WATER AND SANITATION

Presented by
Dr. Emilia Udofia
Lecturer, Department of Community
Health, UGMS
 OUTLINE
• Introduction
• Definitions
• Improved and unimproved sanitation facilities
• Improved and unimproved water sources
• Global and national estimates
• Water: facts, consumption, quality,
framework, systems, health effects and
control measures and treatment
• Waste water: treatment
 INTRODUCTION
• The MDG 7c calls on countries to halve the
proportion of people without sustainable
access to safe drinking water and basic
sanitation by 2015
• The proportion of the population using an
improved sanitation facility (urban and rural)
• The proportion of the population using
improved an improved drinking water source
(urban and rural)
 DEFINITIONS
• An improved sanitation facility is one that
hygienically separates human excreta from
human contact.
• An improved drinking water source is one that
by the nature of its construction adequately
protects the source from outside
contamination, in particular from faecal
matter.
IMPROVED SANITATION FACILITIES
Improved sanitation involves the use of:
• Flush or pour flush connected to a
- Piped sewer system
- Septic tank
- Pit latrine
• Ventilated improved pit latrine
• Pit latrine with a slab
• Composting toilet
UNIMPROVED SANITATION FACILITIES
• Flush or pour flush to elsewhere (not to a
piped sewer system, septic tank or pit latrine)
• Pit latrine without slab/open pit
• Bucket latrine
• Hanging toilet or hanging latrine
• Shared facilities of any type
• No facilities (bush, field)
 IMPROVED WATER SOURCES
• Piped water on premises (household
connection-located in the user’s dwelling, plot
or yard)
• Public stand pipe/tap
• Borehole or tube wells
• Protected (lined) dug well
• Protected spring
• Rain water collection
 UNIMPROVED WATER SOURCES
• Unprotected wells and springs
• Vendors (vended water)
• Tanker trucks
• Cart with small tank or drum
• Surface water: river, dam, lake, pond, stream,
canal, irrigation channels
• Bottled water
DEFINING ACCESS (JMP-WHO/UNICEF)
• Reasonable access to improved sources of
water as being the availability of at least 20
litres per person per day within one kilometre
of the user’s dwelling.
• The proportion of people with reliable access
to safe drinking water is the most important
single indicator of a successful drinking water
supply programme.
 ESTIMATES FOR GHANA
(UNPD 2008 REVISION)
Population (2008) 23,351,000
Total
Improved sanitation 13%
Unimproved :
- Shared facilities 54%
- Other unimproved 13%
- Open defaecation 20%
 ESTIMATES FOR GHANA
(UNPD 2008 REVISION)
Rural Urban 50%

Improved sanitation 7% Improved sanitation 18%

Unimproved: Unimproved :
- Shared facilities 38% - Shared facilities 70%
- Other unimproved 21% - Other unimproved 5%
- Open defaecation 34% - Open defaecation 7%
 ESTIMATES FOR GHANA
(UNPD 2008 REVISION)
Population (2008) 23,351,000

Total improved drinking water sources 82%

- Piped water on premises 17%
- Other improved sources 65%

Unimproved sources 18%

 ESTIMATES FOR GHANA
(UNPD 2008 REVISION)
Rural Urban

Total improved drinking Total improved drinking

water sources 74% water sources 90%
- Piped water on premises - Piped water on premises
3% 30%
- Other improved sources - Other improved sources
71% 60%

Unimproved sources Unimproved sources

26% 10%
 FACTS ABOUT WATER
Properties of pure water: • Constitutes 70% of weight
• Clear of the human body
• Tasteless - Transfers nutrients
• Colourless - Transfers waste
• Odourless - Regulates temperature

• At ATP, it freezes at 0 deg. Adult intake varies from 1-3

C and boils at 100 deg. C quarts/day:
• Has its greatest density at • 50% lost through skin and
4 deg. C lungs
• 50% lost through urine
and faeces
 SAFE FOR CONSUMPTION
Water is said to be safe for consumption when:
• It is free from pathogens.
• It is free from harmful chemicals.
• It is pleasant to taste.
• Usable for domestic purposes.
AVERAGE PER CAPITA CONSUMPTION
• Drinking water: 2 litres/dy in an adult (varies
with climate, activity level and diet).

