Aerial view of mine tailings from the Bagdad copper mine, Arizona, US. (Photo: NNehring/iStock)
Tailings Management: What’s Changed?
It’s been five years since the Brumadinho tailings disaster that triggered
industry-wide reform in mine waste management. E&MJ gathered an expert panel
to debate what progress has been made and how companies can continue their
quest for safer operations.
By Carly Leonida, European Editor
This chain of events, and the Brumadinho failure in particular, triggered the formation of the Global Tailings Review; a group co-convened by the United Nations Environment Programme (UNEP), the International Council on Mining and Metals (ICMM) and Principles for Responsible Investment (PRI) to establish a globally applicable tailings management standard. The Global Industry Standard on Tailings Management (GISTM) came into effect in August 2020, and ICMM members (which represent around one third of the global mining and metals industry) plus a large number of non-member companies began immediate work towards compliance.
While the GISTM provided a catalyst for much of the progress that’s taken place in tailings management over the past five years, it’s important to note that the standard echoes many of the good practices that were already established through the Mining Association of Canada’s Towards Sustainable Mining (TSM) standard. TSM was the first mining sustainability standard to require site-level assessments of key environmental and social risks (including tailings), and compliance is mandatory for members of the 13 national associations implementing TSM that today span five continents. Thanks to this, many companies were already on the path to more robust, sustainable tailings management practices prior to the above events.
Today, interest and goodwill remain high for this topic — everyone wants to do better — but the mining industry is a slow-moving beast, and these remain uncertain times. As with any type of reform, it’s a good idea to periodically take stock of progress and ask: what must be done to sustain progress? To gather some informal opinions and recommendations, I convened my own group of experts. The following article details our discussions.
Better Designs
for Safer Storage
First up was Dr. David Williams, professor
of Geotechnical Engineering at The
University of Queensland in Australia.
Williams was a member of the expert
panel that investigated the technical
causes of the Brumadinho failure and sits
on numerous independent tailings review
boards (ITRBs) for mines worldwide. He
also initiated and continues to deliver the
AusIMM Professional Certificate Course
in Tailings Management.
“What’s changed over the past five
years?” I asked him.
“The GISTM and the mandate for ICMM member companies to comply with it led to considerable efforts by these companies to improve the governance of their active tailings facilities,” said Williams. “Company standards were rewritten to comply with the GISTM, and the key GISTM principles and requirements were addressed directly. This included expanding Engineer of Record (EoR), and Independent Third Party (ITP) and ITRB reviews.”
He added that, while alternative tailings management methods, like stacking and compacting filtered tailings, have been considered by many organizations, relatively few have been implemented, aside from in Brazil, and the State of Minas Gerais in particular, where it has effectively been mandated. “In Minas Gerais, the Brumadinho disaster brought about almost immediate changes to the law, which banned upstream tailings facility construction and required the ‘de-characterization’ within two years of the 40+ upstream tailings dams identified as being at risk,” explained Williams.
“As footprints for new stacks have not been permitted, tailings are being filtered, placed and compacted within existing mine waste dump footprints,” he said. “This is forcing them higher and decreasing their available footprint due to the 1 in 3 side slopes adopted. As the compacted filtered tailings are loaded, they re-saturate and could eventually become potentially liquefiable.”
Williams noted that the level of focus and desire for transparency that Brumadinho triggered continues from many key mining stakeholders. However, he said the loss of confidence and trust in the mining industry, its consultants and regulators to provide transparency, reduce tailings dam incidents and improve tailings management generally is leading to frustration that real change is not evident.
“While the industry has responded reasonably well to engineering issues with tailings facilities, it struggles with social issues and public disclosure,” he told me. “There is a lack of trust on both sides. The lack of community confidence is making permitting of mine expansions and new mines, along with expanded and new tailings facilities ever more challenging in all jurisdictions.”
Compliance with the GISTM (which is focused on improving tailings management governance) does not in itself improve tailings dam safety or reduce the frequency and severity of tailings dam incidents and failures (although it may improve emergency preparedness and response planning). Williams explained that what’s needed to boost tailings dam safety globally is improvements to their engineering. One way this could be achieved is through the separation of tailings containment (the dam) from tailings storage.
“Tailings dams should be designed, constructed and operated to ensure a high margin of stability,” Williams told me. “The tailings to be contained should ideally be dewatered to increase their density and strength, reducing the proportion of stored water, which would require lower dams, saving on their construction costs. The more dense and stronger tailings deposit would also be easier and less costly to rehabilitate to a higher level of post-closure use.”
