Assembly Installation & Maintenance

Multifamily, commercial, and/or industrial facilities, along with properties with an auxiliary water supply and parcels with irrigation meters in the district's service area, are required to have a backflow prevention assemblies.

• The installation of these assemblies may be required through the plan check process and/or an inspection by a cross-connection control specialist.
• The backflow prevention assemblies are required to be tested upon installation, on an annual basis and anytime the assembly is repaired, replaced or relocated.
• The testing must be done by a certified backflow prevention assembly tester appearing on the District's list. Please call the Cross-Connection Division at 909-987-2591 for the list of approved backflow assembly testers. 
• Customers will receive an annual testing notification from the District.

Standard Drawings for Backflow Assembly

• If you are installing a new backflow or replacing a backflow prevention assembly, please refer to Standard Drawing 110: Fire Service Backflow Assembly or Standard Drawing 111: Domestic and Landscape Backflow Installation.
• On the construction sites, a reduced pressure principle backflow prevention assembly (RP) is required at the meter, if more than 100 feet of hose is used after the meter on the fire hydrant. Also, all presoaks will require a RP-type backflow prevention assembly. Please refer to Standard Drawing 124.

Please contact the Cross-Connection Division if you have any questions.