De Beers Canada Inc. has been fined $350,000 for an accidental diesel oil release that entered the environment around Snap Lake Mine, just south of the Arctic Circle, in Yellowknife, Northwest Territories.
On December 7, 2017, an employee of the diamond mine forgot to turn off an outlet valve during a fuel transfer between two above-ground storage tanks, according to a report that came before the Mackenzie Valley Land and Water Board. Some 1,125 litres of diesel spilled into the snow over the top of a containment berm.
The mine had permanently closed and started to transition into maintenance capacity with a 12-person team.
“Contributing factors were that the refueling process commenced within an hour of a crew change and that the operator had spent a lengthy time the previous night restoring power after an outage,” according to the Mackenzie Valley Land and Water Board report.
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The leak was discovered later that day.
According to the report, De Beers employees shovelled “four drums of contaminated ground” out of the affected area, but were unable to excavate the frozen ground that was in close proximity to the buildings and equipment.
No contamination was observed in surface water, according to an inspection of the area.
De Beers pleaded guilty and was sentenced in territorial court to charges under the Canadian Environmental Protection Act for the storage tank system violations.
The company later overhauled its procedures for tank refilling.
The Snap Lake diamond mine, some 220 kilometres northeast of Yellowknife, is no longer in operation. The company had spent some $2.2 billion to build and operate the mine and it was the company’s first mine outside of Africa. Company officials had intended the mine to continue operations until 2028, but it had proved unprofitable ever since its opening in 2008, primarily due to plummeting diamond prices. After its closure in 2017, the company had intended to flood the mine.
As a result of the conviction, De Beers will be added to the Environmental Offenders Registry.
The company also made headlines in 2021 after it acknowledged a failure to fully report methylmercury and total mercury levels at its downstream monitoring stations for the shuttered Victor diamond mine in northern Ontario.