Water samples from 50 domestic wells located <1 kilometer (km) (proximal) and >1 km (distal) from shale-gas wells in upland areas of the Marcellus Shale region were analyzed for chemical, isotopic and groundwater-age tracers. Uplands were targeted because natural mixing with brine and hydrocarbons from deep formations is less common in those areas compared to valleys. Methane (CH4) -isotope and pre-drill CH4 data indicate one proximal sample (5 percent of proximal samples) contains thermogenic CH4 (2.6 milligrams per liter (mg/L)) associated with shale-gas production. Chloride (Cl), bromide (Br), lithium (Li), and neon-20 (20Ne)/argon-36 (36Ar) data suggest that CH4 leaked from a nearby gas well in a gas phase. Another proximal sample contains volatile hydrocarbons (0.03-0.4 micrograms per liter (µg/L)), including benzene, found in some hydraulic fracturing fluid. Modeled groundwater-age distributions, calibrated to tritium (3H), sulfur hexafluoride (SF6), and carbon-14 (14C) concentrations, indicate that water recharged prior to shale-gas development, suggesting surface releases associated with shale-gas production were not the source of those hydrocarbons, although leakage from a nearby gas well directly into the old groundwater cannot be ruled out. Estimated age distributions in the samples span ~20 to >10,000 years and have implications for relating occurrences of hydrocarbons in groundwater to surface releases associated with recent shale-gas production, and to the time required to flush contaminants from the system. This data release contains isotopic tracer, noble gas, and groundwater-age tracer concentration data collected by the U.S. Geological Survey and data for pH, specific conductance, major ions, and methane collected by Chesapeake Energy Corporation.

This dataset contains measurements of dissolved hydrocarbons in from various water sources, as well as ancillary raw calibration data showing the stability of the gas chromatograph with an atomic emission detector and flame ionization detector (GC-AED-FID) analytical system over time. Across multiple studies, samples from tap water, groundwater, surface water, springs, mine outflows, and blank materials were analyzed using this system over a period from 2014 to 2017, comprising 172 samples analyzed. In addition to water samples, 183 calibrations conducted over the same period of time are included to document the stability of the GC-AED-FID system over time. The target analytes in this study were: methane (CH4), ethane (C2H6), ethene (C2H4), ethyne (C2H2), propane (C3H8), propene (C3H6), i-butane (C4H10), n-butane (C4H10), 1-butene (C4H8), propyne (C3H4), i-pentane (C5H12), n-pentane (C5H12), 2-methyl-pentane (C6H14), 3-methyl-pentane (C6H14), hexane (C6H14), and benzene (C6H6).

This USGS Data Release includes hydrologic data compiled for selected years during the period 1990-2017 to support the development and calibration of a numerical groundwater model used to simulate groundwater flow paths at and near former and currently active military bases in Montgomery and Bucks Counties in southeastern Pennsylvania (Goode and Senior, 2020). The hydrologic data compiled for the study area include: 1) withdrawal (pumping) rates for production and other wells; 2) quarry pumping rates; 3) rates of flow discharged to streams from the National Pollution Discharge Elimination System (NPDES) sources, and 4) measured water levels in wells. The data were compiled from various sources described in the metadata for each type of data, with complete references for data sources listed in (Goode and Senior, 2020). Withdrawal (pumping) and discharge rates in the data release represent annual average rates computed as needed from data compiled from various sources. The principal time periods for compiled data include 1990's, 2010, 2013, 2016, and 2017. Some values are estimated where data were missing or not available.

This USGS Data Release includes hydrologic data compiled for selected years during the period 1990-2017 to support the development and calibration of a numerical groundwater model used to simulate groundwater flow paths at and near former and currently active military bases in Montgomery and Bucks Counties in southeastern Pennsylvania (Goode and Senior, 2020). The hydrologic data compiled for the study area include: 1) withdrawal (pumping) rates for production and other wells; 2) quarry pumping rates; 3) rates of flow discharged to streams from the National Pollution Discharge Elimination System (NPDES) sources, and 4) measured water levels in wells. The data were compiled from various sources described in the metadata for each type of data, with complete references for data sources listed in (Goode and Senior, 2020). Withdrawal (pumping) and discharge rates in the data release represent annual average rates computed as needed from data compiled from various sources. The principal time periods for compiled data include 1990's, 2010, 2013, 2016, and 2017. Some values are estimated where data were missing or not available.

