The Upper Tenmile Creek Mining Area site is located in the Rimini Mining District, southwest of Helena, Montana, and consists of numerous abandoned and inactive hard rock mine sites that produced gold, lead, zinc, and copper. Mining began in the Rimini Mining District before 1870 and continued through the 1920s. The site boundary includes the drainage basin of Tenmile Creek upstream of the Helena Water Treatment Plant and includes tributaries that supply water to the plant's five intake pipelines. EPA identified 150 individual mine sites within the watershed boundary. Many of these mine features are above the five City of Helena drinking water intakes which supply over 70 percent of the city's water. The watershed has many stakeholders, including landowners, local communities, local and state government, special interest groups, and several federal agencies, including EPA.
Current Site Status and Cleanup Actions to Date
- In the Record of Decision (ROD), 70 mines and several residential yards were prioritized for cleanup. The ROD also provides an alternate water supply for the community of Rimini.
- In 1999 and 2000, EPA removed over 150,000 cubic yards of waste from the Bunker Hill/Tenmile, Red Mountain, and Suzie mines in the Tenmile watershed and the Buckeye/Enterprise Bullion and Crystal mines in the adjoining Basin Creek watershed.
- EPA conducted several cleanup removals to reduce the risk posed by the sites. This work included the development of the first joint EPA, U.S. Forest Service and U.S. Bureau of Land Management waste repository (Luttrell Repository).
- EPA removed 11,000 cubic yards of lead and arsenic contaminated soils from two mill sites that are in and around residential yards in the vicinity of Rimini.
- EPA removed 10,000 cubic yards of waste from the Lee Mountain Mine site in the town of Rimini.
- In Fiscal Year 2003, EPA managed waste disposal, treated contaminated water, and completed construction of Cell 4 of the Luttrell Repository.
In Fiscal Year 2004, EPA:
- EPA cleaned up residential yards
- Removed contaminated soils from the Rimini Road
- Completed installation of the Rimini community water and wastewater system infrastructure
- Conducted source control of acid mine drainage from Lee Mountain Mine in the town of Rimini
- Started to build both final cover on Cells 1 and 2 of the Luttrell Repository and Cell 5 of the Luttrell Repository.
- EPA's Removal Program cleaned up a mill site surrounding a home.
In Fiscal Year 2005, EPA will:
- Remove contaminated soils from Rimini Road
- Install the Rimini community water and wastewater system infrastructure
- Manage the joint agency Luttrell mine waste repository.
Current Funding Status
- To conduct the above work, more than $10 million has been expended at this site. However, excavation and disposal of the remaining waste at the Lee Mountain Mine was not funded in Fiscal Year 2004.
For more information on the projects at this site, please read the Upper Tenmile Creek Mining Area Fact Sheet on the Region 8 Superfund Web site.
- More than $10 million has been expended at the site.
- For six years, EPA has successfully engineered and coordinated a multi-agency repository for mining waste.
- In 1999 and 2000, EPA removed over 150,000 cubic yards of waste from a number of contaminated areas.
- EPA's investigations and cleanup actions are being conducted on a watershed basis.