Session 2: Urban Water Supply
SANJEEB MOHAPATRA M Tech Environmental Engineering Project Trainee National Environmental Engineering Research Institute, Nagpur Swapnil Kamble Project Assistant ESDM, NEERI, Nagpur
Dr. A P Sargaonkar Principal Scientist ESDM, NEERI, Nagpur
S.R. Watpade Deputy Engineer NMC, Nagpur
Dr. P K Labhasetwar Principal Scientist, WTM, NEERI, Nagpur
Sridevi H. Assistant professor M IT, Manipal, Karnataka
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Outline • • • • • • •
Introduction Objective Literature Review Methodology Result & Discussion Conclusion References 2
Introduction •
Water Distribution System – Raw water source, Treatment Plant, Pumping Station, Reservoir/Tank – Pipe/Distribution Network
•
Hydraulic Integrity – Hydraulics – Water Quality
•
Problems – Developed vs Developing countries – Intermittent supply
•
EPANET Capability – Hydraulics – Water Quality – Limitation
Objective Performance evaluation of the pilot water distribution system for: - Intermittent Analysis - Diurnal Analysis 3
Literature Review
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Hydraulics of Intermittent Supply •
Specific problems include (Halcrow Water Services and Bristol Water Services, 2003; Tiwari,2012): – – – – –
Serious risk to public health Inability to practice effective supply management; Inability to practice effective demand management; Operational inadequacies, which unduly weaken the physical infrastructure; Customer inconvenience. • •
•
W.r.t Time W.r.t Quantity
“Charging” process in pipes •
This is a short period (first 20-30 minutes)
Pressure dependent demands (Vairavamoorthy,2008 Buchberger,2008) Where: Hi: Pressure at a node i Hmin: Minimum required pressure at a node i Hmax: Maximum pressure at a node i Qi: Demand at a node i Qmax: User specified (requested) demand at a node i 5
Household Reservoir
(http://sdteffen.de/diplom/web/node11_ct.html) •Each demand node is represented by artificial reservoir (Buchberger,2008). •Infinite sink •Total head = Elevation + Pressure Head (1 meter)
Equivalent Pipe Diameter The individual reservoir fill rates depend mainly on the headloss over the pipeline that connects the tank to the network. (Bansal,1989;Buchberger,2008; Walski, 2003). Where
=Diameter of equiva =Length of equival =Roughness of equiv =Diameter of individ =Length of individ =Roughness of indi
Fractal Theory and Diurnal Pattern •Hourly Water Consumption •Pump Schedule •Reservoir Design •Electricity Consumption
•Urban water consumption time series has obvious fractal characteristics (J.Q. Liu 2004). 6
Methodology
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Study area Details
Source of Water
Kanhan and Pench River
Supply Mode
Intermittent (Gravity Fed)
Supply Hr
6:00 to 7:30AM
Length of Transmission Main (700mm)
6.4 km
Length of pipes in Distribution Network
11.4425 km
Length of Service Pipes
5m 8
11
33
22
44
55
Figure No.
Study area Description
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Pilot Study area
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IKONAS Image
3
Pipe and Nodes
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Thiessen Polygon
5
Houses
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Calibration and Validation Location ID
Latitude
Longitude
Mean pressure (Meter)
Mean Flow Rate (lps)
34
21°08`09.0`` N
79°05`47.6`` E
1
0.15
104
21°08`02.7`` N
79°05`54.0`` E
1
0.16
100
21°08`03.8`` N
79°05`55.8`` E
0
.35
122
Loca tion ID
Mean Error of pressure
Mean Error of Demand
130
141
34
0.110
0
2003 to 2011
140
140
104
0.046
0
GI
2003
120
120
MS
1980
90
122
100
0.006
2.75
Pipe Type
Year of Installation
Roughness Before Calibration
Roughness After Calibration
CI
1980
75
CI
2003 to 2011
DI
Location ID
Observed Mean pressure (Meter)
Computed Mean pressure (Meter)
Observed Mean Demand (lps)
Computed Mean Demand (lps)
34
1
1.11
7.50
7.50
104
1
1.05
4.80
4.80
100
0
0.01
8.75
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Correlation Between Means of Pressure: 0.945
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Result And Discussion Affected population number is 4065
Pressure condition for Intermittent Water Supply
Continuous Water Supply 11
Transmission Main (700mm) Parameter
Before Calibration
After Calibration
Velocity (m/sec)
1.15
1.57
Unit Head loss (m/km)
3.24
3.25
Distribution main (400mm) Velocity (m/sec)
2.31
3.61
Unit Head loss (m/km)
>5
>5
Results after Validation •From this table it is clear that the diameter of the Distribution main is insufficient. •Total 34 nodes are under pressure of 1 meter, where as minimum recommended pressure is 7meter (CPHEEO, 1999). 12
Conclusion •
Both intermittent and continuous water supply modes were simulated successfully using EPANET.
•
The pilot area is under very low pressure.
•
The continuous supply simulation results relatively higher pressure value, less than 12 meter.
•
It is recommended to avoid the direct tapping of water from the transmission main, rather it is advised to build an elevated service reservoir (ESR) for the pilot study area to maintain the hydraulic integrity.
•
The identified leakage points need to be repaired.
•
This particular information is very essential for Nagpur Municipal Corporation to improve the existing system for effective pressure and flow management
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Reference Bhave, P. R., (1988): Calibrating water distribution network models. Journal of Environmental Engineering, 114:1, pp.120–136. Feder, J., (1988): Fractals. New York: Plenum Press. HydroGen (Hydraulic Model Generator) Version 2.2. (n.d.). ArcScripts Home - ESRI Support. Retrieved September 1, 2012 Archive, On line at: http://arcscripts.esri.com/details.asp?dbid=10117 Jethoo, A. S., & Poonia, M. P., (2011): Water Consumption Pattern of Jaipur City (India), International Journal of Enviromental Science and Development, 2:2, pp. 152-155. JNNURM. (n.d.). JNNURM. Retrieved September 10, 2013 Archive, On line at: http://jnnurm.nic.in/ Manual on water supply and treatment (3rd ed.) (1999): New Delhi: Central Public Health and Environmental Engineering Organisation, Ministry of Urban Development. Ministry of Urban Development. (n.d.). Ministry of Urban Development. Retrieved September 5, 2012 Archive, On line at: http://urbanindia.nic.in/ Peter, I., Zdenek, S., Pradhan A. and Tarai A., (2006): Modeling Intermittent Water Supply Systems with EPANET, 8th Annual WD Symposium, EPA Cincinati, August 27-30. Qian, B. R., (2004): Hurst exponent and financial market predictability. IASTED conference on Financial Engineering and Applications (FEA 2004). pp. 203-209. Rossman, L. A. (2000): EPANET users manual. Cincinnati, OH: United States Environmental Protection Agency, Risk Reduction Engineering Laboratory. Vairavamoorthy, K., Gorantiwar, S.D. And Pathirana A (2008)., Managing urban water supplies in developing countries-Climate change and water scarsity scenarios, Physics nad Chemistry of earth, 33, pp. 330-339. Walski, T. M. (2003): Advanced water distribution modeling and management, Haestead Press.
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