ILLUSTRATION INIIICATES
A TOTAL OFFSET OF
40 MILS (20 MILS + 20 MILS)

Fig. 18.30 Use of a dial indicator

(Permission of DYMAC. a Division of Spectral Dynamics Corporation)

30 2
 282 Water Treatment

18.24 Pump Operation After starting the pump, again check to see that the
direction of rotation is correct. Packing-gland boxes (stuffing
18.240 Starting a New Pump boxes) should be observed for slight leakage (approximately
The initial startup work described in this paragraph should 60 drops per minute) as described in Paragraph 1: Pumps,
be done by a competent and trained person, such as a General Check to see that the bearings do not overheat
manufacturer's representative, consulting engineer, or an from over- or under-lubrication. The flexible coupling should
experienced operator. The operator can learn a lot about not be noisy, if it is, the noise may be caused by misalign-
pumps and motors by accompanying and helping a compe- ment or improper clearance or adjustment. Check to be sure
tent person put new equipment into operation. pump anchorage is tight Compare delivered pump flows
and pressures with pump performance curves. If pump
Before starting a pump, lubricate it according to the delivery falls below performance curves, look for obstruc-
lubrication instructions. Turn the shaft by hand to see that it tions in the pipelines and inspect piping for leaks
rotates freely. Then cr,eck to see that the shafts of the pump
and motor are aligoed and the flexible coupling adjusted.
(Refer to Paragraph 10: Couplings, page 278; also see 18.241 Pump Shutdown
Section 18.23, "Pump Maintennce," page 265.) If the unit is When shutting down a pump for a long period, the motor
belt di wen, sheave (pulley) alignment and belt adjustment
disconnect switch should be opened, locked out, and tagged
should be checked. (Refer to Paragraph 7: Belt Drives.) with reason for tag noted. If the electric motor is equipped
Check the electric voltage with tre motor characteristics and with winding heaters, check to be sure they are turned on.
inspect This helps to prevent condensation from forming which can
weaken the insulation on the windings. All valves on the
suction, discharge, and water-seal lines should be shut
tightly. Completely drain the pump by removing the vent and
drain plugs.
Inspect the pump and bearings thoroughly so that all
necessary servicing may be done during the inactive period.
Drain the bearing housing and then add fresh lubricant.
Follow any additional manufacturer's recommendations.

18.242 Pump-Driving Equipment

Driving equipment used to operate pumps includes elec-
tric motors and internal combustion engines. In rare in-
stances, pumps are driven with steam turbines, steam
engines, air and hydraulic motors.
In all except the large installations, electric motors are
used almost exclusively, with synchronous and induction
types being the most commonly used. Synchronous motors
operate at constant speeds and are used chiefly in large
the wiring See that thermal overload units in the starter are
sizes. Three-phase, squirrel-cage induction motors are most
set properly Turn on the motor just long enough to see that often used in treatment plants. These motors require little
it turns the pump in the direction indicated by the rotational attention and, under average operating conditions, the fac-
arrows marked on the pump. If separate water seal units or tory lubrication of the bearing will last approximately one
vacuum pruner systems are used, these should be started. year. (Check with the manufacturer for average number of
Finally, make sure lines are open Sometimes there is an operating hours for bearings.) When lubricating motors,
exception (see following paragraph) in the case of the remember that too much grease may cause bearing trouble
discharge valve. or damage the winding.
A pump should not be run without first having been Clean and dry all electrical contacts. Inspect for loose
primed To prime a pump, the pump must be completely electrical contacts. Make sure that hold-down bolts on
filled with water In some cases, automatic primers are
motors are secure. Check voltage while the motor is starting
provided. If they are not, it is necessary to vent the casing. and running. Examine bearings and couplings
Most pumps are provided with a valve to accomplish this.
Allow the trapped air to escape until water flows from the
vent; then replace the vent cap. In the case of suction-lift 18.243 Electrical Controls
applications, the pump must be filled with water unless a
self-primer is provided. !n nearly every case, you may start a A variety of electrical equipment is used to control the
pump with the discharge valve open. Exceptions to this, operation of pumps or to protect.electric motors. If starters,
however, are where water hammer or pressure surges disconnect switches, and cutouts are used, they should be
might result, or where the motor does not have sufficient installed in accordance with the local regulations (city and/or
margin of safety or power. Sometimes there are no check county ,:odes) regarding this equipment. In the case of larger
valves in the discharge line. In this case (with the exception motors, the power company often requires starters which do
of positive displacement pumps) it is necessary to start the not overload the power lines.
pump and then open the discharge lines. Where there are The electrode-type, bubbler-type, and diaphragm-type
common discharge headers, it is essential to start the pump water level control systems are all similar in effect to the
and then open the discharge valve A positive displacement float-switch system. Scum is a problem with most water-
pump (reciprocating or piston types) should never be operat- level controls that operate pumps and must be removed on a
ed against a closed discharge line. regular basis.

3A
 Maintenance 283

QUESTIONS 14 Check valves stuck or clogged

Write your answers in a notebook and then compare your 15 Incorrect impeller adjustment
answers with those on page 325. 16 Impeller damaged or worn
18.24A Where would you find out how to lubricate a pump? 17. Packing worn or defective
18 24B What problems can develop if too much grease is 18 Impeller turning on shaft because of broken key
used in lubricating a motor?
19 Flexible coupling broken
20 Loss of suction during pumping may be caused by leaky
18.244 Operating Troubles
suction line, ineffective water or grease seal
The following list of operating troubles includes most of
21 Belts slipping
the causes of failure or reduced operating efficiency. The
remedy or cure is either obvious or may be identified from 22 Worn wearing ring
the description of the cause.

SYMPTOM C HIGH POWER REQUIREMENTS

SYMPTOM A PUMP WILL NOT START
CAUSES.
CAUSES:
I Blown fuses or tripped circuit breakers due to: 1 Speed of rotation too high
2. Operating heads lower than rating for which pump was
A. Rating of fuses or circuit breakers not correct,
designed. resulting in excess pumping rates
B. Switch (breakers) contacts corroded or shorted,
3. Sheaves on belt drive misaligned or maladjusted
C. Terminal connections loose or broken somewhere in
4. Pump shaft bent
the circuit,
5 Rotating elements binding
D. Automatic control mechanism not functioning prop-
erly, 6. Packing too tight
E. Motor shorted or burned out, 7. Wearing rings worn or binding
F. Wiring hookup or service not correct, 8. Impeller rubbing
G. Switches not set for operation,
H. Contacts of the control relays dirty and arcing, SYMPTOM D NOISY PUMP
I. Fuses or thermal units too warm, CAUSES
J. Wiring short-circuited, and 1 Pump not completely primed
K. Shaft binding or sticking due to rubbing impeller, tight
2 Inlet clogged
packing glands, or clogging of pump.
3. Inlet not submerged
2. Loose connections, fuse, or thermal unit
4 Pump not lubricated properly
SYMPTOM B REDUCED RATE OF DISCHARGE 5. Worn impellers
CAUSES: 6. Strain on pumps caused by unsupported piping fast-
ened to the pump
1 Pump not primed
7 Foundation insecure
2. Air in the water
8. Mechanical defects in pump
3. Speed of motor too low
9 Misalignment of motor and pump where connected by
4. Improper wiring flexible shaft
5. Defective motor 10 Rocks in the impeller
6. Discharge head too high 11 Cavitation
7. Suction lift greater than anticipated
8. Impeller clogged
QUESTIONS
9. Discharge line clogged Write your answers in a notebook and then compare your
10. Pump rotating in wrong direction answers with those on page 325.

11. Air leaks in suction line or packing box 18 24C What items would you check if a pump will not
start?
12. Inlet to suction line too high, permitting air to enter
18.24D How would you attempt to increase the discharge
13. Valves partially or entirely closed from a pump if the flow rate is lower than expected?

. 304
284 Water Treatment

18.245 Starting and Stcpping Pumps

The operator must determine what treatment processes
will be effected by either starting or stopping a pump. The
pump discharge point must be known and va'ves either
opened or closed to direct flows as desired by the operator
when a pump is started or stopped

18 2450 Centrifugal Pumps. Basic rules for the operation

of centrifugal pumps include the following items

1. Do not operate the pump when safety guards are not

installed over or around moving parts.

2. Do not start a pump that has been locked or tagged out

for maintenance or repairs

3. Never run a centrifugal pump when the impeller is dry.

Always be sure the pump is primed.

4. Never attempt to start a centrifugal pump whose impeller

or shaft is spinning backwards. QUESTIONS
5. Do not operate a centrifugal pump that is vibrating Write your answers in a notebook and then compare your
excessively after startup. Shut unit down and isolate answers with those on page 325.
pump from system by closing the pump suction and 18.24E Why should a pump that has been locked or tagged
discharge valves Look for a blockage in the suction line out for maintenance or repairs not be started?
and the pump impeller
18 24F Under what conditions might a centrifugal pump be
started against a closed discharge valve?
There are several situations in which it may be necessary
to start a CENTRIFUGAL pump against a CLOSED dis- STOPPING PROCEDURES
charge valve. Once the pump is primed, running and indicat-
ing a discharge pressure, slowly open the pump discharge This ;ection contains a typical S9quence of procedures to
valve until the pump is fully on line. This procedure is used follow to stop a centrifugal pump. Exact stopping proce-
with treatment processes or piping systems with vacuums dures for any pumping system depend upon the condition of
or pressures that cannot be dropped or allowed to fluctuate the discharge system. The sudden stoppage of a pump
greatly while an alternate pump is put on the line. could cause severe WATER HAMMER'6 problems in the
piping system.
Most centrifugal pumps used in water treatment pieits are
designed so that they can be easily started even if they 1 Inspect process system affected by pump, start alternate
haven't been primed. This is accomplished with a positive pump if required, and notify supervisor or log action.
static suction head or a low suction lift. On most of t, Iese 2 Before stopping and operating pump, check its oper-
arrangements, the pump will not require priming as long as ation. This will give an indication of any developing
the pump and the piping system do not leak. Leaks would problems, required adjustments, or problem conditions of
allow the water to drain out of the pump volute. When pumps the unit. This procedure only requires a few minutes
in water systems lose their prime, the cause is often a faulty Items to be inspected include:
check valve on the pump discharge line. When the pump
stops, the discharge check valve will not seal (close) proper- a Pump packing gland.
ly. Water previously pumped then flows back through the 1) Seal water pressure
check valve and through the pump. l he pump is drained and
has lost its prime. 2) Seal leakage (too much, sufficient or too little
leakage)
About ninety-five percent of the time, the centrifugal 3) Seal leakage drain flowing clear
pumps in v.ater treatment plants are ready to operate with
suction and discharge valves open and seal water turned on. 4) Mechanical seal leakage (if equipped)
When the automatic start or stop comma :d is received by b. Pump operating pressures.
the pump from the controller, the pump is ready to respond
properly. 1) Pump suction (Pressure Vacuum)
A higher vacuum than normal may indicate a partial-
When the pumping equipment must be serviced, take it off ly plugged or restricted suction line. A lower vacu-
the line by locking and tagging out the pump controls until all um may indicate a higher suction water level or a
service work is completed. worn pump impeller or wearing rings.

16 Water Hammer The 4nund like someone hammering on a pipe that occurs when a valve is opened or closed very rapidly. When a
valve position is chanted quickly. the watG, pressure in a pipe will increase and decrease back and forth very quickly. This rise and fall
in pressures can do serious damage to the system.
 Maintenance 285

2) Pump discharge pressure NOTE If the pump is not equipped with a check valve,
close discharge valve before stopping pump.
System pressure is indicated by the pump dis-
charge pressure. Lower than normal discharge
pressures can be caused by: b Motor and pump shouid wind down slowly and not
make sudden stops or noises during shutdown.
a) Worn impeller or wearing rings in the pump;
c After equipment has completely stopped, pump shaft
b) A different point of discharge can change dis-
and motor should not start back-spinning. If back-
charge pressure conditions;
spinning is observed in a pump with a check valve or
c) A broken discharge pipe can change the dis- foot valve, close the pump discharge valve SLOWLY'
charge head. Be extra careful if the,, is a plug valve on a line with a
high head because when the discharge valve is part
NOTE. To determine the maximum head a centrifugal pump way closed, the plug valve could slam closed and
can cblvelop, slowly close the discharge valve at the damage the pump or piping.
pump. Read the pressure gage between the pump
ano the discharge valve when the valve is fully 4. Go to power control panel containing the pump motor
closed. This is the maximum pressure the pump is starters just shut down and OPEN motor breaker switch,
capable of developing. Do not operate the pump lock cqt, and tag.
longer than a few minutes with the discharge valve
5. Return to pump and close:
closed completely because the energy from the
pump is converted to heat and water in the pump can a. Discharge valve,
become hot enough to damage the pump.
b Suction valve,
c. Seal water supply valve, and
d Pump volute bleed line (if so equipped).
6. If required, close and open appropriate valves along
piping system through which pump was discharging.

Starting Procedures
This section contains a typical sequence of procedures to
follow to start a centrifugal pump.

1 Check motor control panel for lock and tags. Examine

tags to be sure that NO item is preventing startup of
equipment.
2. Inspect equipment
a. Be sure stop switch is locked out at equipment loca-
tion.
b. Guards over moving parts must be in place.
c. Clean-out on pump volute and drain plugs shoulc '-ie
c. Motor temperature and pump bearing temperature. installed and secure.
If motor or bearings are too hot to touch, further d. Valves should be in closed position.
checking is necessary to determine if a problem has e. Pump shaft must rotate freely.
developed or if the temperature is normal. High tem-
peratures may be measured with a thermometer. f Pump motor should be clean and air vents clear.
d Unusual noises, vibrations. or conditions about the g Pump, motor, and auxiliary equipment lubricant level
equipment. must be at proper elevations.
If any of the above items indicate a change from the h. Determine if any special considerations or precautions
pump's previous operating condition, additional ser- are to be taken during startup.
vice or maintenance may be required during shut-
down. 3. Follow pump discharge piping route. Be sure all valves
are in the proper position and that the pump flow will
3. Actuate stop switch for pump motor and lock out switch. discharge where intended.
If possible use switch next to equipment so that you may
observe the equipment stop. Observe the following items: 4. Return to motor control panel.

a. Check valve closes and seats. a. Remove tag.

Valve should not slam shut, or discharge piping will b. Remove padlock.
jump or move in their supports. There should not be c. Close motor main breaker.
any leakage around the check valve shaft. If check
valve is operated automatically, it should close d. Place selector switch to manual (if you have automatic
smoothly and firmly to the fully closed position. equipment).

3 9U
 286 Water Treatment

5. Return to pump equipment Important rues for operating LICSitive displacement

pumps include
a. Open seal water supply line to packing gland. Be sure
seal water supply pressure is adequate
b. Open pump suction valve slowly.
I. NEVER, NEVER OPERATE A POSITIVE
c Bleed air out of top of pump volute in order to prime
pump Some pumps are equipped with air relief valves
17.6rucsmoto PUMP A&AINCir A C4.04EP
or bleed lines back to the we well for this purpose. VALVE, FhPOCIALW A DI4eweacie awe.
d. When pump is primed, slowly open pump discharge
valve and recheck prime of pump Be sure no air is
escaping from volute.
'1 Excessive pressure could rupture the equipment and
possibly seriously injure or kill someone nearby.
e. Unlock stop switch and actuate start switch. Pump
should start
2 Positive displacement pumps are used to pump solids
(sludge) and meter chemicals. Certain precautions must
be taken to prevent .rijury or damage. If the valves on
6. Inspect equipment. both ends of a sludge line are closed tightly, the line
a. Motor should come up to speed promptly. If ammeter becomes a closed vessel Gas from decomposition of the
is available, test for excessive draw of power (amps) sludge can build up and rupture pipes or valves.
during startup and normal operation. Most three- 3. Positive displacement pumps also are used to meter and
phase induction motors used in water treatment plants pump chemicals. bare must be exercised to avoid venting
will draw 5 to 7 times their normal running current chemicals to the atmosphere.
during the brief period when they are coming up to
need. 4. Never operate a positive displacement pump when it is
dry or empty, especially the progressive-cavity types that
b No unusal noise or vibrations should be observed use rubber stators. A small amount of liquid is needed for
during startup lubrication in the pump cavity between the rotor and the
c. Check valve should be open and no chatter or pulsa- stator.
tion should be observed.
d. Pump suction and discharge pressure readings should In addition to NEVER closinz a discharge valve on an
be within normal operating range for this pump. operating positive displacement pump, the only other differ-
ence (when compared with a centrifugal pump) may be that
e Packing gland leakage should be normal. the positive displacement pump system may or may not
f. If a flow meter is on the pump discharge, record pump have a check valve in the discharge piping after the pump
output Installation of a check valve depends upon the designer and
the material being pumped.
7 If the unit is operating properly, return to the motor Other than the specific differences mentioned in this
control panel and place the motor mode of operation section, the starting and stopping procedures for positive
selector in the prope operating position (manual -auto- displacement pumps are similar to the procedures for centri-
off). fugal pumps.

8. The pump and auxiliary equipment should be inspected

routinely after the pump has been placed back into QUESTIONS
service.
Write your answers in a notebook and then compare your
answers with those on page 326.
QUESTIONS 18 24J What is the most important rule regarding the
operation of positive displacement pumps?
Write your answers in a notebook and then compare your
answers with those on page 325. 18 24K What could happen if a positive displacement pump
is started against a closed discharge valve?
18.24G What should be done before stopping an operating
pump? 18 24L Why should both ends of a sludge line never be
closed tight?
18.24H What could cause a pump shaft or motor to spin
backwards?
18.241 Why should the position (open or closed) of all
valves be checked before starting a pump?
efici of 1-e44cnig of 5 I.ev4oto
18.2451 Positive Displacement Pumps. Steps for starting
and stopping positive displacement pumps are outlined in
this section. There are two basic differences in the operation
MAI NTENANa
of positive displacement pumps as compared with centrifu-
gal pumps. Centrifugal Dumps (due to their design) will
permit an operator error, out a positive displacement pump
will not and someone will have to pay for correcting the Please answer the discussion and review questions be-
damages. fore continuing with Lesson 4.

30i
 Maintenance 287

DISCUSSION AND REVIEW QUESTIONS

Chapter 18. MAINTENANCE
(Lesson 3 of 5 Lessons)

Write your answers to these questions in your notebook 29 Flow can you determine if a new pump will turn in the
before continuing. The question numbering continues from direction intended?
Lesson 2
30. When shutting down a pump for a long pe..od, what
18 When two or more pumps of the same size are installed, precautions should be taken with the motor disconnect
why should they be o,:erated alternately? switch?
19 vOlat should be checked if pump bearings are running 31 How can you determine if a new pump is delivering
hot? design flows and pressures?
20. What happens when the packing is too tight on a
reciprocating pump?
21 Why should adjustments in control valves for recipro-
cating pumps be made when the pump is shut down?
22. Why would you use a stethoscope to check an electric
motor?
23. How would you determine if a motor is running unusual-
ly hot?
24 How would you clean belts on a belt drive?
25. Why should you never replace only one tx. on a
multiple-drive unit?
26. What do rubber weanngs near a belt drive indicate?
27. How can you determine if a chain in a chain-drive unit
has the proper slack?
28. What happens when couplings are not in proper align-
ment?

CHAPTER 18. MAINTENANCE

(Lesson 4 of 5 Lessons)

18.25 Compressors Due to the complexity of compressors, the water treat-

ment plant operator usually will not be repairing them. You
Compressors (Fig 18.31) are commonly used in the will. however, be required to maintain these compressors.
operation and maintenance of water treatment plants They With proper maintenance a compressor should give years of
are used to activate and control pump control systems trouble-free service.
(bubblers), valve operators, and water pressure systems
They are also used to operate portable pneumatic tools, The first step for compressor maintenance, and this
such as jack hammers, compactors, air drills, sand blasters, pertains to any mechanical equipment, is to get the manu-
tapping machines, and air pumps. facturer's Istruction book and read it completely. Each
compressor is different and the particular manufacturer will
A compressor is a device used to increase the pressure cf provide its recommended maintenance schedules and pro-
air or gas. They can be of a very simple diaphragm or cedures. Some of the maintenance procedures are dis-
bellows type such as are found in aquarium pumps, or cussed in the following paragraphs.
extremely complex rotary, piston, or sliding vane type com-
pressors. A compressor usually has a suction pipe with a 1. Inspect the suction filter of the compressor regularly.
filter and a discharge pipe which goes tq an air receiver or The frequency of cleaning depends upon the use of the
storage tank. The compressed air or gas ..1 then used from compressor and the atmosphere around it. Under nor-
the air receiver. mal operations the filter should be inspected at least

3 od
288 Water Treatment

/011111rWagg"
7.

T
WORTHWG7VN

Fig. 18.31 Two-stage piston compressor

(Courtesy Worthington Corporation)

monthly and cleaned or replaced every three to six pressure, and grease fittings are greased at the proper
months Inspect and replace the filter more frequently in interval. Compressors use a certain amount of oil in
areas with excavation and dust. When breaking up their operation and special attention is needed to keep
concrete, inspect the filters daily. the reservoirs full. Care also must be used to not overfill
the crankcase. On some compressors it is possible for
the oil to get into the compression side and lock up the
compressor, or damage it. Remember!

A 1.10010 CANNOT GE comPROOSEP.

When air or gas are compressed, they give off heat and
the compressor becomes very hot. This tends to break
There are several types of filters, such as paper, cloth, down oil faster, so most compressor manufacturers
wire screen, oil bath, and others. The impregnated have special oils recommended for their particular com-
paper filters must be replaced when dirty. The cloth- pressor. Also, due to the heat and contamination, it is
type filters can be washed with soap and water, dried necessary to ...hange oil quite frequently. Compressor
and reinstalled. If a cloth-type filter is used, it is recom- oil should be changed at least every three months,
mended that a spare be kept so one can be cleaned unless manufacturer states differently. If there are filters
while the other is being used. The wire mesh and oil- in the oil system, these also should be changed.
bath type filters can be cleaned with a standard solvent, 3. Cylinder or casing fins should be cleaned weekly with
reoiled or oil bath filled and used again. Never operate a compressed air or vacuumed off. The fins must be clean
compressor without the suction filter because dirt and to insure proper cooling of the compressor.
foreign materials will collect on the rotors, pistons, or
blades and cause excessive wear. 4. Unloader. Many compressors have unloaders that allow
the compressor to start under a no-load condition.
2. Lubrication. Improper or lack of lubrication is probably These can be inspected by observing the compressor.
the biggest cause of compressor failures. Most com- When the compressor starts, it should come up to
pressors require oiling of the bearings. They can have speed and the unloader will change, starting the com-
crank case reservoirs, oil cups, grease fittings, a pres- pression cycle. This can usually be heard by a change in
sure system or separate pump Whatever type, it must sound. When it stops, you can hear a small pop and
be inspected daily. Examine the reservoir dip stick or hear the air bleed off the cylinders. If the unloader is not
sight glass. Make sure that drip-feed oilers are dripping working properly, the compressor will stall when start-
at the proper rate, force feed oilers have the proper ing, not start, or if belt-driven, burn off the belts.

3 41
 Maintenance 289

5 Test the safety valves weekly The pop off or safety 18 25D How often should the condensate from the air
valves are located on the air receiver or storage tank. receiver be drained?
They prevent the pressure from building up above a
18 25E What must be done before testing belt tension on
specified pressure by opening and venting to the atmos-
compressors with your hands?
phere. ir, gas compressors, they vent to the suction side
of the compressor. Some compressors have high pres-
18.26 Valves"
sure cut -off switches, low oil pressure switches. and
high temperature cut-off switches. These switches have
pre-set cut-off settings and must not be changed with-
18.260 Use of Valves
out proper authorization If for any reason any of the Valves are the controlling devices placed in piping sys-
safety switches are not functioning properly, the prob- tems to stop. regulate, L., leck, divert, or otherwise modify the
lem must be corrected before starting the compressor flow of !quids or gases There are specific valves that are
again The safety switch settings should be recorded more suitable for certain ;obs than others. The five most
and the results kept ir the equipment file common valves that you will find in a water treatment facility
are discussed in this section
6. Drain the condensate (condensed water) from the air
receiver daily. Due to temperP:ure changes, the air
receiver will fill with condensate. Each day the conden- 18.261 Gate Valves (Figures 18.32 and 18 33)
sate should be drained from the bottom of the tank
There is usually a small valve at the bottom of the air The basic parts of a gate valve are the operator (handle),
receiver for this purpose. Some air receivers are the shaft packing assembly, the bonnet, the valve body with
seats. the stem, and the disc Gate valves COr,"'.R a large
equipped with automatic drain valves These must be
inspected periodically to insure they are operating satis- rumber of sizes, but the principle of operation is quite
factorily similar for all sizes. One could associate the action of a gate
valve to that of a guillotine having a screw shaft instead of
7 Inspect belt tension on compressors Usually you the rope The valve disc is raised or lowered by a threaded
should be able to press the belt down with hand shaft and is guided on each side to ensure that it will not
pressure approximately three fourths of an inch. This is hang up in the operation. The disc is screwed down until it
done at the center between the two pulleys MAKE wedges Itself between two machined valve seats This
SURE COMPRESSOR IS LUCKED OFF BEFORE MAK- makes a leak-proof seat on both sides of the disc The discs
ING THIS TEST. Do not over-tighten belts because it will are replaceable Some gate valves have discs with wedges
cause overheating and excessive wear on bearings and inside As more force is applied to the screwed stem, the
motor overloading wedges force the discs into tighter contact with the valve
seats
8 Examine operating controls Make sure the compressor
is starting and stopping at the proper settings If it is a Gate valves are either of the rising (Figure 18 32) or non-
dual installation, make sure they are alternating if so rising stem (Figure 18.33) type The rising stem has compan-
designed, inspect gage for accuracy Compare readings ion threads in the valve bonnet. As the valve is opened, the
with recorded startup values or other known, accurate stem is threaded out, lifting the wedged disc In the non-
readings rising type, the stem is held in place in the bonnet by a collar.
The stem is threaded with companion threads in the wedged
9. Many portable compressors are equipped with tool disc As the valve opens, the disc rises on the stem
oilers on the receivers. These are used for mixing a Consequently, the hand wheel stays on the same plane.
small quantity of oil with the compressed air for lubrica-
tion of the tools being used These are located on the Gate valves are not commonly used to control flows With
discharge side of the air receiver. They have a reservoir
the valve partially open, the water velocity is increased
which must be filled with rock drill oil. through the valve and minute particles transported in the
water can cause undue seat wear. However, the vee-ported
10 All compressors should be thoroughly cleaned at least gate valve can be used in controlling flows. As the valve is
monthly Dirt, oil, grease. and other material must be opened. the vee is widened to allow more flow Because of
thoroughly cleaned off the compressor and surrounding the valve design, little damage is done to the valve seats in
area Compressors have a tendency to lose oil around the vee-ported type of gate valve.
piping, fittings and shafts: thus constant cleaning is
required by the maintenance operator to insure proper Suggested operation and maintenance procedures are
and safe operation. listed below
QUESTIONS 1 Open valve fully. When at stop, reverse and close valve
one-half turn.
Write your answers in a notebook and then compare your
answers with those on page 326. 2 Operate all large valves at least yearly to insure proper
operation
18 25A List some of the uses of a compressor in connec-
tion with operation and maintenance of a water 3. Inspect valve stem packing for leaks Tighten as needed
treatment plant.
4. If the valve has a rising stem, keep stem threads clean
18.25B How of ten should the suction filter of a compressor and lubricated
be cleaned?
5. Close vales slowly in pressure lines to prevent water
18.25C Hoy/ often should compressor oil be changed? hammer

17 For additional information on valves, see WATER DISTRIBUTION SYSTEM OPERATION AND MAINTENANCE, Chapter 3, Distribution
System Facilities, Section 3.670, 'Valves," in this series of manuals.
290 Water Treatment

HAND WHEEL LOCKNUT

HAND WHEEL YOKE BUSHING

YOKE STEM

PACKING
PACKING GLAND GLAND
BUSHING
PACKING
REPACKING
SONNET SEAT BUSHING

UPPER
SPREADER

SEAT RING STEM PIN

WEARING DISC RING

PLATE
DISC HALVES
LOWER
SPREADER
EDGE RING

BODY

Fig. 18.32 Rising stem gate valve

(Permission of Stockham Valves & Fittings, Copyright, 1976)

HAND WHEEL STEM

PACKING GLAND
FLANGE
PACKING GLAND

STUFFING SOX PACKING

REPACKING
SEAT BUSHING
BONNET

DISC
DISC BUSHING

DISC RING

BODY SEAT RING

Fig. 18.33 Non-rising stem gate valve

(Permission of Stockham Valves & Fittings, Copyright. 1976)

31 ,,
 Maintenance 291

6. If a valve will not close by using the normal operator, and disc If corrosion has caused exces-
check for the cause. Using a "cheater" (bar-pipe wrench) sive pitting or eating away of metal, as in
will only aggravate your problem. guide ribs in body, repairs may be im-
practical.
18.262 Maintenance of Gate Valves b Check and service all parts of valve com-
pletely. Remove stem from bonnet and
Paragraph 12: Gate Valves examine it for scoring and pitting where
The most common maintenance required by gate valves is packing makes contact. Polish lightly
oiling, tightening, or replacing the stem stuffing box packing. with fine emery cloth to put stem in good
condition. Use soft jaws if stem is put in
Frequency vise
of
Service c. Remove all old packing and clean out
stuffing box Ciean all dirt, scale, and
A 1. REPLACE PACKING. Modern gate valves corrosion from inside of valve bonnet
can be repacked without removing tnem and other parts.
from service. Before repacking, open valve
wide. This prevents excessive leakage d Do not salvage an old gasket. Remove it
when the packing or the entire stuffing box completely and replace with one of prop-
is removed. It draws the stem collar tightly er quality and size.
against the bonnet on a non-rising stem e. After cleaning and examining all pans,
valve, and tightly against the bonnet bush- determine .nether valve can be repaired
ing on a rising stem valve. by ren,uving cuts from disc and body
a. Stuffing box. Remove all nid packing sea, faces or by replacement of body
from stuffing box with a packing hook or seats. If repair can be made, set disc in
a rattail file with bent end. Clean valve vise with face leveled, wrap fine emery
stem of all adhering particles and polish it cloth arcund a flat tool, and rub or lap off
with fine emery cloth. After polishing re- entire bearing sunace on both sides to a
move the fine grit with a clean cloth to smooth, even finish. Remove as little
which a few drops of oil have been metal as possible.
added. f Repair cuts and scratches on body rings,
b. Insert packing Insert new split-ring pack- lapping with an emery block small
ing in stuffing box and tamp it into place enough to permit convenient rubbing all
with packing gland. Stagger ring splits. around rings. Work carefully to avoid
After stuffing box is filled, place a few removing so much metal that disc will
drops of oil on stem, assemble gland, seat too low. When seating surfaces of
and tighten it down on packing disc and seat rings are properly lapped
in, coat faces of disc with PRUSSIAN
2 OPERATE VALVE. Operate inactive gate BLUEI8 and drop disc in body to check
valves to prevent sticking. contact. When good, continuous contact
is obtained, the valve is tight and ready
A 3 LUBRICATE GEARING. Lubricate gate
for assembly. Insert stem in bonnet, in-
valves as recommended by manufacturer.
Lubricate thoroughly any gearing in large stall new packing, assemble other parts,
gate valves. Wash open gears with solvent attach disc to stem, and place assembly
in body Raise stem to prevent contact
and lubricate with grease.
with seats so bonnet can be properly
4 LUBRICATE RISING-STEM THREADS. seated on body before tightening the
Clean threads on rising-stem gate valves joint.
and lubricate with grease
9. Test repaired valve before putting it back
A 5 LUBRICATE BURIED VALVES. If a buried in line to ensure that repairs have been
valve works hard, lubricate it by pouring oil properly made.
down through a pipe which is bent at the
end to permit oiling the packing follower h. If leaky gate valve seats cannot be re-
below the valve nut faced, remove and replace seat rings
with a power lathe Chuck up body with
A 6 REFACE LEAKY GATE VALVE SEATS If rings vertical to lathe and use a strong
gate valve seats leak, reface them immedi- steel bar across ring lugs to unscrew
ately, using the method discussed below. A them. They can be removed by hand with
solid wedge disc valve is used for illustra- a diamond point chisel if care is taken to
tion, but the general method also applies to avoid damaging threads. Drive new rings
other types of reparable gate valves. Pro- home tightly. Use a wrench on a steel Par
ceed as follows: ac. oss lugs when putting in rings by
a Remove bonnet and clean and examine hand. r,lways coat threads with a good
disc and body thoroughly. Carefully de- lubricant before putting threads into the
termine extent of damage to body rings valve body. This helps to make the
18 Prussian Blue. A blue paste or liquid (often on a paper like carbon paper) used to show contact area Used to determine if gate valve
seats fit properly.

31 ,
 292 Water Treatment

Frequency
Because the plug has a resilient coating, it insures a leak-
of
tight seal at the valve seats The Buna-N, neoprene, or viton
Service
plug coating is a very wear resistant compound and can
function well under a wide temperature range. This valve is
threads easier to remove the next time excellent for controlling the flows of slurries and sludges
the seats have to be replaced Lap in found in water treatment facilities
rings to fit disc perfectly.
18.265 Butterfly Valves (Fig. 18.37)
18.263 Globe Valves (Fig. 18.34)
The butterfly valve is used primarily as a control valve. The
The globe valve seating configuration is quite different flow characteristics allow the water to move in straight lines
from the gate valve Globe valves use a circular disc to make witt- little turbulence in the area of the valve disc (butterfly).
a flat surface contact with a ground-fitted valve seat. This is Complete flow shutoff can be accomplished but the PSI
similar to placing your thumb over the end of a tube. The rating is relatively low in comparison to eccentric or gate
parts of the valve are similar in name and function to the gate valves
valve. They can be of the rising or non-rising stem type
The butterfly valve uses a machined disc that can be
What is unique about the globe valve is its internal design opened to 90 degrees to allow full flow through the valve.
(Figure 18.34). This design enables the valve to be used in a Quarter turn operation moves the valve from the 'closed' to
contrang mode The valve seats are not subject to exces- 'open' position The disc is mounted on a shaft eccentric that
sive wear when partially opened like the gate valve. After allows the disc to come into its seat with minimum seating
extended use, the valve may not have a positive shutoff but torque and scuffing of the rubber seat There is no contact
it will still be effective in throttling flows. Procedures for between the disc and the seat until the last few degrees of
operating and maintaining globe valves are similar to the valve closure
procedures outlined for gate valves in Section 18 262 A resilient rubber is used as the seat and is of a continu-
ous form that lc, not interrupted by a shaft connection. Wear
18.264 Eccentric Valves (Figs 18.35 and 18.36) resistance characteristics are good when used in slurry and
The eccentric valve has many desirable features These sludge applications.
features include allowance for high flow capacity, quarter When the valve is closed, the disc is forced against the
turn operation, no lubrication, excellent resistance to wear,
..fibber seat Wedges with jacking screws compress the
and good throttling characteristics. The eccentric valve uses rubber seat via a jack ring. The rubber seat then .,.informs to
a cam shaped plug to match an eccentric valve seat. As the the entire disc circumference. The rubber can be readily
valve is closed, the plug throttles the flow yet maintains a replaced when necessary without complete valve disman-
smooth flow rate The plug does not come into contact with
tling Large valves do not need to be removed from the line
the valve seat until it is in the closed position. for seat rep acement.

IDENTIFICATION PLATE

UNION BONNET

DISC LOCK.NUT

Fig. 18.34 Globe valve

(Permission of Stockham valves and -filings)

31 3
 Maintenance 293

ECCENTRIC ACTION
The DeZurik design matches a single-faced
eccentric or cam-shaped plug with an ec-
centric raised body seat. With rotary
motion only, the plug advances against
the seat as it closes. Here's how it works:

sorx-0111W T.wwwJ

OPENThe plug is out of the flow path.

There is no bonnet or other cavity to fill
with slurry material. Flow is straight-
through with minimum pressure drop.

,- -:;X:.*PLAlli qtr:
!MI

CLOSINGAt any position between open

and closed, the eccentric plug still has not
touched the seat. There is no friction to
cause wear or binding. Flow is still smooth
and straight. Throttling action is excellent
on all types of services from slurries to gas.

CLOSEDThe eccentric plug makes con-

tact with the eccentric seat only in the
fully closed position. Action is easy, with-
out binding or scraping. There is no con-
tinual seat wear. The plug is moved firmly
into the seat to provide a positive, drip-
tight, long-lasting seal.

Fig. 18.35 How eccentric valves work

(Permission of De7urik Corporation. Sartell. Minnesota)

31 4
294 Water Treatment

/1-

Fig. 18.36 Eccentric valve

(Permission of DeZunk Cxporation, Sartell. Minnesota)

31-j
 Maintenance 295

Fig, 18 37 Butterfly valve

(Permission of AmerocanOLrbng Valve. Birmingham, Alabama)

316
296 Water Treatment

18.266 Check Valves (Fig. 18.38) has a dampening feature to cushion the closing of the
clapper.
The term 'check valve' describes its function. A check
valve allows water to flow in one direction only. If the water The wafer check has a circular disc that hinges in the
attempts to flow in the opposite direction, an internal mecha- center (diameter) of the disc Water passing through col-
nism closes the valve and "checks" the flow. Three types of lapses the disc and the stoppage of flow allows the disc to
check mechanisms may be used the swing check, the return to its circular form Because the valve has a tendency
water check, or the lift check. In the swing check, a movee to be fouled up by stringy material, It is not commonly used
ble disc rests at a right angle to the flow and seats against a in handling raw water. Wafer check valves are very effective
ground seat. The moveable disc is called the clapper. The when used with clean water.
clapper can be ore of three types: gravity operated, lever
and weight operated, or lever and sprang operated. In many The lift check uses a vertical lift disc or ball. When there is
installations the water being pumped must be delivered at a flow, the disc or ball is lifted from its ground seat and fluid
desired flow rate and pressure. A clapper with an external passes through the valve As flow stops, the check realigns
means of adjusting the opening in the check valve may be itself with its seat and checks or prevents water backflow.
necessary to produce desired flows and pressures. By The moveable portion can be a spring or gravity return.
positioning the weight on the lever or adiusting the spring The foot valves used in pump suctions are nearly always
tension, a check valve can be made to operate either of the vertical lift disc design. A check valve of this type is
partially or fully open at various pressures and flows. The usually applied to handle clean water.
spring or counter weight also ensures that the check valve
closes at "no flow." This is very helpful if the valve is not in a Backflow prevention by check valves is essential in many
position that will enable gravity alone to operate the clapper applications to:
The gravity-operated clapper does not have an external
adjustment and relies on the weight of the clapper to close
1 Prevent pumps from reversing when power is removed,
the valve at no flow" conditions. 2. Protect water systems from being cross-connected,
3 Aid in pump operation as a dampener, and
Most swing check valves provide for full opening, that is,
the clapper can move up into the bonnet and thus be 4. Ensure "full pipe" operation (pipe is full of water).
r -nletely out of the flow. Head loss in swing check valves Table 18.4 provides a comparison of various types of
mu Je relatively high and this factor must be considered in check valves with features of these valves. Figures 18.39
selecting the device for a particular application. This type of through 18.45 prow drawings and photographs of the
check valve is quite common in pump installations and often different types of ch k valves listed in Table 18.4.

Bronze bushed ductile Body design permits re-

iron clapper arm for moval of clapper arm

Tight closing assured

added srength and im-
pact resistance. S assembly through bon-
net opening.

since clapper arm shaft

is set slightly back of
vertical seat face.

Bronze clapper arm shaft

can he extended through
bode when lever with
weight or spring is re-
qJred.

Fully
seats in
revolving disc
different post-
fitrie,,..
tion on seat ring fate
and distributes wear uni-
formly over the entire ti-
seating fare.

Bronze se at ring is
screwed ;n body and
Bronze or alloy disc ring
made with lugs and can is securely peened into
be replaced with body machined dove - tailed
groove Vertical seating surfaces
in line. It can be furn- provide sensitive seating
ished with a resilient in- action.
sert for bottle-tight ser-
vice on gas or air.

Fig. 18.38 Check valve

(Permission of AmenoanDarling Valve. Birmingham, Alabama)

31/
 Maintenance 297

TABLE 18.4 COMPARISON OF FEATURES OF

DIFFERENT TYPES OF CHECK VALVESa

1. Lowest initital cost

2 Shortest laying length
3. Highest head loss (see head loss curves)
4. Resilient seat (optional)
5. For waste and raw sewage
6. Clean water only
7. Cushion closing
8. Silent closing (positively silent)
9. Free open - Free close
10. Control open or close or both (optional)
11. Vertical installation flow up or down
12. Can be rubber lined
13. Disc position indicator
14. Buried service
15. Outside lever
16. Surge pressure control
17. Reverse flow
18. Up to 600# class
19. Up to 1500# class
20. Lowest head loss (see head loss curves)
21. Up to 2500# class
22. Control open and close standard
23. Shut off valve
24. Throttling valve
25. Vertical installation flow up only
26. Electric motor operated
27. Remote control
28. Control closure upon power failure
29. Resilient seat standard
30. Velocities in excess of 15 FPS
31. Velocities up to 5 FPS
32. Velocities up to 10 FPS

a Permission of APCO/Valve and Primer Corporation.

318
298 Water Treatment

Fig. 18.39 Swing check valves (single disc)

(Permission of APCO/Valve and Primer Corporation)

31.;
 Maintenance 299

Fig. 18.40 Double disc swing check valves (split swing discs)
(Permission of APCO/Valve a Pr er Corporation)
)
300 Water Treatment

sok._ et -II
-.-

Fig, 18.41 Rubber flapper check val,,es (angle seating)

(POrMiSSIOn of APCOIValve and Primer Corporation)

321
 Maintenance 301

Fig. 18.42 Slanting disc check valves (pivot off center)

(Porrnission of APCO/Valve and Primer Corporation)

411

re 4,
302 Water Treatment

,.. ........

4
LIM.

Fig. 18.43 Silent check valves (wafer)

(Permission of APCO/Valve and Primer Corporation)
 Maintenance 303

1 1t I
. 1

I I

I .1

r:-.7.3.7 4 ,r,;-;;--
77 t
I lI

Fig. 18.44 Silent check valves (globe)

(Permission of APCO/Valv and Primer Corporation)

`),''
304 Water Treatment

9
VA_ ci.1

......
-;

Fig. 18.45 Automatic control check valves

(Permission of APCO/Valve and Primer Corporation)

325
 Maintenance 305

18.267 Maintenance of Check Valves The diaphragm-operated globe valve (Figure 18.46) is also
used for modulating service These valves can be equipped
Paragraph 13: Check Valves with pilot control devices to control pressure, flow, or level
either singly or in combination. Maintenance on these valves
Frequency consists of the following:
of
Service 1. Periodically clean any strainers in the pilot control sys-
tem Scheduling should be adjusted to accommodate the
A 1 INSPECT DISC FACING Open valves to rate at which the strainer collects foreign material.
observe condition of facing on swing check
valves equipped with leather or rubber 2. Check the operation of the valve to see that the controls
seats on disc. If metal seat ring is scarred, are, in fact, correctly positioning the valve to accomplish
dress it with a fine file and lap with fine the job.
emery paper wrapped around a flat tool. 3. If the valve is used in an application where it seldom or
A 2. CHECK PIN WEAR. Check pin wear on never is wide open, it 'should periodically be exercised
balanced disc check valve, since disc must manually to cycle from tight shut to wide open. This is to
be accurately positioned in seat to prevent insure that there is no buildup on the stem that could jam
leakage the valve. These valves can be opened wide by drawing
all the pressure from the cover chamber. If water does
18.268 Automatic Valves not stop flowing out of the cover chamber, when the valve
is wide open, it is an indication that the diaphragm is
Water treatment plants usually have a number of auto- leaking and should be replaced.
matically operated valves. The simplest type is either open
or closed and is not required to operate in an intermediate
position. Frequently these valves are similar to gate valves QUESTIONS
that have had their threaded stems and handwheels re- Write your answers in a notebook and then compare your
placed by a smooth shaft and hydraulic piston. Maintenance answers with those on page 326.
on these vP' -..:s is essentially the same as for gate valves.
Other automatically operated valves are used to control 18.26A What is the purpose of valves9
flow in water treatment plants and are usually located at
some point between tight shut and wide open. These are 18 268 List six common types of valwas found in water
commonly called modulating valves. A buttP fly valve with a treatment facilities
hydraulic cylinder operator can be user' for this type of 18 26C What is the purpose of a check valve?
service.
18.26D Why is backflow prevention by check valves essen
teal in many applications?
18 26E What maintenance is required by gate valves9

OM of 1-e,,tzt4 of 5 i41440114
MAINTENANa
Please answer the discussion and review questions be-
fore continuing with Lesson 5.

DISCUSSION AND REVIEW QUESTIONS

Chapter 18. MAINTENANCE
(Lesson 4 of 5 Lessons)

Write your answers to these questions in your notebook 34 Why should inactive gate valves be operated p eriodic-
before continuing. The question numbering continues from ally?
Lesson 3.
35. What factors can cause wear on gate valve se ats?
32. What are the uses of a compressor?
33. What items should be maintained on a compressor9
306 Water Treatment

CLAYTON 100 HYTROL VALVE

OVER BEARING

SPRING

STEM NUT
COVER RETAINING NUT

DIAPHRAGM WASHER
DIAPHRAGM

SPACER WASHER
DISC RETAINER

ISC GUIDE

DISC
SEAT

BODY

COVER BEARING
CLAYTON 100P POWERTROL VALVE

UPPER STEM NUT

STEM

DIAPHRAGM WASHER

POWER UNIT BODY STUD DIAPHRAGM

COVER RETAINING NUT BEARING RETAINER

COVER

POWER UNIT BODY DISC RETAINER

ISC

LOWER STEM NUT

SEAT

Fig. 18.46 Diaphragm operated globe valve

(Permission of CLA-VAL Co )

2'
 Maintenance 307

CHAPTER 18. MAINTENANCE

(Lesson 5 of 5 Lessons)

18.3 INTERNAL COMBUSTION ENGINES 18.302 Starting Problems

Listed below are some items to check if you have prob-
18.30 Gas'Atne Engines19
lems starting a gasoline engine
18.300 Need to Maintain Gasoline Engines 1. No fuel in tank. valve closed
In the water treatment departments of all cities there is 2 Carburetor not choked
occasion to use gasoline-powered engines that drive
pumps, generators, tractors, and vehicles. Although we all 3 Water or dirt in fuel lines of carburetor
drive automobiles that are powered by internal combustion
engines. are you aware of the fundamentals'?

Very few operators actually do the repair of gasoline-

powered engines. Although you may not be able to perform
the duties of an engine mechanic, there are a number of
steps you can take to ensure that your particular engine is
well maintained.
At the end of this section you will have an adequate
knowledge of how a gasoline engine operates in order to
maintain it so as to provide many hours at optimum per-
formance.

18.301 Maintenance
In order to have an engine that will provide you with many
hours of trouble-free operation, it must be well cared for 4 Carburetor flooded
PLEASE REFER TO THE OWNER/OPERATOR MANUAL
FOR YOUR PARTICULAR ENGINE. Typical maintenance 5 Low compression
procedures are as follows:
6 Loose spark plug, and
1 Change engine oil regularly every 25 hours,
7. No spark at plug
2 Clean carburetor air filter every 25 hours;
a Dirty and improper/gapped plug
3 Blow dust and chaff from louvered engine vanes regu-
larly; b Broken or wet ignition cables

4 Clean carbureto, fuel filter/screen every 100 hours; c. breaker points not opening or closing, and

5 Lubricate generator and/or starter motor as recommend- d Magneto grounded

ed, every 100 hours;
18.303 Running Problems
6. Lubricate throttle linkage every 100 hours.
Check the following items :` a gasoline engine does not
7. Clean, gap, or rer,lace spark plug every 100 hours; and run properly
8. Remove carbon deposits from top of piston and valves 1 Engine misses
every ;0 to 3(0 hours.
a Faulty spark plug/gapping
b Weak ignition spark
c Loose ignition cable
d Worn breaker points

e Water in fuel
f Poor compression
2 Engine surges
a Carburetor flooding
b Governor spring connected improperly

19 For additional information on y-soline engines, see INDUSTRIAL WASTE TREATMENT, Chapter 7, Support Systems, Section 74,
"Gasoline Engines," in this series of manuals.

39,'
 308 Water Treatment

3 Engine stops
5 Set throttle to start position or 3/4 full throttle;
a Fuel tank empty
6 Set choke lever or pull out choke on carburetor,
b. Vapor lock 7 Pull recoil starter twice,
c Tank air vent plugged 8 If engine has started, push choke to "off", and
4 Engine overheats 9 If engine does not start after two pulls, disengage the
a Low crankcase oil choke and try three or four more times.
b gnition timing wrong If repeated efforts at starting have been unsuccessful,
remove the high tension voltage wire from the spark. Hold
c Engine overloaded the end of the wire (grasp the insulated portion, NOT the
d Restricted air circulation/high ambient temperature connector) 1/8 inch (3 mm) from the spark plug Pull the recoil
starter. You should see a small blue spark This will indicate
e. Poor grade of gasoline that the points are opening ar.d closing and providing
ignition voltage.
5. Engine knocks
The next step is to remove the spark plug from the
a Poor grade of gasoline
cylinder head (use a'416 inch (20.6 mm) deep socket). Check
b Engine under heavy load at low speed for a carbon buildup on the electrode. A piece of carbon may
have lodged between the center electrode and the side
c. Carbon deposits in cylinder head electrode. Also check to see if the plug is wet with fuel or oil.
d. Spark advanced too far This could indicate that you have flooded the cylinder with
fuel by having he choke on too long. If there is oil residue, it
e. Loose connecting rod bearing could indicate worn piston rings.
Worn or loose piston pin Replace the spark plug with a new one if in doubt. If you
must use the one you have, clean it by buffing with a wire
6. Engine backfires through carburetor
brush. Check the "gar between the center electrode and
a Water or dirt n fuel side electrode; it should be approximately .030 inch (30
thousands of an inch or 0.76 mm).
b Cold engine
Try staring the engine as previously described. If the
c Poor grade of gasoline engine does not sputter or pop, close the fuel shut-off valve,
d. Sticking inlet valves remove fuel sedimentation bowl and clean. Open fuel valve.
Catch a small amount of fuel in the palm of your hand and
e Spark plug heat range too hot examine the fuel for grit or water. If everything looks okay,
replace sediment bowl and open fuel valve.
QUESTIONS Try to start the engine. If you still cannot achieve ignition,
you may have other problems that will require further
Write your answers in a notebook and then compare you:.
checking by a small-engine mechanic Do not feel disgrun-
answers with those on page 326 tled, you have checked for the most common problems.
18.30A List some possible uses of gasoline engines in
water treatment plants. 18.3041 Large Engines. The procedure for starting large
engines is as follows:
18.30B What items would you check if you had problems
starting a gasoline engine?
18.30C What items could cz...ise a gasoline engine to not
run properly?

18.304 How to Start a Gasoline Engine

Because of the wide variety of uses for gasoline-powered
engines, no one starting sequence will apply to all engines.
In general, gasoline engines can be divided into two groups.
In the first group are small engines with magneto ignition
and recoil start. Larger engines with battery-powered igni-
tion and elertric start are in the second group.

18.3040 Email Engines. The procedure for starting small

engines is as follows:
1. Check fuel tank for adequate fuel;
2. Ensure fuel shut off valve iron, the tank to the carburetor
is open: 1. Check fuel tank for fuel;
3. Disengage ignition ground ("kill" switch or mechanism 2. Check crankcase for oil;
that grounds the spark plug);
3. Check radiator for coolant (if water cooled);
4. Check crankcase lubricating oil;
4 Set throttle to 1/2 full position;
 Maintenance 309

5 Pull out choke. 18.31 Diesel Ensines20

6 Turn on ignition switch and ixess start button, 18.310 How Diesel Engines Work (Fig 18 47)
7 After four or five engine revolutions. push in the choke. Diesel engines are similar to gasoline engines and are
and either two or four cycle They can be air or water cooled In
8 Engine should start general the diesel engine is of heavier construction to
withstand the higher pressures resulting from higher com-
After repeated tries, further invest:Dation by a mechanic pression ratios
may be needed
The diesel does not use spark plugs, but instead relies on
NOTE Do not crank engine with the starter rotor for more heat generated by air compressed in the cylinder (1,000
than one minute initially Wait two minutes and try degrees F or 540°C) to ignite the fuel mixture. The fuel is a
again for 45 seconds After three ti ys. let starter petroleum product that is heavier than gasoline and with a
motor cool for 5 minutes before trying again This will higher flash point Gasoline cannot be used in a diesel
avo.d starter motor damage. because it would start to burn from the heat generated by
Preliminary checks for a large engine that won t start are compression before the piston reached the top of the stroke
similar to procedures for small engines A diesel has no carburetor The fuel is sprayed (injected)
Remove spark plug wires Test each one by holding it 1/8 into the cylinder while the cylinder is compressing air The
inch (3 mm) from the spark plug or ground, and turn engine heat of compression ignites the fuel-air mixture and burns,
over with the starter. You should see a small blue spark. If producing power similar to a gasoline engine The introduc-
you have no spark, the points are not opener or high tion of fuel into the cylinder must be "timed" in the same
tension voltage is rot present from the ignition coil. Check manner as spark to the plug in a gasoline engine Fuel is
further as needed pumped by a pumping device that is geared te' ine crank-
shaft
If spark is present, inspect spark plugs. Clean or replace if
needed Diesel fuel. unlike gasoline, does not vapo 'ze readily The
fuel must be broken up in fine particles and sprayed into the
After checking the ignition system. make sure fuel is cylinder The atomization of fuel is accomplished by forcing
present at the carburetor Remove the fuel line at the the fuel through a nozzle at the top of the combustion
carburetor and direct it away from you and the engine chamber As the fuel combines with the air in the cylinder, it
Engage starter motor for two revo Jtions. Fuel should spurt becomes a combustible mixture Since the diesel engine
from the line if the fuel pump is working satisactorily depends upon the heat of compressed air to ignite the fuel-
Replace fuel line and wipe away any fuel that may be present air mixture, compression pressure must be maintained
on the engine. Leaking valves or piston rings (causing "blow by") cannot be
tolerated
With fuel and ignition voltage present, it should start.
Repeat start procedure If you still cannot start the engine, The fuel is also important. The automotive-type diesel is
call on your mechanic to look for the problem. designed to run on a specific type or grade of fuel Trouble
can be expected if an attempt is made to use other than the
NOTE. Some engines have a low oil pressure switch that
proper type
must be manually held in until sufficient oil pressure
is present.
18.311 Operation

Do not use a starting fluid on gasoline engines unless it is In the two-cycle engine, intake and exhaust takes place
a LAST RESORT effort to get a critical piece of equipment during part of the compression and power strokes; whereas,
running. Hard-starting engines should be inspected and the four-cycle engine requires four strokes to complete the
repaired by a reliable mechanic operating cycle During one-half of the cycle, the four-stroke
acts as an air pump. The two-stroke must have a blower (air
After an engine has been star,cd, give it an opportunity to pump) to provide the necessary air to expel the exhaust
warm up before applying the load. Follow manufacturer's gases and re,Tharge the cylinder with fresh air
recommendations for the starting procedure since there is
some variation between different makes of engines In the two-cycle, a series of ports surround the cylinder at
a point higher than the lowest position of the piston. These
are the intake ports that allow air into the cylinder The four-
QUESTIONS cycle engine uses intake valves The incoming air forces the
expended gases out the exhaust valve, leaving the cylinder
Write your answers in a notebook and then compare your full of clean air
answers with those on page 326.
As the piston starts .'s upward stroke, the exhaust valve
18 30D If a gasoline engine will not start and the spark plug closes, the intake ports are sealed off by the piston, and the
is wet with fuel or oil, what has happened? air in the cylinder is compressed Shortly before the piston
reaches the top of the stroke, the required amount of fuel is
18 30E If a gasoline engine will not start and there is an oil
sprayed into the combustion chamber by the fuel Injector.
residue on the spark plug, what has happened?
The intense heat of compression ignites the fuel-air mixture
18.30F After an engine has started, what should be done with the resulting combustion driving the piston down on its
before applying the load? power stroke.

20 For additional information on diesel engines, see INDUSTRIAL WASTE TREATMENT, Chapter 7, Support Systems, Section 7.5, "Diesel
Engines," in this series of manuals.

X01)
310 Water 7 reatment

AIR

AIR ENTERING COMBUSTION CHAMBER AIR BEING COMPRESSED WITH

THROUGH CYLINDER LINER PORTS THE EXHAUST VALVE CLOSED T.3083

Scavenging and Compression

AIR
AIR

CHARGE OF FUEL BEING INJECTED EXHAUST TAKING PLACE AND CYLINDER ABOUT
INTO COMBUSTION CHAMBER TO BE SWEPT WITH CLEAN SCAVENGING AIR
1 T.50141

Power and Exhaust

Fig. 18 47 How diesel engines work

(Source GMC Truck Overhaul Manual Series 53. permission of General Motors Corp I
 Maintenance 311

As the piston nears the bottom of the stroke, the exhaust 2 Is cheaper to operate beca:ise:
valve opens and the spent gases are released, assisted by
a. Diesel fuel may be cheaper. and
the incoming fresh air. The cycle is complete.
b Better fuel efficiency
18.312 Fuel System (Fig. 18.48)
Perhaps the biggest drawbacks against these' engines
The basic parts of the fuel system are: are

1. Primary fuel filter, 1. Initial investment costs, and

2 Secondail fuel filter, 2. Repair costs
3. Fuel injection pump, and The pros and cons must be weighed to provide you with
an engine that will fill your particular needs Whichever
4. Fuel injector. engine you select, remember that a well-cared-for engine
The primary filter removes all coarse particles from the will be there to serve you when it is needed and will provide
fuel and the secondary filter removes any minute particles trouble-free operation that is essential to most users
that remain. This ensures a clean fuel that will not clog the
injector pump or fuel injectors. The heart of the fuel system 18.315 How to Start Diesel Engines
is the injection pump (Fig. 18.49) This pump is a gear-type Diesel engines vary in size and use and have varied
positive-displacement pump that can deliver fuel to the starting procedures. Follow manufacturer's suggested pro-
injector at a very high pressure. Incorporated into the pump cedures for your particular engine. As with the gasoline
is a timing advance mechanism to advance or retard the engine, check fuel. oil, and coolant.
instant when fuel is injected into the cylinder. At high engine
speed, injection would take place sooner in the cycle. The To start a diesel engine, the procedures are as follows
reverse happens for lower speeds.
1. Push in "stop" control,
A governor which uses centrifugal weights and is driven
2. Set throttle to 1/3 full,
by the pump shaft, activates a fuel control unit. When engine
speed increases, the weights are thrown toward th it outer 3. Turn on switch and engage starter, and
limit Geared to the assembly, the fuel control valve is
opened wider allowing more fuel to flow to the injector. 4. Engine should start

We now have higher engine speed, advanced "timing" of Some engines have glow plugs that are energized when
injection. and the necessary fuel to sustain the faster oper- the switch is placed in the start position. They preheat the
ation. When the engine is slowed, the reverse takes place. air-fuel mixture in ti$d cylinder to aid in starting. After the
engine is started, maintain the lower RPM's on the engine
Fuel under pressure is fed from th.q injection pump to the tachometer and allow the engine to warm up. The warm-up
appropriate fuel nozzles. When the pressure reaches ap- pariod is vital to the diesel engine for eft' 'tent engine
proximately 3,00C psi (20.700 kPa or 207 kg/sq cm), the performance. When operating the engine, maintain ade-
valve in the injector opens allowing fuel to be injected into quate engine RPM's as recommended by the manufacturer.
the combustion chambers As line pressure drops, the
return spring closes the nozzle valve. Fuel left in the line is When a diesel engine will not start after repeated tries, a
fed back to the pump through "leak off lines. small amount of starting fluid sprayed into the air intake may
be needed to start the engine. If you use starting fluid, do not
18-13 Water-cooled Diesel Engines get carried away with its use; a little goes a long way. Use it
only as a last resort or as specified by the manufacturer. If
Usually the larger diesel engines are of the water-cooled your efforts have failed to start the engine, have a mechanic
type, similar to gasoline engines. In order to deliver a that is familiar with diesel engines determine the cause of
sustained amount of high horsepower, an effective cooling the problem.
system is necessary to dissipate the extreme heat of com-
bustion. Because of this fact, a water-cooled engine of 18.316 Maintenance and Troubleshooting
comparative horsepower to the air-cooled will cost more to
manufacture, and subsequently to maintain. For detailed maintenance procedu _ -3 for your diesel en-
gine, see your diesel manufacturer's service manual.
18.314 Air-cooled Diesel Engines
When a lighter weight, lower horsepower, and more
compact engine is desired, the air-cooled engine will serve
your needs. You get the benefits of a diesel engine in a
smaller package.
There are some definite advantages to the diesel engine
over the gasoline engine. The initial cost is greater for the
diesel; however, the diesel:
1. Requires less maintenance because there are:
a. No plugs,
b. No contact points to pit.
c. No ignition coils or high tension wires, and
d. Fewer tune-ups.

33.
.
312 Water Treatmer t

SECONDARY
FILTER

EXCESS FUEL
STARTING DEVICE
2 DELIVERY
FUEL INJECTION VALVE
NOZZLE HOLDER 4
ASSEMBLY
4111%,,.

OVERFLOW
VALVE

7II

FUEL SUPPLY 16
PUMP

1,
1
12
14 13 '41gfil 9 FUEL TANK
10

,
PRIMARY 15 0/111111.--adeli.
FILTER

ME HIGH PRESSURE (INJECTION) ,

VIE2LOW PRESSURE (SUPPLY) FUEL

LUBRICATING OIL

1 Nozzle Valve and Body 7 Face Gear 12 Governor Stop Plate

2 Nozzle Valve Spring 8 Tappet and Roller 13 Fulcrum Lever
3 Leak-off Lines 9 Cam 14 Stop Lever
4 Hydraulic Head Assembly 10 Governor Gears 15 Shut-off (when used)
5 Fuel Metering Sleeve 11 Governor Weights 16 Fuel Return Line
6 Pump Plunger T2317

Fig. 18.48 Diesel engine fuel system

{Source Maintenance Manual. permission of General Motors Corp )

33 J
 Maintenance 313

FUEL DELIVERY HYDRAUUC HEAD

EXCESS FUEL
VALVE ASSEMBLY
STARTING DEVICE
CONTE::
GOVERNOR COVER ROD

, ,_
0VER ROW
DROOP SCREW .i.,,

;711' VALVE
Vcr
FUEL SUPPLY
PUMP
CONTROL UNIT
COVER

- ,t

C1V ' PACE GEAR

Vtr
.14

4;

GOVERNOR ,
SPRINGS
: P tigti,
MIMING
_
GOVERNOR
GOVERNOR :'ADVANCE
HOUSING LEVER igCHANISM
SOEVE GOVERNOR
WEIGHTS PUMP HOUSING T2179

Fig. 18.49 Cut-away view of fuel injection pump for 6-cylinder engine
(Source Maintenance' Manual, permission of General Motors Corp )

TROUBLESHOOTING 6. Excessive back pressure.

Certain abnormal conditions which sometimes interfere 7. Improper air box pressure,
with satisfactory engine operation are listed in this section.
8. Restricted air inlet,
Satisfactory 2ngine operation depends primarily on:
9. Low oil pressure, and
1. An adequate supply of air compressed to a sufficiently
10 Improper engine coolant operating temperature.
high compression pressure.
2. The injection of the proper amount of fuel at the right Solutons to these problems can be found in the operation
and maintenance instructions for the engines.
time.
Lack of power, uneven running, excessive vibration, stall-
ing at idle speed and hard starting may be caused by either
low compression, faulty injection in one or more cylinders, or 18.32 Cooling Systems (Fig. 18.50)
lack of sufficient air.
In an air-cooled engine, the heat generated by combustion
Since proper compression, fuel injection and the proper is dissipated by the air circulating past the louvered cylinder
amount of air are important to good engine performance, block. With a water-cooled system, the same effect is
possible problems are listed below: achieved by using water. Each cylinder is surrounded with a
water jacket through which coolant circulates. This is ac-
1. Misfiring cylinders, complished by a water pump that is belt-driven from the
2. Improper compression pressure, crankshaft. The heat transfers from the cylinder wall to the
water which, in turn, is pumped back to the radiator where
3. Engine out of fuel, the heat is dissipated. A fan mounted on the same shaft as
the water pump ensures that a large volume of air is blown
4. Proper fuel flow,
across the radiator coils to facilitate rapid disbursement of
5. Excessive crankcase pressure, heat. The cooled water is then pumped back into the engine.

33
314 Water Treatment

POIATOCI
HOT WATER

WATER JACKET

AIR rt.osv TO
REMOVE HEAT
FROM WATER

--V

-
14.!.

yelk.
COOLED WATER

!SEARING
uNiT

Shaft hall bearings are sealed at each end to keep lubricant in

and water out of bearings. A spring-loaded seal (in color) is used to
avoid water leakage around pump shaft. Note clearance between im-
peller and cover plate

Engine temperatures are regulated by transferring excess

heat to surrounding air.

RADIATOR PREL ,URF TEMPERATURE COMPENSATING

CAP HOLES iN GASKET
THERMOSTAT.
WATER
PUMP----

'Yr

PUMP BYPASS BLOCK DRAIN TAP

PASSAGE

RADIATOR
DRAIN TAP

With water lockets entirely around each cylinder and valve, there rs o great amount of oreo exposed to
the circulating cools:mt.

Fig. 18.50 Water cooling system

(Source Automotive Encyclopedia, permission of the GoodheartWilcox Co Inc )

32.j
 Maintenance 315

Internal combustion engines operate more efficiently marshal codes In addition, the water treatment plant opera-
when their temperature is maintained within narrow limits tor should be familiar with the particular problems associat-
This objective is achieved with the insertion of a thermostat ed with each of the commonly used fuels
in the cooling system which is called a "temperature actu-
ated valve." When the engine is cold, the thermostat remains 18.331 Diesel
closed not allowing the water to circulate back to the
radiator As the engine temperature increases to normal DIESEL This fuel comes in two grades known as #1 and
operating temperature, the thermostat opens. #2 Be sure to use the grade recommended by the engine
manufacturer. Be aware that the fuel grade recommendation
The radiator cap provides a function other than preventing may vary with the season. Diesel fuel is often stored in
coolant from splashing out the filter opening The cap is above ground tanks. The fuel may be kept in storage for
designed to seal the cooling system so that it operates years without deteriorating To protect stored diesel from
under pressure This imprc /es cooling efficiency and pre- water contamination, keep the storage tanks full and use
vents evaporation of coolant. The boiling point of water is special additives.
212 degrees F (100°C) However, for every pound of pres-
sure applied to the system, the boiling point rises 3.25 18.332 Gasoline
degrees F (1.8°C). If your cooling system had a 15 psi (100
kPa or 1 kg/sq cm) radiator cap and used water for coolant, GASOLINE Except for very small quantities, gasoline is
it would have a boiling point near 260 degrees F (127°C) stored in underground tanks This can result in problems for
the operator If the storage tank develops a leak, either fuel
The use of coolant/anti-freeze provides protection against can leak out or water can leak in. Either condition is
the radiator coolant freezing and rupturing the system and
also provides better heat transfer and heat dissipation
characteristics than water. Most of the name-orand coolants
contain rust inhibitors. Rust buildup in the cooling system
interferes with good heat transfer and the sloughing of rust
scale can block narrow passages.
Stationary internal combustion engines such as those
that are used to drive pumps and generators at the water
treatment plants, are often installed in a building where free
circulation of air for radiator cooling may not be possible.
For these installations, a liquid-to-liquid heat exchanger
often replaces the radiator (which is a liquid-to-air heat
exchanger). In this case, instead of the heat in the cooling
jacket water being transferred to the surrounding air, it is
transferred to anotner liquid. usually tap water. This water
may be wasted, if the engine is a standby unit and not
operated very much, or the cooling water may be recovered
in a cooling tower if the engine is in regular use.
In liquid-to-liquid heat exchanger systems a thermostati-
cally controlled valve is usually installed to regulate the flow
of cooling water through the exchanger. This valve should
be checked periodically to see that it: (1) provides sufficient
water flow when the engine is running and (2) closes off tight
when he engine is shut down to prevent waste.
Cooling water from a heat exchanger should not be put
back into a potable water system Any leakage in the heat undesirable Fuel loss ca i not only be an unwanted operat-
exchanger could result in engine jacket coolant contaminat- ing expense, but can be a danger to underground plant
ing the potable water supply.
piping. Gasoline deteriorates rubber and if the piping is put
together with rubber gaskets or rings, the deterioration can
QUESTIONS result in major leaks and broken couplings. Fuel toss can
Write your answers in a notebook and then compare your best be monitored by careful accounting.
answers with those on page 326.
Water leakage into underground fuel tanks can result in
18 31A Why is gasoline not used as a fuel in diesel en- engine stoppages and possible damage to the engine.
gines? Special devices are available for detecting water in gasoline
tanks and such a test should be run routinely. These devices
18 31B List the four basic parts of a diesel fuel system can be obtained by contacting your local wholesale fuel
18.31C What is the purpose of the fuel injection pump? distributor

18.32A How is heat removed from the cylinders in a water- Gasoline, unlike diesel, deteriorates in storage. For en-
cooled engine9 gines that are in normal everyday use, this is not a problem.
However, fuel storage for standby, engine-driven equipment
16.33 Fuel Stur-ye requires further consideration. Engine operation and fuel
tank rej,:enishment should be scheduled so that at least one
18.330 Code Requirements half of the gasoline in storage is used each year. Failure to
do this can result in engines that are hard to start and in the
Storage and use of fuels for internal combustion engines formation of varnish and gummy deposits that can cause
must always be in accordance with local building and fire malfunctions in the parts of the fuel syste,n.
316 Water Treatment

18.333 Liquified Petroleum Gas (LPG) tremendous heat which is generated when it comes in
LIQUIFIED PETROLEUM GAS (LPG). LPG is usually a contact with water. This heat is sufficient to cause a fire
mixture of propane and butane. The proportions of each is Some liquid chemicals such as sodium hydroxide (caustic
varied according to the weather temperature. The cooler the soda) should not be exposed to air because of the formation
weather, the greater the proportion of propane. of calcum carbonate (a solid) due to the carbon dioxide in
This fuel is always stored under pressure in above-ground the air Also some liquid chemicals may "freeze." A 50
tanks that are located out in the open. LPG dues not percent sodium hydroxide solution becomes crystalized
deteriorate in storage and therefore can be kept for many (forms a solid) at temperatures below 55°F (13°C). Therefore
years. a heater may be required to keep the storage area warm or
the solution may have to be diluted down to a 25 percent
LPG is heavier than air and will collect in low areas if there solution.
is any leakage. This poses an extremely dangerous explo-
sive threat that treatment plant operators must constantly Potassium permanganate can be kept indefinitely if stored
guard against. in a cool dry area in closed containers. The drums should be
protected from damage that could cause leakage. Potas-
sium permanganate should be stored in fire-resistant build-
18.334 Natural Gas ings. having concrete floors as opposed to wooden floors. It
NATURAL GAS. This fuel is usually obtained from the should not be exposed to intense heat, or stored next to
local gas company through a metered connection from their heated pipes Any organic solvent, such as greases and oils
distribution system. There is no on-site storage. in general, should be kept away from stored KMnO4.

Natural gas, being lighter than air, tends to rise and Potassium permanganate spills should be swept up and
dissipate from leaks and therefore is less dangerous to removed immediately. Flushing with water is an effective
handle than LPG. Explosions can occur, however, if the way to eliminate spillage on floors. Potassium permangan-
leakage is confined inside a building. ate fires should be extinguished with water.
Carbon should be stored in a clean, dry place, in single or
18.34 Standby Engines double rows, and with access aisles around every stack for
Internal combustion engines must be run periodically to frequent fire inspections. The removal of burning carbon will
ensure that, when needed, they will function properly. An thus be facilitated. Carbon should never be stored in large
engine that is not in regular service should be started up and stacks.
test run at least once a week. The test run should be long The storage area should be of fireproof construction, with
enough for the engine to come up to its normal operating self-closing fire doors separating the carbon room from
temperature before the engine is shut down. If at all possi- other sections. Storage bins for dry bulk carbon should be of
ble, run the engine under its normal load. Just idling an fireproof construction equipped for fire control by the instal-
engine for 20 minutes doesn't give you much of an indication lation of carbon dioxide equipment, or should be so ar-
as to whether it can handle a load. Check and make note of ranged that they can be flooded with a fine spray of water.
the engine instruments. Look for changes that may indicate
a need for repairs. Lube oil pressure and intake manifc'.., Ca; bon storage areas should be protected from contact
pressure (on spark ignition engines without supercharging with flammable materials. (Carbon dust mixed with oily rags
or fuel injection) are two key indicators of engine condition. or chlorine compounds can ignite in spontaneous combus-
tion.) SMOKING SHOULD BE PROHIBITED AT ALL TIMES
DURING THE HANDLING AND UNLOADING OF CARBON
QUESTIONS AND IN THE STORAGE AREA. Carbon should not be stored
where a spark from overhead electric equipment could start
Write your answers in a notebook and then compare your a fire. If a fire occurs, the carbon monoxide hazard should be
answers with those on page 326.
taken into account.
18.33A The storage and use of fuels for internal combus-
Electric equipment should be protected from carbon dust
tion engines must be in accordance with what
codes?
and cleaned frequently or, better, explosion-proof electric
wiring and equipment should be used. (The heat from a
18 33B List four types of fuels commonly used by internal motor may ignite the accumulated carbon dust, this material,
combustion engines. especially when damp, is a glod conductor of electricity and
could short-circuit the mechanism.)
18.34A Hoy' often should standby internal combustion en-
gines be test run when not in regular service? Polymer sc'utions will be degraded (lose their strength) by
biolooical contamination. A good cleaning of polymer stor-
18.34B Under what conditions should standby engines be age tanks is recommended before a new shipment is deliv-
test run? ered to the plant.

18.4 CHEMICAL STORAGE AND FEEDERS`' Liquid chemical storage tanks should have a berm or
earth bank around the tanks to contain any chemicals
released if the tank fails due to an earthquake, corrosion or
18.40 Chemical Storage any other reason.
Certain dry chemicals such as alum, ferric chloride, and Some chemicals such as chlonne and fluoride compounds
soda ash are HYGROSCOPIC.22 These chemicals require are harmful to the human body when they are released as
special considerations to protect them from moisture dunnq the result of a leak. Continual surveillance and maintenance
storage. Dry quicklime should be kept dry because of the of the stoi.age and feeding systems are required.
21 For additional information on chemical feeders, see Chapter 13, Fluoridation, Section 13 30, "Chemical Feeders
22 Hygroscopic (HI-grow-SKOP-ick). Absorbing or attracting moisture from the air.

31
 Maintenance 317

18.41 Drainage from Chemical Storage and Feeders six representative settings of the pump-control scale. Re-
cord the amount pumped at each setting as observed in the
Safety regulations prohibit a single drainage pit which can
sight tube Use this information to develop curves of pump
accept and contain both acid and alkali chemicals because
setting vs chemical dose in mg/L or chemical feed in gallons
of the possibility of an explosion whenever these two types
per day for your plant (Figure 18.52).
of chemicals come in contact. Also, any organic chemical
waste such as a polymer solution should not be allowed to The graph developed by this process is called a calibration
be discharged into a pit or sump which could also receive a curve It can be used to determine the pump setting needed
waste from oxidizing chemicals such as potassium perman- to deliver a required chemical feed rate, or the commonly
ganate (KMnO4) because of the possibility of a fire. There- used range of feed rates can be marked in gallons per day
fore, separate drainage systems or a high dilution of certain directly on the pump control panel.
chemicals are necessary for a safe drainage system.
18.461 Small-Volume Metering Pumps
18.42 Use of Feeder Manufacturer's Manual
Pumps metering a chemical such as sodium hexameta-
Water treatment plants will have a number of chemical phosphate, a lime feed solubility enhancer, feed a very small
feeders to accurately control the i ate at which chemicals are volume per day. The procedure for calibration of these
fed into the water as a part of the treatment processes pumps is similar to the procedure for large-volume units. For
There are many types of feeders and they work on many very low feed rates, pumping times of longer than one
different principles. Study the feeder manufacturer's manual minute may be required to give accurately measurable
that you should find in the treatment plant library for details results.
on maintaining the equipment. Additional information on
chemical feeders is contained in specific chapters on treat- Once the test data have been recorded, convert the test
ment processes that require the use of chemical feeders. results to appropriate units and draw a calibration curve to
be used as for the larger pumps.
18.43 Solid Feeders
18.462 Dry-Chemical Systems
Solid feeders usually handle powdered material and usu-
ally have many moving mechanical parts that need adjust- Dry-chemical feed systems are used for chemicals such
ment, lubrication, and replacement when worn. The chemi- as activated carbon, fluoride, and lime. Two types of sys-
cal supply is usually stored in a hopper. Keep the hopper tems are common, the rocker-dump type and the helix-feed
and feeder clean and dry in order to prevent "bridging" (a type The rocker-dump chemical feed uses a scraper moving
hardened layer which can form an arch and prevent flow) of back and forth on a platform located at the bottom of a
the chemical in the hopper and clogging in the feeder. hopper filled with dry chemical The platform may be adjust-
ed up and down to regulate the thickness of the ribbon of
chemical, and the length of stroke for the scraper can be
18.44 Liquid Feeders adjusted, usually by means of an indicator on an exterior
Liquid feeders handle many types of chemicals, some of arm.
which may be corrosive and/or have a tendency to plug up The helix-type feeder feeds the dry chemical with a
the mechanism. The key to reliable operations is constant rotating screw (helix). The feed rate is adjusted by vary.ng
vigilance and cleaning as needed the drive-motor speed. The speed can usually be varied from
0 to 100 percent.
18.45 Gas Feeders
To calibrate either type of feed system, choose five or six
The principal chemical found in gaseous form at water representative settings of the arm (rocker-dump) or of the
treatment plants is chlorine Chlorine is quite poisonous to motor speed control (helix type), and a, each of the settings
humans and must be handled with great caution catch the amount of chemical fed during a precisely meas-
ured time interval. Next, weight each volume of chemical as
18.46 Calibration of Chemical Feeders23 accurately as possible and convert the information into
pounds per day. Use the data to construct a calibration
To ensure chemical feed rates, liquid-shemical metering curve with one axis representing feeder settings and the
pumps and dry-chemical feed systems should be tested and other representing pounds per day. The curve is used in the
calibrated when first installed and at regular intervals there- same manner as the curves for liquid-feed pumps.
after. This section presents general proceaures for calibrat-
ing several types of liquid- and dry-chemical feeders. FORMULAS

18.460 Large-Volume Metering Pumps To determine the chemical feed rate or flow from a
chemical feeder, we need to know the amount or volume fed
Pumps metering chemicals such as liquid alum deliver a during a known time period. The flow from a chemical feeder
relatively large volume of chemical in a short time period. can be calculated by knowing the volume pumped from a
These pumps can be accurately calibrated with a clear chemical storage tank and the time period.
plastic sight tube and a stopwatch (Figure 18.51).
Volume Pumped, gal
Flow, GPM =
To calibrate 'tne pump, fill the sight tube from the chemical Pumping Time, minutes
solution tank, then set the valve so the tube is the only
source of liquid chemical entering the pump. Run the pump (Volume Pumped, gal) (24 hr/day)
or Flow, GPM =
for exactly one minute (use the stopwatch) at each of five or (Pumping Time, hour)

23 For additional information on L.a:trzt,n of chemical feeders. see Volume I. Appendix Section A 131, 'Chemical Doses. pages
567-570.

3 33
 CLEAR PLASTIC
GRADUATED
CHEMICAL CYLINDER
SOLUTION MARKED IN
TANK MILLILITERS
TO POINT OF
(CHLORINE, ALUM, ETC.)
CHEMICAL INJECTION
CHEMICAL
SOLUTION
FEED PUMP

THE FEED RATE OF A CHEMICAL SOLUTION FEED PUMP CAN BE DETERMINED BY MEASURING THE AMOUNT OF
SOLUTION WITHDRAWN FROM A GRADUATED CYLINDER IN A GIVEN TIME PERIOD. ALLOW THE CYLINDER TO FILL WITH
SOLUTION. THEN CLOSE THE VALVE ON THE LINE FROM THE TANK SO THE FEED PUMP TAKES SUCTION FROM THE
CYLINDER ONLY. OBSERVE THE MILLILITERS OF SOLUTION USED IN ONE MINUTE. COMPARE THIS RESULT WITH THE
DESIRED FEED RATE AND ADJUST THE FEED PUMP ACCORDINGLY.

3
ri 3 Fig. 1851 Calibration of a chemical feed pump
 Maintenance 319

100

60

1.0 20 30 4.0 50 6.0 7.0

CHEMICAL DOSE, mg/L

Fig. 18.52 Chemical feed pump settings for various chemical doses

Liquid polymer feed rates are often measured in pounds 1. Determine the volume of water pumped in gallons.
per day. To calculate this feed rate we need to know the Volume, gal = (0 785) (Diameter, ft)2 (Dron, ft) (7 48 gal/cu ft)
strength of the polymer solution as a percent or as milli-
grams per liter, the specific gravity of the solution, the = (0 785) (4 ft)2 (2 ft) (7 48 gal/cu ft,
volume pumped and the time period. = 188 gal
Polymer [poly Conc. mg/L) (Vol Pumped, mL) (60 min /hr) (24 hr / day)
Feed.
lbs/day (Time Pumped. mm) (1000 mLIL) (1000 mg/gm) (454 gm/lb)
2 Calculate the flow from the chemical feed pump in gallons
To determine the actual feed from a dry chemical feeder, we per minute.
need to know the pounds of chemical fed and the time Volume Pumped. gal
period. Flow, GPM =
(Pumping Time, hr) (60 min/hr)
Chemical (Chemical Fed, Ibs) (60 min/hr) (24 hr/day)
Feed, 188 gal
lbs/day Time, minutes
(7 hr) (60 min/hr)

EXAMPLE 2 = 0 45 GPM

A chemical feed pump lowered the chemical solution in a

four-foot diameter chemical storage tank two feet during a 3 Calculate the flow from the chemical feed pump in gallons
seven-hour period. Estimate the flow delivered by the pump per day.
in gallons per minute aria gallons per day. (Volume Pumped, gal) (24 hr/day)
Flow, GPD =
Known Unknown Pumping Time, hr
Tank Diameter, ft = 4 ft Flow, GPM (188 gal) (24 hr/day)
Chemical Drop, ft = 2 ft Flow, GPD 7 hr
Time., hr = 7 hr = 645 GPD

34 i
 320 Water Treatment

EXAMPLE 3 Ammonia water will detect any chlorine leak. A small piece
Determine the chemical feed in pounds of polymer per day of cloth, soaked with ammonia water24 and wrapped around
from a chemical feed pump. The polymer solution is 2 the end of a short stick, makes a good leak detector Wave
percent or 20,000 mg polymer per liter Assume a specific this stick in the general area of the suspected leak (do not
gravity of the polymer solution c' 1.3. During a test run the touch the equipment with it) If chlorine gas leakage is
chemical feed pump delivered 50 mL of polymer solution occuring. a white cloud of ammonium chloride will form You
during six minutes. should make this test at all gas pipe joints, both inside and
outside the chlorinators, at regular intervals. Bottles of
Known Unknovt ammonia water should be kept tightly capped to avoid loss
of strength. All pipe fittings must be kept tight to avoid leaks.
Polymer Solution. = 2 0% Polymer Feed. NEW GASKETS SHOULD BE USED FOR EACH NEW CON-
lbs/day NECTION
Polymer Conc, mg/L = 20,000 mg/L
Polymer Sp Gr = 1.0 r I
Volumed Pumped, m L= 750 mL -10 Loc.A.-Te A C-14 OR I N E LEAK, DO NOT'
Time Pumped, min = 6 min
SPRAY OR SWAB EQUIPMetVT WI-544
AMMONIA WATi. 2/ WAVE AN Ammo N p, -
Calculate the polymer feed by the chemical feed pump in
SOAKED 12ACi- Q Q P NT' aaust4 INTHE
CxENERAL AQE. AK\ YOU ('....1\S ve.ce0--
pounds of polymer per day. PPESEN OF AAA MY LEAKS .SOME
Polymer (Poly Conc. mg/L) (Vol Pumped. mL) (60 min /hr) (24 hr /day)
oPctz&-rotzz, 1712EF E Z-TO WAVE. A STICK. v4IT1-1
Feed. A CLOTH ON END I 1,-1 RZONIT ThEM
lbs/day (Time Pumped, mm) (1000 mL/L) (1000 mg/gm) (454 gm/lb) WI-Vet-4 1-4AEY ARE Lool4iNa COQ CHL-1...X2.1 NE
LEAKS
(20.000 mg/L) (750 mL) (60 min/hr) (24 hr/day)
(6 mm) (1000 mL /L) (1000 mg/gm) (454 gm/lb)
Do not use a spray bottle in a room where large amounts
7 9 Ihs polymer/day of chlorine gas have already leaked into the air. After one
squeeze. the entire area may be full of white smoke and you
EXAMPLE 4 will have troi .ale locating the leak. Under these conditions,
use a cloth soaked in ammonia water to look for leaks.
Determine the actual chemical fed in pounds per day from
a dry chemical feeder A pie tin placed under a chemical The exterior casing of chlorinators should be painted as
feeder collected 1000 grams of chemical in five minutes. required, however, most chlonnators manufactured recently
have plastic cases otat do not require protective coatings. A
Knuwn Unknown clean machine is a better op,' iting machine. Parts of a
Dry Chemical, gm = 1000 gm Chemical Feed, lbs/day chlorinator handling chlorine gas must be kept dry to prevent
the chlorine and moisture from forming hydrochloric acid.
Time, mm = 5 min Some parts may be cleaned, when required, first with water
Determine the chemical feed in pounds of chemical applied to remove water soluble material, then with wood alcohol,
per day. JIlowed by drying The above chemicals leave no moisture
residue. Another method would oe to wash them with water
Chemical (Chemical Applieo, gm) (60 min/hr) (24 hr/day) and dry them over a pan or heater to remove all traces of
Feed. = moisture.
lbs/day (454 gnr/Ib) (Time, min)
Water strainers on chlorinators frequently clog and re-
(1000 gm) (60 mri/hr) (24 hr/day) quire attention They may be cleaned by flushing with water
(454 gm/lb) (5 min) or. if badly fouled, they may be cleaned with eilute hydro-
chloric acid, followed with a water wise.
635 lbs/day
The atmosphere vent lines from thlormators must be
18.47 Chlorinators open and free. These vent lines evacuate the chlorne to the
outside atmosphere when the chlorinator is being shut
Chlorine gas leaks around chlorinators of containers of down. Place a screen over the end of the pipe to keep
chlorine will cause corrosion of equipment Check every day insects from building a nest in the pipe and clogging it up.
for leaks. Large leaks will be detected by odor; small leaks
may go unnoticed until damage results. A green or reddish When chlorinators are removed from service, as much
deposit on metal indicates a chlorine leak. Any chlorine gas chlorine gas as possible should be removed from the supply
leakage in the presence of moisture will cause corrosion. lines and machines. The chlorine valves at the containers
Always plug the ends of any open connection to prevent are shut off and the chlorinator injector is operated for a
moisture from entering the lines. Never pour water on a period to remove the chlorine gas. In "V" notch chlorinators,
chlorine leak because this will only create a bigger problem the rotameter goes to the bottom of the manometer tube
by enlarging the leak. Chlorine gas reacts with water to form when the chlorine gas has been expelled.
hydrochloric acid.
All chlorinators will give cr sinuous t. )uble-free operation
WARNING if properly maintained and operated 'teach chlorinator manu-
15140-11-4E12 1,1$0012rANT 12.5A.50.) 1=O2 PQevextriN6 facturer provides with each machine a maintenance and
0-41-CQINIE iS11-14-1 -roe SAS I -, operations instruction booklet with line diagrams showing
-roxic. TC MANS. the operation of the component parts of the machine.
Manufacturer's instructions should be followed for mamte-
24 Use a concentrated ammcnia solution containing 28 to 30 percent ammonia as NH3 (this is the same as 58 percent ammonium hydrox-
ide. NH4OH, or commercial 26° Baume).

34
 Maintenance 321

nance and lubrication of your particular chlorinator. If you do the tank surface The polarity of this current is opposite to
not have an instruction booklet, you may obtain one by what it would be if rust were forming The ^,urrent can be
contacting the manufacturer s representative in your area obtained from sacrificial anodes that make the tank into a
giant low voltage battery, or from electronic rectifiers that
are powered from the commercial power lines.
QUESTIONS
Cathodic protection systems provide protection only so
Write your answers in a notebook and then compare your long as they are operating and properly adjusted Systems
answers with those on page 327 with rectifiers should be checked weekly. The inspection
18 4A How can an operator locate information on how to consists of reading and record the DC volt and ammeter
operate. control and maintain chemical feeders9 readings Compare the readings with previous readings and
with the readings recommended by the corrosion engineer
18 4B List three common types of chemical feeders or technician Deviations from normal should be investigated
18 4C Why should chlorine leaks be detected and repaired9 without delay

18 4D How would you search for chlo die leaks9 Once a year, a corrosion specialist should be called in to
take potential profile readings on the inside of the tank and
18.5 TANKS AND RESERVOIRS2: to set the rectifier and recommend new normal current
settings. Over the years, as more and more of the interior
18.50 Scheduling Inspections tank coating fails, the bare surface area to be protected by
the cathodic protection system will increase. For this reason,
Plant tanks should be drained and inspected at regular it is to be expected that the current required to provide
intervals If the interior is well protected. five-year intervals protection will increase in small amounts or increments each
between inspections may be sufficient If the tank is below year
the surface of the ground, be sure the groundwater level is
down far enough (below the bottom of the tank) so the tanks 18.53 Concrete Tanks
will not float on the groundwater when empty or develop
cracks from groundwater pressure. Concrete tanks are not usually coated on the inside and
are painted on the exterior for appearance purposes only.
Schedule inspections of tanks and channels during per- This would seem to indicate that maintenance on concrete
iods of low plant demand so that plant operation won't be tanks is minimal, but this may not be true Concrete tanks
disrupted are all reinforced with steel Steel can rust. If too much steel
is lost to rust, the structural strength of the tank can be
threatened Periodically inspect the tank for signs of rusting.
18.51 Steel Tanks
This is particularly important for pre-stressed concrete tanks
All steel tanks must be protected from rusting Once metal that have a tensioned wire wrap on the extenor. The wires
is lost because of rusting, it can't be recovered. The ex- are small in diameter and even a small amour t of rust could
teriors of the tanks are easily inspected don t forget the reduce the size of the wire to the point where it might fail.
roof and should be repainted, as needed. not only to
protect the steel surface but to provide a pleasing appear- QUESTIONS
ance. he interiors of steel tanks are exposed to a much
harsher environment due either to being constantly sub- Write your answers in a notebook and then compare your
merged or to constant high humidity. answers w ,h those on page 327.

Protective coatings for steel tank interiors must be care-

18 5A How often should tanks and reservoirs be drained
and inspected9
fully selected to provide superior protection and at the same
time impart neither taste nor odors to the water Proper 18 5B Why must the groundwater level be below the bottom
surface preparation and application is as important as the of a tank before it is drained?
coating materials in getting interior protection that will last a
reasonable period of time 18 50 What is an alternative to applying a protective coat-
ing to prevent corrosion of a steel tank9
When interior tank recoating is required, schedule the
work when plant demand is low but not during rainy weather 18.6 BUILDING MAINTENANCE
when it may be impossible to maintain a dry steel surface
warm enough to ensure proper curing of the coating. This Building maintenance is another program that should
type of work is usually done by outside contractors. Con- receive attention on a regular schedule Buildings in a
stant inspection is a must if the work is gang to be treatment plant are usually built of sturdy materials to last for
completed according to the specifications. many years, if they are kept in good repair. In selecting paint
for a treatment plant, it is always a good idea to have a
painting expert help the operator select the types of paint
18.52 Cathodic Protection26
needed to protect the buildings from deterioration. The
An alternative to repainting the submerged interior sur- expert also will have some good ideas as to color schemes
faces of a steel water tank is installation of a cathodic to help blend the plant in with the surrounding area. Consid-
protection system. The rusting of steel is accompanied by eration should also be given to the quality of paint A good
the flow of small electrical currents. Cathodic protection quality, more expensive material will usually grin better
systems prevent rusting of bare steel surfaces by causing service over a longer period of time than the economy-type
an electrical current to flow from anodes hung in the water to products.

25 Also cee WATER DISTRIBUTION SYSTEM OPERATION AND MAINTENANCE, Chapter 2, Storage Facilities, Section 2.4, "Mainte-
nance," in this series of manuals.
26 Also see Chapter 8, Corrosion Control, Section 8.36. "Catholic Protection," in WATER TREATMENT PLANT OPERATION, Volume 1.

343
 322 Water Treatment

Building maintenance programs depend on the age, t;oe 18 6B What factors influence the type of building mainte-
and use of a building New buildings require a thorough nance program that might be needed for your water
check to be certain essential items are available and working treatment plant/
properly Older buildings require careful watching and
prompt attention to keep ahead of leaks, breakdowns, 18.7 ARITHMETIC ASSIGNMENT
replacements when needed, and changing uses of the
building Attention must be given to the maintenance re- Turn to the appendix at the back of this manual and read
quirements of many items in all plant bui' 1ings, such as Section A 35, "Maintenance Also work the example prob-
electrical systems, plumbing, heating, coo. 'g, ventilating, lems and check the arithmetic using your calculator You
floors, windows, roofs, and drainage around the buildings. should be able to get the same answers
Regularly scheduled examinations and necessary mainte-
nance of these items can prevent many costly and time- 18.8 ADDITIONAL READING
consuming problems in the future
1. NEW YORK MANUAL, Chapter 19, "Treatment Plant
In each plant building, periodically check all stairways, Maintenance and Accident Prevention
ladders. catwalks, and platforms for adequate lighting, head 2. TEXAS MANUAL, Chapter 13, "Pumps and Measurement
clearance, and sturdy and convenient guardrails Protective of Pumps
devices should surround all moving equipment. Whenever
any repairs, alterations, or additions are built, avoid building 18.9 ACKNOWLEDGMENTS
accident traps such as pipes laid on top of floors or hung
from the ceiling at head height, which could create serious Major portions of this chapter were taken from the follow-
safety hazards. ing California State University, Sacramento, Operator Man-
uals
Organized storage areas should be provided and main-
tained in an accessible and neat manner. 1. OPERATION OF WASTEWATER TREATMENT PLANTS
KEEP ALL BUILDINGS CLEAN AND ORDEAL Y. Janitorial Volume 11, Chapter 15, "Maintenance," by Norman
work should be done on a regular schedule. All tools and Farnum, Stan Walton, John Brady, Roger Peterson
plant equipment should be kept clean and in tneir proper and Malcolm Carpenter.
place. Floors, walls, and windows should be cleaned at
regular intervals in order to maintain a neat appearance. A 2 OPERATION AND MAINTENANCE OF WASTEWATER
treatment plant kept in a clean, orderly condition makes a COLLECTION SYSTEMS
safe place to work and aids in building good public and Chapter 9, "Equipment Maintenance," by Lee Doty.
employer relations.
3. INDUSTRIAL WASTE TREATMENT
QUESTIONS Chapter 7, "Maintenance," by Roger Ham.
Write your answers in a notebook and then compare your
answers with those on page 327. end of 1444tzt5of 5L4h401,0
18 6A What items should be included in a building mainte-
nance program/
MAINTENANa

DISCUSSION AND REVIEW QUESTIONS

Chapter 18. MAINTENANCE
(Lesson 5 of 5 Lessons)

Write your answers to these questions in your notebook 39 What are the advantages of air-cooled diesel engines as
before continuing to the objective test on page 327. The compared with water-cooled types/
question numbering continues from Lesson 4
40 How should large quantities of gasoline be stored')
36 What factors could cause gasoline engine starting prob- 41 Why i,. "idling not a satisfactory method of testi.ig
lems/ standby engines?

37. Why is rust a problem in water-cooled systems? 42 Why should ory chemical feeders and hoppers be kept
clean and dry?
38 What is the purpose of the filters in the diesel fuel 43 What problems can be caused by chlorine gas leaks
system? around chlorinators or containers of chlorine/
 Maintenance 323

SUGGESTED ANSWERS
Chapter 18, MAINTENANCE

ANSWERS TO QUESTIONS IN LESSON 1 Answers to questions on page 225.

18 11A The two types of current are Direct Current (D.C.)
Answers to questions on page 220 and Alternating Current (A C ).
18 OA A good maintenance program is es- antial for a water 18 11B Amperage is a measurement of work being done or
treatment plant to operate at peak efficiency. "how hard the electricity is working."
18 OB The most important item is maintenance of the 18 11C The proper voltage and allowable current in amps
mechanical equipment pumps, valves, scrapers, for a piece of equipment can be determined by
and other moving equipment. Other items include reading the name plate information or the instruc-
plant buildings and grounds. tion manual for the equipment.
18 OC A good record system tells when maintenance is due
and also provides a record of equipment perform-
ance. Poor performance is a good justification for Answers to questions on page 230.
replacement o- new equipment. Good records help
keep your warranty in force. 18 12A You test for voltage by using a voltage tester
18.0D Both cards are vital in a good recordkeeping system. 18 12B A voltage tester can be used to test for voltage,
The equipment service record card is a permanent or ooen circuits, blown fuses, single phasing of mo-
master card that indicates when or how often certain tors and grounds.
maintenance work should be done. The service rec- 18.12C Before attempting to change fuses, turn off power
ord card is a record of who did that work on what and check both power lines for voltage Use a fuse
date and is ul in determining when the future puller.
maintenance w..,1K is due. 18.12D If the voltage is unknown and the voltmeter has
18 OE Emergency phone numbers for a treatment plant different scales that are manually set, always start
should include the phone numbers for police, fire, with the highest voltage range and work down.
hospital and/or physician, responsible plant officials, Otherwise the voltmeter could be damaged.
local emergency disaster office, emergency team 18.12E Amp readings different from the name plate rating
and CHEMTREC, (800) 424-9300. could be caused by low voltage, bad bearings, poor
18.0F A training program for an emergency team should connections, plugging or excessive load.
include: 18 12F Motors and wirings should be megged at least once
1. Use of proper equipment (self-contained breath- a year. and twice a year if possible.
ing apparatus, repair kits and repair tools), 18 12G An ohm meter is used to test the control circuit
2. Properties and detection of hazardous chemicals, components such as coils, fuses, relays, resistors
3 Safe procedures for handling and storage of and switches.
chemicals,
4. Types of containers, safe procedures for shipping
contain ,rs, and container safety devices,
5. Installation of repair devices, and Answers to questions on page 231.
6. Simulated field emergencies 18.13A The two types of safety devices in main electrical
panels or control units are fuses or circuit breakers.
Answers to questions on page 221. y, cir-
18.13B Fuses are used to protect operators, wi
18.1CA Unqualified or inexperienced people must be ex- cuits, heaters, motors, and various other electrical
tremely careful when attempting to troubleshoot or equipment.
repair electrical equipment because they can be 18.13C A fuse must never be by-passed or jumped be-
seriously injured and damage costly equipment if a
cause the fig..e may be the only protection the
mistake is made.
circuit has; without it. serious damage to equipment
18.10B When machine is not shut off. locked out, and and possible injury to operators can occur.
tagged properly, the folio' ng accidents could oc- 18 13D A circuit breaker is a switch that is opened auto-
cur: matically when the current or the voltage exceeds
1. Maintenance operator could be cleaning pump or falls below a certain limit. Unlike a fuse that has
and have it start, thus losing an arm, hand or to be replaced each time it "blows," a circuit breaker
finger; can be reset after a short delay to allow time for
2. Electrical motors or controls not properly cooling.
grounded could lead to possible severe shock, 18.13E Motor starters can be either manually or automati-
paralysis, or death; and
cally controlled.
3. Improper circuits such as a wrong connection,
safety devices jumped, wrong fuses, or improp- 18.13F Magnetic starters are generally used to start
er wiring can cause fires or injuries due to pumps, compressors, blowers and anything where
incorrect operation of machinery. automatic or remote control is desired.

34:.;
 324 Water Treatment

Answers to questions on page 234.

18.16D Symptoms that a power distribution transformer
18 14A Electrical energy is commonly converted into me- may be in need of maintenanc, or repair include
chanical energy by electric motors. unusual noises, high -'ow oil levels, oil leaks or
18.14B An electric motor usually consists of a stator. rotor, high operating temperatures.
end bells, and windings.
18 14C Motors can be kept trouble free with proper lubrica- Answers to questions on page 247.
tion and maintenance.
18 17A Rusted conduits are of concern because they could
18 14D Motor name plate data should be recorded, com- become the source of a spark which could cause an
pared with manufacturer's data sheets and instruc- explosion.
tions, and placed in a file for future reference. Many
times the name plate is painted, corrodes or is 18 17B Electrical safety check lists are used to make
missing from the unit when the information is need- operators aware of potential electrical hazards in
ed to repair the motor or replace parts their water treatment plant.

Answers to questions on page 236.

18.14E The key to effective troubleshooting is practical, ANSWERS TO QUESTIONS IN LESSON 2
step-by-step procedures combined with a common Answers to questions on page 258
sense approach.
18 14F When troubleshooting: 18.20A Pieces of equipment and special tools commonly
found in a pump repair shop include welding equip-
A. Gather preliminary information. ment, lathes, drill press and drills, power hack saw,
B. Inspect: flame-cutting equipment, micrometers, calipers,
1. Contacts, gages, portable electric tools, grinders, a forcing
2. Mechanical parts, and press, metal-spray equipment, and sand-blasting
3. Magnetic parts. equipment.
18.14G Types of information that should be recorded re- 18 21A The purpose of a pump impeller is to suck water in
garding electrical equipment inclue every change, the suction piping and to throw water out between
repair and test. the impeller blades.
13 21B A suitable screen should be installed on the intake
Answers to questions on page 246. end of suction piping to prevent foreign matter
(sticks, refuse) from being sucked into the pump
18.15A A qualified electrician should perform most of the and clogging or wearing the impeller.
necessary maintenance and repair of electrical
equipment to avoid endangering lives and to avoid 18 21C Suction piping must be up-sloping to prevent air
damage to equipment. pockets from forming in the top of a pipe where air
could be drawn into the pump and cause the loss of
18.15B The purpose of a "kirk-key" system (one key is used suction.
for two locks) is to insure proper connection of
standby power into your power distribution system. 18.210 Cavitation is the formation and collapse of a gas
The commercial power system must be locked out pocket or bubble on the blade of an impeller. The
by the use of switch gear before the standby power collapse of this gas pocket or bubble drives water
is connected to your power distribution system. into the impeller with a terrific force that can cause
pitting on the impeller surface.
18.15C Battery-powered lighting units are considered bet-
ter than engine-driven power sources because they 18 21E An advantage of a double-suction pump is that the
are more economical. If you have a momentary longitudinal thrust from the water entering the im-
peller is balanced.
power outage, the system responds without an
engine-generator startup.
Answers to questions on page 263.
18.15D If water lost from a lead-acid battery is replaced
with tap water, the impurities in the water will 18 22A The purpose of lubrication is to reduce friction
become attached to the lead plates and shorten the between two surfaces and to remove heat caused
life of the battery. by friction.
18 22B Oils in service tend to become acid (contaminated)
Answers to questions on page 247. and may cause corrosion, deposits, sludging and
other problems.
18.16A Electricity is transmitted at high voltage to reduce
18 22C To ensure proper lubrication of equipment, deter-
the size of transmission lines.
mine the proper lubrication schedule, lubricant, and
18 16B If outdoor transformers have exposed high voltage amount of lubricant and prepare a lubrication chart.
wires, the following precautions must be taken:
1. An eight foot (2.4 m) high 'ace is required to Answers to questions on page 264
prevent accessibility by un ilified or unauthor- 18 22D A soft grease has a low viscosity index as com-
ized persons; and pared with a hard grease.
2. Signs attached to the fence must indicate "High 18 22E Oil is used with higher speeds.
Voltage."
18 22F Overfilling with oil or grease can result in high
18.16C The treatment plant operator must keep the exteri-
pressures and temperatures. and ruined seals or
or and surroundings of the switch gear clean. other components.

340
 Maintenance 325

ANSWERS TO QUESTIONS IN LESSON 3 Answers to questions on page 278.

18 23K A properly adjusted horizontal belt has a slight bow
Answers to questions ,n page 272 in the slack side when running. When idle. it has an
18 23A A cross-connection is a connection between two alive springiness when thumped with the hand.
piping systems where an undesirable water (water Vertical belts should have a springiness when
from water seal) could enter a domestic water thumped. To check for proper alignment, place a
supply. straight edge against the puller face or faces. If a
ruler won't work, use a transit for long runs. or the
18 23B Yes. A slight leakage is desirable when the pumps
belt may be examined for wear.
are running to keep the packing cool and in good
condition. 18 23L Always replace sprockets when replacing a chain
because old. out-of-pitch sprockets cause as much
18 23C To measure the capacity of a pump. measure the chain wear in a few hours as years of normal
volume pumped during a specific time period
operation
Volume. gallons
.rapacity. GPM
Time, minutes
Answers to questions on page 280
or 18 23M Improper original installation of equipment. settling
liters Volume. liters of foundations, heavy floor loadings, warping of
Capacity. bases, and excessive bearing wear could cause
sec Time. sec
couplings to become out of alignment.
18 23D Volume. gallons
Capacity. GPM 18 23N Shear pins are designed to fail if a sudden overload
Time, minutes occurs that could damage expensive equipment.
(10 ft) (15 ft) (1 7 ft) (7 5 gal/cu ft)
5 minutes
Answers to questions on page 283.
382 5 GPM
18 24A Pumps must be lubricated in accordance with man-
or ufacturer's recommendations Quality lubricants
liters Volume. liters should be used.
Capacity
sec Time. sec 18 24B In lubricating motors. too much grease may cause
(3 m) (5 m) (0 5 m) (1000 L/cu m) bearing trouble or damage the winding
(5 minutes) (60 sec/min)
25 liters/sec Answers to questions on page 283.
18.24C If a pump will not start. check for blown fuses or
18 23E Before a prolonged shutdown. the pump should be tripped circuit breakers and the cause. Also check
drained to prevent damage from corrosion. sedi- for a loose connection, fuse, or thermal unit.
mentation. and freezing Also. the motor disconnect
18 24D To increase the rate of discharge from a pump, you
switch should be opened to disconnect motor
should loo!. for something causing the reduced rate
of discharge. such as pumping air, motor malfunc-
Answers to questions on page 274 tion. plugged lines or valves, impeller problems. or
other factors.
18 23F Shear pins commonly fail in ieciprocating pumps
because of (1) a solid object lodged under piston.
(2) a clogged disc' urge line, or (3) a stuck or Answers to questions on page 284.
wedged valve
18 24E If a pump that has been locked or tagged out for
18 23G A noise may develop when pumping thin sludge maintenance or repairs is started. an operator
due to water hammer. but will disappear when working on the pump could be seriously injured and
heavy sludge is pumped. also equipment could be damaged.
18 23H Higher than normal discharge pressures in a pro- 18 24F Normally a centrifugal pump should be tarted after
gressive cavity pump may indicate a line blockage the discharge valve is o,.ened. Exceptions are
or a closed valve downstream treatment processes or piping systems with vacu-
ums or pressures that cannot be dropped or al-
lowed to fluctuate greatly while an alternate pump
Answers to questions on page 274
is put on the line. If the pump is not equipped with a
18.231 When checking an electric motor, the following check valve and the discharge pressure is higher
items should be checked periodically, as well as than the suction pressure under static conditions.
when trouble develops: the pump could run backwards and cause damage
1. Motor condition, to the equipment.
2. Note all unusual conditions.
3. Lubricate bearings, Answers to questions on page 286.
4. Listen to motor, and
5. Check temperature. 18 24G Before stopping an ope ating pump:
18.23J The purpose of a stethoscope is to magnify sounds 1 Start another pump (if appropriate): and
and carry them to the ear. This instrument is used 2 Inspect the operating pump by looking for devel-
to detect unusual sounds in electric motors such as oping problems. required adjustments. and
whines, gratings, or uneven noises. problem conditions of the unit.
34.1
 326 Water Treatment

18 24:1 A pump shaft or motor will spin backwards if water 3 Aid in pump operation as a dampener, and
being pumped flows back through the pump when 4 Ensure "full pipe" operation.
the pump is shut off. This will occur if there is a
faulty check valve or foot valve in the system. 18 26E The most common maintenance required by gate
valves is oiling, tightening, or replacing the stem
18.241 The position of all valves should be checked before stuffing box packing.
starting a pump to ensure that the water being
pumped will go where intendcd.
ANSWERS TO QUESTIONS IN LESSON 5
Answers to questions on page 286.
Answers to questions on page 308.
18 24J The most important rule regarding the operation of 18.30A Gasoline engines may be used in water treatment
positive displacement pumps is to NEVER start the plants to drive pumps, generators, tractors, and
pump against a closed discharge valve. vehicles
18.24K If a positive displacement pump is started against a
18.JOB If a gasoline engine will not start. check the follow-
closed discharge valve, the pipe, valve or pump ing items:
could rupture from excessive pressure. The rupture
will damage equipment and possibly seriously in- 1 No fuel in tank, valve closed.
jure or kill someone standing nearby. 2 Thrburetor not choked,
3 Water or dirt in fuel lines of carburetor,
18 24L Both ends of a sludge line should never be closed 4. Carburetor flooded,
tight because gas from decomposition can build up 5. Low compression,
and rupture pipes or valves. 6 Loose spark plug, and
7. No spark at plug.
ANSWE" TO QUESTIONS IN LESSON 4 18 30C A gasoline engine may not run properly due to:
1 Engine miss.,19,
Answers to questions on page 289. 2. Engine surging,
18 25A Compressors are used with water ejectors, pump 3. Engine stopping.
control systems (bubblers), valve operators, and 4. Engine overheating,
water pressure systems. Also they are used to 5. Engine knocking, and
operate portable pneumatic tools such as jack 6. Engine backfiring through carburetor.
hammers, compactors, air drills, sand blasters,
tapping machines, and air pumps. Answers to questions on page 309.
18 25B The frequency of cleaning a suctic i filter on a 18.30D If a gasoline engine will not start and the spark olug
compress depends on the use of a compressor is wet with oil or fuel, this could indicate that the
and the atmL,sphere around it. The filter should be cylinder is flooded with fuel by having the choke on
inspected at least monthly and cleaned or replaced too long.
every three to six months. More frequent inspec-
18 30E If a gasoline engine will not start and there is an oil
tion, cleaning and replacement are required under
dusty conditions such as operating a jack hammer residue on the spark plug, this could indicate worn
on a street. piston rings.
18 25C Compressor oil should be changed at least every 18 30F After an engine has started, give it an opportunity to
three months, unless manufacturer states different- warm up before applying the load.
ly. If there are filters .n the oil system, these also
should be changed. Answers to questions on page 315.
18.25D Drain the condensate from the air receiver daily. 18 31A Gasoline is not used as a fuel in diesel engines
because it would start to burn from the heat gener-
18 25E Before testing belt tension on a compressor with ated by compression before the piston reaches the
your hands, MAKE SURE COMPRESSOR !S top of the stroke.
LOCKED OFF.
18.31B The four basic parts of a diesel fuel system are:
Answers to questions on page 305. 1. Primary fuel filter,
18.26A Valves are the controlling devices placed in piping 2. Secondary fuel filte
systems to stop, regulate, check, divert, or other- 3. Fuel injection pump, and
wise modify the flow of liquids or gases. 4. Fuel injector.
18.26e Six common types of valves found in water treat- 18 31C The purpose of the fuel injection pun d is to deliver
ient facilities include gate valves, globe valves, fuel to the injector at a very high pressure.
eccentnc valves, butterfly valves, check valves and 18.32A Heat is removed from tie cylinders by a water
plug valves. cooling system. Each cylinder is surrounded with a
18.26C The purpose of the check valve is to allow water to water jacket through which the coolant (water)
flow in one direction only. circulates and pulls heat from the cylinder. This is
accomplished by a water pump that is belt-driven
18.26D Backflow prevention by check valves is essential in from the crankshaft.
many applications to:
1. Prevent pumps from reversing when power is Answers to questions on page 316.
removed, 18.33A The storage and use of fuels for internal combus-
2. Protect water systems from being cross-con- tion engines ;lust be in accordance with building
.iected, and fire marshal codes.
 Maintenance 327

18.33B Four types of fuels commonly used by internal Answers to questions on page 321
combustion engines include (1) diesel, (2) gasoline, 18.5A Tanks and reservoirs should be drained and inspect-
(3) liquified petroleum gas (LPG), and (4) natural ed at least once every five years if the interior is well
gas. protected; more often if it is not well protected.
18.34A Standby internal combustion engines not in regular 18.5B The groundwater level should be below the bottom of
service should be started up and test run at least a tank before it is drained so the tank will not float on
once a week. the groundwater when empty or develop cracks from
18.34B Standby engines should be test run long enough fcr groundwater pressure.
the engine to come up to its normal operating 18.5C Cathodic protection is an alternative to applying a
temperature. If at all possible, the engine should be protective coating to prevent corrosion of a steel
run under its normal load tank.
Answers to questions on page 321.
18.4A Information on how to operate, control and maintain
chemical feeders may be found in the feeder manu- Answers to questions on page 322.
facturer's literature.
18.6A A building maintenance program will keep the build-
18.4B The three common types of chemical feeders are (1) ing in good shape and includes painting when neces-
solid feeders, (2) liquid feeders, and (3) gas feeders. sary. Attention also must be given to electrical sys-
18.4C Chlonne is toxic to humans and will cause corrosion tems, plumbing, heating, cooling, ventilating, floors,
damage to equipment windows, and roofs. The building should he kept
18.4D Large chlorine leaks can be detected by smell. Small clean, tools should be stored in their proper place,
leaks are detected by soaking a cloth with ammonia and essential storage should be available.
water and holding the cloth near areas where leaks 18.6B Factors that influence the type of building mainte-
might develop. A white cloud will indicate the pres- nance program needed by a water treatment plant
ence of a leak. include the age, type and use of each building.

OBJECTIVE TEST
Chapter 18. MAINTENANCE

Plerse mark correct answers on the answer sheet as 5. If a pump is going to be shut down for a long period of
directed at the end of Chapter 1. There may be more than time. the pump should be drained.
one correct answer to the multiple choice questions. 1. True
2. False
TRUE-FALSE
1. An Equipment Service Card is another name for a 6. An empty clear well drained for inspection purposes
Service Record Card. could f at up out of the ground when the groundwater
1. True level is high.
2. False 1. True
2. False
2. Building maintenace is NOT part of a treatment plant
operator's duties. 7 All gate valves have non-rising valve stems.
1. True 1. True
2. False 2. False

3. A treatment plant library should contain copies of the 8 The most practical form of emergency lighting is that
plant's drawings and specifications. provided by standby power generators.
1. True 1. True
2. False 2. False

4. Pumps in water treatment plants are driven only by 9 Standby power generators should be operated once a
electric motors. week at full load.
1. True 1. True
2. False 2. False

343
 328 Water Treatment

10 Diesel engines can use gasoline for fuel. 20. Equipment name plate data must be recorded and filed
1. True because the
2. False 1 Filing caoinet is supposed to have this information.
2 Information is needed to order replacement parts.
11 Diesel engines se spark plugs 3 Manufacturer doesn't keep the information on older
1. True models.
2 False 4 Name plate could become corroded.
5. Name plate could get lost
12. A qualified electrician should perform most of the nec-
essary maintenance and repair of electrical equipment 21 Compressor maintenance includes
1. True 1. Cleaning cylinder or casing fins weekly.
2. False 2 Examining the oil reservoir dipstick or sight glass.
3. Inspecting the suction filter of the compressor regu-
13. When a pump is not snut off. locked out, and tagged larly
properly. a plant operator could be maintaining a pump, 4 Keeping the belts as tight as possible
the pump could start. and the operator could lose a 5 Washing off the compressor weekly.
finger.
1. True 22 What is the purpose of an equipment preventive mainte-
2 False nance program?
1 To extend equipment life.
14 Most electrical equipment does not indicate the proper 2 To insure proper and efficient operation of the equip-
voltage on the name plate ment.
1 True 3. To keep operators looking at equipment.
2. False 4. To protect the public's investment spent buying the
equipment.
15. Closing an electrical circuit is like closing a valve on a
5. To provide jobs for operators when they visit a
facility.
water pipe.
1. True 23 When belts are used to drive equipment, important
2. False considerations include
1. Belt dressing should be used monthly for pliability of
belts
2 Belts must be matched sets
3. Guaros are required on all belt drives that are ex-
posed.
MULTIPLE CHOICE 4. Noise or squeal on startup can be corrected by
proper tension
16 Which of the following items are parts of an electric 5. Proper number of belts.
motor?
1. Impeller 24 Some of the advantages of mechanical seals over
2. Rotor packing Include
3. Stator 1. Continual adjusting, cleaning, oi repacking is not
4 Volute required.
5. Windings 2. Lower initial cost.
3 Pump does not have to be dismantled for repair.
17 Centrifugal pump parts include 4 They last longer, thus resulting in labor savings.
1. Diaphragm, 5. Usually there isn't any Jamage to shaft sleeve when
2. Impeller they need replacing.
3. Piston
4. Rotor. 25 Wnat information must be on a warning tag attached to
a locked out switch?
5. Volute.
1. Directions for removing tag
18. Wearing rings are installed in a pump to 2. Name of company that printed tag
3 Name of equipment
1. Hold the shaft in position.
2. Keep the impeller in place. 4. Signature of person who locked out switch and who
3. Plug internal water leakage. is only person authorized to remove tag
5. Time to unlock switch
4. Wear instead of impeller.
5. Wear out the sleeves.
26 Operators should not do actual electrical repairs or
troubleshooting because
19. What could be the cause of a pump's electric motor not
starting? 1. Costly damage can be done to equipment by unauth-
onzed persons.
1. Fuse or circuit breaker out 2. It is too dangerous.
2. Incorrect power supply 3. Many are not adequately trained
3. No power supply 4. They realize their own limitations regarding electrical
4. Pump not hooked to motor work.
5. Rotating parts of motor may be jammed mechanically 5. This is a highly specialized field.
 Maintenance 329

27. If a pump will not start, check for 35. The ignition system for a gasoline engine consists of the
1. Loose terminal connections 1 Battery
2. Nuts, bolts, scrap iron, wood, or plastic in the wrong 2. Coil.
places 3. Distributor
3. Shaft binding or sticking 4. Filter
4. Tripped circuit breake*s. 5. Thermostat.
5. Water in the wet well.
36. If a compressor fails to operate or provide rated capac-
28. How can a chlorine leak be detected? ity. what could be the cause of the problem?
1. By an explosiometer 1 Air cleaner, cap and/or screen clogged
2. By checking the rotamater 2 Air used by compressor is polluted
3. By waving an ammonia-soaked rag 3. Engine fails to develop proper RPMs
4. Green or reddish deposits on metal 4. Faulty oil seal
5. Smell 5. Pressure regulator improperly adjusted

29 What can heppen if you DO NOT penodicalty drain and 37. Maintenance of automatic valves includes
inspect plant tanks and channels? 1 Adjusting the check valve.
1. An emergency situation may develop during a period 2 Cleaning any strainers in the pilot control system.
of high demand. 3. Determining if controls are properly positioning
2. Costly repairs could result. valve.
3. Serious maintenance problems could develop. If valve is inactive, manually exercise valve from tight
4. The operator will not know if cracks are developing in shut tc, wide open position.
underground tanks and channels. 5 Reversing the flow through the valve.
5. The operator will stay out of trouble.
38 Problems that may be encountered when storing gaso-
line include
30 Pump maintenance includes
1. Deterioration of gasoline stored for a long time.
1. Checking operating temperature of bearings.
2 Easy starting of engines.
2. Checking packing gland. 3 Gasoline leaking into an underground water supply.
3. Lubricating the impeller. 4 Lack of gummy deposits on parts of the fuel system.
4. Operating two or more pumps of the same Size 5 Water leaking into the gasoline storage tank.
alternately to equalize wear.
5. Preventing all water seal leaks around packing 39. Steel tanks may be protected from rusting by
glands
1. Alternately wetting and drying walls.
Preventive ma,nteilance of electric motors includes 2. Cathodic protection.
31
3 Maintaining humidity in tank
1. Checking temperature of motor. 4 Protective coatings.
2. Frequently starting and stopping the motor to give it 5 Washing tank walls.
a rest.
3. Keeping motor free from dust, dirt and moisture. 40 Equipment service cards and service record cards
4. Keeping motor outdoors where it can stay cool. should
5. Lubricate bearings. 1. Identify the piece of equipment that the record card
represents.
32. Maintenance of gate valve includes 2. Indicate the work done.
1. Lubricating bearing. 3 Indicate the work to be dore.
2. Lubricating with Prussian Blue. 4 Maintain selective service records.
3. Operating inactive valves to prevent sticking. 5 Record sick leave.
4. Refacing leaky valve seats.
5. Tightening or replacing the stem stuffing box pack- 41 Estimate the pumping capacity of a pump in gallons per
ing. minute if 11 minutes are required for the water level in a
tank to drop 3 feet. The tank is 6 feet in diameter.
33 Proper selection of an emergency lighting unit for a 1 8 GPM
particular location requires careful consideration of 2. 10 GPM
which of the following items? 3. 36 GPM
1. Costs 4 58 GPM
2. Lighting requirements 5. 74 GPM
3. Nearness of vendor to repair failures 42 Calculate the feed rate of a dry chemical feeder in
4. Necessary switch gear pounds per day if two pounds of chemical are caught in
5. Types of batteries a weighing tin during nine minutes.
34. Possible causes of a gasoline engine not starting in- 1. 320 lbs/day
clude 2. 2394 lbs/day
3. 2670 lbs/day
1. Carburetor choked. 4. 2680 lbs/day
2. Carburetor floodeo. 5. 3200 lbs/day
3. Loose spark plugs.
4. Spars at plug.
5. Water in fuel lines of carburetor. eget of 01*e/rive 1724it
35i
 CHAPTER 19

INSTRUMENTATION

by

Leonard Ainsworth
332 Water Treatment

TABLE OF CONTENTS
Chapter 19 Instrumentation

Page
OBJECTIVES . 334
GLOSSARY ...... 335
SYMBOLS .
339

LESSON 1

19.0 Importance and Nature of Measurement and Control Systems 342

19.00 Need for Understanding Measurement and Control Systems . . . .. 342
19.01 Importance to Waterworks Operator. 342
19.02 Purpose and Naw..: 'f the Measurement Process 342
19 03 Explanation of Control Systems 343
19.1 Safety Hazards of Instrumentation Work .... .. . ........... 345
19.10 Be Careful 345
19 11 Electrical Hazards .. 345
19 12 Mechanical Hazards .. 347
19 13 Vaults and Other Confined Spaces . ................. . .... 348
19 14 Falls 348
19.2 Measured Variables and Types of Sensors/Transmitters . 348
19.20 How Variables are Measured 348
19 21 Pressure 349
19 22 Level . .. 349
19.23 Flow (Rate of Flow and Total Flow) . . 356
19.24 Chemical Feed Rate ... . . 360
19.25 Process Instrumentation ... . 360
19.26 Signal Transmitters/Transducers 360

35j
 Instrumentation 333

LESSON 2

19.3 Categories of Instrumentation . . . ..... . . .. 363

19.30 Measuring Elements. . ..... . 363

19.31 Panel Instruments . 363

19 310 Indicators .. . .. 363

19 311 Indicators/Recorders . . . . 363

19 312 Recorders . 364

19 313 Totalizers 367

19 314 Alarms 367

19.32 Automatic Controller ... . . 368

19.33 Pump Controllers 368

19.34 Telemeteriig Links (Phone Lines) 369

19 35 Air Supply Systems 371

19 36 Laboratory Instruments . . . . .. . 374

19.37 Test and Calibration Equipment ....... . ... ..... 374
19.4 Operation and Preventive Maintenance .. 375

19.40 Proper Care of Instruments . 375

19 41 Indications of Proper Function . .. .. . .. ....... .. ........... . 375

19.42 Startup/Shutdown Considerations 378

19 43 Maintenance Procedures and Records . . ... .. .... .................. ... .. ............ 379
19.44 Operational Checks 379

19.45 Preventive Maintenance ..... .. .... ....... .. ... 379

19.5 Additional Reading . . .. .. ..... . . ... ............ ... . . .. . ....... .... 380

Suggested Answers . 381

Objective Test . 383

:3 1 , '',
334 Water Treatment

OBJECTIVES
Chapter 19. INSTRUMENTATION

Following completion of Ci,apter 19, you should be able

to:
1 Explain the purpose and nature of measurement and
control systems,
2. Identify, avoid and correct safety hazards associated with
instrumentation work,
3. Recognize various types of sensors and transducers,
4, Operate and maintain measurement and control instru-
ments,
5. Read instruments and make proper adjustments in oper-
ation of waterworks facilities, and
6. Determine location and cause of measurement and con-
trol system failures and take corrective action.

.1
 Instrumentation 335

GLOSSARY
Chapter 19. INSTRUMENTATION

ACCURACY ACCURACY
How closely an instrument measures the true or actual value of the process variable being measure or sensed.

ALARM CONTACT ALARM CONTACT

A switch that operates when some pre-set low, high or abnormal condition exists.

ANALOG ANALOG
The readout of an rnstrument by a pointer (or other indicating meansl against a dial or scale.

ANALYZER ANALYZER
A device which conducts periodic or continuous measurements of some factor such as chlorine, fluoride or turbid.ty. Analyzers
operate by any of several methods including photocells, conductivity or complex instrumentation.

CALIBRATION CALIBRATION
A procedure which checks or adjusts an instrument's accuracy by comparison with a standard of reference

CONTACTOR CONTACTOR
An electrical switch, usually magnetically operated.

CONTROL LOOP CONTROL LOOP

The path through the control system between the sensor, which measures a process variable, and the controller, which con-
trols or adjusts the process variable.

CONTROL SYSTEM CONTROL SYSTEM

A system which senses and controls its own operation on a close, continuous basis in what is called proportional (or
modulating) control.

CONTROLLER CONTROLLER
A device which controls the starting, stopping, or operation of a device or piece of equipment.

DESICCANT 'OESS-uh-kant) DESICCANT

A drying agent which is capable of removing or absorbing moisture from the atmosphere in a small enclosure

DEPACCATIO:. {DESS-uh-KAY -shun) DESICCATION

A process used to thoroughly dry air; to remove virtually all moisture from air.

DETECTION LAG DETECTION LAG

The time period between the moment a change is made and the moment when such a change is finally sensed by the associat-
ed measuring instrument.

DIGITAL READOUT DIGITAL READOUT

The ust, of numbers to indicate the value or measurement of a variable. The read',ut of an instrument by a direct, numerical
reading of the measured value.

EFFECTIVE RANGE EFFECTIVE RANGE

That portion of the design range (usually upper 90 percent) in which an instrument has acceptable accuracy. Also see RANGE
and SPAN.
336 Water Treatment

FEEDBACK FEEDBACK
The circulating action between a sensor mesuring a process variable and the controller which controls or adjusts the process
variable

HERTZ (HURTS) HERTZ

The number of complete electromagnetic cycles or waves in one second of an electrical or electronic circuit Also called the fre-
quency of the current Abbreviated Hz.

INTEGRATOn INTEGRATOR
A device or meter that continuously measures rAna calculates (adds) total flows in gallons, million gallons, cubic feet, or some
other unit of volume measurement. Also called a TOTALIZER.

INTERLOCK INTERLOCK
An electrical switch, usually magnetically operated Used to interrupt all (local) power to a panel or device when the door is
opened or the circuit is exposed tc service.

LEVEL CONTROL LEVEL CONTROL

A float device (or pressure switch) which sense: changes in a measured variable and opens or closes a switch in response to
that change In its simplest form, this control might be a floating ball connected mechanically to a switch or valve such as is
used to stop water flow into a toilet when the tank is full.

LINEARITY (LYNN-ee-AIR-it-ee) LINEARITY

How closely an instrument measu actual values of a variable through its effective range, a measure used to determine the
accuracy of an instrument.

MEASURED VARIABLE MEASURED VARIABLE

A characteristic or component part that is sensed and quantified (reduced to a reading of some kind) by a primary element or
sensor.

OFFSET (or DROOP) OFFSET

The difference between the actual value and the desired value (or set point), characteristic of proportional controllers that do
not incorporate reset action.

PRECISION PRECISION
Tne ability of an instri.ment to measure a process variable and to repeatedly obtain the same result. The ability of an instrument
to reproduce the same results

PRESSURE ',. PRESSURE CONTROL

A switch which operates on changes in pressure Usually this ,s a diaphragm pressing against a spring. When the force on the
diaphragm overcomes the spring pressure, the switch is actuated (activated).

PRIMARY ELEMENT PRIMARY ELEMENT

The hydraulic structure used to measure flows. In open channels weirs and flumes are primary elements or devices. Venturi
meters and orifice plates are the primary elements in pipes or pressure conduits.

PROCESS VARIABLE PROCESS VARIABLE

A physical cr chemical quantity which is usually measured and controlled in the operation of a water treatment plant or industri-
al plant.

RANGE RANGE
The spread from minimum to maximum values that an instrument is designed to measure. Also see EFFECTIVE RANGE and
SPAN.

RECEIVER RECEIVER
A device which indicates the value of a measurement Most receivers in the water utility field use Oher a fixed scale and mov-
able indicator (pointer) such as a pressure gage or a moving chart with movable pen such as on a circular-flow recording chart.
Also called an INDICATOR.

RECORDER RECORDER
A device that creates a permanent record, on a paper chart or magnetic tape, of the changes of some measured variable.
 Instrumentation 337

REFERENCE REFERENCE
A physical or chemical quantity whose value is known exactly, and thus is used to calibrate or standardize instruments

ROTAMETER (RODE-uh-ME-ter) ROTAMETER

A device used to measure the flow rate of gases and liquids. The gas or liquid being measured flows vertically up a tapered
calibrated tube. li.side the tube is a small ball or a bullet-shaped float (it may rotate) that rises or falls depending on the flow rate
The flow rate may be read on a scale behind or on the tube by looking at the middle of the ball or at the widest part or top of the
float.

SENSOR SENSOR
An instrument that measures (senses) a physical condition or variable of interest Floats and thermocouples are examples of
sensors.

SET POINT SET POINT

The position at which the control or controller is set This is the same as the desired value of the process variable

SOFTWARE PROGRAMS SOFTWARE PROGRAMS

Computer programs. the list of instructions that tell a computer how to perform a given task Some software programs are de-
signed and written i,, monitor and control distribution systems and water treatment processes

SOLENOID (S0-1u-noid) SOLENOID

A magnetically (electrical coil) operated mechanical device. Solenoids 1, an operate pilot valves or electrical switches

SPAN SPAN
The scale or range of values an instrument is designed to measure. Also see RANGE.

