EPA works to clean up the toxic Jumbo Mine near Keystone Resort
The U.S. Environmental Protection Agency is working to clean up the historic but toxic Jumbo Mine in Summit County’s Peru Creek Basin, located about 7 miles east of Keystone Resort.
The mine, which operated from 1915-1918, produced gold, copper, lead and silver. However, it also produced loads of waste rock and tailings piles. Inactive and abandoned for a century, the mine site was identified in the early 1990s by EPA and the Colorado Department of Public Health & Environment, as well as in the Snake River Watershed Plan, as a significant contributor of metal-contaminated flows into Peru Creek and the downstream Snake River.
Hard-rock mining in the Peru Creek area left behind a legacy of contaminated and abandoned mine sites, whose acid mine drainage significantly degrades water quality. The drainage is also home to the Pennsylvania Mine, the largest, longest-operating mine in the watershed. In coordination with Summit County and the Colorado Division of Reclamation, Mining and Safety, EPA completed cleanup actions at the Pennsylvania Mine in 2016.
The Jumbo Mine is another high-priority abandoned mine site in the area identified by the Snake River Watershed Coalition. The coalition says that cleaning up the mine could help improve water quality in the Snake River.
Summit County purchased the land surrounding the abandoned Jumbo Mine in early 2016 for public open space. A covenant placed on the adjacent property containing the abandoned mine site allows for an EPA cleanup, but also limits the county’s liability for the existing environmental issues and associated remediation actions.
“We had been looking to acquire this piece of property for a long time, recognizing that it has many open space values,” said Brian Lorch, Summit County Open Space and Trails director, in a news release. “But before we could take steps to purchase the property, we needed to ensure that it could be cleaned up in an economical manner.”
EPA is implementing the cleanup work as a time-critical removal action under the Comprehensive Environmental Response, Compensation and Liability Act. Last week, the agency began the work, which it plans to complete in about three weeks.
Cleanup activities involve diverting water draining from a mine shaft around or over adjacent tailings piles in a limestone and membrane-lined ditch. According to EPA studies, water quality of the drainage degrades as it crosses the tailings, contributing high levels of suspended and dissolved lead, zinc and other metals into the stream. Diverting drainage around the tailings into a lined ditch should greatly improve water quality.
“The overall approach will help reduce the discharge of metals into Peru Creek,” Lorch said. “A passive treatment approach at the Jumbo Mine site is quite similar to numerous mine cleanups performed elsewhere by the county.”
“We are really happy and grateful to see EPA continue its mine cleanup efforts in the Peru Creek Basin,” Summit County Commissioner Karn Stiegelmeier said in a news release.