Data were collected at 60 surface water and two effluent sites across Iowa in 2019-2020 by staff from the U.S. Geological Survey Central Midwest Water Science Center. Samples were submitted to the National Water Quality Laboratory in Denver, Colorado, and were analyzed for per- and polyfluoroalkyl substances.

Water-quality samples were collected at 49 surface water sites covering a range of land uses across the state of Iowa starting the summer of 2022 and continuing into the spring of 2023 by staff from the U.S. Geological Survey Central Midwest Water Science Center. Samples were submitted to the National Water Quality Laboratory in Denver, Colorado, and were analyzed for 32 per- and polyfluoroalkyl substances. Additional samples for N-(1,3-Dimethylbutyl)-N’-phenyl-p-phenylenediamine (6PPD) and 6PPD-Quinone were sent from a subset of the sites to the Organic Geochemistry Research Laboratory in Lawrence, Kansas.

This data release provides concentration results for per- and polyfluoroalkyl substances (PFAS) collected by volunteer community members, in tapwater samples from 84 private residences, in select areas within the United States. Samples were collected July 1, 2023, through October 3, 2024. Samples were analyzed at the U.S. Geological Survey National Water Quality Laboratory (NWQL) in Denver, Colorado. Exact site location information for these sites is not available because of privacy concerns.

This data release provides concentration results for per- and polyfluoroalkyl substances (PFAS) collected by volunteer community members, in tapwater samples from 83 private residences, in select areas within the United States. Samples were collected July 1, 2023, through November 10, 2023. Samples were analyzed at the U.S. Geological Survey National Water Quality Laboratory (NWQL) in Denver, Colorado. Exact site location information for these sites is not available because of privacy concerns.

Samples were collected for a comparison method development study with the University of Minnesota and the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL) in Lakewood, Colorado. Widely used liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods fail to capture large fractions of total organofluorine in environmental samples confounding the assessment and remediation of fluorinated pollution. Fluorine nuclear magnetic resonance (19F-NMR) is an inclusive method for organofluorine analysis that preserves chemical information about chemical compound classes of organofluorine.

This data release contains concentration and isotope-dilution standard (IDS) recovery data from individual samples that are summarized and interpreted in the U.S. Geological Survey (USGS) Techniques and Methods (T&M) Report "Determination of Per- and Polyfluoroalkyl Substances in Water by Direct Injection of Matrix-Modified Centrifuge Supernatant and Liquid Chromatography-Tandem Mass Spectrometry with Isotope Dilution". This includes results from method validation experiments and quality control data collected in conjunction with custom sample analysis for customers using USGS National Water Quality Laboratory (NWQL) Laboratory Code 9660 between December 15, 2020 and March 2, 2022. Results in the T&M Report are presented as statistical summaries of data from multiple related samples, the individual sample data that underlie those summaries are presented here.

This data release contains concentration and isotope-dilution standard (IDS) recovery data from individual samples that are summarized and interpreted in the U.S. Geological Survey (USGS) Techniques and Methods (T&M) Report "Determination of Per- and Polyfluoroalkyl Substances in Water by Direct Injection of Matrix-Modified Centrifuge Supernatant and Liquid Chromatography-Tandem Mass Spectrometry with Isotope Dilution". This includes results from method validation experiments and quality control data collected in conjunction with custom sample analysis for customers using USGS National Water Quality Laboratory (NWQL) Laboratory Code 9660 between December 15, 2020 and March 2, 2022. Results in the T&M Report are presented as statistical summaries of data from multiple related samples, the individual sample data that underlie those summaries are presented here.

This data release includes concentrations of 24 per- and polyfluoroalkyl substances (PFAS) and physical properties of water-quality samples collected by the U.S. Geological Survey (USGS) at 64 selected sites in rivers and streams in Massachusetts over three rounds of sampling. The samples were collected from August to November 2020 when streamflow conditions were below normal (also considered to be base-flow conditions) at rivers and streams in urban areas that receive treated wastewater from municipal wastewater-treatment facilities, and in rural rivers and streams that are not associated with municipal wastewater discharges and may have other source inputs of PFAS. The measured physical properties include water temperature, specific conductance, pH, dissolved oxygen, and turbidity and the quality-control data from blanks, replicates, laboratory control samples, and laboratory spike samples are provided. The physical properties, along with all of the discrete water-quality PFAS data, except the quality-control data, are also available online from the U.S. Geological Survey's National Water Information System (NWIS) database (https://nwis.waterdata.usgs.gov/nwis). This data release is structured as a set of tab-delimited (.txt) files.The metadata includes descriptions of files: Site_Information.txt, Abbreviations_and_Remark_Codes.txt, and Analysis_Information.txt. This data release also includes a Data Dictionary (Data_Dictionary.txt) that is used to describe environmental sample data (Environmental_Data.txt), and Quality Control field and laboratory blank data (QC_Blanks.txt), field and laboratory replicate data (QC_Replicates.txt), and laboratory control sample and spike data (QC_Laboratory_Control_Samples_and_Spikes.txt).

