Wikipedia
Chemetco was formerly one of the largest United States refiners of copper from recycled or residual sources.
Its maximum output of 120,000 tons per year was approximately half of the entire U.S. copper output from so-called "secondary copper refining." The company website described Chemetco as one of the world's largest copper refiners and reported an estimated revenue in 1999 of $500 m. It was listed in 2000 as the 23rd-largest privately held company in the United States.
The company had a history of environmental problems over its entire career, along with problems managing its wastes and by-products. Eventually, it was convicted of water pollution offences spanning a decade, which contravened US federal law. The company's former site is now a Superfund site on the National Priorities List.