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Backflow Prevention

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Cross-Connection Control and Backflow Prevention Program Background

What is cross-connection? 

A cross-connection is any actual or potential connection between the public or consumer’s potable water system and any non-potable source or substance that presents a hazard to the quality of the public or consumer’s potable water system. Therefore, cross-connection control is the management or “control” of these cross-connections to protect public safety by preventing backflow incidents within the public or water consumer’s potable water system. 

What is backflow? 

Typically, water will flow from the public water supply to the consumer’s plumbing distribution system. Backflow is the undesirable reversal of this flow of water and undesirable substances from the non-potable source to the potable source. 

Loss of supply pressure. Backflow. Normal direction of water flow. Arrow pointing right. Backsiphonage. Backsiphonage is created when there is a negative or reduced pressure in the water supply main. Water main breaks or hydrant flushing are two of the main causes of backsiphonage. Supply pressure 60 psi. System pressure 80 psi. Backpressure. Backpressure is created when the pressure within the customer’s system increases to a point that it exceeds the pressure in the water mains supply system. Boilers, elevated tanks, heating systems and booster pumps are some of the main causes of backpressure.

 

Why do we need a cross-connection control/backflow prevention program? 

The California State Water Resources Control Board's Cross-Connection Control Policy Handbook requires every drinking water system to have a cross-connection control program, also referred to as a backflow prevention program. For this reason, the City of Simi Valley/Ventura County Waterworks District No. 8 (District) developed a comprehensive Cross-Connection Control Plan (CCCP) with the goal of ensuring backflow prevention assemblies are tested annually and records are maintained. The City of Simi Valley adopted the CCCP on October 6th, 2025 under Ordinance No. WWD-19.

 Customer Support

The State of California requires backflow prevention assemblies to be installed on all hazardous cross-connections to help keep our water supply safe. These assemblies must be tested and certified at least once a year to ensure that they are working properly. The District has partnered with BSI Online to assist in administering the backflow program in your community.

You are responsible for hiring a licensed backflow tester to perform the annual test and certification of the backflow assembly (BSI and the District does not test backflow assemblies). As a courtesy each year, a written notice will be mailed to each affected customer when it is time for the annual test of their backflow prevention assembly. A list of local, licensed backflow testers may be found by accessing the link below and entering the Customer Confirmation Number (CCN) provided in the top right corner of the mailed notice:

https://app.bsionlinetracking.com/customer/testing-companies-lookup

Please provide the CCN to your backflow tester, as they will need this number to properly file your backflow test reports via BSI Online. You may also use this CCN at www.bsionline.com to verify when your backflow test has been filed. BSI Online will serve as the primary point of contact for the program and can be contacted below:

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