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About Torch Lake AOC

map showing the state approved boundary of the Torch Lake AOCTorch Lake AOC Boundary MapThe Torch Lake Area of Concern is located on the Keweenaw Peninsula within Houghton County on the northwestern shore of Michigan’s Upper Peninsula and on Lake Superior’s southern shore. The region is locally known as the Copper Country. Deposits of native (elemental) copper are found in the Portage Lakes Lava Series, a long narrow bedrock formation which extends from the tip of the Keweenaw Peninsula southwest to the Michigan-Wisconsin border covering a distance of over one hundred miles.

Copper Contamination

Copper-bearing ore on the Keweenaw Peninsula has been a rich source of copper for people for thousands of years. More recently, it is in the waste products from the industrial milling, smelting and leaching operations of the mined ore that has created the present environmental concern. These industrial processes began during the 1840s and continued until all mining and related operations ceased in 1968.

Those processes left stamp sands and slags deposited either on the surface of the surrounding landscape or in adjacent lakes and streams. Portions of the surficial materials eroded into nearby water bodies. In addition to copper, other contaminants of concern in the AOC are heavy metals, PCBs and polycyclic aromatic hydrocarbons (PAHs).

Beneficial Use Impairments

  • Restrictions on fish and wildlife consumption
  • Degradation of benthos
  • Fish tumors or other deformities  - REMOVED 2007

Learn More about BUIs Exit

Restoring Torch Lake AOC