This dataset consists of summary data for potential landscape sources of per- and poly-fluoroalkyl substances (PFAS). These summary items include facilities from the Environmental Protection Agency (EPA) PFAS Analytics Tools, which were pulled from its Enforcement and Compliance History Online (ECHO), areas affected by fires (burned and urban burned areas) from Monitoring Trends in Burn Severity (MTBS), and landcover data from National Land Cover Dataset (NLCD) and Coastal Change Analysis Portal (C-CAP) around sites sampled as part of a National PFAS Tapwater Reconnaissance. These data are presented as a comma separated file, which includes summaries for all variables listed within a 5-kilometer buffer around each site, with an additional summary of burn areas within a 50-kilometer buffer. The purpose of this effort is to identify and quantify PFAS in drinking water sources at the point-of-use across the United States (US) and these data will be used to identify potential landscape-scale drivers of PFAS contamination in US tapwater (TW).

The U.S. Geological Survey Groundwater Ambient Monitoring and Assessment-Priority Basin Project (USGS GAMA-PBP) collected samples to be analyzed for per-and polyfluoroalkyl substances (PFAS) from domestic and public supply wells from May 2019 to June 2021. The datasets presented here include identification of the 28 PFAS constituents monitored by the project, Identification and brief characterization of the 395 GAMA-PBP wells for which samples were analyzed for PFAS during the study period, and analytical results for those groundwater samples, along with results for quality control samples.

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.

Numerous per- and polyfluoroalkyl substances (PFAS) are of growing concern worldwide, due to their ubiquitous presence, bioaccumulation and adverse effects. Surface waters in the United States have displayed elevated concentrations of PFAS, but so far discrete water sampling has been the commonly applied sampling approach. Here we field-tested a novel integrative passive sampler, a microporous polyethylene (PE) tube, and derived sampling rates (Rs) for 9 PFAS in surface waters. Three sampling campaigns were conducted, deploying PE tube passive samplers in the effluent of two wastewater treatment plant (WWTP) effluent sites plants (WWTPs) and across Narragansett Bay (RI, US) for one month each in 2017/2018. Passive samplers exhibited linear uptake of PFAS in the WWTP effluents over 16-29 days, with in-situ Rs for nine PFASs ranging from 10 mL day-1 (PFPeA) to 29 mL day-1 (PFOS). Similar sampling rates of 19 ± 4.8 mL day-1 were observed in estuarine field deployments. Applying these Rs values in a different WWTP effluent predicted dissolved PFAS concentrations mostly within 50% of their observations in daily composite water samples, except for PFBA (where predictions from passive samplers were 3x greater than measured values), PFNA (1.9), PFDA (1.7) and PFPeS (0.1). These results highlight the potential use of passive samplers as measurement and assessment tools of PFAS in dynamic aquatic environments. This dataset is associated with the following publication: Gardiner, C., A. Robuck, J. Becanova, M. Cantwell, S. Kaserzon, D. Katz, J. Mueller, and R. Lohmann. Field validation of a novel passive sampler for dissolved PFAS in surface waters. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, USA, 41(10): 2375-2385, (2022).

This dataset contains the concentration and quality assurance results for 34 per- and polyfluoroalkyl substances (PFAS). 409 residential and commercial tapwater samples were collected once between May 2021 and May 2022, in the contiguous U.S., Alaska, Hawaii, Puerto Rico, and U.S. Virgin Islands. Of these samples 252 were from publicly supplied tapwater locations, and 155 were sourced from private wells, springs or catchment vessels. Additionally, three surface-water samples were collected in New Hampshire (as denoted with a site code suffix of '_SW' in Table 2a). An additional 85 samples were collected at 3 locations (privately sourced tapwater samples in New Jersey (30) and South Carolina (20), and a publicly supplied source in New Jersey (35)) between September 27, 2021 and December 20, 2021 to evaluate PFAS concentrations over time. Individual homeowner kits were shipped with supplies and protocols so the homeowner could collect and return the samples for analysis. Thirty-six quality-assurance field-blank samples were also collected. Quality-assurance matrix spike and surrogate percent recovery results are also presented. Samples were analyzed at the U.S. Geological Survey, National Water Quality Laboratory in Denver, Colorado. For privacy purposes, all sample locations are anonymized.

