Joseph Benedict N.

Prim

Water Quality
 Water

• Water is a common chemical substance that

is essential for the survival of all known
forms of life. In typical usage, water refers
only to its liquid form or state, but the
substance also has a solid state (ice), and a
gaseous state (water vapor or steam).
Importance of Water
• To function properly, man needs at least 8
glasses of water daily.
• Water plays an important role in the
world economy, as it functions as a
solvent for a wide variety of chemical
substances and facilitates industrial
cooling and transportation.
• Approximately 70% of freshwater is
consumed by agriculture.
• Different bodies of water provide
livelihood and economic security to
different countries.
Water Quality
• Water quality is the physical, chemical, biological, and
aesthetic characteristics of water which determines its
fitness for a variety of uses and for protecting the
health and integrity of aquatic ecosystems.
• Another general perception of water qualityis that of a
simple property that tells whether water is polluted or
not.
• Water quality depends on the local geology and
ecosystem, as well as human uses such as sewage
dispersion, industrial pollution, use of water bodies as a
heat sink, and overuse (which may lower the level of
the water).
 SOURCES OF WATER
and
WATER QUALITY CLASSIFICATION
Water Resource

Surface Water - Ground Water –all water that saturates the A very small amount of the Earth's water is
97% saltwater (oceans and seas) tiny spaces between alluvial material contained within water towers, biological
(sands, gravel, silt, clay) or the crevices or bodies, manufactured products, and food
2.4% glaciers and polar ice caps
fractures in rocks. This includes the stores.
0.6% other land surface water such as aeration zone, aquifers, saturation zones,
rivers, lakes, and ponds capillary water, and water-bearing rocks
Philippine’s Water
Resources
• The Philippines comprises more than 7,100 islands. Large
bodies of water separated three major island groups: Luzon,
Visayas, and Mindanao. Fishing is one of the major industries
of the country. Aside from being a source of food and
livelihood, water source plays an important role in other
industries and domestic households.

• Water resources in the Philippines include inland fresh water,

lake, and coastal and oceanic waters. Inland fresh water
includes rivers, lakes, and ground water.
• There are 421 principal river basins, 19 are considered major
river basins. Marine water encompasses coastal and oceanic
water, the main source of fish and other aquatic plants and
animals
Water Quality in the Philippines
Water quality protection and operation and maintenance of sanitation facilities are a collaborative
undertaking of the Department of Environment and Natural Resources (DENR) through the
Environmental Management Bureau (EMB), Department of Health (DOH), Department of Works and
Sewerage System (DWSS).

The problem is that there are too many policies and laws about water quality that some of them are
not implemented and monitored properly, and some agencies have unclear and overlapping
mandates.

To answer the growing problems of water quality several investment projects were done to monitor
and ensure safe water.
 1 2 3 4
The Philippine government aims to Class AA and SA have the most Hot spots areas of surface water Other hot spots were identified and
maintain the quality of its surface stringent water quality for fresh quality were assessed by province rated on the basis of the objective
waters according to their best surface waters and marine/coastal using Dissolved Oxygen (DO) and of recovering the water quality of
beneficial use. This is embodied in waters; and D and SD waters have Biochemical Oxygen Demand (BOD) surface waters (rivers, lakes, and
the DENR Administrative Order the least stringent water quality for as parameters. Groundwater quality bays) for beneficial use, i.e., Class A
(DAO) No. 34, which classifies fresh surface water and marine was assessed by using Total (for fresh surface waters) for
bodies of water according to the waters, respectively. Dissolved Solids (TDS) and Coliform. drinking, and Class SB ( for coastal
degree of protection required. Saltwater intrusion was mapped and marine waters) for recreation.
based on National Water Resources
Board (NWRB) data.
 • Over half of the Philippine rivers that were classified have
lower quality and cannot be used for drinking unless
treated.
• The coastal areas are densely populated thus causing
water pollution.
Quality of • Philippines’s main source of water is rainfall. The surface
Philippine and ground water quality shows the problem is getting
severe in urban and coastal areas.

