What to look for when completing an AWWA Water Audit for the first time Reinhard Sturm, Vice President Water Systems Optimization, Inc. Paul Johnson, Vice.

What to look for when completing an AWWA

Water Audit for the first time

Reinhard Sturm, Vice PresidentWater Systems Optimization, Inc.

Paul Johnson, Vice PresidentWater Systems Optimization, Inc.

03/14/2013

WaterRF 4372 – Project Background and Scope

11 participating utilities from NA Review of existing water loss

regulations and implementation experiences in NA

Review of international best practices in water loss regulation

Develop utility tested model for component analysis of real losses and evaluation of economically feasible water loss intervention strategies

WRF 4372 – Project Status and Findings

• North American average break frequency literature review and analysis

• Review of select international water loss guidelines and regulations

• Review of national water audit data sets

• Collection and review of water audits and leak repair data from participating utilities

• Beta-testing of WaterRF software tool

WORK COMPLETED: LATEST FINDINGS:

• Quality and consistency of leak repair data collection needs to be improved

• Even aggressive water loss reporting regulations and progressive guidelines under-estimate data quality obstacles

• Group of PU’s shows full range of water loss control experience: both exemplary utilities and those just starting

California – CUWCC BMP1.2

BACKGROUND:

BMP1.2 – Water Loss Control Program (10years)

First four years focus on data validation and water loss accounting Second phase to establish benchmarks and improvements to water loss performance

Six two-day workshops provided between 2010 and 2012 plus a webinar

WSO received the first data set of water audits for data validation

California – CUWCC BMP1.2

2010 Water Data Analysis and Validation:

Simple steps of data validation were applied

Results highlight the problems utilities are facing when completing an audit for the first time!

California – CUWCC BMP1.2

2010 Water Data Analysis and Validation:

36% report implausible resultsData Validity is an issue – more training and outreach neededHowever:

Average data validity score 75.6 (Level IV = 71-90) Average data validity score of utilities reporting negative water

losses 77.051% of utilities report length for service pipe curb stop to meterFinancial data reported often questionableEspecially system input volume and consumption volumes need to be validated

Note: Texas Water Audit Data showed similar data quality issues – 52% of water audits are technically impossible!!!!

California – CUWCC BMP1.2

Water Audit Data Validation

The Most Important Components

Water Audit Tasks – Critical Data Validation

Task: Challenge Accuracy of System Input Meters

Volumetric Meter Test

Comparative Meter Test

Water Audit Tasks – Critical Data Validation

Task: Challenge Accuracy of System Input Meters

Water Audit Tasks – Critical Data Validation

Task: Challenge Accuracy of System Input Meters

Water Audit Tasks – Critical Data Validation

Task: Challenge Accuracy of System Input Meters

Water Audit Tasks – Critical Data Validation

Task: Challenge SCADA Data Accuracy

(( 4-20mA signal) - 4) Maximum Calibration Flow Rate (MGD) = [

16 ] *

Flow-range (MGD)

Reservoir A raw water flowmeter data chain analysis

Comparison of converted 4-20 mA signal and SCADA reading

10

10.5

11

11.5

12

12.5

13

13.5

14

Time

MG

D

raw 4-20 mA signal from meter converted to MGD

SCADA value MGD

Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy

Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy

o Second most significant volume that flows into AWWA water balance

o Two components:

• Billed metered consumption

• Billed unmetered consumption

o Validation is crucial

Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy

Export of raw billing data (audit period plus 2 month on each side)

Typical billing data fields to be included:→ Customer identification fields→ Meter identification fields→ Service type identification fields→ Meter read and consumption fields – units→ Trouble codes or flags

Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy

Confirm relevant consumption volumes:• Which accounts need to be included/excluded• Water and Sewer accounts• Sewer only accounts• AG accounts• Irrigation accounts• System meters

Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy

Validation of consumption volumes:• Look for duplicates – meter numbers

– consumption volumes

• Look for other irregularities: - change of meter size - number of estimates- high consumption- consecutive zero consumption- etc.

Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy

Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy

Validation of consumption volumes:Step 1 – deduct first read from last read for each meterStep 2 – Sum consumption volume for each meterStep 3 – compare results of Step 1 and Step 2 for each meter

Read_Date Current_Read Previous_Read Read_Days Usage2-Oct-06 159 151 6 84-Oct-06 162 159 2 3

29-Oct-07 0 0 45 01-Nov-07 0 0 3 0

29-Nov-07 162 0 28 16227-Dec-07 162 162 28 029-Jan-08 165 162 33 327-Feb-08 166 165 29 128-Mar-08 167 166 30 1

Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy Lag-time Analysis – the simple way:

Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy Lag-time Analysis – the simple way:

Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy Lag-time Analysis – PRORATING:

Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy Lag-time Analysis – PRORATING:

0

100

200

300

400

500

600

1 2 3 4 5 6 7 8 9 10 11 12

Bill

ed M

eter

ed C

on

sum

pti

on V

olu

me

(MG

)

Month

Prorated Monthly Consumption VolumeCity of Hayward - Calendar Year 2009

Water Audit Tasks – Critical Data Validation

Task: Assess Customer Meter Accuracy

Water Audit – Things to Consider

Bring all the stakeholders together Discuss current data collection and validation

efforts – get input from all departments Have a water audit champion who collects all the

data and puts the audit together Use the AWWA water audit data validation score

to assess current data validity and work on improving data validity over time

Use the audit as a management tool to improve financial viability of your utility

Thank You!

[email protected]@wso.us