Bags of waste left Giant Mine – but what was in them? Nobody’s sure.

The federally led Giant Mine Remediation Project says “potentially contaminated or hazardous waste” has been taken off the site – one of the most toxic in Canada – without anyone knowing for sure what it was.

Giant Mine is a former gold mine on the edge of Yellowknife that’s now a four-billion-dollar improvement project set to last for well over a decade.

Much of the site’s contamination is arsenic trioxide, a form of highly toxic dust stored underground that isn’t part of day-to-day operations on the surface. But there are plenty of other contaminants across the sprawling site, such as arsenic, oil and surface-level tailings.

Last month, the remediation team filed a notification to government inspectors declaring – in unusually vague terms – that an unspecified amount of waste had been taken off the site “without following the waste manifesting procedures,” and adding that nobody is certain what was in it.

The incident took place on October 19 according to the notification, which was sent on October 25 by Parsons, the prime contractor at the site.

That notification states the waste was taken to a local facility operated by KBL, a waste management company contracted to dispose of some waste produced at Giant.

Some waste bags may have since been transported out of the territory, according to one person with direct knowledge of the incident.

Asked for more information, Crown-Indigenous Relations and Northern Affairs Canada – the federal agency that handles media requests about Giant’s remediation – did not dispute that some of the waste had been taken to a facility in Alberta, but did not directly comment on that assertion.

Clean Harbors, understood to be that facility’s operator, did not respond to a request for comment.

“The exact volumes and types of waste transported to KBL, the hazardous waste receiver, were not properly tracked or recorded prior to arrival,” Parsons’ notification to inspectors states.

The best information available “suggests that it included materials such as waste oil, oily rags, oily debris and contaminated mineral waste (likely soil),” the document continues.

“Investigations are ongoing to determine the quantity and types of waste that were transported to the facility and if those wastes were properly disposed of as a result of the lack of proper waste documentation. Further information will be provided once it is received.”

On November 2, two weeks after the incident was reported to have taken place, the federal government told Cabin Radio it had no further update regarding what the waste might have been and how hazardous it was.

Project team ‘taking action’

Federal legislation places strict controls on how hazardous material is transported between jurisdictions, while the remediation project’s permitting includes rules designed to stop waste being transported without certainty about the contents.

“The project team, including the main construction manager, Parsons Inc, is taking action to ensure this incident is investigated and any root causes are addressed,” the remediation project’s deputy director, Natalie Plato, told Cabin Radio by email.

“The project team will keep regulators informed as more information becomes available and will review procedures to ensure regulatory requirements are being met.”

Plato added: “While the investigation is ongoing, an additional step has been added to the waste management procedures on site. No waste will leave site until an inspection takes place to ensure there is proper documentation.”

What was in the waste is important information for the facility that ultimately receives the shipment. If a delivery is considered hazardous, for example, it may require storage in a specific area or might simply not be accepted at all.

Often, hazardous waste generated as part of Giant’s remediation is handled within the site rather than being taken away, a person with direct knowledge of operations at the site said. They asked not to be named as they were not authorized to discuss details of their work.

As a result, it’s possible the waste in question should never have left the site in the first place.

Failures in how Giant’s waste is managed also run the risk of affecting public perceptions of site safety.

The Yellowknives Dene First Nation is still pursuing an apology from the federal government for allowing toxic gold production at Giant in the 20th century without appropriate environmental oversight. The First Nation has asserted that damage from the mine will be “felt for generations into the future.”

Public meetings are routinely held to assure residents that the remediation is being managed in a safe and responsible fashion. The Giant Mine Oversight Board, an independent agency that acts as a watchdog over the remediation team, is holding a public meeting next week to discuss the latest research into the best ways to remediate the site.

Inspector critical over pH problem

The waste issue represents a second environmental lapse for the remediation project in the space of a month.

In late September, an effluent treatment plant at the site sent treated water into Baker Creek (and ultimately out into Great Slave Lake) that didn’t meet agreed pH criteria.

An inspection report put the volume of affected water at 400 cubic metres. Samples showed water leaving the plant had a pH of 8.58 to 8.61, fractionally above the maximum discharge criteria of 8.5.

On its own, that exceedance might be considered minor. But federal inspector Tim Morton said the remediation team had waited far too long to alert him to the issue.

In a report published to the NWT’s public registry, Morton said the remediation team had missed “multiple opportunities” over the space of a day to report that pH problem, stressing that environmental regulations demand any such issue be reported “immediately.”

“All future discharges that exceed any criteria must be immediately reported … without delay, regardless of the time of day or circumstances behind the exceedances,” Morton wrote.

“The communication from the licencee has been exceptional until this incident and the inspector expects that reporting such as this does not occur in the future.”