Introductions and Workshop Goals

The workshop will provide a comprehensive approach to Non-Revenue Water identification and reduction, in a cost effective and environmentally beneficial manner. Pure Technologies, a Xylem brand provides an integrated portfolio, which includes several smart solutions for Non-Revenue Water issues that are being faced by municipalities across Ontario.
Clayton MacDougald – Business Development Manager
Kingsley Blease – Project Manager, Non-Revenue Water

Xylem AIA Platform


Transform the economics and reliability of water and related civil infrastructure with software and data analytics-enabled services


Build an integrated portfolio of solutions that attack waste in infrastructure capital and operating budgets


    • Drinking water

Real losses, apparent losses, reliability, capital optimization

    • Wastewater

Combined sewer overflows, sewer health, capital planning

    • Water resources

e.g. ports, harbors, canals, waterways

    • Energy

e.g. oil and gas pipelines; gas and electric utilities


  • Annual multi-billion dollar shortfall to replace or repair aging infrastructure / facilities
  • Increasingly stringent environmental regulations
  • Population growth, growing economic activity and high water losses/use drive the need for cost effective management and maintenance programs

AIA Portfolio

Workshop Outline

  1. International Water Association (IWA) Water Audit
  2. Real Losses – Active Leak Detection: Distribution Mains – District Meter Areas (DMAs)
  3. Real Losses – Active Leak Detection: Transmission Mains
  4. Watermain Condition Assessment
  5. Distribution Sensors and Smart Networks
  6. Environmental Benefits – Greenhouse Gas Reductions
  7. Apparent Losses – Customer Metering Revenue Loss

IWA Water Audit and Water Balance

  • IWA – International Water Association
  • Focus on accounting for all revenue water, to identify Non-Revenue Water (NRW)
  • Water loss in past referred to as “Unaccounted For Water – UFW”. Not to be used any more!
  • Updated in 2009 and 2016 – AWWA: M36 Water Audits and Loss Control Programs – “IWA Methodology”
  • Real Losses – “Active Leak Detection” – to find unreported leaks
  • Apparent Losses – “Customer Meter Under-Registration”
  • North American Best Management Practice (BMP)

Benefits of Reducing NRW

Niagara Region (Reduce Leakage)

  • Preserve limited resource
  • Provide water for population increase
  • Reduce Greenhouse Gas Emissions

Area Municipalities (Reduce Leakage and Increase Customer Revenue)

  • Reduce water purchase costs
  • Reduce emergency repair costs and damage liability
  • Increase revenues from under-registering customer meters

Real Losses – Unreported Leaks (not surfacing)

Real Losses – Unreported Leaks (not surfacing)

Real Losses – Reported Leaks (surfacing)

Real Losses – Reported Leaks (surfacing)

Apparent Losses – Under-Registering Customer Meters Example 1

Apparent Losses – Under-Registering Customer Meters. Example 2.

Water (Real) Losses and Costs

Water Purchased Per Year

m3 per day

Water Purchased Per Year

m3 per year

Water Loss Per Year (13% Water Purchased)

m3 per day

Purchase Cost (Water Only)

$ per m3

Value of Water Loss PER YEAR

$ per year

40,000 14,600,000 1,900,000 $0.60 $1,120,000
20,000 7,300,000 950,000 $0.60 $560,000
10,000 3,600,000 480,000 $0.60 $280,000

Revenue Loss (Apparent Losses)
Under Registering Customer Meters

Water Sold To Customers Per Year

m3 per day

Customer Meter Under- Registration


Water and Sewer Rate

$ per m3

Revenue Loss PER YEAR

$ per year

12,800,000 3% $2.80 $1,080,000
6,400,000 3% $2.80 $540,000
3,200,000 3% $2.80 $270,000
1,600,000 3% $2.80 $135,000

Real and Apparent Losses Total

Water Purchased Per Year Real Losses (Water Loss)


Apparent Losses (Revenue Loss)


Total Losses


14,600,000 $1,120,000 $1,080,000 $2,200,000
7,300,000 $560,000 $540,000 $1,100,000
3,600,000 $280,000 $270,000 $550,000
1,800,000 $140,000 $135,000 $275,000

Think About Costs and Knowledge

Do We Really Know Volumes and Costs?

