Benjamin N Fisher Amanda M. Dondero Elaiya R Jurney Megan L Essig 20250507 Excel, CSV Reston, VA U.S. Geological Survey https://doi.org/10.5066/P96H5XFD This data release contains analytical results from 52 groundwater samples and six quality assurance and quality control samples collected from the Delaware, Genesee, and St. Lawrence River basins. Samples were collected between June and September, 2020 from six production wells and five domestic wells in the Delaware River basin, seven production wells and 10 domestic wells in the Genesee River basin, and 13 productions wells and 11 domestic wells in the St. Lawrence River basin. Of the total wells sampled, 33 were completed in bedrock and 19 were completed in sand and gravel. Samples were collected prior to any treatment or filtration systems, from existing domestic and production wells equipped with permanently installed pumps. Samples were collected and processed using standard USGS methods (see References.csv) and were analyzed for constituents including physicochemical properties, dissolved gases, major ions, nutrients, trace elements, pesticides, volatile organic compounds (VOCs), radiological activity, and indicator bacteria. All analytes are listed with the associated method detection and reporting limits. Samples were analyzed at the USGS National Water Quality Laboratory (NWQL) in Denver, Colorado, and other certified laboratories following published methods (see References.csv). Groundwater samples were collected from domestic and production wells in Delaware, Genesee, and St. Lawrence River basins as part of a larger cooperative program between the USGS and New York State Department of Environmental Conservation to quantify and report on ambient groundwater quality from bedrock and glacial-drift aquifers in upstate New York. 20200629 20200923 ground condition Complete None planned -78.3839 -73.6417 45.0005 41.3311 USGS Thesaurus groundwater quality groundwater hydrogeology water resources water chemistry USGS Metadata Identifier USGS:65203b09d34e44db0e2e4400 Geographic Names Information System (GNIS) Allegany County Delaware County Franklin County Hamilton County Jefferson County Lewis County Orange County Livingston County Monroe County Steuben County St. Lawrence County Sullivan County Wyoming County None Delaware River Basin Genesee River Basin St. Lawrence River Basin none none Benjamin N. Fisher U.S. Geological Survey, New York Water Science Center mailing and physical

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Pembroke NH 03275-3718 603-226-7800 bfisher@usgs.gov In cooperation with the New York State Department of Environmental Conservation No formal attribute accuracy tests were conducted. No formal logical accuracy tests were conducted. Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. No formal positional accuracy tests were conducted. No formal positional accuracy tests were conducted. Data was accessed from the National Water Information System (NWIS) for samples from 20200629 to 20200923 and formatted into tables by results. 2024 Vector G-polygon 0.000000001 0.000000001 Decimal degrees North American Datum of 1983 (NAD 83) Geodetic Reference System 1980 6378137.000000 298.257222 Table_of_Contents.csv List of tables included in this data release. Producer defined. Table of Contents See column headings. Producer defined. See column headings. Site_Information.csv Sites sampled in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. Producer defined. Sites sampled in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. (1) NWIS=National Water Information System. (2) Well Number is assigned to each well by the New York State Department of Environmental Conservation. Well number prefix denotes county: AG, Allegany; D, Delaware; F, Franklin; H, Hamilton; J, Jefferson; L, Lewis; O, Orange; LV, Livingston; MO, Monroe; SB, Steuben; ST, St Lawrence; SV, Sullivan; WO, Wyoming. (3) P=Production Well. D=Domestic Well. (4) 'Delaware' denotes Delaware River Basin; 'Genesee' denotes Genesee River Basin; 'St. Lawrence' denotes St. Lawrence River Basin. (5) 'SG' denotes Sand and Gravel finish, 'B' denotes Bedrock finish. '--' denotes missing or unavailable data. YYYYMMDD denotes sample format is in year, month, and day format. See column headings. Producer defined. See column headings. References.csv References for analytical methods and drinking water standards. Producer defined. References for analytical methods and drinking water standards. 