What is a backflow preventer sprinkler system?

Consider this potential problem in your yard:  you use weed killer on your lawn.  That weed killer soaks into the soil where it meets the irrigation system, which just happens to also be the potable water system for your home. All is well as long as the contaminated water in that system flows in the correct direction.

But what if that contaminated water reverses direction, a phenomenon known as backflow?  What happens then?

The possibility of homeowners drinking contaminated water is the reason why backflow preventers are required at the Federal level, and it is why you need a company like City Backflow Testing to provide affordable backflow testing for your home.