TOWARDS ZERO HARM
A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW
AUGUST 2020 2 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW i CONTENTS
ii ACRONYMS
iv FOREWORD FROM THE CHAIR
v PREFACE
vii KEY MESSAGES
1 SETTING THE SCENE 2 Chapter I Global Tailings Review at a Glance: History and Overview | B. Oberle, A. Mihaylova, A. Hacket 14 Chapter II Mine Tailings Facilities: Overview and Industry Trends | E. Baker, M. Davies, A. Fourie, G. Mudd, K. Thygesen
25 THE SOCIAL DIMENSION 26 Chapter III Social Performance and Safe Tailings Management: A Critical Connection | S. Joyce, D. Kemp 37 Chapter IV Lessons for Mining from International Disaster Research | D. Kemp
47 MANAGEMENT OF TAILINGS: PAST, PRESENT AND FUTURE 48 Chapter V Mine Tailings – A Systems Approach | A. Kupper, D. van Zyl, J. Thompson 64 Chapter VI The role of technology and innovation in improving tailings management | D. Williams 84 Chapter VII Lessons from Tailings Facility Data Disclosures | D. Franks, M. Stringer, E. Baker, R. Valenta, et al 109 Chapter VIII Closure and Reclamation | G. McKenna, D. van Zyl 126 Chapter IX Addressing Legacy Sites | K. Nash
141 BUILDING ORGANISATIONAL CAPACITY 142 Chapter X Addressing the organisational weaknesses that contribute to disaster | A. Hopkins 150 Chapter XI Creating and Retaining Knowledge and Expertise | R. Evans, M. Davies
162 THE GOVERNANCE DIMENSION 163 Chapter XII The Role of the State | M. Squillace 172 Chapter XIII Comparative Analysis of Tailings-related Legislation in Key Mining Jurisdictions | White&Case LLP 186 Chapter XIV Summary of Existing Performance Standards for Tailings Management | C. Dumaresq 206 Chapter XV Insurability of Tailings Related Risk | G. Becker
215 RELATED INITIATIVES 216 Chapter XVI Investor Mining and Tailings Safety Initiative | S. Barrie, E. Baker, J. Howchin, A. Matthews 224 Chapter XVII United Nations Environment Assembly Resolution on Mineral Resource Governance | E. Tonda, D. Franks, A. Kariuki 231 Chapter XVIII Global Research Consortium on Tailings | D. Franks, A. Littleboy, D. Williams Citation: 238 PATHWAYS TO IMPLEMENTATION Oberle, B., Brereton, D., Mihaylova, A. (eds.) (2020) Towards Zero Harm: A Compendium of Papers Prepared for the Global Tailings Review. London: Global Tailings Review. https://globaltailingsreview.org/. 239 Chapter XIX Establishing an Independent Entity | B. Oberle, P. Bateman, D. Kemp ii TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW iii ACRONYMS
AA Anglo American Technical Standard IRP International Resource Panel AG Advisory Group (for the Global Tailings Review) ISO International Organisation for Standardisation ALARP As low as reasonably practical ITRB Independent Tailings Review Board ANCOLD Australian National Committee on Large Dams IUCN International Union for Conservation of Nature APEC Asia-Pacific Economic Cooperation LDI Landform Design Institute APELL Awareness and Preparedness for Emergencies at Local Level m3 cubic metres APRA Australian Prudential Regulation Authority MAC Mining Association of Canada AusIMM Australian Institute of Mining and Metallurgy MEM Ministry of Energy and Mines (British Columbia) BAT Best available technologies MEND Mine Environment Neutral Drainage Program BAP Best available/applicable practices MMSD Mining, Minerals and Sustainable Development BC,CIM British Columbia, Chief Inspector of Mines NGO Non-Government Organisation BLM Bureau of Land Management (US) NOAMI National Orphaned/Abandoned Mines Initiative (Canada) BRA Brazilian Ordinance 70.389/17 NPV Net present value CapEx Capital Expenditure OMS Operation, Maintenance, and Surveillance CDA Canadian Dam Association OpEx Operational Expenditure CEO Chief Executive Officer PAR Pressure and Release Model CoE Church of England PBRISD Performance-Based, Risk-Informed Safe Design COI Community of Interest PMU Project Management Unit CRO Chief Risk Officer PRI Principles for Sustainable Investment CTMC Consortium of Tailings Management Consultants PSI Principles for Sustainable Insurance DBM Design Basis Memorandum QA Quality Assurance EP Expert Panel QC Quality Control ESG environmental, social, and governance RMI Responsible Mining Initiative ESMS Environmental and Social Management System RTFE Responsible Tailings Facility Engineer EU European Union SANS South African National Standards FERC Federal Energy Regulatory Commission (US) SDGs Sustainable Development Goals FMEA Failure Mode and Effects Analysis SMART specific, measurable, attainable, relevant