In early 2008, the company agreed to a $20 million settlement with the U.S. Environmental Protection Agency (EPA) to resolve thousands of violations of the Clean Water Act for routinely polluting waterways in Kentucky and West Virginia with coal slurry and wastewater. Although this was the largest Clean Water Act settlement, the violations were estimated to have fines on the order of $2.4 billion. Over 700 miles of rivers and streams in the coalfields have been buried by the waste rock left over from mountaintop removal, a method of strip mining coal which requires the blowing up of mountain tops, removing from 500 to 800 feet (240 m) of mountaintop in the process. This method of coal mining has created some of the worst environmental disasters in the Mississippi area in regards to the poisoning of waterways, the flooding of local communities, and the destruction of the biodiversity of the Appalachian Mountains in West Virginia, Virginia, Kentucky, and Tennessee.
In October 2000, a Massey Energy subsidiary in Martin County, Kentucky accidentally released 306 million gallons of coal slurry waste from an impoundment into two mountain streams, Coldwater Creek and Wolf Creek. The Martin County sludge spill was called the worst ever environmental disaster in the southeastern United States by the EPA. The spill smothered all aquatic life in the streams and left residents with contaminated drinking water. Cleanup costs for the spill were approximately $50 million.