Mine Closure and Reclamation

Holden Mine Site

US Forest Service
West of Lake Chelan, Washington

Hart Crowser is providing technical support to the Forest Service to oversee the remedial investigation and feasibility study for cleanup at an abandoned copper mine in a remote area. The Holden Mine complex has nearly 10 million tons of tailings and waste rock, and roughly 52 miles of underground workings discharging metals above water quality criteria into Railroad Creek.

 

Khayyam Mine Engineering Evaluation/Cost Analysis

US Department of Agriculture
Prince of Wales Island, Alaska

Hart Crowser evaluated cleanup alternatives and estimated costs for an abandoned copper mine. We also surveyed benthos such as insects, worms, and crustaceans to help assess cleanup requirements for streams with native salmon habitat. We sampled soil, stream sediment, and waste rock for chemical analysis and assessed ecological and human health risks. The benthos survey provided an independent line of evidence to assess potential impacts on the watershed to supplement the more traditional approach based on surface water and sediment quality. The soil, benthos, surface water, and sediment samples were from both potentially impacted areas and reference areas outside the impacted watershed; we collected then statistically compared the sample analytical results. Hart Crowser staff are experienced in working at remote sites like the Khayyam Mine, which is on a mountain ridge in the Tongass National Forest.

 

Abandoned Coal Mine Reclamation Projects

US Department of the Interior, Office of Surface Mining Reclamation and Enforcement
Washington, California, Colorado, and Illinois

Under ongoing contracts with the Office of Surface Mining, Hart Crowser has closed or reclaimed dozens of abandoned coal mines. Abandoned mine issues have included steep or vertical shafts, acid mine drainage, drainage tunnels, and subsidence under roads and structures. The work also involves geophysical studies.

 

Abandoned Mine Site Assessments

Washington State Department of Ecology
Stevens, Ferry, and Pend Oreille Counties, Washington

Hart Crowser provided environmental consulting services to the Washington State Department of Ecology for characterization of abandoned and inactive hard rock mine sites. The 60 sites included former mines and mineral processing facilities for a variety of metals that were identified by Ecology as being eligible for environmental cleanup under the State’s Model Toxics control Act.

 

Lookout and Yellowhead Mines

U.S. Bureau of Land Management
near Metaline Falls, Washington

This project involved sampling waste rock piles and mine portal drainage to assess the need for a CERCLA removal action. The project encompassed abandoned mine entries and five distinct waste piles within a 127-acre area.