On the third anniversary of the Brumadinho disaster that killed 270 people when a tailings dam collapsed at a Vale mine site in Brazil, investors have published the names of companies committed to implementing a new global industry standard for improving safety across the mining sector.

Seventy-nine companies, representing a third of those with tailings dams (by market capitalisation), have committed to implement the new Global Industry Standard on Tailings Management or are assessing their alignment to it. This includes the largest companies that are members of the International Council on Mining & Metals (ICMM) such as BHP, Anglo, Glencore, Rio Tinto and Vale.

However, 183 companies have yet to confirm if they will implement the standard including: Southern Copper, Zijn Mining, ArcelorMittal, Grupo Mexico, Saudi Arabian Mining Company, Ganfang Lithium Co, Boashan Iron & Steel Co, China Northern Rare Earth High-Tech Co, POSCO and Zhejiang Huayou Cobalt.

The US$4.7 billion Church of England Pensions Board set up and leads the 100 strong coalition of investors (representing USD$20 trillion under management) that form the Investor Mining and Tailings Safety Initiative. The church announced that they will vote against the chairs of boards at companies in which they invest that have not confirmed their intention to implement the industry standard. Given the continued risk posed to communities and the environment from tailings dams, the pensions board encouraged other investors to consider following suit to drive compliance with the standard.

Commenting on the companies not committing to implement the Standard, Adam Matthews, Chief Responsible Investment Officer for the Church of England Pensions Board and Chair of the global Investor Mining and Tailings Safety Initiative, said: “If anyone doubts the continued risk posed by tailings dams, there have been 12 incidents at mine sites since Brumadinho leading to further loss of life and destruction of the environment. Tailings safety remains a clear and present risk to communities and the environment as well as to those invested in companies or providing them with insurance or banking facilities. We are not yet confident this issue is being properly addressed.

“We are encouraged by the number of companies that have confirmed they will adopt the Global Industry Standard or are assessing alignment. However, any company that sets itself against the standard will face considerable scrutiny from investors. As a first step we will vote against the chair of those companies and are considering shareholder resolutions. If the chair of a board does not see this as a major risk that requires the highest standards of operation, then they themselves pose a risk to us as a shareholder in that company.”

Since the 2019 Brumadinho disaster on 25 January there have been a further 12 incidents at mine sites involving the collapse of tailings or waste facilities in Angola, Brazil, India, Mexico, Peru and Turkey. Three have involved fatalities (two in Myanmar, with one leading to the loss of 126 lives, and one in Peru).  All have resulted in environmental impacts.  Whilst a number of the incidents happened at non-listed companies, the issue remains a significant risk for boards of public and private companies.

“The legacy of the Brumadinho disaster has to lead to a completely reformed mining sector,” Matthews continued. “We now have a Global Industry Standard where previously one did not exist, and investors are working intensively with the UN, industry and other stakeholders to establish the first independent global institute to verify the standard is being applied at individual mine sites.”

To further support the work of the Mining and Tailings Safety Initiative, it was announced that John Howchin, formerly the Secretary General of the Council of Ethics of the Swedish AP Funds, would become the Global Ambassador for the Initiative to work with investors, mining companies and wider stakeholders in the creation of the independent Global Tailings Management Institute.

“Brumadinho should never have happened,” Howchin said. “Mining companies, regulators, investors and governments carry the responsibility that we secure existing dams, and that any future expansion of mining happens only with the highest best practice standards. Establishing the independent Global Tailings Management Institute gives us that possibility and I am proud to be able to serve as its ambassador to work with investors to drive continued action on tailings dams.”

Industry standard

The Global Industry Standard on Tailings Management was developed with investors, led by the Church of England Pensions Board and the Council on Ethics of the Swedish AP Funds representing the Principles for Responsible Investment, the International Council on Mining & Metals and the United Nations Environment Programme (UNEP). At an investor roundtable held on the eve of the recent anniversary, UNEP and the Church of England Pensions Board announced that an independent Global Tailings Management Institute will become operational in 2022 to support implementation of the standard and play a key role in overseeing independent audits of company compliance, including at mine sites.