and time-bound FoS Factor of Safety SMI Sustainable Minerals Institute (University of Queensland) FPIC Free, prior and informed consent SMRCA Surface Mining Control and Reclamation Act (U.S.) GARD Guide Global Acid Rock Drainage Guide TSF Tailings Storage Facility GIZ German Corporation for International Cooperation TSM Towards Sustainable Mining GTR Global Tailings Review UN United Nations HDTT High Density Thickened Tailings UNDRR United Nations Office of Disaster Risk Reduction HRIA Human Rights Impact Assessment UNEA United Nations Environment Assembly HSE Health and Safety Executive UNEP United Nations Environment Programme IBRAM Brazilian Mining Association UNGP UN Guiding Principles on Business and Human Rights ICMM International Council on Mining and Metals USEPA United States Environment Protection Authority ICOLD International Commission on Large Dams WISE World Information Service on Energy IFC International Finance Corporation WMTF World Mine Tailings Failures IGF Intergovernmental Forum on Mining, Minerals, Metals and Sustainable Development USGS United States Geological Survey IIED International Institute for Environment and Development VET Vocational and Educational Training IM4DC International Mining for Development Centre VSP Verification Service Provider INAP International Network for Acid Prevention WBCSD World Business Council for Sustainable Development iv TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW v FOREWORD FROM THE CHAIR PREFACE
I would like to thank the whole Global Tailings Review team: This collection of individually authored papers (‘chapters’) has been prepared to accompany the release of the Global Industry Standard on Tailings Management the Expert Panel, the Advisory Group, the Co-Conveners (the Standard). The volume performs two main functions: and all authors and co-authors who have generously 1. It provides context to the Standard by informing readers about the reasons why contributed their time and expertise to this volume. I trust the Global Tailings Review (GTR) was initiated, the process that was followed, that the papers contained herein add value to the ongoing and the considerations that guided the development of the Standard. public debate on safe management of tailings facilities and 2. It goes beyond the Standard to review a wide range of issues related to the safe management of tailings facilities, for consideration by the different further reinforce the need for continued action to ensure actors involved – including governments, investors, insurers, international that tragedies like the one in Brumadinho do not continue organisations, educational institutions, and industry professionals. to happen. All members of the Expert Panel, including the Chair, have contributed at least one chapter to the volume, either as sole or co-authors. The compilation also includes invited contributions from other experienced professionals and researchers Particular and special thanks to the co-editors of this working in the area. Several of these contributors were involved in the development volume; Emeritus Professor David Brereton of The of the Standard as members of the Multi-Stakeholder Advisory Group; some contributed in their capacity as representatives of one of the co-convening University of Queensland, for his contributions, ongoing bodies; and others participated on an individual basis. As befits the breadth of support and diligence; and to the GTR Project Manager, the Standard, a broad cross-section of professional and academic disciplines is represented, including engineering, geology, environmental science, social Antonia Mihaylova, who worked tirelessly to bring the sciences, risk management, law, public policy and finance. volume to fruition. The chapters are organised into six sections. Each section contains knowledge, learnings and insights that are relevant to advancing the ultimate goal of the Standard, which is to achieve zero harm to people and the environment, with zero tolerance for human fatalities.
Section One comprises two context-setting chapters. The first chapter, which was authored by the Chair and the Secretariat staff, provides a brief history and Dr. Bruno Oberle overview of the GTR. The second provides an overview of key research findings Chair of the Global Tailings Review and organisational learnings on the frequency, type, location and impact of tailings facility failures and the factors that contribute to these failings.
