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Investigations and Sites

Drill rig drilling a drinking water well.

Investigations and Sites

The State of Michigan is working proactively to identify locations where PFAS may be present as a contaminant. The Michigan Department of Environment, Great Lakes, and Energy (EGLE) is conducting testing in drinking water, groundwater, lakes & streams, soils, sediments, wastewater, and the PFAS foam that can accumulate at lakes and rivers. EGLE is also partnering with the Michigan Department of Health and Human Services (MDHHS), and the Michigan Department of Natural Resources (MDNR) to test fish and wildlife; MDHHS works with local health departments to issue any necessary health advisories. The state of Michigan is committed to sharing information with residents regarding PFAS testing that is occurring throughout the state.

Site investigations get started for a variety of reasons.  At some sites, like Superfund sites, Michigan Department of Environment, Great Lakes, and Energy (EGLE) staff have been overseeing environmental cleanup efforts for many years, and may add PFAS sampling to ongoing sampling if PFAS was known or suspected to have been used at the site. EGLE staff also conduct routine monitoring of rivers and lakes. If a sample exceeds water quality standards, staff work upstream until they find the site contributing to the PFAS. Other sites were sampled due to historical information, such as Carl's Retreading, which was where tires burned for many days and firefighting foam containing PFAS was used. PFAS investigations are also being conducted by responsible parties under various programs overseen by EGLE.   

On August 3, 2020, the groundwater cleanup criteria became PFOA of 8 ppt and PFOS of 16 ppt.  On December 21, 2020, five additional PFAS compounds became effective and enforceable groundwater cleanup criteria: PFNA (6 ppt), PFHxS (51 ppt), PFHxA (400,000 ppt), PFBS (420 ppt), and HFPO-DA (370 ppt).  EGLE staff use all 7 PFAS criteria to guide groundwater investigations, protect public health, and identify MPART PFAS sites.

PFAS cycle

PFAS Cycle

Learn how PFAS cycles through our environment.

Download the PDF

Drinking water and groundwater sample results are compared to:

Analyte Criteria
PFOA 8 ppt
PFOS 16 ppt
PFNA 6 ppt
PFHxS 51 ppt
PFBS 420 ppt
PFHxA 400,000 ppt
GenX (HXPO-DA) 370 ppt

ppt = parts per trillion

The majority of surface water (i.e., waterbody)
samples collected are compared to:

Analyte Criteria
PFOA 170 ppt
PFOS 12 ppt
PFBS 670,000 ppt
PFNA 30 ppt
PFHxS 210 ppt

ppt = parts per trillion

Some water supplies draw water from a waterbody, treat the water, and then use it for drinking water.

If surface water samples are collected directly from a waterbody that is also used as a source for drinking water, then surface water samples are compared to:

Analyte Criteria
PFOA 66 ppt
PFOS 11 ppt
PFBS 8,300 ppt
PFNA 19 ppt
PFHxS 59 ppt

ppt = parts per trillion

Page last updated October 12, 2023.

  • The following explains how the PFAS Investigations page has transitioned over time, how the Michigan Department of Environment, Great Lakes, and Energy (EGLE) investigations get started and what constitutes a PFAS site.

    • On November 13, 2017, the Michigan PFAS Action Response Team (MPART) originally listed 28 investigations which included areas of groundwater contamination as well as rivers and public water supplies.  MPARTs definition of a “site” changed in 2018 such that a site was where one or more groundwater monitoring result exceeds groundwater clean-up criteria.  In August 2018 Gilkey Creek and the Clinton River were no longer classified as a “site” and so were moved to the Watershed Investigations page.  Five public water supply locations previously listed as “sites” were moved to a Drinking Water page. Since that time the PFAS Sites page features groundwater investigations being conducted around the state with a result that exceeds groundwater clean-up criteria.
    • In 2018, EGLE's Remediation and Redevelopment Division established cleanup criteria for groundwater used as drinking water of 70 ppt of PFOS and PFOA, individually or combined.
    • On August 3, 2020, the groundwater cleanup criteria became 8 ppt PFOA and 16 ppt PFOS.  On December 21, 2020, the following 5 additional PFAS compounds became groundwater cleanup criteria: PFNA (6 ppt), PFHxS (51 ppt), PFHxA (400,000 ppt), PFBS (420 ppt), and HFPO-DA (370 ppt).  EGLE staff use all 7 PFAS criteria to guide groundwater investigations, protect public health, and identify MPART PFAS sites. 

    Evolution of Groundwater Cleanup Criteria for PFAS

    Compound Prior to August 3, 2020 Effective August 3, 2020 Effective December 21, 2020
    PFOA 70 ppt (combined with PFOS) 8 ppt 8 ppt
    PFOS 70 PPT (combined with PFOA) 16 ppt 16 ppt
    PFNA N/A N/A 6 ppt
    PFHxS N/A N/A 51 ppt
    HFPO-DA N/A N/A 370 ppt
    PFBS N/A N/A 420 ppt
    PFHxA N/A N/A 400,000 ppt