STANDARD STANDARD
A physical or chemical quantity whose value is known exactly, and is used to calibrate or standardize instruments Also see
REFERENCE

STANDARDIZE STANDARDIZE
To compare with a standard. (1) In wet chemistry, to find out the exact strength of a solution by comparing with a standard of
known strength. This information is used to adjust the strength by adding more water or more of the substance dissolved (2) To
set up an instrument or device to read a standard. This allows you to adjust the instrument so that it reads accurately, or en-
ables you to apply a correction factor to the readings.

STARTERS STARTERS
Devices used to start up motors. Special motor starters gradually start large mo+rNrs to avoid severe mechanical shock to a driv-
en machine and to prevent disturbance to the electrical lines (causing dimming and flickering of lights)

TELEMETRY (tel-LEM-uh-tree) TELEMETRY

The electrical link between the transmitter and the receiver Telephone lines are commonly used to serve as the electrical link

THERMOCOUPLE THERMOCOUPLE
A heat-sensing device made o: two conductors of different metals joined at their ends A thermoelectrical current is produced
when there is a difference in temperature between the ends.

TIME LAG TIME LAG

The time required fog processes and control systems to respond to a signal or to reach a desired level

TIMER TIMER
A device for automatically starting or stopping a machine or other device at a given time

TOTALIZER TOTALIZER
A device or meter that continuously measures and calculates (adds) total flows in gallons, million gallons, cut ic feet or some
other unit of volume measurement. Also called an INTEGRATOR.

TRANSDUCER (trans-DUE-sir) TRANSDUCER

A device which senses some varying condition and converts it to an electrical or other signal for transmission to some other de-
vice (a receiver) for processing or decision making.

35:3
338 Water Treatment

TURN-DOWN RATIO
TURN-DOWN RATIO
The ratio of the design range to the range of acceptable accuracy or precision of an instrument. Also see EFFECTIVE RANGE.

VARIABLE, MEASURED
VARIABLE, MEASURED
A factor (flow, temperature) that is sensed and quantified (reduced to a reading of some kind) by a primary element
or sensor.
VARIABLE, PROCESS
VARIABLE, PROCESS
A physical or chemical quantity which is usually measured and cc ntrolled in the operation of a water treatment plant
dustrial plant. or an in-

17E6AieicAwkAtMttift
 Instrumentation 339

SYMBOLS
Chapter 19. INSTRUMENTATION

Special symbols are used for simplicity and clarity on M Motor.

circuit drawings for instruments. Usually instrument manu- Middle, as in a mid-level switch.
facturers and design engineers provide lists of symbols they P Pressure (or vacuum).
use with an explanation of the meaning of each symbol. This Pump.
section contains a list of typical instrumentation abbrevia- Program, as in a software program.
tions and symbols used in this chapter and also used by the O Quantity, such as a totalized volume (1 for summation
waterworks profession. is also used).
R Recorder (or printer), such as a chart recorder.
ABBREVIATIONS Receiver.
A Analyzer, such as used to measure a water quality Relay.
indicator (pH, temperature). S Switch.
C Controller, such as a device used to start, operate or Speed, such as an increase in the RPM (revolutions
stop a pump. per minute) of a motor.
D Differential, such as a "differential pressure" or D. P. Starter, such as a motor starter.
cell used with a flow meter. Solenoid.
E Electrical or Voltage. T Transmitter
Element, such as a primary element. Temperature.
Tone.
F Flow rate (NOT tot,! flow).
Valve.
H Hand (manual operation). Voltage.
High as in hi-level.
W Weirpt.
I Indicator, such as the indicator on a flow recording Watt.
chart.
I = E/R where I is the electrical current in amps. X Special or unclassiffod variable.
L Level, such as the level of water in a tank. Y Computing function, such as a square-root ( v)
Low, as in a lo-level switch. extraction.
Light, as in indicator light. Z Position, such as a percent valve opening.

TYPICAL SYMBOLS

1. Pressure transmitter #1

2. Level indicator-recorder #2

3. akinitill Flow indicator-controller #3 with

1.11WW hi-low control switches

 340 Water Treatment

4.

Flow rate computer

Flow recorder
and indicator-transmitter
4- 20 ma D.0 and totalizer
(loop W4)

5 Hz d valve #5 10. Relay #1

N.O.

II
R1-1 Contacts Normally Open

FE - 6
6
N.C.
Flow element (tube) #6

R1-2 Contacts Normally Closed

CV- 7
7. Electric control valve #7 Hi

Hi-level
Indicator light (red)

CV -8
8 Pneumatic control valve #8
12. Resistor

1/4J(.1 100 ohms

100 A.

Analyzer (pH) transmitter 480 V AC

9. (either at location 9 or the pH Transformer
13.
level is at 9) ;step-down)

36i
 Instrumentation 341

14. OFF Switch #1 (SPST)* 10A

---......../*-1.
S-1
19.
FUSES
10 amp cartridge
ON

1 amp line fuse

15.
S-2
---. Switch #2 (DPST)*
overload contacts

.-------
20A
20 amp circuit breaker

S-3
16. -----41/' Switch #3 (SPDT)*

20. L1 L2 (OR N)

Line 1 and Line 2

(neutral)
.....L.PB 1 with duplex outlet
Push button switches
17
.01) 110 #1 push tc rr3ke
PB-2 #2 push to creak
Lock-out stop safety 110V AC
L.O.S. felture

H
a
18. 21.
Hand switch

i
Electric motor, 3 phase
0 power 25 horsepower
Hand Off Automatic

SPST means Single Pole, SingleThrow

DPST means Double Pole, Single Throw
SPDT means Single Pole, Double Throw

. .
t,,,,
 342 Water Treatment

CHAPTER 19. INSTRUMENTATION

(Lesson 1 of 2 Lessons)

19.0 IMPORTANCE AND NATURE OF MEASUREMENT constantly and precisely manipulate valves, motors and
AND CONTROL SYSTEMS switches. In effect then, instrumentation provides you with a
staff of hard-working assistants, always on the job to help
19.00 Need for Understanding Measurement and Control you operate your plant and system easily. If you have failed
Systems to adequately appreciate the advantages of automation,
In this chapter, you will learn some basic concepts about consider the alternative methods of operating your plant. For
waterworks measurement instruments and their associated example, in the recent past, or for some older operations in
control systems. Since the water treatment plant operator existence today, the situation described in the following
frequently must monitor, and sometimes control, the distri- paragraph could have occurred.
bution system supplied from the plant, both in-plant and You have a complete and unrestorable power failure in the
field-type instrumentation will be discussed. You will be- circuit which supplies all of the instruments and control
come generally acquainted with the WHAT, HOW, and WHY systems in your conventional water filtration plant. As the
instrument systems measure, and how some measured operator you must try to keep the plant on-line manually by
quantities are controlled automatically. However, this chap- controlling influent and effluent flows, basin levels, pump
ter is not intended to teach you how to "fix" a malfunctioning operation, chemical feeders, and filter valves. You must do
instrument, though some general preventive maintenance all of this by watching and listening, and running to manipu-
steps are induced in the discussion. late valves, start and stop pumps, and reset chemical
Your understanding of the measurement and control bas- feeders. Even if you could do it (and some i ,;g!:t3 on shift it
ics presented here enhance the efficient and effective oper- seems like that IS what you have to do) for a small plant, you
ation of your plant and/or system. Specifically, if you can certainly couldn't exercise close control and do it for a long
recognize a meter as faulty (by the way the pointer acts, for time. If you are trying to operate a larger plant, continued
example), your treatment/distribution decisions will then be operation would be impossible without the instrumentation
based upon that knowledge rather than a blind-faith-in-the- systems functioning_ Accordingly, you would do well to
black-box attitude you might otherwise have to assume. familiarize yourself now with these "eyes, ears, and hands"
that are so esse.thal to your effective performance as a
professional waterworks operator.

19.02 Purpose and Nature of the Measurement Process

Instrument capabilities can greatly extend our range of
personal observations. They also have an additional and
quite important advantage over our senses in that instru-
ments providt. quantitative or measurable information,
wherea3 only qualitative information is available from our
senses. That is to say. instruments provide us with numbers;

Also. the operator who recognizes the general operating

principles of typical instrumentation systems is prepared to
perform not only routine preventive maintenance, but also to
take the minor corrective action sometimes really necessary
to keep the system operating. The operator who knows
enough to free a stuck pen, safely replace a fuse, or drain an
air line can avoid a lot of personal worry and the expense of
an electrician's service call while still protecting the oper-
ational integrity of the plant or system.

19.01 Importance to Waterworks Operator

In a real sense, measurement instruments can be consid-
ered extensions of your human senses, comparable in many the direct senses can only tell us that an observation is
ways to your own wide-ranging and exact eyes and ears. "more than or "less than what the observation was the last
The associated automatic control systems, in turn, are like t!rne it was recently observed. Some very simple water
having extra sets of far-reaching and strong hands, to supply operations can and do get by with such imprecise
 Instrumentation 343

visual observations of a chemical process, rate of flow, or accuracy can be expected, usually from 10 to 90+ percent of
basin level. However, modern water facilities must operate its nominal (des,gn) range, though it is technically not the
"by the numbers" so to speak. and only instrumentation can same LINEARITY r girs to how closely the instrument
provide these numbers (Figure 19.1). measures actual value, of the variable through its effective
range, and thus bears upon its stated accuracy. An ANALOG
A measurement is. by definition. the comparison of the readout of an instrument has a pointer (or other indicating
quantity or PROCESS VARIABLE,' in question to an accept- means) reading against a dial or scale, a DIGITAL display
ed standard ulna of measure. Certain basic units of length, provides a direct, numerical reading.
volume, weiglit, and time have been agreed upon by interna-
tional convention to serve 3s "primary standards." All meas- QUESTIONS
urements of length (level, area, volume, capacity, weight,
pressure, and rate of flow encountered in waterworks prac- Write your answers in a notebook and then compare your
tice ultimately refer to these standards. Thus, the weight of a answers with those on page 381.
100-pound sack o; chemicals, for instance, amounts to 100
19.0A How can measurement instruments be considered
times that of the standard pound; or, the capacity of a tank
an extension of your human senses?
could be 1000 times larger than the standard gallon. Some
important terms often encountered in measurement practice 19.08 What water treatment processes and equipment
will be discussed in '.he following paragraphs. could be monitored or controlled by measurement
and control systems?
ACCURACY refers to how closely an instrument deter-
mines the true or actual value of the process variable being 19.0C What is an advantage of instruments over our human
measured. Accuracy depends upon the PRFCISION, or senses?
general quality and condition of the instrument, as well as 19.0D What is an analog readout?
upon its CALIBRATION. An instrument is calibrated in order
to standardize its measurements. That is, the instrument 19.03 Explanation of Control Systems
itself is nade to measure the value of a standard unit or
referent,; and its indicator is adjusted a.:cordingly. STAN- The terms "controller" and "control sy terns"' are used in
DARDIZATION is a simple calibration procedure done regu- the waterworks field in two different senses. The electrical
larly (by the operator). Most instruments are accurate to panel which controls only the starting/stopping of an electric
about one or two parts in one hundred; this is expressed as motor is referred to as "controller." This controller may
±1 to 2 percent error (or at times 98 to 99 percent accuracy). control a pump's operation or a chemical feeder motor. The
The RANGE of an instri ment is the spread between the control exercised may be manual, through push-buttons or
minimum and the maximum value of the variable it is switches, or ac tomatic with a switch responding to alue of
designed to measure accurately. The EFFECTIVE RANGE is level, pressure, or other variable such as is usually the
that portion of its complete range within which acceptable case with a "Hans'- Off - Automatic' (H.O.A.) function switch.

Mum. fiir

11111111-",,

.1'144
r

Fig. 19.1 Main control panel of a modern water treatment plant

I Process Variable. A physical or chemical quantity which is usually measured dad controlled in the operation of a wa #9r treatment plant
or industrial plant
3 64
344 Water Treatment

This type of so-called controller is more correctly termed a vanabie making it more closely match the set-point. This
motor control station or panel, and will be discussed later. continuous "cut and try" process can result in very fine on-
The other, technically proper, usage of the terms controller going control of variables requiring constant values, such as
and control system identify a system which senses and some flow rates, pressures, levels, or chemical feeds The
controls its own operation on a dose, continuous basis, in term applied to this circulating action of the variable in such
what is called proportional (or modulating) control. This type a controller is FEEDBACK. The path .rough the control
of true controller will be discussed first (Figure 19.2). system is the CONTROL LOOP. The internal settings of 'he
in order for a process variable, whether pressure, level, true controller can be quite critical since close co,,,i of
w o fl DW, to he closely controlled, it must be measured c nds upon sensitive adjustments. Thus, you should not
precisely 2nd continuously. The measuring device sends a co dust any such control system unless you know
sigi131 (electrical or pneumatic, as discussed in a following exactly what you are doing. Many plant and system oper-
section) proportional to the value o; the variable, to the ations have been drastically upset due to such efforts,
actual controller. Within the controller, the signal is com- however well intentioned, of unqualified personnel.
pared to the -sired or set-point value (Figure 19.3). A Examples of the above proportional control of waterworks
differerce between the actual and desired values results in operations which may be encountered are: (1) chlorine
the controller sending out a command signal to the "con- residual analyzer/controller; (2) chemical feed; flow-paced
trolled element: usually a valve, pump, or feeder. Such an (open loop); (3) pressure- or flow-regulating valves; (4)
"error signal" produces an adjustment in the system that continuous level control of filter basins; and (5) variable-
causes a corresponding change in the original measured speed pumping systems for flow/level control.

FLOW
RECORDER/CONTROLLER

asiiaii
ni...
limmu I
&I..o.1.:..?= SET
FLOW mommoso POINT
TOTALIZER imilmININ
inimmosios
EIGEHMOS
/-Thk
PROCESS N
CONTROL
CONTROL SIGNAL
FEEDBACK))
((FEEDBACK)
FLOW L. _OOP

SIGNAL

VALVE
ACTUATOR
D.P.
CELL
PIPELINE
CONTROLLED 11111111111 WATER
FLOW "1"\ FLOW
I (VARIABLE)
gi D.P. TYPE
CONTROL
FLOW VALVE
METER (FINAL
(PRIMARY ELEMENT) :ELEMENT)
NOTE: ELECTRIC SYSTEM SHOWN MAY BE PNEUMATIC ALSO
* D.P. MEANS "DIFFERENTIAL PRESSURE"

Fig. 19.2 Automatic control system diagram, flow

(closed loop proportional)

3E'
 Instrumentation 345

such as a timer In other words, it must be turned on and off

as a result of a measurement of a level, pressure, flow,
1:!_OroacoNtral chemical concentration, or other variable which reaches a
erATION predetermined setting. In the automatic mode (A on the
H.O.A. switch) then, its operation is in fact automatic in the
sense that the vanable is controlled, even though the limits
of its value are quite wide compared to those attainable with
a true controller as previously described. Whereas a filter
basin level controller may allow only an inch or so of water
level change, an on-off system might operate within a few
feet of level difference. In many applications, however, such
wide control is of no particular disadvantage, and some-
times is even oesirable (such as with a distribution system
reservoir level). However, one problem with level controllers
The MOTOR CONTROL STATI_ ,Figures 19.4 and 19.5),
in some water treatment plants is that small changes in the
as mentioned, essentially provides only for on-off operation
of an electnc motor, which in turn powers a pump, valve, or water level over the filters will cause the effluent controller to
chemical feeder. Primarily it is a standard electric motor modulate suddenly. In cases of nsing levels the effluent
panel, with manual operation push-buttons, overload relays,
valve will open suddenly and turbid water from within the
filter may be discharged as treated water.
and function switch (H.O.A. or Hand-Off-Automatic). Addi-
tionally it may include, in good electrical design practice, Terms used in control practice can be now defined oper-
provisions for power failure or loss-of-phase ("fail-safe" ationally in this paragraph. FEEDBACK and CONTROL
circuitry), and such protective devices as high or low pres- LOOP have been mentioned previously, however, the term
sure/temperature/level cut-off switches. For this type of CONTROL LOOP needs qualification. An OPEN-LOOP con-
panel even to be considered a controller (within our second- trol system controls one variable on the basis of another. A
ary meaning of the term), its operation must be controlled by good example of this is a chlorinator "paced" by flow signals
the value or values of some variable, not merely by a device (rather than by the chlorine residual analyzer). C,LOSED-
LOOP control remains as discussed previously, the true
controller. PROPORTIONAL-BAND, RESET and DERIVA-
TIVE actions are adjustments of the controller that bear
*01114.1 upon effectiveness and speed of control action. OFFSET is
the difference between the desired value of the variable (the
SET-POINT) and the controlled (actual) value. DETECTION
LAG, common to chlorinator control systems, refers to the
prolonged period between the moment when a change in
control is effected and the moment when such change is
finally sensed by the associated measuring instrument

4
QUESTIONS
Write you answers in a notebook and then compare your
answers with those on page 381.

) 19.0E What does an on-off type "controller" control?

19.0F List three examples of "proportional control" in
waterworks operations.
,tfx?-k 19.0G What is the purpose of a motor control station?

19.1 SAFETY HAZARDS OF INSTRUMENTATION WORK

19.10 Be Careful
The general principles for safe performance on the job,
summed up as always avoiding unsafe acts and correcting
unsafe conditions, apply as much to instrumentation work
as to other plant operations. However, there are some
special dangers associated with instrument systems, mainly
electrical shock hazards, that merit special mention in this
section. Repetition is well justified for the sake of safe
practice!

19.11 Electrical Hazards

A hidden aspect of energized electrical equipment is that it
NOTE: Controller in photo is the lower instrument with s t "icoKs normal," that is, there are no obvious signs that tend
point at 10 MGD. to discourage one from touching. In fact, there seems to be a
peculiar fascination to "see if it's really live" by touching
Fig. 19.3 Photo of flow recorder/controller in Fig. 19.2 circuit components with a tool, often a screwdriver (usually
41 el, ,,
tj
346 Water Treatment

ELECTRICAL WIRE
MECHANICAL LINK ("GANGED")
A AMPERE: 100A (RATING)
DS DISCONNECT SWITCH SS 1111.

H OA HAND-OFF-AUTO: 00
HP/LP HIGH /LOW "ESSURE A SS

LOS LOCK-OUT STOP N

OFF
4
PB PUSH-BUTTON:
R RELAY: MAY R1 RELAY
COIL T FCT-1-a
CONTACTS
SW SWITCH: OPEN., rit---.. CLOSED
L1/ L2 LINE 1 (HOT) 2 (NEUTRAL)
VAC POWER 60 Hz 30 VOLTS AC ( 60 CYCLES, 3 PHASE )
CB CIRCUIT BREAKER (MAGNETIC)
MS MOTOR STARTER (CONTACTOR)
AUX AUXILIARY CONTACTS

L1 120 VAC 60 HZ 1 ,11 *HOLDING CONTACTS

START
(FROM CONTROL TRANS.) STOP RELAY
CONTROL
CIRCUIT DOOR INTER-
ON
Ii.
FUSE OFF
LOCK
SPACE HEATER R1-a "r OPERATING
TO
HOURS METER
4-1F111.11511L L2
C MS-AUX.
MOTOR ON
LITE

r-t
TEST
100A
LO.S
H2 H3
R1-b
H1
-FtA At
CONTACTS
MAIN
DISCONNECT OVERLOAD PROTECTION
s--.HEATERS
1* H la"
480 VAC TO L'. CONTROL MS1-A
POWER 60 HZ CIRCUIT
CIRCUIT L2 TRANS.
3> H2cin
I
100A
MS2-B
SERVICE
r. H3 Q.0

MS3-C

Fig. 19.4 Motor control panel

(simplified double-line schematic)

36y
 Instrumentation 347

Fig. 19.5 Photo of motor control panel

er you with molten metal or startle you into a bumped head

or elbow. or a bad fall. Again the adage, WHEN IN DOUBT
DON'T.
Usually the operator does not have the test equipment nor
the technical knowledge to correct an electrical malfunction,
other than possibly resetting a circuit breaker, regardless of
how critical the device's function is to plant operations.
Though the foregoing applies mainly to motor control cen-
ters, there also may be a shock hazard within measurement
insti ument cases and the sure destruction of expensive
components when the foolhardy "tool-touch-test" is used.
having an insulated handle. fortunately) but Pven with the Most oanels have an INTERLOCK on the door that inter-
finger Only training, coupled with bad expeneoce at times, rupts -'. (local) power to a panel or device when the door is
is effective in squelching this morbid cunosity Even so, most opened or the circuit is exposed for service Do not discon-
practicing electricians' tools have an "arc-mark trademark' nect or disable interlocks that interrupt all (local) power.
or two. evidence of the need for continuing self-discipline in Warning labels, insulating covers (over "hot" terminals),
this area Though such mention may conjure up humorous safety switches, lock-outs, and other safety provisions on
images of the maintenance person's surprise and "shock" electrical equipment must be used at all times. Your atten-
upon such an incident, one only need consider that electrical tion to this crucial aspect of your work place may save a life,
shock can and does regularly cause disfigurement and even and as the slogan goes. it could be your own!
death (by asphyxiation due to paralysis of the muscles used
in breathing and/or burning) to bring the problem into sober OUESTIONS
perspective. Also, the expense and effort caused by a
needless shorting-out of an electrical device could be signifi- Write your answers in a notebook and then compare your
cant. The point is, PSIST THE URGEto "test" any electrical answers with those on page 381
device with a tool or part of your body!
19.1A What are the general principles for safe performance
If there is ANY doubt in your mind that ALL sources of on the job9
voltage (not merely the local switch) have been switched off,
then DON'T TOUCH, except possibly with the , , obes of a 19 1B How can electrical shock cause death9
test meter Remember, you can't "see" even the highest 19 1C What could happen to you as a result of an electrical
voltage, and an unverified presumption of a dead circuit is "explosion9"
worthless and may be deadly
Do not simulate a known electrical action, for example 19.12 Mechanical Hazards
pressing down a relay armature, within an electrical panel
without a POSITIVE understanoing of the circuitry. Your There exists a special danger when working around
innocent action may cause an electrical "explosion" to show- powered mechanical equipment, such as electric motors,

3 :8
348 Water Treatment

valve operators, and chemical feeders which are operated an electrical shock of even minor intensity can result in a
remotely or by an automatic control system Directly state°. serious fall, a special mention herein is justified. When
the machinery may START or MOVE when you are not working above ground on a ladder, even though you position
expecting it! Most devices are powered by motors with it safely. use the proper non-conductive type (such as
enougn torque or RPM to severely injure anyone in contact fiberglass). are duly cautious on the way up, and comply with
with a moving part Even when the exposed rotating or all other considerations of safety, a slight shock can still ruin
meshing elements are fitted with "guards" in compliance with all your precautions! When required tr do preventive mainte-
safety regulations, a danger may exist A motor started nance from a ladder, turn off th3 power to the equipment if at
remotely may catch a shirt tail, finger, or tool hanging near a all possible If not feasible, take special care to stay out of
loose or poorly-fitted shaft guard contact with any component inside the enclosure of a
The sudden automatic operation of equipment, even if measuring or operating mechanism, and well away from
terminal strips, unconduited wiring ,and "black-boxes
half-expected. may startle one nearby into a fall or slip.
Though not commonly considered essential, the wearing of
Signs indicating that "This equipment may start at anytime"
tend to be ignored after a while Accordingly. you must stay
thin rubber or plastic gloves can reduce your chances of
electric shock markedly (whether on a ladder or off).
alert to the fact that any automatic device may begin to
operate at any time, even if by "off-chance You must stay Make provisions for carrying tools or other required
well clear of automatic equipment, especially when it is not objects on an electrician's belt rather than in your hands
operating. when climbing up or down ladders Finally, never leave tools
or any object on a step or platform of the ladder when you
Lock-out devices on electrical switches must be respect-
ed at all times. The electrician who inserts one to physically climb down. even temporarily. YOU might be the one upon
whom they fall if the ladder is moved or even steadied from
prevem the operation of an electrical circuit is, in effect,
below In this regard. it is always a good idea (even if not
trusting his life and health to the dnvice. Once the lock-out
required) for preventive maintenance personnel to wear a
device is attached to the switch (whether the switch is hard hat whenever working on or near equipment, especially
tagged-off or actually locked with lock and key), the electri-
when a ladder must be used
cian will consider the circuit de-energized and safe and will
feel free to work on it. Consider the potential consequences
then of an unauthorized operator who removes a lock-out to
place needed equipment back into service, presuming the
electrician is finished (as might occur after several hours'
work). The point cannot be overstressed:

RE4PECS ALL LOLL -OUT revic04

AMP ALA. TA&Cver, OFF ECLUIPMENT
AZ, WA LIFE 14 EtaRlic-frev-rb 96L1,
IT MAY WELL BE.

Operators often use power tools on instrumentation and

associated equipment. All power tools present not only a
shock hazard, waterworks being damp places at times, but a
mechanical hazard as well. The use of power tools in the
performance of instrumentation work, with its special na- QUESTIONS
ture. should wait until the operator can have an observer on
hand in case of an accident. Write your answers in a notebook and then compare your
answers with those on page 381.
19.13 Vaults and Other Confined Spaces
19.1D Why should operators be especially careful when
Included as part and parcel of measurement and control working around powered automatic mechanical
systems are those remotely installed sensors and control equipment'?
valves. Quite often these are founo in meter or valve vaults,
or other closed concrete structures. There are some special 19 1E What is the purpose of an electrical lock out device'?
precautions beyond those stated in Chapter 20, "Safety Be 19 1F Why should you brace yourself when operating pow-
sure the ventilation equipment is working properly before er equipment so that electrical current cannot flow
entering The use of power tools, including a soldering iron. from arm to arm in case of an ungrounded tool'?
can be even more dangerous in wet environments. NEVER
stand in water with a power tool. even when off. Brace 19 1G What kind of specific protective clothing items coup
yourself. if necessary, in such a way that electrical current be worn to protect you from electrical shock?
cannot flow from arm to arm in case of an ungrounded tool.
Shocks through the upper body involve your heart and/or
your head, whose importance to you is self-evident! 19.2 MEASURED VARIABLES AND TYPES OF
SENSORS/TRANSMITTERS
19.14 Falls
19.20 How Variables are Measured
All the general safety measures to guard the operator
against falls, a leading cause of lost-time accidents, are A measured variable is any quaiitity which is sensed and
covered in Chapter 20, "Safety," and need not be repeated in nudntilied (reduced to a reading of some kind) by a prima-y
this instrumentation chapter However, if one considers that element ur sensor. In waterworks practice pressure, level,

36
 Instrumentation 349

and flow are the most common .measured variables, some- by placing a small 0. 'flee in the pipe on the water side of the
times chemical feed rates and some -hysicai or -emical air cushion chamoer
water quality (7 ararleristics are also -sed
The sensor is often a transducer ame type, in that it QUESTIONS
converts energy of one kind into some ,ther form to produce Write your answers in a notebook and then compare your
a readout or signal. For example, one type of flow meter answers with those on page 381.
converts the hydraulic action of the wa, r into the mechani-
cal motions necessary to drive a meter indicator, and also 19.2A What is a sensor?
into an electrical signal for a remote readout device. If such a
signal is produced, be electric or j...leumatic, the sensor is
.
19.2B How is pressure measured?
then considered a transmitter. 19 2C Why are some pressure sensors fitted with surging
The signal produced is f-equently not a continuous one and overrange protection?
proportional to the variable (such as an analog signal), but
merely a switch which Is set to detect when the variable goes 19.22 Level
above or below pre-set limits. In this type of on-off contrcl,
the pre-determined settings are called control points. This Systems for sensing the level of water or any other liquid
distinction between continuous and set-point operation level, either continuously or single-point, are probably the
bears upon the two types of controllers discussed previous- most common sensors found in waterworks. Pumps are
ly. The remainder of this section discusses each of the controlled, filters operated, clear wells monitored basins
common variables sensed in waterworks practice. and tanks filled, chemicals fed and ordered, sumps emptied,
and distribution system reservoirs controlled on the basis of
19.21 Pressure liquid level. Fortunately, level sensors usually are simple
devices. A float, for example, is a reliable liquid ley,. I sensor.
Since pressure is defined as a force per unit of area Other types of level sensing devices include direct pressure,
(pound per square inch or kiloPascal), you might expect that pneumatic bubblers, sonar and capacitance probes. Single-
sensing pressure would entail the movement of some flexi- point detection of el is very common to levels controlled
ble element subjected to a force. In fact, that is how pressure by pumps and valve peration.
is always measured. Such pressure elements (a class of
primary elements) consists of strain gages and mechanically A float on the end of a cable (see Figure 19.10) is
deformable devices such as the Bourdon tube (Figures 19.6 frequently us,..d to continuously measure and/or to key
and 19 7), bellows, and diaphragm arrangements. The slight pump/valve operation at control points. For distribution
motion each exhibits, proportional to the applied force, is reservoir or local tank measurement only, the cable rides
then amplified mechanically by levers or gears to position a over a pulley on the lip of the tank, the other end terminating
pointer on a scale or to provide an input for an associated at a "target" which moves and reads against a vertical scale
transmitter. (NOTE: A "blind" transmitter, of any variable, has on the tank's side. These simple systems read out ba *-
no local indicator.) Again, the sensing of pressure can take wards (for example, high levels result in lower scale read-
place only at important points, such a; with pump control ings as shown in Figure 19.10), but are entirely satisfactory
systems. for many purposes. Though the action of the float can key
switches to signal high or low levels, no continuous trans-
There being many classes and brands of pressure sen- mission of level to a remote instrumert is commonly used
sors, it serves no purpose to elaborate further on specific with the simple float-cable system. Targets are often read
types. Some sensors are fitted with surging and overrange through binoculars when this system used on a remote
protection (dampeners) to limit the effect pressure spikes or distribution system reservoir.
water hammer have on the sensor. Most protection devices
function by restricting flow into the sensing element. Surge
protection equipment prevents sudden pressure urges
from overranging instrumentation which can easily -.image
many pressure sensors. One type of overrange protection
uses a mechanical device to prevent the pressure element
from exceeding its upper limit. The actual degree of proc:c-
tion necessary depends on the type and range of the sensor.
A second surge pi ut:Iction device is a snubber (Figui
19.8) which consists of a restrictor through which the
pressure producing fluid must flow. A simple restrictor is
made of a short section of capillary (very small) tubing fitted
into a plug in the pressure pipe to form an orifice. A more
elaborate mechanical snubber responds to surges by mov-
hg a piston or plunger that effectively controls the size of
the orif Some snubbers are subject to cloggii q or being
adjusted so tight as to prevent any response at au to Variations on tl:is scheme to measure liquid levels use
pressure changes. If a pressure sensor is not performing either a perforated steel tape riding on a toothed pulley or
properly, look first '.ar clogging or adjustment that is too fine cable riding over a grooved &I'm The cable transmits
tight. the level sensed as a signal (electrical) proportional to pulley
or drum rotation ( Figures 19.11a and 19 111")). Most of these
A third device is an air cushion chamber (Figure 19.9) devices use a counter-weight on the end of the tape/cable
which is simply constructed yet very effective. The top half c opposite the float to insure tautness. Also, all types of float-
the chamber contains air. "rater flows into the bottom half. A operated sensors work best with the float traveling within a
suUde lhange :1 water pressure compresses the air within long tube called a stilling well, which d_ ripens out unwanted
the chamber. The rate of response can easily be regulated liquid turbulence or waves.

3/0
350 Water Treatment

0,'
r,

BOURDON
TUBE

SPIRAL
-1 SPRING

CONNECTING
LINK

Slide

Inlet

An industrial pressure gage with a Bourdon pressure element

ODIAPH,,AGM °BELLOWS (DCAPSULE

°BOURDON TUBE 0 SPIRAL 0 HELIX

Elastic deformation elements. Pressure tends to expand or

unroll elements as shown by arrows.

Fig. 19.6 Bourdon tuba and other pressure sensing elements

(Permission of Hlise Gauge, Dresser Industries)

37j
 ME%

Instrumentation 351

111.11111-

..
5...' 4o,19 ....,
I"' , . . 1 47

NOTE: Capsule (round disk) below gage protects sensing

element from corrosion by chlorine gas.

Fig. 19.7 'hoto of a chlorine pressure gage

PRESSURE
INSTRUMENT

CAP

PLUNGER CORRECT
LIQUID LEVEL
I/4" PIPING

PRESSURE
BODY SNUBBER
AIR CUS.IION
CHAMBER
SHUT-OFF
VALVE
DRAIN VALVE

Fig. 19.8 Snubber arrangement for surge protection Fig. 19.9 Air cushion chamber for surge protection
 352 Water 1 reatment

used where a mechanical system is impractical, such as

within sealed or pressurized tanks, or with chemically active
liquids.
The probes are small-diameter stainless steel rods that
PULLEY
are inserted into a tank through a special fitting, usually
Al....... through the top but at times in the side of the vessel. Each
.-0--.. If rod is cut to length corresponding to specific liquid level in
0 the case of ti a top-entering probes; in the side-entering
1 setup, a snort rod merely enters the vessel at the appropri-
ate height or depth. One problem encountered with probes
WATER_ -- I
I --t
1

is the accumulation of scum or caking (by CaCO3) on the

/ ------
--
LEVEL
I 1
-, surface of the rods.
A small voltage is applied to the probe(s) by the system's
II
I
II
I
CABLE
GUIDES power supply, with current flowing only when the probe
"sees liquid," that is, becomes immersed. When current flow
-10-
I
is sensed, a switch activates a pump/valve control or
-- alarm(s) at as many control points as necessary. Though at
11

I
times only a single probe is used, with the metal tank
completing the circuit as a ground, usually at least two
-15- i
FLOAT probes are found the ground probe extending all the way
I
to the bottom of the tank so as to be in constant contact with
I the electrically-conducting liquid (a liquid ground as it were).
I
CABLE Levels can be sensed continuously by measurement of
-20-
I liquid pressure near the bottom of a vessel or basin. The
I pressure elements used for level sensing must be quite
TAR GET--------4-P- sensitive to the low pressures created by liquid level (23 feet
I I
(POINTER) 1 I STILLING of water column equals only 10 psi, or 7 meters of water
-25- I WELL column equals 7 kPa or 0.7 kg/sq cm). Therefore, simple
I
I (OPTIONAL) pressure gages such as are found on pumps are not used to
measure water levels. Water level sensors are used to
measure levels of water in systems on filter basins, or in
I I N\ chemical storage tanks where control or monitoring must be
LEVEL -30- I I close, continuous, and positive. Rather than being calibrated
SCALE I
1

I
I
I
1 ) in units of pressure (psi), these gages read directly in units of
liquid level (feet). Single-point control/alarm contacts can be
made a part of this, or any continuous type of level sensor.
( :. :: :- A very precise method of measuring liquid level is the
bubbler tube, w,th its associated pneumatic instrumentation
NOTE. As !quo level drops, float falls and pointer (target) (Figure 19.12). Tne pressure creatt...1 by the liquid level is
rises and vice versa. Therefore, pointer indicates sensed, but not directly as with a mechanical pressure
dept., of water in tank "backwards." element. Air pressure is created in a bubbler tube to just
match the pressure applied by the liquid above the open end
Fig. 19.10 Reservoir level gage. float/target type immersed to some pre-determined depth in the tank or
basin. This AIR pressure is then measured (sensed) as
proportional to liquid level ABOVE THE END OF THE TUBE.
Another common system of level sensing is the displacer This indirect determination of level using air permits the
type (Figure 19.11c). By its nature only single-point determi- placement of the instrumentation anywhere above or below
nations of level can be obtained. tut this type of sensinn for the liquid's surface. whereas direct pressure-to-level gages
on-off control is adequate for many purposes. The displacer must be installed at the very point where liquid pressure
must be sensed.
is a weight, usually of a non-corroding heavy material such
as porcelain, which hangs down on a cable into the liquid These ineumatic devices are adjusted so air JUST BE-
within a stilling well. The cable is supported by a spring GINS to 'bble out of the submerged end of the sensing
which is sized so as to keep an electrical switch (a mercury
vial, usually) in one position with the displacer immersed, but
allowing it to switch to another position when the displacer is
out of the liquid. The basic principle is that the weight is
buoyed up by the liquid when immersed, thus weighing less.
Accordingly, the motion of the displacer is very slight,
typically less than one inch (25 mm) so this design is more
reliable than a float device which may be subject to sticking
in its stilling well.
An alternative to a float or displacer, both of which are
mechanical systems, is the use of electrical probes to sense
liquid level (Figure 19.11d). Again, only single-point determi-
nations can be made this way, though several probes can be
set up to detect several different levels. Level probes are
 Instrumentation 353

TELEMETRY LEVEL LEVEL

TRANS- TRANS- LEVEL SIGNAL
TO PLANT
MITTER MITTER
TOOTHED
DRUM
PULLEY-1 C.W.

NOTE: AS ARROWS CABLE NOTE: SIGNAL PRO-

DEPICT, COUNTER PORTIONAL TO TURNS
CC:.NTER- OF PULLEY/DRUM
WEIGHT MOVES ONLY
WEIGHT FROM LOWEST
A FRACTION OF FLOAT
TRAVEL, DUE TO DIFF- :EMPTY) POSITION.
ERENCE IN DRUM
PERFORATED
DIA. WHERE RESPEC-
TIVE CABLES ATTACHED. FLOAT S.S. TAPE
STILLING WELL

HOLES FLT.

//4
TANK OR RESERVOIR'

Fig. 19.11a Float and cable (continuous) Fig. 19.71b Float and tape (continuous)

LEVEL TRANSDUCER
(MECHANICAL TO ELECTRIC)
4).1 LEVEL
SENSOR CONTROL OR
SIGNAL WIF
ALARM SIGNALS

NOTE: WHEN DISPLACER

LEVEL HI-LEVEL PROBE
COMPLETELi IMMERSED,
SPRING RELAXES TO
CLOSE ELECTRICAL MAY BE
CONTACTS FOR SIGNAL. SIDE-
NOTE: ELECTRIC
ENTERING
SINGLE CURRENT FLOWS
DISPLACER S.S.
POINT BETWEEN COMMON
TO SENSOR RODS
LEVEL AND LEVEL PROBES
SENSING TO SENSE LIQUID
(SEVERAL MAY BE LEVEL.
USED FOR MULTI-
POINT SENSING). LO-LEVEL PROBE
GROUNDING (COMMON) PROBE

BASIN OR TANK /A
Fig. 19.11c Displacer (single-point) Fig. 19.11d Electrical probes (multi-point)

Fig. 19.11 Liquid-level sensing systems

(Let el measurement and single-point sensing)

374
354 Water Treatment

LEVEL
READOUT
UNIT(S)

0
0
ROTAMETER BUBBLER
SETS TUBE
INST. 11Th
0
AIR --10 REG. CONSTANT
SUPPLY FLOW (BACK-) 0
AND
REGULATOR PRES.
FILTER
SENSOR 0

0
X LOWEST - - - --
PURGE VALVE* LEVEL
SENSED
FUNCTIONAL DIAGRAM
TANK OR BASIN
*FOR APPLICATIONS WITH CLOGGING TENDENCY, (ABOVE, BELOW OR LEVEL
EG; CHEMICALS, SLURRIES, WASTEWATER WITH INSTRUMENTATION)

Constant-flow regulator and rotameter on left, back-pres-

sure sensor (DP cell) to right.

Fig. 19.12 Bubbler tube system for measuring liquid level

375
 Instrumentation 355

tube. They automatically compensate for changes in liquid QUESTIONS

level by providing a small, constant flow of air. There is no
advantage to "turning-up-the-amount-of-air" to create mere Write your answers in a notebook and then compare your
intense bubbling (the pressure will still depend on the water answers with those on page 381.
level). In fact, such action may create a sizeable measuring
error in the system and any air flow changes should be left to 19.20 List the major types of liquid level sensors.
qualified instrument se'vice personnel. 19.2E Now can a signal be generated by a flJat element?
Bubbler tube systems are common in filter-level control- 19.2F Under what circumstances are probes used to meas-
lers which must -taintain water levels within a range of a few ure liquid level instead of mechanical systems
inches (or centimeters). Usually tne level transmitter for this (floats)?
use is "blind" since it only controls liquid level and doe not
provide an indication or re ut of the level. 19.2G Now does a bubbler measure the level of a liquid?

tg
r -
e

NI,

14

Rotameters (RATE-of-flow)

Fig. 19.13 Flow se 'sing devices

376
 356 Water Treatment

19.23 Flow (Rate of Flow and Total Flow) liquid flow or gas flow, such as those installed at the readout
The term "flow" can be used to refer to either RATE OF device of a gas chlorinator Sometimes a simple rotameter is
FLOW such as MGD, CFS, and GPM (volume per unit of installed merely to indicate a flow or no-flow cuncliton in a
time). or to TOTAL FLOW in simr,le units of volume such as pipe such as found on chlinnator-injector supply lines.
gallons or cubic feet. Such volumes are usually obtained as
Service meters are the type of flow meters used to record
a running totai, with a comparatively long time period for the
total water usage through individual service connections in a
flow delivery (such as a month). This distinction is important
distribution system (Figure 19.14). The smaller service me-
in the understanding 01 flow instrumentation, most of which
ters are usually one of the positive-displacement types. The
proudes BOTH values (for rate of flow and total flow). Some
larger service meters use the velocity-sensing principle.
flow meters. however, provide only total flow readings.
VELOCITY - SENSING DEVICES measure water speed
While it is possible in principle to measure flow directly, within a pipeline. his can be done by sensing the rate of
such as is done with pressure and most level sensing
rotation of a special impeller (Figure 19.15) placed within the
devices. it is quite impractical. Direct measurement would
involve the r E.;niitant filling and emptying of, say, a gallon
flowing stream; the rate of flow is directly proportional to
impeller RPM (within certain limits). Since normal water
container with water flowing from a pipe on a timed basis.
This method is simply not practical. Therefore, sensing of velocities in pipes znd channels are well under 100 feet per
second (about 8 mph or 3 m/sec), the impeller turns rather
flows in waterworks practice is done 1NFEREN7 ALLY, that
is. by inferring what the flow is from the observation of-some
slowly. This rotary motion drives a train of gears which
finally indicates RATE of flow as a speedometer-type read-
associated hydraulic action of the water. The inferential out. TOTAL flow appears as the cumulative number, similar
techniques that are used in waterworks flow measurement to the odometer (total mileage) on your car.
a (1) velocity sensing, (2) differential-pressure sensing, (3)
iagnetic, and (4) ultrasonic First, let's look at a few other Rotation of the velocity-sensing element is not always
methods used in flow sensing for specialized applications transferred by gears, but may be picked up as a magnetic or
before studying velocity sensing devices. electric signal (pulses) by the instrument system. Nor is
velocity always sensed mechanically; it may also be detect-
ROTAMETERS (Figure 19.13) are transparent tubes with ed or measured purely electrically (the thermister type) or
a tapered bore containing a ball (or float). The ball rises up
within the tube to a point corresponding to a particular rate hydraulically (the pitot tube), but the principle of equating
water velocity with rate of flow within a constant flow-area is
of flow. The rotameter tube is set against, or has etched
the same. Of course, all such flow meters are calibrated to
upon the tube, marks calibrated in whatever flow rate unit is
read out in an appropriate unit of flow rate. rather than
appropriate. Rotameters are used to indicate approximate velocity units.

Service meter (TOTAL flow)

Fig. 19.14 Flow sensing device

 Instrumentation 357

RATE -OF -FLOW

RECORDER
OR
INDICATOR
FLOW
TRANSDUCER/
1112134516171 FLOW TOTALIZER
TRANSMITTER

1 .,---4-1---
*
FLOW C

(
C
* NOTE: MOTION OF PROPELLER
C
C C

C
CAN BE SENSED/TRANSMITTED
MECHANICALLY, MAGNETICALLY
OR ELECTRICALLY, OR ANY
PIPE J FLOW METER OF THESE IN COMBINATION.

SCHEMATIC DIAGRAM

Fig. 19.15 Propel'er (v dc^itv) meter

 358 Water Treatment

Typically, this type of flow element transmits its reading to Measuring flow by this method removes a little hydraulic
a remote site as electrical pulses, although other devices energy from the water. However. the classical ventun tube.
can be used in order to convert to any standard electrical or with its carefully tapered form. allows recovery of well over
pneumatic signal. 95 percent of the original pressure throughout its range of
Preventive maintenance of impeller-type flow meters cen- flows Other ways of constricting the flow do not ollow such
ters around regular lubrication of rotating parts. Propeller high recoveries of pressure, nor the accuracy possible with
modern venturi flow tubes. The Dall tube is a shortened form
of the ventun, with acceptable accuracies for many in-plant
purposes (filter wash-water flows).

TEST FLOW
HEAD RECORDER
PIPE - IP OR
INDICATOR

FLOW
HIGH INTEGRATOR
BYPASS
TAP -44 VALVE

FLOW
meters. as they are called, have a long history of reliability ____....v..
and acceptable accuracy in waterworks practice. When
propeller meters become old, they become susceptible to ../,'. THROAT -----i
under-registration (read low) due to bearing wear and gear- UPSTREAM VERY SECTIONS
train friction. Accordingly, annual tear-down for inspection is
.ndicated. An over-registration is a physical impossibility as
rar as the operating principle goes, but a partially full PREbS. DIFF.
pipeline, wrong gears installed, or a malfunctioning transmit- GRAPH PRES.
ter can cause high readings.
DIFFERENTIAL-PRESSURE SENSING DEVICES (Figures Venturi system (flow rate)
19.16 and 19.17), also called venturi or just differential
meters, depend for their operation upon a basic principle of
hydraulics. When a liquid is forced to go faster in a pipe or
tube. its internal pressure drops. If a carefully sized restric-
tion is placed within the pipe or flow channel. the flowing QNSTRUMENTATIO,D
water must speed up to get all ough it. In doing so, its SAME AS ABOVE
pressure drops a little; and, it always drops the same LOW TAP
amount for the same flow. This small pressure drop, the MAY BE
differential, is the difference between the water pressure HI LO HERE
..40---
before the restriction and within the restriction. This differ-
ence is proportional to the rate of flow. The difference in
pressure is measured very precisely by the instrumentation
SIZED
associated with the certain flow-tube or venturi installed.
Typically, only a difference of a few psi is required. This
small value of pressure difference is often described in
inches of water (head).

FLANGES
ORIFICE
PLATE

Orifice plate installation (flow rate)

Fig. 19.16 Schematic diagrams of

differential pressure flow metering

The orifice plate (Figures 19.16 and 19.17) is inserted

between flanges in a pipe and is a stainless steel plate with a
calculated size hole (orifice) in it. The pressure drop is
sensed right at the orifice, or immediately downstream to

379
 Instrumentation 35"

54-inch Venturi tube

-4"
jez

24-inch Orifice plate

Fig. 19.17 Photos of differential pressure flow meters

3S
 360 Water Treatment

yield a comparatively rough flow indication This drop in qi.ite similar. The process variables of turbidity and pH are
pressure is permanent; that is, a permanent pressure loss alwcvs monitored closely in a mcdern water treatment plant
occurs with onfice plate installations. ( Figure 19 18). Very fr,quently chlorine residuals are also
Difteiential devices require little if any preventive mainte- cont nuously measured and controlled. Usually these three
nance by the operator since there are no real moving parts variables are measured at several locate )ns. For example,
Occasionally, flushing of the hydraulic sensing lines is good turbidity of 31N, settled, and filtered water is frequently
practice. This flushing should only be done by a qualified measured Additionally, other indicators of water quality may
person. When dealing with an instrument sensitive to small be sensed on a continuous basis such as fluoride, electrical
fractions of a psi, opening the wrong valve can damage the conductivity (for TDS), water hardness and alkalinity, and
internal parts Also, if an instrument containing men iry is temperature. In every case, the instrumentation is specific
used, this toxic (and expensive) metal can easily be blown as to operating principle, standardization procedures, pre-
out of the device and INTO THE WATER PIPELINE' Thus, ventive maintenance, and operational checks. The manufac-
all valve manipulations must be understood and done delib- turer's technical manual sets forth routine procedures to
erately after careful planning. check and operate the equipment.

In nearly all cases, the instrumentation associated with the Operators must realize that most process instrumentation
larger flow tubes is transmitted to a remote readout station. is quite sensitive and thus requires careful handling and
Local readout is also provided (sometimes ,nside the case special training to service. No adjustments should be made
only), for purposes of calibration. Differential meter flow without a true understanding of the device. Generally speak-
transmitters may be electrical or pneumatic types (with ing, this category of instrumentation must be maintained by
signal transmitted proportional to the square root of the the water agency's instrument specialist or the factory
differential pressure). representative rather than by an operator (unless specially
instructed)
Venturi meters have been in use for many decades and
can produce very close accuracies year after year. Older 19.26 Signal Transmitters/Transducers
flow tubes are quite long physically (to yield maximum
accuracy and pressure recovery). Newer units are much Common practice measures a variable at one location and
shorter but have even better accuracy. With no moving provides a readout of the value at a remote location, such as
parts, the venture -type meter is not subject to mechanical a main panel board Except in the case of a blind transmitter,
failure as is the pi welter meter. Flow tubes, however, must a local indication is provided at the field site as well as being
be kept clean and without obstructions upstream and down- available at the remote site. Associated with the remote
stream to provide designed accuracy. (panel) readout system quite often are alarm set-points, an
integrator, or a controller (though any of these may exist at
These flow meter types all provide rate of flow incl the measuring site also). Usually a recorder is found only on
The rate of flow is continuously totalized, usually at the read- a panel board along with all other recorders remote from the
out instrument, as the total flow up to that point in time sensor in the field. These system components will be
(recorded in gallons or cubic feet). discussed further in Section 19.3, "Categories of Instrumen-
tation."
QUESTIONS In order to transmit a measured value to a remote location
Write your answers in a notebook and then compare your for readout, it is necessary to generate a signal proportional
answers with those on page 381. to the value measured. This signal is then transmitted to a
receiver which provides a reading based upon the signal.
19.2H What are two types of flow readings? Also, a controller may use the signal to control the measured
19.21 List the two main types of (larger) flow measurement variable.
devices. Presently, two general systems for transmission of sig-
19.2J Smaller service meters are what type of flow meter? nals, electrical and pneumatic, are used in waterworks, as
well as in most other industrial situations. Electricity, of
19 2K How do velocity-sensing devices measure flows? course, requires wiring (though radio transmission or micro-
wave are possible). Pneumatic systems require small-diam-
19.2L How are flows measured with venturi meters?
eter tubing (usually I/4 inch or 6 0- n) between transmitter and
receiver. When the transmitter is quite far removed from the
19.24 Chemical reed Rate receiving station, a special terminology is used for the
electrical link between the two; this is called telemetry. The
Chemical feed -ate indicators are usually a necessary part wiring used is telephone lines, leased from the local tele-
of the particular chemical feed system and thus are usually phone company, or owned by the water agency. Telemetry
not considered instrumentation as such. For example, a dry will be discussed separately in Section 19.33, "Telemetry,"
feeder for lime or dry polymer may be provided with an since the signals are usually a special type.
indicator for feed rate in units of weight per time, such as
lbs/hr or grams/minute. In a fluid (liquid or gas) feeder, the
indication of quantity/time, such as gallons/hour or pounds/
day may be provided by use of a rotameter (Figure 19.13).

19.25 Process Instrumentation

Process instrumentation provides for continuous check-
ing of physical or chemical indicators of water quality in a
treatment plant. TN:wog .ostruments do not include laboratory
instruments (unless sat up tc measure sample water con-
tinuously), although the operating principles are usually

381
 Instrumentation 361

, tk
J.:.,;44

, a ....M.

.(; awn mum*

Turbidimeter

;ue7F:40:V4)4,-* *8-4114--Z
77;
1
-;:41- ot_.
Pe.s
A a
400000wgwmwwsvrg--....

1; LAN:. .".

'
Miti1Irligi44711";..4"444awruPICTiord

pH meter

rig. 19.18 Water treatment plant instrumentation

(Continued on the next page,

382
 362 Water Treatment

4V4TAW.I1 -WIN*

4;00.

Chlorine residual analyzer

Fig. 19.18 Water treatment plant instrumentation

(Cor,Vnued from previous page)

Electric signals used within a water treatment plant are Also, pneumatic systems seem to be more understandable
either voltage (1 to 5 volts D.C.), current (4 to 20 milliamps to operating personnel and thus easier to Knep functioning
D C ), or pulse types. Milliamp signals (4 to 20 ma) are the as desired. As with electrical signal circuits, the transmitter
most common electrical signals for most instrumentation and receivers perform as their names imply. Pneumatic
and control systems in recent years. In any of these, a low controllers, and all other types of equipment, are as avail-
voltage is applied so no severe shock hazard exists (though able as their electrical counterparts. Pneumatic signals are
shorting signal wires may still destroy electrical compo- generated by causing pressures from 3 to 15 psi (20 to 100
nents). Sigral transmission is limited to several hundred kPa or 0 2 to 1.1 kg/sq cm), proportional to the variable, in
feet, with signal strength usually set up for the specific almost every installation, with 9 psi (52 kPa or 0.65 kg/sq
connecting lines. cm) then representing a 50 percent signal.
A power supply to generate the required electrical energy Preventive maintenance of pneumatic components cen-
may be at the transmitter, the receiver, or at another ters around ensuring a c'ean, dry air supply at all times
location. The transmitter may be an integral part of the which requires alert operators.
measurement sensor/transducer, or separately housed. In
any case, the transmitter adjusts the signal to a correspond-
ing value of the measured variable, and the receiver in turn
QUESTIONS
converts this signal to a visible indication which is the Write your answers in a notebec* and then compare your
readout. answers with those on page 381.
Pneumatic signal systems are restricted to comparatively 19.2l How are chemical feed rate., measured?
short distances. Components include a compressor to pro-
vide air under pressure, as well as the necessary air filters 19 2N What process variables are commonly monitored
and an air dryer. The precision of signal transmission by and/or controlled by instruments?
pneumatics is comparable to electrical signals so both 19.20 By what means can values measured at one site be
systems are found about equally in waterworks. read out at a remote location?
Compressed air presents no shock hazard and most 19.2P What are the two general systems used to transmit
plants must have compressors available for other purposes. measurement signals?

OM of t04401,tl of 2 14.44oto
I N4TIZUMENTATI 0 N
383
 Instrumentation 363

DISCUSSION AND REVIEW QUESTIONS

Chapter 19. INSTRUMENTATION
(Lesson 1 of 2 Lessons)

Write the answers to these questions in your notebook 5 What precautions should an operator take before enter-
before continuing. ing a vault'?
1. Why should operators understand measurement and 6. How can water levels be measured'?
control systems?
7 What problems can develop with propeller meters when
2. How can measurement and control systems make an they become old?
operator's job easier?
3. What is the JO ference between precision and accuracy?
4. Why should a screwdriver not be used to test an electrical
circuit?

CHAPTER 19. INSTRUMENTATION

(Lesson 2 of 2 Lessons)

19.3 CATEGORIES OF INSTRUMENTATION

19.30 Measuring Elements

Measuring (or primary) elements are those devices which
make the actual measurement of the variable. Transducers
are usually associated with sensors to convert the sensor's
signal to another magnified action producing a more useable
indication. If remote transmission of tne value is required, a
transmitter may become part of thq transducer. An illustra-
tive example of these three components is the typical ventun
meter: (1) the flow tube is the primary element, (2) the
differential-pressure device ("D.P. cell") the transducer, and
(3) the signal producing components are the transmitter. An
understanding of the separate junctions of each section of
the "flow meter" is important to the proper understanding of more or less blindly. You must realize that there is no
equipment problems. substitute for critical evaluation and informed judgment in
the "trusting" of instrument systems as they relate to impor-
19.31 Panel Instruments (See Figure 19.1, page 343) tant plant functions. You must not rely solely upon the
readings of any single instrument to ensure proper plant
19.310 Indicators operation, but must consult other instruments and closely
watch the other indicators of plant operation. Even the most
The components of measurement and control systems sophisticated and expensive instrument systems require
found on the water plant's main panel board are generally constant maintenance work by specialists and do malfunc-
thought of as the plant instrumentation. These components tion at times
are important to the operator, and hence to plant operation
itself, because they display the variable directly. These panel 19.311 Indicators/Recorders
devices can produce alarm signals to indicate if a variable is
outside its range of expected values. In addition, the control- The major components found on the plant's main panel
lers are often installed on (or behind) the main panel along are indicators and recorders. Indicators give a visual presen-
with the operating buttons and switches for the plant's tation of a variable's value, either as an analog or as a digital
equipment. display (Figures 19.19 and 19.20). The analog display uses
some manner of pointer (or other indicator) against a scale.
However, in this age of cybernetics (a fancy term for A digital display is a direct numerical readout. Recorders,
instrumentation), you can easily be !ulled into an overde- which can also serve as indicators, give a permanent record
pendence on automation to operate the plant processes of how the variable changes with time by way of a moving
364 Water Treatment

chart Whereas there are usually several indicators out in the er operation, readily after such power or heat problems.
plant or field, recorders are usually housed at a central Electronic systems may require the services of an instru-
location in the plant. We wi" discuss both indicators and ment tethnician, or even the factory technician, to become
recorders in the following paragraphs. fully operable again. Accordingly, t ie operator should insist
upon some input into the design phase of instrument sys-
Since there are two types of signal transmission available, tems to ensure that the plant is still operable during power
panel indicators may be of the electric or the pneumatic type. outages, weather, and other contingencies. Standby
The digital readout is a relatively recent development, with power generators and/or batteries are used to keep plants
both advantages and disadvantages. Digitals may be read operating during power outages.
more quickly and precisely from a longer distance, and can
respond virtually instantly to variable changes. But analog
indicators are cheaper, more rugged, and may not even QUESTIONS
require electrical power (the pneumatic type), an advantage
during a power failure. Write your answers in a notebook and then compare your
answers with those on page 382.
Another advantage of the electric or pneumatic analogs or
gages is that a wrong indication (value) is more recognizable 19.3A What is the purpose of indicators?
than with a digital system, and also is more easily repaired 19.3B Describe an analog display.
by the operator.
19.3C Where are recorders usually found at a water treat-
For example, the pointer on a flow meter gage may merely ment plant?
be stuck, as evidenced by a perfectly constant reading. With
a digital reading there is no practical way for the operator to 19 3D What factors can cause electronic instrument prob-
see whether a problem actually does exist, nor is there any lems?
way for the operator to attempt a repair, such as freeing a
pointer. Erratic or unreliable operation, while always a 19.312 Recorders
problem, seems to be worse when digitals are involved since
there is "no way out" for the operator. You often can't tell if Recorders are indicators designed to show how the value
the problem is real, and you can't do anything to "get-by-'til 8 of the variable has changed with time (Figure 19.20). Usually
A.M." as is often required on a night shift. this is done by attaching a pen (or stylus) to the indicating
With au-electronic instrumentation, as advantageous as :t arm, which then marks or scribes the value of the variable
may seem from a technical and economic standpoint, the onto a continuously moving chart. The chart is marked on a
operator has little recourse in case of malfunction of critical horizontal or circular scale in time units. Son"-, models of
instrumentation. Temporary power failures, tripped panel recorders reverse the scales by indicating time on the
circuit breakers, voltage surges (lightning) resulting in blown vertical and variable on the horizontal scales.
fuses, and problems of excessive heat can all result in The chart is driven along at a pi 3cise speed under the pen,
electronic instrument problems. However, electomechani- to correspond with the time markings on the chart. Chart
cal or pneumatic instruments may keep operating, or recov- speeds range from several inches to a fraction of an inch per

Fig. 19.19 Analog chlorine residual indicator

 Instrumentation 365

Fig. 19.20 Digital indicator/recorder combination (24-hour circular chart)

(Permission of Leopold Company. Division of Sybron Corporation)

38G
366 Water Treatment

minute, with the pen and drying time of the ink specific to a available for the operator to read. On a circular
given range of speeds. recorder, the chart makes one revolution every day, week,
or month, and the record of the entire elapsed time period is
There are two main types of recorder charts and record-
visible at any time.
ers: the horizontal strip-chart type and the circular type. The
horizontal strip-chart carries its chart on a roll or as folded ..,hanging of charts is usually the operator's duty, and is
stock, with typically several months' supply of chart avail- easier with circular recorders, though not that difficult with
able. Several hours of charted data are usually visible or most strip-chart units.

44.
girt. ri=3

-1 88 1. w8 2884 8,, 181818,

Jr

Strip-chart recorders

-
t At
17 '.".; k
-L4 4°
C

Seven-day circular-chart recorder

Fig. 19.21 Recorders, strip chart and circular chart

3S
 Instrumentation 367

Recorders may be electric or pneumatic. Pneumatic mod- appropriate numbers on the display, or a fractional multiplier
els frequently have electric chart drives. Purely mechanical ( 0.001, for example) will appear on the face of the totalizer.
units, useful at a remote, unpowered pressure gaging sta-
Every operator shou:d personally be able to CALCULATE
tion. have hand-wound chart drives and are of the circular-
chart type. Other models are battery powered. Recorders total flow for a time period in order to verify that the
integrator is actually producing the correct value. Accuracy
are most commonly described by the nominal size of the
to one or two parts in a hundred ( ± 1 or 2 percent) is usually
strip-chart width or circular-chart diameter (for example, a fl-
inch (100 mm) strip-chart, or a 10-inch (250 mm) circular- acceptable in a totalizer. There are methods to integrate
chart recorder). Figures 19.20 and 19.21 present various (add up) the area under the flow-rate curve on a recorder
popular models of indicators and recorders.
chart, to check total flow for long-term accuracy calcula-
tions.
19.313 Totalizers
19.314 Alarms
The rate of flow as a variable is a time-rate: that is, it
Alarms are visual and/or audible signals that a variable is
involves time directly, such as in gallons per minute, or out of bounds or that a condition exists in the plant requiring
million gallons per day, or cubic feet per second. Flow rate
the operator's attention. For noncritical conditions, the glow
units become units of volume with the passage of time. For
of a small lamp or light on (or outside of) an indicating
example, flow in gallons per minute accumulates as total instrument is sufficient notice. For more important variables
gallons during an hour or day. The process of calculating
and presenting an on-going, i unning total of flow volumes
passing through a meter is termed "integration" or totalizing.
An integrator, also called a totalizer, continually adds up
gallons or cubic feet as a cumulative total up to that point in
time. Virtually all flow indicators and recorders are equipped
with totalizers, though sometimes as separate units (Figures
19.20 and 19.21). Many flow meters ONLY measure the total
quantity of fluid passing through it; the domestic service
meter (common water meter) is an example of this type of
flow meter.
Large quantities of water (or liquid chemical) are common-
ly measured in units of hundreds or thousands of gallons or
cubic feet. This is simply a shorthand means of expressing
the measurement. On the face of a totalizer you will find a
multiplier such as x 100 or x 1000. This indicates that the
reading is to be multiplied by this (or another) factor to yield or conditions, an attentior-getting an.tunciator panel (Figure
the full amount of gallons or cubic feet. If the readout uses a 19.22) with flashing lights and an unmistakable and penetrat-
large unit, such as "mil gal," a decimal will appear between ing alarm horn is commonly used.

allt..

Fig. 19.22 Annunciator (alarm) panel

(each rectangle represents a monitored vocation)
 368 Water Treatment

Annunciator panels all have "acknowledge" and "reset"

features to allow the operator to squelch the alarm sound
(leaving the visible indication alone) and to reset the system
after the alarm condition is corrected. The alarm contacts
(switches) activating the system commonly use the same
instrument as the variables presented on the main panel, or
are wired in from remote alarm sensors in the plant or field.
The operator is usually responsible for setting these alarm
contacts and the operator must use judgment as to the
actual limits of the particular variables that will ensure
meeting proper operational goals. Each system is different
so no attempt will be made here to instruct operating
personn.el in alarm re-setting procedures.
Sometimes, operators fail to reset alarm limits as condi-
tions and judgments change in the plant. It is not uncommon
to see the annunciator panel "lit up: with the operator
ignoring all the alarm conditions as the normal status quo!
SUCH PRACTICE IS NOT ADVISED BECAUSE A TRUE
ALARM CONDITION REQUIRING IMMEDIATE OPERATOR ferent in operation than proportional control. Both methods
ATTENTION MAY BE LOST IN THE RESULTING GENERAL may exercise close control of a variable; however, propor-
INDIFFERENCE TO THE ALARM SYSTEM. For some oper- tional control may be better suited to the purpose. Attempt-
ators, acknowledging an alarm sound to cat rid of the noise ing to set up an "on-off" control system to maintain a variable
is second nature, without due attention to each and every within too close a tolerance may result in rapid on-off
activating condition. Alarm contact limits should always be operation of equipment. Such operation can damage both
reset (or deactivated) as necessary to assure that the the equipment and the switching devices. Therefore, do not
operator is as attentive to the alarm system as possible to attempt to set a level controller, for instance, to cycle the
prevent real emergencies. pump or valve more often than actually necessary for plant
operation.
QUESTIONS In the case of a proportional controller, it too may begin to
Write your answers in a notebook and then compare your cycle its final control element (pump or valve) through a wide
answers with thcse on page 382. range if any of the internal settings, namely proportional
band or reset, are adjusted so as to gain closer control of the
19.3E What is the purpose of recorders? variable than is reasonable. Accordingly, it may be better to
19.3F What are the two types of charts used on recorders?
accommodate to a small offset (difference between set-
point and control point), than risk an upset in control by
19.3G How are charts driven in remote locations where attemg`ing too much control.
there is no electricity available?
19.23 Pump Controllers
19.3H List two types of warnings that are produced by
alarms. Control of pumping systems can be achieved by an
automatic controller which determines the output of a vari-
able-speed pump, or by an on-off type of controller starting/
19.32 Automatic Controller stopping the pump(s) according to a level, pressure. or flow
Section 19.0 explains the nature of control systems, measurement. The control of a variable-speed system was
especially as they are used in waterworks operations. Indi- discussed earlier in the description of the automatic (propor-
cations of proper and improper control need to be recog- tional) control method, so this section v..111 restrict comments
nized even though actu:.1 adjustment of the controller should to on-off pump control.
be left to a qualified instrument technician. By shifting to the Usually an on-off pump control system responds to level
manual mode, you can bypass the operation of any control- changes in a tank or a reservoir of some type. Water level
ler, whether electric, pneumatic, or even hydraulic. Learn can be sensed directly or by pressure change at the pump
how to shift all controllers to manuai operation. This will site. The pump is turned off or on as tank level rises above or
allow you to take over control of a critical system when falls below pre-determined level or pressure limits. Ccrtrol is
necessary in an emergency, as well as at any other time it rather simple in this case.
suits your purposes. For example, you could quickly correct
e "cycling" or "sluggish" recorder indication rather than However, sucr; systems may include several extra fea-
waiting for the controller to correct the condition in time, if it tures to ensure fail-safe operation. To prevent the pump
does at all. from rAning after a loss of signal, electrical circuitry should
be designed so the pump will turn OFF on an OPEN signal
A controller, while admittedly "superhuman" in some of its circuit, and ON only with a CLOSED circuit. Ideally, the
abilities, is still limited. It can only do what ;i has been sensor can distinguish between an open or closed remote
programmed to do. You as the operator can exercise level/pressure contact and an open or shorted telemetry
JUDGMENT based on your experience and observations, so line. Larger pump systems will usually have a low-pressure
do not hes:tate to intervene if a controller is not e,:ercising cut-off switch on the suction side to prevent the pump from
control within sensible limits. Of course, you must be SURE running when no water is available, such as with a dry wet
of your LJnclusions, and competent to take over control if well or a closed suction valve.
you decide to operate manually.
Pumps may also be protected agains.: overheating,
To repeat a few of the more important operational control caused by continuing to pump into a closed discharge
considerations, remember that "on-off" control is quite dif- situation, by a high-pressure cut-off switch on the discharge

9
 Instrun.3ntation 369

piping. Both the high- and low-pressure switches may shut 19.34 Telemetering Links (Phone Lines)
off the pump through a time delay circuit, so that short-term
Remote monitoring or controlling of water distribution
pressure surges can be tolerated within the pump piping. system operational variables, such as level, pressure, and
Usually the low- or high-pressure switches also key an alarm
flow. may require the use of long signal transmission lines.
to notify the operator of the condition. For remote stations.
These lines may be wires (two being required for each
the plant's main panel may include indicator lights to show
circuit) owned by the water agency or telephone lines leased
the pump's operating condition. Figure 19.23 shows a from the local telephone company (Figure 19.25). This lease
typical pump control circuitry.
line arrangement is being use° by many utility agencies. In
Pump control panels (Figure 19.24) may also include most cases, a transmitter generates an audio frequency or
automatic or manual sequencers. This provision allows the tone on l le line. For example, a frequency of 1000 Hz2
total pump operating time required for the particular system produces a medium high-pitched hum on the tone channel
to be distributed equally among all the pumps at a pump (line). Each variable to be transmitted and rece;ved has its
station. A manual switch for a two-pump station, for exam- own tone. This helps limit the number of phone lines needed
ple. will read "1-2" in one position and "2-1" in the other to and from the remote sites. A very limited number of
position. In the first position, pump #1 is the "lead" pump different tones can be sent over the same phone lines and
(which runs most of the time) and #2 the "lag" pump (which then be unscrambled by their individual receivers. A remote
runs less). When the operator changes the switch to "2-1," sensing and control station can send tone signals to the
the lead-lag order of pump operation is reversed, as it water plant and simultaneously receive tone signals to effect
should be penodically, to keep the running time (as read on control at the same site. An example would be a flow/
the elapsed time (E.T.) meters, or as estimated) of both pressure/level sensing station across town, with a control
pumps to about the same number of total hours. In a station valve or pump there under remote manual control. The term
with multiple pumping units, an automatic sequencer regu- "telemetry" is used to denote such use of remote signaling to
larly changes the order of the pumps' startup to maintain monitor and/or control remote station operation. The term
similar operating times for all pumps. "supervisory control" applies to the remote control feature
exercised through telemetry systems.
QUESTIONS With or without use cf tone equipment (which mainly
Write your answers in a notebook and then compare your serves to allow multiple signals on single phone lines), the
answers with those on page 382. actual signal is of the pulse-duration or the pulse-frequency
type in virtually every application in waterworks.3 Pulse-
19.31 Under what conditions might an operator decide to duration, also called pulse-width nr time-duration depending
bypass a proportional-type controller? How could on the brand of equipment, functions by creating a 15
this be done? second (sometimes less) regular signal cycle within the
transmitter. The value of the variable transmitted occupies
19.3J What basic principle should guide you in program- more or less of this basic time cycle; a 50-percent signal
ming the frequency of operation of an "on-off" con- would produce a 71/2-second tone (during the remaining 7V2
trol? seconds the circuit would be silent). Each manufacturer has
1f,.31( How ce n pumps be prevented from running upon selected some standard, usable portion of the 15 second
loss of signal? cycle. For example, one company uses only 9 seconds (from
3 seconds to 12 seconds) of the time to proportion 0 to 400
19.3L How can you ensure that all pumps in a pump station percent of the variable's value. If the panel indicator shows
operate for roughly equal lengths of time? that the depth of water in a remote tank can range from 0 to
9 feet, a tone lasting 6 seconds (67 percent signal) out of the
possible 9 seconds, would cause the indicator to show a
depth of water of 6 feet. In any case, the corresponding
receiver is set up to accept and relay the proper signal to the
indicating/controlling instrumentation. This form of signal
telemetry is very popular, being easy to understand, requir-
ing no sophisticated instrumentation to check or calibrate,
and being virtually insensitive to improper signals origit ,ating
in the telephone lines or at the phone company. A limitation
of this form of signal (time-duration) is when it is used for the
"pacing" of chemi..;a1 feeders, especially coagulants. During
a low flow period, alum feeders will be feeding alum intermit-
tently which will produce very poor coagulation/flocculation
results. A loss of signal or interferen,e causes the indicator
to go to zero or to maximum scale. If you have the opportuni-
ty. ask the instrumentation service person to allow you to
listen to a tone channel, or better, to a phone line carrying
several channels.
From an operational standpoint, there isn't much you can
do if you lose a channel," no matter how important it is to
plant operation. Fuse replacement can be tried, then a call

2 Hz or Hertz (HURTS). The number of complete electromagnetic cycles or waves in one second of an electrical or electronic circuit Also
called the frequency of the current. Abbreviated Hz.
3 Some shortdistance signals operate only by sensing opening or closing of an electncal contact, completely analogous to a local (in-
plant) level or pressure switch.

r
 370 Water Treatment

L1 L2(N)
(120 VAC 60 HZ)

\/ r H.O.A. (PB STATION)

PUMP
,.
POWER
SWITCH)
S
START STOP
5-
CONTROL ON HAND ...11 14
PANEL La_i in* HP LP
FUSE

DOOR
OFF R1-a 6-41--1---
SW.
R1-b AUTO
4i LEVEL *
ril
CONTROL

TEST
I1 * LEVEr. SWITCH
R2 -a CLOSES ON
LOW LEVEL,
OPENS ON

I--
D.S.
0L.S m S1 -A HIGH LEVEL
1.1 -12- i
MOTOR I
I PUMP
POWER
CIRCUIT 240 VAC 4../.____x MS2 -B 11. TO
60 HZ TANK

(0)
L2
3% I
I
I

L3.- tr. n
MS3-C
II

REFER TO FIG. 19.4, page 346, FOR LEGEND OF TERMS AND SYMBOL S

Fig. 19.23 Pump control station diagram (on-off control)

(simplified double-line schematic)
 Instrumentation 371

.4;

Fig. 19.24 Photo of pump control station

to the telephone company to check on its status (phone lines The plant's instrument air supply system consists of a
may be down in an accident or incident), after which the compressor with its controls, master air pressure regulator,
instrument service person must be called in. At times, tone air filter and air dryer, as well as the individual pressure
channels may be lost for several minutes (pens go to top or regulator/filters in the line at each pneumatic instrument
bottom), only to return t .ormal service later; therefore, you (Figure 19.26). Only the instrument air is filtered and dried;
may wish to try to wait out the interruption. An indicator the plant air usually does not require such measures since it
pointer/pen cannot move from its last position during a is being used only for pneumatic tools.
power outage if the readout instrument (electronic) has no
internal power. If you push a pointer/pen up or down and it As air passes through a compressor, it not only picks up
remains in the new position, you have an internal power oil but the air's moisture contert is concentrated by the
problem. Thus a different action would then be required of compression process. Special measures must be taken to
the operator, riot related to a telemetry problem. remove both of these liquids. You can remove oil by filtering
the air through special oil-absorbent elements. A process
Air Supply Systems called DESCCATION4 can be used to remove the water.
19.35
This is simply a matter of either passing the moisture-laden
Pneumatic instrumentation depends upon a constant air through desiccant columns, which regenerate their ab-
source of clean, dry, pressurized air for reliable operation. sorption capacity periodically through heating, or of refriger-
Given a quality air supply, pneumatics can operate seeming- ating the instrument air. The refrigeration method is based
ly forever without significant problems. Without a quality air upon the principle that cold air can hold comparatively little
supply, operational problems can be frequent. The operator moisture within it. You must recognize that the capacity of
of a plant is usually assigned the task of ensuring that the any of these systems of oil or water removal is limited to
"instrument air" is available and dry, though rarely are amounts of liquid encountered under normal conditions.
operators told how to accomplish this (it being assumed
evidently that clean air will "be there automatically). If the compressor :s so worn as to pass more oil than
usual, the oil separation process may permit large amounts
of oil to pass into the air supply. If the air storage tank
contains excessive liquid water (due to irregular or improper
drainage). the air drying system may not handle the excess
moisture. Learn enough about the instrument air system to
be able to open the drain valves, cycle the desiccator, or
bypass the tank, in order to prevent instrumentation prob-
lems due to an Aly, moisture-saturated air supply.

Operators should regularly crack the regulator /filter drain

valves at the site of the plant instruments. An unusual
quantity of liquid drainage may indicate an overloading or

Desiccation (DESS-uh-KAY-shun). A prol;ess used to thoroughly dry air, to remove virtually all moisture from air.

3U?
372 Water Treatment

FIELD (REMOTE) S1ATION

FLOW SYSTEM
RESERVOIR
I PRES.1 FLOW VALVE
CONTROL
LEVEL

1 RCVR.
3 TRANS. 110 V AC
TONE LEASED
UNITS PHONE
LINE
(ONE PAIR ONLY)

LOCAL TELEPHONE
COMPANY OFFICE
h (OR RELAY STATION)

NOTES:

1. SINGLE PAM OF PHONE

LINES TRANSMIT
SEVERAL TONE SIGNALS LEASE-
TO/FROM SITES LINE
(P. L. #---)
SIMULTANEOUSLY.

2. TONE UNITS ARE (FOUR

TRANSMITTERS (TRANS) CHANNELS)
OR RECEIVERS (RCVRS). 1 TRANS. OTHER TONE
POWER SUPPLY ALSO 3 RCVRS. SYSTEMS
NECESSARY.
CABINET

3. AS SHOWN, FIELD STATION

PRESSURE, FLOW AND TANK PR ES.
--47
I FLOW LEVEL
LEVEL MC NITORED, DIRECT IND. REC.
CONTROL EXERCISED OVER --I.
SET REC.
FLOW (WITH PRESSURE AND FLOW
LEVEL CHANGING ACCORDINGLY).
CONTROL
STATION

CENTRAL CONTROL
(WATER PLANT OR STATION)

Fig. 19.25 Diagram of telemetry system

(monitoring and supervisory control)
 Instrumentation 373

-
cll. (ER
CON-
CD TROLLER
PLANT
FILTER FILTER
EFFLUENT CONTROL
VALVE
pi ANT. BUBBLER
PNEUMATIC --41ROTAMETER Fib-TUBE
SYSTEMS
../

TRANS- 3-15 PSI TO REMOTE

LOCAL
20 PSI MITTER READ-OUT
INDICA-
(TYPICAL) TOR PRIMARY
TRANS-
DUCER ELEMENT
FILTER/ PROCESS VARIABLE MONITORING
REGULATORS
PNalMATIC
INSTRUMENTATICN

PRESSURE/
CONTAMINANT
SEPA-
CONIThOL
4 RATOR/
FILTER
.4_,
50 PSI

INSTRUMENT (TYPICAL)
AIR

+-- MOISTURE OIL AND PARTICULATE PRESSURE

REMDVAL REMOVAL REGULATION
DRAIN
A
BYPASS
50-100 PSI
X
GA GE
AIR SAFETY
SUPPLY VALVE
ALTER-
DUTY1 N 91 \
UNIT X NATE
UNIT t RECEIVER

(1 1
COMPRESSORS STORAGE TANK(S) DRAIN

NOTES:
1. COMPRESSOR AND "( ANK OFTEN AN INTEGRAL UNIT.
.:. MDST CRITICAL COMPONENTS HAVE ALTERNATE/STANDBY UNITS.
3. SDME DRAINS MAY BE AUTOMATIC TYPE.

Fig. 19.26 Instrument air system functional diagram

(simplified, not all valves and piping shown)

3q4
 374 Water Treatment

failure in he instrument air filter/drying parts. Also, pneu-

meter broken" does not become popular with the chemist,
matic indicators/recorders should be watched for erratic supervisor, nor the other operators. The byword in the lab is
pointer/pen movements which may well be indicative of air WORK WITH CAUTION. protect valuable and essential
quality or supply problems. equipment and instrumentation.
The seriousness of temporary plant or compressor station
power failures can be lessened if you temporarily turn off all 19.37 Test and Calibration Equipment
non-essential usages of compressed air in the plant. The air
storage tank is usually sized so that these is enough clean, In most larger water plant operations, the plant operating
dry air on hand to last for several hours, if conserved. staff have little occasion to use testing and calibration
Knowing this, you may be able to wait out a power failure meters and devices on the plant instrumentation systems. A
without undue drastic action by observing remaining avail- trained technician will usually be responsible for maintaining
able pressure at the air supply. such systems. There are, however, some general consider-
ations the operator should understand concerning the test-
ing and calibration of plant measuring and control system:.
QUESTIONS With this basic knowledge, you may be able to discuss
Write your answers in a notebook and then compare your needed repairs or adjustments with an instrument technician
answers with those on page 382. and perhaps actually assist with that work. A greater under-
standing of your plant's instrument systems may also enable
19.3M How are signals transmitted over Id..g distances,
you to analyze instrument problems as they bear upon
such as frt m a water storage reservoir to pumps at a continued plant operation, to handle emergency situations
water treatment plant? created by instrument failure, and finally your skills in
19 3N What happens to a remote indicator when a signal is instrument testing and calibration equipment may result in a
lost'? job promotion and/or pay raise.

19.30 What are the essential qualities of the air supply The most useful piece of test equipment is the V-O-M, that
needed for reliable operation of pneumatic instru- is the Volt-Ohm-Milliammeter, commonly called the "multi-
mentation pressure systems'? meter" (Figure 19.28). To use this instrument you will need a
workable understanding of electricity, but once you learn to
19 3P How are moisture ano oil removed from instrument use it. the V-O-M has potential for universal usage in
air'? instrument and general electrical work. Local colleges and
other educational institutions may offer courses in basic
19.36 Laboratory Instruments electricity which undoubtedly include practice with a V-O-M.
You, as a professional plant/system operator, are unlikely to
This category of instrumentation includes those analytical find technical training of greater practical value than this type
units usually found in larger water treatment pi- it laborato- of course or program. Your future use of test and calibration
ries Turbidimeters, colorimeters and comparators, pH, con- equipment in general certainly should be preceded by in-
ductivity (TDS), dissolved oxygen (D.0.), and temperature struction in the i indamentals of electricity.
indicators fit in this classification of instruments (Figure
19.27). We have already seen that process models of each
of these units monitor these same variables out in the plant. QUESTIONS
Operators rarely are required to do anything more tnan
make periodic readings from lab instruments, though stand- Write your answers in a iiotebook and then compare your
answers with those on page 382.
ardizing the particular instrument is often required before
the determination of a sample's turbidity or color is made. 19 3Q Why should an operator be especially careful when
Preventive, and certainly corrective, maintenance (if any) is working in a laboratory'?
handled by the chemist, factory rep, or instrument technician
19.3R Why should an operator become familiar with the
testing and calibration of plant measuring and control
systems'?
19.3S What is a V-0-M9

since each unit is quite specialized and complex. Some of

these countertop instruments or devices are quite delicate
and replacement parts, such as turbidimeter tubes or pH
electrodes, are quite expensive. Moreover, the use of many
of these instruments requires the regular handling of labora"--
tory glassware and other breakable items. The operator
who, through carelessness, lack of knowledge, or simple
hurrying, consistently breaks glassware or "finds the *I'
 Instrumentation 375

si.
5,1' isr 4' i' if'. 4' VIA Ruit' Phi' Pt
1-414i cdii In sn. f. Sb l' lei" I.

6 alllia ltfa 91,it 113 ''ilii 'lliRe "1 Pt

YiAu .714 ir TI' i:-Ph' rr 6
Tr tij ;,c 10.4 I u%
I
trid" 4.
1 1,
j.
II
A^ f rya icrCn
I
I a WI toi

r 13.27 Water laboratory instruments

19.4 OPERA i iOri AND PREVENTIVE MAINTENANCE CONSTITUTES NORMAL FUNCTION, AND FROM A MAIN-
TENANCE STANDPOINT, ENSURING PROPER AND CON-
19.40 Proper Care of Instruments TINUING PROTECTION AND CARE tir: EACH COMPO-
NENT.
Usually instrumentation systems are remarkably reliable
year after year, assuming proper application, setup, oper-
ation and maintenance. Measurement systems may be QUESTIONS
found still in service at some utilities up to 50 years after
installation To a certain extent, good design and application Write your answers in a notebook and then compare your
account for such long service life, but most important is the answers with those on page 382
careful operation and regu:ar maintenance of the instru- 19 4A List the three principles which are the keys to proper
ment's parts or components. The key to such proper "0 & M" instrument 0 & M.
is the operator's practical understanding of the system.
Operators must know how to (1) recognize properly func- 19.4B What generally ,s expected of an operator of instru-
tioning instruments, so as to prevent prolonged and damag- mentation systems from (1) an operations standpoint
ing malfunction. (2) shut down and prepare devices for and (2) a maintenance standpoint?
seasonal or prolonged nonoperation, and (3) perform pre-
ventive (and minor corrective) maintenance tasks to ensure
proper operation in the long term. By contrast, a sensitive
instrumentation system can be quite easily ruined in short 19.41 Indications of Proper Function
order with neglect of ANY ONE of the three principles listed
The usual pattern of day-to-day operation of every meas-
Operators should be familiar with the "Technical Manual" uring and control system in a plant should become so
(also called the "Instruction Book" or "Operating Manual") of familiar to all operators that they almost unconsciously
each piece of equipment and instrument encountered in a sense any significant change. This will be especially evident
plant. Each manual will have a section devoted to the and true for systems with recorders where the pen trac3 is
operation of some component of a measuring or control visible. An operator should watch indicators and controllers
system (though frequently not for the entire system). De- for their characteristic actions. With analog instruments,
tailed descriptions of maintenance tasks and operating each pen or pointer may display its own unique characteris-
checks will usually be found in the same section of the tics (though some may be virtually the same). Thus, the pen
manual. Depending upon the general type of ins.rt ,nt for "Flow Recorder A" may normally scribe out a one-eight-
(electro-mechanical, pneumatic, or electronic), the suggest- inch (3 mm) wide track due to inherent sensitivity or flow
ed frequency of the operation and maintenance/checking variations, whereas "Level Recorder B" may normally pro-
tasks can range from none to monthly. Accordingly, this duce a trace as steady as a rock (Figure 19.29). However, if
section of the Gourse only addresses itself to those general the flu./ pen is noticed as steady one day, or the level
tasks an operator might be expected to perform to operate indicc.,Ion widens due to a quiver, then the operator should
and maintain instrumentation systems. These general tasks suspect a problem. in this regard, signs of possible improper
can be summed up from the OPERATIONS STANDPOINT function (though not NECESSARILY so) include (Figure
AS LEARNING AND CONSTANT ATTENTION TO WHAT 19.29):
 i
Controls, lacks and Indicator

1. Range Switch: Has 12-positions. May be turned in either

direction. There are 5-voltage positions.
INIMIL.__
4-direct current positions. and three re- tt 'e
oesA ;53.....'11,-...3
5
c''4,s
sistance positions used to select desired 1
tp, ,
2. Function Switch:
ranges.
Has 3-positions D.C.. +D.C.. and A.C. To
measure DC voltage. current or resistance.
.
0
'
,----r-12---r-
vt.,..,-4...._
2 6 0 0
d

the function switch is set to D C.. or +D.C. .: 46 . he.

according to the polarity of the applied ,cm ou. mw Artic . It--
...A'A. .,:.
"!-.',:'.'",:4' . . ..... .0111 N DO
A"'" "%,`.°,: My...1 .0* 11.
current or voltage. Turning this switch n
verses the test lead connections without 5
removing the leads from the circuit under
test.
3. ZERO OHMS: This control is used to compensate for vari-
ation in the voltage of the internal batteries
4. Circuit Jacks: There al e 8-jacks. vo in each corner of the
sub-panel They pros ide an electrical con- 4

5. Meter:
nection to the test leads.
4-1 2" indicating instrument. Has a scale
e
for each function and range.
2/

Front Panel Controls, Jacks and Indicator

39
 Instrumentation 377

MEASURING /MONITORING SYSTEMS

4 CHARTS MOVE FROM RIGHT TO LEFT .4

1 °II

0 0 ® O
1 Normal function: Ink trace dark and steady, variable within expected range.
2. Pen skips. Pen dirty, dry, or not on chart; can pen/tubing, re-ink, check contact.
3. Wide trace: "No:sy" system, too sensitive; causes inking problems, can be adjusted out.
4. Flat trace (upscale): OK if usual for system, otherwise check sensor or process.
5. Trace to max. scale: Instrumentation problem (sudden or constant 100% unlikely).
6. Trace to min. scale: Process or sensor off, also may be signal loss.

CONTROL SYSTEMS
SET-POINT

1 Normal control: Pen trace steady, process or set-point changes controlled well.
2. Normal control: Small oscillations normal with process or set-point change.
3. Abnormal control: Excessive departure from set-point, "sloppy" controller.
4 Cycling or hunting: Unstable control, controller settings need adjustment.
5. Damped oscillations: Process upset, control OK if acceptable for process.
5. Worsening oscillations. System out of control due to process or set-point char:ge, service
required. Do not use "auto," switch to "manual" f ". itrol.

Fig. 19.29 Indications of proper and abnormal function

(systems with strip-chart recorders: circular chart indications are similar)

399
 378 Water Treatment

1 Very flat or steady pen trace is the system working at all, audible part of the alarm system is temporally squelched.
or is the variable really that constant?); When the operator returns, the audible alarm system may
2. Excessive pen/pointer quiver (causes undue wear on inadvertently not be reset. In both instances (individual or
parts, can usually be adjusted out); and collective loss of audible alarm) the consequences of such
inattention can be serious. Therefore, get in the habit of
3 Constant or periodic hunting, or spikes, in a pen/pointer checking and re-setting your annunciator system often.
(improper adjustment, control or other problem).
Additionally, it is not uncommon for a pointer or pen to QUESTIONS
become stuck at some position on its scale, usually at the Write your answers in a notebook and then compare your
extreme limits of movement. Pens are particularly prone to answers with those on page 382.
sticking, getting hung-up on the chart edge or in a tear or
hole. Therefore, operators should become observant not 19 4C List three possible signs of an improperly functioning
only of unusual pointer/pen movement, but unusual LACK of flow recorder.
movement by indicators and recorders. In the case of 19 4D Where or how are recording pens most likely to
recorders, you may LIGHTLY TAP an instrument to check on
become stuck or "hung-up?"
the pointer/pen motion. If a gentle tap does not cause slight
movement, a problem may well exist. Anyone hitting or 19 4E What is a common reason for nonoperation of pneu-
shaking a delicate instrument hard, however, in an attempt matic systems?
to check it cut, only reveals a lack of training in this area.
19.4F What is an indication of a serious problem in an
At times, firmly pushing an instrument into its case, or electrical instrument or power circuit"
closing the door completely, may close the interlock switch
and switch the system on, as designed. However, jamming
the device into its case, or slamming a door is NEVER 19.42 Startup/Shutdown Considerations
considered proper action. If a device still doesn't begin to
work, check the power connection and instrument fuse(s), if The startup and periodic (seasonal) or prolonged shut-
any. down of instrumentation equipment requires very little extra
work by the operator. Startup is limited mainly to undoing or
For pneumatic systems, an unnoticed failure of the instru- reversing the shutdown measures taken.
ment air supply is the most common reason for an inopera-
ble instrument. Such a failure of the air supply extends the When shutting down any pressure, flow or level measur-
inoperable situation to all pneumatic systems in the plant. ing system, valve off the access of water to the measuring
Complete functional loss of a single pneumatic instrument is element Exercise particular care, as explained previously,
rather rare, but erratic operation is not uncommon, due to regarding the ORDER in which the valves are manipulated
previously mentioned water or oil in the air supply. for any flow-tube installation. Also, the power source of
some instruments may be shut off, unless the judgment is
One of the surest indications of a serious electrical made that keeping an instrument case warm (and thus dry)
problem in instrument or power circuits is, of course, smoke is in order. In such cases, constantly moving parts, such as
chart drives, should be turned off With an electrical panel
room containing instrumentation, it is good practice to leave
some power components on (such as a power transformer)
to provide space heat for moisture control. In a known moist
environment, sealed instrument cases may be protected for
a while vwth a container of DESICCANTS ("indicating silica
gel which is blue if O.K. and pink when the moisture-
absorbent capacity is exhausted).
Though preventing the access of insects and rodents into
any area appears difficult, general cleanliness seems to help
and/or a burning odor. Such signs of a problem should never considerably Rodenticides are available to control mitt, this
be ignored. Smoke/odor means heat, and no device can is good preventive maintenance practice in any electrical
operate long at unduly high temperatures. Any electrical space Mice will chew off wire and transformer insulation,
equipment which begins to show signs of excessive heating and may urinate on other insulator material, leading to
must be shut down :nimediately, regardless of how critical it serious damage.
is to plant operation. Overheated equipment will very likely Nest-building activities of some birds can also be a
fail soon anyway, with the damage being aggravated by problem Screening buildings and equipment against entry
continued usage. Fuses and circuit breakers are not always by birds has become a design practice of necessity. Insects
designed to de-energize circuits before damage occurs, and and spiders are not known to ca se specific functional
cannot be relied upon to do so. problems. but startup and operation of systems invaded by
Finally, operators frequently forget to reset an individual ants, bees, or spiders should await cleanup of each such
alarm, either after an actual occurrence or after a system component of the system. All of these pests can bite or
test. This is especially prevalent when an annunciator panel sting. so take care!
is allowed to operate day after day with lit-up alarm indica- With pneumatic instrumentation, it is desirable to purge
tors (contrary to good practice) and one more light is not each device with dry air before shutdown. This measure
easily noticeable Also, when a plant operator must be away helps rid the individual parts of residual oil and moisture to
from the main duty station, the system may be set so the minimize internal corrosion while standing idle. As before,
5 Desiccant (DESS- uh -kant) A drying agent which is capable of removing or absorbing moisture from the atmosphere in a small
enclosure.
 Instrumentction 379

periodic blow-off of air receivers and filters keeps these cracked open briefly to cause a drop in reading. Be sure you
liquids out of the instruments to a large degree. Before crack the bypass valve. If you open the wrong valve the
shutdown, however, extra attention should be paid to instru- pressure may be excessive and be beyond the range of the
ment air quality for purging. Before startup each filter/ D.P. cell which could cause some problems. A float suspect-
receiver should again be purged. ed of being stuck (very constant level indication) may be
freed by jiggling its cable, or other measures taken to cause
Finally, pay attention to the pens and chart drives of a slight fluctuation in the reading.
recorders upon shutdown. Ink containers (capsules) may be
removed if deemed necessary, and chart drives turned off. A Whenever an operator or a technician disturbs normal
dry pen bearing against one track (such as zero) of a chart operation during checking or for any reason, operating
for weeks on end is an invitation to startup problems. Re- personnel must be informed ideally PRIOR TO the
inking and chart replacement at startup is an easy matter if disturbance. If a recorder trace is altered from its usual
the proper shutdown procedures were followed. pattern in the process, the person causing the upset should
initial the chart appropriately, with time noted. Some plants
QUESTIONS require operators to mark or date each chart at midnight (or
noon) of each day for easy filing and retrieval.
Write your answers in a notebook and then compare your
answers with those on page 382. In the case where a pen/pointer is thought to be stuck
mechanically that is, it does not respond at all to simulated
19.4G How can moisture be controlled in an instrument'? or actual change in the measured variable, it is normally
19.4H Why should pneumatic instrumentation be purged permissible to open an instrument's case and try to move
before shutdown? the pointer/pen, BUT ONLY TO THE MINIMUM extent
possible to establish its freedom. Further deflection may well
bend or break the device's linkage. A "dead pen" often is due
19.43 Maintenance Procedures and Records only to loss of power or air to the readout mechanism. Any
Preventive maintenance means that attention is given
periodically to equipment in order to PREVENT future mal-
functions. Corrective maintenance involves actual, signifi-
cant repairs which are beyond the scope of this work and
responsibility of the operator (in most cases). Routine oper-
ational checks are part of all P.M. (preventive maintenance)
programs in that a potential problem may be discovered and
thereby corrected before it becomes serious.
P.M. duties for instrumentation should be included in the
plant's general P.M. program. If your plant has no formal,
routine P.M. program, it should have! Such a program must
be set up "on paper." That is, the regular duties required are
printed on forms or cards which the operator (or technician)
uses as a reminder, guide, and record of P.M. tasks per-
formed. Without such explicit measures, experience shows
that preventive maintenance will almost surely be put of hard or repeated striking of an instrument to make it work
indefinitely. Eventually, the press of critical corrective main- identifies the striker as ignorant of good operational practice
tenance (often due to lack of preventive maintenance!) and and can ruin the equipment. Insertion of tools into an
even equipment replacement projects may well eliminate instrument case in a random "fix-it" attempt could damage
forever any hope of a regular P.M. program. The fact that the instrument. Generally speaking, any extensive operating
instrumentation is usually very reliable (being of quality check of instrumentation should be performed by the instru-
design) may keep it running long after r on-maintained ment technician during routine P.M. prog-am activities.
pumps and other equipment have failed. Nevertheless,
instrumentation does require proper attention periodically to
maxim,ze its effective life. P.M. tasks and checks on modern QUESTIONS
instrument systems are quite minimal (even virtually non- Write your answers in a notebook and then compare your
existent on some), so there are no valid reasons for failing to answers with those on page 382.
ever perform these tasks.
19.41 Why should regular preventive maintenance duties
19.4". Operational Checks be printed on forms or cards?
Operational checks are most efficiently performed by 19 4J How are operat:onal checks performed on instru-
always observing each system f ,r its continuing signs of ment equipment')
normal operation. However, some measuring systems may
19 4K What should be done if a recorder trace is altered
be cycled within their range of action as a check on the
from its usual pattern during the process of checking
responsiveness of components. For instance, if a pressure-
an instrument?
sensing system indicates only one pressure for months on
end, and some doubt arises as to whether it's working or
19.45 Preventive Maintenance
not, the operator may bleed off a little pressure at the
primary element to produce a small fluctuation. Or, if a flow The technical manual for each item of instrumentation in
has appeared constant for an overly long period, the bypass your plant should be available so you can refer to it for 0 & M
valve in the D.P. (Differential Pressure) cell pipings may be purposes. When a manual cannot be located, contact the

6 There is no similar easy .vay to check a propeller meter's response.

4ui
380 Water Treatment

manufacturer of the unit. Be sure to give all relevani serial/ instrument cleanings (such as turbidimeters) and stand-
model numbers in your request for the manual. Request two ardizing duties as required by your own plant's estab-
manuals, one to use and one to put in reserve. All equipment lished procedures.
manuals should be kept in one protected location, and
signed out as needed, Become familiar with the sections of As a final note, it is a good Idea to get to know and
these manuals related tc 0 & M, and follow their procedures cooperate fully with your plant's instrument service person.
and recommendations closely. Good communication between this person and the operating
staff can only result in a better all-around operation. If your
A good practice is to have on hand any supplies and spare agency is too small to staff such a specialist (most are), it
parts which are or may be necessary for instrument oper- may be a good idea to enter into an instrumentation service
ation (such as charts) or service (such as pens and pen contract with an established company or possibly even with
cleaner) Some technical manuals contain a list of recom- the manufacturers of the majority of the components. With
mended spare parts which you could use as a guide. Try to rare exceptions, general maintenance persons (even jour-
obtain these supplies/parts for your equipment. A new pen neyman electricians) are not qualified to perform extensive
on hand for a critical recorder can be a lifesaver at times. maintenance on modern instrumentation. Be sure that
Since P 'A measures can be so diverse for different types. someone takes good care of your instruments and they will
brands, and ages of instrumentation, only the few general take good care of you
considerations applicable to all will be covered in this
section. QUESTIONS
1. Protect all instrumentation from moisture (except as Write your answers in a notebook and then compare your
needed by design), vibration, mechanical shock, vanoal- answers with those on page 383.
ism (a very real problem in the field) and unauthorized
19 4L How can the technical manual for an instrument be
access.
obtained if the only copy in a plant is lost?
2 Keep instrument components clean on the outside, and 19 4M What instrument supplies and spare parts should
closed/sealed against inside contamination. This specifi- always be available at your plant?
cally includes spider webs and rodent wastes.
3. DON'T presume to lubricate, adjust, fix, calibrate, free-
19.5 ADDITIONAL READING
up, or modify any component of a system arbitrarily. If
you are not qualified to take any of these measures, then 1 TEXAS MANUAL, Chapter 14, instrumentation.'
don't do it.
2. AUTOMATION AND INSTRUMENTATION (M2). Obtain
4 DO keep record pens and charts functioning as designed from Computer Services, American Water Works Associ-
by frequent checking and service, bleed pneumatic sys- ation, 6666 West Quincy Avenue, Denver, Colorado
tems regularly as instructed, ensure continuity of power 80235. Order No. 30002. Price to members, $18.00;
for electrical devices, and don't neglect routine analytical nonmembers. $23.00

Etict of 14440tt of 2 Leiv4oto

I N4TCUMENTATI ON
DISCUSSION AND REVIEW QUESTIONS
Chapter 19. INSTRUMENTATION
(Lesson 2 of 2 Lessons)

Write the answers to these questions in your notebook 12 What problems are created by oil and moisture in
before continuing with the Objective Test on page 383. The instrument air, and how can these contaminants be
question numbering continues from Lesson 1. removed'?
8 What are the advantages and limitations of analog 13. Why should plant measuring and control systems be
versus digital indicators? regularly tested and periodically calibrated9
9 Why is it poor practice to ignore many of the lamps that 14 What could cause erratic operation of pneumatic instru-
are "lit up" (alarm conditions) on an annunciator panel? ments9
10 How should the constantly lit ur lamps (alarm condi- 15. Why should insects and rodents be kept out of instru-
tions) on an annunciator panel be handled? ments9
11 What controls are available to protect pumps from 16 How could you tell if a float might be stuck and how
damage? would you determine if it was actually stuck?

4 . i ,,,
.....
)
 Instrumentation 381

SUGGESTED ANSWERS
Chapter 19 INSTRUMENTATION

ANSWERS TO QUESTIONS IN LESSON 1 Answers to questions on page 349.

19 2A A sensor is the primary element that measures a
Answers to questions on page 343.
variable. The sensor is often a transducer o; some
19.0A Measurement instruments can be considered an type that converts energy of one kind into some other
extension of your human sens,,ls because they cm form to produce a readout or signal.
perform the same duties as your eyes and ears can 19.2B Pressure is measured by the novemen: of a flexible
directly.
element or a mechanically deformable device sub-
19.0B Water treatment processes and equipment that jected to the force of the pressure being measured.
could be monitored or controlled by measurement 19.2C Some sensors are fitted with surging and overrange
and control systems include influent and effluent protection to limit the effect of pressure spikes or
flows, basin levels, pump operation, chemical feed-
water hammer on the sensor.
ers and filter valves.
19.0C An advantage of instruments over our senses is that
Answers to questions on page 355.
instruments provide quantities or measurable infor-
matio.), whereas only qualitative information is avail- 19 2D Liquid level sensors include floats, displacers,
able from our senses. probes, pressure sensors, and bubbler tubes.
19.0D The analog readout of an instrument has a pointer (or 19.2E A signal can be generated by a float element by
other indicating means) that reads against a dial or attaching the float to a steel tape or cable that is
scale. wrapped around a drum or pulley. The level sensed
is transmitted as a signal (electrical) proportional to
Answers to questions on page 345. the rotation (position) of the pulley or drum.
19.0E An on-off type "controller" controls the automatic 19.2F Probes are used instead of mechanical systems to
starting-stopping of a pump or a chemical feeder measure liquid levels in sealed or pressurized tanks,
motor. or with chemimlly-active liquids.
19.0F Examples of "proportional control" in waterworks 19.2G A bubbler measures the ievel of a liquid by sensing
operations include: (1) chlorine residual analyzer/ (measuring) air pressure necessary to cause bubbles
controller; (2) chemical feed, flow paced (open loop); to just flow out the end of the tube.
(3) pressure- or flow-regulating valves; (4) continu-
ous level control of filter basins; (5) variable-speed Answers to questions on page 360.
pumping system for flow control.
19.2H The two types of flow readings are (1) rate of flow
19.0G The motor control station provides for on-off oper- and (2) total flow (volume).
ation of electric motors.
19 21 The two main types of larger flow measurement
devices are (1) velocity sensing and (2) differential-
Answers to questions on page 347. pressure sensing. Magnetic and ultrasonic devices
19.1A The general principles for safe performance on the are also used.
job are to ALWAYS avoid unsafe acts ana correct 19.2J Smaller service meters are one of the positive-
unsafe conditions. displacement types of total flow meters.
19 1B Electrical shock can cause death by asphyxiation 19.2K Velocity-sensing devices measure flows by sensing
and/or burning. the rate of rotation of a special impeller placed within
19.1C An electrical "explosion" could shower you with mol- the flowing system.
ten metal, startle you into a bumped head or elbow, 19.2L Flows are measured with ventun meters by sensing
or cause a bad fall. the pressure differential between the water pressure
',afore the restriction in the meter or tube, and the
Answers to questions or page 348. pressure within the restriction.
19.1D Operators should be especially careful when working
around powered automatic mechanical equipment Answers to questions on page 362.
because the equipment could start unexpectedly and
cause senous injury. 19.2M Chemical feed rates are measured on a weight or
volumetric basis if the chemical is in a dry solid form.
19.1E The purpose of an electrical lock-out device is to If chemical is in liquid form, s volumetric flow device
positively prevent the operation of an electrical cir- such as a rotameter may be used.
cuit, or to de-energize the circuit temporarily.
19.2N Process variables commonly measured and/or con-
19 1F If electrical current flows through your upper body, trolled by instruments include turbidity, pH, chlorine
electrical shock could harm your heart and/or your residual, fluoride, electrical conductivity, hardness,
head. alkalinity and temperature.
19.1G Thin rubber or plastic gloves can be worn to reduce 19.20 Values measured at one site are transmitted by a
markedly your chances of electrical shock. signal to a receiver at a remote location.

403
382 Water Treatment

19.2P The two general systems used to transmit measure- Answers to oitestions on page 374.
ment signals are electrical and pneumatic systems.
19.3Q Care must be exercised when working in the labora-
tory so as not to break the sensitive instruments,
ANSWERS TO QUESTIONS IN LESSON 2 delicate equipment, or fragile glassware.
19.3R Operators should become familiar with the testing
Answers to questions on page 364. and calibration of plant measuring and control sys-
19.3A The purpose of indicators is to give a visual presen- tems in order to assist instrument technicians, and to
tation of a variable's value, either as an analog cr as better understand the plant's instrumentation sys-
a digital display. tem. Also, development of skills in instrument testing
and calibration equipment may result in a job promo-
19.3B An analog display uses some type of pointer (or tion and/or pay raise.
other indicator) against a scale.
19.3S V-O-M stands for Volt-Ohm-Milliammeter, commonly
19.3C Recorders are usually found in a central location at a referred to as a multi-meter.
water treatment plant.
19.3D Factors that can cause electronic instrument prob- Answers to questions on page 375.
lems include temporary power failures, tripped panel 19.4A The three principles which are the keys to proper
circuit breakers, voltage surges (or lightning) result- instrument 0 & M are:
ing in blown fuses, and excessive heat.
1. Recognizing properly functioning instruments, so
as to prevent prolonged and damaging malfunc-
Answers to questions on page 368. tions,
19.3E Recorders are indicators designed to show how the 2. Shutting down and preparing devices for seasons
value of the variable has changed with time. or prolonged nonoperation, and
3. Performing preventive (and minor corrective)
19.3F Recorder charts may be circular or strip types.
maintenance tasks to ensure proper operation in
19.3G In remote locations where no electricity is available, the long term.
charts are driven by hand-wound drives or batteries.
19.4B General tasks expected of operators of instrumenta-
19.3H Alarms may produce either visual and/or audible tion systems can be summed up (1) from an oper-
signals. ations standpoint as learning and constant attention
to what constitutes normal function, and (2) from a
Answers to questions on page 369. maintenance standpoint, as ensuring proper and
continuing protection and care of each component.
19.31 An operator might bypass a proportional-type con-
troller in an emergency or when, in the judgment of Answers to questions on page 378.
the operator, the controller is not exercising control
within sensible limits. To bypass a controller, switch 19.4 C Three signs that a flow recorder may not be function-
to the manual mode of operation. ing properly are:

19.3J "On -off" controls should be programmed to operate 1. Very flat or steady pen trace (is the system
or cycle associated equipment on and off no more working at all, or is the variable really that con-
often than actually necessary for plant or system stant?);
operation. 2. Excessive pen/pointer quiver (causes undue wear
on parts, can usually be adjusted out); and
19.3K Pumps can be prevented from running 'Joon loss of 3. Constant or periodic hunting, or spikes, in a pen/
signal by electrical circuitry designed so the pump pointer (improper adjustment, control or other
will turn OFF on an OPEN signal circuit and ON only problem).
with a CLOSED circuit.
19.4D Recording pens are most likely to become stuck or
19.3L Pumps in a pump station can be operated for similar "hung-up" on the chart edge or in a tear or hole.
lengths of time by the use of manual or automatic
"sequencers" which switch different pumps to the 19.4E A common reason for nonoperation of a pneumatic
"lead" pump position and the other(s) to the lag" system is the failure of the instrument air supply
position periodically. caused by water and oil.
19.4F An indication of a serious problem in an electrical
Answers to questions on page 374. instrument or power cicuit is the presence of smoke
and/or a burning odor.
19.3M Signals are transmitted over long distances by the
use of signal transmission lines. These lines may be Answers to questions on page 379.
wires owned by the water agency, or telephone lines
19.4G Moisture can be controlled in instruments by a
leased from the local telephone agency. Radio or
space-heat source (such as a power transformer) or
microwave transmission is sometimes used.
by inserting a container of desiccant into its case.
19.3N A loss of signal causes the indicator to go to zero or
19.4H Pneumatic instrumentation should be purged with
to maximum scale, depending on type of signal.
dry air before shutdown to rid the individual parts of
19.30 Pneumatic instrumentation pressure systems must residual oil and moisture and to minimize internal
have a constant source of clean, dry, pressurized air corrosion.
for reliable operation.
19.3P Oil is removed by filtration through special oil-absor- Answers to questions on page 379.
bent elements, and a dryer desiccator or refrigera- 19.41 Regular preventive maintenance duties should be
tion is used to remove moisture from instrument air. printed on forms or cards for use by operators as a

404
 Instrumentation 383

reminder, guide and record of preventive mainte- Answers to questions on page 380.
nance.
19.4L To obtain a technical manual for an instrument, write
19.4J Operational checks are performed by always observ-
to the manufacturer. Be sure to provide all relevant
ing each system for its continuing signs of normal
serial/model numbers in your request to the manu-
operation, and cycling some indicators by certain facturer for a manual.
testing methods.
19.4K If a recorder trace is altered from its usual pattern 19.4M Instrument supplies and spare parts that should
during the process of checking an instrument, the always be available include charts, pens, pen clean-
operator causing the upset should initial the chart ers and ink, and any other parts necessary for
appropriately, with the time noted. instrument operation or service.

OBJECTIVE TEST
Chapter 19. INSTRUMENTATION

Please write your name and mark the correct answers on 8. A measured variable is that quantity which is sensed
the answer sheet as directed at the end of Chapter 1. There and quantified by a primary element or sensor.
may be more than one correct answer to the multiple choice 1. True
questions. 2. False
TRUE-FALSE
9. Pressure is sensed by mechanically immovable ele-
1. Accuracy of an instrument relates to the closeness of a ments.
measurement to the actual value. 1. true
1. True 2. False
2. False
10. Use of a bubbler tube is a very precise method of
2. A digital readout display provides a direct, numerical measuring water levels.
reading.
1. True
1. True 2. False
2. False

3. A motor control station provides for the on-off operation 11. When propeller meters become old, they become sus-
of an electric motor. ceptible to over registration (read hiyh).

1. True 1. True
2. False 2. False

4. The pressing down of a relay armature within an electri- 12. The permanent pressure loss through a ventun meter is
cal panel may cause an electrical "explosion" to shower greater than '.rough an orifice plate.
you with molten metal. 1. True
1. True 2. False
2. False
13. Pneumatic signal systems are commonly used over very
5. A danger may exist around powered mechanical equip- long distances.
ment even when the exposed rotating or meshing
elements have "guards" fitted in compliance with safety 1. True
regulations. 2. False
1. True
2. False 14. Operators may safely rely solely upon the readings of
instruments to ensure proper plant operation.
6. Power tools are often used to calibrate instruments. 1. True
1. True 2. False
2. False
15. Alarms are visual and/or audible signals that a variable
7. Falls are a leading cause of lost-time accidents. is out of bounds.
1. True 1. True
2. False 2. False

i ' 2'
40.;
 384 Water Treatment

16. Several different tone signals can be sent over the same which controls or adjusts the process variable.
pair of phone lines.
1. Control loop
1. True 2. Control system
2. False 3. Feedback
4. Linearity
17. A remote sensing and control station can send tone 5. Telemetry
signals to the water plant and simultaneously receive
tone signals to effect control at the site ove. the same 26 Which of the following items are safety provisions that
lines. may be used on electrical equipment?
1. True 1. Insulating covers
2. False 2. Lockouts
3. Safety switches
18. "Pneumatics" may operate for many years without sig- ,4. Torque ratings
nificant problems if they have a quality air supply. 5. Warning labels
1. True
2. False 27. When working on instruments while standing on a
ladder, you should
19. "Plant air" must be filtered and dried, as with "instrument 1. Carry tools on an electrician's belt.
air." 2. Leave tools on the ladder steps when not working.
1. True 3. Use a non-conductive type of ladder.
2. False 4. Wear a hard hat.
5. Wear thin rubber or plastic gloves.
20. If a gentle tap on an instrument causes a slight pen
movement, the instrument is functioning properly. 28. Pressure is measured or sensed by
1. True 1. Bourdon tubes.
2. False 2. Bellows.
3. Diaphragms.
4. Pistons.
5. Propellers.

MULTIPLE CHOICE 29 are used to measure the level of water.

1. Bubblers
21. Objectives of this chapter include how to 2. Displacers
1. Determine location and cause of measurement and 3. Electrical probes
control system failures. 4. Floats
2. Dismantle an automatic controller and repair it. 5. Stilling wells
3. Safely enter a vault without any ventilation system.
4. Test an electrical circuit with a screwdriver. 30. Velocity may be sensed
5. Use power tools in wet environments. 1. Chemically
2. Electrically
22. Operators should be able to 3. Hydraulically
1. Drain an air line. 4. Mechanically
2. Free a stuck pen. 5. Naturally
3. Repair a turbidimeter.
4. Replace a fuse. 31. Flow measuring devices include
5. Restore proper control of a controller. 1. Impellers.
2. Orifice plates.
23. refers to how closely an instrument measures 3. Propellers.
the actual value of the process variable being meas- 4. Rotameters.
ured. 5. Venturis.
1. Accuracy
2. Calibration 32. Which of the following process variables are usually
3. Precision monitored continuously by instrumentation in a modern
4. Repeatability water treatment plant?
5. Standardization 1. Chlorine residual
2. Conforms
24. Examples of proportional control encountered by water- 3. Iron and manganese
works operators include 4. pH
1. Chemical feed, flow paced. 5. Turbidity
2. Chlorine residual analyzer/controller.
3. Continuous level control of filter basins. 33. Advantages of digital panel indicators include
4. Row regulating valves 1. Cheaper than analog.
5. Pressure regulating valves. 2. Erroneous values easily recognized.
3. Quickly read.
25. is the circulating action between the sensor 4. Respond virtually instantly to variable change.
which measures a process variable and the controller 5. Rugged.
 Instrumentation 385

34. Causes of electronic instrument problems include 2 Air dryers.

3. Compressors.
1. Dirty instrument air.
4. Compressor controls.
2. Excessive heat.
5. Master air pressure regulators.
3. Temporary power failure.
4. Tripped panel circuit breakers.
38. Erratic performance by pneumatic instruments may be
5. Voltage surges.
caused by
35. Controls available to protect pumps from damage in- 1. Carbon dioxide in the air supply.
clude 2. Excessive temperature of air supply.
3. Oil in air supply.
1. High - pressure cut-off switches. 4. Over-pressurized air supply.
2. Lock-out switches. 5. Water in air supply.
3. Low-pressure cut-off switches.
4. Sensors that detect open or dosed signal circuits. 39. An operator should be alert for which of the pen
5. Warning tags. movements that could indicate a ootential problem9

36. Reliable operation of pneumatic instrumentation pres- 1. Constant hunting

2. Periodic spikes
sure system requires
3. Quivering pen movement
1. Clean air. 4. Similar cycles
2. Dry air. 5 Very flat pen trace
3. Pressurized air.
4. Properly lubricated air. 40. Recording pens may get stuck on or in
5. Uninterrupted power.
1. Chart edges.
2. Chart ends.
37. Essential parts of a plant's instrument air supply system 3. Holes.
include 4 Ink.
1. Air filters. 5. Tears.

fad of Olojeaive l'a4t.

40/
CHAPTER 20

SAFETY

by

Joe Monscvitz

404
388 Water Treatment

TABLE OF CONTENTS
Chapter 20. Safety

Page
OBJECTIVES
391
GLOSSARY
392

LESSON 1

20.0 Responsibilities
393
20.00 Everyone Is Responsible for Safety
393
20.01 Regulatory Agencies
393
20.02 Utilities
393
20.03 Supervisors
394
20.04 Operators
394
20.05 First Aid
395
20.06 Reporting
395
20.07 Training
398
20.08 Measuring
399
20.09 Human Factors
400

LESSON 2

20.1 Chemical Handling

402
20.10 Safe Handling of Chemicals
409
20.11 Acids
402
20.110 Acetic Acid (Glacial)
402
20.111 Hydrofluosilicic Acid
403
20.112 Hydrofluoric Acid
403
20.113 Hydrochloric Acid
403
20.114 Nitric Acid
405
20.115 Sulfuric Acid
405
20.12 Bases
405
20.120 Ammonia
406
20.121 Calcium Hydroxide
406
20.122 Sodium Hydroxide (Caustic Soda)
407
 Safety 389

20.123 Sodium Silicate . 407

20.124 Hypochlonte 407

20.125 Sodium Carbonate 408

20.13 Gases 408

20.130 Chlonne (Cl2) 408

20.131 Carbon Dioxide (CO2) 410

20.132 Sulfur Dioxide (SO2) 412

20.14 Salts 412

20.140 Aluminum Sulfate (alum) 413

2(l141 Ferric Chloride 413

20.142 Ferric Sulfate 413

20.143 Ferr )us Sulfate 413

20.144 Sodium Aluminate 413

20.145 Fluoride Compounds 413

2S15 Powders 414

20.150 Potassium Permanganate (KMn04) 414

20.151 Powdered Activated Carbon 414

20.152 Other Powders 415

20.16 Chemical Storage Drains 415

LESSON 3

20.2 Fire Protection 417

20.20 Fire Prevention 417

20.21 Classification 417

20.22 Extinguishers 417

20.23 Fire Hoses 418

20.24 Flammable Storage 419

20.25 Exits 419

20.3 Plant Maintenance 420

20.30 Maintenance Hazards 420

20.31 Cleaning 420

20.32 Painting 420

20.33 Cranes 42Z

421
20.34 Manholes

20.35 Power Tools 421

20.36 Welding 422

20.37 Safety Valves 422

20.4 Vehicle Maintenance and Operation 423

20.40 Types of Vehicles 423

410
1
 390 Water Treatment

20.41 Maintenance 423

20.42 Seat Belts 423
20.43 Accident Prevention 425
20.44 Forklifts . 425

LESSON 4

20.5 Electrical 7quipment .

428
20.50 Electrical Safety 428
20.51 Current - Voltage 428
20.52 Transformers 428
20.53 Electrical Starters 428
20.54 Electrical Motors .. 428
20.55 Instrumentation 429
20.56 Control Panels 429
20.6 Laboratory Safety 429
20.60 Laboratory Hazards 429
20.61 Glassware 429
20.62 ChemicsIs 431
20.63 Biological Considerations 431
20.64 Radioactivity 431
20.65 Laboratory Equipment 431
20.650 Hot Plates 431
20.651 Water Stills 431
20.652 Sterilizers 432
20.653 Pipet Washers 432
20.7 Operator Protection 432
20.70 Operator Safety 432
20.71 Respiratory Protection 432
20.72 Safety Equipment 432
20.73 Eye Protection 433
20.74 Foot Protection 433
20.75 Hand Protection 434
20.76 Head Protection 434
20.77 Water Safety 434
20.8 Preparation For Emergencies 435
20.9 Arithmetic Assignment 435
20.10 Additional Reading 437
Suggested Answers 438
Objective Test 441

411
 Safety 391

OBJECTIVES
Chapter 20. Safety

Following completion of Chapter 20, you should be able

to:
1. List the responsibilities of all persons and agencies
involved in waterworks safety,
2. Identify ano safely handle hazardous chemicals,
3. Recognize fire hazards and properly extinguish various
types of fires,
4. Safely maintain waterworks equipment and facilities,
5. Properly operate and maintain vehicles,
6. Recognize electrical hazards,
7. Safely perform duties in a laboratory, and
8. Protect other operators and yourself while working in and
around waterworks facilities.

4; ?,
392 Water Treatment

GLOSSARY
Chapter 20. SAFETY

DECIBEL (DES-uh-bull) DECIBEL

A unit for expressing the relative intensity of sounds on a scale from zero for the average least perceptible sound to about 130
for the average level at which sound causes pain to humans.

OLFACTORY FATIGUE (ol-FAK-tore-ee) OLFACTORY FATIGUE

A condition in which a person's nose, after exposure to certain odors, is no longet able to detect the odor.

OSHA OSHA
The Williams-Steiger Occupational Safety and Health Act of 1970 (OSHA) is a law designed to protect the health and safety of
industrial workers and also the operators of water supply systems and treatment plants.

TAILGATE SAFETY MEETING TAILGATE SAFETY MEETING

The term TAILGATE comes from the safety meetings regularly held by the construction industry around the tailgate of a truck.

41.3
 Safety 393

CHAPTER 20. SAFETY

(Lesson 1 of 4 Lessons)

20.0 RESPONSIBILITIES than 75,000,000 employees and has been the basis for most
of the current state laws covering employees. Also, many
20.00 Everyone Is Responsible for Safety state regulatory agencies enforce the OSHA requirements.
Waterworks utilities, regardless of size, must have a The OSHA regulations provide for safety inspections,
safety program if they are to realize a low frequency of penalties, recordkeeping and variances. Supervisors must
^ccide;it occurrence. A safety program also provides a understand the OSHA Act and must furnish each operator
means of comparing frequency, disability and severity w.th with the rules of conduct in order to comply with occupation-
other utilities. The utility should identify causes, provide al safety and health standards. The intent of the regulations
training, have means of reporting, and hold supervisors is to create a place of employment which is free from
responsible for the program implementation. Each utility recognized hazards that could cause serious physical harm
should have a safety officer or supervisor evaluate every or death to an operator.
accident, offer recommendations, and keep and apply statis-
tics. The z ffectiveness of any safety program will depend Civil and criminal penalties are allowed under the OSHA
upon ho' J the utility holds its supervisors responsible. If the Law, depending upon the size of the c "isiness and the
utility holds only the safety officer or the employees respon- seriousness of ;he violation. A routine violation could cost an
sible, the program will fail. The supervisors are key in any employer or supervisor up to $1,000 for each violation. A
organization. If they disregard safety measures, essential serious, willful or repeated violation could cause the employ-
parts of the program wi, lot work. The results will be an er or supervisor to be assessed a penalty of not more than
overall poor safety record. After all, the first line supervisor $10,000 for each violation. Penalties are assessed against
is where the work is being performed, and some may take the supervisor responsible for the injured operator. Opera-
advantage of an unsafe situation in order to get the job tors should become familiar with the OSHA regulations as
completed. The organization must discipline such supervi- they apply to their organizations. They must correct viola-
sors and make them aware of their responsibility for their tions and prevent others from occurring.
own and their operators' safety.

20.02 Utiiities
Safety is good business both for the operator and the
agency. For a good safety record to be accomplished, all Water utilities must make safety a part of management's
individuals must be educated and must believe in the pro- responsibility. Each utility should start and maintain a safety
gram. All individuals involved must have the conviction that program by holding its supervisors responsible for the
accidents can be prevented. The operations should be electiveness of the program. The utilities must have a
studied to determine the safe way of performing each job. reporting system to keep records; they may be required to
Safety pays, both in monetary savings and in happiness of submit reports to state and federal agencies. Even if the
the operating staff. utility does not submit reports to other agencies, it should
keep and review such reports on its own, as a means of
20.01 Regulatory Agencies reducing hazards to the operators.
There are many state and federal agencies involved in Each utility should develop policy statements on safety,
ensuring safe working conditions. The one law that has had giving Its objective concerning the operator's welfare (Table
the greatest impact has been the Occupational Safety and 20.1). The statement should be brief, but express the utility's
Health Act of 1970 (OSHA), Public Law 91-596, which 4aok recognition of the ne9d for safety to stimulate efficiency,
effect on December 29, 1970. This legislation affect: more improve service, improve morale and to maintain good

4 1i qi,
 394 Water Treatment

public relations. 'he policy should recognize the human thereby effectively ensure compliance with all aspects of the
factor (the unsafe act) as the most significant cause of utility's safety program.
accidents, and thereby emphasize the operator's responsi-
bility to perform the lob safely. The policy should be one of The problem, however, is one of toe supervisor accepting
providing the operators with proper equipment and safe this responsibility. The supervisor who wishes to complete
working conditions. Finally, it is essential that the policy the job and go on to the next one without taking time to be
reinforce the supervisory responsibility to maintain safe concerned about working conditions, the welfare of opera-
work practices tors, or considering any aspects of safety is a poor supervi-
sor. Only after an accident occurs will a careless supervisor
This policy statement should be made by every utility question the need for a work program based on safety. At
regardless of size. 1 he statement should be written and this point, however, it is too late, and the supervisor may be
given to each operator and all other employees and rein- tempted to simply cover up past mistakes. As sometimes
forced by the supervisory staff. Without such an objective, happens, the supervisor may even be partially or fully
the utility cannot hope to gain the loyalty and respect of its responsible for the accident by causing unsafe acts to take
operators, nor can it achieve efficient plant operation. The place, by requiring work to be performed in haste, by
utility must hold everyone responsible for safety and desig- disregarding an unsafe work environment or by overlooking
nate a specific individual to be responsible for an active, on- or failing to consider any number of safety hazards. This
going safety program. negligent supervisor could be fined, sentenced to a jail term,
or even De barred from working in the profession.
TABLE 20.1 SAFETY POLICY STATEMENT
All utilities should make their supervisors bear the great-
LAS VEGAS VALLEY WATER DISTRICT est responsibility for safety and hold them accountable for
SAFETY STATEMENT WORK RULE #920 planning, implementing and controlling the safety program.
If most accidents are caused and do not just happen, then it
The District recognizes its responsibility for providing the is the supervisor who can help prevent most accidents.
safest working conditions for its employees and customers.
This responsibility is met by means of a safety program Equally important are the officials above the supervisor.
which will be applied through the development of safety These officials include commissioners, managers, public
awareness among the e. nployees, the use of up-to-date works directors, chief engineers, superintendents and chief
safety equipment, and the continual inspection of conditions operators. The person in responsible charge for the entire
and practices by all levels of supervision. agency or operation must believe in the safety program. This
per.on must budget, promote, support and enforce the
It is the responsibility of every empk,yee to develop safe safety program by vocal and visible examples and actions.
working The development of proper attitudes toward The top person's support is absolutely essential for an
safety is the only method to improve safe working habits. effective safety program.
Therefore, training sessions play a large part in the safety
program. The District wants to protect all employees and the 20.04 Operators
public from injury and accidents. To accomplish this goal,
the safety program will involve everyone, and it will require Each operator also shares in the responsibility for an
the active participation and cooperation of all to make it effective safety program. After all, operators have the most
operate effectively. to gain since they are the most likely victims of accidents. A
review of accident causes shows that the accident victim
Safety training sessions are conducted for all Cistrict em- often has not acted responsibly. In some way the victim has
ployees and employees are expected to perform in a safe not complied with the safety regulations, has not been fully
manner Negligent or unsafe conduct by an employee will aware of the working conditions, has not been concerned
subject the employee to disciplinary action. about fellow employees, or just has not accepted any
responsibility for the utility's safety program.
QUESTIONS Each operator must accept, at least in part. responsibility
Write your answers in a notebook and then compare your for fellow operators, for the utility's equipment, for the
answers with those on page 438. operator's own welfare, and even for seeing that the super-
visor complies with established safety regulations. As point-
20.0A Wha` should be the duties of a safety office'', ed out above, the operator has thc, most to gain. If the
operator accepts and uses unsafe equipment, it is the
20.08 Who should be responsible for the ton of operator who is in danger if something goes wrong. If the
a safety program?
operator fails to protect the other operators, it is the opera-
20.0C Who enforces the OSHA requirements? tor who must make up the work lost because of injury. If
operators fail to consider their own welfare, it is they who
20 OD What should be included in a utility's policy statement suffer the pain of any injury, the loss of income, and maybe
on safety? even the loss of life.

20.03 ;supervisors
The success of any safety program will depend upon how
the supervisors of the utility view their responsibility. The
supervisor who has the responsibility for directing work
activities must be safety conscious. This supervisor controls
the operators' general environment and work habits and
influences whether or not the operators compiy with safety
regulations. The supervisor is in the best position to counsel,
instruct and review the operators' working methods and

415
 Safety 395

The operator must accept responsibility for an active role develops into a serious injury, it may be difficult at a later
in the safety program by becoming aware of the utility's date to prove the accident did occur on the job and have the
safety policy and conforming to established regulations utility accept the responsibility for costs. The responsibility
THE OPERATOR SHOULD ALWAYS CALL TO THE SUPER- for reporting accidents affects several levels of personnel.
VISOR'S ATTENTION UNSAFE CONDITIONS, environment, First, of course, is the injured person. Next, it is the respon-
equipment or other concerns operators may have about the sibility of the supervisor, and finally, the
work they are performing. Safety should be an essential part
of the operator's responsibility.
Ci4pons; IA I it.) of kianageinett_tU)
20.05 First Aid
veview the 4.4u4C4 andiate steps
By definition, first aid means emergency treatment for
injury or sudden illness, before regular medical treatment is pievetet suck 4904otevt-t4 (rout
available. Everyone in an organization should be able to give
some degree of pi ompt treatment and attention to an injury.
kappotIN/ iwthe &Uwe.
First aid training in the basic principles arid practices of Accident report forms may be very simple. However, they
life-saving steps that can be taken in the early stages of an must record all details required by law and all data needed
injury are available through the local Red Cross, Heart for statistical purposes. The forms shown here in Figures
Association, local fire departments and other organizations. 20.1 and 20.2 are examples for you to consider for use in
Such training should periodically be reinforced, so that the your plant. The report must show the name of the injured,
operator has a complete understanding of water safety, employee number, division, tale of accident, nature of
cardio-pulmonary resuscitation (CPR) and other life-saving in;_iry, cause of accident, first aid administered, and remarks
techniques. All operators need training in first aid, but it is for items not covered elsewhere. There should be a review
especially important for those who regularly work with process by foreman, supervisor, safety officer, and manage-
electrical equipment or must handle, chlorine and other ment. RECOMMENDATIONS ARE NEEDED AS WELL AS A
dangerous chemicals. FOLLOW-UP REVIEW TO BE SURE THAT PROPER AC-
First aid has little to do with preventing accidents, but it TION HAS BEEN TAKEN TO PREVENT RECURRENCE. In
has an important bearing upon the survival of the injured addition to reports needed by the utility, there are other
patient. A well-equipped first aid chest or kit is essential for reports that may be required by state or federal agencies.
proper treatment. The kit should be inspected regularly by For example, vehicle accident reports must be submitted to
the safety officer to assure that supplies are available when local police departments. If a member of the Public is injured,
needed. First aid kits should be prominently displayed additional forms are needed because of possible subse-
throughout the treatment plant and in company vehicles. quent claims for damages. If the accident is one of occupa-
Special consideration must be given to the most hazardous tional injury, causing lost time, other reports may be re-
areas of the plant such as shops, laboratories, and chemical quired. Follow-up investigations to identify causes and
handling facilities. responsibility may require the development of other specifi.,
types of record forms.
Regardless of size, each utility should establish standard In the preparation of accident reports, it is the operator's
operating procedures (SOP) for first aid treatment of injured responsibility to correctly fill out each form, giving complete
personnel. All new operators should be instructed in the details. The supervisor must be sure no information is
utility's first aid program. overlooked which may be helpful in preventing recurrence.