This data release includes concentrations of 24 per- and polyfluoroalkyl substances (PFAS) and physical properties of water-quality samples collected by the U.S. Geological Survey (USGS) at 64 selected sites in rivers and streams in Massachusetts over three rounds of sampling. The samples were collected from August to November 2020 when streamflow conditions were below normal (also considered to be base-flow conditions) at rivers and streams in urban areas that receive treated wastewater from municipal wastewater-treatment facilities, and in rural rivers and streams that are not associated with municipal wastewater discharges and may have other source inputs of PFAS. The measured physical properties include water temperature, specific conductance, pH, dissolved oxygen, and turbidity and the quality-control data from blanks, replicates, laboratory control samples, and laboratory spike samples are provided. The physical properties, along with all of the discrete water-quality PFAS data, except the quality-control data, are also available online from the U.S. Geological Survey's National Water Information System (NWIS) database (https://nwis.waterdata.usgs.gov/nwis). This data release is structured as a set of tab-delimited (.txt) files.The metadata includes descriptions of files: Site_Information.txt, Abbreviations_and_Remark_Codes.txt, and Analysis_Information.txt. This data release also includes a Data Dictionary (Data_Dictionary.txt) that is used to describe environmental sample data (Environmental_Data.txt), and Quality Control field and laboratory blank data (QC_Blanks.txt), field and laboratory replicate data (QC_Replicates.txt), and laboratory control sample and spike data (QC_Laboratory_Control_Samples_and_Spikes.txt).

These data were collected to understand the occurrence of per- and polyfluoroalkyl substances (PFAS) in drinking water samples at selected public water systems in West Virginia identified to have detections for PFAS above laboratory reporting levels in previously collected raw-water samples (McAdoo and others, 2022). These data are stored in the USGS National Water Information System (NWIS) but are not available to the public from that platform because West Virginia State Law §22-26-4, and USGS policy concerning the release of sensitive water related information, prohibits the release of public water system infrastructure location information. This USGS data release serves as the public release of available data for this project and provides a reference location for all users. Description of Available Datasets: These data are available in Excel (.xlsx) files that contain water-quality and quality-assurance results. The Excel files are duplicated as tab-delimited text files to increase accessibility to nonproprietary formats. The files titled WVDEP_PFAS_FinishedWater_Results contain analytical results for PFAS in drinking water collected at 107 sites located in West Virginia. The files titled WVDEP_PFAS_FinishedWater_Quality_Assurance contain associated field blanks, lab blanks, and replicates used for quality control. Lab blanks are used to assess contamination imparted by the analytical process. Field blanks were collected using certified analyte-free water at the sampling point and used to assess possible cross contamination from sampling materials and sampling technique in the field. Field replicates were collected concurrently with the environmental sample and used to understand the variability of results. The attached XML file titled WVDEP_PFAS_FinishedWater_Metadata contains metadata explaining the provenance of the data and should be thoroughly read to understand data structure and limitations. The files titled WVDEP_PFAS_FinishedWater_Data_Dictionary may be used as a reference to explain codes, terms, and abbreviations used in these datasets. The files titled WVDEP_PFAS_Ongoing_Precision_and_Recovery contain quality assurance samples reported by the laboratory which establishes additional confidence in results over time. Sample Collection, Data Validation, and Quality Assurance: Samples were collected at each public water system’s main finished-water sampling point. U.S. Environmental Protection Agency (EPA) Method 533 (Rosenblum and Wendelken, 2019) and EPA Method 537.1 (Shoemaker, 2020) were used to determine PFAS concentrations in all samples. Samples were analyzed at SGS Wilmington in North Carolina. Reporting and detection levels for PFAS results are specific to the analyte, sample matrix, instrumentation, and laboratory performance. Results throughout this dataset that are reported with a "less than" qualifier represent values that were not detected above the reporting level for that sample and specific analyte. The reporting levels shown in this dataset are synonymous with the minimum reporting level as defined by Rosenblum and Wendelken (2019). A combination of field blanks, laboratory method blanks, isotopically labeled compound recoveries, and ongoing precision and recovery samples were used to assess field techniques and validity of the reported results. Finished water results recorded in the file titled WV_PFAS_Finished_Water_Results met all quality assurance criteria, and no additional qualification was required. References: McAdoo, M.A., Connock, G.T., and Messinger, T., 2022, Occurrence of per- and polyfluoroalkyl substances and inorganic analytes in groundwater and surface water used as sources for public water supply in West Virginia: U.S. Geological Survey Scientific Investigations Report 2022–5067, 37 p., https://doi.org/10.3133/sir20225067. Rosenblum, L., and Wendelken, S.C., 2019, Method 533, Determination of per- and polyfluoroalkyl substances in drinking water by isotope dilution anion exchange