water audits: a simple “how to…”. why perform a water audit?

Water Audits: A simple “How To…”

Why perform a Water Audit?

Water Pumped

Water Sold

Gallons of water being pumped into the distribution system each billing period exceeds the gallons being sold.

Water Loss Control

Monitoring water resources has been conducted for thousands of years.

Roman Adjutage

Julius Frontenus was first Roman Water Commissioner and recognized importance of equitable water distribution (300 BC)

Flow

Water Loss Control

Concept of “water rights” and efficient water use has been debated and fought over for centuries

End result: majority of water is now metered for equitable economic distribution.

Production Mag Meter

Production Venturi Meter

Wholesale 16”Turbine meter

Commercial/Industrial Compound Meter

Water Pumped

Water Sold

Where did it all go??

Water Audit Process: A Top Down Approach

• AdvantageAdvantage: quickly pulls together data and information that is readily available.

• DisadvantageDisadvantage: for most water utilities, incomplete or inaccurate data limitslimits the validity the validity of the top-down water audit.

Water Audit Process: A Top Down Approach with Bottom Up validation

• AdvantageAdvantage: pulls together top down data and field verifies results by field testing of various sorts

• DisadvantageDisadvantage: for water utilities, field testing must follow a strict method and costs extra $$’s for the field work.

Water Audit and M36 Publication

• In April, 2009, AWWA published the third edition of Manual 36 entitled Water Audits and Loss Control Programs

• Manual was prepared under the guidance of the Water Loss Control Committee (WLCC)

• Concurrently, a WLCC subcommittee developed water audit software

• The software was made available through AWWA on their website

http://apps.awwa.org/ebusmain/OnlineStore/ProductDetail/tabid/55/Default.aspx?ProductId=6725

M36 3rd Edition Table of Contents

Chapter 1 – Introduction: Auditing Water Supply Operations and Controlling Losses

Chapter 2 – Conducting the Water Audit

Chapter 3 – Identifying and Controlling Apparent Losses

Chapter 4 – Understanding Real Losses: The Occurrence and Impacts of Leakage

Chapter 5 – Controlling Real Losses: Leakage and Pressure Management

Chapter 6 – Planning and Sustaining the Water Loss Control Program

Chapter 7 – Considerations for Small Systems

Glossary of Terms and Definitions for Water Loss Control

Appendix – Blank Forms, Assessing Water Resource Management, AWWA WLCC Free Water Audit Software, Case Studies

Standard Water Balance Format

WaterImported

OwnSources

TotalSystem

Input

( allowfor

knownerrors )

TotalSystem

Input

(allowfor

knownerrors)

WaterSupplied

WaterExported

WaterSupplied

WaterExported

WaterLosses

AuthorizedConsumption

WaterLosses


RealLosses

ApparentLosses

UnbilledAuthorized

Consumption

BilledAuthorized

Consumption

Non-Revenue

Water

RevenueWater

Leakage & Overflows at Storage

Billed Unmetered Consumption

Billed Metered Consumption

Billed Water Exported

Leakage on Service Lines(before the meter)

Leakage on Mains

Customer Metering & Data Inaccuracies

Unauthorized Consumption

Unbilled Unmetered Consumption

Unbilled Metered Consumption

Start hereMove this direction

The Water Audit Process Roadmap• How is the software obtained?

The Water Audit Process Roadmap• How is the software obtained? Log in…

The Water Audit Process RoadmapAgree to Terms of Use…

The Water Audit Process Roadmap

Which Spreadsheet?

Version 5…

The Water Audit Process RoadmapDownload to your computer …

The Water Audit Process Roadmap….. and “SAVE”…

Completing the Water Audit

• Read the instructions provided in the software

• Follow the tabs

Title Page

Title Page

Hot buttons

What data do I need?

• System input including– Purchased water– Transferred water, imported and exported

• Sales– Metered, billed and unbilled– Unmetered, billed and unbilled

• Estimate of unauthorized consumption• Estimate of meter error or inaccuracy• Estimate of data handling errors


– Physical parameters of the water system• Length of mains• Number of service connections• Average length of customer service line• Average system operating pressure

– Financial data on the system• Annual operating costs• Retail cost per unit• Marginal cost per unit

Where is the data entered?– Look for the whitewhite boxes in the spreadsheet

– Look for the white boxes in the spreadsheet

– That was easy, but what about those small white boxes?

Where is the data entered?

– How many miles of mains are in the system?

Grading the data: an example


WaterImported

OwnSources

TotalSystem

Input

( allowfor

knownerrors )

TotalSystem

Input

(allowfor

knownerrors)

WaterSupplied

WaterExported

WaterSupplied

WaterExported

WaterLosses


WaterLosses


RealLosses

ApparentLosses

UnbilledAuthorized

Consumption

BilledAuthorized

Consumption

Non-Revenue

Water

RevenueWater






Leakage on Mains






How much water is Produced?

YearTotal Gallons

Pumped

2008 2,251,273,500

2009 2,179,328,503

2010 2,105,713,620

Data InputMaster Meter Annual Totals

Master Meter Error adjustment boxes


WaterImported

OwnSources

TotalSystem

Input

( allowfor

knownerrors )

TotalSystem

Input

(allowfor

knownerrors)

WaterSupplied

WaterExported

WaterSupplied

WaterExported

WaterLosses


WaterLosses


RealLosses

ApparentLosses

UnbilledAuthorized

Consumption

BilledAuthorized

Consumption

Non-Revenue

Water

RevenueWater






Leakage on Mains






DETERMINE AUTHORIZED CONSUMPTION

Billed Metered Water Billed Unmetered Water Unbilled Metered Water Unbilled Unmetered Water

How much water is Billed?

