Who needs it
Buildings whose water service carries a backflow prevention device, which is common for commercial, mixed-use and larger residential buildings and for fire sprinkler connections. DEP can also order a device installed where the building's use creates a contamination risk.
Who can test
The test must be performed by a tester certified by New York State. Many Licensed Master Plumbers hold the certification and handle the DEP filing as part of the visit.
If the device fails
The device is repaired or replaced and retested, and the passing result is filed. Failing devices are usually worn checks or relief valves, which are repaired on the same visit or the next.