Cross Connection Control


The Michigan Department of Environment, Great Lakes, and Energy (formerly MDEQ) has mandated that Thomas Township establish a Cross-Connection Control program to eliminate possible contamination into the public water system. A plumbing cross-connection is defined as follows: any physical connection or arrangement between potable (drinkable) water and any source of contamination. In order to enforce Thomas Township’s cross-connection program, we rely on residents to be truthful in helping identify possible cross-connections.


The areas of utmost concern to Thomas Township are underground sprinkler systems, automatic fill systems on pools, spas or hot tubs, water powered sump pumps, and boiler heating systems that use chemicals for corrosion control. All of these items are possible cross-connections and are subject to backflow protection.


You can achieve backflow protection with different types of devices. For example, an underground sprinkler system is protected with a device called a “pressure vacuum breaker” (PVB) and is typically located on the outside of your house.


A device intended to protect water activated sump pumps, boilers with corrosion control, or auto fill spas or pools would be called a “reduced pressure zone” (RPZ) device.


Both of these devices are required to be tested by an ASSE certified plumber to make sure that they are operable and in compliance with the law. You are required to coordinate with a plumber to have these devices tested.


In order to be exempted from this program, please read and fill out the “Cross Connection Exemption Certification Form.” You MUST be able to check all five boxes to be exempted. If you cannot check all boxes, you have a device that requires testing.

Typical Pressure Vacuum Breaker Device (PVB). Installed on homes with Irrigation Systems. This device is required to be tested every 3 years (commercial) or every 5 years (residential) by an ASSE certified Plumber.
Typical Reduced Pressure Zone Device (RPZ). This is typically found located on high hazard accounts at the point of service and would be required to be tested yearly (high hazard) or every three years (low hazard).

If you have either of these devices, you cannot be exempted from Thomas Township’s program, and must have them tested as directed.

Thomas Township Testing Frequency:

Residential PVB – Every 5 Years. Commercial PVB – Every 3 Years. High Hazard RPZ – Yearly. Low Hazard RPZ – Every 3 Years.

Residents will receive a mailer when it’s time to have your device tested.