Backflow Prevention


To protect the public water supply from contamination and ensure the safety of our community’s drinking water, the following backflow prevention rules are established for all customers of Oyster Bay Water District.

Compliance Requirement

All customers connected to the public water supply must comply with the backflow prevention regulations set forth by the New York State Department of Health (NYSDOH) and the Oyster Bay Water District.

Installation of Backflow Prevention Devices

Customers identified as having a potential risk of contaminating the water supply must install and maintain appropriate backflow prevention devices in accordance with NYSDOH regulations.
Backflow prevention devices must be installed by a licensed plumber.

Annual Testing

All backflow prevention devices must be tested annually by a certified backflow prevention tester.
Customers are responsible for scheduling and completing the annual testing of their backflow prevention devices. A list of backflow testers is available upon request. Test reports must be submitted to the Oyster Bay Water District when completed.

Notification of Changes

Customers must notify the Oyster Bay Water District of any changes to their water usage that may impact backflow prevention requirements, such as installation of irrigation systems, chemical injection systems, or other potential sources of contamination.


Non-compliance with backflow prevention rules may result in penalties, including fines and termination of water service. Oyster Bay Water District reserves the right to inspect customer premises to ensure compliance with backflow prevention regulations.

Education and Outreach

Oyster Bay Water District will provide educational resources and outreach efforts to raise awareness about the importance of backflow prevention and help customers understand their responsibilities under these rules.

A list of local certified testers is mailed to all backflow customers. To access a full list of testers certified by Nassau County go to:

Accessibility Options