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Water Quality and Quantity and Simulated Surface-Water and Groundwater Flow in the Laurel Hill Creek Basin, Southwestern Pennsylvania, 1991–2007

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Water Quality and Quantity and Simulated Surface-Water and Groundwater Flow in the Laurel Hill Creek Basin, Southwestern Pennsylvania, 1991–2007 Prepared in cooperation with the Somerset County Conservation District Water Quality and Quantity and Simulated Surface-Water and Groundwater Flow in the Laurel Hill Creek Basin, Southwestern Pennsylvania, 1991–2007 Scientific Investigations Report 2016–5082 U.S. Department of the Interior U.S. Geological Survey Cover: Photo of Laurel Hill Creek as it enters into Laurel Hill Lake at Laurel Hill State Park, Pennsylvania, photo taken on June 22, 2009. (Photograph provided by Daniel Galeone, U.S. Geological Survey) Water Quality and Quantity and Simulated Surface-Water and Groundwater Flow in the Laurel Hill Creek Basin, Southwestern Pennsylvania, 1991–2007 By Daniel G. Galeone, Dennis W. Risser, Lee W. Eicholtz, and Scott A. Hoffman Prepared in cooperation with the Somerset County Conservation District Scientific Investigations Report 2016–5082 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior RYAN K. ZINKE, Secretary U.S. Geological Survey William H. Werkheiser, Acting Director U.S. Geological Survey, Reston, Virginia: 2017 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment—visit http://www.usgs.gov or call 1–888–ASK–USGS. For an overview of USGS information products, including maps, imagery, and publications, visit http://store.usgs.gov. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. Suggested citation: Galeone, D.G., Risser, D.W., Eicholtz, L.W., and Hoffman, S.A., 2017, Water quality and quantity and simulated surface-water and groundwater flow in the Laurel Hill Creek Basin, southwestern Pennsylvania, 1991–2007: U.S. Geological Survey Scientific Investigations Report 2016–5082, 85 p., https://doi.org/10.3133/sir20165082. ISSN 2328-0328 (online) iii Contents Abstract ...........................................................................................................................................................1 Introduction.....................................................................................................................................................2 Purpose and Scope ..............................................................................................................................4 Study Area..............................................................................................................................................4 Climate ...........................................................................................................................................4 Geologic Setting .........................................................................................................................11 Hydrography ...............................................................................................................................11 Methods.........................................................................................................................................................13 Water Quality .......................................................................................................................................13 Surface Water ............................................................................................................................13 Groundwater ...............................................................................................................................13 Water Quantity ....................................................................................................................................16 Streamflow Characterization ...................................................................................................16 Water Use ...................................................................................................................................16 Water-Analysis Screening Tool (WAST) ................................................................................19 GSFLOW Model ...................................................................................................................................20 MODFLOW Overview.................................................................................................................20 PRMS Overview .........................................................................................................................20 Basin Delineation ..............................................................................................................22 Digital Elevation Model ....................................................................................................22 Stream Network ................................................................................................................22 Generation of Hydrologic Response Units ...................................................................22 Climate and Streamflow Data .........................................................................................22 Model Parameterization ...........................................................................................................23 GSFLOW Coupling of PRMS and MODFLOW ........................................................................23 Characterization of Water Quality and Quantity .....................................................................................24 Water Quality .......................................................................................................................................24 Chemistry of Surface Water .....................................................................................................24 Temperature of Surface Water ................................................................................................29 Chemistry of Groundwater .......................................................................................................33 Chemical Relation Between Surface Water and Groundwater .........................................34 Water Quantity ....................................................................................................................................36 Characterization of Low Streamflow ......................................................................................36 Water Use ...................................................................................................................................39 Water-Analysis Screening Tool (WAST) ................................................................................40 Simulation of Surface-Water and Groundwater Flow ...........................................................................42 Surface Runoff–PRMS Model ..........................................................................................................42 Climate Data................................................................................................................................43 Hydrologic Response Units ......................................................................................................43 PRMS Modules ..........................................................................................................................45 Climatic PRMS Modules ..................................................................................................45 Basin-Characterization PRMS Modules .......................................................................45 iv Groundwater - MODFLOW Model ....................................................................................................51 Spatial and Temporal Discretization .......................................................................................51 Boundary Conditions .................................................................................................................51 Infiltration from Precipitation ...................................................................................................53 Streams........................................................................................................................................53 Evapotranspiration ....................................................................................................................53 Wells and Drains ........................................................................................................................53 Aquifer Properties .....................................................................................................................53 MODFLOW Steady-State Calibration .....................................................................................54 GSFLOW–Linkage of PRMS and MODFLOW ..................................................................................56 GSFLOW Model Results ............................................................................................................58 Water Budget .............................................................................................................................58 Simulated Hydrograph Analysis ..............................................................................................60 GSFLOW Model Results and Water
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