Montana DEQ Approves $100 Million Superfund Cleanup Accord for Butte Silver Bow Creek

BUTTE, MT — The Montana Department of Environmental Quality (DEQ) and the U.S. Environmental Protection Agency (EPA) Region 8 announced the formal lodging of an amended Superfund Consent Decree in federal district court, securing $100 million in private and state funding to execute final phase remediation of the Butte Priority Soils Operable Unit.

Restoring Historic Mining Corridors into Public Greenways

The consent decree directs Atlantic Richfield Company (ARCO) to excavate 2 million cubic yards of historic heavy metal mine tailings, replace contaminated soils along Blacktail and Silver Bow creeks, and construct a 50-acre continuous wetlands corridor through central Butte. The project permanently caps toxic copper and arsenic groundwater flows, transforming former industrial slag yards into public walking trails and native trout spawning habitats.

Governor Greg Gianforte affirmed that completing the Butte Superfund cleanup delivers environmental justice to the community and unleashes new economic redevelopment in Uptown Butte.

Butte-Silver Bow County and Citizen Action Endorse

Butte-Silver Bow Chief Executive J.P. Gallagher praised the decree for securing permanent water quality monitoring funds.

Citizens Technical Environmental Committee (CTEC) celebrated the removal of toxic mine waste rather than in-place capping.

Heavy Excavation Schedule

Earthmoving and tailings excavation will commence in the Silver Bow Creek corridor in spring 2027.