Thickness of Coarse-Grained Sediment within the Glacial Deposits

The glacial aquifer system of the United States encompasses all or parts of 25 states and is the most widely used supply of drinking water in the Nation (Maupin and Barber, 2005; Maupin and Arnold, 2010). A series of seven raster data sets were derived from a database of water-well drillers' records that was compiled in partial fulfillment of the goals of the U.S. Geological Survey’s Groundwater Availability and Use assessment program (U.S. Geological Survey, 2002). They contain hydrogeologic information for areas of the U.S. that are north of the southern limit of Pleistocene glaciation, including the total thickness of glacial deposits, thickness of coarse-grained sediment within the glacial deposits, specific-capacity based horizontal hydraulic conductivity and transmissivity of coarse-grained sediment within the glacial deposits, texture-based estimated equivalent horizontal and vertical hydraulic conductivity of the glacial deposits, and texture-based estimated equivalent transmissivity of the glacial deposits. The raster data sets are available for download in both American Standard Code for Information Interchange (ASCII) and Environmental Systems Research Institute (ESRI) Grid formats. These data have value for regional studies of water availability and aquifer vulnerability.