Cleaning up the Ruby Mining District

Standard Mine was one of the three largest producing silver mines in the Ruby Mining District from 1874 to 1974. At an elevation of 11,000 feet, the 10-acre mine is situated in a remote area of Colorado's Gunnison National Forest.

Over the years, mining activities at the site deposited heavy metals like cadmium, copper, lead, manganese, and zinc into soil, surface water and groundwater. Water flowing in from Elk Creek affected Coal Creek, the water supply source for the small resort community of Crested Butte. The Standard Mine site was named a Superfund site by the U.S. Environmental Protection Agency (EPA).

An EPA record of decision called for the 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 the construction of a passive water treatment system to improve water quality in Elk Creek.

The EPA brought in our team of remediation experts to develop a remedial design to protect the surrounding communities' soil and water. 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.