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
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
13 April 2015
Yarra Valley Water Ltd
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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?
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Yarra Valley Water Ltd
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Linkage between WSP and O&M
WHO Framework
Health-based targets
(National regulatory body)
Public health context
and health outcomes
Water Safety Plans
System
System
Assessment
Assessment
Operational
Monitoring
Management
Independent Surveillance
(Surveillance agency)
Plans
Linkage between WSP and O&M
Water Safety Plan Concepts
Water
resources &
sources
Treatment
Distribution
system
Consumer
system
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?)
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Yarra Valley Water Ltd
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Linkage between WSP and O&M
WHO Manual – WSP Components
Preparation
• Assemble the WSP team
System assessment
•
•
•
•
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
Operational Monitoring
• Define monitoring of the control measures
Management and communication
• Verify the effectiveness of the WSP
• Prepare management procedures
• Develop supporting programmes
Feedback and improvement
• Plan and carry out periodic review of the WSP
• Revise the WSP following an incident
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
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Yarra Valley Water Ltd
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Poor O&M = Unsafe Water Supply
Lessons from the past….
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Yarra Valley Water Ltd
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Gideon, Missouri, 1993
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
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Yarra Valley Water Ltd
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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
www.ionizers.org/images/cryptosporidium.jpg acd 2
March 2006

Effect:
• 400,000 ill from 1.2 million in city
• 100 dead
• US$96.2 million
MacKenzie et al, 1984; Corso et al, 2003
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Yarra Valley Water Ltd
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Oulu, Finland, 1998
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
13 April 2015
Yarra Valley Water Ltd
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Walkerton, Ontario, 2000
Hazard (contaminant):
E. coli O157:H7
Campylobacter jejuni
Hazardous event (cause):
www.cdc.gov/ncidod/eid/vol5no1/altek2b.jpg
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
www.ehagroup.com/epidemiology/illnesses/im
ages/e-coli-0157-h7-C.jpg acd 2 March 2006
13 April 2015
• 2,300 ill
• 7 Dead
• $ C$155 million
Yarra Valley Water Ltd
O’Connor, 2002
12
Distribution system re-contamination
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
The List goes on!!
400 + outbreaks in affluent
countries
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Yarra Valley Water Ltd
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Water Safety Plans
for
O&M Improvements
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Yarra Valley Water Ltd
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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
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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
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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
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Yarra Valley Water Ltd
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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
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Yarra Valley Water Ltd
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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
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Yarra Valley Water Ltd
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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
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Yarra Valley Water Ltd
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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)
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Yarra Valley Water Ltd
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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
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Yarra Valley Water Ltd
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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
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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
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Yarra Valley Water Ltd
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Time to develop a
Good O&M Plan
to deliver safe water
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