2.water supply
TRANSCRIPT
URBAN WATER SUPPLY SYSTEM
By Dr. Rabidyuti Biswas
Sources of water Surface water
Ground waterIntake works
Raw water storage
Water treatment plant
Clean water storage
Water distribution system
Water to consumers
Waste water Waste water treatment
Disposal River, lake, water bodies
Demand
COMPONENTS OF URBAN WATER SUPPLY
SYSTEM
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Available waterSurface water
EXISTING WATER SUPPLY SYSTEM
Underground water
Storage and treatmentDemand assessment
Distribution system
Consumers: - residential/ commercial/ industrial
Waste water collection
Treatment of wastewater
Disposal to steams/ drains / rivers (90%)
Irrigations / horticulture (<10%)
BASIC PLANNING CONSIDERATIONS• Area• Population• Per capita demand• Nature and location of facilities• Location of treatment plant, intake, wastewater disposal• Optimization through alternative plans and cost benefit analysis• Water quality and quantity• Plant siting• Mechanization/ instrumentation/ automation• Service building/ other utilities• Design period• Population forecast• Per capita supply/ based on demand• Quantity standard
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Water Balance
Total Water on Earth 1.36 X 109 Km3
Water in the Sea 97.3%Fresh Water 2.7%The Fresh Water is Distributed in to:Ice Caps & Glaciers 2.0844%Ground & Soil Moisture 0.6048% Lakes & Swamps 0.00945%In Atmosphere 0.00108%Streams 0.000027%
WATER SOURCES
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Sources of water
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Surface Water sources are fresh water collected on the ground or in a stream, river, lake, or wetland.
Surface water sources
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Surface water sources
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Sub-Surface water, or groundwater, is fresh water located in the pore space of soil and rocks. It is also water that is flowing within aquifers below the water table.
It is estimated that 15% of world-wide water use is for household purposes.
Choice of site
• Quantity of water available• Quality of source• Possibility of dam construction• Distance of source• Elevation of supply
GROUND WATER SOURCES
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INTAKE POINTS
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INTAKE POINTS
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Dam intake
INTAKE POINTS
Lake water intake
River water intake
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Intake systems
• Device or structure placed in a surface water source to permit the withdrawal of water from the source.
• Used to draw water from lake, reservoirs or rivers in which there is either wide fluctuation in water level or when it is proposed to draw water at the most desirable depth.
Location of intake
• Best quality of water available,• Absence of current, ice float • Navigation channel should be avoided• Away from flooding,• Accessibility, distance of pump station,• Location of power stations and
connectivity.
Total Utilization
Immediate Evaporation
70
Surface Water
115
Year 1974 Year 2025
Percolation into the Soil
215
Irrigation 95
Other Uses
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Other Uses
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77
Total Precipitation in Million Hectare Metre
Availability of Water in India
WATER DEMAD / USES
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WATER DEMAND /USES
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Purpose Consumption
lits/capita/day % Consumption
1 Drinking 05 2.5 2 Cooking 05 2.5 3 Personal cleaning 10 5 4 Washing utensil 10 5 5 Washing cloths 30 15 6 Bathing 70 35 7 Flushing of
toilets 45 22.5
8 Others 25 12.5 Total 200 100
Domestic Water Consumption IS1172: 1993
IS 1172:1993: Code of basic requirements for water supply, drainage and sanitation.
Domestic water consumptionDrinking
3%
Cooking3%
P.Cleaning5%
Utensil w sh5%
Cloth w sh15%
Bathing34%
Toilet f lsh22%
Others13%
Drinking
Cooking
P.Cleaning
Utensil w sh
Cloth w sh
Bathing
Toilet f lsh
Others
IS 1172: 1993
Water consumption standards for Indian cities
Town size (population) Consumption rate (lpcd)Up to 10,000 70- 100
10,000 – 50,000 100- 125
> 50,000 125-200
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Source: UDPFI Guideline, 1996
Standards for water supply
Purpose Potable @30 gpcd (135lpcd)
Non-potable @20 gpcd (90 lpcd)
1 Drinking 05 2 Cooking 10 3 Washing cloths 30 4 Washing utensil 20 5 Washing hand and
faces 10
6 Bathing 60 7 Floor washing 30 8 Flushing of toilets 60 Total @225lpcd 135lpcd 90lpcd
Source: Khare et al 2006.
Estimated Break up of Domestic Water Demand in Delhi
Domestic water demand for DelhiDrinking
2%
Cooking4%
Washing cloths13%
Washing utensil9%
Washing Hand and face
4%
Bathing28%
Floor washing13%
Toilet flushing27%
Continue…..
Continue…….
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30SOURCE: WSP-SA-2007.
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IMPOUNDING RESERVOIR
Impounding reservoir is a tank, used for storage of untreated surplus rainwater for use in dry season. This is also called raw water reservoir
STORAGE OF WATER
Storage of water may be required for raw water and also for clean potable water to meet average daily fluctuation and also for emergency use
Impounding reservoir
• It is a constructed pond in the valley of a stream to store water during excess stream flow and supply water when the flow of the stream is in sufficient to meet demand for water.
RAW WATER STORAGE
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RAW WATER STORAGE
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TREATMENT
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TREATMENT
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Water treatment/ purification is the process of removing contaminants from a raw water source.
Water purification may remove:
• Particulate sand; suspended particles of organic material; parasites, bacteria; algae; virus; fungi; etc. • Minerals calcium, silica, magnesium, etc., and Toxic metals lead; copper; chromium; etc.
Some purification may be selective in the purification process like smell (hydrogen sulphide remediation), taste (mineral extraction), and appearance (iron in capsulation).
