PolyMet Mining Corp. says it will put up $544 million in financial protections for the first three years of construction and mining at its proposed copper-nickel facility in northern Minnesota to insulate taxpayers from any environmental damage that could result.
The so-called "financial assurance" is the last piece required in PolyMet's application for a permit to construct a $650 million mine and processing plant near Hoyt Lakes, the company said.
The assurance estimate in PolyMet's financial proposal, which is considerably higher than the company predicted a year ago, now goes under state review.
Along with other permit requests covering air quality, water quality and a tailings dam, it is expected to be open for public comment early next year.
PolyMet's is the first of what could be several copper-nickel mines in northeast Minnesota, and would be the first to receive state permits. Many northern Minnesota residents have greeted it as hope for returning the Iron Range to its mining heyday.
But the permitting process has grown lengthy, in part because copper-nickel mining carries far greater environmental risks than the region's taconite industry; its runoff waste can produce heavy metals that can contaminate streams and groundwater.
The proposal unveiled Tuesday sets the floor for one of the most critical decisions facing Minnesota: how to protect taxpayers from the risks inherent in such mining — the possibility of acid mine drainage, catastrophic accidents, failure to properly close the mine and, potentially, hundreds of years of water treatment.
State regulators must walk a tightrope of sorts in setting financial protections for the mine's 25-year life. If they ask too little from PolyMet, state taxpayers and the people downstream from the mine could pay the price years later for environmental damage. If they ask too much, a long-awaited project seen as an economic boon for Iron Range could be stopped in its tracks.