• Drinking, personal hygiene and cleaning: 20-

40 litres per person/day in general.
 USES OF WATER
• Drinking/culinary • Power production
• Personal hygiene (hydropower)
(bath/laundry) • Commercial/Industrial
• Housekeeping purposes
• Heating/airconditioning • Fire protection
• Irrigation (agricultural) • Waste removal
• Street cleaning
• Recreational (swimming
pools, public fountains)
 WATER QUALITY
• Drinking water is said to be safe when it meets certain
microbiological and chemical standards.

• WHO/UNICEF Joint Monitoring Program for Water

Supply and Basic Sanitation (JMP) conducted a pilot
survey in 8 countries to evaluate the quality of drinking
water.

• A random sample of 1600 water supplies and 160

households indicated nearly 90% microbiological
compliance for piped water and 40% - 70% for other
improved sources.
 SOME WATER QUALITY STANDARDS
The parameters most commonly used to assess
microbial safety include:
• E. coli is the indicator organism of choice for
faecal pollution. It must not be detected in
any 100ml sample.
• Residual chlorine content – 0.2- 1mg/litre.
• pH because chlorination is ineffective above
pH 9. Alkaline pH requires a longer contact
time or higher free residual chlorine (0.4 -0.5
mg/litre at pH 6-8).
 SOME WATER QUALITY
STANDARDS
• Turbidity (particle count) adversely affects the
efficiency of disinfection. This should be
<5NTU before disinfection.
• For the purpose of surveillance, a water
supply should be visited and assessed every 3-
5 years.
 ADEQUACY OF WATER SUPPLY
• Quality
• Quantity (service level)
• Accessibility
• Affordability (tariff paid)
• Continuity
 WATER SYSTEMS
• Water source
• Treatment plant
• Reservoir
• Distribution system
• Sewerage
• Power supply and back up
 WATER SOURCES
• Rain water (households, small communities)
• Surface water (rivers, ponds, lakes, used in
large communities)
• Ground water (water table, withdrawn by
natural springs, wells, boreholes)
• Seawater and brackish
• Reused water for non- potable purposes
 PROTECTION OF WATER SOURCES
• Avoid discharge of wastes above water supply
• Avoid installing intakes below waste
discharges
• Diversion of local storm water flows
• Enclosure of the water source from animals
• Control of human activities within catchment
boundaries
• Promote community awareness of impact of
human activity on water quality
 A SANITARY WELL
• Is one that is properly located
• Is one that is well constructed
• Is one that is protected against contamination
• To yield water that is relatively safe.
 CHARACTERISTICS OF A SANITARY
WELL
Location:
• Located at least 15 m (50 feet) from potential
sources of contamination.
• It should be located uphill of the potential
sources of contamination.
• Users should not have to carry water >100 m
or (100 yards)
 CHARACTERISTICS OF A SANITARY
WELL (2)
Lining:
• The lining can be made of bricks or stones set
in cement.
• It should span at least 6 m (20 feet) so that
water does not penetrate the well from the
sides.
• The lining should extend 60-90cm (2-3 feet)
above ground level.
 CHARACTERISTICS OF A SANITARY
WELL (3)
Parapet:
• The wall of the parapet should extend 70-
75cm above the ground.

Platform:
• There should be a cement-concrete platform
extending 1 m (3 feet) in all directions.
• It should slope towards a drain on its edge.
 CHARACTERISTICS OF A SANITARY
WELL (4)
• The drain should convey filtered water to a
public drain or soakage pit directing it away
from the filtration area of the well.
Cover:
• The top of the well should have a cover to
prevent introduction of contaminants.
Hand pump:
• Hand pumps should be used to lift water.
 CHARACTERISTICS OF A SANITARY
WELL (5)
• The pump should be robust to withstand
multiple use and rough handling.
• Provision should be made for service of the
pump and repair.

Consumer responsibility:
• Individual ropes and buckets should not be
used for drawing water.
 CHARACTERISTICS OF A SANITARY
WELL (6)
• Washing, ablution and disposal of waste
should not be undertaken in the vicinity of the
well.
• Water should be conveyed from the well in
clean vessels.

