Pro/Con: Can copper mining by done safely?Yes: Regulations will safeguard Minnesota’s environment
By: Rolf Westgard, Duluth News Tribune
The environment-vs.-economics dispute that hangs over Minnesota’s world-class mineral deposits drew a big crowd to the Duluth Entertainment Convention Center last month (“PolyMet public hearing packs the DECC, Jan. 17).
All those minerals — copper, nickel, cobalt, gold and platinum — lie in a band that meanders from southwest to northeast adjacent to the Archean granite of Minnesota’s Iron Range. They arrived 1 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 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 the shutdown and the monitoring of the mine site after closure.
The PolyMet project expects an 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 on the PolyMet project was released by the Minnesota Department of Natural Resources and the U.S. Corps of Engineers. That statement noted that any effluent from the project would 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 Canoe Area Wilderness. The statement was generally positive about the project, and it suggested that if all of PolyMet’s commitments were met there’d be no serious impact on the environment.
The Environmental Protection Agency disagreed and called the draft statement inadequate.
A new, 1,000-plus-page Supplemental Draft Environmental Impact Statement has just been released by the DNR, Corps of Engineers, and U.S. Forest Service in response to the EPA concerns. The new SDEIS generally concurs with the 2009 report, stating that, “The project is not predicted to result in any significant changes to groundwater and surface water flows when compared to existing conditions.” The DEIS noted 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.
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.
Environmentalists are lined up in opposition to the mining, viewing the projects as a serious threat to water quality in the entire region, including in the Boundary Waters.
Project advocates include most area mayors who want these new, quality jobs on the depressed Iron Range.
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, the pit was backfilled with the waste rock and 30,000 tons of limestone to neutralize any drainage that formed. The Flambeau Mining Co. did not have any violations of its permits in construction, operation or closure in 1997.
Many 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 we can.
Rolf Westgard of St. Paul is a professional member of the Geological Society of America and is a guest faculty member 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.” He wrote this for the News Tribune.