While not everyone may understand, and some people are completely unaware, annual backflow testing helps ensure everyone in Washington has access to clean drinking water.

What is a backflow prevention device?

Many homes and businesses are equipped with backflow prevention devices.  A backflow prevention assembly is commonly used in fire control and irrigation systems to protect water supplies from contamination or pollution. Valves are used to control water flow, ensuring that contaminated water does not mix with drinkable water.

In most all water supply systems, the water is constantly maintained at a significant pressure.  This built up pressure is what enables water to flow from the tap and shower etc.  As you may have experienced, sometimes this pressure is reduced or completely eliminated, which is where a backflow prevention assembly becomes critical.

When water pressure fails or is noticeably reduced — for example, when a water main bursts, pipes freeze or there is unexpectedly high demand on the water system — the pressure difference may allow polluted water from the ground or from other sources to be drawn into the water system.  Once the water has been contaminated, everyone who depends on that water supply for clean water will also be at risk for serious harm.

To prevent such an occurrence, Washington requires the use of mechanical backflow prevention assemblies.  Annual testing of these units is required to prevent serious injury to the general public.  If you are a homeowner in Western Washington and own a sprinkler system, you likely have a backflow prevention assembly.