Section Two focuses on the social performance and human rights issues involved in designing and operating tailings facilities and managing the consequences of facility failures. Social performance is a cross-cutting theme that links to most of the topics covered in the Standard, but in particular to Topic I (Affected Communities) and Topic V (Emergency Response and Long-term Recovery). The first chapter in this section explains how and why social performance work is critical to tailings facility management, and describes the logic that underpins the inclusion and integration of social performance elements throughout the Standard. The second chapter presents lessons for the mining industry from international disaster research.
Section Three links to Topics II and III of the Standard (Integrated Knowledge Base and Design, Construction, Operation and Monitoring of the Tailings Facility). The chapters in this section address different aspects of tailings management, from design through to closure. There is a strong focus on how outcomes can be enhanced through technological innovation and improved management and governance. Topics covered include: the benefits of taking a systems approach to tailings management; alternative technologies for storing and managing tailings; strategies for reducing the volume of tailings material generated; ensuring the safe vi TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW vii KEY MESSAGES
closure of tailings facilities and their conversion to beneficial uses; and, dealing To provide guidance to readers, authors of most of the with tailings and other wastes associated with ‘legacy’ mining sites. The section includes a chapter that presents findings from the first detailed analysis of the chapters have prepared a summary of the ‘key messages’ data provided by companies in response to the Church of England disclosure conveyed in their respective chapters. For ease of access, initiative. these messages are grouped together below, as well as Section Four links to the theme of building organisational capability, which is also being listed at the end of each chapter. the focus of Topic IV of the Standard (Management and Governance). The first chapter in this section focuses on how mining companies can strengthen their internal accountability and risk management processes. The second chapter MINE TAILINGS FACILITIES: OVERVIEW AND INDUSTRY TRENDS addresses the challenge of building technical and governance capability and improving knowledge management in the mining industry and regulatory bodies. E. Baker, M. Davies, A. Fourie, G. Mudd, K. Thygesen
Section Five, which links to both Topic IV and Topic V (Disclosure of Information), • Mine tailings are currently an unavoidable waste product of mining. engages with broader questions about the governance framework within which • There has been an increase in the volume of tailings produced for many mineral mining is conducted. It comprises: (1) a chapter on the role of the State in ensuring commodities, due to increased demand for minerals and the continuing decrease the safe design and management of tailings facilities (including a discussion of in ore grades. how this role can be enhanced); (2) a comparative study of relevant regulatory frameworks in a range of mining jurisdictions; (3) a comparison of the Standard • The precise number of active tailings facilities is currently unknown, although with other standards, codes and guidelines relating to tailings management; and initiatives are underway to determine both the location and status of these (4) a chapter focused on the role that the insurance industry can play in driving facilities. improved practices in the mining sector and promoting uptake of the Standard. • Responsible mine closure is integral to mining companies’ core business.
Section Six provides a brief overview of three other initiatives that are aimed at • Mining, conducted responsibly, is acknowledged as a key industry for achieving the contributing to improved tailings management practices in the mining sector. United Nations Sustainable Development Goals (SDGs). These are: the Investor Mining and Tailings Safety Initiative; the United Nations • Failures of tailings facilities are continuing to be reported across the globe. These Environment Assembly (UNEA) Resolution on Mineral Resource Governance; and failures are unacceptable to both the mining industry and society. the proposed Global Research Consortium on Tailings. • The triggers for failures of tailings facilities are well documented and understood Section Seven lays out the different options and the Chair’s recommendation for and, as such, should be anticipated and addressed, starting at the design phase implementation of the Standard and the way ahead. and continuously during operation through to closure (and beyond if necessary). • Communities potentially affected by mining hazards are entitled to information Disclaimer that allows an understanding of a broad range of risks, as well as being informed The views expressed in individual chapters are those of the authors, or the about operator risk reduction strategies. organisations that they represent. Publication of this volume by the GTR does not constitute endorsement of these views by any of the co-conveners.
