What is Backflow?

Backflow is a hazardous situation that can threaten the safety of the public water supply, which is why New York State has mandated the installation and usage of DOH approved prevention devices.

The danger of backflow arises when there is a connection to the water source where water can be drawn back into the pipes. For example, if the water pressure suddenly drops, any water that has puddled near the sprinkler heads, where fertilizers are often present, could be siphoned back into the water supply that the public relies on for drinking. The same thing could happen if a hose is left dangling in a swimming pool, slop sink or fish tank.

A decrease in water pressure is not uncommon. If a hydrant is being used nearby to extinguish a fire or a nearby water main has ruptured, it will cause the pressure to drop suddenly.

When properly installed and maintained, backflow devices guard against these conditions, so please check with our office regarding requirements when installing new plumbing systems including underground irrigation. Please note that underground irrigation systems are often mistakenly called sprinklers.

You can download the New York State Department of Health Application for Approval of Backflow Prevention Devices:

Application for Approval of Backflow Prevention Devices (PDF)

Annual Backflow Test.  Mandated by New York State Department of Health.

The annual test of your backflow device needs to be performed by a certified backflow tester. After the inspection is complete, the paperwork and the results must be submitted to the West Hempstead Water District headquarters.

For a list of certified testers, please call the District at (516) 483-1180.

You can download the New York State Department of Health Test Form:

DOH Certified Test Form (PDF)