Please note that DEP now charges for Backflow Prevention Plans and Exemptions (see the NYC Water Board FY2011 Rate Adoption Notice for the revised billing policies). All fees must be attached to the corresponding application and submitted at the same time. Please also note that several of our forms have changed; please read the forms and associated instructions carefully.
DEP’s Cross-Connection Control Program requires certain businesses to install and operate approved backflow prevention assemblies and enforces Part 5 Section 5-1.31 of the State Sanitary Code and Title 15, Chapter 20 of the Rules of the City of New York.
Backflow assemblies prevent contaminated water or chemicals from flowing back into the drinking water supply if there is a sudden or unexpected change in water pressure. If a property requires a backflow prevention assembly, they must be installed on all water service lines to the property. Appropriate backflow prevention assemblies can be identified by a Professional Engineer, Registered Architect or Licensed Master Plumber.
Effective January 4, 2014, all proposed installations/repairs of Backflow Prevention Assemblies to be utilized on all domestic water services for human consumption (Drinking/Food Prep), must be Lead-Free in compliance with the amended Federal Law (Safe Drinking Water Act).
Information on DEP’s Backflow Prevention Outreach Program
Backflow Prevention Program Brochure
Frequently Asked Questions
Assembly Installation and Inspection Procedure
Revised New York City DEP Supplement to the New York State Department of Health (DOH) Handbook for Cross-Connection Control
This supplement to the DOH handbook provides an overview of DEP’s Cross-Connection control program. It must be used as a guideline for Professional Engineers and Registered Architects in the preparation of Backflow Prevention Assembly Plans for submittal to DEP.
DEP Cross-Connection Control Risk Assessment (Revised May 2017)
This is a guideline for Professional Engineers/Registered Architects for filing Backflow Prevention Assembly Plans for all property types.
Regular Cross-Connection Control Applications
Application for Approval of Backflow Prevention Assemblies
This form must be used by Professional Engineers and Registered Architects to apply for approval of plans for backflow prevention assemblies.
Form for Report on Test and Maintenance of Backflow Prevention Assembly
This form must be used to report on initial tests and annual tests of a backflow prevention assembly. Testing must be conducted by a certified backflow prevention assembly tester. This report must be signed by a Professional Engineer or Registered Architect, a Licensed Master Plumber, and the backflow prevention assembly tester (if different from the Licensed Master Plumber).
Format for Backflow Prevention Assembly Exemption for a Residential Building with One Domestic Line Only
This format must be used by Professional Engineers, Registered Architects or Licensed Master Plumbers to apply for a backflow preventer exemption for a facility with one domestic service only.
Self-Certified Cross-Connection Control Installation Plans and Exemptions
Guidelines for Filling out Forms for Self-certification of Cross-Connection Control Assembly Plans and Exemptions
These guidelines are for Professional Engineers and Registered Architects to self-certify plans for double check valves, double check detector assemblies, and exemptions (facilities do not require a Cross-Connection control assembly).
Self-certification Application for Cross-Connection Control Double Check Valve Assembly Installation Plan - Domestic Service Only
This form must be used by Professional Engineers and Registered Architects when self-certifying the installation plan for a backflow prevention assembly on a domestic service line only.
Self-certification Application for Cross-Connection Control Double Check Detector Assemblies Installation Plan - Fire Service Only
This form must be used by Professional Engineers and Registered Architects when self-certifying the installation plan for a backflow preventer on a fire service line only.
Self-certification for Cross-Connection Control Assembly Installation Exemption - One Domestic Service only
This form must be used by Professional Engineers and Registered Architects to self-certify that a facility with one domestic service line does not require a Cross-Connection control assembly.