The State of Michigan’s groundwater clean-up rules now officially include PFAS compounds, based upon the state’s PFAS limits in public water supplies. Limits for seven PFAS compounds were officially added to the groundwater clean-up rules by the Michigan Department of Environment Great Lakes and Energy (EGLE) on February 15, 2022. The generic clean-up criteria (GCC) for the seven PFAS compounds are as follows:

• Hexafluoropropylene oxide dimer acid (HFPO-DA) 0.370 ppb

• Perfluorobutane sulfonic acid (PFBS) 0.420 ppb

• Perfluorohexane sulfonic acid (PFHxS) 0.051 ppb

• Perfluorohexanoic acid (PFHxA) 400 ppb

• Perfluorononanoic acid (PFNA) 0.006 ppb

• Perflurooctanoic acid (PFOA) 0.008 ppb

• Perfluorooctane sulfonic acid (PFOS) 0.016 ppb

In addition to the groundwater clean-up criteria, EGLE also established groundwater surface water interface criteria (GSI) for PFOA (12 ppb) and PFOS (0.012 ppb). EGLE’s updated groundwater rule expands upon rules approved in 2020 by the Environmental Rules Review Committee, which established standards for safe water at public water supplies for PFAS.

According to EGLE, this announcement provides “regulatory certainty for individuals that cause or are impacted by PFAS contamination in groundwater used for drinking water, because Michigan uses the generic cleanup criteria to determine "facility" status. Determining facility status is the threshold for all responsibilities and requirements of the cleanup program.”

Michigan’s generic cleanup criteria also provides a party responsible for addressing a contaminant with the appropriate tools to determine if response activities or other actions should be taken at a contaminated site to prevent unacceptable exposure to the public. A responsible party can use these generic cleanup criteria as their cleanup levels to achieve "no further action." A responsible party can also use site-specific criteria based on a site-specific risk assessment, approved by the department, in lieu of the generic cleanup criteria, according to the EGLE official announcement on March 23, 2022.

Merit Laboratories is a leading national PFAS environmental laboratory, analyzing drinking water, soil, wastewater, groundwater, and other sample matrices, including biosolids and sludge. Analytical methods performed by Merit for PFAS include drinking water by EPA 533, EPA 537.1, and EPA 537 rev. 1.1, biosolids by ASTM D7968-17 with Isotopic Dilution, and soil, wastewater, groundwater, and surface water by ASTM D7979-19 with Isotopic Dilution and ASTM D7968-17.