Flat Creek IMM

Superior, Mont.	

Site Description

The Flat Creek IMM site is located in and around the Town of Superior, Mont. EPA added the site to
the National Priorities List in 2009. From 1909-30 and again from 1947-53, a company called "Iron
Mountain Mine" (IMM) operated a mine near the town, extracting and processing metals such as
gold, silver and lead. These activities generated large quantities of solid waste in the form of dirt
piles laced with lead and other metals poisonous to humans. This waste was disposed of in
neighboring Flat Creek, whereupon it washed downstream into Superior. Contaminated dirt was also
taken directly from the site and used as fill dirt in Superior for various civic and residential projects.
The Flat Creek IMM site encompasses the abandoned IMM mine, Flat Creek itself and the Town of
Superior.

Current Site Status and Cleanup Actions to Date

•	In 2011, EPA initiated a time-critical removal action to address 33 properties with highly
contaminated soils.

•	Also in 2011, EPA finalized the remedial investigation/feasibility study for the site, and began
construction on the joint permanent repository at Wood Gulch.

•	In July 2012, the Agency issued a Record of Decision (ROD) for Operable Unit 1, Community
Soils in the Town of Superior, to address the remaining contaminated yards.

•	After issuing the ROD, the Agency initiated remedial design activities in anticipation of
cleaning up the remaining yards in the fall of 2012.

•	Once this project is funded and completed, all unacceptable human exposure pathways will
be eliminated for the entire site.

Unfunded Action

Fiscal Year 2012 work that was not funded included excavation, disposal and restoration of
residential properties.

Current Funding Status

To date, EPA has spent approximately $2.2 million on response construction work at the site.

For more information on this site, please read the Flat Creek IMM site information on the Region
8 Superfund web site.


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