Concentrations of inorganic constituents, dissolved organic carbon (DOC), tritium, per- and polyfluoroalkyl substances (PFAS), volatile organic compounds (VOCs), and pharmaceuticals were measured in groundwater samples collected from 254 wells in 2019 and 2020. Concentrations of inorganic constituents, DOC, VOCs, and pharmaceuticals were measured at the U.S. Geological Survey (USGS) National Water Quality Laboratory in Lakewood, Colorado. Concentrations of tritium were measured at the USGS Tritium Laboratory in Menlo Park, California. Concentrations of PFAS were measured at SGS Laboratory in Orlando, Florida. In addition, several geospatial parameters were determined, including: percentages of selected land uses within 500-meter buffers around sampled wells, nitrogen loading from septic systems within 500-meter buffers around sampled wells, distance to nearest wastewater treatment plant, and distance to selected industry and other potential point sources that could be sources of PFAS to the environment. The data were collected as part of the USGS National Water-Quality (NAWQA) project. This data release contains 12 tables of well information, laboratory results, geospatial output, and a data dictionary, including: 1) PFAS_Data_Dictionary.csv – Parameters in each table are defined in this table. 2) PFAS_BLANK.csv – Concentrations of PFAS in equipment, field, and source-solution blank samples. 3) PFAS_ENV.csv – Concentrations of PFAS in environmental samples. 4) PFAS_GEOSPATIAL.csv – Percentages of selected land uses within 500-meter buffers around sampled wells; nitrogen loading from septic systems within 500-meter buffers around sampled wells; distance to nearest wastewater treatment plant; distance to selected industry and other potential point sources that could be sources of PFAS to the environment. 5) PFAS_INORGANICS_AND_OTHER.csv – Concentration of inorganic constituents, DOC, and tritium. 6) PFAS_LAB_BLANK.csv – Concentrations of PFAS in laboratory blank samples. 7) PFAS_PHARMA.csv – Concentrations of pharmaceutical compounds in environmental samples. 8) PFAS_REP.csv – Concentrations of PFAS in replicate samples. 9) PFAS_SPIKE_FIELD.csv – Percent recovery for PFAS in field matrix-spike samples. 10) PFAS_SPIKE_LAB.csv – Percent recovery for PFAS in laboratory reagent-spike and matrix-spike samples. 11) PFAS_VOCs.csv – Concentrations of VOCs in environmental samples. 12) PFAS_WELLS.csv – Site characteristics of the sampled wells.

