Challenges of Coal-Mine Reclamation in Indiana

Abstract

Since the nineteenth century, more than 2.2 billion metric tons (2.4 billion short tons) of coal have been extracted from underground and surface mines of Indiana, directly affecting approximately 2,000 square kilometers (770 square miles) of southwestern Indiana. In addition, coal-preparation facilities have produced deposits of pyritic refuse materials that extend across more than 2,400 hectares (6,000 acres). Some of the environmental effects of these very large-scale activities—particularly those conducted before passage of the Surface Mining Control and Reclamation Act of 1977—include land subsidence, erosion, stream siltation, acidic mine drainage, and groundwater contamination. A great variety of field-scale engineering, chemical, biological, and ecological techniques have been developed and implemented over a period of decades to address these problems, and research is ongoing. The potential also exists for development of geothermal resources related to groundwater in flooded underground mines, representing a high-yield aquifer that contains as much as 640 billion liters (170 billion gallons) of water.