A cross connection is a link between the water supply and a potential source of contamination. Backflow occurs when the water direction in a plumbing system flows backwards creating the potential for a contaminate to enter our public water system. Backflow prevention can be achieved through the use of backflow assemblies, devices or methods.

Fairfax County’s Land Development Services and Fairfax Water work together to safeguard the water supply through implementation and monitoring of the Cross Connections Control and Backflow Prevention Program to identify hazards and ensure testing is conducted as required. Backflow prevention assemblies are required by the building code to be tested annually by a certified tester.