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Well-regulated sulfide mining can be done effectively

An example of an effective sulfide mine is the smaller Flambeau Mine at Ladysmith, Wis.

flambeau mine
The Kennecott copper mine in Ladysmith, Wis., 1997.

The dispute over mining Minnesota’s world-class mineral deposits is drawing big crowds to the public hearings on the new Supplemental Draft Environmental Impact Statement (SDEIS ) on the proposed NorthMet Project. All those minerals — including copper, nickel, cobalt, gold and platinum — lie in a band, meandering from southwest to northeast, adjacent to the Archean granite of Minnesota’s Iron Range. They arrived a billion years ago in the magma during northern Minnesota’s active volcanic history. They are concentrated out of the magma by liquid sulfur, which acts as a “collector,” because these elements prefer the sulphide liquid to the magma by a factor of 1,000 times more.

One of the proposed Minnesota mining ventures is by PolyMet Mining Corp. of Canada. PolyMet’s group includes Swiss commodity and mining giant Glencore, which now owns 18 percent of PolyMet shares. Glencore and PolyMet will need to be financially accountable for shutdown and monitoring of the mine site after closure.

PolyMet’s project expects annual metal production of 39,000 tons of copper, 9,000 tons of nickel, 400 tons of cobalt, 22,000 ounces of platinum, 87,000 ounces of palladium and 13,800 ounces of gold from its lease. A 2009 714-page draft environmental impact statement (DEIS) on the company’s NorthMet Project was released by the Minnesota DNR and the U.S. Corps of Engineers. That DEIS notes that any effluent from the project will end up in the drainage areas of the Partridge and Embarrass Rivers. Those rivers flow south to the St. Louis River and Lake Superior, not north to the Boundary Waters. The DEIS was generally positive about the project, and it suggested that if all of PolyMet’s commitments are met, there is no serious impact on the environment. The Environmental Protection Agency disagreed and called the draft statement inadequate.

General agreement with ’09 report

A new 1,000-plus page document has just been released by the MN DNR, Corps of Engineers, and U.S. Forest Service in response to EPA concerns.  The new SDEIS generally concurs with the 2009 report, stating, “The project is not predicted to result in any significant changes to groundwater and surface water flows when compared to existing conditions.”  The DEIS notes that federal, state, and local taxes from the project would total an estimated $80 million annually. During operations, wages and rents would be about $230 million per year, and $332 million would come from sale of the extracted minerals. 

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The state of Minnesota owns more than 6,000 acres in the region, and Minnesota’s schools could collect at least $2 billion in royalties in the coming decades if these new mining projects proceed. This state property is known as “school trust lands.” Under the Minnesota Constitution, income from such lands is earmarked for the Permanent School Fund, which contributes about $60 per pupil to every school district. An analysis by the DNR projected that the school fund, with assets of $720 million, could more than triple in size with these new royalties over 20 to 25 years. 

Environmentalists are lined up in opposition to the mining, viewing the projects as a serious threat to water quality in the entire region, including the Boundary Waters. Project advocates include most area mayors who want those new, quality jobs on the depressed Iron Range.

The Flambeau Mine example

An example of an effective sulfide mine is the smaller Flambeau Mine at Ladysmith, Wis. Kennecott was the operator of this open-pit copper sulfide mine that operated 140 feet from the Flambeau River in the 1990s. During the mining operation, all of the surface area drainage and pit pumping water went into a treatment plant that successfully purified the water so it could be safely returned to the environment. Upon closure, to avoid long term acid rock drainage (ARD), the pit was backfilled with the waste rock and 30,000 tons of limestone to neutralize any ARD that forms. The Flambeau Mining Co. did not have any violations of its permits in construction, operation and closure in 1997.

In 2012, world energy demand burned more than 2 tons of coal, oil and natural gas for every person on the planet. This sent more than 30 billion tons of carbon dioxide into the atmosphere. World governments are forcing carbon-free renewable-energy programs, like wind turbines and more power lines. This is causing increased demand for nonferrous metals, of which the world now produces just 35 annual pounds per capita. Their price is rising as shortages develop. 

Many NorthMet Project opponents raise the question of whether the mining companies can be trusted to safeguard Minnesota’s environment. A better question could be: “Can we regulate them?” I suggest that we can. 

Rolf Westgard is a professional member of the Geological Society of America and is guest faculty on energy subjects for the University of Minnesota’s Lifelong Learning program. His 2013 fall-quarter class was “Minnesota’s Volcanic Geologic History; from Mountain Building to Minerals.”


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