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There are 237,000 tonnes of arsenic trioxide dust underground at Giant Mine. The federal government, through the Aboriginal Affairs and Northern Development Canada, has undertaken a clean-up of the site and is planning to freeze the toxic dust underground forever. The Giant Mine Remediation Project is currently undergoing an environmental assessment by the Mackenzie Valley Review Board. - Galit Rodan/NNSL photo

SOMBA K'E/YELLOWKNIFE
Lengthy technical sessions held last week as part of the environmental assessment of the Giant Mine cleanup have helped boost community confidence in the project, but far more needs to be addressed, said Kevin O'Reilly of social justice coalition Alternatives North.

The technical sessions were attended by various stakeholders, including representatives from federal, territorial and municipal governments as well as non-governmental organizations. They were held in between two rounds of information requests and, though they were quite thorough, O'Reilly said that many important issues still remain unaddressed. There is the question of perpetual funding, a matter which resides with decision-makers in Ottawa.

As it now stands, 237,000 tonnes of toxic arsenic trioxide dust at the mine will remain underground. In the short term, the 'frozen block' method entails freezing the surrounding ground to make a frozen shell and adding water to the arsenic dust to create a frozen block. The government plans to use thermosyphons and employ a team of eight people to maintain and monitor the frozen arsenic indefinitely - a logistically demanding proposition that worries community members.

"Will there always be the funding available to monitor and replace the thermosyphons?" wondered O'Reilly. "Will there always be money to make sure that fences and berms are in place around the pit? Will there always be money to make sure the tailings are covered properly? I'm not convinced that having people in Ottawa decide on an annual basis is the best way to fund this work."

There is also the issue of what O'Reilly calls "information management" - the communication of information about the site and its maintenance requirements through future generations.

"CDs wear out," said O'Reilly. "The assumption is people have electricity, access to computers. We have to look at some other way of communicating to future generations ... How do you mark these sites in ways that people will understand what's there? Even if they don't have electricity, even if they don't speak our language."

However, Daryl Hockley, principal engineer with SRK Consulting and senior technical adviser to the project, said in an absolute worst case scenario - if all thermosyphons become ineffective - it would take another 20 years before the dust would begin to thaw.

Even then, said Hockley, any arsenic that was released from the system would still end up in the mine water treatment system and would be collected and treated. He said there will not be an environmental impact unless that system completely fails.

At the sessions, Hockley said he expects new information and research to be presented within 10 years, but a "markedly superior" option for handling the arsenic is unlikely to arise in the future.

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