Backflow Prevention Program

The primary objective of the cross-connection control/backflow prevention program is to protect our public potable water system from possible contamination. Protection is accomplished by requiring the installation of an approved backflow prevention assembly.

Learn about Moulton Niguel’s Backflow Prevention Program

What is Backflow?

Backflow is water flowing in the opposite direction from its normal flow. Moulton Niguel’s 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 to enter the potable water distribution system.

What is a backflow



A backflow prevention assembly is an approved, testable assembly which uses check valves and/or relief valves, in different configurations, to prevent potential contaminants from flowing into the potable (drinking) water system.

An approved backflow prevention assembly has gone through an approval process at the Foundation for Hydraulic Research and Cross-Connection Control at the University of Southern California (FCCCHR). Only FCCCHR approved backflow assemblies are accepted as approved backflow prevention assemblies.

Prevention Program

There are more than 5,000 backflow prevention assemblies on water services in the District’s service area. The California Department of Health Services requires each of these assemblies to be tested annually. This testing is done by backflow assembly testers approved by the County of Orange. A list of the certified testers is available in the links below. For more information, please contact the District’s Senior Cross Connection Inspector Jesse Calvillo at (949) 607-9461 or at

Click here to view the Backflow Prevention Assembly Test Form