The bill removed environmental hurdles for Gogebic Taconite’s (GTAC) proposed 4.5 mile long, 1.5 mile wide, 1,000-foot deep open pit iron ore mine in northern Wisconsin’s Gogebic Iron Range.
It created a separate set of regulations for ‘ferrous metallic mining’ of iron ore as opposed to mining for sulfide minerals, which require higher environmental standards because of the potential for acid mine drainage.
However, scientific analysis contained in a July 2012 report, ‘Geochemical, mineralogical and structural characterization of the Tyler Formation and Ironwood Iron Formation, Gogebic Range, Wisconsin,’ shows that sulfide minerals such as pyrite are present both in one layer of the iron formation and throughout the overburden rock that would need removal to mine the iron deposit.
The report, co-authored by Marcia Bjornerud, PhD, a geology professor at Lawrence University in Appleton, Wisconsin, describes a 3-meter thick layer rich in pyrite near the base of the targeted 150-meter thick Ironwood Formation. Joseph Skulan, PhD, a geochemist then with the UW-Geology Museum used backscattered electron microscopy that showed pyrite in that layer constituted up to 20 percent of the rock volume.
Bjornerud, a Geological Society of America Fellow, told Indian Country Today Media Network many scientists were very disheartened by the lawmakers’ disinterest in incorporating sound science into the bill. “There were plenty of us trying to speak out. The only thing they cared about was the jobs, jobs, jobs, mantra.”
Legislators suggested “no need for worry” when they passed the “special laws,” Bjornerud said, because the mining project wasn’t about sulfide, which her work refutes.
“The key issues for water quality are the sulfide in the waste rock, and the sheer scale of waste rock that would have to be dealt with,” Bjornerud said. “The mine site and waste rock piles would lie at the headwaters of the Bad River, whose lower reaches include pristine wild rice sloughs close to where it flows into Lake Superior.
“It’s the overlying rocks that have finely disseminated sulfide in them, mainly pyrite. The ore body tilts steeply into the ground, and you have to remove an overwhelming amount of overlying rock. If sulfides are present in the waste rock, it makes no sense to treat ‘ferrous’ mining as something different from sulfide mining. The whole premise of the bill is flawed.”
Skulan agreed, saying the sulfide minerals mixed in with and above the ore would produce sulfuric acid. “This bill is called a ferrous mining bill to distinguish it from mining minerals that have sulfide in them, sulfide ore body mixed with non-ferrous metals,” Skulan told ICTMN. “It’s a subtle point none of the journalists picked up on.”
The legislators, Skulan said, know nothing about science. “They assume it’s in the bill. Lawyers wrote it. They don’t understand and they refuse to listen to people who do understand it.
“What [the bill] does is assign the pyrite out of existence. It’s as if the legislators tried to describe something in medicine in a language they didn’t understand. It’s like writing a bill that says cancer does not kill you.”
Bjornerud’s report also found that phosphorous content was significant and consistent across all the samples. Excess phosphorous can cause runaway algal growth in streams and lakes, lowering oxygen levels and endangering aquatic life. Given the great volume of waste rock from both formations an open pit mine could generate, a large amount of both sulfur and phosphorous could be oxidized and mobilized via interaction with air and water.
High-grade iron ore (more than 50 percent iron) was mined in the eastern Gogebic Range in the early 1900s. The remaining iron formation is taconite with only 15-25 percent iron. The current market for iron ore is not strong, and for such a low-grade deposit, only open pit mining is economically viable. The iron ore market is also highly cyclical. The Tilden taconite mine in northern Michigan recently furloughed about half the workers.
“The waste piles created by a mine of this kind will be with us for centuries, long after the company that created them is gone,” Bjornerud testified.
GTAC can begin exploratory drilling, but the mine’s not a done deal, Bjornerud said. The State Department of Natural Resources still can say no to the project, and the Great Lakes Indian Fish and Wildlife Commission is prepared to challenge mine development, if a permit is issued, on the basis that it violates treaty-protected fishing and wild rice gathering rights in the Ceded Territories south of Lake Superior.
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