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Water Safety Plans for O&M Improvements Water Safety Conference Kuching, Malaysia 2- 4 November 2010 Asoka Jayaratne Water Quality Specialist Yarra Valley.

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Presentation on theme: "Water Safety Plans for O&M Improvements Water Safety Conference Kuching, Malaysia 2- 4 November 2010 Asoka Jayaratne Water Quality Specialist Yarra Valley."— Presentation transcript:

1 Water Safety Plans for O&M Improvements Water Safety Conference Kuching, Malaysia 2- 4 November 2010 Asoka Jayaratne Water Quality Specialist Yarra Valley Water Melbourne, Australia

2 1 May 20152Yarra Valley Water Ltd Outline  Linkage between Water Safety Plan (WSP) and operation & maintenance (O&M)  Lessons learned from poor O&M practices  WSP as a tool to drive O&M improvements  O&M framework for safe water

3 1 May 20153Yarra Valley Water Ltd Why Do We Need Water Safety Plans?  Aim of water supply system Provide safe drinking water Provide safe drinking water 100% of the time Does zero E coli mean safe drinking water?

4 System Assessment Water Safety Plans Health-based targets (National regulatory body) Independent Surveillance (Surveillance agency) Public health context and health outcomes Linkage between WSP and O&M WHO Framework System Assessment Operational Monitoring Management Plans

5 1 May 20155Yarra Valley Water Ltd Linkage between WSP and O&M Water Safety Plan Concepts A documented plan that: Identifies hazards, assesses risks from catchment to consumer Prioritises risks focus on highest risks Mitigates risks through control measures Meaning: Less output monitoring (final water) More input monitoring (is the system working?) Consumer system Distribution system Water resources & sources Treatment

6 Assemble the WSP team Preparation Describe the water supply system Identify the hazardous events and assess the risk Determine and validate control measures reassess and prioritise risks Develop, implement and maintain an improvement/upgrade plan System assessment Define monitoring of the control measures Operational Monitoring Verify the effectiveness of the WSP Prepare management procedures Develop supporting programmes Management and communication Plan and carry out periodic review of the WSP Revise the WSP following an incident Feedback and improvement Linkage between WSP and O&M WHO Manual – WSP Components

7 1 May 20157Yarra Valley Water Ltd The Link Water Safety Plan Good O&M Processes Well developed O&M Procedures = Effective Water Safety Plan = Safe water 100% of time Poor O&M Procedures = ineffective Water Safety Plan = Potentially unsafe water

8 1 May 20158Yarra Valley Water Ltd Poor O&M = Unsafe Water Supply Lessons from the past….

9 Gideon, Missouri, May 20159Yarra Valley Water Ltd Hazard (contaminant): Salmonella Hazardous event (cause): Pigeons nesting on a water tank roof Tank roof was not sealed and pigeon faeces washed into the tank There was a concentration of Salmonella bacteria in the water tank sediment and at the surface The water tank rapidly drained into the distribution system during a flushing event and chlorine residual was not maintained Effect ~ 500 ill from town of 1,104 7 Dead

10 MacKenzie et al, 1984; Corso et al, acd 2 March 2006 Milwaukee, Wisconsin, 1993  Hazard (contaminant): Cryptosporidium oocysts  Hazardous event (cause): Runoff from heavy spring rains Carrying sewage into Lake Michigan (from which raw water was drawn) Coagulation problems on the filtration system in Milwaukee’s Southern water treatment plant Turbidity did not rise above 1.7 NTU  Effect: 400,000 ill from 1.2 million in city 100 dead US$96.2 million 1 May Yarra Valley Water Ltd

11 Oulu, Finland, May Yarra Valley Water Ltd Hazard (contaminant): Campylobacter Hazardous event (cause): Water and sewer burst at the same time and place The water main was repaired and flushed out but traces of sewage remained in the water main Traces of Campylobacter remained in the water main after it was reinstated The supply was not a chlorinated one Effect ~ 50 medically attended cases from town of around 15,000

12 O’Connor, 2002 Walkerton, Ontario, ages/e-coli-0157-h7-C.jpg acd 2 March Hazard (contaminant): E. coli O157:H7 Campylobacter jejuni Hazardous event (cause): Heaving Spring rains Cow manure washed into the well No on line monitoring Failure to chlorinate Water supplied by local water utility Operators, managers & government cutbacks found responsible Effect 2,300 ill 7 Dead $ C$155 million 1 May Yarra Valley Water Ltd

13 Northampton, UK, 2008 Hazard (contaminant): Cryptosporidium oocysts Hazardous event (cause): Rabbit got into a water tank and released its load of faeces and oocysts Detected by water testing under UK testing regulations Identified by UK molecular typing Effect ~ 30 ill from 250,000 in city UK HPA 1 May Yarra Valley Water Ltd

