Mount Nansen Mine Remediation Project
The work underway to maintain and remediate the Mount Nansen Mine site.
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History of Mount Nansen Mine
The Mount Nansen Mine was once a gold and silver mine located 60 kilometres west of Carmacks, Yukon within the Traditional Territory of the Little Salmon/Carmacks First Nation. The abandoned mine site is located along Pony, Back and Dome Creeks which flow into Victoria Creek and the Nisling River.
Little Salmon/Carmacks First Nation citizens have historically used the area (Enozhí Ddhäw in the Northern Tutchone language) for traditional activities, subsistence hunting and gathering.
Mineral exploration of the area began in the 1940s and active mining occurred over 3 different periods between 1968 and 1999. BYG Natural Resources Inc. (BYG) conducted the most extensive mining adjacent to Pony Creek between 1996 and 1999, producing 41,500 ounces of gold and 234,200 ounces of silver.
Mining exploration and operations at Mount Nansen left behind approximately 540,000 tonnes of tailings and 800,000 tonnes of waste rock. The main environmental concerns on site are soils with elevated concentrations of metals, potentially acid generating waste rock, and potentially acid generating tailings and impacted tailings water.
BYG ceased operations in 1999 due to licensing, pricing and financial issues. The mine site is currently in a state of care and maintenance. This will continue until all regulatory requirements are in place to proceed with active remediation of the site.
Responsible parties
The Mount Nansen Mine became a Type roman numeral 2 mine site under the Yukon Northern Affairs Program Devolution Transfer Agreement on April 1, 2003. Under this agreement, the Government of Canada is responsible for pre-2003 environmental liabilities and associated costs of remediation for abandoned Type roman numeral 2 mine sites, and to work with the Government of Yukon and Affected First Nations to address these sites. The agreement identifies Little Salmon/Carmacks First Nation as an Affected First Nation for the Mount Nansen Mine.
In 2019, a new owner of the site (the Mount Nansen Remediation Limited Partnership) was identified and signed an agreement with the Government of Canada which obligated the Partnership to remediate the site as per the preferred site remediation option.
Also in 2019, the governments of Canada, Yukon, and Little Salmon/Carmacks First Nation signed the Mount Nansen/Enozhí Ddhäw Remediation Project Governments Agreement in which the Government of Canada committed to fund the implementation of the preferred site remediation option agreed to by the parties. The agreement also establishes a new approach for the 3 governments to work collaboratively together on remediation of the site.
In 2021, the Mount Nansen Remediation Limited Partnership officially assumed ownership of the site. While the site is not considered abandoned, it remains a Type roman numeral 2 site and the Government of Canada still funds care and maintenance, site monitoring and remediation planning and implementation through the Northern Abandoned Mine Reclamation Program. The Government of Canada also maintains its oversight role to ensure that the Mount Nansen Remediation Limited Partnership develops and implements a remediation plan which is consistent with the preferred site remediation option agreed to by the parties.
Given the collaborative approach to remediation adopted by governments in the Mount Nansen/Enozhí Ddhäw Remediation Project Governments Agreement, along with the project's commitment to provide training and job opportunities for Little Salmon/Carmacks First Nation citizens and other Yukoners, the Mount Nansen Mine Remediation Project demonstrates progress toward reconciliation.
Mount Nansen Mine Remediation Project activities
The Mount Nansen Mine is in a state of care and maintenance. This work was first lead by the Government of Yukon.
In 2021, the Mount Nansen Remediation Limited Partnership officially assumed ownership of the Mount Nansen Mine site, and responsibility for its remediation. Since then, the company has undertaken care and maintenance activities, along with significant preparatory work for active remediation, including:
- obtaining a water license from the Yukon Water Board
- construction and operation of a water treatment plant to treat contaminated water and discharge treated water into the environment as permitted by the water license
- surface and groundwater monitoring
- road and infrastructure maintenance
- operation, maintenance and surveillance of the tailings storage facility including a dam, spillway and seepage pond
The remediation plan
In 2003, the governments of Yukon, Canada and Little Salmon/Carmacks First Nation began developing a remediation plan.
In 2012, after many years of study and consultation, and following an evaluation process to determine the remediation option that best meets the broad objectives for the site, the parties agreed to implement the preferred site remediation option which will stabilize waste sources by relocating the mine's tailings to the Brown and McDade Pit (the original source of the ore and only pit on site), removing the tailings dam, and restoring Dome Creek.
The broad Mount Nansen Mine Remediation Project objectives, established in the Mount Nansen/Enozhí Ddhäw Remediation Project Governments Agreement, are to:
- protect human health and safety
- protect and restore the environment including land, air, water, as well as fish and wildlife and their habitats
- return the mine site to an acceptable state that reflects original, traditional and pre-mining land use
- maximize local, Yukon and First Nation benefits
- manage risk in a cost effective manner
In August of 2022, the Mount Nansen Remediation Limited Partnership initiated the first step (Pre-Submission Engagement) of the Yukon Environmental and Socio-economic Assessment Board process by submitting their project description (Project 2022-0136) for comment and engagement. The Board issued its Project Proposal Report in November of 2024 which sets out the requirements for the final Project Proposal.