SOCIAL PERFORMANCE AND SAFE TAILINGS MANAGEMENT: A CRITICAL CONNECTION S. Joyce and D. Kemp
• Mining companies should avoid equating the social performance function solely with community engagement, and work to strengthen the scientific, organisational and legal dimensions of this function. • Senior management should ‘hard-wire’ social performance into operational management practices to maximise the value of the function. • Companies should review whether operational-level social performance functions are ‘fit-for-purpose’ (i.e. appropriate to both the tailings facility and the local context) and adequately resourced. • A high level of interdisciplinary effort is required to support the safe management of tailings. • Managers at all levels of a mining company should maintain a willingness to engage in and promote cross-disciplinary conversations on specialist topics such as tailings facility management, and actively support inter-disciplinary work. viii TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW ix
LESSONS FOR MINING FROM INTERNATIONAL DISASTER RESEARCH THE ROLE OF TECHNOLOGY AND INNOVATION IN IMPROVING TAILINGS MANAGEMENT D. Kemp D. Williams • Mining companies could improve their ‘contextual intelligence’ by paying greater attention to the social, environmental and local economic context in which a • If tailings facilities were built to a similar margin of safety to water dams, this project is situated, and the project’s effects on that context. would prevent many tailings facility failures. • Including vulnerability as a relevant factor in root cause analysis would support • There is a commonly held perception in the mining industry that transporting mining companies to account for the structural and systemic aspects of tailings as a slurry to a facility is the most economic approach, but this fails to disaster risk. factor in the true cost of closing and rehabilitating the resulting tailings facility. • Mining companies could consider utilising other relevant frameworks, such as • A rethink is required about the way in which tailings management is costed. A the Sendai Framework for Disaster Risk Reduction 2015-2030. substantial portion of global tailings practice still uses the Net Present Value (NPV) approach with a high discount factor. What is needed is a whole-of-life • Better enabling of social specialists to contribute to tailings risk management cost approach. (e.g. through participation in interdisciplinary processes) could help mining companies to avoid harm. • In practice, not enough tailings facilities have been successfully rehabilitated, due to the difficulty of capping a ‘slurry-like’ (wet and soft) tailings deposit and • Both public and private sector actors should consider broadening the ‘circle of the excessive cost involved, particularly at a time when the mine is no longer knowledge’ on disaster prevention, to include the natural, physical and social producing revenue. sciences, and the lived experiences of affected people. • The implementation of existing and new technologies to tailings management could help to eliminate the risks posed by the nature of conventional tailings facilities that have been responsible for the failures that have occurred, possibly MINE TAILINGS – A SYSTEMS APPROACH removing them altogether. A. Kupper, D. van Zyl, J. Thompson • A fundamental barrier to the implementation of innovative tailings management at those sites that would benefit from these technologies is people’s resistance • Tailings facilities are complex entities that operate as a system within the to change, which is often disguised as unsubstantiated claims about perceived broader context of mining operations, their external societal and environmental high costs, technical obstacles and uncertainty. settings, and their potential to last in perpetuity. • Change is more likely to be achieved in new mining projects than existing • Tailings facilities are complex systems that need to be managed with a systemic operations. Hence, change in tailings management for the industry as a whole approach for effective risk management. will necessarily be generational. • Although there are always immediate technical reasons for tailings facilities failures, the overarching technical and governance factors that allowed the facilities to approach a critical state are, in most cases, the root cause of the LESSONS FROM TAILINGS FACILITY DATA DISCLOSURES failure. D. Franks, M. Stringer, E. Baker, R. Valenta, L. Torres-Cruz, K. Thygesen, • The systematic management approach for tailings facilities involves vertical A. Matthews, J. Howchin, S. Barrie and horizontal integration of all functions (planning, design, construction, operation, management, oversight) that operate and collaborate within a broader • The Investor Mining and Tailings Safety Initiative, as described in Chapter framework. XVII, conducted the most comprehensive global survey of tailings facilities • The resulting management framework must be supported by effective ever undertaken. The trends identified from this dataset highlight the value of communication, transparent and robust data management, and information information disclosure by companies. flows that builds knowledge and experience. Success also requires leadership, • Analysis of company-disclosed data collected through the Initiative indicate that appropriate incentives and a culture of performance. upstream facilities still make up the largest proportion of total reported facilities • Ultimately, the framework and resulting systems management has to be based (37 per cent), although construction rates for upstream facilities have declined in on leadership that drives a culture of system-level performance recent years. • The rate of reported past stability issues for facilities in the data base exceeded one per cent for most construction methods, highlighting the universal importance of careful facility management and governance. • Over 10% of facilities in the database reported a stability issue, and the percentages for upstream, hybrid and centreline facilities were even higher. Statistical analysis provides a high level of confidence that the higher rate of reported stability issues for upstream facilities is not attributable to x TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW xi
