The St. Louis River in northeastern Minnesota was named one of the most endangered rivers in the country Monday by a national conservation group that every year names 10 rivers it considers to be at a tipping point from imminent environmental threats.
The St. Louis, the largest U.S. tributary to Lake Superior and an important wildlife breeding ground, is already contaminated with sulfate and mercury and now faces additional risks from a proposed copper-nickel mine nearby, said the national group American Rivers.
It was one of five rivers nominated because of risks from some kind of mining, and the second Minnesota river to make the list in the last three years because of copper-nickel mining proposals in northeastern Minnesota.
"We can't afford to destroy the largest river feeding Lake Superior," said Jessie Thomas-Blate of American Rivers.
Officials from PolyMet Mining Corp., which is pursuing the copper-nickel project, say the mine, as planned, would meet all state and federal water quality rules.
Toronto-based PolyMet has proposed a $650 million mine near Babbitt and Hoyt Lakes that, if approved, could be the first to tap into one of the largest untouched reserves of copper nickel in the world.
The proposed mine would take over the tailings basin and crushing facility of a long-defunct taconite operation and dig a new open pit mine where a massive wetland exists now.
The operation would drain into streams that lead to the St. Louis River, which meanders for 194 miles through a 3,634-square-mile watershed before spreading out into the St. Louis River estuary near Duluth.