Once water enters your irrigation system it can become contaminated with lawn chemicals and bacteria. Your irrigation system is required to have adequate backflow protection. If you do not, blowing out the system can push this contaminated water back into your home’s water supply and/or the public water system. All systems that contain pumps or injectors for lawn chemicals are considered a high risk and should be equipped with a Reduced Pressure Backflow Assembly (RPBA). If the system does not have pumps or injectors it is considered a moderate risk and requires a Double Check Valve Assembly (DCVA) or a Pressure Breaker Vacuum Assembly (PBVA). However if you plan to use an air compressor on your irrigation system, a PBVA will not provide adequate protection. Please read the next section on Cross Connection Control for more.
For more information or to learn if your system has backflow protection contact the District at 922-5443 or visit these websites:
Spokane Regional Cross Connection Control Chapter
Washington State Department of Health—Office of Drinking Water
Spokane Aquifer Joint Board