Regulations of PFAS (per- and polyfluoroalkyl substances) have been evolving quickly, and more changes are on the way in Michigan. 

In 2020, Michigan established some of the nation’s first drinking water standards for PFAS, setting limits with Maximum Contaminant Levels (MCLs).^[1] For example, the MCL for PFOA (perfluorooctanoic acid) is 8 parts per trillion (ppt) and PFOS (perfluorooctanesulfonic acid) is 16 ppt. 

However, federal regulations will cause EGLE (Department of Environment, Great Lakes, and Energy) to lower Michigan’s MCLs even more. In April 2024, the U.S. Environmental Protection Agency (EPA) passed a national drinking water MCL under the Safe Drinking Water Act, establishing a threshold for PFAS in drinking water of 4 ppt for five kinds of PFAS (including PFOA and PFOS), as well as regulating four PFAS collectively when present as a mixture.^[2] These national MCLs will take effect in 2027.^[3] In 2029, the national MCLs become enforceable, triggering penalties and increased monitoring frequencies.

In Michigan, the EPA has delegated its authority to the state to enforce the Safe Drinking Water Act.^[4] This means that EGLE is the primary agency in charge of creating and enforcing drinking water regulations. Because this authority is delegated, state limits on contaminants in drinking water must be at least as restrictive as federal limits.^[5] Thus, Michigan will need to enact new MCLs on or before 2027.

In recent conversations, EGLE has stated it intends to update the state’s MCLs on or before 2026, which will be at or below the EPA’s level of 4 ppt for each type of PFAS. However, EGLE will not start the process until the Michigan Supreme Court decides a case filed by 3M against the state, which challenges the state’s current MCLs. According to the state, the outcome of the case could dictate the process that the State needs to use for implementing the new MCLs and affect the timeline for the new rules. Either way, new rules are forthcoming.