The Great Lakes PFAS Crisis: A Binational Challenge
The Great Lakes system—comprising Lakes Superior, Michigan, Huron, Erie, and Ontario—contains approximately 21% of the world’s surface freshwater and supports the drinking water supply of 40 million Americans and Canadians. PFAS contamination of this irreplaceable resource, from industrial discharge, military base runoff, atmospheric deposition, and tributary loading from PFAS-impacted watersheds, represents one of the most significant environmental challenges facing North America. US-Canada binational cooperation through the Great Lakes Water Quality Agreement (GLWQA) provides the framework for addressing Great Lakes PFAS—but progress has been limited by the scale of contamination, the complexity of jurisdictional issues, and the resources required for meaningful remediation.
PFAS in Great Lakes Water and Sediments
EPA and Environment and Climate Change Canada (ECCC) monitoring through the GLWQA Lakewide Management Plan (LaMP) documents PFAS contamination across the Great Lakes system. PFOS concentrations in open lake water are generally low (1–5 ng/L) due to dilution in the enormous water volumes—but near-shore areas adjacent to industrial discharge points show significantly higher concentrations (10–100 ng/L). Sediment PFAS concentrations are more concerning: cores from harbors and near-shore areas near industrial cities (Milwaukee, Cleveland, Chicago, Detroit) show PFOS in sediments at 1–50 ng/g—concentrations that bioaccumulate through the food web to reach levels in Great Lakes fish that trigger consumption advisories. Tributaries remain the primary loading pathway—the Fox River (Wisconsin), Maumee River (Ohio), and Niagara River (New York/Ontario) are major PFAS sources to their respective lake basins.
Fish Consumption Advisories in the Great Lakes Basin
Great Lakes fish consumption advisories for PFAS are now issued by all eight Great Lakes states and the Province of Ontario. Michigan’s most restrictive advisories cover Lake Erie tributaries and Green Bay (Lake Michigan), where PFAS in fish tissue exceeds “do not eat” thresholds for sensitive populations (pregnant women, children). Lake Superior—the least industrialized of the lakes—shows the lowest fish PFAS concentrations, while Lake Erie and the southern Lake Michigan shoreline show the highest. The binational Great Lakes Fish Monitoring and Surveillance Program (GLFMSP) tracks PFAS in lake trout, walleye, and coho salmon annually—providing trend data showing that legacy PFAS (PFOS) in fish is declining slowly while newer PFAS compounds are increasing, reflecting the shift in chemical production from long-chain to short-chain compounds.
Military Base PFAS Loading to Great Lakes Tributaries
Military installations in the Great Lakes watershed—Wurtsmith Air Force Base (Michigan), Selfridge Air National Guard Base (Michigan), Great Lakes Naval Station (Illinois), Badger Army Ammunition Plant (Wisconsin)—contribute PFAS to Great Lakes tributaries through contaminated groundwater discharge and stormwater. DoD’s PFAS remediation program is actively investigating and remediating these installations, but groundwater plumes discharging to tributaries are slow to respond to treatment. EPA’s Great Lakes Restoration Initiative (GLRI)—funded at $375 million annually—includes PFAS monitoring and source characterization as priority activities, supporting state and tribal PFAS programs in the basin.
Great Lakes PFAS contamination exemplifies the systemic nature of the challenge: distributed sources, complex pathways, massive scale, and transboundary jurisdiction all require coordinated international action that exceeds the capacity of any single regulatory framework or governmental entity.