Quality:
• It should conform to standards for safe water.
COMPARISON BETWEEN SHALLOW
AND DEEP WELLS
SHALLOW WELLS DEEP WELLS

Water is tapped from above the first Water is tapped from below the first
impervious layer and often less than 10 m impervious layer.
deep.
Often hand dug. Often machine dug.

Water is moderately hard. Water is quite hard.

Water is easily contaminated. Purer water is obtained.

May go dry in the hot season. Provides water all year round.
 WATER TREATMENT MEASURES
• Coagulation (fine suspendable material, colloidal and
bacteria by merging - aluminium sulphate)

• Flocculation (mixing and interparticle contact)

• Sedimentation (bacteria and particulates settle at the

bottom)

• Filtration (removal of fine particles as it passes through

granular media)

• Disinfection (addition of chlorine to destroy microorganisms,

also removes taste and odours, also ozone and UV irradiation)
 WATER TREATMENT MEASURES
• Adsorption (activated carbon removes taste and
odours, variety of organic chemicals)

• Ion exchange (natural or synthetic resins remove

specific ions such as Ca, Mg and replace with Na)

• Distillation (Used to desalinate through evaporation

and condensation)

• Gas exchange (oxygen is added, removes dissolved

gases, iron, manganese, taste and odours)
 PROFILE OF WATER TREATMENT
PLANT

Water from the source is Heavy flocs settle by

Mixers aid the formation
fed into the coagulation gravity in sedimentation
of flocs
chamber tanks removes as sludge

High lift pump delivers Flocs that escape the

Chlorination for
treated water through sedimentation tank are
destruction of harmful
the distribution mains removed by filtration on
organisms, also anti-
and other pipes to the a bed of various sized
corrosives
city sand grains
 CONTROL MEASURES AT THE
DISTRIBUTION SYSTEM
• Distribution systems should be fully enclosed
and storage tanks securely roofed with
external drainage to prevent contamination.
• Backflow prevention devices can be applied.
• Maintenance of positive pressure throughout
the system
• Ensuring adequate disinfection residual
• Ensure efficient maintenance
• Security to avoid tampering
 CONTROL MEASURES FOR NON-
PIPED SYSTEMS
• Wells – adequate setback and a mortar seal
for lining; hand pump for abstraction
• Springs and streams – protect from stray
animals
• Rainwater – cleaning of the roof and gutters;
first flush diversion; leaf litter strainers for
inlets to storage tanks
• Boreholes – encase to a reasonable depth;
seal boreheads to prevent contamination from
surface water or shallow groundwater
 HOUSEHOLD TREATMENT
• Bring water to a rolling boil and cool before
consumption.

• Strain turbid water and add bleach to a bucket

of water, mix and allow to stand for 30 mins.

• Vigorously shake small volumes in a clean,

transparent container for 20s, then expose to
sunlight for 6hrs.
 HOUSEHOLD TREATMENT
• Use of sterilizing tablets
NB:
- A filter with a pore size of 1 micron is
recommended for removal of
Cryptosporidium oocysts, Giardia and other
protozoa
- Quantity of household bleach (5%) is 3-4
drops per litre
 HEALTH EFFECTS
David Bradley classified health effects of water by
disease transmission routes:

• Water borne

• Water washed

• Water based

• Water related
 SUSCEPTIBILITY
• Those at greatest risk of waterborne diseases are:
- Infants and young children
- The debilitated/immunocompromised
- Pregnant women
- The elderly
- Those living in unsanitary conditions
• Guidelines provide minimum requirements for
safe practices to protect the health of consumers
and numerical values to guide indicators for
water quality
 HEALTH EFFECTS OF WATER
CLASSIFICATION TRANSMISSION EXAMPLE

WATERBORNE Pathogen is ingested in Diarrhoeal diseases

drinking water (faeco-oral) Dysentery
Typhoid
WATER WASHED Inadequate hygienic Scabies
conditions and practices; Trachoma
person to person
transmission; water
shortage
WATER BASED Transmitted by an aquatic Schistosomiasis
invertebrate host; Guinea worm
helminths
WATER RELATED Transmitted by insect Dengue
vectors that breeds in or Malaria
near water Trypanosomiasis
Onchocerciasis
 CHEMICALS IN WATER
Possible sources include:
• Natural occurrence – arsenic, flouride,
manganese
• Industrial settings and human dwellings –
cyanide, mercury
• Agricultural activities – nitrate, nitrite
• Water treatment – lead, copper
• Pesticides
• Cyanobacteria
 TREATING WASTE WATER
• The purpose is to produce a disposable
effluent which is harmless and prevent
pollution of the environment.

