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.

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.

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.

The U.S. Geological Survey, in cooperation with the Minnesota Department of Health, conducted a study to determine the occurrence of six unregulated contaminants in source and finished drinking-water samples collected from 67 public water supply systems throughout Minnesota. Minnesota relies on groundwater and surface water sources for drinking water. Land use, such as wastewater discharge and agriculture, is a factor that determines groundwater and surface water quality. The public water supply systems were categorized based on whether the source water is from surface water or groundwater. Groundwater sites were further categorized by expected sources of contamination based on land use: wastewater, agriculture, and mix of wastewater and agriculture. The 67 public water supply systems sampled during this study were composed of 16 surface water (SW), 22 groundwater influenced by wastewater (GWWW), 21 groundwater influenced by agriculture (GWAg), and 8 groundwater influenced by both wastewater and agriculture (GWWW/Ag) facility types. Minnesota finished drinking water from public water supply systems is seldom directly from the source without some degree of treatment. Typically, treatment is to satisfy regulatory requirements or provide aesthetic value rather than designed for the removal of unregulated contaminants. To identify the presence of unregulated contaminants in source and finished drinking water from public water supply facilities, water samples were analyzed for three commonly detected pesticides (atrazine, imidacloprid, and pyrethroids) and three commonly detected pharmaceuticals (caffeine, carbamazepine, and sulfamethoxazole). Concentrations of three target contaminants (atrazine, imidacloprid, and pyrethroids) plus several immunologically similar contaminants and/or three target pharmaceuticals (caffeine, carbamazepine, and sulfamethoxazole) plus several immunologically similar contaminants were determined in source and finished drinking-water samples collected from 22 GWWW, 21 GWAg, 8 GWWW/Ag, and 16 SW public water supply facilities. The target contaminant plus immunologically similar contaminants (as defined by ELISA specifications) are referred to as contaminant groups. Note that each contaminant group may represent a different set of compounds across analyzing laboratories. Samples collected from SW (66 samples) and GWWW/Ag (16 samples) public water supply facilities were analyzed for all six contaminant groups. Samples collected from GWAg (40 samples) facilities were analyzed for the three pesticide groups and samples collected from GWWW (40 samples) facilities were analyzed for the three pharmaceutical groups. A total of 162 water-quality samples were analyzed by three different laboratory entities. All samples were analyzed at the USGS Upper Midwest Water Science Center using the enzyme-linked immunosorbent assay (ELISA) analytical method. All samples were analyzed at the U.S. Geological Survey National Water Quality Laboratory (NWQL) where samples collected for pesticide analysis were analyzed by direct aqueous injection with liquid chromatography and tandem mass spectrometry (LC-MS/MS), except for the target contaminant, atrazine (ATZ1), and samples collected for pharmaceuticals and ATZ1 analysis were analyzed by direct aqueous injection with high performance liquid chromatography and tandem mass spectrometry (HPLC/MS/MS). Samples were also analyzed for select pharmaceuticals at SGS AXYS Services Ltd. (AXYS) by LC-MS/MS. These data are a part of the associated U.S. Geological Survey Scientific Investigations Report 2022-5066 (https://doi.org/10.3133/sir20225066).

The U.S. Geological Survey, in cooperation with the Minnesota Department of Health, conducted a study to determine the occurrence of six unregulated contaminants in source and finished drinking-water samples collected from 67 public water supply systems throughout Minnesota. Minnesota relies on groundwater and surface water sources for drinking water. Land use, such as wastewater discharge and agriculture, is a factor that determines groundwater and surface water quality. The public water supply systems were categorized based on whether the source water is from surface water or groundwater. Groundwater sites were further categorized by expected sources of contamination based on land use: wastewater, agriculture, and mix of wastewater and agriculture. The 67 public water supply systems sampled during this study were composed of 16 surface water (SW), 22 groundwater influenced by wastewater (GWWW), 21 groundwater influenced by agriculture (GWAg), and 8 groundwater influenced by both wastewater and agriculture (GWWW/Ag) facility types. Minnesota finished drinking water from public water supply systems is seldom directly from the source without some degree of treatment. Typically, treatment is to satisfy regulatory requirements or provide aesthetic value rather than designed for the removal of unregulated contaminants. To identify the presence of unregulated contaminants in source and finished drinking water from public water supply facilities, water samples were analyzed for three commonly detected pesticides (atrazine, imidacloprid, and pyrethroids) and three commonly detected pharmaceuticals (caffeine, carbamazepine, and sulfamethoxazole). Concentrations of three target contaminants (atrazine, imidacloprid, and pyrethroids) plus several immunologically similar contaminants and/or three target pharmaceuticals (caffeine, carbamazepine, and sulfamethoxazole) plus several immunologically similar contaminants were determined in source and finished drinking-water samples collected from 22 GWWW, 21 GWAg, 8 GWWW/Ag, and 16 SW public water supply facilities. The target contaminant plus immunologically similar contaminants (as defined by ELISA specifications) are referred to as contaminant groups. Note that each contaminant group may represent a different set of compounds across analyzing laboratories. Samples collected from SW (66 samples) and GWWW/Ag (16 samples) public water supply facilities were analyzed for all six contaminant groups. Samples collected from GWAg (40 samples) facilities were analyzed for the three pesticide groups and samples collected from GWWW (40 samples) facilities were analyzed for the three pharmaceutical groups. A total of 162 water-quality samples were analyzed by three different laboratory entities. All samples were analyzed at the USGS Upper Midwest Water Science Center using the enzyme-linked immunosorbent assay (ELISA) analytical method. All samples were analyzed at the U.S. Geological Survey National Water Quality Laboratory (NWQL) where samples collected for pesticide analysis were analyzed by direct aqueous injection with liquid chromatography and tandem mass spectrometry (LC-MS/MS), except for the target contaminant, atrazine (ATZ1), and samples collected for pharmaceuticals and ATZ1 analysis were analyzed by direct aqueous injection with high performance liquid chromatography and tandem mass spectrometry (HPLC/MS/MS). Samples were also analyzed for select pharmaceuticals at SGS AXYS Services Ltd. (AXYS) by LC-MS/MS. These data are a part of the associated U.S. Geological Survey Scientific Investigations Report 2022-5066 (https://doi.org/10.3133/sir20225066).

