From Friends of the Boundary Waters Wilderness
(Comments were due by October 16, 2017.)
The Minnesota Department of Natural Resources (DNR) recently released two more draft permits for the proposed PolyMet mine. These draft permits would allow PolyMet to build and operate two dams to hold back tailings, or mine waste generated from proposed operations. A waste dam failure is the most catastrophic thing that could go wrong at PolyMet’s proposed sulfide mine.
PolyMet proposes keeping hundreds of millions of gallons of mine waste and polluted water in their “flotation tailings basin” behind a dam that is already forty years old. According to the draft permit, this dam would need “perpetual” maintenance. This means that hundreds or even thousands of years from now, people will need to continue inspecting and repairing the dam regularly, with downstream residents, wildlife, and water under continual threat.
Sulfide mining waste dams have failed around the world, devastating communities and downstream waters. In 2014, the dam holding back toxic mine waste at the Mount Polley mine burst, flooding a pristine lake at the headwaters of the Fraser River. In 2015, the dam at the Samarco mine in Brazil failed, killing 17 people and spreading toxic mud hundreds of miles downstream.
If a dam breach were to occur at PolyMet, more than 30 structures downstream would be inundated within hours. Eventually, the flood of polluted water and waste would reach the St. Louis River and affect the people and wildlife downstream who depend on it. It would likely be the worst environmental disaster in Minnesota history.
Even more troubling, storing mine waste in basins held back by enormous dams is not even necessary for new mines. An expert panel that reviewed the Mount Polley disaster in Canada recommended dry storage technology for all new mines. This technology has never been considered for PolyMet, despite the recommendations of the DNR’s own contractors.
Feel free to contact me with any questions and thank you for all you do to protect the BWCAW and the Quetico-Superior ecosystem.
Jane Reyer Advocacy Director
P.S. In addition to email, you can also submit your concerns by U.S. Mail, with “NorthMet Dam Safety” in the subject to:
Minnesota Department of Natural Resources ATTN: PolyMet NorthMet Project 500 Lafayette Road N, Box 45 Saint Paul, MN 55155-4045