Discuss the major environmental impacts of mining operations.

Because mineral resources are solids which are part of the Earth's crust, extracting them can involve serious ecological disruptions, landscape alteration, and sometimes large-scale pollution of water and air. Mountaintop removal is a technique of coal extraction in which more than 100 vertical meters of a mountaintop are blasted and removed to expose deposits. This causes debris to rain down the hillsides, clogging, and polluting stream sources and thus water supplies, destroying wildlife habitats of and causing the loss of biodiversity. In the case of mining in Appalachia, physical destruction of homes buildings also occurs. Smelting of iron and other ores may produce large of amounts of sulfur oxides which cause acid precipitation and ecosystem destruction. In mining operations that require extraction and washing techniques using water, streams, and groundwater are likely to be contaminated by sulfates (acidification) and soluble toxic metal ions such as selenium, aluminum, manganese, cadmium, and nickel. In addition, other chemicals used in the extraction process may be present in mine tailings and cause further water pollution. The operations of strip mining and open-pit mining remove extensive areas of native vegetation, damage fertile soils, and increase rates of erosion. They also can cause acid-drainage, when sulfide ores are exposed to and oxidized by atmospheric oxygen. The sulfates thus formed are mixed with rainwater and cause the same sorts of damage to soils and plants found in acid deposition from coal-fired industries and electrical generating plants.