Twenty Minutes on Preparation and Implementation of Water Safety - PowerPoint PPT Presentation

Twenty Minutes on Preparation and Implementation of Water Safety Plan for Nagpur Pawan Labhasetwar Scientist & Head, Water Technology & Management Division CSIR-NEERI, Nagpur 1

Outline of presentation • Introduction to water safety plan • Water safety plan – Case study of Nagpur – Catchment – Source – Treatment – Storage – Distribution – Households • Take away

What is a Water Safety Plan? Water Distribution Treatment Consumer resources & system system sources A documented plan that: • Identifies hazards, assesses risks from catchment to consumer • Prioritises risks and focus on highest risks • Mitigates risks through control measures Meaning: • Less output monitoring (final water) • More input monitoring (is the system working?) 3 Yarra Valley Water Ltd

Water Safety Plan Implementation

Study Area – Nagpur • Area : 217 km 2 • Population: 2.5 million (2011) • Water supply regulated by Nagpur Municipal Corporation (NMC) and operated by Orange City Water Private Limited (OCW) • >90% coverage • 350,000 connections • 650 MLD treated water • 50% non-revenue water • 25% population < 135 lpcd • 4-24 hours supply

A step-by-step Approach For WSP Step 1. Assemble the WSP team Step 2. Describe the water supply system Step 3. Identify hazards and hazardous events and assess the risks Step 4. Determine and validate control measures, reassess and prioritize the risks Step 5. Develop, implement and maintain an improvement/upgrade plan Step 6. Define monitoring of the control measures Step 7. Verify the effectiveness of the WSP Step 8. Prepare management procedures Step 9. Develop supporting programmes Step 10. Plan and carry out periodic review of the WSP Step 11. Revise the WSP following an incident

Water System Elements - Catchment Extraction Treatment Storage Watershed Distribution Households Water meter

Totladoh Dam Pench Khairi Reservior Gorwada Lake Mahadula Pumping

Totladoh Dam Pump House Pench Khairi Reservior BPT 2300 mm Line Gorwada Lake Mahadula Pumping Pench 4 WTP

WSP team assisted in identifying ash Catchment pond contamination 7.6 mg/l fluoride Immediate communication between stakeholders– WTP operator and power plant operators (MAHAGENCO)

Zoo activities shifted outside the Catchment catchment

Water System Elements- Treatment Plant Extraction Treatment Storage Watershed Distribution Households Water meter

Unregulated Flow of PAC Dose at Gorewada Treatment Plant

Aquatic Weeds in Clarifier at Old Gorewada Treatment Plant, Nagpur

Treatment Old Gorewada WTP Hazardous events Control Measures Enacted Identified Coagulation with PAC being done, with No coagulant dose mixing ensured by turbulence due to baffles provided at inlet channel Pre-chlorination done with appropriate Algae in raw water dosing and periodic cleaning All electrical and mechanical equipment Poor operation and have been taken under monthly preventive maintenance maintenance contract. Malfunctions are reported immediately and addressed.

Water System Elements - Storage Extraction Treatment Storage Watershed Distribution Households Water meter

Broken Inlet Chamber of Master Balancing Reservoir at Seminary Hill

Leakage from Inlet Valve of Master Balancing Reservoir at Seminary Hill

By-pass valves installed at reservoirs Storage to facilitate cleaning and repair

Water System Elements - Distribution Extraction Treatment Storage Watershed Distribution Households Water meter

Modern Risk Management Principles – IRA-WDS Focus on : Water Distribution System (WDS) Improved Reducing leakage Quantity Management Risk Assessment Study for Contaminant Intrusion + Improved Water Quality Determine how contamination Management may arise Take measures to prevent contamination 3 Modules of IRA-WDS Pipe condition Assessment Model (PCA) Contaminant Ingress Model (CIA) Risk Assessment Model (RAM)

Selection of Study Area for Risk Assessment Study of WDS Data Collection Reshimbagh Study Area with Road Network 1. Nagpur Municipal Corporation (Reshimbagh Office) 2. DRA Consultancy 3. Field survey

GIS Mapping Water Supply Network AutoCAD Maps : DRA consultancy (NMC) Sewer and Drain Network Attribute data Installation year, Diameter, Material, Length, Locations of valves, Bury depth, Manhole No., Ground elevation etc.

