Waste material from a 4 1/2-mile-long open-pit iron mine would cover up to 40 percent of a 3,300-acre site in northern Wisconsin that is now home to wetlands and trout streams, a mining company official said.
How Gogebic Taconite, which wants to build the mine in the Penokee Range, handles that waste and how it plans to protect the area's water-rich ecosystem is at the heart of the debate over the controversial GOP bill that speeds up mine permitting and exempts the mining company from some environmental rules. That bill is moving quickly through legislative committees, speeding toward a vote in the Senate Wednesday.
Changes to Wisconsin's wetland regulations, approved in a separate bill last year but included in the proposed mining legislation, would allow mining companies such as Gogebic to destroy some waterways and wetlands — even certain high-quality wetlands — if they build replacement wetlands elsewhere.
Research, however, shows restoring wetlands in another location, a practice called mitigation, has proved only marginally successful and does not compensate for the flood- and pollution-control functions performed by wetlands at a specific site.
"Beware of promises made that damage will be compensated for," said Joy Zedler, a UW-Madison professor of botany and director of research at the UW Arboretum. "The myths are falling aside right and left with new knowledge. It's like if I told you that I'm going to take your house away from you but I promise to decorate your garage. You lose both area and function."
Gogebic Taconite has proposed a $1.5 billion iron ore mine in the Penokee Range near Mellen that supporters hope will be built if the state Legislature passes legislation to speed up the mine permitting process. The company has said the mine would create 700 jobs over 35 years.
Critics, however, have said the bill does not have enough environmental protections. One of the key concerns is how the company would dispose of mining waste and the waste's impact on wetlands and water.
Two weeks ago, Gogebic received approval from Iron County for renewal of its $20,000-a-year lease option on 3,300 acres (one acre is about the size of a football field) of Iron County forest land just south of where the company would dig the 1,000-foot-deep pit for the mine. The potential list of uses for the land that Gogebic reserves in the lease option is long and includes a taconite processing plant, reservoirs for water or waste material, and areas for storage and disposal of overburden and waste material.
Gogebic president Bill Williams said the land's primary use is likely to be for disposal of the ground waste rock, or tailings, that will be removed from the mining pit. He said as much as 30 percent to 40 percent of the 3,300 acres could be covered by the waste piles.
The acreage includes hundreds of acres of wetlands as well as a lengthy stretch of Tyler Forks, a Class II trout stream, and several smaller tributaries. Just southwest of the leased acreage are the headwaters of the Bad River, which flows south to Lake Superior through the Bad River Chippewa reservation and the tribe's rice beds.
According to an analysis by the Legislative Fiscal Bureau last week — based on Gogebic Taconite's own projections — the mine each year would produce about 18 million tons of tailings, the crushed ore left after the iron is removed, and 11 million tons of overburden, the rock that surrounds the deposit.
Williams made clear that the mine cannot be built without the loss of some natural resources such as wetlands, though he refused to disclose any specific acreages.
"We've tried to make the point that you can't move the ore body," Williams said.
Critics, however, said the loss of wetlands in the leased land could be in the hundreds of acres. And, they add, the loss is made more significant because the land is a headwaters, which heightens the importance of the ecological function of the area's cumulative wetland acreage.
The interlaced web of wetlands in this particular area of the Penokees is important for holding snow and floodwaters, said Erin O'Brien, with the Wisconsin Wetlands Association. If you remove too many acres of the wetlands, she said, you reduce the ability of the landscape to slowly release waters and increase the chances that silt and pollutants will run off the site.
"You alter the force of streams," O'Brien said. "And all of this is flowing into Lake Superior."
Because the water in the wetlands is connected to and helps feed area streams and creeks, eliminating some of the wetlands could also alter the base flow of those waterways and possibly affect the temperatures of coldwater trout streams such as Tyler Forks. The wetlands, she added, also serve as filters, reducing levels of pollutants that could flow into the underlying groundwater, which is a source of drinking water for nearby communities such as Mellen and Ashland.
"You could do a good restoration project somewhere else," O'Brien said, "but if it is not replacing the function on-site, then everything downstream is going to lose."
In a study published last year in the scientific journal PLoS Biology, researchers analyzed 621 restored wetlands from throughout the world and found that their biological functions remained, on average, 26 percent lower than undisturbed, natural wetlands.
Gogebic Taconite will try to minimize storage of wastes on wetlands and in other waterways, Williams said, because mitigation is expensive. He said the acres of wetlands lost will be much less than what critics predict.
The company will also consider using a relatively new waste disposal process called dry stacking that reduces the amount of acreage needed. Traditional disposal of mining waste, Williams said, relies upon tailing impoundments, which are massive, dammed ponds in which the tailings settle. The waste is removed and stacked.
But with dry stacking, the tailings are pumped into a large machine that squeezes out water. The dry tailings can then be shaped into more natural-appearing hills and covered with vegetation immediately. The process takes up only about a tenth of the acreage needed for the settling ponds, Williams said.
Finally, Williams said, dry stacking reduces the amount of runoff from the stored wastes. If any contaminated runoff was discovered, Williams added, it could be treated.
Williams said the company "would not go near" the Tyler Forks trout stream with its storage operations. The popular stream flows along the entire eastern border of the acreage the company has secured for waste disposal. Also flowing through the property are several smaller tributaries that, according to changes proposed in the GOP mining law rewrite, could be filled in if the company agrees to mitigation.