• City

    In August 2020, the Michigan Department of Environment, Great Lakes, and Energy (EGLE) established Maximum Contaminant Levels (MCLs) for seven PFAS compounds.  An MCL is the maximum amount of a contaminant allowed in drinking water. Michigan's MCLs were established through a rigorous administrative rulemaking procedure that relied on a fact-based, scientific process that evaluates contaminants for their potential to have adverse health effects. When the amount of a contaminant in drinking water is higher than the MCL, the water supply must take action such as public notice, treatment to reduce the levels of PFAS contaminants, or additional testing, among other things.

     

    Specific PFAS

    Drinking Water MCL
    Parts per Trillion (ppt)

      PFNA

      6 ppt

      PFOA

      8 ppt

      PFHxA

      400,000 ppt

      PFOS

      16 ppt

      PFHxS

      51 ppt

      PFBS

      420 ppt

      HFPO-DA

      370 ppt

     

     

    Drinking water rules were amended to include the above PFAS MCLs, establishing sampling requirements for these seven PFAS compounds in public water supplies covered under the Michigan Safe Drinking Water Act.  Additional information on Michigan's PFAS MCLs can be found on EGLE's PFAS Drinking Water Rules webpage. 

    Private residential wells are not regulated under the Michigan Safe Drinking Water Act, but Michigan uses the MCLs along with other factors when evaluating private residential well results.

    Prior to Michigan establishing PFAS MCLs in August 2020, MPART used the United States Environmental Protection Agency (USEPA) Lifetime Health Advisory (LHA) level of 70 ppt for decision making purposes. The USEPA LHA standard applies to perfluorooctane sulfonate and perfluorooctanoic acid (PFOS and PFOA) combined, or individually if only one is present.  Learn more about USEPA's LHA for PFOA and PFOS.