Additionally, a separate multi-stakeholder independent advisory panel on tailings dam disclosures, chaired by Professor Elaine Baker from the University of Sydney and Dr Stephen Barrie of the Church of England Pensions Board, announced a six-week consultation on a new disclosure standard for the sector that aligns to the Global Industry Standard on Tailings Management.  It is intended that this would form the basis for a Global Tailings Portal to track the locations of the world’s tailings dams and will be integrated into the Global Institute when it becomes operational.

In addition, work guided by a group of experts is looking at the feasibility of an independent global live monitoring hub that can track the highest risk tailings facilities including using satellite monitoring.  This group is expected to report on its findings by the end of the second quarter of 2022.

Update on Brumadinho

Vale says that it continues to fulfil its reparation obligations and support the communities and people affected by the B1 tailings dam failure in Brumadinho. Since 2019, it has spent R$20billion on individual compensation, environmental recovery, urban infrastructure, and health and professional training amongst others.

Marcelo Klein, Special Director of Reparation and Development at Vale, said. “Our structuring actions have evolved in all territories. We recognise, however, that dissatisfactions persist, and we seek to learn from them. We remain vigilant to the needs of residents and are committed to our reparation commitments, taking care of those affected, improving local infrastructure, reactivating the economy, restoring nature, valuing tourism and respecting the memory of the victims.”

The first step towards environmental recovery has been the removal of the tailings in Brumadinho. Approximately 9Mm³ were released from the B1 dam and almost 50% have already been handled and disposed of in the Córrego do Feijão mine pit.

In all, around 297 hectares of land were impacted by the failure, of which 140 are forested. Twenty-three hectares directly affected by the collapse and emergency works have been reforested, with the planting of approximately 30,000 seedlings of native species in the region.  The forecast for 2022 is that another 24 hectares will be in the recovery process, with the planting of 15,000 seedlings of tree species native to the region and implementation of small-sized vegetation cover. Bioengineering techniques will also be used to recover the soil and control erosion, an important step to effectively restore the ecological balance of the region. In addition, Vale claims that, for the first time in the world, DNA will be rescued from native trees in a partnership with the Federal University of Viçosa.

There are currently 70 monitoring points on the Paraopeba River. More than 38,000 samples have been collected, generating around 5.6 million results on water, soil, tailings and sediment analysis. Automatic monitoring is also carried out through 11 telemetric stations which allows for hourly remote measurement, with data transmission via satellite to increase information efficiency.

Vale has also supported the strengthening of water security for the population of the Metropolitan Region of Belo Horizonte, which collects water from the basins of the Velhas and Paraopeba rivers. Five underground wells have already been reactivated in addition to the construction of four reservoirs for essential customers in the region, such as the hospitals. Other completed work includes the pipeline that interconnects the distribution systems of the Paraopeba River and the Velhas River basin and enables the transfer of water between them.

All of Vale’s mining dams are monitored 24 hours a day, seven days a week by the Geotechnical Monitoring Centre and undergo regular inspections by internal and external teams. Vale says it remains committed to complying with the best international engineering practices, always focusing on the safety of workers and communities neighbouring the structure.

The mining company adds that “one of the pillars” of its work in guaranteeing that dam collapses such as Brumadinho will not be repeated is the elimination of all upstream dams in the country. This is to be carried out in the shortest possible time, with key consideration to the safety of people, workers and the environment. Since 2019, seven of the 30 mapped structures (four in Minas Gerais and three in Pará) have been de-characterised and reintegrated into the environment through the company’s R$ 10 billion De-characterisation Programme.

As such interventions can increase risks, especially for dams with the most critical alert level (level 3), Vale built large containment structures to protect the communities that live nearby and enable the works to be carried out more safely. The company has also been developing, together with its suppliers, innovative technologies to improve worker safety. One solution is the remote operation of equipment such as tractors, excavators and trucks.

On 8 February 2022 Vale announced that 40% of the company’s upstream structures will be eliminated by the end of the year. The de-characterisation process has just started at Dike 4, of the Pontal System, in Itabira.

Dike 4 of the Pontal System, in Itabira, Minas Gerais, Brazil is one of five upstream tailings structures planned to be eliminated in 2022 (Credit: Vale).

At the same time, and in line with international best practices for dam management, the company says it has intensified preventive, corrective and monitoring actions in its structures, advancing towards the goal of having no dam in critical condition (emergency level 3) by 2025. The latest update indicates that 90% of dams of this type will be eliminated by 2029 and 100% by 2035.

