Arizona-based copper miner Asarco has paid a record $1.8 billion to the US government for the environmental clean-up and restoration at 80 contaminated mines in 19 states.
The settlement is part of a bankruptcy re-organization which will let Mexico's leading mining firm Grupo Mexico to take back control of Asarco.
Asarco was founded in 1899 as American Smelting and Refining Company. It filed for bankruptcy protection in 2005 after facing environmental claims totaling over $1 billion.
Commenting on the issue, Mathy V. Stanislaus from Environmental Protection Agency said, "The real winner today is the environment."
The affected sites were in Arizona, Arkansas, Alabama, California, Colorado, Idaho, Illinois, Indiana, Kansas, New Mexico, Ohio, Oklahoma, Texas, Missouri, Montana, Nebraska, New Jersey, Washington and Washington.