Source water for West Virginia’s public water systems is pumped from groundwater aquifers or withdrawn from the state’s rivers and lakes. These systems provide drinking water to a majority of the state’s population and require constant monitoring for known and emerging contaminants. Groundwater contamination from per- and polyfluoroalkyl substances (PFAS) has occurred in West Virginia around industrial facilities and military installations. To understand the potential impact of PFAS contamination in the state’s source waters, West Virginia Department of Environmental Protection (WVDEP) and West Virginia Department of Health and Human Resources (WVDHHR) required information on the state-wide distribution of the contaminant. From May 2019 through May 2021, samples of un-treated water were collected from raw-water supplies at 279 public water systems in West Virginia. Parameters collected at the time of sampling included pH, specific conductance, water temperature, dissolved oxygen, turbidity, and alkalinity. Samples were analyzed at the US Geological Survey (USGS) National Water Quality Laboratory for several inorganic analytes including major ions, trace elements, and nutrients. Samples were also analyzed for 28 PFAS compounds at a contract laboratory that is accredited under the Department of Defense (DoD) Environmental Laboratory Accreditation Program for PFAS analysis compliant with DoD Quality Systems Manual table B15. 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 and provides a reference location for associated reports.

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

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

These data were collected in cooperation with the Virginia Department of Environmental Quality (VADEQ) to document the occurrence of Per- and Polyfluoroalkyl Substances (PFAS) in streams and rivers of Virginia. Specifically, this effort was initiated to: 1. Collect and analyze samples for PFAS at USGS-sampling stations in the Chesapeake Bay River Input Monitoring Network and Non-Tidal Network; 2. Collect and analyze samples for PFAS at VADEQ Probabilistic Monitoring stations; 3. Collect and analyze samples for PFAS at additional DEQ-selected locations; and 4. Quality Assure all data collected in accordance with USGS policies and publicly release those data as a citable USGS Data Release. Description of Available Datasets: These data are available in 2 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 VA_StateWide_Surface_Water_Results contain analytical results for 166 samples of PFAS in surface water collected at 73 locations in the State. These files also 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 VA_StateWide_Metadata contains metadata explaining the provenance of the data and should be thoroughly read to understand data structure and limitations. The files titled Data_Dictionary may be used as a reference to explain codes, terms, and abbreviations used in these datasets. The files titled Ongoing_Precision_and_Recovery contain quality assurance samples reported by the lab which establishes additional confidence in results over time. Data Validation and Quality Assurance: U.S. Environmental Protection Agency (EPA) Draft Method 1633 (U.S. Environmental Protection Agency, 2021) was used to determine PFAS concentrations in surface water. Samples were analyzed at SGS AXYS in British Columbia, Canada, which is accredited by the U.S. Department of Defense Environmental Laboratory Accreditation Program for analysis of PFAS using Draft Method 1633. 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 show in this dataset are synonymous with the minimum level of quantitation as defined by U.S. Environmental Protection Agency (2021). 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. Three samples for 6:2 fluorotelomersulfonate (6:2 FTS), two samples for perfluorooctanesulfonamide (PFOSA), and one sample for perfluorooctanesulfonate (PFOS) did meet quality assurance criteria. Analytical results for these analytes were rejected in six different samples and are represented in the dataset with an “R” qualifier. References: U.S. Environmental Protection Agency, 2021, Draft Method 1633 - Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous, Solid, Biosolids, and Tissue Samples by LC-MS/MS: U.S. Environmental Protection Agency Document EPA 821-D-21-001, 65 p., accessed July 14, 2022, at https://www.epa.gov/system/files/documents/2021-09/method_1633_draft_aug-2021.pdf.

These data were collected in cooperation with the Virginia Department of Environmental Quality (VADEQ) to document the occurrence of Per- and Polyfluoroalkyl Substances (PFAS) in streams and rivers of Virginia. Specifically, this effort was initiated to: 1. Collect and analyze samples for PFAS at USGS-sampling stations in the Chesapeake Bay River Input Monitoring Network and Non-Tidal Network; 2. Collect and analyze samples for PFAS at VADEQ Probabilistic Monitoring stations; 3. Collect and analyze samples for PFAS at additional DEQ-selected locations; and 4. Quality Assure all data collected in accordance with USGS policies and publicly release those data as a citable USGS Data Release. Description of Available Datasets: These data are available in 2 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 VA_StateWide_Surface_Water_Results contain analytical results for 166 samples of PFAS in surface water collected at 73 locations in the State. These files also 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 VA_StateWide_Metadata contains metadata explaining the provenance of the data and should be thoroughly read to understand data structure and limitations. The files titled Data_Dictionary may be used as a reference to explain codes, terms, and abbreviations used in these datasets. The files titled Ongoing_Precision_and_Recovery contain quality assurance samples reported by the lab which establishes additional confidence in results over time. Data Validation and Quality Assurance: U.S. Environmental Protection Agency (EPA) Draft Method 1633 (U.S. Environmental Protection Agency, 2021) was used to determine PFAS concentrations in surface water. Samples were analyzed at SGS AXYS in British Columbia, Canada, which is accredited by the U.S. Department of Defense Environmental Laboratory Accreditation Program for analysis of PFAS using Draft Method 1633. 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 show in this dataset are synonymous with the minimum level of quantitation as defined by U.S. Environmental Protection Agency (2021). 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. Three samples for 6:2 fluorotelomersulfonate (6:2 FTS), two samples for perfluorooctanesulfonamide (PFOSA), and one sample for perfluorooctanesulfonate (PFOS) did meet quality assurance criteria. Analytical results for these analytes were rejected in six different samples and are represented in the dataset with an “R” qualifier. References: U.S. Environmental Protection Agency, 2021, Draft Method 1633 - Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous, Solid, Biosolids, and Tissue Samples by LC-MS/MS: U.S. Environmental Protection Agency Document EPA 821-D-21-001, 65 p., accessed July 14, 2022, at https://www.epa.gov/system/files/documents/2021-09/method_1633_draft_aug-2021.pdf.

