SUSTAINABLE STRATEGIES IN WATER SUPPLY & SANITATION

1. SUSTAINABLE STRATEGIES INWATER SUPPLY &
SANITATION
Dr.K.MAHENDRAN,
PROFESSOR& DIRECTORi/c,
RURALTECHNOLOGYCENTRE,
GANDHIGRAM RURALINSTITUTE –DEEMED UNIVERSITY

2. IMPORTANCE OF WATER
• Water is one of the most important substances on
earth. All plants and animals must have water to
survive. If there was no water there would be no life on
earth
• Apart from drinking it to survive, people have many
other uses for water. These include: cooking
– washing their bodies
– washing clothes
– washing cooking and eating utensilskeeping houses and
communities clean
– recreation; such as swimming pools
– keeping plants alive in gardens and parks

3. Different Sources of Water
• Water resources are divisible into
two distinct categories :
• the surface-water resources
• the ground-water resources.
• Each of these categories is a part
of the earth's water circulatory
system, called the hydrologic
cycle, and is derived from
precipitation, which is rainfall plus
snow.

4. HYDROLOGICAL CYCLE

5. DISTRIBUTE OF WATER ON EARTH
This is how the water is distribute on Earth. If you
could see here that is most amount of water in the
oceans.

6. POTABLE WATER
• Water that is safe for drinking is called
Portable Water.
• It is most important that the water which
people drink and use for other purposes is
Clean water. This means that the water must
be free of germs and chemicals and be clear
(not cloudy).

7. SOME DOMESTIC USES OF WATER

8. WATER POLLUTION
• Water pollution is the contamination of water bodies (e.g.
lakes, rivers, oceans, groundwater).
• Water pollution affects plants and organisms living in these
bodies of water; and, in almost all cases the effect is
damaging either to individual species and populations, but
also to the natural biological communities.
• Water pollution occurs when pollutants are discharged
directly or indirectly into water bodies without adequate
treatment to remove harmful compounds.

9. Types of Water Pollution
• Water pollution
– Any physical or chemical change in water that adversely
affects the health of humans and other organisms
– Varies in magnitude by location
• Eight categories
– Sewage, disease-causing agents, sediment pollution,
inorganic plant and algal nutrients, organic compounds,
inorganic chemicals, radioactive substances, and thermal
pollution

10. SEWAGE OIL SPILLING

11. IMPROVING WATER QUALITY-
PURIFICATION FOR DRINKING WATER
• Treated water
distributed to
customers
• Sewer lines bring
sewage to
treatment plant
• Sewage treated
at sewage
treatment plant

12. SUSTAINABILITY
The maintenance of desired quantity and acceptable
quality standard of water supply services throughout the design
life of the water supply systems may be defined as sustainability.
The sustainability is with reference to:
• Source – quantity and quality
• System – infrastructures

13. Factors affecting sustainability of
water sources
• The depletion or lowering of water levels in groundwater and
surface water sources
• Change/degradation of water quality due to over drawls or
contamination by domestic/industrial wastes/ waste water

14. Elements of Sustainability
• Source Sustainability: Ensuring availability of safe drinking
water in adequate quantity throughout the year
• System Sustainability: Optimizing the cost of production of
water, devising proper protocol for O&M, building capacity
of PRIs and awareness generation
• Financial Sustainability: Proper utilization of Finance
Commission and O&M funds under NRDWP guidelines and
recovering at least 50% cost through flexible methods
devised by the local self government and improving energy
efficiency

15. List of Ground, Surface and Roof
water Harvesting Systems
• Gully plugs
• Recharge Pit
• Contour trench/bund
• Semi-circular trenches on slopes
• Check dam/Nala bund
• Percolation pond/tank
• Sub-surface dyke
• Injection well
• Recharge shaft
• Roof water harvesting
• Traditional water harvesting structures

16. SUPPORT MODEL FOR SELECTION OF
SUSTAINABILITY STRUCTURES

18. 1. Less than 20% of India’s rural population has access to safe & hygienic sanitation
facilities
2. An estimated 650 million Indians defecate in the open every day, and as a result
an estimated 200,000 tons of fecal matter are deposited in the open every day
3. Household waste on streets and in sewers
4. Unsanitary conditions in public toilets in urban areas
5. Industrial & Hazardous Waste on open land creating dump yards, and open
invitation for other types of wastes incl. medical wastes
6. Drinking Water not safe or hygienic in rural areas
7. Each year diarrhea kills over 500,000 people in India. Diseases such as Cholera,
Typhoid, Hepatitis, and Polio still occur in India in significant numbers
SANITARY CONDITIONS & CHALLENGES IN
INDIA

19. DEFINITION OF SANITATION (WHO)
 Sanitation generally refers to the provision of facilities and services for the safe
disposal of human urine and feces.
 Inadequate sanitation is a major cause of disease world-wide and improving
sanitation is known to have a significant beneficial impact on health both in
households and across communities.
 The word 'sanitation' also refers to the maintenance of hygienic conditions,
through services such as garbage collection and wastewater disposal.