  • Into system – Treat and pump water (flowmeter accuracy)
  • Out of system – Customer sales (meter accuracy: under-registration)
  • Out of system – Municipal use (much not metered)
  • Out of system – Leakage (unknown)

How Do We Increase Knowledge?

AWWA / IWA Water Audit and Water Balance

  • Establish Revenue and Non-Revenue Water
  • Complete every year – use full year’s data
    • Source water in, and flowmeter accuracy
    • Water sold, and customer meter accuracy
    • Municipal water use estimates
    • Establish Non-Revenue Water – Leakage, and Customer Meter under-registration (main components)
  • North American Best Management Practice

IWA Water Audit

IWA Balance Areas – 1

***Balance completed with a full years data*** ***Metric units are Megalitres Per Year***

System Input Volume (Water Supplied)

  • Multiple water supplies
  • Exports or other imports
  • Source meter accuracy testing results
  • System Input Volume – corrected for any source meter error

IWA Balance Areas – 2

Revenue Water – Billed Authorised Consumption

  • Billed Metered
  • Billed Unmetered
  • Customer meter accuracy testing results – typically under-registration
  • Total Revenue Water Volume – corrected for customer meter under-registration

IWA Balance Areas – 3

Non Revenue Water – Unbilled Authorised Consumption Unbilled Metered and Unbilled Unmetered

  • Flushing mains and sewers
  • Bleeders / blow offs
  • Fire fighting
  • Cleaning storage tanks
  • Filling water tankers
  • Water taken from hydrants
  • Parks irrigation, street cleaning, etc.

IWA Balance Areas – 4

Non Revenue Water – Apparent Losses Unauthorised Consumption

  • Illegal connections
  • Theft from hydrants

Metering Inaccuracies

  • Under / over registration of customer meters
  • Accounting procedure errors (meter register units / misread meters / dates / incorrect estimates / computer program errors / etc…………..)

IWA Balance Areas – 5

Non Revenue Water – Real Losses Leakage on distribution and transmission mains

  • Holes and cracks in mains
  • Leaks at joints

Leakage and overflows at storage tanks

  • Overflows
  • Buried reservoir structures
  • Drain valves left open, leaking

Leakage on services

  • Holes in service pipes / joints leaking

The Value of an IWA Balance

  • Accounts for and summarizes all areas of water use, and assign values to each – volume and cost
  • Allows you to devise a long-term, cost effective plan of action by prioritising measures to areas of concern, and cost benefit

IWA Water Audit

    Real Water Losses Terminology

  • Current Annual Real Losses (CARL)
    Total loss of water

  • Unavoidable Annual Real Losses (UARL)
    Cannot reduce, even with best program

  • Infrastructure Leakage Index (ILI)
    Ratio of CARL to UARL

  • Non-Revenue Water (NRW)

Ontario IWA Results – ILI and NRW

Utility ILI Non-Revenue Water as Percentage of Water Supplied
1 4.00 34%
2 3.50 18%
3 3.34 20%
4 1.83 11%
5 5.83 33%
6 3.02 20%
Average 3.08 19%

Ontario IWA Results – Customer Meter
Under-Registration (Residential Meters)

Utility Number of Meters Under-Registration Comments Comments
1 39,000 2.9% Calculated
2 47,000 3.4% Calculated
3 38,000 4.3% Tested 360 meters
Average 3.5%

5 Steps for Non-Revenue Water Reduction

  1. Measure: complete AWWA / IWA water audit and water balance
  2. Identify Alternatives: prioritize cost effective measures. Develop multi year program
  3. Implementation: multiple measures, can include:
    • Source Meter Upgrade Program (Region)
    • Active Leak Detection (find unreported leaks)
    • Large Diameter Main Condition Assessment – prevent major breaks
    • Customer Meter Changeout Program (include AMR / AMI)
  4. Monitor: water savings, revenue recovery
  5. Maintenance: savings and revenue over time