QUESTIONS
4afetti Officer utueot review
Write your answers in a notebook and then compare your
answers with those on page 438. Vie repont4 and cietzmiue
20.0E How could a supervisor be responsible for an acci- correftttive actions and maize
dent?
recommetidatioil4.
20.0F What types of safety-related responsibilities must
each operator accept? In day-to-day actions, operators, supervisors and man-
agement often overlook opportunities to counsel individual
20.0G What is first aid? operators in safety matters. Then, when an accident occurs,
20.0H First aid training is most important for operators they are not inclined to look too closely at accident reports.
involved in what types of activities? First, the accident is a series of embarrassments, to the
injured person, to the supervisor and to management.
20.06 Reporting Therefore, there is a reluctance to give detailed consider-
ation to accident reports. However, if a safety program is to
The mainstay of a safety program is the method of function well, it will require a thorough effort on the part of
reporting and keeping of statistics. These records are need- the operator, supervisor and management in accepting their
ed regardless of size of the utility, as they provide a means responsibility for the accident and making a greater effort
of identifying accident frequencies and causes as well as the through good reporting to prevent future similar accidents.
personnel involved. The records can be looked upon as the Accident reports must be analyzed, discussed, and the real
operator's safety report card. Therefore, it becomes the cause of the accident identifieu and corrected.
responsibility of each injured operator to fill out the utility's
accident report. Emphasis on the prevention of future accidents cannot be
overstressed. We must identify the cause= of accidents and
All injuries snould be reported, even if they are minor in implement whatever measures are necessary to protect
nature, so as to establish a record in case the injury operators from becoming injured.

61 .1 6
396 Water Treatment
Date

Name of injured employee Employee # Area

Date of accident Time Employee's Occupation
Location of accident Nature of injury
Name of doctor Address
Name of hospital Address
Witnesses (name & address)

PHYSICAL CAUSES
Indicate below by an "X" whether in your opinion, the accident was caused by:
Improper guarding _ Working methods
. Defective substances or equipment Lack of knowledge or skill
_ Hazardous arrangement Wrong attitude
_ Improper illumination Physical defect
Improper dress or apparel
No mechanical cause
Not listed (describe briefly)

UNSAFE ACTS
Sometimes the injured person is not directly associated with the causes of an accident. Using an "X" to represent the injured
worker and an "0" to represent any other person involved, indicate whether, in your opinion, the accident was caused by:
Operating without authority _ Unsafe loading, placement & etc.
Failure to secure or warn ____ Took unsafe position
Working at unsafe speed _ Worked on moving equipment
Make safety device inoperative Teased, abused, distracted & etc.
Unsafe equipment or hands instead of equip. ____ Did not use safe clothing or personal
protective equipment.
No unsafe act
_ Not listed (describe briefly)

What job was the employee doing9

What specific action caused the accident9
What steps will be taken to prevent recurrence9

Date of Report Immediate Supervisor

REVIEWING AUTHORITY
Comments: Comments:

Safety Officer Department Director Date

Fig. 20.1 Supervisor's accident report

41/
 Safety 397

INJURED: COMPLETE THIS SECTION

Name Age Sex

Address Marital Status

Title Dept Assigned

Place of Accident

Street or Intersection

Date Hour AM PM

Type of Job You Were Doing When Injured

Object Which Directly Injured You Part of Body Injured

How Did Accident Happen'? (Be specific and give details; use back of sheet d necessary).

Diu You Report Accident or Exposure at Once? (Exp'ain "No") Yes No

Did You Report Accident or Exposure to Supervisor?

Give Name Yes No

Were There Witnesses to Accident or Exposure'?

Give Names "(as No

Did You See a Doctor? (If Yes, Give Name) Yes No

Are You Going to See a Doctor? (Give Name) Yes No

Date Signature

SUPERVISOR: COMPLETE THIS SECTION (Fietum to Personnel as soon as Possible)

,Vas an Investigation of Unsafe Conditions and/or

Um-afe Acts Made'? If Yes, Please Submit Copy. Yes No

Was Injured Intoxicated or Misconducting

Himself at Time of Accident? (Explain "Yes") Yes No

Date Disability Last Day Date Back

Commenced Wages Earned on Job

Date Report Completed 19 Signed By

Title

Distribution Canary - Department Head. Pink - Supervisor. White - Personnel

Fig. 20.2 Accident report

-
. _,
413
398 Water Treatment

20.07 Training ture, if available. Tailgate talks should communicate to the

operator specific considerations, new problems, and acci-
If a safety program is to ever work well, management will
dent information. These topics should be published. One
have to accept responsibility for the following three compo-
nents of training: resource for such meetings can be those operators who
have been involved in an accident. Although it is sometimes
1. Safety education of all employees, embarrassing to the injured, the victim is now the expert on
how the accident occurred, what could have been done to
2 Reinforced education in safety, and prevent it, and how it felt to have the injury. Encourage all
3. Safety education in the use of tools and equipment. operators, new and old, to participate in tailgate safety
sessions.
Or to put it another way, the three most important controlling
factors in safety are education, education and education.
Responsibility for overall training must be that of upper
management. A program that will educate operators and
then reinforce this education in seety must be planned
systematically and promoted on a continuous basis. There
are many avenues to achieving this goal.
The safety education program should start with the new
operator. Even before employment, verify the operator's
past record and qualifications and review the pre-employ-
meat physical examination. In the new operator's orienta-
tion, include instruction in the importance of safety at your
utility or plant. Also discuss the matter of proper reporting of Use safety posters to reinforce safety training and to
accidents as well as the organization's policies and prac- make operators aware of the location of dangerous areas or
tices. Give new operators copies of all safety SOP's and show the importance of good work habits. Such posters are
direct their attention to parts that drectly involve them. Ask available through the National Safety Council's catalog.'
the safety officer to give a talk about utility policy, safety Awards for good safety records are another means of
reports and past accidents, and to orient the new operator keeping operators aware of the importance of safety. The
toward the importance of safety to operators and to the awards could be given to individuals in recognition of a good
organization. safety record. Publicity about the awards may provide an
incentive to the operators and demonstrates the organiza-
The next consideration must be one of training the new tion's determination to maintain a good safety record. The
operator in how to perform assigned work. Most supervi- awards may include: AWWA's water drop pins, certificates,
sors think in terms of On-the-Job Training (OJT). However, and/or plaques showing number of years without an acci-
OJT is not a good way of preventing accidents with al, dent. Consider publishing a utility newsletter on safety tips
inexperienced operator. The idea is all right if the operator or giving detat.is concerning accidents that may be helpful to
comes to the organization trained in how to perform the other operators in the organization. Awards may be given to
work, such as a treatment operator from another plant. Then the organization in recognition of its effort in preventing
you only need to explain your safety program and how your accidents or for its overall safety program. A suggestion
policies affect the new operator. For a new operator who is program concerning safety will promote and reinforce the
inexperienced in water treatment or in utility operation, the program and give recognition to the best suggestions. The
supervisor must give detailed consideration to the opera- goal of all these efforts is to reinforce concerns for the safety
tor's welfare. In this instance, the training should include riot of all operators. If safety, as an idea, is present, then
only a safety talk, but the foreman (supervisor) must train the acciden* s can be prevented.
inexperienced operator in all aspects of treatment plant
safety. This training includes instruction in the handling of Education of the operator in the use of tools and equip-
chemicals, the dangers of electrical apparatus, fire hazards, ment is necessary. As pointed out abo OJT is not the
and proper maintenance of equipment to prevent accidents. answer to a good safety record. A good safety record will be
Special instructions will also be needed for specific work achieved only with good work habits and safe equipment. If
environments such as manholes, gases (chlorine and hydro- the operator is trained in the proper use of equipment (hand
gen sulfide (H25)), water safety, and any specific hazards tools or vehicles), the operator is less likely to misuse them.
that are unique to your facility. The new operator must be However, if the supervisor finds an operator misusing tools
checked out on any equipment personnel may operate such or equipment, then it is the supervisor's responsibility to
as vehicles, forklifts, valve operators, and radios. All new reprimand the operator as a means of reinforcing utility
operators should be subjected to a safety orientation pro- policies. The careless operator who misuses equipment is a
gram during the first few days of their employment, and an hazard to other operators. Careless operators will also be
overall training program in the first few months. the cause of a poor safety record in the operator's division
or department.
The next step in safety education is reinforcement. Even if
the operator is well trained, m;stakes can occur; therefore, An important part of every job should be the consideration
the education must be continual. Many organizations use of its safety aspects by the supervisor. The supervisor
the "tailgate" method as a means of maintaining the opera- should instruct the foreman or operators about any dangers
tor's interest in safety. The program should be conducted by involved in job assignmen .s. If a job is particularly danger-
the first line supervisor. Schedule the informal tailgate ous, then the supervisor must bring that fact to everyone's
meeting for a suitable location, keep it short, avoid distrac- attention and clarify utility policy in regard to unsafe acts and
tions and be sure that everyone can hear. Hand out litera- conditions.

1 Write or call your looal safety council or National Safety Council, 444 N. Michigan Avenue, Chicago, Illinois 60611, phone toll free "hot
line" (800) 621-8051 (not applicable within Illinois).

41:3
 Safety 399

If the operator is unsure of how to perform a job, then it is TABLE 20.2 SUMMARY OF TYPES AND CAUSES OF
the operator's responsibility to ask for the training needeo. INJURIES
Each operator must think, act, and promote safety if the
organization is to achieve a good safety record Training is CAUSE OF INJURY
the key to achieving this objective and training is everyone's
en
responsibility maragement, the supe visors, foremen T; en
and operators c
w o
0 w
00
T.)
4 e: c
QUESTIONS To co
c 4s al
c ai _
4s .° E _i
Write your answers in a notebook and then compare your 6
ch
g
W .f./-)
t"
c
c c
rti 0 =
0-
C. X_
° 4F-
,,,C)

answers with those on page 438. .0 c w w ....' .. 0

Type of Injury
Type m 0 To'
u. x x 2 u_
co
ti C/) in 2 i--
20.01 What is the mainstay of a safety program')
Lacerations
20.0J Why should you report even a minor injury? Sprains
20.0K Why should a safety officer review an accident report Eye Injuries
form9
Bites
20 OL A new inexperienced operator must receive instruc-
tion on what aspects of treatment plant safety' Cuts
Bruises
20.0M What should an operator do if unsure of how to
perform a job? Contu,.ions

20.08 Measuring Miscellaneous

To be complete, a safety program must also include some

means of identifying, measuring and analyzing the effects of There are many other methods of analyzing data. Table
the program. The systematic classification of accidents, 20 2 could be rearranged by using cost in dollars rather than
injuries, and lost time is the responsibility of the safety operator-days lost. Not all accidents mean time lost, but
officer This person should use an analytical method which there can he other cost factors. The data analysis should
would refer to types and classes of accidents. Reports also indicate if the accidents involve vehicles, company
should be prepared using statistics showing lost time, costs, personnel, the public, company equipment, loss of chemical,
type of injuries and other data based on a specific time or other factors. Results also should show direct cost and
interval. Such data calls attention to the effectwer ass of the indirect cost to the agency, operator and the public.
program and promotes awareness of the types of accidents
that are happening. Management can use this information to Once the statistical data have been compiled, someone
decide where the emphasis should be placed to avoid must be responsible for reviewing it in order to take preven-
accidents. However, statistical data are of little value if a tive actions. Frequently such responsibility rests with the
report is prepared and then set on the bookshelf or placed in safety committee. In fact, safety committees may cperate at
a supervisor's desk drawer. The data must be distributed several levels, for example management committee, work-
and read by all operating and maintenance personnel ing committee, or an accident review board. In any evert, the
committee must be active, be serious and be reinforced by
management.

Another means of measuring safety is by calculating the

injury frequency rate for an indication of the effectiveness of
your safety program. Multiply the number of disabling injur-
ies by one million and divide by tha total number of employ-
ee-hours worked. The number of injuries per year is multi-
plied by one million in order to obtain injury frequency rate
values or numbers which are easy to use. In our example
problems we obtained numbers between one and one
thousand.
Injury Frequency (Numbe. of Disabling Injuries/year) (1,000,000)
_
Rate Number of Hours Worked/year
As an example, injuries can be classified as fractures,
burns, bites, eye injuries, cuts and bruises. Causes can be These calculations indicate a frequency rate per year,
referred to as heat, machinery, falling, handling, chemicals, which is the usual means of showing such data. Not that this
unsafe acts, and miscellaneous. Cost can be considered as calculation accounts only for disabling injuries. You may
lost time, lost dollars, lost production, contaminated water or wish to show all injuries, but the calculations are much the
any other means of showing the effects of the accidents. same.
Good analytical reporting will provide a great deal of detail
without a lot of paper to read and comprehend. Keep the EXAMPLE 1
method of reporting simple and easy to understand by all
operators, so they can identify with the causes and be aware A rural water company employs 36 operators who work in
of how to prevent the accident happening to themselves many small towns throughout a three-state area. The opera-
and/or other operators. Table 20.2 gives one method of tors suffered four injuries in one year while working 74,880
showing injury and cause in terms of operator-days lost. hours. Calculate the injury frequency rate.

420
400 Water Treatment

operators worked 74,880 hours. Calculate the injury severity

rate

Known Unknown
Number of Hours Lost = 40 hrs/yr Injury Seventy
Number of Hours Worked = 74,880 hrs/yr Rate

Calculate the injury sev' .ity rate.

(Number of Hours Lost/yr) (1,000,000)
Injury Severity Rate =
Number of Hours Worked/yr
(40 hrs/yr) (1,000,000)

Known 74,880 hrs/yr

Unknown
Number of Operators = 36 = 534
Injury Frequency Rate
Number of Injuries = 4/yr Notice that all these data points are based on a one year
time interval which makes them suitatle for use by the safety
Number of Hours Worked = 74,880 yr officer in preparing an annual report
Calculate the injury frequency rate.
Injury Frequency (Number of Disabling Injuries/year)(1,000,000) 20.09 Human Factors
_
Rate Number of Hours Worked/year
First, you may ask, what is a human factor? Well, it is not
(4/yr) (1,000,000) too often that a safety text considers human factors as part
74,880/yr of the safety program. However, if these factors are under-
= 53 4
stood and emphasis is given to their practical application,
then many accidents can be prevented. Human Factors
Engineering is the specialized study of technology relating to
the design of operator-machine interface. That is to say, it
examines ways in which machinery might be designed or
EXAMPLE 2 altered to make it easier to LI,. , safer, and more efficient for
the operator. We hear a lot about making computers more
Of the four injuries suffered by the operators in Example 1,
user friendly, but human factor engineering is just as impor-
one was a disabling injury. Calculate the injury frequency tant to everyday operation of other machinery in the every-
rate for the disabling injuries. day plant.
Known Unknown Many accidents occur because the operator forgets the
Number of Disabling Injuries = 1 yr Injury Frequency human factors. The ultimate responsibility for accidents due
Rate to human factors belongs to the management group. How-
Number of Hours Worked = 74,880 yr
ever, this does not relieve the operator of the responsibility
Calculate the injury frequency rate. to point out the human factors as they relate to safety. After
all, it is the operator using the equipment who can best tell if
Injury Frequency Rate (Nu ber of Disabling Injuries/yr) (1,000,000)
it meets all the needs for an inter-relationship between
(Disabling Injuries) Number of Hours Worked/yr operator and machine.
(1/yr) (1,000,000)
The first step in the prevention of accidents takes place in
74,830/yr the plant design. Even with excellent designs, accidents can
= 13 4 and do happen. However, every step possible must be taken
during design to assure a maximum effort of providing a
Yet another consideration may be lost-time accidents. The safe plant environment. Most often the operator has little to
safety officer's analysis may take into account many other do with design, and therefore needs to understand human
considerations, but in any event, the method given here will factors engineering so as to be able to evaluate these
provide a means of recording and measuring injuries in the factors as the plant is being operated. As newer plants
treatment plant. In measuring lost-time injuries, a severity become automated, this type of understanding may even be
rate can be considered. more important.
A severity rate :s based on ore lost hair for every million
operator-hours worked. The rate is found by multiplying the
number of hours lost by one million and dividing by the total
number of operator-hours worked.
(Number of Hours Lost/yr) (1,000,000)
Injury Severity Rate
Number of Hours Worked/yr

EXAMPLE 3
The water company described in Examples 1 and 2
experienced 40 operator-hours lost due to injuries while the
 Safety 401

Other contributing human factors are the operator's men- QUESTIONS

tal and physical characteristics. The operator's decision-
making abilities and general behavior (response time, sense Write your answers in a notebook and then compare your
of alarm, and perception of problems and danger) are all answers wi;:i those on page 438.
important factors. Ideally, tools and machines should func-
tion as intuitive extensions of the operator's natural senses 20.0N Statistical accident reports should contain what
and actions. Any factors disrupting this flow of action can types of accident data?
cause an accident. Therefore, be on the lookout for such
factors. When you find a system that cannot be acted upon 20.00 How can injuries be classified?
by inspection, change it. You may prevent an accident. If the
everyday behavior of an operator is inappropriate with 20.0P How can causes of injuries be classified?
regard to a specific job, reconsider the assignment to
prevent an accident. 20.00 How can costs of accidents be classified?
The human factor in safety is the responsibility of design
engineers, supervisors and operators. However, the opera-
tor who is doing the work will have a greater understanding
of the operator-machine interface. For this reason, the efti of 1.4244auloc414440144
operator is the appropriate person to evaluate the means of
reducing the human factor's contribution to the cause of
accidents, thereby improving the plant's safety record. Affii,

DISCUSSION AND REVIEW QUESTIONS

Chapter 20. SAFETY
(Lesson 1 of 4 Lessons)

At the end of each lesson in this chapter you will find some 4. Why should water utilities establish a reporting system
discussion and review questions that you should work that supplies data for a permanent record?
before continuing. The purpose of these questions is to
indicate to you how well you understand the material in the 5 Why do operators have the most to gain from an
lesson. Write the answers to these questions in your note- effective safety program?
book before continuing.
6. Who should review accident report forms?
1. Why must waterworks utilities have a safety program?
7. What topics should be included in a safety officer's talk
2. How can a good safety record be accomplished? to new operators?
3. What is the intent of the OSHA regulations? 8. What are the purposes of "tailgate" talks?
 402 Water Treatment

Chapter 20. SAFETY

(Lesson 2 of 4 Lessons)

20.1 CHEMICAL HANDLING

20.10 Safe Handling of Chemicals

The water treatment plant operator handles a wide variety
of chemicals depending on the type of plant. In a simple well
system, chlorine may be the only chemical used. In more
complicated plants, there may be chlorine, other gases,
sulfuric acid, lime, alum, powdered activated carbon and
anhydrous ammonia. All of these chemicals fall into groups:
acids, hydroxides, gases, salts, organics and solvents. Each
group requires you, the operator, to have a good under-
standing of all types of chemicals. You must know how to
handle the many problems associated with each of these treatment and gives their characteristics. This quick refer-
elements or compounds. For example, you must know how ence gives you a guide for learning some of each acid's
to store chemicals, understand the fire problem, the tenden- limitations and its reactivity with other compounds.
cy to "arch"2 in a storage bin, how to feed dry, how to feed
liquid, and how to make up solutions. All of these factors and The antidote to all acids is neutralization. However, one
many more problems may cause an unsafe condition. Over- must be careful in how this is peformed. Most often large
heating gas containers, dust problems with powdered car- amounts of water will serve the purpose, but if the acid is
bon, burns caused by arid, reactivity of each chemical under ingesteo (swallowed), then lime water or milk of magnesia
a variety of conditions that may cause fire and explosion are may be needed. If vapors are inhaled, first aid usually
other safety hazards. You will need to know the usable limits consists of providing fresh air, artificially restoring breathing
because of toxicity, the protective equipment required for (CPR), or supplying oxygen. In general, acids are neutralized
each chemical, each chemical's antidote, and how to control by a base or alkaline substance. Baking soda is often used
fires caused by each chemical. Although you may not to neutralize acids on skin because it is not harmful on
regularly handle all of the chemicals listed here, you may contact with your skin. To understand these reactions, you
come into contact with them from tine to time. Try at least to will need to know some acid-base chemistry. The knowledge
learn all of the characteristics or the chemicals you will use of acid-base chemistry and fast reactions on your part may
regularly. For example, learn the boiling point, explosive reduce the safety hazards involved in handling acids in water
limits, reactivity, flammability,, first aid used for each chemi- treatment.
cal, and other characteristics that may prove helpful in
preventing a safety hazard. Study the chemistry of each 20.110 Acetic Acid (Glacial)
chemical used in the plant in order to have a safe plant in
which to work. In the following discussions we shall concen- This chemical is stable when stored and handled properly.
trate on the characteristics of each compound and point out However, it may react v.olently with certain compounds such
its hazards, reactivity and the information needed to avoid as ammonium nitrate, potassium hydroxide and other alka-
conditions that may cause a safety problem. line materials. Strong oxidizing glacial acetic acid is a
combustible material. Fires involving the acid may be extin-
20.11 Acids guished wi.h water, dry chemical or carbon dioxide. Under
such conditions as adding water, the diluted acid may
Acids are used extensively in water treatment. For exam- produce hydrogen gas when it comes in contact with metals.
ple, hydrofluoric acid in fluoride addition or hydrochloric acid When the chemical is involved in a fire situation, self -
in cleaning Table 20 3 lists many of the acids used in water contained breathing apparatus must be used to protect the

TABLE 20.3 ACIDS USED IN WATER TREATMENT

Available Specific Flam-
Name, Formula Common Name Forms Gravity mability Color Odor Containers
Acetic Acid, CH3COOH Ethanoic Acid Solution 1.05 N/A Clear Sharp, pungent Carboys, drums
Hydrofluosilicic, H2SiF6 Fluosilicic Acid Solution 1.4634 N/A Clear Pungent fumes Drums, trucks
R.R. tank cars
Hydrogen Fluoride, HF Hydrofluoric Acid Liquid 0.987 N/A Clear Fumes, toxic Drums, tank cars
Hydrochloric Acid, HCI Munatic Acid Solution 1.16 N/A Clear to Pu 'gent, Drums, carboys
Yellow suifocating
Nitric Acid, HNO3 Liquid 1.5027 N/A Colorless, Toxic fumes in Drums, carboys,
yellowish presence of light bottles
Sulfuric Acid, H2SO4 Oil of Vitriol; Solution (60-66° Be) N/A Clear Odorless Bottles, carboys,
Vitriol 1.841 drums, truck,
tank cars
2 Arch. To form a bridge or arch of hardened or caked chemical which will prevent the flow of the chemical.
 Safety 403

operator against suffocation and problems caused by corro-

sive vapors

Most people :Ind inhalation of acetic acid vapors in

concentrations over 50 ppm intolerable, resulting in nose
and throat irritations. Repeated exposure to high concentra-
tions may produce congestion of the larynx. Skin contF.ct
with concentrated acetic acid can produce deep burns, with
skin destruction. High vapor concentration may blacken the
skin and produce allergenic reactions and eye irritation.
Possible permanent damage or immediate burns are caused
to the eye if the acid comes into contact with the eye. If the
acid is ingested, severe intestinal irritation will result as well
as burns to the mouth and upper respiratory tract.

Operators should be protected by adequate exhaust facili-

ties to ensure ventilation when working with acetic acid. At a
minimum, exhaust hoods should have air velocity of 100 fpm First aid for eye contact is to thoroughly flush with water
(30 m/min). Wear rubber gloves and an apron to prevent skin for 15 minutes and get medical aid as soon as possible. For
contact. Wear splash-proof goggles or a face shield to skin contact, wash the affected areas with water For gross
prevent any eye contact. Gas-tight goggles may also be (large) contact, remove contaminated clothing under a safety
needed to prevent vapors from irritating your eyes. An eye shower and thoroughly wash entire body for 15 minutes or
wash station must be readily available where this chemical is longer. In case of inhalation, remove operator to fresh air,
being handled. Also, respiratory equipment should be avail- restore breathing, if required, and get medical aid.
able for emergency use Acetic acid can be handled safely
by using adequate ventilation and safety equipment to 20.112 Hydrofluoric Acid
prevent skin and eye contact. Remember also that acetic
acid vapors can cause OLFACTORY FATIGUE(ol-FAK-tore- This acid :s extremely poisonous, and produces terrible
ee). This is a condition in which a person's nose, after sores when allowed to come into contact with the skin. The
exposure to certain odors, is no longer able to detect the z -id is a clear, corrosive liquid that has a pungent odor. All of
odor. Acetic acid is detectable by your nose at 1 ppm, but the precautions discussed for hydrofluosilicic acid apply to
documentation has shown operators tolerating up to 200 this acid also.
ppm.
20.113 Hydrochloric Acid
If a leak or spill should occur, notify safety personnel and
This acqi is used most often for cleaning in and around the
provide adequate ventilation. When cleaning up large spills,
treatment plant and is known as muriatic acid. The acid is
wear self-contained breathing apparatus and equipment to
prevent contact with eyes and skin. To clean up spill areas
also used very frequently in the laboratory. Hydrochloric
acid is stable when properly contained and handled. This
and remove chemical residue, cover the area with sodium
acid is one of me strong mineral acids and therefore, is
bicarbonate and flush away with an excess of water.
highly reactive v%ith metals and these oxides: hydrocarbon,
amine, and carbonate compounds. The acid liberates signifi-
First aid for a etic acid exposure calls for removal of the cant !avers of hydrogen chloride gas (HCI) bei..ause of its
victim to fresh air, rinsing the mouth and nasal passages vapor pressure at room temperature and gives off large
with water and checking for inhalation problems. If the acid amounts of gas when heated. In reactions with most metals,
made contact with the eyes, immediately irrigate with water hydrochlonc acid will produce hydrogen gas.
for at least 15 minutes. Obtain medical attention. For skin
contact problems, wash with water immediately, if the acid Inhalation of HCI vapors or mists for ;ong periods can
was swallowed, g.ve three glasses of milk or water and cause damage to teeth arir' irritation to me nasal passages.
obtain medical attention quickly Acetic acid exposure, like Concentrations u` 750 ppm or more will cause coughing,
all other acids, must be treate immediately to prevent choking and produce severe damage of the mucous mem-
damaae to the victim. branes of the respiratory tract. In concentrations of 1300
ppm, HCI is dangerous to life. Ingocnon can cause burns of
the mouth and diopstive tract.
20.111 Hydrotruosilicic Acid
When handling 11(.1. provide adequate exhaust facilities to
This chemical is hazardous to handle under any condi- ensure ventilation ard wear protective clothing and equip-
tions. Be extrer..aly careful using this acid. The acid is ment to prevent body contact with the acid. Use rubber
colorless, transparent, fuming, corrosive and is a Ii ,aid. A gloves, rubber apron. rubber boots and wear a long-sleeved
pungent odor is created by the acid and contact causes skin shirt when handling ydrochlonc acid To protect your eyes
irritation. When the acid vaporizes, it decomposes into against splashing of the acid, you mU i Near safety goggles
hydrofluoric acid and silicon tetrafluoride. Hydrofluoric acid and/or a face shield. There should iys be an eye wash
can attack glass. When handling the acid, always use station and safety shoNer located near -,reas where th.s acid
complete protective equipment, rubber gloves, goggles or is to be used.
face shield, rubber apron, rubber boots and have lime slurry
barrels, epsom salt solution and safety showers (Figure First aid consists of thoroughly flush ng the ayes with
20.3) available. Always provide adequate ventilation be- running water for 15 minutes and se,,ur 'g medical aid. If
cause its vapor can cause irritation to the respiratory sys- hydrochloric acid comes in contact ,ith skin, wash the
tem. Careful maintenance of protective equipment is essen- affected areas with water For gross co l'aC remove cloth-
tial because the umes of t acid corrode or etch glass on ing under the safety show-. and continu showering for 15
the protective equipment. minutes or longer. Shoula the acid be ingested, give 'me

4 2,1
 404 Water Treatment

Model 01-0354-07Face Wash. Yello-EowlTM,

and Stainless Steel pipe and valve.

Specially Coated Corrosion-Proof Models

In addition to corrosion-resistant Stainless Steel,
various coatings are available for protection
against corrosive atmospheres at additional cost.
The sprayed and baked epoxies as well as the
iew fluorocarbon coatings can be applied on all
galvanized and stainless pipe and fittings. Specify
type of coating required.

1 Plastic Models Available

All PVC plastic models for Face/Eye Washes
as well as combination Shower-Face/Eye Wash
assemblies. Ask your distributor for details.

Part 4'01-1128-06
Shower and wash sign.
Rugged plastic base,
yellow and black con-
trast, 8" x 18".

4
Model 01-0502-19Shower/Face Wash. Yello-
Bowl', Stainless Steel piping, fittings, and valves.

Fig. 20.3 Safety shower with face-eye wash

(Permission of Nevada Safety d Supply)
 Safety 405

water, or water and milk of magnesia. Do not induce materials and protect the containers from damagt or break-
vomiting; get medical aid. In case of inhalation, remove the age
victim to fresh air, restore breathing if required, and get
medical aid.
Store acid containers closed in a clean, cool, open and
well-ventilated area. Keep out of the sun. Keep the acid
away from oxidizing agents or alkaline materials. Provide
emergency neutralization materials in use areas.

20.114 Nitric Acid

Like hydrochloric acid, nitric acid is one of the most
commonly used acids in the water treatment laboratory and
plant. The acid is a powerful oxidizing agent and attacks
most metals. Nitric acid is stable when properly handled and
placed into a proper container. The acid is one of the strong
mineral acids, and is highly reactive with materials such as Because the acid is highly corrosive and causes severe
metals. When handling nitric acid, use protective clothing burns, first aid for sulfuric acid must be immediate to avoid
and equipment to prevent body contact with the liquid. Such substantial damage to human tissue. For eye contact. flush
equipment includes rubber gloves, rubber apron, and safety thoroughly with running water for 15 minutes, get medical
goggles or a face shield for eye protection against splashing aid the first seconds are important. For skin contact,
of the acid. Nitric acid is a strong, poisonous and highly wash affected areas thoroughly with water. For gross (large)
corrosive liquid and must be handled care illy. The acid contact, remove contaminateo clothing under the safety
forms toxic fumes in the presence of I,ght; therefore, it shower with prolonged washing for at least 15 minutes. In
should be kept out of the sun. cases of ingestion, give lime water or water and milk of
magnesia to drink; get medical aid. When working with
Like other acids, nitric acid should be stored in clean, cool, sulfuric acid, avoid skin contact and al nays provide emer-
well-ventilated areas. The areas should have an acid-resist- gency neutralization materials and a safety shower near the
ant floor and adequate drainage. Keep it away from oxidiz- work areas.
ing agents and alkaline materials. Protect containers from
damage or breakage. Avoid contact with skin and provide QUESTIONS
emergency neutralization materials id safety equipment in
use areas. Write your answers in a notebook and then compare your
answers with those on page 438.
First aid for skin contact is to flush thoroughly with water
for 15 minutes. Get medical aid if needed. This acid will 20.10A What does an operator need to know about chemi-
cause burns, but these can be greatly reduced if the contact cals used in a water treatment plant?
area is immediately flushed. For gross (large) contact, re- 20.11A What should be done if an operator inhales acid
move contaminated clothing under a safety shower. For eye
vapors?
contact, flush with water for 15 minutes and get medical aid.
If acid is ingested, give lime water or water with milk of 20.11B Acetic acid will react violently with which com-
magnesia; get medical aid. For inhalation, remove to fresh pounds?
air, restore breathing if required, and get medical aid.
20 11C Under what conditions can acetic acid be handled
20.115 Sulfuric Acid safely?

This mineral acid is highly corrosive and will attack most 20 11D What protective equipment is necessary for han-
metals. Sulfuric acid is also very reactive to the skin and ding hydrofluosilicic acid?
must be handled with extreme care or you will suffer severe 20.11E How can the inhalation of hydrochloric (HCI) vapors
burns. Even when the acid is diluted, it is highly corrosive or mists cause damage to opei,.tors?
and must be contained in rubber, glass or plastic-lined
equipment. The acid will decompose clothing and shoes. 20 11F How should nitric acid be stored?
Sulfuric acid should not come in contact with potassium
permanganate or similar compounds. Sulfuric acid reacts 20.12 Bases
violently with water. ALWAYS POUR ACID INTO WATER
The bases that are used in water treatment are known as
while stirring to prevent the generation of steam and hot hydroxides From a functional standpoint they are used to
water which could boil over the container and cause serious
raise pH. Most common bases are compounds of sodium,
acid burns.
calcium and ammonium which are strong bases. However,
As with other mineral acids, this material is stable when there are other weak bases, such as silicate, carbonate and
properly contained and handled. When you are handling hypochlonte. But from the p:Ant of safety, both weak and
sulfuric acid, you must use protective clothing and equip- strong bases must be given the same consideration when
ment to prevent body contact with the acid. Wear rubber being handled Some are very toxic, and will attack human
gloves, safety goggles and/or a face shield for eye protec- tissue very rapidly and cause burns. Explosive reactions will
tion against splashing. Also wear a rubber apron, rubber occur when bases come in contact with an acid and hazard-
boots, and long-sleeved shirt. The eye wash station and ous decomposition products are created under certain con-
safety shower must be located nearby where the acid is ditions. Bases must be neutralized with dilute acids. Howev-
being handled. The area should be well-ventilated, the acid er, the operator must work carefully because under some
should be stored in closed containers in a clean, cool, open conditions there may be other reactions, suk. as with
area. The area should have an acid-resistant floor which is hypochlorite compounds. Therefore, you should understand
well drained. Keep away from oxidizing agents and alkaline acid-base chemistry before handling any of the basic com-
 406 Water Treatment

pounds used in water treatment Table 20.4 gives some of neutralize liquid ammonia with an acid. The reaction gener-
the common basic compounds used in water treatment. The ates a lot of heat which may speed up the release of
following sections will discuss some of their characteristics ammonia gas.
and the precautiors the operator must use to safely handle
such compounds. First aid for skin contact with ammonia is to flush with
large amounts of water for 5 to 10 minutes and get medical
12.120 Ammonia aid Remove contaminated clothing under a safety shower.
For eye contact, flush thoroughly with water for 15 minutes
The operator may use one of two forms of ammonia, immediately, and get medical aid. In the case of inhalation,
anhydrous or hydroxide. The first (anhydrous) is in a gas remove to fresh air and restore breathing. If required, get
form and requires one type of consideration. The hydroxide medical aid. Nose and throat burns should be washed with
is a liquid and requires another type of consideration. water and rinsed with two percent boric acid solution. Urge
Anhydrous ammonia in the gaseous state is colorless, about the patient to drink large amounts of milk.
0.6 times as heavy as air. In a liquid state, ammcnia is also
colorless, 0.68 times as heavy as water and it vaporizes
rapidly. The ammonia gas is capable of form:ng explosive
mixtures with air. For your own safety, be aware of the
possibility of suffocation since the gas can displace air
which contains oxygen. Although the vapors are not poison-
ous, they can and will irritate the mucous membranes of the
eyes, nose, throat and lungs. Irritation will be detected in
concentrations of 5.0 ppm and when human tissue comes in
contact with the liquid, it will cause severe burns.
When handling ammonia or working in an ammonia e ivi-
ronment, respiratory protection is a requirement. For entry
into emergency areas, use only a self-contained breathing
apparatus. Install a good ventilation system to control va-
pors in the application room. Use protective clothing, rubber
gloves, apron, boots and face and eye protection if you are Ammonium hydroxide is an aqueous (watery) solution of
going to work with ammonia for long periods. anhydrous ammonia aid is quite volatile (will evaporate) at
atmospheric temperatures and pressures. This solution can
Care must be used when staring or transporting contain- cause local skin irritations A strong solution will cause
ers Always keep cylinders with caps in place when not in human tissue destruction on contact with eyes, skin and
use. Store cylinders in a cool, dry location away from heat mucous membranes of the respiratory system, so avoid
and protect from direct si.nlight. Storage near radiators, contact with the rumpound. The solution will cause severe
steam pipes or other sources of neat may raise the pressure burns depending upon solution icentrations and length of
to a dangerous point, whereas dampness -nay cause exces- contact time. The solution's vapor causes the same effects
sive corrosion. Do not store in the same room with chlorine. as the gas First aid should be the same as for anhydrous
Always use lifting clamps or cradles. Avoid hoisting the ammonia.
cylinde ,-; using ropes, cables or slings and never drop the
containers Control ammonia leaks. They can be detected by 20.121 Calcium Hydroxide
odor or by using a cloth swab soaked with hydrochloric acid.
This will form a white cloud of i',mmonium chloride. Hydrated lime (calcium hydroxide) is one form nf lime and
quicklime (calcium oxide) is another form. The hydrated lime
Ammonia gas will burn if it is blended with air in a mixture is the least troublesome of thP two forms. The hydrated lime
containing 15 to 28 percent ammonia by volume. Check is less caustic and is therefore less irritating to the skin, but
cylinder valve stems for leaks. tighten the packing gland nut can cause injury to eyes. However, as a dust, it is just as
only with a special wrench pr lided for such purposes. If a hazardous as quicklime. Quicklime is a strong caustic and
serious leak in a cylinder cannot be controlled, place the irritating to personnel exposed to the compound. When
container in a vat of water. Fifty-three pounds of ammonia quicklime is mixed with water, a great deal of heat is
will dissolve in 100 pounds of water at 68°F (20°C). NEVER generated which i..an cause explosions.

TABLE 20.4 BASES USED IN WATER TREATMENT

Common Available Spec. Gray.
Name, Formula Name Forms or Lbs/Cu Ft Flammability Color Odor Containers
Calcium Hydroxide and Hydrated Lime Dry Powder, 50-70 lbs N/A White Dust Bags, Bulk,
Oxide, Ca(OH)2 or CaO or Quick Lime Lump per cu ft Trucks
Sodium Hydroxide, NaOH Caustic, Lye Lump, Liquid, 1.524 May Cause Opaque Toxic, Drums, Bulk,
Flake Flammable White Pungent Trucks
Condition
odium Silicate, Na2SiO2 Water Liquid 1.35-1.42 N/A Opaque N/A Drums, Bulk,
Glass Trucks
Hypochlorite Compounds, HTH Powder Explosive with White Toxic C12, Cans, Drums
NaOCI, Ca(0C1)2 Antifreeze Pungent
Sodium Carbonate, Na2CO3 Soda Ash Powder 23, 35, and N/A White Dust Bags, Bulk,
65 lbs/cu ft Trucks
 Safety 407

Both quicklime and hydrated lime should be stored in cool, to the skin Consult a physician if required. In case of
dry areas. Care must be taken to avoid mixtures of alum and inhalation, remove victim to fresh air, call physician, or
quicklime, since quicklime tends to absorb the water that transport injured person to a medical facility For ingestion,
forms as alum crystallizes (water of crystallization) away give large amounts of water or milk and immediately trans-
from the alum. In a closed container this could lead to a port injured person to a medical facility, DO NOT INDUCE
violent explosion. Equal care should be taken to avoid VOMITING.
mixtures of ferric sulfate and lime.
You may also have occasion to use sodium hydroxide as
When handling bctti forms of lime, the operator should flakes or pellets All of the precautions stated for liquid
use chemical goggles and a suitable dust mask to protect caustic also apply for the flake form
the eyes arid mucous membranes. Also wear proper cloth-
ing to protect the skin, because with long contact the lime 20.123 Sodium Silicate
can cause dermatitis or burns, particularly at perspiration
This chemical is a liquid as used in water treatment.
points. Always shower after handling quicklime. All opera-
However, it is non-toxic, non-flammable, and non-explosive,
tors should wear a face shield when inspecting lime slakers.
but presents the same hazards to the eyes and skin as any
Hot lime suspension that splatters on the operator may other base compounds. Sodium silicate is a strong alkali and
cause severe burns of the eyes or skin. The hot mist coming
should be handled with care by using goggles or face shield,
from the slakers is also dangerous. The loss of water supply
wearing gloves and protective clothing. The chemical will
to a lime slaker can create explosive temperatures.
cause damage to the eyes and skin, but it is less dangerous
First aid for lime burns, which are like burns from other than other alkaline compounds used in water treatment.
caustics, consists of alternatively washing with water and a
mild acetic acid solution. One may also use large amounts of First aid for the eyes is to flush immediately and thorough-
soap and water. For eye contact, wash immediately with ly with flowing water for at least 15 minutes. Get medical
large amounts of warm water and rinse with a boric acid attention. If sodium silicate makes contact wit' ;kin, wash
solution. Get medical aid. For irritation of nose and throat thoroughly with water, particularly if the solution is hot. Then
because of exposure, see a physician. wash the skin with a 10 percent solution of ammonium
chloride or 10 percent acetic acid. For ingestion, give plenty
20.122 Sodium Hydroxide (Caustic Soda) of water and dilute vinegar, lemon or orange juice. Follow
this with milk, white of eggs beaten with water or olive oil.
Sodium hydroxide is available in pellet and flake forms. Call a physician.
Caustic soda usually comes as a 50 percent solution of
sodium hydroxide. This base is a strong caustic alkali and 2i) 124 Hypochlorite
very hazardous to the operator. This compound is extremely
reactive. Sodium hydroxide absorbs carbon dioxide from the A number of hypochlonte compounds are commercially
air, reacting violently or explosively with acid and a number available for use i water treatment. If you understand the
of organic compounds. Caustic soda 1) dissolves human precautions for one such compound, you will know what
skin, 2) when mixed with water ceases heat, and 3) reacts steps must be taken with other hypochlorite compounds,
with amphotenc metals (such as aluminum) generating hy- su,h as calcium, sodium, or lithium. These chemicals may
drogen gas which is flammable and may explode if ignited. be used in either a liquid or dry form. There are several
Sodium hydroxide can be dissolved in water and the solution grades of hypochlonte compounds, but all are good oxi-
used for the adjustment of pH because it is a liquid and easy dizers and are used for disinfection. When these com-
to feed. This base is extensively used in water treatment. pounds come into contact with organic materials, their
Because of its everyday use, you may forget just how decomposition releases heat very rapidly and produces
h, zardous this compound is and throug.. neglect may injure oxygen and chlorine. Although hypochlorite compounds are
yourself or another operator. Only trained and protected non-flammable, they may cause fires when they come in
operators should undertake spill cleanup. The operator contact with heat, acids, organic or other oxidizable sub-
must act cautiously, dilute the spill with water and neutralize stances.
with a dilute acid, preferably acetic. All solutions of hypochlorito. compounds attack the skin,
When handling caustic soda, control the mists with good eyes or other body tissues with which they come into
ventilation. Protect your nose and throat with an approved contact. When handling hypochlorite, liquid or dry, use
respiratory system. For eye protection, you must wear suitable protective clothing such as rubber gloves, aprons,
chemical workers goggles and/or a full face shield to goggles and/or a face shield. Be i. dare that many times
protect your eyes. There must be an eye wash and safety these compounds are stored in containers and give off
shower at or near the work station for this chemical. Protect chlorine gas when opened. Store these compounds in a
your body by being fully clothed, and by using impervious cool, dry, dark area.
gloves, boots, apron and face shield.
Special precautions to be taken when handling or storing
caustic soda include (1) prevent eye and skin contact, (2) do
not breath dusts or mists. and (3) avoid storing this chemical
next to strong acids. Dissolving sodium hydroxide in water
or other substances generates excessive heat, causes
splattering and mists. Solutions of sodium hydroxide are
viscous and slippery.
First aid for the eyes consists of irrigating the eyes
immediately and continuously with flowing water for at least
30 minutes. Prompt medical attention is essential. For skin
burns, immediate and continuous, thorough washing in
flowing water for 30 minutes is important to prevent damage

42j
 408 Water Treatment

First aid for eyes is to flush with plenty of water tor at least 20.13 Gases
15 minutes and see a ohysician. If hypochlorite compounds
come in contact with the skin, flush thoroughly with water for There are a number of gases used in water treatment
at least 15 minutes, and get medicai attention as needed. In (Table 20 5) Most are supplied in steel drum containers,
case of ingestion, wash out mouth thoroughly with water others must be generated on site. Some gases can be seen,
and give plenty of water to drink, and get medical attention. others call the operator's attention by odor, and still others
For inhalation, move the victim into fresh air and get medical cannot be seen or detected by odor, yet are deadly. In this
attention. section we shall only discuss those which are supplied in
containers that the operator must connect, disconnect,
Over-exposure to any of the hypochlonte compounds may handle or store.
produce severe burns, so avoid contact with these com-
pounds. They are hazardous and can attack skin, eyes, Exposure to the liquid form of these gases usually will
mucous membranes and clothing. cause damage to human tissue, such as skin burns, but the
most important factor to remember is the displacement of
oxygen. Most gases are heavier than ail a' id remove air
20.125 Sodium Carbonate from a room by displacement. Therefore, it is very important
to have the right type of ventilation and respiratory protec-
Soda ash is a mild alkaline compound, but requires safety
tion. Use only the self-contained breathing apparatus when
precautions to minimize hazards when handling the chemi- working in emergency areas.
cal. An adequate ventilation system is needed to control the
dust generated by the compound. Wear protective gear,
such as chemical safety goggles and/or a face shield, a well- 20.130 Chlorine (Cl2)
fitting dust respirator and protective clothing to avoid skin
contact. You should protect yourself by using a t,uitable
cream or petroleum jelly on exposed skin surfaces, such as
neck and hands. This compound's dust irritates the mucous
membranes and prolonged exposure can cause sores in
your nasal past.age.
First aid for exposure to eyes (dust or solution) requires
irrigation with water immediately for at least 15 minutes.
Consult a physician if the exposure has been severe. For
skin exposure, wash with large amounts of water; for
contaminated clothing, wash before reusing. For inhalation
or irritation of the respiratory tract, gargle or spray with
warm water, and consult a physician as needed.

QUESTIONS
Write your answers in a notebook and then compare your
answers with those on page 439.
20.12A What are the two forms of ammonia used by
operators? Safety is of the utmost importance when handling chlo-
rine. Do not treat chlorine cylinders roughly; never drop them
20.12B How should ammonia be stored? or permit collision of two or more cylinders. Never hoist
chlorine cylinders by the neck. Always use lifting clamps or
20.12C What are the two forms of lime used in water cradles
treatment plants? do not use ropes, cables or chains. Store the
cylinders in such a way that they cannot fall. Do not store
20.12D What would you do if someone swallowed sodium chlorine cylinders below ground level and always keep the
hydroxide? protective cap on the cylinder when it is not in use. Mark the
empty containers and store them aside from full cylinders.
20 12E What would you do if sodium silicate came in Always store containers in an upright position in a clean, dry
contact with your skin?

TABLE 20.5 GASES USED IN WATER TREATMENT

Common Available Spe nific
Name, Formula Name Forms Gravity Flammability Color Odor Containers
Ammonia, NH3 Ammonia Liquid-Gas 0.04813 lbs/ None Colorless Irritating Cylinders,
cu ft @ 0°C Tanks, Trucks
Chlorine, Cl2 Liquid Liquid-Gas 1.466 @ 0°C None Greenish Irritating Cylinders,
Chlorine Yellow One Ton Units,
Tank Cars
Carbon Dioxide, Dry Ice Liquid-Gas 0.914 None Colorless Odorless Bulk '_squid
CO2
Under Pressure
Sulfur Dioxide, Sulfuric Acid Liquid-Gas 1.436 (cy 0°C None Colorless Suffocating, Cylinders,
SO2 Anhydride Pungent One Ton Units,
Tank Cars

4`2:j
 Safety 409

location free of flammable materials. The storage area must All employees, ,maintenance personnel and operators who
be equipped with forced-exhaust ventilation with starting handle chlorine must have access to an approved chlorine
switches located.. n the outside of the storage room. Ventila- gas mask (Figure 20.4) They must be instructed in the use
tion must provide at least one complete air change per and maintenance of this equipment. A monthly program
minute. The temperature of the storage room should never should be conducted to familiarize and train each user of the
be permitted to approach 140°F (60°C). Protect the chlorine safety equipment. Those employees who are to use the
cylinder from heat sources and never use an open flame on chlorine emergency equipment should practice with this
cylinders or pipes carrying chlorine. If chlorine is heated, the equipment every six months while wearing a self-contained
increase in temperature will cause an expansion of the gas breathing apparatus. The emergency kit consists of clamps,
which results in an increase in pressure inside of the gaskets, drift pins, hammers, wrenches, and other tools
cylinders or piping, resulting in rupture of the containers. needed for repairing leaks. The operator may not be able to
practice with all of the tools, but inspection and practice
When working with chlorine, be equipped to control chlo- gives the operator an opportunity to do maintenance on the
rine leaks which are most often found in the control valve. emergency equipment.
Repair kits are available for the 100- and 150-pound (45 and
68 kg) cylinders, as is emerpency equipment for the one-ton All operators working with chlorine should be familiar with
(909 kg) tanks for controll;og leaks. Each operator must be methods of detecting chlorine leaks. When testing for leaks,
trained in the use of these emergency kits and must practice use ammonia water on a small cloth or swab on a stick or
with the equipment at least cnce a year. Always check out use an aspirator containing ammonia water. This will form a
even the slightest odor of chlorine; it may indicate a leak. white cloud of ammonia chlorine. Leaks should be repaired
Chlorine leaks only get worse. Small leaks can grow very immediately. Jo not apply the ammonia swab directly to the
rapidly causing serious problems that could have been equipment surface. Also do not spray ammonia into a room
easily solved as a small leak. There should always be two full of chlorine because a white cloud will form and you won't
operators attending a chlorine leak, one to do the repairs be able to see anything.
and the other to act as safety observer. Some repairs
require two operators to do the job (depends on leak and Many plants are equipped with chlorine gas detectors.
repair kit). Once again, use only the self-contained breathing This equipment must be maintained weekly. If not properly
apparatus when repairing a chlorine leak. maintained, it may not be operable when you need it.
Change the electrolyte regularly, test the alarm and keep the
When connecting chlorine cylinders, be very careful with detectors clean and in good repair.
the threaded connections; never use two washers, use only
one. If it does not work weii, remove the washer and use Someone must be assigned the responsibility for mainte-
another one. no not reuse an old or used washer; always nance of the self-breathing apparatus. That operator must
use a new washer. By taking this precaution, by cleaning the keep records of the maintenance problems and of monthly
threads and washer, and by being careful with the thread drills using the gear. The &signed operator should check
setting, many chlorine leaks will be prevented. You MUST be the masks for leaks, loose eyepieces, faulty tubing, or other
aware whether you are using gas or liquid when connecting worn or defective spots. If inspection indicates any defective
the container. On the one-ton (909 kg) tank, the top valve is parts, they should be discarded or repaired by a properly
for gas, the bottom valve is for liquid. If liquid chlorine is trained employee. Remember, in high concentrations of
allowed into a gas feed system it will cause "freezing"3 and chlorine within a confined space where oxygen can be
shut down (plug) the system. Similarly, if liquid gets into the displaced, DO NOT USE THE CANISTER TYPE OF MASK.
gas outlet, it will cause problems by "freezing." You must not NO CANISTER CAN PROVIDE OXYGEN. Therefore, use
panic in this situation. Do not do anything as foolish as only self-contained breathing apparatus or a hose-type
adding heat by open flame or electrical heaters to clear a mask supplied with air (Figure 20.5).
"frozen" (plugged) gas line. Get help from someone expe-
If you are caught in an area containing chlorine, do not
rienced with chlorine cylinders.
panic, but leave immediately. Do not breathe or cough, and
Never make repairs to the valve or chlorine container. Just keep your /' gad high until you are out of the affected area.
stop the leak, perhaps by tightening the packing on the valve The first safety measure you can take when entering a
stem or placing the safety device onto the cylinder. Let the chlorination room is to make sure the ventilating system is
chlorine supplier repair the container. Never use a wrench working. The ventilating system for the chlorination room
longer than six inches (15 cm) to open the cylinder valve, should be working all the time. Doors of chlorination rooms
making one complete turn of the valve stem in a counter- should have panic bars as door openers so that in an
clockwise direction. The one turn will open the valve suffi- emergency you will not have to search for the door opener.
ciently for the r;aximum discharge. As a safety consider- All safety equipment should be located outside of the
ation, cylinders are equipped with fusible metal plugs which chlorination room, but close enough so you can find the
are designed to melt at 158 to 168°F (70 to 76°C). This will al- equidment when needed.
low the cylinder contents to discharge and prevent rupturing
of the tank. On 100- to 150-pound (45 to 68 kg) cylinders, the First aid for eyes exposed to liquid chlorine is immediate
plug is located just below the valve seat. The one-ton (909 irrigation with flowing water for at least 30 minutes. Medical
kg) tanks have six such plugs; three on each end. Should attention is essential. If the eyes are exposed to chlorine
one of these plugs melt, permitting liquid chlorine to dis- gas, immediately irrigate with flowing water for a period of
charge, place the cylinder in a position with the leak at the 15 minutes. Get medical aid. If skin is exposed to liquid
top of the tank so that it permits the chlorine gas (rather than chlorine, it will most likely cause burns. The skin should be
the liquid) to discharge. This action will reduce the amount of washed with flowing water for 30 minutes. If the skin is
chlorine being discharged because the liquid will change to a burned, get medical attention. Chlorine gas can become
gas to escape. In doing so, it will lower the temperature of trapped in the clothing and react with body moisture to forn
the container, reducing the discharge rate.
3 Liquid chlorine becomes a solid around -103 to -10:,"C. The liquid can plug a chlorine gas line which operators refer to as a "frozen"
line.

43
 410 Water Treatment

SCOTT PRESUR-PAK Ha

SPECIFICATIONS BACKPAK STYLE

AIR SUPPLY
Rated Duration at moderate exertion 30 min.
(MESA/NIOSH test
procedure)

Cylinder Capacity at 2216 psi 45 ct,. ft.

USE FACTORS
Weight, as worn, fully charged 32 lbs.
(approx.)
Donning Speed (trained personnel) under 30secs.

Faceplate (Scottoramic winos* cup) Wide vision, antlfogging

Cylinder and Valve connection Straight thread, gasket seal
Cylinder Change Had disconnect, no tools req'd

Harness Webbing (replaceable without Polypropylene

tools or rivets)
Transport and Storage Custom Molded High Density
Polyethylene Case

SHIPPING WEIGHT 48 lbs.

NOTES: POSITIV1 PRESSURE
1h111111.1

Fig. 20.4 Chlorine gas mass

(Permission of Nevada Safety & Supply)

hydrochloric acid which co_ld burn the skin. Remove the

clothing of the victim and wash the body down with water. In
case of inhalation, remove the victim to fresh air, administer
oxygen if available, call a physician or transport the injured
person to a medical facility. Ingestion is not a problem
because chlorine is a gas at room temperature.
Each operator should have a copy of the Chlorine Insti-
tute's CHLORINE MANUAL.4 You should read this manual
and review it at least once every year. The manual gives data
concerning chlorine as an element and gives you 'sugges-
tions for safely handling this hazardous liquid or gas.
20.131 Carbon Dioxide (CO2)
Water plant operators are not often exposed to carbon cer."'ol the accumulating effects of the gas. If you must go
dioxide because of its limited use, but it is hazardous and into a CO2-filled room, use a self-contained breathing appa-
can cause suffocation due to the lack of oxygen. Therefore, ratus, not a canister gas mask. Carbon dioxide displaces
when using CO2 keep in mind the carbon dioxide safety oxygen and you may suffocate with the canister type of
considerations The problem with carbon dioxide is that it is mask. Exposure to carbon dioxide does not require any
odorless, colorless, and will accumulate at the lowest possi- protection of the eyes, skin or other parts of the body, but
ble level because it is heavier than air. take precautions when entering rooms, low spots, or man-
holes that may be filled with carbon dioxide.
Carbon dioxide is obtained in bulk lots, as a liquid under
pressure. This gas must be vaporized before using. CO2 is First aid involves moving the victim to fresh air, giving
also prepared by generation on site In either case, good resuscitation if the victim has stopped breathing, and getting
ventilation will reduce the hazards of using CO2. This will medical attention.

4 CHLORINE MANUAL (4th E( gion), The Chlorine Institute, Inc., 2001 L Street, SW, Washington, DC 20036. Price, $10.00

431
 Safety 411

Dual air supply cylinder being used with 900007 series

hoselin Air-Pak with Egress.

Typical fixed air supply installation usinb 'VI pressure air cylinders.

Fig. 20.5 Hose-type mask supplied with air

(Permission of Nevada Safety I Supply)

-4" It 14 43a
412 Water Treatment

20.132 Sulfur Dioxide (SO2) QUESTIONS

This gas is about 2.3 times as heavy as air and therefore Write your answers in a notebook and then compare your
will accumulate in low areas. Sulfur dioxide is colorless in answers with those on page 439.
the aaseous form. As a liquid it is also colorless arid, when
unconfined, will vaporize rapidly into a gas. The gas is 20.13A Where are chlorine leaks most often found?
extremely irritating and, like chlorine, will react readily with 20.13B What is the purpose of the fusible metal plugs on
the respiratory system if inhaled. Sulfur dioxide causes chlorine cylinders?
varying degrees of irritation to the mucous membranes
eyes, nose, throat and lungs. The damage is caused by the 20.13C How can chlorine leaks be detected?
formatior of sulfurous acid in reaction with moisture in these
locations. Sulfur dioxide can be readily detected in concen- 20.13D What safety considerations must be observed
trations of 3 to 5 ppm. In higher concentrations, it is unlikely when using carbon dioxide?
that you will remain in the area unless you are unconscious
or trapped. If the liquid comes into contact with the skin, it 20.14 Salts
may cause local freezing as the liquid evaporates. There are many salts (chemicals) used in water treatment.
Table 20.6 lists the salts that will be discussed in this
Always use self-contained breathir: apparatus around section. If you would like additional information about com-
sulfur dioxide and never use the canister type. As with other pounds not listed, request a data sheet about specific
gases, good ventilation is essential in a room where sulfur compounds from the suppliers of the chemicals. Review the
dioxide is being used. The fans should be used to dissipate chemistry of the compounds in Table 20.6 and become
any gas vapors that may occur. There should always be an familiar with each chemical's characteristics. You should
eye wash fountain close to the work area where sulfur become well trained in how to handle each chemical and
dioxide is used. know and observe the appropriate safety precautions. For
most of these salts, ventilation, respiratory protection and
First aid for eyes exposed to or splashed with sulfur eye protection will prove adequate. Other problems may
dioxide is washing immediately with water for at least 15 involved chemical solutions and dust. The solution may
minutes, then getting medical attention. In case of inhalation, attack skin and clothing. The dust may attack the respiratory
remove victim to fresh air, give resuscitation if needed, system or cause an explosion. Even though these chemicals
consult a physician or transport the injured person to a do not normally react violently, use the following procedures
medical facility. Sulfur dioxide leaks and injuries should be when handling such salts to reduce the hazards and to
treated similar to chlorine problems. provide a safe working location.

TABLE 20.6 SALTS USED IN WATER TREATMENT

Available Density,
Name, Formula Common Name Forms Lbs/Cu Ft Flammability Color Odor Containers
Aluminum Sulfate, Alum, Filter Alum Liquids, 1.69 (S.G.) None Ivory N/A Bags, Tank
Al2(504)3.14H20 Powder, hump 38-67 Truck, Bulk
Ferric Chloride, Ferrichior, Syrup, Liquid, 60-90 None Dark Brown, N/A Carboys, Tank
FeCI3 Chloride of Iron Lump Yellow-Brown Cars
Fel is Sulfate, Ferrifloc, Ferrisul Powder, 70-72 None Red-Brown N/A Bags, Drums
Fe2(SO4)3 Granule
Ferrous Sulfate, Coppras, Green Crystal, 63-66 None Green N/A Bags, Drums.
FeSO4.7H20 Vitriol Granule, Lump Bulk
Sodium Aluminate, Soda Alum Dry Crystal, (27° Be) None White, Green- N/A Bags, Bulk
Na20 A1203 Liquid Yellow
Fluoride Compounds, Liquid and 50-75 None Blue, Dust Bags, Carboys,
NaF Powder White Tank Trucks
H3Si F6,

Sodium Hexameta- Calgon, Glassy Crystal, 47 Nkine White N/A Bags, Drums
phosphate, (NaPO3)6 Phosphate Flake
Copper Sulfate, Blue Vitriol, Crystal, 60-90 None Blue None Bags, Drums
CuSO4 Blue Stone Lump, Powder
Sodium Chlorite, Technical Powder, Flake, 70 dry Oxidizer Light Orange None Tank Truck,
NaOCI Sodium Chlorite Liquid 100 lb. Drums
Potassium Permanganate Crystal 90-100 Oxidizer Purple None Drums, Bulk
Permanganate,
KMnO4

433
 Safety 413

When handling, stonng or preparing solutions of chemi- First aid for liquid or dry alum is immediate flushing of the
cals, treat them all as being hazardous. All chemicals require eyes for 15 minutes with large amounts of water. Alum
careful consideration. They may be sources A an explosion, should also be washed off the skin with water because
violent reaction, loss of eyesight, burns and illness. prolonged contact will cause irritation.
Do not store ac;d or oasic compounds with salts. Keep
these chemicals in clean, dry area. When handling dry bulk 20.141 Ferric Chloride
materials, store in a fire-safe area. Keep all lids on contain- This is a very corrosive compound and should be treated
ers ind follow the instructions on the container Make sure A S you would treat any acid. Tha salt is highly soluble in
that the operator who is mixing or dispensing these chemi- water, but in the presence of moist air or light, it decom-
cals is well trained and wears proper clothing to meet all poses to give off hydrochloric acid, which may cause other
safety requirements, such as chemical goggles, face shield, problems regarding safety. Avoid prolonged exposure to
rubber gloves, rubber boots, rubber apron and chemical this liquid (there is a dry form but it is not often used). When
respirator. When working with chemical salts, be aware that handling liquid ferric chloride, normal precautions should be
fumes, gases, vapors, dusts or mists may be given off and taken to prevent splashing, particularly if the liquid is hot.
this represents a hazard to the safety of the operator. Use a face shield to protect your eyes and rubber aprons to
PROTECT YOURSELF! protect clothing. This compound will not only attack the
clothing, but also stain it. First aid for eyes exposed to the
20.140 Aluminum Sulfate (alum) liquid is that the eyes must be flushed out immediately for 15
There are two forms of alum; dry and liquid. Both have to minutes with large amounts of water. Ferric chloride should
also be washed off the skin with water as prolonged contact
be handled with care. Dry alum is available in the lump,
will cause irritation and staining of the skin.
ground or powdered form and should be stored in a dry
location because moisture can cause caking. Liquid alum is
20.142 Ferric Sulfate
acidic and very corrosive. Store liquid alum in corrosion
resistant storage tanks such as: This compound produces an acidic solution when mixed
with water. Because of its acidic nature, operators using this
1. Steel, wood (Douglas Fir), or concrete-lined, all lined with
compound should be provided with protection suitable for
8-lb lead,
dry or liquid alum. The hazards associated with the use of
2. Steel, lined with 3/16 inch (5 mm) soft rubber, dry ferric sulfate are those usually connected with an acid.
Use protective clothing, neck cloths, gloves, goggles or face
3. Stainless steel, shield, and a respirator. Avoid prolonged exposure to the
4. Steel, lined with alai:tic if temperature remains below dry form because of its acidic reaction with moisture on the
150°F (65°C), and skin, eyes and throat. The normal precautions should be
used including a dust mask and protective clothing. First aid
5 Glass reinforced epoxy or polyester plastic. for exposure to the eyes requires the eyes to be flushed
immediately with lot* water. The skin should also be
When working with dry alum, use respiratory protection flushed with large amounts of water. Prolonged contact may
and ensure adequate ventilation of the work area. There cause irritation.
should be a good mechanical dust-collection system to
minimize any dust collection.
20.143 Ferrous Sulfate
This chemical may be obtained in liquid or dry form. The
WeVei4 44e.E44e 5a la Co-Rs/ewe safety hazards are some of those for dry or liquid forms of
alum The operator should be provided with adequate venti-
fOrdltaCitafge al441 1.144 lation and respiratory protection The material should be
stored in a clean, dry location. Mechanical dust collecting
141,4t41140 mat; axplexte under equipment must be used to minimize the dust. Wear chemi-
reopereoucton+, cal goggles or a face shield, loose fitting, long-sleeved
clothing, and make an effort to minimize all skin exposure.
First aid for ferrous sulfate in the eyes is to flush out
Exposure to alum dust greater than 15 milligrams per cubic immediately with large amounts of water for 15 minutes. The
meter of air for more than an 8-hour period is dangerous. chemical should be washed off the skin to reduce irritations.
Avoid skin exposure to this chemical by using long-sleeved,
loose fitting, dust-proof clothing. 20.144 Sodium Aluminate
Liquid alum is an acidic solution and should be handled as Sodium aluminate dissolved in water produces a non-
you would handle a weak acid. Reduce exposures to the corrosive solution. In the dry form, its powder consistency
skin and eyes Avoid ingestion. Although the chemical will raises the usual dust problems. There are few hazards with
not cause any lasting internal damage, it will be uncomfort- this compouna, but as with other chemicals, you should use
able Use good ventilation for removing any mists. Rubber precautions when handling it. Use respiratory protection
gloves and protective clothing is recommended. when handling the dry compound to prevent the inhalation of
As a general precaution, avoid prolonged exposure to dry dust First aid for eyes that are exposed is to flush with
or liquid forms of alum. If used dry, a dust mask and goggles water; keep the skin clean with water.
are desirable for the comfort of the operator. Alum dust can 20.145 Fluoride Compounds
be extremely irritating to the eyes. When handling the liquid,
normal precautions should be used to prevent splashing of All fluoride compounds should be treated with care when
the compound onto the operator, particularly the liquid is you are handling them because of their long term accumula-
hot Wear a face shield to protect your eyes and a rubber tive effects. Provide good ventilation; always wear respira-
apron to protect clothing. tory protection; and be careful not to expose any open cuts,

CV* 434
414 Water Treatment

lesions (wounds), or sores to fluoride compounds Clean up To avoid inhalation of potassium permanganate dust, use
any spills promptly ano wash immediately after handling an approved mask wh.ch is an air-purifying half-mask respi-
such compounds. rator with an outblower Safety glasses or a full face shield
should be worn to protect your eyes. Protective clothing that
When handling am' compounds of fluoride, always wear a
should be worn includes rubber or plastic gloves and apron,
face shield and/or chemical goggles, rubber gloves, rubber
and a long-sleeved shirt for handling both dry and dissolved
apron and rubber boots. Your wearing apparel should
potassium permanganate.
always be washed after working around fluoride, and the
respirator should be kept CIP.111 and sanitary Keep the acid !odd exposure will cause sneezing and mild irritation of the
feeder for fluoride in good repair. Use plastic guards to mucous membu.nes Prolonged inhalation of potassium
prevent acid spray from glands or other parts of the chemi- permanganate should be avoided. If potassium permangan-
cal feeder This prevents attack upon the equipment and ate gets on your skin, flood the contacted skin with water If
protects operators All fluoride compounds must be regard- it gets in your eyes, flush with plenty of water and call a
ed as hazardous chemicals that are toxic to operators. Every physician immediately.
means possible must be taken to prevent exposure to these
compounds by use of respirator and protective clothing. 20.751 Powdered Activated Carbon
First aid for fluoride compounds is limited, but the follow- Powdered activated carbon is the most dangerous pow-
ing precautions should be used. For the eyes, flush immedi- der that you will be exposed to as a treatment plant
ately with warm water and consult a physician. For external operator. If you understand how to handle activated carbon
injuries, wash with large amounts of warm water. For properly, other dust problems or powdered chemicals will
poisoning, the victim should drink a glass of lime water, or a not be very difficult for you to handle.
one percent solution of calcium chloride, or a large amount
of milk. See a doctor. There are two problems when handling activated carbon.
One is dust and the second is fire. The two may or may not
be related. The dust causes uncomfortable working condi-
QUESTIONS tions; fire causes damage to equipment and a hazard to
Write your answers in a notebook and then compare your personnel. If the two problems are treated together, it will
answers with those on page 439. reduce the hazards to operators. Left unattended they may
cause loss of life and property. If you will use the following
20 14A What kind of protection does an operator need safety precautions, you can minimize the hazards of han-
when handling salts? ding activated carbon and aid the other operators in han-
dling other powders.
20.14B What is the recommended first aid when either
liquid or dry alum comes in contact with your skin or Store activated carbon in a clean, dry, fireproof location.
your eyes? Keep free of dust, protect from flammable matenals, and do
not permit smoking in the area at any time when handling or
20 14C What happens when ferric chloride is exposed to unloading activated carbon. Install carbon dioxide fire extin-
moist air or light') guishers. Store bagged carbon in single rows. Keep access
aisles free to prevent damage to the bags and thus reduce
20.15 Powders the dust and fire potential.
Electrical equipment in and around activated carbon stor-
20.150 Potassium Permanganate (KMnO4)
age should be explosion proof and protected from the
Under normal conditions in a water treatment plant, potas- carbon dust. Keep the equipment clean and dry. Wet or
sium permanganate :s considered to be a safe chemical. damp carbon is a good conductor of electrical current and
However, potassium permanganate is a strong oxidizing can cause short-circuit fires Heat can also build up from the
agent and will react with certain easily oxidizable sub- motors if covered with carbon dust, causing fires. The key to
stances. Keep potassium permanganate away from the controlling fires with activated carbon is keeping the storage
possibility of reacting with sulfuric acid, hydrogen peroxide, area clean and dust free.
metallic powders, elemental sulfur, phosphorus, carbon,
Next to electrical fires, activated carbon gives the operator
hydrochloric acid, hydrazine, hydroxylamine, and metal hy-
drides. When in contact with potassium permanganate, the the most difficult fire to control. The carbon gives off an
following compounds may ignite: ethylene glycol (anti- intense heat; it burns without smoke or visible flame. The
freeze), glycerine, sawdust compounds, propylene glycol, fires are difficult to locate and are very hard to control. They
and sulfuric oxide. cannot readily be detected in a large storage bin or in large
stacks of bags.
Potassium permanganate is available either as pellets or
as a powder. This chemical can be kept indefinitely if stored
in a cool, dry area in closed containers. The drums should be
Oa* dactivateci cavi,ost
protected from damage that could cause leakage or spillage *haul& be 4,oved iit4yii41¢ ivst05.
Potassium permanganate should be stored in fire-resistant
buildings, having concrete floors instead of wooden floors. You will detect the indications of the fire before seeing any
The chemical must not be exposed to intense heat, or stored evidence of flames, such as the smell of charred paper,
next to heated pipes. Organic solvents, such as greases and burned paint or other odor.
oils, should be kept away from stored potassium perman-
ganate. Do not douse a carbon fire with a stream of water. The
water may cause burning carbon particles to fly, resulting in
Potassium permanganate spills should be swept up and a greater fire problem. The carbon fire should be controlled
removed immediately. Flushing with water is an effective with carbon dioxide (CO2) extinguishers or hoses equipped
way to eliminate spillage on floors. Potassium permangan- with fog nozzles. However, when using CO2, be aware that
ate fires should be extinguished with water. there is a potential of carbon monoxide formation and

Aft

435
 Safety 415

take the precaution of using a self-contained breathing liquid compounds can and will attack skin. but can be
, -..c-_,

apparatus treated by washing with ample amounts of water and/or

soap and water Organic coagulant aids (polymers) are
Activated carbon supports fire without atmospheric oxy- extremely slippery when wet. Floors and walkways should
gen because it may have absorbed sufficient oxygen for be dean and dry to prevent slips and falls.
combustion. The best means of controlling a carbon fire is to
reduce its temperature below the ignition point. This can be As new compounds are introduced to the waterworks
done by applying cold water with fog or spray nozzles and field. ask for training in their use Such a training program
soaking the burning carbon, but do not hit the carbon with a should provide information about detailed safety precau-
stream of water. If the fire is small, just a few bags, they tions, the toxicity of the compound, and the appropriate first
should be ren Dyed to a safe location and dealt with by CO2 aid methods Supervisors have the responsibility to provide
or spray nozzles Blocks of dry ice can be used to control this type of training, either in conjunction with the supplier or
fires in storage bins or other confined areas, but do not sponsored entirely by the utility The training must be
expect this method to be very effective. reinforced periodically for those compounds that are not
often used by the operator A review and updating of
A final word about fire and explosions involving activated information will go a long way in preventing accidents
carbon. Tests performed by carbon manufacturers have not
shown that dust mixtures of carbon have explosive tenden-
cies. Activated carbon is a charcoal and performs in a like
manner, the carbon burns without smoke or visible flame, QUESTIONS
burns very hot, and will spread if doused with a large stream
of water Write your answers in a notebook and then compare your
answers with those on page 439
There are no spec'fic first aid methods for carbon expo-
sure because the carbon will not attack the human body. 20 15A How can potassium permanganate spills be
Carbon does sometimes cause problems with the nasal cleaned up?
passages, however, and may be difficult to wash off your 20 15B What is the most dangerous powder the water
hands and body. Therefore, methods tare are those of treatment plant operator will be exposed to?
prevention Provide good dust collection at the point where
carbon is being unloaded, in storage bins for liquid prepara- 20 15C How should activated carbon be stored?
tion, and in dry storage binc. Wear an approved dust mask, 20 15D How can fires caused by activated carbon be pre-
loose fitting and dust-proof clothing. If there is an excess of vented?
dust, you should use chemical goggles, close your shirt
collar and tape your trousers to cover your ankles. Yo' i wi!! 20 15E How should an activated carbon fire be extin-
need adequate shower facilities and should use mild liquid guished?
soap. Most, if not all, hard soap bars are ineffective in
removing activated carbon dust from pores of the human
body.
20.16 Chemical Storage Drains
20.152 Other Powders Safety regulations prohibit the use of a common drain and
sump for acid and alkali chemicals, oxidizing chemicals and
You may come in contact with other powdered com-
organic chemicals because of the possibility of the release
pounds in the water treatment plant, but they do not present
of toxic gases, explosions and fires If both an acid and an
the problem in handling that activated carbon does. Benton-
alkali chemical come in contact, an explosion could occur. If
ite creates no significant hazard other than dust, and this
an organic chemical such as a polymer solution comes in
can be controlled by using dust collection systems.
contact with an oxidizing chemical such as potassium per-
Similarly, calcium carbonate presents a slight dust hazard manganate, a fire could develop Be sure that if a leak
that can be controlled by a dust collection system. Also, develops from any chemical container or storage facility, the
whet handling calcium carbonate in bags, use the same chemical will not be able to reach, mix or react with another
methods of control that you would use with bags of car bon chemical
Of the many organic coagulant aids used in water treat-
ment, only a few are applied in powder form Most of these
compounds are used in the liq'iid form which reduces the QUESTIONS
danger in their use to operators. The dry compounds pre-
sent a slight hazard in dust irritation to the nasal passages, Write your answers in a notebook -;-,d then compare your
this can be prevented by use of approved dust masks. The answers with those on page 439.
20 16A Why shnuld drains from chemical storage areas not
use common drains and sumps?
20.168 What could happen if a leak from a polymer storage
container comes in contact with potassium perman-
ganate

efa of 6z44014.44 Li244int$

Affiti'
1C1.
436
c,*-
416 Water Treatment

DISCUSSION A!JD REVIEW QUEST!ONS

Chapter 20. SAFETY
(Lessor 2 of 4 Lessons)

Write the answers to these questions in your notebook 15. How should hypochlonte be handled and stored?
before continuing. The problem numbering continues from
Lesson 1
16 What first aid is required for a person overcome by
9 What does an operator need to know about chemicals carbon dioxide?
used in a water tri atment plant?
17 What safety hazards may be caused by salt dust?
10. How can hydrochloric acid be handled safely?
11 How should hydrochloric acid be stored? 18 What types of safety hazards might an operator en-
counter when handling alum?
12. How can ammonia leaks be detected?
13. What is the ;first aid treatment for lime burns? 19 What are the two major problems encountered when
handling activated carbon?
14. What special precautions should be taken when han-
dling and storing caustic soda? 20 How can an operator detect an activated carbon fire?

:
437
 Safety 417

CHAPTER 20. SAFET\

(Lesson 3 of 4 Lessons)

20.2 FIRE PROTEC i ION A Class A fires involve miscellaneous combustible materi-
als These include fabrics, paper, wood, dried grass, hay
20.20 Fire Prevention and stubble.
Fire prevei ton is the best fire protection the plant opera- B. Class B fires involve flammable liquids and vapors. This
tor can afford. Fire protection is just good housekeeping. may include oils, lacquers, fats, waxes, paints, petroleum
The word "housekeeping" best describes the action any products and gas This class is subdivided into two
water plant operator can take to protect from or prevent ubclasses:
fires. This means a well-kept, neat and orderly plant repre-
sents a good fire safety policy. Fire hazards can be easily B-2 are those fires in which the source of flammable
removed. The prompt disposal of cartons, crates and other vapors is substantially in a single place such as
packing materials, a system of waste paper collection, and tent's, vats, spills and trenches.
the removal of other debris can greatly reduce fire hazards. B-3 - are those fires that are complicated by a falling
Provide suitable containers for used wiping cloths and have stream. LPG and other vapor fires are in this class.
fire extinguishers conspicuously located in hallways, near
work areas and near potential fire problem areas. All of C The Class C fire involves electrical equipment such as
tnese housekeeping activities are low-cost measures that starters, breakers and motors. The circuits should always
also improve the appearance of the plant and create a better be killed before extinguishing this type of fire.
work environment. D. Class D fires involve metals such as sodium, zinc, mag-
nesium and other similar metals. Operators rarely
counter this type of fire.

2';.22 Extinguishers
There are many types of hand-held fire extinguishers. All
are classified for class of fires. There is no one extinguisher
that is effective for all fires, so it is important that you
understand the class of fire you are trying to control. You
,rust be trained in ...a use of the different types of extin-
guishers, and the proper types should be If;cated near the
area where that class of fire may ocuur.
A. There are four types of water extinguishers: stored
pressure, cartridge operated, water pump tank, and
soda-acid. All of tnese perform well in Class A fires, but
You can call upon the service of the local fire department they do require maintenance. A preventive maintenance
for advice on fire prevention in and around the treatment schedule on all water extinguishers should include a
plant. You may also ask the utility insurance underwriter for monthly check by the operator responsible for the riain-
cooperation in your fire prevention program. AU operators tenance and completion of appropriate maintenance rec-
should be trained ill the proper use and maintenance of fire ords. Some agencies make the safety officer responsi-
control equipment. These simple steps can reduce fire ble for ensuring that an operator checks the fire
losses to a minimum and prevent most fires from happening extinouishers.
at very low cost to the utility.
You should make a fire analysis of your plant once a year 1. The method of operation for a stored pressure extin-
to determine what new measures should be taken to prevent guisher is simply to squeeze the handle or turn a valve.
fires. As activity changes occur, there may be a need to The maintenance is also simpie: check air pressure,
change the location of hoses and extinguishers or it may be record and recharge the extinguisher as needed.
necessary to add fire control equipment. Fire and police 2. For the cartridge type, the maintenance consists of
departments' telephone numbers must be posted in P con- weighing the gas cartridge and adding water as re-
spicuous location along with escape routes. Post eme, gen- quired. To operate, turn upside down and bump.
cy numbers near all telephones throughout the plant. In
hazardous :Jcations the means of exit should be lighted and 3 To use the water pump tank type cf extinguisher,
all doors equipped with "panic bars." As indicated above, simply operate the pump handle. For maintenance,
your best fire protection or prevention is good housekeep- one has only to discharge the contents and refill with
ing. water annually or as needed.
4. The soda-: id type r Jst be turned upside clown to
20.21 Classification operate; it also requires annual recharging.
Fire classifications are important for determining the type B. The foam type of extinguishers will control Class A and
of fire ex**nguisher needed to control the fir,. Classhications Class B fires well. They, like soda-acid, operate by
also aid 1n recordkeeping and for comparison with other turning upside down and require annual recharging.
agencies. Fires are classified as "A" Ordinarl combusti-
bles, "B" Flammable liquids, "C" Electrical equipment, The foam and water type extinguishers should not be
and "D" Combustible metals. used for fires involving electrical equipment. However,

438
 418 Water Treatment

they can be used in controlling flammable liquids such as You might consider hiring a local fire prevention agency to
gasoline, oil, paints, grease and other Class B fires. perform this part of your maintenance program. These
C The carbon dioxide (CO2) extinguishers are common service agencies will check and maintain the plant's fire
(Figures 20.6 and 20.7). They are easy to operate, Just fighting equipment on a regular basis. This does not relieve
pull the pin and squeeze the lever For maintenance, they the operator of ultimate responsibility for the equipment, but
must be weighed at least semi-annually. Many of these assures that the equipment is in proper working order when
needed
extinguishers will discharge with age. They can be used
on a Class C (electrical) fire. All electrical circuits should
be killed, if possible, before trying to control this type of
fire. A carbon dioxide extinguisher is also satisfactory for
Class B fires, such as gasoline, oil and paint, and may be
used on surface fires of the Class A type.
D. There are two types of dry chemical extinguishers. These
extinguishers are either (1) cartri.ine operated or (2)
stored pressure. These are recommended for Class B
and C fires and may work on small surface Class A fires
1. The cartridge-operated extinguishers only require you
to rupture the cartridge, usually by squeezing the 20.23 Fire Hoses
lever The maintenance is a bit more difficult, requiring
Fire hoses are usually stationed throughout the treatment
weighing of the gas cartridge and checking the condi-
tion of the dry chemical. and pumping plants. These are the type of fire fighting
equipment that an operator may see every day, but never
2 For the stored-pressure extinguishers, the operation give due consideration to their maintenance. Without proper
is the same as the CO2 extinguisher. Just pull the pin maintenance, the hoses may develop dry rot and be un-
and squeeze the lever. The intenance requires a trustworthy at the time they are needed. Under some condi-
check of the pressure gages and condition of the dry tions, you may be tempted to use these hoses for cleaning
chemical settling basins or filters. The fire hoses should only be used
for fighting fires, and after their use, they must be cleaned
As suggested above. a preventive maintenance program and stored properly The hose should be tested penodically
for fire extinguishers requires a considerable amount of time and replaced as required, or at regular time intervals. Check
from the operator and requires a system of recordkeeping with the local fire department for recommendations.

L SPECIFICATIONS CARBON DIOXIDE J

tY Size/Type 5 ' 10 I 15 7 20
.15t Model Number
4-
Horn
322
'I-
I Hose
330
- I Hose
331
t
I Hose
332
-
1
1 1

.
U/L Rating 5B C 10B C 10B C ---7 10B C
Capacity (lbs ) 5 10 15 i._ 20
_
Shipping Wt Os i 15 i 29'2 391/2 511/2
t-
1

Height -t--
1 173." j 24" . 30" 30"
"4`q.g.'
Width 81." .2" 12' ! 13"
t
Depth (-.)lam ) .1 5'." 7" 7" 8"
--1

Range (Ft) ) 3-8

-t
3-8 3-8 -T 3-8
-
Discharge Time -
Seconds
Coast Guard App
-._
10
Yes
10
Yes
- 12 5
Yes
;

1
19
Yes
-<e> Approved Yes Yes Yes 1es
332 331 330
I I

Bracket VW Wall Wall 1 Wall

322 j

lg. 20.6 Carbon dioxide extinguishers

(Permission of Nevada Safety & Supply)

439
 Safety 419

442 425 417T 424 419 441 423

SPECIFICATIONS

Size/Type
21/2
Nozzle
5
Nozzle
6
Nozzle
_ ABC
5
Hose
10 Short
Hose
_
10 Tall
Hose
_ 20
Hose
Model Number 417T 423 442 424 419 441 423
U/L Rating 1A:10 2A:10 3A.40 2A:10 4A.60 4A:60 20A.120

Capacity (lbs.)
Ship. Wt. (lbs.)
B:C
21/2

51/2
B.0
5
81/2
B.0
6
11
B:C
5
101/2
B:C
10
191/2
B:C
10
18
_ B.0
20
40
aPIAStt.Wo.R..1I'AVI It GI k `. AS/ t LECTIliCAL EQUIP

He:ght 141/e" 14%" 151/2" 145/e" 17" 201/2" 24"

Width 3%" 5" o" 8" 91/2" 9" 10"
Depth (Dram.) 3" 41/4" 5" 41/4" 6" 5" 7"
Range (Ft.) 9-15 12-18 12-18 12-18 15-21 15-21 15-21
D.scharge Time-
Seconds 10 10 14 13 17 17 30
Coast Guard Ap. Yes Y. Yes Yes Yes Yes Yes
43> Approved Yes Yes Pend.ng Yes Yes Yes Yes
Bracket Veh/Mar Wall Wall Wall Wall Wall Wall

Fig. 20.7 Typical carbon dioxide extinguishers

(Permission of Nevada Safety /I Supply)

20.24 Flammable Storage plainly labeled operating instructions The room must be
equipped with explosion-proof lights, grounded floor, no
The storage of flammable material should be isolated, if smoking permitted. and distinctive signs indicating that this
possible, from other plant structures Ideally, these storage 00fil IS a flammable storage area.
areas should have explosion-proof lighting. The floor should
be grounded and the operator should only use sparkproof 20.25 Exits
tools when working near cr handling flammable materials.
The room should have an alarm system, be equipped with Access and exit are very important in plant safety There-
automatic extinguishers and have supplementary equipment fore, all exit ins should be distinctly marked and well
located outside of the rcom. In and around the storage area, lighted All doors should open outward and, in hazardous
smoking or welding must be prohibited. The flammable areas. there should be "panic bars" on the doors To provide
storage areas must be clearly marked with distinctive signs positive protection around the filter and sedimentation ba-
and all entrances should be lighted. sins, install hand rails or other enclosures for the protection
of operating personnel as well as visitors.
More often than not, however, you will be compelled to
use rooms within the plant for storage of flammable material In hinh-f ire-hazard occupied areas, there should be at
Here you must make the room fireproof, equip the room with least two means of emt.gency exit located, if possible, at
a fire door, automatic extinguishers and alarms. Keep pas- opposite ends of the room or building. These would include
sageways free from obstructions. Station fire-fighting equip- areas containing woodworking and paint spraying residues
ment at a suitable location, readily accessible and with that burn rapidly or give off poisonous fumes.

440
P
 420 Water Treatment

QUESTIONS 20.32 Painting

Write your answers in a notebook and then compare your There are a number of considerations when painting in a
answers with those on page 439. treatment plant. First, is the paint exposed to the drinking
water being treated and are there toxic compounds in the
20 2A Class A fires involve what types of materials? paint? Next, is the paint being applied by brush or spray? In
20.2B What kinds of fires can be controlled by a foam type either case, is there sufficient ventilation if the operator is
of extinguisher? painting indoors or in a closed area?
20.2C How can an electrical fire be extinguished? When working with toxic paints, for example, those con-
taining lead, zinc, or organics, be sure to clean your hands
20.3 PLANT MAINTENANCE before eating or handling food. Also, avoid exposing your
skin to solvents and thinners and try not to use compounds
such as carbon tetrachloride. When spy -ty painting, always
20.30 Maintenance Hazards
use a respirator to avoid inhaling fumes. Do not allow
Plant maintenance, housekeeping, cleaning up, or what- smoking or open flames of any kind around areas being
ever you wish to call it, is a very important function of the painted. Also, when painting or cleaning the spraying equip-
treatment plant and essential for plant equipment. This ment, avoid closed containers where heat is involved. At a
function requires the use of cleaning materials and hand certain temperature called the flash point, spray or vapors
tools Maintenance may require you to go into a manhole, could ignite and burn the operator or start fires. Always
repair electrical motors, lift boxes and use power tools. All of clean the spray equipment in an area having sufficient
these functions may in some way be hazardous, and if not ventilation If the painting operation is taking place in a paint
given proper consideration, may cause injury, fire, disease booth, use only explosion-proof lighting and permit no open
or even death. flame and no electric switch that may cause a spark.

20.31 Cleaning
Any effort spent keeping the entire plant clean and sani-
tary will provide a much nicer place for you to work and will
also make visitors feel as if the water being produced is
safe. Even if you car just keep all working areas free of
tripping hazards, thi. .vill add greatly to the safety in the
plant

Cleaning duties should be performed at such times of day

or night as to cause a m.nimum of exposure to other
operators. For example, floors become slippery when wet
so give some consideration to the time of day and the type of
wax to be used. When cleaning floors, there are problems of Some of the other hazards when painting include scaffold-
exposure to others of cleaning equipment, mops. mop and ing, rags and threats to your personal health. Be very careful
broom handles, other tools, cleaning compounds, and most when using scaffolding and ladders. The scaffolding must be
of all, wet floors. When cleaning, try to keep others out of the in good repair and conform to current safety regulations.
area Warn others about newly waxed floors. Use wax Ladders must also be in good repair. If they are broken or
compounds containing nonsiip ingredients. Try to do such badly worn, they should be replaced with new ones.
cleaning and waxing during off-duty hours. weekends or at
night. Rags are always a problem if they contain oils, paint or
other cleaning compounds; there is always the possibility of
As part of our maintenance program, pros, ide trash fire. The rags should be placed into a closed metal container
containers for collecting waste paper and for separating to reduce the fire hazard.
used, oily rags. Dispose of garbage and flammable refuse
on a routine, frequent basis. Hazardous waste, acids and As to personal protection, consider using creams to help
caustics should be cleaned up immediately. These steps will
reduce skin exposure to paint and solvents. Alway 1 .se an
add to the safety in the plant and to the safety of operators in approved respirator to reduce inhalation of fumes and paint
the plant. r +5. As a final note, avoid any unnecessary exposure to
1.. . or solvents to the skin.
Keeping aisles, doorways, stairs and work areas free of
refuse reduces hazards of tripping and other injuries, as well
20.33 Cranes
as reducing the possibility of fires. Overhead traveling cranes require safety considerations.
First, only authorized personnel should be allowed to oper-
Cleaning windows is a hazardous occupation, but the ate them. Inspections should be made to check out the
operator who gives due consideration to the task can circuit breaker, limit switches, the condition of the hook, the
perform it safely. If windows are high, time of day is wire rope and other safety devices. The load limits should be
important. Cleaning tools may be dropped and fall on posted on the crane and you should never overload the unit.
pedestrians or vehicles. There may be a need for safety Always check out each lift for proper balance. Uce only a
harnesses; check the harness each time it is used. Make standard set of hand signals. and make sure that each
sure all parts of the harness are in good working condition. operator involved with the crane knows all of the signals.
Cleaning compounds that are acid or alkaline may attack the Personnel in and around an overhead crane should be
harness or the safety rope. Also, such compounds may required to wear hard hats. When making repairs to the
attack human skin: therefore, use rubber gloves when crane lock out the main power switch and allow only
appropriate. authorized personnel to make repairs.
et. ,t i
:....)?1
44j
 Safety 421

Never move loads over areas where operators or other rricinholes should be trained in applying artificial respiration
people are working. Do not let the load remain over the (C.P.R ).
heads of operators or other workers or allow them to work
under loaded cranes. If loads must be moved over populated Smoking should nc be permitted in or around man-
areas, give a warning signal and make sure everyone is in a holes. Always use a mechanical lifting aid (rope and bucket)
safe location. Set up monthly safety inspection forms to be for raising of lowering tools and equipment in and out of a
filled out and placed into the maintenance file. The plart manhole The use of a bucket or basket will keep your hands
supervisor should review the forms and authorize any free when climbing down into or out of the manhole
maintenance necessary on the crane in addition to following
a good preventive maintenance program.

20.34 Manholes
There are m; ^y hazards involved with manholes and all of
them can cause injury to the operator. Just removing the
manhole cover can cause the loss of hands or fingers. You
should never remove the manhole cover with your hands.
Use a manhole hook or special tool such as a pick with a
bent point to remove the lid. Be very careful when lifting the
lid. Use your legs, not your back for lifting. This will help
prevent back strains. Locate the cov- tside the working To review the hazards of underground structures, remem-
area to provide adequate working area Lind the manhole ber to give consideration to proper tools for opening and
opening. closing the manhole. Keep in mind the need for barricades
Next is the problem of traffic around an open manhole. and lights to warn traffic and to prevent endangering other
The public, other operators and vehicles must be protected.
operators. Be sure that operators are trained in artificial
Therefore, barricades, warning devices and lights must respiration methods and in the way to test the manhole for
oxygen, explosive and toxic gases.
conform to local and state regulations. There also should be
a barricade around the manhole to protect the operators. All
personnel around manholes should wear hard hats for their QUESTIONS
safety.
Write your answers in a notebook and then compare your
Always inspect the ladder rungs in the martiole before answers with those on page 439.
using them. They may become loose or corroded and 20.3A What safety precautions should be taken when wax-
therefore should be tested, using your own weight. One ing floors?
should never enter a manhole i.,:one; there should be at leasc
one other person standing by at the top and at least one or 20.3B How should rags containing oils, paint or other
more people within hearing distance in case of injury. cleaning compounds be stored?
Perhaps the greatest threats to operators working in 20.3C What safety precautions should be exercised when
manholes are air contamination or depletion of oxygen. operating an overhead crane?
Many operators have lost their lives because of leaking gas
mains, decaying vegetation or other gases. Never enter a 20 3D How can traffic be warned that operators are work-
manhole without checking the atmosphere for (1) sufficient ing in a manhole?
oxygen, (2) presence of toxic gases (hydrogen sulfide), or (3) 20.3E How should tools and equipment be lowered into and
explosive conditions (methane or natural gas). In any event, removed from manholes?
always provide adequate ventilation. This will remove any
hazardous gases. To check the safety of the atmosphere in 20.35 Power Tools
a manhole, use a gas-detection instrument (Figure 20.8).
These devices can detect explosive gases, oxygen deficien- The two general classes of portable power tools are (1)
cy, and/or toxic conditions. Remember, just because there pneumatic and (2) electrical. Safety precautions for handling
are no toxic or explosive gases present does not mean that these types of tools are much the same for both types. Wear
you may not lose your life because of a deficiency of oxygen. eye and ear protection when operating grinding, chipping,
Normal air contains about 21 percent oxygen. The first buffing. or pavement breaking equipment. Sometimes when
effects of insufficient oxygen occur when the oxygen con- using grinding or buffing tools you will encounter toxic
tent drops to about 15 percent. Operators who work around materials and, therefore, will need respiratory protection. At

Att-
vimimr:i a N.*

Fig. 20.8 Gas-detection instruments (toxic gas, combustible gas and oxygen deficiency)
(Permission of ENMET Corporation)

442
 422 Water Treatment

other times there is a need for full face protection because of storage, and in storage areas for other bagged chemicals.
flying particles: you should use a face shield or at least Avoid welding around oil and grease when possible, and
goggles In the use of electrical tools. always replace worn when that's not possible, at least provide for ventilation of
out extension cord and never expose cords to oils or fumes. When welding or cutting is done in the vicinity of any
chemicals Extension cords also present a tripping hazard if combustible material, you 'rust take special precautions to
left in the way Avoid leaving extension cords in aisles of in prevent sparks or slag from reaching the combustible mate-
work areas Do not hang extension cords over sharp edges rial and causing a fire
which could cut the cord and always store the cords in a
clean, dry location When working in a wet or damp location, Regarding the safety of other personnel in the welding
some consideration should be given to the use of rubber area. eye protection comes first The person using the
mats or insulated platforms. As indicated above, use only welding equipment must wear protect' ' B clothing, gloves,
grounded tools. When using pneumatic tools, never use the helmets and goggles Others in and around the welding
compressed air to clean off your clothing or parts of your operation should be kept at a safe distance. Always be
body Air can enter your tissues or other openings and careful of overhead welding because of falling sparks and
cause problems Always check hose clamps. If they are slag If other operators are (or must be) working in the
loose or worn, tighten or replace as needed. Air hoses, like vicinity of the welding operation, they too must be pr ected
extension cords, are a tripping hazard. Therefore, consider from the rays of arc welding, never look at the welding
tneir location when working with pneumatic tools For the operation without eye protection.
large (3/4 inch or 18 mm) hoses, always use an approved
The storage of welding gas cylinders should be given the
safety-type hose connection with a short safety chain or same consideration as those of other gases in water treat-
ither safety device attached. Air hoses that come apart can
ment. They are stored upright, kept out of radiation of heat
cause injuries as they are whipping about. Like electrical
and sunlight and stored with protective covers in place when
cords, ke.ep air hoses away from oils, chemicals or sharp
objects. not in use. Store cylinders away from elevators and stairs,
and secure them with a chain or other suitable device.
Sandblasting. using a pneumatic tool, requires some
special consideration. The operator should protect all skin 20.37 Safety Valves
surfaces with protective clothing, wear eye and face protec- There are quite a number of safety valves in a water
tion. use a respirator, and be very careful of toxic fumes
which are discharged from a blasting operation
treatment plant, operators are not always aware of their
locations or functions For example, most operators know of
The grinding wheel, pneumatic or electric, requires the the safety plugs on chlorine cylinders, but there are also
same safety considerations. Eye and face protection is large safety valves in any plant that stores large amounts of
required. Do not use this tool without safety guards Be chlorine on site. These containers take on truck load lots of
careful of gloves being caught on the grinding wheel. Never 17 tons (15,540 kilograms). The safety salves on such
operate a wheel with loose nuts on its spindle. When the containers should be certified at least every two years or as
winding wheel is badly worn, replace it and use the proper often as the state requires. Such relief valves must be
wheel and speed of rotation. maintained on a regular basis. Inspect the inside of these
tanks at regular time intervals and keep a record of the
All persons using power tools must be trained in their use findings, for example, evidence of deposits and corrosion.
and maintenance. Use the manufacturer's operations and
maintenance guide for details of proper training. Most Water heater safety valves should be checked on an
injuries by power tools are caused by incorrect setup and annual basis 4nd maintained or replaced as needed. If the
operation due to poor training. plant has a boiler room, the steam safety valve should be
maintained and checked for proper operating pressures.
Finally, a high level of noise is frequently encountered These valves should not discharge in such a manner as to
when operating power tools. For example, air drills produce be a hazard to operating personnel.
95 dB5 and circular saws 1n5 dB. Ear protection must be
provided when exposed tt.. long periods of high levels of There also may be surge relief valves on discharge piping
noise. In areas of noise exposure, all operators F. hould be (high lift) of the treatment plant. These valves also act as a
provided with approved ear protective devices. safety valve to the pumping equipment and must be main-
tained on some regular time interval. They should be
20.36 Welding checked for proper pressure setting, with a" pilct valves
being reconditioned or replaced as needed.
The first safety rule in operation of gas or electric welding
equipment is that the operator be thoroughly trained in the There may be other safety valve located in the pumping
correct operating procedures. The second rule concerns fire plant's hydraulic system for opening and closing discharge
protection. The third rule is personnel protection. None of valves that require maintenance. In the maintenance of
these rules is first or last they should ALL be followed. water treatment plants, you or your supervisor must set up a
maintenance system for all equipment. Hand tools, power
If you are not thoroughly trained in the use of the welding tools and other maintenance equipment must also be kept in
equipment, do not use it. If you absolutely must use the safe working condition. Operators must be furnished protec-
equipment, do so only under the supervision of a trained tion for the eyes, the ears, the hands, the head, feet and at
welder. Whenever such work must be performed in or other times, the body. Work areas should be well ventilated
around a water treatment plant, take time to consider the fire and noise should be reduced whenever possible. Each
problem. For example, welding can be very dangerous in an operator should always be on the lookout for additional
oxidizing chemical location, near powdered activated carbon ways of making the treatment plant a safer place to work.

5 Decibel (dB) (DES-uh-bull) A unit for expressing the relative intensity of sounds on a scale from zero for the average least perceptible
sound to about 130 for the average level at which sound causes pain to humans. i

. r .. q. 443
 Safety 423

QUESTIONS Next, when changing tires, be sure the jack you are using
has sure footing Position the jack at right angles to the
Write your answers in a notebook and then compare your direction of the lift Jack,-, are a problem in general, and you
answers with those on page 440 should make sure that proper jacks are in each vehicle. In
other words, select the proper jack for each job and choose
20 3F What type of protection do operators need when only one that is safe and strong enough. If blocking is
operating portable power tools'?
required. only use safe supports, avoid leaning the jack and
20.3G How can operators be protected from high noise protect hands Always stay a safe diEtance from the jack
levels when operating air drills and circular saws'? handle as many injuries are caused by flying jack handles.
Also, injuries are caused by overloading jacks. In addition,
20 3H What personal protection should be used when oper- where needed, use braces or other supports to prevent
ating welding equipment? tipping the vehicle over, another cause of serious injuries.

Fueling motor vehicles also involves some hazards. \I-

20.4 VEHICLE MAINTENANCE AND OPERATION
ways stop the vehicle's engine. Remember to remove the
fuel hose immediately after using it. You could start a fire if
you carelessly drive off with the hose still attached. Also,
ake sure the cap is replaced tightly on the tank. Do not
permit smoking in the vicinity of gas delivery pumps at
anytime. Avoid any sparks, and skin contact. Use only high-
flash point solvent for cleaning up any gasoline. Some other
safety tips when refueling are: do not let the tank overflow,
always set the brake, hang nozzle up properly onto the
pump and eliminate any leaks on the hose connections.

Most small w -" **zatment plants do rot have hoists or

pits for vehicle lubrication. However, most of the following
suggestions are applicable. First, keep all walkways, steps,
tools and containers free from grease, oil and other dirt. This
20.40 Types of Vehicles will reduce the possibility of accidents caused by these
items. As when maintaining any equipment, use the right
Many types of vehicles are used in the waterworks tools. keep shoes free of all oil or grease and use only non-
industry. However, the plant operator may only come into slip soles on the shoes.
contact with a few. Cars, pickup ti Licks, forklifts, dump
trucks and some electrically driven cars are the types of If the plant is equipped with a hoist, do not permit anyone
vehicles 3 operator is most likely to be involved with and to remain inside the vehicle when it is on the hoist. When
need to ri.. Atain. In addition to motor vehicle safety, this lifting the vehicle, do not permit tools on the hoist or vehicle
section will also consider the storage of fuel for these and that may fall onto you or other personnel in the work area.
other engines in the plant. Keep the driveway free of hoses, tools, and cars and always
keep you hand on the operating level when raising or
20.41 Maintenance lowering the vehicle.
To have a safe motor vehicle, there must be a preventive
Most water treatment plants have assigned specific areas
maintenance program. Figure 20.9 gives a checklist for for washing or steam cleaning vehicles. If your plant does
finding potential safety problems and a means of recording
not have such an area, you should have one assigned. This
the preventive maintenance.
area does not have to be elaborate, but should have water
Tire inflation is a good example of proper safety checks hoses and steam cleaning equipment and be adequately
Not only is it unsafe to operate on under inflated tires, but it drained. The same safety rules apply to makeshift installa-
also causes undue wear on the tire. Therefore, tires should tions as apply to completely equipped cleaning areas. The
be checked regularly for wear, which may be caused by most important consideration is the steam cleaner. Keep the
misalignment or low inflation. If tires are badly worn, they nozzle clean, check water level on coils before turning on
should be replaced. ^lways maintain the recommended the flame, and always wear protection for your eyes and
pressure in the when checking, set the hand brake and face Make sure that the cleaner is adequately ground and
turn off the motor. be careful of cleanin" compounds (see Caustic Section for
burns). Maintain steam hoses, check connections and never
permit horseplay with steam cleaning equipment. As in other
work areas, keep the wash rack free from grease and oil and
oily rags. Hoses should be stored on the rack when not in
use. Always use scaffolding or platforms when cleaning the
tops of vehicles.

20.42 Seat Belts

Many water treatment plant operators have some reason
for not wearing seat belts. The reasons may sound good,
but they won't protect you in the event of an accident. Many
lives would have been saved if seat belts were used. The
water utility should equip all vehicles with seat belts and
require eve' y operator to use them.

k.pt12 l
424 Water Treatment

Month Vehicle NuTiber Assignmnt

WITYS
CHECK
1st 2nd 3rd 4th 5th

1 Oil

2 Water

3 Tires

4 Horn

5 Headlights, High - Lew

6 Tail Lights

7 Turn Signals

Stop Lights

9 Battery Water

10 Fire Extinguisher

11 First Aid Kits

12 Windshield Wipers

13 Visual Inspection Wire Rope

II II
14 "" Hook

II II
15 - 5neaves

II SI
16 - Boom
,. It

17
- Hydraulic Level

18 Operational Test Controls

SERVICE MILEAGE READINGS FUEL CONSUMPTION

Week Present Last Service Difference Start Mileage
1st End Mileage
2nd Total Miles
3rd Fuel Used
4th MPG Average
5th

Fig. gas Mobile Equipment Check List

r
445
 Safety 425

20.43 Accident prevention slippery. Slow down, pump the brakes when stopping and
remember the minimum distance rules. No driver should be
The best overall means of preventing vehicle accidents is
required to operate an unsafe veht.,ie. Keep copies of a
defensive driving. This method requires training and a suitabIe form for reporting mechanical problems in each
certain mental outlook on the part of the vehicle operator. vehicle and encourage operators to use them.
Most, if not all, drivers think they are good at what they do
and this may be true to some extent. However, if each driver 20.44 Forklifts
would operate all vehicles as if all other drivers were the
world's worst drivers, accidents would to greatly reduced Most water treatment plants and pumping stations have a
forklift. Most, if not all, plant operators use this vehicle to
Good drivers check out their vehicles each time they use move chemicals, repair parts, and even use it when making
them and have any maintenance performed when needed.
repairs to lift heavy objects. Therefore, every plant operator
They use proper signals for directional change, always should be trained in the use of the forklift.
observe traffic regulations and show courtesy to others.
Remember that drivers in an agency vehicle represent the Following are a few points regarding safe operation of the
agency. Therefore, good driving ski:Is are good for public forklift with suggestions for operator safety as well as
relations. protection of others who may be in the operating area of the
Another way to avoid accidents is, forklift. Keep all aisles free of boxes and other debris. Do not
permit anyone to ride on the forklift except the operator.
Never overload the forklift. Always be sure the warning

"Po Not tailgate" signals are operational and never leave the power on when
leaving the forklift. Like other vehicles, check out the brakes
before operating. Be careful at intersections of aisles and
always face the direction of travel. If a loaded forklift is to be
This is a very unwise practice which is dangerous to the placed on an elevator, be sure that the load on the forklift
vehicle and hazardous to its operator. A good rule to use and the weight of the vehicle do not exceed the lifting weight
when following another vehicle is the old one-car-length for of the elevator. Also, make sure the forklift load is stacked
every 10 MPH, and if there is !imited visibility, increase that properly before lifting or moving. When handling drums,
distance. Another rule is the I hree Second Rule" which special lifting and retaining devices are needed.
says you must be at least three seconds behind the car in
front of you. Take precautions when backing up. Always set Figure 20.10 is a typical forklift inspection form.
the brake and/or shift to "Park" when parking the vehicle. Be
cautious at intersections. As a defensive driver, always be
ready to give the right of way. No right of way is worth
injuring oneself.
In some cases, even the most defensive and careful driver
has an accident. Because of this, each vehicle should carry
nashlights, flares, flags and a fire extinguisher, along with a
first aid kit. In the event, of an accident, the driver should
know how to fill out all the forms, a supply of which should
be provided in the vehicle.
Remember, when operating a vehicle, an accident can be
prevented '..)y defensive driving. The plant operator shoed
have each member of the staff take a defensive driver
training course. Each driver should develop a defensive
driver frame of mind. Developing a good attitude and driving QUESTIONS
skills are the key to accident prevention when operating a Write your answers in a notebook and then compare your
vehicle. In any event, new employees should be given road answers with those on page 440.
tests in operating the types of vehicles they will be using.
20.4A What cause., tire wear on motor vehicles?
Here are a few reminders when operating a vehicle.
During a storm, roadways or pavement are likely to be 20 4B Motor vehicles should contain what safety devices?

eftei of i.44041004, 1.4244X0

Attfert,

44g
426 Water Treatment

..1r .11111"

SOUTHERN NEVADA WATER SYSTEM

For Truck Operator Inspection
Boom Tilt Back
Operator up Remarks
Brake Up Dn. F R Horn Horn Wheel

FORM 4.268 S.N.W.S.

...i111,

Fig. 20.10 Forklift inspection form

e) '

447
 Safety 427

DISCUSSION AND REVIEW QUESTIONS

Chapter 20. SAFETY
Lesson 3 of 4 Lessons)

Write the answers to these questions in your notebook 25 How can an operator make visitors feel as if the water
before continuing The problem nu7 :feting continues from being produced is safe to drink?
Lesson 2.
26 How would you remove a manhole cover?
21 How can an operator prevent fires in a water treatment
plant? 27. What precautions should be taken when operating
power tools in a wet or damp location?
22. How would you maintain water-type fire extinguishers?
28. What fire hazards should be considered before doing
23. How would you maintain fire hoses in your water any welding?
treatment plant? 29. How would you safely refuel a motor vehicle?
24 What precautions should be taken in areas where 30 What safety precautions should be taken when driving
flammable material is stored? during a storm?

HOW
WHAT
HOW ,k-s-,,
WHAT
4-10
WHA

448
428 Water Treatment

CHAPTER 20. SAFETY

(Lesson 4 of 4 Lessons)

20.5 ELECTRICAL EQUIPMENT Icon 20.2 about electrical fires. For the safety of operating
personnel and the safety of the plant, regularly inspect or
20.50 Electrical Safety have someone inspect both large and small transformers. If
you detect any overheating, have a qualified electrician
As a water plant operator, you ace not expected to be an
inspect ano replace any transformer that is not functioning
expert in electrical equipment, but you must have a working properly.
understanding of electricity. This includes an understanding
of the safety precautions needed to operate the electrical There should be a fence around the transformer station,
equipment. After all, electrical energy is required to power with a locked gate and only a limited number of keys issued
most of the treatment plant operations. The objective of this to plant personnel. The operator may perform routine pre-
section is to show you how to operate safely and to become ventive maintenance such as removing weeds, brush and
involved to a limited degree in the maintenance of electrical general cleanup. Replacing fuses and major maintenance or
equipment. Elect :city is unforgiving to the careless treat- repairs should be made by the power company or qualified
ment plant operator. electricians. Maintenance must be performed by qualified
and well trained personnel.
20.51 Current Voltage
20.53 Electrical Starters
Many types of electrical current are used in water treat-
ment plants and the associated pumping plant. Each day the As a treatment plant operator, your most frequent contact
plant operator is exposed to this equipment, giving little with electrical power will probably be with electrical starters
thought to the potential hazards ,f the equipment. Current on the motor control panels. These devices are used
may come into the plant at a high voltage, for example, 69 throughout the plant and provide an interface between the
KVA, reduced to 4160 volts or 2300 volts. This current may operator and the flow of energy. The starter may be located
power pump motors, blowers and other equipment at lower on a switch panel or there may be a switch that is remotely
voltages of 440, 220, or 120 volts and within starters may be located from the starter. One of the first safety procedures
reduced to 24 or 12 volts or changed over into DC voltages. you should take is to use a special insulated mat on the floor
Given all of these variours voltages, the operator mu^t be at all switchboards. The starter should be provided with
careful not to become CareieSS working with equipment. adequate lighting and clearly marked Start-Stop buttons.
Therefore, become familiar with the types of current and Replace indicating lights as needed without delay. There
voltage in the plant. By knowing this, you will avoid the should always be clear and adequate working space around
mistake of becoming involved with unsafe electrical currents the starter or switch panels. To reduce the hazards of fire in
or practices for which you are not trained. This will also electrical starters, they should be cleaned and maintained on
enable you to know when to ask for a qualified person to a regular basis. Such maintenance must be performed by
perform any necessary repairs. trained, qualified personnel. In electrical starting equipment,
fires can easily occur because of accumulation of dust and
20.52 Transformers dirt on the contactors, or when they become so badly burned
that they do not make proper contact; thus, they become
Electrical power entering a plant is routed through trans-
overheated and start fires. The key to preventing fires in
formers to reduce the voltage in most cases. There are starting equipment is a good preventive maintenance pro-
many types of transformers although the operator may only gram.
think of the larger ones that bring the power into the plant.
Sometimes these are owned by the waterworks and there-
fore the maintenance is the responsibility of the operator.
There are few, if any, plant operators who are qualified to
perform such maintenance. Never attempt to wcrk on a high
voltage transformer without the ass stance of qualified per-
sonnel. Such personnel can be located at ti le power com-
pany or contact an electrical contractor who specializes in
the repair and maintenance of electrical transformers. You
will, however need to keep records of the transformer's
operation. This information is helpful to repair personnel and
is useful to operators who need to know the status of the
transformer.
There are many small transformers within the plant's
operating gear and it is these you may have to maintain.
Most often these low-voltage transformers become over-
20.54 Electrical Motors
worked; they overheat and burn out. Any fire in the electrical
gear can be hazardous. Be very careful when opening a The treatment plant operator is exposed to many types
starter, breaker box or indicating instrumentation if a fire or and sizes of electrical motors. In some plants, the motors
overheated transformer is suspected. Operators have been are old and require more attention because of exposed
badly burned by not thinking before opening such 'devices parts. The newer electrical motors are enclosed and have all
when they smell smoke in pumping stations or treatment parts protected. For the old motors, you should install
plants. When solving problems with hot, overheated, or guards or guard rails to prevent accidental contact with live
burning transformers, remember what you learned in Sec- parts of the motors.

449
 Safety 429

Some of the electric motors may have exposed couplings, outside for those who do the maintenance Moisture or
pulleys, gears nr sprockets that also require consideration corrosive gases must be kept away from the control panels.
For these and other moving devices, a wire cloth gear guard To reduce fire hazard, never store any hazardous material
may be installed The gear guard can also be made of sheet next to switchboards or control panels, Panels carrying
metal However, no matter which type of guard is used. it greater than 600 volts must be permanently marked warning
must be securely fastened onto the floor or some other solid of the hazards Areas of high voltage should be screened off
support The safeguards must be constructed and fitted to and locked with a limited number of keys given to authorized
prevent material being handled by operators from coming personnel only
into contact with the moving parts driven by the motors.
In a safe lockout procedure, the switches are locked open
Another consideration is projections on couplings, pulley and are properly tagged, only the operator who is doing the
shafts and other revolving parts on the motor or on the maintenance should have a key. In fact, all people who
device being driven These projections can be bolts, keys, perform electrical m .intenance should have their own indi-
set screws or other projections The projections should be vidual lock and key so as to maintain control over the
removed, reduced or protected by one of the above guards. equipment being worked on by each individual
Check grounding on al electmai n,otors as part of a
routine maintenance program. The motor frames them- QUESTIONS
selves must be grounded if the wires to the motor are not Write your answers in a notebook and then compare your
enclosed in an armored conduit or other metallic raceway. answers with those on page 440.
Check that all joints are mechanically secure to assure good
grounding. In the cease of portable electric motors, the 20 5A Why should each plant operator become familiar with
simplest way of grounding is an extra conductor in the cord the type of current and voltage in the water treatment
serving the motor. The best way is to install a ground fault plant"
interrupter (G F.I.) receptacle. This device will automatically
disconnect the tool from the power supply if the ground is 20 5B List the moving parts on electrical motors that re-
quire safety guards
not connected and will supply the greatest protection to the
operator and to the equipment. 20 5C What are two hazards created by the lack of a good
When using portable electrical motors always check the lockout procedure for control panels and switch-
service cord. If the cord or receptacles are in poor condition boards',
or showing signs of wear, they should be replaced. A badly
worn cord must never be used in a wet location.
20.6 LABORATORY SAFETY6
20.55 Instrumentation
20.60 Laboratory Hazards
In this area of water treatment the operator is not exposed
to a great deal of hazard, but must give some consideration In general, water plant operators do not experience a
great deal of exposure to hazardous laboratory conditions.
to these devices since they are operated by electrical
However, you will be in contact with glassware, toxic chemi-
current. This is also true of all other automatic equipment.
Although most instruments protect the operator, there is still cals, flammable chemicals, corrosive acids and alkalies.
a degree of hazard when changing charts, calibrating or There may be times when you will be exposed to hazardous
performing other maintenance. First, when calibrating an bacteriological agents. The seriousness of the hazards
depends mainly upon the size of the plant and the operating
instrument, you are exposed to at least 12 Volts DC to 120
procedures in the treatment picot. For your own safety, learn
Volts AC If you become grounded with the 120 Volts AC,
you may be killed or severely injured. Also, when maintaining
the proper procedures for handling laboratory equipment
and chemicals.
automatic control equipment, adjustment of one instrument
may start another device, exposing another operator to a
20.61 Glassware
hazard because of an unexpected start. As mentioned
above, electronic devices operate on low current, but don't An important item in laboratory safety is handling of
forget that there is still high voltage located somewhere in glassware Almost all tests performed by an operator will
the instrument. require the use of some glassware. The operator's hands, of
course, are exposed t., the greatest hazard. To reduce
20.56 Control Panels accident: when handling glassware, never used chipped,
cracked or ,)roken glassware in any testing procedures. All
Control panels and switchboards should only be accessi-
ble to qualified personnel. The plant operator should have a such glassware should be disposed of in a container marked
"For Broken Glass Only Never put broken glass in waste-
standard operating procedure (SOP) for lockout of all electri-
baskets Although it may not be a hazard to the operator, it is
cal equipment (Figure 20.11). Two hazards due to the lack of
a danger to those who clean out the wastebaskets. Clean up
a good lockout procedure are (1) accidentally starting a
piece of equipment exposing a fellow operator to a hazard,
any broken glass and/or spilled chemicals to reduce. haz-
and (2) turning electrical power on when somecie is still ards to others. Never let broken pieces of glass remain in the
worker 3 on the equipment, exposing that person to danger. sink or in sink drains. This may cause cuts to others who
unknowingly try to clean the sink.
Always provide adequate working space in and around Washing glassware is always potentially hazardous. The
control panels. As with electrical motors, the panels must be glassware can be broken while being washed, causing cuts,
well grounded. At some locations there may be a need for or cuts can be caused by chipped or cracked glassware.
special insulating mats, such as in wet locations. Adequate Also, the cleaning compounds themselves can be a problem.
lighting must be available inside the control panel as well as Sometimes strong acid cleaners are used to remove stains

6 See FISHER SAFETY MANUAL. Fisher Scientific Company, 711 Forbes Avenue, Pittsburgh, PA 15210.

450
430 Water Treatment

SOUTHERN NEVADA WATER SYSTEM

Standard Operating r:ocedure
TITLE: SAFETY, EQUIPMENT LOCKOUT Number: 122

SECTION: SAFETY Prepared By:

R LC-2/1/73

OBJECTIVE
The purpose of this procedure is to provide the highest degree of safety to SNWS employees, also to prevent
mechanical damage or undesirable operation of equipment when it is being serviced or repaired.

PROCEDURE

Locks for securing equipment shall be issued to maintenance people and will be available to other personnel
at the superintendent's office. There is some machinery that is designed and equipped with facilities for minor
rep: adjustments and lubrication' Aide in operation. However, in all cases, the equipment must be turned
off ' such repairs or lubrication.
In order to prevent accidental starting or endangering the safety of operating or maintenance personnel, be-
fore performing any woi:c the equipment must be secured. In the event the starter, motor or electrical service
to the equipment cannot be locked out, a "Do Not Operate" safety tag must be attached to the starting mecha-
nism.

During inspection, if an operator finds that the continual operation of a unit may cause damage, it should also
be shut down and locked out. The key to the lockout device should be attached to the Work Cider. Thereafter,
no one other than the Manager, Maintenance Superintendent or Treatment Superintendent or someone
directly ordered by the above is to remove the lockout device.

Fig. 20.11 Standard operating procedure for locking

out of electrical equipment
et ti
451
 Sazety 431

20.63 Biological Considerations

Do not take chances with bacteria. A good policy is to
have each operator immunized with anti-typhoid vaccine and
to keep their booster shots current. Always use good
sanitary practices, particularly when working with unknown
bacteria or known pathogens. Never pipet bacteriological
samples by mouth. ALWAYS USE A PIPET BULB.
When exposed to any bacteria, you should make it a habit
to always wash your hands before eating or smoking. If you
have any cuts or broken skin areas, these wounds should
not come in contact with bacterial agents. You should wear
protective gloves or cover the wound with a bandage when
working with any kind of bacteria.
All work areas should be swabbed down with a good
bacteriological disinfectant before and after preparing sam-
ples. As a gent. al policy, the preparation or serving of food
40110110-..-, should never be permitted in the laboratory. Also, give some
consideration to proper ventilation, because some bacteria
from the glassware. Without protective gloves, you hands may be transmitted via the air system.
could be sei icusly burned by these acids.
20.64 Radioactivity
20.62 Chemicals There are many laboratory and treatment plant instru-
When handling liquid chemicals such as acids and bases, ments that use radioactive isotopes in laboratory tests and
always use safety classes or face shields. If working with research. A plant operator may be exposed to radioactive
ether or hloroform, avoid inhalation of fumes and always do compounds when calibrating sludge density meters or using
this type of work under the ventilation hood. Be sure to turn research isotopes. From a safety standpoint, only qualified
the ventilation fan on. Of course, be careful of open flames personnel should be involved in the use of radio ',live
when using flammables such as ether. As a general rule, do compounds. If radioactive compounds arc present in the
not permit smoking in the laboratory. All chemicals should laboratory, warning signs should be posted. The disposal of
be stored in proper locations; do not set chemicals on the all radioactive compounds must be performed strictly by
laboratory benches where they may cause an accident if qualified laboratory personnel in accordance with govern-
spilled or if the container is broken. ment regulations.

When handling laboratory gases, give consideration to 20.65 Laboratory Equ'Iment

their location and potential accident hazards. Gas cylinders
must be prevented from falling by using safety retaining
devices such as chains. The valve and cylinder regulator
should be protected from being struck by stools, ladders
and other objects.
When mixing acid with water, always pour the acid into the
water while stirring.

Never acid water to acictioaeaue

thelater ittaq Notain on top oil
the ac4, tiii.4 anvoing 4,1atteritt4
auct love -A heat4etterattni,.
20.650 Hot Plates
Alwayt, use safety goggles, yloves and protective garments. You will probably use a hot plate in your ,'r hold odor
When cleaning up acid or alkali spills, dilute with lots of number (TON) tests. Yo,, should turn the hot plate off when
water even if you flush them down the sink drain. Baking not in use, never place bare hands on the hot plate to check
soda can ..,e used to neutralize acids, and vinegar is used to if it is hot. Whln using the hot plate to remove gas or fumes,
neutralize bases. Never allow mercury, gasoline, oil or always use the hood and turn on the hood ventilation fan.
organic compounds into the laboratory drains. Use only a Never place glassware onto a hot plate if the outside of the
toxic waste disposal drain system for these items. Pouring glassware has water or moisture on the surface between the
such compounds down sink drains can cause an explosion, glass and the hot plate. Steam will form at this interface and
allow toxic gases and vapors to ente. ,he lab, or destroy the cause the glass to break. When taking hot glassware off the
piping. hot plate, always us,.: asbestos gloves.
You must never use your mouth with the pipet for transfer-
20.651 Water Stills
ring toxic chemicals, acids or alkalis. Use a suction bulb,
aspirator, pump or vacuum line. If you use your mouth, there Most water stills in the laboratory today are the electrical
is always the danger of getting the toxic solutions into your type. To observe good safety practices, check the items
mouth. described in the electrical safety section of this chapter,

..f. -.:. 1
452
 432 Water Treatment

such as good grounding. Set up a SOP (Standard Operating operator to watch for any safety problems in the plant's
Procedure) for proper operation of the still and follow the reservoirs, pumping stations, or filters You, the operator,
manufacturer's instructions for proper starting and stop- are responsible for yourself. You should never expose
ping. The sti., will require cleaning from time to time. Be very yourself to unsafe conditions.
careful when disassembling the still. Parts may be frozen
together because of hardness in the water and may require A major problem confronting many operators is where ar
an acid wash to separate. Be sure that the boiler unit is full of how can reliable safety vendors and equipment be locate
water before turning the still on. Never allow cold water into State, regional and national professional meetings, such as
a hot boiler unit because it may cause the unit to break. those spoc,sored by the American Water Works Association,
often have displays or exhibits featuring manufacturers of
20.652 Steriliz rs safety equipment. This is an excellent opportunity to meet
the representative of these companies and discuss with
There are two types of sterilizers: (1) dry electrical steriliz- them what equipment they would recommend for your
ers a Id (2) wet sterilizers (autoclaves). In the dry electrical situation. Also other operators who have had experience
sterilizers, check the cords frequently because the high heat with safety equipment of interest to you often attend these
may damage the wiring. Always let the unit cool off before meetings and are anxious to share their experiences with
removing its contents. Wet sterilizers (autoclaves) are under you.
pressure by steam and should be opened very slowly. Use
asbestos gloves and protective clothing when unloading the If you are unable to attend these meetings, the program
autoclave. Cover the steam exhaust with asbestos covering announcements will often have a short description of the
to prevent burns. Any leakage around the door should be types of safety equipment that will be featured by each
repaired by replacing door gaskets, or even the door if it is vendor exhibiting at the conference You can obtain the
worn or bent Always load the autoclave in accordance with vendor's address by looking in professional journals, buy-
the manufacturer's recommendations. Never allow an oper- ers' guides or by writing to the sponsor of the conference.
ator to work with this equipment without proper instruction
in its operation. 20.71 Respiratory Protection

20.653 Pipet Washers

There are many respiratory hazards in and around the
treatment plant that an operator is exposed to daily including
Cleaning pipets can be hazardous. Many laboratories chemical dusts, chemical fumes, and chemical gases such
have s pipet cleaner which contains an acid compound or as chlorine, ammonia, sulfur dioxide, and acid fumes, to
other cleaning agents. Always use protective clothing and a name only a few. Whenever working around or handling
face shield when working with the washer unit. Try to avoid these and other compounds, you must take adequate pre-
dripping or spilling the cleaning compound when transfer- cautions.
ring the pipets. if the acid cor 0 into contact with your skin,
Two types of conditions for which you should be prepared
use the remedies recommenJed in Section 20.11, "Acids." are: (1) oxygen deficient atmosphere, and (2) sufficient
oxygen, but a contaminated atmosphere containing toxic
QUESTIONS gases or explosive conditions. In either circumstance you
Write your drisv...ers in a notebook and then compare your will need an independent oxygen supply. However, an
answers with those on page 440. independent oxygen supply will not protect you from an
explosion.
20.6A Why .s washing glassware always a potential haz-
ard?
Never ¢,vitzr a coxfiect 4pace
20 6B Whr p.. ,dons should be taken when handling
liquid chemicals such as acids and bases? witit an explo4iva atiftgopkere.
20.60 Why nould mercury, gasoline, oil or organic com- Call your local gas company and ask their experts to enter
pounds never be allowed into laboratory drains? the explosive area, if entry is essential, Your independent
20.6D How can an operator be exposed to rao,active oxygen supply should be of the positive-pressure type to
compounds? protect you if there are any leaks. Good ventilation can
reduce explosive conditions.
20.6E Why should cold water never be allowed into the hot
boiler unit of a water still? 20.72 Safety Equipment

20.7 OPERATOR PROTECTION All waterworks safety equipment such as life lines, life
buoys, fire extinguishers, fencing, guards, and respiratory
20.70 Operator Safety apparatus must be kept in good repair. This and other safety
equipment is necessary to protect operators or visitors from
So far in this chapter we have discussed many means by injury or death. Safety equipment may fall into disrepair
which you can protect yourself and your equipme-t. In this because it is only used occasionally and may deteriorate due
section we wish to discuss your own personal protection. to heat, time and other environmental factors. First aid
Take a look at the means of protecting the eye, the foot, the equipment should also be provided and kept resupplied as it
head and most of all look at water safety. After all, a plant is used. The operating staff should be given regular instruc-
operator is always in contact with water. The water may be tions in the use and maintenance of the safety equipment.
found in raw water reservoirs, settling basins, clear wells or
filters. Operators have lost their lives by falling into the Provide protective clothing for all operators handling
backwash gullet. Operators have lost their lives in the chemicals or dangerous materials. Keep the clothing clean
finished water reservoirs. As unlikely as it seems, fatal and store it in a protective environment when not in use.
accidents have happened in the past and will happen again The water utility is responsible for providing outward
in the future. Therefore, it is the responsibility of each opening doors, remote-controlled ventilation, inspection
-1,
P(.1' 453
 Safety 433

windows and similar safety devices where appropriate. This 20.73 Eye Protection
equipment should be exercised, kept clean and well main-
tained so that it will operate when needed.
Respiratory (self-contained breathing) apparatus must be
stored in unlocked cabinets outside of chlorination, sulfur
dioxide, cerbon dioxide, ozone and ammonia rooms. The
storage cabinets must have a controlled environment to
prevent deterioration of the equipment.
The operator has the responsibility to inspect each appa-
ratus for deterioration and need for repair. Safety equipment
is of no use to the operator if it fails when put to use, and
may cost you your life if it is in poor condition. Some self-
contained breathing apparatus (air packs) depend on com-
pressed air to supply the oxygen. Under conditions of
deficient oxygen supply, the canister type of respirator is
useless. You could lose your life by entering a room contain- The water treatment plant operator has only two eyes.
my chlorine gas (which is heavier than air) while depending You may think that everyone is aware of this fact. However,
on a poorly maintained respirator. Although you might have some operators behave as though they have many eyes and
protection from the chlorine, you would not have adequate are very careless about protecting them from hazards.
oxygen. Nev6 take a chance with a toxic gas. In water Because some operators fail to see the value of eye
treatment plants, use only the positive-pressure type of self- protection, it will take a maximum effort on behalf of the
breathing apparatus.
supervisory staff to enforce an adequate eye protection
Many newer plants are being constructed with indepen- program. Them must be an intense program of education,
dent air supplies consisting of a helmet, hose and com- persuasion, and appeal to guarantee compliance with an
pressed air. The helmet is connected by a hose to an eye protection program.
uncontaminated air source. The key word here is "unconta- Most conditions in which a plant operator needs eye
minated." Not only should the operator follow a maintenance protection are not ton difficult to understand. Eye protection
program for the hose and mouth pieces of the apparatus, is needed when handling many of the liquid chemicals, acids
but the operator must maintain the air supply. The air is and caustics. Some of the tests per armed in the laboratory
supplied by mechanical equipment which requires mainte- require eye protection. Only a few moments are required to
nance. The air pressure is controlled by a reduce- or put on a 4.--;e shield or safety glasses, and remember the
regulator which must be kept clean anc. maintainea to be loss of a eye will last a lifetime.
available when needed. Set up a preventive maintenance
program for this equipment. It should be checked out on a
weekly basis, and records should be kept of each inspec- QUESTIONS
tion. The record should show conditions of the hoses, Write your answers in a notebook and then compare your
regulators, air filters, compressors, helmet and any other answers with those on page 440.
apparatus furnished with the system.
20.7A When entering an oxygen-deficient atmosphere,
The old standby, of course, has been the air packs or seif- what type of oxygen supply is recommended9
breathing apparatus. These units are carried by the user,
giving the operator an independent source of air (oxygen). 20.7B Where should respiratory apparatus be stored?
The unit can be used in any concentration of contamination
of gases, dust or anywhere the atmosphere is oxygen 20.7C How frequently should independent air supply equip-
deficient. There are two types of units. One type of unit ment be checked out and what should be inspected?
depends on compressed air or oxygen, and the second 20 7D How can compliance with an eye protection program
system generates oxygen by use of chemicals in a canister. be encouraged?
The oxygen is generated by the moisture exhaled by the
user. Because this equipment is not used daily in the water 20.7E Under what conditions does an operator need eye
treatment plant, there must be a preventive maintenance protention9
program, with records, inspection and operator check out.
As with any system, self-breathing equipment requires main-
tenance. This is vital because the op ator's life will depend 20.74 Foot Protection
on how well ttl's apparatus performs. There are few situations under which a water treatment
plant operator needs foot protection. In the normal routine of
Training is another important consideration. Even though
you may have used the breathing apparatus many times in daily operation of the plant, there are not many hazards to
the past, you should be checked out each month on the the operator's feet. But in some plants the operator also
equipment. There should be a maximum allowable time for
performs plant maintenance. Here the steel toed safety
putting on the apparatus. The apparatus should be checked shoes are useful. The shoe should b able to resist at least a
300-pound (136 kg) impact. An important consideration in
out under field conditions, such as using ammonia or some
other non-toxic gas. Remember, it is too late to learn how any plant finder operating conditions is the use of rubber
fast an operator can put on a self-breathing apparatus when boots. Th a rubber boots are needed when handling acid or
a room is filled with chlorine. caustic, or when the operator is working in wet conditions
such as reservoirs, filters or chemical tanks. Under these
Be aware that there have been cases where operators circumstances, the agency should have an adequate supply
have been saved because they knew how to use the of boots in various sizes. If these conditions are something
breathing apparatus properly. Only repe,.ted practice will that the operator is exposed to daily or weekly, the agency
enable you to master this survival skill. should give the operator a pair of boots for personal use.

