As a mining engineer and graduate from the Colorado School of Mines, I dedicated my career to extracting minerals to support a modern society. Now my engineering and operating experience in 12 different open pit and underground salt, iron, uranium, and gold mines across the U.S. over the past 45 years, tells me Minnesotans should be deeply concerned about the long-term impacts for the Boundary Waters Canoe Area Wilderness (BWCA) watershed if the sulfide-copper and nickel minerals of the geologic Duluth Complex of northern Minnesota are mined according to the proposed Twin Metals mine plan.
First, the sulfide minerals of the Duluth Complex are significantly different from the low sulfur iron ores of the Mesabi Iron Range. The resulting waste dumps, tailings ponds, and abandoned mines from sulfide minerals all would be potential sources of acid mine drainage, heavy metals and other pollutants, contaminating clean water. If this area is mined, these sulfide wastes would need to be treated differently and isolated in a “geologic sarcophagus” in perpetuity, to try to protect the headwaters of the greatest source of fresh water on the planet.
Second, engineering can reduce but not eliminate risk, especially with sulfide minerals mining. Pipe, valves, pumps, liners and other parts of a mine do wear out and fail, and often the failures are not predicted. And of course all people are fallible, including engineers and miners, so it is impossible to say in advance that there won’t be mine design flaws, operator errors, and missed signs of an impending failure.
Third, and I say this as an experienced mining engineer, you can’t trust the startup mining company or the new mining operator to keep its most important promises. The executives making the promises today probably won’t be in charge when it’s time to keep them, and future mine permit amendments likely would expand the footprint of the mining project, increasing environmental risk. Start-up mining projects (mining juniors) are traded like commodities on the open market and there is no guarantee the new owner has any proven business or mining experience in a water rich place like Minnesota. The new owner could be a shell company, a convenient box into which the real mining company drops all the risk and long-term liabilities, and bankruptcy courts protect the main corporation’s profits. Twin Metals is owned by the Chilean company Antofagasta PLC, meaning the local mine executives might not have the authority to keep their promises made here in Minnesota.
Minnesota has provided valuable resource extraction for more than 100 years along the Iron Range. But the Duluth Complex is a very different rock type with higher pollution risk in a very sensitive environmental area, requiring more prescriptive mining rules and closer regulation than the historic iron ore mining.
As a lifelong engineer and miner and a native Minnesotan, I feel it is my duty to say this. The threat to the BWCA from a mine like what Twin Metals is proposing along lakes and under a river just upstream from the wilderness waters could be devastating under current best mining practices, and in my considered opinion, too risky to be allowed.
Even new sulfide mining and processing technology and practices like lime neutralization, cementation, double lined (ponds, tailings basins, and waste dumps), and topographic isolation of tailings, which are currently available and costly, would not take the risk away of a design flaw, or operator error, or failure to supervise for hundreds of years, or future decisions to cut corners because of a lower than expected ore grade or a market downturn. We should want this type of mining to be proven first, in a low environmental risk area. But sulfide copper and nickel mining should never be attempted on the border of the BWCA. The risks are simply too great.
Chris Baldwin, a third generation Iron Ranger, lives in Hibbing.
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