Environmental Opportunities Related to Underground and Surface Coal Mines in Southwest Indiana Terry R. West and Richard Fisher Earth & Atmospheric Sciences Dept. Purdue University

An extensive area of southwest Indiana, Pennsylvanian in age, contains prominent coal seams mined for 100 years or more. Significant surface strip mines and underground works occur in 17 Indiana counties yielding 186,000 acres underground and 284,000 at the surface. Prior to the SMCRA Act of 1977 strip mine reclamation was lacking, yielding elongated lakes in final cut areas.

Where underground water-filled mines occur in conjunction with surface mine lakes, an opportunity exists to exchange water volumes. This exchange of water volumes may lead to environmental opportunities such as Energy storage and heat exchange. Along with the economic environmental aspects there remains the possibility for other benefits in areas such as recreation to come from abandoned mine land.

Some of these advantages have already been pursued bringing about new ideas for use of reclaimed land. Engineering problems may ensue including underground collapse, surface subsidence and water quality aspects. These problems can become a major factor in more densely populated areas of the region. These concerns are addressed in this discussion.

Stratigraphic column of bedrock in Greene and Sullivan Counties

Schematic of area strip mining

Surface and subsurface coal mines in Indiana.

Surface coal mines in Indiana.

Underground coal mines in Indiana.

Subsidence areas due to mining in Indiana.

Summary 17 of 92 Indiana counties contain coal mines 186,000 acres underground, 284,000 at surface. Unreclaimed strip mines commonly have lakes in the final cut. Both surface and underground water bodies occur in some locations. Energy storage, heat exchange and recreation yield environmental opportunities. Engr. geology concerns: underground collapse, surface subsidence, water quality and location. Densely populated areas have greatest benefits and concerns.