Plymouth Township is required by the State of Michigan to maintain a water cross-connection control program to identify and eliminate any possible contaminants that might enter the public water system. The Township has had a program for commercial and industrial customers for several years; however, in order to fully comply with the State mandate, we must now include residential customers as part of this program. Plymouth Township has contracted with HydroCorp of Troy, MI to assist with facilitating this program.

The new residential program will consist of inspections of the exterior of homes and require periodic testing of backflow prevention assemblies, which are typically found on your lawn irrigation systems.

We’ve created a five-year rotational schedule for inspections and testing. HydroCorp will begin inspections in ‘Zone 1’ this Spring as indicated on the map below. Homeowners will receive advance notice and all inspections will be done outside of the home.

To find out which inspection zone you reside in, and additional information about the residential program, please visit the Township’s Water Cross-Connection Control Program website at