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Using good science to make sound decisions about complex projects is something on which we can all agree. Unfortunately, despite the belief that PolyMet Mining's permitting process is "science-driven" ("Dayton's timely stance on PolyMet," Nov. 1), this project is on a disastrous course to ignore good science and violate the laws and regulations designed to protect the environment. Below are just two specific examples of this.

First, under the proposed PolyMet plan, the mine would produce contaminated water that would be collected and treated indefinitely, perhaps for hundreds of years. A lot happens as centuries roll by, and the likelihood of the contaminated water polluting the surface and groundwater is as certain a bet as one will ever find. Certainly, PolyMet will not be around hundreds of years from now to monitor and take care of that pollution.

State regulations do not allow PolyMet's proposed plan. State regulations provide that, at closure, the mine operator must "permanently prevent substantially all water from moving through or over the mine waste." When adopting this rule, the Minnesota Department of Natural Resources (DNR) explained that "merely collecting contact water and treating it in order to meet water quality standards, without a substantial effort to minimize the amount of water contacting the waste, has been rejected. … [T]he potential for longterm failure of such a system, when the operator is no longer available to correct the situation, is too great."

State officials have allowed the PolyMet project to move through the permitting process for all these years, despite this fundamental design flaw that puts mining waste in contact with water for potentially hundreds of years, flying in the face of good science and the state's own laws and regulations.

Second, state officials have allowed PolyMet to cherry-pick its science during the permitting process, particularly when trying to predict the amount of water pollution. One of the most worrisome sources of pollution at a mine like PolyMet is unearthed rock and pit walls, which release toxic metals when they come in contact with water. This is no mining pit where anyone would ever want to swim. Both PolyMet and the DNR did years of testing of PolyMet's rock and had plenty of good data, but when it came to predicting the level of toxic pollution in the water, they threw these data out the window. Instead, they used 2013 information from a mine in the Yukon Territory in an effort to downplay the water contamination that would result after the mine closes. Ironically, the water quality at that mine has continued to deteriorate since 2013.

We at the Friends of the Boundary Waters Wilderness do not oppose all mining. However, copper sulfide mining presents excessive and unacceptable risks in this water-rich environment.

PolyMet would be Minnesota's first copper sulfide mine. While the permitting process is long, it is not based on sound science and does not follow Minnesota's own environmental laws and regulations. Minnesota deserves better.

Chris Knopf is executive director of Friends of the Boundary Waters Wilderness.