PFAS Contamination in the City of Madison and Dane County
PFAS contamination has been detected in the city of Madison and Dane County in soil, municipal wells, surface water and groundwater.
Yahara Chain of Lakes and Starkweather Creek: Surface Water and Fish
In summer 2019, DNR collected water chemistry and fish tissue samples from waterbodies near known or suspected PFAS contamination sites as part of a water quality PFAS initiative.
Starkweather Creek in Madison had the highest concentration of PFOA and PFOS among the samples taken by the DNR statewide in 2019. There are known discharges of PFAS compounds to soil, surface water, stormwater and groundwater on the Dane County airport property where PFAS-containing firefighting foam products were used.
In response to these findings, the DNR took the following steps.
- In mid-September 2019, DNR staff collected additional bluegill and largemouth bass for PFAS analysis from Lake Monona near the Starkweather Creek outlet. PFOS was detected in all fish collected from Lake Monona and Starkweather Creek. As a result, DNR and Wisconsin Department of Health Services (DHS) updated the Lake Monona and Starkweather Creek Fish Safe-Eating Guidelines [PDF] in early 2020 and recommended that people consume some species of fish less frequently than the prior Safe Eating Guidelines.
- In October 2019, additional surface water sampling was conducted at the four original sampling locations as well as 11 new locations in Starkweather Creek and five locations in Lake Monona. The purpose of the sampling was to gain a better understanding of the distribution and concentrations of PFAS in Starkweather Creek. Read the Jan. 15, 2020, news release and the informational packet, which contains a map of sampling locations, water quality results and fish results.
- Surface water sampling was conducted in 2020 on lakes Mendota, Monona, Upper Mud, Waubesa and Kegonsa, as well as along sections of the Yahara River between the lakes. Samples were also collected from Lake Wingra and Nine Springs Creek, in the location just before Nine Springs Creek enters the Yahara River. PFAS compounds were discovered throughout the areas sampled. For more information, read the Jan. 21, 2021, news release.
- Based on results of fish tissue sampling in 2020, DNR and DHS issued PFAS-based fish consumption advisories for Yahara Chain waters in Dane and Rock counties on June 9, 2021. Elevated levels of PFOS were found in several species collected from lakes Monona, Kegonsa and Waubesa. The new advisories include Wingra Creek, Starkweather Creek, Lake Monona, Lake Waubesa, Upper and Lower Mud Lake, Lake Kegonsa and the Yahara River downstream to where it meets the Rock River. Low levels of PFOS were found in fish sampled from Lake Mendota and Lake Wingra and no PFOS consumption advice has been issued for those lakes. These advisories have been issued based on fish consumption guidelines set by the Great Lakes Consortium. Learn more about the new advisories. A complete list of consumption advisories can also be found in the 2020-2021 Choose Wisely booklet.
The Department of Health Services (DHS) sent a letter to DNR on October 4, 2019, which assesses the health risks of PFAS in surface waters in the Starkweather Creek area.
DHS has made the following recommendations in order to best protect people and pets from potential PFAS exposure in all surface waters, including Starkweather Creek.
- Avoid drinking or accidentally swallowing the water.
- Wash your hands after wading or playing in the water.
- Rinse pets after contact with water to avoid swallowing PFAS that may be on their fur.
Read more about the health impacts of PFAS.