Environmental Concerns
Serious environmental problems have been caused by strip-mining.  Mountains are torn down and the topography of a region is seriously changed. In addition, when an area is stripped, soil is exposed to erosion.  Erosion occurs when exposed rocks bury fertile soil.  Rainwater runs down the bare slopes carrying mud and sticks from the rocks. As a result, streams may come polluted with acids and mud.  Such problems can be reduced by returning as much topsoil as possible and replanting the area.
Reclamation of strip mine sites is required by federal law. The United Stated Department of Interior, the United State Environmental Protection Agency and state agencies are responsible for regulation of the environmental aspects of coal mining. All new strip-mined land must be returned as nearly as possible to its original condition. However, opponents to strip mining argue that is it impossible to put back a mountain once it is torn down.
Underground mines also create environmental hazards. Longwall mining, a method in which machines take the coal from underground and allow the mine to collapse as the machine retreats, often results in widespread land subsidence.   Both underground and strip mining also have the problem of mine waste, or slag. These slag piles can cause acid drainage that seeps into water supplies.

Air pollution can be a problem when coal is burned unless control devices such as filters are used on smokestacks. Federal pollution standards prohibit the burning of medium or high sulfur coals without some means of controlling sulfur dioxide pollution. Some of the sulfur dioxide is removed by cleaning the coal, but filters are still required.

Air pollution can be a problem when coal is burned unless control devices such as filters are used on smokestacks. Federal pollution standards prohibit the burning of medium or high sulfur coals without some means of controlling sulfur dioxide pollution. Some of the sulfur dioxide is removed by cleaning the coal, but filters are still required.

Specially designed preparation plants are used by mining companies to clean coal.  The chief impurities in coal are ash and sulfur. The entire process consists of sorting, washing and drying. Scrubbers can also be used to control sulfur dioxide by absorbing fumes as they pass through a plant’s smokestack. These scrubbers are being tested by power plants, but are not fully effective or economical. Several coal conversion processes are in the experimental stages but are too costly for commercial use.