‘confounding’ factors such as differences in facility age, the volume of material • To avoid future problems, industry should focus on: (a) reducing the volume of stored, or the level of seismic hazard. tailings and other waste produced from current operations; and (b) developing new projects with tailings elimination in mind from the outset. • Based on company commissioned modelling, hybrid, upstream, downstream and centreline facilities are more likely than other types of facilities to be • Mining companies should work towards zero tailings impoundment by associated with a higher consequence of facility failure. considering tailings to be a product that may have value for both mining and other industries. Companies should also contribute to the development of a • Facilities with higher consequence of failure ratings were also more likely to resource-efficient circular minerals economy. report a stability issue. • There are significant economic opportunities to re-process legacy tailings to • Based on the data provided by companies, the uptake of filtered and in-situ extract materials of value. Governments can facilitate this by creating supportive dewatering of tailings across the wider industry has not significantly increased policy settings. over recent decades. This is notwithstanding that dry-stack (and in-pit/natural landform facilities) report fewer past stability issues and are typically associated with lower consequence of failure ratings. ADDRESSING THE ORGANISATIONAL WEAKNESSES THAT CONTRIBUTE TO DISASTER CLOSURE AND RECLAMATION A. Hopkins G. McKenna, D. van Zyl • Accident analysis should always seek to identify the organisational causes of the accident. • Current practice at most mining operations largely divorces the long-term closure and reclamation of tailings facilities from the operational dam • Shareholders should hold boards accountable for the on-going management of construction, tailings deposition, and geotechnical dam safety considerations. major accident risks. This artificial division leads to higher life-cycle costs, reduced performance and • Boards should ensure that at least one of their members has expertise in the increased risk. relevant major accident risks and is able to advise the board on the status of • Closing and reclaiming tailings facilities presents numerous challenges, major accident risk management within the organisation and of the implications especially if these challenges are overlooked during the initial design and of board decisions for major accident risk. construction of these mining landforms. • Mining companies should have an executive responsible for major accident risk • Landform design provides a framework for inclusion of all aspects of the life (an Accountable Executive) answering directly to the CEO. This executive should cycle of a tailings facility. This is a multidisciplinary process for building mining also have a direct reporting line to the board and should be held to account by landforms, landscapes, and regions to meet agreed-upon land use goals the board. and objectives. The process ideally begins with the initial designs of tailings • Where a major part of an employee’s role is to ensure compliance with landforms (or in the case of most existing sites, adopted midstream) and standards and procedures, as is the case for the responsible tailings facility continues long after operations have ceased. engineer, the employee should have dual reporting lines: a primary line that • Tailings landforms are important features in the mine’s closure landscape that culminates with the Accountable Executive and a secondary line to the local site will last for millennia and will serve as a major component of mines enduring manager. Any performance review should be carried out by a supervisor in the legacy. Mines, by working with their regulators and local communities, can line reporting to the Accountable Executive. help establish a positive mining legacy by returning lands for use by local • Neither the Accountable Executive, nor staff in lines reporting to that position communities in a timely manner. should be incentivised in relation to production, profit or cost reduction. This applies, in particular, to the Responsible Tailings Facility Engineer (RTFE). • For employees whose primary role is to contribute to production, albeit safely, ADDRESSING LEGACY SITES any bonuses paid should have a component for safety or facility integrity. This K. Nash should not be based on quantitative metrics but on qualitative judgements about the employee’s contribution to safety and operational integrity. It will be up to • Legacy mines and the wastes associated with them remain a significant employees to make this case during performance reviews. problem for governments, industry and communities. • Companies should incentivise the reporting of issues relating to major accident • This problem has been recognised for a long time, but only intermittent and risk. limited progress has been made in addressing it. A stronger regulatory and • Long term bonuses that vest after a period of years should be modified to take governance response is required globally to achieve a stepwise change. account of how well major accident risk is managed. • Closure and site remediation practice should aim to: (a) better protect public and environmental health and safety; and (b) establish conditions which maximise beneficial post-mining land use options in the longer term. xii TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW xiii
