State and local county health departments have detected per- and polyfluoroalkyl substances (PFAS) in groundwater downgradient of airports and military and firefighting training areas in Long Island, New York. However, the occurrence and spatial distribution of PFAS throughout the surficial aquifer is not well established. Shallow groundwater samples were collected in 2018 from two observation well networks; the Sentinel network and Wastewater Treatment Plant groundwater (WTPGW) network. The Sentinel network is an island-wide group of wells screened within the shallow upper glacial (surficial, <100 feet deep) aquifer, which were sampled to assess the occurrence of PFAS in different land-use settings. The WTPGW network consisted of shallow (<60 feet deep) wells located downgradient of decentralized wastewater treatment systems discharging to groundwater, which were sampled to determine if these systems are a source of PFAS to groundwater. Each sample was analyzed for 18 PFAS compounds. This sample collection documents the first Long Island-wide assessment for ambient PFAS contamination within the shallow aquifer system. An extensive quality-assurance and quality-control program developed specifically for the expected low level (<200 nanograms per liter [ng/L]) PFAS environmental concentrations within the groundwater networks revealed no detections of the 18 PFAS compounds analyzed. This indicates that selected equipment, cleaning, sampling, and handling procedures are sufficient to provide data that reflects environmental conditions. Twenty-six of the 37 wells sampled in the Sentinel network had one or more PFAS compounds detected, and up to 8 compounds were detected in a single sample. Ten PFAS compounds have been detected in these samples, with individual compound concentrations ranging from 3.4 to 93 ng/L. Land-use settings for these sample sites varied between medium- and high-density residential and mixed-use commercial properties. Seven monitoring wells surrounding leach fields from three different decentralized wastewater treatment systems (WTPGW network) found four or more PFAS in each groundwater sample. Twelve PFAS compounds have been detected in these samples, with individual compound concentrations ranging from 5 to 620 ng/L. The greatest variety of PFAS was detected at the site that served an assisted living and rehabilitation facility and a hotel while the highest PFAS concentrations were detected at the site that served a strip mall (commercial property).

This U.S. Geological Survey (USGS) data release contains groundwater quality data for twelve wells in Suffolk County, New York and associated quality assurance results. Samples were collected between 2021 and 2023 and analyzed for per- and polyfluoroalkyl substances (PFAS), pesticides, and pharmaceuticals. Measurements of pH, specific conductance, dissolved oxygen, water temperature and turbidity were recorded at the time of sample collection. Samples collected for quality assurance and quality control (QAQC) include sequential replicates, field blanks, equipment blanks, source solution blanks, and laboratory-control samples. Laboratory-control samples for PFAS analysis included method blanks, isotope dilution standard recoveries, and spikes recoveries.

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

This dataset includes per-and polyfluoroalkyl substances (PFAS) and pharmaceuticals monitored at 62 sampling sites in tributaries of the Laurentian Great Lakes. Chemicals were evaluated in a sediment sample (PFAS only) and water concentrations were estimated using polar organic chemical integrative samplers (POCIS). Sediment samples were collected from the 62 sites in June and July 2018, which were analyzed for 23 PFAS compounds using liquid chromatography tandem mass spectrometry (LC/MS/MS). Duplicate sediment samples were collected at 23 sites. Overall, 22 of the 23 sediment PFAS compounds analyzed were detected in samples from at least one site. Pharmaceuticals and PFAS samples were collected instream by deploying two POCIS at each site for approximately 30 days during the period of May through October 2018. POCIS were compromised at two sites, so POCIS data are only included for 60 of the 62 sites. POCIS blanks and replicates were also collected at six sites. Replicate POCIS were deployed within the same stream cross section. Blanks were collected by exposing prepared POCIS to the air during the time it took to deploy and retrieve the sampler. POCIS blank samples were extracted along with field samples at the end of the deployment period. POCIS extracts were analyzed for 107 pharmaceuticals (USGS National Water Quality Laboratory schedule 2440). A separate POCIS extract was analyzed for 34 PFAS using high-performance liquid chromatograph (HPLC) coupled to a triple quadrupole mass spectrometer (MS/MS). Of these compounds, 49 pharmaceuticals and 17 PFAS had POCIS uptake rates, allowing calculations of time-weighted mean concentration over the approximately 30-day deployment. Collectively, there were 69 pharmaceuticals and 21 PFAS detected in environmental POCIS samples.

