Are There Environmental Costs?
(Indiana Geological Survey)
The environmental costs associated with coal mining is primarily acid mine drainage. Coal, and the mineral pyrite which is associated with coal deposits, contain high sulfur content. When this is dug up and brought the surface, the atmosphere and water leach out the sulfur, producing sulfuric acid which acidifies surface waters. Additionally, other heavy metals present in coal can leach out into water supplies.
Strip mining also destroys a significant amount of ecosystems as the landscape is torn apart. Streams can be destroyed or removed, any vegetation is removed, and the topography is permanently changed, removing any hills or valleys. However, federal and state laws mandate that strip mines "reclaim" the land by removing any materials that can contribute to acid mine drainage, to restore the topography, and finally to plant grass and trees. After 30 years, a reclaimed area can change via succession back to its original or modified ecosystem.
However, many mines (surface and underground) were abandoned prior to environmental laws. Waste coal debris at these abandoned sites exacerbates acid mine drainage problems.
Coal has many other additional environmental concerns when it is burned for energy. Indiana coals are known as high sulfur coals, because they contain significant trace amounts of sulfur. This sulfur is released into the atmosphere when the coal is burned. This sulfur pollution causes medical problems to those who breathe it in and is said to blame for the increase in acid rain in the northeastern US. Many power companies now mix Indiana/Appalachian high sulfur coals with low sulfur coals from the Powder River Basin in eastern Wyoming to reduce their sulfur dioxide emissions.
Another big concern with the burning of coal is the release of carbon dioxide to the atmosphere. Carbon dioxide is a strong greenhouse gas and contributes to the human-induced warming of the atmosphere seen over the past 100 years. We will learn more about this topic in our "Energy", "Climate Change" and "Air Pollution" modules.