Coal mining in the Appalachian Mountains, particularly mountaintop removal, has caused severe water contamination due to acid mine drainage and the release of heavy metals.

Water contamination is a significant environmental challenge in the Appalachian Mountains caused by coal mining activities. Acid mine drainage, a byproduct of mining, occurs when sulfide minerals in exposed rock react with air and water, producing sulfuric acid. This acid, along with heavy metals such as arsenic, selenium, and lead, leaches into nearby streams and groundwater. These pollutants degrade water quality, harm aquatic ecosystems, and pose health risks to communities. Efforts to mitigate this include stricter environmental regulations and reclamation projects, but challenges remain due to the scale and legacy of mining operations.