Water • Clean water should be the priority. Fifty-eight percent of

ground water wells that were sampled were
Resources contaminated with coliform. Water contamination
contributes to low water quality resulting in water
pollution. This is the result of urbanization. As people
flock into the metropolis and build homes, water quality
problems arise.
 • The parameters for water quality are determined by the intended
use. Work in the area of water quality tends to be focused on
Categories water that is treated for human consumption or in the
environment.
For Human Consumption
or Drinking-Water

• World Health Organization has set the Guidelines for

Drinking-water Quality of which the primary purpose
is the protection of public health.
• Water is essential to sustain life, and a satisfactory
(adequate, safe, and accessible) supply must be
available to all. Improving access to safe drinking-
water can result in tangible benefits to health.
• The great majority of evident water-related problems
are the result of microbial (bacteriological, viral,
protozoan, or other biological) contamination.
Nevertheless, an appreciable number of serious
health problems may occur as a result of the
chemical contamination of drinking water.
 • Alkalinity
• Color of water
• pH
• Taste and odor
• Dissolved metals and salts (sodium,
chloride, potassium, calcium,
manganese, magnesium)
• Microorganisms such as fecal
coliform bacteria (Escherichia coli),
Cryptosporidium, and Giardia
lamblia
• Dissolved metals and metalloids
(lead, mercury, arsenic, etc.)
• Dissolved organics: colored
dissolved organic matter (CDOM),
dissolved organic carbon (DOC)
• Radon
Human Consumption or • Heavy metals

Drinking-Water -Parameters
Environmental Water Quality
• Also called ambient water quality, pertains to water bodies
such as lakes, rivers, and oceans.
• Ambient water quality standards vary significantly due to
different environmental conditions, ecosystems, and intended
human uses.
• Toxic substances and high populations of certain
microorganisms can present a health hazard for non-drinking
purposes such as irrigation, swimming, fishing, rafting,
boating, and industrial uses. These conditions may also affect
wildlife which use the water for drinking or as a habitat.
Modern water quality laws general specify protection of
fishable/swimmable use and antidegradation of current
conditions.
Environmental Water Quality
• Environmental advocates express desires to return water bodies to pristine,
or pre-industrial conditions.
• Current environmental laws focus of the designation of uses and therefore
allow for some water contamination as long as the particular type of
contamination is not harmful to the designated uses.
• Given the landscape changes in the watersheds of many freshwater bodies,
returning to pristine conditions would be a significant challenge. In these
cases, environmental scientists focus on achieving goals for maintaining
populations of endangered species and protecting human health.
 Physical Properties
Color, odor, temperature, solids (residues), turbidity,
oil content, and grease content.
Chemical Properties
pH
Conductivity
Environmental Dissolved oxygen (DO)

Water Quality– Nitrate

Orthophosphate
Parameters Chemical oxygen demand (COD)
Biochemical oxygen demand (BOD)
Pesticides
Biological Properties
Bacteriological parameters: coliforms, fecal coliforms,
specific pathogens, and viruses.
COMPONENTS OF WATER QUALITY
(microbial, biological, chemical, and physical aspects)
and
MEASUREMENTS
 Drinking water should not include
microorganisms that are known to be
pathogenic.

Components of
Water Quality It should also not contain bacteria that
would indicate excremental pollution, the
Microbial primary indicator of which are coliform
bacteria that are present in the feces of
Aspect warm-blooded organisms.

