Dust from the Faro lead-zinc mine is blowing across hundreds of kilometres of pristine wilderness.
When wind kicks up past 20 kilometres an hour, dust particles from the massive toxic tailings pit are pushed into the air and along the ground.
It settles in unpolluted areas of the Rose Creek Valley and travels as far as Pelly Crossing.
Studies, commissioned by the mine management, have determined the dust isn’t hazardous to animals or humans.
But before a plan to clean up the Faro mine complex can be finalized, the problem needs to be controlled.
The reclamation management team has decided to chemically spray down troublesome parts of the tailings pit to seal in the dust until the cleanup plan is finalized.
But don’t call it a Band-Aid solution, said John Brodie, a technical engineer with the reclamation project.
“It’s an engineered temporary dust control program,” he said.
“We’ve evaluated the options and selected a method designed for proven dust control.”
Dust control is part of the long-term planning for the billion-dollar Faro mine reclamation project.
Spraying a chemical over troublesome spots on the tailings pit surface will seal in the dust by creating a hard crust.
The material — an organic compound — is mixed with water and shot from a sprayer mounted on a vehicle.
It’s the same method used to hold down dust at the Giant gold mine in the Northwest Territories.
“It’s heavily used on highways to keep dust down and for other construction projects,” said Brodie.
The compound has undergone rigorous testing at the US Environmental Protection Agency.
The extra layer of chemical is safe and won’t cause future problems, said Brodie.
Wet weather has delayed spraying, but the rain means dust isn’t a problem.
Once started, spraying will continue until the closure team finalizes a reclamation plan.
More than 70 million tonnes of ore tailings, a fine, sand-like material, remain in the ecologically sensitive area.
About 55 million remain in the Rose Creek Valley.
The tailings — piled an average of 14 metres deep, 40 metres in some spots — are held in a massive reservoir.
Dust is spread in all directions, but primarily down the Rose Creek Valley, an area rich in vegetation and wildlife.
The dust is measurable but only with scientific equipment, said Brodie.
“It’s not like you see dunes of sand anywhere,” he said.
The project’s management team commissioned an environmental assessment after dust was found outside the “footprint” of the Faro mine complex.
The study by Gartner-Lee Ltd. — and subsequent environmental assessment by SENES Consultants — identified the dust problem.
It found contamination in caribou, ptarmigan, beaver and other wildlife.
The levels are “comparable to some of the highest concentrations reported in the world for vegetation growing adjacent to mining and metal-processing facilities,” reads the report.
A lead level three times the norm was found in samples taken from a 769-square-kilometre area around the mine site.
Lead was found in absorbent moss near Pelly Crossing, 180 kilometres northwest of the mine.
The report stressed the contamination is not a health hazard.
“Under the current conditions, there is not a significant risk to humans or animals,” said Faro reclamation technical adviser Bill Slater.
Brodie and Slater declined to confirm the cost of spraying.
“It’s less than a couple thousand dollars (a year),” said Brodie.
Ottawa will spend upwards of $900 million over several decades to clean up the Faro mine.
After that, it’s estimated up to $3 million will be spent annually for an estimated 500 years to ensure the damage is contained.
The four levels of government — Ottawa, the territory, the Ross River Dena Council and the Selkirk First Nation — are creating the plan.
To stop the airborne dust permanently, the tailings pit could be covered in a two-metre waste-rock and soil combination.
“We aren’t going to see a permanent solution for another few years,” said Slater.
“We wanted to in the short term limit the dust transport and do something to stop it.”