Los Angeles Department of Water and Power (LADWP) Backflow...

Who must test

All approved backflow assemblies must be inspected and tested annually, or more often if LADWP decides it is necessary (Rule 16-D, Section 9.2). Source.
Since July 1, 2025, both commercial and residential fire sprinkler systems are subject to new cross-connection control requirements, which may include mandatory backflow assemblies or retrofits. Source.
Existing residential fire sprinkler systems that do not meet all the listed criteria must be retrofitted with a double check (DC) assembly at the service connection within ten years of the CCCPH effective date. Source.

Assemblies must be tested immediately after the customer receives LADWP's Periodic Test and Maintenance Report; test records are kept on file for at least three years. Source.

Under Rule 16-D effective July 1, 2025, testing must be done by a backflow tester holding a valid certification from a certifying organization recognized by the State Water Board. Source.
The superseded 2015 version of Rule 16-D required testers to be licensed by the Los Angeles County Department of Public Health; the 2025 rule replaced this with State Water Board recognized certification. Source.

After reasonable notice, LADWP will deny or discontinue water service where a required assembly is not installed, tested and maintained, has been removed or bypassed, or an unprotected cross-connection exists; service is restored only after compliance. Source.
Failure, refusal or inability to install, test and maintain a required assembly is grounds for disconnecting water service until defects are corrected. Source.

LADWP runs a Cross Connection Control Program required by the State Water Resources Control Board's Cross-Connection Control Policy Handbook (CCCPH); the rules are in Water Service Rule 16-D (effective July 1, 2025). Source.

Read October 6, 2026. Program page: ladwp.com.