Backflow Rules


Many appliances connected to a consumer’s water system may cause a backflow hazard. Direct connections to irrigation systems; private wells; solar or geothermal heating systems; chemical tanks or vats; swimming and decorative pools and even some handheld showerheads require varying degrees of backflow protection.

All new water services and existing services with aesthetically objectionable appliances must have an approved double-check valve assembly installed at the water meter in accordance with Locust Valley Water District plans and specifications. Consumers with connections to hazardous systems requiring a reduced pressure zone device must have a professional engineer or registered architect develop and submit plans to the district for Nassau County Department of Health approval.

Consumers with an approved backflow prevention device are mandated by New York State law to have the device tested annually by a state certified tester and submit a New York State Department of Health form 1013 to the water district.

To insure the quality of its drinking water and protect its consumers, the district will terminate water service or test and invoice the account of any consumer failing to test their backflow prevention device annually. Devices which fail testing must be repaired or replaced within 30 days.

Any consumer with a system supplied by an alternate source of water (private well, pond, etc.) must have that system physically separated from the district water supply. No valving or cross-connection, either permanent or temporary, between the two systems is permitted.

No introduction of chemicals (antifreeze, herbicides, pesticides, etc.) to piping systems supplied by the district is permitted.

This is only a partial list of requirements regarding cross-connection control and backflow prevention. For further details or information, please contact the Locust Valley Water District.