Excepted Waste Sites: Six Historic Abandoned Mine Sites Near Yellowknife
There are six mine sites in the Yellowknife/ Dettah area known collectively as the “Excepted Waste Sites.” These sites include:
These sites are known as the Excepted Waste Sites as they were “excepted” from the Devolution Agreement and responsibility was not assigned to either the GNWT or Canada. It was agreed that responsibility for these six sites would be negotiated at a later date. The GNWT and Canada are in the process of negotiating the responsibility for these sites. Currently, the GNWT is conducting pre-remediation work with funding support from Canada. This includes completing additional environmental site assessment and risk assessment work and planning for remediation.
Ptarmigan Mine
Ptarmigan Mine is a former gold exploration and mine site, located on the Ingraham Trail, approximately 15 kilometers (km) northeast of Yellowknife. The mine was first staked by prospectors in 1936. It produced gold between 1941 and 1942 before restrictions caused by World War II shut down operations. In the mid 1980s, the site was acquired by a new company and the old Ptarmigan mine shaft was back in production by 1987. The mine closed in 1997.
Is there contamination?
Environmental Site Assessments have been completed at Ptarmigan Mine by Canada and the GNWT, however, additional environmental site assessment and risk assessment work needs to be completed before site conditions are fully understood. Environmental site assessments to date have identified metal and petroleum hydrocarbon (fuel) contamination in soil, groundwater, surface water, and/or sediment. Asbestos and lead paint are also present onsite.
Is there a concern with Mine Tailings? What is the dust suppression program?
There are two tailings areas associated with Ptarmigan Mine. A dust suppression program commenced in summer 2023. Dust suppressant was applied to the mine tailings to create a solid crust to reduce risks from wind-blown dust. It will be reapplied as necessary. It is important that the public stay off these areas to protect the crust. Dust suppression is only effective if it’s not disturbed.
Ptarmigan Mine Tailings Areas
Is Ptarmigan Mine dangerous? Can I use the site?
Ptarmigan Mine Site has many hidden dangers, and the public should not enter the site. The dangers include:
- Unsafe Buildings – Buildings are in disrepair and are unsafe to enter. They could collapse at any time. Do not enter or climb on any buildings onsite.
- Climbing buildings is extremely dangerous and could lead to serious injury or death. Fencing has been installed around the perimeter of the headframe and mill complex to keep people out of these areas and buildings. Please respect the measures that have been put in place to restrict access to these areas. They are there to protect you.
- Mine Tailings – Mine tailings look like sand and have high metal concentrations. There are two tailings areas associated with Ptarmigan Mine. As part of care and maintenance, a dust suppression program commenced in summer 2023. Tailings areas should not be disturbed. Do not drive or walk in these areas.
- Mine Openings – Mine openings are extremely dangerous. Do not approach or enter mine entrances or mine openings, underground workings, vent shafts or trenches. Falling down a mine opening could result in serious injury or death.
- Contaminated Soil – Areas of petroleum hydrocarbon (ex. fuel) and metal contaminated soil have been identified. Avoid disturbing the soil.
- Contaminated Surface Water and Groundwater – Metals in surface water and groundwater have been identified. Do not consume surface water. In general, drinking untreated surface water is not recommended because of bacteria and viruses (E. coli from animal droppings, which can cause beaver fever) that can make you sick.
- Contaminated Sediment – Petroleum hydrocarbon (ex. fuel) contamination has been identified in sediments. Avoid disturbing the sediment.
- Hazardous Building Materials – Hazardous building materials such as asbestos and lead paint are present onsite. Do not disturb building materials or debris or remove any materials from these sites.
Given these known risks the GNWT and Canada are requesting members of the public stay out of the Ptarmigan Mine site. Follow signage in the area, respect any barriers or fences that have been put up, and steer clear of any workers completing work on the site. Be safe, do not enter this site. Stay Out – Stay Alive!
The Other Historical Abandoned Mines Sites
The six historic abandoned mine sites are in the Yellowknife/Dettah area.
Tom Mine
Tom Mine is located approximately 1 km north of Ptarmigan Mine. Tom Mine is located west of the Cassidy Point access road between Jerry Lake to the west and Tom Lake to the east.
