Backflow Devices

Cross Connection Control and Backflow Devices


As stated previously, one of the primary responsibilities of the Big Flats Water Department is to ensure the quality and quantity of water meets the needs of the public. We accomplish this by using a multipronged approach. It is not just one thing, but several things we do that help meet our goal. One of those ‘prongs’ is our backflow program, also known as Cross Connection Control.

Backflow refers to the reversal of the flow of water. Backflow is serious because it can lead to contamination of a water supply.  Our department requires all residential customers to have a doublecheck valve installed after the meter. This device protects our municipal water supply from any ‘backflow’ of potential contaminants flowing back through from the household. This device prevents the reverse flow from entering the water supply. These residential are not testable and have been known to fail, preventing water from both entering the premises and the water supply. This is not a common occurrence, but it has happened. In those cases, the homeowner has replaced the nontestable doublecheck device. They are available at the local plumbing supply.

Commercial accounts are all required to have backflow protection in place. The type of device required depends on the hazard and application. The devices range from a testable doublecheck valve to a full-on Reduced Pressure Zone device (RPZ).  The Town of Big Flats has the authority to approve the design of up to a 2” device.  Anything above a 2” device has to be engineered by a licensed design engineer or architect.  Those larger than 2” require the submission and approval of plans by the Water Systems Supervisor and the NYSDOH. This process may take up to 8 weeks. We will not allow water to be turned on until these devices are approved, installed, tested and signed off by the design engineer or architect. Please see our Backflow Policy for more information regarding the commercial applications.


Examples of Backflow Devices

Non-testable Doublecheck                                 Testable Doublecheck Valve (DCV)                  Reduced Pressure Zone (RPZ)          

               (Residential)                                                                   (Low Hazard)                                                                  (High Hazard)

    ResidentialDCV                               DCV                              CommlRPZ



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