Sulfide Mining: Myth vs. Fact

MYTH: The average sulfur content in Duluth Complex rock is one percent, which is very low compared to other mines, meaning that acid mine drainage will not be a problem.

• FACT: Other mines with similar or even lower average sulfur content in the rock have created significant acid mine drainage problems (e.g., Brohm Mine, South Dakota).
• FACT: Minnesota Department of Natural Resources research has found that Duluth Complex rock with sulfide content as low as .08 percent can produce sulfuric acid.
• FACT: There is a lot of rock in the Duluth Complex deposit that is in the five to six percent sulfide range.
• FACT: Average sulfide content is less important than the volume of reactive rock. Duluth Complex rock is a low grade deposit, which means the volume of rock extracted is enormous and almost all of it that is mined will be stockpiled as waste rock. Waste rock piles at the NorthMet site would be approximately the size of 500 football fields, 20 stories high.
• FACT: Duluth Complex rock is very low in the carbonate minerals that act like antacids to neutralize the sulfuric acid. So, even though the rock is low in sulfides, it still has a very high risk of creating acid mine drainage.

MYTH: The mining will be done in existing mining zones where little of the natural landscape remains.

• FACT: PolyMet’s NorthMet mine site is currently forest and wetlands. Mining at that site would destroy approximately 1,200 acres of wetlands, one of the largest wetlands destructions ever permitted by the Army Corps of Engineers. Wetlands are an important resource for sequestering carbon and slowing climate change, the destruction would release significant carbon into the atmosphere.
• FACT: The NorthMet project is on public land that was acquired by the Forest Service in the 1930s with a stipulation it could not be used for mining. Currently, the mine site is part of a large tract of undeveloped, public land open for backcountry recreation.
• FACT: Mining exploration has been occurring right up to the very edges of our treasured Boundary Waters Canoe Area Wilderness. Mining by Franconia Mineral Company, Duluth Metals and possibly others would be adjacent to and actually underneath Birch Lake, a lake on the South Kawishiwi River where it flows out of the BWCAW and then back into the wilderness.

MYTH: New techniques employed by mining operations would prevent the pollution that has occurred elsewhere with this form of mining.

• FACT: Mining companies seeking to mine in Minnesota aren’t the first to claim that their mines won’t pollute. A 2006 study found that, while 100 percent of mines looked at predicted no water pollution, 76 percent ended up polluting the water anyway. Additionally, 89 percent of the most high-risk mines-those near water supplies-that caused water pollution predicted that they would not.
• FACT: One person’s new technology is another’s unproven and untested experiment. There are no known commercial uses of autoclaves for processing ore or geothermal liners underneath waste rock piles. These mines would make a guinea pig of our fragile lake country.

MYTH: Sulfide mining in northeastern Minnesota would be an important domestic supply of these metals.

• FACT: Mining companies are based in Canada. Additionally, only copper is proposed to be processed on the Iron Range. The other minerals will be processed at a location which has not yet been disclosed by mining companies. PolyMet Mining also recently signed a contract with the Swiss corporation Glencore to sell its minerals to Glencore, which means Americans will still be at the whim of multi-national corporations and international markets.
• FACT: Clean water and unburdened tax dollars are also increasingly important resources.