'N/A' denotes not applicable. See column headings. Producer defined. See column headings. Constituents_Analyzed.csv Constituents that were analyzed in groundwater samples collected from wells in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. Producer defined. Constituents that were analyzed in groundwater samples collected from wells in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. 'µg/L' denotes micrograms per liter. 'ng/L' denotes nanograms per liter. 'mg/L' denotes milligrams per liter. 'µS/cm' denotes microsiemens per centimeter. 'pCi/L' denotes picocuries per liter. 'CFU' denotes colony forming unit. 'CaCO3' denotes calcium carbonate. 'SiO2' denotes silicon dioxide. 'N' denotes nitrogen. 'P' denotes phosphorus. 'mL' denotes milliliter. '--' denotes missing or unavailable data. 'MDL' denotes method detection limit. 'RL' denotes reporting limit. '*' denotes for dissolved gas method, method reporting level is equivalent to MDL. Constituents analyzed using the following methods were from unfiltered water samples: dissolved gases, LC1369, LC2689, LC2708, LC3211, LC3301, SH1080, SH2246, SH4437, SM9223B, SM9222, SM9222D, SM9215B, and Colilert-18. Constituents analyzed using the following methods were from filtered water samples: SH2437 and SH25. Constituents analyzed using the following method were from filtered water samples, unless otherwise noted as unfiltered: SH1723. See column headings. Producer defined. See column headings. Phys._Prop._and_Diss._Gases.csv Drinking water standards and concentrations of physicochemical properties and dissolved gases detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. Producer defined. Drinking water standards and concentrations of physicochemical properties and dissolved gases detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. (1) NWIS=National Water Information System. (2) Well Number is assigned to each well by the New York State Department of Environmental Conservation. Well number prefix denotes county: AG, Allegany; D, Delaware; F, Franklin; H, Hamilton; J, Jefferson; L, Lewis; O, Orange; LV, Livingston; MO, Monroe; SB, Steuben; ST, St Lawrence; SV, Sullivan; WO, Wyoming. (3) 'Delaware' denotes Delaware River Basin; 'Genesee' denotes Genesee River Basin; 'St. Lawrence' denotes St. Lawrence River Basin. (4) U.S. Environmental Protection Agency (2018) secondary drinking-water standard. Physicochemical properties measured using field methods (see 'References' table). Dissolved gases analyzed using dissolved gas method (see 'References' table). Color analyzed using Major Ions method 1723 (see 'References' table). '--' denotes missing or unavailable data. 'U' denotes presence undetected. 'M' denotes presence detected. '<' denotes less than value. 'mg/L' denotes milligrams per liter. See column headings. Producer defined. See column headings. Major_Ions_and_Diss._Solids.csv Drinking water standards and concentrations of major ions and dissolved solids detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. Producer defined. Drinking water standards and concentrations of major ions and dissolved solids detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. (1) NWIS=National Water Information System. (2) Well Number is assigned to each well by the New York State Department of Environmental Conservation. Well number prefix denotes county: AG, Allegany; D, Delaware; F, Franklin; H, Hamilton; J, Jefferson; L, Lewis; O, Orange; LV, Livingston; MO, Monroe; SB, Steuben; ST, St Lawrence; SV, Sullivan; WO, Wyoming. (3) 'Delaware' denotes Delaware River Basin; 'Genesee' denotes Genesee River Basin; 'St. Lawrence' denotes St. Lawrence River Basin. (4) U.S. Environmental Protection Agency (2018) maximum contaminant level. (5) New York State Department of Health (2018) maximum contaminant level. (6) U.S. Environmental Protection Agency (2018) secondary drinking-water standard. (7) U.S. Environmental Protection Agency (2018) drinking-water advisory taste threshold. Major ions and dissolved solids analyzed using the SH1723 method (see 'References' table). '--' denotes missing or unavailable data. '<' denotes less than value. 'mg/L' denotes milligrams per liter. 'CaCO3' denotes calcium carbonate. 