PolyMet officials say their proposed copper-nickel mine would have a big economic impact for the entire state. Spokesman Bruce Richardson says new technology is making it easier to separate the two minerals, and that’s why they want to start mining copper and nickel here. The proposed mine would be near Babbitt, and the proposed processing plant would be near Hoyt Lakes. Opponents of the project are concerned about the potential impact it could have on the water supply in the region.