Butte (Berkeley Pit and Silver Bow Creek)

The list of contaminated sites that are national priorities for federal clean-up under CERCLA (Superfund, 1980), kept by EPA (40 CFR Part 300, Appendix B). Listing makes a site eligible for long-term remedial action paid by the Superfund; sites are proposed and then listed through Federal Register notices, and deleted when no further response is needed.

Includes federal facilities (Defense, Energy). Dates are the years of the Federal Register notices (final listing, deletion); 'listed' is empty for proposed sites. Some sites still on the list have had partial deletions. Contaminants and media: contaminants of concern from decision documents (RODs, ROD amendments, ESDs; EPA, fiscal years 1981-2024, SEMS document HQ/406315); for sites with no decision document (mostly proposed or recently listed) the contaminants are those EPA records for the site (FOIA-015, document HQ/406366), with no medium. 'Deleted' means EPA found no further response needed, which can include land-use controls still in force.