PolyMet's sulfide mine threats of toxic pollution, dam failure and threats to downstream communities continues. https://youtu.be/UnBQTPjNotw NEW Video. Update on PolyMet sulfide mine threats of toxic pollution, dam failure and threats to downstream communities. Call Gov. Tim Walz and at 651-201-3400 and ask him to reopen PolyMet permits due to improper process and dam