Massey Energy Company Inc. has agreed to pay a $20 million civil penalty in a corporate-wide settlement to resolve Clean Water Act violations at coal mines in West Virginia and Kentucky, the Justice Department and U.S. Environmental Protection Agency announced earlier this month.

This is the largest civil penalty in EPA’s history levied against a company for wastewater discharge permit violations.

“The measures required by this settlement represent a significant step forward in the way that mining facilities currently address Clean Water Act compliance,” said Ronald J. Tenpas, Assistant Attorney General in charge of the Justice Department’s Environmental and Natural Resources Division. “This settlement will greatly benefit citizens in West Virginia and Kentucky and improve many of our nation’s waters for years to come.”

As part of the settlement, Massey, the fourth largest coal company in the United States, has agreed to take measures at all of its facilities that will prevent an estimated 380 million pounds of sediment and other pollutants from entering the nation’s waters each year. These compliance measures are unprecedented in the coal mining industry, according to the EPA.

In a complaint filed last May, the government alleged that Massey violated its Clean Water Act permits more than 4,500 times between January 2000 and December 2006. The complaint alleged that the company discharged excess amounts of metals, sediment, and acid mine drainage into hundreds of rivers and streams in West Virginia and Kentucky. Many of the pollutants were discharged in amounts 40 percent or more than allowed. Some pollutants were discharged at levels more than 10 times over the permit limits.

The complaint also alleged that Massey spilled large amounts of slurry, which is waste-containing metals and sediment, into local waterways numerous times. The spills occurred as a result of failures in the processing, storage and transportation of coal slurry.

In addition to the penalty, Massey will invest approximately $10 million to develop and implement a set of procedures to prevent future violations. Massey, the largest coal producer in Central Appalachia, will also set aside 200 acres of riverfront land in West Virginia for conservation purposes and protection from future mining.