Backflow is the undesirable reversal of flow from the intended direction in potable water distribution piping caused by either backsiphonage or backpressure conditions. 

If there is a backflow or backsiphonage at your property without the properly maintained appropriate backflow assembly you could pollute or contaminate our drinking water. Non-treated water from an irrigation canal, water pooled around a sprinkler head with fertilizer on it, hoses that are either submerged while filling up pools or used to apply chemical fertilizers or pesticides are all common potential threats to our potable water system. 

Backflow Assemblies are testable mechanical devices that prevent pollutants or contaminants from entering our public drinking water supply. Both residential homes and commercial buildings may be required to have the appropriate backflow assembly properly installed, maintained, and annually tested.

Most properties DO have backflow assemblies and all are required to be tested at a minimum of once per year. For example, if you have a lawn sprinkler system that is supplied by your local water purveyor you are required to have an approved backflow assembly properly installed and annually tested.