Between 1948 and 2004, the Giant Mine was a major economic driver for Yellowknife and the Northwest Territories. Mining operations at the site, which grew over the years to encompass more than 870 hectares, including a number of ponds and small lakes, were halted in July 2004. Since 2005, Aboriginal Affairs and Northern Development Canada (AANDC) and the Government of Northwest Territories (GNWT) have co-managed the site, with the Deton’Cho Nuna Joint Venture providing on-site care and maintenance. However, when the mine closed, 237,000 tonnes of arsenic trioxide were left behind in underground chambers.
The remediation project proposes to leave behind a site suitable for future community use as the community sees fit. In August 2014, the decision was made to move forward in implementing the measures outlined in the environmental assessment. The project’s goal is to ultimately protect public health and safety and the environment through longterm containment and management of the site’s waste, water treatment, and surface cleanup at the site.
In February of 2018, the main construction manager for the project was selected. Term 1 of the work will centre around responsibility for site care and maintenance and emerging risks on site, as well as supporting planning efforts for the full remediation in Term 2. This work will start immediately and will be undertaken until March 31, 2020. In Term 2, set to begin in 2020, the construction manager will oversee the implementation of the overall remediation plan and associated activities.