Analysis of Data on Pipe Breakages No of Breaks = 107 No of Breaks in pipes = f(Installation Year, Traffic load) No of Bursts = 81 No of Bursts in pipes = f(Installation Year, Material type) Pipe Material Installation Year Traffic Diameter Source : NMC Local Authorities

1. Very High Risk GIS Mapping & Risk Assessment 2. High Risk

WS line passing through zone of High Risk due to Bad contamination due to open drain Pipe Condition and sewer crossing WS Pipe ID: 1135 Material: CI Diameter: 100mm Installation year: 1980 Traffic: Busy Breakage: 2 /year Bursts: 2 /year Leakage: 0.21 lps Pipe Condition: Bad WS Pipe ID: 1141 Material: CI Diameter: 100mm Installation year: 1980 Traffic: Quiet Leakage: 0.08 lps Pipe Condition: Good

Pressure and leakage monitoring Pressure measurement points 2 Leakage points

Water quality testing for various Physico-chemical and microbial parameters at Reshimbagh and Wanjari Nagar  At ESR  At critical locations in distribution system  At Consumer end (critical locations of Chandan Nagar and Siras Peth) Water Storage tanks

Physico-Chemical and Microbial Analysis: Consumer end samples Sampling Area Siras Peth Chandan Nagar Sample Id SP-1 SP-2 SP-3 CNPT-1 CNPT-2 CNPT-3 CNPT-4 ( O C) Temp 29.4 30.4 30.2 31.1 31.1 31.1 30.8 pH 8.4 8.1 8.3 7.8 8.1 7.9 8 EC (µS/cm) 286 294 285 269 245 249 242 TDS (mg/L) 171.6 176.4 171 161.4 147 149.4 145.2 Turbidity (NTU) 0.4 0.8 0.2 9 1 1.8 1.3 Res. Cl (ppm) <0.1 0 0.1 0 0.1 0 0.1 Total Hard (mg/L) 108 108 112 126 96 69 104 Ca Hard (mg/L) 72 70 72 72 64 64 68 Mg Hard (mg/L) 36 38 40 54 32 32 36 Total Alk (mg/L) 166 184 180 196 176 168 164 Chloride (mg/L) 23 18 42 33 32 28 34 TC ND ND ND 7600 ND 1040 ND (CFU/ FC ND ND ND 6000 ND 126 ND 100ml) FS ND ND ND 50 ND 96 ND

Distribution Control Measures  550 km pipeline has been laid using HDD technology to speed up laying of pipeline.  HDPE pipes will eliminate the problem of water pilferage  Repair and upgradation of existing system in pilot area resulted in longer supply hours and improved water quality.

Water System Elements- Households Extraction Treatment Storage Watershed Distribution Households Water meter

Average FC Count At Different Locations From Source to P-O-U 90 80 70 60 CFU/100ml 50 40 30 20 10 0

Sanitary Survey at Select Households A yes answer is interpreted as a risk Question asked : Yes answer Is storage design for dipping: 88%  Do they use dipper with short/no handle: 67%  Is the vessel accessible for children: 58%  Do they pour back excessive water: 43%  Is the vessel made of non-durable material: 33%  Do they lack lid on storage vessel: 17%  Is the inside of the vessel hard to clean: 13%  Are there signs of dirt around opening: 11%  The three most common risks are : 1. Storage designed for dipping 2. Use of short/no handle or hand for extraction 3. Storage vessels accessible for children. Unimproved storage, poor handling habits, unsafe extraction which could be a pathogen entrance route.

Risk Matrix

Total Hazards Identified – 109 + 13 Earlier identified Catchment 28 7 Earlier addressed SURFACE WATER 1 New identified New addressed 3 Pumping Station 4 Break Pressure Tank 13 8 2 Storage Treatment Plant 42 28 8 16 13 Consumer 10 ? Distribution 5

Take away Water Safety Plan is a useful tool if it is implemented in right spirit

Acknowledgement • Conference Organiser • World Health Organisation • Nagpur Municipal Corporation • Orange City Water Private Limited • Director, NEERI • My colleagues - Aabha, Anisha, Priyanka, Viji and Priya • Dr Kapil Chandrayan

Thanks