Water Authority Cross Connection Control Program

The Cross Connection Control Program is the designated Enforcement Authority to enforce cross connection control by containment under the provisions of the Water Authority Cross Connection Control Ordinance .

To protect the public water system, businesses and institutions that use hazardous materials are required to install backflow prevention devices at the service connection. In addition, all irrigation systems must have backflow prevention devices.

What is a Cross-Connection?

Under certain conditions, cross-connected plumbing can allow a contaminating substance to backflow into the potable public water system. The customer’s water system begins at the service connection, the water meter, and continues throughout the customer’s home or business. The public water system includes all the pipes, conduits, tanks, receptacles, fixtures, treatment equipment and appurtenances used to produce, treat, store and convey potable water to the customer’s service connection.

What is a Backflow?

Water normally flows from a high water pressure to a lower water pressure.

Backflow is the undesirable reversal of water flow.  Contaminated water from cross-connected plumbing within a customer’s water system can backflow into the public water system.  Backflow may be caused by a backpressure or backsiphonage condition.

Backpressure occurs when water is forced or pushed backwards because the customer’s water system pressure exceeds the operating pressure of the public water system.  Examples of conditions that can contribute to an increase in water pressure include: circulating pumps, booster pumps, injection pumps, boilers, and pressure vessels and elevated piping systems.

Backsiphonage occurs when water from the customer’s water system is drawn backward as a result of negative or decreased pressure in the water supply system.  A backsiphonage condition could be caused by a waterline break or by flowing a fire hydrant in the public water system.

Backflow Prevention

Approved methods and types of backflow prevention assemblies and devices include:

1. Air Gap (AG).
2. Reduced Pressure Principle Backflow Prevention Assembly (RP).
3. Pressure Vacuum Breaker Backflow Prevention Assembly (PVB).
4. Spill-Resistant Vacuum Breaker Backflow Prevention Assembly (SVB).
5. Double Check Valve Backflow Prevention Assembly (DC). DCs are approved for use only on limited installations and approved by the Cross-Connection Engineer.
6. Atmospheric Vacuum Breaker (AVB) Device.

A Certified Backflow Prevention Device Tester must inspect and test backflow prevention assemblies in accordance with approved methods and procedures and complete and submit accurate and timely reports to the Cross Connection Control Program. The tester must report any discovered discrepancies associated with an existing backflow prevention assembly or device or existing cross-connections within the customer's water system to the customer and to the Cross Connection Control Program.

For more information call the Cross Connection Office at 857-8210 or e-mail This e-mail address is being protected from spam bots, you need JavaScript enabled to view it .