COMPONENTBASED ANALYSIS FOR WATER LOSS A TOOLKIT FOR PRACTITONERS AND APPLICATION IN SANDAKAN

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COMPONENT-BASED ANALYSIS FOR WATER LOSS-A
TOOLKIT FOR PRACTITONERS AND APPLICATION IN
SANDAKAN

• 14th June 2005

Presented by Richard Pilcher Principal
Operations Engineer Halcrow Water Services
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Overview of Presentation

• Assessment of water loss or Non-Revenue Water
  (NRW)
• FastCalc - the International Toolbox approach to
  practical leakage management
• Developing a NRW Reduction Strategy
• Sandakan Case Study

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Problem-Solving using the Toolbox approach
Economic Intervention Policy and Economic
Leakage Levels
Infrastructure Condition Assessment
Performance Indicators
IWA Water Balance, UARL, BABE and FAVAD concepts,
local parameter values, and national data
Components of Real Losses and Water Balance
Nightflow Analysis
Night-Day Factor
Pressure/Leakage Relationships
Pressure Management
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Assessment of Water Loss or Non-RevenueWater

• An assessment or audit of water loss identifies
• how much
• where
• why
• water is being lost.
• The objective of an audit is to assess the level
  of water loss and assists a water utility to
  plan, prioritise and manage an active leakage
  reduction strategy

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Three Methods of Assessing Real Losses

• Water Balance (most frequently used)
• Compare input volume over a period with
  components of consumption
• Component-based Analysis (BABE)
• Assess annual volumes lost from different types
  of leaks on different parts of the system
• Volume lost from each type of leak
• number of leaks x average flow rate x average
  run time
• Night Flow Analysis
• Measure inflow at night to individual sectors
• Take away estimates of night consumption
• What remains is background (undetectable) leakage
  and unreported leaks

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NRW - Assessment
The IWA Water Balance
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Assessment of NRW Investigations and Data
Collection

• Distribution system
• do source meters exist?
• if so are they accurate?
• how are the flows recorded?
• Customer billing
• are customer meters accurate?
• what is the integrity of the billing system (data
  processing)?
• Unauthorised use
• what level of problem is unauthorised use (meter
  tampering and theft)?

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A simple IWA Annual Water Balance Data
entry values Calculated values
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An IWA Water Balance Using Part of the FastCalc
Software
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Assessment of NRW How Reliable are Water
Balance Calculations?

• All volumes entered into a Water Balance are
  subject to error, to a greater or lesser extent
• But how reliable are calculated values for
  volumes of Non Revenue Water, Apparent and Real
  Losses?
• Use normal (Gaussian) statistical approach for
  this type of uncertainty analysis
• assess 95 confidence limits for each data entry
• calculate 95 confidence limits for each derived
  volume (NRW), Real Losses and Apparent Losses

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Assessment of NRW Using the 95 Techniques

• This is a powerful technique particularly so
  where
• data is not very reliable
• high variances identify priorities for improving
  data
• The results are surprising
• Easy to calculate with customised software such
  as Fastcalc

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Assessment of NRW Component Based Analytical
Software

• Use this software to
• derive water balance and an economically
  justifiable leakage management strategy
• set leakage performance criteria
• manage system pressure to achieve optimum
  performance - operational leakage control
• plan, prioritise and manage an active leakage
  reduction campaign

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Developing A Typical NRW Reduction Strategy

• Understand the timescale and funding for the
  reduction
• Set target interim and final
• Determine the appropriate mix of NRW reduction
  activities
• Implementation of activities
• Monitor and maintain (sustainability)

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Overview of the Sandakan System

• Second largest city in Sabah
• Population approx. 400,000
• Number of connections 35,000
• System input 80Mld
• Shortfall of water 37
• Length of pipework 570km
• 58 pipework Asbestos Cement
• 70km length of transmission main with known high
  losses

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Sandakan NRW Reduction Project Assessment of NRW

• Assessment of Losses
• Investigation and data collection
• Calculation of Water Balance
• Application of FastCalc
• Development of Strategy
• Develop Digital Mapping System
• Construct hydraulic model
• Analyse burst data, pipe samples
• Develop mains replacement programme

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NRW - Assessment

• The IWA Water Balance for Sandakan 2002

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Resons for High Water Loss in Sandakan

• Poor materials / infrastructure
• high burst frequency of AC pipes
• high leaks on service
• connections
• Water shortage
• rationing
• fluctuating pressures
• (exacerbate burst frequencies)
• Water pilferage
• - damage to fittings through theft
• of water

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Sandakan NRW Reduction Project Strategy
Implementation

• Implementation of Strategy
• design of District Meter Zones (DMZs)
• active leakage control
• reduction of physical losses by 15Mld
• pressure management
• Prompt and efficient repair of leaks
• training and technology transfer
• mains replacement programme to replace
  approximately 100km

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Sandakan NRW Reduction Project-Progress to Date

• Active Leakage Control
• 56 DMZs
• operational
• 5 pressure managed zones implemented
• 1600 leaks located and repaired
• 13 Mld water saved
• Mains Replacement
• 115 km identified for replacement
• 75km pipe laid

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NRW - Assessment
The IWA Water Balance for Sandakan 2004
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LEAKAGE
CALCULATOR
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