Per- and Polyfluoroalkyl Substances (PFAS) in Tapwater From Private Wells in Clinton County, Iowa, and Whiteside County, Illinois, 2024

Between June 2024 and December 2024, tapwater samples were collected from 48 homes that use private well water as their drinking water source. All homes were located within a 50-kilometer radius of the 3M Cordova Facility in Cordova, Illinois, and analyzed for per- and polyfluoroalkyl substances (PFAS). The sampling effort was undertaken by the University of Iowa and samples were sent to the United States Geological Survey (USGS) for analysis. Household water was sampled from the kitchen tap by individual homeowners, after any treatment system(s). Samples were collected in triplicate into 5 milliliter (mL) polypropylene tubes, chilled in the field and during shipping, and frozen until analysis. At the USGS, samples were prepared with a direct injection method and analyzed with a Thermo Fisher Scientific™ Orbitrap Exploris™ 120 high resolution mass spectrometer coupled to a Vanquish Flex liquid chromatograph. This data release documents the sample preparation, analytical method, and results.