454
434 Safety

20.75 Hand Protection In most areas of a water treatment plant, there is really no
The treatment plant operators hands are always exposed need for a hard hat. However, there are certain hazardous
to hazards. These include not only minor scratches or cuts, conditions under which the operators should be required to
but also exposure to chemicals that may not attack immedi- wear a metal, plastic-impregnated fabric, or fiberglass hat.
ately. Some compounds, such as alum, attack the skin The hard hat should have a suspended crown with an
slowly. Because there is no immediate pain, you may think adjustable head band; provide good ventilation; and be
there is no damage. This is not true; the attack on the skin is water resistant. Operators should be required to wear the
slow and may cause an infection at a later date. Therefore, hard hats when work is being performed overhead, or in any
when handling chemicals, always use rubber gloves. As part location where .here is danger of tools or other materials
of a safety package, each operator should be issued a pair falling, for example, working in filters, settling basins or
of rubber gloves and also a pair of leather gloves. These trenches. There has been a long history showing the value
of hard hats in reducing injuries and death.
gloves should be replaced when they no longer provide the
necessary protection.
20.77 Water Safety
There are other compounds such as solvents that will
absorb through the skin and can cause long-term effects. Every operator in a treatment plant is exposed to situa-
For such special problems, there is a need for neoprene tions in which the operator's life can be lost due, either
gloves. Another problem is that of handling hot materials, directly or indirectly, to water. Although during you daily
such as laboratory flasks and beakers. Here you may need activity you may never think in terms of drowning, this
asbestos fabric gloves. When we rig around machinery hazard is always present in the treatment plant. If you are
that is revolving, wea.ing gloves or other hand protection working at a reservoir or a lake in a boat, you may think of
can be dangerous. If a glove gets caught in the machinery, water safety, but still never pay real attention to the danger.
you could become injured. Don't let your protective equip- Starting at the treatment plant, you can take simple
ment itself become a hazard. measures that will reduce hazards. To reduce the hazard of
Be sure that the gloves you are wearing are the right type slipping when working around clarifiers or settling basins,
for the job you are doing. The gloves should allow for quick use non-skid surfaces on ladders and walkways going into
removal and be in good condition. Always check for cracks and out of clarifiers or sedimentation basins. Be very cau-
and holes, flexibility and grip. Keep them clean and in good tious during cold or wet weather. Water freezes into ice
which is slippery.
condition. They e are many types of gloves and the proper
type should be worn for each job. Keep all handrails or other guards in good repair; replace
1. CLOTH GLOVES protect irom general wear, dirt, chaf- any that become unsafe. Many older plants do not have
ing, abrasions, wood slivers and low heat. protective handrails; install rails or chain off the unsafe area
to a:i employees and mark off with warning signs. The
2. LEATHER GLOVES protect from sparks, chips, rough unsafe areas can be guarded with 343-inch (9 mm) manila
material and moderate heat. rope, chains or cables that you may have around the plant.
3. RUBBER GLOVES protect against acids and some Filters are an important area of safety consideration
chemical burns. because there is always activity in or around each filter, such
as washing or maintenance. Here you should make repairs
4. NEOPRENE AND CORK-DIPPED GLOVES give better to handrails immediately when needed. Station emergency
grip on slippery or oi4 jobs.
gear around the filter areas; equipment such as life jackets
5. ASBESTOS OR ALUMINIZED GLOVES are heat-resist- are good, but buoys, 3/8-inch (9 mm) manila line or a long
ant to protect against sparks, flames and heat. wooden pole are much more useful. These types of devices
can be used to rescue someone who has fallen into the filter.
6. METAL MESH GLOVES protect from cuts, rough mate- An operator should never work in the filte when it is being
rials and blows from edge tools. backwashed. There is always the danger of falling into the
7. washwater gullet and being unable to get out before drown-
PLASTIC GLOVES protect from chemicals and corro- ing.
sive substances.
8. INVISIBLE GLOVES (barrier creme) protect from exces-
Sedimentation basins, flocculation basins or clarifiers
present many of the same problems as filters. Maintain
sive water contact and from substances which dissolve
in skin oil handrails, place warning signs or put up guard ropes or
chains. Also keep life rings and manila or nylon lines in good
repair. A lift ring, life pole and lines should be stationed at
20.76 Head Protection
each basin. A good idea is to shelter the safety gear from the
weather, but do not cause the gear to become inaccessible.
In reservoir operation and maintenance you will encounter
two types of water: (1) raw water and (2) treated water. In a
raw water reservoir or lake, you have to worry only about
personnel safety. In a treated water rase: mir, you must also
be concerned about the safety of the viater going to the
customer. If you are working out of a boat, make sure that
everyone in the boat is wearing a !;fe jacket. Also take on
board both a safety line and bugs. Cold weather conditions
are an added problem. Even though you may be a good or
excellent swimmer, the thermal shock of cold water may
quickly paralyze you, making you unable to save yourself.
Under such conditions, if a second operator goes into the
water to save you, there may be two lives lost.

455
 Water Treatment 435

Of course, when taking a boat out on the water it should 20.8 PREPARATION FOR EMERGENCIES'
first be checked out for safety. Check the bilge pump, Emergencies are very difficult to plan and prepare for
ventilation in the compartments, the safety cushions, fire because you never know what will happen and when it will
extinguishers, battery and the engine. Also check for safety occur. Catastrophic events could include floods, tornados,
equipment, life jackets, lights, mooring lines and fuel. If , 'I hurricanes, fires and earthquakes. Serious injuries to any-
are applying copper sulfate powder or solution, other safety one on the plant grounds is an emergency.
equipment will be needed, such as respiratory and eye
protection equipment. Prepare a de' !led equipment check- Conduct periodic tours of your facilities with the local fire,
list to use each time the boat goe , out onto the lake or police and emergency response organizations to familiarize
reservoir. The boat should never be taken out on choppy them with the site, potentially hazardous *cations, and
waters or when the wind is high. location of fire hydrants will be very helpful if an emergency
ever occurs. Emphasize to these people that if a disaster
On some occasions, there is a need for underwater occurs, how important it is for your plant to be a top priority
examination of valves, intake or other underwater equip- for assistance because the entire community relies on you
ment or apparatus. Such work should only be performed by for its drinking water.
employees who are trained in underwater diving. If there are
no qualified divers on your staff, you should hire such You should know the names and phone numbers of your
personnel to do the diving and underwater inspections. local and state civil preparedness coordinators.
There are organizations with people who do this type of
work and they are well qualified in underwater examinations. If a chemical emergency occurs such as a chemical spill,
If an operator on staff is to do the diving, the operator should leak, fire, exposure. or accident, phone CHEMTREC, 800-
be certified by a local diving school or other certifying 424 -9300. CHEMTREC, (Chemical Transportation Emergen-
agency. The operator's certificate should always be kept cy Center) provides immediate advice for those at the scene
current and the operator should be required to perform the of a chemical emergency, and then quickly and promptly
number of dives necessary to keep this certification current. alerts experts from the manufacturers whose products are
involved for more detailed assistance and appropriate follow
up
Prepare a procedure for quick and efficient handling of all
accidents or injuries occurring in your treatment facilities
and your outside crews. All personnel must be familiar with
these procedures and must be prepared to carry them out
with a minimum amount of delay or confusion.
A copy of these procedures must be posted in all working
areas accessible to a phone and in all vehicles containing
work crews. Names, addresses and phone numbers of
operators in each working area should be listed in that area
and aiso those immediately available (day or night) by
telephone.
Everyone must study these procedures carefully and be
able to respond properly and quickly. '(our health and life
may depend on these procedu, es.
Table 20.7 is an example of a typical safety procedure and
In closing, all plant operators should know how to swim. If Table 20.8 :s a checklist of what must be done if someone is
they do net, they should take a Red Cross class and learn seriously injured.
the minimum fundamentals to save their own lives. Any
operator working over open water should be required to
wear a buoyant vest. All basins should have approved safety QUESTIONS
vests, buoys and life lines stationed at outside edges.
Write your answers in a notebook and then compare your
answers with those on page 441.
QUESTIONS
20.8A What types of emergencies should operators be
Write your answers in a notebook and then compare your prepared to handle?
answers ,rite those on page 440.
20 8B Who should be contacted if a serious chz-lical
20.7F Under what operating conditions should an operator emergency occurs such as a chemical spill, leak, fire,
wear rubber boots? exposure or accident?
2C.7G Under what specific conditions should an operator
be very careful wearing gloves?
20.9 ARITHMETIC ASSIGNMENT
20.711 Why should operators never work in a filter when it is
Turn to the Appendix at the back of this manual and read
being backwashed?
Section A.36, "Safety." Work the example problems on your
20.71 Wh- items should be checked before an operator electronic pocket calculator. You should be able to get the
takes a boat out in the water? same answers.

7 Some of the information in this section was provided by M Richard '3 Metcalf, Training Officer, County of Onondaga, New York

456
 TABLE 20.7 EMERGENCY SAFETY PROCEDURE TABLE 20.8 INJURED PERSON CHECKLIST
1. DO NOT MOVE THE INJURED PERSON 1. CALL AMBULANCE SERVICE, Phone
except when conditions would cause additional injury,
such as a gas leak or a fire. LOCATION OF INJURED
STREET
2. ADMINISTER ONLY SUCH AID AS NECESSARY TO
PRESERVE LIFE TREAT FOR SHOCK
(a) clear throat and restore breathing TOWN
(b) stop bleeding
(c) closed heart massage
BUILDING LOCATION
3. DO NOT ATTEMPT MEDICAL TREATMENT such az.;
(a) do not apply splints or attempt to set broken bones
(b) do not remove foreign objects from the body PHONE NUMBER
(C) do not administer liquids or oxygen
NUMBER OF PERSONS INJURED
4. NOTIFY YOUR SUPERVISOR
IF AN AMBULANCE IS REQUIRED: NATURE OF INJURY
1. CALL AMBULANCE phone
2. Give this information carefu;'y and accurately: 2. POST OPERATOR TO DIRECT THE AMBULANCE
(a) Location of the injured -- be specific. NAME, ADDRESS, PHONE OF INJURED PERSON
1. Street location and number, Town or City
"Remember some streets have north or south NAME
or east or west designation use the full street
name. Also, many streets in different towns ADDRESS
have the same name specify the Town.
2. Location within the Plant area
(b) Phone number from which you are calling
(c) Number of persons injured and nature of the injury
(d) Post an operator to direct the ambulance to the PHONE
victim
3. Upon arrival of the ambulance:
3. GIVE ABOVE INFORMATION TO AMBULANCE CREW
(a) give name, address and phone number of the
injured person to the ambulance crew NAME AND LOCATION OF HOSPITAL
(b) notify relatives of injury and hospital to which HOSPITAL NAME
person is being taken
(Medical treatment cannot be given witnout the ADDRESS
permission of the injured or a relative, if a minor)
4. Call your supervisor
IF AN AMBULANCE IS NOT REQUIRED:
1. Take injured: (see map) (Phone
ask for Emergency Room) PHONE
Emergency Room
St. Joseph's Hospital 4. NOTIFY RELATIVES
301 Prospect Avenu-,
2. If possible, call ahead. --live the names of injured and 5. NOTIFY SUPERVISORS
nature of injury.
6. MAKE OUT ACCIDENT REPORT AS SOON AS
3. Notify relatives of injury and address of hospital POSSIBLE
4. Call your supervisor
457
 438 Water Treatment

SUGGESTED ANSWERS
Chapter 20. SAFETY

ANSWERS TO QUESTIONS IN LESSON 1 rine and hydrogen sulfide (H2S)), war safety, and
any specific "azards that are unique to your facility.
Answers to questions on page 394. All new operators should be subjected to a safety
20.0A A safety officer should evaluate every accident, offer orientation program during the first few days of
recommendations, and keep and apply statistics employment, and an overall training program in the
first few months.
20 OB The supervisors should be responsible for the imple-
mentation of a safety program. 20 OM If an operator is unsure of how to perform a job, then
it is the operator's responsibility to ask for the
20.0C Both state and federal regulatory agencies enforce training needed.
the OSHA requirements.
20.00 Each utility should develop a policy statement on Answers to questions on page 401.
safety, giving its objective concerning the operator's
20.0N Statistical accident reports should contain accident
welfare. The statement sho, ild be brief, but give the
statistics showing lost time, costs, type of injuries
utility's recognition of the need for safety to stimulate
and other data, based on some time interval.
efficiency, improve service, improve morale and to
maintain good public relations. The policy should 20 00 Injuries can be classified as fractures, burns, bites,
recognize the human factor (the unsafe act), and eye injuries, cuts and bruises.
emphasize the operator's responsibility. The opera- 20.0P Causes of injuries can be classified as heat, machin-
tors should be provided with proper equipment and ery, falling, handling chemicals, unsafe acts and
safe working conditions. Finally, the policy must miscellaneous.
reinforce the supervisory respor-ibility to maintain
safe work practices. 20.00 Costs of accidents can be classified as lost time lost
dollars, lost production, contaminated water or any
Answers to questions on page 395. other means of showing the effects of the accidents
20.0E A supervisor may be responsible, in part or COL:- ANSWERS TO QUESTIONS IN LESSON 2
pletely, for an accident by causing unsafe acts to
take place, by requiring that work be performed in Answers to questions on page 405.
haste, by disregarding an unsafe environment of the
work :lace, or by failing to consider any number of 2010A An operator needs to know how to handle the
safety hazards. problems associated with the chemicals used in a
water treatment plant. The operator needs to know
20.0F Each operator must accept, at least in part, responsi- how to store chemicals, the fire problem, the ten-
bility for fellow operators, for the utility's equipment, dency to "arch" in a storage bin, how to feed dry.
for the operator's own welfare, and even for seeing Dw to feed liquid, and how to make up solutions.
that the supervisor complies with establishes safety Overheating gas containers, dust problems with
regulations. powdered carbon, burns caused by acid, reactivity
of each chemical under a variety of conditions that
20.0G First aid means emergency treatment for injury or may cause fire and explosions are other safety
sudden illness, before regular medical treatment is hazards that an operator needs to know about and
available. know how to control. Also, the operator :weds to
20.0H First aid training is most important for operators who know the usable limits because of toxicity, the
regularly work with electrical equipment and those -rotective equipment required for each chemical,
who must handle chlorine. each chemical's antidote, and how to control fires
caused by each chemical.
Answers to questions on page 399. 20.11A To give first aid vhen acid vapors are inhaled,
20.01 The mainstay of a safety program is the method of remove the victim to fresh air, restore breathing, or
reporting and keeping statistics. give oxygen when necessary.
20 OJ Even a minor injury should be reported because it 20 11B Acetic acid will react violently with ammonium ni-
may be difficult at a later date to prove the accident trate, potassium hydroxide and other alkaline mate-
occurred on the job in order to have the utility accept rial.
the responsibility for costs. 20 11C Acetic acid can be handled safely the operator
20.0K A safety officer should review an accident report uses adequate ventilation and prevents skin and
form to el ) determine corrective actions and (2) make eye contact.
recommendations. 20.110 When handling hydrofluosilicic acid, always use
20.0L A new inexperienced operator must receive instruc- complete protective equipment including rubber
tion on all aspects of plant safety. This training gloves, goggles or face shield, rubber apron, rub-
includes instruction in the handling of cnemicals, the ber boots and have lime slurry barrels, epsom salt
dangers of electrical apparatus, fire hazards, and solut'on and safety showers available. Always pro-
proper maintenance of equipment to prevent acci- vide adequate ventilation.
dents. Special instructions are required for specific 20 11E Inhalation of hydrochloric (HCI) vapors or mists can
work environments such as manholes, gases (chlo- cause damage to teeth and irritation to the nasal

459
 438 Water Treatment

SUGGESTED ANSWERS
Chapter 20. SAFETY

ANSWERS TO QUESTIONS IN LESSON 1 rine and hydrogen sulfide (H2S)), war safety, and
any specific "azards that are unique to your facility.
Answers to questions on page 394. All new operators should be subjected to a safety
20.0A A safety officer should evaluate every accident, offer orientation program during the first few days of
recommendations, and keep and apply statistics employment, and an overall training program in the
first few months.
20 OB The supervisors should be responsible for the imple-
mentation of a safety program. 20 OM If an operator is unsure of how to perform a job, then
it is the operator's responsibility to ask for the
20.0C Both state and federal regulatory agencies enforce training needed.
the OSHA requirements.
20.00 Each utility should develop a policy statement on Answers to questions on page 401.
safety, giving its objective concerning the operator's
20.0N Statistical accident reports should contain accident
welfare. The statement sho, ild be brief, but give the
statistics showing lost time, costs, type of injuries
utility's recognition of the need for safety to stimulate
and other data, based on some time interval.
efficiency, improve service, improve morale and to
maintain good public relations. The policy should 20 00 Injuries can be classified as fractures, burns, bites,
recognize the human factor (the unsafe act), and eye injuries, cuts and bruises.
emphasize the operator's responsibility. The opera- 20.0P Causes of injuries can be classified as heat, machin-
tors should be provided with proper equipment and ery, falling, handling chemicals, unsafe acts and
safe working conditions. Finally, the policy must miscellaneous.
reinforce the supervisory respor-ibility to maintain
safe work practices. 20.00 Costs of accidents can be classified as lost time lost
dollars, lost production, contaminated water or any
Answers to questions on page 395. other means of showing the effects of the accidents
20.0E A supervisor may be responsible, in part or COL:- ANSWERS TO QUESTIONS IN LESSON 2
pletely, for an accident by causing unsafe acts to
take place, by requiring that work be performed in Answers to questions on page 405.
haste, by disregarding an unsafe environment of the
work :lace, or by failing to consider any number of 2010A An operator needs to know how to handle the
safety hazards. problems associated with the chemicals used in a
water treatment plant. The operator needs to know
20.0F Each operator must accept, at least in part, responsi- how to store chemicals, the fire problem, the ten-
bility for fellow operators, for the utility's equipment, dency to "arch" in a storage bin, how to feed dry.
for the operator's own welfare, and even for seeing Dw to feed liquid, and how to make up solutions.
that the supervisor complies with establishes safety Overheating gas containers, dust problems with
regulations. powdered carbon, burns caused by acid, reactivity
of each chemical under a variety of conditions that
20.0G First aid means emergency treatment for injury or may cause fire and explosions are other safety
sudden illness, before regular medical treatment is hazards that an operator needs to know about and
available. know how to control. Also, the operator :weds to
20.0H First aid training is most important for operators who know the usable limits because of toxicity, the
regularly work with electrical equipment and those -rotective equipment required for each chemical,
who must handle chlorine. each chemical's antidote, and how to control fires
caused by each chemical.
Answers to questions on page 399. 20.11A To give first aid vhen acid vapors are inhaled,
20.01 The mainstay of a safety program is the method of remove the victim to fresh air, restore breathing, or
reporting and keeping statistics. give oxygen when necessary.
20 OJ Even a minor injury should be reported because it 20 11B Acetic acid will react violently with ammonium ni-
may be difficult at a later date to prove the accident trate, potassium hydroxide and other alkaline mate-
occurred on the job in order to have the utility accept rial.
the responsibility for costs. 20 11C Acetic acid can be handled safely the operator
20.0K A safety officer should review an accident report uses adequate ventilation and prevents skin and
form to el ) determine corrective actions and (2) make eye contact.
recommendations. 20.110 When handling hydrofluosilicic acid, always use
20.0L A new inexperienced operator must receive instruc- complete protective equipment including rubber
tion on all aspects of plant safety. This training gloves, goggles or face shield, rubber apron, rub-
includes instruction in the handling of cnemicals, the ber boots and have lime slurry barrels, epsom salt
dangers of electrical apparatus, fire hazards, and solut'on and safety showers available. Always pro-
proper maintenance of equipment to prevent acci- vide adequate ventilation.
dents. Special instructions are required for specific 20 11E Inhalation of hydrochloric (HCI) vapors or mists can
work environments such as manholes, gases (chlo- cause damage to teeth and irritation to the nasal

459
 Safety 439

passages. Concentrations of 750 ppm or more will 20 14C When exposed to moist air or light, ferric chloride
cause coughing, choking and produce severe dam- aecomposes and gives off hydrochloric acid.
age to the mucous membranes of the respiratory
tract. In concentrations of 1300 ppm, HCI is danger- Answers to qu' ;ions on page 415.
ous to life.
20.15A Potassium permanganate spills can be swept up.
Flushing with water is an effective way to eliminate
20 11F Nitric acid should be stored in clean, cool, well- spillage on floors.
ventilated areas. The area should have an acid-
resistant floor and adequate drainage. Keep away 20 15B Powdered activated carbon is the most dangerous
from oxidizing agents and alkaline materials. Pro- powder the water treatment plant operator will be
tect containers from damage or breakage. Avoid exposed to.
contact with skin and provide emergency neutral- 20.15C Activated carbon should be stored in a clean, dry,
ization materials and safety equipment in use fire-proof location. Keep free of dust, protect from
areas. flammable materials, and do not permit smoking in
the area at any time when handling or unloading
Answers to questions on page 408. activated carbon.
20 12A Operators use two forms of ammonia. The gaseous 20.15D The key to preventing activated carbon fires is
form (anhydrous) and the liquid form (hydroxide) keeping the storage area clean and free of dust.
are used by operators.
20.15E Carbon fires should be controlled by carbon dioxide
20.12B Care must be used when storing or transporting (CO2) extinguishers or hoses equipped with fog
ammonia containers. Always keep cylinders with nozzles. An activated carbon fire should not be
caps in place when not :n use. Sore cylinders in a doused with a stream of water. The water may
cool, dry location away from haat and protect from cause burning carbon particles to fly, resulting in a
direct sunlight. Do not store in trio same room with greater fire problem.
chlorine.
2C 2C The two forms of lime cted in water treatment Answers to questions on page 415.
plants are (1) hydrated lime (calcium hydroxide) and 20.16A Safety regulations prohibit the use of common
(2) quicklime (calcium oxide). drains and sumps from chemical storage areas to
20.12D If someone swallowed sodium hydroxide, give avoid the .1ossibility of chemicals reacting and
large amounts of water or milk and immediately producing toxic gases, explosions and fires.
transport t a medical facility; do not induce vomit- 20.16B If a polymer solution comes in contact with potas-
ing. ,ium permanganate, a fire could deviop.
20.12E If sodium silicate comes in contact with your skin,
wash thoroughly with water, followed by washing
with a 10 percent solution of ammonium chloride or ANSWERS TO QUESTIONS IN LESSON 3
10 percent acetic acid.
Answers to questions on page 420.
Answers to questions on page 412. 20.2A Class A fires involve miscellaneous combustible ma-
20.13A Chlorine leaks are most often found in the control terials. These include fabrics, paper, weed, dried
valve. grass, hay and stubble.
20.13B The purpose of the fusible metal plugs is to melt at 20.2B Foam extinguishers can control Class A and Class B
158 to 168°F. If a cylinder becomes overheated, the fires. They can control ordinary combustitles ("Al
plugs will melt and let the gas escape rather than such as fabrics, paper, wood and grass, as well as
the cylinder bursting. flammable liquids and vapors ( "B") such as oils,
lacquers, fats, waxes, paints, petroleum products
20.13C Chlorine leaks can be detected by the odor, by the and gas.
use of ammonia water on a small cloth or swab on a
stick, or by the use of an aspirator containing 20.2C An electrical fire can be extinguished by the use of
ammonia water. (Remember not to spray ammonia carbon dioxide (CO2) extinguishers or with a dry
into a room full of chlorine because a white cloud chemical extinguisher.
will form and you won't he able to see anything.)
Also, a chlorine gas detec 'or may be used. Answers to questions on page 421.
20.13D Carbon dioxide is a safety hazard because it is 20.3A When waxing floors use compounds containing
ci-' dess, colorless, and will accumulate at the nonslip ingredients. Warn others about newly waxed
lc 3t possible level. Carbon dioxide will displace floors. Try to do cleaning and waxing during off-duty
oxygen so you must use a self-contained breathing nniirs, weekends or at night.
apparatus. 20.3E Rags are always a problem and if they contain oils,
paint or other cleaning compounds there is always
Answers to questions on page 414. the possibility of fire. The rags should be placed into
20.14A For handling most salts, ventilation, respiratory a closed metal container to reduce the fire hazard.
protection and eye protection will prove adequate. 203C When operating an overhead crane, the following
20.14B First aid when liquid or dry alum gets intc the eyes safety precautions must be exercised:
consists of flushing them immediately 'or 15 min- 1. Allow only trained and authorized personnel to
utes with large amounts of water. Alum should be operate the overhead crane,
washed off the skin with water because prolonged 2. Inspectihe circuit breaker, limit switches, condi-
contact will cause skin irritation. tion of hook, wire rope and other safety devices,

460
440 Water Treatment

3. Post load limit on crane and never overload Answers to questions on page 432.
crane,
4. Check each lift for proper balance, 20 6A Washing glassware is always a potential hazard
5. Use a standard set of hand signals, because the glassware can be broken while being
6. Be sure everyone in vicinity wears a hard hat, washed, causing cuts, or cuts can be caused by
7. Allow only authorized personnel to make re- chipped or cracked glassware. If your hands come in
pairs, contact with strong acid cleaners, the acids may
8. Lock out the main power switch before repairs cause serious burns.
begin, 20 6B When handling liquid chemicals such a'., acids and
9 Try to avoid moving loads over populated areas, bases, always use safety glasses or face shields.
arid
20 6C Never allow mercury, gasoline, oil or organic com-
10. Set up monthly safety inspection forms to be pounds into the laboratory drains. Use only a toxic
filled out and placed into the maintenance file.
waste disposal drain system for these items. Letting
20 3D Traffic can be warned that operators are working in a such compounds down sink drains can cause an
'nhole by the use of barricades, signs, flags, lights explosion, allow toxic gases and vapors to enter the
and other warning devices. Warning devices and lab or destroy the piping.
procedures must conform to local and state regula- 20.6D The plant operator may be exposed to radioactive
tions.
compounds when calibrating sludge density meters
20.3E Operators should always use a mechanical lifting aid or using research isotopes.
(rope and bucket) for raising or lowering tools and 20 6E Never allow cold water into the hot boiler unit of a
equipment into and out of a manhole. The use of a water still because it may cause the unit to break.
bucket or basket will keep your hands free when
climbing down into or out of a manhole.
Answers to questions on page 433.
Answers to questions on page 423. 20.7A When entering an oxygen-deficient atmosphere, you
20.3F Operators should wear eye and ear protection when should have an independent oxygen supply of the
operating grinding, chipping, buffing, or pavement- positive-pressure type to protect you if there are any
breaking equipment. Sometimes when using grind- leaks in your mask.
ing or buffing tools, operators encounter toxic dusts 20.78 Respiratory apparatus must be stored outside of
or fumes and therefore need respiratory protection. chlorinating, sulfur dioxide, carbon dioxide, ozone
At other times there is a need for full face protection and ammonia rooms in an unlocked cabinet. The
because of flying particles. storage cabinets must have a controlled environment
20.3G Operators can be protected from high noise levels by to prevent deterioration of the equipment.
wearing approved ear protection devices. 20 7C Independent air supply equipment should be
20.3H When operating welding equipment, the operator checked out on a weekly basis, and records kept of
should wear protective clothing, gloves, helmets and each inspection. The record should show conditions
goggles. of the hoses, regulators, air filters, compressors,
helmet and any other apparatus fucnished with the
system.
Answers to questions on page 425. 20.7D To obtain compliance with an eye protection pro-
20.4A Tire wear is caused by misalignment and low infla- gram. supervisors should undertake an intense pro-
tion gram of education, persuasion, and appeal.
20.4B Motor vehicles should have flashlights, flares, flags 20 7E An operator needs eye protection when handling
and a first aid kit. many of the liquid chemicals, acids and caustics.
Many of the tests performed in the laboratory also
require eye protection.
ANSWERS TO QUESTIONS IN LESSON 4

Answers to questions on page 429. Answers to questions on page 435.

20.5A Each operator should become familiar with the type 20 7F Rubber boots are needed when handling acid or
of current and voltage in the plant in order to avoid caustic. or when tne operator is working in wet
any mistake of becoming involved with unsafe elec- conditions such as reservoirs, filters or chemical
trical circuits or praciices for which they are not tanks.
trained. This will also permit operators to ask for a 20.7G An operator should be very careful wearing gloves
qualified person to perform any necessary repairs. when working around machinery that is revolving.
20 5B Moving parts on electrical motors that require safety 20.7H Operators should never work in a filter when it is
guards include exposed couplings, pulleys, gears being backwashed because there is always the dan-
and sprockets, as well as projections such as bolts, ger of falling into the wastewater gullet and being
keys, or set screws. unable to get out before drowning.
20.5C Two hazards due to the lack of a good lockout 20 71 Before taking a boat out on the water, it should be
procedure for control panels and switchboards are checked out for safety. The operator should check
(1) accidentally starting a piece of equipment expos- the bilge pump, ventilation in tha compartments, the
ing a fellow operator to a hazard, and (2) turning safety cushions, fire extinguishers, battery and the
electrical power on when someone is still working on engine. For safety equipment, check oars, life jack-
the equipment, exposing that person to danger. ets, lights, mooring lines and fuel.

*:1 47, 1
../ t- -
461
 Safety 441

Answers to questions on page 435. 20.86 If a serious chemical emergency occurs such as a
20.8A Operators should be prepared for catastrophic chemical spill, leak, fire, exposure, or accident,
events such as floods, tornados, hurricanes, fires phone CHEMTREC, 800-424-9300
and earthquakes. Serious injuries to anyone on the
plant grounds is an emergency.

OBJECTIVE TEST
Chapter 20. SAFETY

Please write your name and mark the correct answers on 10 Never neutralize ammonia with an acid.
the answer sheet as directed at the end of Chapter 1. There 1. True
may be more than one correct answer to the multiple choice 2 False
questions.
11. Quicklime is less caustic than hydrated lime.
TRUE-FALSE
1. True
1. The OSHA Law provides for civil penalties only. 2. raise
1. True
12. When quicklime is mixed with water, a great deal of heat
2. False is generated and explosions can occur.
2. Supervisors can prevent most accidents. 1. True
2. False
1. True
2. False 13. The loss of water supply to a lime slaker can create
3. First aid training will prevent accidents. explosive temperatures.

1. True 1. True
2. False 2. False

4. On-the-job training is a good way of preventing acci- 14. The storage area for chlorine cylinders must have force-
dents for an inexperienced operator. exhaust ventilation.

1. True 1. True
2. False 2. False

5. Acetic acid exposure must oe treated immediately to 15. Never use an open flame on cylinders or pipes carrying
prevent damage. chlorine.

1. True 1. True
2. False 2. False

6. Potassium permanganate fires should be extinguished 16. AD safety equipment should be located inside the chlo-
with water. rination room.
1. True 1. True
2. False 2. False

7 Some weak bases will attack human tissue very rapidly 17. First aid for a sulfur dioxide victim is similar for the
and cause burns. victim of any acid injury.
1. True 1. True
2. False 2. False
8. Bases most be neutralized with dilute acids.
18. Never use the same conveyor for quicklime and alum.
1. True
2. False 1 True
2. False
9. Ammonia gas is capable of forming explosive ixtures
with air. 19. Ferric chloride is an acid.
1. True 1. True
2. False 2. False

462
 442 Water Treatment

20 Ferric chloride should be treated as you would treat any 32. A routine OSHA violation could cost an employer up to
acid. _____ for each violation.
1. True 1. $1000
2. False 2. $2500
3. $5000
21. Activated carbon burns without smoke or visible flame 4. $7500
1. True 5. $10,000
2. False
33. A supervisor could be responsible for an accident, in
part or complete, by
22. Explosion-proof lighting must be used in paint booths.
1. Causing unsafe acts to take place.
1. True
2. Disregarding an unsafe work environment.
2. False 3. Overlooking a potential hazard.
4. Requiring operators to attend safety meetings.
23. Never use compressed air to clean off your clothing or 5. Requiring work to be performed in haste.
Parts of your body.
1. True 34. A review of accident causes shows that the accident
2. False victim often has not
1. Accepted any responsibility for the safety program.
24. Never look at a welding operation without eye protec- 2. Acted responsibly.
tion. 3. Been concerned about fellow operators.
4 Been fully aware of the working conditions.
1. True 5. Complied with the safety regulations.
2. False
35. Tailgate safety meetings should be
25. Chlorine may be the only chemical used in a simple well 1. Held where distractions can be avoided.
system. 2. Held where everyone ca "i hear.
1. True 3. Held in an auditorium.
2. False 4. Kept short.
5 Scheduled in a suitable location.
26. A special insulated mat should be used on the floor at all
switch boards. 36. Hydrofluosilicic acid is
1. True 1. Corrosive.
2. False 2. Fuming.
3. Pungent.
4. Transparent.
27. Badly worn electrical cords should be used only in wet 5. Yellow.
locations.
1. True 37. Hydrochloric acid is highly reactive with
2. False 1. Amine.
2. Carbonate.
28. In the laboratory, broken glass should be disposed of in 3. Glass.
wastebaskets. 4. Metals.
5. Porcelain.
1. True
2. False 38. Nitric acid
1. Attacks glass.
29. Always pour acid into water, never" the reverse. 2. Attacks most metals.
1. True 3. Forms fumes in the presence of light.
2. False 4. Is a powerful reducing agent.
5. Is unstable even when properly handled.
30. Never enter a confined space with an explosive atmos-
phere. 39. Sulfuric acid may be contained in -lined contain-
ers.
1. True
2. False 1. Glass
2. Metal
3. Plastic
4. Rubber
MULTIPLE CHOICE 5. Wooden
31. A safety officer should be responsible for 40. The most common strong bases are compounds of
1. Applying accident statistics. 1. Ammonia.
2. Evaluating every accident. 2. Calcium.
3. Implementing safety program. 3. Carbonate.
4. Keeping accident statistics. 4. Hypochlonte.
5. Offering recommendations. 5. Sodium.

463
 Safety 443

41. Sodium hydroxide 50. Hazardous atmospheric conditions that may be encoun-
1. Absorbs carbon dioxide from the air. tered in manholes include
2. Causes heat when mixed with water. 1 Hydrogen sulfide.
3. Dissolves human skin. 2. Insufficient oxygen.
4. Is used to neutralize lime. 3 Methane.
5. Is very hazardous to the operator. 4. Natural gas
5. Nitrogen.
42. Dissolving sodium hydroxide in water
51. Which of the following rules apply to the operation of
1 Causes splintering. gas or electric welding equipment9
2. Develops sludges.
3. Generates excessive heat. 1. Adequate fire protection must be provided.
4. Lowers pH. 2. Have a buddy observe your performance.
5. ProaJces mists. 3. Operators must be thoroughly trained.
4. Protection of other personnel must be provided and
used.
43. Types of hypochlonte compounds used in water treat- 5 Work during regular hours only.
ment plants include
1 Calcium. 52. Types of safety valves in a water treatment dant that
2. Iron. should be inspected and maintained on a regular basis
3. Lithium include:
4. Magnesium. 1 Butterfly valves.
5. Sodium. 2. Chlorine relief valves
3. Gate valves.
44. Chlorine cylinders may be lifted using J. Surge relief valves.
1. Cable:, 5. Water heater valves.
2. Chains.
3. Clamps. 53 What safety precautions must be exercised around
4. Cradles. vehicle wash and steam cleaning areas?
5. Ropes. 1. Always use scaffolding or platforms when cleaning
the tops of vehicles.
45. Chlorine cylinders should be stored 2 Check level of water on coils before turning on
steam.
1. Below ground level. 3. Eye and face protection is not necessary.
2 In a clean, dry location.
4. Keep the steam nozzle clean.
3. On their sides. 5. Keep the wash rack free from oil and grease.
4 So they cannot fall.
5. With the protective cap off. 54. Good drivers
1. Always observe traffic regulations
46. Improper handling, storing or preparing solutions of 2 Check out their vehicles each time they use them.
chemicals can cause 3 Drive defensively.
1. Burns. 4. Operate vehicles as if all other drivers are the world's
2. Cost savings. worst drivers.
3. Explosions. 5 Use proper signals for directional change.
4. Illness
5. Loss of eyesight. 55 When safely operating a forklift, be sure to
1. Always face the direction of travel.
47. The most dangerous powder the water treatment plant 2 Check warning lights for proper operation.
operator could be exposed to is 3 Leave the power on when leaving the forklift to keep
1. Alum. the battery charged.
2. Calcium carbonate. 4. Never overload the forklift.
3. Potassium permanganate. 5. Use special lifting and retaining devices when han-
4. Powdered activated carbon. dling drums.
5 Quicklime. 56. The purpose of most transformers where power enters
a water treatment plant is to
48. The operator's BEST fire protection or prevention is
1. Decrease electrical resistance.
1. Anrally making a fire analysis of plant. 2. Detect overheating.
2 Good housekeeping. 3. Increase the electrical voltage
3. Properly locating fire extinguishers 4. Reduce the electrical voltage.
4. Providing suitable containers for used wiping cloths 5. Transform low voltage to high voltage.
5. Removal of fire hazards.
57. Hazardous conditions an operator may encounter in the
49. Class A fires involve laboratory include
1. Electrical equipment. 1. Alkalies.
2. Fabrics. 2. Distilled water
3. Oils. 3. Flammaole chemicals.
4. Paints. 4. Glassware.
5. Sodium. 5. Toxic chemicals.

464
444 Water Treatment

58. Toxic chemicals, acids or alkalis can be transferred with 4. Fumes.

a pipet by using 5. Gases.
1. Aspirators.
2. Pumps. 60. Types of gloves that an operator may need include
3. Suction bulbs. 1. Asbestos fabric. I'
4. Vacuum lines. 2 Cloth.
5. Your mouth. 3. Leather.
4. Neoprene.
59. Respiratory hazards in and around the treatment plant 5. Rubber.
that operators are exposed to on a daily basis include
1. Acids.
2. Bases.
3 Dusts. eiut of Dilative TM

4. t

465

4111=05..11
 CHAPTER 21

ADVANCED LABORATORY PROCEDURES

by

Jim Sequeira

46G
446 Water Treatment

TABLE OF CONTENTS
Chapter 21. Advanced Laboratory Procedures

Page
OBJECTIVES 447

LESSON '.

21.0 1_1'...e of a Spectrophotometer 448

21.1 Test Procedures* 449
1. Algae Counts 449
2. Calcium 450
3. Chloride 451
4. Color 453
5. Dissolved Oxygen 454
6. Fluoride 457

LESSON 2

7. Iron (Total) "61

8. Manganese 463
9. Marble Test (Calcium Carbonate Stability Test) 466
10. Metals 467
11. Nitrate 468
12. pH 471
13. Specific Conductance 471
14. Sulfate 472
15. Taste and Odor 474
16. Trihalomethanes 479
17. Total Dissolved Solids 479
Suggested Answers 482
Objective Test 484

Test Procedures in C"^nter 11 include alkalinity, chlorine residual, chlorine demand, coliform bacteria, hardness, ja, test, pH,
temperature and turbk.

467
 Lab Procedures 447

OBJECTIVES
Chapter 21. ADVANCED LABORATORY PROCEDURES

Following completion of Chapter 21, you should be able

to:
1. Explain how a spectrophotometer analyzes samples of
water, and

2. Perform the following field or laboratory tests - algae

counts, calcium, chloride, color, dissolved oxygen, flu-
cride, iron, manganese, marble test, metals, nitrate. pH,
specific conductance, sulfate, taste and odor, trtalo-
methanes and total dissolved solids.

468
448 Water Treatment

CHAPTER 21. ADVANCED LABORATORY PROCEDURES

(Lesson 1 of 2 Lessons)

21.0 USE OF A SPECTROPHOTOMETER

In the field of water analysis, many determinations such as
iron, manganese, and phosphorus are based on the color
intent formed when a specific color developing reagent is
added to the sample being tested. Measuring the intensity of
tile color enables the concentration of the substance to be
Refracting Sample
determined. The simplest means of accomplishing this is prism cuvette Photo-
through either nessler tubes or a pocket comparator. The White electric
color developed in a sample is compared by the operator to light source Ex -t tube
slit
a series of known standards, to each of which has been
added the sumo color developing reagents. For the analysis (1) in units of percent transmittance (%T), an arithmetic
of phosphyrus present in a water sample, for example, scale with units graded from 0 to 100%; and
ammonium molybdate reagent is added as the color devel-
oping reagent. If phosphorus is present, a blue color deve!- (2) in units of absorbance (A), a logarithmic scale of
ops. The more phosphorus there is, the deeper and darker nonequal divisions graduated from 0.0 to 2.0.
the blue color.
Both the units percent transmittance and absorbance are
The human eye can detect some differences in color associated with color intensity. That is, a sample which has a
intensity: however, for very precise measurements an instru- low color intensity wiII nave a high percent transmittance but
ment called a spectrophotometer (SPEK-tro-fo-TOM-uli-ter) a low absorbance.
is used. 50
THE SPECTROPHOTOMETER. A spectrophotometer is
an instrument generally used to measure the color intensity
of a chemical solution. A spectrophotometer in its simplest
form consists of a light source which is focused on a prism
or other suitable light dispersion device to separate the light
into its separate bands of energy. Each different wave length
or color may be selectively focused through a narrow slit. PERCENT TRANSMITTANCE
This beam of light then passes through the sample to be Absorbance
measured. The sample is usually contained in a glass tube
called a cuvette (QUE-vet). Most cuvettes are standardized As illustrated above, the absorbance scale is ordinarily
to have a 1.0 cm light path length, however many r 'her sizes calibrated on the same scale as percent transmittance on
are available. spectrophotometers. The chief usefulness of absorbance
lies in the fact that it is a logarithmic function rather than
After the selected beam of light has passed through the
linear (arithmetic) and a law known as Beer's Law states that
sample, it emerges and strikes a photoelectric' cell. If the
the concentration of a light-absorbing colored solution is
solution in the sample cell has absorbed any of the light, the
total energy content will be reduced. If the solution in the directly proporilonal to absorbance over a given range of
concentrations. If or,e were to plot a graph showing (%T)
sample cell does not absorb the light, then there will be no
change in energy. When the transmitted light beam strikes
percent transmittance versus concentration on straight
graph it line paper and another showing absorbance versus
the photoelectric tube, it generates an electric current that is conce ration on the same paper, the following curves
proportional to the intensity of light energy striking it. By (graphs) would result:
connecting the photoelectric tube to a galvanometer (a
device for measuring electric current) with a graduated
scale, a me:as of measuring the intensity of the transmitted
beam is achieved.
The diagram at the top of the next column illustrates the
working parts of a spectrophotometer.
The operator should always follow the working instruc-
tions provided with the instrument.
Concentration Concentration
UNITS OF SPECTROSCOPIC MEASUREMENT. The
scale on spectrophotometers is generally graduated in two CALIBRATION CURVES: The c ,b ration curve is used to
ways: determine the concentration of the water quality indicator

469
 Lab Procedures 449

(iron or manganese) contained in a sample. Three s.eps In this example, an absorbance reading of 0 32 was read
must be completed in order to prepare a calibration graph. on the unknown solution or sample, which indicates a
concentration of about 0.37 mg/L.
First, a series of standards roust be prepared. A standard
is a solution which contains a known amount of the same
chemical constituent which is being determined in the sam-
QUESTIONS
ple. Write your answers in a notebook and then compare your
answers with those on page 482.
Secondly, these standard solutons and a sample contain-
ing none of the constituent being tested for (usually distilled 21.0A When measuring the color intensity of phosphorus,
water and generally referred to as a blank) must be treated what color is measured?
with the developing reagent in the same manner as the
sample would be treated. 21.0B What are the units of measurements for spectropho-
tometers?
Thirdly, using a spectrophotometer the absorbance or 21.0C Using the above .bsorbance vs. concentration cali-
transmittance at the specified Nave length of the standards ation graph, if the absorbance reading of 0.60 was
and blank must be determined From the values obtained, a read on an unknown solution or sample, what was
calibration curve of absorbance (or %T) versus concentra- the concentration of the unknown?
tion can be plotted. Once these several points have been
plotted, you can then extend tl-e plotted points by connect- 21.1 TEST PROCEDURES
ing the known points w;th a straight line. For example, with
the data given below one could construct the following 1. Algae Counts
calibration curve.
A. Discussion
4bsorbance Concentration, mg/L
The quality of water in any lake, reservoir or stream has a
0.0 0.0
0.25
very direct effect on the abundance and types of aquatic
0.30
0.50
organisms found. By knowing the nature and numbers of
0.55
these aquatic organisms one can obtain a good idea of the
0.80 0.75
water quality. A biological method used for measuring water
quality is the collection, coui sting, and identification of algae
10
- 99 -400
0.I -/40/
O 03
,01

0
Ol
02

0.0
12

Concentration, mg/L
Once you have established a calibration curve for the
water quality indicator in question, you can easily determine
the amount of that substance contained in a solution of
unknown concentration. You merely take an absorbance
reading on the color developed by the unknown and locate it
on the vertical axis. Then a straight tine is drawn to the right contained in a particular body of water. Information from
on the graph until it intersects with the experimental stan- algae counts can serve one or more of the following pur-
dard curve. A line is then dropped to the horizontal axis and poses:
this value identifies the concentration of your unknown
water quality indicator. 1. Help explain the cause of color and turbidity and the
presence of tastes and odors in the water,
2. Help explain the clogging of screens or filters, and
1.0
3. Help document variability in the water quality.
2 0.8 Algae counting and identification may be done very simply
or it may be developed into a highly technical operation. The
0 0.6 beginner should use great caution applyin7 the results of
algae identifications until considerable experience has been
01 gained.

0.2
Som,. operators perform algae counts on both the raw
water and treated water. Taking algae counts on treated
0
0.0
1 1 water is a means of studying the entiveness of coagula-
0.25 0.50 0.75 1.0 tion and the performance of filters. 1, filters are perform-
ing properly, there should not be any countable algae in. the
Concentration, mg/L treated water.
 450 Water Treatment

(Calcium)

B. Materials and Procedures 2 Enochrome Blare Black R indicator.

See page 1043, STANDARD METHODS, 16th Edition.' 3 Standard EDTA titrant, 0.01 M. Standardize against
Standard Calcium Solution and store in plastic polyeth-
2. Calcium ylene bottle.
4 Standard Calcium Solution. Store in polyethylene plastic
A Discussion
bottle. 1 mL of this solutior' = 1 mg calcium hardness as
In most natural waters, calcium is the principal cation. The CaCO3 or 400.8 micrograms (pg) Ca
element is widely distributed in the common minerals of 5 1 1 HCI. Carefully add 50 mL concentrated HCI to 50
rocks and of soil. Calcium in the form of lime or calcium mL distilled water.
hydroxide may be used to soften water or to control corro-
sion through pH adjustment. 6 Ammonium hydroxide, 3 N.
B. What is Tested? 7. Methyl Orange indicator bolubon.

Sample Common Range, mg/L

E. Procedure
Raw and Treated Surface Water 5 tc 50
Well Water
1. Taxe a clean beaker and add 50 mL of sample.
10 to 100
2 Add 2.0 mL NaOH solution.
C. Apparatus Required
3. Add 0.1 to 0.2 g indicator mixture.
Buret, 25 mL
Buret support 4. Titrate immediately with EDTA titrant until last reddish-
Graduated cylinder, 100 mL purple tinge disappears. Mix with magnetic stirrer du:-
Beaker. 100 mL ing titration.
Magnetic stirrer 5. Calculate calcium concentration
Magnetic stir-bar

D. Reagents
F. Example

(NOTE: Standardized solutions are commercially Results from calcium testing of a treated water sam-
available for most reagents. Refer to STANDARD ple were as follows:
METHODS if you wish to prepare your own reagents.)2 sample size = 50 mL
1. Sodium hydroxide, NaOH, 1 N. mL EDTA titrant used, A = 7.3 mL

OUTLINE OF PROCEDURE FOR CALCIUM

mL OF EDTA -1----

Z
2. Add 2 mL NaOH 3. -Mate with
1. Add 50 mL to a clean and 0.2 g EDTA. Mix
beaker. indicator with magnetic
mixture. stirrer

I STANDARD METHODS FOR THE EXAMINATION OF WAL7F1 AND WASTEWATER, 16th Edition, 1985, Order No. 10035. Available from
Computer Services, American Water Works Association, 6606 W. Quincy Avenue, Denver Colorado 80235. Price to members. $72.00;
nonmembers, 890.00.
2 See "Prepared vs. Do-lt-Yourself Reagents,Thy Josephine W. Boyd, OPFLOW, Vol. 9. No. 10, October 1983.
:-

4 71
 Lab Procedures 451

(Chloride)

G Calculation

mg Ca/L = A x 400.8'
mL of sample
(7.3 mL) >. 400 8
50 mL
= 58 mg/L

400.8 is a constant fo' his calculation.

H. Precautions
1. Titrate immediately after adding NaOH solt.tion.
2. Use 50 mL or a smaller oortion of sample diluted to 50
mL with distilled water so that the calcium content is
about 5 to 10 mg. E. Procedure

3. For hard waters with alkalinity greater than 300 mg 1. Place 100 mL or a suitable portion of sample diluted to
CaCO3/L. use a smaller portion or neutralize alkalinity 100 mL in a 250 n-.L Erlenmeyer flask.
with acid, boiling for one minute, and cooling before 2. Add 1.0 mL K2CrO, indicator solution.
beginning the titration.
3. Titrate with standard silver nitrate to a pinkish yellow
I. Reference end point. Be consistent in end point recognition. Com-
pare with known standards of various chloride concen-
See page 199, STANDARD METHODS, 16th Edition. trations.

3. Chloride
A. Discussion F. Calc,..lation

Chloride occurs in all natural waters, usually as a metallic Chloride (as CI), mg/L = (A-B) x N / 35,450
salt. In most cases, the chloride content increases as mL of sample
mineral content increases. Mountain water supplies usually
are quite low in chloride while groundwaters and valley A = mL AgNO3 used for titration of sample
rivers often contain a considerable amount. The maximum B = mL AgNO3 used for blank
allowable chloride concentration of 250 mg/L in drinking
water has been established for reasons of taste rather than N = normality of AgNO3
as a safeguard against a physical or a health hazard. At
concentrations above 250 mg/L, chloride may give a salty
taste to the water which is objectionable to many people.
G. Example
I. What is Tested? Sample size = 100 mi.
Sample Common Range, mg/L A = mL AgNO3 used for sample = 10.0 mL
8 = mL AgNO3 used for blank = 0.4 mL
Surface or GrounOwater 2 to 100
N = normality of AgNO3 = 0 0141 N
0 4) x (0.0141) x 35.450
Chloride. mg/L = (10.0
C. Apparatus Required 100
Graduated cylinder, 100 mL = 48 mg/L
Buret, C0 mL
Erlenmeyer flask, 250 mL
Pipet, 10 mL H. Special Notes
Magnetic stirring apparatus
1 Sulfide. thiosulfate, and sulfite ions interfere, but can be
D. Reagents removed by treatment with 1 mL of 30 percent hydrogen
peroxide (H202).
(NOTE: Standard solutions may be purchased from
chemical suppliers.) 2. Highly colored samples must be treated with an alumi-
num hydroxide suspension and then filtered.
1. Chloride-free water distilled or deionized water.
3. Orthophosphate in excess of 25 mg/L and iron in
2. Potassium chromate (K2Cr0,) indicator solution. excess of 10 mg/L also interfere.
3. Standard Silver Nitrate Titrant, 0.0141 N. 4. If tne pH of the sample is not between 7 to 10, e '',uSt
4. Standard Sodium Chloride, 0.0141 N. with 1 N sulfuric acid or 1 N sodium hydroxide.

472
 452 Water Treatment

(Chloride)

OUTLINE O' PROCEDURE FOR CHLORIDE

1. Place 100 mL or other 2. Add 1 mL chromate indicator.

measured sample in flask.

3. Place flask on magnetic stirrer and

titrate with standard silver *rate.

5. Procedure for standardization of AgNO3:

EXAMPLE
a. Add 10 mL (1 mg CI) standard sodium chloride
solution to a clean 250 mL Erlenmeyer flask. 10.0 mL NaCI standard used
b. Add 90 mL distilled water. 10.0 mL AgNO3 used in titration
0.01:1 N = norm, ity of NaCI standard
c. Titrate as in Section E above.
Normality, N, =10.0 mL x 0.0141
AgNO3
Normality, N, = mL CaCI standard x 0.0141 10 mL
AgNO3 mL Ag NO3 used in titration
= 0.0141

i ^
473
 Lab Procedures 453

(Color)

I. Reference D. Reagents
See page 286, STANDARD METHODS, 16th Edition 1 Color Standard. Use a stock standard with a color of
500 units.
QUESTIONS 2 Prepare color standards by adding the following incre-
Write your answers in a notebook and then compare your ments of stock color standard to a nessler tube and
answers with those en page 482. diluting to 50 ml.

21.1A Does the quality of water in any lake, reservoir or Color Unit Standard mL of Stock Color Standard
stream effect the abundance and types of aquatic 1 0.1
oroanisms found in the water? Yes or No? 2 0.2
:3 0.3
21.1B How are calcium compounds used to treat water? 4 0.4
21.1C How soon should a sample be titrated for calcium 5 0.5
after the sodium hydroxide (NaOH) solution has been
Protect these standards against eve, ,ration and con-
added?
tamination when not in use.
21.1D Why are concentrations of chloride above 250 mg /L
objectionable to many people? E. Procedure
1. Fill a clean matched nessler tube to the 50 mL mark with
4. Color sample.
A. Discussion
2. Compare the sample with the various color standards
Colo' in water supplies may result from the presence of by looking downward vertically through the tubes to-
metallic ions (iron, manganese, and copper), organic matter ward a white surface.
of vegetable or soil origin, and industrial wastes. The most Match as closely as possible sample color with a color
3.
common colors which occur in raw water are yellow and
standard.
br.,.vn. There are two general types of color found in water.
True color results from the presence of dissolved organic F. Other Procedures
substances or from certain minerals such as copper sulfate Color may also be measures by the use of
dissolved in the water. Suspended materials (including col-
1. Color comparator kits, and
2. Spectrophotometer c.

G. Note.;
1. If the color exceeds 70 units, dilute sample with distilled
water in known proportions until tie color is within
range of the standards. Calculate color units by the
following equation:

Color units = A x 50
B

where:
A = estimated color of diluted sample
ladel substances) ca I add what is called apparent color. B = mL of sample taken from dilution
True color is normally removed or at least reduced by
coagulation and chlorination or ozonation. The method 2. If turbidity is greater than one unit, consult STANDARD
given below is suitable only for the measurement of color in METHODS for pretreatment for turbidity removal.
clear treated water supplies having a turbidity of less than
one unit of turbidity. When greater amounts of turtidity are H. Refe.ence
present in the sample, some fcern of pretreatment for See page 67, STANDARD METHODS, 16th Edition.
turbidity removal must be used before measuring the color.
B. What is Tested? QUESTIONS
Sample Common Range, mg /L Write your answers in a notebook and then compare your
answers with those on page 482.
Treated Surface Water 1 to 10
21.1E What are the most common colors woich occur in
Groundwater 0 to 5 raw water?
C. Apparatus Required 21.1F How can truo color be removed from water?
Nessler tubes, matched, 50 mL tall form 21.1C. When not in use, stock color standards should be
Pipet, 1.0 mL protected against what?

4 74
 454 Water Treatment

(Dissolved Oxygen)

OUTLINE OF PROCEDURE FOR COLOR

1. Fill nessler tube to 50 mL 2. Compare sample to color

standards.

5. Dissolved Oxygen Magnetic stirrer

A. Discussion Magnetic stir-bar
Pipets, 10 mL
Dissolved oxygen (DO) is important to the Nater treatment
plant operator for a number of reasons. In surface waters, Method B (Membrane Electrode Method)
dissolved oxygen must be present in order for fish and Follow manufacturer's instructions. To be assured
smaller aquatic organisms to survive. The taste of water is that the DO probe reading is accurate, the probe must
improved by dissolved oxygen. However, the presence of be calibrated frequently. Take a sample that does not
dissolved oxygen in water can contribute to corrosion of contain substances that interfere with either the probe
piping systems. Low or zero dissolved oxygen levels at the reading or the Modified Winkler procedure. Split the
bottom of lakes or reservoirs often cause taste and odor sample. Measure the DO in one portion of the sample
problems in drinking water. using the Modified Winkler procedure and compare this
result with the DO probe reading on the other portion of
B. What is Tested? the sample. Adjust the probe reading to agree with the
Sample Common Range, mg/L results from the Modified Winkler procedure. To obtain
good results when using a probe, you should be aware
Surface Water 5 to 11 of the following PRECAUTIONS:
Groundwaters 0 to 2 a. Periodically check the calibration of the probe,
Some reservoirs and lakes may have zero DO near he b. Keep the membrane in the tip of the probe fro' i drying
bottom. out,
c. Dissolved inorganic salts, such as found in sea water, can
C. Apparatus Required influence the readings from a probe,
Method A (Sodium Azide Modification of Winkler d. Reactive compounds, such as reactive gases and sulfur
Method) compounds, can interfere with the output of a probe, and
Buret, graduated to 0.1 mL e. Don't place the probe directly over a diffuser because you
Buret support want to measure the dissolved oxygen in the water being
BOD bottle, 300 mL treated, not the oxygen in the air supply to the aerator.
.4
475
 Lab Procedures 455

(Dissolved Oxygen)

The reagents are to be added in the quantities, order, and

methods as follows:
1 Collect a sample to be tested in 300 mL (BOD) bottle
taking special care to avoid aeration of the liquid being
collected. Fill bottle completely and add cap.

2. Remove cap and add 1 mL of manganous sulfate

solution below surface of the liquid.

3. Add 1 mL of alkaline-iodide-sodium azide solution be-

low the surface of the liquid.

4. Replace the stopper, avoid trapping air bubbles, and

shake well by inverting the bottle several times. Repeat
this shaking after the floc has settled halfway. Allow the
floc to settle halfway a second time.

5. Acidify with 2 mL of concentrated sulfuric acid by

D. Reagents allowing the acid to run down the neck of the bottle
above the surface of the liquid.
(Standardized solutions may be purchased from chemi-
cal suppliers.)
6. Restopper and shake well until t ie precipitate has
1. Manganous Sulfate Solution. dissolved. The solution will then be ready to titrate.
2. Alkaline Iodide-sodium Azide Solution. Handle the bottle carefully to avoid acid burns.

3. Sulfuric Acid: Use concentrated reagent-grade acid 7. Pour 201 mL from bottle into an Erlenmeyer flask.
(H2504). Handle carefully, since this material will burn
hands and clothes. Rinse affected parts with tap water
to prevent injury. 8. If t' solution is brown in color, titrate with 0.025 N PAO
until the solution is pale yellow color. Add a small
CAUTION: When working with alkaline azide and sul- quantity of starch indicator and proceed with Step 10.
furic acid, keep a nearby water faucet (Note: Either PAO or 0.025 N sodium thiosulfate can ba
running for frequent hand rinsing. used.)
4. 0.025 N Phenylarsine Oxide (PAO) solution.
9. If the solution has no brown color, or is only slightly
5. 0.025 N Sodium Thiosulfate solution. colored, add a small quar.tity of starch indicator. If no
blue color dew .:Ips, there is zero Dissolved Oxygen. If a
For preservation, add 0.4 g or 1 pellet of sodium blue color does develop, proceed to Step 10.
hydroxide (NaOH). Solutions of "thio" should be used
within two weeks to avoid loss of accuracy due to
decomposition of solution. 10. Titrate to the first disappearance -0 the blue color.
Record the number of mL of PAO usea.
6. Starch solution.
E. Procedure 11. The amount of oxygen dissolved in the original solution
will be equal to the number of mL of PAO used in the
SODIUM AZIDE MODIFICATION OF THE WINKLER titration provided significant interfering oubstances are
METHOD not present.
NOTE: The sodium azide destroys nitrate which would mg DO/L = mL PAO
otherwise interfere with this test.
F. Example
A sample is collected from just upstream of a river intake
to a water treatment facility. The water temperature is 18°C.
The sample is tested for DO and the operator uses 9.1 mL of
0.025 N PAO titrant.

G. Calcuiation
The DC titration of 201 mL sample required 9.1 mL of
0.025 N PAO. Therefore, the dissolved oxygen (DO) concen-
tration in the sample is 9.1 mg /L.
The percent saturation of DO in the river can be calculated
using the dissolved oxygen saturation values given in Table
21.1. Note that as the temperature of water increases, the
DO saturatior value (10C% Saturation Column) decreases.

r
si y
,
4,
476
456 Water Treatment

(Dissolved Oxygen)

OUTLINE OF PROCEDURE FOR DO

Brown floc; 5. Add

DO present. 2 mL
H2SO4.
4. Mix by
inverting.

Reddish-
brown
iodine
solution.

1. Take 2. Add 3. Add

300 mL 1 mL 1 mL
. sample. MnSO4 KI +
----lip,.
below NaOH
surface. below White floc;
surface. no DO.

Titration of Iodine Solution:

1. Pour 201 mL
into flask.

Reddish- Pale
Brown Yellow Blue Clear

2. Titt ate 3. Add Starch End Point

with PAO or Indicator.
Sodium
Thiosulfate.

477
., f li:
: :'
 Lab Procedures 457

(Fluoride)

Table 21.1 gives 100 percent DO saturation values for H Precautions

temperatures in °C and °F.
1. Samples for dissolved oxygen measurements should be
DO Saturation, % = DO of sample, mg/L x 100%
collected very carefully. Do not let sample remain in
contact with air or be agitated. Collect samples in a 300
DO at 100% Saturation, mg/L
ml BOD bottle. Avoid entraining or dissolving atmos-
For example, given pheric oxygen.
9.1 mg/L x 100% 2. When sampling from a water line under pressure, attach
DO Saturation, %
a tube to the tap and extend tube to bottom of bottle. Let
9.5 mg/L
bottle overflow two or three times its volume and
= 0.9C x 100% replace glass stopper so no air bubbles are entrapped.
= 96% 3. Use suitable sampler for streams, reservoirs or tanks of
moderate depth such as that shown in Figure 21.1. Use
where a Kemmerer-type sampler for samples collected from
9.1 mg/L = DO of sample depths greater than 6'12 feet (2 m).

9 5 mg/L = DO at 100% Saturation at 18°C 4. Always record temperature of water at time of sampling.
(river temperature) 5. Use the proper bottle with matched stopper.
6. When working with a lake or reservoir, examine the
TABLE 21.1 temperature and DO profile (measure temperature and
DO at surface and at various depths all the way down to
EFFECT OF TEMPERATURE ON OXYGEN SATURATION the bottom).
FOR A CHLORIDE CONCENTRATION OF ZERO mg/L
7. Measure the DO in the sample as soon as possible.
mg/L DO at
°C °F Saturation I. Reference
0 0 14.6 See page 418, STANDARD METHODS, 16th Edition.
1 33.8 14.2
2 35.6 13.8
3 37.4 13.5 6. Fluoride
4 39.2 13.1 A. Discussion
5 41.0 12.8 Fluoride may occur naturally or it may be added in
6 42.8 12.5 controlled amounts. The concentration of fluoride in most
7 44.6 12.2 natural waters is less than one mg/L. There are, however,
8 46.4 11.9 several areas in the United States which have natural
9 48.2 11.6 fluoride concentrations of as high as 30 mg/L. The impor-
10 50.0 11.3 tance of fluoride in forming human teeth and the role of
11 51.8 11.1 fluoride intake from drinking water in controlling the chwac-
12 53.6 10.8 teristics of tooth structure has been realized only within the
13 55.4 10.6 past 40 to 50 years. Studies have shown that a fluoride
14 57.2 10.4 concentration of approximately 1.0 mg/L reduces dental
caries of young people without harmful effects on health.
15 60.0 10.2
16 61.8 10.0 B. What is Tested?
17 63.6 9.7
18 65.4 9.5 Sample Common Range, mg/L
19 67.2 9.4 Fluoridated Water 0.8 to 1.2
20 68 0 9.2
C. Apparatus Required
21 69.8 9.0 Spectrophotometer for use at 570 nanometers
22 71.6 8.8 way.iiength
23 73.4 8.7 Pipe .s, 5 ml
24 75.2 8.5 Flas <J, Erlenmeyer, 125 nil
25 77.0 8.4
D. Reagents
1. Stock fluoride solution. 1.0 ml = 0.100 mg F.
2. Standard fluoride solution: Dilute 100 mL stock fluoride
solution to 1000 nil with distilled water; 1.0 ml = 0.010
mg F.
3. SPADNS solution. This solution is stable indefinitely if
protected from direct sunlight.
4. Zirccnyl-acid reagent.

478
 458 Water Treatment

(Fluoride)

n Copper Tubing

Thermometer COO

.n Rubber Gasket

I
V., in .)
Copper Tubing
in Brass

- 61/41r1 --I Thermometer

Tube Open

C.ip il in Or3M .
in High)
Brazed to Cover

Fig. 21.1 DO sampler

(Reprinted from STANDARD METHODS, 15th Edition by
permission Copyright 1980. the American Public Health Association)

5. Acid zirconyl-SPADNS reagent: Mix equal volumes of Erlenmeyer flask. (If sample contains residual chlorine,
SPADNS solution and zirconyl-acid reagent. The com- add one drop NaAsO2 solution per 0.1 mg chlorine
bined reagent is stable for at least 2 years. residual and mix.)
6. Reference solution: Add 10 mL SPADNS solution to 100 2. Add 5.0 mL each of SPADNS solution and zirconyl-acid
mL distilled water. Dilute 7 mL concentrated HCI to 10 reagent, or 10.0 mL acid zsrconyl-SPADNS reagent.
mL and add to the diluted SPADNS solution. The Mix.
resulting solution, used for setting the instrument refer-
ence point (zero), is stable and may be reused indefi- 3 Set spectrophotometer to 0.730 absorbance with refer-
nitely. Alternatively, use a prepared standard as a ence solution containing zero mg /L of fluoride (see G.
reference. Example).
7. Sodium aroenite solution. (CAUTION. Toxic avoid 4. Read absorbance at 570 nm with spectrophotometer
ingestion). and determine the amount of fluoride from L.dndard
curve.
E. Procedure
NOTE: A colorimeter may also be used to measure flu-
1. Measure 50 mL of sample and add to a clean 125 mL oride.

4M
 Lab Procedures 459

(Fluoride)

F. Construction of Standard Calibration Curve H. Calculation

1. Using the standard fluoride solution, prepare the follow- 1. Prepare a standard curve by using data from prepared
ing standards in 100 mL volumetric flasks. standards. From above example:
Fluoride
mL of Standard Fluoride Solution Fluoride Concentration, mg/L Absorbance
Placed in 100 mL Volumetric Flask Concentration, mg/L
0.0 0.730
5.0 0.50 0.5 0.625
75 0.75 0.75 0.560
10.0 1 00 1.0 0.500
12.5 1.25
1.25 0.444

2. Dilute flasks to 100 mL. The graph below is a result of plotting concentration of
fluoride standards versus their corresponding absorbance.
3. Transfer 50 mL to 125 mL Erlenmeyer flask.
4. Determine amount of fluoride as outlined previously.
C. Prepare a standard curve by plotting the absorbance
values of standards versus the corresponding fluoride 0 700

concentrations.
W
G. Example °Z o
4
Results from a series of tests for fluoride were as follows: CCI
CC
0
U) osao
CCI
Flask Volume, <
No. Sample mg/L Absorbance
1 Distilled Water 50 0.730 0 400
2 C Street Weil 50 0.470
3 Plant Effluent 50 0.510
4 0.5 mg/L F 50 0.625
5 0.75 mg/L F 50 0.560 025 0.50 075 10 125
6 1.0 mg/L F 50 0.500
7 1.25 mg/L F 50 0.444 FLUORIDE, mg/L

OUTLINE OF PROCEDURE FOR FLUORIDE

1. Measure 50 mL of sample into 2. Add 5 mL each of SPADNS

flask. Dechlorinate if solution and zirconyl-acid 3. Measure absorbance at 570 nm
necessary. reagent. with spectrophotometer.

480
460 Water Treatment

(Fluoride)

2 Obtain concentration of unknown samples from curve. in the listed quantities, the sample must be distilled prior

-
to analyF:s.
- .
Substance Concentration mg/L
,_----__---
Alkalinity 5,000
0 700 Aluminum 0.1
Chloride 7,000
Iron 10
0 SOO

± .1__
...__
..
PLANT EFFLUENT
-4. Hexametaphosphate
Phosphate
Sulfate
1.0
16
200

0 500
2. Samples and standards should be at the same tempera-
--.-.41-
.-----: .1.7.--=77.--7-7.- C STREET WELL .---.-,.4- ture throughout color development.
---._ -- -- J. Reference
0 400
-- -
--.------
See page 359, STANDARD METHODS, 16th Edition.

0.2S 0.50 075 10 t. QUESTIONS

FLUORIDE, mg/L Write your answers in a notebook and then compare your
answers with those on page 482.
PLANT EFFLUENT = 0.90 mg/L
C STREET WELL = 1.2 mg/L 21.1H Why is the presence of dissolved oxygen (DO) in
water in piping systems of concern to operators?
I. Precautions
21.11 What is the common range of fluoride in fluoridated
1. Whenever any of the following substances are present drinking water?

eta of cervercloilon (44401/14

ArVANCED lAgoizoo CY
Pcoarace4

DISCUSSION AND REVIEW QUESTIONS

Chapter 21. ADVANCED LABORATORY PROCEDURES
(Lesson 1 of 2 Lessons)

At the end of each lesson in this chapter you will find some 4. The maximum allowable chloride concentration in drink-
discussion and review questions +hat you should answer ing water has been established on what basis?
before continuing. The purpose of these questions is to
indicate to you how well you understand the material in this 5. What are the two general types of color found in water
lesson. Write the answers to these questions in your note- and what is the cause of each type?
book before continuing.
1. What is the purpose of spectrophotometer calibration 6 Why is dissolved oxygen ,J0) in water important to the
curves? treatment plant operator?
2. How would you prepare a spectrophotometer calibration
graph? 7. What precautions would you take when collecting a lake
sample for a dissolved oxygen measurement?
3. Why are algae counts in raw water importeht to opc ra-
ters? 8. How does fluoride get into drinking waters?

46j
 Lab Procedures 461

Chapter 21. ADVANCED LABORATORY PROCEDURES

(Lesson 2 of 2 Lessons)

7. Iron (Total) stock iron solutions are stable for several months. The
A. Discussion
standard iron solutions are not stable; prepare daily as
needed by diluting the stock solution. Visual standards in
Iron is an abundant and widespread constituent of rocks nessler tubes are stable for several months if sealed and
and soils. The most common form of iron in solution in protected from light.
groundwater and in water under anaerobic conditions (bot- 1. Hydrochloric acid, HCI.
tom of a lake or reservoir) is the ferrous ion, Fe+2. Ferric iron
can occur in soils, in aerated water, and in acid solutions as 2. Hydroxylarnine solution.
Fe3+, ferric hydroxide and polymeric forms depending upon
pH. Above pH of 4.8, however, the solubility of the ferric 3. Ammonium acetate buffer solution. Because even a
species is less than 0.1 mg/L. Colloidal ferric hydroxide is good grade of NH4C2H302 contains a significant amount
commonly present in surface water and small quantities may of iron, prepare new reference standards with each
persist even in water that appears clear. buffer preparation.

Iron in a domestic water supply can be the cause of 4. Sodium acetate solution.
staining laundry, concrete, and porcelain. A bitter astringent 5. Phenanthrohne solution. (NOTE: One milliliter of this
reagent is sufficient for no more than 100 lig Fe.)
6. Stock iron solution. 1.00 mL = 0.200 mg Fe.
7. Standard iron solutions. Prepare daily for use. Pipet
50.00 mL stock solution into a one-liter volumetric flask
and dilute to mark with iron-free distilled water; 1.00 mL
= 0.010 mg Fe.

E Procedure
For Total Iron
1. Measure 50 mL of thoroughly mixed sample into a 125
mL Erlenmeyer flask.
2. Add 2 mL concentrated HCI and 1 mL hydroxylamine
solution.
3. Heat to boiling. Boil sample until volume is reduced to
20 mL. Cool to room temperature.
taste can be detected by some people at levels above 0.3 4. Transfer to 100 mL volumetric flask.
mg/L. When iron reacts with oxygen, a red precipitate (rust)
is formed. 5. Add 10 mL acetate buffer solution and 2 mL phenan-
throline solution. Dilute to 100 mL mark with iron-free
B. What is Tested? distilled water. Mix thoroughly.

Source Common Range, mg/L 6. After 15 minutes, measure the absorbance at 510 nm
and determine the amount of iron from the standard
Untreated Surface Water 0.10 to 1.0 curve.
Treated Surface Water <0.01 to 0.20
Groundwater <0.01 to 10 F. Construction of Standard Calibration Curve
1. Using the standard solution, prepare the following stan-
C. Apparatus Required dards in 100 mL volumetric flasks.
Spectrophotometer for use at 510 nm mL of Standard Iron Solution Iron Concentration
Acid-washed glassware. Wash all glassware with con- Placed in 100 mL Volumetric Flask mg/L
centrated HCI and rinse with distilled water to remove
0 0
deposits of iron oxide.
Flasks, Erlenmeyer, 125 mL 1.0 0.10
Pipets, 5 and 10 mL 2.5 0.25
Flasks, Volumetric, 100 mL 5.0 0.50
Hot plate 7.5 0.75
10.0 1.00
D. Reagents
2. Dilute flasks to 100 mL.
Use reagents low in iron. Use iron-free distilled water. 3. Transfer 50 mL to 100 mL volumetric flask.
Store reagents in glass-stoppered bottles. The hydrochloric
acid and ammonium acetate solutions are stable indefinitely 4. Add 1.0 mL hydroxylamine solution and 1 mL acetate
if tightly stoppered. The hydroxylamine, phenanthroline, and solution to each flask.

, 1t,
,J 48?
462 Water Treatment

(Iron)
OUTLINE OF PROCEDURE FOR IRON

1. Measure 50 mL into flask. 2. Add 2 mL conc. HCI acid 1 mL

hydroxylamine solution.

3. Heat to boiling. Reduce volume 4. Transfer to 100 mL volumetric

to 20 mL. Cool. flask.

( . .)
5. Add 10 mL acetate buffer and 6. Measure absorbance at 510 nm
2 mL phenanthroline solution. with spectrophotometer.
Dilute to 100 mL.

4,§,3
 Lab Procr:dures 463

(Iron)

5. Dilute to about 75 mL. add 10 mL phenanthrohne 2. Obtain concentration of unknown clear well and river
solution, dilute to 100 mL mark. Mix thoroughly. samples from curve.
6. Measure absorbance at 510 nm against the reference
blank.
400
7. Prepare a standard curve by plotting the absorbance
values of standards versus the corresponding iron 700
.. . ___ ...
concentrations.
100
- ..----. ...... -.
G. Example 300

Results from a series of tests for total iron were as 400

---,-.
follows:
,300
---------
200 7, PLANS
Flask # Sample Absorbance : I
. WELL
- . . 1 . : . _ . . ..."..' . : -1.7_:::::::::
._- .
1 Distillea Water 0.000 100 17:77_
2 Plant Clear Well 0.100
3 River Sample :- i
0.420
010 0.20 030 040 030 00 0 70 0 0 SO 100 1 10
4 0.10 mg /L Fe Standard 0.066
5 0.25 mg /L Fe Standard 0.161
6 0.50 mg /L Fe Standard 0.328
IRON, mg/L
7 0.75 mg /L Fe Standard 0.495 PLANT CLEAR WELL = 0.16 mg/L Fe
8 1.00 mg /L Fe Standard 0.658 RIVER SAMPLE = 0.66 mg/L Fe

I. Notes
H. Calculation 1. Iron in well water or tap samples may vary in concentra-
1. Prepare a standard curve by using data from prepared tion and form with duration and degree of flushing
standards. From the above example: before and during sampling.
2. For precise determination of total iron, use a separate
container for sample collection. Treat with acid at time
Concentration Iron, of collection to place iron in solution and prevent
Ing/L Absorbance deposition on walls of sample container.
C.0 0.000
0.10 0.066
3. Exercise caution when handling sulfuric acid.
0.25 0.161
0.50 0.328 J. Reference
0.75 0.495 See page 215, STANDARD METHODS, 16th Edition.
1.00 0.658
8. Manganese
The graph below is a result of plotting concentration of A Discussion
standards versus their corresponding absorbance Although manganese is much less abundant than iron in
the earth's crust, it is one of the most common elements and
widely distributed in rocks and soils. Some groundwaters
. _ .

OO

-.- ---
.700

00

.504
4 ...., ............. "'

400
`
.4-..
4-.
.300

200
_
=------= ________ i

100

010 0.20 0.30 040 030 0.0 070 010 0 10 100 1 10

IRON, mg/L

484
464 Water Treatment

(Manganese)

that contain objectionable amounts of iron also contain 2. Dilute flasks to 100 mL.
considerable amounts of manganese, but groundwaters that
contain more manganese than iron are rather unusual. 3. Transfer to 250 mL Erlenmeyer flask.
Manganese in surface waters occurs both in suspension 4. Determine amount of manganese as outlined previ-
and as a solutle complex. Although rarely present in excess ously.
of 1 mg/L, manganese imparts objectionable stains to
laundry and plumbing fixtures. Manganese will alsc cause 5. Prepare a standard curve by plotting the absorbance
stains on the walls of tanks and driveways in treatment values of standards versus the corresponding manga-
plants. nese concentrations.

B. What is Tested? G. Example

Source Common Range. mg/L Results from a series of tests for manganese were as
Treated and Untreated follows:
Surface Water <0.01 to 0.10
Groundwater <0.01 to 1.0 Flatik Sample Absorbance
1 Distilled Water 0.000
2 Plant Effluent 0.000
C. Apparatus Required
3 Jones St. Well 0.030
Spectrophotometer for use at 525 nm 4 0.05 mg/L Mn Standard 0.009
Hot plate 5 0.10 mg/L Mn Standard 0.018
Flask, Erlenmeyer, 250 mL 6 0.20 mg/L Mn Standard 0.036
Pipets, 5 and 10 mL 7 0.30 mg/L Mn Standard 0.053
Flask, Volumetric, 100 and 500 mL 8 0.40 mg/L Mn Standard 0.071

D. Reagents
H. Calculation
1. Special reagent.
1 Prepare a standard curve by using data from prepared
2. Ammonium persulfate, (NH4)2S208, standards. From the above example:
3. Standard manganese solution. 1 mL --- 0.01 mg Mn. Concentration Manganese,
Prepare dilute solution daily. mg/L Absoliance
4. 1% HCI: Add 10 mL concentrated HCI carefully to 990 0.0 (distilled water) 0.000
mL distilled water. 0.05 0.009
5. Hydrogen peroxide, H202, 30 percent. 0.10 0.018
0.20 0.036
0.30 0.053
E. Procedure 0.40 0.071
1. Measure 100 mi. of thoroughly mixed sample into a 250
mL Erlenmeyer flask which as been marked with a line The graph below is the result of plotting concentration of
at the 90 mL level. standards versus their corresponding absorbance.
2. Add 5 mL special reagent and 1 drop H202.
- -- --
3. Concentrate to 90 mL by boiling. Add 1 gram ammonium ._
.030
persulfate. Cool immediately under water tap. _-
. - --
4. Dilute to 100 mL. ow
- - - - .- ------- - -- ---
5. Measure the absorbance at 525 nm with a spectropho- .070
-- --
tometer and determine the amount of manganese from
the standard curve. 040

.0S0
-__ -
.._ - __......... - -. . -.
---.-
_-
- .... --

...-.,
F. Construction of Calibration Curve
1. Using the standard manganese solution, prepf....3 the - -...--.
--.- - --
following standards in 100 mL volumetric flasks.

-
.032
1
- .. _-
mL of Standard Manganese Solution Manganese --- ..-- ..... - -7- -
LI_ -
- -
Placed in 100 mL Vc tumetric Flask Concentration, mg/L
010 __ .
0 0 - -
.
.
.
.
..... -....-.-- -.-
_
1.0 0.10
2.0 0.20 10 20 30 40 SO

3.0 0.30
4.0 0.40 MANGANESE, mg/L

tt
485
 Lab Procedures 465

(Manganese)

OUTLINE OF PROCEDURE FOR MANGANESE

1. Measure 100 mL into flask. 2. Add 5 mL special reagent and

1 drop H202.

airs:

3. Concentrate to 90 mt. then add 4. Measure absorbance at 525 nm with

1 g ammonium persulfate. spectrophotometer.
Dilute to 100 mt after
cooling.

2. Obtain concentration of unknown plant effluent and well 1. Notes

sample from curve. If turbidity or interfering color is present, use the follow-
1.
ing "bleaching" method: as soon as the spectrophotom-
.. 2 .7=2= : _:: ::..2: .1 ---__= =--::t-.- -_- eter reading has been made, add 0.05 mL hydrogen
1:- peroxide solution directly to the optical cell. Mix and
read again as soon as the color has faded. Deduct
absorbance of bleached solution from initial absorb-
ance to obtain absorbance due to manganese.
---- _
NO.----------..- - ------,---
-
....... ...--4,--/_-.
.-..-
--

__
- -- -

. ,- . . - ...... --..----.
---..--
_

2. Determine manganese as soon as possible after sam-

ple collection. If this is not possible, acidify sample with
ase
nitric acid to pH less than 2.

J. Reference
. ----,
JONES STREET WELL: - See page 229, STANDARD METHODS, 16th Edition.
OM
K7.....=
= .--- ...

--, - QUESTIONS
ow t
Write your answers in a notebook and then compare yt. it
answers with those on page 483.
10 20 b 40 SO

21.1J Iron in a domestic water supply may cause what

MANGANESE, mg /L
problems?
PLANT EFFLUENI = <0.01 mg/L Mn 21.1K Why must all glassware be acid washed when ana-
JONES ST. WELL = 0.17 mg/L Mn lyzing samples for iron?

486
 465 Water Treatment

(Marble Test)

21.1L In what forms does manganese occur in surface D. Reagents

waters?
1. Calcium carbonate, reagent grade.
21.1M If the manganese concentration in a sample cannot
be measured immediate: what would you do? 2. Reagents for determining pH and hardness.

9. Marble Test (Calcium Carbonate Stability Test)

E. Procedure

A. 1. Measure he temperature of the water to be tested.

Discussion
2. Measure the pH, hardness and, if desired, the alkalinity
The Marble Test is intended to determine the degree to
which a sample of water is saturated with calcium carbon- of the sample being tested.
ate. Water in intimate contact with powdered calcium car- 3. Insert the stirring bar in the BOD bottle and fill with the
bonate (calcite) will approach saturation. The water being water being tested. Adjust the water temperature to
tested should not be exposed to atmospheric carbon diox- within 1°C of the initial temperature. Add approximately
ide. The Marble Test must be conducted at the specific one (1) gram of calcium carbonate and stir for five
,(\ minutes at a rate high enough to keep the calcium
carbonate in suspension and the sample vigorously
agitated.
4. Recheck the temperature. If the temperature has
changed more than one degree Celcius, repeat the
stirring with a fresh sample whose temperature has
been adjusted so that the final temperature will be within
one degree Celcius of the initial temperature.
5. Immediately measure the final pH.
6. Rh,' the remaining sample. Determine the hardness
and, if desired, the final alkalinity on the filtrate (water
that passed through the filter).

F. Example
o .0
Results from a series of tests for the calcium carbonate
temperature because the solubility of calcium carbonate precipitation potential were e follows:
varies with temperature. However, equipment that will main-
tain a constant temperature (either lower or higher than Filtered Water Sample
room temperature) while mixing the solution is not common- Initial Temperature 14°C
ly available in water treatment plants. The only other way to Final Temperature 14°C
keep a reasonable uniform temperature is to run the test as
rapidly as possible. Initial pH 8.7
Final pH 9.1
B. What is Tested? Initial Hardness 34 mg/L
Final Hardness 38 mg/L
Source Common Range*
Initial Alkalinity 24 mg/L
Untreated Surface Water -1 to +1 Final Alkalinity 27 mg/L
Treated Surface Water -0.2 to +0.2
Well Water -0.1 to +1 G. Calculation
Calcium Carbonate
Initial pH Final pH = Initial Hardness - Final Hardness
Precipitation
Potential
C. Apparatus Required
The Langelier Index3 is approximately equal to the initial
Bottle, BOD, 300 mL pH - final pH. If the value of this index is less than 0.2, this
Magi ietic stirrer
value will indicate that the water is very near the saturation
Stir-bar level. In any event, the sign of this value will be the same as
Thermometer the sign of the Langelier Index. That is to say, both the
Funnel, glass, 125 mm Langelier Index and the calcium carbonate precipitation
Filter paper, Watman #50 (18.5 inch) potential will be negative if the water is undersaturated and
Equipment for determining pH and hardness positive if the water is supersaturated.

3 Langelier Index (Li). An index reflecting the equilibrium pH of a water with respect to calcium and alkalinity. This ,ndex
lining water to control both corrosion and deposition of scale. is used in stab-
Langelier Index = pH pH::
Where pH = actual pH of the water, and
pHs = pH at which water having the same alkalinity and calcium content is just saturated with calcium carbonate.

487
 Lab Procedures 467

(Marble Test)

OUTLINE OF PROCEDURE FOR MARBLE TEST

2. Transfer to BOD bottle and

add 1 g calcium carbonate.
1. Measure temperature, pH Mix.
hardness, and alkalinity
of sample being tested.

3. Measure final pH and 4. Filter. 5. Determine hardness

temperature and alkalinity of
filtrate.

From the example above: these materials. The apalyseo of these metals is generally
done by using atomic absorption spectroscopy or colorimet-
Calcium Carbonate
= Initial Hardness. mg/1 Final Hardness. mg/i. ric methods. The term "metals" would include the following
Precipitation
Potential elements:
= 34 mg/1 - .38 mg/1
Aluminum Cobalt Potassium
= -4 Antimony Copper Selenium
Lange lier Index Initial pH - Final pH Arsenic Iron Silver
Barium Lead Sodium
= 8.7 9.1
Berrylliuro Magnesium Thall;um
= -0 4 Cadmium Manganese Tin
Calcium Mercury Titanium
This water is undersaturated (and therefore corrosive) with
Chromium Molybdenum Vanadium
respect to calcium carbonate.
Nickel Zinc
10. Metals
B. Reference
A. Discussion
For materials and procedures see:
The presence of certain metals in drinking water can be a
matter of serious concern because of the toxic properties of Page 143, STANDARD METHODS, 16th Edition.

4RR
 468 Water Treatment

(Nitrate)

QUESTIONS Filter holder assembly

Write your answers in a notebook and then compare yo 1r Filter flask
answers with those on page 483.
pH meter
21.1N Why is temperature important when running the
Marble Test? Separatory funnel, 250 mL

21.10 The results from the Marble Test produce an initial Pipets, volumetric, 1, 2, 5, and 10 mL
pH of 8.9 and a final pH of 8.6. Would this water be D Reagents
considered corrosive?
1. Granulated cadmium: 40 to 60 mesh (available from: EM
21.1P How are the concentrations of most metals in water
measured? Laboratories, Inc., 500 Executive Boulevard, Elmsford,
New York 10523, Catalog No. 2001 Cadmium, Coarse
Powder and HACH Company, Catalog No. 74560-26).
2. Copper-Cadmium: The cadmium granules (new or used)
are cleaned with 6 N HCI and copperized with 2 percent
solution of copper sulfate in the following mar.ner:
a. Wash the oath nium with 6 N HCI and rinse with
distilled water. The color of the cadmium should be
silver.
b. Swirl 25 gm cadmium in 100 rng/L portions of a 2
percent solution of copper sulfate for 5 minutes or
until the blue color partially fades, decant and repeat
11. Nitrate with fresh copper until a brown precipitate foi /is.
A. Discussion
c. Wash the copper-cadmium with distilled water at
Nitrate represents the most completely oxidized form of least 10 times to remove all the precipitated copper.
nitrogen found in water. High levels of nitrate in water The color of the cadmium should now be black.
indicate biological wastes in ihe final state of stabilization or 3. Preparation of reaction column: Insert a glass wool plug
runoff from fertilized areas. High nitrate levels degrade into the bottom of the reduction column and fill with
water quality by stimulating excessive algal growth. Drinking distilled water. Add sufficient copper-cadmium granules
water that contains excessive amounts of nitrate can cause to produce a column 18.5 cm in length. Maintain a level
infant methemoglobinema (blue babies). For this reason, a of distilled water abovo the copper-cadmium granules
level of 10 mg/L (as Nitrogen) has been established as a to eliminate entrapment of air. Wash the column with
maximum level. The procedure given below measures the 200 mL of dilute ammonium chloride - EDTA solution
amount of both nitrate and nitrite nitrogen present in a (reagent 5). The column is then activated by passing
sample by reducing all nitrate to nitrite through the use of a through the column 100 mL of solution composed of 25
copper-cadmium column. The total nitrate (any nitrite pre- mL of a 1.0 mg/L NO2-N standard and 75 mL of
sent originally plus the reduced nitrate) is then measured concentrated ammonium chloride - EDTA solution.
colonmetrically. Use a flow rate of 7 to 10 mL per minute. Collect the
reduced standard until the level of solution is 0.5 cm
B. What is Tested? above the top of the granules. Close the screw clamp to
stop flow. Discard the reduced standard.
Sample Common Range, mg/L
4. Measure about 40 mL of concentrated ammonium chlo-
Treated Surface Water <0.1 to 5 ride - EDTA and pass through column at 7 to 10 mL
Groundwater 0.5 to 10 per minute to wash nitrate standard off column. Always
leave at least 0.5 cm of liquid above top of granules. The
column is now ready for use.
C. Apparatus
5. Dilute ammonium chloride - EDTA solution. Dilute 300
Reduction column. The column in Figure 21.2 was con- mL of concentrated ammonium chloride - EDTA solu-
structed from a 100 mL volumetric pipet by removing the top tion (reagent 4) to 500 mL with distilled water.
portion. This column may aiso be constructed from two
pieces of tubing joined end to end. A 1(' cm length of 3 cm 6. Color reagent.
I.D. tubing is joined to a 25 cm length of 3.5 mm i.D. tubing. A
7. Zinc sulfate solution.
column may be purchased from MACH Company. Order by
Code No. 14563-00, $85.20, Post Office Box 389, Loveland, 8. Sott:tim hydroxide, 6 N.
Colorado 80539.
9. Ammonium hydroxide, concentrated.
Spectrophcitometer for use at 540 nm, providing a light 10. Hydrochlonc acid, 6 N. Dilute 50 mL concentrated HCI to
path of 1 cm cr longer
100 mL with distilled water.
Beakers, 125 mL 11. Copper sulfate solution, 2 percent.
Glass wool 12. Nitrate stock solution. 1.0 mL = 1.00 mg NO3-N. Pre-
serve with 2 mL of chloroform per liter. This solution is
Glass fiber filter or 0.45 micron membrane filter stable for at least six months.

483
 Lab Procedures 469

(Nitrate)

WINIVINIMM
--)--- CUT

100 M L
CM I.D.
VOLUMETRIC
10 cm PIPET

2 cm 3.5 MM I.D.

CU/ CD

25 cm

18.5 cm GLASS WOOL PLUG

CLAMP

MIIN.1110
CUT
TYGON TUBING
I

Fig. 21.2 Reduction column

490
 470 Water Treatment

(Nitrate)

13. Nitrate standard solution. 1.0 mL = 0.01 mg NO3-N. Flask # Volume absorbance
Dilute 10.0 mL of nitrate stock solution (reagent 12) to
1000 mL with distilled water. 1 Jones St. Well 25 mL 0.440
2 Blank (distilled water) 25 mL 0.00
14. Chloroform. 3 0.10 mg/L NO3-N 25 mL 0.075
4 0.20 mg/L NO3-N 25 mL 0.142
E. Procedure 5 0.50 mg/L NO3-N 25 mL 0.355
6 1.00 mg/L NO3-N 25 mL 0.700
Removal of Interferences (if necessary).
Turbidity removal. Use one of the following methods to H. Calculation
remove suspended matter that can clog the reduction 1. Using graph paper, plot the absorbance values of
column.
working standards versus their known concentrations.
a. Filter sample through a glass fiber or a 0.45 micron For example, from the above data the following graph
pore size filter as long as the pH is less than 8, or can be constructed.

b. Add 1 mL zinc solution (reagent 7) to 100 mL sample 0 $00

EN
and mix thoroughly. Add enough (usually 8 to 10 - .

drops) sodium hydroxide sc. lution (reagent 8) to 0 700

obtain a pH of 10.5. Let treated sample stand a few
minutes to allow the heavy flocculent precipitate to 0 600
IIMaw
settle. Clarify by filtering through a glass fiber finer. t----
0500 MOMIlll
Reduction of Nitrate to Nitrite.
0.400
,--. --,---
1. Using a pH meter adjust the pH of sample (or standard) ---'t
-=-I4---- -
to between 5 and 9 either with concentrated HCI or
concentrated NH4OH.
0.300
M ---1
2. To 25 mL of sample (or standard) or aliquot diluted to 25 0 200
--77 7.7-
_
mL. add 75 mL of concentrated ammonium chloride - -
0 100
EDTA solution and mix. __,__ _ _4_ _
-- -
3. Pour sample into column and collect reduced sample at
19 20 30 .40 50 60 70 $0 10
a rate of 7 to 10 mL per minute. 90

4. Discard the first 25 mL. Collect the rest of the sample NITRATE & NITRITE-NITROGEN, mg11.
(approximately 70 mL) in the original sample flask.
Reduced samples should not be allowed to stand longer
than 15 minutes before addition of color reagent.
2. Read concentration of NO3 + NO; nitrogen in plant
5. Add 2.0 mL of color reagent to 50 mL of sample. Allow effluent from graph shown below.
10 minutes for color development. Within two hours
measure the absorbance at 540 nm against a reagent mg /L nitrate + nitrite nitrogen in sample = 0.62 mg/L
blank (50 mL distilled water to which 2.0 iriL color 000
reagent has been added).
0 700
- -.--- -
F. Construction of Standard Calibration Graph
1. 0 600
Prepare working standards by pipeting the following
- - ..----
volumes of nitrate stanaard solution into each of five
100 mL volumetric flasks. 0 500
---f ----- - --
.7:--2.-. JONES STREET WELL --- .---.: --- --
--..
._ -
--- -- ------
--- - - - --
Add this volume of Nitrate Concentration of 0.400

0 -- -- ---,--
Standard Solution to 100 mL flask NO3-N in mg/L
0 300
-+.----,-----
0.0 0.00
1.0 0.10 i i
1-
2.0 0.20
0 200
7-1
12------IT.""-" 1-...:_, --I
--- ----e- --i--- - - .-:_t
4 ,
5.0 0.50 0 100
-- - -- - -- - i__
10.0 1.00 "-- i --"--1-.1-4:77_-_---_:-- : 1:: -_
Dilute each to 100 mL with distilled water and mix. 10 .29 .30 40 .50 60 70 80 90 10
2. Determine the amount of nitrate-nitrite as outlined
above in the procedure for reduction of nitrate to nitrite. NITRATE & NITRITE-NITROGEN, mg/L
(NO3 + (NO2 - N)
3. Plot on a sheet of graph paper the absorbance versus
concentration.
3. Determine concentration of Nitrite-Nitrogen (NO2-N) in
G. Example sample using nitrite procedure.
Results from the analyses of samples and working stand- 4. Subtract nitrite from NO2 + NO3- nitrogen concentration.
ards for nitrate-nitrite were as follows: The result is the amount of nitrate nitrogen in sample.

4
491
 Lab Procedures 471

(pH)

5. For example, if the sample of Jones St. Well used in the writing these very small numbers, hydrogen, ion activities are
above example contained no nitrite nitrogen then the expressed in terms of pH, with
nitrate nitrogen (NO3--N) would be 0.62 mg/L.
pH = logic, 1

I Notes [H+]

1. If concentration of citrate in the sample is greater than 1 The relation between pH, H. and OH at 25°C is shown in
mg/L, then the s^,mple must be diluted. Table 21.2.
2. Cadmium metal is , '-ly to' c thus caution must be Most natural waters have pH values between 6 5 and 8.5.
ex ..,9d In its use. ,ubbtli gloves should be used Human blood has a pH of 7.4 and the gastric juices in your
w, , -i- ,c; ii is handled. stomach have a pH of approximately 0.9 to aid in the
digestion of food.
Alum coagulates most effectively at pH values near 6.8.
The pH of natural waters is controlled by the relative
amounts of carbon dioxide, bicarbonate, and carbonate
ions. Rain water usualiy has a pH of slightly less than 7
because carbon dioxide from the air dissolves to form
carbonic acid.

QUESTIONS
Write your answers in a noteuook and ther, compare your
answers with those on page 483.
21.10 How is nitrate measured in the nitrate test?

J. Reference 21.1R If turbidity is interfering with a nitrate analysis, how

can turbidity be removed?
See page 394, STANDARD METHODS, 16th Edition.
21.13 The pH of natural waters is usually controlled by the
12. pH by Jack Rossum relative amounts of what ions?

DISCUSSION
TABLE 21.2 RELATION BETWEEN pH, 14+
This discussion is presented to give you a better under- AND OH- AT 25°C
standing of what a pH value actually represents. Procedures
for measuring pH are given in Chapter 11, "Laboratory
Proccdures." Activity of El* Activity of OH-
moles/L moles/L pH
Pure water dissociates according to the following reac-
1. 0.000 000 000 000 01 0
tion:
0.1 0 000 000 000 000 1 1

H2O = H* + OH-. 0 01 0.000 000 000 001 2

0 001 0.000 000 000 01 3
At 25°C and a pH of 7, the activity of the hydrogen ion is 0 000 1 0.000 000 000 1 4
equal to the activity of the hydroxyl ion at .000 000 1 moles/li- 0 000 01 0.000 000 001 5
ter. "Activity' is a term used by chemists to allow real atoms, 0.000 001 0.000 000 01 6
molecules and ions to behave as if they were perfect 0.000 000 1 0.000 000 1 7
particles (having zero size). Activity is obtained by multiply- 0.000 000 01 0.000 001 8
ing the concentration by an activity coefficient. The value of 0.000 000 001 0.000 01 9
the activity coefficient depends on the electrical charge on 0.000 1 10
0.000 000 000 1
the particle, the temperature and the other substances 0.000 000 000 01 0.001 11
dissolved in the water. For hydrogen ion the activity coeffi- 0.000 000 000 001 0.01 12
cient at f'5°C varies from 0.996 in pure water to 0.900 in 0.000 000 000 000 1 0.1 13
water containing 400 mg/L of dissolved solids. Activities are 0.000 000 000 000 01 1. 14
expressed in moles per liter which is assumed to be the
number of grams per liter since the molecular weight of
hydrogen ion is 1.008 (almost 1.0). 13. Specific Conductance
When the activities of the hydrogen and hydroxyl ions are A. Discussion
equal, the solution is neutral. If hydrogen ions are in excess,
Spe, .: conductance or conductivity is a numerical ex-
the solution is acid and if hydroxyl ions are in Excess, the
solution is alkaline. An important property of water is that for
pression (expressed in micromhos per centimeter) of the
any temperature, the product of the activities of these ions is ability of a water to conduct an electrical current. This
a constant. At 25°C, this constant is .00U 000 000 000 01. number depends on the total concentration of the minerals
dissolved in the sample (TDS) and the temperature.
In a strong solution of hydrochloric acid, the hydrogen on Changes in conductivity am normal may indicate changes
activity may be as high as 1 mole per liter, while in a strong in mineral composition of the water, seasonal variations in
solution of lye, the hydroxyl on concentration may be as lakes and re,.,rvoirs, or intrusion of pollutants. The custom
high as 1 mole per liter. To avoid the inconvenience of of reporting conductivity values in microhmos/cm at 25°C

7 L. o 449
472 Water Treatment

(Sulfate)

requires the accurate determination of each sample's tem- (b) Dissolve 147.9 mg anhydrous Na2S0, in distilled
perature at the time of conductivity measurement water and dilute to 1,000 mL.
Specific conductance is measured by the use of a conduc-
tivity meter. E Procedure
1 Place 100 mL of sample or a suitable portion diluted to
B. What is Tested? 100 mL into a clean 250 mL Erlenmeyer flask
Common Range, 2. Add 5 0 mL of conditioning reagent and mix
Sample micromhos/cm
3. While stirring, add a spoonful of barium chloride crys-
Raw and Treated 30 to 500 tals. Stir for exactly 1 minute.
Surface Waters
4. Measure turbidity at 30-second intervals for 4 minutes.
Groundwater 100 to 1000 Consider turbidity to be the maximum reading obtained
in the 4-minute interval.
C. Materials and Procedure
F. Construction of Standard Catibration Curve
Follow ins ument manufacturer's instructions. Also see
page 76, STANDARD METHODS, 16h Edition. 1. Using the standard solution prepare the following
standards in 100 mL volumetric flasks.
mL of Standard Sulfate Solution Sulfate
14. Sulfato Placed in 100 mL Volumetric Flask Concentration, mg/L
A. Discussion 5.0 50
100 100
The sulfate ion is one of the major anions occurring in 150 150
natural waters. Sulfate ions are of importance in water 20 0 20.0
supplies because of the tendency of appreciable amounts to 25 0 25 0
form hard scales in boilers and heat exchangers. The 2. Dilute flasks to 100 mL.
secondary maximum contaminant level for sulfate listed in
the Safe Drinking Water Act is 250 mg/L. 3. Transfer to 250 mL Erlenmeyer flask.
B. What is Tasted? 4. Determine amount of sulfate as outlined previously.
Sample Common Range, mg/L 5 Prepare a standard curve by plotting turbidity values of
Raw or Treated Water Supply standards versus the corresponding sulfate concentra-
5 - 100
tions. Set nephelometer (or spectrophotometer) at zero
C. Apparatus Required sulfate concentration using distilled water as a control.

Turbidimeter OR spectrophotometer
Stopwatch or timer G. Example
Measuring spoon, 0 3 mL
Magnetic stirrer Results from a series of tests for sulfate were as follows:
Magnetic stir-bar Flask Sample Volume Turbidity
Pipet, 10 mL
1 Distilled Water 100 mL 0
Flasks, Erlenmeyer, 250 mL
2 Plant Effluent 100 mL 35
D. Reagents 3 Jones St. Well 50 mL 45
4 5.0 mg/L SO, Standard 100 mL 11
(Note. Standardized solutions are commercially avail- 5 10.0 mg/L SO, Standard 100 mL 29
able.) 6 15.0 mg/L SO, Standard 100 mL 40
7 20.0 mg/L SO, Standard 100 mL 53
1. Conditioning reagent.
2. Barium chloride, BaCl2, crystals: Sized for turbidimetric H. Calculation
work.' To ensure uniformity of results, construct a 1. Prepare i standard curve by using data from prepared
standard curve for each batch of BaCl2 crystals. standards From tile above example:
3 Standard suliate solution: Prepare a standard sulfate Concentration Sulfate, mg/L Turbidity, TU
solution as described in (a) or (b) below; 1.00 mL = 0.10
mg SO,. 0.0 0.0
5.0 11
(a) Dilute 10.41 mL standard 0.0200 N H250, titrant 10.0 29
specified in Alkalinity Test, Chapter 11, to 100 mL 15.0 40
with distilled water. 20.0 53

Baker No. 0974 or equivalent.

493
 .

"

I SOO

11011.

SO . S . - . . .

ESS wissumosimumesmi

_Ammo
Bowes woo

JONES STREET WELL

4
:1108111 .11110E1
Ins
4

O M 412
MOM
IPSOMMI
O M
MM. 0011.811

E MI MMMMM

:a

goal
4. MMM

mu earl s2
H
,MEMO
111111
474 Water Treatment

(Taste and Odor)

3. Correct (if necessary) for samples of less than 100 mL 15. Taste and Odor
by using the following formula:
A. Discussion
Sulfate, (Graph Sulfate, mg/L)(100 mL)
mg/L SO, Taste and odor are sensory clues that provide the first
Sample Size, mL warning of potential hazards in the environment. Water, in its
Using data from example. pure form, cannot produce odor or taste sensations. Howev-
er, algae, actinomycetes, bacteria, decaying vegetation,
(ample Concentration metals, and pollutants can cause tastes and odors in drink-
Volume Turbidity from Graph ing water. Corrective measures designed to reduce unpleas-
Plant Effluent 100 mL 35 TU 13 mg/L ant tastes and odors include aeration or the addition of
Sulfate, mg/L = 13 mg/ f. chlorine, chlorine dioxide, potassium permanganate or acti-
vated carbon.
Odor is considered a quality factor affecting acceptability
Sample Concentration of drinking water (and foods prepared with it), tainting of fish
Volume Turbidity from Graph and other aquatic organisms, and aesthetics of recreational
Jones St Well 50 mL 45 TU 17 mg/L waters. Most organic and some inorganic chemicals contrib-
(Culfate, mg/L)(100 mL)
ute to taste and odor. These chemicals may originate from
Sulfate, mg/L municipal and industrial waste discharges, from natural
Sample Size, mL sources (such as decomposition of vegetable matter), or
(17 mg/L)(100 mL', from associated microbial activity.
(50 mL)
= 34 mg/L SO4

Notes
1. A spectrophotometer can be used to measure ab-
sorbance of barium sulfate suspension. Use at 420
nanometer (nm) wavelength.
2 Color or suspended matter will interfere when present in
large amounts. Correct for these items by testing blanks
from which barium chlonde is withheld.
3 Analyze samples and standards with their temperatures Some substances, such as certain inorganic salts, pro-
in the range of 20 to 25°C. duce taste without odor. Many other sensations considered
to cause taste actually cause odors, even though the sensa-
J. Reference tion is not noticed until the water is in the mouth.
See page 467, STANDARD METHODS, 16th Edition. Taste, like odor, is one of the chemical senses. Taste and
odor are different in that odors are sensed high up in our
QUESTIONS nose and tastes are sensed on our tongue. Taste is simpler
than odor because there may be only four true taste sensa-
Write your answers in a notebook and then compare your tions: sour, sweet, salty, and bitter. Dissolved inorganic salts
answers with those on page 483. of copper, iron, manganese, potassium, sodium, and zinc
21.1T What is the meaning of spec;fic conductance or can be detected by taste.
conductivity? Operators must remember that a tasteless water is not the
21.1U Sulfate sons are of concern in drinking water for what most desirable water. Distilled water is considered less
reason? pleasant to drink than a high-quality water. The taste test
must determine the taste intensity by the threshold test and
21 1V A 50 mL sample from a well produced a turbidity also evaluate the quality of the drinking water on the basis of
reading of 40 Tl1 using a nephelometer (turbidi- desirability for consumers.
meter). What was the sulfate concentration in mg/L ?

495
 Lab Procedures 475

(Taste and Odor)

B. Apparatus Required To prepare more dilute samples, prepare an interme-

diate dilution consisting of 20 mL sample diluted to 200
Sample bottles, glass-stoppered or with TFE-lined clo-
mL with odor-free water. Use this dilution for the thresh-
sures
old determination. Multiply the threshold odor number
Constant temperature bath
(T 0.N.) obtained by 10 to correct for the intermediate
Odor flasks (500 mL glass stoppered Erlenmeyer flasks)
dilution.
Transfer and volumetric pipets or graduated cylinders
(200, 100, 50, and 25 mL) If an odor cannot be detected in the first dilution,
Measuring pipets (10 mL, graduated in 0 1 mLs) repeat the above procedure using sample containing
Thermometer (0 to 110°C) the next higher concentration of odor-bearing water and
continue this process until odor is detected clearly.
C Precautions
3. Based on the results obtained in the preliminary test,
Use preliminary tests to select the persons to make taste prepare a set of dilutions using Table 21.3 as a guide.
or odor tests. Use only persons who want to participate in Prepare the five dilutions shown in the approprime
the test. Avoid distracting odors such as those caused by column and the three next most concentrated in the
smoking, foods, soaps, perfumes, and shaving lotions. The next column to the right in Table 21.3. For example, if
testers should not have colds or allergies that affect odor odor was first noted in the flask containing the 50 mL
response. Do not have the testers perform too many tests sample in the preliminary test, prepare flasks containing
and allow frequent rests so the testers won't become tired 50, 35, 25, 17, 12, 8.3, 5.7, and 4.0 mL sample, each
and lose their sensitivity. Keep the room in which the tests diluted to 200 mL with odor-free water. This procedure
are conducted free from distractions, drafts and odors. is necessary to challenge the range of sensitivities of
A panel of five or more testers is recommended for the entire panel of testers.
precise work. Do not allow the testers to prepare the
samples or to know the dilution concentrations being evalu-
ated. Familiarize testers with the procedure before they TABLE 21.3 DILUTIONS FOR VARIOUS ODOR
particip I in a panel test. Present most dilute sample first to INTENSITIES
avoid tiring the senses with a concentrated sample. Keep PRELIMINARY TEST
temperature of sample during test within 1°C of the specified
temperature. Use opaque or darkly colored flasks to avoid Sample Volume in Which Odor First Noted
biasing the results due to turbid or colored waters being
200 mL 50 mL 12 mL 3.8 mL
tested.
FINAL TEST
D. Procedure
Volume in mL of Sample to be Diluted to 200 mL
ODOR
200 50 12 (Intermediate
1. Determine the approximate range of the threshold odor 140 35 8.3 dilution)
number by adding 200 mL, 50 mL, 12 mL, and 2.8 mL of 100 25 5.7
sample to 500 mL glass-stoppered Erlenmeyer flasks 70 17 4.0
containing odor-free water' to make a total volume of 50 12 2.8
200 mL. Use a separate flask containing only odor-free
water as a reference for comparison. Heat dilutions and Insert two or more blanks near the expected thresh-
reference to desired test temperature (usually 60°C or old. but avoid any repeated patterns. Do not let the
140°F). testers know which dilutions are odorous and which are
2. Shake flask containing odor-free water, remove stop- blanks. Instruct each tester to smell each flask in
per, and sniff vapors. Test sample containing least sequence, beginning with the least concentrated sam-
amount of odor-bearing water in the same way. If an ple, until odor is detected with certainty.
odor can be detected in this dilution, prepare more 4. Record observations by indicating whether odor is
dilute samples. noted in each flask. For example
mL Sample Diluted
to 200 mL 12 0 11 25 0 35 50
Response + + +

5. Calculate the threshold odor number (T.O.N.) as shown

in E. Calculations.
TASTE THRESHOLD TEST
1. The taste threshold test is used when the purpose is
quantitative measurement of detectable taste. When
odor is the predominant sensation, as in the case of
chlorophenols, the threshold odor test takes priority.
2. Use the dilution and random blank system described for
odor tests when preparing taste samples.

4 See STANDARD METHODS, 16th Edition, page 85, for directions on how to prepare odor -free water.

, r.
496
476 Water Treatment

(Taste and Odor)

3. Present each dilution and blank to the tester in a clean 7 Present each dilution and blank to the tester in a clean
50-mL plastic container filled to the 30-mL level. Use 50-mL plastic container filled to the 30-mL level. Use
high quality clear plastic containers. Discard the plastic high quality clear plastic containers. Discard the plastic
container when finished. Do not use glass containers containers when finished. Do not use glass containers
because the soap used to clean the glass could leave a because the soap used to clean the glass could leave a
residue which may affect the results. residue which may affect the results.
8. Each tester is presented with a list of nine statements
about the water ranging on a scale from very favorable
to very unfavorable (Table 21.4). The testers task is to
select the statement that best expresses the tester's
opinion. The scored rating is the scaie number of the
statement selected. The panel rating is the arithmetic
mean (average) of tne scale numbers of all testers.

9. Rating involves the following steps:

a. Initial tasting of about half the sample by taking water
into the mouth, holding it for several seconds, and
discharging it without swallowing;
4. STANDARD METHODS recommends maintaining the b. Forming an initial judgment on the rating scale;
sample presentation at 40 ± 1°C (104 ± 2°F).
c. A second tasting is made in the same manner as the
NOTE: Some operators use normal water tempera- first;
tures for taste tests or a temperature of 15°C
(59°F). d. A final rating is made for tne sample and tie result is
recorded on the appropr;ate data form;
5. Present the series of samples to each tester. Pair each
sample with a known blank. e. Rinse mouth with taste- and odor-free water; and

6. Have each tester taste the sample by taking into the f. Rest one minute before repeating steps a through e
mouth whatever volume is comfortable, holding it in the on the next sample.
mouth for several seconds, and discharging the sample
without swallowing the water. TABLE 21.4 ACTIoN TENDENCY RATING S "ALE FOR
TASTE RATING TEST
7. Have the tester compare the sample with the blank and
record whether a taste or aftertaste is detectable in the 1. I would be very happy to drink this water as my everyday
s: .ale. drinking water.
8. Submit samples in an increasing order of concentration 2. I would be happy to accept this water as my everyday
until the tester's taste threshold has been passed. drinking water.
9. Calculate individual threshold and threshold of the panel 3. I am sure that I could accept th's water as my everyday
as shown in E. Calculations. drinking water.
TASTE RATING TEST 4. I could accept this water as my everyday drinking water.

1 When the purpose of the test is to estimate the taste 5. Maybe I could accept this water as my everyday drinking
acceptability, use the "taste rating test" procedure de- water.
scribed below.
6. I don't think I could accept this water as my everyday
2. Samples for this test usually represent treated water drinking water.
ready for human consumption. If experimentally treated 7. I could not accept this water as my everyday drinking
water is tested, BE CERTAIN THAT THE WATER IS
water.
SAFE TO DRINK (no pathogens and no toxic chemicals
present). 8. I could never drink this water.
3. Give testers thorough Instructions and trial or orienta- 9. I can't stand this water in my mouth and I could never
tion sessions followed by questions and discussions of drink it.
procedures.
4. Select panel members on basis of performance in trial
sessions.
5. When testing samples testers work alone.
6. Present samples at a temperature that testers find
pleasant for drinking water. Maintain this temperature
by the use of a water bath apparatus. A temperature of
15°C (59°F) is recommended, but in arty case, do not let
the test temperature exceed tap water temperatures
that are customary at the time of the test. Specify the
test temperature in reporting results.
... .
!: t 497
 Lab Procedures 477

(Taste and Odor)

10. Independently randomize sample order for each tester. EXAMPLE 1

Mow at least 30 minutes rest between repeated rating
sessions. Testers should not know the composition or Calculate the threshold odor nun ber (T.O.N.) for a sample
source of samples. when the first detectable odor occurred when the 25 mL
sample was diluted to 200 mL (175 mL of odc--free water
was added to the 25 mL sample).
E. Calculations
Known Unknown
FORMULAS
A or Sample Size, mL = 25 mL T.O.N.
1. ODOR B or Odor-Free Water, mL = 175 mL
The threshold odor number (T.O.N.) for an indiv;dual Calculate the threshold odor number, T.O.N.
tester is calculated using the following formula:
T.O.N. = A B
TON =A -B A
A
25 mL + 175 mL
where:
25 roL
A = mL sample and
=8
B = mL odor-free water.

The threshold odor number for a group is presented as EXAMPLE 2

the geometric mean of the individual tester thresholds.
Determine the geometric mean threshold odor number for
Geometric Mean = (X, x X2 X X3 X ... Xn)' in a panel of five testers given the results shown below.
where: Known Unknown
X, = threshold odor number for tester number 1, Tester 1, X, = 8 Geometric Mean Threshold
Tester 2, X2 = 6 Odor Number
X2 = threshold odor number for tester number 2,
Tester 3, X3 = 12
X3 = threshold odor number for the nth tester, Tester 4, X4 = 8
and Tester 5, X5 = 4
n = total number of testers.
Calculate the geometric mean
2. TASTE THRESHOLD
Geometric Mean (X, x X2 x X3 x X4 x X5)1/n
Calculate the individual tester's threshold taste num- T.O.N.
ber and the threshold taste number for a panel using the = (8 x 6 x 12 x 8 x 4)1/5
same formulas that are used for the threshold odor
2
tests. = (18432)0

3. TASTE RATING = 7.1

Determine the taste rating for a water by calculating

the arithmetic mean and STANDARD DEVIATIONS of all EXAMPLE 3
ratings given for each sample.
Calculate the threshold taste number for a sample when
the first detectable taste occurred when the 50 mL sample
Arithmetic X, + X3 Xn was diluted to 200 mL (150 mL of taste-free water was
Mean, X added to the 50 mL sample).
Known Unknown
where: X, = taste rating for tester number 1,
A or Sample Size, mL = 50 mL Threshold Taste
X2 = taste rating for tester number 2, Number
Xn = taste rating for nth tester, and B or Taste-Free Water, mL = 150 mL
n = number of testers.
Calculate the threshold taste number.
Standard Deviation = [ (X1 g)2 + (X2 R)2 + (Xn - g)2 ] 1/2
Threshold Taste Number =A + B
n 1
A

(x12 + x22 + x02) - (X1 + X2 + Xn)2 /n = 50 mL + 150 mL

Or = I 1/2

n 1 50 mL
=4

5 Standard Deviation. A measure of the spread or dispersion of data.

498
478 Water Treatment

(Taste and Odor)

EXAMPLE 4
Determine the taste rating for a water by calculating the
arithmetic mean and standard deviation for the panel ratings
given below.
Known Unknown
Tester 1, X, = 4 1. Arithmetic Mean,
Tester 2, X2 = 2 2. Standard Deviation, S
Tester 3, X3 = 3
Tester 4, X4 = 5
Tester 5, X5 = 3
Tester 6, X6 = 1

1. Calculate the arithmetic mean, X, taste rating.

Arithmetic Mean, X = x, + X2 + X3 + X4 + X5 + X6
Taste Rating

=4 + 2 + 3 + 5 + 3 + 1
6
_18
6

=3

2. Calculate the standard deviation, S, of the taste rating.

Standard (X, -X)2 (X2-X)2 (X3-X)2 p(4_502 ((5_,R)2 (X6-X)2 v2

Deviation,
n-1
S

[ (4-3)2 + (2-3)2 + (3-3)2 + (5-3)2 + (3-3)2 + (1-3)2

6 1

=[ (1)2 + (-1)2 + 02 + (2)2 + 02 + (-2)2 5

[ 1 + 1 + 0 + 4 + 0 + 4 ]°5
5

= 15

= (2)5 5

= 1.4

499
 Lab Procedures 479

(Tnhalomethanes)
or
Standard r (X12 + X22 + X32 + X42 + X52 + X62) - (X1 +X2+ X3+X4+ X 5-1-X6)2 /n
Deviation,
S
n 1
i
(42+22+32 +52 +32 +12) ,
(4+2+3+54-3+1)2/6 V2

6 1

[ (16+4+9+25+9+1) (18)2/6 ]cl 5

5

i64 54 16
5

= [ 10 106
5i
= (2)"
= 1.4 (same answer as before)

F. Reference surface water, water taken from a surface source is more

Odor: 1.. ely to produce high THM levels than most groundwaters.

See page 85, STANDARD METHODS, 16th Edition. Generally, the THM producing reaction is:

Taste: Chlorine + Precursors = Chloroform + Other THMs

See page 122, STANDARD METHODS, 16th Edition. Chloroform is the most common THM found in drinking
water and it is usually present in the highest concentration.
The presence in drinking wrier of chloroform and other
QUESTIONS THMs and synthetic organic chemicals may have an adverse
Write your answers in a notebook and then compare your effect on the health of consumers: therefore, human expo-
answers with those on page 483. sure to these chemicals should be reduced.

21.1W List the items that can cause tastes and odors in B. Reference
drinking water. For materials and procedures see:
21.1X Calculate the threshold odor number (T.O.N.) for a Page 591, STANDARD METHODS, 16th Edition.
sample when the first detectable odor occurred when
the 12 mL sample was diluted to 200 mL (108 mL of
odor-free water was added to the 12 mL). NOTE. A gas chromatography analyzer is required for this
analysis.
16. Trihalomethanes
A. Discussion 17. Total Dissolved Solids
The trihalornethanes (THMs) are members of the family of A. Discussion
organohalogen compounds which are named as derivatives
of methane. Current analytical chemistry applied to drinking "Total dissolved solids" (TDS) refer to material that passes
water has thus far detected chloroform, bromodichloro- through a standard glass-fiber filter disc and remains after
methane, dibromochloromethane, bromoform, and dichioro- evaporation at 180°C. The amount of dissolved solids pre-
iodometh ane. sent in water is a consideration in its suitability for domestic
use. In general, waters with a TDS conten. of less than 50
The principal sources of chloroform and other tnhalo- mg/L are most desirable for such purposes. The higher the
methanes in drinking water is the chemical interaction of TDS concentration, the greater the likelihood of tastes and
chlorine added for disinfection and other purposes with the odors and also scaling problems. As TDS increases, the
commonly present natural humic substances and other number of times the water can be recycled and reclaimeu
precursors produced either by normal organic decomposi- before requiring demineralization decreases. In potable wa-
tion or by the metabolism of aquatic organisms. Since these ters, TDS consists mainly of inorganic salts, small amounts
natural organic precursors are more commonly found in of organic matter, and dissolved gases.6

Reference. CHEMISTRY FOR ENVIRONMENTAL ENGINEERING, Third Edition, 1978, by Clair N. Savyer and Perry L. McCarty.
Published by McGraw-Hill Book Company, 1221 Avenue of the Americas, New York, New York 10010. Price $50.95.
500
 480 Water Treatment

(Total Dissolved Solids)

B. What is Tested? E Example

Sample Common Range, mg/L Results from weighings were
Raw and Treated 20 to 700 Clean dish
Surface Waters = 47.0028 grams (47,002.8 mg)
Dissolved residue + dish = 47.0453 crams (47,045.3 mg)
Groundwater 10C to 1000
Sample volume = 100 mL
C. Apparatus Required
F Calculations
Glass-fiber filter discs (Millipore AP40; or Gelman Type
A/E) (A-13) x 1000
1 Total Dissolved Solids, mg/L =
Flask, suction 500 mL
mL sample volume
Filter holder or Gooch crucible adapter
Gooch crucibles (25 mL if 2.2 cm filter used) where, A = weight of dish and
Evaporating dishes, 100 rriL (high-silica glass) dissolved material
Drying oven, 180°C in milligrams (mg)
Steam bath
Vacuum source B = weight of clean
Disiccator dish in milligrams
Analytical balance (mg)
Muffle furnace, 550°C 2. From example,
Total Dissolved (AB) x 1000
D. Procedure Solids. mg/L
mL sample volume
Preparatior of Dish (47,045 3 rag 47,002 8 mg)(1000 mL/L)
1. Ignite a clean evaporating dish at ..,50 ± 50°C for one 100 mL
hour it muffle furnace.
= 425 mg/L
2. Cool in desiccator then weigh and record weight. Store
in desiccator until needed. G. Comments
Preparation of Glass-fiber Filter Disc Because excessive residue in the evaporating dish may
form a water-entrapping crust, use a sample that yields no
1. Place the disc on the filter apparatus or insert into the more than 200 mg of resioue.
bottom of a suitable Gooch crucible. While vacuum is
applied, wash the filter disc with three successive 20 mL H. Reference
volumes of distilled water. Continue the suction to
remove all traces of water from the disc and discard the See page 95, STANDARD METHODS, 16th Edition.
washings.
Sample Analysis QUESTIONS
1. Shake the sample vigorously and tr2nsfer -.00 to 150 Write your answers in a notebook and then compare your
mL to the funnel or Gooch crucible by means of a 150 answers with those on page 483.
mL graduated cylinder. 21.IY How are trihatomethanes produced?
2 Filter the sample through the glass-fiber filter and con- 21.1Z What are "total dissolved solids" (TDS)?
tinue to apply vacuum for about three minutes after
filtration is complete to remove as much water as
possible.
3 Transfer 100 mL of the filtrate to the weighed evaporat-
ing dish and evaporate to dryness on a steam bath. euzi of ide#24oh:002 (.4440$14
4. Dry the evaporated sample for at least one hour at
180°C. Cool in desiccator and weigh. Repeat drying
cycle until constant weight is obtained or until weight
ANANeet, aSDRA'(OQY
loss is less than 0.5 mg. PoactiCer4

501
 Lab Procedures 431

(Total Dissolved Solids)

OUTLINE OF PROCEDURE FOR TOTAL DISSOLVED SOLIDS

Ap

ci
1. Ignite dish at 550°C 2. Cool 3. Weigh and store
for 1 hour in muffle in desiccator.
furnace

4. Place glass-fiber
disc in crucible. 5. Wash filter-crucible 6 Pour 100 mL sample
with distilled water. into Gcoch crucible.

77 O
7. Filter out suspended 8. Evaporate to

i
.INSIMIIIO.
material. Transfer 100 mL dryness on
of filtrate to weighed dish. steambath.

9. Dry evaporated sample

for 1 hour at 183°C

10. Cool in desiccator.

11. Weigh.

502
 482 Water Treatment

DISCUSSION AND REVIEW QUESTIONS

Chapter 21. ADVANCED LABORATORY PROCEDURES
(Lesson 2 of 2 Lessons)

Please write the answers to these questions in your 17. Why are sulfate ions of concern in water supplies?
notebook before continuing with the Objective Test on page
484. The questio.i numbering continues from Lesson 1. 18 How would you attempt to reduce unpleasant tastes
and odors in drinking water?
9 Why is iron undesirable in a domestic water supply?
19. Why should exposure to THMs be reduced?
10. What precautions must be exercised when collecting
samples to be analyzed for iron? 20. Why is the amount of din solved solids present in water a
consideration in its suitability for domestic use?
11. How would you obtain the manganese concentration in
a sample by using a spectrophotometer if turbidity or
color was interfering with the results?
12. What is the purpose of the Marble Test?
13. Why is the presence of certain metals in drinking water
of serious concern?
14. How would you interpret the results of lab tests which
indicate high levels of n'trate in a raw water sample?
15. When performing the nitrate determination, why should
caution be exercised when using cadmium and what
precautions should be used?
16. How would you interpret the meaning of changes (away
from normal) in conductivity ,n water?

SUGGESTED ANSWERS
Chapter 21. ADVANCED LABORATORY PROCEDUYIES

ANSWERS TO QUESTIONS IN LESSON 1 through pH adjustmont.

Answers to questions on page 449. 21.1C Titrate sample for calcium immediately after adding
sodium hydroxide (NaOH) solution.
21.0A The intensity of a blue color is measured when
measuring the concentration of phosphorus in water. 21 1D Chloride concentrations above 250 mg/L are objec-
tionable to many people due to a salty taste.
21.0B The scale in spectrophotc.meters is usually graduat-
ed in two ways: Answers to questions on page 453.
1. In units of percent transmittance (%T), anthr e-
tic scale with units graded from 0 to 100%. 41,10 21.1E The most common colors which occur in raw water
2. In units of absorbance (A), a logarithmic scab are yellow and brown.
nonequal divisions gradua' ed from 0.0 to 2.0. 21.1F True color is normally removed or at least decreased
21.0C If the absorbance reading w,.s 0.60, the unknown by coagulation and chlorination or ozonation.
concentration was 0.70 mg /L. 21.1G Stock color standards should be protected against
evaporation and contamination when not in use.
Answers to questions on page 453.
21.1A Yes, the quality of water in any lake, reservn,r or Answers to questions on page 460.
stream has a very direct effect on the abundance and 21.1H The presence of dissolved oxygen (DO) in water can
types of aquatic organisms found. contribute to corrosion of piping systems.
21.1B Calcium in the form of lime or calcium hydroxide may 21.11 The common range of fluoride in fluoridated drinking
be used to soften water or to control corrosion water is 0.8 to 1.2 mg /L.

503
 Lab Procedures 483

ANSWERS TO QUESTIONS IN LESSON 2 form hard scales in boilers and heat exchaligers.

