Contaminant Data from a Survey of Minnesota Source and Finished Drinking Waters, 2019-2022

The U.S. Geological Survey, in cooperation with the Minnesota Department of Health, conducted a study to determine the occurrence of unregulated contaminants in source and finished drinking waters throughout Minnesota. Minnesota relies on both groundwater and surface water sources for drinking water, which may be vulnerable to influences such as wastewater discharge and/or agricultural activities. Thus, drinking water facilities apply some form of treatment to source waters prior to distribution. Although drinking water treatment is mostly focused on satisfying regulatory requirements, it may provide secondary benefits for removal of unregulated contaminants. In 2019, 2021, and 2022, paired source and finished drinking water was collected from 100 facilities and characterized for select organic contaminants. Samples were analyzed for some combination of alkylphenols, benzotriazoles/benzothiazoles, hormones, illicit drugs, personal care products, pesticides, per- and polyfluoroalkyl substances, pharmaceuticals, plasticizers, and wastewater indicators, depending on potential influences from the watershed.