Huron River PFAS Levels Drop Sharply

The Michigan Department of Environment, Great Lakes, and Energy (EGLE) today announced that its ongoing monitoring for per- and polyfluoroalkyl substances (PFAS) in the Huron River has shown a decline in PFAS levels in the watershed. The declining PFAS levels appear to correspond with efforts by the Michigan PFAS Action Response Team (MPART) to work with local wastewater treatment plant operators and their industrial customers to reduce PFAS contamination in wastewater streams entering the watershed.

Since the start of monitoring in July 2018, PFAS levels in the Huron River downstream of Norton Creek have dropped from a maximum detection of 1,400 parts per trillion (ppt) to a maximum detection of 6.1 ppt according to EGLE’s August 2020 sampling update. Levels in Norton Creek, thought to be a major source of the Huron River PFAS levels, declined by 99.8 percent from a maximum detection of 5,600 ppt in 2018 to a maximum detection of 12.2 ppt in August 2020.

In 2018, EGLE, the City of Ann Arbor, and the City of Wixom identified elevated levels of perfluorooctanesulfonic acid (PFOS) in fish and surface waters in the Huron River. Based on this information, the Michigan Department of Health and Human Services (DHHS) issued a “Do Not Eat” fish advisory from the Huron River where North Wixom Road crosses into Oakland County (including Norton Creek) to the mouth of the Huron River as it enters Lake Erie in Wayne County.

From 2018 to present, EGLE has sampled fish, surface water, and sites of interest extensively within the Huron River watershed to identify potential sources. In 2018, testing required by EGLE’s Industrial Pretreatment Program per- and polyfluoroalkyl substances (PFAS) Initiative, revealed the city of Wixom Wastewater Treatment Plant (WWTP) as a significant source of PFOS to Norton Creek, which flows into the Huron River in Oakland County. The City of Wixom has worked with an industrial facility upstream of the WWTP to install PFOS treatment which resulted in dramatically reduced levels of PFOS discharged from the WWTP to Norton Creek.

In combination with the surface water surveys, EGLE has collected and analyzed fish from 21 water bodies throughout the Huron River watershed to assist with the PFAS source tracking effort. In addition, EGLE is working with WWTPs and industrial direct dischargers to reduce and eliminate PFAS discharges to rivers, lakes, and streams.

While substantial progress has been made on known sources to the watershed, additional efforts are underway to identify other potential sources. At this time, EGLE is pursuing source investigations in the Regan Drain, including Washago Pond in Wayne County, and Willow Run in Washtenaw and Wayne counties due to elevated levels of PFOS detected in those waterbodies.

Fish were collected again in 2020 throughout the watershed, including Kent Lake, Base Line Lake, Argo Pond, Ford Lake, Flat Rock, Silver Lake, and Washago Pond, and have been sent to the DHHS laboratory for PFAS analysis. Results from the analysis will be used to better inform surface water investigations and existing fish advisories in the watershed.

DHHS continues to review fish fillet results to determine when and if advisories for the Huron River and connected water bodies can be relaxed. The actions MPART is taking to identify and eliminate sources of PFOS in the watershed is part of ongoing efforts with the goal of ensuring the river is meeting its designated uses including fishing and recreating.

For more detailed information on the work MPART is doing within the watershed, please visit the Huron River Watershed Investigation timeline.