Michigan department of Environmental Quality recently approved permits allowing Kennecott Minerals Co. to operate a nickel and copper mine in the Upper Peninsula. The mine, which Kennecott calls Eagle Project, is near Marquette, Mich., would target an underground deposit expected to yield 250 million to 300 million lbs of nickel and about 200 million lbs of copper. Utah-based Kennecott, a subsidiary of the London-based mining conglomerate Rio Tinto, also needs approval from the Michigan Department of Natural Resources. Opponents fear the Marquette County mine would generate sulfuric acid that would leach into the nearby headwaters of the Salmon Trout River, a Lake Superior tributary. The company repeatedly has said it would protect the environment.