Public Notice: EPA Begins Fourth Five-Year Review of Milltown

Summary

EPA, in cooperation with the state of Montana, is beginning the fourth five-year review of the Milltown Reservoir Sediments Superfund site in Milltown, Montana. Five-year reviews evaluate remedies to determine whether they remain protective of human health and the environment. This five-year review will be released in 2026.

The site includes about 120 miles of the Clark Fork River upstream of the Milltown Dam and Reservoir. To manage cleanup efforts, the EPA broke the Site into three operable units (OUs). OU1 was originally the Milltown Drinking Water Supply and is now part of OU2. OU2 is the Milltown Reservoir Sediments area. OU3 is the Clark Fork River area upstream of OU2 and downstream of the Silver Bow Creek/Butte Area Superfund site and the Anaconda Smelter Superfund site. The Montana Department of Environmental Quality is the lead agency for OU3.

Cleanup began in 1984 and is complete at the Milltown Reservoir Sediment area (OU2). Groundwater and surface water monitoring are ongoing. Cleanup is ongoing in the Clark Fork River area (OU3). 

We want to hear from you! 

Community members are encouraged to share information that may be helpful in the five-year review process. Community members who have questions or who would like to be interviewed are asked to contact EPA by January 31, 2025.