Backflow & Testing

Backflow testing is critical to the protection of our public water supply. Backflow can occur when street water pressure drops, reversing the flow into the water supply. Backflow double-check valves safeguard the water supply by preventing water from reversing direction.

New York State Sanitary Code Part 5, Section1.31 (a) (3) requires that every backflow device be tested by a certified backflow tester once a year. Jericho Water District requests that this test be done prior to June 30 of each year. We recommend coordinating testing with the opening of your sprinkler system in the spring. Once the tester has performed the test and completed the Backflow Test Form, copies must be submitted to Nassau County Health Department and Jericho Water District. Forms should include your Jericho Water District account number, your address and your phone number. Test results should be submitted in one of the following ways:

Certified Testers

Most plumbing and sprinkler installation/maintenance companies have certified backflow testers and it’s wise to check with them regarding testing. You can access a list of certified testers at

For more information, contact the Nassau County Health Department, New York State District Office or email the Bureau of Water Supply Protection at