Mount Polley disaster spurs scrutiny of Minnesota nonferrous mine plans

This screenshot from aerial footage by Canadian Global News shows the sludge from the tailings pond flowing from the site of the breach.

This screenshot from aerial footage by Canadian Global News shows the sludge from the tailings pond flowing from the site of the Mount Polley Mine breach near Likely, British Columbia.

Sometime in the middle of the night on Monday, Aug. 4, the dam holding together a tailings basin at a British Columbian copper and gold mine gave way, sending 1.3 billion gallons of tainted, sludgy water into local streams and lakes.

Officials tell residents in the closest town, Likely, B.C., not to use the water from several lakes and rivers near the Mount Polley Mine, including a precautionary ban stretching all the way to the well-known Fraser River. (And no, “Likely” is not a made-up name from a ham-handed eco-novel. It’s a real town named for an old mining boss named John A. Likely). Mount Polley is operated by Imperial Metals of Vancouver.

The CBC reports that Canadian and provincial officials now assess the full extent of the damage and how something like this even happened. Global News is reporting that Mount Polley Mine employees are saying that tailings pond breaches have happened before, just never to this extent. Meantime, the breach compromises the town’s drinking water and sidelines its tourism economy, which had co-existed with mining, for an indeterminate amount of time. Possibly a very long time.

Already, copper mining critics cite this disaster as Exhibit A that these mines threaten local ecosystems. Many here in Minnesota wonder: if this tailings pond breach can happen at an active mine in Canada, where regulations are similarly stringent to U.S. law, how on earth can we be confident in a tailings pond at a proposed nonferrous mine in northern Minnesota? After all, those tailings basins are supposed to last 500 years, according to PolyMet’s own Environmental Impact Statement estimates.

That was the very question I posed to LaTisha Gietzen, PolyMet spokesperson, yesterday. How would PolyMet prevent what happened at Mount Polley from happing at a nonferrous mine in the Lake Superior watershed?

Though the specific details of what happened at Mount Polley aren’t yet known, Gietzen pointed out several differences between what’s known about the Mount Polley mine and PolyMet’s proposal in Hoyt Lakes, Minnesota.

“We have a high level of confidence that our tailings impoundment is and will remain safe based on the size, design, location, construction and general nature of the structure,” said Gietzen.

Among the observable differences between Mount Polley and PolyMet, Gietzen said the Mount Polley Mine taps into a porphyry deposit in a much hillier location — two factors that influence the toxicity and water pressure in the pond.

“Porphyry deposits often contain higher sulfide levels and clay,” said Gietzen. “The clay tends to keep material in suspension and hamper drainage in tailings. PolyMet plans to mine a low sulfide deposit that does not have appreciable amounts of clay minerals. Therefore the geochemistry of our tailings will be different and the water in our tailings basin will be in the pH neutral range.”

The high clay and silt content of the Mount Polley breach would account for the sludgy nature of the spill. Gietzen adds that PolyMet proposes using the outline of LTV Steel’s old iron ore tailings pond, one that has been time-tested.

“We already maintain an existing structure that has been there more than 40 years and, to our knowledge, never had a breach,” said Gietzen. “The design of that structure is proven and tested and we’ll be applying a similar design to an adjacent tailings structure, but employing some modern techniques.

Among those techniques, PolyMet aims to use existing fill materials from other areas on site in addition to the flotation tailings themselves, buttressing the exterior face of the dam with rock to add stability.

Gietzen adds that underground cutoff walls around more than half of the structure will help manage the overall water management and drainage system. She also says that the lack of seismic activity in Northern Minnesota, along with a very gradual slope and regular DNR inspections will all combine to make the PolyMet tailings basin more secure.

Assurances aside, however, the vocal mining opposition group Mining Truth issued a statement pointing out that the same engineering firm that build the failed dam in British Columbia advised PolyMet and the Minnesota DNR during the ongoing permitting process for PolyMet’s NorthMet nonferrous mine project near Hoyt Lakes.

“Minnesotans are being asked to put a lot of faith in these companies that their projects won’t endanger the mine’s workers or the surrounding environment,” said Paul Danicic, Executive Director of the Friends of the Boundary Waters Wilderness. “It’s deeply disturbing that the same firm that designed the collapsed tailings dam was hired by PolyMet and the Minnesota DNR. We’re being asked to trust these companies with Minnesota’s water.”

It’s true: engineers are fallible, and it would be wise for every mining operation in the world to take another look at the design of their tailings basins based on this terrible disaster. Responsible companies will learn from this and react appropriately. PolyMet says it will be seeking third-party engineering consultants to confirm the safety of their plans once they are permitted.

Mining the minerals we use in everyday products is inherently risky and, to some degree, inherently necessary. The question for Northern Minnesota is whether the need for and benefit from new nonferrous mining is greater than the risks and costs. Incidentally, this is what mining companies talk about behind boardroom doors. Communities and states should do the same, and lay out the considerations plainly in public view.

What happened in British Columbia simply must not be allowed to happen in Minnesota; the effects would be culturally and economically devastating. But we should also acknowledge that there is an acceptable amount of risk to take when it comes to mining necessary minerals. The challenge is finding the tipping point.

