Torch Lake AOC
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The Torch Lake Area of Concern (AOC) is one of the 31 U.S.-based AOCs across the Great Lakes designated under the 1987 Great Lakes Water Quality Agreement. The boundary of the Torch Lake AOC includes Torch Lake and its immediate environs. Immediate environs are areas along the shore of Torch Lake where waste from the production of copper contributed directly to the contaminant loadings of Torch Lake.
Mining of native copper found in the region's bedrock formations began during the 1840s and continued until 1968 when all mining related operations ceased. Waste products from industrial milling, smelting and leaching operations of the mined ore are the main source of pollution in Torch Lake. In addition to copper, other contaminants of concern in the AOC are heavy metals, PCBs and polycyclic aromatic hydrocarbons.
Beneficial Use Impairments
An interim success of remediation and restoration work is removing Beneficial Use Impairments (BUIs). BUIs are designations given by the International Joint Commission, representing different types of significant environmental degradation. BUIs are removed when sufficient environmental health improvements have been demonstrated through monitoring. The list below shows which BUIs have been removed, and which remain. Once all BUIs are removed, the process of delisting the AOC can begin.
- Restrictions on Fish and Wildlife Consumption
- Degradation of Benthos
- Fish Tumors or Other Deformities – Removed 2007
- General information about BUIs: Beneficial Use Impairments for the Great Lakes AOCs
EPA has continually worked with federal, state and local partners to identify and implement remediation and restoration work with the ultimate goal of removing the AOC designation. Evolving projects aimed at improving the environmental health of Torch Lake include the Torch Lake Great Lakes Legacy Act Focused Feasibility Study and the Torch Lake Degradation of Benthos BUI benthos pilot study project.
The Torch Lake Degradation of Benthos BUI project is a benthos pilot study funded by the Great Lakes Restoration Initiative. The developing plan will include construction of a series of pilot-scale shoreline capping and habitat restoration test plots. It will determine the potential to improve the density and diversity of the Torch Lake benthic community. Construction of the pilot study test plots was completed in spring 2021 with monitoring taking place in fall 2021 and 2022.
Torch Lake GLLA Focused Feasibility Study
On August 20, 2019, EPA signed a Great Lakes Legacy Act Project Agreement with Honeywell International, Inc. to perform a focused feasibility study at the Torch Lake AOC. This is the first GLLA project agreement signed at the Torch Lake AOC. The study is being performed in two areas of Torch Lake, the Lake Linden Recreational Area and the Hubbell Processing Area.
The study is focusing on developing remedial alternatives for addressing PCB, lead and arsenic contaminated sediment in both areas, as well as mining waste abandoned in the lakebed in the Hubbell Processing Area. Addressing contaminated sediment in these two areas will contribute to removing the Restrictions on Fish and Wildlife Consumption BUI.
The project agreement also includes removal of hazardous piles along Torch Lake for source control. Source control work, conducted by Honeywell, was completed in fall 2019. Additional sampling took place in summer of 2020. The study is expected to conclude in 2022.
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