Bunker Hill CERCLA Site Project
Coeur d’Alene Basin, Idaho

TerraGraphics has provided technical oversight assistance for the Bunker Hill Mining and Metallurgical Complex Superfund Site (BHSS) as prime contractor to the Idaho Department of Environmental Quality (IDEQ) for over 14 years. This comprises the original 21-square mile “Box” site and expansion into the 1,500-square mile Coeur d’Alene Basin (Basin) CERCLA site. The majority of work is being conducted with the U.S. Environmental Protection Agency (EPA) funding under the Cooperative Agreement with the State of Idaho.

The BHSS work covers involvement in virtually all aspects of the project from Remedial Investigation/Feasibility Study (RI/FS) and Remedial Design/Remedial Action (RD/RA) to negotiation assistance, Human Health Risk Assessment (HHRA), and generation of Records of Decisions (ROD), Explanation of Significant Differences (ESDs), and Five-Year Reviews. Significant RD/RA in the “Box” included remediation of approximately 1,500 residential/ commercial properties by the site’s potentially responsible parties (PRPs), demolition of the smelter complex, excavation of two million cubic yards of contaminated unconfined tailings, development of more than 100 acres of on-site repositories, and restoration of 200 acres of river floodplain and 1,200 acres of barren hillsides.

Additional elements to the Basin ROD and associated cleanup include:

  • eight additional communities requiring yard remediation,
  • 33 miles of the Coeur d'Alene River and floodplain,
  • over 200 abandoned mine and mill sites,
  • dozens of mine waste-contaminated side drainages to the South Fork Coeur d'Alene River, and
  • comprehensive flood control and infrastructure improvements to protect and enhance Superfund remedies.

TerraGraphics has been involved throughout the Basin as the State’s technical oversight representative during the RI/FS and RD/RA.