Cleaning up the Ruby Mining District for communities today and tomorrow.
Home to one of the three largest producing silver mines in the Ruby Mining District from 1874 to 1974, the 10-acre Standard Mine is located at an elevation of 11,000 feet in a remote and isolated area of the Gunnison National Forest in Gunnison County, Colorado.
Over the years, mining activities at the site caused heavy metals like cadmium, copper, lead, manganese and zinc to be deposited into soil, surface water and groundwater. Coal Creek, the water supply source for the small resort community of Crested Butte, was affected by water flowing in from Elk Creek. The Standard Mine site was named a Superfund site by the U.S. Environmental Protection Agency.
An EPA record of decision called for implementation of remedial action in two phases. Phase one included contaminant controls, construction of a concrete flow-through bulkhead, waste rock stabilization, adit discharge controls, interim monitoring and institutional controls. If necessary, phase two was anticipated to include construction of a passive water treatment system to improve water quality in Elk Creek.
In an effort to protect the surrounding communities’ soil and water, the EPA brought in our team of remediation experts to develop a remedial design. Two years into the project, our role was expanded to include construction of the remedial action.
Despite limited mountaintop construction seasons, our team successfully installed a flow‐through bulkhead and completed contaminant controls. Working closely with EPA and stakeholders, we developed an emergency action plan that incorporated community priorities for protecting the Crested Butte water supply.
During remedial action, our team engineered a bypass adit as an alternative to an expensive rehabilitation of unstable ground near the entrance, saving the EPA approximately $1.3 million, minimizing environmental risk, and creating a safer entrance for the community.
With construction complete, we’re implementing the water quality monitoring program to assess phase one’s efficacy and determine whether additional actions are necessary.