Backflow Prevention

What Is Backflow?

Backflow is the reversal of the flow of water in the plumbing system. It can occur when the pressure in the water main or a home’s plumbing system changes.

What is a backflow prevention assembly, and do I need one?

A backflow prevention assembly is a device that provides a mechanical barrier to backflow. If you have a sprinkler system installed at your home, you are required by the Uniform Plumbing Code to have an approved backflow assembly installed and annually inspected. It’s a good idea to test your backflow assembly every spring when you turn your irrigation system on.

What if I have a pressurized irrigation system?

If there is no physical connection between the pressurized irrigation system and the public water supply, there is no need to have a backflow assembly. If there is any connection between the two water supply systems, you must have a backflow assembly installed and tested annually.

How am I at risk if there is a backflow incident?

If there is backflow at your home, you could contaminate your drinking water with non-treated water from an irrigation canal or water pooled around a sprinkler head that has fertilizer on it. Also, if you use your hose to fill a wading pool or hot tub, a reversal of the water flow could siphon pool or spa chemicals back through the garden hose and into your house’s plumbing.
Garden hoses that are used to apply chemical fertilizers or pesticides are also susceptible to drawing contaminants into your home. If your home was built after 1985, it should be equipped with backflow-preventing hose bibs. If your home is older, you need to check to make sure you have the proper protection for outside faucets.
If there is a backflow incident at just one home in a neighborhood, there is the potential for contaminants to spread into the public water supply, threatening your neighbors. A properly operating backflow assembly can help prevent this.