An important part of the District’s water quality program is the Cross-Connection Control Program. When a water line is connected to equipment containing a non-potable substance, this is known as a cross-connection. Contamination may occur when water flows through a cross-connection from a non-potable source, such as a fire sprinkler system, irrigation system, or heating and cooling system, into the potable water system. This can happen through a process known as backflow.
Backflow occurs when water flows in the opposite direction from its normal flow. The Districts potable water system is designed to keep the water flowing to you. When hydraulic conditions within any water system deviate from “normal,” the direction of water flow can be reversed. This creates a backflow condition and the potential for contaminated water entering the potable water distribution system. To prevent this from occurring, the District requires backflow prevention devices be installed upstream of all cross-connections.
There are more than 500 backflow prevention assemblies on water services in our service area. The California Division of Drinking Water requires each of these assemblies to be tested annually. This testing is done by licensed backflow assembly testers approved by the District. The District sends out notifications each summer to the owners of these devices to remind them that they must be tested. This notification also includes a backflow test form and a list of approved testers. If you need the approved tester list outside of our annual cycle, please contact us.
More information can be found in District Administrative Water Code Division XI. To speak with a District cross-connection and backflow prevention expert, please call 530-583-4692 or email us at [email protected].
A reduced pressure principle backflow prevention device (pictured) is the most common backflow device present in the District system.