20. STEPS TO SOLVE SANITATION PROBLEMS IN INDIA
1. Identify project area based on agreed upon priorities
2. Determine criteria & parameters to improve sanitation
3. Determine the population, demographics, needs of business and institutional
sector
4. Determine types of sanitation facilities required for each unique application
5. Determine feasible technologies for each application
6. Understand the role of local govt. NGOs, and volunteer organizations in the local
project area
7. Check applicable local regulations affecting each project

21. LIST OF TECHNOLOGIES CURRENTLYAVAILABLE FOR
SANITATION AND TOILET SYSTEMS, GLOBALLY
1. Twin Pit (ventilated latrine) sanitation technology utilized by Sulabh
Technology
2. Pour Flush Latrines
3. Composting latrines
4. Aqua privies
5. AfriSan waterless technology
6. Vacu-tug technology
7. Portable plastic (polyethylene) toilets
8. Septic Tanks with drain fields
9. Sewerage collection and treatment systems

22. CRITERIA TO CONSIDER IN SELECTION OF
VIABLE TECHNOLOGIES
1. Availability of water for sanitation & toilet systems
2. Availability of electricity or need for electrical generators
3. Vicinity to solid waste disposal facilities
4. Pick up service for liquid or semi-solid sanitary waste
5. Geological characteristics of local area, depth of seasonal high groundwater
level, soil density & porosity
6. The magnitude of sanitation facility needs (# of toilets reqd. , number of
customers to be served at normal and peak hours, services reqd. for large
institutions, schools, govt. buildings, community centers, etc. )

23. SUCCESS MODEL FOR SANITATION PROJECTS
FOR PROMOTION OF GREENER ENVIRONMENT
Five ‘E’s
1. Environment - protect it
2. Energy - conserve it
3. Education & Awareness - promote it
4. Excellence in Innovation – practice it
5. Engage local govt, regulators, stakeholders, investors and consultants –
make informed & practically sound decisions for better quality of life that is
sustainable for generations

24. DEVELOPMENT OF A SUSTAINABLE & ECO-
FRIENDLY SANITATION SYSTEM
 Develop environmentally acceptable sanitation facilities (incl. toilet systems,
etc.) and install them so that they do not degrade living conditions or cause
unhygienic conditions
 Provide wastewater treatment plants (incl . package plants) for larger
communities, institutions, schools, etc. with provision for water recycling
 Develop adequate solid waste disposal facilities for wastewater sludges,
domestic waste vacuumed from dry toilets or other waste that has no other
uses.

25. Cont...
 Ensure that water for drinking is kept separate from water used for toilets, to
avoid cross contamination.
 Develop a system to regularly maintain the toilets and the wastewater
systems to prevent bad odors, flies, and other similar nuisances
 Develop systems to encourage waste composting so that it can be converted
to fertilizers that can be used for agricultural applications.
 Establish public awareness programs on sanitation & hygiene in all
communities that have existing or new sanitation facilities

26. STRATEGIES FOR ‘SANITATION PROJECT
SUCCESS’ IN DEVELOPING COUNTRIES
 Secure full understanding of local laws, regulations, policies procedures &
politics
 Form alliances with local partners and stakeholders that can promote the
message of sanitation and hygiene in rural areas.
 Provide technical solutions that are practical & sustainable in a local
economy, be a pioneer or innovator, not a follower
 Try to utilize indigenous materials & products as much as possible, this will
create tangible benefits to local economy

27. Cont…
 Work closely with regulators so that they fully understand the benefits of
your services and products
 Make solutions more cost effective & efficient to implement, think “months
instead of years”.
 Avoid middlemen and business brokers who might impede progress and
inject politics & corruption into decision making
 Utilize motivational approaches to change sanitation behaviors in
communities, utilize ‘demand based’ approaches, with meaningful
contributions by local community members and end users of sanitation
services

28. A Sanitary latrine should satisfy the following
criteria
1. Surface soil should not be contaminated
2. Should not contaminate Surface water
3. Should not pollute ground water
4. Should be no handling of fresh excreta
5. Should not be accessible to flies and animals
6. Should be free from odors
7. Method /Technology should be simple, inexpensive and user friendly