According to Vale, the elimination of upstream dams is part of the cultural transformation process that the company has been going through since the Brumadinho dam collapse. In Brazil, the de-characterisation is also one of the main milestones in the evolution of Vale’s dam management model focused primarily on the safety of structures and people who live nearby. The model is in line with the Global Industry Standard for Tailings.

Vale, as a member of the International Council on Mining and Metals, has made a public commitment to be 100% compliant with the global standard’s 77 requirements in all of its tailings disposal facilities by 2025. The company says it plans to end 2025 with a new and higher level of safety in its operations.

Innovative tailings monitoring

Luna Innovations has launched a new structural health monitoring solution for the mining industry to monitor tailings dam structures. Combining Luna’s systems for both distributed sensing and discrete sensing, the new solution claims to be comprehensive and economical.

Deployed in Canada, Brazil and Asia, Luna’s innovative fibre optic sensing solutions help mining operators mitigate risks by providing an early warning of a potential issue.

“Our deployments in tailings dams are a clear example of how Luna’s breadth of fibre optic capabilities combines to deliver a more comprehensive and effective solution to help ensure the safety of infrastructure like tailings dams,” says Luna’s President and CEO, Scott Graeff. “With thousands of such dams around the world, Luna is pleased that our initial deployments throughout the globe are successfully operational and actively monitoring these critical structures.”

In December 2020, Luna acquired distributed acoustic sensing capability with the acquisition of OptaSense.  Throughout the course of 2021, the OptaSense products were improved and integrated with Luna’s fibre optic sensing solutions resulting in significant new capabilities for long-range monitoring of critical infrastructure.

The tailings dam monitoring solution combines distributed acoustic and strain monitoring acquired from OptaSense, with Luna’s discrete point monitoring systems based on fibre Bragg grating sensors. The result is a comprehensive system able to monitor major events throughout an entire site while also able to look inside structures at critical parameters which can be precursors of potential events, such as pore pressure and spot inclination. This integrated structural health monitoring solution is also applicable to many other infrastructure projects beyond tailing dams such as bridges, tunnels and other major structures.

Zululand tailings dam failure

On 24 December 2021, a slurry dam wall failure at the Zululand Anthracite Colliery in South Africa resulted in a pollution spill of 1500m3 of coal slurry. An engineering firm has been appointed to confirm the exact root cause of the failure and the investigation is currently in process.

The end wall of slurry pond 3 had been newly installed following the loading out of dry slurry during November 2021. Four days prior to the failure 66mm of heavy rain was also recorded.

Immediately after the spill, all pumping to the slurry ponds was stopped. The end wall of the slurry pond was rebuilt and is awaiting professional engineer certification before being brought back into service. The integrity of the other slurry pond containment walls will also be checked, and improvements made where necessary.

In the medium term, a filter press will be installed in the coal washing plant, to remove the slurry from the water, and minimise the likelihood of slurry spilling in future. This action is planned for completion by the end of March 2022.

Numerous surface and groundwater monitoring points have been utilised to monitor groundwater and surface water quality, and monitoring will continue for the next 12 months. Further monitoring downstream towards the estuary is being conducted in accordance with directives from relevant authorities.

On 18 January, ZAC met with the joint operations committee made up of the Department of Mineral Resources and Energy, the Department of Water and Sanitation, the KZN Department of Economic Development, Tourism and Environmental Affairs, and Ezemvelo KZN Wildlife. ZAC provided them with relevant updates on clean-up efforts and investigations into the incident. It says it is complying with directives from relevant regulatory authorities and setting out monitoring of the potential negative impacts of the incident.

ZAC has been producing and washing anthracite in the Okhukho area of Zululand for the last 38 years. It is located 25km from Nongoma, and 40km from Ulundi, in the heart of rural Zululand. Areas of interest bordering the mining area are the Mfolozi River, and the Mfolozi section of the Hluhluwe Mfolozi game park.

ZAC employs 1100 people in the area, either directly or as contractors servicing the operation. As a vital cog in the local community, ZAC says it appreciates the importance of managing the varied demands placed upon it, while operating sustainably and for the benefit of the local community.

This article first appeared in International Water Power magazine.