There is no doubt in my mind that this mine would have some effect on the surrounding area. This video really sums it up.
Two companies, Northern Dynasty, of British Columbia, and Anglo American, a giant multinational based in England, have teamed up as the Pebble Partnership to evaluate the potential for an open-pit mine—possibly up to two miles wide and 1,700 feet deep—and an underground mine of similar scale. The prospect alarms many, especially those who depend on or value the salmon above all else. They fear that the Pebble mine would destroy the fishery, largely by contaminating the water.