A cross connection is a potential connection between any part of a water system used to supply water for drinking purposes, and a connection to a source not approved as safe for human consumption. Under this condition, contamination of the drinking water system may occur by back-siphonage or back pressure. Back-siphonage is caused by negative or reduced pressure in the drinking supply system. Some of the causes of back-siphonage are undersized piping and water line repairs at a location lower than a service point. Back pressure occurs when a pressurized non-drinking water piping system is connected to a drinking water system operating at lower pressure. Some of the causes of back pressure are booster pumps supplying make-up water to industrial fluid piping systems from potable water systems and interconnection with other piping systems operating at high pressure.The responsiblity of implementing the various elements of an effective cross connection program requires the full cooperation of water users, the Water District, and health agencies. Each must carry his/her share of a coordinated cross connection control program in order to prevent contamination of the potable water supply.

It is the duty of the water user on any premises on which backflow prevention devices exist to have competent inspections made at least once a year, or more often in those instances inspections indicate repeated failure. All testing shall be performed by a certified backflow tester. The District will notify the owner 30 days in advance when routine testing is needed and supply them with the necessary forms and a list of certified testers. 

If you would like to know more about this topic, get a list of District approved backflow device assembly/testers, a copy of Resolution No. 482, or a copy of the District’s Cross Connection Policy, please contact the District office at (805)688-6015. 

Click on the link for the District's approved companies and individuals providing backflow prevention and assembly testing.