Looking to the future, it’s inevitable that the increasing demand for metals and minerals and the decreasing grades of orebodies will lead to further increases in tailings production. Williams believes that tailings reprocessing and reuse also offer valuable solutions.
“While there may be some potential for the reprocessing of tailings to yield metals and minerals, this will still leave the bulk of the tailings to be managed,” he said. “They could be dewatered and redeposited to form denser, stronger deposits. However, uses need to be found for the bulk of tailings, such as using sand fractions as a replacement for natural and quarried sand, and the use of tailings in the manufacture of building products such as concrete, bricks and as fill.”
Lifting Standards Uptake
Globally
I wanted to learn more about the role of
mining standards in improving tailings
management, particularly those that include
elements of external scrutiny and
validation. David Clarry, who served as
vice president of sustainability at Hudbay
Minerals until January 2024 after a 13-year
tenure, and former board member and
chair at the MAC, has experience of both
their development and implementation.
“The differences between TSM and the GISTM are quite subtle,” he told me. “Both are good standards. The GISTM has more global coverage by major companies. However, TSM has a more robust structure of oversight. If companies really want to move the needle on responsible tailings management, I encourage them to focus on the effectiveness of their implementation of either standard.”
We discussed the potential acceleration in industry-wide performance that could be unlocked through the consolidation of key standards, and the next day, the Consolidated Mining Standard Initiative (CMSI), formed by The Copper Mark, Mining Association of Canada, ICMM and the World Gold Council (WGC),, published a draft consolidated standard for public consultation.
“For me, the element of external review that the GISTM, TSM and consolidated standard prescribe is key,” said Clarry. “Knowing that a third-party expert will scrutinize company practices can shift internal dialogues, particularly among management, and creates more room for healthy discussion on potential risks and improvements.”
Good dam design is important to tailings safety, but so too is way in which TSFs are built and operated. For example, the placement of material and management of water levels are dynamic activities and, recognizing this, the MAC reexamined TSM following the Mt Polley disaster to ensure adequate emphasis was placed on operational performance.
“One of the biggest changes I’ve seen in the last five years, is the elevation and integration of tailings management into wider operational performance metrics,” said Clarry. “At some operations, tailings management traditionally fell to the environmental group. This meant the team at the mill where the tailings are produced didn’t pay enough attention to their impact on tailings management, for example in water management. Assigning accountability for tailings management to the mill manager better integrates decision criteria.”
When asked how the industry can continue to push the envelope on tailings management, Clarry re-emphasized the importance of standards adoption. There are lots of operators globally who, for different reasons, have yet to align themselves with the GISTM, TSM or others. Helping them understand and find ways to overcome any barriers is central to lifting the industry’s collective performance.
“Most commodity markets are too diffuse to exert the pressure needed to drive continuous improvement in tailings management,” he said. “Having investors place greater value on the uptake of riskbased standards has been really helpful. Some are doing a great job at this, but overall, there’s more that investors could do to encourage adoption — for example, integrating conformance into more sustainability ratings. Regulators also have a part to play. For instance, standards adoption could play a greater role in project permitting in the future.”
Clarry concluded: “Whichever standards operators choose to adopt, having external verification against them is vital. The transparency that provides will help earn society’s trust, both in individual operators and the industry more broadly.”
Implementing the GISTM
Next was Aidan Davy, co-chief operating
officer of the ICMM. I wanted to talk
about what has been achieved through
the GISTM, which elements of implementation
members are finding most
challenging and future opportunities.
At the point of launch (August 5, 2020), all ICMM members committed to conform with the GISTM for all of their facilities. Priority was established for those with the two highest consequence classifications — extremely high and very high — which had a conformance deadline of August 2023, and the remaining facilities have a target of August 2025. Additionally, 57 non-member companies publicly committed to implementing the standard, although Davy noted that as they’re operating outside of ICMM’s membership commitments, their timelines for implementation are not as clear cut.
“Collectively, those 81 companies account for more than 50% of the industry by market capitalization,” he told me. “The scale of commitment was a big achievement. When our members made their first disclosures in August 2023, it was clear that many of them had seen significant benefits from implementing the standard.”
He explained that many organizations saw transformative improvements in tailings engineering, management and governance, and also in tailings monitoring. Additionally, elevating tailings governance to the board and executive level has driven greater accountability and transparency. “Members also reported a change in their collective mindset,” added Davy. “There’s been a realization that good tailings management practices require integrated, systems-level thinking and action. It’s no longer a matter purely for tailings professionals.”
