Torch Lake sits on Michigan's Keweenaw Peninsula and landed on the federal Superfund list in 1986 after decades of copper mining left stamp sands and slag buried in lake sediments and spread across the shoreline. Mining ran from the 1890s until 1969, and the waste left behind contaminated solid waste in tailing piles, sediments, soil, groundwater, and surface water across a roughly 2,700-acre site. The primary ecological concern is severe damage to bottom-dwelling organisms in Torch Lake and nearby water bodies caused by metal loading from mine waste.
EPA identified 23 contaminants of concern at the site. Heavy metals include lead, mercury, cadmium, arsenic, chromium, nickel, and copper, along with aluminum, barium, beryllium, cobalt, manganese, silver, and vanadium. Organic compounds include phthalates and polycyclic aromatic hydrocarbons such as benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene, fluoranthene, and pyrene. The Michigan Department of Public Health issued a fish consumption advisory for Torch Lake due to PCBs and mercury found in fish tissue.
The main cleanup action involved capping about 800 acres of slag piles and tailings with soil and vegetation. Construction began in September 1998 and finished in September 2005. A pilot revegetation project on Gull Island tested whether plants could grow without clean soil cover, with roughly 35,000 plants installed between 2003 and 2004. By 2007, trees and shrubs had established in some areas. EPA has determined that human exposure is currently under control across the entire site and that contaminated groundwater is stabilized with no unacceptable discharge to surface water. Portions of the site were deleted from the National Priorities List between 2004 and 2013 as cleanup goals were met. The site is divided into seven operable units covering tailing piles, surface water, Lake Linden, the Quincy Smelter, Mason Sand, and an assay building mercury site. State-performed remedial action on tailing piles at Torch Lake started in August 2025, with completion estimated between June and August 2026.
The most recent five-year review, completed in March 2023, confirmed that response actions protect human health and the environment in the short term. Continued protectiveness depends on compliance with institutional controls and ongoing monitoring. Operation and maintenance activities are Michigan's ongoing responsibility. Zoning restrictions limit land uses that conflict with cleanup levels. Redevelopment is active, with residential communities built on portions of the site and a recreation area with nature trails and a campground on Gull Island. A reuse plan envisions the Quincy Smelter area as part of a National Historic Landmark with waterfront recreation.
Community members can engage through EPA staff assigned to the site. The next five-year review is estimated between March and May 2028. EPA is also working with individual property owners on deed restrictions to protect the remedy's long-term effectiveness.