'SiO2' denotes silicon dioxide. See column headings. Producer defined. See column headings. Nutrients_and_Organic_Carbon.csv Drinking water standards and concentrations of nutrients and organic carbon detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. Producer defined. Drinking water standards and concentrations of nutrients and organic carbon detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. (1) NWIS=National Water Information System. (2) Well Number is assigned to each well by the New York State Department of Environmental Conservation. Well number prefix denotes county: AG, Allegany; D, Delaware; F, Franklin; H, Hamilton; J, Jefferson; L, Lewis; O, Orange; LV, Livingston; MO, Monroe; SB, Steuben; ST, St Lawrence; SV, Sullivan; WO, Wyoming. (3) 'Delaware' denotes Delaware River Basin; 'Genesee' denotes Genesee River Basin; 'St. Lawrence' denotes St. Lawrence River Basin. (4) U.S. Environmental Protection Agency (2018) maximum contaminant level. (5) New York State Department of Health (2018) maximum contaminant level. Nutrients and organic carbon were analyzed using the SH25 and LC3211 methods, respectively (see 'References' table). '--' denotes missing or unavailable data. 'N' denotes nitrogen. 'P' denotes phosphorus. '<' denotes less than value. 'mg/L' denotes milligrams per liter. See column headings. Producer defined. See column headings. Trace_Elements.csv Drinking water standards and concentrations of trace elements detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. Producer defined. Drinking water standards and concentrations of trace elements detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. (1) NWIS=National Water Information System. (2) Well Number is assigned to each well by the New York State Department of Environmental Conservation. Well number prefix denotes county: AG, Allegany; D, Delaware; F, Franklin; H, Hamilton; J, Jefferson; L, Lewis; O, Orange; LV, Livingston; MO, Monroe; SB, Steuben; ST, St Lawrence; SV, Sullivan; WO, Wyoming. (3) 'Delaware' denotes Delaware River Basin; 'Genesee' denotes Genesee River Basin; 'St. Lawrence' denotes St. Lawrence River Basin. (4) U.S. Environmental Protection Agency (2018) maximum contaminant level. (5) New York State Department of Health (2018) maximum contaminant level. (6) U.S. Environmental Protection Agency (2018) secondary drinking-water standard. (7) U.S. Environmental Protection Agency (2018) action level. Trace elements were analyzed using the SH1080, SH1723, LC2708, and LC3301 methods (see 'References' table). '--' denotes missing or unavailable data. 'E' denotes estimated value. '<' denotes less than value. 'µg/L' denotes micrograms per liter. See column headings. Producer defined. See column headings. Pesticides.csv Drinking water standards and concentrations of pesticides detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. Producer defined. Drinking water standards and concentrations of pesticides detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. (1) NWIS=National Water Information System. (2) Well Number is assigned to each well by the New York State Department of Environmental Conservation. Well number prefix denotes county: AG, Allegany; D, Delaware; F, Franklin; H, Hamilton; J, Jefferson; L, Lewis; O, Orange; LV, Livingston; MO, Monroe; SB, Steuben; ST, St Lawrence; SV, Sullivan; WO, Wyoming. (3) 'Delaware' denotes Delaware River Basin; 'Genesee' denotes Genesee River Basin; 'St. Lawrence' denotes St. Lawrence River Basin. (4) U.S. Environmental Protection Agency (2018) maximum contaminant level. (5) New York State Department of Health (2018) maximum contaminant level. Pesticides were analyzed using the SH2437 method (see 'References' table). '--' denotes missing or unavailable data. 'E' denotes estimated. '<' denotes less than value. 'ng/L' denotes nanograms per liter. '**' denotes unspecified organic contaminant. See column headings. Producer defined. See column headings. Volatile_Organic_Compounds.csv Drinking water standards and concentrations of volatile organic compounds detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. Producer defined. Drinking water standards and concentrations of volatile organic compounds detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. (1) NWIS=National Water Information System. (2) Well Number is assigned to each well by the New York State Department of Environmental Conservation. Well number prefix denotes county: AG, Allegany; D, Delaware; F, Franklin; H, Hamilton; J, Jefferson; L, Lewis; O, Orange; LV, Livingston; MO, Monroe; SB, Steuben; ST, St Lawrence; SV, Sullivan; WO, Wyoming. (3) 'Delaware' denotes Delaware River Basin; 'Genesee' denotes Genesee River Basin; 'St. Lawrence' denotes St. Lawrence River Basin.