Comprehensive Permitting for Underground Copper and Zinc Mine

Background

Crandon Mining Company (Nicolet Minerals Company) retained Foth to assist in the acquisition of permits associated with the development of a proposed underground copper and zinc mine advanced by Exxon/Rio Algom/BHP in the 1990s. More than 40 permits were needed from the Wisconsin Department of Natural Resources and other federal, state and local agencies. The permitting effort was one of the most comprehensive in the United States and had a high public profile, requiring careful management of regulatory and public affairs. 

Approach

Our team completed all hydrologic-related studies and modeling analysis subject to review by numerous state and federal agencies, and the USGS. The hydrologic study area encompassed nearly 50 square miles and included a hydrologic monitoring record over a 25-year period. Foth’s hydrologic studies addressed groundwater and surface water systems including streams, lakes, and wetlands. Significant effort was devoted to balancing environmental, social and economic considerations. Our tasks included preparation of:

• A comprehensive feasibility study for tailings and waste rock management facilities.
• Feasibility studies for water management and treatment facilities.
• Wetland permit applications and associated mitigation plans.
• Mitigation plan for surface water impacts due to mine dewatering.
• Underground mine closure plan,
• Groundwater and surface water quality impact assessments for the tailings facility and underground mine.
• Comprehensive water resource modeling.
• Air quality impact analysis,
• Hydrogeologic evaluation of the regional aquifers, the crown pillar, and groundwater interactions with wetlands and lakes.
• Geophysical mapping of lake beds, and
• Geochemical characterization of tailings and waste rock.

Results

We successfully addressed a number of challenges for our client, including estimating mine dewatering impacts on lakes, streams and wetlands; developing a plan to mitigate adverse impacts to surface water due to mine dewatering; and treating mine water to standards that exceed safe drinking water requirements and discharging it back into a watershed that contributes to a state-designated Outstanding Water Resource. We also designed a tails management facility and mine closure plan that provides long-term protection of groundwater and surface water resources. While this project was eventually sold to local Native American interests, Foth retains copies of all records of the project dating back to the 1970s.