Answers to questions on page 465. 21.1V A 50 mL sample from a well produced a turbidity
reading of 40 TU using a nephelometer. What was
21.1J Problems that may be caused by iron in a domestic the sulfate concentration in mg/L9
water supply include staining of laundry, concrete,
Known Unknown
and porcelain. A bitter astringent taste can be detect-
ed by some people at levels above 0.3 mg/L. Sample Size, mL = 50 mL Sulfate, mg/L
Turbidity, TU = 40 TU
21.1K All glassware must be acid washed when analyzing
samples for iron to remove deposits of iron oxide 1. Determine the sulfate concentration from the
which could give false results. graph.
21.1L Manganese occurs both in suspension and as a Sulfate Concentration, mg/L = 15 mg/L
soluble complex in surface wat rs.
2 Calculate the sulfate concentration in mg/L.
21,1M If the manganese concentration cannot be deter-
mmed immediately, acidify sample with nitric acid to Sulfate, mg/L = (Graph Sulfate, mg/L)(100 mL)
pH less than 2. Sample Size, mL

Answers to questions on page 468. =(15 mg/L)(100 mL)

21.1N Temperature is important in the Marble Test because 50 mL
the solubility of calcium carbonate varies with tem- = 30 mg!L
perature. Therefore, the test must be performed
immediately after the sample is collected and as Answers to questions on page 479.
rapidly as possible.
21.1W Tastes and odors can be caused in drinking water by
21.10 Lange lier Index Initial pH Final pH algae, actinomycetes, bacteria, decaying vegetation,
metals and pollutants (most organic chemicals and
8.9 8.6 some inorganic chemicals). Dissolved inorganic salts
0.3 of copper, iron, manganese, potassium, souium and
zinc can be detected by taste.
Since the Lange lier Index is positive, the water is
supersaturated with calcium carbonate and not con- 21 1X Calculate the threshold odor number (T.O.N.) for a
sidered corrosive. sample when the first detectable odor occurred when
the 12 mL sample was diluted to 200 mL (188 mL of
21.1P The concentration of most meals in water is deter- oder-free water was added to the 12 mL).
mined by using atomic absorption spectroscopy or
colonmetric methods Known Unknown
A or Sample Size. mL = 12 mL T.O.N.
Answers to questions on page 471.
B or Odor-Free Water. mL = 188 mL
21.10 In the nitrate test, all nitrate is reduced to nitrite and
Calculate the threshold odor number, T O.N.
then measured rolonmetrically.
T 0 N. A 4- B
21.1R Removal of turoidity interfering with nitrate analyses
can be accomplished by one of the following meth- A
ods to remove suspended matter that can clog the
12 mL + 188 mL
reduction column.
1. Filter sample through a glass fiber or a 0.45 12 niL
micron pore size filter ay. long as the pH is less
= 17
than 8, or
2. Add 1 mL zinc solution to 100 mL of sample and Answers to questions on page 480.
mix thoroughly. Add enough sodium hydroxide
solution to obtain a pH of 10.5. Let treated sample 21 1Y The principal source of chloroforr, and other tnhalo-
stand a few minutes to allow the heavy flocculent methanes in dnnking water is chemical interac-
precipitate to settle. Clarify by filtering through a tion of chlorine added for disinfection and other
glass fiber filter. purposes with the commonly present natural humic
substances and other precursors produced either by
21 1S The pH of natural waters is controiled by the relative normal organic decomposition or by the metabolism
amounts of carbon dioxide, bicarbor.ate, and carbon- of aquatic organisms.
ate ions.
21.1Z "Total Dissolved Solids" (TDS) refer to material that
Answers to questions on page 474. passes through a standard glass-fiber disc and re-
mains after evaporation at 180°C.
21.1T Specific conductance or conductivity is a numerical
expression (expressed in micromhos per centimeter)
of the ability of a water to conduct an electrical
current. This number depends on the total concen-
tration of the mineral dissolved in the sample (TDS)
and the temperature.
21.1U Sulfate ions are of importance in water suppl'es
because of the tendency of appreciable amounts to

564
 484 Water Treatment

OBJECTIVE TEST
Chapter 21. ADVANCED LABORATORY PROCEDURES

Please write your name and mark the correct answers on 12 Above a pH of 4.6 the solubility of the ferric iron species
the answer sheet as directed at the end of Chapter 1. l'here increases considerably.
may be more than one correct answer to the multiple choice
questions. 1 True
2 False
TRUE-FALSE
13 Colloidal ferric hydroxide may persist in small quantities
1 Measuring the intensity of the color enables the concen- in surface waters that appear clear.
tration of a substance in water to be measured. 1 True
1. True 2. False
2. False
14. Manganese is much more abundant in the earth's crust
2. The human eye is more precise than a spectrophotom- than iron
eter.
1. True
1. True 2. False
2. 7.alse
15. Manganese in surface waters occurs both in suspen-
3 A sample which has a low color intensity will have a low sion and as a soluble complex.
percent transmittance but a high absorbance. 1. True
1. True 2. False
2. False
16. During the Marble Test, the water being tested should
4 In most natural waters calcium is the principal anion. not be exposed to atmospheric carbon dioxide.
1. True 1 True
2. False 2 False
5 Chloride usually occurs in natural waters as a basic salt. 17 Nitrite represents the most completely oxidized form of
1. True nitrogen found in water.
2 False 1. True
2. False
6. Usually the chloride content in water increases as the
mineral content decreases. 18. The nitrate test measures both nitrate and nitrite.
1. True 1. True
2. False 2. False

7 True color results from the presence of suspended 19 Taste and odor are sensory clues which provide The first
materials. warning of potential hazards in the environment.
1. True 1. Tnie
2. False 2 False
8 The formation of a white floc' during the DO test indi- 20 Water taken from a groundwater source is more likely to
cates that there is DO present in the sample. produce high ThM levels than most surface waters
1. True 1. True
2. False 2 Fame
9 As the temperature of water increases, the DO satura-
tion value increases.
1. True
2. False

10. Always record temperature of water when collecting a MULTIPLE CHOICE

dissolved oxygen sample.
21 Analyses of which of the following water quality charac-
1. True
teristics are based on the measurement of color inten-
2. False say',
11. Iron is an abundant and widespread constituent of rocks 1. Dissolved oxygen
and sods. 2. Iron
3. Manganese
1. True 4. pH
2. False 5 Phosphorus

505
 Lab Procedures 485

22. Color intensities can be converted to concentrations of 30 Objections to manganese in domestic waters include
substances using 1 Corrosivity.
1. Amperometnc titration. 2 Ciscolored di iveways.
2 Ness ler tubes 3 ttardnes.
3 pH prohes 4. Stained laurVry
4 Pocket comparators. 5. Stained plumbing fixtures
5 Spectrophotometers.
31. Metals found in drinking water include
23. The quality of water in any lake, reservoir or stream has 1 Calcium
a very direct effect on the of aquatic organisms 2 Chloride
found in the water. 3. Iron
1 Absorbance 4. Nitrogen.
2 Abundance 5 Sodium.
3. Aliquots
4. Percent transmittance 32 High levels of nitrate in a domestic water supply are
5. Transparency undesirable becaule of
1. Hardness.
24. The recommended maximum allowable concentration 2 Health threat due to infant methemoglobinema
of chloride in drinking water is 3 Laundry stains.
1. 50 mg/L 4 Nitrate stains.
2. 100 mg/L 5 Potential for stimulating excessive algae growth.
3. 150 mg/L
4. 200 mg/L 33. Alum coagulates most effectively at pH values near
5. 250 mg/L
1. 4.3
25. Ions that interfere with the chlonde test include 2.56
1 Iron. 3 68
2. Orthophosphate. 4. 7.5
3. Sulfide. 5. 8.3
4. Sulfite.
5. Thiosulfate 34. Tastes and odors in drinking waters can be produced by
1. Algae
26 Color in water supplies may result from 2. Bacteria
1. Copper. 3. Decaying vegetation.
2. hardness. 4. Hardness.
3 Iron. 5. Pollutants.
4 Manganese.
5. Organic matter. 35 In potable waters TDS consists mainly of
1. Dissolved minerals.
27 Precautions that must be exercised when using a d-s- 2. Inorganic salts.
solved oxygen (DO) probe include 3 Organic matter.
1. Acidify the sample. 4. Soluble acids.
2. Keep the membrane in the tip of the probe from 5. Vitamins.
drying out.
3 Keep the sample Iced. 36 Calculate the threshold odor number (T.O.N ) for a
4. Periodically check the calibration of the probe. sample when the first detectable odor oc"urred when
5. Remove reactive compounds that can interfere with the 17 rnL sample was diluted to 200 mL (183 mL of
the output. odor-free water was added to the 17 mL).
1 4
28. Samples being tested for fluoride must be distilled if the 26
samples contain exc6 sive amounts of 38
Aluminum. 4 12
2. Hardness. 5. 17
3. Hexametaphosphate
4. Nitrate.
5. Sodium hydroxide.

29. Iron in a domestic watei a pply can cause

1. Bitter tastes.

ela of objeetiw Te4t,

2. Consumer complaints.
3. Corrosion.
4. Staining ,,,f concrete.
5. Staining of lau-dry.

5oR
 CHAPTER 22

DRINKING WATER REGULATIONS

by
Tim Gannon

Revised
by
Jim Sequeira
 488 Water Treatment

TABLE OF CONTENTS
Chapter 22. Drinking Water Regulations

Page
OBJECTIVES 491
GLOSSARY 492

LESSON 1

22.0 History of Drinking Water Laws and Standards 493

22.1 1986 Amendments to the Safe Drinking Water Act 494
22.10 Major Aspects 494
22.11 Schedule 496
22.2 Disinfectants and Disinfection by-products 496
22.3 Surface Water Treatment Rule, (SWTR) 496
22.30 Requirements for Non-Filtered Systems 497
22.31 Requirements for Filtered Water Systems 497
22.32 Monitoring Rc.juirements of the SWTR 497
22.33 Turbidity Requirements of the SWTR 497
22.4 Types of Water Systems 498
22.40 Community Water Systems 498
22.41 Non-Community Water Systems 498
22.5 Interim Primary Drinking Water Standards 498
22.50 Establishment of Drinking Water Standards 498
22.51 Types of Contaminants 498
22.52 Immediate Threats to Health 499
22.520 Bacteria 499
22.521 Nitrate 499
22.53 Setting Standards 499

LESSON 2

22.6 Primary Drinking Water Standards 501

22.60 Inorganic Chemical Standards 501

22.600 Arsenic 503

22.601 Barium 503

5Os
 Water Quality Regulations 489

22.602 Cadmium 503

22.603 Chromium 503

22.604 Fluoride 503

22.605 Lead 503

22.606 Mercury 503

22.607 Selenium 503

22.608 Silver 503

22.61 Organic Chemical Standards 504

22.610 Trichloroethylene (TCE) 505

22.611 1,1-Dichloroethylene 505

22.612 Vinyl Chloride 505

22.613 1,1,1-Trichloroethane 505

22.614 1,2-Dichloroethane 505

22.615 Carbon Tetrachloride 505

22.616 Benzene 505

22.617 1,4-Dichlorobenzene (p-dichlorobenzene) 505

1. Turbidity Standards 505

22.63 Microbiological Standards 506

22.630 Coliform 506

22.631 Multiple-Tube Fermentation Method 506

22.632 Membrane Filter Method 506

22.633 Chlorine Residual Substitution 506

22.634 Draft Coliform Rule 506

22.635 Giardia 507

22.64 Radiological Standards 507

22.7 Secondary Drinking Water Standards 508

22.70 En:orcement of Regulations 508

22.71 Secondary Maximum contaminant Levels . 508

22.72 Monitoring 509

22.73 Secondary Contaminants 509

22.730 Chloride 509

22.731 Color 509

22.732 Copper 510

22.733 Corrosivity 510

22.734 Fluoride 510

22.735 Foamiwg Agents 510

22.736 Iron and Manganese 511

22.737 Iron 511

22 738 Manganese 511

9949
490 Water Treatment

22.739 Odor 511

22.740 pH 512
22.741 Sulfate 512
22.742 Total Dissolved Solids 512
22.743 Zinc 512
22.8 Sampling Procedures 513
22.80 Safe Drinking Water Regulations. 513
22.81 Initial Sampling 513
22.82 Routine Sampling . 513
22.83 Check Sampling 513
22.84 Sampling Points 513
22.85 Sample Point Selection 514
22.86 Sampling Schedule 515
22.87 Sampling Route 515
22.88 Sample Collection 515
22.9 Reporting Procedures 515
22.10 Notification for Community Systems 515
Suggested Answers 527
Objective Test 530
Appendix Coliform Sarri:.s.les Required Per Population Served 533

510
 Water Quality Regulations 491

OBJECTIVES
Chapter 22. DRINKING WATER REGULATIONS

Following completion of Chapter 22, you should be able

to:
1. Identify the two basic types of water systems,
2 List the types of primary contaminants,
2,. Explain the proposed Surfer.; Water Treatment Rule
(SVVTR),
4. Describe the Interim Primary Drinking Water Standards,
5 List the secondary contaminants,

6 Develop and conduct a sampling program,

7. Record and report results, and
8. Comply with notification requirements.

51.1
492 Water Treatment

GLOSSARY

Chapter 22. DRINKING WATER REGULATIONS

ACUTE ACUTE
When the effects of an exposure ,:ause severe symptoms to occur quickly, the symptoms are said to be acute because they are
belf and severe.

CHECK SAMPLING CHECK SAMPLING

Whenever an initial or routine sample analysis indicates that a Maximum Contaminant Level (MCL) has been exceeded, CHECK
SAMPLING is required to confirm the routine sampling results. Check sampling is in addition to the routine sampling program.

CHELATING AGENT (key-LAY-ting) CHELATING AGENT

A chemical used to prevent the precipitation of metals (such as copper).

CHLORAMINATION (KLOR-ah-min-NAY-shun) CHLORAMINATION

The application of chlorine and ammonia to water to form chloramines for the purpose of disinfection.

CHRONIC CHRONIC
Effects of repeated exposures over a long period of time which eventually cause symptoms that continue for a long time.

INITIAL SAMPLING INITIAL SAMPLING

The very first sampling conducted under the Safe Drinking Water Act for each of the applicable contaminant categories.

MBAS MBAS
Methylene-Blue-Active Substances. These substances are used in surfactants or detergents.

MCL MCL
Maximum Contaminant Level. The largest allowable amount. MCLs for various water quality indicators are specified in the Na-
tional Drinking Water Regulations.

pCi/L pCi/L
PicoCurie per Liter. A picoCurie is a measure of radioactivity. One picoCurio of radioactivity is equivalent to 0.037 nuclear disin-
tegrations per second.

ROUTINE SAMPLING ROUTINE SAMPLING

Sampling repeated on a regular basis.

SURFACTANT (SIR -fac -TENT) surfactant

Abbreviation for surface-active agent. The active agent in detergents that possesses a high cleaning ability.

THRESHOLD ODOR NUMBER THRESHOLD ODOR NUMBER

TON. The greatest dilution of a sample with odor-free water that still yields a just-detectable odor.

TU TU

Turbidity units. Turbidity units are a measure of the cloudiness of water. If measured by a nephelometric (deflected light) instru-
mental procedure, turbidity units are expressed in nephelometric turbidity units (NTU) or simply TU. Those turbidity units ob-
tained by visual methods are expressed in the Jackson Turbidity Units (JTU) which are a measure of the cloudiness of vater,
they are used to indicate the clarity of water. There is no real connection between NTUs and JTUs. The Jackson turbidimeter is
a visual method and the nephelometer is an instrumental method based on deflected light.

, 512
 Water Quality Regulations 493

CHAPTER 22. DRINKING WATER REGULATIONq

(Lesson 1 of 2 Lessons)

All water treatment plant operators need to be thoroughly greater chance of developing certain cancers than those in
familiar with the state and federal laws and standards that neighboring areas whose drinking water came from ground-
apply to domestic water supply systems. These regulations water sources. Heightened public awareness and concern
are the goals and guideposts for the water supply industry. regarding cancer became major factors behind the push for
Their purpose is to assure the uniform delivery of safe and legislative action on the issue of drinking water contamina-
aesthetically pleasing drinking water to the public. tion. The finding of suspected carcinogens in drinking water
This chapter will introduce the major drinking water regu- established a widespread sense of urgency that led to the
lations and explain the monitoring and reporting require- passage and signing into law of the Safe Drinking Water Act
in December, 1974.
ments. For more detailed information, you will need to refer
to current copies of your state's regulations and the most
recent federal standards. These publications snould be
made readily available to all operators since operators will
only know whether their system is in compliance by compar-
ing monitoring test data with the actual current regulations.

The Safe Drinking Water Act (SDWA) gave the federal

government, through the U.S. Environmental Protection
Agency (EPA), the authority to:
Set national standards regulating the levels of conta-
minants in drinking water; .

Require public water systems to monitor and report

their levels of identified contaminants; and
Establish uniform guidelines specifying the acceptable
treatment technologies for cleansing drinking water of
unsafe levels of pollutants.
While the SDWA gave EPA responsibility for promulgating
drinking water regulations, it gave state regulatory agencies
the opportunity to assume primary responsibility for enforc-
22.0 HISTORY OF DRINKING WATER LAWS AND ing those regulations.
STANDARDS
Over the past decade, implementation of the SDWA has
Up until shortly after the turn of thu century, there were no greatly improved compliance with basic drinking water purity
standards for drinking water. The first standards, estab- across the nation. However, recent EPA surveys of surface
lished in 1914, were designed in large part to control water and groundwater indicate the presence of synthetic
waterborne bacteria and viruses that cause diseases such organic chemicals in 20 percent of the nation's water
as cholera, typhoid, and dysentery. These new standards sources, with a small percentage at levels of concern. In
were ovewhelmingly successful in curbing the spread of addition research studies suggest that some naturally oc-
such diseases. However, with time and technology, other curring contaminants may pose even greater risks to human
types of contaminants, this time chemicals, again stirred health than the synthetic contaminanta. Further, there is
public concern. In 1962 the U.S. Public Health Service (the growing concern about microbiological and radon contami-
forerunner of the U.S. Environmental Protection Agency) nation.
revised the national drinking water standards to include
limits on select organic chemicals. In the years following passage of the SDWA, Congress felt
that EPA was slow to regulate contaminants and states were
In 1972 a series of reports detailing organic contamination lax in enforcing the law. Consequently, in 1986 Congress
in the drinking water supplied to the residents of New enacted amendments designed to strengthen the 1974
Orleans from the Mississippi River triggered profound SDWA. These amendments included language modifica-
changes in drinking water regulations. A study by the tions, set deadlines for the establishment of maximum
Environmental Defense Fund found that people drinking cortaminant levels, placed g. eater emphasis on enforce-
treated Mississippi River water in New Orleans had a ment, authorized penalties for tampering with drinking water

513
494 Water Treatment

supplies and mandated the complete elimination of lead 3. Filtration requirement for surface water supplies,
from drinking water. In addition, the SDWA amendments
placed considerable emphasis on the protection of under- 4. Disinfection of all water supplies, and
ground drinking water sources. 5. Prohibition of the use of lead products in materials
used to convey drinking water.
22.1 1986 AMENDMENTS TO THE SAFE DRINKING The 1986 Amendments require the regulation of many
WATER ACT more contaminants. The Amendments state that:
22.10 Major Aspects The EPA must regulate nine contaminants within a
The 1986 SDWA amendments require that the EPA, the year of enactment (1987), another 40 within two years
states, and the water supply industry undertake significant (1988), and the rest within three years (1989) for a total
new programs in the very near future to clean up the of 83. These 83 contaminants (shown in Table 22.1)
country's drinking water supplies. The major aspects of the include 14 volatile organic chemicals (VOCs), five mi-
1986 Amendments to the SDWA include: crobiological parameters and turbidity, 23 inorganics
(I0Cs), and five radionuclides.
1. Compulsory revisions to the regulations for new con-
taminants (as described below), In addition to the promulgation of standards for the 83
contaminants, EPA must develop at least 25 more
2. Definition of an approved treatment .echnique for primary standards by 1991 and 25 additional standards
each regulated contaminant, every three years thereafter.

TABLE 22.1. CONTAMINANTS REQUIRED TO BE REGULATED BY

THE SDWA AMENDMENTS OF 1986

VOLATILE ORGANIC CHEMICALS

Trichloroethylene Chlorobenzene
Tetrachloroethylene Dichlorobenzene
Carbontetrachloride Trichlorobenzene
1,1,1-Trichloroethane 1,1-Dichloroethylene
1,2-Dichloroethane trans-1,2-Dichloroethylene
Vinyl chloride cis-1,2-Dichloroethylene
Methylene chloride Benzene

MICROBIOLOGICAL AND TURBIDITY

Total coliforms Viruses

Turbidity Standard plate count
Giardia lambli Legionella

INORGANICS

Arsenic Molybdenum
Barium Asbestos
Cadmium Sulfate
Chromium Copper
Lead Vanadium
Mercury Sodium
Nitrate Nickel
Selenium Zinc
Silver Tahllium
Fluoride Beryllium
Aluminum Cyanide
Antimony

514
 Water Quality Regulations 495

TABLE 22.1. CONTAMINANTS REQUIRED TO BE REGULATED BY

THE SDWA AMENDMENTS OF 1986 (continued)

ORGANICS

Endrin Vydate
Lindane Simazine
Methoxychlor PAHs
Toxaphene PCBs
2,4-D Atrazine
2,4,5-TP Phthalates
Aldicarb Acre; :amide
Chlorodane Dibromochloropropane (DBCP)
Diaquat 1,2-Dichloropropane
Endothall Pentachlorophenol
Glyphosate Picloram
Carbofuran Dinoseb
Alachlor Ethylene dibromide (EDB)
Epichlorohydrin Dalapon
Toluene Dibromomethane
Adipates Xylene
2,3,4,8-TCDD (Dioxin) Hexachlorocyclopentadiene
1,1,2-Trichloroethane

RADIONUCLIDES

Radium 226 and 228 Gross alpha particle activity

Beta particle and photon Uranium
radioactivity Radon

Contaminants on the above list of 83 or which maximum contaminant level goals (MCLGs) were not proposed as of November
13, 1985.a

Methylene chloride Thallium

Antimony Beryllium
Endrin Cyanide
Dalapon 1,1,2-Trichloroethane
Diaquat Vydate
Endothall Simazine
Glyphosate PAHs
Adipates Atrazine
2,3,4,8-TCDD ( Dioxin) Phthalate
Trichlorobenzene Picloram
Standard plate count Dinoseb
Legionella Hexachlorocyclopentadiene
Sulfate Nickel

a Note. MCLGs have also not been proposed for the seven cintaminants EPA is proposing to delete from the list of 83 conta-
minants. These seven are zinc, silver, aluminum, sodium, dibromomethane, molybdenum, and vanadium.

515
496 Water Treatment

EPA can substitute up to seven other contaminants for 22.0A What were the first drinking water standards de-
those on the list if it finds this will provide greater signed to control?
health protection.
22.1A List the major aspects of the 1986 Amendments to
By 1988, EPA must specify criteria for filtration of the SDWA.
surface water supplies.
22.1B Why will water systems not be required to meet
By 1990, EPA must specify criteria for disinfection of Phase I regulations until two-and-a-half years after
surface and groundwater supplies. the law was passed?
Even prior to the passage of the 1986 Amendments, the
EPA used a regulatory approach when reviewing drinking
water contaminants. This type of approach, coincides with
the regulation requirements imposed by the Amendments,
considers pollutants in four phases:
Phase I: Volatile Organic Chemicals (VOCs)
Phase II: Synthetic Organic Chemicals (SOCs), inorganic
chemicals, and microbiological contaminant
regulations
Phase III: Radionuclide Contaminants Regulations
Phase IV: Disinfectant By-Product Contamination Regu-
lations
22.11 Schedule
The EPA's schedule for compliance with the SDWA
Amendments of 1986 is listed below.
June 1987- Promulgate MCLs for at least 9 chemi-
cals. EPA has prepared MCLs for 8 22.2 DISINFECTANTS AND DISINFECTION
VOCs, fluoride, and lead. BY- PRODUCTS

December 1987- Promulgate criteria for the mandatory The EPA's initial draft list of 25 regulated compounds (the
filtration of surface water sources. This first of three such lists to be issued at three year intervals)
has been delayed until 1988. emphas;:.es limits on the concentration of disinfection re-
January 1988 - Publish a list of contaminants which siduals and disinfection by-products. These new regulations
may require regulation by EPA. Begin are expected to set lower MCLs for trihalomethanes (THMs)
monitoring of 33 unregulated VOCs. plus limit disinfectants (chlorine, chlorine dioxide, chlora-
mines, hypochiorite ion, and ozone), inorganic by-products
June 1988- Promulgate MCLs for at least 40 conta- (chlorite), and organic by-products which are principally
minant chemicals in water. other chlorinated compounds (halogenated acids, alcohols,
June 1989- Promulgate MCLs for at least 34 conta- aldehydes, and ketones and halonitriles). Compliance with
minant chemicals in water. these standards is likely to radically alter current water
January 1991- Promulgate MCLs for 25 contaminant treatment disinfection practices by curtailing the use of
chemicals in water. This is the first of a chlorine and increasing the use of alternatives aL.cn as
triannual promulgation of 25 MCLs. ozone and chloramines.

At first glance, this schedule for setting standards appears Of the substances mentioned above, only trihalomethanes
reassuring. Keep in mind, however, that protection from (THMs) are regulated at the present time.. THMs are the
regulated contaminants does not occur the instant a regula- product of chlorine combining with organic material in the
tion is published. The Act requires the regulation of nine water. They are suspected of being carcinogenic. The MCL
contaminants within 12 months of its passage. These Phase established for total trihalomethanes (TTHMs) is 0.10 milli-
I contaminant limits were promulgated in 1987, but because grams per liter or 100 micrograms per liter. EPA is expected
the drinking water program is a federal-state partnership, to strengthen this standard by reducing the MCL and consid-
states are allowed 18 additional months to adjust their own ering whether additional standards of this type are neces-
regulations. Therefore, water systems will more than likely sary.
not be required to meet Phase I regulations ur til two-and-a-
half years after the law was passed. 22.3 SURFACE WATER TREATMENT RULE (SWTR)

All public water systems must comply with the regulations.

In 1987, the EPA prepared a draft Surface Water Treat-
This includes all public and privately owned systems that: ment Rule (SWTR) that specifies which water supplies that
must be filtered and provides performance criteria for both
1. Have at least 15 service connections which are used filtered water sources and those treated by disinfection only.
at least 60 days out of the year, or The draft SWTR specifically requires that:
2. Serve an average of at least 25 people at least 60 days 1. All surface water systems must disinfect.
out of the year.
2. All surface water systems must filter unless they meet
QUESTIONS source water quality criteria and site-specific condi-
tions. States will determine which systems will need to
Write your answers in a notebook and then compare your install filtration or upgrade existing filtration and disin-
answers with those or gage 527. fection.

516
 Water Quality Regulations 497

3. All systems will necrl to achieve the removal or the filtered water turbidity must be less than 1 NTU in
inactivation criteria of Giardia and enteric viruses. at least 95 percent of the measurements taken each
month.
4. Only qualified operators will be entitled to operate the
systems. 2. Filtered water must never exceed five TUs.
The general performance criteria to be met by surface 3. A disinfectant residual in the distribution system of 0.2
water systems are primarily directed toward acute health mg/L in 95 percent of the samples be maintained.
risks from waterborne microbiological contaminants. The
requirements are: As a further measure of filtration/disinfection perfor-
mance, the SWTR refers to the use of CT (residual concen-
1. At least 99.9 pr ;ent removal and/or inactivation of tration x time) values for various disinfectants. Conformance
Giardia lamblia ...ists, and with CT values could be the means of meeting Giardia and
virus inactivation limits. It is expected that most states will
2. At least 99.99 percent removal and/or inactivation of follow EPA recommendations and include CT analysis for
enteric viruses. evaluating disinfection effectiveness.
In general, compliance by the surface water purveyor 22.32 Monitoring Requirements of the SWTR
could be through one of the following alternatives:
Unfiltered surface water systems must:
1. Meeting the criteria for which filtration is not required
and providing disinfection according to the specific 1. Monitor raw water for coliforms (frequency is depen-
requirements in the SWTR, or dent on system size) and turbidity every 4 hours
(continuous monitoring allowed with measurement
2. Providing filtration and meeting disinfection criteria every 4 hours);
required for those supplies that are filtered.
2. Continuously monitor the disinfectant residual enter-
Mandatory filtration is expected to affect the small and ing the distribution system;
medium-sized water systems most severely. A few large
surface water systems do not filter their water; more than 3. Sample the distribution system for disinfectant residu-
nine million people drink unfiltered water in Seattle, New als (frequency depends on system size);
York City, and Boston alone. However, most of the unfiltered 4. Monitor daily to demonstrate that the level of disinfec-
surface water systems serve communities with fewer than tion achieved is 99.9 percent inactivation of Giardia
10,000 residents. and 99.99 percent inactivation/rer.:.-,a1 enteric vi-
22.30 Requirement for Non-Filtered Systems ruses.

To avoid mandatory filtration, a water utility must meet: Filtered system; must:

1. Source water quality criteria (coliforms and turbidity 1. Perform turbidity measurements of representative
levels), and water every 4 hours (which can be continuous moni-
toring);
2. Certain site-specific conditions,
(a) has disinfection that achieves 99.9 percent inacti- 2. Continuously monitor the disinfectant residual enter-
vation of Giardia and 99.99 percent inactivation of ing the distribution system;
viruses. 3. Sample in the distribution system for disinfectant
(b) watershed control or sanitary surveys that satisfy residuals (sampling frequency depends on system
regulatory requirements. size).
(c) no history of waterborne disease outbreak without
making treatment corrections. 22.33 Turbidity Requirements of the SWTR
(d) compliance with long-term conform maximum con-
To avoid filtration, the level of a system's unfiltered water
taminant level (MCL).
(e) compliance with total trihalomethanes MCL, if the turbidity would have to be less than 5 TU. For filtered water
systems, the filtered water must be less than either 0.5 TU or
system serves more than 10,000 people.
less than 1 TU for 95 percent of the time, depending upon
If a system cannot meet the source water quality criteria the technology being used, and must at no time exceed 5
and site-specific conditions listed above, then the system TU.
must install and operate appropriate filtration facilities.

22.31 Requirements for Filtered Water Systems

For systems that filter, the primary concern is adequate
disinfection and filtration performance. The requirements
are:
1. For conventional or direct filtration systems, the fil-
tered water turbidity must be less than or equal to 0.5
TU1 for at least 95 percent of each month's measure-
ments. For slow sand or diatomaceous earth filtration,
,Nall4116.---....----.,_
1 Turbidity Units. Turbidity units are a measure of the cloudiness of water. If measured by a nephelometric (deflected light) instrumental
procedure, turbidity units are expressed in nephelometric turbidity units (NTU) or simply TU. Those turbidity units obtained by visual
methods are expressed in Jackson Turbidity Units (JTU) which are a measure of the cloudiness of water, they are used to indicate the
clarity of water. There is no real connection between NTUs and JTUs. The Jackson turbidimeter is a visual method and the nephelometer
is an instrumental method based on deflected light.

517
 498 Water Treatment

Unfiltered systems are required to begin with a clean 22.40 Community Water Systems
source water and have a watershed that is protected from
human activities that might otherwise have an adverse A community water systein is defined as follows:
impact on water quality. Unfiltered systems would have very
little, if any, virus contamination. For these systems, the
1. Has at least 15 service connections used by all-year
residents, or
major concern is Giardia contamination from animal activi-
ties that cannot be prevented by watershed protection. The 2. Services at least 25 all-year residents.
purpose of the turbidity limit for unfiltered water is to ensure
22.41 Non-Community Water Systems
a high probability that turbidity does not interfere with
disinfection of Giardia cysts. The turbidity limit of 5 TU A non-community water system is defined as follows:
serves this purpose.
1. Has at least 15 service connections used by travelers
or intermittent users at least 60 days a year, or
2. Services a daily average of at least 25 people at least
60 days a year.
Any water system that provides services for fewer con-
nections or persons listed above is not covered by the
SDWA. However, regardless of size, all operators must
strive to provide consumers with a potable drinking water.
22.5 INTERIM PRIMARY DRINKING WATER STANDARDS
22.50 Establishment of Drinking Water Standards
The drinking water standards established by EPA reflect
the best scientific and technical judgment available. They
were refined by the suggestions and advice of the 15-
member National Drinking Water Advisory Council, made up
of representatives of the general public, state and local
agencies, and experts in the field of public water supply. The
Department of Health and Human Services as well as other
agencies and organizations contributed to the developmen
of the National Interim Primary Drinking Water Regulations.
The regulations set achievable levels of drinking water
quality to protect your health. They are called "interim"
regulations because research continues on drinking water
contaminants. The existing standards may be strengthened
and new standards may be established for other substances
For filtered water systems, the major burden for Giardia based on studies being conducted by the National Academy
removal rests with filtration. With conventional treatment of Sciences, EPA, and others.
and direct filtration, low turbidity levels (<0.5 TU) are
needed to ensure effective Giardia cyst removals. Disinfec- EPA has established standards (maximum contaminant
tion of either Giardia or viruses will not be hampered at these levels) for ten chemicals, six pesticides, bacteria, radioactiv-
turbidity levels. ity. turbidity, and trihalomethanes. Most of these substances
occur naturally in our environment and in the foods we eat
For slow sand filtration and diatomaceous earth filtration, The national drinking water standards set by EPA reflect the
effective Giardia removal does not necessarily correlate with levels we can safely consume in our water. taking into
low treated water turbidities. However, to ensure effective account the amounts we are exposed to from these other
virus inactivation, a low filtered water turbidity is needed. sources
Viruses are much smaller than Giardia, and thus a lower
turbidity limit of 1 TU is needed compared with the turbidity 22.51 Types of Contaminants
level of 5 TU for unfiltered supplies to ensure effective
disinfection. Five types of primary contaminants are considered to be
of public health importance:
QUESTIONS 1 INORGANIC CONTAMINANTS. such as lead and mer-
Write your answers in a notebook and then compare your cury,
answers with those on page 527.
2. ORGANIC CONTAMINANTS, which now include pesti-
22.2A What are THMs? cides, herbicides and tnhalomethanes, but may be ex-
panded to include solvents and other synthetic organic
22.3A What does the draft Surface Water Treatment Rule compounds;
(SWTR) specifically require?
3. TURBIDITY, such as small particles suspended in water
22.3B How can a water utility avoid mandatory filtration? which interfere with light penetration and disinfection;
22.4 TYPES OF WATER SYSTEMS 4. MICROBIOLOGICAL CONTAMINANTS, such as bacte-
ria, virus, and protozoa; and
All the drinking water regulations apply to two types of
public water systems: (1) community water systems, and (2) 5 RADIOLOGICAL CONTAMINANTS, which include natural
non-community water systems. and man-made sources of radiation.

518
 Water Quality Regulations 499
The maximum contaminant level goal represents what
22.52 Immediate Threats to Health
EPA believes to be a safe level of consumption based solely
Only two substances for which standards have been set on its studies of health effects. It is, however, a goal rather
pose an immediate threat to health whenever they are than an immediately achievable constituent limit. To develop
exceeded. (1) bacteria, and (2) nitrate. more realistic, enforceable limits, EPA further revises the
MCLG to take into account existing laboratory detection
22.520 Bacteria technology, costs, and reasonableness. After adjusting for
Co liform bacteria from human and animal wastes may be these factors, EPA sets the maximum contaminant level
found in drinking water if tile water is not properly treated. (MCL) as close to the MCLG as is realistically feasible. The
These bacteria usually do not themselves cause diseases important difference between the two levels is that the
transmitted by water, but indicate that other harmful organ- MCLG is a nonenforceable goal and the MCL is an enforce-
isms may be present in the water. Waterborne diseases able standard.
such as typhoid, cholera, infectious hepatitis, and dysentery
The Maximum Contaminant Levels (MCLs) are the highest
have been traced to improperly disinfected drinking water.
permissible concentration of a particular substance in water.
Certain coliforms have been identified as the cause of
The MCLs apply whether the contaminant is from naturally
"travelers" diarrhea.
occurring sources or from man-made pollution. More types
of contaminents must be monitored by community than by
22.521 Nitrate
non-community systems as shown on Table 22.2.
Nitrate in drinking water above the national standard of
100 mg/L (as N) poses an immediate threat to children under
three months of age. In some infants, excessive levels of
nitrate have been known to react with intestinal bacteria
which change nitrate to nitrite which reacts with the hemo-
globin in the blood This reaction will reduce the oxygen
carrying ability of the blood and produce an anemic condi-
tion commonly known as "blue baby."
Non-community systems MAY be allowed to serve water
containing up to 90 mg/L nitrate if.
1. The water is not available to infants six months of age
and younger.
2. Posting of the potential health hazard is maintained;
3 State and local health authorities are notified and agree;
and
4. No threat to health will result

22.53 Setting Standards

The process by which EPA establishes drinking water
standards is both long and complicated. A standard is the
maximum level of a substance that EPA has deemed accept-
able in drinking water. The first step in the setting of a TABLE 22.2 CONTAMINANTS MONITORED BY
standard is to study the human and animal health effects of a COMMUNITY AND NON-COMMUNITY WATER SYSTEMS
given chemical. These studies are normally performed using Community Water Systems
rats or mice. Based on these studies, E °A establishes a "no
observed adverse effect" level (abbreviated as "NOAEL"). A Period of Exposure
safety far',o is added to the NOAEL and the result is an Contaminant Which May Affect Health
accepir.ole daily intake limit of the chemical in question. The Long-term
Inorganic Chemicals
limit is adjusted to take into account the average weight and
(except nitrate)
water consumption of the consumer, and the resulting figure
is called a maximum contaminant level goal, or MCLG . Inorganic Chemicals (nitrate only) Short-term
Organic Chemicals Long-term
Turbidity Short-term
Microbiological Contaminants Short-term
Radiological Contaminants Long-term

Non-Community Water Systems

Period of Exposure
Contaminant Which May Affect Health
Inorganic Chemicals Short-term
(nitrate only)
Turbidity Short-term
Microbiological Contaminants Short-term

519
 500 Water Treatment

QUESTIONS 22.58 Why is nArcte considered an immediate threat to

Write your answers in a notebook and then compare your public health?
answers with those on page 528.
22.4A Define a community water system. eta of 14",4gtitl 42 V.44044
22.5A List the five types of primary contaminants which are
considered to be of public health importance. vrZINK1410 wAra CaawA1tot44

DISCUSSION AND REVIEW QUESTIONS

Chapter 22. DRINKING WATER REGULATIONS

(Lesson 1 of 2 Lessons)

At the end of each lesson in this chapter you will find some
water systems most severely?
discussion and review questions that you should answer
before continuing. The purpose of these questions is to 4. What is a community water system?
indicate to you how well you understand the mat,- rial in the
5. What is the difference between a community and a non
lesson. Write the answers to these questions in your note-
book before continuing. community water system?
1. 6. What are Maximum Contaminant Levels (MCLs)?
What will be the impact of the 1986 Amendments to the
SDWA on water treatment disinfection practices? 7. Why is turbidity undesirable in a finished or treate
2. Why are THMs regulated? water?
3. 8 How do coliform bacteria get into drinking water ar
Mandatory filtration is expected to affect what sized
what does their presence indicate?
 Water Quality Regulations 501

CHAPTER 22. DRINKING WATER REGULATIONS

(Lesson 2 of 2 Lessons)

22.6 PRIMARY STANDARDS

Primary Standards or MCLs are set for substances that about inorganic chemicals are not centered on cancer, but
are thought to pose a threat to health when present in rather on their suspected links to several different human
drinking water at certain levels. Because these substances disorders. For example. lead is suspected of contributing to
are of health concern, primary standards are enforceable by mental retardation in children.
law. (In contrast, secondary standards relate to cosmetic Presently, only ten inorganic chemicals are regulated but
factors and are not federally enforceable.) A primary stan- several others are being studied and considered possible
dard can also be referred to as a maximum contaminant
candidates. They are: aluminum, antimony, molybdenum,
level (MCL). In July 1987 EPA finalized MCLs for eight asbestos, sulfate, copper, vanadium, sodium, nickel, zinc,
volatile organic chemicals bringing the number of primary
thallium, beryllium, and cyanide. The following paragraphs
standards to 30. Table 22.3 lists the currant (January, 1988) briefly discuss each of the inorganic contaminants regulated
primary standards and health concerns associated with the
by the national drinking water standards. Waters exceeding
contaminants. .he MCL for these elements for short periods of time will
pose no immediate threat to health. However, studies show
22.60 Inorganic Chemical Standards that these substances must be controlled because con-
Inorganic chemicals are metals, salts, and other chemical sumption of drinking water that exceeds these standards
compounds that do not contain carbon. The health concerns over long periods of time may prove harmful.

0
A ir 41

521
 502 Water Treatment

TABLE 22.3 PRIMARY DRINKING WATER STANDARDS

CONTAMINANT MCL (mg/L) HEALTH EFFECT

Inorganics

Arsenic 0.05 dermal/nervous system toxicity

Barium 1.00 circulatory system effects
Cadmium 0.01 kidney effects
Chromium 0.05 liver and kidney effects
Lead 0.05 nervous system/kidney damage
toxic to infants & pregnant women
Mercury 0.002 nervous system/kidney disorders
Nitrate 10.0 Methemoglobinemia ("blue-baby"
syndrome)
Selenium 0.01 gastrointestinal effects
Silver 0.05 skin discoloration
Fluoride 4.00 skeletal damage
Organics

Endrin 0.000,
Lindane
nervous system/kidney effects
0.004 nervous system/liver effects
Methoxychlor 0.10
2,4-D
nervous system/kidney effects
0.1 liver/kidney effects
2,4,5-TP Silvex 0.01 liver/kidney effects
Toxaphene 0.005 cancer risk
Benzene 0.005 cancer
Carbon Tetrachloride 0.005 possible cancer
p-Oichlorobenzene 0.075 possible cancer
1,2-Dichloroethane 0.005 possible cancer
1,1-Dichloroethylene 0.007 liver/kidney effects
1,1,1-Trichloroethane 0.2 nervous system effects
Trichloroethylene (TEC) 0.005 possible cancer
Vinyl Chloride 0.002 cancer risk
Trihalomethanes 0.10 cancer risk
Microbiological

Total Coliforms 1 per 100mL indicators of disease-causing

organisms
Physical

Turbidity 1-5 TU interferes with disinfection

Radionuclides

Gross alpha particles 15 pCi /L cancer

Gross beta particles 4 mrem/yr cancer
Radium 226 & 228 5 pCi/L bone cancer
 Water Quality Regulations 503

22.600 Arsenic 22.604 Fluoride

This element occur s naturally in the environment. espe- This is a natural mineral and many drinking waters contain
cially in the western United States and it is also used in some fluoride. Fluoride produces two effects, depending on
insecticides Arsenic is found in foods. tobacco. shellfish. its concentration, and EPA has set both primary and secon-
drinking water and I n the air in some locations. The national dary limits to regulate it. At levels of 6 to 8 rtigIL fluoride may
standard for arsenic IS 005 milligrams per liter of water cause skeletal fluorosis which is a britthng of the bones and
Water that continuo usly exceeds the national standard by a stiffening of the joints. On the basis of this health hazard,
substantial amount over a lifetime may cause fatigue and fluoride has been added to the list of primary standards.
loss of energy Extremely high levels can cause poisoning
At levels of 2 mg/L and greater fluoride may cause dental
fluorosis which is discoloration and mottling of the teeth,
especially in children. EPA has recently reclassified dental
fluorosis as a cosmetic effect raised the primary drinking
water standard from 1.4 - 2 mg/L to 4 mg/L, and established
a secondary standard of 2 mg/L for fluoride.

22.605 Lead
This metal is found in the air and in our food. Lead comes
from galvanized pipes. solder used with copper pipes. auto
exhausts. and other sources. The maximum amount of lead
permitted in drinking water by the national standards is 0 05
milligrams per liter of water. Excessive amounts well above
this standard may result in nervous system disorders or
brain or kidney damage.

22.606 Mercury
Mercury is found naturally throughout the environment.
22.601 Barium Large increases in mercury levels in water can be caused by
industrial and agricultural use. The health risk from mercury
Althou gh not as widespre d as arsenic, this element also
is greater from mercury in fish than simply from waterborne
occurs naturally in the environment in some areas Barium
mercury. Mercury poisoning may be ACIKE2 in large doses,
can also enter water supplies through industrial waste
or CHRONIC3 from lower doses taken over an extended
dischar ges Small doses of barium are nog harmful Howov-
er. it is quite dangerous when consumed in large quantities time period.
and wi II bring on increased blood pressui e. nerve darm'ye.
and e en death. 1 ne maximum amount of barium allowed in 22.607 Selenium
drink' ng water by the national standard is one milliorarn per
liter o f water. This mineral occurs naturally in soil and plants, especially
in western states Selenium is found in meat and other
22.6 02 Cadmium foods. Although it is believed to be essential in the diet, there
are indications that excessive amounts of selenium may be
0 nly extremely small amounts of this elen e, it are found in toxic. Studies are under way to determine the amount
natural waters in the United States Waste discharges from required for good nutrition and the amount that may be
the electroplating, photography, insecticide. and metallurgy harmful.
ind ustnes can increase cadmium levels, however The most
The national standard for selenium is 0.01 milligrams per
CO mmon source of cadmium in our drinkin water is from
liter of water. If a person's intake of selenium came only
g alvanized pipes and fixtures The maximum amount of from drinking water, it would take an amount many times
c admium allowed in drinking water by the national stanuard
s 0 010 milligrams per liter of water greater than the standard to prrsduce any ill effects.

22.603 Chromium 22.608 Silver

This metal is found in cigarettes. some of our foods. and This metal should pose no problem Silver is sometimes
the air. Some studies suggest that in very small amounts, used in proprietary water treatment devices for disinfecti%
chromium may be essential to human beings. but this has water The maximum amount of silver allowed in drinking
not been proven The national standard for chromium is 0 05 water by the national standard is 0 05 milligrams per liter of
milligrams per liter of water. water

2 Acute. When the effects of an exposure cause severe symptoms to occur quickly, the symptoms are said to be acute because they are
brief and severe.
3 Chronic. Effects of repeated exposures over a longer period of time which eventually cause symptoms that continue for a long time
i'.'
.
523
 504 Water Treatment

QUELTIONS 22.61 Organic Chemical Standards

Write your answers in a notebook and then compare your Organic chemicals are either natural or synthetic chemical
answers with those on page 528. compounds that contain carbon. Synthetic organic chemi-
22.6A What are inorganic chemicals?
cals (SOCs) are man-made compounds and are used
throughout the world as pesticides, paints, dyes, solvents,
22.6B Why is arsenic listed as a primary contaminant? plastics. and food additives. Volatile organic chemicals
(VOCs) are a subcategory of organic chemicals. These
22.6C What are two detrimental effects 31 excessive levels chemicals are termed "volatile" as they evaporate easily. The
of fluoride? most commonly found VOCs are trihalomethanes (THMs),
22.6D What are the sources of lead in drinking water? trichioroethylene (TCE), tetrachloroethylene, and 1,1-dich-
loroethano. THMs were the first regulated VOC when EPA
finalized regulations in 1979.
The most common sources of organic contamination of
drinking water are pesticides and herbicides, industrial sol-
vents, and disinfection by-prcducts (trihalomethanes). Mil-
lions of pounds of pesticides are used on croplands, forests,
lawns, and gardens in the United States each year. They
drain off into surface waters or seep into underground water
supplies. Spills, poor storage, and haphazard disposal of
organic chemicals have resulted in widespread groundwater
contamination. This is a critical problem since groundwater,
once contaminated, may remain that way for a long time.
Many organic chemicals pose health problems if they get
into drinking water and the water is not properly treated. The
maximum limits for pesticides in drinking water are shown
on Table 22.3 (page 502). Based on a review of the available
toxicological data, EPA has categorized the eight regulated
VOCs as shown on Table 22.4.
As directed by Congress in the 1986 Amendments, the
EPA will regulate 83 contaminants by 1989 (including 14
VOCs and 35 SOCs) and will undertake 0udies of at least 25
additional contaminants for potential regulation by 1990.

TABU_ 22.4 HEALTH EFFECTS CATEGORIES OF THE VOCS

Category I: Known or Probable Human Carcinogens

Benzene
Vinyl Chloride
Carbon etrachloride
1,2-Dichloroethane
Trichloroethylene

Category II: Limited But Insufficient Evidence of Carcinogenicity

1,1- Dichioroethylene - causes liver and kidney damage in animals at high doses; also affects central nervous
system and heart

Category III: Inadequate or No Evidence of Carcinogenicity

1,1,1-Trichloroethane - causes depression of central nervous system and changes in the cardiovascular system
and liver in humans and animals

p-Dichlorobenzene - causes liver damage and is suspected of being an animal carcinogen

524
 Water Quality Regulations 505

22.610 Trichloroethylene (TCE) 1. Interfering with disinfection by reducing the ability of

the disinfectant to inactivate or kill disease-causing
Although the use of trichloroethylene is declining because organisms.
of stringent regulations, it was, for many years, a common
ingredient in household products (spot removers, rug clean- 2. Exerting a chlorine demand which makes it difficult to
ers, air fresheners), dry cleaning agents, industrial metai maintain a residual throughout the distribution sys-
cleaners and polishers, refrigerants, and even E.nesthetics. tem.
Its wide range of use is perhaps why TCE is the organic
contaminant most frequently encountered in groundwater. 3. Interfering with the bacteriological examination of the
The MCL for TCE is 0.005 mg/L. water, and

22.611 1,1-Dichloroethylene 4. Not satisfactorily reducing "tastes and odors" and

"asbestos fibers."
This solvent is used in manufacturing plastics and, more
recently, in the production of 1,1,1-trichloroethane. The MCL The MCLs for turbidity which apply to surface water only
for this chemiczq is 0.2 mg/L. are shown on the ooster provided with this manual and are:
The monthly average turbidity MCL may not exceed 1
22.612 Vinyl Chloride
TU. At state option this may be raised to 5 1 O. Some
Billions of pounds of this solvent are used annually in the states require 0.5 TU where there is a major hazard of
United States to produce polyvinyl chloride (PVC), the most wastewater (sewage) contamination of the water sup-
widely used ingredient for manufacturing plastics through- ply.
out the world. There is also evidence that vinyl chloride may
be a biodegradation end-product of tri- and tetrachloroethy-
Five turbidity units based on an average for two
consecutive days.
lene under certain environmental conditions. The MCL for
vinyl chloride is 0.002 mg/L. The 5 TU MCL was included as a state option because
there are certain types 'If turbidity that do not interfere with
22.613 1,1,1-Trichloroethane
bacteriological effectiveness of disinfection. In such cases,
This chemical has replaced TCE in many industrial and the state may authorize the 5 TU MCL for a water system on
household products. It is the principa! solvent in septic tank a case-by-case basis.
degreasers, cutting oils, inks, shoe polishes, and many other
products. Among the VOCs found In groundwaters, 1,1,1- The two-day-average turbidity limit is designed to protect
trichloroethane and TCE are encountered most frequently against the presence of a high turbidity during certain
and it the highest concentrations. The MCL for this contami- periods, such as periods of heavy runoff, when the adequa-
nant is 0.2 mg/L cy of the treatment is particularly critical to protect the
public.
22.614 1,2-Dichloroethane
Daily turbidity sample requirements from non-community
1,2-Dichloroethane is used as a solvent for fats, oils, systems using surface water can be relaxed by the state or
waxes, gums, and resins. The MCL for this chemical is 0.005 local health agency provided certain criteria are met.
mg/L.
The turbidity standards are currently being reviewed and
22.615 Carbon Tetrachloride revised under the Surface Water Treatment Rules recently
Carbon tetrachloride was once a popular household sol- drafted. These are discussed in Section 22.33, "Turbidity
vent, a frequently used dry cleaning agent, and a charging Requirements of the SVVTR."
agent for fire extinguishers. Since 1970, however, carbon
tetrachloride has been banned from all use in consumer
goods in the United States and in 1978, it was banned " an QUESTIONS
aerosol propellant. Currently its principal use is in ,ne
Write your answers in a notebook and then compare your
manufacture of fluorocarbons which are used as refriger-
ants. The MCL for carbon tetrachloride is 0.005 mg/L (5 answers with those on page 528.
ug/L). 22.6E What are organic chemicals?
22.616 Benzene 22.6F What have been the common uses of trictiloroethy-
Benzene is useo primarily in the synthesis of styrene (for lens (TCE)?
plastics), phenol (for resins), and cyclohexane (for nylon). 22.6G What is the MCL for turbidity'
Other uses include the production of detergents, drugs,
dyes, and insecticides. Benzene is still being used as a
solvent and as a component of gasoline. The MCL for
benzene is 0.005 mg/L (5 ug/L).
22.617 1,4- Dichlorobenzene (p-dichlorobenzene)
The principal uses of this chemical are in moth c Jntrol
(balls, powders) and as lavatory deodorants. The MCL is
0.075 mg/L (75 ug/L).
22.62 Turbidity Standards
Turbidity is undesirable in a finished or treated water
because it causes cloudiness resulting in an unattractive
water. However, the major reason that turbidity is undesira-
ble is because it causes a health hazard by:
' .
 506 Water Treatment

22.63 Microbiological Standards The coliform MCLs using the membrane filter method are
Bacteria, viruses, and other organisms have long been such that the numbers of colonies shall not exceed any of
the following.
recognized as serious contaminants of drinking water. Or-
ganisms such as Giardia cause almost immediate gastroin- 1 One per 100 mL as the arithmetic mean of all samples
testinal illness when people consume them in water. Even examined per month,
though most recent attention has been focused on the
chemical contaminants of drinking water, the EPA has 2. Four per 100 mL in more than one sample when fewer
continued to pay special attention to improving treatment than 20 samples are examined per month, and
effectiveness with regard to microbiological contaminants.
3 Four per 100 mL in more than five percent of the samples
Currently only total coliforms are regulated. EPA, however,
when 20 samples or more are examined per month.
is considering creating MCLs for Giardia, viruses, standard
plate count, and Legionella. In addition, EPA will publish final
rules for filtration in 1988 and disinfection by June 1991.
Filtration and disinfection of water should effectively control 22.633
the th7eat posed by microbiological contaminants. Chlorine Residual Substutution
At the discretion of the state and based upon a review of
22.630 Coliform the water system, chlorine residual testing may be substitut-
ed for some of the bacteriological testing. Chlorine residual
Coliform bacteria are an indication of possible disease- testing could give the operator a quicker indication of the
producing organisms being present in the water supply. condition of the system. However, the following require-
MCLs :,ave been established to indicate when a coliform ments must be met:
concentration could indicate the likely presence of disease-
causing bacteria These MCLs have been established for 1 Samples must be taken at points which are representa-
both the membrane filter method and the multiple-tube tive of conditions within the distribution system.
fermentation method of testing.
2 Chlorine residual testing can replace only up to 75
percent of the bacteriological testing.
22.631 Multiple-Tube Fermentation Method
3. At least four chlorine residual tests must be taken to
substitute for one bacteriological sample.
The multiple-tube fermentation method of testing for coli-
forms determines the presence and the number of conforms 4 A free chlorine residual of at least 0.2 mg/L must be
by the multiple-tube dilution method. This is a process maintained throughout the distribution system.
whereby 10 mL of the sample is added to each of five tubes.
The tubes contain a culture media and an inverted vial. If gas 5 If free chlorine residual falls below 0.2 mg/L. check
accumulates in the inverted vial, it indicates presumptive samples must be taken for bacteriological testing and a
evidence of coliform organisms in that portion of the sample. report must be submitted to the state within 48 hours, and
Should no gas form in the vial, that portion of the sample is 6 Chlorine residual must be determined daily.
negative.
In order to meet the total trihalomethanes (TTHM) MCL,
For all systems, regardless of the number of samples some water treatment plants practice CHLORAMINATION.4
taken per month, conforms must not be present in more than Chlora,nination is the application of chlorine and ammonia to
10 percent of the portions per month. For systems requirEJ
form chloramines. Experience has shown that satisfactory
to take fewer than 20 samples per month, not more than one chlorine residuals and bacteriological test results can be
monthly sample can have three or more portions positive. obtained at remote locations in distribution systems pro-
For systems required to take 20 or more samples per month. vided
not more than five percent of the monthly samples can have
three or more portions positive. For water systems that C x T > 120 after filtration
regularly take 10 or fewer samples per month. ONE positive
sample may be discarded if:
where C is the chlorine residual in mg/L. and

1 The system chlorinates and maintains a residual. T lc the chlorine contact time in minutes.
For example, if a clear well provides a minimum contact time
2 The system takes two check samples on consecutive
days, and of 120 minutes, then the chlorine residual should be at least
one mg/L after 120 minutes.
3. This exclusion has NOT been used in the previous month.

22.632 Membrane Filter Method

22.634 Draft Coliform Rule
This method provides for filtering a 100 mL water sample The EPA has also prepared a draft coliform rule which
through a thin, porous, cellulose membrane filter under a was published in November of 1987. The Total Coliform Rule
partial vacuum The filter is placed in a sterile container and proposes to revise the MCL for total coliform and estab-
incubated in contact with a special liquid called a "culture lishes a nonenforceable health goal, termed maximum con -
medium" which the bacteria use as a food source. Colonies tar ,inant level goal of zero. The Rule also proposes changes
of bacteria then grow on the media The coliform colonies in monitoring requirements, analytical methodology, and
are visually identified, counted, and recorded as the number required responses to a positivo coliform test. These pro-
of coliform colonies per 100 mL of sample. posed changes are summarized below.

Chloramination (KLOR-ah-min-NAY-shun). The application of chlorine and ammonia to water to form chloramines for the purpose of
disinfection.

526
 Water Quality Regulations 507

Monitoring Frequency. For systems which service 3,300 Radioactivity is the only contaminant or which standards
persons or fewer, five samples per month are required. eve been set that has been shown to cause cancer.
Fewer samples will be required if the system filters and However, the possible exposure to radiation in drinking
disinfects surface water and groundwater For systems water is only a fraction of the exposure from all natural
which service more than 3,300 persons, the sampling fre- sources. The n-.3in source of radioactive material in surface
quency is based on population. The population size categor- water is fallout trom nuclear testing Other sources could be
ies have been reduced yet the minimum number of samples nuclear power plants, nuclear fuel processing plants and
required has not changed substantially from the existing uranium mines. Those sources are monitored constantly
regulations. and there is no great risk of contarnin.ation, barring acci-
dents.
Analytic& Methodology. The proposed MCL for coliform
will be based on the presence or absence of total coliforms Alpha and radium radioactivity occur naturally in parts of
in a sample, rather than on estimates of coliform density. the West, Midwest, and Northeast in groundwater. Stan-
The total coliform analyses must be conducted in accor- dards for those types of radioactivity and for man-made, or
dance with STANDARD METHODS,5 Method 908, "Multiple- beta radiation have been set at levels of safety comparable
Tube Fermentation Technique for Members of the Coliform to other contaminants.
Group," wth a standard sample volume of 100 mL.
The MCLs for radiological contaminants are divided into
Response to Positive Coliform Testing. The monthly MCL two categories: (1) natural radioactivity which results from
for systems that analyze fewer than 40 samples per month well water passing through deposits of naturally occurring
requires that no more than one sample per month can be radioactive materials; and (2) man-made radioactivity such
coliform positive. For water systems that collect more than as might result from industrial wastes, hospitals or research
40 samples per month, no more than five percent of the laboratories. Table 22.5 summarizes the MCLs for radioac-
samples collected can be coliform positive. The long-term tivity.
MCL for systems that analyze fewer than sixty samples per
year is that no more than five percent of the most recent 60
samples can be coliform positive. For systems with at least
sixty samples per year, no more than five percent of all TABLE 22.5 MCLs FOR RADIOACTIVITY
samples in the most recent 12-month period can be coliform
positive.
Maximum Co;itaminant
If coliforms are detected in any sample, the water purvey- Constituent Level, pCi/La
or must collect a set of five repeat samples on the same day
Combined Radium 226 and 5
from the same location. If coliforms are detected in a repeat
Radium 228
sample, the system must analyze the coliform positive
culture medium to determine if fecal coliforms are present. If Gross Alpha Activity 15
fecal coliforms are present, the coliform MCL has been (including Radium 226 but
violated and the appropriate health agency must be notified excluding Radium and Uranium)
immediately. If the MCL has not been violated, another set of Tritium 20,000
five repeat samples must be collected and analyzed.
Strontium-90 8
22.635 Giardia Gross Beta Particle Activity 50
The protozoan Giardia lambha is presently the organism
most implicated in waterborne disease outbreaks in the
United States. These microscopic creatures are found main- a pCi/L PicoCurie per Liter A picoCurie is a measure of
ly in mountain streams. Once inside the body, they cause a radioactivity One picoCurie of radioactivity is equivalent to
painful and disabling illness. The infection caused by Garda 0 037 nuclear disintegrations per second
s called Giardiasis. The symptoms of Giardiasis are usually
severe diarrhea, gas, cramps, nausea, vomiting, and fatigue.
Giardia and viruses have been added to the traditional
coliform and turbidity indicators of microbiological quality. In Monitoring for natural radioactivity contamination is re-
this case, the Recommended Maximum Contaminant Levels quired every four years for both surface water and ground-
(RMCLs) are zero because the organisms are pathogens, or water community systems Routine monitoring procedures
indicators of pathogens, and should not be present in ,o follow are.
drinking water. 1 Test for gross aim -a activity, if gross alpha exceeds 5
22.64 Radiological Standards pCi/L. then

Radon, radium, and uranium are three radioactive ele- 2 'rest for radium 226. if radium 226 exceeds 3 pCi/L. then
ments sometimes found iri drinking water. These materials 3 Test for radium 228
occur naturally in the ground and dissolve into groundwater
supplies. Because these radioactive materials are frequently The following MCLs apply for natural radioactivity
occurring potent carcinogens, EPA will regulate radon and 1 Gross alpha activity 15 pCi/L. and
strengthen the standard for radium in water supplies by
June 1989. 2 Radium 226 and radium 228 5 pCi/L.

5 E TANDARD METHODS FOR THE EXAMINATION OF WATER AND WASTEWATER. 16th Edition, 1985. Order No. 10035. Available from
...
,omputer Services, American Water Works Association, 6666 W. Quincy Avenue, Denver, Colorado 80235. Price to members, $72.00,
nonmembers, $90.00.

52 7
 508 Water Treatment

QUESTIONS 22.7 SECONDARY DRINKING WATER STANDARDS

Write your answers in a notebook and then compare your 22.70 Enforcement of Regulations
answers with those on page 528.
The National Secondary Drinking Water Regulations con-
22.6H EPA is considering the creation of microbiological trol contaminants in drinking water that primarily affect the
standard MCLs for what factors? aesthetic qualities relating to the public acceptance of drink-
ing water. At considerably higher concentrations of these
22.61 For water systems that regularly take 10 or fewer contaminants, health implications may also exist as well as
samples per month, under what circumstances may aesthetic degradation. These regulations are not federally
ONE positive sample be discarded?
enforceable; however, some states have passed laws re-
22.6J The MCLs for radiological contaminants are divided quiring the state health agency to enforce the regulations.
into what two categories? 22.71 Secondary Maximum Contaminant Levels
Secondary Maximum Contaminant Levels (SMCLs) apply
to public water systems and, in the judgment of the EPA
Administrator, are necessary to protect the public welfare or
for public acceptance of the drinking water. The SMCL
means the maximum permissible level of a contaminant
which is delivered to the free-flowing outlet of the ultimate
user of a public water system. Contaminants added to the
water under circumstances controlled by the user, except
those resulting from corrosion of piping and plumbing
caused by water quality, are excluded by definition. Current-
ly there are 13 secondary standards (see Table 22.6).

TABLE 22.6 SECONDARY DRINKING WATER STANDARDS

CONTAMINANT MCL EFFECT

Chloride 250 mg/L taste and corrosion of water

pipes
Color 15 Color aesthetic
Units

Copper 1 mg/L taste and staining of porcelain

Corrosivity Non- aesthetic and health related as
Corrosive corrosive water can leach pipe
materials into drinking water
Fluoride 2 mg1 L dental fluorosis (a brownish
discoloration of the teeth)
Foaming Agents 0.5 mg/L aesthetic
Iron 0.3 mg/L taste and staining
Manganese 0.05 mg/L taste and staining
Odor 3 Threshold aesthetic
Odor Numbera

pH 6.5 to 8.5 corrosion control

Sulfate 250 mg/L taste and laxative effects
Total Dissolved Solids 500 mg/L taste and possible relationship
between low hardness and heart
disease
Zinc 5 mg/L taste

a Threshold Odor Number (TON). The greatest dilution of a sample with odor-free water that still yields a jus'-detectable odor.

528
 Water Quality Regulations 509

States may establish higher or lower levels depending on 22.73 Secondary Contaminants
local conditions, providing that public health and welfare are
adequately protected. 22.730 Chloride

The MCL for chloride is 250 mg/L.

UNDESIRABLE EFFECTS
1 Objectionable salty taste in water.
2. Corrosion of the pipes in hot water and other systems.
STUDIES ON THE MINERALIZATION OF WATER INDI-
CATE THE FOLLOWING
1. Major taste effects are producted by anions (where TDS
was studied).
2. Chloride produces a taste effect somewhere between the
milder sulfate and the stronger carbonate.
3 Laxative effects are caused by high levels of sodium and
magnesium sulfate.
CORROSION EFFECT
Aesthetic qualities are important factors in public accep-
tance and confidence in a public water system. States are 1 Studies indicate that corrosion depends on concentration
encouraged to implement SMCLs so that the public will not of TDS (TDS may contain 50 percent chloride ions).
be driven to obtain drinking water from potentially lower 2 Domestic plumbing, water heaters and municipal water-
quality, higher risk sources. Many states have chosen to works equipment will deteriorate when high concentra-
enforce both Primary and Secondary MCLs to assure that
tions of chloride ions are present.
the consumer is provided with the best quality water avail-
able. EXAMPLE:

22.72 Monitoring Where the TDS = 200 mg/L (Chloride = 100 mg/L), water
heater life will range from 10 to 13 years. Water heater life
Collect samples for secondary contaminants at a free- declines uniformly as a function cf TDS 1 year short-
flowing outlet of water being delivered to the consumer. ened life per 200 mg/L additional TDS.
Monitor contaminants in these regulations at intervals no
less frequent than the monitoring performed for inorganic
chemical contaminants (every three years) listed for the 22.731 Color
Interim Primary Drinking Water Regulation or applicable to
community water systems. Collect monthly distribution sys- T' ie MCL for color is 15 color units. The level of this water
tem physical water quality monitoring samples for color and quality indicator is not known to be a measure of the safety
odors. More frequent monitoring would be appropriate for of water However, high color content may indicate:
specific contaminants such as pH, color, odor or ethers
under certain circumstances as directed by the state.

QUESTIONS
Write your answers in a notebook and then compare your
answers with those on page 528.

22.7A Under what conditions are seco -idary drinking water

regulations enforceable?
22.7B LiA the secondary drinking water contaminants.
22.7C How frequently should the contaminants in the sec-
ondary regulations be monitored?

1 High organic chemical contamination.

2. Inadequate treatment, and
3 High disinfectant demand and the potential for production
of excess amounts of disinfectant by-products.
Color may be caused by:
1. Natural color-causing solids such as aromatic, polyhy-
droxy, methoxy and carboxylic acids,
2. Plum and humic acid fractions, and
3. Presence of metals such as copper, iron, and manga-
nese.
 510 Water Treatment

Rapid changes in color levels may provoke more citizen 22.734 Fluoride
complaints than relatively high, constant color levels.
Fluoride as recently been added to the list of secondary
22.732 Copper drinking water standards. Fluoride produces two effects,
depending on its concentration. At levels of 6-8 mg /L
The MCL for copper is 1.0 mg/L. Copper in drinking water fluoride may cause skeletal fluorosis which is a brittling of
usually results from the reaction of aggressive water on the bones and stiffening of the joints. For this reason fluoride
copper plumbing. Treatment of surface water in storage has been aided to the list of primary standards (those that
reservoirs to control algae may also cause high levels of have health effects).
copper
At levels of 2 mg /L and greater fluoride may cause dental
UNDESIRABLE EFFECTS fluorosis which is discoloration and mottling of the teeth,
especially in children. EPA has recently reclassified dental
1 Imparts some taste to water (astringent taste) fluorosis as a cosmetic effect, raised the primary drinking
2 Blue or blue-green staining of porcelain at low levels (0 5 water standard from 1,4-2 mg/L to 4 mg /L, and established a
mg /L in soft waters). At higher levels, 4 mg/L causes secondary standard of 2 mg/L for fluoride.
staining of clothing and blond hair
3. Larger doses will produce Wilson's Disease. 22.735 Foaming Agents
4. Prolonged doses result in liver damage. The MCI. for foaming agents is 0 5 mg/L
5 Concentrations greater than one mg /L can produce in-
soluble green curds when reacting with soap UNDESIRABLE EFFECTS
DIETARY REQUIREMENTS 1 Causes frothing and foaming which are associated with
contamination (greater than 1.0 mg /L).
1. Adults require 2.0 mg daily.
2 Children of preschool age require 0.1 mg for normal 2. Imparts an unpleasant taste (oily, fishy, perfume-like)
growth. (less than 1.0 mg/L).
3. Water provides an additional supplement to ensure an
adequate intake. INFORMATION ITEMS
1. Because no convenient foamability test exists and be-
4. Excess copper intake or inability to metabolize copper is cause SURFACTANTS' are one major class of sub-
called Wilson's Disease and can be arrested by the use of stances that cause foaming, this property is determined
CHELATING AGENTS.6
indirectly by measuring the anionic surfactant concentra-
tion in the water (MBAS) .6
22.733 Corrosivily
2 Surfactants are synthetic organic chemicals and are the
A drinking water should be non-corrosive. However, a principal ingredient of modern household detergents.
significant level of corrosion is very difficult to define and
explain The corrosivity of water depends on the complex 3 The requirement for biodegradability led to the wide-
characteristics of water which are related to pH, alkalinity, spread use of Linear Alkyl Benzene Sulfonate (LAS), an
dissolved oxygen, and total dissolved solids plus other anionic surfactant.
factors. A number of different measurements have been
proposed to determine the degree of corrosivity of water, 4 Concentrations of anionic surfactants found in drinking
but none is completely satisfactory (see Chapter 8, Corro- waters range from 0 to 2 6 mg /L in well supplies and 0 to
sion Control). 5 mg/L in surface water supplies.
AL /ERSE EFFECTS
5 LAS are essentially odorless. The odor and taste charac-
1. Aifects the aesthetic quality (turbid waters promote de- teristics are likely to arise from the degradation of waste
posits under stagnant conditions encouraging bacteri- products rather than the detergents.
ological growths), and causes taste and odor problems in
the water supply. 6 If water contains an average concentration of 10 mg/L
surfactants, the water is likely to be entirely of
2. Serious economic impact (loss of system piping, water wastewater origin.
loss from deteriorating distribution system).
7 From a toxicological standpoint an MCL of 0.5 mg/L.
3 Health implications (toxic corrosion products such as assuming a daily adult human intake of 2 liters, would
lead, cadmium and copper). give a safety factor of 15,000.

6 Chelating Agent (key-LAY ting) A chemical used to prevent the precipitation of metals (such as copper)
7 Surfactant (sir-FAC-tent) Abbreviation for surface-active agent The active agent in detergent that possesses a high cleaning ability
8 MBAS Methylene-Blue-Active Substances. These substances are used in surfactants or detergents.

530
 Water Quality Regulations 511

22.736 Iron and Manganese 4 The application of chlorine increases the likelihood of
precipitation of manganese at low levels
1. Iron and manganese we frequently found together in
natural waters and pro,.;Ace similar adverse environmen- 5 Unless the precipitate is removed, precipitates reaching
tal effects and color problems. Excessive amounts of iron pipelines will promote bacterial growth
and manganese are usually found in groundwater and in TOXIC EFFECTS
surface water contaminated by industrial waste dis-
charges. 1. Toxic effects are reported as a result of inhalation of
manganese dust or fumes.
2. Prior to 1962, both were covered by a single recommend-
ed limit. 2 Liver cirrhosis has arisen in controlled feeding of rats.
3. In 1962, the U.S Public Health Service recommended
separate limits for both iron and manganese to reflect
more accurately the levels at which adverse effects occur
for each.
4. Both are highly objectionable in large amounts in water
supplies for either domestic or industrial use.
5. Both impart color to laundered goods and plumbing
fixtures
6. Taste thresholds in drinking water are considerably high- 3 Neurological effects have been suggested, however,
er than the levels which produce staining effects. these effects have not been concretely determined.
7. Both are part of our daily nutritional requirements, but NUTRITIONAL REQUIREMENTS
these requirements are not met by the consumption of 1. Daily intake of manganese from a normal diet is about 10
drinking water. mg.

22.737 Iron 2. Manganese is essential for proper nutrition.

3. Diets deficient in manganese will interfere with growth,
The MCL for iron is 0.3 mg/L. blood and bone formation, and reproduction.
UNDESIRABLE EFFECTS
1 At levels greater than 0.05 mg/L some color may develop, QUESTIONS
staining of fixtures may occur, and precipitates may form Write your answers in a notebook and then compare your
2. The magnitude of the staining effect is directly propor- answers with those on page 528.
tional to the concentration. 22.7D Why is chloride a secondary contaminant?
3. Depending on the sensitivity of taste perception, a bitter,
22.7E How does copper usually get into drinking water?
astringent taste can be detected from 0.1 mg/L to 1.0
mg/L. 22.7F Why are corrosive waters undesirable as drinking
water?
4. Precipitates that are formed create not only color prob-
lems but also lead to bacterial growth of slimes and of the 22.7G What is the impact of chlorine on manganese?
iron-loving bacteria, CRENOTHRIX, in wells and distribu-
tion piping. 22.739 Odor
NUTRITIONAL REQUIREMENTS The MCL for odor is a THRESHOLD ODOR NUMBER
1. Daily requirement is one to two mg, but intake of larger (TON)9 of 3. Important facts to remember when dealing with
quantities is required as a result of poor absorption. odors include:

2. The limited amount of iron permitted in water (because of 1. Taste and odor go hand-in-hand
objectionable taste or staining effects) constitutes only a 2 Absence of taste and odor helps to maintain the consum-
small fraction of the amount normally consumed and ers confidence in the quality of their water, even though it
does not have toxicologic (poisonous) significance. doesn't guarantee that the water is safe.

22.738 Manganese 3. Research indicates that there are only four true taste
sensations.
The MCL for manganese is 0.05 mg/L a. Sour,
b. Sweet,
UNDESIRABLE EFFECTS c. Salty, and
1. A concentration of more than 0.02 mg/L may cause d. Bitter.
buildup of coatings in distribution piping.
2. If these coatings slough off, they can car-1 brown
blotches in laundry items and black precipitates.
3. Manganese imparts a taste to water above 0.15 mg/L.

9 Threshold Odor Number (TON). The greatest dilution of a sample with odor-free water that still yields a just detectable odor.
-5

531
 512 Water Treatment

4 All other sensations ascribed to the sense of taste are 6 Tastes may sometimes be detected at 200 mg/L of
actually odors even though the sensation is not noticed sulate, but generally are detected in the range of 300 to
until the material is taken into the mouth. 400 mg/L
5 Odor tests are less fatiguing to_people testing for tastes
and odors than taste tests. 22.742 Total Dissolved Solids (TDS)

6. Taste and odor tests are useful: The MCL for total dissolved solids is 500 mg/L.
a. As a check on the quality of raw° and treated water, UNDESIRABLE EFFECTS
and
b. To help control odor throughout the plant. 1
TDS imparts adverse taste effects at greater than 500
mg/L
7. Odor is a useful test.
a. For determining the effectiveness of different kinds of 2 Highly mineralized water influences the deterioration of
treatment, and disti ibution systems as well as domestic plumbing and
b. As a means for tracing the source of contaminants applia ices (the life of a hot water heater will decrease
one year with each additional 200 mg/L of TDS above a
22.740 pH typi,;a1 200 mg/L value).

The MCL for pH is defined as pH values beyond the 3. Mineralization can also cause precipitates to form in
acceptable range from 6.5 to 8.5 A wide range of pH values boilers and other heating units, sludge in freezing proc-
in drinking water can be tolerated by consumers. esses, rings on utensils and precipitates in food being
cooked.
UNDESIRABLE EFFECTS
4. There may be a great difference between a detectable
1 When the pH increases, the disinfection activity of chlo- concentration and an objectionable concentration of the
rine falls significantly. neutral salts. Many people can become acclimated to
high levels.
2. High pH may cause increased nroduction of chloroform
and other tnhalomethanes during chlorination. 5. Studies show that the temperature of mineralized waters
3 Both excessively high and low pHs may cause increased influences their acceptability to the public.
corrosivity which can in turn create taste problems,
staining problems, and significant health hazards.
22.743 Zinc

4. Metallic piping in contact with low pH water will impart a The MCL for zinc is 5 mg/L.
metallic taste.
UNDESIRABLE EFFECTS
5. If the piping is iron or copper, high pH will cause oxide
1. High concentrations of zinc produce adverse physiologi-
and carbonate compounds to be deposited leaving red or cal effects.
green stains
6. At a high pH drinking water acquires a bitter taste. 2 Zinc imparts z. bitter, astringent taste whir,. i is distinguish-
able at 4 mg/L Also at 4 mg/L a metallic taste will exist
7. The high degree of mineralization often associated with
basic waters results in encrustation of water pipes and 3 Zinc will cause a milky appearance in water at 30 mg/L.
water-using appliances 4. Zinc may increase lead and cadmium concentrations.
22.741 Sulfate 5 The activity of several enzymes is dependent on zinc.

The MCL for sulfate is 250 mg/L 6. Cadmium and lead are common contaminants of zinc
used in galvanizing steel pipe. Even if the MCL of five
UNDESIRABLE EFFECTS AT HIGH LEVELS mg/L of zinc were dissolved from galvanized water pipe,
to produce five mg/L, the cadmium dissolved would be
1. Tends to form hard scales in boilers and heat exchang- less than 0.01 mg/L and the lead dissolved would be less
ers.
than the 0.05 mg/L MCL.
2. Causes taste effects.
..._
3. Causes laxative effect. This effect is commonly noted by ....,

newt'mers or casual or intermittent users of water high

in sulfate. Water containing more than 750 mg/L of
sulfate usually produces the laxative effect while water
with less than 600 mg/L sulfate usually does not An
individual can become acclimated to sulfate in drinking
water.
4. Sodium sulfate and magnesium sulfate are more active
as laxatives, whereas calcium sulfate is less active.
5. When the magnesium content is 200 mg/L, the most
sensitive person will feel the laxative effect, however,
magnesium sulfate levels between 500 mg/L and 1000
mg/L will induce diarrhea in most Lidividuals.

10 When testing raw water, be sure there are no pathogens or toxic chemicals present.

.0.4.
> .
4. 532
 Water Quality Regulations 513

PHYSIOLOGICAL EFFECTS Understanding and implementing each of these steps will

help ensure the success of your operation.
1 A concentration of 30 mg/L can cause nausea and
fainting.
22.81 Initial Sampling
2 Zinc salts act as gastrointestinal irritants. This symptom
of illness is acute and transitory. "Initial sampling" refers to the very first sampling you do
3 The vomit:rig concentration range is 675 to 2,280 mg/L under the SDWA for each of the applicable contaminant
categories When you start and when you complete this
4 A wide margin of safety exists between normal food sampling depends on:
intake and concentrations in water high enough to cause
1. The type of contaminant being monitored,
oral toxicity
2. Whether the system is a community or non-community
water system, and
DIETARY REQUIREMENTS
3. Whether the water source is a surface or groundwater
1. The daily requirement for preschool children is 0 3 mg supply.
Zn/kg of weight.
2. Total zinc in an adult human body averages two grams. The poster inside the back cover of this manual outlines
the Interim Primary Drinking Water Standards and summa-
3. Zinc most likely concentrates in the retina of the eye and rizes the initial sampling program for each contaminant
in the prostate. category (also see Table 22.7 for required sampling pro-
4. Zinc deficiency in animals leads to growth retardation. gram). In column 7 in the poster and column 5 in Table 22.7
as well as in other places, several state options are listed.
You should be familiar with the requirements of your particu-
lar state.
QUESTIONS

Write your answers in a notebook and then compare your 22.82 Routine Sampling
answers with those on page 529. ..outine sampling refers to sampling repeated on a regular
22.7H What are the undesirable effects of abnormal pH basis. Table 22.7 and column 5 on the poster summarize the
values? routine sampling requirements for each contaminant cate-
gory.
22.71 Why are high levels of sulfate undesirable in drinking
water?
22.7J Why are high levels of zinc undesirable in drinking 22.83 Check Sampling
water?
Whenever an initial or routine sample analysis indicates
that an MCL has been exceeded, check sampling is required
to confirm the routine sampling results. Check sampling is in
addition to the routine sampling program. Although check
sampling cannot be scheduled in advance, there are specific
check sampling procedures to follow. The number of sam-
ples, sampling points, and frequency of sampling vary
according to the particular contaminant. For example, 'he
regulations specify that wherever a coliform bacteria check
sample is required, the location from whi,711 the sample was
taken cannot be eliminated from future routine sampling
without prior state approval.
iiIIIIIIIIiiiiilikhilivilqi, III

22.84 Sampling Points

Some of the samples required to determine compliance

with the primary regulations can be taken from the routine
sampling points. By coordinating the present sampling
22.3 SAMPLING PROCEDURES points with the sampling program required by the regula-
tions, additional monitoring costs can be minimized. Table
22.80 Safe Drinking Water Regulations 22.7 summarizes what, where and how often you need to
sample for both community and non-community water sys-
The Safe Drinking Water Act and accompanying regula- tems. The number of sampling points required will depend
tions require that you must take the following actions to on the specific size of the population served and layout of
comply: each water system.
1. Sampling, As noted in Table 22.7, samples for turbidity must be
taken at the points where water enters the distribution
2. Testing, system and samples collected for coliform bacteria. inorgan-
3. Recordkeeping, and ics, organics and radiochemicals must be taken from the
consumers' faucets at representative points within the distri-
4. Reporting. bution system.

5 qi
 514 Water Treatment

TABLE 22.7 REQUIRED SAMPLING

What Testsa What Testsa Where How Oftena How Oftena

(Community (Non- Samples Taken (Community System) (Non-Community System)
System) Commur4y
System)
Inorganics Inorganics (at At the Systems using surface water EVERY All Systems STATE OPTION
state option) consumer's YEAR
faucet° Systems using groundwater only. EVERY
THREE YEARS
Organics Organics (at At the Systems using surface water. EVERY All systems. STATE OPTION
state option) consumer's THREE YEARS
faucet° Systems using groundwater only STA FE
OPTION
Turbidity Turbidity At the point(s) Systems using surface water. DAILY Systems using surface or
where water Systems using groundwater only: STATE surface and groundwater:
enters the OPTION DAILY
distribution Systems using groundwater
system only: STATF OPTION
Coliform Coliform At the Depends on number of people served by All systems: ONE PER
Bacteria Bacteria consumer's the water system (see Appendix at end of QUARTER (for each quarter
faucet° chapter) water is served to public)
Radiochemicals Radiochemicals At the Systems using surface water. EVERY All systems. STATE OPTION
(Natural) (Natural) (at consumer's FOUR YE Ar'S
state option) faucet° System: sing groundwater o ,Iy. EVERY
FOUR YEARS
Radiochemicals Radiochemicals At the Systems using surface water servinc All systems. STATE OPTION
(Man-made) (Man-made) consumer's populations greater than 100,000: EVERY
(at state option) faucet° FOUR YEARS
All other systems. STATE OPTION

a This information is summarized on the poster inside the back cover

b The faucets selected must be representative of conditions within the distribution system.

At the very minimum, a small system (with population of 25

to 1000) must sample for turbidity and coliform bacteria and
also must have two sampling points.
1. One where the water enters the distribution system, and
2 One at a consumer faucet at a representative point in the
distribution system.

QUESTIONS

Write your answers in a notebook and then compare your

answers with those on page 529.
22.85 Sampling Point Selection

22.8A What do the words "Initial Sampling' mean? The two major considerations in determininy the number
and location of sampling points are that they should be:
22.8B What is routine samplina7
1 Representative of each different surface water source
22.8C What is check sampling: entering the system, and
22.8D What are the minimum sampling requirements for a 2. Representative of conditions within the system such as
small system with a population of 100 people? deadends. loops, storage facilities and press' Ire zones.

534
 Water Quality Regulations 515

22.86 Sampling Schedule QUESTIONS

A sampling schedule should be prepared which indicates Write your answers in a notebook and then compare your
all of the samples that will be collected during a yearly answers with those on page 529.
period The schedule should include the following informa- 22.8E List the information that should be included in a
Von sampling schedule.
1 Sampling frequency, 22.8F List the elements necessary to the collection of an
2. Sampling point designation, acceptable sample.

3 Location (address),
4. Type of test.
5. Sample volume, and
6 Special handling instructions.
This schedule should be reviewed with your state health
department to determine adequacy to meet the SD'NA
regulations

22.87 Sampling Route

After selection of the sampling points and preparation of
the sampling schedule, the next step is to select a route.
Arrange your route so that samples that must be analzyed
immediately are not delayed while other sampling is done. 22.9 REPORTING PROCEDURES
Field data forms must be completed by the person doing the
sampling and submitted to the laboratory with the samples. The primary purpose of the SDWA is to protect the
public's health There are two general categories of report-
ing called for by the Act:
22.88 Sample Collection 1 Reporting to the public (public notification), and
Good sampling techniques are the key to a meaningful
2 Reporting to the state
and useful sampling program. The following eight steps are
nece...:ary to the collection of an acceptable sample: There are three types of reports that must be sent to the
state:

1 Obtain a sample that is truly representative of tne existing 1. Routine sampling reports,
condition, 2. Check sample i_ports, and
2 Flush the line before sample collection, 3. Violation reports
3 Fill the sample bottle without leaving any air pocket, Tables 22.9 through 22.21 outline reporting procedures
for various contaminants.
4. Analyze residual chlorine when the sample is taken;

5 Handle and store the sample so that it does not become

contaminated before it reaches the laboratory, 22.10 NOTIFICATION FOR COMMUNITY SYSTEMS
6. Use preservation techniques. These preservation meth- In general, public notification for community systems is
ods are generally. only required in the circumstances shown in Table 22.8.
a. pH control, and
b. Refrigeration;

7 Keep accurate records of every sample collected includ-

ing. TABLE 22.8 PUBLIC NOTIFICATION
a Date and time sampled,
Required Notification
b. Location sampled,
c. Name of sample collected, Type of Violation Mail Newspaper Broadcast
d. Bottle number, Violation of Primary MCL x x x
e. Type of sample, and
f Name of person collecting sample. Any person collect- Failure to comply with x
ing samples should be required to complete a form testing procedure
providing the above information at the time of sample variance or exception
collection. This form should be supplied by the labora granted
tory; and
Monitoring failure
8. Keep the time between the collection of the sample and Compliance schedule not
analysis as short as possible. followed

535
516 Water Treatment

Currently, public notification of violations of the drinking specify the types of notice to be used to provide information
water regulations is cumbersome, but the 1986 Amend- to consumers as promptly and effectively as poss;ble, taking
ments to the Safe Drinking Water Act (SDWA) provide into account both the seriousness of any potential adverse
greater flexibility. The EPA must amend its existing notifica- health effects and the likelihood of reaching all affected
tion regulations within 18 months of enactment and must people.

TABLE 22.9 REPORTING PROCEDURES

INORGANIC CHEMICALS (EXCEPT NITRATE) AND ORGANIC CHEMICALS

LTake Samples

I
/ 1
Lit no MCL is exceeded If one or more MCLs are exceeded
T

Routine
Report this to
reporting the state within
required 7 days

AND

Take three addit onal (check)

samples at same sampling
point within one month Then
determine the average value of
the original and three check
samples

1
If a% age value does If avei'age value
1
not exceed the MCL exceeds the MCL

I
Routine Report this to the
reporting state within 48
required hours

AND

TIZto.; the
1 public

AND

Monitor at the frequency c lsignated by

the state, continuing until a MCL has
not been exceeded in two successive
samples or until a monitoring schedule is
set up as a condition to a variance,
exemption or enforcement action.

Average value =
TOTAL of Original Sample + 3 check samples
4

536
 'Water Quality Regulations 517

TABLE 22.10 REPORTING PROCEDURES NITRATE

I Take Sample

If the MCL 1 If the MCL

is not exceeded is exceeded

I
Rout ne An additional (check)
repo ting sample must be taken
required within 24 hrs.

If the average (mean) of If the average (mean)

original and check of original and check
sample DOES NOT sample does exceed the MCL
exceed the MCL

Report this to the

Rout ne state within 48
repo ting hours
required

1
Notify the
AND

public

AND
1
Monitor at the freluency designated by
the state until the MCL has not
been exceeded in two successive
samples or until a monitoring schedule
is set up as a condition to variance,
exemption, or enforcement action.

537
518 Water Treatment

TABLE 22.11 REPORTING PROCEDURES DAILY TURBIDITY MONITORING

ITake Sample

[ If the sample does I

1
If the sample 1

not exceed 1 TU' exceeds 1 TU'

Routine An additional (check)

reporting sample must be taken
required within 1 hour

If check sample does

not exceed 1 TU'
I

I
TIf check sample
exceeds 1 TU'

Routine [eport this to

reporting the state within
required 48 hours

' MCL of 5 TU may be established at state option

TABLE 22.12 REPORTING PROCEDURES

WHEN CALCULATING TWO-DAY TURBIDITY AVERAGES

Using values from original samples

on days MCL was not exceeded, and
check sample values for days the
MCL was exceeded, calculate the
two-day average'

If the average of two If the average of two

samples taken on consecutive samples taken on consecutive
days does not exceed 5 TU days exceeds 5 TU

I
Routine Report this to
reporting the state within
required 48 hours

AND
I
Notify
t:
the p ublic

' The average is based on the results of samples taken on CONSECUTIVE DAYS.

538
 Water Quality Regulations 519

TABLE 22.13 REPORTING PROCEDURES

WHEN CALCULATING MONTHLY AVERAGE TURBIDITY VALUES

Using values from original samples

on days MCL was not exceeded, and
check sample values for days the
MCL was exceeded, calculate the
average monthly value.

I
I 1

If monthly average IIf monthly average

of the daily samples of the daily samples
does not exceea 1 TU- Iexceeds 1 TU-

i I
E
1 Routine Report this to
[reporting the state within
i equired 48 hours
AND
I
Notify
MCL of 5 TU may be established at state option. I the public

TABLE 22.1'. REPORTING PROCEDURES

MICROBIOLOGICAL CONTAMINANTS MEMBRANE FILTER METHOD

ITake Sample

I
F I
If 4 colonies/100 mL If 4 colonies/100 mL
is not exceeded is exceeded

I
Rout ne At least two consecutive
repo tang daily check samples must
required to taken from the same
sampling point

I
If none of the check If any of the check
samples contain one or samples contain one or
more colonies/100 mL I
more colonies/100 mL

I
Routine rReport this to
reporting the state within
required 48 hours
AND
I
Collect additional check samples
on a daily basis or at a frecuency
established by the state, until the
results obtained from at least 2
consecutive check samples show
less than one coliform colony/100 mL
539
520 Water Treatment

TABLE 22.15 REPORTING PROCEDURES

WHEN CALCULATING MONTHLY MEMBRANE
FILTER RESULTS

I. CALCULATE i
THE MONTHLY Using values from original
AVERAGE samples ONLY,* calculate
VALUE 1 the monthly average value

I i
If the monthly average of If the monthly average of
the daily samples does not the daily samples exceeds
exceed 1 colony/100 mL 1 colony/100 mL

Routine Report this to

1 reporting the state within
I required 48 hours

AND

[-Notify
the public

II. DETERMINE THE

NUMBER OF TIMES Using values from original
4 COLONIES/100 mL samples ONLY, determine the
WAS EXCEEDED number of times 4 colonies/
L 100 mL was exceeded-

I
If the MCL"' If the MCL
is not exceeded is exceeded I

Routine Report this to

reporting the state 1

required 48 hours

I AND

INotify
the public

Check sample values aro not to be used when calculating the monthly average.
For systems taking FEWER THAN 20 SAMPLES PER MONTH, merely count the number of samples exceeding 4 colonies/
100 mL.
For systems taking 20 OR MORE SAMPLES PER MONTH, calculate the percentage of samples exceeding 4 colonies/
100mL.
The MCL states that coliform presence shall not exceed 4 colonies/100 mL in more than one sample 'f fewer than 20 sam-
ples collected per month or 4 colonies/100 mL in more than 5% of the samples if 20 or more are examined per month.

540
 Water Quality Regulations 521

TABLE 22.16 REPORTING PROCEDURES

MICROBIOLOGICAL CONTAMINANTS-MULTIPLE-TUBE FERMENTATION METHOD (10 mL)

I-
1 TakeSample

J 1
If there are fewer If 3 or more tubes
than 3 tubes positive are positive in a
in a single sample single sample

Rout ne At least two consecutive

reportinc daily check samples
required must be taken from the
same sampl, i point

If none of the check If any of the check

samples contain one or samples contain one or
more positive tubes wore positive tubes

Rout ne Report this to

reporting the state within
required 48 hours

AND

Collect additional check samples

on a daily basis or at a frequency
established by the state, until
the results obtained from at least
2 consecutive check samples show
no positive tubes.

d
n
54.11
522 Water Treatment

TABLE 22.17 REPORTING PROCEDURES

WHEN CALCULATING MONTHLY MULTIPLE-TUBE
FERMENTATION (10 mL) RESULTS

I. CALCULATE THE
MONTHLY
171sing values from original
samples ONLY*. calculate the
PERCENTAGE
monthly percentage 1

i
t I
If 1000 or less of the --1 If more than 10% of
tubes for the month are 1
the tubes for the
positive month are positive

T I
Routine 7 1, Report this to
reporting the state within
;

:
required j 48 hours

AND

Notify
the public _,

II. DETERMINE THE

Using values from original
NUMBER OF TIMES
samples ONLY', determine the
3 OR MORE TUBES
number of times 3 or more
WERE POSITIVE
tubes were positive."

If the MCL If the MCL

I is not exceeded is exceeded

1 I
Routine r
1 Report this to
reporting 4th8ehsotautres within 1
required j
AND
1

I Notify
I
[ the public

Check sample values are not to be used when calculating the monthly percentages.
" Foy systems taking FEWER THAN 20 SAMPLES PER MONTH, merely count the number of samples which contained 3 or
more positive portions.
For systems taking 20 OR MORE SAMPLES PER MONTH, calculate the percentage of samples containing 3 or more posi-
tive portions.
The MCL states that not more than 1 sample. may have 3 or more portions positive when fewer than 20 samples :,re exam-
ined per month OR not more than 5% of the samples may have 3 or more portions positive when 20 or more samples are
examined per month.

542
 Water Quality Regulations 523

TABLE 22.18 REPORTING PROCEDURES

MICROBIOLOGICAL CONTAMINANTS CHLORINE RESIDUAL

rake
Daily Sample

If the free chlorine rlf the free chlorine

residual is 0.2 mg/L or residual is less than
greater 0.2 mg/L

Routine IA check sample must be

reporting 1 taken within one hour
required

L
If the check sample If check sample irdicates that
indicates that the free the free chlorine residual is
chlorine residual is 0.2 less than 0.2 mg/L
mg/L or greater

Report this to
Routine the state within
reporting 48 hours
[ required
AND

Take a sample for coliform

bacterial analysis from
that sampling point,
preferably within one hour

AND

I
Report the results of the 1

conform test to the state

within 48 hours

-I
> -...
.
543
524 Water Treatment

TABLE 22.1 i REPORTING PROCEDURES

RADIOLOGICAL CONTAMINANTS NATURAL
(Test for gross alpha activity)

Take quarterly samples

or composite quarterly

Average the results' 1

I
If gross alpha If gross alpha If gross activity is
activity is activity is greater OR greater than 15 pCi/L
5 pCi/L or less than 5 pCi/L

I I
J
Report this to
Rout ne Lab must test the state within
reporting for radium 226 48 hours
required
AND
1

I I Notify the
If radium 226 If radium 226 public
is 3 pCi/L or is greater than
less 3 pCi/L

1 L
Rout ne I Lab must rest for 1

reporting I radium 228

...1
required

r
I
If radium 226 + raditor-. 228
i r[If radium 226 I
+ radium 228 1
L is 5 pCi/L or less I
J Lis
is greater than 5 pCi/L
J

I
r Routine 1I
L
[Report this to the
i
reporting state within 48 hours
j
1 1

IL required
AND

Notify
the public

AND

Monitor at quarterly intervals

until the annual average concen-
tration no longer exceeds the
MCL or until a monitoring
schedule is set up as a condition
to a variance, exemption or
enforcement action.

Average = Sum of four values

4
No averaging is required if the quarterly samples were composted. In that case, use the results of the single sample.
This step is required only for the initial monitoring period and not for routine monitoring, EXCEPT AS REQUIRED BY THE
STATE.

544
 TABLE 22.20 REPORTING PROCEDURES
RADIOLOGICAL CONTAMINANTS MAN-MADE

(Applicable Only to Surface Water Systems Serving Populations of 100,000 or More)

I
Take quarterly samples Average the Compare the results with the
or composite quarterly results' following limits:
Gross beta 50 pCi/L
Strontium 90 8 pCi/L
Tritium 20,000 pCi/L

i 1

If none of the If gross beta is If either tritium If tritium and

three limits are greater than or strontium 90 strontium 90 are
exceeded 50 pCi/L limits are exceeded BOTH present in
the sample in any
I I I concentration
Routine An analysis of the sample must IReport this to
repor.ing be performed to identify the the state within I
required major radioactive constituents 48 hours Calculate the sum
present. The appropriate organ of annual dose
and total body doses must be AND equivalents to bone
calculated tc Jetermine whether Notify
marrow
the 4 mrem/yr MCL is exceeded- the public
1

1
I
If no total body or If any total body or
If the sum of annual If the sum of annual
individual organ doses individual organ
dor q equivalents to dose equivalents to
exceed 4 mrem/yr doses exceed 4 mrem/yr bone marrow does not bone marrow exceeds
exceed 4 mrem/yr 4 mrem/yr
1 I
Rout ne Report this to the I I
reporting state within 48 hours Routine Report this to the
required reporting state within 48
AND
1
required hours
Notify
the public AND
I
Notify she public

Average = Sum of four values

4
No averaging is required if the quarterly samples wide composited. In that case, use the results of the single sample.
It is likely that the laboratory will not make these calculations. You will probably have to get help from state water supply personnel in making these calculations.
545
546
526 Water Treatment

TABLE 22.21 REPORTING PROCEDURES TOTAL TRIHALOMETHANES

(ApplicaOle to Community Surface Water Systems
Serving Populations of 10,000 or More)

4 samples per quarter,

report arithmetic
average to State within
30 days

After completing
one year sampling

SURFACE WATER SYSTEM, GROUNDWATER SYSTEMS

can be reduced to a can be reduced to one
minimum of 1 sample/ MAXIMUM TTHM POTENTIAL
quarter per year for each treatment
plant

Calculate running
,nnual average MCL Change of source I yes
quarterly of water or treatment
program

yes ino I no
If Avg>MCL
no no
any sample any sample
no >0.10 mg/L mg/L

Report to state and/or I yes yes

EPA within 30 day.. of
receipt of results Take check sample
promptly

If check sample
positive
Notify State yes
within 48 hours

Notify public
Monitor at the frequency
designated by the State

Send copy of
notice to State

MCL.
Total thhalomethanes (the sum of
the concentrations of
bromodichloromethane,
dibromochloromethzne,
tribromomethane (bromoform) and
trichioromethane (chloroform))
0.10 mg/L

54 7
 Water Quality Regulations 527

QUES JNS 22.10A If an MCL is violated, what is the required public

notification?
Write your answers in a notebook and then compare your
answers with those on page 529.
22.9A What are the two general categories of reporting
called for by the SDWA? eta. of 1444gitt,2442 1..44apo
22.9B What are the three types of reports that must be sent
to the state9 MINKINO Wee a:411, 110W

DISCUSSIO.; AND REVIEW QUESTIONS

Chapter 22. DRINKING WATER REGULATIONS
(Lesson 2 of 2 Lessons)

Write the answers to these questions in your notebook 15. Why is the aLtEence oi tastes and odors in drinking
before continuing with the Objective Test on page 530. The water import-it?
problem numbering continues from Lesson 1.
16. Why are high levels of total dissolved solids undesirable
9. Why is there a prime y drinking water standard for in drinking water?
turbidity?
17. Why wasn't hydrogen sulfide listed under the Secon-
10. What are the most common sources of organic contami- dary Drinking Water Standards?
nation if drinking water?
11. What do secondary drinking water regulations control? 18. How is the number of sampling points determined?

12. Why are secondary drinking water regulations impor- 19. What are the major considerations in determining the
tant? number and location of sampling points?
13. How may color be caused in water?
20. How is a sampling route selected?
14. Why are iron and manganese undesirable in drinking
water? 21. How can samples be preserved?

SUGGESTED ANSWERS
Chapter 22. DRINKING WATER REGULATIONS

ANSWERS TO QUESTIONS IN LESSON 1 5. Prohibition of thr use of lead products in materials

Answers to queLtions on pr le 496. used to convey orinking water.

22.0A The first 0; inking water standards were designed to 22.1B Water systems will not be required to meet Phase I
control waterborne bacteria and viruses that can regulations until two-and-a-half years after the law
cause diseases such as cholera, typhoid, and dysen- was passed because the Act requires promulgation
tery. of regulations within 12 months and an additional 18
months must be given for the states to adjust their
22.1A The major aspects of the 1986 Amendments to the own regulations.
SDWA include:
Answers to questions on page 498.
1. Compulsory revisions to the regulations for new
contaminants, 22.2P. Trihalomethanes (THMs) are the product of chlorine
combining with organic material in the water; they are
2. Definition of an approved treatment technique for suspected carcinogens.
each regulated contaminant,
22.3A The draft Surface Water Treatment Rule (SWTR)
3. Filtration requirement for surface water supplies, specifically requires that
4. Disinfection of all water supplies, and 1. All r lace water systems must disinfect,

t, x L.7)
528 Water Treatment

2. M surface water systems must filter unless they 22.6F Trichloroethylene (TCE) has been widely used as an
meet source water quality criteria and site-specific ingredient in many household products (spot remov-
conditions, ers, rug cleaners, air fresheners), dry cleaning
3. All systems will need to achieve the removal or agents, industrial metal cleaners and polishes, refrig-
inactivation criteria of Giardia and enteric viruses, erants, and even anesthetics.
and
22.6G The monthly average turbidity MCL may not exceed
4. Only qualified operators will be entitled to operate 1 TU. At state option this may be raised to 5 TU.
the systems. Some states require 0.5 TU where there is a major
hazard of wastewater (sewage) contamination of the
22.3B A water utility can avc I mandatory filtration by water supply.
meeting (1) source water quality criteria (coliforms
and turbidity levels), and (2) certain site-specific
conditions regarding disinfection, watershed control, Answers to questions on page 508.
lack of waterborne disease outbreaks, compliance 22.611 EPA is considering tha creation of MCLs for Giardia,
with coliform MCL, and total THM MCL. viruses, standard plate count, and Legionella.
Answers to questions on page 500. 22.61 For water systems that regularly take 10 or fewer
22.4A A community water system is defined as follows: samples per month, ONE positive sample may be
discarded ii:
1. Has at least 15 service connections used by all-
year residents, or 1. The system chlorinates and maintains a residual,
2. Services at least 25 all-year residents. 2. The system takes two check samples on consecu-
tive days, and
22.5A The five types of primary contaminants which are
considered to be of public health importanc3 are: 3. This exclusion has NOT been used in the previous
month.
1. Inorganid contaminants,
22.6J The MCLs for radiological contaminants are divided
2. Organic contaminants, into two categories: (1) natural radioactivity which
3. Turbidity, results from well water passing through deposits of
naturally occurring radioactive materials; and (2)
'4. Microbiological contaminants, and man-made radioactivity such as might result from
industrial wastes, hospitals or research laboratories.
5. Radiological contaminants.
22.5B Nitrate in drinking water above the national standard Answers to questions on page 509.
poses an immediate threat to children under three
months of age. In some infants, excessive levels of 22.7A Secondary drinking water regulations are enforce-
nitrate have been known to react with intestinal able after a state has passed a law requiring the state
bacteria which change nitrate to nitrite which reacts health agency to enforce the regulations.
with hemoglobin in the blood to produce an anemic 22.7B The secondary drinking water contaminants include:
condition commonly known as "blue baby."
1. Chloride 8. Manganese
ANSWERS TO OW 'e T IN LESSON 2
2. Color 9. Odor
Answers to questions on page J04.
3. Copper 10. pH
22.6A Inorganic chemicals Pre metals, salts, and other
4. Corrosivity 11. Sulfate
chemical compounds that do not contain carbon.
5. Foaming Agents 12. Total Dissolved Solids
22.6B Arsenic is listed as a primary contaminant because
water that continuously exceeds the national stan- 6. Fluoride 13. Zinc
dard by a substantial amount over a lifetime may
cause fatigue and loss of energy. Extremely high 7. Iron
levels can cause poisoning.
22.7C Contaminants in the secondary regulations should
22.6C At levels of 6 to 8 mg /!_ fluoride may cause skeletal be monitored at intervals no less frequent than the
fluorosis which is a brittling of the bones and stiffen- monitoring performed for inorganic contaminants
ing of tie joints. At levels of 2 mg/L and greater listed in the Interim Primary Drinking Water Regula-
fluoride may cause dental fluorosis which is discolor- tions or applicable to community water systems.
ation and mottling of the teeth, especially in children. More frequent monitoring would be appropriate for
specific contaminants such as pH, color, odor or
22.6D Lead may enter drinking water from galvanized others under certain circumstances as directed by
pipes, solder used with copper pipes, and through the state.
the air from auto exhausts.
Answers to questions on page 505. Answers to questions on page 511.
22.6E Organic chemicals are either natural or synthetic 22.7D Chloride is a secondary contaminant because it
chemical compounds that contain carbon. Synthetic affects the aesthetic quality of water by imparting an
organic chemicals (SOCs) are man-made com- objectionable salty taste in water and because it
pounds that are widely used as pesticides, paints, causes corrosion of the pipes in hot water and other
dyes, solvents, plastics, and food additives. systems.

543
 Water Quality Regulations 529

22.7E Copper usually gets into drinking water from the 22.8C Whenever an initial or routine sample analysis indi-
reaction of aggressive water on copper plumbing. cates that an MCL has been exceeded, CHECK
SAMPLING is required to confirm the routine sam-
22.7F Reasons why corrosive waters are undesirable as pling results. Check sampling is in addition to the
drinking water include: routine sampling program.
1 Affects the aesthetic quality (turbid waters), and
causes taste and odor problems .n the water
supply; 22.8D At the very minimum, a small system with a popula-
2. Has serious economic impact (loss of piping sys- tion of 100 people must sample for turbidity and
tems and water loss from leaks); and coliform bacteria and also must have two sampling
3. Presents health implications (toxic corrosion points.
products such as lead, cadmium and copper). 1 One where the water enters the distribution sys-
tem, and
22.7G The application of chlorine to waters containing 2 One at a consumer faucet at a point representa-
manganese increases the likelihood of precipitation tive of the distribution system.
at low levels. Unless the precipitate is removed,
precipitates reaching pipelines will promote bacterial
growth. Answers to questions on page 515.

22.8E Information that should be specified in a sampling

Answers to questions on page -13. program includes:
1. Sampling frequency,
22.7H The undesirable effects of abnormal pH values in- 2. Sampling point designation,
clude: 3. Location,
1. When the pH increases, the disinfection activity of 4 Type of test,
chlorine falls significantly; 5. Sample volume, and
2. High pH may cause increased halogen reactions, 6. Special handling instructions.
which produce chloroform and other trihalometh-
anes during chlorination;
3 Both excessively high and low pHs may cause 22.8F The following elements are necessary to the cc lee-
increased corrosivity which can in turn create tion of an acceptable sample:
taste problems, staining problems, and significant 1 Obtain a sample that is truly representative of toe
hea' hazards; existing condition,
4. Metallic piping in contact with low pH water will 2. Flush the line before sample collection,
impart a metallic taste; 3. Fill the sample bottle without leaving any air
5. If piping is iron or copper, oxide and carbonate pocket,
compounds will be deposited leaving red or green 4. Analyze residual chlorine when the sample is
stains; taken,
6. At high pH, drinking water acquires a bitter taste, 5. Maintain the sample so that it does not become
and contaminated before it reaches the laboratory,
7. The high degree of mineralization often associat- 6. Use preservation techniques (pH control and re-
ed with basic waters results in encrustation of frigeration),
water pipes and water-using appliances. 7. Keep accurate Jcords of every sample collected
(date, time, location, name of sample, bottle num-
ber, type of sample, and name of person collect-
22.71 High levels of sulfate are undesirable because they: ing sample), and
1. Tend to form hard scales in boilers and heat 8. Keep the time between the collection of the sam-
exchangers, ple and analysis as short as possible.
2. Cause taste effects, and
3. Cause a laxative effect.
Answers to questions on page 527.
22.7J High levels of zinc are undesirable in drinking water
because they:
1 Produce adverse physiclogical effects, 22.9A The two general categories of reporting called for by
2. Impart undesirable tastr, ), the SDWA are:
3. Cause a milky appearance in the water, and 1. Peporting to the public (public notification), and
4. May increase lead and cadmium concentrations. 2. Reporting to the state.

Answers to qt.estions on page 514. 22.9B The three types cf reports that must be sent to the
state are:
1. Routine sample rer,orts,
22.8A "Initial Sampling' refers to the very first sampling you 2. Check sample reports, and
do under the Safe Drinking Water Act for each of the 3. Violation reports.
applicable contaminant categories.

22.8B Routine sampling refers to sampling repeated on a 22 10ARequired public notification for the violation of an
regular basis. MCL includes mail, newspaper and broadcast.
539 Water Treatment

OBJECTIVE TEST
Chapter 22. DRINKING WATER REGULATIONS

Please write your name and mark the correct answers on 11 Maio taste e1fccts in water are produced by cations.
the answer sheet as directed at the end of Chapter 1. There
1 Tn. e
may be more than one correct answer to the multiple choice
questions. 2 False

12 The level of color in water is a measure of the safety of

TRUE-FALSE
water
1 All public water systems must comply with the regula- True
tions of the Safe Drinking Water Act 2 False
1 True
2. False 13 Rapid changes in color levels may produce more citizen
complaints than relatively high, constant color levels.
2 MCLs apply only to contaminants from man-mac 1 True
Lion. 2 False
1. True
2. False 14 EPA drinking water regulations are called "interim" regu-
lations because research continues on drinking water
3. More types of contaminants nust be monitored by non- contaminants.
community than community systems. 1 True
1 True 2 False
2. False
15 Taste tests are less fatiguing than odor tests.
4. MCLs have beer established to indicate when a con- 1 True
form concentration could indicate the likely presence of 2 False
disease-causing bacteria.
1. True 16 If a water doesn't have any taste or odor, then it is safe
2. False to drink
1 True
5 Monitoring for natural radioactivity is required onlY for 2 False
groundwater community systems.
1. True 17 Consumers can tolerate a wide range of pH values in
2. False drinking water
1 True
6. The concerns with inorganic chemicals in drinking water 2 False
are centered on cancer.
1. True 18 At low pH levels drinking water acquires a bitter taste.
2 False 1 True
2 False
7 Conform bacteria in water are used to indicate the
potential presence of pathogens 19 Samples should be collected from consumers' faucets
1. True which are representative of conditions within the distri-
2. Feist bution system.
1. True
8. Barium can enter drinking water through natural 2 False
sources in the environment or industrial waste dis-
charges 20 Check sampling is part of the toittine sampling program.
1. True 1 True
2. False 2 False
21 When samples are delivered to the lab, lab personnel
9 The health risk from mercury is greater from waterborne must complete the field data forms upon acceptance of
mercury than simply from eating fish. the samples.
1 True 1 True
2 False 2 False
10 Secondary drinking water regulations are federally en- 22 The primary purpose of the Safe Drinking Water Act is
forceable to protect the public's health.
1 True 1. True
2. False 2. False

551
 Water Quality Regulations 531

23 Sampling points must include representative locations 32. The Safe Drinking Water Act gave the U.S. Environmen-
of each different water source entering the system tal Protection Agency the authority to
1. True 1. Establish uniform guidelines of drinking water tech -
2 False Ilogies.
2. iss.i3 NPDES permits to water purveyors.
24 Sample lines should be flushed before collecting a 3. Promulgate pretreatment effluent standards for
sample POTWs.
1. True 4. Require monitoring and reporting for public water
2 False systems.
5. Set national standards for regulating levels of conta-
25 Failure to comply with a testing procedure requires minants in drinking water.
notification of consumers by newspaper
1 True
2 False 33. The draft Surface Water Treatment Rule (SWTR) re-
quires that a disinfection residual of mg/L in 95
percent of the samples be maintained.
1. 0.2
MULTIPLE CHOICE 2. 0.5
3. 1.0
26. The regulations of the Safe Drinking Water Act which 4. 2.0
operators must deal with extensively include 5. 5.0
1 Maximum Contaminant Levels.
2. Reporting requirements. 34. Substances for which drinking water standards have
3. Sampling and testing requirements. been set and which pose an immediate threat to health
4. Siting requirements. whenever the standards are exceeded include
5. Variations in the regulations.
1. Arsenic.
27 Types of primary contaminants which are considered to 2. Co !dorm bacteria.
be of public health importance include 3. Lead.
4. Mercury.
1. Corrosivity contaminants. 5. Nitrate.
2. Foaming contaminants.
3. Inorganic contaminants.
4. Microbiological contaminants. 35. Arsenic is commonly found in
5 Turbidity
1. Beverages.
2. Candy.
28. Contaminants which may affect public health after a 3. Food.
short-term exposure include 4. Shellfish.
1. Microbiologica contaminants. 5. Tobacco.
2. Nitrate.
3 Organic chemicals.
4. Radiological chemicals. 36. Cadmium can enter drinking water from
5. Tnhalomethanes.
1. Canneries.
The MCLs for organic chemicais presently include 2. Electroplating.
3. Insecticides.
1. Herbicides. 4. Metallurgy
2. Oils. 5. Photographic processes.
3 Pesticides.
4. Solvents.
5 Tnhalomethanes.
37. Water with a high color content may indicate
30. The MCL established for total trihalomethanes (TTHMs) 1 High disinfection demand.
is 2 High organic chemical contamination.
1. 0.1 micrograms per liter. 3. High pH.
2. 1.0 microgram per liter. 4. Iradequate treatment.
3. 0.10 milligrams per liter. 5. Potential for production of excess amounts of disin-
4. 1.0 milligram per liter. fection by-products.
5. 10 milligrams per liter.

31. A state may allow a water utility to reduce the frequency 38. Reasons why copper is undesirable in drinking water
of sampling for THMs after taking into consideration include
1. Age of persons living in community. 1. Causes blue or green staining of porcelain.
2. Health of community. 2. Imparts some taste to water.
3. Level of natural organics in water. 3. Kills algae.
4. Quality and stability of raw water. 4. Results in liver damage after prolonged doses.
5. Type of treatment. 5. Stains blond hair.

:552
532 Water Treatment

39. True taste sensations include 44. Samples should be collected at the consumers' faucet
1. Bitter. for which of the following contaminants?
2. Rotten. 1. Coliform hacterta
3. Salty 2 Inorganics
4 Sour. 3. Organics
5. Sweet. 4. Radiochemicals
5. Turbidity
40. Undesirable effects from high levels of sulfate in drink-
ing water include causing 45. Community systems must sample for radioctornicals
1. Formation of hard scales in boilers and heat ex- every
changers. 1. Six months.
2. Laxative effects. 2 Year.
3. Precipitation of calcium sulfate. 3 Two years.
4. Taste effects. 4. Three years.
5. Undesirable odors in water. 5 Four years.
41 High levels of total dissolved solids are undesirable in 46. To collect an acceptable sample you must
drinking water because they cause
1. Flush the line before sample collection.
1. Adverse tastes. 2. Keep the time between sample collection and analy-
2 Deterioration of distribution systems. sis as long as possible.
3. Precipitates to form in boilers. 3. Obtain a sample truly representative of the existing
4. Sludge in freezing processes condition.
5. Water to be reused more often. 4. Use preservation techniques.
5. Use the proper reporting form.
42. Which of the following actions are required of operators
by the Safe Drinking Water Act?
1. Organizing
2. Recordkeeping
3. Reporting
4. Sampling
5. Testing

43. When you start and when you finish your "Initial Sam-
pling'. program depends on
1. Available budget.
2. Option exercised by state.
3. Type of contaminant being monitored.
4. Whether the system is a community or non-commu-
nity water system.
5. Whether the water source is a surface or a ground-
water supply. eta of ObjeetiwIt

553
 Water Quality Regulations 533

APPENDIX
Coliform Samples Required Per Population Served
Minimum Number of Minimum Number of
Population Served Samples per Month Population Served Samples per Month
25 to 1,000 1t 90,001 to 96,000 95
1,001 to 2,500 2 96,001 to 111,000 100
2,501 to 3,300 3 111,001 to 130,000 110
3,301 to 4,100 4 130,001 to 160,000 120
4,101 to 4,900 5 160,001 to 190,000 130
4,901 to 5,800 6 190,001 to 220,000 140
5,801 to 6,700 7 220,001 to 250,000 150
6,701 to 7,600 8 250,001 to 290,000 160
7,601 to 8,500 ... ................... 9 290,001 to 320,000 170
8,501 to 9,400 10 320,001 to 360,000 180
9,401 to 10,300 11 360,001 to 410,000 190
10,301 to 11,100 12 410,001 to 450,000 200
11,101 to 12,000 13 450,001 to 500,000 210
12.001 to 12,900 14 500,001 to 550,000 220
12,901 to 13,700 15 550,001 to 600,000 230
13,701 to 14,600 16 600,001 to 660,000 240
14,601 to 15,500 17 660,001 to 720,000 250
15,501 to 16,300 18 720,001 to 780,000 260
16,301 to 17,200 19 780,001 to 840,000 270
17,201 to 18,100 20 840,001 to 910,000 280
18,101 to 18,900 21 910,001 to 970,000 290
18,901 to 19,800 22 970,001 to 1,050,000 300
19,801 to 20,700 23 1,050,001 to 1,140,000 310
20,701 to 21,500 24 1,140,001 to 1,230,000 320
21,501 to 22,300 25 1,230,001 to 1,320,000 330
22,301 to 23,200 26 1,320,001 to 1,420,000 340
23,201 to 24,000 27 1,420,001 to 1,520,000 350
24,001 to 24,900 28 1,520,001 to 1,630,000 360
24,901 to 25,000 29 1,630,001 to 1,730,000 370
25,001 to 28,000 30 1,730,001 to 1,850,000 380
28,001 to 33,000 35 1,850,001 to 1,970,000 390
33.001 to 37,000 40 1,970,001 to 2,060,000 400
37,001 to 41,000 45 2,060,0014o 2,270,000 410
41,001 to 46,000 50 2,270,001 to 2,510,000 420
46,001 to 50,000 55 2,510,001 to 2,750,000 430
50,001 to 54,000 60 2,750,001 to 3,020,000 440
54,001 to 59.000 65 3,020,001 to 3,320,000 450
59,001 to 64,000 70 3,320,001 to 3,620,000 460
64,001 to 70 000 75 3,620,001 to 3,960,000 470
70,001 to 76,000 80 3,960,001 to 4,310,000 480
76,001 to 83,000 85 4.310,001 to 4,690,000 490
83,001 to 90,000 90 More than 4,690,001 500
Source: EPA
t . I community water system serving 25 to 1,000 persons, with written permission from the state, may reduce this sampling frequency, ex-
cept in no case sh ill it be reduced to less than one per quarter The decision by the state will be based on a history of no coliform bacte-
rial contamination for that system and on a sanitary survey by the state showing the water system to be supplied solely by a protected
groundwater source. free of sanitary defects.

554
i
 CHAPTER 23

ADMINISTRATION

by
Tim Gannon

Revised
by
Jim Sequeira

555

IM.
536 Water Treatment

TABLE OF CONTENTS
Chapter 23. Administration

Page
OBJECTIVES 538
23.0 Office Procedures 539
23.00 Budgeting 539
23.01 Water Rates 540
23.02 Procurement of Material 541
23.03 Treatment Plant Records 543
23.030 Purpose of Records 543
23.031 Types of Records 543
23.032 Types of Plant Operation Data 544
23.033 Maintenance Records 544
23.034 Inventory Records 544
23.035 Equipment Records 545
23.036 Disposition of Plant Records 545
23.04 Organizational Planning 545
23.1 Personnel Administration 547
23.10 Supervision 547
23.11 Staffing 547
23.12 Training 548
23.13 People 548
23.14 Operator Certification 549
23.140 Need for Certified Operators 549
23.141 Why Should Water Utility Operators re Certified? 549
23.1410 Safety 549
23.1411 F lotion of the Public's Investment 549
23.1412 Employee Pride and Recognition 549
23.142 ABC 549
23.2 Public Relations 549
23.20 Establish Objectives 549
2321 Utility Operation 549
23.22 The Mass Media 550
23.23 Being Interviewed 550

556
 Administration 537

23.24 Public Speaking 550

23.25 Telephone Contacts 551

23.26 Customer Inquiries 551

23 27 Plant Tours 551

23.3 Emergency Planning 552

23.4 Handling the Threat cif Contaminated Water Supplies 553

23.40 '^-iiance 553

23.41 Toxicity 553

23.42 Effective Dosages 554

23.43 Protective Measures 554
23.44 Emergency Countermeasures 554
23.45 In Case of Contaminiation 555

23.5 Additional Reading 556

Discussion and Review Questions 556

Suggested Answers 557

Objective Test 559

557
538 Water Treatment

OBJECTIVES
Chapter 23. ADMINISTRATION

Following completion of Chapter 23, you should be able

to.

1. Organize the general operation, maintenance and admin-

istrative activities of a water utility,
2. Explain the importance of and need for operator certifica-
tion,
3. Develop and implement a public relations program,
4 Prepare a contingency plan for emergencies,
5. Collect, organize, file, retrieve, use and dispose of plant
records, and
6. Successfully operate and maintain the water supply and
water treatment facilities of your utility agency.
 Administration 539

CHAPTER 23. ADMINISTRATION

Administering the operation and maintenance of a water

treatment plant involves more than just the technical aspects
of plant operations. Supervision, recordkeeping, emergency
planning, public relations, and ordering supplies, for exam-
ple, ars all necessary parts of the overall operation of a
water treLanent plant facility. Whether an individual is a chief
operator or novice, he or she should at least have a general
idea of the administrative procedures associated with treat-
ment plant operations.
23.0 OFFICE PROCEDURES
23.00 Budgeting
Budgeting is the art of predicting the amount of money
necessary to achieve an organization's goals. Preparation In preparing a budget, value judgments mu::: be made
of a budget requires effective planning. Planning and bud- about Cie efficiency of your operations. You should con-
geting are both essential administrative functions. Planning stantly re-evaluate your operating procedures to consider
identifies your goals, and budgeting identifies how much more efficient use of personnel and materials. When making
money is needed to achieve these goals. these value judgments. examine how better operating re-
sults can be attained through more efficient operating proce-
Planning involves designing programs, setting goals and dures. In examining personnel requirements. determine if
objectives, and making basic policy decisions for the organi- personnel could be reassigned to perform more tasks more
zation as a whole. Budgeting, on the other hand, involves efficiently Look for ways to reduce the expenses for power
analyzing the many functions that the organization must and fual. All phases of your operation and maintenance
perform to implement each program. Table 23.1 illustrates should be carefully examined to prepare an accurate and
the relationship between planning and budgeting. Notice realistic budget. Failure to do so will generally result in waste
that a third component, evaluation, is needed to determine and inefficiency. Preparation of the budget should not be
whether the goals and plans that have been set are reason- viewed as a paper exercise but as a means of achieving
able and achievable in terms of the money available. Ideally, specified goals. improving performance standards, and rais-
these three components form a dynamic process in which ing the quality of services to your community.
your goals and the budget are periodically reviewed and
revised to reflect a realistic assessment of your organiza- Budget preparation should be a group project and effort.
tion's priorities and financial resources. Preparing a budget with staff involvement will create an

TABLE 23.1 PLANNING AND BUDGETING RELATIONSHIP

PLANNING
Establishes plans and BUDGETING EVALUATION
programs Determines costs to Tests budget against plan
Sets goals and objectives achieve plans Determines tradeoff between
Makes basic policy decisions goals and costs

Revisions

Periodic Review Foal

Budget and
Operating Plan I

559
540 Water Treatment

atmosphere of interest and a feelinc of active participation in 23.01 Water Rates

one of the most important annual activities of a water utility.
Staff personnel can actively participate in the budget pro- The process of determining the cost of water and estab-
cess by providing information on operating requirements. lishing a water rate schedule for customers is a subject of
Moreover, new programs, positions, and equipment that are much controversy. There is no single set of rules for
contemplated should be thoroughly researched and justified determining water rates. The establishment of a rate sched-
by staff to facilitate the budgetary process. ule involves many factors including the form of ownership
(investor or publicly owned), differences in regulatory control
For large and small utilities alike, the amount of anticipat- over the water utility (state commission or local authority),
ed income is also an important factor in budgeting. Using the and differences in individual viewpoints and preferences
previous year's budget and actual income for that year can concerning the appropriate philosophy to be followed to
give you a good idea of what program increases might be meet local conditions and requirements.
feasible for the future.
After the budget is approved, it should be reviewed by
staff members who have budget-related responsibilities to
give them a clear understanding of the organization's finan-
cial constraints for the upcoming year.
An excellent too! to help you control and monitor the
crganization's operations is the monthly budget status re-
port. It is good management practice to compare expendi-
tures with budgeted amounts at frequent regular intervals.
Also evaluate your present financial status in terms of the
amount of the year that has passed and the pace of
expenditures. Figure 23.1 is an example of a budget status
report. A prudent administrator will a:ways take care to
thoughtfully analyze expenditures so that the budget is not
exceeded.
CURRENT
MODIFIED ENCUMBERED EXPENDED TOTAL UNOBLIGATED
NAME BUDGET AMOUNT AMOUNT OBLIGATIONS AMOv-T PERCENT USED
4252 ENGR & ARCH 5,000 30,565 4,434 34,999 -29,999 *41***
4258 OTR PROF SvC 93,500 37,5)4 37,514 55;985
4260 INTDEP ALLOC 244,407 0 81,469 81,469 162,938 33.33
4261 TRANSPORTNT 1,500 0 547 147 5,353 9.80
4262 (EA': 700 0 21 21 679 3.00
4263 LODGING 5,500 0 54 54 1,446 3.60
4270 MBR FEES 4,200 0 3,179 3,179 5,020 75.70
4271 NEWSPAPERS 200 0 307 307 -507 *****
4272 REGIST & TUT 5,000 0 659 659 4,341 13.18
4276 AUTO ALLOW 5,800 0 750 750 1,050 41.67
7123qtUMP LIAB EX 124.060 0 0 0 524,000 .00
4292 PROP INS PRE 87,600 0 0 0 87,600 .00
4293 CRIM INS 141411 400 0 0 0 400 .00
-4321 BANK FEES 5.000 563 563 436 56.34
4376 CONTR TYPE i 130,000 0 3,450 3,450 126,550 2.65
4405 CHEM & GASES 0 0 4 4 -4 .00
4403-FOOD-(HUMAi0 0 T7- 13/ -I .00
4451 OFC SF'Y & mT 2,200 0 2,088 2,088 111 94.93
4412 EUGR & DRFT 200 200 0 200 0 *it.**
4422 JANITORIAL -200- 0 6Y 69 530 34 72
4431 SAFETY EQUIP 0 0 3 3 -3 .00
4433 PHOTO SUPPLY 50 64 64 -14 ****,
4435 AUDIO/VISUAL 5,000 0- 4y 4.Yt
4443 ELECT SUPPLY 0 0 38 38 -38 .00
4453 BOOKS & PmPL 300 0 99 99 200 33.31
4461SMAE-TOOLY-- 6-,140 531-- 5,906 3,/02 sy.fu
4462 COMPTR SUPLY 4,395 476 1,560 2,037 2,357 46.35
4471 CONSTR SUPL 0 0 7 7 -7 .00
4481-VEHCLE ACCES -0 0 3 -J .00

CLASS SUBTOTAL :S.;

777,292 40,016 15807 1957824 --581,467 25719-
4630 MACH & EQUP 21,765 0 13,681 13,681 8,084 62.86
4632-NEW '57HICLES 9.000 3- -0 0 '97000 .00

CLASS SUBTOTAL 4FA

30,765 0 -137685 173-,76181 177884 44.47
4710 CIP LBR REIM 0 0 -978 -978 978 .00

CLASS SUBTOTAL 5CP

0 0 -978 -978 978 .00
DRG-TOTAIL "3151-- 5-,556-,010 40,016 4287594------468,611 1,0877398 30.12

Fig. 23.1 Budget status report

560
 Administration 541

Generally, the development of water rate schedules in- below the reorder point, a new item is added to stock, or an
volves the following procedures: item has been requested that is not stocked. Most organiza-
tions require employees to submit a requisition (similar to
A determination of the total revenue requirements for the
the one shown in Figure 23.2) when they need to purchase
period that the rates are to be effective (usually one equipment or supplies. When the requisition has been
year).
approved by the authorized person (a supervisor or pur-
A determination of all the cost components of system chasing agent, in most cases) the items are ordered using a
operations. That is, how much does it cost to treat the form called a purchase order. A purchase order contains a
water? How much does it cost to distribute? How much number of important items. These items include: (1) the date,
does it cost to install a water service to a customer? How (2) a complete description of each item and quantity needed,
much are administrative costs? (3) prices, (4) the name of the vendor and (5) a purchase
order number.
Distribution of the various component costs to the var-
ious customer classes in accordance with their require- A copy of the purchase order should be retained in d
ments for service. suspense file or on a clipboard until the ordered items arrive.
This procedure helps keep track of the items that have been
The design of water rates that will recover from each ordered but have not yet been received.
class of customers, within practical limits, the cost to
serve that class of customers. All supplies should be processed through the storeroom
immediately upon arrival. When an item is received it should
Sales of water to customers may be metered or unme- be so recorded on an inventory card. The inventory card will
tered In the case of metered sales, the charge to the keep track of the numbers of an item in stock, when last
customer is baseri on a rate schedule applied to the amount ordered, cost, and other information. Furth6rnore, by al-
of water used through each water meter. If meters are not ways logging in supplies immediately upon receipt, you are
used, the charge per customer is based on A flat rate per in a position to reject defective or damaged shipments and
period of time per fixtoe, foot of frontage, number of rooms, control shortages or errors in billing. Some utilities use
or other measurable unit. Although the flat rate basis still is personal computers to keep track of orders and deliveries.
fairly common, meter-based rates are more widely used.
See SMALL WATER SYSTEM OPERATION AND MAIN-
TENANCE, Chapter 8, 'Setting Water Rates for Small Water QUESTIONS
Utilities," for an explanation and examples of how to deter- Write your answers in a notebook and then compare your
mine and set water rates. This publication is available from answers with those on page 557.
Ken Kerri, Office of Water Programs, California State Uni-
versity, Sacramento, 6000 J Street, Sacramento, CA 95819. 23.0A What is bt. igeting?
Price, $20.00.
23.0B How can waste and inefficiency be reduced or elimi-
23.02 Procurement of Material nated?
Ordering repair parts and supplies usually is done when 23.0C List the important items usually contained on a
the on-hand quantity of a stocked part or --nemical falls purchase order.