• It is the process of removing contaminants

from waste water.

• The by-products are an effluent and sludge

that can be discharged or reused.
 SEWAGE
• It includes household liquid waste from baths,
showers, toilets, kitchens, sinks and is
discharged through sewers.
• Storm water run off and surface water from
roofs may also be constituents of sewage.
• It can also include liquid waste from industry
and commerce.
• Sewers for storm water is usually different
from sanitary sewers.
 SEWAGE
• Sewage can be treated close to location in:
- Septic tanks
- Biofilters
- Aerobic treatment systems

• It can also be collected through a network of

pipes and pumps to a central treatment plant.
 SEWAGE TREATMENT
This generally involves a pre-treatment stage
and 3 main stages:

- Primary treatment

- Secondary treatment

- Tertiary treatment
 PRETREATMENT
• Screening – removes large objects carried in
the sewage stream using bar or mesh screens
of varying sizes.
• Grit removal – permits sand, grit, stones and
broken glass to settle in a chamber and is
removed.
• Fat and grease removal – skimmers collect fat
floating on the surface in a tank; air may be
used to recover fat as a froth
 PRIMARY TREATMENT
• Large tanks called clarifiers are used for
sedimentation of sludge which is removed for
treatment.
• Oil and grease floats on top which is removed
and sometimes used for saponification.
• It may remove 60 – 65% of suspended solids
and 30-35% of biological oxygen demand.
 SECONDARY TREATMENT
• This degrades the biological content of sewage
from human and food waste, soaps and
detergent.
• Bacteria and protozoa digest the organic
content and bind the less soluble fractions
into a floc.
• It is an aerobic process.
• The systems can be classified as fixed film or
suspended growth systems.
 SECONDARY TREATMENT
• The fixed film uses trickling filters and rotating
biological contactors – these grow biomass on
the media and sewage passes over the surface.
Removes more organic material and suspended
solids.
• Oxidation and nitrification take place on the filter
converting the organic solids into a coagulated
mass which being heavier settles in a
sedimentation tank (secondary settling tank)
 SECONDARY TREATMENT
• Suspended growth systems uses activated
sludge where the biomass is mixed with
sewage. This uses smaller space.
• Activated sludge uses processes in which
dissolved oxygen promotes growth of a
biological floc that removes organic material.
• Particulate material is trapped and nitrates
can be converted to nitrogen gas.
 TERTIARY TREATMENT
• The end product of secondary treatment is an
effluent with low levels of organic material
and suspended matter.
• The purpose of tertiary treatment is to
upgrade the quality of water before it is
discharged into the receiving environment.
• It may involve more than one process in which
case disinfection is usually the last.
 TERTIARY TREATMENT
Processes include:
• Filtration (sand - to remove residual suspended
matter, activated carbon – to remove residual
toxins)
• Lagooning (provides aerobic environment and
reeds to remove fine particulates)
• Engineered reedbeds (provides aerobic
environment)
• Nutrient removal (removal of nitrogen and
phosphorus to reduce proliferation of algae)
 TERTIARY TREATMENT
• Disinfection (uses ozone, chlorine, UV
radiation and sodium hypochlorite; reduces
the number of microorganisms in water)
 READING ASSIGNMENT
1. Define the following: 5. List 4 parameters of
• Improved sanitation water quality
facility 6. List 4 main components
• Improved drinking of a water system
water source 7. What is sewage?
2. List 4 examples of each 8. List the steps in the
3. List 6 main processes of treatment of waste
water treatment water
4. List 5 parameters to 9. List 4 health effects of
assess adequacy of water with examples
water supply 10. List 2 properties of
water