CREATING AND RETAINING KNOWLEDGE AND EXPERTISE COMPARATIVE ANALYSIS OF TAILINGS – RELATED LEGISLATION IN KEY MINING JURISDICTIONS R. Evans and M. Davies White & Case LLP • Technical expertise in the design and management of tailings facilities is unevenly distributed across the globe, as is access to relevant education • A comparison of the laws and regulations from a cross-section of nine key programmes. mining jurisdictions indicates that many of the Principles of the Standard are well-reflected in the laws and regulations of some of these jurisdictions. • There is a need to go beyond a narrow engineering design focus and embed a However, overall the ambitions of the Standard, when compared to domestic multi-disciplinary approach within tailings-related education. law, set a higher threshold for achieving the degree of integrity, safety and • The ability to understand and apply Risk Management frameworks is a critical community protection necessary for the development and management of capability for tailings governance and needs to be explicitly addressed in tailings facilities. education initiatives. • Where the research has identified certain areas in which the Standard sets a • It is essential that all education and training programmes related to mine tailings, higher bar than legislation in Key Jurisdictions, this could provide the impetus for including university courses, have a strong practical as well as theoretical focus, regulators to consider where changes could be made to address tailings facility and draw on experience and learning from case studies of failures. safety and management. • At a time of increased concern regarding the management of tailings facilities, • The overall results of the analysis of tailings safety legislation in the Key our ability to educate specialists and those charged with managing such Jurisdictions, expressed as average scores, show how the Standard can be a facilities is limited by a shortage of qualified and experienced educators. catalyst for improving the regulation of tailings facilities. They also highlight the need for a consistent global approach to tailings facility management, safety • Globally, there are very few programmes that address the operational and operation. governance aspects of tailings facilities. The international development sector should be encouraged to support the development and deployment of such • The gap between the most and least aligned Key Jurisdictions draws out the programmes in countries that cannot easily access this expertise. need for more emphasis on catastrophic failure, accountability and engagement of communities as the starting point of tailings dams regulation. Working backward from a worst-case scenario informs the approach to permitting, approvals and enforcement from the beginning, which in turn sets the tone for THE ROLE OF THE STATE iteration and improvement. M. Squillace • While legislation is an essential tool for regulating tailings facility safety and management throughout the lifecycle, other forms of best practice exist and • States play a critical role in the success or failure of tailings facilities. jurisprudence is also developing. Both of these may also be effective in helping • The Standard offers a roadmap for States for how to establish an effective to achieve the goals of the Standard. regulatory programme for tailings facilities. • States have understandable concerns about their capacity to fund and implement a regulatory programme. Operators should therefore be expected SUMMARY OF EXISTING PERFORMANCE STANDARDS FOR TAILINGS to bear the cost of the programme, including the cost of training competent MANAGEMENT personnel. C. Dumaresq • States bear a substantial part of the burden when people and the environment suffer from tailings facility failures. States should therefore embrace • When development of the Standard was initiated, several other standards requirements for adequate performance bonds to assure full reclamation and related to tailings management were already in place. Like the Standard, safe closure, and for insurance to cover liability for injuries to third parties. these standards address tailings management, governance, and community engagement and public disclosure. • States are uniquely positioned to monitor the performance of Operators and to take appropriate enforcement action where violations of tailings facility • International Council on Mining and Metals (ICMM) Performance Expectations requirements occur. were introduced in 2020 and are being implemented by ICMM’s 27 members. Commitments relevant to the Standard are described in: • States that lack the capacity to adopt and implement a sound regulatory programme with well-trained staff should work with other countries and the - Position Statement: Tailings Management (2016) international community to build that capacity. - Position Statement: Indigenous Peoples (2013) - Position Statement: Partnerships in Development (2010) - Position Statement: Water Stewardship (2017) xiv TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW xv