“We’ve definitely seen sustained momentum from society, and from operators that have committed to the GISTM,” he said. “However, we’ve seen a drop in interest from some external stakeholders, particularly investors. Not all investors fall into that category. Principles for Responsible Investment (PRI), for example, was a partner in developing the GISTM, and we’re engaging with them to bring the Global Tailings Management Institute to life. But 2-3 years ago, every conversation I had with an investor touched upon tailings, and that’s not the case today.”
Davy pointed to the good work that the Investor Mining and Tailings Initiative (IMTSI) has done in keeping tailings a priority for investors and ensuring that they follow up on calls to action that were issued to the mining industry. The IMTSI was founded in 2019 following the Brumadinho dam collapse. It’s led by the Church of England Pensions Board and the Swedish Council on Ethics. The coalition has over 100 investors who manage around US$16 trillion.
“Our other partner in establishing the GISTM was UNEP which has sustained interest through successive UNEA resolutions,” he added. “That’s good, but I’d like to see UNEP advocate more assertively with its member countries to integrate the GISTM into their regulatory systems. That will help to effect change at scale.”
Growing, Learning
and Innovating Together
Like Clarry, Davy noted the importance
of working collaboratively to simplify the
complex landscape of responsible mining
standards.
“Rather than being overinvested in
our own standards, we, together with
the WGC, MAC and The Copper Mark,
took a step back and asked ourselves
what would be in the best interests of the
mining and metals industry and its stakeholders,”
he told me.
“The responsible mining standards landscape has grown to be incredibly complicated. It’s very hard for external stakeholders, downstream companies and miners to know which standards to comply with, and there’s a danger of diverting valuable resources away from meaningful actions on the ground. That complexity could also devalue the benefits that robust standards can bring, because stakeholders aren’t sure which ones to trust.
“All four organizations have made a deep commitment and investment into consolidating our standards into one, and we’re handing control of that consolidated standard to an independent body with multi-stakeholder governance to ensure its long-term sustainability. To accelerate uptake, any company that wants to align with the standard and is committed to responsible practices can implement the standard and access related content, rather than requiring them to be members of ICMM, MAC or the WGC.”
As Williams noted earlier, as the mining and metals industry ramps up production to meet society’s needs and the requirements of the energy transition and more tailings are created, tailings innovation is becoming increasingly important. In September 2024, the ICMM co-hosted the MIT Global Summit on Mine Tailings Innovation conference. The event, which took place at the Massachusetts Institute of Technology, brought together researchers, industry experts, innovators, start-ups and more, to work on a single goal: accelerating the development of solutions to reuse, reduce and reimagine mine tailings. “We were very pleased with the level of engagement from our member companies and the diverse range of stakeholders participating,” said Davy. “Attendees left the conference with a real sense of excitement around new opportunities to reduce tailings. It’s important the mining industry capitalizes on the flurry of activity and investment that’s taking place in tailings innovation. The work that we do today to develop and test emerging technologies and storage methods could mean a future with fewer tailings.”
Social Responsibility:
Whose Job Is It to Engage?
As Davy noted, good engagement with
affected communities is a core part of responsible
tailings management. However,
it’s not a skillset that comes naturally
to a large portion of the tailings management community. Companies that embrace
social performance expertise early
on and develop the skills needed to ensure
information is received and understood
as intended are more likely to build
strong, mutually beneficial relationships
with their host communities.
The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) has organized multiple workshops on tailings and mine waste management over the past 20 years, shifting gradually from a purely technical focus in design and risk management, to include more sustainability and governance aspects.
“While this occurred in a seemingly logical progression to meet the wider objectives of standards such as the GISTM and TSM, we’ve found, surprisingly, that many in the geotechnical world of tailings have recently withdrawn interest and support for our efforts, both from the volunteer side, as well as in attendance,” said Karen Chovan, CEO of Enviro Integration Strategies and incoming Tailings Lead, Environmental & Social Responsibility Society (ESRS) at CIM.
Specializing in tailings management and a decade-long volunteer with ESRS, Chovan co-facilitates these workshops alongside Alistair Kent, senior civil engineer at Merit Consultants and a CIM Fellow, with 47 years’ experience in mine waste management.
The duo found this hesitancy troubling and set out to understand why. Their research identified several reasons. Firstly, difficulty in effectively communicating complex technical information and the purposes of different analyses to non-technical audiences.
