For years, many have questioned the federal government’s ability to remediate the once prosperous, now arsenic-laden Giant mine in Yellowknife, N.W.T.
Located on the rocky shore of Great Slave Lake, the mine contains 237,000 tonnes of water-soluble arsenic trioxide and 13.5 million tonnes of contaminated
tailings spread over 95 hectares – the equivalent of around 175 football fields.
Since Aboriginal Affairs and Northern Development Canada (AANDC) took control of the site’s remediation in 1999, after then-owner Royal Oak Mines Inc. went
bankrupt, a full cleanup has been discussed and debated ad nauseam.
But in June, the Mackenzie Valley Environmental Impact Review Board decided to approve the environmental assessment for the federal government’s plan to
freeze the arsenic trioxide in 15 giant underground chambers and isolate it from the surrounding environment. This so-called frozen block met hod, according to the government, “offers the least risk, including low risk to worker health and safety, and low risk of arsenic
release over the long term.”
Given the review board’s 27 recommendations that come with approval, however, AANDC will have to address hard truths about Giant mine that were overlooked
in the frozen block approach. For one, the board has noted public concern over the project’s indefinite time frame: “Given enough time, the project is
eventually likely to cause significant adverse effects.”
Approving the project in perpetuity would have increased the likelihood that an ecological disaster could result from uncommon events like massive flooding
or an earthquake, said Alan Ehrlich, the board’s manager of environmental assessments and lead on the Giant mine file. The board recommended reducing the
project’s time frame to 100 years. “The board felt it would create an acceptable level of risk and reduce the probability of these kinds of things
happening,” Ehrlich said.
Before settling on the frozen block method, which would cost $1.9 million annually in perpetuity, the government reviewed 56 management alternatives,
including a more detailed look at 12 of those options. However, Ehrlich said, the environmental assessment was limited in scope, leaving the board just one
option to evaluate, with no plans to look at future technological innovations.
This, said Erlich, is a crucial point. In the past 100 years, technology has made the unimaginable a possibility. “One hundred years ago there was no
television, no sliced bread, no ball point pens and arsenic was added to food as a preservative,” he said. For this reason, the board suggested the project
also be reviewed every 20 years, to determine its effectiveness and whether a new technological innovation is able to deal with the mine’s toxic legacy.
Funding was another key issue that influenced the recommendation to implement a 100-year time frame, said Ehrlich. “Many members of the public were
concerned that the government’s priority on funding could change over the 100-year period,” he explained. “The public was worried about the longer term and
the board felt the time period would be enough to meet the project’s objectives to make the initial implementation still worthwhile.”
While the government says it is too early to determine how costs of the $400-million project may be affected by the board’s report, it will be reviewing
the recommendations. In an email, an AANDC spokesperson indicated the government has four options: adopt the review board’s recommendations; refer the
recommendations back to the review board for further consideration; consult the review board to adopt the recommendations with modifications; or consult
the review board and escalate the proposed project to an environmental impact review by a panel.
So if a permanent solution is the goal, are there any promising developments? Emerging technologies have not yet passed the litmus test, since the
government researched other potentially viable options nearly a decade ago.
One Canadian company believes it has a potential answer to the problem. Toronto-based BacTech inquired about the cleanup in 2012. Its bioleaching
technology uses naturally occurring bacteria to stabilize toxic metal compounds in order to prevent future harmful leaching of the material into the
environment. Without a completed project under its belt, BacTech recently secured funding to complete a number of studies on a potential arsenopyrite (the
same compound found in Giant’s tailings ponds) cleanup project at the abandoned Snow Lake mine in Manitoba. The company hopes to develop the Snow Lake
project at no taxpayer burden by recovering gold from the stockpile as revenue.
These types of innovative technologies are what the board wants the government to look at continually over the course of the 100 years, said Ehrlich.