Operable Unit Information
West Side Soils was originally called Non-Priority soils, as distinct from Butte Priority Soils, and was meant to address mining contamination outside of urban Butte, mostly large mining waste rock dumps and contaminated groundwater. The EPA completed the first major step in the Superfund process in 2024: the West Side Soils Remedial Investigation Report. EPA also evaluated metal contamination of the Blacktail Creek watershed, which is located south of Butte.
In addition to sampling soils, groundwater and surface water, the investigation report included ecological and human health risk assessments. That work continues.
What’s New
Superfund updates.
EPA Residential Lead Proposed Plan Fact sheet (June 2026)
EPA’s fact sheet describing the Proposed Plan to lower residential lead cleanup level and increase the number of homes remediated.
EPA Residential Lead Proposed Plan (June 2026)
Complete document: EPA’s Proposed Plan to lower residential lead cleanup level and increase the number of homes remediated.
Spring 2026 Superfund Update: Diggings East construction scheduled for summer 2026
What’s next for Butte Superfund? Construction of the Diggings East stormwater pond and park project begins this summer.