Gov. Dayton's 'due diligence' on PolyMet copper mine

Gov. Mark Dayton is on the road this week, visiting two mines in neighboring states to do what he calls his "due diligence."

He wants to see firsthand both the good and the bad that could come from a new proposed Polymet copper mine in northeast Minnesota.

Friday, it will be the good: Dayton is visiting Eagle Mine in Michigan's Upper Peninsula. The new Michigan mine just opened this year, creating 400 jobs.

MPR News' Tom Weber talked with two journalists who have covered these mines to discuss what Dayton will see there, and how that may affect his decision.

Charles Ray is a producer for South Dakota Public Broadcasting. He's covered the fall-out from the Gilt Edge mine for several years.

"The Gilt Edge mine is an open pit mine," Ray said. "And the rocks they exposed in this mine contain a lot of Sulphur, so when it rains on these rocks, the water then runs off and turns into sulfuric acid. That can run down the stream."

The mining company that opened Gilt Edge in the 1980s later went bankrupt. They left $6 million for clean-up, but that hasn't even come close to covering the cost, which is now over $100 million. And there's no end in sight.

"Officials tell us the water treatment will have to go on here basically forever," Ray said. "There's no end to the cost of treating water that's running off the mine."

In Michigan, it will be a different view for Dayton. John Flesher, a correspondent for the Associated Press, has covered Eagle Mine extensively.

The Upper Peninsula's mine only opened a year ago. And as a newer mine, Flesher said, it has more environmental protections in place. It's also an underground mine, which eliminates the rain issue that plagues Gilt Edge.

But that doesn't mean it's without risks. It took more than five years of applications and court rulings for the Eagle Mine to open after its initial approval was met with concern by environmentalists.

"There was a lot of concern during this very lengthy permitting process about potential damage to Lake Superior and some of the rivers that flow through that area," Flesher said.

Dayton will have all this to consider when he decides the future of the proposed copper mine. On one hand, it will be a newer mine, on the other, it will be an open pit mine — the same variety as Gilt Edge.

The possibility of an environmental disaster was clearly on Dayton's mind when he returned from his Gilt Edge visit.

"Our responsibility is to insist upon the impossible perfection," Dayton said. "And to get as absolutely close to it as humanly possible."