• The Mining Association of Canada (MAC) Towards Sustainable Mining® (TSM®) the like should actively promote the acceptance of the Standard within their was introduced in 2004 and is being implemented at over 60 facilities. TSM respective spheres of influence. has also been adopted by industry associations in several other countries. • This support can be further enhanced by supranational organisations such as Requirements relevant to the Standard are described in: the UN and the World Bank, along with global initiatives such as the Principles for Responsible Investment (PRI) and the Principles for Sustainable Insurance - Tailings Management Protocol (2004, revised 2017 & 2019). (PSI). - Indigenous and Community Relationships Protocol (2004, revised 2019). - Water Stewardship Protocol (2019). INVESTOR MINING AND TAILINGS SAFETY INITIATIVE • The Initiative for Responsible Mining Assurance (IRMA) Standard for Responsible Mining was launched in 2018 and is currently being implemented at two mines. S. Barrie, E. Baker, J. Howchin, A. Matthews Requirements relevant to the Standard are described in: • A coalition of 112 international investors with over USD $14 trillion in assets - Environmental Responsibility Requirements under management was established in 2019 to improve understanding and - Chapter 4.1: Waste and Materials Management transparency related to the social and financial risk associated with tailings dams. - Chapter 4.2: Water Management • Investors are increasingly scrutinising company performance on environmental, - Business Integrity Requirements (3 relevant chapters). social, and governance (ESG) criteria. Tailings storage facilities have implications - Planning for Positive Legacies Requirements (6 relevant chapters). for all three ‘ESG’ pillars. - Social Responsibility Requirements (3 relevant chapters). • Investors have taken the view that tailings represent a systemic challenge for the mining sector and for other sectors linked to mining through the supply chain • There are no existing standards for technical design, which is a topic addressed in the Standard. However, guidance from organisations such as the International • The Investor Mining and Tailings Safety Initiative has made a number of Commission on Large Dams (ICOLD) is frequently incorporated into legal interventions, including calling for a Global Tailing Standard, asking for improved requirements (e.g. site-specific permits for tailings dams). disclosure from 727 extractive companies, and collating and organising those disclosures in an accessible database: The Global Tailings Portal. • The response to the disclosure request has been positive. As of March 2020, INSURABILITY OF TAILINGS RELATED RISK 152 companies have confirmed that they have tailings storage facilities (this includes both operator and joint venture interests). The 152 companies G. Becker represent approximately 83% of the publicly listed mining industry by market capitalisation, and includes 45 of the 50 largest companies. • Tailings facilities are integral to almost any mining activity. While the facilities themselves represent minor economic value compared to the remainder of the • The Initiative continues to work for safer, and more well understood tailings operation, their leakage or rupture can have considerable consequences for facilities. It is pursuing projects on insurance and disclosure, tailings monitoring, people, ecosystems and property. and the removal of the most dangerous dams. • Even if the highest available standards for the safe construction, maintenance and operation of tailings facilities are strictly adhered to, it will never be possible to have full control over forces of nature such as extreme weather events or earthquakes; nor can human error be ruled out. • The insurance industry stands ready to meet its role in alleviating the potentially catastrophic effects of a tailings facility failure on innocent third parties and the mining operators themselves. An indispensable prerequisite, however, is that the insured party undertakes whatever is humanly possible to prevent such an incident from occurring. • What these precautions should include, in terms of technical to organisational measures, has been defined in the Standard. Adherence to the Standard must be seen as a premise for any insurance cover. • Consideration should be given to organising insurance cover in the form of a pool, with a view to creating sufficient capacity to cover the risks of tailings facility failures. • As the mining sector is a global industry, the Standard should likewise be applied globally. National governments, regulatory bodies, insurance associations and xvi TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 1