0

5000000

10000000

15000000

20000000

25000000

30000000

Jan

Feb

Mar Apr

May Jun Jul

Aug

Sep

Oct

Nov Dec

Cu. Ft.

2009

Billed

Residential

Commercial

0

5000000

10000000

15000000

20000000

25000000

30000000

Jan

Feb

Mar Apr

May Jun Jul

Aug

Sep

Oct

Nov Dec

Cu. Ft.

2010

Billed

Residential

Commercial

Billing Data Sample

Size Number % of sample0.625 1227 89.23%0.75 43 3.12%

1 32 2.32%1.25 0 01.5 18 1.31%

2 25 1.81%3 6 0.43%4 5 0.36%6 4 0.29%8 4 0.29%

12 1 0.07%

10% statistically Significant Random Sample 95% confidence level

Average annual revenue per sampled meter record

Meter Size Cu. Ft. Revenue

0.625 6,737 $211.170.75 11,946 $311.29

1 20,718 $490.641.25 no data no data1.5 76,194 $3,770.29

2 97,335 $1,878.733 505,217 $7,991.874 470,220 $7,923.426 2,336,430 $42,795.008 9,496,130 $127,088.00

12 13,382,700 $179,486.00

Data Input


WaterImported

OwnSources

TotalSystem

Input

( allowfor

knownerrors )

TotalSystem

Input

(allowfor

knownerrors)

WaterSupplied

WaterExported

WaterSupplied

WaterExported

WaterLosses


WaterLosses


RealLosses

ApparentLosses

UnbilledAuthorized

Consumption

BilledAuthorized

Consumption

Non-Revenue

Water

RevenueWater






Leakage on Mains






2010 Pumped vs. Billed & Difference

-10.0

-5.0

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

Jan

Feb

Mar Apr

May Jun Jul

Aug

Sep

Oct

Nov

Dec

%Differences

Month

% Differences (Pumped vs Billed) by yr

2008

2009

2010

2011

Year Aver % Dif.

2008 14.4

2009 13.0

2010 14.1

2011 **18.4

Calculated Data from Input


WaterImported

OwnSources

TotalSystem

Input

( allowfor

knownerrors )

TotalSystem

Input

(allowfor

knownerrors)

WaterSupplied

WaterExported

WaterSupplied

WaterExported

WaterLosses


WaterLosses


RealLosses

ApparentLosses

UnbilledAuthorized

Consumption

BilledAuthorized

Consumption

Non-Revenue

Water

RevenueWater






Leakage on Mains






Data Input

What does this really mean??


WaterImported

OwnSources

TotalSystem

Input

( allowfor

knownerrors )

TotalSystem

Input

(allowfor

knownerrors)

WaterSupplied

WaterExported

WaterSupplied

WaterExported

WaterLosses


WaterLosses


RealLosses

ApparentLosses

UnbilledAuthorized

Consumption

BilledAuthorized

Consumption

Non-Revenue

Water

RevenueWater






Leakage on Mains






Data Input

Service Connection Diagram

Note differences in lengths for service connections

Data Input

How did the system do?

WATER AUDIT DATA VALIDITY SCORE:

PRIORITY AREAS FOR ATTENTION:

1: Volume from own sources

2: Master meter error adjustment

3: Customer metering inaccuracies

Based on the information provided, audit accuracy can be improved by addressing the following components:

*** YOUR SCORE IS: 78 out of 100 ***A weighted scale for the components of consumption and water loss is included in the calculation of the Water Audit Data Validity Score

For more information, click here to see the Grading Matrix worksheet

Validity Score

Water Balance Filled Out

Grading the data: an example

Audit Validity Score

Making the Grade78 out of 100

Grading Matrix… lots of pages of grades

– Performance Indicators• NRW% by volume• Volumetric losses• Losses per connection per day• Losses per mile of main• Infrastructure Leakage Index (ILI)

Grading the system

Grading the system

ILI= CARL / UARL

UARL

ILI= infrastructure Leakage Index

ILI= CARL / UARLUARL

UARL considerations

Interpreting the Grades: ILI

Smaller System Considerations

**Systems under 80 miles of main and less than 3000 connections will not show ILI.

Service Connection Density < 32 per mile (rural systems) will have Real Losses per length of main per day calculated

Interpreting the Grades: NRW volume

– Follow the trend– See any “suspect” data?

Total Losses

050

100150200250300350400450

Janu

ary

Febr

uary

Mar

chApr

ilM

ayJu

ne July

Augus

t

Septe

mber

Octob

er

Novem

ber

Decem

ber

MG

Month

Vo

lum

e

2008

2009

2010


WaterImported

OwnSources

TotalSystem

Input

( allowfor

knownerrors )

TotalSystem

Input

(allowfor

knownerrors)

WaterSupplied

WaterExported

WaterSupplied

WaterExported

WaterLosses


WaterLosses


RealLosses

ApparentLosses

UnbilledAuthorized

Consumption

BilledAuthorized

Consumption

Non-Revenue

Water

RevenueWater






Leakage on Mains






Water Balance Filled Out

Audit Dashboard

Grading Matrix

Developing Actions

– Monitor, Maintain and / or Manage– Improve data– Develop a “bottom up” audit– Refer to M36 and other AWWA references– Other publications, IWA and privately authored– Review case studies– Comments to [email protected]

Recoverable Losses

Speed & Quality of Repairs

As

se

t M

an

ag

em

en

t

Pre

ss

ure

M

an

ag

em

en

t

Active Leak Control Program

UARL:UARL:Unavoidable Annual Real Losses

UARL

ELLELL

ELLELL: Economic Level of Leakage

Questions?

Don’t play Possum with Water Loss Management!!

water audits: a simple “how to…”. why perform a water audit?

Documents