The risks associated with permitting an array of copper and nickel mining projects targeted for northern Minnesota got a lengthy hearing at the State Capitol on Friday.

The timing is critical.

PolyMet Mining, which bought the old LTV taconite mine in Hoyt Lakes, hopes to gain permits and begin mining early next year. Duluth Metals just announced this week that it has one of the richest copper and nickel depositories in the world along the Duluth Complex near Ely. Franconia Minerals is also in the midst of copper exploration.

The projects are controversial. They represent a potential windfall for the state with thousands of new jobs for the beleaguered Iron Range, more than $1 billion in royalties, taxes and educational funding, and more than $500 million in capital investments. However, environmentalists argued that copper and nickel mining hold significant risk to the environment and taxpayers.

Scores of geologists, environmentalists, professors, state officials and mining experts testified Friday before the joint hearing and a room packed with spectators.

Sen. Ellen Anderson of St. Paul and Rep. Tom Rukavina of Virginia, the DFLers who cochaired the hearing, said the information session would help the politicians learn more about the risks and rewards of copper mining, which is a first for Minnesota, and nickel mining, which will be a first for the nation.

Officials from the Sierra Club, Minnesota Center for Environmental Advocacy and the Friends of the Boundary Waters Wilderness warned that waste-rock tailings from copper mines could leach sulfuric acid into rivers, streams and ground water.

PolyMet Chief Operating Officer Joe Scipioni and environmental head LaTisha Gietzen told legislators that they are well aware of the environmental concerns and plan to get their $380 million project right. Crushed rock tailings will have liners under them and covers over them to prevent sulfuric acid runoff. Canada-based PolyMet also plans to recycle all water used in the mining, crushing and metal extraction to try to keep the ground safe.

Clyde Hanson was not persuaded. The Sierra Club official brought a poster-sized aerial photo of PolyMet's proposed mining site to the hearing and pointed to a large body of water surrounded by acres of trees. "This is where the mine will be," he said. While PolyMet's protective actions work in the short term, what will happen when the mine eventually shuts down? he asked. Linings and covers for the crushed tailings need to be replaced at least every 50 years to prevent seepage into lakes streams and rivers.

David Chambers of the Center for Science in Public Participation told legislators that most mines end up having some form of seepage problem. He said there are dangers to sulfuric "acid mine drainage" because it raises mercury levels in fish and exposes people to mercury, lead, arsenic and more.

Thomas Power of the University of Montana downplayed any economic bonanza such projects might bear, noting that mining towns are never known to be prosperous for long because of the severe boom-and-bust cycles associated with the industry. "This is the roller coaster that often is mining," he said. "The problem is not just the instability of mining, it's the overreliance on mining" that threatened communities in Montana and the Iron Range in the past.

Pete Pastika, city administrator for Babbitt, testified that such sentiments were "lies, damned lies and statistics." The idea that the mining alone dampened Iron Range employment was "flawed logic" he said, because it didn't take into account technology and equipment improvements over time. He insisted that mining can exist without harming the environment, saying it just takes careful planning and money to make projects safe.

Dee DePass • 612-673-7725