56j
 P ;I I BID 90 2 pur _ °SE ORDER NO
CITY OF SVRAMENTO
REQUISITION Uut DATE DATE
3 DEt PAR TO <o 6
1
7 Rty 9 REOuiSti ION NO .0 REFER QUESTIONS TO
fu60 ORGAN COST CTR °DAC T

DATE
II
TUN
12 .4.0
CORNODiT Y 11 QUART T y " PINCE VENDORS uSt THESE COLS ONLY
CODE NO DESCRIPTION
UNIT uniT "' BRAND OFFERED " LOT PRICE 1.0P EACH ITEM

.-

It DE PT
51,4) SALES
THIS REQUISITION WILL BE REPRODUCED TO CREATE A TOTAS TAO
PURCHASE ORDER QUICKLY AND PROVIDE FASTER DELIVERY
IT ()TOG BY INVOICE
OF THESE ITEMS TO YOUR DEPARTMENT PLEASE FOLLOW AMOUNT
INSTRUCTIONS CAREFULLY
TEL NO 24

20 EST OF COST 22 SPECIAt REQUIREMENTS OR INSTRUCTIONS PRE viOuS PO NO OR MD NO OR RECOMMENDED VENDORS

vENDuR FI

ADDRESS
IN

CITY 5 TA Tt AN0 2.. (CI

21
11 CERTIFICATION IS HEREBY MADE THAT Tot ABOA IS A I EGAt CHARGE AGAINST THE APPROPRIATION iNDICA TED

NUMBER OF
TERNS Ttt NO tO)

REOUIS ToON
DEPT HEAD BY
ATTACHMENT
ROB DESTINATION
SHEETS DELivtRy ILI

564,T? OFf iCtAt. ;int BY TiTtt

Fig 23.2 Purchase order form

 Administration 543

9 Providing data for cost analysis and preparation of

budgets.
10 Providing data for future engineering designs, and
11 Providing information for monti ly and annual reports.

23.031 Types of Records

There are many different types of records that are re-
quired for effective management and operation of water
supply, treatment and distribution system facilities. Below is
a listing of some essential records:
1. Source of supply,
2. 1peration,
3. Laboratory,
4. Maintenance,
5. Chemical inventory and usage,
6. Purchases,
7. Chlorination station,
8. Main disinfection,
23.03 Treatment Plant Records 9. Cross-connection control,
23.030 Purpose of Records 10. Personnel,

Accurate records are a very important part of effective 11. Accidents, and
operation of a water treatment plant and distribution system 12. Customer complaints.
facilities. Records are a valuable source of information. They
can save time when trouble develops and provide proof that
problems were identified and solved. Pertinent and complete
r" )rds should be used as a basis for plant operation.
interpreting results of water treatment, preparing preventive
maintenance programs and preparation of budget requests.
When accurately kept, records prc vide an essential basis for
des.gn of future changes or expansions A the treatment
plant. and also can be used to aid in the design of other
water treatment plants where similar water may be treated
and similar problems may develop.
If legal questions or problems occur n connection with the
treatment of the water or the operation of the plant accurate
and complete records will provide evidence of what actually
occurred and what procedures were followed.
Records are essential for effective management of water
treatment facilities and to satisfy legal requirements. Some
of the important uses of records include:
1. Aiding operators in solving treatment and water quality
problems
2. Providing a method of alerting operators to changes in
source-water quality,
3. Showing that the treated water is acceptable to the
consumer,
4. Documenting that the final product meets plant per-
fortn,:nce standards, as well as the standards of the
regulatory agencies,
5. Determing performance of treatment processes, equip-
ment, and the plant,
6. Satisfying legal requirements,
7 ,ng in answering complaints,
8. Anticipating routine maintenance,

564
544 Water Treatment

23.032 Types of Plant Operations Data' b Backwash,

(1) Total hours,
Plant operations logs can be as different as the plants and (2) Head losses,
water systems whose information they record. The differ- (3) Total washwater used, and
ences in amount, nature, and format of data are so signifi- (4) Duration and rate of back/surface wash,
cant that any attempt to prepare a "typical" log would be very 10 Meteorologic,
difficult. This section will outline the kinds of data that are a Rainfall, evaporation, and temperature of both water
usually required to help you develop a useful log for your 'nd air, and
facilities.
b. Weather (clear, cloudy, windy);
Treatment plant data such as total flows, chemical use, 11 Remarks
chemical doses, filter perforn ance, reservoir levels, quality Space should be r D"ided to describe or explain unusu-
control tests, and rainfall and ,off information represent al data or events. Extensive notes should be entered on
the bulk of the data required for proper plant operation. a daily worksneot or diary.
Frequently, however, source and distribution system data
such as reservoir storage and water quality data are includ-
ed because of the impact of this information on plant
operation and operatc esponsibilities. Typical plant oper-
ations data include:
1. Plant title, agency and location;
2. Date,
3. Names of operators and supervisors on duty;
4. Source of supply,
a. Reservoir elevation and volume of storage,
b. Reservoir inflow and outflow,
c. Evaporation and precipitation,
d. Apparel' runoff, seepage loss, or infiltration gain,
and
e. Production figures from wells;
5. Water treatment plant,
a. Plant inflow,
b. Treated water flow,
c. Plant operating water (backwash), and 23.033 Maintenance Records
d. Clear well level;
A good plant maintenance effort depends heavily upon
6. Distnbution system, good recordkeeping. There are several areas where proper
a. Flows to system (system demand), records and documentation can definitely improve overall
b. Distribution system reservoir levels and changes, plant performance.
and
23.034 Inventory Records
c. Comparison of production with deliveries (unac-
counted for water', An inventory consists of the supplies the treatment plant
needs to keep on hand to operate the facility. These mainte-
7. Chemical inventory and usage,
nance supplies may include repair parts, spare valves,
a. Chemical inventory/storage (measured use and de- electrical supplies, tools, and lubricants. The purpose of
liveries),
maintaining an inventory is to provide needed parts and
b. Metered or estimated plant usages, and
supplies quickly, thereby reducing equipment downtime and
c. Calculated usage of chemicals (compare with actual work delays.
use);
8. Quality control tests,
In deciding what supplies to stock, keep in mind the
a. Turbidity,
economics involved in buying and stocking an item as
opposed to depending upon outside availability to provide
b. Chlorine residual,
c. Conforms,
needed supplies. Is tt-1 item critical to continued plant or
d. Odor, process operation? S. uld certain frequently used repair
e. Color, and parts be kept on-hand? Does the item have a shelf -life?
f Other; Inventory costs can be held to a minimum by keeping on
hand only those parts and supplies for which a definite need
9. Filter performance, exists or which would take too long to obtain from an outside
a. Operation, vendor. A "definite need" for an item is usually demonstrated
(1) Total hours, all units, by a history of regular use. Some items may be infrequently
(2) Filtered water turbidines, used but may be vital in the event of an emergency; these
(3) Head losses, items should also be stocked. Take care to exclude any
(4) Levels, and parts and supplies that may become obsolete, and do not
(5) Flow rates; stock parts for equipment scheduled for replacement.

I Also see Chapter 10, Plant Operation, Section 10.6, "Operating Records and Reports," for additionaldetails and recordkeeping forms.

565
 Admini&dation 545

Tools should be inventoried. Tools that are u_ad by 23.0E What is "unaccounted for water?"
operators on a daily basis should be permanently signed out
to them. More expensive tools and tools that are only 23.0F What chemical inventory and usage records should
occasionally used, however, should be kept in a storeroom. be kt.pt?
These tools should be signed out only when needed and 23.04 Organizational Planning
signed back in immediately after use.
A definite plan of organization is essential to effectively
23.035 Equipment Records operate a water treatment plant. Operators and othur per-
You WI need to keep accurate records to monitor the sonnel need to understand their respective positions and
operation and maintenance of plant equipment. Equipment duties in the whole picture of management. Only then can
control cards and work orders can be used to: they devote their full time and energy to the effective
discharge of their proper functions while avoiding duplica-
Record important equipment data such as make, model, tion .of effort and the confusion, interpersonal friction and
serial number, and date purchased, working at cross purposes which could result from the lack
Record maintenance and repair work performed to date, of a clearcut plan.

Anticipate preventive maintenance nee and The need for a plan applies to both small and large
organizations. In fact, a clearly defined organizational struc-
Schedule future maintenance work. ture may be even more important in a small utility since each
operator represents a greater percentage of the staff and
23.036 Disposition of Plant Records may perform a wider variety of ;unctions.
Good recordkeeping is very important because records
indicate potential problems, adequate operation, and are a
good waterworks practice. Usually the only records required
by the health agency is the summary of the daily turbidity of
the treated surface water as it enters the distribution system.
Chlorine residual and bacterial counts are often required.
Other records that may also be required include:
1. Total trihalomethane (TTHM) data (frequency of this
report is based on the number of people served),
2. The daily log and records of the analyses to control the
treatment process may be required when there are
chronic treatment problems,
3. Chlorination, constituent removal, and sequestering rec-
ords may be required from small systems (especially
those demonstrating little understanding of the proc-
esses), and
4. Records showing the quantity of water from each source
in use may be required from systems with sources
producing water not meeting state and/or local health
department water quality standards.
An imp' -It question is how long records should be kept.
Records snould be kept as long as they may be useful.
Some information will become useless after a short time,
while other data may be valuable for many years. Data that There are definite guidelines which are useful in develop-
might be used for future design or expansion should be kept ment of such an organizational plan:
indefinitely. Laboratory data will always be useful and should
be kept indefinitely. Regulatory agencies may require you to 1 Organization should be based specifically upon the ob-
keep certain water quality analyses (bacteriological test jectives to be achieved and the activities to be performed,
results) and customer complaint records on file for specified 2. Each person should have only one boss and all direction
time periods (10 years for chemical analyses and bacteri- and guidance should come from that supervisor,
ological tests).
3 The number of supervisory levels above the working level
Even if old records are not consulted every day, this does should be kept to a minimum,
not lessen their potootial value. For orderly records handling
and storage, sot up a schedule to periodically review old 4 Each supervisor should have a limited number of people
reviews and to dispose of those records that are no longer to directly supervise (fewer than 6),
needed. A decision can be made ',yhen a record is estab- b. Delegation of authority should be as complete as possi-
lished regarding the time period for which it must be re- ble with the lowest levels of the work force allowed to
tained. make as many decisions as appropriate to that level,

QUESTIONS 6. The responsibility for performance of each individual

should be pie-determined and then made perfectly '-'gar
Write your answers in a notebook and then compare your to the individual and the staff, and
answers with those on page 557.
7. Lines of management authority must be maintained and
23.0D List some of the important uses of records. not weakened by staff or functional authority.

566
546 Water Treatment

To establish an organizational plan, you will need a clear 3. Organizational planning should actively include all levels
understanding of the purposes and relationships of line and of the organization;
staff organizations. Both must be maintained to promote
harmony and maximum effec''veness. 4. The organizational plan should be published in charts and
manuals so that it is known to all personnel;
The line organization is the chain of command that ex-
5. Pfeil: -lust be tailored to a specific organization and its
tends from the manager down to the lowest level of person-
personnel and rarely can be copied from another utility
nel engaged in the actual operation of the utility. This line without sc me revisions;
organization is the framework for directly accomplishing the
objectives of the water utility agency or company. The 6. Good organizational planning can be measured in good
personnel in these positions (Table 23.2) are responsible for operator morale and effectiveness, and also in dollars
meeting the util y's objectives. Without clearly defined ob- and cents when unnecessary jobs are eliminated and
jectives, the line organization will find it difficult to function good performance is encouraged; and
effectively.
7. A good organizational plan is dynamic and should be
The staff organization, on the other hand, is not in the line capable of changing to meet the abilities of the operators
of command. Staff consists of those positions that exist to and the objectives of the utility.
provide advice and service to the line personnel to assist
them in carrying out their objectives. Secretaries, reception- The organization should strive to locate weak points and
ists, clerks, lawyers, accountants, and purchasing agents to meet changing requirements. There are several signs
are usually considered staff personnel. which may indicate difficulties, so they should be watched
for. The following are some of these signs.
Organizational planning should be reviewed periodically to
eliminate weaknesses, strengthen the structure and in- 1. Physical, mental and emotional overloading which causes
crease the effectiveness of management. Remember the undue fatigue,
following points when considering an organizational plan. 2. Indecisiveness in management which delays decision
making,
1. Organizations may gradually change to meet changing
objectives, and must have regular attention if a logical 3. Poor teamwork resulting from poor supervisory practices
pattern is to be maintained; or personal inadequacies of a supervisor, and
2. A good organizational plan is only a tool for helping 4. Failure tG train subordinates v. hich causes problems
people work together. ihe plan cannot provide for suc- when supervisors are promote) or move on to ar.other
cessful performance beyond the capabilities of the group; job.

TAKE 23.2 EXAMPLE OF AN ORCiAnIZATION CHART

FOR A PUBLICLY OWNED WATER UTILITY

Director
of
Publ.-; Works

LLegal I
Water Supply
Assistance I Accounting
I Manager

Source of Distribution
Supply 0 & M System 0 & M Purification

Treatment Plant I
Superintendent I

Plant
Laboratory
Operator.;

567
 Administration 547

QUESTIONS longer judged by what they can do themselves but rather

their value depends upon what they get done through
Write your answers in a notebook and then compare your others.
answers with those on page 557.
Every new supervisor must learn to assign to other people
23.0G List the guidelines which are useful in development work he can probably do better himself. And as anyone in 3
of an organizational plan. supervisory position knows, delegating to others is no
23.0H What is the primary purpos.. of the staff organiza- simple task; it is easier said than done. Four mistakes thai
tion? new supervisors often make are:

23.0: rlOW does management benefit from organizational They get their fingers into employees' work too often.
planning? g They do a lot of work themselves that employees should
23.0J List the signs that may indicat. .o a water utility be doing.
potential weak points or approaching organizational They fail to train and coach people so they can do the job
problems. as well as the supervisor can.
23.1 PERSONNEL ADMINISTRATION They expect too much of those who work for them,
especially at first.
Personnel administration is the "people side" of the admin-
istrative process. Effective personnel administration begins
with reasonable policies and effective supervisory skills.
23.10 Supervision
If you are responsible for the supervision of other opera-
tors, you are responsible for their safety and also their
professional development. Your responsibilities may include
assioning tasks to specific operators, being sure they under-
stand the assignment and know how to do the job safely,
and eventually making sure that the job was done properly.
Also as a supervisor you must be able to communicate
effectively with your superiors. the operators you supervise
and the consumer you serve To be a successful supervisor
you should:
1. Know how to do your job and the jobs you expect the
operators to do who work for you.
2. Know the abilities. knowledge, skills and limitations of the
operators you supervise.
3 Have sufficient technical knowledge and judgment to 23.11 Staffing
know when you can safely make necessary technical Obviously. the most important factors which will influence
deco -ions and when you need to call for the advice of an the size and qualifications of staff required are the number
expert of services and also the size and complexity of the treatment
4 Be able to help t-lin the ope. ators who work for you. both processes and faciloes that must be operated and main-
for job improve. it and for preparation for advancement tained Other important factors might include age and condi-
in the organization. tion of facilities and expected population growth rates.
5 Be a good representative of your supervisor and your Several avenues could be taken to determine staffing
utility agency. requirements. There are formulas based on the size and
complexity of facilities. Another possibility is to determine
6. Have integrity and be fair and objective in your relations staff size based on population served. Perhaps the best
with the operators who work for you, approach is to prepare a list of tasks that must be per-
formed. how long it will take to do each task, and the
7. Be cooperative with other people in your organization knowledge and skills required to perform the tasks. Analysis
and the public. of this information will provide an indication of the qualifica-
tions and size of staff needed to operate and maintain your
8. Encourage innovation and new ideas, facilit es
9. Select the right people for the organization, and items that most be considered when developing stLfling
10. Provide objective recognition. Praise people for good requirements include the work load. objectives and funds
performance and relate rewards to performance, not evadable. The size, condition and complexity of facilities will
seniority or personal relationships. nave a greet influence on the work loau. Other items that
should be considered include how constant is the work load,
are there seasonal variations. Is your recordkeeping system
When a person becomes a supervisor, a new factor enters adequc .a and u,)-to date. and are all maintenance activities
the picturepeople. Getting other people to do what needs scheduled as efficiently as possible. Today in many areas
to be done, organizing their work, and motivating them is as population growth is a fa.:t of life. Plans must b made for
much a specialty as any other kind of work a person may staff and facilities to be capable of providing sufficient
have previously done. When individuals move into a supervi- potable water and distribution system pressures as growth
sory position, they cross an important line. They are no occurs Records that substantiate efficient use of existing

568
 548 Water Treatment

staff, productivity of staff. and a positive need for future staff the field. This particular training course is a result of
are most helpful. such efforts.
Important questions to be answered in relation to staffing 4. Informal training. Effective training techniques include
are What are your objectives'," and "What level of mainte- informal meetings using drawings from available materi-
nance do you plan for your facilities'?" A typical objective als, suppliers, knowledge of experienced crews mem-
might be to deliver potable water at adequate pressures to bers, and invited guests to talk over how to do specific
consumers at the lowest possible cost year after year Once jobs. Suppliers are often available to train new operators
you have identified your objectives and determined how well and retrain existing operators on use of equipment.
they are being met now, you can decide how to do a better
lob and the staffing needed to accomplish your objectives. 5. Training for supervisors. Every manager and supervisor
During budget hearings you can present graphs or charts must develop a personal cc-itinuing education program.
showing how you are doing and what you could accomplish Managers must keep up to cute with technical advances
with a better trained and/or larger staff. in their field and also develop management skills.

Available funding is another important factor that must be A supervisor snould participate in whatever training is
faced when acquiring the staff you need to operate and available NOW. As suggested in this section, it is possi-
maintain your facilities. Whatever objectives you may devel-
ble to train crews to perform effectively even without
formal training aids. It is inefficient supervision to assign
op, or however extensive an operation and maintenance
program you devise, you will probably be restricted, to some
crews to perform work without some form of auequate
degree, by the amount of funds available. training. The lack of formal courses or training material
does not make adequate training impossible, it only
Fortunately e amount of funds available does not have makes it more difficult. ...
to be the sole determining factor in the implementation of
your desired operation and maintenance programs. Hope-
fully, in this course, you have learned the value of good
records. As an indicator of the existing condition of your
facilities, and as proof of cost-effective improvement, re-
cords can justify additional funding when it is warranted.

23.12 Training
A prime responsibility of every supervisor is to see that all
operators are properly trained to recognize all hazards and
to effectively accomplish the tasks they are assigned. Su-
pervisors must motivate operators to use safe procedures.
This section lists and describes possible sources and types
of training available for operators.
1. On the job. Much of the training offered or given in the
past has been some type of "on-the-job training" usually
given by available and experiences operators. This type
of training is important and has been very effective.
Proof of its effectiveness is indicated by the fact that
many consumers have received potable water as a
result of the efforts of such training. 23.13 People
One possible limitation of this type of training is that it How does the manager or administrator deal with people?
could be too narrow in scope. "In-house" training tends Every day we have to work with our supervisors, the !mak,
to be limited to local conditions, philosophies, and the people we work with and the people who work for rm. In
experience unless the instructor makes special efforts this manual we have tried to outline how to get the jcb done,
to broaden the scope. Initial safety training should be how to create a climate for good morale and how to provide
completed BEFORE cn-the-job training. training opportunities for operators.
2. Professional magazines and papers. Another valuable A very highly specialized .. id has developed on how to
source or training has been available through arttles motivate people, deal with co-workers, and how to super-
printed in local or national professional magazines. vise or manage people Norking for you. We believe these
Local or area waterworks associations periodically pre- are complex topics that are beyond the scope of this
sent workshops where experienced operators offer manual. If you have a need for or wish to learn more on how
papers that are of value in training less experienced to deal with people, we suggest enrolling in courses or
people in the operation and maintenance of waterworks reading books on supervision or personnel management.
facilities. Such workshops make information ava"..hle to
smaller organizations in remote areas who would other- QUESTIONS
wise not have the benefit of such broad experience. Write your an.wers in a notebook and then compare your
3. Formal training. Recently, through the efforts of local answers with those on page 557.
and state waterworks associations, the American Water 23.1A What are the responsibilities of a suj.arvisor?
Works Association, and the U.S. Environmental Protec-
tion Agency, attempts are being made to make formal 23.1B List the important factors which will influence the size
training available to all operator's. Such training also is and qualifications of staff required by a water utility
being made available to others not now in the water- agency.
works field, but who would like to prey re for jobs within 23.1C What should onerators be trained to do?

569
 Administration 549

23.14 Operator Certification should be recognized by an increase in salary and other

employee benefits.
23.140 Need for Certified Operators
Virtually all states and Canadian provinces require that a
certified operator be in charge of a utility agency's water
supply system and water treatment plant. Water supply and
treatment facilities are often classified on the basis of thi
number of services and/or the capacity of the treatmer
plant as well as on the complexity of the treatment pro-
cesses in the plant. This classification and the size of the
plant usually determine the numbers and grade levels of
certified operators needed by the plant. To qualify for higher
levels of certification, operator s need greater combinations
of education and experience. Education may be obtained by
attending technical schools, community colleges, short
courses, workshops, and successfully completing courses
like this one. Once the required education and experience
have been obtained for a higher level of certification, the
operator must successfully pass a certification examination.
This examination is based on what the operator needs to
know to work at a plant with a specific plant classification.
That is to say, the higher the certification you seek, the more
extensive the test will be. 23.142 ABC
ABC stands for the Association of Boards of Certification
23.141 Why Should Wafer Utility Operators Be Certified? for Operating Personnel in Water Utilities and Pollution
23.1410 Safety Control Systems. If you wish to find out how to become
certified in your state or province, contact:
Certified water supply system and treatment plant opera-
tors earn their certifi"ites by knowing how to do their jobs Executive Director, ABC
safely. Preparing fo, -artification examinations is one means Post Office Box 786
by which operators learn to identity safety hazards and to Ames, Iowa 5010-0786
follow safe procedures at all times under all circumstances. Phone: (515) 232-3778

Although it is extremely important, safety is not the sole ABC will provide you with the name and address of the
benefit to be derived from a certification program. Other appropriate contact person
benefits are aescribed below.
QUESTIONS
23.1411 Protection of the Public's Investment
Write your answers in a notebook and then compare your
Vast sums of public funds have been invested in the answers with those on page 558.
construction of water supply and treatment iacilities. Certifi-
cation of operators assures utilities that these facilities will 23.1D Name several ways water supply and treatment
be operated and maintained by qualified operators who facilities are generally classified.
possess a certain level of competence. These operators 23.1E How can an operator achieve higher levels of certifi-
should have the knowledge and skills not only to prevent cation?
unnecessary deteriorat an and failure of the facilities, but
also to improv.: operation and maintenance techniques. 23.1F How can an operator find out how to become certi-
fied?
23.1412 En.Ployee Pride and Recognition
23.2 PUBLIC RELATIONS
Achievement of a level of certification is a public acknowl-
edgment of a water supoly system or treatment plant 23.20 Establish Objectives
operator's skills and knowledge. Presentation of certificates
at an official meeting of the governing body will place the The first step in organizing an effective public relations
operators in a position to receive recognition for their efforts campaign is to establish objectives. The only way to know
and may even get press coverage and public opinion that is wnether your program is a success is to have a clear idea of
favorable. An improved public image will give the certified what you expect to achievefor example, better customer
operator more credibility in discussions with property own- relations, greater water conservation, and enhanced organi-
ers. zational credibility. Each objective must be specific, achiev-
able, and measurable. It is also important to know /our
Recognition for their personal efforts will raise the self- audience and tailor various elements of your public relations
esteem of all certified operators. Certification will also give effort to specific groups you wish to reach, such as commu-
water supply system and treatment plant operators an nity leaders, school children, or the average customer. Your
upgraded image that has been too long denied them. If objective may be the same in each case, but what you say
properly publicized, certification ceremonies will give the and how you say it will depend upon pur target audience.
public a more accurate image cm the many dedicated, well
23.21 Utility Operations
qualified operators working for them. Certification provides
a measurable goal that operators can strive for by preparing Good public relations begin 3t home. Dedicated, service-
themselves to do a better job. Passing a certification exam oriented employees provide for better public relations than

:-..5,70
 550 Water Treatment

paid advertising or complicated public relations campaigns. It is not difficult to get press coverage for your event or
For most people, contact with an agency employee estab- press conference if a few simple guidelines are followed:
lishes their first impression of the competence of the organi-
zation, and those initial opinions are difficult to change. 1. Demonstrate that your story is newsworthy, that it
involves something unusual or interesting.
in addition to ensuring that employees are adequately
trained to do their jobs and knowledgeable about the utility's 2. Make sure your story will fit the targeted format
operations, management has the responsibility to keep (television. radio, or newspaper).
employees informed about the organization's plans, prac- 3. Provide a spokesperson who is interesting, articulate,
tices, and goals. Newsletters, bulletin boards, and regular, and well prepared.
open communication between supervisors and subordi-
nates will help build understanding and contribute to a team
spirit.
23.23 Being !nterviewed
Whether you are preparing for a scheduled interview or
are simply contacted by .he press on a breaking news story,
here are some key hints to keep in mind when being
interviewed.
1. Speak in personal terms, free of institutional jargon.
2. Do not argue or show anger if the reporter appears to
be rude or overly aggressive.
3. If you don't know an answer, say so and offer to find
out. Don't bluff.
4. If you say you will call back by a certain time, do so.
Reporters face tight deadlines.
5. State your key points early in the interview, wncisely
and clearly. If the reporter wants more information, he
or she will ask for it.
6. If a question contains language or concepts with
which you disayee, don't repeat them, even to deny
them.
7. Know your facts.
8. Never ask to see a story before it is printed or
broadcast. Doing so indicates that you doubt the
reporter's ability and professionalism.
Despite the old adage to the contrary, the customer is not
always right. Management should try to instill among its 23.24 Public Speaking
employees the attitude that while the customer may be
confused or unclear about the situation, everyone is entitled Direct contact with people in your community is another
to courteous treatment and a factual explanation. Whenever effective tool in promoting your utility. Though the audiences
possible, employees should phrase responses as positively, tend to be small, a personal, face-to-face presentation
or neutrally as possible, avoiding negative language. For generally leaves a strong and long-lasting impact on the
r xample, Your complaint" is better stated as "Your ques- listener.
tion". You should have ... is likely to mcke the customer
defensive, while Will you please .. . is courteous and Depending upon the size of the organization, your utility
respectful. You made a mistake" emphasizes the negative, may wish to establish a speaker's bureau and send a list of
"What we'll do . . . is a positive, problem-solving approach. topics to service clubs in the area. Visits to high schools and
college campuses can also be beneficial, and educators are
23.22 The Mass Media often loaing for new and interesting topics to supplement
their curriculum.
We !ive in tne age of communications, and one of the most
erfer,:tive and least expensive ways to reach people is Public speaking takes prantice. It is important to be well
through the mass mediaradio, televisior, and newspa- prepared while retaining a personal, informal style. Find out
pers. Each medium has different needs and deadlines, and how long your talk is expected to be, and don't exceed that
obtaining coverage for your issue or event is easier if you time frame. H ve a definite beginning, middle, and end to
are aware of these constraints. Television must have strong your presentation. Visual aids such as charts, slides, ur
visuals, for example. When scheduling a press conference, models c.an assist in conveying your message. The use of
provide an interesting setting and be prepared to suggest humor and anecdotes can help to warm up the audience and
good shots to the reporter. Radio's main advantage over build rapport between the speaker and the listener. Just be
television and newspapers is immediacy, so have a spokes- sure the humor is natural, not forced, and that the point of
person available and prepared to give the interview over the your story is accessible to the particular audience. Try to
telephone if necessary. Newspapers give more thorough, in- keep in mind that audiences only expect you to do your best.
depth coverage to stones than do the broadcast media, so They are interested in learning about their water supply and
be prepared to spend extra time with print reporters and will appreciate that you are making a sincere effort to inform
provide written backup information and additional contacts. them about an important subject.

2 -, 571
 Administration 551

5. SUMMARIZE THE PROBLEM. Repeat your under-

standing of the situation back to the caller. This will
assure the customer that you understand the problem
and offer the opportunity to clear up any confusion or
missed communication.
6. PROMISE SPECIFIC ACTION. Mike an effort to give
the customer an immediate, clear, and accurate an-
swer to the problem. Be as specific as possible,
23.25 Telephone Contacts without overstepping your authority or promising
something you can't deliver.
First impressions are extremely important, and frequently
a person's first contact with your water utility is over the In some cases, you may wish to have a representative of
telephone. A person who answers the phone in a courteous, the utility visit the customer and observe the problem first
hand. If the complaint involves water quality, take samples if
pleasant, and helpful manner goes along way toward estab-
lishing a friendly, cooperative atmosphere. necessary and report back to the customer to be sure the
problem has peen resolved.
Following a few simple guidelines will help to start your
utility off on the right note with your customers: Complaints can be a valuable asset in determining con-
sumer acceptance and pinpointing water quality problems.
1. ANSWER CALLS PROMPTLY. Your conversation will Customer calls are frequently your first indication that some-
get off to a better start if the phone is answered by the thing may be wrong. Responding to complaints and inquiries
third or fourth ring. promptly can save the utility money and staff resources, and
minimize the number of customers who are inconvenienced.
2. IDENTIFY YOURSELF. This adds a personal note and Still, education can greatly reduce complaints about water
lets the caller know who he ol she is talking to. quality. Information brochures, utility bill inserts, and other
3. PAY ATTENTION. Don't conduct side conversations. educational tools help to inform customers and avoid future
Minimize distractions so you can give the caller your complaints.
full attention, avoiding repetitions of names, address-
es, and other pertinent facts. 23.27 Plant TOW:.
4. MINIMIZE TRANSFERS. Nt.body likes to get the run- Tours of water treatment p. ants can be an excellent way to
around. Few things are more frustrating to a caller inform the public about your utility's efforts to provide a safe,
than being transferred from office to office, repeating high quality water supply. Political leaders, such as the City
the situation, problem or concern over and over again. Council and members of the Board of Supervisors, should
Transfer only those calls that must be transferred, and be invited and encouraged to tour the facilities, as should
make certain you are referring the caller to the right school groups and service clubs.
person. Then, explain why you are transferring the
call. This lets the caller know you are referring him or A brochure describing your utility's goals, accomplish-
her to a co-worker for a reason and reassures the ments, operations, and processes can he, a good supple-
customer that the problem or question will be dealt ment to the tour and should be handed out at the end of the
with. In some cases, it may be better to take a visit. The more visually interesting the brochure is, the more
message and have someone return the call than to likely that it will be read, and the use of color, photographs,
keep transferring the customer's call. graphics or other design features is encouraged. If you have
access to the necessary equipment, production of a video
tape program about the utility can also add interest to the
23.26 Consumer Inquiries facility tour.
No single set of rules can possibly apply to all types of
consumPr questions or complaints about water quality and
servaze. There are, however, basic principles to follow in
responding to inquires and concerns.
1. BE PREPARED. Your employees should be familiar
enough with your utility's organization, services and
policies to either respond to the question or complaint
or locate the person who can.
2. LISTEN. Ask the customer to describe the problem
and listen carefully to the explanation. Take written
notes of the facts and addresses.
3. DON'T ARGUE. Callers often express a great deal of
pent-up frustration in their contacts with a utility. Give
the caller your full attention. Once you've heard them
out, most people will calm down and state their
problems in more reasonable terms.
The tour Itself should be conducted by an employee who
4. AVOID JARGON. The average consumer lacks the is very familiar with plant operations and can answer the
technical knowledge to understand the complexities types of questions that are likely to arise. Consider includ-
of water quality. Ube plain, non-technical language ing:
and avoid telling the consumer more than he or she
needs to know. 1. A description of the sources of water supply,

("_1 572
552 Water Treatment

2. History of the plant, the years of operation, modifica- Ft rther, in observing today's international tension and the
tions and innovations over the years, po ..tial for nuclear war, the effect such actior would have
3. Major plant design features, including plant capacity on the operation of water utilities must be seriously consid-
and safety features, ered. When such catastrophic emergencies occur, the utility
must be prepared to minimize the effects of the event and
4. Observation of the treatment processes, including have a plan for rapid recovey to avoid serving contaminated
filtration, sedimentation, flocculation and disinfection, water to the consumers. Such preparation should be a
specific obligation of every utility manager.
5. A visit to the laboratory, including information on the
quality of water distributed to consumers, and
Once it is recogn:ed that all water treatment plants are
6. Anticipated improvements, expansions, and long- subject to a variety of emergency situations, the vulnerability
range plans for meeting future service needs. of that treatment unit to the effects of a disaster must be
Plant tours can contribute to a water utility's overall assessed If the extent of damage can be estimated for a
program to ga'n financing for capital improvements. If the series of most probable events. the weak elements can be
City Council or other governing board has seen the treat- studied, and protection and recovery operations can center
ment process first hand, it is more likely to understand the on these elements.
need for enhancement and support future funding. Although all elements are important for the utility to
function, experience with disasters points out elements that
QUESTIONS are most subject to disruption These elements are:
Write your answers in a not. cook and then compare your 1 The absence of trained personnel to make critical deci-
answers with those an page 558. sions and carry out orders,
23.2A What is probably the single most important aspect of 2 The loss of power to the treatment facilities,
a successful public relations effort?
3. An inadequate amount of supplies and materials, and
23.2B What attitude should management try to develop 4. Inadequate communication equipment.
among its employees regarding the consumer?
The following steps should be taken in assessing the
23.2C How can you prepare ycurself for an interview with vulnerability of a system:
the news media?
1 Identify and describe the treatment components,
23.2D How can plant tours be most beneficial for a water
utility? 4 Assign assumed disaster charactenstice.,
3. Estimate disaster effects on system components,
23.3 EMERGENCY PLANNING
4 Estimate water demand, quality and quantity during and
Contingency planning is an essential facet of water utility following a potential disaster, and
management and one that is often overlooked. Although 5 Identify key system components that would be primarily
utilities in various locations will be vulnerable to somewhat responsible for system failure.
different kinds of natural disasters, the effects of these
disasters in many cases will be quite similar. As a first step If the assessment shows a system is unable to meet
towards an effective contingency plan, each utility should estimated requirements because of the failure of one or
make an assessment of its own vulnerability and then more critical treatment components, the vulnerable ele-
develop and implement a comprehensive plan of action. ments have been identified. Repeating this procedure using
several -typical disasters will usually point out treatment
All water utilities suffer from common problems, such as plant weaknesses. Frequently the same vulnerable element
equipment breakdown, leaking pipes and variations in water appears for a variety of assumed disaster events.
quality and quantity. During the past few years there has You might consider, for example, the case of the addition
also been an increasing amount of vandalism, civil disorder, of toxic pollutants to water supplies. The list of toxic agents
toxic spills, and employee strikes which have threatened to that may have a harmful effect on humans is almost endless.
disrupt water utility operations. Natural disasters Such as However, it is recognized that there is a relationship be-
floods, earthquakes, hurricanes, forest fires, avalanches, tween the quantity of toxic agents added and the treatment
and blizzards are a more or less routine occurrence for provided for the supply. Adequate chlorination is effective
some utilities. against most biological agents. Other considerations are the
amount of dilution water and the solubility of the chemical
agents. There is the possibility that during normal detention
times many of the biological agents will die off with adequate
chlorination.
Although the drafting of an emergency plan for a water
system may be a difficult job, the existence of such a plan
can be of critical importance during an emergency situation.

An emergency operations plan need not be too detailed,

since all types of emergencies cannot be anticipated and a
complex response program can be more confusing than
helpful. Supervisory personnel must have a detailed descrip-
tion of their RESPONSIBILITIES during emergencies. A

573
 Administration 553

water quality officer should be primarily responsible for the

SAFETY of the water supply Supervisory people need
information, supplies, equipment and the assistance of
trained personnel All these can be provided through a
properly-constructed emergency operation plan that is not
extremely detailed.

The following outline should be followed when developing

an emergency operations plan:

1. Make a vulnerability assessment,

2. Inventory organizational personnel,
3. Provide for a recovery operation (plan),
4. Provide training programs for operators in carrying out
the plan,
5. A plan should include ' )cal and regional coordination
such as health depart- .ent, police, and fire,
6. Establish a communications procedure, and
7. Provide protection for personnel, plant equipment, rec-
ords and maps.
For additional information on emergencies see Chapter 7,
By following these steps, an emergency plan can be Disinfection, Section 7 52, "Chlorine Leaks," Chapter 10,
developed and maintained even though changes in person- Plant Operation, Section 10.9, "Emergency Conditions and
nel may occur. "Emergency Simulation" training sessions, Procedures, and Chapter 18, Maintenance, Section 18.02
including the use of standby power, equipment and field test "Emergencies."
equipment will insure that equipment and personnel are
ready at times of emergency. QUESTIONS
Write your answers in a notebook and then compare your
A list of phone numbers for operators to call in an answers with those on page 558.
emergency should be complete and posted by a phone for
emergency use. You should prepare a list for your plant 23 3A What is the first step towards an effective contingen-
now, if you have not already done so. cy plan for emergencies?
23.38 How would you handle undesirable biological agents
1. Plant supervisor, suspected in the water supply during an emergency?
2. Director of public works or head of utility agency, 23 3C Why is a too detailed emergency operation plan not
needed nor desirable?
3. Police,
23.3D An emergency operations plan should include what
4. Fire, specific information')
5. Doctor (2 or more),
6. Ambulance (2 or more), 23.4 HANDLING THE THREAT OF CONTAMINATED
7. Hospital (2 or more), WATER SUPPLIES2

8. Chlorine supplier and manufacturer, 23.40 Importance

9 CHEMTREC (800 424-9300 for hazardous chemical More than 50 water utilities in southern Louisiana were
spills sponsored by the Manufacturing Chemists Asso- threatened with cyanide poisoning in their water supplies in
ciation), one yea'. Such threats can occur anywhere, and every water
utility should be prepared to handle this type of emergency.
10. Pesticides (800-424-9300 for the National Agricultural
Chemists Association Cleanup Crews),
11. U.S. Coast Guard's National Environmental Response 23.41 Toxicity
Center (800-424-8802), The term toxicity is often used when discussing contami-
12. EPA Hazardous Materials Headquarters (Monday nation of a water supply with the intention of creating a
through Friday, 8:00 a.m. to 4:30 p.m., 202-245-3045; serious health hazard. Toxicity is the ability of a contaminant
other times call 202-554-2329), and (chemical or biological) to cause injury when introduced to
the body. The degree of toxicity varies with the concentra-
13. FDA Poison Control Center (202-496-7691 or 202 -963- tion of contaminant required to cause injury, the speed with
7512). which the injury takes place, and the severity of the injury.

2 This section was reprinted from OPFLOW. Vol No. 3 March 1983, by permission. Copyright 1983, the American Water Works
Association.
 554 Water Treatment

The effect of a toxic contaminant, once added to a ....,ster TABLE 23.3

supply, depends on several things. First the amount of EMERGENCY LIMITS OF SOME CHEMICAL POLLUTANTS
contaminant added can vary, as can the size of the water IN DRINKING WATERa
supply. In general, it takes larger quantities of a contaminant
to be toxic in a larger water supply. Second, the solubility of Concent. ation Limits, mg /L
the contaminant can vary. The more soluble the substance is Emergency
in water, the more likely it is to cause problems. Finally the Short Term
detention time of the contaminant in the water can vary. For Chemical (Three days) Long Term
example, many biological agents will die before they can
cause a problem in the water supply. Cyanide (CN) 50 001
Aldan 0 05 0 032
Generally,the terms acute and chronic are used to de- Chlordane 0 06 0 003
scribe toxic agents and their effects. An acute toxic agent DDT 14 0.042
causes injury quickly. When the contaminant causes illness Dieldrin 0.0b 0 017
in seconds, minutes, or hours after a single exposure or a Endrin 0.01 0 001
single dose, it is considered an acute toxic agent. A chronic Heptachlor 0.1 0.018
agent causes injury to occur over an extended period of Heptachlor epoxide 0.05 0.018
exposure. Generally, the contaminant is ingested in repeat- Lindane 2.0 0.056
ed doses over a period of days, months, or years. Methoxychlor 28 0.035
Toxaphene 14 0.005
23.42 Effective Dosages Beryllium 01 0 000
Boron 25 0 1 000
When deter lining the effective dosage of a contaminant 2 4-D 20 0.1
(the amount of that contamrant necessary to cause injury) Ethylene chlorohydnn 2.0
the following facts must be considered: Organiphosphorus and
1. Quantity or concentration of the contaminant, carbamate pesticides 2.0 0.100
Trinitrc, oluene (NO2)(C6H2CH3) 0 75 0.005
2. Duration of exposure to the contaminant,
a These !nits. based on current knowledge and informed
3. Physical form of the contaminant (size of particle; phys- judgment. have been recommended by knowledgeable
ical state solid, liquid, gas), persons in the field of toxicology. They are subject to
4. Attraction of the contaminant to the organism being change should new information indicate the need. Addi-
contaminated, tional information on some of the chemicals listed can be
found in "Report of the Secretary's Commission on Pesti-
5. Solubility of the contaminant in the organism, and cides and Their Relationship to Environmental Health,"
6. Sensitivity of the organism to the contaminant. Parts I and II. USDHEW, Washington, D C., Dec. 1.369.

Concentration of a contaminant can be expressed in two

ways. The maximum allowable concentration (MAC) is the
maximum concentration of the contaminant allowed in drink-
ing water. Table 23.3 lists sc,veral contaminants and their Because utility operators "know" their water supply (they
MACs, specifically for shoil-term emergencies ranging up to know its characteristics), any subtle changes in taste, odor,
three days. The MACs should not be confused with concen- color and chlorine demand are instantly recognized. Once it
tration required to have an acute effect on the population. has been determined that the water supply may be contami-
Lethal dos 50 (LD 50), is used to express the concentration nated water samples can be tested. Tests can either be
of a contaminant that will produce 50 percent fatalities from done at the utility's laboratory, if it is a large utility, or the
an average exposure. samples can be sent to the state health department.
Finally, the utility can maintain a high chlorine residual.
23.43 Protective Measures Generally. chlorine residuals of one mg/L or higher effective-
ly oxidize or destroy most contaminants. For example,
A utility can take three approaches to protect its water infectious hepatitis virus will not survive a free residual
supply from contamination. First, the utility can isolate those chlorine level of 0.7 mg/L
reservoirs that offer easy access to the general public.
These reservoirs can be fenced off and patrolled, cr they 23.44 Emergency countermeasures
can be covered. If access to on-line reservoirs is limited,
persons attempting to contaminate the water supply will Following is a list of emergency countermeasures that,
generally be forced to look to larger bodies of water. when user over a short time period, can increase protection
of a water supply:
Contamination of these large water bodies requires larger
quantities of contamirRnt, increases the detention time of 1 Maintaining a high chlorine residual in the system,
the contaminant, and increases the likelihood of its detec-
tion. 2 Having engineers, chemists, and medical personnel on
24-hour alert,
As a second means of protection, the water utility can
develop an extensive detection and monitoring program. 3 Continuously monitoring key points in the distribution
Detecting any contaminant that might be added to a water system (monitoring chlorine residual is mandatory),
supply is difficult and expensive. However, because most 4. Increasing security around exposed on-line reservoirs,
contaminants cause secondary effects in a water supply,
such as taste, color, odor, or chlorine demand, detection is 5 Sealing off access to manholes within a three- to six-
easier. block radius of highly populated areas,

575
 Administration 555

6 Setting up emergency crews that can isolate sections of community, treatment measures may be available that will
the distribution system. and remove the contaminant or reduce its toxicity
7 Staffing the treatment facility on a 24-hour basis Table 23.4 lists a series of emergency treatment steps that
can be taken when identified chemicals are added to the
system. These emergency treatment methods are effective
23.45 In Case of Contamination only if the contaminant has been identified.
If contamination of the water supply is discovered. the
immediate concern must be the safety of the public If the QUESTIONS
contaminated water has entered the distribution system.
immediate public notification is the highest priority The local Write your answers in a notebook and then compare your
police chief. sheriff or other responsible governmental au- answers with those on page 558.
thority will help to spread the word Alternate sources of 23.4A What does the word toxicity mean?
water may need to be provided
23 48 The degree of tonicity varies with what factors?
If the contaminated water has not entered the distribution
system it may be possible to isolate the contaminated 23 4C List possible secondary effects in a water supply
source and continue to supply eater from other. unaffected which may allow detection of a contaminant without
sources If the contaminated water is the only source for the specific testing

TABLE 23.4
EMERGENCY TREATMENT FOR REDUCING CONCENTRATION OF SPECIFIC CHEMICALS
IN COMMUNITY WATER SUPPLIESa

Concentration Treatment Concentration Treatment

Arsenicals Nerve Agents
Unknown organic and Precipitation with fen, ic sulfate (Organophosphorus Superchlonnation at pH 7 to
inorganic arsenicals in and liming to pH 6 8, followed by compounds) provide at least 40 mg/L residual
groundwater at sedimentation and filtration. after 30-min chlorine contact
concentrations of 100 mg/L time, followed by dechlonnation
and conventional clarification
Cyanides
processes
Hydrogen cyanide Prechlonnation to free residual
with pH 7, followed by Pesticides
coagulation, sedimentation, and 2,4-DCP (2.4-Dichlorophenol) Adsorption on activated carbon
filtration Caution housed and impurity in commercial followed by coagulation.
facilities must be adequately 2,4-D herbicides) sedimentation, and filtration
ventilated. DDT (dichloro- Chemical coagulation,
Precipitation with ferrous or diphenyltnchloroethane). sedimentation and filtration.
ferric salts to form Prussian blue concentrations of 10 g/L
(Iron ferric cyanide) followed by
coagulation, sedimemation, and Dieldnn, concentrations of 10 Chemical coagulation,
clarification As long as an g/L sedimentation, and filtration.
excess of iron coagulant is Supplemental treatment with
applied, the filtered water should activated carbon may be
be nontoxic even though it is necessary.
blue. Endnn, concentrations of 10 Chemical coagulation,
Acetone cyanohydnn Same as for hydrogen cyanide g/L sedimehtation, and filtration.
Cyanogen chloride Same as for hydrogen cyanide Supplemental treatment with
activated carbon may be
Hydrocarbons necessary.
Kerosene peak Preapplications of bleaching clay
concentrations of 140 mg/L and activated carbon, plus some Lindane, concentrations of 10 Application of activated carbon
increase in normal dosages of g/L followed by chemical
alum, chlorine dioxide, lime, and coagulation, sedimentation. and
carbon, to provide treatment filtration.
enabling continued production of Parathion, concentrations of Chemical coagulation,
water 10 g/L sedimentation, and filtration.
Miscellaneous Organic Supplemental treatment with
Chemicals activated carbon may be
LSD (lysergic acid derivative) Chlorination in alkaline water, or necessary. Omit prechlorination
water made alkaline by addition as chlorine reacts with parathion
of lime or soda ash, to provide a to form paraoxon, which is more
free chlorine residual. Two parts toxic than parathion.
free chlorine are required to
react with each part LSD.

a Source Graham Walton. Chief, Technical Services. National Water Supply Research Laboratory, USSR Program. Oct. 24, 1968
556 Water Treatment

23.5 ADDITIONAL READING

1. TEXAS MANUAL, Chapter 18 "Effective Public Rela-
tions in Water Works Operations," and Chapter 19,
"Planning and Financing."
2. WATER RATES (M1). Obtain from Computer Services,
AWWA, 6666 West Quincy Avenue, Denver, Colorado
80235. Order No. 53001. Price to members, $13.50,
nonmembers, $17.00.
3. WATER UTILITY MANAGEMENT PRACTICES (M5).
Obtain from Computer Services, AWWA, 6666 West
Quincy Avenue, Denver, Colorado 80235. Order No.
30005. Price to members, $16.50; nonmembers, $20.50.
4. EMERGENCY PLANNING FOR WATER UTILITY MAN-
AGEMENT (M19). Obtain from Computer Services,
AWWA, 6666 West Quincy Avenue, Denver, Colorado
80235. Order No. 30019. Price to members, $13.50,
nonmembers, $17.00.

DISCUSSION AN) REVIEW QUESTIONS

Chapter 23. ADMINISTRATION

Please answer these discussion and review questions 11. Why are records important"
before continuing with the Objective Test on page 559. The
purpose of these questions is to indicate to you how well you 12 Why should public water systems be operated by
understand the material in the 'esson. Write the answers to trained and certified personnel?
these questions in your notebook. 13 What is the difference between planning and budgeting',
1 Why must a utility have clearly defined objectives" 14. What factors should be considered when determining a
2. How can the success of good organizaticnal planning water rate schedule for a utility"
be measured', 15 List the possible sources or types of training available
3. How can the numbers and grade levels of certified for operators.
operators required at a water treatment plant be deter-
mined?
4. What is the first step in organizing an effective public
relations effort',
5. How can management keep employees well informed?
6. What is the value of consumer complaints"
7. What telephone procedures can be used to help your
utility favorably impress people who contact the agency
by phons?
8. How would you assess the vulnerability of a water
supply system"
9. How can a utility protect its water supply from contami-
nation?
10 What would you do if you discovered that contaminated
water has entered your distribution system"

577
 Administration 557

SUGGESTED ANSWERS
Chapter 23. Administration

Answers to questions on page 541. 2. Each person should have only one boss and all
23.0A Budgeting is the art of predicting the amount of direction and guidance should come from that
supervisor,
money necessary to achieve an organization's goals.
23.013 Waste and inefficiency can be reduced or eliminated
3. The number of supervisory levels above the
working level should be kept to a minimum,
by carefully examining all phases of operation and
maintenance when preparing accurate and realistic 4. Each supervisor should have a limited number of
budgets. people to directly supervise (fewer than 6),
23.0C Important items usually contai' sd on a purchase 5. Delegation of authority should be as complete as
order include: (1) the date, (2) a complete description possible with the lowest levels of the work force
of each item and quantity needed, (3) prices, (4) the allowed to make as many decisions as are ap-
name of the vendor, and (5) a purchase order num- propriate to that level,
ber.
6. The responsibility for performance of each indi-
Answers to questions on page 545. vidual should be pre-determined and then made
23.0D Some of the important uses of records include: perfectly clear to the individual and the staff, and

1 Aiding operators in solving treatment and water

7. Lines of management authority must be main-
quality problems, tained and not weakened by staff or functional
authority.
2. Providing a method of alerting operators to
23.0H The staff organization provides advice and service to
changes in source-water quality,
the line personnel to assist them in meeting their
3. Showing that the treated water is acceptable to objectives.
the consumer,
23.01 Organizational planning can benefit manag dent by
4. Documenting that the final product meets plant correcting weaknesses in the organization of a utility.
performance standards, as well as the stan- It can also strengthen the structure and increase the
dards of the regulatory agencies, effectiveness of management, thereby reducing
costs and increasing efficiency.
5. Determining performance of treatment pro-
cesses, equipment, and the plant, 23.0J Signs that may indicate to a utility potential weak
points or approaching organizational problems in-
6. Satisfying legal requirements, clude:
7. Aiding in answering complaints, 1. Physical, mental and emotional overloading
8. Anticipating routine maintenance, which causes undue fatigue,

9. Providing data for cost analysis and prepara- 2. Indecisiveness in management which delays de-
tion of budgets, cision making,
10. Providing data for future engineering designs, 3. Poor teamwork resulting from pcor supervisory
and practices or personal inadequacies of a supervi-
sor, and
11. Providing information for monthly and annual
reports. 4. Failure to train subordinates which causes prob-
lems when supervisors are promoted or move on
23.0E "Unaccounted for water" is the difference between to another job.
the amount of treated water that enters the distribu-
Answers to questions on page 548.
tion system and water that is delivered to consumers.
23 lA A supervisor is responsible for the safety and profes-
23.0F Chemical inventory and usage records that should be
kept include:
sional development of operators. Other responsibil-
ities may include assigning tasks to specific opera-
1. Chemical inventory/storage (measured use and tors, being sure they understand the assignment and
deliveries), know how to do the job safely, and eventually making
sure that the job was done properly.
2. Metered or estimated plant usages, and
23.1B The most important factors which will influence the
3. Calculated usage of chemicals (compare with size and qualifications of staff required include the
actual use). number of services and also the size and complexity
Answers to questions on page 547. of the treatment processes and facilities that must be
operated and maintained. Other important factors
23.0G Guidelines which are useful in development of an might include age and condition of facilities and
organizational plan include: expected population growth rates.
1. Organization should be based specifically upon 23.1C Operators should be properly trained to recognize all
the objectives to be achieved and the activities to hazards and to effectively accomplish the tasks they
be performed, are assigned. Supervisors must motivate operators
., ., . -.
'.
%

578
558 Water Treatment

to use safe procedures. reporter s ability and professionalism.

Answers to questions on page 549. 23.2D Plant tours are an excellent method of informing the
public of the water utility's efforts to provide a safe,
23.1D Water supply and treatment facilities are often classi-
wholesome wIter supply.
fied on the basis of the number of services and/or the
capacity of the treatment plant as well as on the Answers to questions on page 553.
complexity of the treatment processes in the plant.
23.3A The first step towards an eftective contingency plan
23.1E An operator can achieve higher levels of certification for emergencies is to make an assessment of vulner-
by gaining the necessary education and experience ability. Then a comprehensive plan of action can be
for the next level of certification. The operator then developed and implemented.
must successfully pass the next level certification
examination. 23.3B Adequate chlorination is effective against most bio-
logical agents during an emergency. Other consider-
23.1F To find out how to become certified, contact your ations include the amount of dilution water and the
state certification board or the Association of Boards possibility that the biological agents will die off during
of Certification (ABC) in Ames, Iowa. normal detention times with adequate chlorination.

Answers to questions on page 552. 23.3C A detailed emergency operation plan is not needed
since all types of emergencies cannot be anticipated
23.2A Probably the single most important aspect of a public and a complex response program can be more
relations effort is employee job satisfaction and confusing than helpful.
performance.
23.3D An emergency operations plan should include:
23.2B Management should try to develop among its em- 1. Vulnerability assessment,
ployees the attitude that even though the consumer
is not always right, every consumer is always entitled 2. Inventory of personnel,
to courteous treatment and a proper explanation of
anything the consumer does not understand. 3. Provisions for recovery operation,

23.2C Proper preparation for an interview with the news 4. Provisions for training programs for operators in
media includes: carrying out the plan,

1. Speak in personal terms, free of institutional 5. Inclusion of coordination plans with health, po-
jargon. lice and fire departments,

2. Do not argue or show anger if the reporter 6. Establishment of a communications procedure,

appears to be rude or overly aggressive. and

3. If you don't know an answer, say so and offer to 7. Provisions for protection of personnel, plant
find out. Don't bluff. equipment, records and maps.

4. If you say you will call back by a certain time, do Answers to questions on page 555.
so. Reporters face tight deadlines. 23.4A Toxicity is the ability of a contaminant (chemical or
5. State your key points early in the interview, biological) to cause injury when introduced into the
concisely and clearly. If the reporter wants more body.
information, he or she will ask for it. 23.4B The degree of toxicity varies with the concentration
6. If a question contains language or concepts with of contaminant required to cause injury, the speed
which you disagree, don't repeat them, even to with which the injury takes place, and the severity of
deny them. the injury.

7. Know your facts. 23.4C Possible secondary effects in a water supply which
may allow detection of a contaminant without specif-
8. Never ask to see a story before it is printed or ic testing include taste, odor, color and chlorioe
broadcast. Doing so indicates that you doubt tho demand.

579
 Administration 559

OBJECTIVE TEST
Chapter 23. ADMINISTRATION

Please write your name and mark the correct answers on MULTIPLE CHOICE
the answer sheet as directed at the end of Chapter 1 There
may be more than one correct answer to the multiple choice 11 A clear-cut organizational plan reduces or avoids
questions 1. Confusion.
2 Duplication of effort.
TRUE-FALSE 3 Effective communication.
4 Friction
1 A definite plan of organization is essential to effectively 5 Working at cross purposes
operate a water treatment plant
1 True
2 False
12 Each supervisor should supervise no more than
people.
_
1 6
2 The staff organization is in the line of command 2. 12
1 True 3. 18
2 False 4. 24
5. 30
3 Organizational plans can be copied from one maior
utility to another 13 Staff personnel shown on a water utility organization
1 True chart include
2 False 1 Accountants.
2 Lawyers.
4 Radio End television give more thorough coverage of 3 Operators.
stories than newspapers 4. Secretaries.
1 True 5. Superintendent.
2 False
14 Water utility operators should become certified to
5 Usually the same vuli,er able plant element appears as a 1 Be able to do a better job of operating the facilities.
problem for a variety of disaster events 2. Improve the utility's safety record.
1 True 3. Increase employee pride and recognition.
2 False 4. Learn how to identify safety hazards.
5 Protect the public's investment in the utility.
6 Operators must be available during nights, weekends.
and holidays to respond to emergencies 15 Management has a responsibility to keep employees
well informed about the organization's
1 True
2 False 1 Personnel actions (firings and demotions).
2. Plans.
7 In a water treatment plant continuity of supply is of 3. Practices.
prime importance 4 Purposes.
5. Union dues.
1 True
2 False 16 Management can keep employees well informed by
using
8 A set of rules can be established that will apply to all
types of people with consumer complaints 1. Bulletin board announcements
2. Local newspapers
1 True 3. Memos.
2 False 4. Straight talk from supervisors to subordinates.
5 The office gossip.
9. Try to be friendly and courteous at all times to people
with complaints. 17 Information provided during a plant our should include
1 True 1 Description of the sources of water supply.
2 False 2 Information on quality of water distributed to con-
sumers
10 Complaints should be welcomed and act.urately re- 3 Plans for improvement.
corded 4 Plant design features.
1 True 5 Theory of hydraulic turbulence in sedimenta.ion
2 False. basins.
560 Water Treatment

18. Emergencies that confront water utilities include 3. You should have.
1. Budget cuts. 4. Your complaint.
2. Employee strikes. 5. Your question.
3 Fires
4. Floods. 22 To help your utility make friends with people who
5. Vandalism. contact the agency by phone. you should
1 Answer after 3 or 4 rings so callers will know you are
19 Elements of a water utility which are most likely to be busy
weak points during a disaster include 2. Answer by saying "Hello
1. Absence of trained personnel to make critical deci- 3 Extend a pleasant greeting.
sions. 4 Leave word when away from the phone.
2. Inadequate amount of supplies and materials. 5 Route the call to someone who can take a message.
3. Inadequate communication equipment
4. Loss of power to the treatment facilities. 23 When determing the effective dosage of a contaminant
5. Shortage of funds to pay contractors. (the amount of that contaminant necessary to cause
injury), which of the following facts must be considered?
20. The first step in organizing an effective public relations 1. Duration of exposure to the contaminant
campaign is to 2 Quality or concentration of the contaminant
1. Call a press conference. 3 Sensitivity of consumers to the contaminant
2. Conduct plant tours. 4 Solubility of tne contaminant
3. Establish objectives. 5. Who is the suspected source of the contaminant
4. Meet with community leaders.
5. Publish brochures. 24. Accurate records are very important because they
1 Are a valuable source of information.
21. When responding to consumer complaints or questions, 2 Can save time when trouble develops.
proper response phrases include 3. Help prepare preventive maintenance programs.
4. Provide proof that problems were identified and
1. Will you please. solved.
2. You made a mistake. 5. Serve as a basis for plant operation.

tad of otyjective Ta÷t:

581
 APPENDIX
Final Examination

How to Solve Water Treatment Plant

Arithmetic Problems

Water Abbreviations

Water Words

Subject Index

5
WATER TREATMENT PLANT OPERATION
VOLUME II

FINAL EXAMINATION
AND
SUGGESTED ANSWERS

583
 Final Exam 563

FINAL EXAMINATION

This final exaiumation was prepared TO HELP YOU 5 In the lime softening process. magnesium is precipi-
review the material in this manual. The questions are divided tated out as magnesium carbonate.
into four types: 1. True
1. True-False. 2. False
2. Multiple Choice.
6. Acid softening may be used instead of soda ash soften-
3. Short Answers. and mg.

4. Problems. 1 True
2. False
To work this examination:
1. Write the answers to each question hi your notebook. 7 Dry ice should be used to keep THM samples cool when
shipping and storing.
2. After you have worked a group of questions (you aecide
how many). check your answers ''h the suggested 1. True
answers at the end of this exam, aria 2. False

3 if you missed a question and don't understand why. 8. THMs are produced faster in corrosive waters than in
reread the material in the manual. scale forming waters
1 True
You may wish to use this examination for review purposes 2 False
when preparing for civil service and certification examina-
tions. 9 When h gher mineral concentrations occur in the feed-
Since you have already completed this course, you do not water the mineral concentrations will decrease in the
have to send your answers to California State University. product water
Sacramento. 1 True
2 False
True-False
10 An increase in feedwater temperature will decrease the
1. Iron and manganese are essential to the growth of water fi ix
many plants and animals, including humans 1 True
1. True 2 False
2. False
11 Sedimentation tanks should be inspected and repaired
2 Only one cell of iron bacteria is needed to start an when the tanks are emptied and cleaned.
infestation of iron bacteria in a well 1 True
1 : rue 2 False
2. False
12 A precoat of filter sand is required to dewater gelatinous
3. Fumes from hydrofluosilicic acid are safe to breathe alum sludge when using a vacuum filter.
1. True 1 True
2. False 2 False

4 Insoluble deposits should be removed from chemical 13 Before attempting to cnange fuses. turn off power and
feed lines. check both power lines for voltage.
1. True 1 True
2. False 2 False

. ,

584
 564 Water Treatment

14 Mechanical energy :s commonly converted to electrical Multiple Choice

energy by electric motors.
1
Red water complaints in drinking water may be caused
1 True by
2 False
1. Corrosive water
2 Ferric hydroxide
15 Always replace sprockets when replacing a chain. 3 Iron bacteria
1 True 4 Iron in the water
2 False 5 Red day or sat

16 A transducer Is the primary element that measures a 2 Chemicals used to oxidize iron and manganese include
variable. 1 Alum
1 True 2 Chlorine.
2 False 3 Hydrogen sulfide.
4 Lime.
5 Potassium permanganate
17 Thin rubber or plastic gloves can be worn to reduce
markedly your chances of electrical shock
3 Important features of a fluoridation system include
True
1
prevention of
2 False
1. Backsiphonage.
2 Leaks
18. If an operator is unsure of how to perform a job. then it 3 Monitoring.
is the operator s responsibility to ask for the training 4 Overfeeding.
needed 5. Underfeeding.
1. True
2 False 4 When shutting down a fluoride chemical feed system,
operators should
19 Inhalation of hydrochloric (HCI) vapors or mists can 1 Confirm that safety guards are in place.
cause damage to the nasal passages. 2. Drain and clean the mix and feed tanks.
1 True 3 Examine all fittings and drains for leaks.
2 False 4. Flush out all solution lines.
5 Inspect all equipment for binding and rubbing.
20 Distilled water is considered pleasant to drink.
5 Benefits that could result from the lime-soda ash softer
1 True ing process include
2 Faise
1. Control of corrosion.
2 Increase in sodium content of softened water
21 Dissolved oxygen in water can contribute to corrosion 3 Increase in water hardness.
of piping systems 4. Reduction in sludge disposal problems.
5 Removal of iron and manganese
1 True
2 False
6 Records that should be kept by the operator or an ion
exchange softening plant include
22 If the manganese concentration in a sample cannot be 1. Blend rates.
determined immediately. acidify the sample with acetic 2 Gallons of brine used each day.
acid
3 Pounds of lime used each day.
1 True 4 Results of jar tests.
2 False 5 Total flow per day that bypasses unit

23 Non-commu lay water systems serve consumers less 7 A min,hium of _ samples per quarter (every 3 months)
than 60 days per year for THM analysis must be taken on the same day for
1 True each treatment plant in the distribution system.
2 False 1 2
24
24. The MCL compliance for trihalomethanes is determined
36
by the running average of four monthly averages
48
5 10
1. True
2. False
8 Group 1 techniques for controiling THMs include
25. An acute toxic agent causes injury to occur over an 1 Aeration,
extended period of time. 2 Chloramines.
3 Chlorine dioxide.
1. True 4 Ozone
2. False 5 Potassium permanganate
 Final Exam 565

9 The reverse osmosis elements should be cleaned when 18. An operator must accept responsibility for
the operator observes
1 Being sure that safety equipment will work when
1. Higher differential pressures ncedec:
2 Higher operpting pressures 2 r:eflow operators.
3. Higher suspended solids in product water. 3 Operator's own welfare
4. Lower product water flow rate 4. Seeinc;, that the supervisor complies with safety re-, J-
5. Lower salt rejection labor :.
5 Utility's equipment.
10. Problems encountered in electrodialysis operation in-
clude 19 Ammonia cylinders should be stored
1. Alkaline sc2:es in the concentrating compartments. 1 Away from heat
2 Fouling of m_nbranes 2. In cool. dry locations
3 Sealing of membranes by inorganic materials. 3. In the same room with chlorine.
4. Sealing of membranes by organic materials. 4 With caps in place when not in use
5. Strengthening of membranes. 3 With protection from direct sunlight.
11 Sludge may oe dewatered by the use of 20. True color is normally removed or at least decreased by
1 Belt filter presses. 1. Chlorination
2. Centrifuges 2. Coagulation.
3. Flocculators. 3. Filtration.
4 Solar lagoons. 4. Ozonation
5. So lids-contact units. 5 Sedimentation.
12 Problems created by discharging sludge to sewers 21 High levels of nitrate in a domestic water supply are
include undesirable because of
1. Fees charged could be very high. 1. Hardness.
2. Increasing flow capacity of sewers. 2 Health threat due to Infant methemoglobinema.
3 Monitoring requirements increase. 3. Laundry stains
4 Operational problems may develop at wastewater 4. Nitrate tastes.
treatment plant. 5. Potential for stimulating excessive algae growth.
5 Possibility of causing a sewer blockage.
13. A good maintenance record system tells 22. Primary contamrants which are considered to have
1 How to handle consumer complaints. public health importance include
2. Performance of equipment 1. Lead.
3. Quality of raw water. 2 Mercury.
4. Quality of treated water. 3 Nitrate.
5. When maintenance is due. 4 Odor.
5 Sulfate.
14 A voltage tester can be useo to test for
1 Blown fuses 23 Turbidity is undesirable in drinking water because high
2. Grounds. turbioity
3. Open circuits.
4. Single phasing of motors. 1 Increases corrosivity.
5. Voltage. 2 Interferes with disinfection.
3 Interferes with micribiological determinations.
15 Before a prolonged shutdown, 1)1 ml:L; should be 4 Prevents maintenance of an effective disinfectant.
drained to prevent damage from 5. Produces aesthetic problems
1. Cavitation.
2. Corrosion. 24 Possible approaches for a utiiity to take to protect its
3. Freezing. water supply from contamination include
4. Sedimentation 1 Developing an extensive detection and monitoring
5. Water hammer. program.
2 Fencing off and patrolling reservoirs.
16 Velocity sensing devices measure flows by sensing
3 Having police lock up potential sourceL of contami-
1. Inches of water (head). nation
2. Loss of hydraulic energy 4. Isolating reservoirs that offer easy access to the
3 Pressure differential. general public
4. Pressure within a restriction. 5 Maintaining a low chlorine residual in the water.
5. Rate of rotation.
25 Important uses of records include
17. Reliable operation of pneumatic instrumentation pres-
sure systems requires 1. Aiding operators in solving treatment and water
quality problems.
1. Clean air. 2. Anticipating routine maintenance.
2. Dry air. 3. Providing data for future engineering de gns
3. Moisturized air. 4. Satisfying legal requirements.
4. Pressurized air. 5. Showing that the treated water is acceptable to the
5. Uninterrupted power. consumer

. ,..., ,5 8 G
 566 Water Treatment

Short Answers 2 Determine the setting on a potassium permanganate

chemical feeder in pounds per million gallons if the
1. How can the growth of iron bacteria in water systems be chemical dose is 2 1 mg/L
controlled?
3 A reaction basin 17 feet in diameter and 4 5 feet deep
2 Why should water being treated for iron and manganese treats a flow of 400,000 gallons per day. What is the
by ion exchange not contain any dissolved oxygen? average detention time in minutes?
3 Why should both underfeeding and overfeeding of flu- 4 A flow of 0 9 MGD is to be treated with an 18 percent
oride compounds be avoided? solution of hydrofluosilicic acid (H2SiF6). The water to be
4. How would you dispose of empty fluoride chemical treated contains no fluoride and the desired fluoride
container? concentration is 1.1 mg/L. Assume the hydrofluosilicic
acid weighs 9.6 pounds per gallon Calculate the dro-
5 Why must water be stabilized after softening? fluosilicic acid feed rate in gallons per day.
6 Why should the same chemical hopper or feeder not be 5 A flow of 400 GPM is to be treated with a 2 4 percent
used to feed both lime and alum at different times? (0.2 pounds per gallon) solution of sodium fluoride
7 Why are trihalomethanes in drinking water of concern to (Nal") The water to be treated contains 0.5 mg/L of
w,ter treatment plant operators? fluoride ion and the desired fluoride ion concentration is
0 9 mg/L Calculate the sodium fluoride feed rate in
8 Where are samples collected for THM analyses? gallons per day. Assume the sodium fluoride has a
fluoride purity of 43.4 percent.
9 What are the common membrane demmeralizmg proc-
esses? 6 How many gallons of water with a hardness of 15 grains
10 What causes "flux decline?" per gallon may be treated with an ion exchange softener
with an exchange capacity of 24,000 kilograms?
11. How can sludge be removed from sedimentation tanks?
12. Why are source water stabilizing reservoirs helpful for 7 How many hours will an ion exchange softening unit
water treatment plants? operate when treating an average flow of 350 GPM?
The unit is capable of softening 700,000 gallons of
13 Why should a qualified electrician perform most of the water before requiring regeneration.
necessary maintenance and repair of electrical equip-
ment?
8 A water utility collected and analyzed eight samples
14 Why are battery-powered lighting units considered bet- from a water distribution system on the same day for
ter than engine-driven power sou, ces? TTHMs. The results are shown below.
15. Why must a suitable screen be installed on the intake Sample No. 1 2 3 4 5 6 7 8
end of pump suction piping? TTHM, pg//. 90 100 120 90 80 110 120 80
16 What is an analog instrument? What was the average for the day?
17 How are liquid levels in chemically-active liquids meas- 9 The results of the quarterly average TTHM measure-
ured? ments for two years are given below Calculate the
18 How can pumps in a pump station be operated for running annual average of the four quarterly measure-
similar lengths of time? ments in micrograms per liter
Quarter 1 2 3 4 1 2 3 4
19. What items should be included in a utility's policy
statement on safety? Ave Quarterly
73 98 118 92 84 112 121 79
TTHM. pg/L
20 Why do safety regulations prohibit the use of common
drains and sumps from chemical storage areas' 10 Estimate the ability of a reverse osmosis plant to reject
minerals by calculating the mineral rejection as a per-
21 What problems may be caused by iron in a domestic
water supply? cent The feedwater contains 1600 mg/L TDS and the
product waled' is 145 mg/L.
22. What is the main source of tnhalomethanes in drinking
water? 11 Estimate the percent recovery of a reverse osmosis unit
with a 4-2-1 arrangement if the feed flow is 2.4 MGD and
23. Why are nitrate concentrations above the national the product flow is 2 0 MGD.
standard considered an immediate health threat?
12 Calculate tric: pumping capacity of a pump in gallons per
24 Why are high levels of sulfate undesirable in drinking
water? minute if 14 minutes are required for the water level in a
:ank to drop 4.5 feet The tank is 11 feet in diameter.
25 How can operators Improve their technical knowledge
and skills? 13 Calculate the feed rate of a dry chemical feeder in
pounds per day if 2.8 pounds of chemical are caught in a
weighing tin during eight minutes
Problems
14. Calculate the threshold odor number (T.O.N.) for a
1 Determine the setting on a potassium permanganate sample when the first detectable odor occurred when
chemical feede, in pounds per day if the chemical dose the 35 mL sample was diluted to 200 mL (165 mL of
is 2.1 nig/L and the flow is 0.53 MGD. odor-free water was added to the 35 mL sample).

587
 Final Exam 567

15 Determine the taste rating for a water by calculating the 16 A small water system collected 12 samples during one
arithmetic mean for the panel ratings given below month After each sample was collected, 10 mL of
Tester No. 1 2 3 4 5 6 7
sample was placed in each of 5 fermentation tubes At
Rating 4 2 7 3 6 5 8
the end of the month, the results indicated that 3 out of a
total of 60 fermentation tubes were positive. What
percent of the portions tested during the month were
positive'?

SUGGESTED ANSWERS FOR FINAL EXAMINATION

1. True Iron and manganese are essential to the growth 14 False Electrical energy is commonly converted into
of many plants and animals, including humans. mechanical energy by electric motors.
2 True Only one cell of iron bacteria is needed to start 15. True Always replace sprockets when replacing a
an infestation of iron bacteria in a well chain.
3 False Hydrofluosilicic acid produces poisonous fumes 16. False A sensor is the primary element that measures a
4 True Insoluble deposits should be removed from variable.
chemical feed lines.
17. True Thin rubber or plastic gloves can be worn to
5 False In the lime softening process, magnesium is reduce markedly your chances of electrical
precipitated out as magnesium hydroxic.a. shock.
6 False Caustic soda softening may be used instead of 18 True If an operator is unsure of how to perform a job,
soda ash. then it is the operator's responsibility to ask for
the training needed.
7. False Do not use dry ice when shipping and storing
THM samples because the sample water can 19 True Inhalation of hydrochloric (HCI) vapors or mists
freeze and break the bottle. can cause damage to the nasal passage.
8 False THMs are produced faster in scale forming 20. False Distilled water is not considered pleasant to
waters (hig'. pH) than in corrosive waters.
drink.
9 False When higher mineral concentrations occur in the
feedwater, the mineral concentrations will in- 21 True Dissolved oxygen in water can contribute to
crease in the product water. corrosion in piping systems

10. False An increase in feedwater temperature will in- 22 False If the manganese concentration in a sample
crease the water flux. cannot be determined immediately, acidify the
sample with nitric acid, not acetic acid.
11. True Sedimentation tanks should be inspected and
repaired when the tanks are emptied and 23. alse Non-community water systems serve consum-
cleaned. ers at least 60 days a year.
12. False A precoat of diatomaceous earth is required to 24 False i ne MCL compliance for trihalomethanes is de-
dewater gelatinous aium sludge when using a termined by', 3 running average of four quarter-
vacuum filter. ly averages.
13. True Turn off power and check both power lines for 25. False A 3hronic toxic agent causes injury to occur over
voltage before changing fuses, an extended period of time.
568 Water Treatment

Multiple Choice 16 5 Velocity-sensing devices measure flows

by sensing rate of rotation.
1. 1, 2, 3, 4 Red water complaints in drinking water
may be caused by corrosive water, ferric 17 1. 2, 4 Reliable operation of pneumatic instru-
hydroxide, iron bacteria and iron in the mentation pressurc.. systems requires
water clean air, dry air and pressurized air.
2 2, 5 Chemicals used to oxidize iron and man- 18 1, 2, 3, 4, 5 An operator must accept responsibility for
ganese include chlorine and potassium being sure that safety equipment will work
permanganate. when needed (your life may depend on it).
fellow operators, operator's own welfare.
3 1. 2. 4. 5 Imuortant features of a fluoridation system seeing that the supervisor complies with
include prevention of ber..ksiphonage, safety regulations and the utility's equip-
leaks, overfeeding and underfeeding ment
4. 2, 4 When shutting down a fluoride chemical 19 1, 2, 4, 5 Ammonia cylinders should be stored in
feed system. operators should drain and cool, dry locations with caps in place when
clean the mix and feed tanks and flush out not in use and away from heat, direct
all sc "ition lines. sunlight arid chlorine
5. 1. 5 Benefits that could result from the lime- 20 1. 2, 4 True colc is normally removed or at least
soda ash softening process include con- decreased by chlorination, coagulation, or
trol of corrosion and removal of iron and °zonation.
manganese. Other items listed are limita-
tions 21. 2, 5 High levels of nitrate in a domestic water
6 1. 2, 5 Records that should be kept by the opera-
supply are undesirable because of the
health threat due to infant methemoglobin-
tor of an ion exchange softening plant
ema and the potential for stimulating ex-
include blend rates, gallons of brine used cessive algal growth
each day and total flow per day that by-
passes unit. 22 1. 2, 3 Lead. mercury and nitrate are primary con-
72 A minimum of 4 samples per quarter (ev- taminants which are considered to have
ery 3 months) for THM analysis must be pi.blic health importance.
taken on the same day for each treatment
plant in the distribution system. 23. 2, 3, 4. 5 Turbidity is undesirable in drinking water
because high turbidity interferes with dis-
8. 2. 3. 5 Chloramines, chlorine dioxide and potas- infection, interferes with microbiological
sium permanganate are Group 1 tech- determinations, prevents maintenance of
niques for controlling THMs. an effective disinfectant, and produces
aesthetic problems.
9 1. 2. 4. 5 The revPrse osmosis elements should be
cleaned when the operator observes high- 24 1, 2, 4 Possible approaches for a utility to take to
er differential pressures, higher operating protect its water supply from contamina-
pressures, lower product water flow rate. tion include developing an extensive de-
and lower salt rejection. tection and monitoring program, fencing
10 1, 2, 3. 4
off and patrolling reservoirs, isoldting res-
Problems encountered in electrodialysis
ervoirs that offer easy access to the ; sner-
operation include alkaline scales in the al public, and maintaining a HIGH chlorine
concentrating compartments, fouling of residual in the water
membranes, and sealing of membranes by
both organic and inorganic materials. 25. 1. 2. 3, 4, 5 Important uses of records include aiding
11 1, 2, 4 Sludge may be dewatered by the use of operators in solving treatment and water
belt filter presses. centrifuges and solar quality problems. anticipating routine
lagoons maintenance, providing data for future en-
gineering designs, satisfying legal require-
12 1, 3, 4. 5 Problems created by discharging sludge to ments. and showing that the treated water
sewers include: fees charged could be is acceptable to the consumer.
very high, monitoring requirements in-
crease. operational problems may develop Short Answers
at wastewater treatment plant, and possi-
b..ity of causing a sewer blockage. 1 The growth of iron bacteria can be controlled by main-
taining a free chlorine residual at all times throughout
13 2. 5 A good maintenance record system tells the system.
performance of equipment and when
maintenance is due. 2 Water being treated for iron and manganese by ion
exchange should not contain any dissolved oxygen
14 1, 2, 3, 4, 5 A voltage tester can be used to test for because the resin will become fouled with iron rust or
blown fuses, grounds, open circuits, single insoluble manganese dioxide.
phasing of motors and voltage.
3 Underfeeding should be avoided because of the loss of
15 2, 3, 4 Before a prolonged shutdown, pumps benefits expected from fluoridation. Overfeeding should
should be drained to prevent damage from be avoiding due to the potential harm to consumers and
corrosion, freezing and sedimentation. the waste of chemicals and money.

583
 Final Exam 569

4. Empty fluoride chemical containers can be lisposed of woi king conditions Finally, the policy must reinforce the
by thoroughly rinsing all containers with \ vater to re- supervisory re,ponsibility to maintain safe work prac-
move all traces of chemicals before allowing the con- tices
tainers to leave the plant Containers may be burned if a 20 Safety regulations prohibit the use of common drains
nuisance will not be created Remember that fluoride and sumps from chemical storage areas to avoid the
fumes can kill vegetation. possibility of chemicals reacting and producing toxic
5. Water must be stabilized after softening to prevent gases. explosions and fires
corrosion or the formation of scale in pipes 21 Problems that may be caused by iron in a domestic
6 The same chemical hopper or feeder should not be water supply include staining of laundry, concrete, and
used to feed both lime and alum because the resulting porcelain A bitter astringent taste can be detected by
chemical reactions could generate enough heat to some people at levels above 0 3 mg/L
cause a fire. 22 The main source of trihalomethanes in drinking water is
7 Tnhalomethanes in drinking water are of concern to the chemical interaction of chlorine added for disinfec-
water treatment plant operators because of tie possible tion and other purposes ;th the commonly present
heatlh effects. natural humic substances and other THM precursors.
produced either by normal organic decomposition or by
8 Twenty-five percent of the samples collected for THM the metabolism of aquatic organisms
analyses are collected from the extremiti s of the distri-
23 Nitrate concentrations in drinking water above the na-
bution system (the farthest points from the plant) and 75
tional standard are considered an immediate threat to
percent must be representative of the population children under three months of age. In some infants,
served
excessive levels of nitrate have been known to react
9. The common membrane demineralizing processes are with intestinal bacteria which change nitrate to nitrite
reverse osmosis and electrodialysis. which react with hemoglobin in the blood to produce an
anemic condition commonly known as "blue baby.'
10 "Flux decline" is the loss of water flow through the
membrane due to compaction plus fouling. 24 High levels of sulfate e undesirable in drinking water
because they tend to form hard scales in boilers and
11. Sludge can be removed from sedimentation tanks by heat exchangers, cause taste effects, and cause a
mechanical rakes or scrapers or a vacuum-type sludge laxative effect.
removal device may be used.
25. Operators can improve their technical knowledge. and
12 Source water stabilizing reservoirs are helpful because skills by training. Sources or types of training include on
they reduce the turbidity in the water being treated and the job, trade magazines and papers, workshops, for-
thus reduce the volume of sludge. mal training in classrooms, and home-study courses.
13. A qualified electrician should perform most of the nec- Problems
essary maintenance and repair of electrical equipment
to avoid endangering lives and to avoid damage to 1. Determine the setting on a potassium permanganate
equipment chem cal feeder in pounds per day if the chemical dose
is 2.1 mg/L and the flow is 0 53 MGD.
14. Battery-powered lighting units are considered better
than engine-driven power sources because they are Known Unknown
more economical Also if you have a momentary power Chemical Feeder,
Flow, MGD = 0.53 MGD
outage, the system rP ^nds without an engine gener- lbs/day
ator startup. Dose, mg/L = 2.1 mg/L

15 A suitable screen must be installed on the intake end of Determine the chemical feeder setting in pounds per
pump suction piping to prevent foreign matter (sticks, day
refuse) from being sucked into the pump and clogging Chemical Feeder, = (Flow. MGD)(Dose. mg/L)(8 34 lbs/gal)
or wearing the impeller. lbs /day
(0 53 MGD)(2 1 mg/L)(8.34 lbs/gal)
16. An analog instrument has a pointer (or other indicating
means) for reducing a dial or scale. 9 3 lbs/day
17 Liquid levels in chemically-active liquids are measured 2 Determine the setting on a potassium permanganate
with probes. chemical feeder in pounds per million gallons if the
chemical dose is 2 1 nig/L
18 Pumps in a pump station can be operated for similar
lengths of time by the use of manual or automatic Known Unknown
"sequencers" which switch different pumps to the "lead" Dose, lbs/MG
pump position and the others to the "lag" position Dose, mg/L = 2.1 mg/L
periodically. Convert the dose from milligrams per liter to pounds per
19 A utility's policy statement on safety should give its million gallons
objective concerning the operator's welfare The state- (Dose, mg/L)(3.785 L/gal)(1 .000,000)
ment should give the utility's recognition of the need for Dose, lbs/li
safety to stimulate efficiency, improve s.arvice, improve (1000 mg/gm)(454 gm/lb)(1 Million)
moral and to maintain good public relations. The policy 2 1 mg/L)13 785 L/gal)(1.000,000)
should recognize the human factor (the unsafe act). and
emphasize the operator's responsibility The operators (1000 mg/Qv/01-154 gm,'110)(1 Milton)
should be provided with proper equipment and safe 17 5 it2s'MC2

590
570 Water Treatment

3 A reaction basin 17 feet in diameter and 4 5 feet deep Known Unknown

treats a flow of 400,000 gallons per day. What is the
average detention time in minutes? Flow, MGD 400 GPM Feed Rate. gal/day
NaF Solution. % 2 4%
Known Unknown NaF Solution, 0 2 lbs/ga!
Diameter. ft = 17 ft Detention Time, min lbs/gal
Depth. ft = 4 5 ft Desired F. mg/L = 0 9 mg/L
Flow, GPD = 400,000 CPD Actual F, mg/L = 0.5 mg/L
Purity. % - 43.4%
1. Calculate the basin volume in cubic feet
Basin Vol, cu ft = (0.785)(Diameter, ft)::(Depth. ft)
1 Convert the flow from gallons per minute to million
gallons per day
= (0 785)(17 ft)2(4.5) Flow. (Flow. gal/min)(60 min/hr)(24 hr/day)(1 Million)
= 1021 cu ft MGD
1.000,000
2 Convert the basin volume from cubic feet to gallons. (400 gal/min)(60 min/hr)(24 hr/day)(1

Basin Vol, gal = (Basin Vol, cu ft)(7.48 gal/cu ft) 1.000.000

= 0 576 MGD
= (1021 cu ft)(7 48 gal /cu ft)
= 7637 gai 2 Determine the fluoride dose in milligrams per liter.
3 Determine the average detention time in minutes in Feed Dose, mg/L Desired Dose. mg/L Actual F. mg/L
the reaction basin. 0 9 mg/L 0.5 mg/L
Detention Time. (Basin Vol, gal)(24 hr/day)(60 min/hr) = 0 4 mg/L
min
Flow, gal/day
3. Calculate the feed rate in pounds of fluoride ion per
(7637 gal)(24 hr/day)(60 min/hr) day.
400.000 gal/day Feed Rate,
lbs F/day - (Flow, MGD)(Feed Dose, mg/L)(8 34 lbs/gal)
27 5 minutes
= (0.576 MGD)(0 4 mg/L)(8.34 ibs/gal)
4 A flow of 0 8 MGD is to be treated with an 18 percent
solution of hydrofluosilicic acid (H2S1F6). The water to be = 1.9 lbs/day
treated contains no fluoride and the desired iluonde
concentration is 1.1 mg/L. Assume the hydrofluosilicic 4 Convert the feed rate from pounds of fluoride per day
acid weighs 9.6 pounds per gallon. Calculate the hydro- to gallons of sodium fluoride solution per day.
fluosilicic acid feed rate in gallons per day Feed Rate, (Feed Rate, lbs F /day)(100 %)
Known gal/day
Unknown (NaF Solution, lbs F/gal)(Purity, %)
Flow. MGD = 0 8 MGD Feed Rate, gal/day (1 9 lbs F /day)(100 %)
Acid Solution, % = 18% (0.2 lbs/gal)(43.4°/0)
Acid. lbs/gal = 9 6 lbs/gal
= 22 gal/day
Desired F, mg/L - 1 1 mg/L
6 How many gallons of water with a hardness of 15 grains
1 Calculate the hydrofluosilicic acid feed rate in pounds per gallon may be treated by an ion exchange softener
per day with an exchange capacity r... 24,000 kilograms?
Feed Rate. (Flow MGD)(Desired F. mg /L)(8 34 lbs/gal)(100%) Known
lbs/day
Unknown
Acid Solution. %
Hardness' = 15 grains/gal Water Treated,
(08 MGD)(1 1 mg/L)(8 34 lbs/gal)(100 0) grains/gal gallons
18%
Exchange
41 lbs acid/day Capacity, = 24,000.000 grams
2 Determine the teed rate of the acid in gallons per day. grains
Feed Rate, Feed Rate, lbs/day Calculate the gallons of water that may be treated.
gal/day
9.6 lbs/gal Water Treated, gal = Exchange Capacity, grains
41 lbs/day Hardness, grains/gal
9 6 lbs acid/gal acid 2 4,000,000 grains
= 4.3 gal acid/day 15 grains/gal
5. A flow of 400 GPM is to be treated with a 2.4 percent 1,600,000 gallons
(0.2 pounds per gallon) solution of sodium fluoride = 1 6 M gallons
(NaF). The water to be treated contains 0.5 mg/L of
fluoride ion and the desired luoride ion concentration is 7. Hew many hours will an ion exchange softening unit
0 9 mg/L Calculate the sodium fluoride feed rate in operate when treating an average flow of 350 GPM?
gallons pe day. Assume the sooium fluoride has a The unit is capable of softening 700,000 gallons of
fluoride purity of 43.4 percent. water before requiring regeneration.

591
 Final Exam 571

Known Unknown
QUARTERS 2 3. 4 AND 1
Ave Daily Flow. GPM = 350 GPM Operating Time. Annual Running TTHM 98 ug/L 118 ug/L 92 ug/L 84 ug/L
Water Treated, gal = 700.000 gal hr Average ug/L
4
Estimate how many hours the softening unit can oper- 392 p giL
ate before requiring regeneration
4

Operating Time. hr Water Treated ggal

98 ug/L
(Ave Daily Flow. gal/min)(60 min/hr)
700.000 gal QUARTERS 3. 4. 1 AND 2

(350 gal/min)(60 min/hr) Annual Running TTHM 118 p 9/ L 92 Mg/L 84 ug/L - 117 ug/L
Average ug/L
4
33 3 hours
406 ug/L

8. A water utility collected and analyzed eight samples 4

from a water distribution system on the same day for 102 ugiL
TTHMs. The results are shown below
QUARTERS 3, 4. 1 AND 2
Sample No. 1 2 3 4 5 6 7 8
Annual Running TTHM 92 go. 84 A 9/ L 112 ug/L 121 p 9/ L
TTHM. ug/L 90 100 120 90 80 110 120 80 Average ug/L
4

What was the average for the day') 409 Aga

4
Known Unknown
102 ug/t.
Re Its from analysis of 8 Average TTHM level
TTY -1M samples for the day
QUARTERS 1. 2. 3 AND 4
C... Jlate the average TTHM level in micrograms per
liter Annual Running TTHM 84 ugll 112 ug/L 121 ug/L 79 ug/L
Average ug/L
4
Ave TTHM Sum of Measurements, uoiL
ug/L 396 PO.
Number of Measurements
4
90 pg/L 100 ug/L 120 ug/L 90 4g/L.
60 gg/L 11 0 ug/L 99 ug/L
1 20 gg/L 80 gg/L
8
SUMMARY OF RESULTS
790 ug//.
8 Quarter 1 2 3 4 1 2 3 4

99 gg/L Ave Quarterly 73 98 118 92 84 112 121 79

ITHM. pig/L
9 The results of the quarterly average TTHM measure- Annual Running
ments for two years are given below Calculate the 95 98 102 102 99
TTHM. ugJL
running annual average of the four quarterly measure-
ments in micrograms per liter

Quarter 1 2 3 4 1 2 3 4

Ave Quarterly 10 Estimate the ability of a ;Tverse osmosis plant to reject

TTHM pg/L 73 98 118 92 84 112 121 79 minerals by calculating the mineral rejection as a per-
cent The feedwater contains 1600 mg/L TDS and the
Known Unknown product water is 145 rng/L
Results from analysis of 2 Running annual aver- Known Unknown
years of TTHM sampling age of quarterly TTHM
Feedwater TDS. 1600 mg/L Mineral
measurements
mg/L Rejection. °,0
Calculate the running annual average of the quarterly

P0
TTHM measurements Product Water TDS. 145 mg/L
mg/L
Annual Running TTHM Sum of Ave TTHM for Four Quarters
Average ug/L
Number of Quarters Calculate the mineral rejection as a percent
QUARTERS 1. 2 3 AND 4 Mineral Rejection °0 roduct TDS, mg/L
(1 )(100°
Annual Running TTHM 73 AA ga 98 Ai gil. 118 g/L 92 gy L Feed TDS, mg/L
Average ug/L
145 mg/L
(1 !(100°0)
381 A g, L 1600 mg/L
4
(1 0 09)(100°0)
95 ug,,L 91°.

59,2
572 Water Treatment

11 Estimate the percent recovery of a reverse osmosis unit the 35 mL sample was diluted to 200 mL (165 mL of
with a 4-2-1 arrangement if the feed flow is 2 4 MGD and odor-free water was added to the 35 mL sample).
the product flow is 2.0 MGD
Known Unknown
Known Unknown Size of Sample. nit_ T0N
35 nit_
Product Flow. MGD 2 0 MGD Recovery. '0 Odor-Free Water. mL 165 mL
Feed Flow, MGD 2 4 MGD
Calculate the threshold odor number. T 0 N
Calculate the recovery as a percent.
TON. Size of Sample, mL Odor -Free Water, mL
Recovery. °., (Product Flow, MGD)(100°0) Size of Sample. mL
Feed Flow. MGD
35 mL 165 mL
(2 0 MGD)(100%)
35 mL
24 MGD
-6
83°0
12 Calculate the pumping capacity of a pump in gallons per 15 Determine tne taste rating for a water by calculating the
minute if 14 minutes are required for the water level in a arithmetic mean for the panel ratings give below
tank to drop 4.5 feet The tank is 11 feet in diameter Tester No 1 2 3 4 5 6 7
Known Unknown Rating 4 2 7 3 6 5 8
Drop. ft 4.5 ft Pump Capacity.
Known Unknown
Diameter, ft -- 11 ft GPM
Taste Ratings Arithmetic Mean, X
Pumping Time, min - 14 min
Calculate the arithmetic mean X. taste rat ng
1 Calculate the volume pumped in gallons
Arithmetic Mean X X1 X2 X3 X4 X6 X6 X2
Volume, gal (0 785)(Diameter. ft)2(Drop, ft)(7 48 gal/cu ft) Taste Rating n
(0 785)(11 ft)2(4 5 ft)(7 48 gal/cu ft)
4.2.7.3.6.5.8
3197 gallons 7

2 Estimate the pumping capacity in gallons per minute 35

Pumping Capa,.ty. Volume Pumped. gallons 7
GPM
Pumping Time. min 5

3197 gallons
14 min
16 A small water system collected 12 samples during one
month After each sample was collected, 10 mL of
228 GPM sample was placed in each of 5 fermentation tubes. At
the end of the month, the results indicated that 3 out of a
13 Calculate the feed rate of a dry chemical feeder in total of 60 fermentation tubes were positive What
pounds per day if 2.8 pounds of chemical are caught in a percent of the portions tested during the month were
weighing tin during eight minutes positive?
Known Unknown Known Unknown
Chemical, lbs = 2.8 lbs Chemical Feed, Number Positive Portions,
Time, min = 8 min lbs/day 3 posi
positive /mo
Positive/mo %/mo
Calculate the chemical feed rate in pounds of chemical Total Portions
per day. 60 portions
Tested
Chemical Feed. (Chemical, lbs)(60 min/hr)(24 hr/day)
lbs/day Calculate the percent of portions tested during the
Time, min month which were positive
(2 8 lbs)(60 minihr)(24 hr/day) (Number Positive/mo)(100%)
Portions Positive. %/mo
8 min Total Portions Tested
= 504 lbs/day (3 positive/mo)(100'0)

14. Calculate the threshold odor number (T.O.N.) for a 60 portions

sample when the first detectable odor occurred when 5%/mo

5 (,; 3
 APPENDIX

HOW TO SOLVE WATER TREATMENT PLANT

ARITHMETIC PROBLEMS

(VOLUME II)

by

Ken Kerri

524
574 Water Treatment

TABLE OF CONTENTS
HOW TO SOLVE WATER TREATMENT PLANT ARITHMETIC PROBLEMS

Page
A.1 Basic Conversion Factors (English System; . 575
A.2 Basic Formulas 575
A.3 Typical Water Treatment Plant Problems 578
A.30 Iron and Manganese Control . 578
A.31 Fluoridation 578
A.32 Soi+ening . .. . ......... . .. ......... . .. ... ....... . 580
A 33 Tnhalometha nes ..... 583
A.34 Demineralization 584
A 35 Maintenance 584
A.36 Safety 585
A 37 Advanced Laboratory Procedures 585
A.4 Basic Conversion Factors (Metric System) . 587
A.5 Typical Water Treatment Plait Problems (Metric System) 587
A.50 Iron and Manganese Control .
587
A.51 Fluoridation . .. . . ....... ...... 588
A 52 Softening ..... ... ...... ... . ..... ..... . 590
A 53 Tnhalomethanes 593
A.54 Demineralization 594
A.55 Maintenance .
594
A.56 Safety 595
A.57 Advanced Laboratory Procedures ..... 596
 Arithmetic 575

SOLVING WATER TREATMENT PLANT OPERATION PROBLEMS

(VOLUME II)

A.1 BASIC CONVERSION FACTORS (ENGLISH SYSTEM) DENSITY

UNITS 8.34 lbs = 1 gal 8.34 lbs/gal
62 4 lbs = 1 cu ft 62.4 lbs/cu ft
1,000,000 = 1 Million 1.000.000/1 Million
LENGTH DOSAGE
12 in = 1 ft 12 in/ft 17.1 mg/L = 1 grain/gal 17 1 mg/L/gpg
3 ft = 1 yd 3 ft/yd 64.7 grams = 1 mg 64.7 grains/mg
5280 ft = 1 mi 5280 ft/mi
PRESSURE
AREA
2.31 ft water = 1 psi 2.31 ft/psi
144 sq in = 1 sq ft 144 sq in/sq ft 0.433 psi = 1 ft water 0.433 psi/ft
43,560 sq ft = 1 acre 43.560 sq ft/ac 1 133 ft water = 1 in Mercury 1.133 ft water/in Mercury
VOLUME
FLOW
7.48 gal = 1 cu ft 7.48 gal/cu ft
1000 mL = 1 liter 1000 mL /L 694 GPM = 1 MGD 694 GPM/MGD
3.785 L= 1 gal 3.785 L/gal 1 55 CFS = 1 MGD 1.55 CFS/MGD
231 cti in = 1 gal 231 cu in/gal
TIME
WEIGHT
60 sec = 1 min 60 sec/min
1000 mg = 1 gm 1000 mg/gm 60 min = 1 hr 60 min/hr
1000 gm = 1 kg 1000 gm/kg 24 hr = 1 day 24 hr/day
454 gm = 1 lb 454 gm/lb
2 2 lbs = 1 kg 2.2 lbs/kg NOTE In our conversion factors the values in the right
POWER hand column may be written either as 24 hr/day or 1
day/24 hours depending on which units we wish to
0.746 kw = 1 HP 0.746 kw/HP convert to our desired results.

A.2 BASIC FORMULAS

IRON AND MANGANESE CONTROL
1 a. Stock Solution. (Polyphosphate, grams)(1000 mg/gm)
mg/mL (Solution, liter)(1000 mL /L)

lb. Dose. mg/L (Stock Solution. mg/mL)(Volume Added. mL)

Sample Volume. L

lc Dose. lbs/MG (Dose. mg/L)(3.785 L/gal)(1.000.000)

(1000 mg/gm)(454 gm/lb)(1 Million)
2. Chemical Feeder, = (Flow. MGD)(Dose, mg/L)(8 34 lbs/gal)
lbs/day

3. Detention (Basin Vol. gal)(24 hr/day)(60 min/hr)

Time, min
Flow, gal/day
4 KMnO, Dose, mg/L = 0.6(Iron, mg/L) + 2.0(Manganese, mg/L)
FLUORIDATION
5. Feed Rate, (Feed Rate. lbs F/day)(100%)
gal/day (NaF Solution, lbs F /gal)(Purity. %)

596
576 Water Treatment

6 Feed Solution, (Flow, gal/day)(Feed Dose, mg/L)

gal/day
Feed Solution, mg/L
7. Fluoride Ion (Molecular Weight of Fluonde)(100%)
Purity, %
Molecular Weight of Chemical
8a Feed Dose, mg/L = Desired Dose, mg/L Actual Conc, mg/L
8b. Feed Rate, Feed Rate, lbs F/day
lbs/day
lbs F/lb Commercial Na2SiF6
9 Feed Solution, (Flow Vol, gal)(Feed nose, mg /L)
gal
Feed Solution, mg/L
10 Mixture (Tank, gal)(Tank %) + (Vendor, gal)(Vendor, %)
Strength, %
Tank, gal + Vendor, gal

SOFTENING
11. Total Hardness, _Calcium Hardness, _Magnesium Hardness,
mg/L as CaCO3 mg/L as CaCO3 mg/L as CaCO3
12. If alkalinity is greater than total hardness,
Carbonate Hardness, Total Hardness,
mg/L as CaCO3 mg/L as CaCO3

and
Noncarbonate Hardness, = 0
mg/L as CaCC'3
13. If alkalinity is less than total hardness,
Carbonate Hardness, = Alkalinity, mg/L as CaCO3
mg/L as CaCO3
an I
Noncarbonate Hardness, Total Hardness, Alkalinity,
mg/L as CaCO3 mg/L as CaCO3 mg/L as CaCO3

14a. Phenolphthalein ,A X N x 50,000

Alkalinity,
mL of sample
mg/L as CaCU3

14b Total Alkalinity, BxNx 50,000

mg/L as CaCO3 mL of sample
15a. Hydrated Lime (A B C + D)1.15
(Ca(OH)2) Feed, mg/L Purity of Lime, as a decimal
15b. Soda Ash (Na2CO3) Noncarbonate Hardness, )(106/100)
Feed, mg/L mg/L as CaCO3
15c. Total CO2 Feed, = (Ca(OH)2 excess, mg/L)(44/74)
lbs/day + (Mg2` residual, mg/L)(44/24.3)
16 Feeder Setting, = (Flow, MGD)(Conc, mg/L)(8 34 lbs/gal)
lbs/day

17. Feed Rate, lbs/min Feeder Setting, lbs/day

(60 min/hr)(24 hr/day)

18 Hardness, mg/L (Hardness, grains/gal)(17.1 mg /L)

1 grain/gal
19. Exchange Capacity,
= (Resin Vol, cu ft)( Removal Capacity'
grains grains/cu ft
20. Water Treated, gal = Exchange Capacity, grains
Hardness, grains/gal
 Arithmetic 577

21. Operating Time. hr Water Treated, gal

(Ave Daily Flow, gal/min)(60 min/hr)

22. Salt Needed. lbs .._/ Salt Required, 1 i Hardness Removed. gr

' lbs/1000 qr '

23 Bypass Flow. GPD (Total Flow, GPD)(Plant Eff1 Hardness, gpg)

Raw Water Hardness, gpg
TRIHALOMETHANES
_ Sum of Measurements, pg/L
24. Ave TTHM, pg/L
Number of Measurements
25. Annual Running TTHM Sum of Ave TTHM for Four Quarters
Average, pg//. Number of Quarters

DEMINERALIZATI0i4

26. Flow, GPD/sq it (Flux, gm/sq cm-sec)(1 Liter)(1 Gal)(100 cm)2 (3600 sec)(24 hr)
(1000 gm)(3.785 L)(3.28 ft)2 (1 hr)(1 day)

27. Mineral Rejection, % Product TDS, mg/L )(100%)

Feed TDS, mg/L

28. Recovery, % (Product Flow, MGD)(100%)

Feed Flow, MGD

29. Pump Capacity, GPM Tank Volume, gal

Pumping Time min

30. Flow, GPD (Volume Pumped, gal)(24 hr/day)

Time, hr
31. Polymer Feed, (Poly Conc, mg/L)(Vol Pumped, mL)(60 min/hr)(24 hr/day)
lbs/day (Time Pumped, min)(1000 mL/L)(1000 mg/gm)(454 gm/lb)
32. Chemical Feed. (Chemical, gm)(60 min/hr)(24 hr/day)
lbs/day (454 grn /Ib)(Time, min)
SAFETY

33. Injury Freq Rate (Injuries, number/yr)(1,000,000)

Hours Worked, number/yr

34. Injury Severity Rate (Number of Hours Lost/yr) (1,000,000)

Number of Hours Worked/yr
ADVANCED LABORATORY PROCEDURES
35. Threshold Odor Size of Sample, mL + Odor-Free Water, mL
Number (T.O.N.) Size of Sample, mL
36. Geometric Mean = (X, x X2 x X3 X . .. Vin
37. Threshold Taste Size of Sample, mL + Taste-Free Water, mL
Number Size of Sample, mL
38a. Arithmetic Mean, X X, -4- X2 + X3 : .. . Xn
Taste Rating n

(xi _ R)2 + (x2 R)2 + (xn X)2 05

38b. Standard Deviation, S
Taste Rating n 1

(x 2 + x22 + x02) (X1 4. X2 + xn)2 /r) 05

Or
n 1

39. Portions Positive, (Number Positive/mo)(100%)

Total Portions Tested

598
 578 Water Treatment

A.3 TYPICAL WATER TREATMENT PLANT PROBLEMS EXAMPLE 3

A.30 Iron and Manganese Control A reaction basin 14 feet in diameter and 4 feet deep treats
a flow of 240,000 gallons per day. What is the average
EXAMPLE 1 detention time in minutes?

A standard polyphosphate solution is prepared by mixing Known Unknown

and dissolving 1.0 grams of polyphosphate in a container Diameter. ft = 14 ft Detention Time, min
and adding distilled water to the one-liter mark. Determine Depth, ft = 4 ft
the concentration of the stock solution in milligrams per
Flow, GPD = 240.000 GPD
milliliter. If 6.0 milliliters of the stock solution are added to a
one-liter sample, what is the polyphosphate dose in milli- 1. Calculate the basin volume in cubic feet.
grams per liter and pounds per million gallons?
Basin Vol, cu ft = (0.785)(Diameter, ft)2(Depth, ft)
Known Unknown
= (0.785)(14 ft)2(4 ft)
Polyphosphate. gm = 1.0 gm 1. Stock Solution, mg/mL
Solution, L = 1.0 L 2. Dose, mg/L = 615 cu ft
Stock Solution. mL = 6 mL 3. Dose, lbs/MG 2 Convert the basin volume from cubic feet to gallons.
Sample. L =1L
Basin Vol, gal = (Basin Vol, cu ft)(7.48 gal/cu ft)
1. Calculate the concentration of the stock solution in milli- = (615 cu ft)(7.48 gal/cu ft)
grams per milliliter.
= 4600 gal
Stock Solution. (Polyphosphate, gm)(1000 mg/gm)
mg/mL 3. Determine the average detention time in minutes for the
(Solution. L)(1000 mL /L) reaction basin.
(1.0 gm)(1000 mg/gm) Detention Time, (Basin Vol. gal)(24 hr/day)(60 min/hr)
(1 L)(1000 mL /L) min
Flow, gal/day
= 1.0 mg/mL (4600 gal)(24 hr/day)(60 min/hr)
240,000 gal/day
2 Determine the polyphosphate dose in the sample in
milligrams per liter. = 28 minutes

Dose. mg /L = (Stock Solution. mg/mL)(Vol Added, mL) EXAMPLE 4

Sample Volume. L Calculate the potassium permanganate dose in milligrams
(1 0 mg/mL)(6 mL) per liter for a well water with 2.4 mg/L iron before aeration
and 0.3 mg/L after aeration. The manganese concentration
1L is 0.8 mg /L both before and after aeration.
= 6.0 mg/L Known Unknown
3 Determine the polyphosphate dose in the sample in Iron. mg /L = 0.3 mg/L KMnO4 Dose. mg /L
pounds of phosphate per million gallons. Manganese. mg/L = 0 8 mg/L

Dose. lbs/MG (Dose. mg/L)(3.785 L/gal)(1,000.000) Calculate the potassium permanganate dose in milligrams
per liter
(1000 mg/gm)(454 gm/lb)(1 Million)
KMnO4 Dose. mg /L = 0 6(Iron. mg /L) + 2 0(Mangarese. mg /L)
(6.0 mg/L)(3.785 L/gal)(1.000,000)
-- 0 6(0.3 mg /L) + 2 0(0 8 mg /L)
(1000 mg/gm)(454 gm/lb)(1 Million)
= 1 78 mg/L
= 50 lbs/MG
NOTE: If there are any oxidizable compounds (organic
color, bacteria, or hydrogen sulfide) in the water,
EXAMPLE 2
the dose .rill have to be increased.
Determine the chemical feeder setting in pounds of poly-
phosphate per day if 0.62 MGD is treated with a dose of 6 A.31 Fluoridation
mg /L.
EXAMPLE 5
Known Unknown
Determine the setting for a chemical feed pump in gallons
Flow, MGD = 0.62 MGD Chemical Feeder, lbs/day per day when the desired fluoride dose is 1.8 pounds of
Dose, mg/L = 6 mg/L fluoride per day. The sodium fluoride solution contains 0.2
Determine the chemical feeder setting in pounds per day. pounds of fluoride per gallon and the fluoride purity is 43.4
percent.
Chemical Feeder.
= (Flow. MGD)(Dose, mg/L)(8.34 lbs/gal) Known Unknown
lbs/day
= (0.62 MGD)(6 mg/L)(8.34 lbs/gal) Feed Rate. lbs F/day = 1.8 lbs F/day Feed Rate,
NaF Solution, lbs F/gal = 0.2 lbs F/gal gal/day
= 31 lbs/day Purity, % = 43.4%

599
 Arithmetic 579

Determine the setting on the chemical feed pump in gallons Known Unkno Nn
per day. Flow, MGD = 1.7 MGD Feed Rate, lbs/day
Feed Rate, (Feed Rate, ibs F /day)(100 %) Raw Water F, mg/L = 0.2 mg/L
gal/day (NaF Solution, lbs F /gal)(Pur :ty, %) Desired F. mg/L = 1 1 mg/L
Chemical, lbs F/lb = 0 6 lbs F/lb
(1.8 lbs F /day)(100 %)
1. Determine the fluoride feed dose in milligrams per liter.
(0.2 lbs F /gal)(43.4 %)
Feed Dose. mg/L = Desired Dose, mg/L Actual Conc. mg/L
= 20.7 gal/day
= 1 1 mg/L 0 2 mg/L
or = 21 gal/day
= 0 9 mg/L
2 Calculate the fluoride feed rate in pounds per day.
EXAMPLE 6
Feed Rate. = (Row. MGD)(Feed Dose, mg/L)(8 34 lbs/gal)
Determine the setting on a chemical feed pump in gallons lbs F/day
per day if 500,000 gallons per day of water must be treated = (1 7 MGD)(0.9 mg/L)(8 34 lbs/gal)
with 0.9 mg/L of fluoride. The fluoride feed solution contains
13,000 mg/L of fluoride. = 12 8 lbs F/day
Known Unknown 3. Determine the chemical feed rate in pounds of commer-
Flow, gal/day = 500,000 gal/day Feed Pump, cial sodium silicofluoride per day.
Fluoride, mg/L = 0.9 mg/L gal/day
Feed Rate, Fee ate, lb i:/day
Feed Solution, mg/L = 18,000 mg/L lbs/day lbs F/lb Corninercial Na2SiF6
Determine the setting on the chemical feed pump in gallons 12.8 lbs F/day
per day. =
0.6 lbs F/lb Commercial Na2SiF6
Feed Solution, (Flow, gal/day)(Feed Dose, mg/L)
= 21.3 lbs/day Commercia' Na2S'F2
gal/day Feed Solution, mg/L
EXAMPLE 9
(500,000 gal/day)(0.9 mg/L)
18,000 mg/L The feed solution from a saturator containing 1.8 percent
fluorid:: ion 's used to treat a total flow of 250,000 gallons of
= 25 gal/day water. The raw water has a fluoride ion content of 0.2 mg/L
and the desired fluoride level in the treated water is 0.9 rag/
L. How many gallons of feed solution are needed?
EXAMPLE 7
Known Unknown
Determine the fluoride ion purity of Na2SiF6 as a percent.
Flow Vol, gal = 250,000 gal Feed Solution, gallons
Known Unknown Raw Water F, mg/L = 0.2 mg/L
Fluoride Chemical, Na2SiF6 Fluondo Puwv Desired F, mg/L = 0.9 mg/L
Determine the molecular weight of fluoride and Na2Sif-6. Feed Solution, %F = 1.8% F
Symbol (No. Atoms) (Atomic Wt) = Molecular Wt 1. Convert the feed solution from a percentage fluoride ion
to milligrams fluoride ion per liter of water.
Nat (2) (22.99) = 45.98
Si (1) (28.09) = 28.09 1 0% F = 10,000 mg F/L
=
F6 (6) (19.00) 114 00
Feed Solution, mg/L = (Feed Solution, %)(10,000 mg/L)
Molecular Weight of Chemical = 188 07 1.0 °/-
(1.8% F)(10,000 mg/L)
Calculate the fluoride ion purity as a percent.
1.0%
Fluoride Ion (Molecular Weight of Fluonde)(100%)
Purity, % = 18,000 mg/L
(Molecular Weight of Chemical)
2. Determine the fluoride feed dose in milligrams per liter.
(114.00)(100%)
Feed Dose. mg/L = Desired Dose, mg/L Raw Water F, mg/L
188.07
= 0.9 mg/L 0.2 mg/L
= 60.62%
= 0 7 mg/L
3. Calculate the gallons of feed solution needed.
EXAMPLE 8
Feed Solution, gal = (Flow Vol, gal)(Feed Dose, mg/L)
A flow of 1.7 MGD is treated with sodium silicofluoride. Feed Solution, mg/L
The raw water contains 0.2 mg/L of fluoride ion and the
desired fluoride concentration is 1.1 mg/L. What should be (250,000 gal)(0.7 mg/L)
the chemical feed rate in pounds per day? Assume each 18,000 mg/L
pound of commercial sodium silicofluonde (Na2SiF6) con-
tains 0.6 pounds of fluoride ion. = 9.7 gallons

600
 580 Water Treetment

EXAMPLE 10 2. Determine the noncarbonate hardness in mg/L as

CaCG3
A hydrofluosilicic acid (H2S1F6) tank contains 350 gallons
of acid with a strength of 19.3 percent. A commercial vendor Since the alkalinity is greater than tne total hardness,
delivers 2500 gallons of acid with a strength of 18 1 percent
to the tank What is the resulting strength of the mixture as a Noncarbonate Hardness, 0
percentage/ mg/L as CaCO3

Known Unknown In other words, all of the hardness is in the carbonate

Tank Contents, gal = 350 gal Mixture Strength, % form.
Tank Strength, % = 19.3%
EXAMPLE 13
Vendor, gal 2500 gal
Vendor Strength, cY0 = 18 1% The alkalinity of a water is 92 mg/L as CaCO3 and the total
hardness is 105 mg/L. What is the carbonate and noncar-
Calculate the strength of the mixture as a percentage. bonate hardness in mg/L es CaCO3'
(Tank. gal)(Tank. °/0) + (Vendor. gal)(Vendor. °/0)
Mixture Strength. °A, Known Unknown
Tank, gal + Vendor. gal
Alkalinity, = 92 mg/L as CaCO3 1. Carbonate
(350 galX19 3%) + (2500 gal)(18 1%) mg/L Hardness, mg/L
350 gal + 2500 gal Total as CaCO3
0755 + 45.250 Hardness, = 105 mg/L as CaCO3 2. Noncarbonate
2850
mg/L Hardness, mg/L
as CaCO3
= 182%

A.32 Softening 1 Determine the carbonate hardness in mg/L as CaCO3.

Since the alkalinity is less than the total hardness (92
EXAMPLE 11 mg/L < 105 mg/L)
Determine the total hardness of CaCO3 for a sample of Carbonate Hardness,
water with a calcium content of 33 mg/L and a magnesium = Alkalinity, mg/L as CaCO3
mg/L as CaCO3
content of 6 mg/L.
Known = 92 mg/L as CaCO3
Unknown
Calcium, mg/L = 33 mg/L Total Hardness, 2 Determine the noncarbonate hardness in mg/L as
Magnesium, mg/L = 6 mg/L mg/L as CaCO3 CaCO3.

Since the alkalinity is less than the total hardness (92

Calculate the total hardness as milligrams per liter of calcium mg/L < 105 mg/L)
carbonate equivalent.
Total Hardness, Noncarbonate
Calcium Hardness,+ Magnesium Hardness,
mg/L as CaCO3 mg/L as CaCO- mg /L as CaCO3
Hardness, Total Hardness, Alkalinity,
mg/L as mg/L as CaCO3 mg/L as CaCO3
= 2.5(Ca. mg /L) + 4.12(Mg. mg/L) CaCO3
= 2.5(33 mg /L) + 4 12(6 mg/L) = 105 mg/L 92 mg/L
= 82 mg/L + 25 mg/L = 13 mg/L as CaCO3
= 107 mg /L as CaCO3

EXAMPLE 12 EXAMPLE 14
The alkalinity of a water is 120 mg/L as CaCO3 and `: le Results from alkalinity tar ations on a water sample were
total hardness is 105 mg/L as CaCO3. What is the ca,00nate as follows.
and noncarbonate hardness in mg/L as CaCO3'
Known
Known Unknown Sample size, mL = 100 mL
Alkalinity, 1. Carbonate mL titrant used to pH 8.3, A =1.1 mL
= 120 mg/L as CaCO3
mg/L Hardness, mg/L Total mL of titrant used, B = 12.4 mL
Total as CaCO3 Acid normality, N = 0.02 N H2504
Hardness, = 105 mg/L as CaCO3 2. Noncarbonate
mg/L Hardness, mg/L Unknown
as CaCO3 1. Total Alkalinity, mg/L as CaCO3
1. Determine the carbonate hardness in mg/L as CaCO3. 2 Bicarbonate Alkalinity. mg/L as CaCO3
3. Carbonate Alkalinity, mg/L as CaCO3
Since the alkalinity is greater than the total hardness, (120 4. Hydroxide Alkalinity, mg/L as CaCO3
mg/L > 105 mg/L),
See Table 14.4, page 74 for alkalinity relationships among
Carbonate Hardness, Total Hardness, constituents
mg/L as CaCO3 mg/L as CaCO3
1. Calculate the phenolphthalein alkalinity in mg/L as
= 105 mg/L as CaCO3 CaCO3.

601
 Arithmetic 581

Phenolphthalein Alkalinity, =Ax N x 50,000 C = (Hydroxide, mg/L)(74/100)

mg/L as CaCO3 mL of sample =0
(1.1 mL)(0.02 N)(50,000)
D = (Mg2+, mg/L/74/24.3)
100 mL
= (38 mg/L)(74/24.3)
= 11 mg/L as CaCO3
= 116 mg/L
2. Calculate the Otal alkalinity in mg/L as CaCO3.
Hydrated Lime
Total Alkalinity, =B x N x 50,000 (Ca(OH)2) Feed, (A + B + C + D)1.15
mg/L as CaCO3 mL of sample mg/L Purity of Lime, as a decimal
(12.4 mL)(0.02 N)(50,000) (12 mg/L + 93 mg/L + 0 + 116mg/L)1.15
100 mL 0.90

= 124 mg/L as CaCO3 (224 mg/L)(1.15)

0.90
3. Refer to Table 14.4 for alkalinity constituents. The second
row indicates that since P is less than 1/2T (11 mg/L < = 282 mg/L
1/2(124 mg/L)), bicarbonate alkalinity is T-2P and carbon-
ate alkalinity is 2P.
Bicarbonate Alkalinity, T 91, 2. Calculate the soda ash required in milligrams per liter.
mg/L as CaCO3 Noncarbonate
= 124 mg/L - 2(11 mg/L) Hardness, Total Hardness, Carbonate Hardness,
mg/L as mg/L as CaCO3 mg/L as CaCO3
= 102 mg/L as CaCO3 CaCO3
= 240 mg/L 125 mg;L
Carbonate Alkalinity, = 2P
mg/L as CaCO3 = 115 mg/L as CaCO3
= 2(11 mg/L)
Soda Ash (Na2CO3) Noncarbonate Hardness, ) (106/100)
= 22 mg/L E.s CaCO3 Feed, mg/L mg/L as CaCO3

Hydroxide Alkalinity, = (115 mg/L)(106/100)

= 0 mg/L as CaCO3
mg/L as CaCO3 = 122 mg/L

EXAMPLE 15
3. Calculate the dosage of carbon dioxide required for
Calculate the hydrated lime (Ca(OH)2) with 90 per:ent recarboiiation.
purity, soda ash, and carbon dioxide requirements in milli-
Excess Lime. mg/L = (A + B + C + DX(115)
grams per liter for the water shown below.
= (12 mg/L + 93 mg/L + 0 + 116 mg/LX0.15)
Known
= (221 mg/LX0 15)
Softened Water After
Constituent_ Source Water Recarbonation and Filtration = 33 mg/L
CO2, mg/L 7 mg/L = 0 mg/L Total CO2 Feed, = (Ca(OH)2 excess, mg/L)(44/74)
Total Alkalinity, mg/L = 125 mg/L as CaCO3 = 22 mg/L as CaCO3
mg/L + (Mg2+ residual, mg/L)(44/24.3)
Total Hardness. mg/L= 240 mg/L as CaCO3 = 35 mg/L as CaCO3
mg2+, mg/L 38 mg/L as CaCO3 = 8 mg/L as CaCO3 = (33 mg/L)(44/74) + 8 mg/LX,' 4/24.3)
pH 76 =88
= 20 mg/L + 15 mg/L
Lime Purity, % 90%
= 35 mg/L
Unknown
1. Hydrated Lime, mg/L
2. Sda Ash, mg/L EXAMPLE 16
3. Carbon Dioxide, mg/L The optimum lime dosage from the jar tests is 180 mg/L. If
1. Calculate the hydrated lime k:.....a(OH)2) required in milli- the flow to be treated is 1.7 MGD, what is the feeder setting
grams per liter. in pounds per day and the feed rate in pounds per minute?
Known Unknown
A = (CO2, mg/L)(74/44)
Lime Dose, mg/L = 180 mg/L 1. Feeder Setting, lbs/day
= (7 mg/L)(74/44) 2. Feed Rate, lbs/min
Flow, MGD = 1.7 MGD
=12 mg/L 1. Calculate the feeder setting in pounds per day.
B = (Alkalinity, mg/L)(74/100) Feeder Setting, (Flow, MGD)(Lime, mg/L)(8.34 lbs/gal
lbs/day
= (125 mg/L)(74/100) = (1.7 MGD)(180 mg/L)(8.34 tbs/gal)
= 93 mg/L
= 2,550 lbs/day

, 602
 582 Water Treatment

2. Calculate the feed rate in pounds per minute Known Unknown

Feed Rate, lbs/min Feeder Setting, lbs/day Resin Vol, Exchange Capacity,
600 cu ft
cu ft grains
(60 min/hr)(24 hr/day)
Removal Cap,
2,550 lbs/day 25,000 gr/cu ft
gr/cu ft
(60 min/hr)(24 hr/day)
= 1 8 lbs/min Estimate the exchange capacity in grains of hardness.
Exchange Capacity,
EXAMPLE 17 grains (Resin Vol, cu ft)(Removal Capacity, gr/cu ft)
= (600 cu ft)(25,(,^0 gr/cu ft)
How much soda ash is requ (pounds per day and
pounds per minute) to remove 40 mg/L noncarbonate hard- = 15,000,000 grains of hardness
ness as CaCO3 from a flow of 1.7 MGD'
Known Unknown EXAMPLE 20
Noncarbonate 1. Feeder Setting,
Hardness Removed, = 40 mg/L lbs/day How many gallons of water with a hardness of 12 grains
mg/L as CaCO3 per gallon may be treated by an ion exchange softener with
2. Feed Rate,
Flow, MGD = 1.7 MGD an exchange capacity of 15,000,000 grains?
lbs/min
1. Calculate the soda ash dose in milligrams per liter. See Known Unknown
Section 14.316, "Calculation of Chemical Dosages," page Hardness, Water Treated,
= 12 grains/gal
77, for the following formula. grains/gal gallons
Soda Ash mg/L Noncarbonate Hardness, )(106/100) Exchange
mg/L as CaCO3 Capacity, = 15,000,000 grams
grains
= (40 mg/L)(106/100)
Calculate the gallons of water that may be treated.
= 43 mg/L
2. Determine the feeder setting in pounds per day. Water Treated, gat = Exchange Capacity, grains
Hardness, grains/gal
Feeder Setting,
lbs/day (Flow. MGD)(Soda Ash, mg/L)(8.34 lbs/gal)
= 15,000,000 grains
= (1.7 MGD)(43 mg/L)(8 34 lbs/gal)
12 grains/gal
= 610 lbs/day
= 1,250,000 gallons
3. Calculate the soda ash feed rate in pounds per minute.
Feed Rate, Feeder Setting, lbs/day
lbs/min EXAMPLE 21
(60 min/hr)(24 hr/day)
How many hours will an ion exchange softening oit
610 lbs/day
operate when treating an average daily flow of 750 GPM?
(60 min/hr)(24 hr/day) The unit is capable of softening 1,250,000 gallons of water
before requiring regeneration.
= 0.43 lbs/min
Known Unknown
EXAMPLE 18
Ave Daily Flow, = 750 GPM Operating Time, hr
What is the hardness in milligrams per liter for a water with GPM
a hardness of 12 grains per gallon') Water Treated,
1,250,000 gal
Known Unknown gal
Hardness, gpg - 12 grains/gallon Hardness, mg/L Estimate how many hours the softening unit can opera, -
before requiring regeneration.
Calculate the hardness in milligrams per liter.
Operating Time, hr = Water Treated, gal
Hardness, mg/L (Hardness, grains/gal)(17.1 mg/L) (Ave Daily Flow, gal/min)(60 min/hr)
1 grain/gal
1,250,000 gal
(12 grains/gal)(17.1 mg/L)
(750 gal/min)(60 min/hr)
1 grain/gal
= 27.8 hours
= 205 mg/L

EXAMPLE 22
EXAMPLE 19
Determine the pounds of salt needed to regenerate an ion
Estimate the exchange capacity in grains of hardness for exchange softening unit capable of removing 15,000,000
an ion exchange unit which contains 600 cubic feet of resin grains of hardness if 0.25 pounds of salt are required for
with a removal capacity of 25,000 grains per cubic foot. every 1000 grains of hardness removed.

