A Minnesota environmental group says ongoing runoff from a 1970s copper exploration site near Ely contains levels of toxic metals that could harm aquatic life.
The group Friends of the Boundary Waters Wilderness said it found the toxic metals in samples of water runoff from the old International Nickel exploration site about 15 miles southeast of Ely and a couple miles from the Boundary Waters Canoe Area Wilderness. The group also claims the Minnesota Pollution Control Agency and Minnesota Department of Natural Resources have ignored the old site.
They say the finding shows Minnesota's copper-bearing rock could cause an acid problem during future mining operations.
"The levels of copper, nickel, iron and arsenic are all in violation" of state water quality standards, said Betsy Daub, policy director of Friends of the BWCAW. "We don't know if the runoff is reaching the Kawishiwi River or not, or if it's causing any damage, because the state hasn't been monitoring the problem for more than 30 years."
A state PCA official said Monday that publicity about the study might prompt his agency and the DNR to retest the site.
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Richard Clark, a hydro-geologist with the Minnesota Pollution Control Agency, said the lab results "make sense, they don't surprise me'' but that a recent site inspection showed little or no runoff moving into nearby streams or rivers.
Neither the PCA nor DNR has sampled the site since 1976.
Clark said he visited the site two weeks ago when concerns were first brought to his attention and that he found it dry, with no runoff. He said he's been to the site several times in recent years and not seen any environmental damage as rainwater percolates through a pile of waste rock from the test mine and slowly seeps out.
"There was a report issued in 1974 when the mining was completed that said the volume and nature of the discharge at that site didn't pose any threat" to nearby waterways, Clark said. "The decision in the 1970s (not to conduct further tests) predates my arrival here. But it's my guess that report is why testing was discontinued."
Clark said PCA and DNR officials are discussing whether to retest at the site after the friends group's finding.
The small test mining operation was conducted at the site in 1974 by International Nickel Co. to check deposits of copper and other valuable metals. It is near current copper exploration sites and copper mines proposed by both Twin Metals, formerly Duluth Metals, and Franconia, which have found vast deposits of valuable copper, nickel, platinum and other metals.
The friends group is asking for increased restrictions on copper mining proposals in the area because of the threat of acidic runoff. When copper-bearing rock is exposed to air and water during mining it can leach sulfuric acid that can damage streams and aquatic life.
Several supporters of copper mining in Minnesota, including mining company geologists, have said the rock near Ely is too low in sulfur to cause acid runoff. But Daub said the findings call those claims into question.
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"We now know we are getting acid drainage where the companies are saying we would not get it," Daub said. "This was a small test site of about 10,000 tons total and it's causing acid runoff decades later. Twin Metals is proposing mining 40,000 tons per day."
But Frank Ongaro, executive director of the Mining Minnesota industry group, said the finding, even if accurate, has little bearing on future mining operations.
"This was 36 years ago, pre-environmental review ... and pre-mineland reclamation laws," Ongaro said. "Projects being proposed now will have to demonstrate that they can mine process and handle their waste and still meet Minnesota standards or they will not get a permit. These projects are being engineered precisely to address all the waste issues that may arise from any mining operation."
