BackFlow Prevention

Approved Backflow Tester List

Backflow Test Report Form

Approved Backflow Prevention Devices

Standard Installation Drawing 2" & Smaller

(Please note: the District accepts original or printed forms signed by the backflow tester only.)  

Backflow prevention - what is it, and why do we need it?

The idea that we can turn on the faucet and receive potable water is not a new concept. Maintaining a reliable, safe product has always been a primary concern.

The State Health Department's backflow requirements, as outlined in 'Title
17' Section 7593 and enforced by the local water purveyors, ensures the potability of VWD water. The backflow prevention device is used to stop the water from re-entering the street main from a backpressure or a backsiphonage condition. Backpressure occurs when the customer pressure becomes greater than the District water pressure. Backsiphonage occurs when the District main pressure becomes negative, such as when a line breaks or a fire hydrant gets hit.

Backflow prevention assembly is designed to assist in transporting water from the water main to a home or business by preventing the reverse flow of any pollutants or contaminates into the District's system. The unit is required to be tested at least once a year by District-approved, certified testers. The test assures that "at the time of the test" the backflow assembly is working according to "design standards". If an assembly fails a certification test, the assembly then needs to be repaired, re-tested and 'certified' in a timely manner to show that the device is working properly.