High-quality trout stream gets PFAS advisory

The Department of Natural Resources (DNR) and the Department of Health Services (DHS) have announced a PFAS-related consumption advisory for the Black Earth Creek. Consuming fish from the creek, leading to the confluence with Blue Mound Creek in Dane County, is not recommended due to high levels of PFOS (perfluorooctane sulfonate).

PFOS are a type of PFAS (per- and polyfluoroalkyl substances), which are sometimes called “forever chemicals.” Used in slews of products for decades, the man-made compounds do not break down in the environment or within living bodies. High levels of PFAS exposure has been linked to various chronic diseases from cancers to thyroid disorders.

High levels of PFOS were detected in brown trout, which were sampled from the Black Earth Creek, near Cross Plains. The DNR and DHS, as a result, are recommending limiting meals using the trout to once a week.

The Black Earth Creek is classified as a class 1 trout stream. It’s a designation reserved for “high-quality trout waters that have sufficient natural reproduction to sustain populations of wild trout, at or near carry capacity.” Class 1 streams are so high quality that they don’t require stocking, and make up 5,365 or 40% of Wisconsin’s trout streams.

Regulating PFAS, particularly for drinking water, has been an uphill battle. Recently, the Wisconsin DNR’s Natural Resources Board rejected recommendations for PFAS levels in drinking water, which were crafted by ongoing scientific research.