This dataset contains the lithologic class and topographic position index information and quality-assurance and quality-control data not available in the online National Water Information System for 54 domestic wells sampled by the U.S. Geological Survey in Clinton County, Pennsylvania, May-September 2017. The topographic position index (TPI) for each well location was computed on the basis of a 25-meter digital elevation model (U.S. Geological Survey, 2009) using criteria reported by Llewellyn (2014) to indicate potential classes for topographic setting. The bedrock geologic unit and primary lithology were determined for each well location on the basis of the digital bedrock geologic map of Pennsylvania (Miles and Whitfield, 2001). The quality-assurance and quality-control data (such as blanks or replicates) were collected at a subset of sites to ensure that the data met specific data-quality objectives outlined for the study.

This dataset contains the lithologic class and topographic position index information and quality-assurance and quality-control data not available in the online National Water Information System for 54 domestic wells sampled by the U.S. Geological Survey in Clinton County, Pennsylvania, May-September 2017. The topographic position index (TPI) for each well location was computed on the basis of a 25-meter digital elevation model (U.S. Geological Survey, 2009) using criteria reported by Llewellyn (2014) to indicate potential classes for topographic setting. The bedrock geologic unit and primary lithology were determined for each well location on the basis of the digital bedrock geologic map of Pennsylvania (Miles and Whitfield, 2001). The quality-assurance and quality-control data (such as blanks or replicates) were collected at a subset of sites to ensure that the data met specific data-quality objectives outlined for the study.

This dataset contains the lithologic class and topographic position index information and quality-assurance and quality-control data not available in the online National Water Information System for 54 domestic wells sampled by the U.S. Geological Survey in Clinton County, Pennsylvania, May-September 2017. The topographic position index (TPI) for each well location was computed on the basis of a 25-meter digital elevation model (U.S. Geological Survey, 2009) using criteria reported by Llewellyn (2014) to indicate potential classes for topographic setting. The bedrock geologic unit and primary lithology were determined for each well location on the basis of the digital bedrock geologic map of Pennsylvania (Miles and Whitfield, 2001). The quality-assurance and quality-control data (such as blanks or replicates) were collected at a subset of sites to ensure that the data met specific data-quality objectives outlined for the study.

This dataset contains the lithologic class and topographic position index information and quality-assurance and quality-control data not available in the online National Water Information System for 72 domestic wells sampled by the U.S. Geological Survey in Bradford County, Pennsylvania, May-August 2016. The topographic position index (TPI) for each well location was computed on the basis of a 25-meter digital elevation model (U.S. Geological Survey, 2009) using criteria reported by Llewellyn (2014) to indicate potential classes for topographic setting. The bedrock geologic unit and primary lithology were determined for each well location on the basis of the digital bedrock geologic map of Pennsylvania (Miles and Whitfield, 2001). The quality-assurance and quality-control data (such as blanks or replicates) were collected at a subset of sites to ensure that the data met specific data-quality objectives outlined for the study.

This dataset contains the lithologic class and topographic position index information and quality-assurance and quality-control data not available in the online National Water Information System for 72 domestic wells sampled by the U.S. Geological Survey in Bradford County, Pennsylvania, May-August 2016. The topographic position index (TPI) for each well location was computed on the basis of a 25-meter digital elevation model (U.S. Geological Survey, 2009) using criteria reported by Llewellyn (2014) to indicate potential classes for topographic setting. The bedrock geologic unit and primary lithology were determined for each well location on the basis of the digital bedrock geologic map of Pennsylvania (Miles and Whitfield, 2001). The quality-assurance and quality-control data (such as blanks or replicates) were collected at a subset of sites to ensure that the data met specific data-quality objectives outlined for the study.

Data on 17 metrics of shale gas development in the Pennsylvania portion of the Upper Susquehanna River basin that was collated from a variety of sources and summarized at the upstream catchment scale. Data were also standardized by upstream area and transformed into rank scores based on metric distribution and then summarized into a Disturbance Intensity Index (DII). See Maloney et al. 2018 for detailed descriptions of each data sets and limitations of data. (Maloney, K. O., J. A. Young, S. P. Faulkner, A. Hailegiorgis, E. T. Slonecker, and L. E. Milheim. 2018. A detailed risk assessment of shale gas development on headwater streams in the Pennsylvania portion of the Upper Susquehanna River Basin, U.S.A. Science of The Total Environment 610:154-166. http://www.sciencedirect.com/science/article/pii/S0048969717319654)