These data were collected to understand the occurrence of per- and polyfluoroalkyl substances (PFAS) in the middle Chickahominy River watershed. Specifically, this effort was initiated to: 1. Determine concentrations of PFAS in surface water at select locations in the middle Chickahominy River watershed; 2. Determine concentrations of PFAS in edible portions of fish at select locations in the middle Chickahominy River watershed; 3. Determine concentrations of PFAS in bed sediment at select locations in the middle Chickahominy River watershed; and 4. Quality Assure all data collected in accordance with USGS policies and publicly release those data as a citable USGS Data Series. These data are available in four 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 Middle_Chickahominy_Fish_Tissue_Results contain analytical results for PFAS in tissue samples collected from various fish species at different locations. The files titled Middle_Chickahominy_Sediment_Results contain analytical results for PFAS in sediments collected at four locations in the watershed. The files titled Middle_Chickahominy_Surface_Water_Results contain analytical results for PFAS in surface water collected at eleven locations in the watershed. These files also 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 Middle_Chickahominy_Metadata contains metadata explaining the provenance of the data and should be thoroughly read to understand data structure and limitations. The files titled Data_Dictionary may be used as a reference to explain codes, terms, and abbreviations used in these datasets. The files titled Ongoing_Precision_and_Recovery contain quality assurance samples reported by the lab which establishes additional confidence in results over time.

These data were collected to understand the occurrence of per- and polyfluoroalkyl substances in drinking water samples at public water systems identified to have perfluorooctanoic acid or perfluorooctane sulfonic acid above laboratory reporting levels in previously collected raw-water samples, and provide a review of the analytical results. The West Virginia Department of Health and Human Resources will use this data to determine the potential risk to public health from PFAS contamination in these public water systems.

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 for per- and polyfluoroalkyl substances (PFAS) were collected from 10 domestic wells to assess the extent to which PFAS is coming from the groundwater aquifer or from another source within the home. Specific objectives included: 1. Collect well construction information; 2. Collect samples for analysis of PFAS directly from the aquifer at domestic wells; 3. Collect samples for analysis of PFAS from two locations within the home to compare with samples collected directly from the aquifer; 4. Quality Assure all data in accordance with USGS policies; and 5. Release data to the public as a citable USGS Data Release. 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 VDH_PFAS_Results contain analytical results and field measurements for samples collected from 10 locations in Virginia. The files titled VDH_PFAS_Quality_Assurance contain associated equipment blanks, field blanks, lab blanks, and replicates used for quality control. Lab blanks are used to assess contamination imparted by the analytical process. Equipment blanks were used to assess possible contamination from sampling equipment. Field blanks were collected using certified analyte-free water at each environmental sample 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 VDH_PFAS_Metadata contains metadata explaining the provenance of the data and should be thoroughly read to understand data structure and limitations. The files titled VDH_PFAS_Data_Dictionary may be used as a reference to explain codes, terms, and abbreviations used in these datasets. The files titled VDH_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: Ten homes were sampled as part of this project and at each location domestic wells were the main source of water. At each home, one sample was collected directly from the aquifer by accessing the well and using pre-cleaned, PFAS-free sampling equipment. Field measurements (pH, specific conductance, temperature, dissolved oxygen, turbidity) were collected in a flow-through cell and recorded with the well sample, before contact with in-house plumbing and before treatment. One sample was collected at the main point of use within the home (typically the kitchen faucet). One sample was collected at an intermediate location within the homes plumbing system located between the well and kitchen faucet. Analyte concentrations were compared between sampling locations within the homes plumbing system to assess the contribution of PFAS from the aquifer and understand possible contribution of PFAS from the homes pluming system. U.S. Environmental Protection Agency (EPA) Method 533 (Rosenblum and Wendelken, 2019) was 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, carbon-13 labelled internal standard compound recoveries, and ongoing precision and recovery samples were used to assess field techniques and