Skip to main content

On guard against PFAS in Michigan waters

Today’s MI Environment story by EGLE staffer Brandon M. Armstrong comes from the State of the Great Lakes report.

Seven state agencies, including the Michigan Department of Environment, Great Lakes, and Energy (EGLE), are part of the Michigan PFAS Action Response Team (MPART), coordinating resources to address concerns about per- and polyfluoroalkyl substances (PFAS).

Aquatic biologist Mike McCauley holds two walleye collected from the Flint River in August 2022 for the Michigan Fish Contaminant Monitoring Program.

Aquatic biologist Mike McCauley holds two walleye collected from the Flint River in August 2022 for the Michigan Fish Contaminant Monitoring Program.


These toxic “forever chemicals” persist in the environment and can accumulate in the food chain and the human body. As part of this work, EGLE’s Fish Contaminant Monitoring Program collects fish from about 50 water bodies a year, with help from state, federal, and tribal partners, to test for PFAS and other contaminants.

The fish are processed as they would be for eating (for example, as fillets) and sent to the Michigan Department of Health and Human Services’ (MDHHS) lab for analysis. Test results provide data used to monitor contaminant trends and inform fish consumption advisories and guidelines. These advisories are designed for the health and safety of all fish consumers, especially children and people who are elderly, pregnant, or have health problems.

The most common contaminants causing fish consumption advisories and guidelines in Michigan are mercury, polychlorinated biphenyls (PCB), perfluorooctanesulfonic acid (PFOS, a type of PFAS), and dioxins. These persistent bioaccumulative contaminants are of most concern because they remain in the environment for a long time and build up in fish through the food chain.

Testing fish also helps MPART determine where additional PFAS investigation is needed. For example, elevated PFOS in fish from Pike Lake in the Upper Peninsula’s Luce County led to an MPART investigation of a 2012 fire where some type of firefighting foam was known to have been used. This investigation involved learning more about the foam and sampling potentially affected surface waters, nearby residential wells, and drinking water wells used at two state campgrounds.

MPART also works with agencies in other states to stay current on PFAS issues in the Great Lakes region. The Wisconsin Department of Natural Resources (WDNR) recently issued a consumption advisory for rainbow smelt from Lake Superior based on elevated levels of PFOS. Soon after, MDHHS also issued a precautionary fish consumption to match the WDNR advisory. EGLE then worked with its partners to collect rainbow smelt from lakes Superior, Huron, and Michigan, as well as two inland lakes. Results indicate that rainbow smelt from these water bodies have elevated PFOS concentrations. MDHHS is reviewing sample data to determine if the consumption guidelines need to be updated.

EGLE has also tested other fish species from Lake Superior and found that PFOS levels in lake trout and whitefish from Lake Superior were below the MDHHS fish consumption screening values. In addition, many of the tested surface waters in Michigan’s Lake Superior watershed have met Michigan’s water quality values for PFOS. These data support the notion that there is not a significant source of PFAS to Lake Superior but rather reflect how this contaminant builds up at much higher rates in rainbow smelt compared to other fish species.

Aquatic biologist Mike McCauley collects fish from the Carp River near Negaunee

Aquatic biologist Mike McCauley collects fish from the Carp River near Negaunee.


Recently, EGLE received two grants that will expand MPART’s knowledge of PFAS in fish:

• $600,000 from the U.S. Environmental Protection Agency for a project entitled “Fish Contaminant Monitoring in Select Environmental Justice (EJ) Areas of Michigan.” EGLE will try to collect at least two species of fish in 20 EJ areas. Many of these locations are water bodies used for youth fishing events. The data will inform the MDHHS fish consumption advisories and guidelines. Sampling will conclude in 2023.

• $191,130 from the U.S. Fish and Wildlife Service for a project entitled “Evaluating Persistent Chemicals of Mutual Concern (CMCs) in Prey Fish of Fish-Eating Birds of Michigan.” CMCs include PFAS, as well as polybrominated diphenyl ethers (PBDEs), PCBs, and mercury. This study will evaluate CMCs in fish eaten by bald eagles and herring gulls along the shoreline of Lake Huron and in PFAS-impacted tributaries of Lake Huron.

MPART continues to sample fish from across the state to protect public health and the environment and to help identify and mitigate sources of PFAS. For the latest updates on PFAS in Michigan’s fish and surface waters, visit the MPART surface water workgroup page. More information on Michigan’s fish consumption guidelines can be found on the Eat Safe Fish website.