Chlorine is the usual disinfectant, as it is

readily available and inexpensive.
Unfortunately, it is not fully effective, as
currently used, against all organisms.
Components of Water
Quality
Biological Aspect

• Parasitic protozoa and helminths are also indicators

of water quality. Species of protozoa can be
introduced into water supply through human or
animal fecal contamination.
• Most common among the pathogenic protozoans are
Entamoeba and Giardia.
• Coliforms are not appropriate direct indicators
because of the greater resistance of these protozoans
to inactivation by disinfection.
• A single mature larva or fertilized egg of parasitic
roundworms and flatworms can cause infection when
transmitted to humans through drinking water.
• Chemical contamination of water sources may be due to
certain industries and agricultural practices, or from
natural sources.
• When toxic chemicals are present in drinking water,
there is the potential that they may cause either acute
or chronic health effects.
• Chronic health effects are more common than acute
effects because the level of chemicals in drinking water
are seldom high enough to cause acute health effects.

Components of Water Quality

Chemical Aspect
 • The turbidity, color, taste, and odor of water can be
monitored.
• Turbidity should always be low, especially where
disinfection is practiced. High turbidity can inhibit the
effects of disinfection against microorganisms and
Components of enable bacterial growth.
• Drinking water should be colorless, since coloration
Water Quality may be due to the presence of colored organic matter.
• Organic substances also cause water odor, though
Physical Aspect odors may result from many factors, including
biological activity and industrial pollution.
• Taste problems relating to water could be indicators of
changes in water sources or treatment process.
Inorganic compounds such as Mg, Ca, Na, Cu, Fe, and
Zn are generally detected by the taste of water.
 • The complexity of water
quality as a subject is
reflected in the many types
of measurements of water
quality indicators. Some
measurements that can be
made on-site are
temperature, pH, dissolved
oxygen, and conductivity.
• More complex
measurements that must be
made in a laboratory setting
require a water sample to be
collected, preserved, and
analyzed at another location
Water Quality Measurement (e.g., microbiological tests).
Measurement #1
pH
• pH, or the "potential of hydrogen", is a measure of the
concentration of hydrogen ions in the water.
• This measurement indicates the acidity or alkalinity of the
water. On the pH scale of 0 -14, a reading of 7 is considered to
be "neutral." Readings below 7 indicate acidic conditions,
while readings above 7 indicate the water is alkaline or basic.
• Naturally occurring fresh waters have a pH range between 6.5
and 8.5. The pH of the water is important because it affects
the solubility and availability of nutrients, and how they can be
utilized by aquatic organisms.
• The main significance of pH in domestic water supplies relates
to its effects on water treatment.
 The pH of a water does not have direct health consequences
except at extremes:

pH <4.0, severe danger of health effects due to dissolved toxic

metal ions are expected. Water tastes sour.

At pH 4.0 –6.0, toxic effects associated with dissolved metals,

Measurement including lead, are likely to occur. Water tastes slightly sour.

#1 At target water quality range of 6.0 to 9.0, no significant effects

on health are expected.

pH At pH 9.0 –11.0, the probability of toxic effects associated with

deprotonated species increases sharply. Water tastes bitter.

At pH>11.0 –severe danger of health effects due to

deprotonated species. Water tastes soapy.

Treatment option would be the addition of an acid or an alkali.

Measurement # 2
Dissolved Oxygen (DO)
• Dissolved oxygen is the amount of oxygen dissolved
in water, measured in milligrams per liter (mg/L).
• This component in water is critical to the survival of
various aquatic life in streams, such as fish.
• The ability of water to hold oxygen in solution is
inversely proportional to the temperature of the
water. For example, the cooler the water
temperature, the more dissolved oxygen it can
hold.
• Common standard for water is that DO is at 8.0
mg/L
• The Philippines standard is 5 mg/L
 • Biological Oxygen Demand is a measure of how much oxygen is used by
microorganisms in the aerobic oxidation, or breakdown of organic matter in
the streams.
• Usually, the higher the amount of organic material found in the stream, the
more oxygen is used for aerobic oxidation.

