just some counter points, nothing positive to add -

"PolyMet is estimating 400 jobs will be created when running at full capacity. That's 400 jobs  for 20 years"

Yeah, maybe --  mining has always been boom and bust, boom and bust -  prices go up, and new mines open all around the world, supply and demand works, so supplies go up, prices and demand go down, and the mines get shut down and miners laid off.  The Molybdynum mine near Leadville is classic example for this - it'll be open for a few years, or a year, or a half year, then shut down for a year or years.  Hell on the local economy if there isn't alternative employment.   (Look what happened to Atikokan when those iron mines shut down)   If prices/demand go down, and the remaining minerals aren't economic to dig, they just shut in the mine and wait/hope price and demand go back up - so that 20 years may stretch to 60 in the long run - and as long as the mine isn't technically played out, why would they close it down and reclaim/revegetate ?  a lot cheaper to just say they are waiting for the market to turn around again.

not quoting, but it was said that the technology to do the mine environmentally safely/correctly is available, and rules are stricter than years ago --- maybe         but there were rules and technology in place to keep the Exxon Valdez off the rocks; there were rules and technology enough to keep Challenger and Columbia from blowing up; there were rules and technology in place to prevent 3-Mile Island and Chernobyl; there were rules and technology in place to prevent that coal slurry pond from cutting loose.        So what happens to the rules and technology when some plant manager gets his budget cut, and maybe cuts cost on the monitoring equipment, or buys a cheap valve, or......

al long as you can't prevent human nature and greed from exercising bad judgement and cost cutting, you got no real guarantee that the rules and technology will actually do what they are supposed to  - those instances may be only 1 in a thousand, or one in a million - but the cost of those instances is really high - is such a potential cost worth the potential benefit of those supposed 400 jobs ??  That big swamp area sounds like its pretty unique as is

Nickel may be important to national security - don't know, but my guess is if its mined in US, it'll wind up being shipped to China so they can make more Nicad batteries for us to buy back -- worth it ?

Just like the current debates over the national deficit - do we have the moral right to bankrupt future generations ?  500 years out ?  what's wrong with "storing in place" those minerals in MN and buying the metal form other producers.  

Similar argument to drilling in ANWAR for oil we "need" now - my thinking is as long as we can buy the oil elsewhere now,  let's keep that in reserve for future generations, in case it is ever desperately enough needed to really be worth taking the risks associated with extracting it.  Most or maybe all of the oil that flows thru the Alaska Pipelin used to be sold to Japan - closer for shipping and less environmental issues about delivery to shore from the tankers - my guess is most of the oil under ANWAR would go the same way.  That may be off topic, but I see it as a similar situation to the mine in question.  Do we need that mineral that badly now?

and last, but not least - I think there should be a total moratorium on all mining until they redo that 1890's mining law.  Mining should be similar to oil and gas exploration, where the landower - the government in this case (that's us) gets a 1/8th (or more) royalty - that is, 1/8th the value of the extracted mineral, right off the top.  Why should we continue to give this stuff away ?  If that royalty makes the project uneconomical for now, well good.  I want "my" share.