The U.S. Geological Survey collected water-quality samples from 3,199 sites between May 2004 and April 2022 for the California Groundwater Ambient Monitoring and Assessment Program Priority Basin Project (GAMA-PBP). The GAMA-PBP is a cooperative project with the California State Water Resources Control Board (SWRCB). The primary objectives of the GAMA-PBP are: (1) to assess the quality of groundwater resources used for public and domestic drinking water supplies, (2) to develop understanding of the natural and anthropogenic processes controlling groundwater quality and changes in groundwater quality, and (3) to improve the availability and usefulness of groundwater quality information to public. This data release publishes site type information and a generalized use category for the sites. The dataset comprises 3,053 wells, 81 springs, and 65 other types of sites. The generalized use category is partially derived from, but is not equivalent to, the use of site and use of water fields from the USGS National Water Information System (NWIS) data archive. Of the 2,903 wells and springs from which water is withdrawn for use, 1,651 are classified as production (includes sites used for public, commercial, industrial, institutional, and desalination water supplies), 973 as domestic, 264 as irrigation, and 15 as other water supply uses. Of the remaining sites, 225 are classified as observation wells, 6 are wells and springs from which water is withdrawn and not used, 63 are distribution system taps, and 2 are other types of sites. GAMA-PBP data are also served to the public through the SWRCB's GAMA Groundwater Information System (GAMAGIS), along with data from other federal, state, and local agency sources, and the generalized use categories in this data release are compatible with the use categories in SWRCB GAMAGIS. Prior to publication of this data release, SWRCB GAMAGIS classified all GAMA-PBP sites as "municipal", which resulted in erroneous characterization of approximately half of the sites. The generalized classification provided in this data release greatly improves the accuracy of site characterization, while still complying with Federal policies concerning release of location information for some types of sites. Version 1.0 posted September 29, 2021 Version 2.0 posted August 31, 2022 Changes in Version 2.0 1) A total of 143 sites were added to the data release. Seventy-one (71) sites were sampled for the first time by the GAMA-PBP between July 2021 and April 2022 after publication of Version 1.0 of this data release. Seventy-two (72) sites were sampled prior to publication of Version 1.0, but were inadvertently omitted. 2) A new Site_Type, DISTRIBUTION SYSTEM, was added, and a process step was added to describe how and why it is used. Of the 72 sites omitted from Version 1.0, 63 were distribution system sites sampled in 2012-2013. 3) The GAMAIDs for two sites were corrected. Site 342959117133002 is S8-MOBSU-U09 (given as S8-MOBSU-U10 in Version 1.0), and Site 342959117133003 is S8-MOBSU-U10 (given as S8-MOBSU-U09 in Version 1.0) 4) A second GAMAID was added to seven WELL sites that were also sampled as DISTRIBUTION SYSTEM sites under a different GAMAID but the same USGS Site_Number (363700121500001, 365425121452201, 354000120410001, 354501120413301,354911120452701, 360600121000001, 361631121112001) 5) The USE_CATEGORY for 8 sites was changed for consistency with how use of those sites is described elsewhere. Three natural springs and one unused well were changed from the category OTHER to the category OBSERVATION (413600122240001, 383548122360601, 382925122294901, 373738119045501). Four wells were changed from category WATER SUPPLY, OTHER (364800118110001, 382307122311301) or category OBSERVATION (382702122423701, 365000120450001) to category PRODUCTION to reflect that the sites are standby or not currently in use but when the water is used, the use is in the PRODUCTION category. 6) References were added to the process steps

The U.S. Geological Survey collected water-quality samples from 3,359 sites between May 2004 and November 2024 for the California Groundwater Ambient Monitoring and Assessment Program Priority Basin Project (GAMA-PBP). The GAMA-PBP is a cooperative project with the California State Water Resources Control Board (SWRCB). The primary objectives of the GAMA-PBP are: (1) to assess the quality of groundwater resources used for public and domestic drinking water supplies, (2) to develop understanding of the natural and anthropogenic processes controlling groundwater quality and changes in groundwater quality, and (3) to improve the availability and usefulness of groundwater quality information to public. This data release publishes site type information and a generalized use category for the sites. The dataset comprises 3,213 wells, 81 springs, and 65 other types of sites. The generalized use category is partially derived from, but is not equivalent to, the use of site and use of water fields from the USGS National Water Information System (NWIS) data archive. Of the 3,063 wells and springs from which water is withdrawn for use, 1,696 are classified as production (includes sites used for public, commercial, industrial, institutional, and desalination water supplies), 1,123 as domestic, 263 as irrigation, and 16 as other water supply uses. Of the remaining sites, 229 are classified as observation wells, 6 are wells and springs from which water is withdrawn and not used, 63 are distribution system taps, and 4 are other types of sites. GAMA-PBP data are also served to the public through the SWRCB's GAMA Groundwater Information System (GAMAGIS), along with data from other federal, state, and local agency sources, and the generalized use categories in this data release are compatible with the use categories in SWRCB GAMAGIS. Prior to publication of this data release, SWRCB GAMAGIS classified all GAMA-PBP sites as "municipal", which resulted in erroneous characterization of approximately half of the sites. The generalized classification provided in this data release greatly improves the accuracy of site characterization, while still complying with Federal policies concerning release of location information for some types of sites. Version 1.0 posted September 29, 2021 Version 2.0 posted September 2, 2022 Version 3.0 posted October 25, 2023 Version 4.0 posted April, 2025