One of the concerns of the Washington State Department of Health involves drinking water cross connections. A cross connection is any connection between a safe drinking water source and an unsafe source of water or liquid. This connection presents a health risk and needs to be eliminated or controlled.
Under certain conditions, the water can flow in the reverse direction as a result of system pressure loss. This is known as backflow. There are two types of backflow: Backsiphonage and Backpressure.
Backsiphonage is backflow caused by negative or reduced pressure in the supply lines that may be the result of a main break or firefighting activities in the area.
Backpressure is caused when a non drinking water system pressure is greater than the drinking water system due to a pump, boiler, elevation difference, or air or steam pressure.
Safe drinking water is a resource that all of us depend on. We need to be aware that system integrity is a community effort and responsibility. Please eliminate potential cross connections to ensure a healthy future for yourself, your family, and all members of the community.