UW study finds Wisconsin rivers contributing to 'forever chemical' concentrations in bay of Green Bay, Lake Michigan
Laura SchulteMADISON – Tributaries feeding into the bay of Green Bay play a large role in moving "forever chemicals" into Lake Michigan, according to a study by University of Wisconsin- Madison researchers, even though the chemical levels in the rivers are below recommended state standards.
Christy Remucal, an associate professor with the UW Department of Civil and Environmental Engineering, and postdoctoral investigator Sarah Balgooyen looked at the water and sediments within 41 of the tributaries that feed water into the bay, and the impact water from tributaries broadly could be having on the Great Lakes. The study was funded by the Wisconsin Sea Grant.
"I think one of the big take home messages is that of the rivers we studied, we found that three large rivers — the Fox, the Menominee and the Peshtigo — contribute over two-thirds of the load of PFAS to the bay," she said. "That may seem kind of obvious, but it's important to note that the concentrations of these three rivers are well below the levels of concern."
PFAS, or per- and polyfluoroalkyl substances, are a family of man-made chemicals used for their water- and stain-resistant qualities in products like clothing and carpet, nonstick cookware, packaging and firefighting foam. The family includes 5,000 compounds, which are persistent, remaining both in the environment and human body over time.
The chemicals have been linked to types of kidney and testicular cancers, lower birth weights, harm to immune and reproductive systems, altered hormone regulation and altered thyroid hormones. The chemicals enter the human body largely through drinking water.
The study focused on a smaller group within the family of PFAS, known as perfluoroalkyl acids, or PFAAs. The group includes compounds such as PFOA and PFOS, which are two of the most well-researched in the PFAS family, and are less likely to break down within the environment, making them "forever chemicals."
The compounds currently aren't regulated in Wisconsin, though standards will go before the Natural Resources Board — the policy setting arm of the Department of Natural Resources — later this month before they are sent to the Legislature for approval. If approved, the standards would largely set a limit of 20 parts per trillion in drinking and ground water, with lower standards for surface waters used as drinking water supplies.
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Remucal said that the findings of the study suggest that the state could potentially look at regulating surface waters in a different way.
"Right now, the current approach is to focus on sites with really high concentrations, and of course that's important if you're swimming in the water or eating fish from the river," she said. "If we want to think about protecting the Great Lakes, we do need to think about these large tributaries that have relatively low concentrations."
She said out of the 41 tributaries sampled during the study, only one had levels above the state's recommended standards, which was a ditch that runs from the Tyco Fire Products facility to the bay.
While the other tributaries had lower level of PFAS, they were still all emptying into the same location: the bay of Green Bay.
Remucal said that instead of surface water standards, agencies could regulate the "loading" of PFAS going into the Great Lakes, and try to address that to keep levels lower.
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"We do this for other wastewater regulations and things like that, but it hasn't really been proposed for PFAS before," she said.
Above all, Remucal said, the study highlights that work needs to be done to keep these chemicals out of the environment to begin with.
"There's no way you could run something like the Fox River through a treatment system. It's just way too big. And so big picture, what we need to do is prevent these chemicals from getting in the environment in the first place," she said. "That's really the only way to solve the issue. Once they're out in the environment, especially in such a large river, there's not much we can do about it. Which is kind of a downer, but it's the truth."
The study was shared with the DNR, Remucal said, and will be used to inform the Wisconsin PFAS Action Council, made up from representatives from state agencies, which has suggested priorities for the state when it comes to addressing "forever chemicals" and their impacts on residents, the environment and businesses.
Laura Schulte can be reached at leschulte@jrn.com and on Twitter at @SchulteLaura.