ARCHIVED - What's Happening at Giant Mine? - August 2014

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On August 14, 2014, the Honourable Bernard Valcourt, Minister of Aboriginal Affairs and Northern Development, on behalf of the Responsible Ministers for this project, released the decision on the Report of Environmental Assessment (EA).

In accordance with this decision, the Giant Mine Remediation Project Team is preparing to move forward with the implementation of the EA measures. General discussions with stakeholders to prioritize the measures have already begun.

While the regulatory process for a project of this scale takes time, the Project Team’s immediate priority is to advance the current project in order to protect the health and safety of Canadians, as well as the integrity of the environment. Care and maintenance and site stabilization activities will continue until remediation can begin.

The EA measures need to be considered and advanced before an adequate "consolidated project description" can be prepared suitable for licencing by the Mackenzie Valley Land and Water Board.

With the consolidated project description’s submission, the application process for a Water Licence and Land Use Permit will resume (the Project Team submitted an initial application for a Water Licence in 2007). These authorizations are required before full remediation can begin.

For more information on the Giant Mine Remediation Project follow @GiantMine on Twitter or read the Frequently Asked Questions.

Roaster update

Work continues to decontaminate and deconstruct the final five roaster complex buildings at Giant Mine. Throughout the month of July, workers bagged and labeled a total of 917 cubic metres of contaminated roaster waste. These bags will be stored in the Material Storage Area on the Central tailings pond onsite at the mine until the final closure plan for the site is implemented.

The roaster deconstruction project is on schedule to be completed in the fall. Work completed throughout July and early August includes:

Allis-Chalmers (AC) Roaster: Workers completed the final cleaning and wash down of the AC Roaster interior in August. Contractors will carry out an inspection of this building before conducting final air testing in the building’s interior. Once the air is deemed clear and all final inspections are complete, workers will begin preparing for deconstruction.

Calcine Plant: Workers continued to decontaminate and deconstruct the interior of this structure throughout July and August. This work includes removing asbestos insulation, cleaning interior equipment, steel, and duct work, removing contaminated piping and other arsenic waste, and deconstructing the tanks inside this building.

Workers dressed in yellow personal protective equipment, complete with gas masks, spray pressurized water at a metal staircase inside the roaster’s Calcine Plant at Giant Mine on July 15th, 2014.
Workers dressed in personal protective equipment wash down a metal staircase in the roaster’s Calcine Plant on July 15th, 2014.

Dorrco Roaster: Recent work completed inside this building includes the removal of interior arsenic waste, tank deconstruction, and general interior decontamination.

Site Update

Some of the Giant Mine site infrastructure is more than 60 years old. As part of ongoing risk management at the site, the Giant Mine Remediation Project Team monitors this infrastructure to reduce risks to on-site staff, the public, and the environment.

Through ongoing inspections, the Project Team recently identified structural concerns related to the C-Shaft Headframe at Giant Mine. In particular, project engineers are concerned about deteriorating wood on the frame and the danger associated with parts falling. To ensure the protection of both worker safety and the environment, work to stabilize this structure is required.

The iconic C-Shaft Headframe towers over the Giant Mine site.
Work is required to stabilize the iconic C-Shaft Headframe.

The team has already begun the in-depth inspection and assessment required before work to address the deteriorating structure and its associated risks can begin.

The team will move forward with this work as soon as possible and anticipates that it will complete C-Shaft stabilization by the summer of 2015.

On July 13 and July 30, spills were reported to the Nunavut/NWT Spill Line. There were no regulatory infractions or violations of the Water License as a result of either occurrence.

On July 13, 2014, a pipeline transporting water from the Northwest tailings pond to the effluent treatment plant developed a pinhole leak and discharged a small amount (170 litres) of untreated mine water near the highway junction across from the Akaitcho gate. The leak was caused by a worn out seal on the joint. The public was not at risk at any time, and no long-term environmental impacts are anticipated; the spill was both small in volume and limited to an area that is known to be contaminated. The inspector visited the site and was satisfied with initial measures to repair the leak.

On July 30, 2014, approximately 200 litres of wastewater spilled at the roaster deconstruction site – an area already significantly impacted with arsenic from historical mining operations. The majority of the spill contained shower wastewater from the decontamination unit that overflowed while being poured into the top of the storage tank. Given the low volume and highly localized nature of the spill, along with swift corrective action, there was no increased risk to workers or to the environment as a result of this incident.


