Plainview Water District’s Backflow Testing Program

New York State requires that all backflow devices attached to the public water system to be tested annually to ensure they are properly operating as a measure to protect the public water supply from contamination. The backflow protection device is a mechanical double-check valve that prevents the reversal of water flow during a loss of water pressure in a street water main, which may occur due to firefighter usage or a water main break.

Backflow devices are required on all commercial properties and residential properties with the following:

  • Inground sprinklers
  • Fire lines
  • Swimming pool
  • Private wells that are interconnected with public water supply

Backflow devices are required to be inspected annually by a certified tester.

List of Certified Backflow Testers with Contact Numbers

Certified New York State backflow testers must complete a test report which can be found here.

Click here for a complete list of backflow testers certified in Nassau County as provided by New York State Department of Health.

Please ensure that a completed copy of your test report is submitted to the Plainview Water District and the Nassau County Health Department. For your convenience, please email this form to the district at 

For more questions pertaining to backflow devices and protocol, please visit our Backflow FAQ Page.

Additional forms related to Backflow installations and information:

Irrigation System Installation Application Form

Application for Approval of Backflow Prevention Devices (DOH 347)

District Information Letter regarding Backflow


RPZ Valve
Double-Check Valve