Marin Backflow Preventer Installation · Marin County
Marin Water now requires a backflow preventer on more and more properties. If you've received a notice, are upgrading a meter, adding new water service, installing fire suppression, or making changes that trigger a cross-connection review — CPR Enterprises installs approved backflow preventers and helps Marin property owners stay compliant.
Mark walks through a typical backflow preventer installation, explains what Marin Water is asking property owners to do, and shows the finished installation with an attractive protective cover that helps the assembly blend into the property.
A backflow preventer is an approved assembly that stops water from flowing backward from a private property into the public drinking water system. Backflow can happen because of pressure changes, backpressure, or back-siphonage — and Marin Water requires an approved backflow preventer wherever that risk exists.
Marin Water identifies common property conditions that can require a backflow preventer, including irrigation systems, fire suppression systems, pools, spas, wells, docks, fountains, pressure boosting systems, graywater systems, rainwater collection systems, boilers, radiant heat systems, and similar cross-connection hazards.
In simple terms: if something on your property could potentially allow non-drinking water, chemicals, stagnant water, or other contaminants to enter the public water supply, Marin Water may require a backflow preventer.
Marin Water states that a backflow preventer may be required for new services, meter upgrades, fire suppression systems, water allotment changes, and when a Marin Water cross-connection survey determines that one is needed. Non-compliance can result in termination of water service under Marin Water District Code.
If Marin Water determines that your property needs a backflow preventer, they will identify the type of assembly and where it must be installed. Backflow preventers must be approved and comply with the Marin Water Cross-Connection Control Plan. The two most common types are Double Check Valve Assemblies (DCVA) and Reduced Pressure Principle Assemblies (RPPA).
Once installed, the backflow preventer requires annual backflow testing by a certified backflow prevention assembly tester using a properly calibrated gauge. Marin Water notes that if a tester is not on its certified backflow testing list, the test results cannot be accepted.
Backflow notices can be confusing, with technical language and deadlines. Mark helps translate the requirement into a clear, manageable project.
Decades of local building experience means the assembly is installed in the right place — with care for how your property looks when the work is done.
Backflow preventers are important — but they're not always attractive. Many backflow preventer installations sit near the meter, driveway, front yard, or other visible areas of the property.
CPR Enterprises offers a practical backflow preventer cover that helps protect the assembly and gives the finished installation a cleaner, more polished appearance.
"The goal is simple — meet the requirement without leaving the homeowner with an eyesore."
Marin Water sends physical notices before annual backflow testing is due, and annual backflow testing is required to ensure the assembly continues to function properly. A failed test requires repair or replacement followed by a passing test.
Marin Water states that non-compliance with annual backflow testing requirements can result in termination of water service.
If you've received a notice, need a new installation, or aren't sure what your next step should be, CPR Enterprises can help you move forward.
For more than 40 years, Mark has built, repaired, solved, and improved properties throughout Marin. CPR Enterprises brings that same hands-on experience to backflow prevention work: clear communication, practical solutions, careful installation, and respect for how your property looks when the job is done.
This isn't just about installing a valve — it's about helping Marin property owners protect the public water system, meet local requirements, and get the job done right.
Received a Marin Water backflow notice? Planning a meter upgrade, fire sprinkler system, irrigation work, or other project that may require backflow protection? Contact CPR Enterprises for trusted local help.
Service Area · Marin County & Surrounding Communities