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What We Can Learn From California’s Water Loss Audits


Sue Mosburg

Program Manager, Sweetwater Authority; Chair, California-Nevada Section Water Loss Control Committee

Oct. 1 will mark the third year that validated water loss audits have been required for California’s urban retail water systems for compliance with SB 555. For the first round of audits in 2017, affected water systems received assistance through California-Nevada Section’s American Water Works Association (CA-NV AWWA) Water Loss Technical Assistance Program (WL TAP).  

It’s now on water systems operators to compile the audit, ensure it’s validated, and submit required documentation to California’s Department of Water Resources (DWR). Because data is typically owned by different departments, water suppliers are encouraged to adopt a team approach when compiling their audits.

Water audits must be validated

Water loss audits submitted to DWR must be compiled using the AWWA Free Water Audit Software and must be Level 1 validated, following criteria established by the Water Research Foundation (WRF) in Project 4639 (2016). 

Built on the methodology detailed in AWWA’s M36, Water Audits and Loss Control Programs, the Free Water Audit Software, is the industry standard to identify and categorize water volumes entering a system while simultaneously assessing operational efficiency and accounting practices. Level 1 validation results in a better understanding of the data and business practices that inform the audit, and is currently required in California, Georgia, and Hawaii. 

In California, a water supplier may validate its own audit, provided the person performing the validation did not also participate in compiling it. All validators must meet the requirements set forth in California water code (23 CCR § 638). As of June 30, this means all validators must hold a Water Audit Validator (WAV) certificate issued by CA-NV AWWA. 

WAV information and listings of current certificate holders are posted on the section’s website. For those with a solid foundation in water loss auditing, WAV two-day classes are regularly scheduled across California. 

Performance benchmark development

SB 555 requires the California State Water Resources Control Board (SWRCB) to adopt rules for achieving volumetric water loss performance standards by July 1, 2020. In adopting these rules, the board shall employ full-life cycle cost accounting. 

As a result, SWRCB staff have been reviewing water loss audit data, collecting information through the electronic annual report, and holding a series of informal workshops to collect stakeholder input on a proposed four-phased approach aligned with the implementation timeline of Senate Bill 606 and Assembly Bill 1668, which will set the overall water efficiency targets for California’s urban retail water systems.

Take action now

The proposed framework includes a requirement for water systems to employ effective pressure controls and monitoring, and also requires water systems to complete a system-wide component analysis using the Leakage Component Analysis Model (developed as part of WRF project 4372). This must be done multiple times by 2027.

With formal rule making set to begin later this year, and with SB 555 requiring that each audit submission include a list of actions taken to reduce losses and improve data validity, the time is now to bring your water system’s water loss team together to develop a water loss control plan. To help you, Water Research Foundation Project 4695 Guidance on Implementing an Effective Water Loss Control Plan was released earlier this year.

Sue Mosburg, Program Manager, Sweetwater Authority; Chair, California-Nevada Section Water Loss Control Committee, [email protected]

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