Chevron Mining has made settlements with the US Department of Justice, the US Environmental Protection Agency (EPA) and the state of New Mexico to pay $143m to clean up the Chevron Questa Mine Superfund site.
The company said it will perform a pilot project to cover approxmately 275 acres of the tailing facility where mine waste or tailings are stored, install groundwater extraction systems and operate a water treatment plant.
More than $5.2m will also be paid to reimburse the EPA’s past costs for overseeing the site clean-up.
The US Department of Justice Environment and Natural Resources Division assistant attorney general John Cruden said: “This settlement will advance substantial cleanup work at the Questa site, and require actions to prevent future contamination of the Red River.
“This settlement is the product of excellent cooperation between the state and federal governments and CMI to continue the vital cleanup work at the Chevron Questa mine site.”
US Attorney of the District of New Mexico Damon Martinez said: “This settlement builds on the consent decree entered in September of last year and represents another affirmative step towards remedying the serious environmental damages suffered by this beautiful area of New Mexico as a result of decades of extensive mining activities.
“In addition to requiring crucial cleanup work, the settlement includes important measures to prevent further contamination of the environment and provides for extensive monitoring to ensure compliance.”
The 2015 decree was entered into by the US on behalf of the US Fish and Wildlife Service of the Department of the Interior and the Forest Service of the Department of Agriculture, and New Mexico on behalf of the New Mexico State Office of Natural Resource Trustee.
Under that decree, CMI paid more than $4.2m to restore, replace or acquire natural resources damaged by mine activities.
The latest programme will cover and revegetate roughly 275 acres of the tailings facility, improving and installing new systems that prevent contaminated water from reaching the Red River.
Previously known as the Molycorp Mine, the Chevron Questa Mine operated from 1919 and was closed permanently in 2014.
While the mine was operating, approximately 328 million tonnes of acid-generating waste rock were excavated and deposited in nine large waste rock piles.