Mining in the Mountains
Scattered throughout the mountains of western Canada, often hidden behind locked gates at the end of gravel roads, are mines. Although they are concealed from much of society, it is worth highlighting the role of mining in these rapidly-changing, remote landscapes.
Teck Coal operates extensive mining operations in the Elk River Valley of southeastern British Columbia. Photo: Garth Lenz
Mining operations target valuable mineral resources, such as coal, copper, or gold, that are locked away in earth’s geology. A mine begins with prospecting, the process of locating economically-viable concentrations of minerals. After securing financial support, mining operations then extract the rocks from mountains to access the minerals. Such extraction may entail tunnelling underground, digging massive open-pits, removing the tops of mountains, or sifting through surface sediments. The mined rock is then mechanically and chemically manipulated to isolate the tiny concentration of targeted resources from the “waste” rock. For example, in southeastern B.C., Teck Coal produces 840 million tonnes of waste rock annually to access twenty-seven million tonnes of steelmaking coal that underlies the Canadian Southern Rockies.[1]
Mining provides important jobs to remote communities and resources for humanity, but mines and their related infrastructure can pose substantial environmental risks. Mining activities disturb landscapes and mobilize toxicants that are otherwise locked away in rocks. One common impact from mines is acid rock drainage, whereby sulfur-rich rocks are exposed to air and water, resulting in acidic runoff to downstream waters. Mining can also release metals, like arsenic, copper, and selenium, that can persist for centuries, if not millennia. Remnants of Roman Empire mining still pollute European rivers.[2] To contain toxicants, waste rock and processed slurries from mining are often stored in tailings facilities—or simply placed in river valleys—in perpetuity. But valleys filled with waste rock result in the permanent burial of stream headwaters, and tailings storage reservoirs can fail. These failures can be subtle, such as toxicants leaching out in groundwater, or catastrophic, such as the partial breach of Mount Polley’s tailings dam that released over seven million cubic meters of contaminated slurry downriver and into a sockeye salmon rearing lake in the plateau country of B.C.[3]
While there have been advances in mining remediation and technology, some mines perpetually harm ecosystems because mitigation practices fall short in addressing long-term environmental impacts.[4] Below, we discuss several unique challenges for the environmental sustainability of mining in western Canadian landscapes.
First, the rugged nature of western Canadian mountains can exacerbate the impacts and risks of mining. These are some of the steepest, wettest, and snowiest places on Earth. Avalanches, landslides, and other natural hazards can damage mines and the infrastructure they have in place for risk mitigation. To address such challenges, mining in mountains relies upon marvels of engineering that push the limits of technology and infrastructure. For example, the proposed KSM mine crossing the Unuk and Nass River watersheds would require over five billion US in capital expenditures to create three open pits, four dams for tailings ponds – including what would be one of the highest dams in North America – and twin twenty-three kilometres of sub-glacial tunnels for transporting ore.[5] Access to remote mountain mines demands the creation of new roads and power systems in otherwise roadless, high-elevation landscapes. In an extreme example, the currently operating Brucejack Mine in the Unuk River watershed is accessed via an eleven-kilometre-long road on a glacier.
Reaching Brucejack Mine in the Unuk River watershed shared between British Columbia and Alaska requires traversing an 11 km road over Knipple Glacier. Photo: Garth Lenz
Occurring in the headwaters of western rivers, mountain mines can pose downstream risks. Mountains are the birthplace of clean cold water, gravel, and other resources for downstream communities and ecosystems. Even high in the mountains where fish do not exist, mining impacts can spread downstream into important fish habitats and human communities. An extreme example of such downstream damage was the historic flood of 1908 that carried five-and-a-half million cubic metres of toxic sludge, laden with arsenic, lead, zinc, and copper, over just under two-hundred kilometres downstream from a massive copper mining complex in western Montana.[6] These downstream risks can even cross international boundaries, complicating effective mining oversight.[7] Communities in southeastern Alaska dependent on healthy salmon populations are concerned that they are bearing the burden of environmental risks posed by upstream Canadian mines and have repeatedly called for their stricter regulation, oversight, and enforcement.[8]
The tailings reservoir for Red Chris Mine sits in the headwaters of the Stikine River watershed shared between British Columbia and Alaska. Photo: Garth Lenz
There is increasing global pressure to further extract mountains’ minerals. The United States recently identified the amounts, types, and sources of minerals that would enable them to keep up with their growing consumption. On the top of the list of sources, second only to China, was Canada.[9] The “golden triangle,” a region of northwestern B.C., whose rivers drain through the coast mountains into southeastern Alaska, is experiencing a modern-day gold rush; companies spent $165 million in exploration in 2018, nearly twice the investments made in 2016.[10] With the rapid retreat of glaciers and permanent ice due to climate change, mining companies are further exploring these newly exposed landscapes for the next big mineral deposit. We anticipate that there will be continued pressure for mining in the mountains.
