By Matt Doll, Minnesota Environmental
On Thursday, Twin Metals announced some major changes to its proposal to conduct sulfide ore mining near Ely. Twin Metals’ new waste storage plan would move its storage location from the St. Louis River’s headwaters into the Boundary Waters watershed, where the mine itself would also sit. Some of the tailings would also be put back into the mine itself in this scenario.
Additionally, instead of storing its tailings – waste rock and sand from which ore has been removed – in a slurry behind a water-filled storage dam, Twin Metals would instead institute “dry stack” storage, which uses dirt, linings, and vegetation to attempt to keep toxic runoff from flowing out of the waste into nearby waters.
While dry stacking involves a very different set of risks from a tailings dam, the fundamental fact of the issue has not changed. Sulfide mining has never been conducted in the United States without significant pollution to the surrounding water and ecosystem. The storage of the tailings is only part of the picture.
The Twin Metals mine would lie in vulnerable, interconnected waters in the BWCA watershed, where the headwaters are pristine. It’s impossible to overstate the value of these ecosystems and freshwater resources – value that could be permanently stolen by sulfide pollution.
The Twin Metals announcement does not change the question to which Minnesotans deserve an answer: How can we be sure that sulfide mines won’t irrevocably damage our precious waters and communities?
If these mines can’t offer a satisfactory answer that is full, honest, and transparent, Minnesota shouldn’t be expected to pay the price.