Backflow Prevention Postcard

The Virginia Construction Code has required a backflow preventer to be installed to separate potable and non-potable water since 1973.  For high hazard situations, it requires backflow prevention assemblies to be tested on a continuing basis.

In 1994 the updated Virginia Construction Code was modified to explicitly state that lawn irrigation systems are required to have high hazard backflow assemblies installed for protecting the potable water and are to be tested on a continuing basis.

In 2003 the Virginia Construction Code expressly identified backflow prevention requirements for residential lawn irrigation systems.

Additionally, since 1993, the Virginia Waterworks Regulations has required all customers to protect the drinking water supply by installing and testing annually backflow preventers for in ground lawn irrigation systems.

Fairfax Water regularly reviews and determines new ways to strengthen our backflow prevention program.  Fairfax Water is reaching out to customers who may have in-ground lawn irrigation systems to inform them about backflow prevention requirements and how they protect drinking water from contamination.

When it’s time to turn on your irrigation system for the season, ask the company you hire to test the backflow assembly.  If they do not test backflow assemblies, you can find a certified tester on the Fairfax County Website. See the Authorized Vendor List  and select one that serves residential properties. 

The Authorized Vendor will complete the test and submit the test report to Fairfax County on your behalf.  You should receive a confirmation email from Fairfax County and then will be all done for the year.

You are receiving this postcard as part of Fairfax Water’s outreach efforts to raise awareness about cross-connection control and backflow prevention requirements for irrigations systems. 

If you do not have an irrigation system, please disregard the postcard.

Typically, residential customers will have either a Pressure Vacuum Breaker (PVB) or a Reduced Pressure Principle Backflow Assembly (RP) Installed on their residential lawn irrigation system.

Example of a PVB

Example of a RP

If you cannot locate one of the above backflow preventers on your property, when it’s time to turn on your irrigation system for the season, ask the company you hire to locate your backflow preventer for you and show you where it is.  

If the irrigation system can be turned on, the backflow preventer should be tested to make sure it is functioning properly.

The other option is to permanently cap the irrigation system.

In some cases, customers have a low hazard, dual check valve backflow device installed (pictured below).  This device is insufficient for preventing possible highly hazardous contamination of your drinking water during a backflow event.   We encourage all our customers to install a testable assembly in accordance with current Virginia Department of Health (VDH) and Virginia Construction Code requirements as soon as practical.  To find an authorized vendor, please follow this link: Authorized Vendor List.

An example of a Dual Check Valve Backflow Device

To prevent possible contamination of your drinking water, we encourage all our customers to install a testable assembly in accordance with VDH and the Virginia Construction Code requirements.  To find an authorized vendor, please follow this link: Authorized Vendor List.

When it’s time to turn on your irrigation system for the season, ask the company you hire to test the backflow assembly.  If they do not test backflow assemblies, you can find a certified tester on the Fairfax County Website. See the Authorized Vendor List  and select one that serves residential properties. 

The Authorized Vendor will complete the test and submit the test report to Fairfax County on your behalf.  You should receive a confirmation email from Fairfax County. The test should then be repeated and reported to Fairfax County each year after that.

As long as your system is unprotected or the testable backflow preventer is not certified as operational, you put your family and neighbors at increased risk of drinking water contamination.

We encourage all customers to install a testable assembly in accordance with VDH and Building Code requirements as soon as practical.  To find an authorized vendor, please follow this link: Authorized Vendor List.

Additional information can be found at Cross-Connection Control & Backflow Prevention | Fairfax Water - Official Website and Fairfax County website.