Michigan is moving rapidly toward promulgating health-based drinking water standards for perfluoroalkyl and polyfluoroalkyl substances (PFAS). In March 2019, Michigan’s governor directed the Michigan PFAS Action Response Team to form a Science Advisory Workgroup “to review both existing and proposed health-based drinking water standards from around the nation to inform the rulemaking process for appropriate Maximum Contaminant Levels (MCLs) for Michigan by no later than July 1, 2019” and directed what is now the Department of Environment, Great Lakes, and Energy (EGLE) “to immediately file a Request for Rulemaking to establish enforceable MCLs for PFAS in our drinking water supplies.” The governor commanded that proposed regulations be completed “on an accelerated schedule with input from stakeholders by no later than October 1, 2019.”[1]

On June 27, 2019, the Science Advisory Workgroup issued a report recommending health-based drinking water values for seven PFAS compounds and screening values for other compounds.[2] In its report, the Workgroup discloses a number of uncertainties and limitations. For example, it concedes that given “the relatively short timeframe” for which to accomplish the tasks it was charged to perform, it did not fully review the scientific literature on PFAS (“the Workgroup confirmed that the focus of the effort was to utilize the existing and proposed national and state-derived PFAS assessments to inform its decision-making process as opposed to conducting a full systematic review of the available scientific literature on PFAS”). (Report, p. 5.) Elsewhere, the Workgroup acknowledges that while the estimates it used to derive the values were based on toxicological studies, “there is a loss of certainty in applying these estimates to free-living human populations.” (Id., p. 6.) Indeed, the Workgroup concedes that for the seven PFAS compounds for which it developed drinking water values, “there remains significant scientific uncertainty,” and concedes that “additional study” is required for many health outcomes, modes of action, and cumulative exposure risks. (Id. p. 9.)

Despite these uncertainties and limitations, EGLE is moving forward with rule promulgation process, with a final rule expected by April 2020 adopting the Workgroup’s recommended values as MCLs.[3] As part of the process, EGLE is currently soliciting input from invited stakeholder groups, conducting what it calls “listening sessions.” For purposes of these sessions, EGLE has circulated a rough draft of the new PFAS MCL rules. EGLE intends to send the draft rules to the governor by October 1, 2019, which will trigger a formal public comment and hearing process. If your business may be affected by the new PFAS rules, we urge you to develop an immediate strategy that maximizes your input on the rulemaking process and proposed rules.