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

Abstract

Since the late 1960s, the Illinois State Geological Survey has been develo** three-dimensional (3-D) geologic map** methods specifically for the protection of groundwater and for hel** 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 develo** 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 map** 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 map** 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.