The Mount Nansen Remediation Limited Partnership plans to take the next step in the environmental and socio-economic assessment process by formally submitting the Mount Nansen Remediation Project Proposal, the remediation plan, to the Board for assessment in 2025.
Progress to date
Key project milestones to date include:
- selection and agreement on a site remediation option by the governments of Canada, Yukon and Little/Salmon Carmacks First Nation (2012)
- signing of the Mount Nansen/Enozhí Ddhäw Remediation Project Governments Agreement (2019)
- mount Nansen Mine site sold to the Mount Nansen Remediation Limited Partnership (2021)
- the Mount Nansen Remediation Limited Partnership began operating a water treatment plant (2022)
- the Mount Nansen Remediation Limited Partnership initiating the assessment process by submitting their project description to the Yukon Environmental and Socio-economic Assessment Board for comments and engagement (2022)
Timeline of events and progress to date:
- 2025
- Demolition of the abandoned mill at the Mount Nansen Mine, a key step toward cleaning up the site and restoring the land for people, wildlife and the environment
- Nansen pilot solar project offset 40% of camp diesel use, saving 5,000 Liters of fuel and 15 t CO₂ eq
- 2024
- Yukon Environmental and Socio-economic Assessment Board issued its Mount Nansen Project Proposal Report, concluding the first step in the assessment process
- 2022
- Mount Nansen Remediation Limited Partnership submitted remediation project description for review and comment from the Yukon Environmental and Socio-economic Assessment Board and stakeholders
- Mount Nansen Remediation Limited Partnership constructed and began operating a water treatment plant
- 2021
- Mount Nansen Remediation Limited Partnership officially assumed ownership and responsibility for the site, with the Government of Canada maintaining its funding and oversight role. The site is no longer abandoned, but remains a Type roman numeral 2 mine site under the Devolution Transfer Agreement.
- The Yukon Water Board issued the Mount Nansen Remediation Limited Partnership a 5-year Type B water license for care and maintenance activities
- 2019
- Mount Nansen Remediation Limited Partnership, a joint-venture, was selected as the preferred purchaser of BYG assets from the court-appointed receiver.
- Agreement signed by the Government of Canada and the Mount Nansen Remediation Limited Partnership, the new owner of the site, obligating it to remediate the site as per the preferred site remediation option.
- 2016
- The court-appointed receiver began a proposal solicitation process to select a company to buy the remaining assets of BYG and carry out a remediation plan consistent with the preferred site remediation option.
- 2014
- Site characterization report completed and used by the court-appointed receiver to solicit proposals to develop, permit and implement a remediation plan consistent with the preferred site remediation option.
- 2012
- Agreement by the governments of Canada, Yukon and Little Salmon/Carmacks First Nations to proceed with the preferred site remediation.
- 2011
- Evaluation process concluded by the governments of Canada, Yukon and Little Salmon/Carmacks First Nation to determine the remediation option that best meets the broad objectives for the site.
- 2003
- The Yukon Northern Affairs Program Devolution Transfer Agreement came into effect on April 1 and the Mount Nansen Mine became an abandoned Type roman numeral 2 mine site.
- Government of Yukon assumed responsibility for care and maintenance.
- The governments of Canada, Yukon and Little Salmon/Carmacks First Nation began planning and developing a remediation plan.
- 1999
- Mount Nansen Mine was considered abandoned. The Government of Canada took charge of care and maintenance of the site.
- 1968 to 1969, 1975 to 1976, and 1996 to 1999
- These 3 periods of active mining produced 41,500 ounces of gold and 234,000 ounces of silver, along with approximately 540,000 tonnes of tailings and 800,000 tonnes of waste rock.
- 1940s
- Mineral exploration at Mount Nansen began.
- Pre 1940s
- Little Salmon/Carmacks First Nation people used the area known as Enozhí Ddhäw for traditional activities, subsistence hunting and gathering.
Consult the Mount Nansen Remediation Limited Partnership website for additional information and updates
Next steps
The Mount Nansen Remediation Limited Partnership is working towards finalizing their project proposal, with submission to the Yukon Environmental and Socio-economic Assessment Board expected in 2025.
It is expected that the project will pass the assessment and permitting phase in 2029 so that active remediation can begin.
Remediation is expected to take 3 years to complete.
Contracting and jobs
Work associated with the Mount Nansen Remediation Project is being contracted by the owner of the site.
Consult the Mount Nansen Remediation Limited Partnership website for information on contracting and job opportunities.
Contact us
Mount Nansen Mine Remediation Project
415C-300 Main Street
Whitehorse, Yukon
Y1A 2B5
Phone: 1-800-661-0451
Email: YTcontaminatedsites-sitescontaminesYT@rcaanc-cirnac.gc.ca