This file contains land cover and water chemistry data. This dataset is associated with the following publication: Smucker, N.J., A. Kuhn , M.A. Charpentier, C.J. Cruz-Quinones, C.M. Elonen , S.B. Whorley, T.M. Jicha , J.R. Serbst , B.H. Hill , J.D. Wehr, and J. Lake. Quantifying Urban Watershed Stressor Gradients and Evaluating How Different Land Cover Datasets Affect Stream Management. ENVIRONMENTAL MANAGEMENT. Springer-Verlag, New York, NY, USA, 57(3): 683-695, (2016).

Water quality data collected from multiple streams in the Chesapeake Bay watershed. This dataset is not publicly accessible because: owned by University of Maryland co-authors. It can be accessed through the following means: email senior author, Dr. Sujay Kaushal skaushal@umd.edu. Format: Excel files. This dataset is associated with the following publication: Kaushal, S., C. Maas, P. Mayer, T. Newcomer Johnson, S. Grant, M. Rippy, R.R. Shatkay, J. Leathers, A. Gold, C. Smith, E.C. McMullen, S. Haq, R. Smith, S. Duan, J. Malin, A. Yuculak, J.E. Reimer, K. Delaney Newcomb, A. Sides Raley, D.C. Collinson, J.G. Gallella, M. Grese, G. Sivirichi, T.R. Doody, P. Vikesland, S.V. Bhide, L. Krauss, M. Daugherty, C. Stavrou, M. Etheredge, J. Ziegler, A. Kirschnick, W. England, and K.T. Belt. Longitudinal stream synoptic monitoring tracks chemicals along watershed continuums: a typology of trends. Frontiers in Environmental Science. Frontiers, Lausanne, SWITZERLAND, 11: 1122485, (2023).

This data release contains groundwater-quality data for nitrate and chloride, and well information for sample sites for aquifers in the Great Lakes Basin within the United States. Water-quality data and well information were derived from a dataset compiled from the U.S. Geological Survey (USGS) National Water Information System and numerous agencies and organizations at the state, regional, and local level. The data presented in this data release are data pulled from the USGS National Water Quality Program groundwater assessment team’s internal dataset, informally referred to as the National Groundwater aggregation (NGA). Data collected in the Great Lakes Basin by the U.S. and Canada augment the NGA. Specifically, only geochemical parameters of interest (nitrate and chloride) from wells in the national groundwater aggregation are presented in this data release, while data from springs were not used.

The U.S. Geological Survey collected groundwater samples from 49 wells used for domestic and small system drinking water supplies in Amador, Placer, Sutter, and Sacramento Counties, California in 2017. The wells were sampled for the Sacramento Metropolitan (SacMetro) Shallow Aquifer Study Unit of the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project’s assessment of the quality of groundwater resources used for domestic and small system drinking water supplies. Domestic and small-system wells are commonly screened at shallower depths than public-supply wells. The SacMetro study unit consisted of three “study areas” corresponding to three California Department of Water Resources groundwater subbasins: the North American and South American subbasins of the Sacramento Valley groundwater basin, and the Cosumnes subbasin of the San Joaquin Valley groundwater basin. Wells in the SacMetro study unit were in alluvial aquifers composed of sediments derived from the Sierra Nevada Mountains east of the study unit. The study unit was divided into 56 approximately 58 square kilometer grid cells, and a domestic or small-system well was sampled in 49 of those cells. Groundwater samples from all 49 wells were analyzed for field water-quality parameters, volatile organic compounds, pesticides and pesticide degradates, nutrients, major ions and trace elements, arsenic speciation, chromium (VI), perchlorate, gross alpha and gross beta particle activities, sulfur hexafluoride, tritium, carbon-14 in dissolved inorganic carbon, noble gases, stable isotopic ratios of water and dissolved nitrate, and microbial indicators. Groundwater levels were measured in 44 of the 49 wells. All results are presented in this data release, except results for pesticide and pesticide degradates. In 2017, the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program sampled 22 monitoring wells located in the SacMetro study unit as part of ongoing NAWQA studies of groundwater quality in different land-use settings. Of the 22 wells, 21 were part of an urban land-use network and 1 was part of a rice land use network. Results for analyses of perchlorate, chromium (VI), and stable isotopic ratios are presented in this data release, and results for analyses of field water-quality parameters, volatile organic compounds, pesticide and pesticide degradates, nutrients, major ions and trace elements, dissolved organic carbon, and tritium will be presented in a data release to be published separately by NAWQA. This data release supports the following publication: Groundwater Quality in the Sacramento Metropolitan shallow aquifer, California: U.S. Geological Survey Open-File Report 2019-1047, 4p., https://doi.org/10.3133/ofr20191047.

