A long-awaited mining project that promises economic renewal for Minnesota's Iron Range has been delayed repeatedly in the past year because federal regulators are insisting the company conduct more rigorous research to predict its environmental ramifications on the wildest and most scenic corner of the state.

In the latest delay, announced last week, PolyMet Mining Corp. said its two-year-old environmental review will not be made public until next fall.

That means the copper-nickel mine, first proposed in 2006, would not begin construction until 2014 at the earliest if the project is approved.

The new delay is related to questions the Environmental Protection Agency raised Sept. 1 about the validity of the company’s computer model because it did not include sufficient data from the mine site.

“Any modeling…using this inadequate number of samples would have results that are not scientifically defensible,” the EPA said in a letter to the state and federal officials who are overseeing the environmental review. PolyMet says it has since reached agreement with the EPA on the computer model and is gathering the data the agency requested. 

Ken Westlake, the EPA’s chief reviewer, said the model and the data are crucial to the accuracy of the environmental analysis.

“It predicts how the (mine) will perform,” he said this week. “And that is the essence of environmental impact.”

The project has been long anticipated because of its promise to create hundreds of jobs on the Iron Range. But it has also been hugely controversial because of its potential effect on water and recreation. Environmental groups, cabin owners and some local residents have fought it since its inception, saying the environmental risks of acid drainage from waste rock and the mine's tailings basin are far greater than those of taconite and iron ore mining.

Additional wells

PolyMet's first environmental review, completed in 2010 under the auspices of state and federal regulators, was sharply criticized by the EPA and advocacy groups because the project it described would have likely violated state and federal clean-water laws.

The company said this week it is making progress in addressing the concerns raised by the EPA, as well as those of Indian tribes, environmental groups, and state and federal regulators overseeing the environmental review. But the process is complex and significantly larger in scope than the first review, and is simply taking longer than anticipated, said LaTisha Gietzen, spokesperson for PolyMet.

"We don't get to control the schedule," she said.

Throughout the process, the company has agreed to requests for new information and data, she said.

At the EPA's urging, PolyMet has constructed about 20 wells around the planned site to collect baseline water-quality data. It's also made significant changes in the design of the project to address pollution concerns, Gietzen said.

Still, the delays are raising concerns among environmental groups as well. This week, Paula Maccabee, an attorney for Water Legacy, sent a letter to the agencies overseeing the review, criticizing what she said is their willingness to rely on PolyMet's assumptions rather than on data.

"Their assumptions are designed to hide the truth, not find the truth," she said.

State officials overseeing the review said they, too, are on board with the EPA's requests.

"The EPA says we need to go further," said Bill Johnson, mining section lead for the environmental review unit of the Minnesota Department of Natural Resources. "New data ... [are] being collected."

Several groups have asked the DNR and other agencies for an update on the process, which is scheduled for later this month.

First in Minnesota

The PolyMet project has strong local and political support because of the company's expectation that it could generate as many as 350 jobs for the 20-year life of the mine, plus many hundreds more in spin-off economic activity for the region.

The Iron Range project would be the first mine of its kind in Minnesota, one that extracts and crushes sulfide-bearing rock to produce such metals as copper, nickel and palladium, which are in high demand for computers, cellphones, wind turbines and other new technologies. Several more copper mining projects closer to the Boundary Waters Canoe Area are also in development.

The PolyMet open pit mine would be near Babbitt. The ore would be processed at the former LTV Steel Mining Co. Erie Plant in Hoyt Lakes.

But environmentalists say that northeastern Minnesota, with forests, lakes and wetlands that make it one of the most beautiful and popular areas in the state, is the wrong place for such a mine. The risk of acid runoff and the leaching of heavy metals, they argue, are too great a risk. They also say it could threaten some of the declining number of Minnesota's naturally occurring stands of wild rice, a major concern for Indian tribes, because the plant does not grow well in water high in sulfates, another potential byproduct of the mine and ore processing.

PolyMet and other proponents of the mining resurgence say new technologies, legally required financial protections and sharp regulatory oversight would protect the region and its $700 million tourism industry.

But the repeated delays in completing the environmental review are an indication of how difficult it will be to fulfill that promise, environmental groups say.

"What else do you expect when you put a mine in the middle of a wetland," said Greg Seitz, communications director for Friends of the Boundary Waters.

Josephine Marcotty • 612-673-7394