Measurement • This depletes the amount of dissolved oxygen available to other aquatic life.
This measurement is obtained over a period of five days, and is expressed in
mg/L.
#3 • Philippines standard for BOD in water is not more than 5 mg/L

Biological
Oxygen
Demand
(BOD)
Surface Water
Class A and
Coastal and
Marine Water
Class SB
Measurement #4
Temperature
• Temperature is a measure of how cool or how warm the
water is, expressed in degrees Celsius (C).
• Temperature is a critical water quality parameter, since it
directly influences the amount of dissolved oxygen that is
available to aquatic organisms.
• Water temperature that exceeds 18°C (for Class A Waters)
has a deleterious effect on several fish species in streams.
• Salmonids, for example, prefer waters of approximately 12
to 14 degrees Celsius.
Measurement #5
Conductivity
• Conductivity is the ability of the water to conduct an
electrical current, and is an indirect measure of the
ion concentration.
• The more ions present, such as that of carbonate,
bicarbonate, chloride, suphate, nitrate, Na, K, Ca, and
Mg, the more electricity can be conducted by the
water.
• This measurement is expressed in microsiemens per
centimeter (uS/cm) at 25°C. The target water quality
range is 0 –70.
Measurement #6
Total Dissolved Solids (TDS)
• Total dissolved solids is a measure of the amount of
particulate solids that are in solution.
• This is an indicator of nonpoint source pollution problems
associated with various land use practices.
• The TDS concentration is directly proportional to the
electrical conductivity of water.
• Since conductivity is much easier to measure than TDS, it
is routinely used as an estimate of the TDS concentration.
• TDS is expressed in (mg/L) with target water quality range
of 0 –450 mg/L.
Measurement #7
Turbidity
• Turbidity is a measure of the clarity of the water.
• It is the amount of solids suspended in the water.
• It can be in the form of minerals or organic matter.
• It is a measure of the light scattering properties of water, thus
an increase in the amount of suspended solid particles in the
water may be visually described as cloudiness or muddiness.
• Turbidity is measured in Nephelometric Turbidity Units (NTU).
• Standard is 5 NTU’s
Measurement #8
Fecal Coliform Bacteria
• Fecal coliform bacteria are microscopic organisms that live in
the intestines of all warm blooded animals, and in animal
wastes or feces eliminated from the intestinal tract.
• Fecal coliform bacteria may indicate the presence of disease-
carrying organisms which live in the same environment as the
fecal coliform bacteria.
• The measurement is expressed as the number of organisms
per 100 mL sample of water (#/100mL).
• Standard Fecal Coliform Bacteria is 100 organisms per 100 mL
 • Biological monitoring metrics
have been developed in many
places, and one widely used
measure is the presence and
abundance of members of the
insect orders Ephemerontera
(Mayfly), Plecoptera (Stonefly)
and Trichoptera (Caddisfly)
• Generally, within a region, the
greater the number of taxa from
these orders, the better the water
quality.
• Without the laboratory scale
analysis, an individual can use this
biological indicator to get a
general reading of water quality
Environmental Water Quality (such as the benthic macro-
invertebrate indicator key).

– Biological Assessment
SOURCES OF
CONTAMINATION
 • Construction and mining sites, disturbed land
areas, streambank erosion and alterations,
cultivated farmland
• Fertilizer on agricultural, residential, commercial
and recreational lawns, animal wastes, effluent
Sources of from aquaculture facilities, leaky sewers and septic
tanks, atmospheric deposition, municipal
Contamination wastewater
• Pesticide applications, disinfectants (chlorine),
automobile fluids, accidental spills, illegal dumping,
urban stormwater runoff, industrial effluent
• Wastewater effluent, organic matter, leaking
sewers and septic tanks, animal waste
 • Failing septic tanks, animal waste, runoff from
livestock operations, wildlife, improperly
disinfected wastewater effluent
• Salt applications to snow and ice
Sources of • Leaky automobiles, industrial areas, illegal dumping
Contamination • Hydrological modifications that influence the
amount of fresh or saline waters entering a system
• Heated landscape areas, runoff from impervious
areas, tree removal along streams, wet detention
ponds
Sources of Point and Nonpoint pollution
Point Sources Nonpoint Sources

