Sulfide ores contain metals (such as nickel, copper and cobalt) that are bonded to sulfur, forming sulfide minerals. When these ores are exposed to air and moisture, a chemical reaction occurs that generates sulfuric acid that migrates into the surrounding environment and, through leaching, releases heavy metals present in the waste rock, pit walls, and tailings basins of mining operations. The sulfuric acid along with dissolved heavy metals released onto the land will seep into the rich aquifers below and then into streams and lakes at levels that are toxic to fish and other aquatic life. This type of pollution is commonly referred to as Acid Mine Drainage (AMD) and has the potential to devastate entire ecosystems. The close proximity of sulfide mines to valued water bodies such as lakes and rivers of the Mississippi watershed intensifies the magnitude of this issue. All of the water bodies in the Tamarack area are linked by multiple aquifers.
To make matters worse, the sulfide mining industry has a poor history of stewardship, integrity and accountability. To date, no sulfide mine has been able to operate without causing some form of pollution in the surrounding environment. Talon Metals (who plans to mine in Tamarack, Minnesota) points to the Flambeau Mine in Wisconsin and the Michigan Eagle Mine as a model cases of environmental stewardship; however, both sites have serious environmental issues.
Many organizations have noted that anytime a sulfide mine has been built in a water rich area, the water has been contaminated. Of course, new mines open over time so no single reference can ever be "up to date" in support of this statement. Nevertheless, we can show that no mine has been found to not contaminate the local water based environment, particularly in wetland areas.
Thus we have not found a Nickel / Copper mine that has not polluted. Some people raise the question as to whether the Wisconsin Flambeau mine or Michigan Eagle mine has polluted or not.
Flambeau Mine Wisconsin
Here we note that the federal district court found that the mine discharged copper contamination at levels exceeding state standards www.casemine.com/judgement/us/5914f59aadd7b0493498b3f0). However, the Seventh Circuit Court of Appeals then ruled that this case could not proceed further, since Flambeau was entitled to a "permit shield" because it had no notice its state permit wasn’t valid so was entitled to rely on that permit. Nevertheless, the court did rule that the mine did release pollution.
In addtion, consider:
This independent work was done by experienced PhD scientists and demonstrate significant pollution from the Flambeau Mine. Indeed, the Flambeau Mine Corporation does not deny any of this nor do they produce additional results to argue an opposite claim.
Eagle Mine Wisconsin The Eagle Mine is still in operation and historically we see that AMD often does not manifest for a number of years after closure. However, even now given just a few years of operation, we see significant anomalies in monitoring when looking at the official mine report to the Michigan Government. If you look: ( www.michigan.gov/-/media/Project/Websites/egle/Documents/Reports/OGMD/2020-ogmd-eagle-mine-annual-report.PDF.
In addition, visits to the Eagle mine indicate serious issues with their tailings pile (they refuse to show you the tailings pile yet aerial photography clearly shows issues) and many other issues that will manifest as the mine proceeds. The point is that one cannot find a Sulfide Mine that is not damaging in a wet environment.
The existence of a sulfide mine in an area harms communities. The inevitable contamination of local water will negatively impact the wild rice beds that are currently used to sustain many in the community. In addition, fish and wildlife are negatively impacted resulting.
Talon Metals ( proposed Tamarack mine) has said that when mining operations cease in 12 years, they will simply cover the 75 acre, 82 foot high tailings pile that holds toxic high sulfide tailings. Covers and liners are known to work temporarily (pubmed.ncbi.nlm.nih.gov/23625128/) but in the long run leave a large toxic waste dump for tax dollars to deal with in perpetuity.
Property values drop as nobody wants to buy property that is or will certainly be contaminated in the future. Who wants property next to a toxic mine?
Finally, since the Tamarack mine will be in operation for only 12 years or less, the community is faced with a situation where a few jobs are created for a short time but with no permanent residents left to deal with the aftermath.
For more information on the dangers of sulfide mining:
Mining Action Group (savethewildup.org/about/sulfide-mining-101/)
Mine EPA Superfund Sites - use your browser to search on keyword "mine" www.epa.gov/superfund/national-priorities-list-npl-sites-state
Earthworks - Copper Sulfide Mining (earthworks.org/issues/copper_sulfide_mining/)
U.S. Copper Porphyry Mines Report providing 14 detailed case studies on mining polution.
Sahoo, P. K., Kim, K., Equeenuddin, S. M., & Powell, M. A. (2013). Current approaches for mitigating acid mine drainage. Reviews of environmental contamination and toxicology, 226, 1–32. https://doi.org/10.1007/978-1-4614-6898-1_1
Onello, E., Allert, D., Bauer, S., Ipsen, J., Saracino, M., Wegerson, K., Wendland, D., & Pearson, J. (2016). Sulfide Mining and Human Health in Minnesota. Minnesota medicine, 99(8), 51–55.
Official mine report to the Michigan Government ( www.michigan.gov/-/media/Project/Websites/egle/Documents/Reports/OGMD/2020-ogmd-eagle-mine-annual-report.PDF.