20260622 09420500 1.0 FALSE Keefer1997_Geologic_Sensitivity_Legacy 2718241.210480 3852470.636242 4047024.902734 6066897.271445 1 002 Projected GCS_North_American_1983 Linear Unit: Foot_US (0.304801) Illinois State Transverse_Mercator <ProjectedCoordinateSystem xsi:type='typens:ProjectedCoordinateSystem' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xmlns:xs='http://www.w3.org/2001/XMLSchema' xmlns:typens='http://www.esri.com/schemas/ArcGIS/3.7.0'><WKT>PROJCS[&quot;Illinois State Transverse_Mercator&quot;,GEOGCS[&quot;GCS_North_American_1983&quot;,DATUM[&quot;D_North_American_1983&quot;,SPHEROID[&quot;GRS_1980&quot;,6378137.0,298.257222101]],PRIMEM[&quot;Greenwich&quot;,0.0],UNIT[&quot;Degree&quot;,0.0174532925199433]],PROJECTION[&quot;Transverse_Mercator&quot;],PARAMETER[&quot;False_Easting&quot;,3280833.3333333],PARAMETER[&quot;False_Northing&quot;,3937000.0],PARAMETER[&quot;Central_Meridian&quot;,-89.5],PARAMETER[&quot;Scale_Factor&quot;,0.9998529411767059],PARAMETER[&quot;Latitude_Of_Origin&quot;,36.66666666666666],UNIT[&quot;Foot_US&quot;,0.3048006096012192]]</WKT><XOrigin>-15165000</XOrigin><YOrigin>-42190000</YOrigin><XYScale>3048.0060960121928</XYScale><ZOrigin>-100000</ZOrigin><ZScale>10000</ZScale><MOrigin>-100000</MOrigin><MScale>10000</MScale><XYTolerance>0.0032808333333333331</XYTolerance><ZTolerance>0.001</ZTolerance><MTolerance>0.001</MTolerance><HighPrecision>true</HighPrecision></ProjectedCoordinateSystem> 20260730 11415300 20260730 11415300 FGDC 500000 250000 Illinois State Geological Survey 20260730 ArcGIS Metadata 1.0 Illinois Groundwater Sensitivity Map 1997 Illinois State Water Survey Illinois State Geological Survey Illinois State Water Survey and Illinois State Geological Survey Champaign, Illinois vector digital data Illinois Nature Preserves groundwater vulnerability assessment GIS data Groundwater Sensitivity Vulnerability of Illinois Nature Preserves to Potential Ground-Water Contamination, Volume I: Methodology and Initial Assessment This polygon feature layer represents a statewide screening map of shallow groundwater sensitivity to contamination in Illinois. The map predicts the potential for movement of contaminants from the land surface into shallow groundwater using intrinsic soil and geologic characteristics, including soil leaching or water-flux characteristics and the depth to the uppermost aquifer. The layer was prepared for the Illinois Nature Preserves vulnerability assessment described by Locke et al. (1997), which used the sensitivity map to screen Illinois nature preserves and surrounding areas for potential groundwater contamination concerns. This dataset provides a statewide screening tool for groundwater protection, environmental assessment, natural resource planning, and prioritization of locations where more detailed site-specific hydrogeologic review may be warranted. It is intended for regional analysis and screening, not as a substitute for detailed site investigations. Copyright (C) 1997, 2026 The Board of Trustees of the University of Illinois Illinois State Geological Survey 217-333-4747 615 East Peabody Drive Champaign Illinois 61820 US isgs@illinois.edu 8:00 a.m. - 4:30 p.m., Monday-Friday, U.S. Central Time Illinois United States groundwater ground water groundwater sensitivity groundwater vulnerability aquifer sensitivity aquifer hydrogeology contamination soil leaching Illinois Nature Preserves groundwater ground water groundwater sensitivity groundwater vulnerability aquifer sensitivity aquifer hydrogeology contamination soil leaching Illinois Nature Preserves Illinois United States These data are appropriate for statewide and regional screening and prioritization. They are not appropriate as a geodetic, legal, engineering, or site-specific hydrogeologic base and are not intended as a substitute for surveyed locations or detailed site-specific studies. The source maps used in the sensitivity model were published at a scale of 1:250,000, and Locke et al. (1997) identified the sensitivity map as a 1:500,000 screening product. Evaluations requiring highly accurate local predictions should incorporate