Mining activities occurred at various times but development of the mine didn’t start until 1985, and full production began in 1986. The mined ore was processed at Ptarmigan Mine and Giant Mine. The mining operations ended in 1997.
Tin Mine
The Tin Mine (also referred to as Cassidy Point Mine) is a former gold exploration and mining site, located approximately 20 km northeast of Yellowknife on the north tip of Cassidy Point at Prosperous Lake.
The original Tin Mineral Claims were staked in 1939 and prospecting began during the late 1930s and early 1940s. In 1986, the mine opening was blasted and a high-grade section of ore was removed for processing off-site. No further mining was completed after this time.
Crestaurum Mine
The Crestaurum Mine site is located on the northwest shore of Daigle Lake, Northwest Territories. The site is approximately 15 km north of Yellowknife.
Exploration mine development activities were carried out on the site from 1944 to 1947. Underground development work continued until February 1947, at which time the shaft was allowed to flood. The mine site burned down in 1957.
Rodstrom Mine
The Rodstrom mine is a former gold exploration and mining site that is located approximately 1.5 km north of Long Lake (Fred Henne Territorial Park) and is within Yellowknife city limits.
The claim was staked in 1962. Diamond drilling was conducted in 1963-1964. In 1979 further drilling and blasting work was completed on-site. In 1994, additional material was mined. No further mining was completed after this time.
Burwash Mine
Burwash Mine is a former gold exploration and mining site, located approximately 1.9 km east of Yellowknife across Yellowknife Bay of Great Slave Lake, and approximately 500 meters south of Burwash point, within Yellowknife municipal boundaries.
The mine operated from 1935 - 1936. Various drilling and prospecting activities occurred between 1935 and 1945. In 1970 the mine shaft was backfilled with waste rock. Further prospecting of the mine site was carried out in 1992 and 1993. No further mining was completed after this time.
FAQs
Can I use the other Historical Abandoned Mines Sites?
All of these sites have some level of contamination and hazards. The public should not enter any of the sites. The dangers include:
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Mine Openings – Mine openings are extremely dangerous. Do not approach or enter mine entrances or mine openings, underground workings, vent shafts or trenches. Falling down a mine opening could result in serious injury or death.
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Ground Stability – Rock walls are not as stable as they may look. Rocks may fall or collapse at any time.
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Contamination – Contaminated soil, groundwater, sediment and/or surface water are present at these sites. It is unknown if these areas of contamination pose a risk to human or ecological health. Do not drink surface water, create dust, or remove soil or waste rock from any of the sites.
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Hazardous Materials – Sites contain asbestos and materials with lead paint. Do not disturb building materials or debris or remove any materials from these sites.
Given these known risks, the GNWT and Canada are requesting members of the public stay out of these sites. Follow signage in the area, respect any barriers or fences that have been put up, and steer clear of any workers completing work on the site. Be safe, do not enter these sites. Stay Out – Stay Alive!
I see people onsite, why are they allowed onsite but not me?
People will be working on these sites to complete additional assessment and care and maintenance work in 2023 and 2024. The contractors completing work at the sites will have site specific health and safety plans to follow to complete work safely. Heavy equipment may be present onsite at this time. Please do not enter the site to approach these workers. If you have questions about the project, please contact ecc_communications@gov.nt.ca.
Although these mines are abandoned, trespassing laws do apply. Anyone rescued from an abandoned mine may face criminal trespass charges. Tools, equipment, building materials and other items on these sites are not to be removed from the site. Warning signs are posted for everyone’s safety. Vandalizing or removing signs or removing tools, equipment or materials from the sites is a crime.
What are the GNWT and Canada doing to remediate these sites?
Remediation cannot begin until we have a clear understanding of the contamination and risk at the sites. In 2023, the GNWT began completing additional environmental site assessment and risk assessment work. Once this work is complete, the GNWT and Canada will assess remediation options.
Will the public or stakeholders be involved with the remediation process?
The GNWT is committed to engaging with Indigenous governments and Indigenous organizations, the public and stakeholders on this project. The GNWT will hold information sessions to provide project updates as work progresses.