14 Brisbane, Australia 2009  Hazard (contaminant): Fluoride  Hazardous event (cause): Fluoride mistakenly pumped into water main whilst there was no flow within that main Levels of fluoride exceeded guideline values for lifetime exposure Most of the water returned to plant for backwash so only minimal exposure  Effect no illness likely public confidence issues Pascoe, May 2015Yarra Valley Water Ltd14

15 32% of waterborne disease outbreaks in US are caused by microbial pathogens in the water distribution system Source: AWWA and Centres for Disease Control and Prevention Distribution system re-contamination

16 1 May 2015Yarra Valley Water Ltd16 The List goes on!! outbreaks in affluent countries

17 1 May Yarra Valley Water Ltd Water Safety Plans for O&M Improvements

18 1 May Yarra Valley Water Ltd Driver for O&M Improvements  WSP Drives Improvements Structure to identify gaps in routine/emergency maintenance Identify gaps in operational procedures based on level of risks Infrastructure upgrades leading to improved operations  Benefits Longer term cost savings due to reduced incidents and events Improved operational efficiency

19 1 May Yarra Valley Water Ltd WSP for O&M Improvements Australian Examples – Yarra Valley Water  Gaps in tank inspection and maintenance program  Improved spot chlorination method  Improved storage area security procedures

20 1 May Yarra Valley Water Ltd WSP for O&M Improvements Australian Examples - YVW  Equipment calibration programs  Treatment chemical (hypochlorite) QA procedures storage and shelf life impurities batch control  Water quality focus on water mains construction and replacement process – new industry Code  Incident and emergency management protocols

21 1 May Yarra Valley Water Ltd WSP for O&M Improvements Lao – Pakse Water Supply  Identified key O&M issues related to treatment  Sand filter short circuiting (mud ball formation) is a critical risk  Control measures Regular inspection and cleaning of sand filter bed Refilling when required

22 1 May Yarra Valley Water Ltd WSP for O&M Improvements Australian Examples Treatment Plants – Melbourne Water Improved Disinfection Plant Contingency Plans Well defined critical limits Alarms Response procedures Improved O&M Protocols Identify systemic issues Treatment upgrades based on risk Addition of UV Mn removal step

23 1 May Yarra Valley Water Ltd WSP for O&M Improvements Examples from India  Pilot WSP - Hyderabad Metropolitan Water Supply and Drainage Board Identified O&M issues based on level of risk  funding requirements Leakage from sewers Infiltration from storm water drains Illegal sewer connection

24 1 May Yarra Valley Water Ltd WSP for O&M Improvements Examples from India Pilot WSP - Hyderabad Metropolitan Water Supply and Drainage Board Treatment plant operational issues Non uniform dispersion of chlorine Inconsistent alum dosing Sand filter backwash not based on head loss Non representative lab sample program Inadequate chlorine residual monitoring

25 1 May Yarra Valley Water Ltd O&M Plan - Key Components  Standard Operating Procedures (SOP) for operation of water supply system from the catchment to consumer including Operational Manuals  Procedures for programmed and unscheduled (emergency) maintenance activities  Emergency and Incident Management Protocols and Manuals  Equipment calibration and maintenance programs  Asset information data capture and management systems

26 1 May Yarra Valley Water Ltd O&M Plan - Key Components  Key Performance Indicators (KPI)  Monitoring, reporting & review of KPI (government regulated/self regulated)  Long term asset management strategy and funding arrangements  Staff and contractor training programs  Quality Control / Quality Assurance systems, internal and third party Auditing (of WSP, O&M process and KPIs)

27 1 May Yarra Valley Water Ltd O&M Plan Examples - Storage  Reservoir water quality monitoring program  off take levels Normal operation Events (floods, after fires, algal blooms)  Reservoir inspection program - security  Algae management plan  Contingency plan for high rainfall events

28 1 May Yarra Valley Water Ltd O&M Plan Examples - Treatment  Maintenance program – filters, equipment…..  Water treatment plant operational procedures  Operations and Emergency Response Manuals  Contingency plans for treatment plant failures  Treatment chemical quality control procedures

29 1 May Yarra Valley Water Ltd O&M Plan Examples - Distribution  Storage tank operational procedures – taste and odour, chlorine….  Storage tank structural inspection and cleaning program  Valve and hydrant inspection programs  Water main break repair procedures (flushing, disinfection, shut down)  Mains replacement program (prioritised based on risks)  Backflow/cross connection prevention program  Asset information system - data collection, analysis and reporting

30 1 May Yarra Valley Water Ltd Time to develop a Good O&M Plan to deliver safe water


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