At National Arctic Park in Alaska, a bank of this lake thawed, causing it to drain. Photo via Wikimedia
For decades, mine operators in Northern Canada have stored waste rock and tailings waste—the "pulverized rock slurry" byproduct of mineral processing that's filled with skeevy chemicals like arsenic, lead, and mercury—in frozen dams reinforced with permafrost, an option far cheaper than constructing artificial structures to house the goop. But if such walls thaw, allowing air and water to interact with the highly reactive tailings, widespread "acid mine drainage" (AMD) could occur. Such a process can generate sulphuric acid and result in the leaching of heavy metals into nearby soil and water sources."Permafrost degradation is going to affect everything," says Magdalena Muir, research associate at the University of Calgary's Arctic Institute of North America. "When you have frozen infrastructure, you don't have to build an artificial structure and probably get used to not having to worry too much about breaches. But as soon as you have soil that behaves just like any other soil, you have all the issues you'd have in southern Canada."The Canadian mining sector produces around one million tons of waste rock and 950,000 tons of tailings per day. As a result, the prospect of widespread AMD could be disastrous for the Canadian North: such scenarios would obviously be nightmares to contain, with the remoteness and cold climate seriously impeding cleanup. Think the Deepwater Horizon of the Arctic, except not nearly as visible and minus the dead dolphins to draw attention to the disaster. And like methane bubbling out of the permafrost, the situation only gets worse as it unfolds.
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Mount Polley Mine prior to the dam breach. Photo via Wikimedia
Orphan Mines, Zombie Mines, and Straight-Up Disasters
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Great Slave Lake in the Northwest Territories. Photo via Wikimedia
Raising the (Very Low) Bar for Environmental Protection
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The Future Defrosted
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