Canada, Government of

Government of Canada, Public Works and Government Services Canada

Giant Mine saw its 1st gold brick poured in 1948.  In 1999, Giant Mine went into receivership and the Court assigned the site to the Department of Indian Affairs and Northern Development (DIAND), who in turn sold the mine to Miramar Giant Mine.  The sale did not include the pre-existing environmental conditions, including the 237,000 tonnes of arsenic trioxide stored underground; therefore, to ensure the mine was managed safely, DIAND created the Giant Mine Remediation Project.  The remediation plan calls for the long-term storage and maintenance of the 237,000 tonnes of arsenic trioxide dust stored in sealed chambers and stopes underground using the frozen block method.  The plan also provided for demolish of more than 100 buildings and facilities on the surface of the Giant Mine and covering the tailings ponds.

Nuna's Role 

Giant Mine Care and Maintenance, Yellowknife, Northwest Territories, Canada - 2006 - Present

In 2004, NUNA, through its joint venture with DETON'CHO Corporation, was contracted by Public Works Government Services Canada to provides care and maintenance at the Giant Mine site which includes:

  • Maintaining site facilities and equipment.

  • Maintaining underground access and hoisting and pumping equipment.

  • Maintaining site security.

  • Bulk fuel storage demolition.

  • Selected building demolition.

  • Pipe works upgrade.

  • Surface water management improvements.

  • Operation of the effluent treatment plant.

Giant Mine, Yellowknife, Northwest Territories, Canada – Freeze Optimization Study - 2009 -2010

Under the Giant Mine Care and Maintenance contract with the Government of Canada, DETON'CHO / NUNA performed construction services to support a trial project designed to optimize methods of freezing the underground arsenic storage chambers. Work included:

  • Surface drilling by a variety of methods (mud rotary, coring and down hole hammer) and installation of piping for a mechanical freezing system.

  • Instrumentation installations.

  • Underground development required for horizontal drilling and freeze pipe installation.

  • Surface civil works and site grading.

  • Bulkhead construction.