We previously wrote regarding a Michigan state court ruling that struck down Michigan’s PFAS regulations related to drinking water enforceable limits, with the ensuing appeal in December 2022 by the state. The state filed its legal brief at the end of February 2023 with the Michigan Court of Appeals, advancing several arguments of note. The significance of the Michigan PFAS challenge is that the arguments and lower court ruling provide clues as to similar arguments that we predict will be advanced when certain companies challenge federal drinking water standards and the CERCLA PFAS designation in courts.

Michigan PFAS Challenge

Michigan recently enacted PFAS drinking water standards for seven types of PFAS – PFOA (8ppt), PFOS (16ppt), PFNA (6ppt), PFHxA (400,000ppt), PFHxS (51ppt), PFBS (420 ppt) and the Gen-X chemical HFPO-DA (370 ppt). 3M challenged the regulations in court on three grounds: (1) Michigan had not shown that the standards were necessary, (2) the standards were enacted in a manner such that they were arbitrary and capricious and (3) there were deficiencies in the state’s regulatory-impact statement (a required part of the regulatory process).  The Court dismissed the first two arguments; however, it found in favor of 3M on the third ground. In short, the Court found that Michigan had not properly considered the cost impacts of the standards to companies and so the impact statement that was written was faulty.

While the ruling technically does strike down the Michigan regulations, the Court also ruled that it would stay its decision and not make it effective until final judgment is entered. As such, the Michigan PFAS regulations will remain in effect during the period of time when the current appeal is pending. The Court also made note that the entire lawsuit and the drinking water standards could be moot if the EPA’s drinking water standards are ultimately more aggressive than Michigan’s.

Michigan filed legal briefing with the Michigan Court of Appeals at the end of February 2023. In relevant part, the state argues that the regulatory impact statements that it submitted with the PFAS drinking water regulations already have all required information in them and that “unsupportable cost estimates” such as the ones it feels 3M is asking for are not required. In addition, the state argues that the lower court improperly inserted itself into the rulemaking process and improperly overrode the substantial administrative process that the state undertook in drafting the drinking water standards.

Impact On PFAS Developments

The Michigan court ruling certainly demonstrates to companies contemplating whether to legally challenge the EPA’s upcoming PFAS drinking water MCLs or the proposed CERCLA designation of PFOA and PFOS that there are courts willing to scrutinize the undertaken legislative process to ensure that all necessary procedures were followed. This will be especially important as we have previously predicted that the drinking water standards are likely to be challenged on grounds similar to the Michigan lawsuit (as well as others) and the CERCLA designation is likely to be heavily opposed in court proceedings due to the EPA not conducting a rigorous RIA process.