This dataset contains the concentration and quality assurance results for inorganic and organic analytes collected for the U.S. Geological Survey (USGS), Ecosystems Mission Area, Environmental Health Infrastructure Program, Tapwater Exposure Project conducted in Minnesota, in August of 2019. Samples were obtained from multiple publicly distributed water sources in Minnesota in 2019. Due to privacy concerns, the exact location where samples were collected are not reported and station identification numbers have been anonymized. Water-quality samples were analyzed for pesticides, pharmaceuticals, volatile organic compounds and per- and polyfluoroalkyl substances at the USGS National Water Quality Laboratory (NWQL), Denver, Colorado; disinfection byproducts were analyzed at the USGS Organic Chemistry Research Laboratory (OCRL), Sacramento, California; inorganic analytes (cations, anions, nitrate, and trace elements) were analyzed at the USGS Redox Chemistry Laboratory (RCL), Boulder, Colorado; cyanotoxins were analyzed at the USGS Organic Geochemistry Research Laboratory (OGRL), Lawrence, Kansas. Water samples for bioassay analyses (estrogen, androgen, and glucocorticoid receptor) were extracted at the OGRL and analyzed at the U.S. Environmental Protection Agency, Durham, North Carolina.

This dataset contains the concentration and quality assurance results for inorganic and organic analytes collected for the U.S. Geological Survey (USGS), Ecosystems Mission Area, Environmental Health Infrastructure Program, Tapwater Exposure Project conducted in Minnesota, in August of 2019. Samples were obtained from multiple publicly distributed water sources in Minnesota in 2019. Due to privacy concerns, the exact location where samples were collected are not reported and station identification numbers have been anonymized. Water-quality samples were analyzed for pesticides, pharmaceuticals, volatile organic compounds and per- and polyfluoroalkyl substances at the USGS National Water Quality Laboratory (NWQL), Denver, Colorado; disinfection byproducts were analyzed at the USGS Organic Chemistry Research Laboratory (OCRL), Sacramento, California; inorganic analytes (cations, anions, nitrate, and trace elements) were analyzed at the USGS Redox Chemistry Laboratory (RCL), Boulder, Colorado; cyanotoxins were analyzed at the USGS Organic Geochemistry Research Laboratory (OGRL), Lawrence, Kansas. Water samples for bioassay analyses (estrogen, androgen, and glucocorticoid receptor) were extracted at the OGRL and analyzed at the U.S. Environmental Protection Agency, Durham, North Carolina.

Concentrations of a wide variety of environmental organic contaminants were measured in surface waters of the Lake Mead National Recreation Area (Nevada and Arizona) in 2010 to provide a measure of exposure to resident fish species. These contaminants were sampled using the semipermeable membrane device (SPMD) and the polar organic chemical integrative sampler (POCIS) which allow for the determination of the average contaminant concentrations over a month-long study period. Contaminants measured included polycyclic aromatic hydrocarbons, polychlorinated biphenyls, organochlorine pesticides, pharmaceuticals, select illicit drugs, and other chemicals related to wastewater treatment plant effluents. In addition, sediments, periphyton, fish feeds, and other materials from the Willow Beach fish hatchery were screened for polychlorinated biphenyls which are historically present in many hatcheries across the Nation.

Concentrations of a wide variety of environmental organic contaminants were measured in surface waters of the Lake Mead National Recreation Area (Nevada and Arizona) in 2010 to provide a measure of exposure to resident fish species. These contaminants were sampled using the semipermeable membrane device (SPMD) and the polar organic chemical integrative sampler (POCIS) which allow for the determination of the average contaminant concentrations over a month-long study period. Contaminants measured included polycyclic aromatic hydrocarbons, polychlorinated biphenyls, organochlorine pesticides, pharmaceuticals, select illicit drugs, and other chemicals related to wastewater treatment plant effluents. In addition, sediments, periphyton, fish feeds, and other materials from the Willow Beach fish hatchery were screened for polychlorinated biphenyls which are historically present in many hatcheries across the Nation.

In June and July of 2020, 45 groundwater wells in McHenry County, Illinois, were sampled for water quality (field properties, major ions, nutrients, and trace metals) and 12 wells were sampled for contaminants of emerging concern (pharmaceuticals, pesticides, and wastewater indicator compounds). Quality-assurance and quality-control samples were collected during the June and July 2020 sampling that included equipment blanks, field blanks, and replicates. The results of these samples were used to understand the sources of bias and variability associated with sample collection, processing, storage, and shipping. This data release contains one comma separated values files containing the results of the quality-control sample collection for general water quality (metals, nutrients, and major ions) and contaminants of emerging concern (wastewater indicator compounds and pharmaceuticals). Water-quality data from the associated groundwater monitoring well data are available at the National Water Information System (NWIS) web database (https://doi.org/10.5066/F7P55KJN). Results and discussion of the water quality and contaminants of emerging concern can also be found in the associated scientific investigation report referenced.