Bureau of Environmental Engineering
Backflow Prevention
Backflow prevention devices are mechanical units that prevent the reversal of water flow and subsequent contamination of the water supply from irrigation systems, etc. This may occur when there is a loss of water pressure in the street water main due to a water main break, over pumping of fire hydrants, or a generalized system pressure loss.
Homeowners and Facilities may be required to install a backflow prevention device on their water service line. You may call your public water supplier to determine if a backflow prevention device is needed and to determine the type of device required.
A Cross Connection Control Guide has been prepared to present the New York State Department of Health policy and requirements for cross-connection control. Additional information on the program can be found here along with the Guidelines for Designing Backflow Prevention Assembly Installations.
If you have additional questions you may call the Office of Water Supply Operations at (516) 227-9692.