The U.S. Geological Survey collected groundwater samples from 49 wells used for domestic and small system drinking water supplies in Amador, Placer, Sutter, and Sacramento Counties, California in 2017. The wells were sampled for the Sacramento Metropolitan (SacMetro) Shallow Aquifer Study Unit of the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project’s assessment of the quality of groundwater resources used for domestic and small system drinking water supplies. Domestic and small-system wells are commonly screened at shallower depths than public-supply wells. The SacMetro study unit consisted of three “study areas” corresponding to three California Department of Water Resources groundwater subbasins: the North American and South American subbasins of the Sacramento Valley groundwater basin, and the Cosumnes subbasin of the San Joaquin Valley groundwater basin. Wells in the SacMetro study unit were in alluvial aquifers composed of sediments derived from the Sierra Nevada Mountains east of the study unit. The study unit was divided into 56 approximately 58 square kilometer grid cells, and a domestic or small-system well was sampled in 49 of those cells. Groundwater samples from all 49 wells were analyzed for field water-quality parameters, volatile organic compounds, pesticides and pesticide degradates, nutrients, major ions and trace elements, arsenic speciation, chromium (VI), perchlorate, gross alpha and gross beta particle activities, sulfur hexafluoride, tritium, carbon-14 in dissolved inorganic carbon, noble gases, stable isotopic ratios of water and dissolved nitrate, and microbial indicators. Groundwater levels were measured in 44 of the 49 wells. All results are presented in this data release, except results for pesticide and pesticide degradates. In 2017, the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program sampled 22 monitoring wells located in the SacMetro study unit as part of ongoing NAWQA studies of groundwater quality in different land-use settings. Of the 22 wells, 21 were part of an urban land-use network and 1 was part of a rice land use network. Results for analyses of perchlorate, chromium (VI), and stable isotopic ratios are presented in this data release, and results for analyses of field water-quality parameters, volatile organic compounds, pesticide and pesticide degradates, nutrients, major ions and trace elements, dissolved organic carbon, and tritium will be presented in a data release to be published separately by NAWQA. This data release supports the following publication: Groundwater Quality in the Sacramento Metropolitan shallow aquifer, California: U.S. Geological Survey Open-File Report 2019-1047, 4p., https://doi.org/10.3133/ofr20191047.

This data release contains site information and potential explanatory factor data for 1,899 groundwater sites. These sites were used to assess groundwater quality in aquifers used for domestic and public drinking water supply in the southeastern San Joaquin Valley. The southeastern San Joaquin Valley (SESJV) study unit consists of five study areas whose boundaries are defined by the eponymous California Department of Water Resources groundwater subbasins of the San Joaquin Valley groundwater basin: Madera-Chowchilla, Kings, Kaweah, Tule, and Tulare Lake. The sites consist of 198 wells representing the domestic-supply aquifer and 1,701 wells representing the public-supply aquifer. The domestic-supply aquifer wells were sampled in 2013-2015 by the USGS for either the California Groundwater Ambient Monitoring and Assessment Program Priority Basin Project (GAMA-PBP) or the USGS National Water Quality Assessment project (NAWQA). The public-supply aquifer wells were either sampled by the USGS for the GAMA-PBP in 2005-2018 or have water-quality data in the California State Water Resources Control Board Division of Drinking Water (SWRCB-DDW) public database. The data types in this data release include site identification and location, well construction and lithology data, land use characteristics, groundwater age and oxidation-reduction classifications and aridity indices. Not all sites have data for all fields. Water-quality data for the sites are available from U.S. Geological Survey (2023), and California State Water Resources Control Board Division of Drinking Water (2023). The study design and the assessment results are presented in Burow and others (2024).

