ch1 water supply
Post on 04-Apr-2018
223 Views
Preview:
TRANSCRIPT
-
7/31/2019 Ch1 Water Supply
1/18
1. Water supply
Sudha Goel, Ph.D.
Assistant Prof. (Env. Eng.)Dept. of Civil Eng., IITKgp
Kharagpur 721 302
-
7/31/2019 Ch1 Water Supply
2/18
Objectives
Water supply: adequate quantity and safe, potablewater Sourcing and source protection
Treatment
Disposal of sludges Wastewater treatment: to mitigate
Public health concerns contamination of water
supplies (SW and GW), and soil, Environmental concerns - Ecological conservation,
recreational requirements
2
-
7/31/2019 Ch1 Water Supply
3/18
Design of water and wastewater systems
Identify need (demand) in terms of QUANTITY AND
QUALITY Identify SOURCES that can fulfill needs
Source Protection Programs
Criteria for source selection include: Quantity
Quality
Location Cost of development, collection and distribution
Sustainability
3
-
7/31/2019 Ch1 Water Supply
4/18
Water Usage Withdrawals = consumption + returns
Withdrawal = water extracted from surface or groundwater bodies
Consumption = water used but not returned (eg.,drinking, cooking, evaporation, transpiration, irrigation)
Returns (non-consumptive uses) = water returned towater body and can be used in the future
Compare per capita water use: Developed (e.g. US) = 1280 gal/cap-d = 1280x3.785 = 4845
L/cap-d
Developing (e.g. India) = 609 m3/cap-year = 1669 L/cap-d
4
-
7/31/2019 Ch1 Water Supply
5/18
Offstream water use involves the withdrawal or diversion ofwater from a surface or ground water source for:
Domestic and residential uses (consumptive) Industrial uses (both)
Agricultural uses (consumptive) Energy development uses (both)
Instream water uses are those which do not require a diversion orwithdrawal from the surface or ground water sources, such as:
Examples of non-consumptive water uses Water quality and habitat improvement, i.e., eco-conservation Recreation Navigation (Quality not an issue) Fish propagation Hydroelectric power production (Quality not an issue)
Quality is dependent on water use, i.e., not all water usesrequire the same water quality
5
-
7/31/2019 Ch1 Water Supply
6/18
Indian water uses
India: State of the Environment (2001) 6
-
7/31/2019 Ch1 Water Supply
7/18
Designated-Best-Use
Class of
water Criteria
1. Total Coliforms Organism MPN/100ml shall be 50 or less
2.pH between 6.5 and 8.5
3.Dissolved Oxygen 6mg/l or more
4.Biochemical Oxygen Demand 5 days 20C 2mg/l or less
1. Total Coliforms Organism MPN/100ml shall be 500 or less
2. pH between 6.5 and 8.5
3.Dissolved Oxygen 5mg/l or more
4. Biochemical Oxygen Demand 5 days 20C 3mg/l or less
1. Total Coliforms Organism MPN/100ml shall be 5000 or less
2.pH between 6 to 9
3.Dissolved Oxygen 4mg/l or more
4. Biochemical Oxygen Demand 5 days 20C 3mg/l or less
1.pH between 6.5 to 8.52. Dissolved Oxygen 4mg/l or more
3.Free Ammonia (as N) 1.2 mg/l or less
1.pH between 6.0 to 8.5
2.Electrical Conductivity at 25C micro mhos/cm Max.2250
3.Sodium absorption Ratio Max. 264. Boron Max. 2mg/l
Table 1 : Use based classification of surface waters in India
Drinking Water Source without
conventional treatment but after
disinfection
Propagation of Wild life andFisheries
D
Irrigation, Industrial Cooling,
Controlled Waste disposal
E
A
Outdoor bathing (Organised) B
Drinking water source after
conventional treatment and
disinfection
C
7CPCB
-
7/31/2019 Ch1 Water Supply
8/18
8
-
7/31/2019 Ch1 Water Supply
9/18
9
Domestic consumption of water (L/capita-day)
Use IS 1172-
1983, Lcd
IS 1172-
1993 (India),Lcd
AWWA, 1999, gcd
Drinking 4.5 5 (2.5%)
Cooking 49.5 5 (2.5%)
Bathing 75 (37.5%) 12.8 (18.5 %)
Washing clothes 25 (12.5%) 15.0 (21.7 %)
Washing utensils 15 (7.5%) 1.0 (1.4 %)
Cleaning homes 15 (7.5%) 10.9 (faucet 15.7 %)
Gardening 15 (7.5%) Outdoor use (
Flushing toilets, etc 22.5 45 (22.5%) 18.5 (26.7%)
Losses 9.5 (13.7%)
Public uses street
cleaning, fires,
flushing sewers,fire extinguishing
22.5
Industry and
commerce
22.5
Animal maintenance 13.5Total 135 200 (100%) 69.3 (100%) or 262
-
7/31/2019 Ch1 Water Supply
10/18
-
7/31/2019 Ch1 Water Supply
11/18
Factors affecting losses
Leakage at joints and corrosion of pipes
Pressure in distribution systems: higher pressure leads to higherlosses due to leakage
System of supply: Intermittent supply leads to fewer leakagelosses
Metering: unaccounted water loss is easy to monitor, leaks can bedetected and fixed
Unauthorized connections are reduced where supply is metered;easy to detect illegal connections where supply is metered.
11
-
7/31/2019 Ch1 Water Supply
12/18
Per capita consumption wrtpopulation and sewerage
12
-
7/31/2019 Ch1 Water Supply
13/18
13
-
7/31/2019 Ch1 Water Supply
14/18
Temporal variations in demand Seasonal: based on climate and crop requirements,
commercial, industrial (cracker industry), tourist spots
(religious or secular), institutional (schools, colleges,camps) activities can be seasonal
Daily: Fig 2.1 (SKG) and fig. 2.1 (KND). Trend isslightly different from the sources noted below. Daily
max can range from 1.8x daily average (SKG) to 2.5times daily average (KND).
Generally two peaks in a day: higher peak in morning
(0500 to 1100) and (1700 to 2300) and lowest flow(2300 to 0500) based on VW, SKG and AWWA (nodefinitive information). Specific and average trendscan be different for all the reasons discussed
previously. 14
-
7/31/2019 Ch1 Water Supply
15/18
15
-
7/31/2019 Ch1 Water Supply
16/18
-
7/31/2019 Ch1 Water Supply
17/18
Per capita water supply in Indian cities
17
-
7/31/2019 Ch1 Water Supply
18/18
18
top related