In early August, Det’on Cho Nahanni Construction Ltd. was awarded an $11.6 million Interim Underground Stabilization contract. This contract was awarded after the construction company successfully bid on the competitive tender for underground stabilization. Within this contract, the Yellowknife-based contractor will excavate, relocate, and process tailings into a paste by mixing them with water and a small amount of cement. This paste will be pumped underground to stabilize some of the mine’s stopes – underground voids created during the mining process. The contract was awarded August 8, 2014.

Shipping containers have begun arriving onsite as part of a $2.3M contract awarded to Tervita Corporation on July 4th, 2014. These 242 containers will temporarily store the transportation of dangerous goods (TDG) bags containing arsenic-impacted waste from the site stabilization activities. Containers will be delivered to the site weekly throughout the summer and fall, with an option to purchase additional containers as needed. Tervita Corporation has an office in Yellowknife.

For more information on procurement opportunities, visit

Underground stabilization project update

The underground stabilization project is being implemented in order to mitigate risks associated with underground flooding from Baker Creek, rock collapse, or subsidence. Once the contractor, Det’on Cho Nahanni Construction Ltd., has mobilized to the site and provided the required approved plans and documentation as part of the start-up to this contract, they will begin excavating and stockpiling tailings. This work is anticipated to begin in September and finish up by mid to late October. Drivers near the mine site may notice increased heavy machinery activity related to this work.

Air Quality Monitoring

Extremely smoky conditions from nearby forest fires continued to set off the air quality monitor alarms throughout July and August. None of these alarms were credited to onsite activities.

Because the widespread smoke caused monitors to show elevated readings at the roaster complex and site fence-line locations, the Project Team was even more vigilant than usual in monitoring changes between upwind and downwind locations, watching for dust generation, and implementing dust prevention.

A supplemental air quality monitoring program was initiated July 21, 2014, associated with underground and surface drilling. This quality assurance measure will continue until the drilling work is complete - anticipated for late August. Readings from these supplemental monitors are included in the weekly air quality monitoring reports posted on the ENR website. An air quality monitoring program will also be implemented when work associated with the Interim Underground Stabilization Contract (which includes excavating and stockpiling tailings) begins this fall.


The Project Team’s Semi-Annual Report is now available on the Mackenzie Valley Land and Water Board’s online public registry. This document covers November 1, 2013, to April 30, 2014. Past reports are also available on the registry.

Engagement update

Grace Blake, the inaugural winner of the Star of Excellence Safety Award sponsored by Golder Associates Ltd., holds up a plaque engraved with her name.
Grace Blake accepts the
inaugural Star of Excellence
Safety Award, sponsored
by Golder Associates Ltd.
Photo Credit:
Bill Braden Photography

Members of the Giant Mine Remediation Project Team continued to meet with stakeholder groups throughout the months of July and August. On July 11th, team members met with the Yellowknives Dene First Nation (YKDFN) Giant Mine Advisory Committee to discuss the air quality monitoring program, site activities and work plan priorities.

The team also met with the Giant Mine Working Group on July 10th and August 14th. This group provides a forum for interested parties to discuss and make recommendations on technical, operational and project activities regarding the remediation of Giant Mine. It includes representatives from the Yellowknives Dene First Nation, the City of Yellowknife, Alternatives North, Fisheries and Oceans Canada, and Environment Canada. Recent meeting topics have included a general site update, spill reporting, and an air quality update related to widespread smoke in the Yellowknife area.

Health and Safety

On July 31, 2014, Grace Blake became the inaugural winner of the Star of Excellence Safety Award sponsored by Golder Associates Ltd. Golder is the lead contractor providing mining support services at Giant Mine and had committed to supporting local communities through Aboriginal training and apprenticeship, and have worked with local educators in developing a mine training award for Aboriginal students.

This award is presented to the student with the highest grades in the Safety Bootcamp associated with the Underground Miner Program at Yellowknife’s Mine Training Society. This course aims to reinforce a safety conscious culture on mine sites in the North and other places where students may find work.

This new award in Health and Safety excellence and leadership will be presented twice annually to one student from each of the summer and fall sessions. Each recipient receives a plaque and a cheque for one thousand dollars in honour of outstanding achievement. The next presentation will take place in late November.

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