29. Design of the pit - Factors
Bacteria play a major role in decomposing the excreta
Aerobic digestion – in the presence of Oxygen
Anaerobic digestion - in the absence of Oxygen ., -in the fluid
The final product is Nitrogen, Ammonia, Nitrites and Nitrates
Gases and salts leaches into the soil, Pathogens and ova are destroyed, Final
product is rich in Nutrient which is small in quantity
Effective Capacity of a wet pit latrines per person per year would be 37 liters or
1.4 cu.ft
The amount of sludge (wet) after one year digestion period per person would be
36.5liters (1.3cu.ft).Five member family require 185 Liters or 6.5 cu.ft per year

30. PIT
Circular pit -Square pit-Rectangular pit
Lined Pit
Open Joints –Bricks, Hollow blocks, Stone, Rings with holes, Bamboo, cut tree
limbs with cement mortar. The pit may be Direct or Indirect with connected
with pipes.
Simple Un lined Pit
Circular pits are suitable for unlined pit. But it should be shallow to avoid any
wall collapse. Earthen mount will prevent run off water entering into the pit.
Simple squatting platform with hole and lid may be useful to make the pit a
sanitary one. It may be useful in a place where dry condition prevail

32. VENTILATED IMPROVED PIT (VIP)
1. A ventilated improved pit latrine (VIP) is similar to a single pit latrine with
addition of a vertical vent pipe.
2. Through the aeration in VIPs, odour and fly nuisances are reduced.
3. The VIP needs no water for its function.
4. Lining the pit prevents it from collapsing and provides support to the
superstructure.
5. Despite their simplicity, well‐designed single VIPs can be completely smell free,
and more to use than some other water‐based technologies.

33. Design considerations
1. The vent pipe should have an internal diameter of at least 110 mm and reach
more than 300mm above the highest point of the toilet superstructure.
2. It can be made out of PVC, bricks, pet bottles or iron pipes. Wind passing over
the top creates a suction pressure within the vent pipe and induces an air
circulation.
3. The vent works best in windy areas, but where there is little wind, its
effectiveness can be improved by painting the pipe black.
4. The heat difference between the pit (cool) and the vent (warm) creates an
updraft that pulls the air and odours up and out of the pit.

34. ADVANTAGES OF VIP LATRINE
1. Excavation of humus is easier than faecal sludge
2. Significant reduction in pathogens
3. Potential for use of stored faecal material as soil conditioner
4. Flies and odours are significantly reduced (compared to non‐ventilated pits)
5. Less chances for transmission of excreta related disease than lid or cover
6. Good health and hygiene practice
7. Can use as fertilizer after one year composting
8. Better life and environment
9. Construction and maintenance are easy
10. Suitable for water scarce area, as no need for water except occasional cleaning
of the squat plate

35. Disadvantages
1. VIPs are slightly more expensive than normal pit latrines.
2. Leachate can contaminate groundwater
3. No specific reuse of faeces and urine
4. Pits are susceptible to failure/overflowing during floods; stagnant water in pits
may promote insect breeding
5. Manual removal of humus is required
6. Possible contamination of groundwater
7. Higher capital costs than Single VIP; but reduced operating costs if
self‐emptied

38. RURAL PAN – COMMERCIAL PAN

39. DIFFERENCE LEACH PIT & SEPTIC TANK

42. ECO TOILET
ECO toilet is the type of dry toilet that uses a predominantly aerobic
processing system to treat human excreta. It is an alternate to flush
toilets.

43. Advantages – ECO TOILET
1. Water use reduction
2. Shock loading capacity
3. Odour problems Reduced
4. Lower household maintenance cost
5. End product recycled
6. Reduced grey water loading
7. Independence
8. Recycling
9. Unusual sites

44. Disadvantages - ECO TOILET
1. Construction
2. Maintenance
3. Management
4. Health Issues
5. Conditions

48. LEACH PIT RINGS

49. A mould is prepared in the interior of the squatting pan
and trap. The cement and sand can be used to cast
the plate and trap.
After setting, the pan and trap is cured.
The finished squatting pan and trap is transported to
the site. The latrine slab- Circular/Square is cast with
the squatting plate and trap is integral part of the slab
Hardened and cure slab is placed over the pit.
The squatting plate and trap may be made from
Ceramics, PVC, Cement, mosaic.

