Almost 50 years after Hudson-Yukon Mining Company ceased production at its underground mine near Burwash Landing, there’s an application to reclaim the Wellgreen mill and tailings ponds.

The Wellgreen property was first discovered in 1952, according to the Yukon government’s file on the Wellgreen project.

Hudson Bay explored and drilled the property from 1952 to 1956 when it transferred ownership to a subsidiary, Hudson-Yukon Mining Company.

Wellgreen remained idle from1957 to 1968, when Hudson-Yukon began further exploration work.

It put the underground mine into production for a variety of metals in 1972 but ceased operations after just one year because of falling commodity prices and unexpected underground conditions, according to the government file.

The company did build a tailings dam so that the tailings would be kept submerged to prevent them from becoming acid-generating, which was common practice back then.

Paul Inglis of Environment Yukon said it’s his understanding that completing the tailings dam to the federal specifications at the time did allow Hudson-Yukon to recover its security bond.

But the tailings ponds are not always submerged, and although they have not yet become acid-draining, the threat is there, said the manager of the Site Assessment and Remediation Unit.

Inglis said the Kluane and White River First Nation have expressed concern.

The file was transferred to the remediation unit from the Department of Energy, Mines and Resources about 18 months ago as it was determined the remediation unit was best suited to manage the reclamation project under the circumstances, he explained.

Inglis said he doesn’t know who will pick up the estimated $15 reclamation and closure cost but suspects it will be shared somehow, though that’s not part of the work he and his department are doing on the project.

The Wellgreen project was not identified as a Type II site in the Devolution Transfer Agreement that saw the responsibility for mining transferred from Ottawa to the Yukon government on April 1, 2003.

Type II mines were to remain the responsibility of the federal government as they were permitted by the federal government, and they include former mine sites like the Faro mine, Mount Nansen near Carmacks and the United Keno Hill mining complex.

The job of the reclamation unit is to shepherd the Wellgreen project through the environment assessment and permitting process, he said.

Inglis estimates they’ve spent just over $1 million preparing for the assessment, which includes preliminary design work.

The proposal was submitted to the assessment board in July.

The board is still reviewing the proposal and is not yet accepting public comments on the project, which is expected to take no more than six months to complete, not including the ongoing monitoring for several years afterward.

Inglis said while it would be ideal to be in the field working next year, it’s likely going to be in 2022, as the permitting process includes obtaining a water licence as well.

There is currently no evidence from downstream observations and monitoring that there’s been any contamination from the tailings facility, Inglis said.

The thing is, he explained, once the tailings become acid-generating, it becomes very difficult to stop it.

He said there is no liner beneath the tailings.

The plan is to cover the tailings with a permanent, engineered top cover that will be impermeable so that the tailings will remain dry and not exposed to air, and therefore not a threat to become acid generating, Inglis explained.

The government file on Wellgreen indicates in the one year of production, the Hudson-Yukon company milled 171,625 tonnes of ore. It produced 33,853 tonnes of concentrate, or paydirt.

Under the proposal submitted to the Yukon Environmental and Socio-economic Assessment Board, the tailings will be converted with clay and granular material excavated from the former mill site, once the site is cleared of all remaining material such as the concrete footings.

The footings were left behind after Hudson-Yukon removed the mill and transferred it to another mine site.

The footings will be placed on top of the tailings and will be covered along with the tailings.

The tailings dam will be bulldozed and the material will be pushed on top of the tailing to form part of the top cover, according to the project proposal.

A ditch will be dug around one side of the tailings to divert water from a small creek that runs into the tailings.

The top cover and the excavated area around the mill will be contoured and revegetated.

A temporary water treatment plant will be installed to treat any water coming out of the tailings area.

It’s expected the project will create 35 jobs, with the crews staying in accommodations at either Burwash Landing or Destruction Bay.