Michigan’s PFAS Action Response Team (MPART) is working to implement Governor Whitmer’s March 26, 2019directive that the state propose new drinking water standards for an undetermined subset of the thousands of per- and polyfluoroalkyl substances (PFAS) by October 1, 2019. MPART, on April 11, 2019, appointed three scientists to a Science Advisory Workgroup and directed the workgroup to review existing and proposed health-based drinking water standards for various PFAS compounds from around the nation.

The Michigan Department of Environmental Quality (MDEQ), soon to be part of the new Department of Environment, Great Lakes and Energy (EGLE), was directed by the Governor to work with the Science Advisory Workgroup to develop health-based values for PFAS compounds by the end of June -- an ambitious but critical step for developing Safe Drinking Water Act maximum contaminant levels (MCLs) in drinking water. Thereafter, MDEQ will propose draft rules, seeking stakeholder input that, according to the governor’s directive, must be proposed by October 1st. Following administrative rulemaking procedures, a final MCL drinking water standard could be adopted by April 2020. The directive leaves to agency deference which of the thousands of PFAS compounds MDEQ will select for developing MCLs.

Michigan, like most states, has typically (if not always) simply adopted those MCLs developed federally by the U.S. Environmental Protection Agency (EPA). States have called on the EPA to develop MCLs for certain PFAS compounds. In response, the EPA’s PFAS Action Plan, released earlier this year, stated the agency was moving forward with the MCL process for PFOA and PFOS—two of the most well-known and prevalent PFAS chemicals. The EPA, however, did not provide a timeline and the implication was that federal MCLs could take several years or more. The next federal action under the Safe Drinking Water Act that the agency describedwas to propose a “regulatory determination,” which would provide the opportunity for the public to contribute to the information the EPA will consider related to regulating certain PFAS compounds for drinking water. Some states, like Michigan, have decided not to wait for this EPA process to continue with indeterminate outcomes and timeframes, and have instead undertaken to set their own state-based MCLs.

PFAS regulatory approaches continue to emerge and evolve. This MCL development is just one of the many actions that are being taken in Michigan and many other states across the nation.