The discovery led to a massive post-war staking boom in Yellowknife. Giant Mine entered production in 1948 and ceased operations in 2004. It produced over of gold. Owners of the mine have included Falconbridge, Pamour of Australia, and Royal Oak Mines. When Royal Oak went bankrupt in 1999 the Department of Indian Affairs and Northern Development took over responsibility for cleaning up the Giant mine site. Miramar Mining Corporation subsequently entered into an arrangement with the government whereby Miramar held the mine operation in care and maintenance, continued underground dewatering operations, and removed the remaining ore from underground for treatment at the nearby Con Mine process facility . According to an article published in The Star in 2006, there were 15 sealed underground storage chambers 250 feet below ground containing a total of of deadly arsenic trioxide dust, containing up to 60% organic and inorganic arsenic. The dust was a byproduct of extracting gold from the mineral and was collected and stored in sealed underground chambers from 1951 to 1999. Prior to legislated collection and underground storage in 1951 arsenic was released directly into the atmosphere during the roasting process. Arsenic trioxide readily dissolves in water; in 2006 underground flooding around Giant Mine's Mill Pond's underground chamber which contained of arsenic trioxide dust threatened to migrate out of the chamber if it was flooded and dump large amounts of arsenic into Yellowknife Bay.
Bombing
On September 18, 1992, at the height of a labour dispute during the tenure of Royal Oak Mines ownership, an explosion in a drift of the mine, underground, killed nine men riding through a transport tunnel in a man-car. The strikebreakers who lost their lives were Chris Neill, 29, Joe Pandev, 55, Norm Hourie, 53, David Vodnoski, 25, Shane Riggs, 27, and Vern Fullowka, 36. The remaining three men were replacement workers Robert Rowsell, 37, Malcolm Sawler, 38, and Arnold Russell, 41. Mine employee Roger Warren was later convicted of placing the bomb. The strike/lockout ended in 1993, pursuant to an order by the Canada Labour Relations Board. A civil suit also resulted on behalf of the families of the replacement workers killed in the explosion In 2008, the nine Giant Mine widows lost their $10-million civil judgment when the Northwest Territories Supreme Court overturned an earlier ruling.
Contamination
Mining operations over five decades have created a massive environmental liability, a problem which the mine's previous owners left to the Government of Canada and Government of the Northwest Territories to sort out. The site's footprint includes 8 open pits, 4 tailing ponds, of contaminated soils, and approximately 100 buildings including a roaster/bag house complex that is highly contaminated with arsenic trioxide dust and fibrousasbestos. The remediation plan proposed by the SRK Consulting Inc. and SENES Consultants Limited, the leading technical advisors since 2000 to Aboriginal Affairs and Northern Development Canada on the Giant Mine Remediation Project, includes underground issues such as dust that contains arsenic trioxide, and remediation of the surface, water and Baker Creek.
Remediation
reported that the "greatest challenge associated with the remediation of Giant Mine" is the safe long term storage of the arsenic trioxide dust, the lethal byproduct of extracting gold from the mineral arsenopyrite ore stored underground. Their top priority for the Giant Mine site remediation is an "effective, long-term management" of arsenic trioxide. Arsenic trioxide dust, which contains approximately 60% arsenic, is highly lethal even in small doses. It is odourless, tasteless and water-soluble. The taxpayer-funded remediation plan to permanently freeze the underground arsenic trioxide dust chambers was approved by the Canadian federal government in August 2014. According to the federal civil servant in charge of the clean-up, Jane Amphlett, using technology like that used in ice-hockey rinks, coolants will permanently freeze the storage chambers containing the arsenic trioxide dust to keep groundwater seepage out in what is called the "Frozen Block Method." A Yellowknife community museum is envisioned for part of the former Giant Mine townsite.
Film
The events and aftermath of the Giant Mine labour dispute and explosion were dramatized in the 1996 CBCtelevision movieGiant Mine. Additionally the contamination is the topic of the interactive documentary "Shadow of a Giant" by Saskatchewan filmmaker Clark Ferguson who was artist in residence with Western Arctic Moving Pictures in 2013.
