Professional Backflow Testing & Prevention Services

Backflow occurs when contaminated water flows backward into the clean water supply — the reverse of its intended direction. This can happen when a drop in water pressure (from a water main break, fire hydrant use, or heavy demand) creates a siphon effect that pulls non-potable water, chemicals, or sewage back into the drinking water system.

Backflow prevention devices (BPDs) are mechanical valves that allow water to flow in only one direction, blocking any reverse flow. They are required by plumbing codes at specific points in the water system — including irrigation connections, fire sprinkler systems, boiler feeds, laboratory and medical equipment, chemical injection systems, and any connection where non-potable water could contact the potable supply.

Most municipalities require annual testing and certification of backflow prevention devices by a licensed and certified tester. During testing, the device is isolated and tested with specialized gauges to verify that the check valves and relief valves are operating within manufacturer specifications. A passing test results in a certification form that is filed with the local water authority.

Licensed plumbers install new backflow prevention devices (reduced pressure zone assemblies, double check valve assemblies, and pressure vacuum breakers), perform annual testing and certification, and repair or replace devices that fail testing. If your property requires a backflow device, your local water utility will notify you of the testing schedule and requirements.