Water treatment
The aim of water treatment is To produce and maintain water that is
hygienically safe, aesthetically attractive and palatable in an economic manner.
Treatment process
• Clarification• Sedimentation• Filtration• Disinfection • Other specific treatment
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TREATMENT
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TREATMENT
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TREATMENT
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TREATMENT
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TREATMENT
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Location of treatment plant
• Hill side is better location, • Highest flood level should be considered,
and platform should be above the level,
Other components
• Service building with – houses, laboratories, offices, washing room,
store room, chemical house and • pump house are required in all treatment
plant or even in pumping station.
CLEAN WATER RESERVOIR The clean water reservoir used for the
storage of pure/ filtered water after treatment until it is pumped into distribution or into service reservoir before distribution to the consumer and it provides for fluctuations in demand. Maximum one-day storage is recommended for clean water for sanitary point of view.
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CLEAN WATER RESERVOIR• The clean water reservoir’s wall must be of brick/ RCC or
stone masonry wall inside plastered with 2.5 cm cement mortar and made watertight.
• The reservoir should be divided into compartments so that the repair and cleaning may be possible in turn.
• The accessories required for these types of reservoirs are inlet, outlet, water level indicator, and manhole, ladder, overflow pipes etc.
• These reservoirs are generally made underground.
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CLEAN WATER STORAGE
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CLEAN WATER STORAGE
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CLEAN WATER STORAGE
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SERVICE RESERVOIRS• Service reservoirs are built to provide storage to
meet the fluctuating demands and to serve as balancing tanks to maintain the pressure during the hours of greatest demand.
• These reservoirs allow the pumps to work for a normal rate and to take rest. They meet emergent demands due to fire and failure of pumps and also reduce the hours of pumping.
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Types of service reservoirs Ground service reservoir Elevated service reservoir or high service
reservoir or overhead tank Balancing reservoir
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Location of service reservoir
• Used to regulate pressure in the distribution system
• Central location is the ideal place• However tail end reservoir is also
preferable
Service reservoirs
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Service reservoirs
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Service reservoirs
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Capacities of service reservoirs
• The capacity should be such that the reservoirs may store excess water for balancing the rate of pumping.
• Pumping is usually done for 8 to 10hrs a day and hence the minimum capacity must be of 14-16hrs average daily flows for storage when the pump is idle.
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DISTRIBUTION SYSTEM
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Design of distribution system
Depends on • Topography• Layout/ spread and expansion of city• Existing population, expected future
population, commercial and industrial land use
• Layout of road
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DISTRIBUTION SYSTEM
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DISTRIBUTION SYSTEM
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Fire hydrant
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Fire hydrant
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IS 908:1987: Specifications for fire hydrants
DISTRIBUTION SYSTEM
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WASTE WATER
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WASTE WATER
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WASTE WATER
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WASTE WATER
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WASTE WATER
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WASTE WATER MANAGMENT
• Treatment• Reuse / recycling• Disposal
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WASTE WATER DISPOSAL
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GREY WATER RECYCLE
GREY WATER RECYCLE
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Conceptual waste water reuses system Estimated Grey and black water generation system (Per capita wastewater generation in group housing apartments)
Grey water Total 100 lpcd (48 %) Black water, total 110 lpcd (52% of total wastewater) To sewer systems To grey water Treatment systems (With in the group housing plot)
Kitchen Sink (20lpcd)
Flushing of toilets (60lpcd) (27% of demand)
Bath, washing of hand & face (60+10) lpcd
Washing cloths (30lpcd)
Floor cleaning (30lpcd)
Case I Grey water Can be used for irrigation and Horticulture (can be acceptable for road side & parks out side residential plots) Case II Grey water
Can be used for flushing of toilet and fire demand. Acceptable option to the resident.
Case III Grey water
Can be used for drinking (high cost) May not be acceptable by resident
Septic tank (storage)
Septic tank (storage) Disinfections Simple
Filtration
Septic tank (storage) Disinfections Filtration ,
UV or RO
Process of Grey water for different uses
Sources of water Surface water
Ground waterIntake works
Raw water storage
Water treatment plant
Clean water storage
Water distribution system
Water to consumers
Waste water Waste water treatment
Disposal River, lake, water bodies
Rainwater
Grey water
Recycled
Flushing,horticulture
Demand
Reduceddemand
Ground water recharge
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Available water Surface water
CONCEPTUAL WATER SUPPLY SYSTEM
Underground water
Storage and treatment
Potable water demandDistribution system
Consumers: - residential/ commercial/ industrial
Waste water collection
Treatment of wastewater
Disposal to steams/ drains / rivers
Irrigations / horticulture
Recycled water (20-30%)
Rainfall/ runoff (10 - 15%) Recharge
Non-potable water demand
Demand reduction/ water saving equipments/ policy (20 - 25%)
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PLANNING OF WATER SUPLLY
ORGANISATIONS AND JURISDICTIONS
1.National level – CPH&EEO2.State level or regional level – PHE3.Individual community/ town/ city – Local Government
Though the responsibility of the various organizations in charge of planning of water supplies in each of these cases is different, still they have to work/ function with in the priority fixed by the national and stage governments.
PHYSICAL PLANNER & URBAN WATER SUPPLY
1. WATER SYPPLY SYSTEM
2. CLASSIFICATION
3. METHODS
4. COMPONETS
5. AREA REQUIREMENTS WITH CAPACITIES
6. POLICIES AND INSTITUTIONAL ARRANGEMENT
7. MANGEMENT APPROACHES
8. MANAGEMENT PRACTICES
9. BEST MANAGEMENT PRACTICES (ABROAD AND INDIA)
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