The diverse community of people who care about the future of mountain ecosystems in western Canada are facing important questions. Some are technical: how can evaluation, regulation, and operations of mines be improved to decrease risks to important species and ecosystems? Some questions are value-based and demand that we weigh the costs and benefits of mines: for example, are there areas that are too ecologically-sensitive or important to risk with mining? Other questions are politically sensitive: given that mining companies consistently donate millions of dollars to B.C. governments, making them some of the biggest corporate donors, are mining benefits and risks fairly considered in decision-making?[11] Looking forward, we face difficult decisions and potential trade-offs: can gold mining co-exist with grizzly bears? Coal with caribou? Steel with salmon? These difficult decisions should be made with the best available science and with balanced accounting of the risks and benefits of mountain mining.
Looking upstream on the mainstem Tulsequah River, a large tributary to the Taku River on the traditional lands of the Taku River Tlingit First Nation. The red building on the right side of the photo marks the location of Tulsequah Chief Mine, which ended operations in the 1950s and has been leaking acid mine drainage. Photo: Chris Sergeant/ Flathead Lake Biological Station.
Erin Sexton is a Senior Scientist and Chris Sergeant is a Research Scientist with the Flathead Lake Biological Station (FLBS) of the University of Montana. Jonathan Moore is a Professor in the Faculty of Science and Faculty of Environment at Simon Fraser University. They participated in a workshop held in late October 2019 at FLBS to advance scientific knowledge on mining impacts on watersheds. The working group comprised thirty-nine science and policy experts from academic institutions, state/provincial and federal agencies, Indigenous governments, and non-governmental organizations gathered to participate in the collaborative workshop. Those in attendance included representatives from Alaska, Idaho, Montana, Washington, British Columbia, and Ontario. For more information about this gathering, please visit our website.
References
1. Teck. Beyond: 2018 Annual Report. Accessed at: https://www. teck.com/media/2018-Teck-Annual-Report.pdf (2018).
2. Olías, M., and Nieto, J.M. Background conditions and mining pollution throughout history in the Río Tinto (SW Spain). Environments, 2(3), 295–316 (2015).
3. Petticrew, E.L. et al. The impact of a catastrophic mine tailings impoundment spill into one of North America’s largest fjord lakes: Quesnel Lake, British Columbia, Canada. Geophysical Research Letters, 42, 3347–3355 (2015).
4. Palmer, M.A. et al. Mountaintop Mining Consequences, Science, 321, 148-149 (2010). [DOI: 10.1126/science.1180543]
5. Ghaffari, H. et al. 2016 KSM (Kerr-Sulphurets-Mitchell) prefeasibility study update and preliminary economic assessment. Available at: https://www.miningdataonline.com/reports/ KSM_PFS_PEA_112016.pdf (2016).
6. US EPA ROD R08:84 April 1984. Superfund Record of Decision: Milltown Site, MT http://www.epa.gov/region8/superfund/sites/ mt /milltowncfr/reservoirou.html
7. Sexton, E.K., et al. (2020). Canada’s mines pose transboundary risks. Science, 368(6489),376-377. DOI: 10.1126/science.abb8819
8. Murkowski, L. et al. Multistate delegation letter to British Columbia Premier Horgan, dated 13 June 2019. Accessed at: https://www.murkowski.senate.gov/download/multistate-delegation-letter-to-premier-horgan (2019).
9. Media Note. Office of the Spokeperson. October 4, 2019. First Meeting of the U.S.-Canada Critical Minerals Working Group. https://ca.usembassy.gov/first-meeting-of-the-u-s-canada-critical-minerals-working-group/
10. British Columbia Mineral and Coal Exploration Survey. Available at: https://amebc.ca/wp-content/uploads/2019/03/EY-BC-minerals-coal-exploration-survey-2018_web.pdf (2018).
11. Vancouver Sun. Big corporate donors give big to the B.C. Liberals. Available at: https://vancouversun.com/business/local-business/ big-corporate-donors-give-big-to-the-b-c-liberals.