This data release provides the concentration results for per- and polyfluoroalkyl substances (PFAS) collected on French Island, in the town of Campbell, Wisconsin, sampled quarterly beginning in 2021. These samples were collected from groundwater wells (potable and non-potable taps) by the U.S. Geological Survey (USGS) Upper Midwest Environmental Science Center (UMESC). Three U.S. Environmental Protection Agency (EPA) certified laboratories were contracted to analyzed samples for this study. Samples from the first sampling in 2021, were analyzed by SGS Axys Laboratory (AXYS) in British Columbia, Canada. Samples from the second sampling in 2021 were analyzed at the Wisconsin State Laboratory of Hygiene (WSLH), University of Wisconsin-Madison, Madison, Wisconsin. Subsequent samples were analyzed at Northern Lake Service, Inc. (NLS), Crandon, Wisconsin. All samples were analyzed using liquid chromatography/tandem mass spectrometry (LC/MS-MS). UMESC used three analytical labs because of the dynamic nature of sampling needs and design that shifted from an initial determination of water-supply contamination to a quarterly sampling scheme. The initial laboratory (AXYS) was selected because of an existing contract for PFAS tissue analysis for research that allowed for rapid submission and results. The second laboratory (WSLH) was selected to meet Wisconsin PFAS monitoring criteria and improve sample delivery within the U.S. The third laboratory (NLS) was selected using the USGS acquisitions contract process to find a certified laboratory to accomplish the long-term monitoring sampling plan. All three laboratories were selected from the EPA list of PFAS certified laboratories.