Proposed Remediation Site Work The bottom sediment of Torch Lake is planned to be capped with a 16-inch layer of sand having a 1% organic carbon content. Due to the extensive area of the lake (~2400 acres), remediation will occur in phases. Model Predictions
The bottom sediment of Torch Lake is planned to be capped with a 16-inch layer of sand having a 1% organic carbon content. Due to the extensive area of the lake (~2400 acres), remediation will occur in phases.
The table below presents the Hazardous Substances Research Center (HSRC) Capping Model predictions of pore water copper concentrations at the cap-sediment interface.
Figure 2. Project focus area for the Torch Lake Superfund site.
Figure 1. Location of Torch Lake Superfund site OUII. Map courtesy of www.epa.gov.
Time after Capping (years)
Pore Water Copper Concentration (mg/L)
Accelerating the Natural Remediation of Torch Lake
Lindsey Anderson, David McCaw, Amanda McKenna,
Kathryn Price, Tim Rank, Aimee Rathbun,
Kris Scherer, Tiffany Torrance
Advised by Noel Urban, Ph.D.
Department of Civil and Environmental Engineering
The EPA has decided on a “No Action” Plan for the remediation of copper-contaminated sediments in Torch Lake (Keweenaw Waterway, Houghton County, MI). The goal of this study is to propose an alternative solution in the case that the “No Action” Plan proves ineffectual.
Financing the project will be accomplished through grants from various state, federal, and non-governmental programs.
original $15.2 million
& Assessment Program
History of Torch Lake
Milling and Smelting Operations (1868-1968)
The troubles with Torch Lake commenced in 1868 when the first copper mill opened on its shoreline, and waste particles (tailings) were dumped into the water. Advancements in extraction technology in 1916 and 1920 resulted in further chemical treatment, and discarded tailings introduced reagents, such as lime, creosotes and xanthates, to Torch Lake. When the last mill closed in 1968, approximately 200 million tons of tailings filled 20% of the former lake.
CERCLA Classification (1986)
Concern for Torch Lake surfaced in the 1970’s when excessive concentrations of copper and fish tumors were found. Although it is not evident that the contamination caused the abnormalities, a fish consumption advisory was issued by the Department of Health. Even more significant was the severe degradation of benthic life in the lake. By June 1986, the Torch Lake area was considered an Environmental Protection Agency (EPA) Superfund site. Remedial efforts were allocated $15.2 million of Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) funds, plus a 10% state match.
Reclamation Activities (1986-current)
Reconnaissance of Torch Lake commenced in 1988, and due to the region’s extensive size and complexity, the area was divided into three operable units (OU) of which OUII is the focus of this study. Operable Unit II consists of groundwater, surface water, Torch Lake sediments, Portage Lake, Portage Canal, and other water bodies; this project is specifically concerned with Torch Lake sediments. The EPA, in collaboration with the Natural Resources Conservation Service (NRCS), resolved that no action be taken to reclaim OUII as any anthropogenic influences on the water and sediments would only resuspend contaminants. Stamp sands on the shoreline were stabilized with rip-rap and a vegetative cover in the summer of 2004, and long-term monitoring continues. The Torch Lake Public Action Committee (TLPAC), established in 1997, is responsible for educating the public on remediation efforts.
Superfund sites do not require state or federal permits for work to be conducted; however, the intent of all relevant permits must be followed. Examples of applicable regulations include the following:
Evaluation of EPA’s “No Action” Plan
*Denotes measurement was obtained at the “hot spot”, an area of extreme contamination.
Even after 30 years of no action, the lake water copper concentration has not met the EPA’s Recommended Water Quality Criteria of 13.0mg/L. If, by 2008, sampling indicates that copper concentrations have still not reached this level and benthos remain severely impaired, the EPA’s “No Action” Plan will have proven ineffectual, and the proposed alternative could be implemented.
Timeline of Events