Your drinking water is pushed from the city’s water main into your property’s plumbing by pressure and it should only flow in one direction. Sometimes, due to pressure changes in pipes, the water can flow backwards into city water lines and could contaminate the public water supply with human waste or chemicals.
New York State law requires certain properties and businesses to install, maintain and test backflow prevention devices, which stop contaminated water from flowing backwards into the main water supply. Failing to do so could result in fines or the disconnection of your water service.
Download Protect Your Water: Install a Backflow Prevention Device, available in: English, Español, 简体中文, русский, Kreyòl ayisyen, 한국어, বাংলা, Polski, العربية, Français, اردو.
To request backflow prevention forms by mail, call 311. For more general water and sewer information, visit Water and Sewer Forms.
Types of Properties that Must Install Backflow Prevention Devices
Unless they receive a specific exemption from DEP, the following types of businesses are required to use backflow prevention devices:
You may also have your Registered Architect or Professional Engineer consult our Backflow Prevention Risk Assessment Guide to determine whether or not your property requires a backflow prevention device. If your property or business type is not included in the list and you have a specific question about your legal requirements, please call 311 to have your inquiry directed to DEP.
For answers to commonly asked questions, visit Backflow Prevention FAQs
Backflow Prevention Device Installation & Testing Procedure
To install a backflow prevention device, you must hire a Professional Engineer (PE) or Registered Architect (RA) to prepare a backflow prevention plan for your property. The PE or RA will send the plan(s) to DEP for approval. If the plans are approved, DEP will notify you via mail. You will then need to hire a Licensed Master Plumber (LMP) to install the backflow prevention device.
After the LMP installs the device, you are required to have a New York State certified tester test it to ensure it was installed properly. For a list of certified testers, visit NY State Department of Health Certified Backflow Testers. It may be the case that your LMP is also a certified tester.
For the intial testing of a newly installed device, the test form should be filled out by a certified tester and signed by an LMP and the RA or PE who submitted the initial backflow prevention plan. The signed test report should be submitted to DEP within 30 days of the installation of the device.
Once installation and initial testing are finalized, you are then required to have your backflow prevention device tested every 12 months by a certified tester. You will receive a notification letter in the mail when your backflow prevention device is due for its annual test. Failure to perform this annual test could result in fines or the disconnection of your water service. For the annual test, the test form needs to be filled out by the certified tester and signed by an LMP.
You can sign up to get email reminders about the testing requirements and dates for your backflow device(s).
Backflow Prevention Application & Exemption Forms for Trade Professionals
This form is to be filled out and used by Professional Engineers (PE) or Registered Architects (RA) to apply for approval of backflow prevention device plans.
Download the Backflow Prevention Device Approval Form
This form is used to submit both initial and annual test results for backflow prevention device(s). Testing must be conducted by a certified tester upon installation and every 12 months thereafter. For testing of a newly installed device, this form must be filled out by the certified tester and signed by an Licensed Master Plumber (LMP) and the Professional Engineer (PE) or Registered Architect (RA) who submitted the initial backflow prevention plan. For the follow up annual tests, the form must be signed by a certified tester and an LMP.
Download the Backflow Prevention Device Test Form
This form must be used by PEs or RAs to apply for a backflow prevention device exemption for a facility with one domestic service only.
Download the Backflow Prevention Device Exemption Form for a Residential Building with One Domestic Line Only
Self-Certified Backflow Prevention Device Plans & Exemption Forms for Trade Professionals
These guidelines are for Professional Engineers (PE) or Registered Architects (RA) to self-certify plans for double check valves, double check detector assemblies, and back flow prevention device exemptions.
Download the Guidelines for Filling out Forms for Self-certification of Backflow Prevention Device Plans and Exemptions
This form must be used by PEs or RAs when self-certifying the installation plan for a backflow prevention device on a domestic service line only.
Self-Certification Application Form: Domestic Service Line Only
This form must be used by PEs or RAs to self-certify that a facility with one domestic service line does not require a backflow prevention device.
Self-Certification Exemption Form: One Domestic Service Line Only
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