603
 Arithmetic 583

Known Unknown EXAMPLE 25

Hardness = 15.000,000 grains Salt Needed, lbs The results of the ,uarterly average TTFIM measurement
Removed, gr for two years are given below. Calculate the running annual
average of the four quarterly measurements in micrograms
Salt Required. 0.25 lbs salt/1000 gr per liter.
lbs/1000 gr
Quarter 1 2 3 4 1 2 3 4
Salt Ave Quarterly 77 88 112 95 83 87 109 89
Needed, = (Salt Required, lbs/1000 gr)(Hardness Removed, gr) TTHM, pg /L
lbs
0 25 lbs salt ) (15,000.000 g ns) Known Unknown
=(
1000 grains Results from analysis of two Running Annual Average of
years of TTHM sampling quarterly TTHM
= 3750 lbs of salt
measurements
Calculate the running annual average of the quarterly TTHM
EXAMPLE 23 measurements.
Estimate the bypass flow around an ion exchange soften- Annual Running TTHM Sum of Ave TTHM for Four Quarters
er if the plant treats 250.000 gallons per day with a source Average. gg/L Number of Quarters
water hardness of 20 grains per gallon if the desired product
water hardness is 5 grains per gallon. QUARTERS 1, 2, 3 AND 4
Known Unknown Annual Running TTHM 77 yg/L + 88 pg/L + 112 pg/L + 95 pg/L
Average. pg/L
4
Total Flow, GPD = 250.000 GPD Bypass Flow, GPD
Source Water 20 grains/gallon
372 ug /L
Hardness, gpg 4

Plant Effl = 93 pg/L

= 5 grains/gallon
Hardness. gpg
QUARTERS 2, 3, 4 AND 1
Annual Running TTHM 88 pg/L + 112 pg/L + 95 pg/L 83 pg/L
Estimate the bypass flow in gallons per day. Average, pg/L
4

Bypass Flow, GPD

ATotal Flow, GPD)(Plant Effl Hardness. gpg)
378 pg/L
Source Water Hardness. gpg 4

(250.0'0 GPD)(5 gpg) = 95 pg/L

20 gpg
QUARTERS 3, 4, 1 AND 2
= 62.500 GPD
Annual Running TTHM 112 pg/L + 95 pg/L + 83 pg/L 87 pg/L
Average. AWL
4

A.33 Trihalomethanes 377 pg/L

4
EXAMPLE 24
= 94 pg/L
A water utility collected and analyzed eight samples from a
water distribution system on the same day for TTHMs. The QUARTERS 4, 1, 2 AND 3
results are shown below.
Annual Running TTHM 95 yg/L + 83 pg/L + 87 pgIL + 109 pg/L
Sample No. 1 2 4 35 6 7 8 Average. pgIL
4
TTHM, pg /L 80 90 100 90 110 100 100 90
374 pg/L
What was the average TTHM for the day? 4

Known Unknown = 94 yg/L

Results from analysis Average TTHM level
of 8 TTHM samples for the day QUARTERS 1, 2, 3 AND 4
Annual Running TTHM 83 pg/L + 87 pg/L - 109 pg/L + 89 pg/L
Average, pg/L
Calculate the average TTHM level in micrograms per liter 4

Ave TTHM, Sum of Measurement. gg/ L = 368 +9/1-

AgIL 4
Number of Measurements
80 gg/ L + 90 gg/L + 100 gg/ L + 90 gg/ L 92 pg/L
+ 110 AgIL + 100 AgIL + 100 AgIL + 90 AgIL
SUMMARY OF RESUL i S
8
Quarter 1 2 3 4 1 2 3 4
760 gg/ L Ave Quarterly * 77 88 112 95 83 87 109 89
8 TTHM. pg /L
Annual Running 93 95 94 94 92
= 95 gg/L TTHM Ave, pg /L
584 Water Treatment

A.34 Demineralization Known Unknown

EXAMPLE 26 Length, ft = 8 ;t Pump Capacity, GPM
Width, ft = 6 ft
Convert a water flux of 12 x 10-4 gm/sq cm-sec to gallons Depth, ft = 3 ft
per day per square foot.
Time, min =12 min
Known Unknown
Water Flux, Flow, GPD/sq ft 1 Calculate the volume pumped in cubic feet.
= 12 x 10 -4 gm/sq cm-sec
gm/sq cm-sec
Volume Pumped, cu ft = (Length, ft)(Width, ft)(Depth, ft)
Convert the water flux from gm/sq cm-sec to flow in
GPD/sq ft. -- (8 ft)(6 ft)(3 ft)
Flow. (Flux. gm/sd cmsecX1 Lder)(1 Gal)(100 cm)2(3600 secX24 nr) = 144 cu ft
GPD /sq
(1000 gmX3 785 LX3 28 ft)2(1 nrX1 day)

(00012 gm /so cm-secX1 Laerx1 Gaixt 00 cm)2(3600 secX24 nr) 2 Convert the volume pumped from cubic feet to gallons.
(1000 gran 785 LX3 28 ft)2(1 hrX1 day) Volume Pumped, gal = (Volume Pumped, cu ftX7.48 gal/cu ft)
25 5 GPO/v:1 ft
= (144 cu ft)(7 48 gal/cu ft)
EXAMPLE 27 =1077 gal

Estimate the ability of a reverse osmosis plant to reject

3. Calculate the pump capacity in gallons per minute.
minerals by calculating the mineral rejection as a percent.
The feedwater contains 1800 mg/L TDS and the product Pump Capacity, GPM Volume Pumped, gal
water TDS is 120 mg/L.
Pumping Time, min
Known Unknown 1077 gal
Feedwater TDS, = 1800 mg/L Mineral Rejection,
mg/L 12 min

Product Water TDS, =120 mg/L = 90 GPM

mg/L
EXAMPLE 30
Calculate the mineral rejection as a percent.
A small chemical feed pump lowered the chemical solution
Mineral Rejection, % = (: Product TDS, mg/L x100%) in a 2.5-foot diameter tank 2.25 feet during seven hours.
Feed TDS, mg/L Estimate the flow delivered by the pump in gallons per
minute and gallons per day.
= 120 mg/L
)(100 %)
1800 mg/L Known Unknown
= (1 0.067)(100%) Tank Diameter, ft = 2.5 ft Row, GPM
Chemical Drop, ft = 2.25 ft Flow, GPD
= 93.3% Time, hr = 7.0 hr
EXAMPLE 28
1 Determine the gallons of chemical solution pumped.
Estimate the percent recovery of a reverse osmosis unit Volume, gal = (0.785XDiameter, ft)2(Drop, ftX7 46 gal/cu ft)
with a 4-2-1 arrangement if the feed flow is 2.0 MGD and the
product flow is 1.75 MGD. = (0.785X2.5 ft)2(2 25 ftX7 48 gal/cu ft)

Known Unknown = 63 gallons

Product Flow, MGD = 1.75 MGD Recovery, 2 Estimate the flow delivered by the pump in gallons per
Feed Flow, MGD = 2.0 MGD minute and gallons per day.
Calculate the recovery as a percent. Flow, C =Volume Pumped, gal
Recovery, % = (Product Flow, MGM() 00%) (Time, hr)(60 min/hr)

Feed MGD = 83 gallons

(1.75 MGD,(100%) (7 hr)(60 min/hr)
2.0 MGD = 0.2 GPM

= 87.5% or

Flow, GPD (Volume Pumped, gal)(24 hr/day)

A.35 Maintenance
Time, hr
EXAMPLE 29
(83 gallons)(24 hr/day)
Calculate the pumping capacity of a pump in gallons per 7 hr
minute when 12 minutes are required for the water to rise 3
feet in an 8 foot by 6 frxit rectangular tank. = 285 GPD

80a
 Arithmetic 585

EXAMPLE 31 EXAMPLE 34
Determine the chemical feed in pounds of polymer per day Calculate the injury severity rate for a water company
from a chemical feed pump The polymer solution is 1.8 which experienced 57 operator-hours lost due to injuries
percent or 18,000 mg polymer per liter Assume a specific while the operators worked 97,120 hours during the year
gravity of the polymer solution of 1 0. During a test run the
chemical feed pump delivered 650 mL of polymer solution in Known Unknown
4.5 minutes.
Number of = 57 hrs/yr Injury Severity Rate
Known Unknown Hours Lost
Polymer Solution, % = 1 8 % Polymer Feed, Number of
lbs/day = 97,120 hrs/yr
P,;',,,,,er Conc. mg/L = 18,000 mg/L Hours Worked
Polymer Sp Gr =10
Volume Pumped. mL = 650 mL Calculate the injury severity rate
Time Pumped, min = 4.5 min
Injury Severity Rate (Number of Hours Lost/yr)(1.000,000)
Calculate the polymer fed by the chemical feed pump in Number of Hours Worked/yr
pourds of polymer per day.
(57 hrs/yr)(1,000.000)
Polymer
Feed. (Poly Conc. mg/L)(Vol Pumped. mL)(60 min/hr)(24 hr/day) 97,120 hrs/yr
lbs/day
(Time ramped, min)(1000 mL/L)(1000 mg/gm)(454 gm/lb) = 587
(18.000 mg/L)(650 mL)(60 min/hr)(24 hr/day)
(4 5 min)(1000 mL/L)(1000 mg/gm)(454 gm/lb) A.37 Advanced Laboratory Procedures
= 8 2 lbs/day
EXAMPLE 35
Calculate the threshold odor number (T O.N.) for a sample
EXAMPLE 32
when the first detectable odor occurred when the 70 mi.
Determine the actual chemical fe0 in pounds per day sample was diluted to 200 mL (130 mL of odor-free water
from a dry chemical feeder. A pie tin placed under the was added to the 70 mL sample)
chemical feeder caught 824 grams of chemical during five
minutes Known Unknown
Known Unknown Size of Sample, mi. = 70 mL T.O.N.
Odor-Free Water, mi. = 130 mL
Chemical, gm = 824 gm Chemical Feed, lbs/day
Time. min = 5 min
Calculate the threshold odor number, T.O.N.
Determine the chemical feed in pounds per day.
T 0 N = Size of Sample, mi. + Odor-Free Water, mL
Chemical Feed. lbs/day = (Chemical, gm)(60 min/hr)(24 hr/day) Size of Sample, mi.
(454 gm /Ib)(Time, min)
(70 mL + 130 mL
(824 gm)(60 min/hr)(24 hr/day)
70 mL
(454 gm /Ib)(5 min)
=3
523 lbs/day

A.36 Safety EXAMPLE 36

EXANiPLE 33 Determine the geometric mean threshold odor number for

a panel of six testers given the results shown helow.
Calculate the injury frequency rate for a water utility where
there were four injuries in one year and the operators Known Unknown
worked 97,120 hours.
Tester 1, X, = 2 Geometric Mean
Known Unknown Tester 2, X2 = 4 Threshold Odor Number
Injuries. 4 injuries/yr Injury Frequency Tester 3, X3 = 3
number/yr Rate Tester 4, X4 = d
Hours Worked, Tester 5, X5 = 6
97,120 hrs/yr
number/yr Tester 6, X6 = 2
Calculate the injury frequency rate.
Calculate the gec metric mean
Injury Freq Rate (Injuries. number/yr)(1,000 000)
Geometric Me in = x X2 x X3 x X4 x X5 x ;Pin
Hours Worked. number/yr T.O.N.
(4 injunes/yr)(1,000,000) =(2 x 4 x 3 X 8 xGx 2)1/6
97,120 hrs/yr = (2304)° 167
-- 41.2 = 3.6

606
586 Water Treatment

EXAMPLE 37 Calculate the threshold taste number

Calculate the threshold taste number for a sample when Threshold
the first detectable taste occurred when the 8.3 mL sample Taste Sample Size, mL + Taste-Free Water, mL
was diluted t) 200 mL (191 7 mL of taste-free water was Number
Sample Size, mL
added to the 8.3 mL sample).
8.3 mL + 191 7 mL
Known Unknown
8 3 mL
Sample Size, mL = 8 3 mL Threshold Taste
Taste-Free Water, mL = 191.7 Number = 24

(See top of right column for solution )

EXAMPLE 38
Determine the taste rating for a water by calculating the
arithmetic mean and standard deviation for the panel ratings
given below.
Known Unknown
Tester 1, X, = 2 1. Arithmetic Mean, X
Tester 2, X2 = 5 2 Standard Deviation, S
Tester 3, X3 = 3
Tester 4, X4 = 6
Tester 5, X5 =,- 2
Tester 6, X6 = 6

1 Calculate the arithmetic mean, X. taste rating.

Arithmetic Mean, R X, + X2 + X3 + X, + X5 + X6
Taste Rating
n

2+5+3+6+2+6
6
24
6

=4

2. Calculate the standard deviation, S, of the taste rating.

Standard [ (X,- X)2 + (x2-5)2 1- (X3-i)2+ (X4 -X)2 + (X5 -X)2 + (X6-X)2 05
Deviation.
n 1
S

[ (2-4)2 + i 4)2 + (34)2 + (6- -4)2 + (2-4)2 (6-4)2 °5

5 1

(-2)2 + (1)2 ' ( -1)2 + (2)24 (-2)2 + (2)2

5
105

E4+ 1 + 1 4- 4 4 4 + 4 05

= [ 18 ]°5
5

= (3.6)°5
= 1.9

607
 Arithmetic 587
Or
Standard (X,2 + X22 + X32 + X42 + X52 + X62) (X, + X2+ X3+ X4+ X5 +X6)2 /n
Deviation,
n 1
S

E (22+52+32 +62+22+62) (2+5+3+6+2+6)2/6 05

n 1

[ (4+25+9+36+4+36) (24)2/6 05

I114 96
5

.[__ ]°,

= /s3.6)°5

= 1.9

EXAMPLE 39 WEIGHT
A small water system collected 14 samples during one 1000 mg = 1 gm 1000 mg/gm
month. After each sample was collected, 10 mL of each 1000 gm = 1 kg 1000 gm/kg
sample was placed in each of 5 fermentation tubes. At the
end of the month, the results indicated that 2 out of a total of DENSITY
70 fermentation tubes were positive. What percent of the
1 kg = 1 liter 1 kg/L
portions tested during the month were positive?
PRESSURE
Known Unknown
Number Portions Positive, 10.015 M = 1 kg/sq cm 10.015 m/kg/sq cm
= 2 positive/mo 1 Pascal =1 N/sq m
Positive/mo /m o 1 Pa/N/sq m
1 psi = 6895 Pa 1 psi/6895 Pa
Total Portions = 70 portions
Tested FLOW
3785 cu m/day = 1 MGD 3785 cu m/day/MGD
Calculate the percent of the portions tested dunnq the 3.785 ML/day = 1 MGD 3.785 ML/day/MGD
month which were positive.
(Number Positive/mo)(10000) hectare
Portions Positive, % /mo
Total Portions Tested
(2 positive/mo)(100%)
70 portions A.5 TYPICAL WATER TREATMENT PLANT PROBLEMS
= 3 % /mo
A.50 Iron and Manganese Control

EXAMPLE 1
A.4 BASIC CONVERSION FACTORS (METRIC SYSTEM)
LENGTH A standard polyphosphate solution is prepared by mixing
and dissolving 1.0 grams of polyphosphate in a container
100 cm = 1 m 100 cm/m and adding distilled water to the one-liter mark. Determine
3 281 ft= 1 m 3.281 ft/m the concentration of the stock solution in milligrams per liter.
If 6 milliliters of the stock solution are added to a one-liter
AREA
sample, what is the polyphosphate dose in milligrams per
2.4711 ac = 1 ha* 2.4711 ac/ha liter and milligrams per kilogram?
10,000 sq m = 1 ha 10,000 sq m/ha Known Unknown
VOLUME Polyphosphate, gm = 1.0 gm 1. Stock Solut!on, mg/mL
1000 mL = 1 liter 1000 mL /L Solution, L =1.0 L 2. Dose, mg/L
1000 L= 1 cu m 1000 L/cu m Stock Solution, mL =6 mL 3. Dose, mg/kg
3.785 L= 1 gal 3.785 L/gal Sample, L =1L

608
588 Water Treatment

1. Calculate the concentration of the stock solution in milli- Known Unknown

grams per milliliter. Diameter, m =4 m Detention Time, min
Stock Solution, (Polyphosphate, gm)(1000 mg/gm) Depth, m =1.2 m
mg/mL (Solution, L)(1000 mL/L) Flow, MLD = 0.9 MLD
(1.0 gm)(1000 mg/gm) 1. Calculate the basin volume in cubic meters.
(1 L)(1000 mL/L) Basin Vol, cu m = (0.785)(Diameter, m)2(Depth, m)
= 1.0 mg/mL = (0.785, t m)2(1.2 m)
= 15.1 cu m
2. Determine the polyphosphate dose in the sample in
milligrams per liter. 2. Determine the average detention time in minutes for the
reaction basin.
Dose, mg/L = (Stock Solution, mg/mL)(Vol Added, mL)
Detention Time, (Basin Vol. cu mX24 hr/day)(60 min/hrX1000 Lim m)
Sample Volume, L min
(Flow. MLDX1,000,000/M)
=(1.0 mg/mL)(6 mL)
(15 1 cu mX24 hr/dayX60 min/hrX1000 L /cu m)
1L (0 9 MLDX1,000,000/M)
= 6.0 mg/L = 24 minutes

3. Determine the polyphosphate dose in the sample in

milligrams of phosphate per kilogram of water. EXAMPLE 4

Dose, mg/kg = (Stock Solution, mg/L)(Vol Added, mL) Calculate the potassium permanganate dose in milligrams
(Sample Volume, L)(1 kg,'L) per liter for a well water with 2.4 mg/L iron before aeration
and 0.3 mg/L after aeration. The manganese concentration
(1.0 mg/mL)(6 mL) is 0.8 mg/L both befcre and after aeration.
(1 L)(1 kg/L) Known Unknown
= 6.0 mg/kg Iron, mg/L = 0.3 mg/L KMn04 Dose, mg/L
Manganese, mg/L 0.8 mg/L
EXAMPLE 2
Calculate the potassium permanganate dose in milligrams
Determine the chemical feeder setting in grams per sec- per liter.
ond and kilograms per day if 2 4 MLD (mega or million liters
KMn04 Dose. mg /L = 0.6(Iron, mg/L) + 2.0(Manganese, mg/L)
per day) are treated with a dose of 5 mg/L.
= 0.6(0.3 mg/L) + 2 0(0.8 mg/L)
Known Unknown
= 1.78 mg/L
Flow, MLD = 2.4 MLD 1. Chemical Feeder, gm/sec
Dose, mg/L = 5 mg/L 2. Chemical Feeder, kg/day NOTE: If there are any oxidizable compounds (organic
color, bacteria, or hydrogen sulfide) in the water,
1. Determine the chemical feeder setting in grams per the dose will have to be increased.
second.
Chemical Feeder, (Flow, MLDXDose, mg/LX1,000,000/M)
gm/sec A.51 Fluoridation
(24 hr/dayX60 min/hrX60 sec/minX1000 mg/gm)

(2 4 MLDX5 mg/LX1,000,000/M) EXAMPLE 5

(24 hr/dayX60 min/hr)(60 sec/minX1000 mg/gm) Determine the setting for a chemical feed pump in gallons
per day when the desired fluoride dose is 0.9 kilograms of
= 0.139 gm/sec fluoride per day. The sodium fluoride solution contains 0.025
or = 139 mg/sec kilograms of fluoride per gallon and the fluoride purity is 43.4
percent.
2. Determine the chemical feeder setting in kilograms per Known Unknown
day.
Feed Rate, lbs F/day = 0.9 kg F/day 1. Feed Rate,
Chemical Feeder. (Flow. MLD)(Dose, mg/L)(1.000.000/M) liters/day
NaF Solution, kg F/L = 0.025 kg F/L
kg/day (1000 mg/gm)(1000 gm/kg) 2. Feed Rate,
Purity, % = 43.4%
mL/sec
(2.4 MLD)(5 mg/L)(1,000,000/M)
(1000 mg/gm)(1 000 gm/kg) Determine the setting on the chemical feed pump in liters per
day.
= 12 kg/day
Feed Rata, (Feed Rate, hp F /day)(100 %)
L/day (NaF Solution, kg F/L)(Purity, %)
EXAMPLE 3
A reaction basin 4 meters in diameter and 1.2 meters deep (0.9 kg F /day)(100 %)
treats a flow of 0.9 MLD. What is the average detention time (0.025 kg F/L)(43.4 %)
in minutes?
- 83 liters/day

609
 Arithmetic 589

2. Convert the feed rate from kilograms per day to grams Calculate the fluoride ion purity as a percent.
per second.
Feed Rate, (Feed Rate, kg/day)(1000 gm/kg) Fluoride Ion (Molecular Weight of Fluoride)(100 %)
gm/sec (24 hr/day)(6C min/hr)(60 sec/min) Purity, % (Molecular Weight of Chemical)
(0.9 kg/day)(1000 gm/kg) (114.00)(100%)
(24 hr/day)(60 min/hr)(60 sec/min) 188.07

= 0.010 gm/sec = 60.62%

or = 10 mg/sec
3. Determine the setting on the chemical feed pump in EXAMPLE 8
milliliters per second. A flow of 6.5 MLD is treated with sodium silicofluoride.
The raw water contains 0.2 mg/L of fluoride on and the
Feed Rate, (Feed Rate, gm/sec)(100%)(1000 mL /L) desired fluoride concentration is 1.1 mg/L. What should be
mL/sec (NaF Solution, kg F;L)(Purity, %)(1000 gm/kg)
the chemical feed rate in kilograms per day and milligrams
per second? Assume each gram of commercial sodium
(0.010 gm/sec)(100°/0'1(1000 m1.11.) silicofluoride (Na2SiF6) contains 0.6 grams of fluoride ion.
(0.025 kg F/L)(43.4%)(1000 gm/kg) Known Unknown
= 0.92 mL/sec Flow, MLD =6.5 MID 1. Feed Rate,
Raw Water F, mg/L = 0.2 mg/L kg/day
EXAMPLE 6 2. Feed Rate,
Desired F, mg/L = 1.1 mg/L
Determine the setting on a chemical feed pump in liters mg/sec
Chemical, grit F/gm = 0.6 gm F /gm
per day and milliliters per second if 2 megaliters per day of
water must be treated with 0.9 mg/L of fluoride. The fluoride
feed solution contains 18,000 mg/L of fluoride. 1. Determine the fluoride feed dose in milligrams per liter.

Known Unknown Feed Dose, mg/L = Desired Dose, mg/L Actual Conc, mg/L
Flow, MLD = 2 MLD 1. Feed Pump, = 1.1 ;ng/L - 0.2 mg/L
Fluoride, mg/L = 0.9 rngl L liters/day
= 0.9 mg/L
Feed Solution, mg/L = 18,000 mg/L 2. Feed Pump,
ml/sec
2. Calculate the chemical feed rate in kilograms per day.
1. Determine the setting on the chemical feed pump in liters
per day. Feed Rate. (Flow, MLDXFeed Dose. mg/LX1,000,000/M)
kg/day
Feed Pump,= (Flow, MLD)(Feed Dose, mg/L)(1,000,000/M) (Purity. gm F/gm chemicalX1000 mg,gmX1000 gm/kg)
liters/day
Feed Solution, mg/L (6 5 MLDX0 9 mg/LX1,000,000/M)

(2.0 MLD)(0.9 mg/L)(1.000,000/M) (0 6 gm F/gm chemicalX1000 mg/gmX1000 gm/kg)

18,000 ing/L = 9 75 kg/day

= 100 liters/day
3. Calculate the chemical feed rate in milligrams per second.
2. Determine the setting on the chemical feed pump in
n iilliliters per second. Feed
Rate, (Flow. MLCADose, mg/LX1.000.000/M)
Feed Pump, (Flow, MLDXFeed Dose, mg/LX1,000,000/M)
mL/sec mg/sec (Runty, gm F/gm chemical)(24 hr/dayX60 min/hrX60 sec/min)
(Feed Solution, mg/LX24 hr/dayX60 min/hrX60 sec/min)
(6 5 MLDX0.9 mg/LX1.000,000/M)
(2 MLDX0.9 mg/LX1.000,000/M)
(0 6 gm F/gm chemical)(24 hr/day)(60 min/hrX60 sec/min)
(18,, JO mg/LX24 hr/dayX60 min/hrX60 sec/min)
= 113 mg/sec
= 1 16 mL/sec

EXAMPLE 7
EXAMPLE 9
Determine the fluoride ion purity of Na2SiF6 as a percent.
The feed solution from a saturator containing 1.8 percent
Known Unknown fluoride ion is used to treat a total flow of 0.95 megaliters
Fluoride Chemical, Na2S1F6 Fluoride Purity, % (M L) of water. The raw water has a fluoride ion content of 0.2
mg/L and the desired fluoride level in the treated water is 0.9
Deter mine the molecular weight of fluoride and Na2SiF6. mg/L. How many gallons of een solution are needed?
Symbol (No. Atoms) (Atomic Wt) = Molecular Wt Known Unknown
Nat (2) (22.99) = 45.98 Flow Vol, ML = 0.95 ML Feed Solution, liters
Si (1) (28.09) = 28.09 Raw Water F, mg/L = 0.2 mg/L
F6 (6) (19.00) = 114.00 Desired F. mg/L = 0.0 mg/L
Molecular Weight of Chemical = 188.07 Feed Solution, %F = 1.8% F
590 Water Treatment

1. Convert the feed solution from a percentage fluoride ion Total Hardness, Calcium Hardness,_ Magnesium Hardness,
to milligrams fluoride ion per liter of water. mg/L as CaCO3 mg/L as CaCO3 mg/L as CaCO3

1.0% F = 10,000 mg F/L = 2 5(Ca, mg/L) + 4.12(Mg, mg/L)

= 2 5(33 mg/L) -t- 4.12(6 mg/L)
Feed Solution, mg/L = (Feed Solution, %)(10,000 mg /L)
1.0% = 82 mg/L + 25 mg/L

(1.8% F)(10,000 mg/L) = 107 mg/L as CaCO3

1.0%
EXAMPLE 12
= 18,000 mg/L The alkalinity of a water is 120 mg/L as CaCO3 and the
total hardness is 105 mg/L as CaCO3. What is the carbonate
2. Determine the fluoride feed dose in milligrams per liter and noncarbonate hardness in mg/L as CaCO3?
Feed Dose, mg/L = Desired Dose, mg/L Raw Water F, mg/L Known Unknown
= 0.9 mg/L 0 2 mg/I Alkalinity, = 120 mg/L as CaCO3 1. Carbonate
= 0.7 mg/L mg/L Hardness, mg/L as
CaCO3
Total
3 Calculate the liters of feed solution needed. 2. Noncarbonate
Hardness, = 105 mg/L as CaCO3
mg/L Hardness, mg/L as
Feed (Flow Vol, ML)(Feed Dose, mg/L)t1,000,000/M) CaCO3
Solution, L
Feed Solution, mg/L
1. Determine the carbonate hardness in mg/L as CaCO3.
(0.95 ML);0 7 mg/L)(1,000,090/M)
Since the alkalinity is greater than the total hardness, (120
18,000 mg/I.
mg/L > 105 mg/L),
= 37 liters
Carbonate Hardness, Total Hardness,
mg/L as CaCO3 mg/L as CaCO3
EXAMPLE 10
= 105 mg/L as CaCO3
A hydrofluosilicic acid (H2SiF6) tank contains 1300 liters of
acid with a strength of 19.3 percent. A commercia! vendor 2 Determine the noncarbonate hardness in mg/L as
delivers 10,000 liters of acid with 1 strength of 18.1 percent CaCO3
to the tank. What is the resulting strength of the mixture as a
percentage? Since the alkalinity is greater than the total hardness,
Noncartonate Hardness, 0
Known Unknown mg/L as CaCO3
Tank Contents, liters = 1300 L Mixture Strength, %
In other words, all of the hardness is in the carbonate
Tank Strength, % = 19.3% form.
Vendor, L = 10,000 L
Vendor Strength, % = 18.1% EXAMPLE 13
Calculate the strength of the mixture as a percentage. The alkalinity of a water is 92 mg/L as CaCO3 and the total
Mixture (Tank, L)(Tank, %) + (Vendor, L)(Vendor, %) hardness is 105 mg/L What is the carbonate and noiicar-
Strength. % bonate hardness in mg/L as CaCO3?
Tank, L + Vendor, L
(1300 L)(19 3%) + (10,000 L)(18 1%)
Known Unknown
1300 L A 10,000 L Alkalinity, = 92 mg/L as CaCO3 1. Carbonate
mg/L Hardness, mg/L as
25,090 + 181.000 CaCO3
Total
11,300 2. Noncarbonate
Hardness, = 105 mg/L as CaCO3
= 18 2% mg/L Hardness, mg/L as
CaCO3
A.52 Softening
1. Determine the carbonate hardness in mg/L as CaCO3.

EXAMPLE 11 Since the alkalinity is less than the total hardness (92
mg/L < 105 mg/L)
Determine the total hardness of CaCO, for a sample of
water with a calcium content of 33 mg/L and a magnesium Carbonate Hardness, Alkalinity, mg/L as CaCO3
content of 6 mg/L. mg/L as CaCO3

Known Unknown = 92 mg/L as CaCO3

Calcium, mg/L = 33 mg/L Total Hardness, 2. Determine the noncarbonate hardness in mg/L as
Magnesium, mg/L = 6 mg/L rog/L as CaCO3 CaCO3.
Calculate the total hardness as mill grams per liter of calcium Since the alkalinity is less than the total hardness (92
carbonate equivalent. 611 mg/L < 105 mg/L)
 Arithmetic 591

Noncarbonate EXAMPLE 15
Hardness, Total Hardness, Alkalinity,
mg/L as mg/L as CaCO3 mg/L as CaCO3 Calculate the hydrated lime (Ca(OH)2) with 90 percent
CaCO3 purity, soda ash, and carbon dioxide requirements in milli-
= 105 mg/L 92 mg/L grams per liter for the water shown below.
= 13 mg/L as CaCO3
Known
Softened Water After
Constituents Source Water Recerbonation and Filtration
CO2, n.,/i. = 7 mg/L - 0 mg/L
EXAMPLE 14
Total Aikalinity. mg/L = 125 mg/L as CaCO3 = 22 mg/L as CaCO3
Results from alkalinity titrations on a water sample were Total Hardness, mg/L= 240 mg/L as CaCO3 = 35 mg/L as CaCO3
as follows: mg2+. mg/L - 38 mg/L as CaCO3 = 8 mg/L as CaCO3
pH =76 =88
Known Lime Purity. % = 90%

Sample size, mL = 100 mL

Unknown
mL titrant used to pH 8.3, A = 1.1 mL
1. Hydrated Lime. mg/L
Total mL of titrant used, B = 12.4 mL
2 Soda Ash. mg/L
Acid normality, N = 0.02 N H 2SO4 3 Carbon Dioxide. mg/L

Unknown
1. Calculate the hydrated lime (Ca(OH)2) required in milli-
1. Total Alkalinity, mg /L as CaCO3 grams per liter.
2. Bicarbonate Alkalinity, mg/L as CaCO3
3. Carbonate Alkalinity, mg/L as CaCO3 A = (CO2, mg/LX74/44)
4. Hydroxide Alkalinity, mg/L as CaCO3 = (7 mg/L)(74/44)
See Table 14.4, page 74, for alkalinity relationships among =12 mg/L
constituents.
B = (Alkalinity, mg/L)(74/100)
1. Calculate the phenolphthalein alkalinity in mg/L as
CaCO3. = (125 mg/LX74/100)

Phenolphthalein Alkalinity, A x N x 50,000 = 93 mg/L

mg/L as CaCO3 mL of sample C = (Hydroxide, mg/L)(74/100)
(1.1 mL)(0.02 /V)(50,000) =0
100 mL
D = (Mg2+, mg/L)(74/24.3)
= 11 mg/L as CaCO3
= (38 mg/L)(74/24.3)
2. Calculate the total alkalinity in mg/L as CaCO3. = 116 mg/L
Total Alkalinity, B x N x 50,000
mg/L as CaCO3 mf_ of Hydrt,,tc;! Lime
(Ca(OH)2) Feed, (A + B + C + D)1.15
(12.4 mLX0.02 N)(50,000) mg/L
Purity of Lime, as a decimal
100 mL (12 mg/L + 93 mg/L + 0 + 116mg/L)1.15
= 124 mg/L as CaCO3 0.90
(221 mg/L)(1.15)
3. Refer to Table 14.4 for alkalinity constituents. The second 0.90
row indicates that since P is less than 1/21 (11 mg/L <
1/2(124 mg/L), bicarbonate alkalinity is T-2P and carbon- = 282 mg/L
ate alkalinity is 2P.
Bicarbonate Alkalinity,= T -- 2P
mg/L as CaCO3 2. Calculate the soda ash required in milligrams per liter.
= 124 mg/L 2(11 mg/L)
Noncarbonate Hardness. Total Hardness. Carbonate Hardness.
= 102 mg/L as Ca003 mg/L as CaCO3 mg/L as CaCO3 mg/L as CaCO3
= 240 mg/L - 125 mg/L
Carbonate Alkalinity, = 2P
mg/L as CaCO3 -, 115 mg/L as CaCO3
= 2(11 mg/L) Soda Ash (Na2CO3) Noncarbonate Hardness, ) (106/100)
= 22 mg/L as CaCO3 Feed. mg/L mg/L as CaCO3

Hydroxide Alkalinity, = 0 mg/L as CaCO3 = (115 mg/LX106/100)

mg/L as CaCO3 = 122 mg/L

62
592 Water Treatment

3. Calculate the dosage L.f carbon dioxide required for Feeder Setting, (Row, MLD)(Soda Ash, mg/L)(1,000,000/M)
recarbonation. kg/day
(1000 mg/gm)(1000 gm/kg)
Excess Lime. mg /L - (A + B + C + DX0 15)
(6 5 .ALD)(40 mg/L)(1,000,000/M)
= (12 mg/L + 93 mg/L 0 + 116 rrig/LX0 15) (1000 mg/gm)(1000 gm/kg)
= (221 mg /L)(0 15)
= 260 kg/day
= 33 mg/L

Total CO2 Feed, = (Ca(OH)2 excess, mg/L)(44/74) 3. Calculate the soda ash feed rate in grams per second.
mg /L + (Mg2' residual, mg/L)(44/24 3) Feed Rate, (Flow, MLD)(Soda Ash. mg/L)(1,000,000/M)
gm/sec
= (33 mg/L)(44/74) + (8 mg/L)(44/24.3) (1000 mg/gm)(24 hr/day)(60 min/hr)(60 sec/min)
= 20 mg/L 4- 15 mg/L (6.5 MLD)(40 mg/L)(1,000,000/M)
= 35 mg /L (1000 mg/gm)(24 hr/day)(60 min/hr)(60 sec/min)
= 3 0 gm/sec

EXAMPLE 16
The optimum lime dosage from the jar tests is 180 mg/L. If
the flow to be treated is 6.5 MLD, what is the feeder setting EXAMPLE 18
in kilograms per day and the feed rate .n grams per second? What is the hardness in grains per gallon for a water with a
hardness of 200 mg/L?
Known Unknown
Known Unknown
Lime Dose, mg/L = 180 mg/L 1. Feeder Setting, kg/day
Hardness. mg/L = 12 mg/L Hardness, grains/gallon
Flow, MLD = 6.5 MLD 2. Feed Rate, gm/sec
Calculate the hardness in grains per gallon.
1. Calculate the feeder setting in kilograms per day.
Hardness, (Hardness, mg/L)(1 grain/gal)
R(eder Setting, =(Flow, MLD)(Lime, mg/L)(1,000,000/M) grains/gal
kg/day 17.1 mg/L
(1000 mg/gm)(1000 gm/kg)
=(200 mg/L)(1 grain/gal)
=(6.5 MLD)(180 mg/L)(1,000,000/M)
17.1 mg/L
(1000 mg/gm)(1000 gm/kg)
= 1170 kg/day
= 11.7 grains/gal

2. Calculate the feed rate in grams per second.

Feed Rate, (Flow, MLDHLime, mg/L)(1,000,000/M)
gm/sec EXAMPLE 19
(1000 mg/gm)(24 hr/day)(60 min/hr)(60 sec/min)
(6.5 MLD)(180 mg/L)(1,000,000/M) Estimate the exchange capacity in milligrams of hardness
(1000 mg/gm)(24 hr/day)(60 min/hr)(60 sec/min) for an ion exchange unit which contains 20 cubic meters of
resin with a removal capacity of 14,000 milligrams per cubic
= 13.5 gm/sec meter.
Known Unknown
EXAMPLE 17 Resin Vol, cu m = 20 cu m Exchange Capacity,
How much soda ash is required (kilograms per day and Removal Cap, milligrams
14,000 mg/cu m
grams per second) to remove 40 mg/L noncarbonate hard- mg/cu m
ness as CaCO3 from a flow of 6.5 MLD? Estimate the exchange capacity in milligrams of hardness.
Known Unknown Ex...hange Capacity.
milligrams = (Resin Vol. cu m)(Removal Capacity. mg/cu m)
Noncarbonate Hardness, 1. Feeder
= (20 cu m)(14.000 mg/cu m)
Removed, mg/L as = 40 mg/L Setting,
CaCO3 kg/day - 280.000 mg of hardness
Flow, MLD = 6.5 MLD 2. Feed Rate,
gm/sec
1 Calculate the soda ash dose in milligrams per liter. See EXAMPLE 20
Section 14.316, "Calculation of Chemical Dosages," page
77, for the following formula. How many liters of water with a hardness of 200 mg/L may
be treated by an ion exchange softener with an exchange
Soda Ash, mg/L = ( Noncarbonate Hardness 9(106/100) capacity of 280,000 milligrams?
mg/L as CaCO3
Known Unknown
= (40 mg/L)(106/100)
Hardness, mg/L = 200 mg/L Water Treated,
= 43 mg/L Exchange liters
Capacity, = 280,000 milligrams
2. Determine the feeder setting in kilograms per day. mg

613
 Arithmetic 593

Calculate the liters of water that may be treated 1 Estimate the bypass flow in cubic meters per day.
Water Treated, Exchange Capacity, mg Bypass Flow, (Total Flow, cu m/day)(Plant Effl Hardness. mg/L)
cu m/day
liters Hardness, mg/L Source Water Hardness. mg/L
(1000 cu m/day)(80 mg/L)
280,000 mg
350 mg/L
200 mg/L
= 229 cu m/day
= 1400 liters
2 Estimate he bypass flow in megaliters per day.
EXAMPLE 21 Bypass Flow. (Total Flow cu m/day)(Plant Effl Hardness. mg/L)(1000 LIcu m)
MLO
How many hours will an ion exchange softening unit (Source Water Hardness. mg/L)(1 000 000/M)
operate when treating an average daily flow of 50 liters per (1000 cu m/day)(80 mg/LX1000 L /cu m)
second. The unit is capable of softening 4,500,000 liters of (350 mg/L)(1 000 000/M)
water before requiring regeneration.
= 0 229 MLO
Known Unknown
Ave Daily Flow, L/sec = 50 L/sec Operating Time, hr
Water Treated, L = 4,500,000 L
A.53 Trihalomethanes
Estimate how many hours the softening unit can operate
before requiring regeneration. EXAMPLE 24
Operating Water Treated, L A water utility collected and analyzed eight samples from a
Time, hr water distribution system on the same day for TTHMs The
(Ave Daily Flow, L/sec)(60 sec/min)(60 min/hr)
results are shown below.
4,500,000 L
(50 L/sec)(60 sec/min)(60 min/hr) Sample No. 1 2 3 4 5 6 7 8
TTHM, pg/L 80 90 100 90 110 100 100 90
= 25 hours
What was the average TTHM for the day?
EXAMPLE 22
Known Unknown
Determine the kilograms of salt needed to regenerate an Results from analysis Average TTHM level
ion exchange softening unit capable of removing 225,000 of 8 TTHM samples for the day
milligrams of hardness if 7 kilograms of salt are required for
every 1000 milligrams of hardness removed. Calculate the average TTHM level in micrograms per liter.
Known Unknown Ave TTHM. Sum of Measurement, pgIL
pgIL
Hardness Salt Needed, kg Number of Measurements
= 225,000 mg
Removed, mg 80 pgIL + 90 pgIL + 100 tig/L + 90 pgIL
+ 110 pgIL + 100 pgIL + 100 ligIL + 90 pgIL
Salt Required, 7 kg salt/1000 mg
kg/1000 mg 8

Calculate the kilograms of salt needed to regenerate the ion 760 pgIL
exchange softening unit. 8
Salt Needed. = 95 pgIL
- (Salt Required, kg/1000 mg)(Hardness Removed. mg)
kg

(7 kg salt)(225,000 mg)
1000 mg EXAMPLE 25
= 1575 kilograms of salt The results of the quarterly average TTHM measurement
for two years are given below. Calculate the running annual
EXAMPLE 23 average of the four quarterly measurements in micrograms
per liter.
Estimate the bypass flow in cubic meters per day and
megaliters per day around an ion exchange softener in a Quarter 1 2 3 4 1 2 3 4
plant that treats 1000 cubic meters per day with a source Ave Quarterly 77 88 112 95 93 87 109 89
water hardness of 350 mg/L if the desired product water TTHM, AWL
hardness is 80 mg/L.
Known Unknown Known Unknown

Total Flow, Results from analysis of two Running Annual Average of

= 1000 cu m/day 1. Bypass Flow,
cu m/day cu m/day years of TTHM sampling quarterly TTHM
2. Bypass Flow, measurements
Source Water
Hardness, = 350 mg/L MLD Calculate the running annual average of the quarterly TTHM
mg/L measurements.
Plant Effl Hardness, = 80 mg/L Annual Running TTHM Sum of Ave TTHM for Four Quarters
mg/L Average, pgIL Number of Quarters

614
 594 Water Treatment

QUARTERS 1, 2, 3 AND 4 Flux, gm/sq cm-sec

Flow, L/sq cm-sec
Annual Running TTHM 77 mg/L + 88 mg/L -( 112 mg/ + 95 lag/ L
Average. ;10.
1000 gm/L
4
12 x 10-4 gm/sq cm-sec
372 lag/L
4
1000 gm/L

93 pg/L
= 12 x 10 -7 L/sq cm-sec

2. Convert the water flux from gm/sq cm-sec to flow in liters

QUARTERS 2, 3, 4 AND 1
per day per square centimeter.
Annual Running TTHM 88 pg/L + 112 Aga + 95 mg/L 83 m9/1- Flow, (Flux. gm/sq cm-sec)(60 sec/min)(60 min/hr)(24 hr/day)
Average. mg/L
4 L/sq
cmday 1000 gm/L
378 tig/l.
4 (0 0012 gm/sq cm-sec)(60 se^/mm)(60 min/hr)(24 hr/day)
= 95 mg/ L 1-i00 gm/L
= 0 10 L/sq cm-day
QUARTERS 3, 4, 1 AND 2
Annual Running TTHM 112 pg/L + 95 pg/L + 83 mg/L + 87 Aga
Average. pg/L EXAMPLE 27
4

377 pg/L Estimate the ability of a reverse osmosis plant to reject

4 minerals by calculating the mineral rejection as a percent.
= 94 pg/L
The feedwater contains 1800 mg/L TDS and the product
water TDS is 120 mg/L.

QUARTERS 4, 1, 2 AND 3 Known Unknown

Annual Running TTHM 95 AO. + 83 mgIL + 87 pg /L + 109 mg/L Feedwater TDS, nig,L = 1800 mg/L Mineral Rejection, %
Average. mg/L
4 Product Water TDS, mg/L = 120 mg/L
374 pg/L Calculate the mineral rejection as a percent.
4
Mineral Rejection, % =(1 Product TDS, mg/L )(100%)
94 mg/L
Feed TDS, mg/L

QUARTERS 1, 2, 3 AND 4 120 mg/L )(100%)

Annual Running TTHM 83 pg/L 87 mg/ L + 109 mg/L + 89 pg/L
1800 mg/L
Average. pg/L
4 = (1 0.067)(100%)
368 pg /L = 93 3%
4

= 92 jig/ L EXAMPLE 28
Estimate the percent recovery of a reverse osmosis unit
SUMMARY OF RESULTS with a 4-2-1 arrangement if the feed flow is 8 0 MLD and the
Quarter 1 2 3 4 1 2 3 4 product flow is 7.0 MLD
Ave Quarterly
77 88 112 95 83 87 109 89 Known Unknown
TTHM, pg/L
Annual Runny g Product Flow, MLD = 8.0 MLD Recovery, %
93 95 94 94 92
TTHM Ave, pg/L Feed Flow, MLD = 7.0 MLD
Calculate the recovery as a percent.
A.54 Demineralization
Recovery, % = (Product Flow, MLD) (100%)
EXAMPLE 26 Feed Flow, MLD
Convert a water flux of 12 x 10 4 gm/sq cm-sec to liters (70 M LD)(100%)
per second per square centimeter and liters per day per 8.0 MLD
square centimeter.
= 87.5%
Known Unknown
Water Flux, 12 x 10-4 1 Flow, liters per A.55 Maintenance
gm/sq cm-sec gm/sq cm-sec sec/sq cm
2. Flow, Wei s per EXAMPLE 29
day/sq cm
1. Convert the water flux from gm/sq cm-sec to flow in liters Calculate the pumping capacity of a pump in liters per
per second per square centimeter. second when 12 minutes are required for the water to rise
1.0 meters in a 2.5 meter by 2.0 meter rectangular tank.

615
 Arithmetic 595

Known Unknown Known Unknown

Length, m = 2.5 m Pump Capacity, L/sec Polymer Solution, % = 1.8 % 1. Polymer Feed,
Width, m = 2.0 m Polymer Conc, mg/L = 18,000 mg/L kg/day
2. Polymer Feed,
Depth, m = 1.0 m Polymer Sp Gr = 1.0
gm/sec
Time, min =12 min Volume Pumped, mL = 650 mL
Time Pumped, min = 4.5 min
1. Calculate the volume pumped in cubic meters.
1. Calculate the polymer fed by the chemical feed pump in
Volume Pumped, cu m = (Length, ft)(Width, m)(Depth, m) kilograms of polymer per day.
Polymer Feed. (Vol Pumped, mLXPoly Conc. mg/LX60 min/hrX24 hr/day)
= (2.5 in)(2.0 m)(1.0 m) kg/day
(Time Pumped. minX1000 mL/LX1000 mg/gmX1000 gm/kg)
= 5.0 m
(650 mLX18.000 mg/LX60 min/hrX24 hr/day)
(4 5 minX1000 mL/LX1000 mg/gmX1000 gm/kg)
2. Calculate the pump capacity in liters per second.
3 7 kg/day
Pump Capacity, (Volume Pumped, cu m)(1000 L/cu m)
Liters/sec 2 Calculate the polymer fed by the chemical feed pump in
Purnding Time, min
grams of polymer per second.
0 cu m)(1000 L/cu m) Polymer Feed. (Vol Pumped. mLXPoly Conc. mg/L)
12 min gm/sec
(Time Pumped, minX1000 mL/LX60 Sec/minX1000 mg/gm)

= 417 L/sec (650 mLX18,000 mg/L)

(4 5 minX1000 mL/LX60 secirmnX1000 mg/gm)

EXAMPLE 30 = 0 043 gm /sec

or - 43 mg/sec
A small chemical feed pump lowered the chemical solution
in a 0.8-meter diameter tank 0.7 meters during 7.0 hours
EXAMPLE 32
Estimate the flow delivered by the pump it, liters per second
and milliliters per second. Determine tht actual chemical feed in kilograms per day
and grams per second from a dry chemical feeder. A pie tin
Known Unknown
placed under the chemical feeder caught 824 grams of
Tank Diameter, m = 0.8 m 1. Flow, L/sec chemical during five minutes.
Chemical Drop, m= 0 7 m 2 Flo- , mL/sec
Known Unknown
Time, hr = 7 0 hr
Chemical, gm = 824 gm 1. Chemical Feed, kg/day
1 Deternine the liters of chemical solution pumped Time, min = 5 min 2. Chemical Feed,
Volume, liters = (0 785)(Diameter, m)2(Drop, m)(1000 L/cu m) gm/sec

= (0 785)(0 8 m)2(0 7 m)(10011 L/cu m) 1. Determine the chemical feed in kilograms per day.

= 352 liters Chemical Feed, (Chemical, gm)(60 min/hr)(24 hr/day)

kg/day (Time, min)(1000 gm/kg)
2. 1.:stimate the flow delivered by the pump in liters per
second. = (824 gm)(60 min/hr)(24 hr/day)

Flow, L/sec = Volume Pumped, L (5 min)(1000 gm/kg)

(Pumping Time, hr)(60 min/hr)(60 sec/min)
= 237 kg/day
352 L
2. Determine the chemical feed in grams per secorki.
(7 0 hr)(60 min/hr);60 sec/min)
Chemical Feed, Chemical, gm
= 0.014 L/sec gm/sec
(Time, min)(60 sec/min)
3. Estimate the flow aelivered by the pump in milliliters per
second. 824 gm

(Vciume Pumped, L)(1000 mL/L)

(5 min)(60 sec/min)
Flow, mL/sec
(Pumping Time, hr)(60 min/hr)(60 sec/min) = 2 75 gm/sec
(352 L)(1000 mL/L) A.S6 Safety
(7.0 hr)(60 min/hr)(60 sec/min)
EXAMPLE 33
= 14 mL/sec
Calculate the injury frequency rate for a water utility where
there were four injuries in one year and the operators
EXAMPLE 31 worked 97,120 hours.
Determine the chemical feed in kilograms of polymer per Known Unknown
day and grams per second from a chemical feed pump. The
Injuries, = 4 injuries/yr Injury Frequency
polymer solution is 1.8 percent or 18,000 mg polymer per
number/yr Rate
liter. Assume a specific gravity of the polymer solution of 1.0.
During a test run the chemical feed pump c ivered 650 mL Hours Worked = 97,120 hrs/yr
of polymer sc!ution in 4.5 minutes. number/yr

61E$
 596 Water Treatment

Calculate the injury frequency rate. Known Unknown

Injury Freq Rate (Injures, number/yr)(1,000,000) Tester 1, X, = 2 Geometric Mean
Hours Worked, number/yr Tester 2, X2 = 4 Threshold Odor Number
Tester 3, X3 = 3
(4 injunes/yr)(1,000,000)
Tester 4, X4 = 8
97,120 hrs/yr Tester 5, X5 = 6
= 41.2 Tester 6, X6 = 2

Calculate the geometric mean.

Geometric Mean = (X, x X2 X X3 X X4 X X5 X X6 )1/r)
T O.N.
EXAMPLE 34 =(2 x4x3x8x6x2)1/6
Calculate the injury severity rate for a water company = (2304)° 167
which experienced 57 operator-hours lost dud to injuries
while the operators Jrked 97,120 hours during the year. = 3.6

Known Unknown
Number of Injury Severity Rate EXAMPLE 37
= 57 hr/yr
Hours Lost
Calculate the thresholc' taste number for a sample when
Number of the first detectable taste occurred when the 8.3 mL sample
= 97,120 hrs/yr
Hours Worked was diluted to 200 mL (191.7 mL of taste-free water was
added to the 8.3 mL sample).
Calculate the injury severity rate.
Known Unknown
Injury Severity Rate (Number of Hours Lost/yr)(1,000,000)
Sample Size, mL =8.3 mL Threshold Taste
Number of Hours Worked/yr
Taste-Free Water, mL =191.7 Number
(57 hrs/yr)(1,000,000)
Calculate the threshold taste number.
97,120 hrs/yr
Threshold Sample Size, mL + Taste-Free Water, mL
587 Taste Number
Sample Size, mL
8.3 mL + 191.7 mL
8.3 mL
= 24
A.57 Advanced Laboratory Procedures

EXAMPLE 35
Calculate the threshold odor number (T.O.N.) for a sample EXAMPLE 38
when the first detectable odor occurred when the 70 mL Determine the taste rating for a water by calculating the
sample was diluted to 200 mL (130 mL of odor-free water arithmetic mean and standard deviation for the panel ratings
was added to the 70 mL sample). given below.

Known Unknown Known Unknown

Size of Sample, mL = 70 mL T.0 N Tester 1, X1 = 2 1. Arithmetic Mean,
Odor-Free Water, mL = 130 mL Tester 2, X2 = 5 2. Standard Deviation, S
Calculate the threshold odor number, T.O.N. Tester 3, X3 = 3
Tester 4, X4 = 6
T.O.N. = Size of Sample, mL + Odor-Free Water, mL Tester 5, X5 = 2
Size of Sample, mL Tester 6, X6 = 6
(70 mL + 130 _
1. Calculate the arithmetic mean, X, taste rating
70 mL
Arithmetic Mean, X x, + X2 + X3 + X4 + X5 + X6
=3 Taste Rating

2+5+3+6+2+6
6

EXAMPLE 36 24
6
Determine the geometric mean threshold odor number for
a panel of six testers given the results shown below. =4

617
 Arithmetic 597

2. Calculate the standard deviation, S, of the taste rating.

Standard r (X, i)2 + (X2 X)2 + (X3 X)2 + (X4-502 + (X5-5)2 + (X6 g)2
Deviation,
n
S
1
Jos
(2-4)2 + (5-4)2 + (3-4)2 + (6-4)2 + (2 -4)2 + 0-4)2 05

r
6 1

=[ (-2)2 +(1)2 + (-1)2 + (2)2 4(-2)2 + (2)2

5

4+1+1 i4+4+4 05

=1- 181°5
5
..._

= (3 6)° 5

= 1.9

or
Standard _ (X12 + X22 + X32 + X42 +- X52 + X62) (Xi +X2+ X3+X4+ X5+ X6) 2 /n 5

Deviation,
n 1
S

(22+62+32 +62 +22 +62) (2+5+3+6+2+6)2/6 35

n 1

(4+25+9+36+4+36) (24)2/6 ]°5

5

[114 96 1° 5
5

=r18105
L 5j

= (3 6)°5
= 1.9

EXAMPLE 39
A small water system collected 14 samples during one Calculate the percent of the portions tested during the
month. After each sample was collected, 10 mL of each month which were positive.
sample was placed in each of 5 fermentatior tubes. At the
end of the month, the results indicated that 2 out of a total of
70 fermer.ation tubes were positive. What percent of the Portions Positive, %/mo = (Nurnber Positive /mo)(100 %)
portions tested during the month were positive9 Total Portions Tested

Known Unknown (2 positive /mo)(100 %)

Number Portions Positive, 70 portions
= 2 pc ;itive/mo
Positive/me %/mo
Total Portions = 3%/mo
70 portions
Tested

618
 WATER ABBREVIATIONS

ac acre km kilometer
ac-ft acre-feet kN kilonewton
of acre feet kW kilowatt
amp ampere kWh kilowatt-hour
°C degrees Celsius L liter
cfm cubic feet per minute lb pound

cfs cubic feet per second lbs/sq in pounds per square inch
CI Curie m meter
cm centimeter M mega

cu ft cub,". feet M million

cu in cubic inch mg milligram

cu m cubic meter mg/L milligram per liter
cu yd cubic yard MGD million gallons per day
°F degrees Fahrenheit mL milliliter
ft feet or foot min minute
ft-lb/min foot-pounds pc' minute mm millimeter

g gravity N Newton
gal galloi, ohm ohm

gal/day gallons per day Pa Pascal

gm gram pCi picoCune

GPD gallons per uay psf pounds per square foot
GPM gallons per minute psi pounds per square inch

9P9 grains per gallon psig pounds per square inch gage
gr grain ppb parts per billion
ha hectare ppm parts per million
HP horsepower sec second
hr hour sq ft square feet
in inch sq in square inches
k kilo W watt
kg kilogram

619
 WATER WORDS
A Summary of the Words Defined

in

WATER TREATMENT PLANT OPERATION

and

WATER SUPPLY SYSTEM OPERATION

PROJECT PRONUNCIATION KEY

by Warren L Prentice

The Project Pronunciation Key is designed to aid you in SYLLABLE

the pronunciation of new words. While this Key is based Word 1st 2nd 3rd 4th 5th
primarily on familiar sounds, it does not attempt to follow any
particular prononciation guide. This Key is designed solely acid AS id
to aid operators in this program. coagulant co AGG you lent
You may find it helpful to refer to other available sources biological BUY o LODGE ik cull
for pronunciation help. Each c*.rrent standard dictionary
contains a guide to its own pronunciation Key. Each Key will
be different from each other and from this Key. Examples of
the differences between the Key used in this program and The first word ACID has its first syllable accented. The
the WEBSTER'S NEW WORLD DICTIONARY "Key", are second word, COAGULANT, has its second syllable accent-
shown below. ed. The third word, BIOLOGICAL, has its first and third
In using this Key, you should accent (say louder) the syllables accented.
syllable which appears in capital letters. The following chart
is presented to give examples of how to pronounce words We hope you will find the Key useful in unlocking 'he
using the Project Key. pronunciation of any new word.

4)

1 The WEBSTER'S NEW WORLD DICTIONARY, Second College Edition, 1972, was chose,' rather than an unabridged dictionary because
of its availability to the operator. Other editions may be slightly different.

620
602 Water Treatment

WATER WORDS

ABC .^,BC
See Association of BOARDS of Certification

ABSORPTION (ab -SORP -shun) ABSORPTION

Taking in or soaking up of one substance into the body of another by molecular or chemical action (as tree roots absorb dis-
solved nutrients in the soil).

ACCURACY ACCURACY
How closely an instrument measures the true or actual value of the process variable being measured or sensed.

ACID RAIN ACID RAIN

Precipitation which has been rendered (made) acidic by airborne pollutants.

ACIDIC (uh-SID-ick) ACIDIC

The condition of water or soil which contains a sufficient amount of acid substances to lower the pH below 7 0.

ACIDIFIED (uh-SID-uh-FIE-d) ACIDIFIED

The addition of an acid (usually nitric or sulfuric) to a sample to lower the pH below 2 0. The purpose of acidification is to "fix" a
sample so it won't change until it is analyzed.

ACRE-FOOT ACRE-FOOT
A volume of water that covers one acre to a depth of one foot, or 43,560 cubic feet (1233.5 cubic meters).

ACTIVATED CARBON ACTIVATED CARBON

Adsorptive particles or granules of carbon usually obtained by heating carbon (such as wood). These particles or granules have
a high capacity to selectively remove certain trace and soluble materials from water

ADSORBATE (add-SORE-bait) ADSORBATE

The material beano removed oy the adsorption process.

ADSORBENT (add-SORE-bent) ADSORBENT

The material (activated carbon) that is responsible for removing the undesirable substance in the adsorption process.

ADSORPTION (add-SORP-shun) ADSORPTION

The collection of a gas, liquid, or dissolved substance on the surfac or interface zone of another material.

AERA PION (air-A-shun) AERATION

f he process of adding air to water Air can be added to water ay either passing air through water or passing water through air

AEROBIC (air-O-bick) AEROBIC

A condition in which "free" (atmospheric) or dissolved oxygen is present in the water.

AESTHETIC (es-THET-ick) AESTHETIC

Attractive or appealing.

AGE TANK AGE TANK

A tank used to store a chemical solution of known concentration for feed to a chemical feeder. Also called a DAY TANK.

621
 Words 603
AIR BINDING
AIR BINDING
A situation where air enters the fil*er media Air is harmful to both the filtration and backwash processes. Air can prevent the
passage of water during the filtration process and can cause the loss of filter media during the backwash process.
AIR GAP
OliNKING
AIR GAP
An open vertical drop, or vertical empty space, that separates a drinking MATER

(potable) water supply to be protected from another water system in a

water treatment plant or other location. This open gap prevents the
contamination of drinking water by backsiphonage or backflow because
there is no way raw water or any other water can reach the drinking water

AIR PADDING
AIR PADDING
Pumping dry air into a container to ass 3t with the withdrawal of a liquid or to force a liquefied gas such as chlonne out of a
container.

AIR STRIPPING
AIR STRIPPING
A treatment process used to remove dissolved gases and volatile substances from water Large volumes of air are bubbled
through the water being treated to remove (strip out) the dissolved gases and volatile substances.

ALARM CONTACT
ALARM CONTACT
A switch that operates when some pre-set low, high or abnormal condition exists.

ALGAE (Al-gee)
ALGAE
Microscopic plants which contain chlorophyll and live floating or suspended in water. They also may be attached to structures,
rocks or other submerged surfs es. Excess algal growths can impart tat-tes and odors to potable water. Algae produce oxygen
during sunlight hours and use oxygen during the night hours. Their biological activities appreciably affect the pH . 'd dissolved
oxygen of the water.

ALGAL BLOOM (AL-gull)

ALGAL BLOOM
Sadden, massive growths of microscopic and macroscopic plant life, such as green or blue-green algae, which develop in lakes
and reservoirs.

ALGICIDE (AL-gi-SIDE)
ALGICIDE
Any substance or chemical specifically formulated to kill or control algae.

ALIPHATIC HYDROXY ACIDS (AL-uh-FAT-ick) ALIPHATIC HYDROXY ACIDS

Organic acids w,:h carbon atoms arranged in branched or unbranched open chains rather than in rings

ALIQUOT (AL-Ii-kwot)
ALIQUOT
Portion of a sample

ALKALI (AL-ka-lie)
ALKALI
Various soluble salts, principally of sodium, potassium, magnesium, and calcium, that have the property of combining with
acids to form neutral salts and may be usad in chemical water treatment processes.

ALKALINE (AL-ka-LINE)
ALKALINE
The condition of water or soil which contains a sufficient amount of alkali substances to raise the pH above 7.0.

ALKALINITY (AL-ka-LIN-it-tee)
ALKALINITY
The capacity of water to neutralize acids This capacity is caused by the water's content of carbonate:, bicarbonate, hydroxide,
and occasionally borate, silicate, and phosphate. Alkalinity is expressed in milligrams per liter of equivalent calcium carbonate.
Alkalinity is not the same as pH because water does not have tc he strongly basic (high pH) to have a high alkalinity. Alkalinity is
a measure of how much acid can be added to a liquid without causing a great change in pH.

ALLUVIAL (uh-LOU-vee-ul)
ALLUVIAL
Relating to mud and/or sand deposited by flowing water. Alluvial deposits may occur after a heavy rain storm.

ALTERNATING CURRENT (A.G.) ALTERNATING CURRENT (A.C.)

An electric current that reverses its direction (positive/negative values) at regular intervals.

622
604 Water Treatment

ALTITUDE VALVE ALTITUDE VALVE

A valve that automatically shuts off the flow into an elevated tank ., en the water level in the tank reaches a predetermined lev-
el The % Ave automatically opens when the pressure in the distribution system drops below the pressure in the tank.

AMBIENT TEMPERATURE (AM-bee-ent) AMBIENT TEMPERATURE

Temperature of the surrounding air (or other medium). For example, temperature of the room where a gas chlorinator is in-
stalled.

AMERICAN WATER WORKS ASSOCIATION AMERICAN WATER WORKS ASSOCIATION

A professional organization for all persons working in the water lltiu field For information on AWWA membership and publica-
tions, contact AWWA, 6666 W. Quincy Avenue, Denver, Colorado 80235

AMPERAGE (AM- purr -ay,;) AMPERAGE

The strength of an electric current measured in amperes The amount of electric current flow, similar to the flow of water in gal-
lons per minute.

AMPERE (AM-peer) AMPERE

The unit used to measure current strength The currant produced by an electromotive force of one volt acting through a resis-
tance of one ohm.

AMPEROMETRIC (am-PURR-o-MET-rick) AMPEROMETRIC

Based on the electric current that flows between two electrodes in a solution.

AMPEROMETRIC TITRATION AMPEROMETRIC TITRATION

A means of measuring concentrations of certain substances in water (such as strong oxidizers) based on the electric current
that flows during a chemical reaction. See TITRATE

AMPLITUDE AMPLITUDE
The maximum strength of an alternating current during its cycle, as distinguished from the mean or effective strength.

ANAEROBIC (AN-air-O-bick) ANAEROBIC

A condition in which "free" (atmospheric) or dissolved oxygen is NOT present in water.

ANALOG ANALOG
The readout of an instrument by a pointer (or other indicating means) against a dial or scale.

ANGSTROM (ANG-strem) ANGSTROM

A unit of length equal to one tenth of a nanometer or one ten-billionth of a meter (1 Angstrom = 0.000 000 000 1 meter). One
Angstrom is the approximate diameter of an atom.

ANALYZER ANALYZER
A device which conducts periodic or continuous measurement of some factor such as chlorine, fluoride or turbidity. Analyzers
operate by any of several methods including photocells, conductivity or complex instrumentation.

ANION (AN-EYE-en) AN ION

A negatively charged ion in an electrolyte solution, attracted to the anode under the influence of a difference in electrical poten-
tial. Chloride (Cr) is an anion.

ANIONIC POLYMER (AN-eye-ON-ick) ANIONIC POLYMER

A polymer having negatively charged groups of ions, often used as a filter aid and fc 'ewatering sludges

ANNULAR SPACE (AN-you-ler) ANNULAR SPACE

A ring-shaped space located between two circular objects, such as two pipes. ANNULAR SPACE

PIPE LINER

PIPE

ANODE (an-O-d) ANODE

The positive pole or electrode of an electrol ;ic system, such as a battery The anode attracts negatively charged particles or
ions (anions).

6 ..,9 .1
 Words 605
APPROPRIATIVE APPROPRIATIVE
Water rights to or ownership of ^ water supply which is acquired for the beneficial use of water by following a specific legal
procedure

APPURTENANCE (uh-PURR-ten-nans) APPURTENANCE

Machinery, appliances, structures and other parts of the main structure necessary to allow it to operate as intended, but not
considered part of the main structure.

AQUEOUS (A-kwee-us) AQUEOUS

Something made up of, similar to. or containing water; watery.

AQUIFER (ACK-wi-fer) AQUIFER

A natural underground layer of porous, water-bearing materials (sand, gravel) usually capable of yielding a large amour1t or
supply of water

ARTESIAN (are-TEE-zhun) ARTESIAN

Pertaining to groundwater, a well, or underground basin where the water s under a pressure greater than atmospheric and will
rise above the level of its upper confining surface if given an opportunity to do so.

ASEPTIC (a-SEP-tick) ASEPTIC

Free from the living germs of cPsease, fermentation or putrefaction. Sterile.

ASSOCIATION OF BOARDS OF CERTIFICATION ASSOCIATION OF BOARDS OF CERTIFICATION

An international organization representing over 110 boards which certify the operators of waterworks and wastewater facilities.
For information on ABC publications regarding the preparation of and how to study for operator certification examinations, con-
tact ABC, P.O. Box 786, Ames, Iowa 50010-0786.

ASYMMETRIC (A-see-MET-rick) ASYMMETRIC

Not similar in size, shape, form or arrangement of parts on opposite sides of a line, point o: plane.
ATOM ATOM
The smallest unit of a chemical element, composed of protons, neutrons and electrons.

AVAILABLE CHLORINE AVAILABLE CHLORINE

A measure of the amount of chlorine a.ailable in chlorinated lime, hypochlorite compounds, and other materials that are used
as a source of chlorine when compared with that of elemental (liquid or gaseous) chlorine.

AVAILABLE EXPANSION AVAILABLE EXPANSION

The vertical distance from the sand surface to the underside of a trough in a sand filter. This distance is also called
FREEBOARD.

AVERAGE AVERAGE
A number obtained by adding quantities or measurements and dividing the sum or total by the number of quantities or measure-
ments Also called the ARITHMETIC MEAN.
Average = Sum of Measurements
Number of Measurements
AVERAGE DEMAND AVERAGE DEMAND
The total demand for water during a period of time divided by the number of days in that time period. This is also calleo the
AVERAGE DAILY DEMAND.

AWWA AWWA
See AMERICAN WATER WORKS ASSOCIATION

AXIAL TO IMPELLER AXIAL TO IMPELLER

The direction in which material being pumped flows around the impeller or flow parallel to the impeller shaft.
AXIS OF IMPELLER AXIS OF IMPELLER
An imaginary line running along the center of a shaft (such as an impeller shaft).

BACK PRESSURE BACK PRESSURE

A pressure that can cause water to backflow into the water supply when a i.ser's water system is at a higher pressure than the
public water system.

624
606 Water Treatment

BACK FLOW BACKFLOW

A reverse flow condition, created by a difference in water pressures, which causes water to flow back into the distribution pipe::
of a potable water supply from any source or sources other than an intended source Also see BACKSIPHONAGE.

BACKSIPHONAGE BACKSIPHONAGE
A form of backflow caused by a negative or below atmospheric pressure within a water system. Also see BACKFLOW.

BACKWASHING BACKWASHING
The process of reversin . the flow of water back through fhe filter media to remove the entrapped solids.

BACTERIA (back-TEER-e-uh) BACTERIA

Bacteria are living organisms, micrc scopic in size, which usually consist of a single cell Most bacteria use organic matter for
their food and produce waste prod icts as a result of their life processes.

BAFFLE BAFFLE
A flat board or plate, deflector, guide or similar device constructed or placed in tik, wing water or slurry systems to cause more
uniform flow velocities, to absorb energy, and to divert, guide, or agitate liquids (water, chemical solutions, slurry)

BAILER (BAY-ler) BAILER

A 10- to 20-foot-long pipe equipped with a valve at the lower end. A bailer is used to remove slurry from the bottom or the side
of a well as it is being drilled

BASE METAL BASE METAL

A metal (such as iron) which reacts IA h dilute hydrochloric acid to form hydrogen. Also see NOBLE METAL

BATCH PROCESS BATCH PROCESS

A treatment process in which a tank or reactor is filled, the water is treated or a chemical solution is prepared, and the tank is
emptied The tank may then be filled and the process repeated.

BENCH SCALE TESTS BENCH SCALE TESTS

A method of studying different ways or chemical doses for treating water on a small scale in a laboratory.

BIOCHEMICAL OXYGEN DEMAND BIOCHEMICAL OXYGEN DEMAND

BOD The rate at which microorganisms use the oxygen in water whiIF stabilizing decomposable organic matter under aerobic
conditions In decomposition, organic matter serves as food for th:, bacteria and energy results from its oxidation.

BIOLOGICAL GROWTH BIOLOGICAL GROWTH

The activity and growth of any and all living organisms.

BLANK BLANK
A bottle containing only dilution water or distilled water, the sample being tested is not added. Tests are free :fritly run on a
SAMPLE and a BLANK and the differences are compared.

BOD (pronounce as separate letters) BOD

Biochemical Oxygen Demand The rate at which microorganisms use the oxygen in water while stabilizing decomposable or-
ganic matter under aerobic conditions In decomposition, organic matter serves as food for the bacteria and energy results
from its oxidation

BONNET (BON-it) BONNET

The cover on a gate valve.

BOWLS, PUMP BOWLS, PUMP

The submerged pumping unit in a well, including the shaft, impellers and housing.

BRAKE HORSEPOWER BRAKE HORSEPOWER

(1) The horsepower required at the top or end of a pump shaft (input to a pump).
(2) The energy provided by a motor or other power source.

BREAKPOINT CHLORINATION BREAKPOINT CHLORINATION

Addition of chlorine to water until the chlorine demand has been satisfied At th:s point, further additions of chlorine will result in
a free residual chlorine that is directly proportional to the amount of chlorine added beyond the breakpoint.
 Words 607
BREAKTHROUGH BREAKTHROUGH
A crack or break in a filter bed allowing the passage of floc or particulate matter through a filter. This will cause an increase in
filter effluent turbidity A breakthrough can occur (1) when a filter is first placed in service, (2) when the effluent valve suddenly
opens or closes, and (3) during periods of excessive head loss through the filter (including when the filter is exposed to negative
heads).

BRINELLING (bruh-NEL-ing) BRINELLING

Tiny indentations (dents) high on the shoulder of the bearing race or bearing A type of bearing failure

BUFFER BUFFER
A solution or liquid whose chemical makeup neutralizes acids or bases without a great change in pH

BUFFER CAPACITY BUFFER CAPACITY

A measure of the capacity of a solution or liquid to neutralize acids or bases. This is a measure of the capacity of water for
offering a resistance to changes in pH.

C FACTOR C FACTOR
A tactor or value used to indicate the smoothness of the interior of a oipe. The higher the C Factor, the smoother the pipe, the
greater the carrying capacity, and the smaller the friction or energy losses from water flowing in the pipe To calculate the C
Factor, measure the flow, pipe diameter, distance between two pressure gages, and the friction or energy loss of the water be-
tween the gages.

C Factor = Flow, GPM

193 75 (Diameter, ft)263 (Slope)054

CAISSON (KAY-sawn) CAISSON

A structure or chamber which is usually sunk or lowered by digging from the inside Used to gain access to the bottom of a
stream or other body of water

CALCIUM CARBONATE EQUILIBRIUM CALCIUM CARBONATE EQUILIBRIUM

A water is considered stable when it is just saturated with calcium carbonate. In this condition the water will neither dissolve nor
deposit calcium carbonate Thus, in this water the calcium carbonate is in equilibrium with the hydrogen ion concentration.

CALCIUM CARBONATE (CaCO3) EQUIVALENT CALCIUM CARBONATE (CaCO3) EQUIVALENT

An expression of the concentration of specified constituents in water in terms of their equivalent value to calcium carbonate
For example the hardness in water which is caused by calcium, magnesium and other ions is usually described as calcium car-
bonate equivalent.

CALIBRATION CALIBRATION
A procedure which checks or adjusts an instrument's accuracy by comparison with a standard or reference

CAPILLARY ACTION CAPILLP Rv ACTION

The movement of water through very small spaces due to molecular forces.

CAPILLARY FORCES CAPILLARY FORCES

The molecular forces which cause the movement of water through very small spaces.

CAPILLARY FRINGE CAPILLARY FRINGE

The porous material just above the water table which may hold water by capillarity (a property of surface tension that draws wa-
ter upwards) in the smaller void spaces

CARCINOGEN (car-SIN-o-jen) CARCINOGEN

Any substance which tends to produce cancer in an organism.

CATALYST (CAT-uh-LIST) CATALYST

A substance that changes the speed or yield of a chemical reaction without being consumed or chemically changed by the
chemical reaction.

CATALYZE (CAT-uh-LIZE) CATALYZE

To act as a catalyst. Or, to speed up a chemical reaction.

CATALYZED (CAT-uh-LIZED) CATALYZED

To be acted upon by a catalyst

626
608 Water Treatment

CATHODE (KA-thow-d) CATHODE

The negative pole or electrode of an electrolytic cell or system. The cathode attracts positively charged particles or ions
(cations).

CATHODIC PROTECTION (ca-THOD-ick) CATHODIC PROTECTION

An electrical system for prevention of rust, corrosion, and pitting of metal surfaces which are in contact with water or soil A
low-voltage current is made to flow through a liquid (water) or a soil in contact with the metal in such a manner that the external
electromotive force renders the metal structute cathodic This concentrates corrosion on auxiliary anodic parts which are delib-
erately allowed to corrode instead of letting the structure corrode

CATION (CAT-EYE-en) CATION

A positively charged ion in an electrolyte solution, attracted to the cathode under the influence of a difference in electrical poten-
tial Sodium ion (Na') is a cation.

CATIONIC POLYMER CATIONIC POLYMER

A polymer having positively charged groups of ions: often used as a coagulant aid.

CAVITATION (CAV-uh-TAY-shun) CAVITATION

The formation and collapse of a gas pocket or bubble on the blade of an impeller or the gate of a valve The collapse of this gas
pocket or bubble drives water into the impeller or gate with a terrific force that can cause pitting on the impeller or gate surface
Cavitation is accompanied by loud noises that sound Ike someone is pounding on the impeller or gate with a hammer.

CENTRATE CENTRATE
The water leaving a centifuge after most of the solids have been removed

CENTRIFUGAL PUMP (sen-TRIF-uh-gull) CENTRIFUGAL PUMP

A pump consisting of an impeller fixed on a rotating shaft that is enclosed in a casing, and having an inlet and discharge con-
nection. As the rotating impeller whirls the water around, centrifugal force builds up enough pressure to force the water through
the discharge outlet

CENTRIFUGE CENTRIFUGE
&mechanical device that uses centrifugal or rotational forces to separate solids from liquids

CHECK SAMPLING CHECK SAMPLING

Whenever an initial or routine sample analysis indicates that an MCL has been exceeded, CHECK SAMPLING is required to
confirm the routine sampling results. Check sampling is in addition to the routine sampling program.

CHECK VALVE CHECK VALVE

A special valve with a hinged disc or flap that opens in the direction of normal flow and is forced shut when flows attempt to go
in the reverse or opposite direction of normal flow.

CHELATING AGENT (key-LAY-tang) CHELATING AGENT

A chemical used to prevent the precipitation of metals (such as copper).

CHELATION (key-LAY-shun) CHELATION

A chemical complexing (forming or joining together) of metallic cations (such as copper) with certain organic compounds, such
as EDTA (ethylene diamine tetracetic acid) Chelation is used to prevent the precipitation of metals (copper). Also see
SEQUESTRATION.

CHLORAMINATION (KLOR-am-i-NAY-shun) CHLORAMINATION

The application of chlorine and ammonia to water to form chloramines for the purpose of disinfection.

CHLORAMINES (KLCR-uh-means) CHLORAMINES

Compounds formed by the reaction of hypochlorous acid (or aqueous chlorine) with ammonia.

CHLORINATION (KLOR-uh-NAY-shun) CHLORINATION

The application of chlorine to water, generally for the purpose of disinfection, but frequently for accomplishing other biological
or chemical results (ailing coagulation and controlling tastes and odors)

CHLORINATOR (KLOR-uh-NAY-ter) CHLORINATOR

A metering device which is used to add chlorine to water
 Words 609
CHLORINE DEMAND CHLORINE DEMAND
Chlorine demand is the difference between the amount of chlorine added to water and the amount of residual chlorine
remaining after a given contact time Chlorine demand may change with dosage, time, temperature, pH, and nature and amount
of the impurities in the water.
Chlorine Demand, mg/L = Chlorine Chlorine
Applied. mg/L Residual. mg/L

CHLORINE REQUIREMENT CHLORINE REQUIREMENT

The amount of chlorine which is needed for a particular purpose Some reasons for adding chlorine are reducing the number of
conform bacteria (Most Probable Number), obtaining a particular chlorine residual, or oxidizing some substance in the water. In
each case a definite dosage of chlorine will be necessary This dosage is the chlorine requirement.

CHLOROPHENOLIC (klor-o-FEE-NO-lick) CHLOROPHENOLIC

Chiorophenolic compounds are phenolic compounds (carbolic acid) combined with chlorine.

CHLOROPHENOXY (KLOR-o-fuh-KNOX-ee) CH LOROPHENOXY

A class of herbicides that may be found in domestic water supplies and cause adverse health effects. Two widely used chloro-
phenoxy herbicides are 2,4-D (2,4-Dichlorophenoxy acetic acid) and 2,4,5-TP (2,4,5-Trichlorophenoxy propionic acid (silvex)).

CHLORORGANIC (klor-or-GAN-nick) CHLORORGANIC

Organic compounds combined mth chlorine These compounds generally originate from, or are associated with, life processes
such as those of algae in water.

CIRCLE OF INFLUENCE CIRCLE OF INFLUENCE

The circular outer edge of a depression produced in the water table by the pumping of water trom a well. Also see CONE OF
INFLUENCE and CONE OF DEPRESSION

(SEE DRAWING ON PAGE 600]

CIRCUIT CIRCUIT
The complete path of an electric current, including the generating apparatus or other source, or, a specific segment or section
of the complete path.

CIRCUIT BREAKER CIRCUIT BREAKER

A safety device in an electrical circuit that automatically shuts off the circuit when it becomes overloz .,ed. The device can be
manually reset.

CISTERN (SIS-turn) CISTERN

A small tank (usually covered) or a storage facility used to store water for a home or farm Often used to store rain water.

CLARIFIER (KLAIR-uh-fire) CLARIFIER

A large circular or rectangular tank or basin in which water is held for a period of time during which the heavier suspended
solids settle to the bottom Clarifie.s are also called SETTLING BASIN 3 and SEDIMENTATION BASINS

CLEAR WELL CLEAR WELL

A reservoir for the storage of filtered water of sufficient capacity to prevent the need to vary the filtration rate with variations in
demand Also used to provide chlorine contact time for disinfection.

COAGULANT AID COAGULANT AID

Any chemical or substance used to assist or modify coagulation.

COAGULANTS (co-AGG-you-lents) COAGULANTS

Chemicals that cause very fine particles to clump together into larger particles. This makes it easier to separate the solids from
the water by settling, skimming, draining or filtering.

COAGULATION (co-AGG-you-LAY-shun) COAGULATION

The clumping together of very fine particles into larger particles caused by the use of chemicals (coagulants). The ch,--nicals
neutralize the electrical charges of the fine particles and cause destabilization of the particles. This clumping together makes it
easier to separate the solids from the water by settling, skimming, draining, or filtering.

COLIFORM (COAL-i-form) COLIFORM

A group of bacteria found in the intestines of warm-blooded animals (including humans) and also in plants, sod, air and water.
Fecal conforms are a specific class of bacteria which only inhibit the .ntestines of warm-blooded animals. The presence of con-
form bacteria is an indication that the water is polluted and may contain pathogenic organisms.

628
610 Water Treatment

CIRCLE OF
INFLUENCE

TOP OR PLAN VIEW

GROUND SURFACE-

+ORIGINAL WATER LEVEL

k_ CIRCLE
OF INFLUENCE
CONE OF
DEPRESSION

WELL

SIDE OR ELEVATION VIEW

 Words 611

COLLOIDS (CALL-bolds) COLLOIDS

Very small, finely divide I solids (particles that do not dissolve) that remain dispersed in a liquid for a long time due to their small
size and electrical charge. When most of the particles in water have . negative electrical charge, they tend to repel each other
This repulsion prevents the particles from dumping together, becoming heavier, and settling out

COLORIMETRIC MEASUREMENT COLORIMETRIC MEASUREMENT

A means of measuring unknown chemical concentrations in water by measuring a sample's color intensity. The specific color of
the sample, developed by addition of chemical reagents, is measured with a photoelectric colorimeter or is compared with "col-
or standards" using, or corresponding with, known concentrations of the chemical.

COMBINED AVAILABLE RESIDUAL CHLORINE COMBINED AVAILABLE RESIDUAL CHLORINE

The concentration of residual chlorine which is combined with ammonia (NH3) and/or orgy is nitrogen in water as a chloramine
(or other chloro derivative) yet is still available to oxidize organic matter and utilize its bactericidal properties

COMBINED RESIDUAL CHLORINATION COMBINED RESIDUAL CHLORINATION

The application of chlorine to water to produce combined available residual chlorine. This rt. sidual can be made up of
monochloramines, dichloramines, and nitrogen trichlonde.

COMPLETE TREATMENT COMPLETE TREATMENT

A method of treating water which consists of the addition of coagulant chemicals, flash mixing, coagulation-flocculation,
sedimentation and filtration. Also called CONVENTIONAL FILTRATION.

COMPOSITE (come-PAH-zit) (PROPORTIONAL) SAMPLES COMPOSITE (PROPORTIONAL) SAMPLES

A composite sample is a collection of individual samples c'. ..led at regular Intel 'els, usually every one or two hours during a
24 -,lour time span. Each individual sample is combined wan the others in proportion to the rate of flow when the sample was
collected. The resulting mixture (composite sample) forms a representative sample and is analyzed to determine the average
conditions during the sampling period

COMPOUND COMPOUND
A substance compc7ed of two or more elements whose composition is constant. For example, table salt (sodium chloride-
NaCI) is a compound.

CONCENTRATION POLARIZATION CONCENTRATION POLARIZATION

(1) The ratio of the salt concentration in the membrane boundary layer to the salt concentration in the water being treated The
most common and serious problem resulting from concentration polarization is the increasing tendency for precipitation of
sparingly soluble salts and the deposition of particulate matter on the membrane surface.
(2) Used in corrosion studies to indicate a depletion of ions near an electrode.
(3) The basis for chemical analysis by a polarograph.

CONDITIONING CONDITIONING
Pretreatment of sludge to facilitate removal of water in subsequent treatment processes

CONDUCTANCE CONDUCTANCE
A rapid method of estimating the dissolved-solids content of a water supply. The measurement indicates the capacity of a san-
ple of water to carry an electrical current, which is related to the concentration of ionized substances in the water Also called
SPECIFIC CONDUCTANCE.

CONDUCTIVITY CONDUCTIVITY
A measure of the ability of a solution (water) to carr: an electric currer'

CONDUCTOR CONDUCTOR
A substance, body, device or wire that readily conducts or carries electrical current.

CONDUCTOR CASING CONDUCTOR CASING

Tne outer casing of a well. The purpose of this casing is to prevent contaminants from surface waters c :,hallow -oundwaters
from entering a well.

CONE OF DEPRESSION CONE OF DEPRESSION

The depression, roughly L.c,nical in shape, produced in the water table by the pumping of water from a well Also see CIRCLE
OF INFLUENCE and CONE OF INFLUEN3E.

[SEE DRAWING ON PAGE 610]

630
 612 Water Treatment

CONE OF INFLUENCE
CONE OF INFLUENCE
The depression, roughly conical in shape, produced in the water table by the pumping of water from a well. Also see CIRCLE
OF INFLUENCE and CONE OF DEPRESSION

[SEE DRAWING ON PAGE 600]

CONFINED SPACE*
CONFINED SPACE
A space defined by the concurrent existence of the following conditions.
A Existing ventilation is insufficient to remove dangerous air contamination and/or oxygen deficiency which may exist or de-
velop, and
B Ready access or egress (getting out) for the removal of a suddenly disabled employee (operator) is difficult due to the loca-
tion and/or size of the opening(s)
Also see definitions of DANGEROUS AIR CONTAMINATION and DEFICIENCY.

CONSOLIDATED FORMATION CONSOLIDATED FORMATION

A geologic material whose particles are stratified (layered), cemented or firmly packed together (hard rock), usually occurring at
a depth below the ground surface. Also see UNCONSOLIDATED FORMATION.

CONTACTOR
CONTACTOR
An electrical switch, usL,91Iy magnetically operated

CONTAMINATION
CONTAMINATION
The introduction into water of microorganisms, chemicals, toxic substances, wastes, or wastewater in a concentration that
makes the water unfit for its next intended use

CONTINUOUS SAMPLE
CONTINUOUS SAMPLE
A flow of water from a particular place in a plant to the location where samples are collected for testing. This continuous stream
may be used to obtain grab or composite samples Frequently, several taps (faucets) will flow continuously in the laboratory to
provide test samples from various places in a water treatment plant.

CONTROL LOOP
CONTROL LOOP
The path through the control system between the sensor, which measures a process vanabie, and the controller, which con-
trols or adjusts the process variable.

CONTROL SYSTEM
CONTROL SYSTEM
A system which senses and controls its own operation on a close, continuous basis in what is called proportional (or
modulating) control.

CONTROLLER
CONTROLLER
A device which controls the starting, stopping, or operation of a device or piece of equipment

CONVENTIONAL FILTRATION
CONVENTIONAL FILTRATION
A meti-iod of treating water which consists of the addition of coagulant chemicals, flash mixing, coagulation-flocculation,
sedimentation and filtration Also called COMPLETE TREATMENT. Also see DIRECT FILTRATION and IN-LINE FILTRATION.

CONVENTIONAL TREATMENT CONVENTIONAL TREATMENT

See CONVENTIONAL FILTRATION. Also called COMPLETE TREATMENT.

CORPORATION STOP
CORPORATION STOP
A water service shutoff valve located at a street water main This valve cannot be operated from the ground surface because it
is buried and there is no valve box. Also called a CORPORATION COCK.

CORROSION
CORROSION
The gradual decomposition or destruction of a material by chemical action, often due. to an electrochemical reaction. Corrosion
may be caused by (1) stray current electrolysis, (2) galvanic corrosion caused by dissimilar metals, or (',") differential-
concentration cells. Corrosion starts at the surface of a material and moves inward.

CORROSION INHIBITORS
CORROSION INHIBITORS
Substances that slow the rate of corrosion.

* CONFINED SPACES, General Industry Safety Orders, Article 108, Title 8, California Administrative Code, Cal/OSHA Consultation
Service, Sacramento, California, October, 1980.

631
 Words 613

CORROSIVITY CORROSIVITY
An indication of the corrosiveness of a water The corrosiveness of a water is described by the water's pH, alkalinity, hardness,
temperature, total dissolved solids, dissolved oxygen, and the Langelier Index.

COULOMB (C00-lahm) COULOMB

A measurement of the amount of electrical charge conveyed by an electric current of one ampere in one second One cc.Jlomb
equals about 6.25 x 1018 electrons (6,250,000,000,000,000,000 electrons).

COUPON COUPON
A steel specimen inserted into water to measure the corrosiveness of water. The rate of corrosion is measured as the loss of
weight of the coupon (in milligrams) per surface area (in square decimeters) exposed to the water per day.
10 decimeters = 1 meter = 100 centimeters

CROSS-CONNECTION CROSS-CONNECTION
A connection between a drinking (potable) water system and an unapproved water supply For example, if you have a pump
moving nonpotable water and hook into the drinking water system to supply water for the pump seal, a cross-connection or
mixing between the two water systems can occur. This mixing may lead to contamination of the drinking water.

CURB STOP CURB STOP

A water service shutoff valve located in a water service pipe near the curb and between the water main and the building. This
valve is usually operated by a wrench or valve key and is used to start or stop tlows in the water service line to a building. Also
called a "curb cock."

CURIE CURIE
A measure of radioactivity One Curie of radioactivity is equivalent to 3.7 1010 or 37,000,000,000 nuclear disintegrations per
second.

CURRENT CURRENT
A movement or flow of electricity Water flowing in a pipe is measured in gallons per second past a certain point, not by the
number of water molecules going past a point Electric current is measured by the number of coulombs per second flowing past
a certain point in a conductor. A coulomb is equal to about 6.25 .. 1018 electrons (6,25,000,000,000,000,000 electrons) A flow
of one coulomb per second is called one ampere, the unit of the rate of flow of current.

CYCLE CYCLE
A complete alteration of voltage and/or current in an alternating current (A.C.) circuit.

DANGEROUS AIR CONTAMINATION DANGEROUS AIR CONTAMINATION

An atmosphere presenting a threat of causing death, injury, acute illness, or disablement due to the presence of flammable
and/or explosive, toxic or otherwise injurious or incapacitating substances.
A Dangerous air contamination due to the flammability of a gas or vapor is defined as an atmosphere containing the gas or va-
por at a concentration greater than 20 percent of its lower explosive (lower flammable) limit.
B Dangerous air contamination due to a combustible particulate is defined as a concentration greater than 20 percent of the
minimum explosive concentration of the particulate.
C Dangerous air contamination due to the toxicity of a substance is defined as the atmospheric concentration immediately
hazardous to life or health.

DATEOMETER (day-TOM-uh-ter) DATEOMETER

A small calendar disc attached to motors and equipment to indicate the year in which the last maintenance service was per-
formed.

DATUM LINE DATUM LINE

A line from which heights and depths are calculated or measured Also called a DATUM PLANE c a DATUM LEVEL.

DAY TANK DAY TANK

A tank used to store a chemical solution of known concentration for feed to a chemical feeder A day tank usually stores suffi-
cient chemical solution to properly treat the water being treated for at least one day. Also called an AGE TANK.

DEAD END DEAD END

The end of a water main which is not connected to other parts of the distribution system by means of a connecting loop of pipe.

DECANT DECANT
To draw off the upper layer of liquid (water) after the heavier material (a solid or another liquid) has settled.

632
 614 Water Treatment

DECHLORINATION (dee-KLOR-uh-NAY-shun) DECHLORINATION

The deliberate removal of chlorine from water The partial or complete reduction of residual chlorine by any chemical or phys-
ical process.

DECIBEL (DES-uh-bull) DECIBEL

A unit for expressing the relative intensity of sounds on a scale from zero for the average least perceptible sound to about 130
for the average level at which sound causes pain to humans.

DECOMPOSITION DECOMPOSITION
The conversion of chemically unstable materials to more stable forms by chemical or biological action. If organic matter decays
when there is no oxygen present (anaerobic conditions or putref^..ction), undesirable tastes and odors are produced. Decay of
organic matter when oxygen is present (aerobic conditi, Is) tends to produce much less objectionable tastes and odors.

DEFLUORIDATION (de-FLOOR-uh-DAY-shun) DEFLUORIDATION

The removal of excess fluoride in drinking water to prevent the mottling (Drown stains) of teeth.

DEGASIFICATION (DEE-GAS-if-uh-KAY-shun) DEGASIFICATION

kk water treatment process which removes dissolved gases from the water The gases may be removed by either mechanical or
chemical treatment methods or a combination of both.

DEMINERALIZATION (DEE-MIN-er-al-uh-ZAY-shun) DEMINERALIZATION

A treatment process which removes dissolved minerals (salts) from water.

DENSITY (DEN-sit-tee) DENSITY

A measure of how heavy a substance (solid, liquid or gas) is for its size. Density is expressed in terms of weight per unit volume,
that is, grams per cubic centimeter or pounds per cubic feet. The density of water (at 4°C or 39°F) is 1.0 gram per cubic centi-
meter or about 62.4 pounds per cubic foot.

DESALINIZATION (DEE-SAY-leen-uh-ZAY-shun) DESALINIZATION

The removal of dissolved salts (such as sodium chloride, NaCI) from water by natural means (leaching) or by specific water
treatment processes.

DESICCANT (DESS-uh-kant) DESICCANT

A drying agent which is capable of removing or absorbing moisture from the atmosphere in a small enclosure.

DESICCATION (DESS-uh-KAY-shun) DESICCATION

A process used to thoroughly dry air; to remove virtually all moisture from air.

DESICCATOR (DESS-uh-KAY-tor) DESICCATOR

A closed container into which heated weighing or drying dishes are placed to cool in a dry environment. The dishes may be
empty or they may contain a sample. Desiccators contain a substance, such as anhydrous calcium chloride, which absorbs
moisture and keeps the relative .umiclity near zero so that the di-,h or smote will not gain weight from absorbed moisture.

DESTRATIFICATION (de-STRAT-uh-fuh-KAY-shun) DESTRAT;FIC.4TION

The development of vertical mixing within a lake or reservoir to eliminate (either totally or partially) separate layers of
temperature, plant, or animal life This vertical mixing can be caused by mechanical means (pumps) or through the use of forced
air diffusers which release air into the lower layers of the reservoir.

DETECTION LAG DETECTION LAG

The time period between the moment a change is made and the moment when such a change is finally sensed by the associat-
ed measuring instrument.

DETENTION TIME DETENTION TIME

(1) The theoretical (calculated) time required for a small amount of water to pass through a tank at a given rate of flow.
(2) The actual time in hours, minutes or seconds that a small amount of water is in a settling basin, flocculating basin or rapid-
mix chamber In storage reservoirs, detention time is the length of time entering water will be held before being drafted for
use (several weeks to years several months being typical).
Detention Time, hr = (Basin Volume, gal)(24 hr/day)
Flow, gal/day

DEW POINT
DEW POINT
The temperature to which air with a given quantity of water vapor must be cooled to cause condensation of the vapor in the air.

633
 Words 615

DE WATER DEWATER
(1) To remove or separate a portion of the water present in a sludge or slurry. To dry sludge so it can be handled and disposed
of
(2 ) To remove or drain the water from a tank or a trencn.

D IATOMACEOUS EARTH (DYE-uh-toe-MAY-shus) DIATOMACEOUS EARTH

A fine, siliceous (made of silica) "earth" composed mainly of the skeletal remains of diatoms

DIATOMS (DYE-uh-toms) DIATOMS

Unicellular (single cell), microscopic algae with a rigid (box-like) internal structure consisting mainly of silica.

DIGITAL READOUT DIGITAL READOUT

Use of numbers to indicate the value or measurement of a variable. The readout of an instrument by a direct, numerical reading
of the measured value.

DILUTE SOLUTION DILUTE SOLUTION

A solution that has been made weaker usually by ths ton of water.

DIMICTIC (die-MICK-tick) DIMICTIC

Lakes and reservoirs which freeze over and normally go through two stratification and two mixing cycles within a year.

DIRECT CURRENT (D.C) DIRECT CURRENT (D.C.)

Electrical current flowing in one direction only and essentially free from pulsation.

DIRECT FILTRATION DIRECT FILTRATiON

A method of treating water which consists of the addition c: coagular! chemicals, flash mixing, coagulation, minimal
flocculation, and filtration. The flocculation facilities may be omitted, but the physical-chemical reactions will occur to some ex-
tent. The sedimentation process is omitted. Also see CONVENTIONAL FILTRATION and IN-LINE FILTRATION.

DIRECT RUNOFF DIRECT RUNOFF

Water that flows over the ground surface or through the ground directly into streams, rivers, or lakes.

DISCHARGE HEAD DISCHARGE HEAD

The pressure (in pounds per square inch or psi) measured at the centerline of a pump discharge and very close to the discharge
flange, converted into feet.
Discharge Head, ft = (Discharge Pressure, psi)(2 31 ft/psi)

DISINFECTION (dis-in-FECK-shun) DISINFECTION

The process designed to kill most microorganisms in water, including essentially all pathogenic (disease-causing) bacteria
There are several ways to disinfect, with chlorine being most frequently used in water treatment. Compare with STERILIZA-
TION.

DISTILLATE (DIS-tuh-late) DISTILLATE

In the distillation of a sample, a portion is evaporated, the part that is condensed afterwards is the distillate.

DIVALENT (die-VAY-lent) DIVALENT

Having a valence of two, such as the ferrous ion, Fez'.

DIVERSION DIVERSION
Use of part of a stream flow as a water supply.

DPD (pronounce as separate letters) DPD

A method of measuring the chlorine residual ir a ter. The residual may be determined by ether titrating or comparing 3 devel-
oped color with color standards. DPD stand or N,N-diethyl-p-phenylene-diamine.

DRAFT DRAFT
(1) The act of drawing c; removing water from a tank or reservoir.
(2) The water which is drawn or removed from a tank or reservoir.

634
 616 Water Treatment

DRAWDOWN DRAWDOWN
(1) The drop in the water table or level of water in the ground when water is being pumped from a well.
(2) The amount of water used from a tank or reservoir.
(3) The drop in the water level of a tank or reservoir

DYNAMIC PRESSURE DYNAMIC PRESSURE

When a pump is operating, the vertical distance (in feet) from a reference point (such as a puma centerline) to the hydraulic
grade line is the dynamic head.
Dynamic Pressure, psi = (Dynamic Head, ft) (0.433 psi/ft)

EDUCTOR (e-DUCK-ter) EDUCTOR

A hydraulic device used to create a negative pressure (suction) by forcing a l.quid through a restriction, such as a Venturi. An
eductor or aspirator (the hydraulic device) may be used in the laboratory in place of a vacuum pump. As an injector, it is used to
produce vacuum for chlorinators.

EFFECTIVE RANGE EFFECTIVE RANGE

That portion of the design range (usually upper 90 percent) in which an instrument has acceptable accuracy. Also see RANGE
and SPAN.

EFFECTIVE SIZE (E.S 1 EFFECTIVE SIZE (E.S.)

The diameter of the particles in a granular sample (filter media) for which 10 percent of the total grains are smaller and 90 per-
cent larger on a weight basis Effective size is obtained by passing granular material through sieves with varying dimensions of
mesh and weighing the material retained by each sieve. The effective size is also approximately the average size of the grains.

EFFLUENT (EF-loo -ent) EFFLUENT

Water or other liquid raw, partially or completely treated flowing FROM a reservoir, basin. treatment process or treatment
plant.

EJECTOR EJECTOR
A device used to disperse a chemical solution into water being treated.

ELECTROCHEMICAL REACTION ELECTROCHEMICAL REACTION

Chemical changes produced by electricity (electrolysis) or the production of electricity by chemical changes (galvanic action). In
corrosion, a chemical reaction is accompanied by the flow of electrons through a metallic path. The electron flow may come
from an external force and cause the reaction, such as electrolysis caused by a D.C. (direct current) electric railway or the elec-
tron flow may be caused by a chemical reaction as in the galvanic action of a flashlight dry cell.

ELECTROCHEMICAL SERIES ELECTROCHEMICAL SERIES

A list of metals with the standard electrode potentials given in volts. The size and sign of the electrode potent.al indicates how
easily these elements will take on or give up Plectrons, or corrode. Hydrogen is conventionally assigned a value of zero.

ELECTROLYSIS (ee-leck-TRAWL-uh-sis) ELECTROLYSIS

The decomp' :ion of material by an outside electrical current

ELECTROLYTE (ee-LECK-tro-LIGHT) ELECTROLYTE

A substance which dissociates (separates) into two or more ions when it is dissolved in water.

ELECTROLYTIC CELL (ee-LECK-tro-LIT-ick) ELECTROLYTIC CELL

A device in which the chemical decomposition of material causes an electric current to flow. Also, a device in which a chemical
reaction occurs as a result of the flow of electric current. Chlorine and caustic (NaOH) are made from salt (NaCI) in eletrolytic
cells.

ELECTROMOTIVE FORCE (E.M.F.) ELECTROMOTIVE FORCE (E.M F.)

The electrical pressure available to cause a flow of current (amperage) when an electrical circuit is closed. See VOLTAGE.

ELECTROMOTIVE SERIES ELECTROMOTIVE SERIES

A list of metals and alloys presented in the order of their tendency to corrode (or go into ;, Jiution). Plso called the Galvanic Se-
ries. This is a practical application of the theoretical ELECTROCHEMICAL SERIES.

ELECTRON ELECTRON
An extremely small, negatively charged particle, the part of an atom that determines its chemical properties

635
 Words 617
ELEMENT ELEMENT
A substance which cannot be separated into its constituent parts and still retain its chemical identity For example. sodium (Na)
is an element.

END BELLS END BELLS

Devices used to hold the rotor and stator of a motor in position.

END POINT END POINT

Samples are titrated to the end point This means that a chemical is added, drop by drop, to a sample until a certain color
change (blue to dear, for example) occurs This is called the END POINT of the titration. In addition to a color change, an end
point may be reached by the formation of a precipitate or the reaching of a specified pH. An end point may be detected by the
use of an electronic device such as a pH meter

ENDEMIC (en-DEM-ick) ENDEMIC

Something peculiar to a particular people or locality, such as a disease which is always present in the population.

ENDRIN (EN-dnn) ENDRIN

A pesticide toxic to freshwater and marine aquatic life that produces adverse health effects in domestic water supplies.

ENERGY GRADE LINE (EGL) ENERGY GRADE LINE (EGL)

A line that represents the elevation of energy !lead of water flowing in a pipe, conduit or channel. The line is drawn above the
hydraulic grade line (grarfient) a distance equal to the velocity head (V2/2g) of the water flowing at each section or point along
the pipe or channel. AL .ee HYDRAULIC GRADE LINE.

[SEE DRAWING ON PAGE 618]

ENTERIC ENTERIC
Of intestinal origin, especially applied to wastes or bacteria.

ENTRAIN ENTRAIN
To trap bubbles in water either mechanically through turbulence or chemically through a reaction.

ENZYMES (EN-zimes) ENZYMES

Organic substances (produced by living organisms) which cause or speed up chemical reactions. Organic catalysts and/or bio-
chemical catalysts.

E.P A E.P.A.
U.S. Environmental Protection Agency.

EPIDEMIC (EP-uh-DEM-ick) EPIDEMIC

A disease that occurs in a large number of people in a locality at the same time and spreads from person to person.

EPIDEMIOLOGY (EP-uh-DE-me-ALL-o-gee) EPIDEMIOLOGY

A branch of medicine which studies epidemics (diseases which affect significant numbers of people during the same time peri-
od in the same locality). The objective of epidemiology is to determine the factors that cause epidemic diseases and how to pre-
vent them.

EPILIMNION (EP-uh-LIM-knee-on) EPILIMNION

The upper layer of water in a thermally stratified lake or reservoir. This layer consists of the warmest water and has a fairly
uniform (constant) temperature. The layer is readily mixed by wind action.

EQUILIBRIUM, CALCIUM CARBONATE EQUILIBRIUM, CALCIUM CARBON 4TE

A watt r is cot. lered stable when it is just saturated with calcium carbonate. In this condition the water will neither dissolve nor
deposit calcium carbonate. Thus, in this water the calcium carbonate is in equilibrium with the hydrogen ion concentration.

EQUIVALENT WEIGHT EQUIVALENT WEIGHT

That weight which will react with, displace or is equivalent to cne gram atom of hydrogen.

ESTER ESTER
A compound formed by the reaction between an acid and an alcohol with the elimination of a molecule of water.

EUTROPHIC (you-TRO-fick) EUTROPHIC

Reservoirs and lakes which are rich in nutrients and very productive in terms of aquatic anima. and plant life.

636
 ENERGY
GRADE
LINE
HYDRAULIC
GRADE
LINE

es 2124

FLOW

ENERGY
../"A GRADE
LINE
HYDRAULIC
GRADE
LINE

I IA

Aestc"
00411.0A11*."
FLOW

'OA t0°OG ..ccAr.,..Nw-,cvv,Twit^..AW,c7">-"X5,14:T.

'4'4°S)

RA 0,
*-'14 Ate°GGOPcON*.
i)r3".1
 Words 619
EUTROPHICATION (you-TRO-fi-KAY-shun)
EUTROPHICATION
The increase in the nutrient levels of a lake or other body of water, this usually causes an increase in the growth of
animal and plant life aquatic

EVAPORATION
EVAPORATION
Process by which water or other liquid becomes a gas (water vapor or ammonia vapor)

EVAPOTRANSPIRATION (ee-VAP-o-TRANS-purr-A-shun)
EVAPOTRANSPIRATION
The process by which water %,apor passes into the atmosphere from living plants. Also called TRANSPIRATION.

FACULTATIVE (FACK-ul-TAY-tive)
FACULTATIVE
Facultative bacteria can use either molecular (dissolved) oxygen or oxygen obtained from food material such as sulfate or
ni-
trate ions in other words, facultative bacteria can live under aerobic or anaerobic conditions.
FEEDBACK
FEEDBACK
The circulating action between a sensor measuring a process variable and the controller which controls or adjusts the
variable process

FEEDWATER
FEEDWATER
The water that is fed to a treatment process; the water that is going to be treated.

FINISHED WATER
FINISHED WATER
Water that has pa3sed through a water treatment plant, all the treatment processes are completed or "finished." This water
is
ready to be delivered to consumers. Also cued PRODUCT WATER.

FIX SAMPLE
FIX, SAMPLE
A sample is "fixed" in the field by adding chemicals that prevent the water quality indicators of interest in tne sample from
chang-
ing before final measurements are performed later in the lab.

FLAGELLATES (FLAJ-el-LATES)
FLAGELLATES
Microorgan.srrs that move by the action of tail-like projections.
FLAME POLISHED
FLAME POLISHED
Melted by a flame to smooth out irregularities Sharp or broken edges of glas3 (such as the end of a glass tube) are rotated
in a
flame until the edge melts slightly and becomes smooth.

FLOAT ON SYSTEM
FLOAT ON SYSTEM
A method of operating a water storage facility Daily flow into the facility is approximately equal to the average daily demand for
water When consumer demands for water are low, the storage facility will be filling. During periods of high demands, the facility
will be emptying.

FLOC
FLOC
Clumps of bacteria and particulate impurities that have come together and formed a cluster. Found in flocculation tanks and
settling or sedimentation basins.

FLOCCULATION (FLOCK-you-LAY-shun)
FLOCCULATION
The gathering together of fine particles after coagulation to Porn, iarger particles by a process of gentle mixing.

FLUIDIZED (FLEW-id-l-zd)
FLUIDIZED
A mass of solid particles that is made to flow like a liquid by injection of water or gas is said to have been fluidized. In
water
treatment, a bed of filter media is fluidized by backwasning water through the filter.

FLUORIDATION (FLOOR-uh-DAY-shun)
FLUORIDATION
The addition of a chemical to increase the concentration of fluoride ions in drinking water to a predetermined optimum limit to
reduce the incidence (number) of dental caries (tooth decay) in children. Defluondation is the removal of excess fluoride in
drinking water to prevent the mottling (brown stains) of teeth.

FLUSHING
FLUSHING
A method used to dean water distribution lines. Hydrants are opened and water with a high velocity flows through the pipes,
removes deposits from the pipes, aryl flows out the hydrants.

FLUX
FLUX
A flowing or flow

638
620 Water Treatment

FOOT VALVE FOOT VALVE

A special type of check valve located at the bottom end of the suction pipe on a pump This valve opens when the pump oper-
ates to allow water to enter the suction pipe but closes when the pump shuts off to prevent water from flowing out of the suction
pipe

FREE AVAILABLE RESIDUAL CHLORINE FREE AVAILABLE RESIDUAL CHLORINE

That portion of the total available residual .;hlonne composed of dissolved chlorine gas (Cl2), hypochlorous acid (HOCI), and/or
hypochlonte ion (OCI ) remaining in water after chlorination. This does not include chlorine that has combined with ammonia,
nitrogen, or other compounds.

FREE RESIDUAL CHLORINATION FREE RESIDUAL CHLORINATION

The application of chlorine to water to produce a free available chlorine residual equal to at least 80 percent of the total residual
chlorine (sum of free and combined available chlorine residual).

FREEBOARD FREEBOARD
(1) The vertical distance from the normal water surface to the top of the confining wall. FREEBOARD
(2) The vertical distance from the sand surface to the underside of a trough in a sand fil-
IEATER DEPTH
ter. This distance is also called AVAILABLE EXPANSION.
I
FRICTION LOSSES FRICTION LOSSES
The head, pressure or energy (they are the same) lost by water flowing in a pipe or cha..del as a result of turbulence caused by
the velocity of the flowing water and the roughness of the pipe, channel walls, and -estnctions caused by fittings. Water flowing
in a pipe loses pressure or energy as a result of friction losses. Also see HEAD LOSS.

FUNGI (FUN-ji) FUNGI

Mushrooms, molds, mildews, rusts, and smuts that are small non-chlorophyll-bearing plants lacking roots, stems and leaves.
They occur in natural waters and grow best in the absence of light. Their decomposition may cause objectionable tastes and
odors in water.

FUSE FUSE
A protective device having a strip or wire of fusible metal which, when placed in a circuit, will melt and break the electrical circuit
if heated too much. High temperatures will develop in the fuse when a current flows through the fuse in excess of that which the
circuit will carry safely.

GAGE PRESSURE GAGE PRESSURE

The pressure within a closed container or pipe as measured with a gage. In contrast, absolute pressure is the sum of atmos-
pheric pressure (14.7 lbs/sq in) PLUS pressure within a vessel (as measured by a gage). Most pressure gages read in "gage
pressure" or psig (pounds per square inch gage pressure).

GALVANIC CELL GALVANIC CELL

An eletrolytic cell capable of producing electrical energy by electrochemical action. The decomposition of materials in the cell
causes an electric (eleci. on) current to flow from cathode to anode.

GALVANIC SERIES GALVANIC SERIES

A list of metals and al'oys presented in the order of their tendency to corrode (or go into solution). Also called the
ELECTROMOTIVE SERIES. This is a practical application of the theoretical ELECTROCHEMICAL SERIES.

GALVANIZE GALVANIZE
To coat a mete (especially iron or steel) with zinc. Galvanization is the process of coating a metal with zinc.

GARNET (GAR-nit) GARNET

A group of hard, reddish, glassy, mineral sands made up of silicates of base metals (calcium, magnesium, iron and
manganese). Garnet has a higher density than sand.

GEOLOGICAL LOG GEOLOGICAL LOG

A detailed description of all underground features discovered during the drilling of a well (depth, thickness and type of
formations).

GEOPHYSICAL LOG GEOPHYSICAL LOG

A record of the structure and composition of the earth encountered when drilling a well or similar type of test hole or boring.

GERMICIDE (GERM-uh-S:DE) GERMICIDE

A substance formulated to kill germs or mi roorganisms. The germicidal properties of chlorine make it an effective disinfectant.

633
 Words 621
GIARDIASIS (gee-are-DYE-uh-sis) GIARDIASIS
Intestinal disease caused by an infestation of Giardia flagellates

GRAB SAMPLE GRAB SAMPLE

A single sample collected at a particular time and place which represents the composition of the water only at that time and
place.

GRADE GRADE
(1) The elevation of the invert (lowest point) of the bottom of a pipeline, canal, culvert or similar conduit
(2) The inclination or slope of a pipeline, conduit, stream channel, or natural ground surface, usually iz,spressed in terms of the
ratio or percentage of number of units of vertical rise or fall per unit of horizontal distance A 0.5 percent grade would be a
drop of one-half foot per hundred feet of pipe.

GRAVIMETRIC GRAVIMETRIC
A means of measuring unknown concentrations of water quality indicators in a sample by WEIGHING a precipitate or residue of
the sample.

GRAVIMETRIC FEEDER GRAVIMETRIC FEEDER

A dry chemical feeder which delivers a measured weight of chemical during E, specific time period.
GREENSAND GREENSAND
A sand which looks like ordinary filter sand except that it is green in color. This sand is a natural ion exchange mineral which is
capable of softening water and removing iron and manganese.

GROUND GROUND
An expression representing an electrical connection to earth or a large conductor which is -t the earth s potential or neutral
voltage.

HARD WATER HARD WATER

Water having a high concentration of calcium and magnesium ions A water may be considered hard if it has a hardness greater
than the typical hardness of water from the region Sorie textbooks define hard water as water with a hardness of more than
100 mg/L as calcium carbonate.

HARDNESS, WATER HARDNESS, WATER

A characteristic of water caused mainly by the salts c' calcium and magnesium, such as bicarbonate, carbonate, sulfate, chlo-
ride and nitrate Excessive hardness in water is undesirable because it causes the formation of soap curds, increased use of
soap, deposition of scale in boilers, damage in some industrial processes, and sometimes causes objectionable tastes in drink-
ing water.

HEAD HEAD
The vertical distance (in feet) equal to the pressure (in psi) &t a specific point. The pressure head is equal to the pressure in psi
times 2.31 ft/psi.

HEAD LOSS HEAD LOSS

The head, pressure or energy (they are tne same) lost by water flowing in a pipe or channel as a result of turbulence caused by
the velocity of the flowing water and the roughness of the pipe, channel walls or restrictions caused by fittings. Water flowing in
a pipe loses head, pressure or energy as a result of friction losses. Also see FRICTION LOSSES.
HEADER HEADER
A large pipe to which a series of smaller pipes are connected. Also called a MANIFOLD.
HEAT SENSOR HEAT SENSOR
A device that opens and closes a switch in response to changes in the temperature. This device might be a metal contact, or a
thermocouple which generates a minute electrical current proportional to the difference in heat, or a variable resistor whose
value changes in response to changes in temperature. Also called a TEMPERATURE SENSOR.

HECTARE (HECK-tar) HECTARE

A measure of area in the metric system similar to an acre. One hectare is equal to 10,000 square meters and 2.4711 acres.
HEPATITIS (HEP-up-TIE-tis) HEPATITIS
Hepatitis is an inflammation of the liver usually caused by an acute viral infection. Yellow ;aundice is one symptom of hepatitis.

HERBICIDE (HERB-uh-SIDE) HERBICIDE

A compound, usually a mar-made organic chemical, used to kill or control plant growth.

640
622 Water Treatment

HERTZ HERTZ
The number of complete electromagnetic cycles or waves in one second of an electrical or electronic circuit Also called the fre-
quency of the current Abbreviated Hz

HIGH-LINE JUMPERS HIGH-LINE JUMPERS

Pipes or hoses connected to fire hydrants and laid on top of the ground to provide emergency water service for an isolated por-
tion of a distritrition system

HOSE BIB HOE= BIB

Faucet. A location in a water line where a hose is connected

HTH (pronounce as separate letters) HTH

High Test Hypochlonte Calcium hypochlonte or Ca(0C1)2

HYDRATED LIME HYDRATED LIME

Limestone that has been burned and treated with water under controlled conditions until the calcium oxide portion has been
converted to calcium hydroxide (Ca(OH)2) Hydrated lime is quicklime combined with water CaO - H2O - Ca(OH)2. Also called
slaked lime. Also see QUICKLIME

HYDRAULIC GRADE LINE (HGL) HYDRAULIC GRADE LINE (HGL)

The surface or pro.ila or water flowing in an open channel or a pipe flowing partially fi II. If a pipe is under pressure, the hydrau-
lic grade line is at the level water would rise to in a small vertical tube connected to ins pipe Also see ENERGY GRADE LINE
[..,EE DRAWING ON PAGE 6181
HYDRAULIC GRADIENT HYDRAULIC GRADIENT
The slope of the hydraulic grade line. This is the slope of the water surface in an open channel. the slope of the water surface of
the groundwater table. or the slope of the water pressure for pipes under pressure.

HYDROGEOLOGIST (HI-dro-gee-ALL-u' rust) HYDROGEOLOGIST

A person who studies and works with groundwater.

HYDROLOGIC CYCLE (HI-dro-L0J-ick) HYDROLOGIC CYCLE

The process of evaporation of water into the air and its return to Earth by precipitation (rain or snow) This process also in-
cludes transpiration from plants. groundwater movement. and runoff into rivers. streams and the ocean. Also called the WATER
CYCLE

HYDROLYSIS (hi-DROLL-uh-sis) HYDROLYSIS

A chemical reaction in which a compound is converted into another compound by taking up water

HYDROPHILIC (HI-dro-FILL-ick) HYDROPHILIC

Having a strong affinity (liking) for water. The opposite of HYDROPHOBIC.

HYDROPHOBIC (HI-dro-FOE -back) HYDROPHOBIC

Having a strong aversion (dislike) for water The opposite of HYDROPHILIC.

HYDROPNEUMATIC (HI-dro-new-MAT-ick) HYDROPNEUMATIC

A water system, usually small, in which a water pump is automatically controlled (started and stopped) by the air pressur ) in a
compressed-air tank.

HYDROSTATIC PRESSURE (HI-dro-STAT-ick) HYDROSTATIC PRESSURE

(1) The pressure at a specific elevation exerted by a body of water at rest, or
(2) In the case of groundwater, the pressure at a specific elevation due to the weight of water at higher levels in the same zone
of saturation.
HYGROSCOPIC (HI-grow-SKOP-ick) HYGROSCOPIC
Absorbing or attracting moisture from the air.

HYPOCHLORINATION (HI-poe-KLOR-uh-NAY-shun) HYPOCHLORINATION

The application of hypochlonte compounds to water for the purpose of disinfection.

HYF'OCHLORINATORS (HI-poe-KLOR-uh-NAY-tors) HYPOCHLORINATORS

Chlorine pumps, chemical feed pumps or devices used to dispense chlorine solutions made from hypochlontes such as bleach
(sodium hypochlonte) or calcium hypochlonte into the water being treated.

641
 Words 623
HYPOCHLORITE (HI-poe-KLOR-ite) HYPOCHLORITE
Chemical compounds containing available chlorine, used for disinfection They are available as liquids (bleach) or solids
(powder, granules and pellets). Salts of hypochlorous acid.

HYPOLIMNION (Hl-poe-LIM-knee-on) HYPOLIMNION

The lowest layer in a thermally stratified lake or reservoir This layer consists of colder. more dense water, has a constant tem-
perature and no mixing occurs

IMHOFF CONE IMHOFF CONE

A clear, cone-shaped container marked with graduations. The cone is used to measure
the volume of settleable solids in a specific volume (usually one liter) of water.

IMPELLER IMPELLER
A rotating set of vanes in a pump designed to pump or lift water

IMPERMEABLE (im-PURR-me-uh-BULL) IMPERMEABLE

Not easily penetrated The property of a material or soil that does not allow, or allows only with great difficulty, the movement or
passage of water.

INDICATOR (CHEMICAL) INDICATOR (CHEMICAL)

A substance that gives a visible change. usually of color, at a desired point in a chemical reaction. generally at a specified end
point.

INDICATOR (INSTRUMENT) INDICATOR (INSTRUMENT)

A device which indicates the result of a measurement Most indicators in the water utility field use either a fixed scale and mov-
able indicator (pointer) such as a pressure gage or a movable scale and movable indicator like those used on a circular-flow re-
cording chart. Also called a RECEIVER

INFILTRATION (IN-fill-TRAY-shun) INFILTRATION

The gradual flow or movement of water into and through (to percolate or pass through) the pores of the soil. Also called PER-
COLATION.

INFLUENT (IN-flu-ent) INFLUENT

Water or other liquid raw or partially treated flowing INTO a reservoir, basin, treatment process or treatment plant.

INITIAL SAMPLING INITIAL SAMPLING

The very first sampling conducted under the Safe Drinking Water Act for each of the applicable contaminant categories.
IN-LINE FILTRATION IN-LINE FILTRATION
The addition of chemical coagulants directly to the filter inlet pipe The chemicals are mixed by the flowing water. Flocculation
and sedimentation facilities are eliminated This pretreatment method is commonly used in pressure filter installation. Also see
CONVENTIONAL FILTRATION and DIRECT FILTRATION.

INORGANIC i:4oRGANIC
Material such as sand, salt, iron, calcium salts and other mineral materials Inorganic substances are of mineral origin, whereas
organic substances are usually of animal or plant origin. Also see ORGANIC.

INPUT HORSEPOWER INPUT HORSEPOWER

The total power used in operating a pump and motor.
Input Horsepower, HP (Brake Horsepower,HP)(100%)
Motor Efficiency, %

INSECTICIDE INSECTICIDE
Aiiy substance s. chemical formulated to kill or control insects

INSOLUBLE (in-SAWL-you-bull) INSOLUBLE

Something that cannot be dissolved

INTEGRATOR INTEGRATOR
A devicf. or meter that continuously measures and calculates (adds) total flows in gallons, million gallons, cubic feet, or some
other knit of volume measurement. Also called a TOTALIZER.

642
624 Water Treatment

INTERFACE INTERFACE
The common boundary layer between two substances such as water and a solid (metal), or between two fluids such as water
and a g. -; (air); or between a liquid (water) and another liquid (oil).
INTERLOCK INTERLOCK
An electrical switch, usually magnetically operated Used to interrupt all (local) power to a par...I or device when the door is
opened or the circuit exposed to service.
INTERNAL FRICTION INTERNAL FRICTION
Friction within a fluid (water) due to cohesive forces
INTERSTICE (in- TUR- stuhz) INTERSTICE
A very small open space in a rock or granular material. Also called a void or void space. Also see PORE
INVERT (I N-vert) INVERT
The lowest point of the channel inside a pipe, conduit, or canal
ION ION
An electrically charged atom, radical (such as S0,2 ), or molecule formed by the loss or gain of one or more electrons.

ION EXCHANGE ION EXCHANGE

A water treatment process involving the reversible interchange (switching) of ions between the water being treated and the sol-
id resin Undesirable ions in the water are switched with acceptable ions on the resin.
ION EXCHANGE RESINS ION EXCHANGE RESINS
Insoluble polymers, used in water treatment, that are capable of exchanging (switching or giving) acceptable cations or anions
to the water being treated for less desirable ions.

IONIC CONCENTRATION IONIC CONCENTRATION

The concentration of any ion in solution, usually expressed in moles per liter.

IONIZATION (EYE-on-uh-ZAY-shun) IONIZATION

The splitting or dissociation (separation) of molecules into negatively and positively charged ions

JAR TEST JAR TEST

A laboratory procedure that simulates a water treatment plant's coagulation/flocculation units with differing chemical doses
and also energy of rapid mix, energy of slow mix, and settling time. The purpose of this procedure is to ESTIMATE the minimum
or ideal coagulant dose required to acnieve certain water quality goals. Samples of water to be treated are commonly placed in
six jars. Various amounts of chemicals are added to each jar, stirred and the settling of solids is observed. The dose of chemi-
cals that provides satisfactory settling removal of turbidity and/or color is the dose used to treat the water being taken into the
plant at that time When evaluating the results of a jar test, the operator should also consider the floc quality in the flocculation
area and the floc loading on the filter.

JOGGING JOGGING
The frequent starting and stopping of an electric motor.
JOULE (jewel) JOULE
A measure of energy, work or quantity of heat. One joule is the work done when the point of application of a force of one new-
ton is displaced a d ;stance of one meter in the direction of force
KELLY KELLY
The square section of a rod which causes the rotation of the drill bit. Torque from a drive table is applied to tne square rod to
cause the rotary motion. The drive table is chain or gear driven by an engine.

KILO KILO
(1) Kilogram.
(2) Kilometer.
(3) A prefix meaning "thousand' used in the metric system and other scientific systems of measurement

KINETIC ENERGY KINETIC ENERGY

Energy possessed by a moving body of matter, such as water, as a result of its motion.

KJELDAHL NITROGEN (KELL-doll) KJELDAHL NITROGEN

Nitrogen in the form of organic proteins or their decomposition product ammonia, as measured by the Kjeldahl Method.

643
 Words 625
LANGELIER INDEX (LI) LANGELIER INDEX (LI)
An index reflecting the equilibrium pH of a water with respect to calcium and elk-. ,itv This index is used in stabilizing water to
control both corrosion and the deposition of scale
Langelier Index = pH pHs
where pH = actual pH of the water, and
pHs = pH at which water having the same alkalinity and calcium content is just saturated with calcium carbonate.

LAUNDERING WEIR (LAWN-der-ing weer) LAUNDERING WEIR

Sec:imentation basin overflow weir A plate with V-notches along he top to assure a uniform flow rate and avoid short-circuit-
ing.

LAUNDERS (LAWN-ders) LAUNDERS

S'edimentation basin and filter discharge channel consisting of overflow weir plates (in sedimentation basins) and conveying
troughs.

LEAD (LEC-d) LEAD

A wire or conductor that can carry electricity.

LEATHERS LEATHERS
0 rings or gaskets used with piston pumps to provide a seal between the piston and the side wall.

LEVEL CONTROL LEVEL CONTROL

A float device (or pressure switch) which senses changes in a measured variable and opens or closes a switch in response tc
that change In its cimpk.st form, this control might be a floating ball connected mechanica.ly to a switch or valve such as is
used to stop water flow into a toilet when the tank is full.

LiNDANE (LYNN-dane*/ LINDANE

A pesticide that causes adverse health effects in domestic water supplies and also is toxic to freshwater and marine aquatic
life

LINEARITY (LYNN-ee-AIR-it-ee) 1 NIEARITY

How closely an instrument measures actual values of a variable through its effective range, a measure ust,..1 to determine the
am. ,icy of an instrument.

LITTORAL ZONE (LIT-or-al) LITTORAL ZONE

(1) That portion of a body of fresh water extending from the shoreline lakeward to the limit of occupancy of rooted plants.
(2) The strip of land along the shoreline between the high and low water levels.

OGARITHM (LOG-a-nth-m) LOGARITHM

f he exponent that indicates the power to which a number must be wised to produce a given number. For example. if B2 = N,
the 2 is the logarithm of N (to the base B), or 102 = 100 and log10 100 = 2. Also abbreviated to "log."

LOGGING, ELECTRICAL LOGGING, ELECTRICAL

A procedure used to deter nine the porosity (spaces or voids) of formations in search of water-bearing formations (aquifers).
Electrical probes are lowered into wells, an electrical current is induced at various depths and the resistance measured of var-
ious formations indicates the porosity of the material.

M or MOLAR M or MOLAR
A molar st-Jiution consists of one gram molecular weight of a compound dissolved in enough water to make one liter of solution.
A grani molecular weight is the molecular weight of a compound in grams. For example, the molecular weight of sulfuric acid
(H2604) is 98 A one M solution of sulfuric acid would consist of 98 grams of H2SO4 dissolved in enough distilled
water to make one liter of solution.

MACROSCOPIC (MACK-row-SKAWP-ick) ORGANISMS MACROSCOPIC ORGANISMS

Organisms big enough to be seen by the eye without the aid of a microscope.

MANDREL (MAN-drill) MANDREL

A special tool used to push beo-ings in or to pull sleeves out.

MANIFOLD MANIFOLD
A large pipe to which a SE ..3 of smaller pipes are connected. Also called a I-.c.ADER.

644
626 Water Treatment

MANOMETER (man-NAH-mut-ter) MANOMETER

An instrument for measuring pressure Usually, a manometer is a glass tube filled with a liquid that is used to measure the dif-
ference in pressure across a . ow-measuring device such as an orifice or Venturi meter. The instrument used to measure bl000
pressure is a type of manometer.

VENTURI METER

-----Thi MANOMETER
---34

MAXIMUM CONTAMINANT LEVEL (MCL) MAXIMUM CONTAMINANT LEVEL (MCL)

See MCL.

MBAS MBAS
Methylene - Blue - Active Substances. These substances are used in surfactants or detergents.

MCL MCL
Maximum Contaminant Level The largest allowable amcunt. MCLs for various water quality indicators are specified in the Na-
tional Interim Primary Drinking Water Regulations (NIPDWR)

MEASURED VARIABLE MEASURED VARIABLE

A characteristic or compunent part that is sensed and quantified (reduced to a reading of some kind) by a primary element or
sensor.

MECHANICAL JOINT MECHANICAL JOINT

A flexible device that joins pipes or fittings together by the use of lugs and bolts.

MEG MEG
A procedure used for checking the ins...,ation resistance on motors, feeders, buss bar systems, grounds, and branch circuit wir-
ing. Also see MEGGER.

MEGGER (from megohm) MEGGER

An instrument used for checking the insulation ' esistance on motors, feeders, buss bar systems, grounds, and branch circuit
wiring. Also See MEG.

MEGOHM MEGOHM
Meg means one million, so 5 megohms means 5 million ohms. A megger reads in millions of ohms.

MENISCUS (meh-NiS-cuss) MENISCUS

The curved top of a column cf liquid (water, oil, mercury) in a :Anal! tube. When the liquid wets the sides of the container (as with
water), the curve forms a valley. When the confining sides are not wetted (as with mercury), the curve forms a hill or upward
bulge.

WATER MERCURY

(READ (READ
BOTTOM) --- TOP)

MESH MESH
One of the openings or spaces in a screen or woven fabric The value of the mesh is usually given as the number of openings
per inch This value does not consider the diameter of the wire or fabric, therefore, the mesh number does not always have a
definite relationship to the size of the hole.

645
 Words 627

MESOTROPHIC (MESS-o-TRO-fick) MESOTROPHIC

Reservoirs and lakes which contain moderate quantities of nutrients and are moderately productive in terms of aquatic animal
and plant life.

METABOLISM (meh-TAB-uh-LIZ-um) METABOLISM

(1) "oe biochemical process in which food is used and wastes are formed by living organisms.
(2) All biochemical reactions involved in cell formation and growth.

METALIMNION (MET uh-LIM-knee-on) METALIMNION

The middle layer in a thermally stratified lake or reservoir In this layer there is a rapid decrease in temperature with depth. Also
called the THERMOCLINE.

METHOXYCHLOR (meth-OXY-klor) METHOXYCHLOR

A pesticide which causes adverse health effects in domestic water supplies and is also toxic- to freshwater and marine aquatic
life. The chemical name for methoxychlor is 2,2-bis (p-methoxyphenol)-1,1,1-trichloroethane.

METHYL ORANGE ALKALINITY METHYL ORANGE ALKALINITY

A measure of the total alkalinity in a water sample The alkalinity is measured by the amount of standard sulfuric acid required
to lower the pH of the water to pH level of 4.5, as indicated by the change in color of methyl orange from orange to pink.
Methyl orange alkalinity is expressed as milligrams per liter equivalent calcium carbonate.
mg /L mg /L
See MILLIGRAMS PER LITER.

MICROBIAL GROWTH (my-KROW-bee-ul) MICROBIAL GROWTH

The activity and growth of microorganisms such as bacteria, algae, diatoms, plankton and fungi

MICRON (MY-kron) MICRON

A unit of length. One millionth of a meter or one thousandth of a millimeter. One micron equals 0.00004 of an inch.

MICROORGANISMS (MY-crow-OR-gan-IS-zums) MICROORGANISMS

Living organisms that can be seen individually only with the aid of a microscope.
MIL MIL
A unit of length equal to 0.001 of an inch. the diameter of wires and tubing is measured in mils, as is the thickness of plastic
sheeting.

MILLIGRAMS PER LITER, mg /L MILLIGRAMS PER LITER, mg /L

A measure of the concentration by weight of a substance per unit volume. For practical purposes, one mg /L of a substance in
fresh water is equal to one part per million parts (ppm). Thus a liter of water with a specify.; gravity of 1.0 weighs one million
milligrams. If it contains 10 milligrams of calcium, the ci ,ncentration is 10 milligrams per million mill.grams, or 10 milligrams per
liter (10 mg /L), or 10 parts of calcium per million parts of water, or 10 parts per million (10 ppm).

MILLIMICRON (MILL-uh-MY-kron) MILLIMICRON

A un.. of length equal to 10 3/4 (one thousandth of a micron), 10 6 millimeters, or 10 9 meters, correctly called a nanometer, nm.

MOLAR MOLAR
See M for MOLAR.

MOLE MOLE
The molecular weight of a substance, usually expressed in grams.

MOLECULAR WEIGHT MOLECULAR WEIGHT

The molecular weight of a compound in grams is the sum of the atomic weights of the elements in the compound. The molecu-
lar weight of sulfuric acid (H2504) in grams is 98.
Element Atomic Weight Numtar of Atoms Molecular Weight
H 1 2 2
S 32 1 32
0 16 4 64
98
MOLECULE (MOLL-uh-KULE) MOLECULE
The smallest division of a compound that still retains or exhibits all t.le properties of the substance.

646
628 Water Treatment

MONOMER (MON-o-MER) MONOMER

A molecule of low molecular weight capable of reacting with identical or different monomers to form polymers.

MONOMICTIC (mo-no-MICK-tick) MONOMICTIC

Lakes and reservoirs which are relatively deep, do not freeze over during the winter months, and undergo a single stratification
and mixing cycle during the year These lakes and reservoirs usually become destratified during the mixing cycle, usually in the
fall of the year.

MONOVALENT MONOVALENT
Having a valence of one, such as the cuprous (copper) ion, Cu'.

MOST PROBABLE NUMBER (MPN) MOST PROBABLE NUMBER (MPN)

See MPN.

MOTILE (MO-till) MOTILE

Capable of self-propelled movement A term that is sometimes used to distinguish between certain types oforganisms found in
water

MOTOR EFFICIENCY MOTOR EFFICIENCY

The ratio of energy delivered by a motor to the energy supplied to it during a fixed period or cycle. Motor efficiency ratings will
vary depending upon motor manufacturer and usually will range from ,8.9 to 90.0 percent

MPN (pronounce as separate 'etters) MPN

MPN is the Most Probable Number of coliform-group organisms per unit volume of sample water. Expressed as the number of
organisms per 100 mL of sample water.

MUDBALLS MUDBALLS
Material that is approximately round in shape and varies from pea-sized up to two or more inches in diameter. This material
forms in filters and gradually increases in size when not removed by the backwashing process.

MULTI-STAGE PUMP MULTI-STAGE PUMP

A pump that has more than one impeller. A single-stage pump has one impeller

N or NORMAL N or NORMAL
A normal solution contains crie gram eqs .valent weight of reactant (compound) per liter of solution. The equivalent weight of an
acid is that weight which contains one gram atom of ionizable hydrogen or its chemical equivalent. For example, the equivalent
weight of sulfuric acid (H2504) is 49 (98 divided by 2 because there are two replaceable hydrogen ions). A one N solution of
sulfuric acid would consist of 49 grams of H2504 dissolved in enough water to make one liter of solution.

NATIONAL ENVIRONMENTAL NATIONAL ENVIRONMENTAL

TRAINING ASSOCIATION TRAINING ASSOCIATION
A professional organizaiton devoted to serving the environmental trainer and promoting better operation of waterworks and
pollution control facilities For information on NETA membership and publications, contact NETA, P.O. Box 346, Valparaiso, In-
diana 46383.

NATION, L INSTITUTE OF NATIONAL INSTITUTE OF

OCCUPATIONAL SAFETY AND HEALTH OCCUPATIONAL SAFETY AND HEALTH
See NIOSH.

NATIONAL INTERIM PRIMARY NATIONAL INTERIM PRIMARY

DRINKING WATER REGULATIONS DRINKING WATER REGULATIONS
Commonly referred to as NIPDWR.

NATIONAL SAFE DRINKING WATER REGULATIONS NATIONAL SAFE DRINKING WATER REGULATIONS
Commonly referred to as NSDWR.

