Societal and Economic Benefits of Three-Dimensional Geological Mapping for Environmental Protection at Multiple Scales: An Overview Perspective from Illinois, USA

Abstract

Since the late 1960s, the Illinois State Geological Survey has been developing three-dimensional (3-D) geologic mapping methods specifically for the protection of groundwater and for helping decision makers and the public assess the environment of the State. When the geologic framework is well understood, land-use planning can be more effective in preventing contaminants from entering aquifers. Approaches and procedures for creating issue-driven geologic maps for groundwater protection have been developed for scales from 1:24 000 to 1:500 000. Because the procedures for developing 3-D geological information have been consistent, the resulting maps are relatively uniform. Issue-driven maps for aquifer sensitivity derived from interpretations of the 3-D successions of geologic materials provide guidance to regulators seeking to ensure maximum protection for groundwater where aquifers are especially vulnerable, and avoid overprotection where natural safeguards exist.

Scientifically defensible benefit:cost studies in Illinois and Kentucky document the economic importance of having geologic information available to a wide variety of users over extended periods of time. The economic studies showed that for every State government dollar spent on geologically mapping 21 1:24 000-scale quadrangles in Winnebago and Boone Counties, Illinois returned as much as $55 in potential reduced costs for environmental cleanup. The comprehensive 20-year geologic mapping program that produced 707 1:24 000-scale quadrangles for the State of Kentucky yielded between $25 and $39 in returns for every State and Federal dollar spent.