Chovan explained: “For example, the requirements of performing dam breach and flood mapping analyses are based on the conservative assumption that the dam will fail, without consideration of the controls in place to prevent or mitigate failure, with possible results of significant or complete discharge of the contained materials.
Second, they noted a lack of alignment in processes for determining ‘credible failure modes,’ ‘probability of failure,’ and ‘risk’ within professional networks, and often a general misunderstanding and use of those technical terms by non-practitioners. Chovan explained: “Currently there are two distinct definitions used for ‘credible,’ each of which meet the intent of the newest standards of practice, where companies must clearly understand and declare their basis of application. Another example lies in calls for transparency around risks posed by these facilities, and how that information is then displayed and/or interpreted by others. For instance, on a global tailings portal showcasing data about each companies’ tailings facilities, there are charts listing the number of facilities in each consequence classification category — but this is merely one component of measuring risk.”
She added that to fully understand the level of risk, one must also know what the probability for failure of that same facility is; a high consequence classification does not always equal high risk, but this is not the story that the classification category conveys.
“Lastly, as we were informed by one senior consultant heavily involved in tailings management, their clients (i.e., mining companies) don’t necessarily want them involved in the engagement process,” said Kent. “It seems that management often bring in experts in social engagement who don’t want engineers near the public consultation process.”
He added: “Increasingly, we hear about inexperienced but overly confident ‘experts’ in the areas of social engagement and community relations pushing away the engineering input that the community is most concerned about.”
The Importance
of Leadership Buy-in
Coincidentally, two other reviews complement
Kent and Chovan’s investigation.
They explained that a paper recently
published by Kemp et al. “Disclosure
hesitancy and disaster risk: a survey of
tailings professionals in the global industry”
(Minerals Engineering, 2024), presents
a relevant analysis about disclosure
hesitancy by tailings professionals. Kent
noted that it painted a picture of disclosure being constrained by corporate fear,
abetted by skepticism about the public’s
ability or right to know and participate.
Kent said: “Significantly, Kemp’s paper points to the positive benefits of proactive disclosure about complex technical projects in other industries, such as chemical and nuclear. We have much to learn from them, which should be an opportunity to improve our industry’s image, facilitate GISTM compliance, and garner public and investor trust and funding.”
Kent and Chovan identified a related concern, and likely impediment to the challenges described above, which is a lack of mandate from the C-suite. In a recent E&MJ article titled, “Being Responsible for Responsible Mining: Why Mining Directors Need Greater ESG Competency.” Industry experts noted that concerning gaps still exist at the highest levels of leadership when it comes to true competency in environmental, social and governance (ESG) matters.
Further, the article indicated that although the mining industry has made significant strides in embracing ESG principles over the past decade, it’s future and social license to operate hinge on its ability to embed authentic sustainability leadership at the highest levels. Chovan and Kent believe that the C-suite should be encouraging and mandating technical teams to be full participants in the engagement process. “This reticence conflicts with professional engineer’s and geoscientist’s ethical training, which reminds us of our responsibility to be in the thick of both promoting and communicating good practices,” Kent told me.
“We want to encourage the next generations of tailings professionals to take responsibility for effective engagement very seriously, as an integral part of everything they do. The engineering profession must take the lead in integrating design and engagement processes. There can be no other logical way to achieve social and sustainability goals, ergo social license.”
Chovan concluded: “We need more individuals involved with tailings management, from a wide variety of disciplines, to get engaged in engagement through formal trainings, and practice within their own organizations. Geotechnical engineers should take the lead in professing and explaining their design competency and their ability to communicate through a well-structured fair and open process. The C-suite needs to provide the mandate for this to happen in a deep and whole-hearted way.”
We Must Continue
to do Better
It’s clear that much has changed for the better
in mine tailings management over the
past five years, but there are also aspects
where greater attention is still required.
While it should not have taken a tragic
event to catalyze change, it did. And it
is the industry’s collective responsibility,
as a steward of the energy transition, a
major tenant of land globally and a good
neighbor to communities, to remember
that and keep pushing for progress. We
all have a role to play in responsible tailings
management.
1 https://www.nature.com/articles/
s43247-023-01086-9
2 https://www.andrewleestrust.org/blog/wp-content/uploads/2024/03/QMM_2021-2023_Water_Report_Evaluation_Emerman_Revised.pdf
3 https://earthworks.org/resources/
safety-first/