site-specific soils, geologic, hydrologic, and water-quality information. ISGS information must be obtained directly from the ISGS or from an authorized distributor. Be aware that ISGS information obtained from an unauthorized third party may have been altered subsequent to original distribution, or may no longer be current. Vulnerability of Illinois Nature Preserves to Potential Ground-Water Contamination, Volume I: Methodology and Initial Assessment 1997 Locke, Randall A., II Berg, Richard C. Wehrmann, H. Allen Miller, Michael V. Keefer, Donald A. Illinois State Water Survey Champaign, Illinois report Illinois State Water Survey Contract Report 612 Final report prepared for the Illinois Nature Preserves Commission, March 1997. Vulnerability of Illinois Nature Preserves to Potential Ground-Water Contamination, Volume I: Methodology and Initial Assessment 1997 Locke, Randall A., II Berg, Richard C. Wehrmann, H. Allen Miller, Michael V. Keefer, Donald A. Illinois State Water Survey Champaign, Illinois report Illinois State Water Survey Contract Report 612 Potential for Agricultural Chemical Contamination of Aquifers in Illinois: 1995 Revision 1995 Keefer, Donald A. Illinois State Geological Survey Champaign, Illinois report and map plates Illinois State Geological Survey Environmental Geology 148 Esri ArcGIS 13.7.0.1901 true -91.586260 -87.380220 42.514701 36.952784 publication date of source report 1997 The groundwater sensitivity model was developed for regional predictions using readily available statewide soils and geologic data. The model defines broad categories of shallow groundwater sensitivity based only on intrinsic material properties; potential contaminant sources and water quality data were not incorporated. The 1997 report cautions that highly accurate predictions for specific locations should also use site-specific soils and geologic information. During preparation for the ISGS/PRI Geospatial Data Clearinghouse, Robert Paul removed extraneous join FID fields and added the GWS_Text field. No changes were made to geometries, projection, or groundwater sensitivity values. 1 -91.586260 -87.380220 42.514701 36.952784 The use constraints as stated for the data apply also to the metadata. Refer to the Use Constraints section of the Identification Information section. The access constraints as stated for the data apply also to the metadata. Refer to the Access Constraints section of the Identification Information section. Attribute values represent the groundwater sensitivity classes assigned by the GIS model described by Locke et al. (1997). The current preparation for Clearinghouse publication did not alter the original sensitivity codes or mapped geometries. The layer contains polygon features classified by groundwater sensitivity code. No attribute values outside the documented GWS domain are expected. The GWS_Text field was added as a plain-language description of the existing GWS code values. The dataset represents the statewide shallow groundwater sensitivity screening map used in the 1997 Illinois Nature Preserves vulnerability assessment. The source model defined four broad intrinsic sensitivity categories, with additional categories used in the GIS layer for surface water and disturbed land. Horizontal positional accuracy reflects the statewide source datasets and GIS processing used to create the sensitivity map. The model used statewide soils and geologic maps at 1:250,000 scale and the resulting screening map was presented at 1:500,000 scale. The data should not be used where surveyed, engineering, legal, or detailed site-specific positional accuracy is required. Soil characteristics from the statewide STATSGO soil association map and database were interpreted using travel time and drainage class indices adapted from Keefer (1995) to define water-flux categories. 1997 Statewide geologic materials from the ISGS stack-unit map were interpreted to identify aquifer materials, including sand and gravel, fractured limestone and dolomite, and sandstone, and to distinguish aquifers within 20 feet, aquifers between 20 and 50 feet, and areas without mapped aquifers within 50 feet of land surface. 