The federal Safe Drinking Water Act (SDWA) requires that all public water systems (community and noncommunity) provide an adequate supply of safe drinking water to customers and consumers. The Michigan Department of Environment, Great Lakes, and Energy (EGLE) is responsible for implementing and managing the SDWA at the state level. One of the regulations is the 1989 Total Coliform Rule (TCR).

On April 1, 2016, the Revised Total Coliform Rule (RTCR) went into effect replacing the old regulations. Total coliform bacteria function as indicator organisms. Their presence indicates a potential pathway allowing contamination into the distribution system exists. The RTCR establishes a maximum contaminant level (MCL) for E. coli.