NEPHELOMETRIC (NEFF -eI -o -MET -rick) NEPHELOMETRIC

A means of measuring turbidity in a sample by using an instrument called a nephelometer. A nephelometer passes light through
a sample and the amount of light deflected (usually at a 90-degree angle) is then measured.

NETA NETA
See National Environmental Training Association.

647
 Words 629
NEWTON NEWTON
A force which, when applied to a body having a mass of one kilogram, gives it an acceleration of one meter per second per
second.

NIOSH NIOSH
The National Institute of Occupational Safety and Health is an organization that tests and approves safety equipment for par-
ticular applications NIOSH is the primary Federal agency engaged in research in the national effort to eliminate on-the-job haz-
ards to tne health and safety of working people. The NIOSH Publications Catalog contains a listing of NIOSH publications main-
ly on industrial hygiene and occupational health To obtain a copy of the catalog, write to NIOSH Publications, 4676 Columbia
Parkway, Cincinnati, Ohio 45226.

NIPDWR NIPDWR
National Interim Primary Drinking Water Regulations.

NITROGENOUS (nye-TRAH-jen-us) NITROGENOUS

A term used to describe chemical compounds (usually organic) containing nitrogen in combined forms. Proteins and n.trates
are nitrogenous compounds.

NOBLE METAL NOBLE METAL

A chemically inactive metal (such as gold) A metal that does not corrode easily and is much scarcer (and more valuable) than
the so-called useful or base metals. Also see BASE METAL.

NOMINAL DIAMETER NOMINAL DIAMETER

An approximate measurement of the diameter of a pipe. Although the nominal diameter is used to describe the size or diameter
of a pipe, it is usually not the exact inside diameter of the pipe.

NONIONIC POLYMER (NON-eye-ON-ick) NONIONIC POLYMER

A polymer that has nc net electrical charge.

NONPOINT SOURCE NONPOINT SOURCE

A runoff or discharge from a field or -,milar source A point source refers to a discharge that comes out the end of a pipe.

NONPOTABLE (non-POE-tuh-bull) NON POTABLE

Water that may contain objectionable pollution, contamination, minerals, or infective agents and is considered unsafe and/or
unpalatable for drinking.

NORMAL NORMAL
See N for NORMAL.
NPDES PERMIT NPDES PERMIT
National Pollutant Discharg 3 Elimination System perm't is the regulatory agency document designed to control all discharges of
pollutants from point sources in U.S. waterways. NPDES permits regulate discharges into navigable waters from all point
sources of pollution, including industries, municipal treatment plants, large agricultural feed lots and return irrigation flows.

NSDWR NSDWR
National Safe Drinking Water Regulations

NUTRIENT NUTRIENT
Any substance that is ESSIr alated (taken in) by organisms and promotes growth. Nitrogen and phosphorous are nutrients which
promote the growth of c.inae. There are other essential and trace elements which are also considered nutrients.

OCCUPATIONAL SAFETY AND HEALTH ACT OF 1970 OCCUPATIONAL SAFETY AND HEALTH ACT OF 1970
See OSHA.

ODOR THRESHOLD ODOR THRESHOLD

The minimum odor of a water sample that can just be detected after successive dilutions with odorless water. Also called
THRESHOLD ODOR.

OFFSET (or DROOP) OFFSET

The difference between the actual value and the desired value (or set point), characteristic of proportional contrc,,,er s that do
not incorporate reset action.
OHM OHM
The unit of electrical resistance. The resistance of a conductor in which one volt produces a current of one ampere.

:d 649
 620 Water Treatment

OLFACTORY FATIGUE (oh-FAK-tore-ee) OLFACTORY FATIGUE

A condition in which a person's nose, after exposure to certain odors, is no longer able to detect the odor.
1
OLIGOTROPHIC (AH-lig-o-TRO-fick) OLIGOTROPHIC
Reservoirs and lakes which are nutrient poor and contain little aquatic plant or animal life.

ORGANIC ORGANIC
Substances that come from animal or plant sources Organic substances always contain carbon (Inorganic materials are
chemical substances of mineral origin ) Also see INORGANIC.

ORGANICS ORGANICS
(1) A term used to refer to chemical compounds made from carbon molecules These compounds may be natural materials
(such as animal or plant sources) or man-made materials (such as synthetic organics). Also see ORGANIC.
(2) Any form of animal of plant hie Also see BACTERIA.

ORGANISM ORGANISM
Any form of animal or plant life. Also see BACTERIA.

ORIFICE (OR-uh-fiss) ORIFICE

Ai-, opening (hole) in a plate. wall or partition An orifice flange or plate placed in a pipe consists of a slot or a calibrated circular
hole smaller than the pipe diameter The difference in pressure in the pipe above and at the orifice may be used to determine
the flow in the pipe.

ORP ORP
Oxidation-Reduction Potential The electrical potential required to transfer electrons from one compound or element (the
oxidant) to another compound or element (the reductant). used as a qualitative measure of the state of oxidation in water treat-
ment systems.

ORTHOTOLIDINE (or-tho-TOL-uh-dine) ORTHOTOLIDINE

Orthotolidine is a colorimetric indicator of chlorine residual If chlorine is present, a yellow-colored compound is produced. This
reagent is no longer approved for chemical analysis

OSHA (O -shuh) OSHA

The Williams-Steiger Occupational Safety and Health Act of 1970 (OSHA) is a law designed to protect the health and safety of
industrial workers and also the operators of water supply systems and treatment plants.

OSMOSIS (oz-M0E-sss) OSMOSIS

The passage cf a liquid from a weak solution to a more concentrated solution across a semipermeable membrane. The mem-
brane allows the passage of the water (solvent) but not the dissolved solids (solutes) This process tends to equalize the condi-
tions on either side of the membrar 9.

OVERALL EFFICIENCY, PUMP OVERALL EFFICICNOY, PUMP

The combined efficiency of a pump and motor together Also called the WIRE-TO-WATER EFFICIENCY.

OVERDRAFT OVERDRAFT
The pumping of water from a groundwater basin or aquifer in excess of the supply flowing into the basin. This pumping results
in a deoletion or "mining' of the groundwater in the basin.

OVERFLOW RATE OVERFLOW RATE

One of the guidelines for the design of setting tanks and clarifiers in treatment plants Used by operators to determine if tanks
and clarifiers are hydraulically (flow) over- or underloaded. Also called SURFACE LOADING.
Overflow Rate. GDP/sq ft Flow. gallons/day
Surface Area, sq ft

OVERTURN OVERTURN
The almost spontaneous mixing of all layers of water in a reservo.r or lake vvher, the water temperature becomes similar from
top to bottom This may occur in the fall/winter when the surface waters cool to the same temperature as the bottom waters and
also in the spring when the surface waters warm after the ice melts.

OXIDATION (ox-uh-DAY-shun) OXIDATION

Oxidation is the addition of oxygen, removal of hydrogen, or the removal of electrons from an element or compound in the envi-
ronment, organic matter is oxidized to more stable substances. The opposite o: REDUCTION.
 Words 631

OXIDATION-REDUCTION POTENTIAL OXIDATION-REDUCTION POTENTIAL

The electrical potentiai required to transfer electrons from one compound or element (the oxidant) to another compound or ele-
ment (the reductant), used as a qualitative measure of the state of oxidation in water treatment systems.

OXIDIZING AGENT OXIDIZING AGENT

Any substance. such as oxygen (02) or chlorine (Cl2). that will readily add (take on) electrons The opposite is a REX, :ING
AGENT

OXYGEN DEFICIENCY OXYGEN DEFICIENCY

An atmosphere containing oxygen at a concentration of less than 19.5 percent by volume.

OZONATION (O -zoe- NAY -shun) OZONATION

The application of ozone to water for disinfection or for taste and odor control

PACKER ASSEMBLY PACKER ASSEMBLY

An inflatable device used to sea: the tremie pipe inside the well casing to prevent the grout from entering the inside of the con-
ductor casing.

PALATABLE (PAL-a-ta-ble) PALATABLE

Water at a desirable temperature that is free from objectionable tastes. odors, colors, and turbidity Pleasing to the senses.

PARSHALL FLUME PARSHALL FLUME

A device used to measure the flo v in an open channel. The flume narrows to a throat of fixed dimensions and then expands
again The rate of flow can be calculated by measuring the difference in head (pressure) before and at the throat of the flume.
STILLING
/ WELL

FLOW

THROAT
PLAN

WATER SURFACE

.....,..-- FLOW

ELEVATION

PARTICLE COUNT PARTICLE COUNT

The results of a microscopic examination of treated water with a special particle counter which classifies suspended particles
by number and size

PARTICULATE (oar-TICK-you-let) PARTICULATE

A very small solid suspended in water which can vary widely in size, shape. density, and electrical charge. Colloidal and dis-
persed particulates are artificially gathered together by the processes of coagulation and flocculation.

PARTS PER MILLION (PPM) PARTS PER MILLION (PPM)

Parts per million parts. a measurement , f concentration on a weight or volume basis This term is equivalent to milligrams per
liter (mg/L) which is the preferred term

PASCAL PASCAL
The pressure or stress of one newton per square meter. (Abbreviated Pa)
1 psi 6895 Pa - 6.895 kN/sq m 0 0703 kg/sq cm

PATHOGENIC ORGANISMS (path-o-JEN-ick) PATHOGENIC ORGANISMS

Oryaiisms, including bacteria. virUSt_ ,r cysts. capable of causing diseases (typhoid. cholera. dysentery) in a host (s'ich as a
pers.,n) There are many types of organisms which do NOT cause disease. These organisms are called non-pathogenic.

PATHOGENS (PATH-o-jens) PATHOGENS

Pathogenic or disease-causing organisms

650
632 Water Treatment

PCBs PCBs
See POLYCHLORINATED BIPHENYLS.

pCi/L pCi/L
PicoCurie per Liter A picoCurie is a measure of radioactivity. One picoCurie of radioactivity is equivalent to 0.037 nuclear disin-
tegrations per second.

PEAK DEMAND PEAK DEMAND

The maximum momentary load placed on a water treatment plant, pumping station or distribution system. Ihis demand is usu-
ally the maximum average load in one hour or less, but may be specified as the instantaneous or with some other short time
period.

PERCENT SATURATION PERCENT SATURATION

The amot.nt of a substance that is dissolved in a solution compared with the amount that could be dissolved in the solution, ex-
pressed as a percent.

Amount of Substance
Percent Saturation, = That is Dissolved x 100%
Amount That Could Be
Dissolved in Solution

PERCOLATING WATER (PURR-co-LAY-ting) PERCOLATING WATER

Water that passe.-., through soil or rocks under the force of gravity.

PERCOLATION (PURR-ko-LAY-shun) PERCOLATION

The slow passage of water through a filter medium; or, the gradual penetration of soil and rocks by water.

PERIPHYTON (puh-RIF-uh-tawn) PERIPHYTON

Microscopic plants and animals that are firmly attached to solid surfaces under water such as rocks, logs, pilings and other
structures.

PERMEABILITY (PURR-me-u:. BILL-uh-tee) PERMEABILITY

The property of a material or soil that permits considerable movement of water through it when it is saturated.

PERMEATE (PURR-me-ate) PERMEATE

(1) To penetrate and pass through, as water penetrates and passes through soil and other porous materials.
(2) The demineralized water.

PESTICIDE PESTICIDE
Any substance or chemical designed or formulated to Kill or control weeds or animal pests Also see ALGICIDE, HERBICIDE,
INSECTICIDE,and RODENTICIDE.

PET COCK PET COCK

A small valve or faucet used to dram a cylinder or fitting.

pH (pronounce as separate letters) pH

pH is an expression of the intensity of the basic or acid condition of a liquid. Mathematically, pH is the logarithm (base 10) of tne
reciprocal of the hydrogen ion activity.

pH = Log 1

(H.)

The pH may range from 0 to 14, where 0 is most acid, 14 most basic, and 7 neutral Natural waters usually have a pH between
6.5 and 8.5.

PHENOLIC COMPOUNDS (FEE-noll-LICK) PHENOLIC COMPOUNDS

Organ: compounds that are derivatives of benzene.

PHENOLPHTHALEIN ALKALINITY (FEE-nol-THAY-leen) PHENOLPHTHALEIN ALKALINITY

The alkalinity in a water semple measured by the amount of standard acid required to lower the pH to a level of 8.3, as indicated
by the change in color of phenolphthalein from pink to clear. Phenolphthalein alkalinity is expressed as miligrams per liter
equivalent calcium carbonate.

651
 Words 633

PHOTOSYNTHESIS (foe-tow-SIN-thuh-sis) PHOTOSYNTHESIS

A process in which organisms. with the aid of chlorophyll (green plant enzyme), convert c-artln dioxide and inorganic
substances into oxygen and additional plant material, using sunlight for energy. All green plants c ^w by this process.

PHYTOPLANKTON (Fl-tow-PLANK-ton) PHYTOPLANKTON

Small, usually microscopic plants (such as algae), found in lakes, reservoirs, and other bodies of water.

PICO PICO
A prefix used in the metric system and other scientific systems of measurement which means 10 12 or 0.000 000 000 001.

PICOCURIE PICOCURIE
A measure of radioactivity. One picoCurie of radioactivity is equivalent to 0.037 nuclear disintegrations per second.

PITLESS ADAPTER PITLESS ADAPTER

A fitting which allows the well casing to be extended above ground while having a discharge connection located below the frost
line Advantages of using a pitless adapter include the elimination of the need for a pit or pump house and it is a water-tight
design. which helps maintain a sanitary water supply.

PLAN VIEW PLAN VIEW

A diagram or photo showing a facility as it would appear when looking down on top of it.

PLANKTON PLANKTON
(1) Small, usually licroscopic, plants (phytoplank -ln) and animals (zoopiankton) in aquatic systems.
(2) All of the smaller floating, suspended or self-propelled organisms in a body of water.

PLUG FLOW PLUG FLOW

A type of flow tat occurs in tanks, ')asins or reactors when a slug of water moves through a tank without ever dispersing or
mixing with the rest of the water flowing through the tank.

PMCLs PMCLs
Primary Maximum Contaminant Levels. Pnmary MCLs for various water quality indicators are established to protect public
health.

POINT SOURCE POINT SOURCE

A discharge that comes out of the end of a pipe. A nonpoint source refers to runoff or a discharge from a field or similar source.

POLE SHADER POLE SHADER

A copper bar circling the laminated iron core inside the coil of a magnetic starter.

POLLUTION POLLUTION
The impairment (reduction) of water quality by agricultural, domestic, or industrial wastes (including thermal and atomic
wastes), to a degree that has an adverse effect on any beneficial use of water.

POLYCHLORINATED SIPHENYLS POLYCHLORINATED BIPHENYLS

A class of organic compounds that cause adverse health effects in domestic water supplies.

POLYELECTROLYTE (POLLY-ee-LECK-tro-lite) POLYELECTROLYTE

A high-molecular-weight (r 'ively heavy) substance having points of positive or negative electrical charges that is formed by
either natural or man-made Icesses. Natural polyelectrolytes may be of biological origin or derived from starch products and
cellulose derivatives. Man-made polyelectrolytes consist of simple substances that have been made into complex, high-
molecular-weight substances. Used with other chemical coagulants to aid in binding small suspended particles to larger
chemical flocs for their removal from water. Often called a POt MER.

POLYMER POLYMER
A chemical formed by the union of many monomers (a molecule of low molecular weight). Polymers are used with other chemi-
cal coagulants to aid in binding small suspended particles to larger chemical flocs for their removal from water. All
polyelectrolytes a7e polymers, but not all polymers are polyelectrolytes.

PORE PORE
A very small open space in a rock or granular material. Also see INTERSTICE.

".
t , 652
 634 Water Treatment

POROSITY POROSITY
(1) A measure of the spaces or voids in a material or aquifer.

(2) The ratio of the volume of spaces in a rock or soil to the total volume. This ratio is usually expressed as a percentage.

Porosity, % (Volume of Spaces)(100%)

Total Volume

POSITIVE BACTLR'OLDG!CAL SAMPLE POSITIVE BACTERIOLOGICAL SAMPLE

A water sample in which gas is produced by coliform organisms during incubation in the multiple tube fermentation test. See
Chapter 11, Lab Procedures, "Coliform Test," for details.

POSITIVE DISPLACEAfir'NT PUMP POSITIVE DISPLACEMENT PUMP

A type of piston', diaphragm, gear or screw pump that delivers a constant volume with each stroke. Positive displacement
pumps are used as chemical solution feeders.

POSTCHLORINATION POSTCHLORINATION
The addition of chlorine to the plant effluent, FOLLOWING plant treatment, for disinfection purposes.

POTABLE WATER (POE-tuh-buli) POTABLE WATER

Water that does not "int= objectionable pollution, contamination, minerals, or infective agents and is considered satisfactory
for drinking.

POWER FACTOR POWER FACTOR

The ratio of the true power passing through an electric circuit to the product of the voltage and amperage in the circuit. This is a
measure of the lag or load of the current with respect to the voltage.

PPM PPM
See PARTS PER MILLION.

PRECHLORINATION PRECHLORINATION
The addition of chlorine at the headworks of the plant PRIOR TO other treatment processes mainly for disinfection and control
of tastes, odors and aquatic growths. Also applied to aid in coagulation and settling.

PREC TATE (pre-SIP-uh-TATE) PRECIPITATE

(1) An insoluble, finely divided substance which is a product of a chemical reaction within a liquid.
(2) The separation f-om solution of an insoluble substance.

PRECIPITATION (pre-SIP-uh-TAY-shun) PRECIPITATION

(1) The process by which atmospheric moisture falls onto a land or water surface as rain, snow, hail, or other forms of mois-
ture.
(2) The chemical transformation of a substance in solution *o an insoluble form (precipitate).
PRECISION PR ECISION
The ability of an instrument to measure a process variable and to repeatedly obtain the same result. The ability of an instrument
to reproduce the same results.

PRECURSOR, THM (pre-CURSE-or) PRECURSOR, THM

Natural organic compounds found in all surface and groundwaters These compounds MAYreact with halogens (such as chlo-
rine) to form tnhalomethanes (try-HAL-o-MEIH-hanes) (THMs); they MUST be present in order for THMs to form.

PRESCRIPTIVE (pre-SKRIP-tive) PRESCRIPTIVE

Water rights which are acquired by diverting water and putting it to use in accordance with specified procedures. These proce-
dures include filing a request to use unused water in a stream, river or lake with a tate agency.

PRESSURE CONTROL PRESSURE CONTROL

A switch which operates on changes in pressure. Usually this is a diaphragm pressing against a spring. When the force on the
diaphragm overcomes the spring pressure, the switch is actuated (activated).

PRESSURE HEAD PRESSURE HEAD

The vPrt-.7di distance (in feet) equal to the pressure (in psi) at a specific point. The pressure head is equal to the pressure in psi
times 2.31 ft/psi.

653
 Words 635
PRESTRESSED PRESTRESSED
A prestressed pipe has been reinforced with wire strands (which are under tension) to give the pipe an active resistance to
loads or pressures on it.

PRIMARY ELEMENT PRIMARY ELEMENT

The hydraulic structure used to measure flows. In opE channels, weirs and flumes are primary elements or devices. Venturi
meters and orifice plates are the primary elements in pipes or pressure conduits.
PRIME PRIME
The action of filling a pump casing with water to remove the air Most pumps must be primed before startup or they will not
pump any water.

PROCESS VARIABLE PROCESS VARIABLE

A physical or chemical quantity which is usually measured and controlled in the operation of a water treatment plant or an in-
dustrial plant.

PRODUCT WATER PRODUCT WATER

Water that has passed through a water treatment plant All the treatment processes are completed or finished. This water is the
product from the water treatment plant and is ready to be delivered to the consumers. Also called FINISHED WATER.

PROFILE
PROFILE
A drawing showing elevation plotted against distance, such as the vertical section or side view of a pipeline.

PRUSSIAN BLUE PRUSSIAN BLUE

A blue paste or liquid (often on a paper like carbon paper) used to show a contact area. Used to determine if gate valve seats fit
properly.

PSIG
PSIG
Pounds per Square Inch Gage pressure The pressure within a closed container or pipe measured with a gage in pounds per
square inch. See GAGE PRESSURE.

PUMPING WATER LEVEL PUMPING WATER LEVEL

The vertical &stance in feet from the centerline of the pump discharge to the level of the free pool while water is being drawn
from the pool.

PURVEYOR, WATER (purr-VAY-or) PURVEYOR, WATER

An agency or person that supplies water (usually potable water).

PUTREFACTION (PEW-truh-FACK-shun) PUTREFACTION

Biological decomposition of organic matter, with the production of ill-smelling and tasting products, associated with anaerobic
(no oxygen present) conditions.

QUICKLIME QUICKLIME
A material that is mostly calcium oxide (CaO) or calcium oxide in natural association with a lesser amount of magnesium oxide.
Quicklime is capable of combining with water to form hydrated lime. Also see HYDRATED LIME

RADIAL TO IMPELLER RADIAL TO IMPELLER

Perpendicular to the impeller shaft. Material being pumped flows at a right angle to the impeller.

RADICAL RADICAL
A group of atoms that is capable of remaining unchanged during a series of chemical reaL bons. Such combinations (radicals)
exist in the molecules of many organic compounds; sulfate (SO2 ) is an inorganic radical.

RANGE
RANGE
The spread from minimum to maximum values that an instrument is designed to measure. Also see SPAN and EFFECTIVE
RANGE.

RANNEY COLLECTOR RANNEY COLLECTOR

This water collector is constructed as a dug well from 12 to 16 feet (3.5 to 5 m) in diameter that has been sunk as a caisson near
the bank of a river or lake Screens are driven radially and approximately honzonfolly from this well into the sand and the gravel
deposits underlying the river.

[SEE DRAWING ON PAGE 636]

654
636 Water Treatment

GROUND SURFACE

WATER TABLE

COLLECTOR PIPE

ELEVATION VIEW

PLAN VIEW OF COLLECTOR PIPES

RANNEY COLLECTOR

RAW WATER RAW WATER

(1) Water in its natural state, prior to any treatment.
(2) Usually the water entering the first treatment process of a water treatment plant.

REAERATION (RE-air-A-shun) REAERATION

1 3 introduction of air through forced air diffusers into the lower layers of the reservoir. As the air bubbles form and rise
tnrough the water, oxygen from the air dissolves into the water and replenishes the dissolved oxygen. The rising bubbles also
cause the lower waters to rise to the surface where oxygen from the atmosphere is transferred to the water. This is sometimes
called surface reaeration.

REAGENT (re-A-gent) REAGENT

A pure chemical substance that is used to make new products or is used in chemical tests to measure, detect, or examine other
substances.

RECARBONATION (re-CAR-bun-NAY-shun) RECARBONATION

A process in whit,n carbon dioxide is bubbled into the water being treated to lower the pH. The pH may also be lowered by the
addition of acid Recarbonation is the final stage in the lime-soda ash softening process. This process converts carbonate ions
to bicarbonate ions and stabilizes the solution against the precipitation of carbonate compounds.

J
61-a '""
 ---7.1

Words 637
RECEIVER RECEIVER
A device which indicates the value of a measurement. Most receivers in the water utility field use either a fixed scale and mov-
able indicator (pointer) such as pressure gage or a moving chart with movable pen such as on a circular-flow recording chart.
Also called an INDICATOR.

RECORDER
RECORDER
A device that creates a permanent record, on a paper chart or magnetic tape, of the changes of some measured variable.

REDUCING AGENT REDUCING AGENT

Any substance, such as base metal (iron) or the sulfide ion (S2 ,) that will readily donate (give up) electrons. The opposite is an
OXIDIZING AGENT.

REDUCTION (re-DUCK-shun) REDUCTION

Reduction is the addition of hydrogen, removal of oxygen, or the addition of electrons to an element or compound. Under an-
aerobic conditions (no dissolved oxygen present) sulfur compounds are reduced to odor-producing hydrogen sulfide (H2S) and
other compounds. The opposite of OXIDATION.

REFERENCE REFERENCE
A physical or chemical quantity whose value is known exactly, and thus is used to calibrate or standardize instruments.

RELIQUEFACTION (re-LICK-we-FACK-shun) RELIQUEFACTION

The return of a gas to the liquid state; for example, a condensation of chlorine gas to return it to its liquid form by cooling.

REPRESENTATIVE SAMPLE REPRESENTATIVE SAMPLE

A portion of material or water that is as nearly identical in content and consistency 3s possible to that in the larger body of
material or water being sampled.

RESIDUAL CHLORINE RESIDUAL CHLORINE

The amount of free and/or available chlorine remaining after a given contact time under specified conditions

RESIDUE
RESIDUE
The dry solids remaining after the evaporation of a sample of water or sludge. Also see TOTAL DISSOLVED SOLIDS.

RESINS RESINS
See ION EXCHANGE RESINS.

RESISTANCE RESISTANCE
That property of a conductor or wire that opposes the passage of a current, thus causing electrical energy to be transformed
into heat.

RESPIRATION RESPIRATION
The process in which an organism uses oxygen for its life processes and gives off carbon dioxide.

REVERSE OSMOSIS (oz-MOE-sis) REVERSE OSMOSIS

The application of pressure to a concentrated solution which causes the passage of a liquid from the concentrated solution to a
weaker solution across a semipermeable membrane. The membrane allows the passage of the water (solvent) but not the dis-
solved solids (solutes). The liquid produced is a demineralized water. Also see OSMOSIS.

RIPARIAN (ri- PAIR- ee -an) RIPARIAN

Water rights which are acquired together with title to the land bordering a source of surface water.lae right to put to beneficial
use surface water adjacent to your land

RODENTICIDE (row- DENT -i. i-SIDE) RODENTICIDE

Any substance or chemical used to kill or control rodents.

ROTAMETER (RODE-uh-ME-ter) ROTAMETER

A device used to measure the flow rate of gases and liquids. The gas or liquid being measured flows vertically up a tapered,
calibrated tube Inside the tube is a small ball or bullet-shaped float (it may rotate) that rises or falls depending on the flow rate.
The flow rate may be read on a scale behind or on the tube by looking at the middle of the ball or at the widest part or top of the
float.

ROTOR ROTOR
The rotating part of a machine. The rotor is surrounded by the stationary (non-moving) parts (stator) of the machine.

656
638 Water Treatment

ROUTINE SAMPLING ROUTINE SAMPLING

Sampling repeated on a regular basis.

SACRIFICIAL ANODE SACRIFICIAL ANODE

An easily corroded material deliberately installed in a pipe or tank. The intent of such an installation is to give up (sacrifice) this
anode to corrosion wh:le the water supply facilities remain relatively corrosion free
SAFE DRINKING WATER ACT SAFE DRINKING WATER ACT
Commonly referred to as SDWA An Act passed by the U S Congress in 1974. The Act establishes a cooperative program
among local, state and federal agencies to insure safe drinking water for consumers.

SAFE WATER SAFE WATER

Water that does not contain harmful bacteria, or toxic materials or chemicals. Water may have taste and odor problems, color
and certain mineral problems and still be considered safe for drinking.
SAFE YIELD SAFE YIELD
The annual quantity of water that can be taken from a source of supply over a period of years without depleting the source per-
manently (beyond its ability to be replenished naturally in "wet years").

SALINITY SALINITY
(1) The relative concentration of dissolved salts, usualy sodium chloride, in a given water.
(2) A measure of the concentration of disc Jived mineral substances in water.

SANITARY SURVEY SANITARY SURVEY

A detailed evaluation and/or inspection of a source of water supply and all conveyances, storage, treatment and distribution
facilities to insure its protection from all pollution sources.
SAPROPHYTES (SAP-row-FIGHTS) SAPROPHYTES
Organisms living on dead or decaying organic matter. They help natural decomposition of organic matter in water.

SATURATION SATURATION
The condition of a liquid (water) when it has taken into solution the maximum possible quantity of a given substance at a given
temperature and pressure.

SATURATOR (SAT-you-RAY-tore) SATURATOR

A device which produces a fluoride solutior ror the fluoridation process The device is usually a cylindrical container with granu-
lar sodium fluoride on the bottom Water flows either upward or downward through the sodium fluoride to produce the fluoride
solution

SCFM SCFM
Cubic Feet of air per Minute at Standard conditions of temrNerature, pressure and humidity (0°C / 14.7 psia / 50% relative hu-
midity).

SDWA SDWA
See SAFE DRINKING WATER ACT.

SECCHI DISC (SECK-key) SECCHI DISC

A flat, white disc lowered into the water by a rope until it is Just barely visible. At this point, the depth of the disc from the water
surface is the recorded Secchi disc transparency.

SEDIMENTATION (SED-uh-men-TAY-shun) SEDIMENTATION

A water treatment process in which solid particles settle cut of the water being treated in a large clarifier or sedimentation
basin.

SEIZE UP SEIZE UP
Seize up occurs when an engine overheats and a part expands to the point where the engine will not run Also called "freezing."

SENSOR SENSOR
An instrument that measure (senses) a physical condition or variable of interest. Floats and thermocouples are examples of
sensors.
SEPTIC (SEP-tick) SEPTIC
A condition produced by bacteria when all oxygen supplies are depleted li severe, bottom deposits and water turn black, give
off foul odors, and the water has a greatly increased chlorine demand.

657
 Words 639
SEQUESTRATION (SEE-k:.,es-TRAY-Ghun)
SEQUESTRATION
A chemical complexing (fo -ning or joining togethF of metallic c tons (such as iron) with certain inorganic compounds, such
as phosphate Sequestration prevents the prec cn of the rr 2t^ls (iron). Also see CHELATION
SERVICE PIPE
SERVICE PIPE
The pipeline extending from the water main to the pudding served or to the consumer's system

SET POINT
SET POINT
The position at which the control 0- controller IQ set This is the same as the desired value of the
process variable.
SEWAGE
SEWAGE
The used water and solids that flow from homes through sewers to a wastewater treatment plant. The preferred
WASTEWATER. term is

SHEAVE (SHE-v)
SHEAVE
V-belt drive pulley which is commonly made of cast iron or steel.

SHIM
SHIM
Thin metal sheets which are inserted between two surfaces to align or space the surfaces correctly. Shims
can be used any-
where a spacer is needed. Usually shims are 0.001 to 0.020 inches thick.

SHOCK LOAD
SHOCK LOAD
The arrival at a water treatment plant of raw water containing unusual amounts of algae, colloidal matter, color,
suspended
solids, turbidity, or other pollutants.

SHORT-CIRCUITING
SHORT- CIRCUITING
A condition that occurs in tanks or basins when some of the water travels faster than the rest c the flowing water. This
is usual-
ly undesirable since it may result in shorter contact, reaction, or settling times in comparison with the theoretical
(calculated) or
presumed detention times.

SIMULATE
SIMULA-E
To reproduce the action of some process, usually on a smaller scale.

SINGLE -STAGE PUMP

SINGLE-STAGE PUMP
A pump that has only one impeller A multi-stage pump has more than one impeller.

SLAKE
SLAKE
To mix with water with a true chemical combination (hydrolysis) taking place, such as in the sluing of lime.

;LAKED LIME
SLAKED LIME
See HYDRATED LIME.

SLOPE
SLOPE
The slope or inclination of a trench bottom or a trench side wall is the ratio of the
vertical distance to the horizontal distance or "nse over run." Also see qRADE (2).

2 VERTICAL

1 HORIZONTAL

2:1 SLOPE
SLUDGE (sluj)
SLUDGE
The nttleable solids separates from water during processing.

SLURRY (SLUR-e)
SLURRY
A watery mixtur3 or ^uspens;nn c I insoluble (not dissolved) matter; a thin watery mud or any substance resembling it (si. 1h
grit slurry or a lime iurry). as a

658
640 Water Treatment

SMCLs SMCLs
Secondary Maximum Contaminant Levels Secondary MCLs fcr various water L,Jality indicators are establ.,.d to protect pub-
lic welfare

SNARL SNARL
Suggested No Adverse Resp-mse Level The concentration of a chemical in water that is expected not to cause an adverse
health effect

SOFTWARE PROGRAMS SOFTWARE PROGRAMS

Compute programs, the list of instructions that tell a computer how to perform n given task or tasks.

SOFT WATER SOFT WATER

Water having a low concentration of calcium c.nd magnesium ions According to U S. Geological Survey gui -lines, soft water is
water having a hardness of 60 milligrams per liter or less.

SOLENOID (SO-luh-noid' SOLENOID

A magnetically (electrical coil) operated mechaiical device. Solenoids can operate pilot valves or electrical switches.

SOLUTION SOLUTION
A liquid mixture of dissolved substances In a solution it is impossible to see all the separate parts.

SOUNDING TUBE SOUNDING TUBE

A pipe or tube used for measuring the depths of water.

SPAN SPAN
Th" scale or range of values an irr.trument is designed to measure. Also see RANGE.

SPECIFIC CONDUCTANCE SPECIFIC CONDUCTANCE

A rapid method of estimating the dissolved-solids content of a water supply. The measurement indicates the capacity of a sam-
ple of water to carry an electrical current, which is related to the concentration of ionized substances in the water. Also called
CONDUCTANCE.

SPECIFIC GRAVITY SPECIFIC GRAVITY

Weight of a particle, suLstance, or chemical solution in relation to the weight of water. Water has a specific gravity of 1.000 at
4°C (39°F) Particulates in raw water may have a specific gravity of 1.005 to 2.5.

SPECIFIC YIELD SPECIFIC YIELD

The quantity of water that a unit volume ..,1 saturated permeable rer:k or soil will yield when drained by gravity. Specific yield may
be expressed as a ratio or as a percentage by volume.

SPOIL SPOIL
Excavated material cuch as soil from the trench of a water main.

SPORE SPORE
The reproductive uody of an organism which is capable of giving rise to a new organ sm either directly or indirectiy. A viable
(able to live and grow) bc.f.y regarded as the resting stage of ar "rganism. A spore is usually more resistant to disinfectants and
heat than most organisms.

SPRING LINE SPRING LINE

Theoretical center of a pipeline. Also, the guideline for laying a course of bricks.

STALE WATER STALE WATER

Water which has not flowed recently and may have picked up tastes and odors from distribution lines or storage facilities.

STANDARD STANDARD
A physical or chemical quantity whose value is known exactly, and is used to calibrate or standardize instruments. Also see
REFERENCE.

STANDARD METHODS STANDARD METHODS

STANDARD METHODS FOR THE EXAMINATION OF WATER AND WASTEWATER. A joint publication of the American Public
Health Association, American Wat. 'forks Association, and the Water Pollution Control Federation which outlines the
procedures used to analyze the impun. es in water and wastewater. 0 r ..-,
CI J 3
 Words 641

STANDARD SOLUTION STANDARD SOLUTION

A solution in which the exact concentration of a chemical or compound is known.
STANDARDIZE STANDARDIZE
To coml. are with a standard.
(1) In wet chemistry, to find out the exact strength of a solution by comparing it with a standard of lf.lown strength.
(2) To set up an instrument or device to read a standard This allows you to adjust the instrument so that it reads accurately, or
enables you to apply a correction factor to the readings.

STARTERS STARTERS
Devices used to start up large motors gradually to avoid severe mechanical shock to a driven machine and to prevent dis-
turbance to the electrical lines (causing dimming and flickering o. ghts).
STATIC HEAD STATIC HEAD
When water is not moving, the vertical distance (in feet) from a specific )int to the water surface is the static head. (The static
pressure in psi i. the static head in feet times 0.433 psi/ft.) Also see uYNAMIC PRESSURE and STATIC PRESSURE.

STATIC PRESSURE STATIC PRESSURE

When water is not moving, the x, ical distance (in feet) from a specific point to the water surface is th- static head. The static
pressure in psi is the static hea- in feet times 0.433 psi/ft. Also see DYNAMIC PRESSURE and STA '3 HEAD.
STATIC WATER DEPTH STATIC WATER DEPTH
The vertical distance in feet from the centerline of the pump discharge down to the surface level of the free pool while no water
is being drawn from the pool or water table.

STATIC WATER LEVEL STATIC WATER LEVEL

(1) The elevation or level of the water table in a well when the pump is not operating.
(2) The level or elevation to which water would rise in a tube cc ',noted .o an artesian aquifer, or basin, or conduit under pres-
sure.

STATOR STATOR
That portion of a machine which contains the stationary (non-moving) parts that surround the moving parts (rotor).

STERILIZATION (STARE-uh-bah -ZAY-shun) STERILIZATION

The removal or destruction or all micrnorganisms, including pathogenic and other bacteria, vegetative forms and spores.
Compare with DISINFECT ION.

STETHOSCOPE STETHOSCOPE
An instrument used to magnify sounds and convey them to the ear.

STRATIFICATION (STRAT-uh-fuh-KAY-shun) STRATIFICATION

The formation of separate layers (of temperature, plant, or animal life) in a lake or reservoir. Each layer has similar
characteristics such as all water in the layer has the same temperature. Also see THERMAL STRATIFICATION.

SUBMERGENCE SUBMERGENCE
The distance between the water surface and the media surface in a filter.

SUBSIDENCE (sub-SIDE-ence) SUBSIDENCE

The dropping or lowering of the ground surface as a result of removing excess water (overdraft or over pumping) from an
aquifer. After excess water has been removed, the soil will settle, become c.. -npacted and the ground surface will drop.
SUCTION LIFT SUCTION LIFT
The NEGATIVE pressure [in feet (meters) of water or inches (centimeters) of mercury vacuum] on the suction side of the pump.
The pressure can he measured from the centerline of the pump DOWN TO (list) the elevation of the hydraulic grade line on the
suction side of the pump.

SUPERCHLORINATION (SU E-per-KL0Fi-uh-NAY-shun) SUPERCHLORINATION

Chlorination with doses that are deliberately selected to produce free or combined residuals so large as to require
dechlorination.

SUPERNATANT (sue-per-NAY-tent) SUPERNATANT

A removed from settled sludge Supernatant commonly refers to the liquid between the sludge on the bottom and the water
surface of a basin or container.
1.
.. ,..

660
 642 Water Treatment

SUPERSATURATED SUPERSATURATED
An unstable conditio,i of a solution (water) in which the solution contains a substance at a concentration greater than the satu-
ration concentration for the substance

SURFACE LOADING SURFACE LOADING

One of the guidelines for the design of settling tanks and clarifiers in treatment plants Used by operators to determine if tanks
and clarifiers are hydrau:ically (flow) over- or underloaded. Also called OVERFLOW RATE.
Surface Loading, GPD/sq ft = Flow, gallon/day
Surface Area, sq ft

SURFACTANT (sir-FAC-ter,t) SURFACTANT

Abbreviation for surface-active agent The active agent in detergents that possesses a high cleaning ability.

SURGE CHAMBER SURGE CHAMBER

A chamber or tank connected to a pipe and located at or near a valve that may quickly open or close or a pump that may
suddenly start or stc- When the flow of water in a pipe starts or stops quickly, the surge chamber allows water to flow into or
out of the pipe and minimize any sudden positive or negative pressure waves or surges in the pipe.

CLOSED
ON TOP

TYPES Or SURGE CHAMBERS

SURGE CHAMBER

SUSPENDED SOLIDS SUSPENDED SOLIDS

(1) Solids t:sat either float on the surface or are suspended in water o: other liquids. and which are largely removable by labora-
tory filtering.
(2) The quantity of material removed from water in a laboratory test, as prescribed in STANDARD METHODS FOR TI,ZEXAMI-
NATION OF WATER AND WASTEWATER and referred to as nonfilterable residue.

661
 Words 643

TAILGATE SAFETY MEETING TAILGATE SAFETY MEETING

The term TAILGATE comes from the safety r'eetings regularly held by the construction industry around the tailgate of a truck.

TCE TCE
See TRICHLOROETHANE.

TDS TDS
See TOTAL DISSOLVED SOLIDS.

TELEMETRY (tel-LEM-uh-tree) TELEMETRY

The electrical link between the transmitter and the receiver Telep' me lines are commonly used to serve as the electrical line.

TEMPERATURE SENSOR TEMPERATURE SENSOR

A device that opens and closes a switch in response to changes in the temperature This device might be a metal contact, or a
thermocc Joie that gener3ts minute e actrical current proportional to the difference in heat, or a variable resistor whose value
changes in response to changes in temperature. Also called a HEAT SENSOR.

THERMAL STRATIFICATION (STRAT-uh-fuh-KAY-shun) THERMAL STRATIFICATION

The formation of layers of different temperatures in a lake or reservoir. Also .,...ee STRATIFICATION.

THERMOCLINE (THUR-moe-KLINE) THERMOCLINE

The middle layer in a thermally stratified lake or reservoir In this layer there is a rapid decrease in temperature with depth. Also
called the METALIMNION.

THERMOCOUPLE THERMOCOUPLE
A heat-sensing device made of two conductors of different metals Joined at their ends. An electric current is produced when
there is a difference in temperature between the ends.

THICKENING THICKENING
Treatment to remove water from the sludge mass to reduce the volume that must be handled.

THM THM
See TRIHALOMETHANES.

THM PRECURSOR THM PRECURSOR

See PRECURSOR, THM.

THRESHOLD ODOR THRESHOLD ODOR

The rr mum odor of a water sample that can just be detected after successive dilutions with odorless water. Also called
ODOR . IRESHOLD.

THRESHOLD ODOR NUMBER THRESHOLD ODOR NUMBER

TON. The greatest dilution of a sample with odor-free water that still yields a lust-detectable odor.

THRUST BLOCK THRUST BLOCK

A mass of concrete or similar material appropriately placed around a pipe to prevent movement when the pipe is carrying water.
Usually placed at bends and valve structures.

TIME LAG TIME LAG

The time requir^d for processes and control systems to respond tc a signal or to reach a desired level.
TIMER TIMER
A device for automatically starting or stopping a machine or other device at a given time.

TITRATE (TIE-trate) TITRATE

To TITRATE a sample, a chemical solution of known strength is added on a drop-by-drop basis until a certain color change,
precipitate, or pH change in the sample is observed (end point). Titration is the process of adding the chemical reagent in
increments until completion of the reaction, as signaled by the end point.

TOPOGRAPHY TOPOGRAPHY
The arrangement of hills and valleys in a geographic area.

662
644 Water Treatment

TOTAL DISSOLVED SOLIDS (TDS) TOTAL DISSOLVED SOLIDS (TDS)

All of the dissolved solids in a water TDS is measured on a sample of water that has passed through a eery fine mesh filter to
remove suspended solids The water passing through the filter is evaporated and the residue represents the dissolved solids.
Also see SPECIFIC CONDMTANCE.

TOTAL DYNAMIC HEAD (TDH) TOTAL DYNAMIC HEAD (TDH)

When a pump is lifting or pumping water, the vertical distance (in feet) from the elevation of the energy grade line on the suction
side of the pump to the elevation of the energy grade line on the discharge side of the pump.

TOTAL RESIDUAL CHLORINE TOTAL RESIDUAL CHLORINE

The amount of available chlorine remaining after a given contact time. The E um of the combined available residual chlorine and
the free available residual chlorine. Also see RESIDUAL CHLORINE

TOTALIZER TOTALIZER
A device or meter that continuously measures and calculates (adds) total flows in gallons, million gallons, cubic feet, or some
other unit of volume measurement. Also called an INTEGRATOR.

TOXAPHENE (TOX-uh-FEEN) TOXAPHENE

A chemical that causes adverse health effects in domestic water supplies and also is toxic to freshwater and marine aquatic life.

TOXIC (TOX-ick) TOXIC

A substance which is poisonous to an organism.

TRANSDUCER (trans-DUE-sir) TRANSDUCER

A device which senses some varying condition and converts it to an electrical or other signal for transmission to some other de-
vice (a receiver) for processing or decision making.

TRANSMISSION LINES TRANSMISSION LINES

Pipelines that transport raw water from its source to a water treatment plant. After treatment, water is usually pumped into pipe-
lines (transmission lines) that are connected to a distribution grid system.

TRANSMISSIVITY (TRANS-miss-SW-it-tee) TRANSMISSWITY

A measure of the ability to transmit (as in the ability of an aquifer to transmit water)

TRANSPIRATION (TRAN-spur-RAY-shun) TRANSPIRATION

The process by which water vapor is released tc the atmosphere by living plants. This process is similar to people sweating.
Also called EVAPOTRANSPIRATION.

TREMIE (TREH-me) TREMIE

A device ,,sed to place concrete or grout under water

TRICHLOROETHANE (TCE) (try-KLOR-o-ETH-hane) TRICF.L.OROETHANE (TCE)

An organic chemical used as a cleaning solvent that causes adverse health effects in domestic water supplies.

TRIHALOMETHANES (tri-HAL-o-METH-hanes) TRIHALOMETHANES

Derivatives of methane, CH,, in which three halogen atoms (chlorine or bromine) are substituted for three of the hydrogen
atoms Often formed during chlorination by reactions with natural organic materials in the water. The resulting compounds
(THMs) are suspected of causing cancer.

TUBE SETTLER TUBE SETTLER

A device that uses bundles of small bore (2 to 3 inches or 50 to 75 rnm) tubes installed on an incline as an aid to sedimentation.
The tubes may come in a variety of shapes including circular and rectangular As water rises within the tubes. settling solids fall
to the tube surface. As the sludge (from the settled solids) in the tube gains weight, it moves down the tubes and settles to the
bottom of the basin for removal by conventional sludge collection means Tube settlers are sometimes installed in
sedimentation basins and clarifiers to improve penile removal.

TUBERCLE (TOO-burr-cull) TUBERCLE

A protective crust of corrosion products (rust) which builds up over a pit caused by the loss of metal due to corrosion.

663
 Words 645

TUBERCULATION (too-BURR-que-LAY-shun)
TUBERCULATION
The development or formation of smali mounds of corrosion products (rust) on the inside of iron pipe. These mounds
(tubercules) increase the roughness of the inside of the pipe thus increasing resistance to water flow (.ocreases the C Factor).

TURBID
TURBID
Having a cloudy or muddy appearance.

TURBIDIMETER
TURBIDIMETER
.7 3 TURBIDITY METER.

TURBIDITY (ter-BID-it-tee)
TURBIDITY
The cloud/ appearance of water caused by the presence of suspended and colloidal matter. In the waterworks field, a turbidity
measurement is used to indicate the clarity of water. Technically, turbidity is an optical property of the water based on the
amount of light reflected by suspended particles Turbidity cannot be directly equated to suspended solids because Nhite par-
ticles reflect more light than dark-colored particles and many small particles will reflect more light than en equivalent large
particle.

TURBIDITY METER
TURBIDITY METER
An instrument for measuring and comparing the turbidity of liquids by passing light through them and determining how much
light is reflected by the particles in the liquid.

TURBIDITY UNITS (TU)

TURBIDITY UNITS (TU)
Turbidity units are a measure of the cloudiness of water. If measured by a nephelometnc (deflected light) instrumental
procedure, turbidity units are expressed in nephelometric turbidity units (NTU) or simply TU. Those turbidity units obtained by
visual methods are expressed in Jackson Turbidity Units (JTU) which are a measure of the cloudiness of water, they are used
to indicate the clarity of water. There is no real connection between NTUs and JTUs. The Jackson turbidimeter is a visual meth-
od and the nephelometer is an instrumental method based on deflected light.

TURN-DOWN RATIO
TURN-DOWN RATIO
The ratio of the design range to the range of acceptable accuracy or precision of an instrument. Also see EFFECTIVE RANGE.

UNCONSOLIDATED FORMATION UNCONSOLIDATED FORMATION

A sediment that is loosely arranged or unstratified (not in layers) or whose particles are not cemented together (soft rock); oc-
curring either at the ground surface or at a depth below the surface. Also seE CONSOLIDATED FORMATION.

UNIFORMITY COEFFICIENT (U.C.) UNIFORMITY COEFFICIENT (U.C.)

The ratio of (1 r e diameter of a grain (particle) of a size that is barely too large to pa..0 through a sieve that allows 60 percont of
the material (t:q eight) to pass through, to (2) the diameter of a grain (particle) of a size that is barely too large to pass through
a sieve that allows 10 percent of the material (by weight) to pass through.
Particle Diameters.
Uniform.;/ Coefficient =
Particle Diameterw,

VARIABLE FREQUENCY DRIVE VARIABLE FREQUENCY DRIVE

A control system that allows the frequency of the current applied to a motor to be varied. The motor is connected to a low-
frequency source while standing still; the frequency is then increased gradually until the motor and pump (or other driven ma-
chine) is at the desired speed.

VARIABLE, MEASURED VARIABLE. MEASURED

A factor (flow, temperature) that is sensed and quantified (reduced io a reading of some kind) by a primary element or sensor

VARIABLE, PROCESS VARIABLE. PROCESS

A physical or chemical quantity which is usually measured and controlled in the operation of a water treatment plant or an in-
dustrial plant.

VELOCITY HEAD VELOCITY HEAD

The energy in flowing water as determined by a vertical height (in feet or meters) equal to the square of the velocity of flowing
water divided by twice the acceleration due to gravity (V2/2g).

664
646 Water Treatment

VENTURI METER VENTURI METER

A flow measuring device placed in a pipe. The device consists of a tube whose diameter gradually decreases to a throat and
then gradually expands to the diameter or the pipe. The flow is determined on the basis of the differences in pressure (caused
by different velocity heads) between the entrance and throat of the Venturi meter.

F
VENTURI METER

tp-

MANOMETER

NOTE Most Venturi meters have pressure sensing taps rather than a manometer to measure the pressure difference. The
t'nstream tap is the high pressure tap or side of the monometer.

VISCOSITY (vis-KOSS-uh-tee) VISCOSITY

A property of water, or any other fluid, which resists efforts to change its shape or flow. Syrup is more viscous (has a higher
viscosity) than water. The viscosity of water ncreases significantly as temperatures decrease. Motor oil is rated by how thick
(1,,3cc,$) it is; 20 weight oil is considered relativoly this while 50 weight cil is relatively thick or viscous.
VOID VOID
A pore or open space in rock, soil or other granular material, not occupied by solid matter. The pore or open space may be
occupied by air, water, or other gaseous or liquid material. Also called a void space or interstice.

VOLATILE (VOL-uh-tull) VOLATILE

A substance that is capable of being evaporated or easily changed to a vapor at relatively low temperatures. For example, gas-
oline ig a highly volatile liquid.

VOLATILE ACIDS VOLATILE ACIDS

Acids produced during digestion. Fatty acids which are soluble in water and can be steam-distilled at atmospheric pressure.
Also called "organic acids." Volatile acids are commonly reported as equivalent to acetic acid.

VOLATILE LIQUIDS VOLATILE LIQUIDS

Liquids which easily vaporize or evaporate at room temperatures.

VOLATILE SOLIDS VOLATILE SOLIDS

Those solids in water or other liquids that are lost on ignition of the dry solids at 550°C.

VOLTAGE VOLTAGE
The electrical pressure evadable to :ause a flow of current (amperage) when an electrical circuit is closed. See ELECTHOMO-
TIVE FORCE (E.M.F.).

VOLUMFTRIC VOLUMETRIC
A measurement based on the volume of some 'actor. Volumetnc titration is a means (1 measenng unknown concentrattons of
water quality indicators in a sample by determining the volume of titrant or liquid reagent needed to complet, partictrlar reac-
tions.

VOLUMETRIC FEEDER VOLUMETRIC FEEDER

A dry chemical feeder which delivers a measured volume of chemical during a specific time period.

VORTEX VORTEX
A revolving mass of water which forms a whirlpool. This whirlpool is caused by water flowing out of a smell opening in the bot-
tom of a basin or reservoir. A funnel-shaped opening is created downward from the water surface.

WASTEWATER WASTEWATER
The used water and solids from a commun,Zy (including used water from industrial processes) that flow to a treatment plant.
Storm water, surface water, and groundwater infiltration also may be included in the wastewater ;hat enters a wastewater treat-
ment plant. The term "sewage" usually refers to household wastes, but this word is being replaced by the term ''wastewater."
 Words 647
WATER HAMMER WATI.R HAMMER
The sound like someone hammering on a pipe that occurs it hen a valvc is opened or ciosed very i- apidly. When a valve position
is changed quickly, the water pressure in a pipe will increise and decrease back and forth very quickly. This rise and fall in
pressures can do serious damage to the system.

WATER PURVEYOR (purr-VAY-or) WATER PURVEYOR

An agency or person that supplies water (usually potable water).

WATER TABLE WATER TABLE

The upper surface of the zone of saturation of groundwater in an unconfined aquifier.

WATT
WATT
A unit of power equal to one joule per second The power of a current of one ampere flowing across a potential differenc-s of
one volt.

WEIR (weer)
. /EIR
(1) A wall or plate placed in an open channel and used to measure the flow of water. The depth of the now over the weir can be
used to calculate the flow rate, or a chart or conversion table may be used.
(2) A wall or obstruction used to control flow (from settling tanks and clarifiers) to assure uniform flow rate and avoid short-
circuiting.

WEIR DIAMETER (weer) WEIR DIAMETER

Many circular clarifiers have a circular weir within the outside edge DiAMETEr.
of tile clarifier. All the water leaving the clarifier flows over this weir. DIAMETER

The diameter . the weir is the length o a line from one edge of a
weir to the opposite edge and passing through the center of the
. Min AP Vjtio .......,,....--
circle formed by the weir. TOP VIEW olo: S sEcTo

WEIR LOADING WEIR LOADING

A guideline used to determine the length of weir needed on settling tanks and clarifiers in treatment plants. Used by operators
to determine if weirs are hydraulically (flow) overloaded.
Weir Loading, GPM/ft = Flow, GPM
Length of Weir, ft

WELL LOG WELL LOG

A record of the thick 'csss and characteristics of the sod, rock and water-bearing formations encountered during the drilling
(sinking) of a well.

WET CHEMISTRY WET CHEMISTRY

Labor story procedures used to analyze a sample of water using liquid chemical solutions (wet) instead of, or in addition to, lab-
oratoi 'i instruments.

WHOLESOME WATER WHOLESOME WATER

A water that is safe and palatable for human consumption.

WIRE-TO-WATER EFFICIENCY WIRE -TO- WATER EFFICIENCY

The efficiency of a pump and motor together. Also called the OVERALL EFFICIENCY.

YIELD YIELD
The quantity of water (expressed as a rate of flow GPM, GPH, GPD, or total quantity per year) that can be collected for a
given use from surface or groundwater sources. The yield may vary with the use proposed, with the plan of development, and
also with economic considerations. Also see SAFE YIELD.

ZEOLITE ZEOLITE
A type of ion exchange material used to soften water. Natural zeolites are siliceous compounds (made of silica) which remove
calcium and magnesium from hard water and replace them with sodium. Synthetic or organic zeolites are ion exchange materi-
als which remove calcium or magnesium and replace them w.th either sodium or hydrogen.
666
648 Water Treatment

ZETA POTENTIAL ZETA POTENTIAL

In coagulation and flocculation procedures, the difference in the electrical charge between the dense layer of ions surrounding
the particle and the charge of the bulk of the suspended fluid surrounding this particle. The zeta potential is usually measured in
millivolts.

ZONE OF AERATION ZONE OF AERATION

The comparatively dry soil or rock located between the ground surface and the top of the water table.

ZONE OF SATURATION ZONE OF SATURATION

The sod or rock located below the top of the groundwater table. By definition, the zone of saturation is saturated with water.
Also see WATER TABLE.

ZOOPLANKTON (ZOE-PLANK-ton) ZOOPLANKTON

Small, usually microscopic animals (such as protozoans), found in lakes and reservoirs.

66re"
 SUBJECT INDEX

A iron and manganese, 6

Aeration
ABC, 549 iron and manganese, 12, 13, 17
Accident trihalomethanes, 124-127, 129
prevention, 425 Aii cooled engines, 311
reports, 395-397. 05, 436 Air release assembly, 102
Accuracy, instrumentation. 343 Air supply systems, 371, 373
Acetic acid (glacial), 402 Air temperatures, fluoridation, 29
Acid feed systems, 37, 157 Alarms
Acids fluoridation, 44
chemical handling, 402 instrumentation, 367, 3b8
safety, 402 reverse osmosis, 157
Activated carbon, 125, 126, 129, 414 Algae counts, 449
Additional reading, 21, 58, 106, 130, 173, 322, 380, 437 Alignment, pimps, 253, 271, 278-280
Administration Alkalinity, sof. fig, 71, 73, 74, 82
ABC, 549 Alternating current (A.0 223
budgeting, 539 Alum, 413
certification, 549 Alum sludge, 200
complaints, 551 Aluminum sulfate, 413
consumer complaints, 551 Amendments to SDWA, 494-496
contaminated water supplies, 553 Ammeter, 227, 228
contingency planning, 552 Ammonia, 406
continuing education, 548 Amplitude, 223
disposition of plain records, 545 Amps, 224
emergencies, 552 Analog, 343, 363, 364
employee pride, 549 Analysis
interviews, 550 also see Laboratory test procedures
line organization, 546 iron and manganese, 7, 8
mass media, 550 Annunciator panels, 367, 368
newspapers, 550 Aquifer, 9
office procedures, 539 Arch, chemicals, 402
operator certification, 549 Arithmetic assignment, 21, 58, 106, 130, 173, 322, 435
organization procedures, 545 Arsenic, 503
pAople, 548 Atmospheres, explosive, 432
planning, 539 Autoclaves, 432
planning for emergencies, 552 Automatic
plant tours, 551 controller, 368
pride, employee, 549 valves, 305
procurement of materials, 541, 542 Auxiliary electrical power, 244, 245
public relations, 549
public speaking, 550
purchase order, 541, 542
radio, 550 B
rates, water, 540
recognition, 549 Backflow, 13
records, plant, 543, 544 Backsiphonage, 21
staff, 546 Backwash, ion exchange, 95, 100
staffing, 547 Backwash recovery ponds, 187
supervision, 547 Backwash wastewater, 200
teevision, 550 Bacteria
tours, 551 iron and manganese, 6, 7, 21
training, 548 regulations, 499
water rates, 540 Barium, 503
Adsorption, 125, 126 Bases
Adverse effects chemical handling, 405
hardness, 71 safety, 405

Fit. 668
650 Water Treatment

Bases Chemical feeders

chemical handling, 405 acid feed systems, 37
safety, 405 batch systems, 37, 38
Batch systems %7, 38 calculating doses, 54-58
Batteries, 223, 245 calculations, 319, 320
Bearings, pump, 253, 258, 259, 271, 273 calibration, 317, 318
Beer's Law, 448 chemical storage, 316
Belt drives, pumps, 274, 277 chlorinators, 320
Belt filter presses, 186, 191, 194 day tank, 38, 40
Belts, compressors, 289 diaphragm pumps, 31
Bench scale tests dose, 317-3 t9
iron and manganese, 13, 20 drainage, 317
trihalomethanes, 124, 126, 128 dry chemical, 317
Benefits, softening, 71, 75 dry feeders, 31, 37, 53
Blending, ion exchange, 105 electronic pumps, 31, 33, 45
Blown fluse, 227 feed rate, 317-320
Blue baby, 499 gas, 317
Booster shots, immunization, 431 gravimetric feeders, 31, 36
Brackish water, 141, 142 instrumentation, 360
Breakers, circuit, 224, 230 liquid, 317
Breakpoint chlorination, 14 maintenance. 20, 52, 316
Brine metering, 317
disposal, d'imineralization, 142 operation, 44
disposal, process wastas, 184, 185, 195, 200 peristaltic pumps, 31, 32, 45
electrodialysis, 163 positive displacement pumps, 31
ion exchange, 96-98, 100 saturators, 38, 39, 41, 53
reverse osmosis, 157, 161 shutdown, 52
Bromide, 119, 123, 124 solid, 317
Bubbler tube, 352, 354 solution feeders, 31, 37
Budgeting, 539, 540 solution preparation, 45
Buildings, maintenance, 321, 322 startup, 44
Butterfly valves, 292, 295 storage, chemical, 316
Bypass, ion exchange, 105, 106 volumetric feeders, 31, 34, 35, 37
By-products, disinfection, 496
Chemical flush system, 168
C Chemical handling
acetic acid (glacial), 402
Cadmium, 503 acids, 402
Calcium carbonate equivalent, 71, 72 activated carbon, 414
Calcium carbonate stability test, 466 alum, 413
Calcium test procedures, 450 aluminum sulfate, 413
Calculations ammonia, 406
chemical feeders, 319, 320 bases, 405
fluoridation, 54-58 calcium hydroxide, 406
ion exchange softening, 101-105 carbon dioxide, 416
lime-soda ash softening, 77, 85-90 caustic soda, 407
reverse osmosis, 146, 147, 151 chlorine, 408
trihalomethanes, 122 Chlorine Manual, 410
Calibration drains, 415
chemical feeders, 317, 318 ferric chloride, 413
instrumentation, 343, 374 ferric sulfate, 413
Calton dioxide, 76, 82, 410, 416 ferrous sulfate, 413
Carbonate hardness, 71 fluoride compounds, 413
Cartridge filters, 157, 168, 171 gas-detection equipment, 421
Casing, pumps, 254, 253, 259 gas mask, 409-411
Cathodic protection, 321 gases, 408
Caustic soda, 407 hydrochloric acid, 403
Caustic soda softening, 71, 81 hydrofluoric acid, 403
Cavitation, pumps, 256, 257 hydrofluosilicic acid, 402
Centrifugal pumps, 249, 257, 284, 285 hypochlonte, 407
Centrifuges, 186, 191, 195-197 muriatic acid, 403
Certification, 549 nitric acid, 405
Chain drives, pumps, 277 potassium permanganate, 414
Charts powdered activated carbon, 414
circular, 364-367, 377 powders, 414
fluoridation, 45-47 safety, 402, 431
strip, 364-367, 377 safety shower, 403, 404
Check sampling, 513 salts, 412
Check valves, 271, 273, 296-305 self-contained breathing apparatus, 409-411
Chelating agent, 510 sodium aluminate, 413
I.
663r
 Index 651
sodium carbonate, 408 valves, 289
sodium hydroxide 407
sodium silicate, 407
Concentration of sludges, 186
storage, 316 Concentration polarization, 151
Concrete tanks, 321
sulfu.- dioxide, 412
Conditioning of sludges, 185
sulfuric acid, 405
Conductors, 225
Chemical metering pumps, 258
Confined spaces, 187, 348
Chemical reactions, lime-soda ash softening, 75-77 Consumer complaints, 551
Chemical storage, 316, 415
Chemicals, labc atory, 431 Contaminated water supplies
Chemistry contamination, 553-555
softening, 72 countermeasures, 554
effective dosages, 554
tnhalomethanes, 119, 123
CHEMTREC (800) 424-9300, 220 emerrjancy treatment, 555
Chloramination, 506 lethll dose 50 (LD 50), 554
Chloramines, 128, 129 maxiniun. allowable concentration (MAC), 554
Chloride protective nivasures, 554
response, 555
regulations, 509
toxicity, 553
test procedures, 451
Chlorination treatment, emergency, 555
Contingency planning, 552
iron and manganese, 9-14, 17, 20
reverse osmosis, 157 Continuing education, 548
Control
Chlorinators, 320, 321
iron and manganese, 6, 9
Chlorine, 119, 123, 124, 126, 129, 408 loop, 344
Chlorine dioxide, 124, 125, 128, 129 panels, 429
Chlorine Manual, 410
pumps, 273
Chlorine residual substitution, 506, 523 systems, 342-347, 377
"Christmas Tree" arrangement, 151, 152
Chromium, 503 trihalomethanes, 124
Controllers, 343-345, 368
Circuit breakers, 224, 230 Controls
Circuits, 223, 225
compressors, 289
Circular charts, 364-367, 377 panels, 429
Classification, fire protection, 417 systems, 342-347, 377
Cleaning
Coding systems, engines, 311, 313-315
membranes, 161
Copper, 510
safety, 420
stacks, 168 Corrosivity, 510
Couplings, 253, 278-280
tanks, 185, 187
Cranes, 420
Coagulants, 82
Crenothrix, 511
Coagulation/sedimentation/filtration, 124, 126, 129 Cross-connection, 265
Code requirements, fuel storage, 315
Coliform rule, 506, 507 Current, electrical, 223, 225, 228, 428
Cuvette, 448
Coliforms, 498, 506, 533 Cycle, electrical, 223
Collecting samples, 7, 515
Collection of sludges, 184 D
Collection systems, wastewater, 195, 200 Dall tube, 358
Colloidal suspensions, 6 Dateometer, 274
Colloids, 156
Day tank, 38, 40
Color
Decant, 187
iron and manganese, 6 Dechlonnation, 13
regulations, 509 Decibel, 422
removal, 82 Demineralization
test procedures, 453 also see Electrodialysis
Community water systems, 498, 499 and Reverse osmosis
Comparator, pocket, 448
brackish water, 141, 142
Complaints, 551
brine disposal, 142
Compliance schedule, 496 distillation, 142, 143
Compounds, fluoride, 29, 30, 53 electrodialysis, 142, 143, 163
Compressors feedwater, 142
belts, 289 freezing, 142, 143
controls, 289 ion exchange, 142, 143
drain, 289
mineralized waters, 141
filter, 287 processes, 142, 143
fins, 288
reverse osmosis, 142, 143
lubrication, 288 salinity, 142
maintenance, 287 sea water, 142
types, 287 total dissolved solids, 141
unloader, 288 Desiccant, 378
use, 287 Desiccation, 371

670
652 Water Treatment

Design review current, 223, 225, 228, 428

electrodialysis, 168 cycle, 223
fluoridation, 42 direct current (D.C.), 223
Dewatering of sludges, 184, 186, 190 electri; motors, 234-241
Dial indicators, 280, 281 electromotive force (E.M.F.), 2z1
Diaphragm operated valves, 305, 306 emergency lighting, 245, 246
Diaphragm pumps, 31 fundamentals, 221
Diarrhea, -travelers," 499 fuse puller, 226
Diesel fuses, 223, 226, 22" , 230
engines, 309, 310 ground 231
fuel storage, 315 ground fault interrupter (G.F.I.), 429
Differential-pressure sensing, 356, 358, 359 hazards, 221
Digital, 343, 363-365 hertz, 223
Direct current (D.C.), 223 instrumentation, 429
Direct current, electrodialys;3, 165, 166, 168, 171 insulation, motors, 234
Dirty water insulation resistance, 229
iron and manganese, 6 insulators, 225
red water, 21 kirk-key, 245
Disinfection alternatives, 128 lighting, emergency, 245, 246
Disinfection by-products, 496 limitations, 221
Disposal of magnetic starters, 231-233
slue)es, 179, 184-186, 195 mair,.enance, 220, 274
spent brine, 98, 174, 184-186, 195 megger, 229
Disposition of plant records, 545 megohm, 229
Dissolved oxygen test procedures, 454 meters, electrical, 225
Distillation, 142, 143 motor insulation, 234
Divalent, 7, 70 motor starters, 231, 428
DO samples, 457, 458 motors, 223, 234-241, 274, 428
DO saturation table, 457 name plate, 234, 236
Dose, chemical feeders, 317-319 ohm, 224
Downflow saturators, 38, 41 ohm meters, 230
Drainage waters, plant, 202 Ohm's Law, 224
Draining tanks, 185, 187, 188 overload relays, 231
Drains panels, control, 429
chemical feeders, 317 phase, 223
chemical handling, 415 power requirements, 225
compressors, 289 protection devices, 230
Drinking water regulations recordkeeping, 236, 242, 243
see Regulations, drinking water safety, 221, 247, 428
Driving equipment, pumps, 282 standby power generation, 244, 245
Drowning, 434 starters, 231, 428
Dry chemical feeders, 31, 37, 53, 317 switch gear, 230, 246
Drying beds, 190-193, 200 switches, 223
Dust, fluoridation, 53 tag, warning, 222
Dy amic types of pumps, 250 testers, 225
thermal overloads, 231
E transformers, 223, 246, 247, 428
transmission, 246
Eccentric valves, 292-294 troubleshooting, 234, 237-241
Effects of voltage testing, 225, 227, 428
iron and manganese, 6 volts, 221, 223, 225, 246
trihalomethanes, 119 warning tag, 222
Electric motors, 234-241, 274-276 watts, 224
Electrical equipment Electrical ti; 'ards, 345
additional reading, 247, 248 Electrode tab, 171
alternating current (A.C.), 223 Electrodialysis
ammeter, 227, 228 also see Demineralization
amplitude, 223 and Reverse osmosis
amps, 224 additional reading, 173
auxiliary electrical power, 244, 245 advantages, 163
batteries, 223, 245 arithmetic assignment, 173
beware, 220 brine, 163
blown fuse, 227 cartridge filters, 168, 171
breakers, 224, 230 chemical flush system, 168
circuit breakers, 224, 230 cleaning stacks, 168
circuits, 223, 225 description, 163, 164
conductors, 225 design, 168
control panels, 429 direct current, 165, 166, 168, 171
controls, 282 electrode tab, 171

671
 Index 653

electrodialysis polarity reversal (EDR), 165, 168 Ester, 147

energy requirements, 163 Explosive atmospheres, 432, 433
feedwater quality, 171 Extinguishers, fire, 417-419
flow diagram, 168-170 Eye protection, 433
fouling, 164
Langelier Index, 164 F
log sheet, 172
membranes, 163-168, 173 Falls, injury, 348
multi-compartment units, 165, 167 Feasibility analysis process, 121
operation, 158, 171 Feed rate, chemical, 317-320
piping, 168 Feedback, instrumentation, 344
pH, 171 Feeders, chemical
power supply, 168 see Chemical feeders
pressures, 168 Feedwater
pretreatment, 168 demineralization, 142
principles, 165 electrodialysis, 171
pumping equipment, 168 reverse osmosis, 161
recordkeeping, 172 Federal Register, 119, 129
safety, 171, 173 Ferric chloride, 413
scaling, 164, 171 Ferric sulfate, 413
specifications, 168 Ferrous sulfate, 413
stack, 164, 168, 171 Filter backwash wastewater, 200
stages, 164 Filter, compressor, 287
temperature, 168 Filter presses, 186, 195, 198
Electrodialysis polarity reversal (EDR), 165, 168 Filtration, iron and manganese, 13, 14, 16-20
Electrolyte, 245 Fins, compressors, 288
Electromotive force (E.M.F.), 221 Fire prevention, 417
Electronic chemical pumps, 31, 33, 45 Fire protection
Elements, instrumentation, 363 classification, 417
Emergencies extinguishers, 417-419
administration, 552 flammable storage, 419
phone numbers, 220 hoses, 418
preparation for, 435 prevention, 417
procedures, 220, 552 storage, flammables, 419
safety, 435 First aid
team, 220 equipment, 432
Emergency fluoride, 53
lighting, 245, 246 safety, 395
treatment, 555 Flammable storage, 419
Employee pride, 549 Flanges, pumps, 253
End bells, 234 Floats, level, 349, 352, 353
Endemic, 29
Flow measurement
Energy requirements, electrodialysis, 163 Dall tube, 358
Enforcement, regulations, 509
differential-pressure sensing, 356, 358, 359
Engines
magnetic, 356
air cooled, 311
orifice, 358, 359
cooling systems, 311, 313-315
positive displacement, 356
diesel, 309, 310
propeller meter, 356-358
fuel storage, 315 rate of flow, 356
fuel system, 311-313
rotameter, 355, 356
gasoline, 307
service meters, 356
governor, 311
ultrasonic, 356
lubrication, 307
velocity sensing, 356. 357
maintenance, 307, 311
ventun, 358, 359
operation, diesel, 309
problems, 307 Fluoride, regulations, 503
running, 307 Fluoridation
standby, 316 additional reading, 58
starting, 307-309, 311 air temperatures, 29
alarms, 44
trouoleshooting, 307, 311, 313
water cooled. 311 arithmetic assignment, 58
batch mix, 38
Equipment
calculating doses, 54-58
gas detection, 421
charts, 45-47
lab safety, 431
chemical feeders, 31-42
records, 545
(also see Chemical feeders)
safety, 432
compounds, 29, 30, 53, 413
service card, 218, 219
day tank, 38, 40
Equivalent weight, 72
design review, 42
Establishment, regulations, 498 downflow saturators, 38, 41

.'y
654 Water Treatment

Fluoridation (continued) Gasoline

engines, 307
dust , 53
fuel storage, 315
first aid, fluoride, 53
Gate valves, 289, 29G
fluoride ion, 29
hydrofluosilicic F cid, 29, 30, 42, 43, 45, 49 GF1 (ground fault interrupter), 429
Giardia, 497, 507
importance, 29
Interim Primary Drinking Water Regulations, 29 Glassware, laboratory sr.rety, 429
Globe valves, 292, 305, 306
levels, 29
log sheets, 44, 45, 49-51 Gloves, 434
maintenance, 52
Governor, engines, 311
maximum contaminant level (MCL), 29 Gravirrietric chemical feeders, 31, 36
Greensand, iron and manganese, 14, 16-20
operation, 44
optimum level, 29 Ground, electrical, 231
Ground fault interrupter (G.F.I.), 429
overfeeding, 42, 48
Group 1 and 2 THM treatment techniques, 129
poisoning, fluoride, 53
programs, 29 H
public notification, 48
records, 44, 45, 49-51 Hand protection, 434
safety, 53, 54 Handling of chemicals
safety equipment, 44, 53, 54 see Chemical handling
sanitary defects, 52 Handling proces.. wastes, 179, 18b
saturator, 38, 39, 41, 53 Hard hat, 434
shutdown, 52 Hard water, 70
sodium fluoride, 29, 30, 38 Hardness, 70-72, 75, 76, 505
sodium silicofluoride, 29, 30, 48, 50 Hardness leakage, 101
solution preparation, 45 Hazardous gases, 421
specification review, 42 Hazards
startup, 44 drowning, 434
systems, 30, 37 electrical, 221, 345
training, 54 gases, 421
treatment charts, 45-47 instrumentation, 345-348
underfeeding, 48 laboratory, 429
upflow saturators, 38, 39, 41 maintenance, 420
Fluoride mechanical, 347
compounds, 413 Head protection, 434
ion, 29 Health effects
test procedures, 457 iron and manganese, 6
Flux decline, 146 trihalomethanes, 119
Flux, reverse osmosis, 145, 146 VOCs, 504, 505
Foaming agents, 510 Health regulations, 498, 499
Foot protection, 433 Hartz, 223, 369
Foot valves, 271, 296 History of drinking water laws, 493
Forklifts, 425 Hollow fine fiber, reverse osmosis, 153, 155
Formation of THMs, 119, 123, 124, 126 Horizontal centrifugal pumps, 257
Fouling, electrodialysis, 164 Hoses, fire, 418
Freezing, demineralization, 142, 143 Hot plates, 431
Frequency of sampling, 514, 533 Human factors, safety, 400
Fuel storage Hydrated lime, 76, 406
code requirements, 315 Hydrochloric acid, 403
diesel, 315 Hydrofluoric acrd, 403
gasoline, 315 Hydrofluosilicic e cid, 29, 30, 42, 43, 45, 49, 402, 403
liquid petroleum gas (LPG), 316 Hydrogen sulfide, e,05
natural gas, 316 Hyd-olysis, 147, 150, 157
Fuel systems, engines, 311-313 Hygroscopic, 316
Fueling vehicles, 423 Hypochlorite, 407
Fuse
blown, 227 I
puller, 226
Fuses, 223, 226, 227, 230 mmeuiate threats to health, 499
mmunization, shots, 431
rnpeller, pumps, 249, 251, 258, 259
G ndicators, instruments, 363
nitial sampling, 512
Gas, chemical feeders, 317 norganic chemicals, regulations, 501, 502, 516
Gas-detection equipment, 421 nspection of
Gas masks, 409-411 pumps, 286
Gases tanks, 321
chemical handling, 408 Instrumentation
safety, 408 accuracy, 343
 Index 655
air supply systems, 371, 373 ultrasonic flow sensing, 356
alarms, 367, 368 vaults, 348
analog, 343, 363, 364 velocity sensing, 356, 357
annunciator panels, 367, 368 VOM, 374, 376
automatic controller, 368 Insoluble compounds, 6
bubbler tube, 352, 354 Insulation, motors, 234
calibration, 343, 374 Insulation, res'stance, 229
categories, 363 Insulators, 225
charts, strip and circular, 364-367, 377 Integrator, instrument, 367
chemical feed, 360 Interim Primary Drinking Water Standards
circular chart, 364-367, 377 arsenic, 503
confined spaces, 348 bacteria, 499
control loop, 344 barium, 503
control systems, 342-347, 377 cadmium, 503
controllers, 343-345, 368 chromium, 503
differential pressure sensing, 356, 358, 359 establishment, 498
digital, 343, 363-365 fluoride, 503
electrical equipment, 429 immediate threats to health, 499
electrical hazards, 345 lead, 503
elements, 363 long-term threats to health, 499
feedback, 344 mercury, 503
floats, 349, 352, 353
National Drinking Water Advisory Council, 498
flow, 356-360 nitrate, 499, 517
hazards, 345-348 radioactivity, 507
importance, 342 regulations, 29, 498
indicators, 363 selenium, 503
integrator, 367 silver, 503
laboratory, 374, 375 Internal combustion engines
level sensing, 349, 352-354 see Engines
magnetic flow sensing, 356 Interviews, 550
maintenance, 375, 379, 380 Inventory, 544
measurement, 342, 348, 363, 377 Ion exchange
mechanical hazards, 347 demineralization, 142, 143
motor control station, 345-347 iron and manganese, 11
multi-meter, 374 softeners, 99
"on-off" controls, 368
trihalomethanes, 125, 126
operation, 375, 379 wastes, 200
panel, 343, 363
Ion exchange resin, 11, 125, 126
pH, 360, 361, 374 Ion exchange softening
phone lines, 369, 372
also see Lime-soda ash softening
pneumatic systems, 360, 362, 367, 374, 378 and Softening
precision, 343
air release assembly, 102
pressure sensing, 349-351
backwash, 95, 100
probes, 352, 353
blending, 105
process control, 368 brine, 96-98, 100
proportional control, 368 bypass, 105, 106
pump controllers, 368-371 calculations, 101-105
rate of flow, 356
description of process, 91-94
recorders, 363-367, 377 disposal of spent brine, 98
records, 379
hardness leakage, 101
rotameters, 355, 356, 360
iron and manganese problems, 97, 98, 100
safety, 345, 429 limitations, 72
sensors, 348
maintenance, 99
shutdown, 378, 379 monitoring, 97, 98
signal transmitters, 360 operation, 96, 97
snubber, 349, 351
recordkeeping, 106
standardization, 343 resin, 91, 94, 95
startup, 378, 379 rinse, 96, 97, 100
strip chart, 364, 366, 367, 377 salt solution characteristics, 103
surge protection, 349, 351
sanitary defects, brine storage tanks, 99
symbols, 339-341 service, 95, 96, 100
telemetering, 360, 369, 372 shutdown, 101
testing, 374
split treatment, 105
total flow, 356 startup, 101
totalizers, 365-367 testing, 97
transducers, 057, 360
tro-')Ieshooting, 100
transmitters, 348, 357, 360 wastes, 200
troubleshooting, 376, 378 zeolite, 91
turbidimeter, 360, 361, 374

674
656 Water Treatment

Iron and Manganese glassware, 429

adverse effects, 6 nazards, 429
aeration, 12, 13, 17 hot plates, 431
analysis, 7, 8 immunization, 431
bacteria, 6, 7, 21 pipet washers, 402
bench scale tests, 9, 13, 20 radioactivity, 431
breakpoint chlorination, 14 shots, booster, 431
chlorination, 9-14, 17, 20 sterilizers, 432
collecting samples, 7 water stills, 431
color, 6 Laboratory test procedures
control, 6, 9 algae counts, 449
dechlorination, 13 calcium, 450
dirty water, 6 calcium carbonate stability test, 466
effects, 6 chloride, 451
filtration, 13, 14, 17 color, 453
greensand, 14, 16-20 dissolved oxygen, 454
health effects, 6 fluoride, 457
ion exchange, 11 iron (total), 461
ion exchange problems, 97, 98, 100 manganese, 463
limits, 6 marble test, 466
maintenance, 15, 20 metals, 467
measurement, 6, 20 nitrate, 468
monitoring, 15, 20 odor, 474
need to control, 6 pH, 471
objections, 6 specific conductance, 471
occurrence, 6 sulfate, 472
operation, 16-20 taste and odor, 474
oxidation, 12, 13 total dissolved solids, 479
permanganate, 13, 17-19 thhalomethanes, 479
pH, 12, 17, 19 Lagoons, process wastes, 187
phosphate treatment, 9-11 Landfills, sanitary, 186, 195, 200, 201
polyphosphate treatment, 9-11 Langelier Index, 73, 164
problems, ion exchange, 97, 98, 100 Lead, 503
proprietary processes, 14 Leakage, hardness, 101
red water problems, 21 Lethal dose 50 (LD 50), 554
regulations, 511 Let's Build a Pump, 249
reservoirs, 6 Level controls, 282
samples, 7 Level sensing instruments, 349, 352-354
sludge handling and disposal, 200 Library, maintenance, 218, 220
tastes and odors, 6 Lighting, emergency, 245, 246
troubleshooting, 21 Lime, 76, 82
zeolite, 14 Lime sludge, 200
Iron, regulations, 511 Lime-soda ash softening
Iron (total), test procedures, 461 also see Ion exchange softening
ano Softening
alkalinity, 82
J application of lime, 82
benefits, 75
calculation of dosages, 77, 85-90
Jar tests, softening, 85-90 carbon dioxide, 76, 82
Jogging, 237 caustic soda softening, 77, 81
chemical reactions, 75-77
coagulants, 82
K color removal, 82
handling lime, 82
hardness removal, 76
Kemmerer-type sampler, 457, 458 hydrated lime, 76
Kirk-key, 245 jar tests, 85-90
lime, 76, 82
lime-soda ash softening, 75, 81
L lime softening, 78, 79
limitations, 75
Laboratory instrumentatioi 4, 375 marble test, 83
Laboratory safety National Lime Association, 82
autoclaves, 432 partial lime softening, 78
biological considerations, 431 permanent hardness, 76
booster shots, 431 polyphosphate, 78, 83
chemicals, 431 quicklime, 76, 84
eauipment, 431 recarbonation, 76, 78, 79, 83

61
 Index 657
recordkeeping, 85 manuals, 218
safety, 82, 84 manufacturers, 218
slake, 76, 84 mechanical equipment, 249
sludge, 85, 200 painting, 420
split treatment, 78-81 power tools, 421
stability, 73. 76, 83 preventive, 218
storage of lime, 82 program, 218
supersaturated, 76 pumps, 209, 265
temporary hardness, 76 recordkeeping, 218, 544
Lime softening, 78, 79 records, 218
Limitations reservoirs, 321
ion exchange softening. 72 safety, 420, 423, 424
lime-soda ash softening, 75 service record card, 218, 219
softening, 71, 72, 75 steel tanks, 321
Limits tanks, 321
fluoride, 29 toots, power, 421
iron and manganese, 6 valves, 289, 291, 292, 305
Line organization, 546 vehicles, 423, 424
Linear Alkyl Benzene Sulfonate (LAS), 510 welding, 422
Liquid chemical feerfers, 317 Manholes, 421
Liquid petroleum gas (LPG), 316 Manganese
Location of sampling, 514 also see Iron and manganese
Lock out, safety, 429, 430 aeration, 12, 13
Log sheets limits, 6
electrodialysis, 172 oxidation, 13
fluoride, 44, 45, 49-51 regulations, 511
reverse osmosis, 159, 160 test procedures, 463
Long-term threats to health, 503 Man-made radioactivity, 507
LPG (liquid petroleum gas), 316 Manuals, maintenance, 218
Lubrication Manufacturers, 218
compressors, 288 Marble test, 83, 466
engines, 307 Maximum allowable concentration, (MAC), 554
maintenance, 262-264 Maximum Contaminant Level (M :L) (primary standards)
mechanical equipment, 262-?64 chlorine residual substitution, 503
pumps, 253, 262-264 fluoride, 29, 503
valves, 291 inorganic chemicals, 498, 516
man-made radioactivity, 507
membrane filter, 506
microbiological contaminants, 506
M multiple-tube fermentation, 506
natural radioactivity, 507
organic chemicals, 498
Magnetic flow measurement, 356 radiological contaminants, 507
Magnetic starters, 231-233 regulations, 499, 509
Maintenance trihalomethanes, 119, 498, 526
administration, 544 turbidity, 498
buildings, 321, 322 types, 498
cathodic protection, 321 MBAS, 510
chemical feeders, 20, 52, 316 MCLs, 499
chlorinators, 320, 321 Mass media, 550
cleaning, 420 Measurement
compressors, 287 instrumentation, 342, 348, 363, 377
concrete tanks, 321 iron and manganese, 6, 20
cooling systems, 311, 313-315 safety, 399
cranes, 420 Mechanical equipment
diesel engines, 309, 310 centrifugal pumps, 249
electrical equipment, 220, 274 Let's Build a Pump, 249
engines, 307, 311 lubrication, 262-264
equipment service card, 218, 219 maintenance, 249
fluoridation, 52 pumps, 249
gasoline engines, 307 repair shop, 249
hazards, 420 Mechanical seals, 271
inspection tanks, 321 Megger, 229
instrumentation, 375, 379, 380 Megohm, 229
ion exchange softeners, 99 Membrane filter, 506, 519, 520
iron and manganese, 15 Membranes
library, 218, 220 electrodialysis, 163-168, 173
lubrication, 262-264 reverse osmosis, 142. 145, 146, 161
manholes, 421 Mercury, 503

' k
r q
676
658 Water Treatment

Metals, test procedures, 467 Operation

Metering chemical feeders, 317 chemical feeders, 44
Meters, electrical, 225 diesel engines, 309
Methemoglobinema, 468 electrodialysis, 168, 171
Microbiological contaminants, 506, 519, 521-523 fluoridation, 44
Microbiological organism fouling, 157 greensand, 19
Mineral rejection, 146-148 instrumentation, 375, 379
Mineralized waters, 141 ion exchange softeners, 95, 96
Monitoring iron and manganese, 16-20
ion exchange softening, 97, 98 reverse osmosis, 156-161
iron and manganese, 15, 20 safety, 394, 432
process wastes, 183, 202 valves, 289, 291
regulations, 498 Operator certification, 549
reverse osmosis, 159-161 Operator protection
SWTR, 497 atmospheres, explosive, 432
trihalomethanes, 121, 123, 128 drowning, 434
wastes, 183, 202 equipment, safety, 432
Motor explosive atmospheres, 433
contro: station, 345-347 eye protection, 433
electrical, 223, 234-241, 274, 428 first aid equipment, 432
insulation, 234 foot protecticn, 433
pump, 223-241, 256 gas detection equipment, 421
safety, 428 gloves, 434
starters, 231, 428 hand protection, 434
Multi-compartment units, electrodialysis, 165, 167 hard hat, 434
Multi-meter, 374 hazardous gases, 421
Multiple-tube fermentation, 506, 521 head protection, 434
Muriatic acid, 403 noise, 422
respiratory protection, 409-411, 432, 433
safety, 394, 432
N safety equipment, 432
self-contained breathing apparatus, 409-411, 432, 433
Name plate, 234, 236 traffic, 421
National Drinking Water Advisory Council, 498 water safety, 434
National Electrical Safety Code, 162 Optimum level, fluoride, 9
National Lime Association, 82 Organic chemicals, regulations, 498, 502, 504, 505, 516
Naticnal Secondary Drinking Water C'iagulations Organization procedures, 545, 546
lee Secondary Drinking Water Regulations Orifice flow measurement, 358, 359
National Safety Council, 398 OSHA, 393
Natural gas, 316 Osmosis, 142, '144
Natural r:idioactivity, 507 Overfeeding fluohde, 42, 48
Nessler tubes, 448, 453, 461 Overload relays, 231
Oxidation
Newspapers, 550
Nitrate iron and manganese, 12, 13
tnhalomethanes, 125, 126
regulations, 499, 517
test procedures, 468 Oxygen saturation table, 457
Nitric acid, 405 Ozone, 125, 126, 128, 129
Noise protection, 422
Noisy pump, 283
Non-community water systems, 498, 499 P
Noncarbonate hardness, 76
Notification 515 Packing
NPDES Permit, 98, 183 pumps, 255, 265-269, 272
valves, 291
Painting, 420
0 Panels
control, 429
Objections instrumentation. :343, 363
iron and manganese, 6 Partial lime softening, 78
Occurrence, iron and manganese, 6 Parts, valves, 289
Odor People, 548
regulations, 511 Peristaltic pumps, 31, 32, 45
test procedures, 474 Permanent hardness, 76
Office procedures, 539 Permanganate, potassium
Ohm, 224 handling, 414
Ohm meters, 230 iron and manganese, 13, 17-19
Ohm's Law, 224 safety, 414
Olfactory fatigue, 403 trihalcmethanes, 124, 126, 129
"On -off" controls, 368 PermeEte, 153, 157

677
 Index 659
pH decant, 187
instrumentation, 360, :J61, 374 oewatering of sludges, 184-186, 190
regulat ons, 512 disposal of sludges and brines, 179, 184-186, 195
test procedures, 471 draining tanks, 185, 187, 188
pH, effects on drying beds, 190-193, 200
electrodialysis, 171 filter backwash wastewater, 200
reverse osmosis, 147, 150, 156, 157 filter presses, 186, 195, 198
softening, 73, 74 handling, 179, 165
trihalomethanes, 123 ion exchange wastes, 200
Phase, electrical, 223 iron sludge, 200
Phenols, 513 lagoons, 187
Phone lines, 369, 372 landfills, 186, 195, 200, 201
Phosphate treatment, 9-11 lime sludge, 200
Pipet washers, 432 monitoring, 183, 202
Piston pumps, 257, 259 need for handling and disposal, 183
Planning NPDES Permit, 183
administration, 539 ponds, 187
emergencies, 552 Public Law 92-500, 183
Plant reporting, 202
drainage waters, 202 sand drying beds, 190-193, 200
maintenance, 420 sanitary landfills, 186, 195, 200, 201
tours, 551 sewers, 195, 200
Pneumatic systems, 360, 362, 367, 374, 378 sludge pumps, 202
Pocket comparators, 448 sludge volumes, 184
Po!soning, fluoride, 53 solar lagoons, 187, 190
Pole shader, 237 sources, 183, 184, 4.86
Policy statement, safety, 393, 394 supernatant, 190
Polyphosphate treatment tanks, draining and cleaning, 185
iron and manganese, 9-11 temperature effects, 184
reverse osmosis, 156, 157 thickening, 185, 186
softening, 78, 83 vacuum filters, 186, 195, 199
Ponds, process wastes, 187 vacuum tank truck, 189, 190, 200
Positive displacement flow measurement, 356 volumes of sludges, 184
Positive displacement pumps, 31, 286 wastewater collection systems, 195 200
Potassium permtnganate Water Pollution Control Act, 183
see Permanganate Procurement of materials, 541, 542
Powdered activated carbon, 414 Program, maintenance, 218
Powders, 414 Progressive cavity pumps, 257-261, 273
Power requirements, 225, 283 Propeller meter, 356-358
Power supply, electrodialysis, 168 Propeller pumps, 273
Power tools, 421 Proportional control instrumentation, 368
Precision, instrumentation, 343 Proprietary processes, iron and manganese, 14
Precursors, THM, 119, 123, 124, 126 Protection devices, electrical equipment, 230
Preparation for emergencies, 435 Protective measures. water supply, 554
Pressure sensing inst-mentation, 349-351 Prussian blue, 291
Pressures, elef;trodialysis, 168 Public Law 92-500, 183
Pretreatment Public notification, fluoride, 48
electrodialysis, 168 Public relations, 549
reverse osmosis, 156 Public speaking, 550
Prevention of fires, 417 Pumping equipment electrodialysis, 168
Preventive maintenance, 218, 265 Pump controllers, instrumentation, 368-371
Pride, employee, 549 Pump maintenance
Primary standards, 498, 501 alignment, 271, 278-280
a!so see Interim Primary Standards bearings, 271, 273
Prime, pumps, 282, 284 belt drives, 274, 277
Probes, instrumentation, 352, 353 chain drives, 277
Process control instrumentation, 368 chock valves, 271, 273, 296-305
Process variable, 343 controls, 273
Process wastes couplings, 278-280
alum sludge, 200 dial indicators, 280, 281
backwash recovery ponds, 187 electric motors, 234-241, 274-276
backwash wastewater, 200 foot valves, 271, 296
belt 1,Iter presses, 186, 191, 194 mechanical seals, 271
brine, 184, 185, 195, 200 packing, 265-269, 272
centrifuges, 186, 191, 195-197 preventive maintenance, 265
cleaning tanks, 185, 187 progressive cavity pumps, 273
collectiot. of sludges, 184 propeller pumps, 273
collection systems, 195, 200 reciprocating pumps, 272
concentration, 186 shear pin, 272, 280
conditioning, 185 shutdown, 271

678
660 Water Treatment

Pump maintenance (continued) Rei:ordkeeping

variable speed belt drives, 278 electrical equip:nent 236, 242, 243
wearing rings, 271 electrodiatysis, 172
Pump operation equipment, 545
centrifugal pumps, 284, 285 fluoridation, 44, 45, 49-51
discharge, 283 ir strumentation, 379
driving equipment 282 inventory, 544
electrical controls, 282 ion exchange softening, 106
inspection, 286 lime-soda ash softening, 85
level controls, 282 maintenance, 218, 544
noisy pump, 283 plant, 543-545
positive displacement pumps, 31, 286 process wastes, 202
power requirements, 283 reverse osmosis, 159, 160
prime, 282, 284 softening, 85
rotation, 282 Recovery, reverse osmosis, 151, 161
shutdown, 282, 284, 286 Red water problems, 21
starting, 282-286 Regulations, drinking water
troubleshooting, 283 arsenic, 503
Pumping equipment, electrodialysis, 168 bacteria, 499
Pumps barium, 503
alignment, 253, 271, 278-280 cadmium, 503
bearings, 253, 258, 259, 271, 273 check sampling, 513
casing, 254, 258, 259 chloride, 509
cavitation, 256, 257 chlorine residual substitution, 506, 523
centrifugal pumps, 249-257, 284, 285 chromium, 503
chemical metering, 258 culiforms, 498, 533
couplings, 253, 278-280 color, 509
displacement, 250 community water systems, 499
dynamic types, 250 copper, 510
flanges, 253 corrosivity, 510
horizontal centrifugal pumps, 257 establishment, 498
impeller, 249, 251, 258, 259 filtration, 497
Let's Build a Pump, 249 fluoride, 503
lubrication, 253, 262-264 foaming agents, 510
maintenance health, 498, 499
see Pump maintenance immediate threats to health, 499
motors, 223-241, 256 initial sampling, 513
packing, 255, 265-270, 272 inorganic chemicals, 498, 519
piston type, 257, 252 Interim Primary Drinking Water Standards, 498
progressive cavity, 257-261, 273 iron, 511
reciprocating, 257, 259, 272 lead, 303
rings, wearing, 254-256 long-term threats to health, 498, 499
screw flow, 257-261 macimum contaminant levels, 498-509
seal, 255 MC:Ls, 499
shaft, 251, 253, 258, 259 membrane filter, 506, 519, 520
sleeves, 251, 253, 258, 259 mercury, 503
stuffing boxes, 255 microbiological contaminants, 506, 519, 521-523
suction, 253, 254, 256 monitoring, 497
vertical centrifugal pumps, 257-259 multiple-tube fermentation, 506, 521
wearing rings, 254-256 National Drinking Water Advisory Council, 498
Purchase order, 541, 5A2 natural radioactivity, 507
nitrate, 499, 517
non-community water systems, 499
0 notification, 515
odor, 511
Quicklime, 76, 84, 406 organic chemicals, 498, 516
pH, 512
primary standards, 498
R
radioactivity, 507
radiological contaminants, 507, 524, 525
Radio, 550 regulations, 513
Radioactivity, 431, 507 reporting procedures, 515-526
Radiological contaminants, 507, 524, 525 required sampling, 514
Rate of flow instrumentation, 356 routine sampling, 513
Rates, water, 542 Safe Drinking Water Act, 513
Recarbonation 76, 78, 79, 83 sampling points, 514
Reciprocating pumps, 257, 259, 272 sampling procedures, 513-515
Recognition, employee, 549 Secondary Drinking Water Regulations, 509-515
Recorders, instrument3, 363-367, 377 selenium, 503

679
 Index 661

short-term exposure, 499 Rinse, ion exchange softening, 96, 97, 100
silver, 503 Rotameter, 355-356, 360
solvents, 498 Rotation of pump operation, 282
standards 498 Rotor, 234
sulfate, 512 Route, sampling, 515
total dissolved solids (TDS), 512 Routine sampling, 513
trihalomethanes, 498, 526
turbidity, 498, 518, 519
zinc, 512
Regulatory agencies, safety, 393 S
Rejection, mineral, 146
Repair shop, 249
Reporting procedures, 515-526 Safe Drinking Water Act, 493, 494, 513
Reporting, safety, 395-397, 435, 436 Safety
Reporting, waste disposal, 202 accident prevention, 425
Representative sample, 121 accident reports, 395-397, 435, 436
Required sampling, 514 acetic acid (glacial), 402
Reservoirs, 6. 321 acids, 402
Resin, ion exchange, 91, 94, 95, 125 activated carbon, 414
Respiratory protection, 409-411, 432, 433 additional reading, 437
Responsibilities, safety, 393, 394 alum, 413
Reverse osmosis (RO) aluminum sulfate, 413
also see Demineralization ammonia, 406
and Electrodialysis atmospheres, explosive, 432
acid feed system, 157 autoclaves, 432
additional reading, 173 bases, 405
alarms, 157 biological considerations, 431
arithmetic assignment, 173 booster shots, 431
brine, 157, 161 calcium hydroxide, 406
calculations, 146, 147, 151 carbon dioxide, 410
cartridge filters, *.57 caustic soda, 407
chlorination, 157 chemical handling, 402, 431
"Christmas Tree" arrangement, 151, 152 chemical storage drains, 415
cleaning membrane, 161 chemicals, laboratory, 431
colloids, 156 chlorine, 408
concentration polarization, 151 Chlorine Manual, 410
definition, 142 class'fication, fires, 417
feed, 161 cleaning, 420
flow diagram, 158 control panels, 429
flux, 145, 146 costs, 399
flux decline, 146 cranes, 420
hollow fine fiber, 153, 155 current, 428
hydrolysis, 147, 150, 157 drains, 415
layout, 158 drowning, 434
leg sheet, 159, 160 electrical equipment, 22-., 247, 426
membrane, 142, 145, 146, 161 electrodialysis, 171, 173
microbiological organisms, 157 emergencies, 435
mineral rejection, 146-148 equipment, 432
monitoring, 159-161 explosive atmospheres. 432, 433
operation, 156-161 extinguishers, fire, 417-419
osmosis, 142, 144 eye protection, 433
permeate, 153, 157 ferric chloride, 413
pH effects, 147, 150, 156, 157 ferric sulfate, 413
polyphosphate treatment, 156, 157 ferrous sulfate, 413
pretreatment, 156 fire protection, 417
recordkeeping, 159, 160 first aid, 395
recovery, 151, 161 flammable storage, 419
rejectior, mineral, 146 fluoridation, 53, 54
safety, 162 fluoride compounds, 413
sealants, 156 foot protection, 433
spiral wound, 153, 154 forklifts, 425
suspended solids, 156 fueling vehicles, 423
temperature effects, 147, 149, 150, 156 gas detection equipment. 421
threshold treatment, 156 gas masks, 409-411
troubleshooting, 161 gases, 408
tubular, 153 glassware, 429
turbidity, 156 gloves, 434
types of plants, 153 hand protection, 434
Rings, wearing, 254-256 handling chemicals, 402

680
62 Water Treatment

Safety (continued) transformers, 428

hard hat, 434 underwater inspection, 435
hazardous gases, 421 unsafe acts, 394
hazards, laboratory, 429 utilities, 393
hazards, maintenance, 420 valves, 422
head protection, 434 iehicles, 423
hot plates, 431 voltage, 428
human factors, 400 water, 434
hydrated lime, 406 water, stills, 431
hydrochloric acid, 403 welding, 422
hydrofk oric acid, 403 Safety check, vehicles, 423, 424
hydrofluosilicic vid, 403 Safety equipment
hypochlorite. 407 fluoridation, 44, 53, 54
immunization. 431 operator protection, 432
instrumentation, 345, 429 shower, 403, 404
laboratory, 429-431 Safety shower, 403, 404
lime-soda ash softening, 82, 84 Salinity, 142
lock out, 429, 430 Salt solution characteristics, 103
maintenance, 420, 423, 424 Salts
manholes, 421 handling, 412
measuring, 399 safety, 412
motors, 428 Sampling
muriatic acid, 403 iron and manganese, 7
National Safety Council, 398 points, 514
nitric acid, 405 trihalomethanes, 121. 122
noise, 422 Sampling procedures
operator, 394, 432 check sampling, 513
OSHA, 393 collection, 515
painting, 420 frequer.cy, 514, 533
panels, control, 429 how often, 514
pipet washers, 432 initial sampling, 513
plant maintenance, 420 location, 514
policy statement, 393, 394 number of samples, coliform, 533
potassium permanganate, 414 required sampling, 514
powdered activated carbon, 414 route, 515
powders, 414 routine sampling, 513
power tools, 421
Safe Drinking Water Regulations, 513
quicklime, 406 sampling points, 514
radioactivity, 431 schedule, 515
regulatory agencies, 393 Sand drying beds, 190-193, 200
reporting, 395-397, 435, 436 Sanitary defects
respiratory protection, 409-411, 432, 433 brine storage tanks, 99
responsibilities, 393, 394 fluoridation, 52
reverse osmosis, 162 Sanitary landfills, 186, 195, 200, 201
safety check, vehicles, 423, 424 Saturators, fluoridation, 38, 39, 41, 53
safety shower, 403, 404
salts, 412 Scaling
seat belts, 423 electrodialysis, 164, 171
self-contained breathing apparatus, 409-411, 432, 433 reverse osmosis, 156
shots, booster, 431 Schedule
shower, safety, 403, 404 compliance, 496
sodium aluminate, 413 sampling, 515
sod!um carbonate, 408 Screw flow pumps, 257-261
sodium hydroxide. 407 Sea water, 142
sodium silicate, 407 Seal, pump, 255
softening, 82, 84 Seat belts, 423
standard operating procedures (SOP), 395, 429, 430, 432 Seats, valves, 291
starters, 428 Secondary Drinking Water Regulations
sterilizers, 432 chloride, 509
stills, water, 431 color, 510
storage, chemicals, 415 copper, 510
storage, flammables, 419 corrosivity, 510
sulfur dioxide, 412 enforcement, 508
sulfuric acid, 405 foamir ' agents, 510
supervisors, 394 hardness, 513
tailgate training, 398 hydrogen sulfide, 513
tools, power, 421 iron, 511
traffic, 421 iron and manganese, 511
training. 398

681
 Index 663
manganese, 511 stability, 73, 76, 83
maximum contaminant levels (MCLs), 508, 509 temporary hardness, 76
monitoring, 509 total hPi-dness, 71
odor, 511 zeolite, 91
oft 512 Solar lagoons, 187, 190
phenols, 513 Solid chemical reeders, 317
sulfate, 512 Solution feed: .s, 31, 37
total dissolved solids (TDS), 512 Solution p.-cparation, fluoridation, 45
zinc, 512 Solvents, 498
Selenium, 503 Specific conductance test procedures, 471
Self-contained breathing apparatus, 409- 411,,432, 433 Specification rev;ew
Sensoi s, instrimenta 348 electrodialysis, 168
Service, ion exchange softeners, 95, 96, 100 fluoridation, 42
Service meters, 356 Spectrophotometer
Service record card, 218, 219 absorbance, 448
Sewers, 195, 200 calibration, 448
Shaft, pump, 251, 253, 258, 259 description, 448
Shear pin, 272, 280 percent transmittance, 448
Short-term exposure, 499 standards, 449
Shots, booster, 431 transmittance, 448
Shower, safety, 403, 404 units, 448
Shutdown Spiral wound membrane, 153, 154
chemical feeders, 52 Split treatment
fluoridation, 52 on exchange softening, 105
instrumentation, 378, 379 lime-soda ash softening, 78-81
ion exchange softeners, 101 Stability, water, 73, 76, 83
pumps, 271, 282, 284, 286 Stack, electrodialysis, 164, 198, 171
Signal transmitters, 360 Staff, 546
Silver, 503 Staffing, 547, 548
Slake, 76, 84 Stages, electrodialysis, 164
Sleeves, pump, 251, 253, 258, 259 Standard deviation, 477
Sludge pumps, 202 Standard operating procedures (SOP), 395, 429, 430, 432
Sludge, softening, 85 Standardization, instrumentation, 343
Sludge volumes, 184 Standards, drinking water, 498, 499, 501, 505
Snubber, 349-351 Standby engines, 316
Sodium Standby power generation, 244, 245
aluminate, 413 Starters, electrical, 231, 428
carbonate, 408 Startup
fluoride, 29, 30, 38 chemical feeners, 44
hydroxide, 407 engines, 307-309, 311
silicate, 407 fluoridation, 44
silicofluoride, 29, 30, 48, 50 instrumentation, 378, 379
Softening ion exchange softeners, 101
also see Ion exchange softening pumps, 282-286
and Lime-soda ash softening Stator, 234
additional reading, 106 Steel tanks, 321
alkalinity, 71, 73, 74, 82 Sterilizers, 432
arithmetic assignment, 106 Stethoscope, 274
basic methods, 75 Stills, water, 4C1
benefits, 71, 75 Storage of
calcium carbonate equivalent, 71, 72 chemicals, 316, 415
carbonate hardness, 71 flammables, 419
chemical reactions, 75-77 fuel, 315, 316
chemistry, 72 lime, 82
hard water, 70 safety, 415
hardness, 70-72, 75, 76 Strip chart, 364, 036, 367, 377
importance, 71 Stuffing boxes, pumps, 255
ion exchange softening, 91 Suction, pumps, 253, 254, 256
Al tests, 85-90 Sulfate
Langelier Index, 73 regulations, 512
lime-soda ash softening, 75, 81 test procedures, 472
limitations, 71, 72, 75 Sulfur dioxide, 412
need, 71 Sulfuric acid, 405
noncarbonate hardness, 76 Supernatant, 190
permanent hardness, 76 Supersaturated, 76
pH, 73, 74 Supervision, 547
recordkeeping, 85 Supervisors, safety, 394
safety, 82, 84 Surface Water Treatment Rule (SWTR), 496-498
sludge, 85 Surfactant, 510
682
664 Water Treatment

Switch gear, e:ectrical, 230, 246 disinfection alternatives, 128

Switches, electrical, 223 existing treatment processes, 124
Symbols, instrumentation, 339-341 feasibility analysis process, 121
Synthetic resins, 125, 126 Federal Register, 119, 129
formation, 119, 123, 124, 126
I Group 1 a.id 2 treatment techniques, 129
health effects, 119
ion exchange resins, 125, 126
Tag, warning, 222 maximum contaminant level (MCL), 119
Tailgate training, 398 monitoring, 121, 123, 128
Tanks options for control, 124
draining and cleaning, 185 oxidation, 125, 126
steel, maintenance, 321 ozone, 125, 126, 128, 129
Taste rating scale, 476 pH, THM formation, 123
Tastes and odors potassium permanganate, 124, 126, 129
iron and manganese, 6 precursors, THM, 119, 123, 124, 126
test procedures, 474 problem, 119
Telemetering, instrumentation, 360, 369, 372 regulations, 498, 526
Television, 550 resins, synthetic, 125
Temperature effects sampling, 121, 122
electrodialysis, 168 sources of water, 124
process wastes, 184 synthetic resins, 125, 126
reverse osmosis, i 47, 149, 150, 156 temperature, THM formation, 123
THM formation, 123 test procedures, 479
Temporary hardness, 76 ultraviolet light, 125
Test procedures variance, 129
see Laboratory test procedures Troubleshooting
Testers, electrical, 225 electrical equipment, 234, 237-241
Testing, instrumentation, 374 engines, 307, 311, 313
Testing ion exchanoe softeners, 97 instrumentation, 376 -378
Thermal overloads, 231 ion exchange softeners, 100
Thickening wastes, 185, 186 iron and manganese, 21
Threshold Odor Number (TON), 474, 511 pumps, 283
Threshold treatment, 156 reverse osmosis, 161
Titrate, 72 Tubular membranes, 1C3
TON (Threshold Odor Number), 474, 511 Turbidimeter, 360, 361, 374
Tools, power, 421 Turbidity regulations, 497, 498, 505, 518, 519
Total dissolved solids (TDS), 141, 479, 512
Total flow, instrumentation, 356
U
Total hardness, 71
Totalizers, instrumentation, 365-367
Ultrasonic flow measurement, 356
Tours, plant, 551
Ultraviolet light, 125
Toxicity, 553
Underfeeding, fluoridation, 48
Traffic, 421
Underwater inspection, 425
Training
Unloader, compressor, 288
administration, 548
Unsafe acts, 394
fluoridation, 54
Upflow satin ato(s, 38, 39, 41
safety, 398
Utilities, safety, 393
Transducers, 357, 360
Transformers, 223, 246. 247, 428
Transmission, electrical, 246 V
Transmitters, 348, 357, 360
"Travelers" diarrhea, 499 Vacuum filters, 1 EsG, 195, 199
1 l'eatment charts, fluoridation, 45-47 Vacuum tank truck, 189, 190, 200
Treatment, emergency, 555 Valves
Trihalomethanes automatic, 305
activated carbon, 125, 126, 129 butterfly, 292, 295
additional reading, 130 check, 271, 273 296-305
adsorption, 125, 126 compressor. 289
aeration, 124-127, 129 diaphragm operated, 305, 306
arithmetil assignment, 130 ecce.itric, 292-294
bench-scale studies, 124, 126, 128 foot, 271, 296
bromide, 119, 123, 124 gate, 289, 290
calculations, 122 globe, 292, 305, 306
chemical reactions, 119, 123 lubrication, 291
chloramines, 128, 129 maintenance, 289, 291, 2(12, 305
operation, 289, 291
chlorine, 119, 123, 124, 126, 129
packing, 291
coagulatior/sedimentation/filtration, 124, 126, 129
parts, 289
control strategies, 124

683
 Index 665
safety, 422 VOM, 374, 376
seats, 291
types, 297 W
use, 289, 296
wafer check valve, 296, 297, 302 Wafer check valve, 296, 297, 302
Variable speed belt drives, 278 Warning tag, 222
Variance, THM, 129 Wastewater collection sy3tems, 195, 200
Vaults, instrumentation, 348 Water
Vehicles cooled engines, 311
accident prevention, ?25 hammer, 284
forkufts, 425. 426 Pollution Control Act, 183
fur! -.; 421 rates, 542
mar lance, 423, 424 safety, 434
operation, 423 stills, 431
safety check, 423, 424 Watts, 224
seat belts, 423 Wearing rings, pumps, 271
types, 423 Welding, 422
Velocity sensing flow measurement, 356, 357 Wilson's disease 502
Venturi, 358, 359
Vertical centrifugal pumps, 257-259 Z
Viscosity, 262
Volatile, 125 Zeolle
Volatile organic chemicals, 504 iron and manganese, 14
Voltage testing, 225, 221, 428 softening, 91
Volts, 221, 223, 225, 246 Zinc, 504
Volumes of sludges, 184
Volumetric feeders, 31, 34, 35, 37

684
 p A A I

MOSAIC MOW.

MR Alt INORGANIC REPORT RESULTS TVITHM1111 LIA TS AfTER /OR All /OR All ION Alt
BARIUM TRIP% CONTAMINANTS OSTICE CO...MN/NOP TEST O. WHIM INORGANIC ...ORGANIC INORGANIC
IA) MOIST It OATS IMMO TIM CONTAINTTTTT CONTAmMTS
AN CONTAIN..
TTTTT LISTED
MONTH IN MINCH TIM RISUtTIS
5URIACIW REWIND !EMT NITRATE laCIPT NITRATE ERUPT
TZAR II ANT CONUMIN,T
UNIT M OATS ICHLOWING ENO O/
CACMUI S m mon TIM NUOUMI0 MONITOIONG MEWS Vol mCl
TIES MUST St OE NOT.T Naomi I
P511100 VINICHIVER IS SHOOTER
P ORTED TO TN( OATS. mCl IS MIME WHEN TOO AVER
GROUNOWATE RS WITT. I OuS AND ANTI HOME OHO, AGE OI THE OMG
T AOODIONAL SAMPIRIG MAL AND THOU
CHROMIUM 1101.44. MONIES IC AL 00 ADDITIONAL
CHICK URINES) CNICR SAMPLES
MUSTS! *110 YLMO& THE
IN ONE MONTH WHEN THE TTTTT GE DI act THE PUS
THE MO (IC MUST In NO
1moll ADDITIONAL TINTO
ICAO ael ms4. CHIC. SAm ES SIR.
MEWS,. MCL
THIS WIT I RE
FORIELITO THE TTTTT

INORGANIC MERCURT 110102 mo/t

CHEMICALS

Ill EPROM

SOLVER

SODIUM

TOR NI
DONT
MOUNDS
IOW NI TTTTT
PO1NOOATl ONE T w,,I It TOO Av.R
ONLY AGE OI THE 00
M TH4 GE Of NM GOAT AND TOO
to TTTTT LAS NI MEIN VIM COWEN ORIGINAL MO C.C1( SAMPLE
TRAM.. I [MOE Tot CITICR SALMI MOWS THE
TIEING( CHIC. MEWS Tot MCI WE Tot PUS
SAMPLE MUST et REIM TO THE TTTTT lIC MUST OE NO
CMORMATIO THINK HAS wINNN MI ORS
NTOROCARSONS PISMIRES
!KIRIN

LINOANE ANT CONTAMINANT WHEN TIM AAAAA 01 DI VININ THE EMIR

I ECIEOING MCI THE ORIGINM. AND AGE Of TM 001
THOITCML OA MUST II 1EPORVE0 TO TIM!! 001T10 NAL faNAl AND
!TAT! WITHIN I OATS CHIC. 310PLE S STU IOOITIONAI
TORAPHINE REPORT RESULTS MaNNI 15 OATS AND TOM AOOITIONAL !ECM. THE MCI ColC UNINIS
COSMETIC/10 OR WITIUN ICNICR, &MMUS TO Mod MUST in HE MT MEWS
SUMAC( MATERS tV TINS IA) EMIT M OATS POLIO WING THE MONTH In TARN WITHIN 0141 FORTIORI TIM TIN MC. THE
CHLOROMENOVTIMEM/CIDES IN WHICH THE RESULT IS PICINI° LIGON. WI MIN NI !IRS PuntC MUST RE
OPTION NONNI
III MST II OATS I011 OWING ENO OP
a ..s.a matt; /OR GROUND. THE RIMMED MONITONING
LAD PI1100 WHICHEVER IS 51101110

VOLATILE 0.014 CMILOCAL1

UNTO. II MS NO.
CANON TETRACHLORIDE 11.6 /not
OKOLOACNINIENI OM mot WIMP CPC( OON
!EC(DSYCL CH(CK WITIN MIRAGE OF ORAA,
12 IN0T0001tHANE tees mot EVERT V MANS OHO. NM SAMPLES MUST II T/ON sm.tts RcHos MCL THE
OBTAINED OuARVIOU MANIC (RUSTS[ HOTWIE
11 MCMOROITHYLEME SOT mot
1 1 I TO/Cl. DAMMAM( it rem.
TRKIROAOLIMUNI OM mot
VWYI 011.011.011 SECO NIL
TOTAL TIONALOMEVIMNIS RNA

R (FOOT RE SEMIS MINN II TUTS TTTTT

COMPUTKIN OP TEST OR WIN.
TOTAL AT Rod 1UNMMD ANNUAL AAAAA GE Or
(A) NM MOATS IMMO.° TOT
TOIMMOMETIMMES 11111.44. OWNER, T CMTOMNATE SUMAC( MOURN M MINGO 11,1 MUM. IS O NE CHICK SAM.. 10 AVERAGE !EMI:11NC. ANT IT MD WINCH
MD GOOUNMATIOS RECEIVED COWAN REIM S Oh IMOLAI TO MEE OS MCI
ntoucto mONITEINNG wO ION 45 NOS WO NO
IS) MOST Is RATS /OIL ARNO INA Or SAMPI NN 0.01111101 Puelt
TIM Agnomen .01.1 DOING
 IUIAO411II(IAI((A0(fl TU
0(00MT Y((UtT(*ITIOI1 IIOAII AITtO
0t'IOO 01 t(T 00 OIT001 0 * TU00.0,l IAOPU
*41000001*1011
00*1 HOT IOTttt(0( 0,01 Al OAlltOtt00010 Tilt
(III! II ACt 0(0 TonAl
flJ.SiOITy 0101ittCTIOlA lAMPS IAOI01051AT(OAS( 0(4 VU 00
T11000ITT I
.AC*nt iuMAct IA011TOII110ICH lIlt OtlulT IS *10010 10$
SAD*,I 0*4*0100 ttttCTllt *ATtOI 041(0 tCt1Mt0 w COtCK 141A( OAT '1(01St 0(1 TUIN IltICttOtO Tot
C47OtIIOOAL COOT100AS TOt lACE IS t*CttOtO ((TOOT TO TOO (TATt n,IIIC Suflit
* ACTt040L001CAL TtItIp (30(0%, 1101o%(0000'01445011007 (IC((o(o ((00*710 Wl1I$(AAI111(
TOO Ot0014tOIAOTIIT000AO 3011(100
001TU AVG (10 IC0111tCUTIYT TOO ITATt WITI101AI 4*1
00000 *400000(0.110000(0

IA0000AOt Pl(TtO Tot ToTAS 0000000(11000(1

COII1001A SHAlL HOT tlCttOI MOlT It (01(00(0
000 00310 00001 POY011TION ST T100003000I101 S0010105 7*100
((0 .000(000 TIlt OVtOASt 01 TAut (00 tIAlArtt ' ,OAIHAI1001(T(0
OtOATIlt CHtCO If (bOOSt (AAftIt tICttO(
Ott SOOTHLY (*0015(1 00*0(0
(4001(1
*
0(0 IIIilL IHTT,ATt AT ((AlT I
*
it o, sot 0 tgcttoto THt
0000040 SOOt T0AI1 Wet (Aunt soiboos (TATt SlflT$0TIOTOItOIIHO(
It (((1 THAII it r*o*nto co C0li(tCUTOt 001(1 COtCO M o, coico i*unt co.nson It AlIT MCLII
,iuuot, e' PttOt001A(*St (AIA0011i500WT tICttOtO
(tcTtono SOOTH OS * '10 000 P0000ATIOI1 (AIAt( 0(0 VI1010CtOTAOI COIItCT A001T100A( (AIAP(($
oil Pont t cot.coot* It Vol *11*
uoot THA.i,. ot (ASflt$
II III 1(00(0 001tTOTT1I(TATI*ITOI*AAIIIO( (IC 1*1.1ST St OiOTIfItO
soon. COI101T1011( * DAIlY 00 Al 0,ltCTtO IT Tot
T,YO00000nAon.ntu00110 *too , %T%TO1AT10100 NINTH UI0IO II (01%I0000I%OC
(10000TH ,11lI.,TA0 .100(11(0 tOStNTAT,00TUIt
UTIOtOAII.TCIA(C300tt000400
_____________________________________ 100111*00 3 0*000(10*1 (((3 ToOl I 0(0 I(C..( It ANT tACt 00 ticttoto Tot
tto,tOTAT1011 Tout - II ilL tICL001 001 (TATtMIflIStHOTI1100IIOAIO(
IOATION
AOLOGACAI, C01000IAS..CTtOLA C0lI101IA( 1000( NOT St 00(1 T 000ITIOt WAIl CHICO (AUnt C0.itIOIA(
I2000P000011 o.u*o*o*t 0000lit (004* ttOIAtI1TATI010 TOOt -0000000 TOt P0t(t.iCt Ut COII000IA It
C001AU110$TS (lIT MONt TOAI1 (1.07000 CA(CI.I$ATIOO(
TI031 (10 IAOIOIH NOT 0*001 TIOWI PONTTOTOOTAI(*ITOOU000
TOLlS (AMPOt SAT 0*0(100 04 * (IliGIt (AAlttt 001ATAPN( 000(10 NOTICt 00(0
C11500lOt Ot$IQTJA( (bI8(T4TU cOo100s 40) 00 (lOOt 000
*0.0 000TIQIi( P0(ITOt *0(11 T100 01000TOt(U(T(1111IIN 010*11 AITtO HOT APPLY TOOt(,
ltflTOANlI$ASY$t( A0((005 $TAT( AYOIOYO( C04i*ttTIO3001 T((T 0101ITOO.
000TIO1ANUUTIA?tCY(C0(AIAPO COOT COt000it
.0(0000 MONTH 00 IllS Al A101t *110 COI1TIWUI C111000it (((bOAt (lJl(TITU 005100AL (bOOt (III
T(. Ot TOt 0(00,0(0 (010 UI1TIL AT ((AlT
HOT MOOt THA.IIII. OflASP%t( A (lIT 00 OAI((OttO*YlG Toot I CO0(tCUTIYI TOOl 0(3,0000 ISNOTA
tOIIATt(T$IAAIOtSUI$T.TUTtO OAI(VCO(C0 (A001t((00000 OttICItIiTOt(100AL 41(00
0*10*1(3011*0H1 000TIOO( (00 tACH COI0000 Tt(T TO MONT1AIO 40 KTHIOt(ULTI( II
IAAII*AUIACOI1TAUI.
00(0(401*0110030000000*10 St 3011011UTtO A CA (((OVAL
OtCtOV (0051TIY( TIJItH 1110(0 ((TOOT T0(TATt*bTObO
*1000*00 C0$LtCT (004(00'
lOOT ((Itt
ttt(OAt tIAIINtOPtOtAQIilO Tt$T((IJ(TItC0300CTtO OUT 01,1011 ,00AT((Ott010ASt000( IACTtOIA (Aunt *1T010A H',
AT ((AlT IC)0 TtST 0100*, Tilt 0(0000(0 1001TO*IAi$ 'If 10000 ((PONT SACItO,At Ot(bJtT( TO
(Hoot 000T100(AOt 0*1(0 Ott SITSIIUM (Ott (t30005 IOATIOH( *0(01(0
01 010000 *10011(0(0 IS(001TtO OtSOtATIOH$ PASO INTl $TATt WITHIN Al 0*0 0? COlA
OtGOIAT100( PASt (INTl 0*( ntT100 Ot *005*141
MHT000 000

t:C?A0((ocltTot0TtOT(O* $TAT( OPTION

703
(0(00* TtAO( ,COun.Aoct *UtOtOtAO*0AltOAGt tACt 540lAltlCttO$
RA0101.001CM. 1(11.1*1 tICttOS 3.0' t *,T,I tACO lASSO 00 0,10001 St TIlt tACO T411PT,IS
COHONMIOS TIlT 00*0.103 IIOAII444II10010 11*00715(141 0 1(011010 11Th 0*0.1ST $0 01
AOALT(l(Ot (OLIN COO(tCUIII( OtCtIYtO 000TtO to Tot ((Alt *ITOOI (IC U(T lit
1*00*01 0.111.01111 SPOt OIlAOltO(l
Ill (lIT II OAT( tOIL011,iSt000t 001
000((OtTAAC011111 CAAH1AAIIt 000000 ACC(PT
TOO 0(01.100(0 IIOOIIT005 (TATt QPTIOII
ST000THN* (C 010400 WHICIIOOtO 0(00*1(0 AlIt TO Tilt (TATI
(T000TH)1A10 ItO(

Ot007T Ot(U(T(*IT1AI,i II OAT( At 0(0

C0I*fltIl000t Tt(T 004010110 T 00
40AGANIC IT I I
" 0 I 40 o * oc
00100 C 151115
0
$104'
(11
CHEMICALS 00(00 0 00 0 05
0(000*1(0
U 0(0 MOOt It (00(0 WITHI,i IA 001 (lCttO( 'Cl tACt Ot000T TO 70* POetIC (01(00
COIIKT,OAI(*OtH(,iOAOltO(t 'II (lIlt II OAI(t0tt01010 (0(0 Ot Tot $TAT( *bTObO 400*11 NOIItIOOAAA

II (000TtO
01000 *IOlC011t'i TO TOO (TATt

L
(TATt 0?ThOIi

A ITU AOHT001 AItOASt vu OtP011 OtOUtT( *,THIO IIOAI( AtTtO

IAOAIIOTAO(OAS( MAY *000, AT COMPStT100 Of ((IT 00 *IT010
(TATtOPTION 000,00(0 IT 00(1 Ito I003101TT 000(tIII011001 IJ5100TM000OCNS0IA01110001. 00000*001001
TUB110100 TI010IOIVT 0
(AtAOSt (O*tACt I I (NIT 00 OAI( 001t0115G UI COtCO (Aunt *ITI(,iIHO If COIA(t Ali AItOA St If Tot AV(OASI 0(1 T004
4011* * II.
OIl 0010 00 01 0 000 01
$ ohl
* IAAINTtNOIACt001tItCTIOtCI1
O($IOOAL ((ATt 111I?IiAIIIO( to O(POOTTOTH( OTATt*IT010 T04005LIC IAUSTSI
III (lIlT II OAT( tO$t010ISt0000 *1001
3 SCCTt010105ICAL Tt(T(4 Tot OtOUIOt0004lIT00003 *011(1(0011*
0* 0(101(0 ACC(PTAI(0
P0*100 *1115(11(0 II 3000TIO
II (TUAIO OIICOII(tCUTblt ¶0107 11110

M(TAWIAAN0(T(O tfltASOA,ittI(TtO
C00000IAIIIA0LNOTtICItV .PtOlI415(Q0 It A IlliCIt (AUnt tICt(O( A
TIS *000*0000 Ott (01111*0 oLlnti 0* (tO 00(004 lIiIT,ATt AT ((AlT I
*0(0 TW 0011 MOV T00$ 000(40405(04 COIi(tCUTIYt 0*1(1 COtCO (AlA IAHIA3011II 7*100 4* ANT OCt IN
(((1 THAN 00 IAtAflt$ COLLtCTtO PAN .tt(tOOtAlAtAt(A P50410001ST t AMY tACt II IlCttOtO Tot tICttOtO Tot 01.10
COO 0*CAIAC 00010111 004000 10001,1104000 THOS3000 COSUCT A001TIOIiAI $AIAP(t( (TATt SUIT St IAOTIYItO 111*1 LICIAU(T ItOOT0ltO
BIOLOGICAL I

000PLt( 00*00 MOOt 54tt$ (000040 AIAAI1OtOACCtP

OtoOlTpt(US7(*IT010 ii on At TtO OAIST 00 Al OIYtCTtO IT Tot
COf4OAAIINA,110 .100011*141 COUtTICIIAOt Tt(T 4)0 *lTloO STATI 01011 ATLtA(TICON(tC lOAMY COtCO $AtAflt (000,001 tACIt TO Tot (TATL
Tot 00(1, ICt Of (0(0(000 Ot
01*11*? 0(00 *0(000 1011
0,,
00 004 Al 0*110 * 0(0 00 0* 4111
0* (1 IA ION Ut
C010000lI SnAIL 010*00 POOSOI1T 0100*0
St000Tt Y(CtIVtO
$ fAll I
THAN W.CPOOOTIOIIN00YM0000IIOT 000! (0(00(1411 OIl Ti ( ttOUtNTATI0NT00t.lII(4 P0* ((0 tO ATIOII Ut ttCttOtO Tot Put
10(1(00 A SAOITAOT (00111 I TOIl'
T0OII1(AINTJOATHA$TJOIfM010000YTIOOIN 0) OMITS OAI(IAU01100t0000 It TNt (IC SUIT It HOTItIIO
P0SIT01I 3000(1(001(0103 S*t( Aut TIM OtOUIOlO(iOIiIT001IIO II A (010(1 (Aunt CO,iTAli( (TATtMU(TSt000II0010IAIHO( Ni AIAAIiNtOACCtPT
t1000110P10110HTTI 00 0(0000 WTIICM(VtOIS(HOHTtO coocoo. 01 3 00 SOot TI Alit TO TNt (TAT!
POHTIOIi(HOT,AT(CIIAC$(AtAtt It AI1TCHtCO$AtAtStCOl*tIOA(
lIST (00* TwIll 41.011*00521 MAY KAYO 3
100ASA001IANO COliTIliUt TOO tOtOCt 0
0* 0000 000TTOIIS P051,010 *041131 010 OT011TO
00*
040*0 $Ot$flfi1
(0*00400(0 MOuTH UNTIL AT ((A$T I COIi(tCUTO( OIl!

OAItT C0(CO $AtAPtt$ 1110000

11011 C00001MTT M000TONO*0010TJ500 ACC0100IO PO(ITIOt TUSt(
TO (fl'T,0114401TOP HATONaO OiTt(IS0000fl .1 T10o$ 000TIOH( *070540 fit (COCOA
00140(10*1010 010I*.ATIONOO
. I ' s .c 000*101110000(10 NOt OtGi.S.A.
TOOlS 015.0 $4STI

687 688
 SECONDARY DRINKING WATER REGULATIONS STATE OPTION)
NAME Of MONITORMO REOUIREMENTS RECOMMENDED
CONTAINMENT ROUTINE SMMUNO ROUTINE
SUCL
AND TESTING REPORTING

CAROMS TA apt
TOR All CONTAMINANTS T REPORT RE SUITS
COLON Nam. MOATS
IS DOLOR SORTS COWS, IRON Of TEST
OR MM..

COMA I NHS SUS 011NC T MOSS IRE

OUSNT MONITORING OR !PICNIC MAO MAST ISOA,S
',AAR OuOroNG INS
MONTH IN SHNCH
CONNOSINTS NON-CONNOSEER THE MEANT IS
REM'S°
NO LESS I AlOvENT THAN THE
HONUIDAREG PERAIDANNCE VON al MASI IS OATS
'SOUNDS MOINCANIC CHI INCAlS COSTAR I OMONING !NO
DHSS. MAWS IN THE NOON" Of INS NSOINSSO
NoNTORING
AN)0
FOANIO IsNACHEvEN IS
ANON" ASIA.% SHOAT,"

IRON

HANG...ESC
OM amyl

1 TNR11410l0
0 OCR NUMMISI

PH
SS OS

I'
!MEATS ,.Thr-1-

TM RA

TOTAL OISSOLVE0
4
SOLIDS TON WS RA

MEC .1;" SRNS

ce)

Jo
V 14

PRIONNE04-1.112
REVISED Stu MATER °UAW, NE GutAT6ONS ST Tat CANNON IN VOtUul N
ADAPTED /RCN SATE ONNuuNG *ATOM ACT TECHNICAL
ILIVESIO SAM WATER TREATMENT PLANT OPERATION PUILNNSS T
SSIST N CS TRAINING PROJECT UNDER CANT CASEMENT
f °ONO AVON a C MSSOMN UNIVSOISIT SACRAMENTO,
MRCS 55110 1.2/544 O. RN0E0 To THE AM/RICAN TT. Ts, woos s
000 WHET SACRA/ TD CAl.f ORNIA MI6
ASSOCIATION It THE US EN rUIONN TTTTT MST IC TION GEHCT

690
689