Does a Backflow Prevention Device | RPZ Installation Require a New Water Line Installation?

As of recently the requirement for a backflow prevention device (BPD) is becoming more common throughout NYC.   The city continues to monitor the water supply in efforts to avoid any contamination from entering the city water.  As part of the continued efforts, the city has established the “Cross Connection Control Program” which requires certain types of businesses and houses to install a backflow prevention device on their water main.

water_main_repairIt is not a requirement to change the entire water line when installing the BPD however, it is common that the water line may be repaired or replaced when installing a new Backflow Prevention Device.  There are several variables that do require a repair or replacement of the water line, the most common are the age and the existing material of the pipe. In some cases it may make financial sense for the property owner to change the main due to these variables.

The most common reason for replacing the water line when installing a new backflow device is if the water line cannot be turned off for the backflow installation. The water line from the city water main in the roadway, to inside the building, must be turned off for the backflow installation.   In many cases the internal house control valve is too old and no longer functions.  If a curb valve exists, the plumber will try to locate the valve on the outside of the building to turn the water off, replace the non-functional valve and install the new BPD device.  If a curb valve does not exist or is no longer functional, a licensed plumber must obtain DOT street opening permits and close the water supply from the tap connection valve located beneath the roadway.  At this point the plumber may install a curb valve in addition to the new house control valve and backflow device.  Pending the age, material type and overall condition of the existing water line, the property owner may decide to replace the entire pipe from the roadway to inside the building.  The replacement may also be required as per DEP (Department of Environmental Protection) regulations.

waer_line_w_cv_and_wcReplacing the entire water line will avoid any additional issues that may arise when working on an old and corroded pipe.  If the pipe is too corroded there may be no choice but to replace the main as the existing pipe must be in such condition that will not allow for a repair.  If the existing water line is over 20-30 years old, the property owner should weigh the pros and cons of replacing the main while the street is opened. Replacing the pipe at this point in time will avoid the owner from having to perform any additional work on the main in the coming years and potentially save thousands of dollars.

If you are working with DOB (Department of Buildings) or DEP approved plans that require a different size water main or sprinkler main from the existing, you will have no choice but to replace the existing water line in full.  Once the new line is installed the piping will be inspected while the roadway/sidewalk excavations are still open.


What type of water main or sprinkler main requires DEP inspections?

If you are repairing or replacing any type of fire sprinkler main it is required to schedule DEP inspections on the new installation.   The only type of domestic water line that requires a DEP on-site inspection is if the main is larger than 2”.  Any main 2” in size or smaller can be self-certified by the Licensed Master Plumber.

Please contact 311 if you have any additional questions regarding the Cross Connection Program


If you have any additional questions please feel free to contact Harris Water Main & Sewer Contractors @ 718-280-9525 – Serving the 5 Boroughs for over 90 years