Yukon gov't to spend 3 years remediating abandoned Minto mine site

The underground workings of the Minto mine in central Yukon are being allowed to naturally flood, in accordance with the territorial government's remediation plan. The territorial government took over responsibility for the site after the mine was  closed and abandoned by the now-defunct Minto Metals Corp. last May. (Yukon government - image credit)
The underground workings of the Minto mine in central Yukon are being allowed to naturally flood, in accordance with the territorial government's remediation plan. The territorial government took over responsibility for the site after the mine was closed and abandoned by the now-defunct Minto Metals Corp. last May. (Yukon government - image credit)

The Yukon government is planning to spend three years remediating the Minto mine site, regardless of whether another company buys it.

The mine, located near Pelly Crossing, Yukon, on the traditional territory of the Selkirk First Nation, was closed and abandoned by the now-defunct Minto Metals Corp. last May. The government took over the site the next day.

Remediation of the site has already cost $20 million, and spending is expected to grow to $24 million by the end of the fiscal year in March. Another $21.5 million is budgeted for next year.

The money is coming out of the $75.2 million in security that Minto Metals furnished before the closure.

Yukon officials provided an update to the budget and remediation work on Thursday.

An ice bridge will be completed this week, and then crews will begin trucking equipment and diesel fuel to the site. Hazardous waste will be trucked out.

There are also 76,000 kilograms of expired explosives at the site that will be destroyed "in a safe and environmentally friendly way," according to Darren Stahl, the territory's director of assessment and abandoned mines.

This summer, three months of water treatment will lower the pit water levels, to make room for the low-grade ore that was left behind above ground.

In this map of the abandoned Minto mine site, provided by the Yukon government, waste dumps circled in orange are going to be regraded and covered, while the low grade ore deposits, circled in blue, will be deposited underwater.
In this map of the abandoned Minto mine site, provided by the Yukon government, waste dumps circled in orange are going to be regraded and covered, while the low grade ore deposits, circled in blue, will be deposited underwater.

In this satellite image of the mine site, waste dumps circled in orange will be regraded and covered, while the low-grade ore deposits, circled in blue, will be deposited underwater. (Yukon government)

"It's going to be a busy set of earthworks this year, of moving, reshaping, recontouring, excavating some of the other wastes, putting them under water," said Stephen Mead, assistant deputy minister of mineral resources.

Potential buyer won't affect remediation timeline

Receiver PricewaterhouseCoopers (PwC) has been managing Minto Metals Corp.'s affairs since the company went under.

It's narrowed the field down to one potential buyer for the abandoned mine site and set an April deadline for the deal. If the sale falls through, PwC will liquidate the assets.

If a new buyer purchases the site, they'll be subjected to the same extensive approval process as any mining company entering the Yukon.

Mead said that the timeline of that process, in combination with the state of the site, means that the sale won't affect the plan for remediation.

"These are very old waste dumps from some time ago, they're areas that we know really have to be remediated irrespective of the future of the site," Mead said.

Mead said that the prospective buyer might be interested in exploring the entirety of Minto's claims, which span a much larger area than the actual work site.

"There were reserves in front of them that they didn't get to," Mead said.

If the next owner is interested in developing a larger area, it will only lengthen the mine's operating timeline.