Forever chemicals found in fish across Dane, Marathon, Portage waterways

The Wisconsin Department of Natural Resources (DNR) has issued fish consumption advisories for several water systems. Fish species in Marathon County’s Lake Wausau and the Stevens Point Flowage in Portage County were found to have high levels of PFOS (perfluorooctane sulfonate) and PFAS (per- and polyfluoroalkyl substances), man-made compounds linked to chronic disease like cancers, birth defects, and thyroid disorders. Over in Dane County, portions of the Yahara Chain were found to contain fish with high levels of PFAS and PFOS as well.

The developments have compelled the DNR to issue fish consumption advisories. Black crappie, bluegill, rock bass and yellow perch fished from Lake Wausau should only be eaten once a week. Common carp and redhorse fished from the same lake should only be eaten once a month. The same species and timetables are set for fish caught in the Stevens Point Flowage. Dane County’s portions of the Yahara Chain waters only included white bass, to be eaten just once a month. The Yahara Chain in Dane County spans Wingra Creek, Starkweather Creek, Lake Monona, Lake Waubesa, upper and lower Mud Lake, Lake Kegonsa, and the Yahara River downstream, where it meets the Rock River.

These new advisories are in addition to other fish consumption advisories still enacted for the same waterways. PFAS and PFOS are part of a larger group of man-made chemicals which were used in many products from non-stick pans to firefighting foam. The chemicals don’t break down in the environment, nor in the body. They’ve been linked to numerous health ailments in humans and other animal species. Like in other parts of the country, Wisconsin’s PFAS and PFOS contamination stems from contamination and waste from private industry.

The DNR is also seeking data on the water quality of lakes, streams and rivers statewide. Every two years, the department  asks Wisconsinites to submit biological, chemical and physical surface water data. The data will be combined with information collected by the DNR to best assess the condition of Wisconsin’s water systems. The DNR is particularly interested in data that documents improvements due to pollution controls, healthy water, supports restoration and protection of water bodies. It also wants to identifypublic health risks and and collect data that could be used for water quality criteria development and assessments.

Data must be submitted electronically, and be in specific Excel spreadsheet formats. The submitted data should include a Quality Assurance Project Plan (QAPP), data in the specified Excel format, location information, and general information about the submitter. Templates and instructions can be found on the Surface Water Public Participation webpage, and data received as hard copies or PDFs won’t be accepted. Guidance on minimum data requirements is currently undergoing revision, and the 2024 version is on the DNR website.