PolyMet Mining reported project improvements and further progress in the environmental review of its 100%-owned copper-nickel-precious metals project located in the established mining district of the Mesabi Iron Range in northeastern Minnesota. The reduced environmental impacts include reductions in sulfur dioxide, mercury and greenhouse gas emissions at the plant site, capture of groundwater and surface seepage with the construction of an in ground containment system to the north and west of the existing tailings basin, all contact water discharged from the project will be treated through reverse osmosis, or RO, plants. Based on a pilot scale RO treatment plant that has successfully treated over 1.5M gallons of water to date, contact water discharge will meet applicable state and federal water quality standards, including Minnesota's wild rice standard for sulfate. These design improvements have been incorporated into the groundwater, surface water and air dispersion models that assess potential environmental impacts of the project.
- Natural Resources