(4) U.S. Environmental Protection Agency (2018) maximum contaminant level. (5) New York State Department of Health (2018) maximum contaminant level. (6) Total trihalomethanes (bromodichloromethane, dibromochloromethane, tribromomethane [bromoform], trichloromethane [chloroform]): New York State Department of Health maximum contaminant level and U.S. Environmental Protection Agency maximum contaminant level = 80 µg/L. Volatile organic compounds were analyzed using the SH4436 and SH4437 methods (see 'References' table). '--' denotes missing or unavailable data. 'E' denotes estimated value. 'M' denotes presence detected. '<' denotes less than value. 'µg/L' denotes micrograms per liter. '*' denotes principal organic contaminant. '**' denotes unspecified organic contaminant. See column headings. Producer defined. See column headings. Radionuclides.csv Drinking water standards and radionuclide activity detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. Producer defined. Drinking water standards and radionuclide activity detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. (1) NWIS=National Water Information System. (2) Well Number is assigned to each well by the New York State Department of Environmental Conservation. Well number prefix denotes county: AG, Allegany; D, Delaware; F, Franklin; H, Hamilton; J, Jefferson; L, Lewis; O, Orange; LV, Livingston; MO, Monroe; SB, Steuben; ST, St Lawrence; SV, Sullivan; WO, Wyoming. (3) 'Delaware' denotes Delaware River Basin; 'Genesee' denotes Genesee River Basin; 'St. Lawrence' denotes St. Lawrence River Basin. (4) U.S. Environmental Protection Agency (2018) maximum contaminant level. (5) New York State Department of Health (2018) maximum contaminant level. (6) U.S. Environmental Protection Agency (2018) proposed maximum contaminant level. (6) U.S. Environmental Protection Agency (2018) proposed alternative maximum contaminant level. Gross alpha radioactivity and gross beta radioactivity were analyzed using the LC2689 method (see 'References' table) Radon-222 was analyzed using the LC1369 method (see 'References' table). '--' denotes missing or unavailable data. '<' denotes less than value. 'pCi/L' denotes picocuries per liter. See column headings. Producer defined. See column headings. Bacteria.csv Drinking water standards and concentrations of bacteriological indicators detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. Producer defined. Drinking water standards and concentrations of bacteriological indicators detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2020. (1) NWIS=National Water Information System. (2) Well Number is assigned to each well by the New York State Department of Environmental Conservation. Well number prefix denotes county: AG, Allegany; D, Delaware; F, Franklin; H, Hamilton; J, Jefferson; L, Lewis; O, Orange; LV, Livingston; MO, Monroe; SB, Steuben; ST, St Lawrence; SV, Sullivan; WO, Wyoming. (3) 'SUSQ' denotes Susquehanna River Basin; 'CHAMP' denotes Lake Champlain River Basin. (4) U.S. Environmental Protection Agency (2018) maximum contaminant level. (5) New York State Department of Health (2018) maximum contaminant level. Bacteriological indicators analyzed using Standard Method 9222D/G and Standard Method 9215B (see 'References' table). '--' denotes missing or unavailable data. 'E' denotes estimated value. 'MPN' denotes most probable number. 'CFU' denotes colony forming unit. '<' denotes less than value. 'mL' denotes milliliter. See column headings. Producer defined. See column headings. ScienceBase U.S. Geological Survey mailing and physical

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Denver CO 80225 USA 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. 20250801 Benjamin N. Fisher U.S. Geological Survey, New York Water Science Center mailing and physical

331 Commerce Way

Pembroke NH 03275-3718 603-226-7800 bfisher@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998