Harmful Impacts of the PolyMet Sulfide Mine

It is widely recognized that sulfide mining in Minnesota would have devastating effects on our wilderness areas and water quality. Many Minnesotans recognize that sulfide mining has a dismal track record of 100 percent failure to protect water quality in a water-rich environment, like that of northern Minnesota. In other words, sulfide mining is virtually guaranteed to contaminate Minnesota’s surface water and groundwater with acid mine drainage and toxic metals.
Acid mine drainage flows through a stream in western Pennsylvania. Photo by Nathaniel Warner.
What is less widely-known, but of enormous importance to understand, is the wide range of harms posed by the PolyMet copper-nickel mine. Downstream communities, human health, environmental injustice, and climate change would all be adversely impacted. PolyMet’s relationship with Glencore, a notorious multinational bad actor, exacerbates these threats to people and the environment.

Catastrophic Tailings Dam Failure

PolyMet suggests that its mine would have only local impacts, since it would be 175 “river miles” from Lake Superior. However, a United Nations environment report on tailings dam failures found that a tailings dam failure could release a “tsunami-like wave of mine waste.” In the case of the Fundão tailings dam failure in Samarco, Brazil, mine waste traveled 385 miles downriver until it reached the Atlantic Ocean. PolyMet’s tailings dam uses the same unreasonably dangerous “upstream” tailings dam construction that failed in Samarco and has resulted in 66% of major tailings dam breaches worldwide. If the PolyMet tailings dam failed, mine waste could flow down the St. Louis River and contaminate Lake Superior.

Mercury & Harm to Human Health

The PolyMet mine would release mercury into the air and water, emit sulfur air pollution, and discharge sulfate to water. Mine operations would excavate, drain, and rewet wetlands. All of these damaging effects would increase mercury contamination of fish, threatening the developing brains of Minnesota fetuses, infants, and children. The PolyMet mine would also discharge toxic arsenic and lead, and would emit dangerous particulates into the air. Groups representing more than 30,000 Minnesota doctors, nurses, and other health professionals called for (but did not secure) a health impact assessment before the PolyMet mine was approved.

Environmental Injustice

Environmental justice is the basic principle that tribes and low-income or minority communities should not bear a disproportionate burden of harm from actions permitted by the government. But, the PolyMet sulfide mine would be located on 1854 Treaty lands where the Ojibwe people have treaty rights to hunt, fish, and gather plants. PolyMet sulfate pollution would destroy downstream wild rice (manoomin) a resource vital to Ojibwe people for food, culture, and economics. Increased mercury contamination from the PolyMet mine would also have a disproportionate impact on the downstream Fond du Lac Reservation and on tribal members who rely on fish for subsistence. The PolyMet sulfide mine would result in environmental injustice.

Climate Change Harm

Mining of copper and other recyclable metals creates a substantial – and avoidable – impact on climate crisis. Data from PolyMet environmental review shows that the annual impact of the PolyMet mine would be one-fourth the carbon dioxide equivalent footprint of the entire city of Duluth. As an alternative to the harmful impacts of mining and processing, existing copper can be recycled over and over. Recycling copper would save 90% of the fossil-fuel energy of a project like PolyMet.

Glencore Engagement with PolyMet

Glencore is a huge foreign corporation based in Switzerland with more than $200 billion in annual revenues. This notorious global mining and commodities giant acquired a 72% controlling interest in PolyMet in June 2019, after all of PolyMet’s permits were issued. Glencore, now effectively in control of the PolyMet mine project, is also known as one of the world’s worst corporations due to labor rights abuses, environmental degradation, and failure to take responsibility for toxic pollution. Glencore is also under criminal investigation in several countries for bribery and corruption.