The site is being cleaned up using a collaborative watershed approach. To date, EPA has been unable to identify a viable potentially responsible party (PRP), so the cleanup on private land is being 90 percent paid for with federal funds and 10 percent with state funds. Cooperating agencies have combined resources to expedite a watershed cleanup. The U.S.
| City | Helena |
|---|---|
| County | Lewis And Clark County |
| State | Montana |
| Coordinates | 46.48091, -112.25399 |
Upper Tenmile Creek Mining Area is a federal Superfund site in Montana. The Superfund program, created by Congress in 1980, addresses sites where hazardous substances have been released or threaten release into the environment. EPA scores potential sites using the Hazard Ranking System; those that score high enough are placed on the National Priorities List.
Current status: Cleanup underway. Active cleanup is underway, meaning EPA has approved a remediation plan and work is in progress. Cleanup timelines vary widely — some sites take decades depending on contamination depth, groundwater involvement, and funding availability.
EPA has identified 9 contaminants of concern at this site, including aluminum, arsenic, cadmium. Contamination has been detected in surface water, soil, sediment, solid waste, leachate, groundwater.
If you live near this site and have health concerns, your state health department can provide site-specific guidance. EPA maintains a community involvement program for most NPL sites, and site documents — including the Record of Decision, five-year reviews, and public health assessments — are typically available through EPA's Superfund site profile.