Image courtesy of Base Titanium

On January 25^th 2019, three years on from the Mariana tragedy in Brazil, disaster struck again, as the tailings dam at Vale’s Brumadinho mine in Minas Gerais burst, killing 293 people and causing extensive environmental damage in the region. At Exposibram in Belo Horizonte, August 2019, photos of all 293 victims were placed around Vale’s stand in the exhibition hall. Before the first presentation at the tailings management roundtable, the lawyer representing the victims and their families described in detail how the chemical waste that had descended upon the town had killed them. If ever the industry needed to be shocked into action, it was at this moment.

In the wake of the Brumadinho tragedy, the International Council on Mining and Metals (ICMM) conducted a multi-stakeholder review with investors and the United Nations Environment Programme (UNEP), which resulted in the Global Industry Standard on Tailings Management being launched in August 2020.

The investment community was represented by the Investor Mining & Tailings Safety Initiative, led by a group of asset owners and fund managers, including the Church of England Pensions Fund, the New Zealand Superannuation (NZ Super), as well as Swedish and Dutch pension funds. The current group now controls over US$24 trillion in assets, according to Adam Matthews, investment team director for the Church of England Pensions Board, and co-chair of the Investor Mining and Tailings Safety Initiative. “We intend to make a clear requirement to companies that, if they wish to retain continued investment and support of banking facilities and insurance, they must show compliance… There is an inevitability here, but also an opportunity to work collaboratively to drive the change that is needed,” he said, stressing that “investors do not invest in a vacuum” and sector-wide reform is necessary if mining companies expect to retain investment.

The investigation led by the Investor Mining & Tailings Safety Initiative revealed that around a tenth of tailings dams – 166 of the 1,635 dams studied — have had safety issues in the past. Considering there are more than 3,500 tailings dams globally, the challenge at hand will require buy-in from all parties, and not just the major ICMM members. Tom Butler, former ICMM CEO, weighed in on the subject: “I have spoken to a number of companies and private equity funds that invest in smaller companies, who have made it clear to the companies they invest in that the Standard must be adhered to.”

Butler also added that the UN has had a lot of interest in the Standard from countries who want to make sure that this is applied.

The Global Tailings Standard comprises six topic areas, 15 principles and 77 auditable requirements, and will ultimately be supported by implementation protocols that will provide detailed guidance for certification or assurance as applicable, and for equivalence with other standards, explained Butler. He ended with a warning: “The writing is on the wall for anyone who thinks that they can get by without paying proper attention to the Standard.”

Rising demand for tailings services

Dan Etheredge, general manager of Klohn Crippen Berger’s (KCB) South American office in Lima, revealed that 2020 was one of the most active years ever for the engineering firm that specializes in tailings management, and credited the Global Tailings Standard for generating more awareness on the subject.

Etheredge commented that the bulk of KCB South America’s projects are tailings related, such as seismic hazard assessment updates to site selection studies, and commented on how clients have started taking a more long-term approach in their thinking. “For example, they have 10 years capacity left on their existing facility and want to know what their options are moving forward – do I go to a new facility, or do I raise the dam of the existing facility. Thoughts are also moving more towards lowering risks profiles – instead of having one massive structure with an extreme consequence classification, analyzing the impact of a couple of smaller structures with lesser classifications.”

The industry response to Brumadinho, including the Global Tailings Standard, will hopefully prevent such tragic events in the future. However, it is important to examine how a catastrophe on this scale, at a facility owned by one of the five biggest mining companies in the world, could reoccur after a similar failure in 2015. Furthermore, as industry-wide compliance will not happen overnight, could this happen again?

A lack of high-level expertise could be one factor contributing to the risk. “There are a huge number of tailings dams in the world. Klohn Crippen Berger (KCB) has nearly 600 employees who are constantly fully booked on tailings projects and we probably serve only 5% of the market,” related Dan Etheredge.

For Doug Morrison, CEO of the Centre of Excellence for Mining Innovation (CEMI), the industry must recognize that the increasing delay in getting approval for mining projects is almost all related to environmental impact. Moreover, the failings at Brumadinho and Samarco were the result of a flawed approach to tailings management. “Nothing about the nature of these tailings ponds was going to change by simply leaving them there. If you rely on human beings to execute perpetual care and maintenance for decades, if not centuries, eventually mistakes will be made.”

Morrison suggests that the two mainstream methods of tailings management – subaqueous deposition and dry stacking – are set up to fail as they require perpetual human intervention. CEMI’s Mine Tailings Consortium has come up with a radically different way to manage tailings, by splitting the waste stream into two, in an SST process (separation, sequestration and treatment). “Secondly, we were looking for a useful way to use the benign tail that is left behind, and once the contaminated material has been recycled or stored, then the benign material can be used for agricultural purposes,” elaborated Morrison, who stated that the value of production in the time companies would save obtaining a social license to operate would dwarf the incremental increase in operating costs to maintain the SST system. “The net benefit to the industry would be significant from both a sustainable and a financial standpoint,” he concluded.

Eduardo Ruiz, general manager of Amphos21, emphasized the relevance of tailings facilities in the overall site-wide water balance of a mine, due to water being a destabilizing element. “The trend is to design and operate facilities that have a lower amount of water,” he said, noting that while new technologies are being applied in new projects, there are also a lot of older, conventional mines where the risks and long-term conditions need to be better understood. “Standards are definitely improving with more automatization, control and monitoring, so this is a segment where we are going to see a lot of work in the future.”

As a diversified mining country with long mining heritage, Peru has developed a lot of tailings experience. Antonio Samaniego, director of SRK Consulting and former president of IIMP, described the progress made on the topic of tailings management in Peru, including his work with the Global Mining Professionals Association (GMPA), a group including ICM, SME, IIMP, and other institutions worldwide. “Last year we had a meeting in Arequipa where we created the Global Action on Tailings (GAT) working group. We have meetings every three months and we are working on several initiatives related to this field,” he added.

Peruvian mining contractor Pevoex has seen an uptick in demand for tailings work, particularly for tailings dam expansion projects, according to general manager, Rómulo Mucho. “These projects are highly technical, as they involve a critical facility with associated risks, as seen with the dam failures in Brazil in recent years,” said Mucho, who spoke of the strict criteria for projects including Quellaveco, for which Pevoex is a subcontractor of the company building the tailings dam.

Mucho added that the industry is adopting solutions like filtered tailings, for instance at Cerro Lindo, but the cost of such solutions make them more applicable to projects with lower volumes.

ESG at the forefront for investors

The heightened focus on tailings management is also being taken notice of by investors, as ESG has become at the forefront of investment strategy. Michael Scherb, founder and CEO of Appian Capital Advisory LLP, elaborated: “ESG comes up in nearly every interaction with investors. It used to be a buzzword, then it became a checklist, and now it has become a real thematic in underwriting.”

Scherb suggests that industry experts need to explain to institutional investors (like pension plans and sovereign wealth funds) the good that mining does in the world, involving communities, jobs, health, and infrastructure investment in remote parts of countries which may not usually receive benefits.

While the negative public image of mining may not reflect the way much of the modern industry is run, the need to eradicate disasters such as Brumadinho and Samarco should not be understated. If global issues such as tackling climate change and electrifying the economy are to be addressed, an acceptance of mining needs to be fostered through impeccable environmental stewardship. For this to happen, the highest profile companies such as Vale and Rio Tinto must lead the way, and prove that errors in recent years are a thing of the past.