50. • The water dependent latrines can be further categorized on the
basis of:
• Flushing (pour flush or mechanical flush) ;
Location of pit
• onset type: if latrine room is just above the pit;
• offset type: if pit is slightly offset from the latrine room;
• Water quantity required (pour flush latrine: where 1/2-2 liters of
water is required for manual flushing;
• Excreta disposal system (pit latrine: where excreta is collected and
decomposed within a pit; The pour flush latrine is a specially
designed water-sealed bowl, which requires 1.5 - 2 liters of water
for flushing the excreta.
• This water seal latrine eliminates entry of odor and prevents
rodents to the latrine room from pit through the bowl. This pour
flush latrine consists of a single pit either just below the bowl
(onset type) or may be offset from the bowl (offset type) using the
pour flush type bowl (pan and trap).

51. SELECTION CRITERIA FOR
TECHNOLOGY
• Sustainability and lasting long-term benefits (impact);
• immediate benefits (quality, convenience, reliability)
• operation and maintenance;
• Up gradibility, working life, eventual replacement
possibilities;
• cost-effectiveness (capital and recurrent costs and type of
• materials requirements for construction); Affordability
• accessibility
• scope of up- gradibility
• Local skilled workers
• Sanitary latrine criteria
• Soil conditions

52. WATER SEAL LATRINES
Pour-flush Toilets
•It consists of a slab into which a special bowl is incorporated. The slab can
be fitted directly over a pit or slightly close to the pit.
•The pit may be single or double
•One to two liters of water is sufficient to flush the contents into the pit
•Because of the water seal, there is no fly breeding
•Odor can not escape out from the pit
The function of a water dependent latrine relies mainly on the usage of
water. Without water these latrines fail to operate. The water flushes out
excreta from bowl, which consists of a water-seal generally known as a
trap

53. RURAL PANS & TRAPS
The pan length = 450 mm
The slope is more than 45 degree
The water seal is 20mm
The passage for faeces is 750 mm
RURAL PANS & TRAPS

54. Rural Pans & Traps

55. PAN ABOVE THE PIT

56. ADVANTAGES OF PAN ABOVE THE PIT
•Odor free
•Little chance for transmission of excreta related disease
•Good health and hygiene practice
•Appropriate where water is available
•Long life time and no need to move for many years
•Water requirements for flushing is low (1/2-2 liters)
•Construction and maintenance are cheap and easy
•Offset type can be adjusted in any type of dwelling without causing
any smell nuisance
•Suitable for less populated areas where space is available for
relocating the latrine
•Possible to upgrade it into twin pit pour flush system (for offset type)

57. Special conditions – Soil and water
Table
Block Cotton Soil Areas
• The black cotton soils absorbs water and expands
• The pit may collapse
• The porosity of the soil is very low – leaching
capacity is low
• Circular pit - lining with rings made up with
cement and sand
• with re enforcement and holes for leaching
• A coarse sand envelop around the pit – 10 cms to
20cms

60. OTHER FACTORS
• Privacy is one of the factors that determines the use of
toilets in India
• The seats for male and female should be opposite direction
• The doors should open inwards
• The pans which is sticky or does not allow easy cleaning are
not accepted
• Latrines designed for too large number of users not
maintained properly
• One seated latrine is sufficient for a family
• For camps, markets, community, one seat for every 25-30 is
needed
• For schools one seat for every 20-25 Girls

61. SEPTIC TANKS
• It is costly
• It is suitable for Institutions where group of people live
together
• It has a covered settling tank where primary treatment takes
place
• It requires secondary treatment. Therefore the effluent from
septic tank must be treated properly by a Dispersion trench
or by a soak away pit. All this require land and money.
• Size of the tank has to be designed properly
• It requires de sludging

62. Super structure continued User’s taste ,
affordability,local materials, durability, existing
structures, privacy determine the superstructure.
Provide options for the users
Examples are Mud walls - plastered inside –Brick walls-
cement Hollow blocks Thatched wall and roof – leaves
of Coconut and Palmarah Tiled roof – Mangalore tiles,
cement tiles, asbestos sheet, tin roof,GI sheet
Jute/Gunny cloths, flexi/ Rexin sheets, bamboo Hilly
areas- slate stones - roof with slate of stones Ferro
cement walls and roof Stone walls
Remember
It always better to use existing structure of the house
for superstructure

64. SUPER STRUCTURE

67. • Latrines are part of the house., It should
adequately cared
• Only required water should be used for cleansing
• No antiseptic/disinfectant should be used
• No solid matters should be thrown in to the pan
• Water seal must always filled with water
• Platform should be dry
• Adequate lighting and ventilation keeps latrine
• Latrines gives privacy, promotes health of the
households
• It helps you to save time and energy
• It gives pride to family members and to the
country

68. Thank you…