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Tailings storage facilities are with us for the long term, but must be responsibly managed

26 May 2021

Discarded waste is a by-product of human existence. It provides archaeological insights into our past, but also practical and ethical dilemmas for our present and future.

By Aidan Davy, COO and Director for Environment, ICMM.

The existence of middens (ancient domestic waste dumps) provides archaeologists with rich insights into the lives of past civilisations, and evidence that waste disposal has been intimately associated with human habitation and enterprise for millennia. As the size of human settlements increased with the industrial revolution, so too did public recognition of the public health concerns associated with poor waste management practices. As a result, related regulations emerged from the mid-1800s to protect both people and planet from harm. The mining industry is no different.

‘Tailings’, a type of mining waste, is produced when valuable minerals are separated from rock. Taking the form of fine mineral particles in a liquid slurry, tailings was historically disposed of in nearby rivers and streams or low-lying areas. In the 1930s, the emergence of regulations on tailings management marked a shift towards tailings storage facilities (TSFs), where tailings were contained with the intention of eventual dewatering and rehabilitation. Over subsequent decades, advances in tailings engineering practices and management have led to both an increase in the numbers of TSFs, and to increases in their scale.

Responsible management of tailings facilities

In common with all waste streams, ideally, tailings generation would be avoided or reduced through re-using and recycling, but we are yet to see cost-effective options that can be implemented at scale. In the last few years, ICMM has identified aspects of metal and mineral recovery that have the potential to eliminate or dramatically reduce the generation of tailings, but TSFs are still with us for the long term.

While estimates vary on the number of TSFs globally, the catastrophic failures of two TSFs in Brazil (Samarco in 2015 and Brumadinho in 2019), with their associated tragic loss of life and environmental damage, has rightly drawn global attention to the importance of effective tailings management. Following the catastrophic failure at Brumadinho, ICMM, the Principles for Responsible Investment (PRI), and UN Environment Programme (UNEP) convened the Global Tailings Review to establish an international standard for the safer management of tailings facilities.

This led to the launch of the Global Industry Standard for Tailings Management (the Standard) in August 2020. The Standard “strives to achieve the ultimate goal of zero harm to people and the environment with zero tolerance for human fatality”. At the point of launch, ICMM members committed to implement the Standard, such that all facilities with ‘Extreme’ or ‘Very high’ potential consequences will be in conformance with the Standard within three years, and all other facilities within five years. This is an ambitious timeline – but the consequences of TSF failures are such that time-bound leadership is both important and necessary for rebuilding trust. However, the Standard primarily focuses on ‘what’ companies should do to responsibly manage TSFs, rather than ‘how’.  Consequently, ICMM has developed two additional resources to support responsible tailings management.

Firstly, the Conformance Protocols: Global Industry Standard on Tailings Management will help operators and independent third parties to assess the implementation of the Standard’s requirements across their portfolio of TSFs, and ultimately demonstrate conformance. The Conformance Protocols map faithfully to the Standard’s 77 requirements and outline 219 clear and concise audit criteria for assessing conformance, supported by illustrative examples.

Secondly, ICMM’s Tailings Management: Good Practice Guide is intended to support the safe and responsible management of tailings across the global mining industry, with the ultimate goal of eliminating fatalities and catastrophic events. It provides guidance on good governance and good engineering practices to support continual improvement in the management of TSFs and to help foster and strengthen a corporate safety culture. The Guide is informed by the requirements of the Standard and the commitments in ICMM’s Tailings Governance Framework: Position Statement. It will help operators work through how to integrate these into their own tailings management programmes.

These resources underscore the sustained commitments of ICMM’s members to implement the Standard in a timely manner and to responsibly manage the TSFs within their portfolios. This commitment extends from planning and design through to the point where they no longer pose ongoing material risks to people or the environment (known as ‘safe closure’). These two resources are publicly available on ICMM’s website for use by the wider mining and metals industry.

Looking to the future

While we have been working to strengthen tailings management, we haven’t stood still on our long-term ambition of developing cost-effective alternatives to conventionally managed TSFs. For the past two years, ICMM has been exploring which emerging technologies offer the greatest potential in this regard.

Later this year, in collaboration with several other organisations, we will produce a roadmap that outlines future implementation pathways for three technologies identified as having a high potential to reduce tailings – ‘continuous sorting’, ‘batch sensing’ and ‘continuous mining machines’. This will be an important milestone on our journey towards tailings reduction.