Certified Backflow Prevention Assembly

Cross Connection Control - What is It?

• Certified Backflow Assembly Testers
• Installing a Reduced Pressure Backflow Assembly (RPBA) with a Stop-and-Waste Ball Valve
• Installing a Double Check Valve Assembly (DCVA) with a Stop-and-Waste Ball Valve
• Backflow Prevention Assembly Test Form
• General City Applications and Forms
• Call Before You Dig. It's the Law!

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.).

Examples of potential cross connections include automatic lawn sprinkler systems, fire sprinkler systems, carbonated beverage machines, car washes, and dry cleaners. Even in your own home, you can unwittingly create a cross connection by putting the garden hose in a swimming pool, pet’s water bucket or fish tank to fill it or putting it down the drain to flush out debris when it’s backed up or connecting your garden hose to a plant fertilizer or bug spray unit.

Without protective devices and assemblies (referred to as backflow prevention assemblies), 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- WAC 246-290-490) 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 a common backflow preventor 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 preventors 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.

It is the City’s responsibility to protect customers from contaminated water. The Water Department manages the Cross Connection Control Program and tracks the results of annual backflow prevention assembly testing (conducted by certified Backflow Assembly Testers). List of Certified Testers can be located here.

The Water Department performs inspections of new construction to determine what cross connection precautions are required, if any. Customers are encouraged to assist with the success of this program by attaining the proper permits for plumbing changes (including new irrigation installation) and arranging for annual testing of existing assemblies by a certified tester.

Any questions regarding this program can be addressed to the Water Department at: 

(509) 782-3513.

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