Description: In June 1992, the USGS and USEPA made a synoptic survey of water table elevations across the southern Lake Michigan coast. Groundwater levels were measured in wells and at surface-water stations. The water table data was reported in Appendix I of Kay et al. (1996). This shapefile dataset was constructed by projecting the locations in latitude and longitude from Appendix I in ArcMap, then reprojecting those points to Albers Equal-Area Conic Projection, Standard parallels 41 degrees 30' and 41 degrees 50', central meridian -87 degrees 22' 30.Vector data, including confident and inferred water table elevation (altitude) contours, well point data, surface water lines, cartographic lines, and cartographic labels were optically extracted from a PDF of plate 1 from Kay et al. (1996). The original map base was USGS topographic quadrangle data, Albers Equal-Area Conic Projection, standard parallels 41 deg 30 min N and 41 deg 50 min N, central meridian -87 deg 22 min 30 s. The raw dataset was scrubbed of elevation labels and boundary grid markers. The geospatial location was assigned to the polyline file by constructing a fishnet grid to match the gridlines in Plate 1. The fishnet was constructed using the fishnet tool, with meridians every 5 min. The Spatial Adjustment tool was used to match the gridlines from Kay et al. (1996) with the constructed fishnet. The fishnet allowed conversion from DMS to DD by spatially rectifying the image. The elevation contours were attributed with their elevations and confident or inferred status.Included lines are gridlines, predicted and inferred contour lines, and surface water lines.Linetype: elevation, water elevation contoursElevation: Given as feet above sea level for the elevation Linetype. Elevation of "0" means elevation was not given.Carto_Symb: continuous, denotes elevation contour lines with higher degree of confidence (Kay et al. 1996); inferred, denotes elevation contour lines with lower degree of confidence (Kay et al. 1996).Depression: true, depression in water table altitude; False, elevation lines do not form a depression.Note that the interpreted water table surface represents a short period in time and likely changes seasonally and episodically.The original map projection was USA_Contiguous_Albers_Equal_Area_Conic_USGS_version2, reported on Plate I:Authority: CustomProjection: AlbersFalse_Easting: 0.0False_Northing: 0.0Central_Meridian: -87.375Standard_Parallel_1: 41.5Standard_Parallel_2: 41.8333Latitude_Of_Origin: 23.0Linear Unit: Meter (1.0)Geographic Coordinate System: GCS_North_American_1983Angular Unit: Degree (0.0174532925199433)Prime Meridian: Greenwich (0.0)Datum: D_North_American_1983Spheroid: GRS_1980Semimajor Axis: 6378137.0Semiminor Axis: 6356752.314140356Inverse Flattening: 298.257222101Original map taken from:R.T. Kay, R.F. Duwelius, T.A. Brown, F.A. Micke, and C.A. Witt-Smith, 1996, Geohydrology, Water Levels and Directions of Flow, and Occurrence of Light-Nonaqueous-Phase Liquids on Ground Water in Northwestern Indiana and the Lake Calumet Area of Northeastern Illinois: U.S. Geological Survey Tech. No. 95-4253, De Kalb, IL.