• PFAS Sampling
    in Lakes & Streams


  • PFAS is the family of per- and
    polyfluoroalkyl substances. One of the
    most commonly detected substances is
    perfluorooctanesulfonic acid (PFOS),
    in part because it bioaccumulates, or
    builds up, in fish. 

    The Michigan Department of Environment, Great Lakes, and Energy (EGLE) Water Resources Division collects fish and water samples from Michigan lakes and streams for contaminant analysis. Fish are collected to help identify where fish consumption advisories are needed, and surface water samples are collected to help identify sources of PFAS.  As of July 2020, nearly 2,200 fish fillets from 86 water bodies and over 1,000 surface water samples from 298 water bodies have been analyzed for PFAS.

    The Water Resource Division’s monitoring efforts play a large role in the identification of sources causing elevated fish, surface water, point source, or drinking water PFAS concentrations.  As new discharges and detections come to light, the WRD mobilizes staff to collect water and fish tissue samples to pinpoint sources of PFAS and contribute key data that can be used to develop public health advisories. Water Resource Division staff also work with the responsible entities to reduce usage of PFAS and treat PFAS on-site.

    Below is a summary of some of our efforts.

    In 2011, PFOS concentrations in fish collected
    near Wurtsmith were as high as 424 parts per
    billion (ppb) in smallmouth bass and 9,580 ppb
    in pumpkinseed. The "Do Not Eat" advisory
    kicks in for results greater than 300 ppb PFOS.

    EGLE first analyzed PFAS in surface water in 2001 when 21 Michigan streams were sampled for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).  The study found varying levels of both substances, but the concentrations were not considered to be a problem based on what was known about PFAS at the time.

    The discovery in 2011 of very high levels of PFOS in fish from a pond near the former Wurtsmith Air Force Base in Oscoda prompted a more intensive statewide sampling of Michigan rivers in 2013 and 2014.  The results of this reconnaissance study indicated several rivers had PFOS concentrations above background levels in either water, fish, or both.


  • Surface Water PFAS Sampling

    EGLE's Water Resources Division has since conducted numerous targeted PFAS sampling efforts to monitor rivers and lakes used as drinking water sources, and to help identify sources of PFAS in rivers and lakes.  In 2016 and 2017 Water Resources Division staff expanded the 2013-2014 statewide reconnaissance effort by conducting focused investigations in areas where elevated PFAS levels had been found or were suspected. Those areas included:

    • Clark’s Marsh, Van Etten Lake, and the Au Sable River near Oscoda and the former Wurtsmith Air Force Base
    • Silver Lead Creek near Gwinn and the former KI Sawyer Air Force Base
    • Lake St. Clair and the Clinton River near Mt. Clemens
    • Flint River and its major tributaries near Flint and Lapeer, including Gilkey Creek 

    The Water Resources Division sampling efforts have found sources of PFAS contamination that are now being addressed.

    In 2017, 2018, and 2019 surface water PFAS samples were collected from 17, 68, and 188 water bodies in Michigan, respectively.  In 2017, 2018, and 2019 fish PFAS samples were collected from 20, 47, and 55 water bodies in Michigan, respectively.  Significant sampling events have targeted the Kalamazoo River, Grand River, Huron River, Clinton River, Flint River, St. Joseph River, and the River Raisin. Visit the Watershed Investigations page to learn more about these monitoring efforts. In 2020, watershed scale monitoring efforts are planned for the Escanaba, Shiawassee, Ecorse, and Saginaw Rivers and additional follow-up sampling is occurring in the Huron, Flint, Kalamazoo, and St. Joseph River Watersheds.

    EGLE Water Resources Division works with the Michigan Department of Natural Resources to collect fish to be used by the Michigan Department of Health and Human Services to determine if a fish consumption advisory is needed. In 2020, fish collections for PFAS analyses are planned in the St. Joseph River, Huron River, Clinton River, Maple River, Muskegon River, Grand River, Manistique River, Pere Marquette River, Black River, Munuscong River, Flint River, Escanaba River, and Au Sable River Watersheds.