A Look at the Contamination and Cleanup at Giant Mine in the Northwest Territories

YELLOWKNIFE – The cleanup of one of the greatest environmental damages in Canadian history is underway at Giant Mine in the Northwest Territories. Here are some facts about the gold mine and the efforts to fix it:

Mine life: It operated from 1948 to 2005 and produced 220 tons of gold.

Site Size: Covers 900 hectares just outside of Yellowknife along the shores of Great Slave Lake.

What remains: There are approximately 100 buildings, 25 large piles of scrap metal and rusting machinery, 30 kilometers of road, eight surface mines, six tailings ponds and 13 underground chambers.

Main contaminants: Approximately 13.5 million tonnes of arsenic-contaminated soil is on the surface; 237,000 tons of arsenic trioxide are in underground chambers; and an unknown amount of asbestos is found in the site buildings.

Cleanup Plan: The plan is to freeze underground arsenic in perpetuity, pump and treat seepage from the mine in perpetuity, destroy hazardous waste at a licensed facility, bury and cover non-hazardous waste.

Final objective: The objective is to clean up parts of the site to residential standards and others to industrial standards. Some parts must remain banned in perpetuity.

Timeline: The remediation must be completed in 2038. It was previously set at 2031.

Cost: The cost to taxpayers was estimated at $940 million in 2014. A revised estimate is expected on October 27.

This report from The Canadian Press was first published on September 28, 2022.

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