In water supply systems, water is normally maintained at a significant pressure to enable water to flow from your faucet, shower, etc. When pressure fails or is reduced, as may happen if a water main bursts, pipes freeze or there is unexpectedly high demand on the water system, the pressure in the pipe may be reduced and may allow contaminated water from the ground, from storage or from other sources to be drawn into the system.
Back pressure is another way that an undesirable contaminant may enter potable water piping. Sources of back pressure may be from pumps in the water distribution system, boilers, heat exchanging equipment, or power washing equipment. In these cases, there may be an almost constant risk of overcoming the static water pressure in the piping. To reduce the risk of contamination, a backflow prevention device should be fitted to prevent this reverse of flow into the water system. A backflow prevention device is also important when chemicals are used, for instance for commercial/industrial descaling (boilers) or when bleaches are used for residential power washing.
In summary, the backflow prevention device protects water supplies from contamination or pollution due to backflow.
In the United States, the Environmental Protection Agency (EPA) holds local water suppliers responsible for maintaining a certain amount of purity in potable water systems. The City of Wilton Manors requires annual testing of backflow prevention devices. A check valve is a common form of backflow prevention. In most cases, the law requires a double check (DC) valve, a Reduced Pressure (RP) Principle Device, or an air gap when backflow prevention is mandated.
The City has contracted with BSI Online to administer the City's backflow recertification program. Please visit the Backflow Assembly Tests Fact Sheet for information about the testing process.