At the 1933 Chicago World’s Fair, 98 people died from Dysentery due to sewage from the toilets that backed up into the water system. More recently, the neighbors to a food processing company discovered that their water was tainted with apple juice; not a health hazard to most but the coffee probably tasted funny. These events and many others like them are the result of cross connections. A cross connection is any potential or actual physical connection between potable water and a non potable fluid. These connections can range in severity from severe hazards (involving sewage or hazardous substances) to aesthetic problems (juice, dirt, etc.).

Without protective assembly devices, (referred to as backflow prevention assembly devices), the potable water supply can become contaminated by any customer in the system. A Cross Connection Control Program is required by the Washington State Department of Health and the United States Environmental Protection Agency (through the Safe Drinking Water Act) to protect the public from contaminated water. This program calls for facility inspections to identify and eliminate cross connections as well as annual testing of backflow prevention assemblies.

Although many people are not aware of it, we see common backflow preventers every day. The average household sink, whether in the bathroom or a kitchen, utilizes an air gap to prevent the potable water supply from becoming contaminated. Other appliances that utilize water (namely, clothes washers) have built-in backflow preventers as well. Some businesses, specifically hospitals and shops that use hazardous chemicals, are isolated from the rest of the system with heavy duty backflow prevention assemblies.

Your City or Water district is responsible for protecting you from contaminated water. Customers assist with the success of this program by attaining the proper permits for plumbing changes (including new irrigation installation). Arrange for a test of the backflow assembly by a certified backflow tester. Then call your City/Utility District for an inspection of the backflow assembly installation. You will need 3 copies of the Test Report, one for the Certified Backflow Tester, one for your City Inspector/Utility District Inspector, and one for your records. For your convenience, the Test Report form and a link to the Washington State certified Backflow Testers list is provided: