| Risk management


worldwide. Although the Global Industry Standard on Tailings Management (GISTM) was recently introduced, critics say it was almost entirely written by the mining industry and claim it is a document that is highly favourable to their interests. In 2020, the Global Tailings Review, a process co-convened by the trade industry association the International Council on Mining and Metals (ICMM), the UN Environment Programme, and Principles for Responsible Investment, released the GISTM. MiningWatch Canada says that although it came well short of the recommendations in the aforementioned publication Safety First, “it was an important first attempt at international tailings dam regulation”. ICMM members have committed to implementing the GISTM at all mines within five years, but it is unclear what progress has been made, and tailings failures continue. Since November 2021, there have been at least ten failures, leaks or overflows.


“Effective tailings management is impossible without civil society oversight as well as that of the role of independent professionals,” said Hassen Lorgat of the Benchmarks Foundation in South Africa and convenor of the South African Tailings Working Group. “This means that the laws and practices of corporations must change. This is urgent especially in the time of the climate crisis.” Dr Steven Emerman is an internationally recognised geologist specialising in groundwater and mining, who has evaluated numerous proposed and existing tailings storage facilities around the world. He gives the example of the Copper Mountain Tailings Management Facility in British Columbia, Canada. Emerman claims that the mine will not release its dam safety reviews which were “extremely critical about the stability of that tailings dam”, and neither will the BC government.


Emerman, who has testified on tailings dams before the US House Subcommittee, European Parliament and the UN National Assembly, and is also Chair of the


Closed and care and maintenance Operating 17% 46% 54% 83% 83% Proposed 17%


Classification: High, very high & extreme Low, significant & N/A


Body of Knowledge Subcommittee of the US Society on Dams, said that according to the GISTM the report should be released and made available to the public. “I’ll just emphasise that tailings dams in BC are among tallest in the world,” Emerman says. “Proposals to raise the height of East Dam at Copper Mountain to almost 260m would make it the second tallest tailings dam in the world. The West Dam at the same facility would be the third tallest.” The concern here is that the height of a tailings dam is one of the many drivers of risk that can lead to failure. Others include high seismicity, high precipitation, closed facilities or those under care or maintenance, the volume of tailings stored, plus upstream construction methods. Upstream construction is considered as a less desirable form of dam construction from a safety standpoint. Although the dams are inexpensive as they use minimum amounts of construction material, as they are built on top of uncompacted tailings, upstream dams are known to have higher rates of stability issues and are susceptible to failure by liquefaction.


f


Summary of recommendations from Safety First: Guidelines for Responsible Mine Tailings Management (2022)


● Make safety the guiding principle in design, construction, operation and closure of tailings facilities.


● Ban new tailings facilities in locations that would not allow for timely assisted evacuation of inhabited areas in the event of dam failure.


● Ban upstream dams at new mines and close existing upstream dams.


● Design dams to avoid any potential loss of life, which must be considered an extreme event.


● Mandate the use of best available technology for tailings facilities, including the use of filtered tailings, and implement rigorous controls for safety, including after mine closure.


● Demonstrate understanding of local conditions and tailings characteristics with robust monitoring systems.


● Develop appropriate emergency preparedness/response plans.


● Ensure the independence of reviewers to promote safety and transparency.


● Address financial risks, including proper financial assurance and insurance.


● Attempt to eliminate all credible failure modes to have safer facility closures.


● Establish grievance procedures, whistleblower protection, and community-based safety oversight for potentially affected communities.


● Obtain consent from potentially affected communities and guarantee the right to say ‘no’ to proposed or expanded tailings facilities.


● Make information regarding mine safety publicly available in relevant languages.


● Offer affected communities access to independent technical experts.


● Require corporate boards of directors assume full responsibility for the risks (including financial risks) and the consequences of tailings facility failures.


The Safety First report and recommendations were endorsed by 157 scientists, community groups, Indigenous peoples, and civil society groups. It was based on consultation with over 200 stakeholders and experts across five continents. See earthworks.org/safety-first and miningwatch.ca/safety-first


Above: Percentage of mine sites with tailings storage facilities in British Columbia, Canada according to status and dam failure consequence classification. A low consequence classification corresponds to no loss of life; significant is a low potential for multiple losses of life; high is a loss of fewer than ten lives; very high is a loss of fewer than 100 lives; and extreme is a loss of greater than 100 lives


www.waterpowermagazine.com | November 2022 | 35


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