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 President Water 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 BMP 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 BMP Water Data Analysis and Validation: 36% report implausible results Data Validity is an issue – more training and outreach needed However: Average data validity score 75.6 (Level IV = 71-90) Average data validity score of utilities reporting negative water losses 77.0 51% of utilities report length for service pipe curb stop to meter Financial data reported often questionable Especially 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
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 meter Step 2 – Sum consumption volume for each meter Step 3 – compare results of Step 1 and Step 2 for each meter Read_DateCurrent_ReadPrevious_ReadRead_DaysUsage 2-Oct Oct Oct Nov Nov Dec Jan Feb Mar
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: PREVIOUS READING DATE CURRENT READING DATE CONSUMPTION JUL-07 AUG-07 SEP-07 OCT-07 NOV-07 DEC-07 JAN-08 FEB-08 MAR-08 APR-08 MAY-08 JUN-08 TOTAL 07-Jun-0709-Jul Jul-0707-Aug Sep Sep-0704-Oct Oct-0705-Nov Nov-0707-Dec Dec-0708-Jan Feb Mar Apr Apr-0806-May May-0806-Jun Jun-0808-Jul TOTALS
Water Audit Tasks – Critical Data Validation Task: Validate Billing Data Accuracy Lag-time Analysis – PRORATING:
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!