Investigation finds Ptarmigan, an old mine in limbo, needs work

Last modified: October 8, 2021 at 10:53am

The former Ptarmigan mine north of Yellowknife needs a human health risk assessment and action to stop dust blowing onto the nearby road, an investigation brought on by a complaint has found.

Ptarmigan was a gold mine in the 1940s, 1980s, and 1990s. The Ingraham Trail highway runs between the mine and one of its tailings ponds. Nearly 300,000 tonnes of tailings, or mine waste, remain at the site.

Soil samples taken in and around the tailings areas show levels of arsenic above national guidelines, with similar results in some samples for cadmium, lead, and other metals.


In a news release on Friday, the territorial government said dust suppression to reduce material blowing onto the Ingraham Trail would now begin in spring 2022. Fences restricting access to the site will be fixed this fall.

A human health and ecological risk assessment – needed to determine the level of risk posed to people and the environment – will begin “in the next fiscal year,” the GNWT said, and is expected to be complete by the winter of 2023.

However, none of this work may have been ordered had it not been for a complainant asking for the site to be investigated.

Ptarmigan is one of six contaminated sites in the NWT for which no government yet claims full responsibility. While the mine is on land handed to the territory during Devolution in 2014, the territorial and federal governments are still negotiating which of them will take responsibility for cleaning up Ptarmigan’s environmental legacy.

The GNWT has completed site assessments and an action plan – and installed some signs and fencing – but little other work has taken place.


Action to address the dust at Ptarmigan only began after someone used the territory’s Environmental Rights Act to apply for an investigation.

“It is a frequent occurrence when driving past that area that there are clouds of dust and debris that the wind carries into the air from the old ponds,” the applicant wrote, according to the investigation report completed last month and released by the territory on Friday. The report does not name the applicant.

“The dust is likely all over land around the Treminco/Ptarmigan mine,” the applicant continued. “Not only is a person exposed to the likely unhealthy dust when driving past in a vehicle, on a motorcycle or a bicycle, but any use of the land near the old Treminco/Ptarmigan mine site seems it would result in unnecessary exposure to this dust.

“Plants, fish, mammals, birds and insects are also potentially affected.”


The Ptarmigan mine's location, northeast of Yellowknife
The Ptarmigan mine’s location, northeast of Yellowknife. Image: GNWT
A GNWT map shows the Ingraham Trail bisecting the Ptarmigan mine and one of its tailings ponds
A GNWT map shows the Ingraham Trail bisecting the Ptarmigan mine and one of its tailings ponds.

The Environmental Rights Act allows residents to apply for an investigation if they reasonably believe something is happening that is likely harming or may harm the environment.

The territory says environment minister Shane Thompson received the applicant’s request on January 5 this year and an investigation commenced on the same day.

That investigation led to the analysis of soil samples and the discovery of elevated levels of arsenic and other metals. Its findings were enough to convince Thompson of “the need to address the dust blowing over the Ingraham Trail,” his office said in response.

The investigation report calls for the completion of a human health and ecological risk assessment as the next step, which will help to assess the exact impact of that dust.

“These findings do not necessarily mean that there is risk to the environment or to people in the area. The human health and ecological risk assessment will determine the level of risk,” the territorial government said in Friday’s news release.

“It is important that residents avoid the Ptarmigan mine site, including the tailings area, to reduce any risk,” that news release added.

“Please follow signage in the area and respect any barriers or fences that have been put up. We urge ATV and snow machine users to be especially careful to avoid accessing the area. Avoiding the area will prevent disturbance of the tailings and allow the dust suppressant to work once applied.”

Ptarmigan has long been a site of concern for environmental advocates.

Five years ago, Frame Lake MLA Kevin O’Reilly told the CBC action to address contamination at Ptarmigan post-Devolution needed to speed up.

“We know that contaminants are moving off the site and it’s well past the time for the governments to take some action and do something here,” he said at the time.

Thompson, in a statement on Friday, said: “We are grateful to the individual who requested the investigation and we welcome future resident engagement in environmental management.”