This data release contains site information and potential explanatory factor data for 1,899 groundwater sites. These sites were used to assess groundwater quality in aquifers used for domestic and public drinking water supply in the southeastern San Joaquin Valley. The southeastern San Joaquin Valley (SESJV) study unit consists of five study areas whose boundaries are defined by the eponymous California Department of Water Resources groundwater subbasins of the San Joaquin Valley groundwater basin: Madera-Chowchilla, Kings, Kaweah, Tule, and Tulare Lake. The sites consist of 198 wells representing the domestic-supply aquifer and 1,701 wells representing the public-supply aquifer. The domestic-supply aquifer wells were sampled in 2013-2015 by the USGS for either the California Groundwater Ambient Monitoring and Assessment Program Priority Basin Project (GAMA-PBP) or the USGS National Water Quality Assessment project (NAWQA). The public-supply aquifer wells were either sampled by the USGS for the GAMA-PBP in 2005-2018 or have water-quality data in the California State Water Resources Control Board Division of Drinking Water (SWRCB-DDW) public database. The data types in this data release include site identification and location, well construction and lithology data, land use characteristics, groundwater age and oxidation-reduction classifications and aridity indices. Not all sites have data for all fields. Water-quality data for the sites are available from U.S. Geological Survey (2023), and California State Water Resources Control Board Division of Drinking Water (2023). The study design and the assessment results are presented in Burow and others (2024).

The U.S. Geological Survey collected groundwater samples from 71 wells used for domestic and small system drinking water supplies in Stanislaus and Merced counties of California during 2020-2021. The wells were sampled for the Modesto-Turlock-Merced Domestic-Supply Aquifer Study Unit of the State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project’s assessment of the quality of groundwater resources used for domestic and small system drinking water supplies. The study unit was defined by the extent of the Modesto, Turlock, and Merced subbasins of the San Joaquin Valley groundwater basin. The study unit was divided into 62 grid cells and one or more domestic or small system well was sampled in 60 of the cells. Groundwater samples from a total of 71 sampled wells were analyzed for field water-quality parameters, volatile organic compounds, pesticides and pesticide degradants, stable isotopes of water, nutrients, major ions and trace elements, hexavalent chromium, perchlorate, per- and polyfluoroalkyl substances (PFAS), and microbial indicators. Groundwater levels were measured in 56 out 71 wells.

The U.S. Geological Survey collected groundwater samples from 71 wells used for domestic and small system drinking water supplies in Stanislaus and Merced counties of California during 2020-2021. The wells were sampled for the Modesto-Turlock-Merced Domestic-Supply Aquifer Study Unit of the State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project’s assessment of the quality of groundwater resources used for domestic and small system drinking water supplies. The study unit was defined by the extent of the Modesto, Turlock, and Merced subbasins of the San Joaquin Valley groundwater basin. The study unit was divided into 62 grid cells and one or more domestic or small system well was sampled in 60 of the cells. Groundwater samples from a total of 71 sampled wells were analyzed for field water-quality parameters, volatile organic compounds, pesticides and pesticide degradants, stable isotopes of water, nutrients, major ions and trace elements, hexavalent chromium, perchlorate, per- and polyfluoroalkyl substances (PFAS), and microbial indicators. Groundwater levels were measured in 56 out 71 wells.

Water quality data. This dataset is associated with the following publication: Papenfus, M., B. Schaeffer, A. Pollard, and K. Loftin. Exploring the potential value of satellite remote sensing to monitor chorophyll-a for U.S. lakes and reservoirs.. ENVIRONMENTAL MONITORING AND ASSESSMENT. Springer, New York, NY, USA, 192: 808, (2020).