1997 The STATSGO-derived soil information and statewide geologic map were combined in ARC/INFO using the categorical model described by Locke et al. (1997) to define broad categories of shallow groundwater sensitivity to contamination. 1997 Legacy dataset prepared for the ISGS/PRI Geospatial Data Clearinghouse by Robert Paul. Extraneous join FID fields were removed and the GWS_Text attribute was added. No geometry, projection, or classification values were modified. 2026 Soil association and soil property information used to derive soil water-flux and leaching characteristics. 250000 State Soil Geographic (STATSGO) database and soil association map for Illinois STATSGO 1991 United States Department of Agriculture, Soil Conservation Service digital map and database publication date 1991 Statewide geologic materials information used to identify aquifer materials and depth to the uppermost aquifer within 50 feet of land surface. 250000 Stack-Unit Mapping of Geologic Materials in Illinois to a Depth of 15 Meters STACKUNIT 1988 Berg, Richard C. Kempton, John P. Illinois State Geological Survey Champaign, Illinois map publication date 1988 Methodology for interpreting soil travel time, drainage class, depth to aquifer, and aquifer sensitivity to contamination. 250000 Potential for Agricultural Chemical Contamination of Aquifers in Illinois: 1995 Revision KEEFER1995 1995 Keefer, Donald A. Illinois State Geological Survey Champaign, Illinois report and map plates Illinois State Geological Survey Environmental Geology 148 publication date 1995 Published description of the shallow groundwater sensitivity model and its use for statewide screening of Illinois nature preserves. 500000 Vulnerability of Illinois Nature Preserves to Potential Ground-Water Contamination, Volume I: Methodology and Initial Assessment LOCKE1997 1997 Locke, Randall A., II Berg, Richard C. Wehrmann, H. Allen Miller, Michael V. Keefer, Donald A. Illinois State Water Survey Champaign, Illinois report Illinois State Water Survey Contract Report 612 publication date 1997 5011 Illinois Groundwater Sensitivity Map Polygon features representing statewide shallow groundwater sensitivity classes. Illinois State Water Survey and Illinois State Geological Survey Feature Class 5011 OBJECTID Unique ESRI object identifier. ESRI Sequential unique whole numbers that are automatically generated. FID OID 4 0 0 Shape Feature geometry. ESRI Coordinates defining polygon features. Shape Geometry 0 0 0 GWS Groundwater sensitivity code. Illinois State Water Survey and Illinois State Geological Survey 0 Surface Water Locke et al. (1997) groundwater sensitivity classification. 1 A-Very High Locke et al. (1997) groundwater sensitivity classification. 2 B-High Locke et al. (1997) groundwater sensitivity classification. 3 C-Moderate Locke et al. (1997) groundwater sensitivity classification. 4 D-Limited Locke et al. (1997) groundwater sensitivity classification. 8 Disturbed Land Locke et al. (1997) groundwater sensitivity classification. 9 Surface Water Locke et al. (1997) groundwater sensitivity classification. GWS Integer 4 0 0 GWS_Text Plain-language groundwater sensitivity class description corresponding to the GWS code. Dataset documentation prepared for Clearinghouse publication. Text description of the groundwater sensitivity class. GWS_Text String 512 0 0 Shape_Length Polygon perimeter in US Survey Feet. ESRI Positive real numbers. Shape_Length Double 8 0 0 Shape_Area Polygon area in square US Survey Feet. ESRI Positive real numbers. Shape_Area Double 8 0 0 Attribute items are in typical ESRI polygon feature class format. The GWS attribute stores the groundwater sensitivity class code. The GWS_Text attribute provides the corresponding text label. Documented GWS classes are 1, A-Very High; 2, B-High; 3, C-Moderate; 4, D-Limited; 8, Disturbed Land; and 0 or 9, Surface Water. Locke et al. (1997), Vulnerability of Illinois Nature Preserves to Potential Ground-Water Contamination, Volume I: Methodology and Initial Assessment. File Geodatabase Feature Class dataset Simple FALSE 5011 TRUE FALSE