Laboratories Offering Home Testing
PFAS MCLs and Drinking Water
Statewide Testing Initiative
PFAS Sites and Areas of Interest
There are two major classes of firefighting foam: Class A and Class B. Class B is also called Aqueous film forming foam (AFFF) and is usually created using PFAS. It is a highly effective foam used for fighting high-hazard flammable liquid fires, like gasoline, oil, and jet fuel.
Official Correspondence
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In August 2020, the Michigan Department of Environment, Great Lakes, and Energy (EGLE) promulgated rules establishing maximum contaminant levels (MCLs) for seven PFAS compounds under the authority of the Safe Drinking Water Act.
These maximum contaminant levels apply to approximately 2,700 public drinking water supplies in Michigan.
A maximum contaminant level (MCL) is the maximum amount of a contaminant allowed in drinking water.
Compliance with Michigan’s MCLs for PFAS is determined based on a calculated running annual average of sample results for a public water supply. When the running annual average of a contaminant in drinking water is higher than the MCL, the water supply must take action as outlined in the Safe Drinking Water Act or its accompanying administrative rules.
Such actions may include public notice, treatment to reduce the level of PFAS contaminants, or additional testing, among others.
|
Specific PFAS |
Drinking water MCL (ppt) |
|---|---|
|
PFNA |
6 ppt |
|
PFOA |
8 ppt |
|
PFHxA |
400,000 ppt |
|
PFOS |
16 ppt |
|
PFHxS |
51 ppt |
|
PFBS |
420 ppt |
|
HFPO-DA |
370 ppt |
ppt = parts per trillion
Drinking water rules in Michigan 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. 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 (US EPA) Lifetime Health Advisory (LHA) level of 70 ppt, established in 2016, for decision making purposes. At that time, the The US EPA Lifetime Health Advisory standard applied to perfluorooctane sulfonate and perfluorooctanoic acid (PFOS and PFOA) combined, or individually if only one is present.
In 2022, US EPA issued updated interim Lifetime Health Advisory's for PFAS and PFOA, replacing the 2016 Lifetime Health Advisory. Learn more about drinking water health advisories on the US EPA website.
In April 2024, US EPA announced the final National Primary Drinking Water Regulation (NPDWR) for six PFAS. US EPA established Maximum Contaminant Levels (MCLs) for six PFAS in drinking water: PFOA, PFOS, PFHxS, PFNA, and HFPO-DA as contaminants with individual MCLs, and PFAS mixtures containing at least two or more of PFHxS, PFNA, HFPO-DA, and PFBS using a Hazard Index MCL. US EPA also finalized health-based, non-enforceable Maximum Contaminant Level Goals (MCLGs) for these PFAS.
Public water supplies must complete initial monitoring by June 2027, with ongoing compliance monitoring and reporting required after that date. Beginning in June 2029, public water supplies that have PFAS in drinking water which exceeds one or more of the US EPA MCLs must take action to reduce PFAS levels provide notification to the public of the violation.
In March 2019, EGLE began the process of rule promulgation by submitting a request for rulemaking, citing the need to establish standards for PFAS in public drinking water supplies to protect human health and the environment under the authority of the Safe Drinking Water Act.
In April 2019, the Michigan PFAS Action Response Team (MPART) formed a Science Advisory Workgroup to assist the rulemaking process by preparing a report recommending health-based values for PFAS in drinking water. The Workgroup was comprised of national experts in toxicology, epidemiology, and remediation of PFAS, assisted by multiple experts within EGLE and the Michigan Department of Health and Human Services (MDHHS). The Science Advisory Workgroup's June 2019 report recommended health-based values (HBVs) for seven (7) PFAS contaminants based on their review and evaluation of PFAS studies nationwide. HBVs establish a level of contamination below which there is not expected to be adverse health impacts, but HBVs are not on their own enforceable. Using the HBVs recommended by the Workgroup, EGLE proposed amendments to its drinking water rules that established MCLs.
Following submittal of the rules and supporting documentation to the Michigan Environmental Rules Review Committee (ERRC) in October 2019, and following discussion and public comment, the ERRC in November 2019 unanimously found that the proposed rules satisfied the Administrative Procedures Act and voted to move forward with formal rulemaking.
The official public comment period was open between December 2019 and January 2020. During this period, written comments were submitted to EGLE. Public hearings took place on January 8, 14, and 16, 2020, during which additional public comments were received in person. In all, over 3,300 written comments were received, logged, and reviewed by EGLE Drinking Water and Environmental Health Division staff.
A summary of public comments was prepared and provided to the ERRC ahead of their February 27, 2020, meeting, along with updated draft rule language. The ERRC voted to approve the rules as submitted at that meeting. The rules were then provided to the Michigan Office of Administrative Hearings and Rules and prepared prior to submission to the Joint Committee on Administrative Rules (JCAR) in March 2020.
JCAR did not take any action during the fifteen session days that the proposed rule was before it, and the rules became final on August 3, 2020.