Giant Mine's tailings pond dust blows toward Yellowknife again

The latest incident of dust blowing off tailings ponds from the contaminated Giant Mine site toward Yellowknife-area communities sparked concerned calls to the Yellowknives Dene First Nation office and a video posting to YouTube late last week.

The video, posted last Friday, appears to show a cloud of dust hovering above Back Bay, between Giant Mine and the community of Ndilo.

Aboriginal Affairs and Northern Development Canada, which is responsible for cleaning up the abandoned gold mine, has confirmed the dust came from tailings on the surface of the site.

On Friday, Johanne Black, a staffer with the Yellowknives Dene's land and environment department, wrote to Natalie Plato at AANDC, saying "residents are phoning the band office of this concern." Black wanted to know what the government was doing to contain the dust.

Plato, a deputy project director with Aboriginal Affairs, says workers at the site stopped work and dampened the tailings with water, as was done during similar incidents in the past. She said the incident "did not pose any immediate risk to workers, the public or the environment."

According to AANDC, four ponds at the site contain approximately 16 million tonnes of tailings covering about 95 hectares — the equivalent of 300 football fields. There are also tailings on the shores of Great Slave Lake.

The government says there is "very little arsenic trioxide in the tailings" and that "most of the arsenic in the tailings is in stable forms, including (naturally occurring) arsenopyrite."

Work to cover tailings still years away

Former Ndilo Chief Fred Sangris called on the government to cover the tailings back in 2009. But the government said it couldn't do that because its remediation plan hadn't been approved at that time.

The plan has since been approved by regulators, though conditions attached to that plan still require the plan to be fine-tuned. In its latest public update on the project, the government said it expected remediation work would begin in 2020.

According to that plan, the tailings will be covered with one layer of quarried rock and a second, top layer of fine-grained soil.

During a previous dust dispersion incident in May 2014, tailings at the site were dampened and then covered with a surface seal.