Bethpage Water District Blog

Thursday, May 30, 2019

What is a backflow device?

    The water we provide in the distribution system is consistently under pressure so when you turn on your faucet, it comes out with force. Once the water goes passed your meter, there is a device that prevents the water from flowing in a reverse direction or “backflowing” to prevent contamination. These are generally installed on Bethpage homes built after 1983 and/or homes with irrigation systems.

    Some other criteria which may require a backflow device are water cooled refrigeration, use of a photo dark room, in ground pools and some water cooled solar systems. An example of a backflow condition would be if fertilizer or pesticides have been used on a lawn and the residue remains on the sprinkler head, then in a reverse flow condition, that tainted water COULD be allowed to enter the distribution system without a certified backflow device.

    A reverse flow condition is possible if plumbing work is being done within the house and the water is shut off or the water main in the street has been shut off.
Fire pump trucks have also been known to cause reverse flow from pulling water from the water main with such great force, it creates a suction in the pipes. Back siphoning, such as a hose in a pool could siphon the water back into the water main if the water pressure has a sudden decrease or has been turned off.

    It is required by law to be tested annually by a certified tester in order to maintain its proper operation. The District provides this service to our residents if you call and schedule an appointment.


Why does a backflow device need to be tested annually?

    As part of New York State sanitary law, all backflow prevention devices must be tested annually. The responsible party to ensure that this is completed is the local water supplier. It is needed to prove the validity of the device and its ability to operate in a simulated backflow condition.


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