Backflow Assembly

Posted: May 23, 2023 at 11:05 a.m.

Whether you have lived here your whole life or are new to the area, you may not know what a backflow assembly is.

A backflow assembly allows potable water to flow into your home, business, irrigation system, or fire sprinkler system but will prevent it from flowing in the opposite direction. This in turn will prevent contaminants from potentially entering your home or business plumbing and distribution system through a cross-connection. A cross-connection is an actual or potential connection between a potable water source and a non-potable substance, such as a garden hose submerged in a bucket of soapy car wash water. If there were a pressure loss in the main line, the soapy water from the bucket could get sucked through the hose and back into the public water supply.

Having a Cross-Connection Control Program helps prevent situations like that from contaminating potable water. Our program identifies certain hazards and requires backflow assemblies where those hazards exist.

Examples of Backflow Incidents:

“In December 1983, effluent from a wastewater treatment plant in San Antonio, Texas, backflowed into the potable water system at the plant because of maintenance activities.  Eight employees reportedly suffered gastrointestinal problems. Fortunately, a reduced-pressure principle backflow-prevention assembly was in place at the water service connection to the plant. This assembly contained contamination within the plant site.”

(American Water Works Association, Recommended Practice for Backflow Prevention and Cross-Connection Control, AWWA Manual M14, Second Edition, 1990)