What is an RPZ?

What is an RPZ?

The Village of Bannockburn takes pride in providing safe drinking water to our residents. The water that reaches your home or business meets all State and Federal drinking water standards and is safe to drink. However, contamination can occur within your own piping system. The greatest potential hazard is known as an unprotected “cross connection”, which can cause backflow to occur.

What is an RPZ?

An RPZ is a Reduced Pressure Zone device (RPZ) is a type of backflow prevention device used to protect water supplies from contamination.

The State of Illinois requires all RPZ devices be inspected annually by a certified private plumber/contractor.

What is an RPZ

If you have recently purchased a home, you may notice a device like the photo below mounted on the side of your house. This is the backflow device for your irrigation system. This device is important because it protects the public water supply from contamination. This device requires yearly testing by a cross connection control inspector.

What is an RPZ


Does it need to be tested every year?

Yes. Annual testing makes sure the device is in working condition. Working devices keep your family and the community safe from contamination.

What does a backflow preventer do?

The device stops the flow of non-potable water from a lawn or fire sprinkler system into a building. It is safest to keep non-potable water out of homes, businesses, and the public water supply.

Are there different kinds of backflow devices other than the RPZ type?

Yes, but only Reduced Pressure Zone (RPZ) type devices are acceptable for lawn irrigation systems. If you have any other type device it cannot pass the inspection.

My lawn irrigation system is old, and it passed its original inspection, Am I grandfathered in with my non-RPZ backflow device?

No. Because these devices connect to the public water supply, State Code does not allow it. Non-compliant devices can impact the health and safety of your family and your neighbors.