This dataset includes per-and polyfluoroalkyl substances (PFAS) and pharmaceuticals monitored at 62 sampling sites in tributaries of the Laurentian Great Lakes. Chemicals were evaluated in a sediment sample (PFAS only) and water concentrations were estimated using polar organic chemical integrative samplers (POCIS). Sediment samples were collected from the 62 sites in June and July 2018, which were analyzed for 23 PFAS compounds using liquid chromatography tandem mass spectrometry (LC/MS/MS). Duplicate sediment samples were collected at 23 sites. Overall, 22 of the 23 sediment PFAS compounds analyzed were detected in samples from at least one site. Pharmaceuticals and PFAS samples were collected instream by deploying two POCIS at each site for approximately 30 days during the period of May through October 2018. POCIS were compromised at two sites, so POCIS data are only included for 60 of the 62 sites. POCIS blanks and replicates were also collected at six sites. Replicate POCIS were deployed within the same stream cross section. Blanks were collected by exposing prepared POCIS to the air during the time it took to deploy and retrieve the sampler. POCIS blank samples were extracted along with field samples at the end of the deployment period. POCIS extracts were analyzed for 107 pharmaceuticals (USGS National Water Quality Laboratory schedule 2440). A separate POCIS extract was analyzed for 34 PFAS using high-performance liquid chromatograph (HPLC) coupled to a triple quadrupole mass spectrometer (MS/MS). Of these compounds, 49 pharmaceuticals and 17 PFAS had POCIS uptake rates, allowing calculations of time-weighted mean concentration over the approximately 30-day deployment. Collectively, there were 69 pharmaceuticals and 21 PFAS detected in environmental POCIS samples.

Per- and polyfluoroalkyl substances (PFAS) and co-occurring inorganic and organic contaminants are widely distributed in the environment and understanding their surface water sources is critical for water resource management. In November 2021, 13 sites were sampled along a stream reach in the Neshaminy Creek basin in southeastern Pennsylvania utilizing a time of travel sampling approach. The reach had known potential PFAS source inputs and documented PFAS detections in water samples. This data release describes the sampling approach, sample processing, laboratory analytical methods, and contains the results. Site (Table1_NC_2021_Site_Info) and constituent information (Table2_Constituents) are provided in tab delimited text (txt) files. Results are provided in a machine readable format in Table3_Reporting_Long.txt for the following hydrologic metrics and chemical constituents: (1) field parameters (instantaneous discharge, water and air temperature, barometric pressure, pH, specific conductance, and dissolved oxygen), (2) optical properties (ultraviolet (UV)-visible absorbance, and fluorescence), (3) dissolved organic carbon and total dissolved nitrogen, (4) major anions, (5) major and trace elements, (6) PFAS, (7) pharmaceutical compounds, and (8) volatile organic compounds. Table_4_Wide_Summary.xlxs is a summary file including the reported values, laboratory standard deviations, remark codes, and qualification codes from Table3_Reporting_Long.txt as eight wide format pivot tables.

Per- and polyfluoroalkyl substances (PFAS) and co-occurring inorganic and organic contaminants are widely distributed in the environment and understanding their surface water sources is critical for water resource management. In November 2021, 13 sites were sampled along a stream reach in the Neshaminy Creek basin in southeastern Pennsylvania utilizing a time of travel sampling approach. The reach had known potential PFAS source inputs and documented PFAS detections in water samples. This data release describes the sampling approach, sample processing, laboratory analytical methods, and contains the results. Site (Table1_NC_2021_Site_Info) and constituent information (Table2_Constituents) are provided in tab delimited text (txt) files. Results are provided in a machine readable format in Table3_Reporting_Long.txt for the following hydrologic metrics and chemical constituents: (1) field parameters (instantaneous discharge, water and air temperature, barometric pressure, pH, specific conductance, and dissolved oxygen), (2) optical properties (ultraviolet (UV)-visible absorbance, and fluorescence), (3) dissolved organic carbon and total dissolved nitrogen, (4) major anions, (5) major and trace elements, (6) PFAS, (7) pharmaceutical compounds, and (8) volatile organic compounds. Table_4_Wide_Summary.xlxs is a summary file including the reported values, laboratory standard deviations, remark codes, and qualification codes from Table3_Reporting_Long.txt as eight wide format pivot tables.

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.