When you break this debate out of the emotional, culturally-motivated battle between developers and environmentalists you see that we have a question that can probably be answered, if we’re willing to use math honestly to determine what the future of Northern Minnesota could and should look like.

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This item was cross-posted with my “Up North Report” blog at the Star Tribune.


  1. John Ramos says

    I’m looking forward to watching the president of Imperial Metals drink a big glass of tailings pond water, like he says he would. Maybe he could mix it with tomato juice and vodka and make a Sludgy Mary. Yum.

  2. Paul Schoonover says

    Mr. Brown,
    I’m a fan of your writing and appreciate your insight on all things Iron Range. However, after reading this piece, and others like it, I would press you to make your ideas more clear, for the benifit of all Minnesotans.
    The position of ‘I’m for (sulfide ore) mining,as long as it’s done right’ is a political paradox equal to one who says they’re for war, as long as no one dies.
    For example, you say “what happened in BC simply must not be allowed to happen here”. That statement, in and of itself, is an endorsement for NO sulfide ore mining in our sate, as no amount of legislation, regulation, enforcement, or company promises/assurance will ever ensure that it won’t happen here. You must know this… It’s like saying if only there were more cops there would be no crime.
    Similarly, the assertion that there is some “honest” mathematical equation that will unequivocally show whether or not sulfide ore mining is a good idea for Minnesota is irresponsible at best. Unless of course you know what that equation is, and are just waiting for the right time to share it with us. The assertion gives the reader the opportunity to fill in his own x’s, y’s, and z’s to come up with whatever answer suits his values. Do you know the equation?
    You have a great platform for expressing your thoughtful, and insightful ideas, which I believe are beneficial to the region and state. I would encourage you to not stop short of your true thoughts and beliefs.

  3. Hi Paul – If I believed that no nonferrous mining of any kind should be allowed in Minnesota, that’s exactly what I would say. My opinions, ever developing with new information, are more nuanced than that. I am skeptical about these projects, but as I wrote in this piece there is a constant balance between risk and need when it comes to mining. Do I know what that is exactly? It is my understanding that an open and honest permitting process and legal review is supposed to produce this determination. If it doesn’t, then there is something horribly wrong with the whole system and we’re all wasting our time.

    If I told everyone what to think on this issue, no one would listen — except, of course, for people who already agree. I leave it open because persusasion requires people to feel ownership in the outcome.

    My biggest complaint about the nonferrous debate in MN is that the claims about job creation are grossly overstated and that the amount of energy this process has absorbed has irresponsbily derailed most meaningful discussion about economic diversification. I am for economic diversification and a future that does not require mining for Northern Minnesota to thrive. It need not exclude responsible mining, but it must include economic diversification. If you want Northern Minnesotans to accept something as unambiguous as a moritorium on nonferrous mining, they must be convinced that it’s in their interest. Only a diverse economy provides this.

    I expect that earnestly filed environmental challenges will tie up new mining in the courts for years. Meantime, I am arguing that rural broadband, community development, public art and entrepreneurship will create an alternative view of Northern Minnesota that will win us independence from the remote rule of mining companies.

    • Paul Schoonover says

      My opinions are ever developing with new information and are nuanced as well.
      I feel a responsibility to learn, research, and consider all arguments, but also to come to a personal conclusion- based on the information available and my personal value system. Isn’t that the best we can do?
      Therefore I have considered the “risk vs. need” equation you speak of. It is my opinion that there is little need for this particular type of mining when it unquestionably brings with it the risk of the type of environmental disaster that happened in BC. The point of my original comment could be summed-up by pointing out that you say “this CANNOT happen here”, but if we dance with this devil, it very well could.
      As to the “open and honest permitting process”, there is certainly “something horribly wrong with the process”. As you know, the DNR is charged with the tasks of both promoting and regulating all mining activity in the state. Very disconcerting. Furthermore, they are scrutinized to maximize profitability for the state in all mining activities through royalties. “Waste if time”, you say?
      I agree with you on all other points and appreciate the response.

  4. It’s incredibly frustrating to me as a life-long, middle-age, relatively-educated Iron Ranger to see how simplistic both sides make the issue and try to make us who live here appear. The conversation has become so extreme that each side has to make more and more ridiculous claims to try to outdo the other.

    Of course we know that there are risks, but we also know that mining provides residents here middle-class lifestyles that most of us strive for. To simplify it down to “all mining good” or “all mining bad” is not possible if you live here and have kids who you hope can also live here for their lives, too.

    Extremists on both sides lie seemingly without care for anyone who actually lives here.

  5. David Gray says

    If someone requires mining to present zero risk then they are against all mining. Almost no commercial activity takes place with zero risk. As Aaron observed it is a matter of balancing risk against gain. Of course most of the anti-mining zealots aren’t local so for them there is no gain.

  6. Short-term vs long-term risks, costs, actual gains are issues that many folks don’t seem want to discuss., certainly not in depth, not without freaking out. If only so much emotion and effort was given to moving away from putting all our eggs in one basket.

    We cannot have infinite economic growth on a finite planet.

  7. The size of the plant has nothing to do with how much economic growth is possible…my God kissa, what plant are you from?

  8. Geraldinesasquatch says

    A likely story.

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