1935

• Burwash Yellowknife Mines Ltd. stakes 21 claims, including the future Giant Mine

1937

• Yellowknife Gold Mines Ltd. acquires Burwash's assets, which become part of a subsidiary – Giant Yellowknife Gold Mines Ltd. (GYGML)

1948

• June 3: first gold brick is poured
• Tailings deposited into Back Bay

1949-1951

• Airborne arsenic emissions estimated at 7,500 kg/day

1950

• GYGML initiates first studies into arsenic in surrounding environment, leading to revised operations

1951

• Cold Cottrell Electrostatic Precipitator (ESP) installed to remove arsenic trioxide from roaster gases
• Arsenic emissions drop to 5,500 kg/day
• Arsenic trioxide dust pumped into mined-out storage chambers 80-250 feet below surface in permafrost

1952

• Mill processes 400 to 700 tons of ore per day

1953

• Tailings dam construction marks beginning of engineered tailings disposal

1955

• Hot Cottrell ESP installed to capture gold-bearing arsenic dust

1957

• Tailings dam #2 is built
• Arsenic removal from tailings effluent commences

1958

• Mill processing rate increases to 1,000 tons per day
• Dracco baghouse facility constructed to collect arsenic trioxide dust

1959

• Airborne arsenic emissions drop to 200 – 300 kg/day

1962

• Arsenic trioxide storage moves to mined-out stopes located in permafrost zone

1967

• Improved tailings effluent treatment circuit commissioned

1970

• Commissioner's Lands Act proclaims surface land transfers to the Government of the Northwest Territories (GNWT), including Giant Mine site

1974

• Open pit mining begins

1981

• New tailings effluent treatment plant commences operation

1981-1986

• Koppers Corp. of Georgia, U.S.A. purchases 6,700 tons of arsenic trioxide dust from Giant Mine until the price drops ending Koppers Corp's purchases
• Regular inspection of storage chambers begins

1987

• Northwest Tailings Pond built to accommodate re-processed tailings

1990

• Royal Oak Resources Ltd. gains control of Giant Yellowknife Gold Mines Ltd.

1991

• Royal Oak Mines Inc. formed

Black & white photos courtesy of the Prince of Wales Northern Heritage Centre
Aerial overview picture courtesy of Paul Vescei

1992

• Explosion during labour strike results in deaths of nine miners

1997

• Indian and Northern Affairs Canada (INAC) along with Royal Oak Mines, Environment Canada, the GNWT and the City of Yellowknife, co-host a technical workshop to discuss management of arsenic trioxide at Giant Mine

1999

• Royal Oak Mines goes into receivership and Giant Mine is transferred to INAC
• INAC starts work on action plan to manage arsenic trioxide dust stored underground
• INAC sells Giant Mine assets to Miramar Giant Mine Ltd., a division of Miramar Mining Corporation. INAC takes on role of caretaker for pre-existing environmental liabilities on the property, including arsenic trioxide dust stored underground

2000

• SRK Consulting wins international competition to become lead technical advisor to INAC on the management of arsenic trioxide dust

2001

• Technical advisor completes report “Study of Management Alternatives – Giant Mine Arsenic Trioxide Dust”
• Public technical workshop held to review report
• Remediation work completed on former Back Bay tailings beach
• Miramar Giant Mine Ltd. submits an abandonment and restoration plan to the Mackenzie Valley Land and Water Board

2002

• INAC and community stakeholders appoint Independent Peer Review Panel to assess options for long-term management of arsenic trioxide dust
• Tier 2 human health and ecological risk assessments conducted to assess risks of current arsenic releases from the mine site, as well as potential future releases under various arsenic trioxide management alternatives
• Field testing initiated of deep thermosyphon

2003

• Independent Peer Review Panel tables its review of technical advisor's final report
• Technical advisor tables its final report “Arsenic Trioxide Management Alternatives – Giant Mine” at a public workshop in January
• INAC initiates extensive public communications campaign regarding management alternatives for Giant Mine
• Giant Mine Community Alliance is established and holds its first meeting
• The Giant Mine Remediation Project teams hosts a workshop in May
• INAC seeks approval to proceed with project description

2004

• INAC announces decision to proceed with the Frozen Block Method as the preferred long-term management alternative for storage of arsenic trioxide dust

2005

• INAC and the GNWT sign a Cooperation Agreement to work together on surface and subsurface remediation of Giant Mine
• Miramar terminates its obligations under the Reclamation Security Agreement. Giant Mine becomes an abandoned mine site
• Deton' Cho Nuna Joint Venture wins a contract to assume responsibility for interim care and maintenance of Giant Mine

2006

• A Remediation Plan for the immediate and long-term cleanup of the mine is developed by INAC's technical advisors and reviewed by independent experts

2007

• INAC submits the Remediation Plan along with a water license application to the Mackenzie Valley Land and Water Board
• Deton'Cho Nuna Joint Venture is awarded a multi-year contract for care and maintenance at Giant Mine

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Giant Mine Remediation Joint Project Office

2^nd Floor, Waldron Building, 5103 - 48th St.,
Yellowknife, NT X1A 1N5
Tel.: (867) 669-2426
Fax: (867) 669-2439
Email: giantmine@ainc-inac.gc.ca
www.giant.gc.ca
QS-Y289-006-EE-A1
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Chronologie historique