Backflow is the undesired or unintended reversal of flow, where water and/or other liquids, gases, or other substances can enter the public water supply.

A cross-connection is an interconnection between the public water supply and a non-potable source.

Typically, water flows in one direction from the public water supply to the customer. In the event of backsiphonage or backpressure, a backflow condition may occur where water moves against its usual direction of flow, instead moving from the external water source through a pathway – known as a cross-connection – to the public water supply.

• Cross-Connection: An interconnection between a potable water supply and a non-potable source via any actual or potential connection or structural arrangement between the potable water supply and any source containing liquid, gas, or other substances not from an approved water supply.
• Backsiphonage: Backsiphonage occurs when a sudden reduction in water pressure reverses the flow of water, creating suction, and drawing potential contaminants into the public water system.
• Backpressure: Backpressure occurs when water in an external system exceeds the pressure of the public water system, altering the direction of flow between the two systems.

To ensure safe drinking water in the event of a backflow incident, the City of Westminster complies with the Cross-Connection Control Policy Handbook (CCCPH) adopted by the State Water Resources Control Board. The CCCPH regulates cross-connections through the establishment and enforcement of standards, as well as the routine, annual testing of backflow prevention devices.

Backflow prevention devices are typically required on industrial and commercial water services, and, on some occasions, residential properties based on the property’s degree of hazard, determined by the City’s Cross-Connection Control Specialist. The devices are tested upon installation and customers are notified by the City for subsequent annual testing.

For more information about the City’s Cross-Connection Control Program, please contact the City’s Cross-Connection Control Specialist, Billy Tran, at (714) 548-3690.

Backflow Testers

Policy Statement

To ensure the safety and integrity of the city's potable water supply, all individuals conducting backflow prevention device testing within the city limits must be approved by the Cross Connection Control (CCC) Specialist. Approval is contingent upon meeting the following criteria:

• Valid Business License: The backflow tester must possess a current business license issued by City Hall, authorizing them to conduct business within the city.
• Current Tester Certification: The backflow tester must hold a valid certification from a recognized backflow prevention training program, demonstrating compliance with state and local standards for backflow testing.
• Current Gauge Calibration: The backflow tester must provide documentation verifying that all testing gauges used for backflow device testing have been calibrated within the past 12 months by an accredited calibration service.

Approval Process  

• Backflow testers must submit proof of the above criteria to the CCC Specialist for review.
• The CCC Specialist will verify the submitted documentation and, upon confirmation that all three criteria are met, issue approval for the tester to conduct backflow testing within the city.
• Approval is valid for one year or until the expiration of the business license, tester certification, or gauge calibration, whichever occurs first.
• Testers must renew their approval annually by resubmitting current documentation to the CCC Specialist.

Test Report 

• Blank Backflow Test Report