Abandoned Mine Lands Investigation and Restoration Services

Providing regulatory-driven investigations.

AML One-Sheeter

Agencies and environmental managers are faced with the growing challenge of dealing with active, abandoned, and inactive mining operations, which are impacting the land that they manage. CES has extensive experience in providing a variety of regulatory driven investigations including: Preliminary Assessments (PAs), Site Inspections (SIs), Engineering Evaluations/Cost Analysis (EECAs), Remedial Investigation/Feasibility Studies (RIFS), and Removal/ Remedial Design, Implementation, and Closure. CES is focused on providing the following services for abandoned mine lands:

Preliminary Assessments and Site Inspections
Ecological and Human Health Risk Assessments
Engineering Evaluation / Cost Analysis
Remedial Investigations / Feasibility Studies
Removal / Remedial Actions (Design-Build options)
Physical Hazards Assessment and Closure

Project Summary:
Monte Cristo Mining Area | Removal Action
2017 ACEC Engineering Excellence Award Winner

The Monte Cristo Mining Area (MCMA) includes abandoned gold mines, processing facilities, and haulage ways that primarily operated from about 1893 to 1907 in a remote area of the northern Cascade Range in Washington. Lands in the MCMA are a patchwork of Forest Service administered lands, patented claims, Inventoried Roadless Areas (IRA), and the Henry M. Jackson (HMJ) Wilderness. Abandoned mines and processing operations resulted in elevated concentrations of metal contaminants, primarily arsenic and lead, along a 9.5-mile stretch of the South Fork Sauk River and tributaries.

A Removal Action (RA) was conducted by Cascade Earth Sciences in 2015 to address physical and chemical hazards associated with a mill, assay shack, mines, ore collection terminals, and haulage ways. Removal of approximately 2,000 yards of waste rock from the Pride of the Woods Mine (located within the HMJ Wilderness) necessitated the use of a Vertol 107-II heavy-lift helicopter to both transport excavators to the remote location, and to transfer material to the repository.

This project is a 2017 American Council of Engineering Companies of Oregon (ACEC) Engineering Excellence Award recipient. In conjunction with the U.S. Forest Service, the CES team successfully implemented removal action for the Monte Cristo Mining Area (MCMA).

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Project Summary:
Azurite Mine | CERCLA Removal Action Project

The Azurite Mine is an abandoned gold mine in a remote area in the North Cascades of Washington State. Since 2004, CES has been working for Region 6 of the Forest Service on this CERCLA project, including the Site Inspection, Reprocessing Study, Removal Design, and Removal Action implementation. The Removal Action began in July 2011 under a design-build contract structure with CES, and was completed at the end of September 2011. The repository was constructed on a 2.5:1 slope, and the liner consisted of a traditional HDPE liner and other geomembranes, along with a geogrid and a talus rock cover to blend in with the surrounding area. All borrow material was generated onsite because hauling material to the site was impractical. There will also be ongoing semi-annual inspections to monitor the constructed repository, revegetation, and to collect aquatic samples to assess the success of the Removal Action.