Michigan PFAS regulatory concentrations are set to decrease in 2027. Michigan Department of Energy, Great Lakes and Environment (EGLE) has confirmed the State must lower its PFAS drinking water standards to align with the US Environmental Protection Agency’s (USEPA) new national limits. Per- and Polyfluoroalkyl Substances (PFAS) | US EPA. That is because Michigan enforces the Safe Drinking Water Act under delegated authority from the USEPA and thus standards must be at least as strict as the federal standards. The federal standards were adopted in 2024 but are set to become effective in 2027 and will become enforceable in 2029. Those standards are as follows:
- PFOA and PFOS – 4 parts per trillion (ppt)
- PFHxS, PFNA, and HFPO-DA – 10 ppt
- Mixtures of two or more of PFHxS, PFNA, HFPO-DA and PFBS must have a hazard index of ≤1
One company is challenging the current Michigan regulatory standards in court which has held up adoption of the new federal standards in Michigan. That company is 3M. In 2021, 3M challenged the scientific and procedural basis of Michigan’s PFAS water standards. In August of 2024, the court rejected the scientific objections but struck down the rules and regulatory limits on procedural grounds. The basis for striking down the regulatory standards was that EGLE failed to prepare a proper Regulatory Impact Statement (RIS), which would include an estimate of compliance costs for businesses and affected groups.
The Michigan Attorney General then appealed the decision to the Michigan Supreme Court, which in March 2025, vacated the ruling and remanded the case back to the lower court for further review. Specifically, the lower court was asked to reconsider the following:
- Mootness – whether 3M’s challenge to the 2019 PEAS rule became moot after Michigan promulgated a newer rule set forth in 2020.
- Exemption to mootness – whether the case can continue even if technically moot.
- Failure to exhaust administrative remedies – whether 3M should have requested a declaratory ruling from EGLE before suing, as required by Michigan Law (MCL 24.264).
- Impact on jurisdiction and standing – if remedies were not exhausted properly, did the trial court even have the authority to hear the case?
At this time, the current regulations are still in place as the case works its way through the courts.
In the first potential outcome to the case, the court upholds EGLE’s PFAS rules. This would mean stricter PFAS compliance obligations remain and expand to meet federal requirements. Businesses that produce, use, store, discharge, or manage PFAS would have continued testing and reporting requirements for wastewater, stormwater, drinking water supplies, or groundwater as shown on the Per- and Polyfluoroalkyl Substances Initial Monitoring: A Quick Reference Guide. They could also potentially have new cleanup responsibilities because drinking water limits automatically trigger groundwater cleanup criteria as Michigan has set the drinking water limits as their groundwater treatment standards. In addition, there could be higher operational costs due to implementing remedial treatment technologies, the need for PFAS free reformulations or needing additional environmental and legal support. A benefit of this ruling would be that there are greater regulatory clarity and certainty. There would be predictable compliance paths, clear regulatory expectations, and the ability for companies to plan long-term capital and risk strategies.
The second outcome would be that the court strikes down EGLE’s PFAS rules again. This would lead to temporary easing of regulatory burdens and lead to short-term cost savings. For example, businesses would avoid costly testing and monitoring, and cleanup standards tied to drinking water limits would not be enforceable. The problem here is that it would increase long-term uncertainty and would be only a temporary reprieve as the state is required to move forward with the stricter federal standards. In addition, this could lead to increased litigation for businesses tied to contamination and property damage. Businesses could lose the advantage of regulatory certainty and face court driven standards.
Of course, this could also lead to more back and forth between the courts. In this scenario, everyone loses. The ongoing regulatory uncertainty complicates business budgeting, environmental compliance planning, and capital allocation strategies. It would also likely lead to increased long-term compliance costs from additional insurance, due diligence costs, legal support, and needing to have cash reserves for future cleanup requirements. In short, both the public and regulated industries benefit from certainty.
This case is being watched across the country as it has the potential to shape nationwide PFAS litigation strategies. Not only will it be a road map for challenging PFAS rules on procedural grounds, but it could signal that the courts may scrutinize the costs of PFAS cleanup more aggressively. This means that cost may be taken into account along with the science in determining required cleanup standards.
For further assistance with or information, please contact Leslie Hartig from our Trinity Consultants Ann Arbor office.
