The NWT government says the Diavik diamond mine waited more than a month to report a spill involving 450,000 cubic metres of “mine-impacted water.”
The GNWT says the spill took place on February 7 but was not reported until March 16 – at which point it appeared beneath a month of other spills in the territory’s online database.
In a Tuesday news release, the GNWT said it had been “made aware” of the spill, had sent inspectors, and was satisfied there had been “no release into the environment” as the entire spill took place within a containment pond.
Diavik, providing comment after this article was first published, said the situation was being taken seriously.
Spills of any sort are a sensitive matter in the NWT at the moment, particularly their prompt reporting, given the fallout from the months-long Kearl tailings seepage in northern Alberta and widespread criticism of both Imperial Oil and Alberta’s regulator for the way multiple incidents were – or were not – reported.
The NWT government said the Diavik spill was “caused by breakage in a pipeline which transports mine-impacted water.” All of the spilled water entered the Diavik mine’s North Inlet containment pond, which was where the water had been heading in the first place. As a result, the GNWT stated, pipeline operators at the time “believed the spill was not categorized as reportable.”
Only a month later, the territory stated, did the mine’s environment team realize what had happened and file a formal spill report.
No spill report or associated documentation could be found in a search of the public registry used to record such incidents in the NWT.
The territorial government’s statement continued: “GNWT inspectors have visited the site and confirmed the entire spill is within an established containment pond at the mine site, and none has been released into the environment, including Lac De Gras.
“The GNWT has requested Diavik divert and repair the pipeline. The company is acting appropriately to address the issue.”
For a sense of the spill’s size, swimming pools like Yellowknife’s municipal pool have a volume of around 500 to 1,000 cubic metres.
The phrase “mine-impacted water” usually refers to water used in mining operations that can, as a consequence, carry contaminants. It is considered wastewater.
A separate spill at Diavik on March 19, involving a smaller but still significant amount of wastewater and another pipe leak, is also listed in the spills database. No information regarding that spill was immediately available.