• Wastewater effluent, both municipal and industrial • Runoff from agriculture (including return flow from irrigated
agriculture)
• Runoff and leachate from waste disposal sites • Runoff from pasture and range
• Runoff and infiltration from animal feed lots • Urban runoff unsewered areas and sewered areas with a
population of less than 100,000
• Runoff from mines, oil fields, and unsewered
industrial sites • Septic leachate and runoff from failed septic systems

• Storm sewer outfalls from cities with a population of • Runoff from construction sites smaller than two hectares
greater than 100,000 • Runoff from abandoned mines

• Runoff from construction sites larger than two • Atmospheric deposition over a water surface
hectares • Activities on land that generate contaminants, such as logging,
wetland conversion, construction and development of land or
• Overflows of combined storm and sanitary sewers waterways
MEANS OF TREATMENT
Means of Treatment
• Coagulation–the separation or precipitation of particles in
a dispersed state from a suspension resulting from their
growth. This may result from the addition of an electrolyte
(coagulant), prolonged heating, or from a condensation
reaction between a solvent and solute.
 • Flocculation–the addition of
chemical reagents
(flocculants) to bring small
particles together in flocs
through the process of
coagulation, aggregation, or
biochemical reaction of fine
suspended particles.

Means of Treatment
 Means of treatment

• Ion exchange–the interchange of ions of like

charge, usually on a solid medium and is
used in water treatment, such as water
softening.
Means of Treatment

• Ozonation–is a water treatment process that

destroys microorganisms and degrades organic
pollutants through the infusion of ozone, a gas
produced by subjecting oxygen molecules to high
electrical voltage.
Means of
treatment
• Reverse Osmosis –a technique in
the desalination of water in which
pressure is applied to the surface
of the saline solution, forcing pure
water to pass through a semi-
permeable membrane which
prevents passage of other ions.
 • Distillation–the process of
producing gas or vapor from
a liquid by heating the liquid
in a vessel and then
collecting and condensing
the vapors into liquids.

Means of Treatment
Methods of treatment
• Electodialysis–the process of selective diffusion through a
membrane conducted with the aid of an electromotive
force applied to electrodes on both sides of the membrane.
Means of Treatment
• Disinfections–to kill living organisms (ex.
chlorination, ozonation, use of potassium
permanganate, UV light, or silver ions.
Means of Treatment

• Filtrations/ultra-filtrations –ex.
A bed of sand or pulverized coal,
or through a matrix of fibrous
material supported on a
perforated core.
Means of treatment
Adsorption–ex. using activated alumina, activated carbon or activated carbon (GAC).
Means of treatment
• Aeration–a process of exposing water to air by dividing the
water into small drops, by forcing air through the water, or
by combination of both. It is used to add oxygen to water
and to remove CO2, hydrogen sulfide, and taste-producing
gases or vapors .
Means of treatment
Boiling–to kill some bacteria.
WATER QUALITY
MANAGEMENT
 Water Quality
Management
Water quality management is the planning for the
protection of a water’s quality
• for various beneficial use,
• for the provision of adequate wastewater
collection, treatment, and disposal of
municipalities and industries, and
• for activities that might create water quality
problems, and regulating and enforcing programs
to accomplish the planning goals, and law and
regulations dealing with the water pollution
control.
 Water Quality
Management

• The United Nations, in its recent

examination of global water scarcity
(1997) identified water quality as
one of the key concerns in Asia in
the next century. This concern is
based on the fact that water quality
degradation is so severe in many
Asian countries that it is placing
serious constraints on economic
growth. It continues to be a serious
problem for human health and it is
causing widespread negative
environmental effects.
 References

• Introduction to Environmental Engineering by Davis and Cornwell

• https://www.slideshare.net/dannadannadanna/lecture-12-water-quality
• https://www.slideshare.net/saniyamehmood37/water-treatment-plant-of-environmental-
engineering