GLOBAL RESEARCH CONSORTIUM ON TAILINGS D. Franks, A. Littleboy, D. Williams SETTING • Industry and public sector investment in research have expanded the approaches available to deal with tailings management challenges, but much of this learning remains underutilised. • The University of Queensland, in partnership with a wide range of research and THE SCENE education institutions, is exploring the potential to establish a global research and education consortium to support improved tailings management. • The overarching aim of the consortium would be to develop transdisciplinary knowledge-solutions (science, technology and practices) that address the technical, social, environmental and economic risks of tailings. • The vision of the consortium is a multi-party collaborative initiative of the world’s leading thinkers and practitioners in tailings and mine waste management: researchers, industry professionals, consultants, regulators, civil society and community representatives. • A global research consortium on tailings could tackle a bold and globally significant agenda with the potential for meaningful impact. • Members of the consortium would benefit from robust, transdisciplinary, game- changing research with partners that have deep knowledge of the sector. • Discussions are currently underway with Amira Global, an independent minerals research management organisation with a long-track record in the sector, to develop the initiative. 2 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 3
SETTING THE SCENE
which includes continuous dialogue, meaningful 2.2 INDEPENDENT CHAIR engagement and effective facilitation of consensus. CHAPTER I The selection of the independent Chair took The model also requires that the key participants have approximately two months. The three co-conveners a level of mutual trust, are willing to share control and GLOBAL TAILINGS agreed that it was vital to select an individual who was are prepared to accept outcomes that may not always not closely associated with any one of the three key appear to be optimal from their own perspectives. REVIEW AT A GLANCE: sets of stakeholders within the mining sector: industry, government and civil society. Knowledge of the sector The three co-conveners, UNEP, ICMM and PRI were HISTORY AND OVERVIEW was therefore considered secondary to the ability to each represented by two individuals: Bruno Oberle, Chair of the Global Tailings Review lead and facilitate consensus among highly diverse views. This proved prescient, as one of the most Antonia Mihaylova, Project Manager, Global Tailings Review 1. UNEP: Ligia Noronha, Director, Economy Division challenging aspects of the Chair’s role was to facilitate Audrey Hackett, Senior Adviser – Strategy and Delivery, Global Tailings Review and Elisa Tonda, Head of the Consumption and consensus within the Expert Panel and amongst the Production Unit co-conveners, while working towards a very ambitious 2. ICMM: Tom Butler, CEO and Aidan Davy, COO timeline. In May 2019, Dr Bruno Oberle was appointed 1. INTRODUCTION on Tailings Management (‘the Standard’) and Chair of the Review (see Box 1). associated documents 3. PRI: Adam Matthews, Director of Ethics and The catastrophic failure of a tailings facility at Vale’s Engagement for the Church of England and John Corrego do Feijão mine in Brumadinho in January • explains how the Review was conducted and the Howchin, Secretary-General – The Council on Box 1: Brief Biography of the Chair of the 2019 was a tipping point for the mining sector. Standard formulated, focusing particularly on key Ethics Swedish National Pension Funds Review, Dr Bruno Oberle A month after this tragedy, on 26 February 2019, roles the International Council on Mining and Metals The three parties had an equal say throughout • provides an overview of the content and structure After completing his studies in environmental (ICMM) made a public commitment to establish a the process. Key decisions were made by mutual of the Standard science, engineering and economics at the Swiss new standard for the safer management of tailings agreement, beginning with the development of the Federal Institute of Technology (SFIT), Dr Oberle facilities. Having engaged on similar issues in the • presents some reflections on the process. foundational Scope and Governance document and founded and managed consultancy companies in past, on 27 March 2019, a joint public announcement the selection of the independent Chair. the field of environmental management. In 1999, was made that the initiative would be co-convened Parts A and B of the chapter provide an overview of Dr Oberle was appointed Deputy Director of the by the ICMM, the United Nations Environment the process and the Standard respectively. Part C In terms of input to the process, each of the co- Federal Office for the Environment, Forests and Programme (UNEP) and the UN-backed Principles for contains observations and reflections on the process. conveners brought their areas of expertise and the Landscape of Switzerland and, in 2005, Director Responsible Investment (PRI), with each party having perspectives of their constituents. The ICMM was also of the newly established Federal Office for the an equal stake and say in decision making. This in a position to provide resourcing and administrative Environment. Dr Oberle represented Switzerland marked the launch of the Global Tailings Review (‘the support to the Project Management Unit (PMU). PART A: THE PROCESS in international negotiations as Secretary of Review’). The Scope and Governance document established State for the Environment. He also played a key steering role in the Global Environmental Facility The co-convened model of equal representation 2. THE GOVERNANCE MODEL: ROLES AND working assumptions, the overall scope of the Review (GEF) and in establishing the Green Climate from industry, investor and government stakeholders RESPONSIBILITIES and set certain parameters. It also retained flexibility Fund (GCF). Since 2016, Dr Oberle has been a was designed to give civil society and the public for the Chair and the Expert Panel (‘the Panel’) to Maintaining independence and taking a multi- Professor for Green Economy and Resource confidence that the initiative would have the revisit the scope as the work progressed. The scope stakeholder approach were at the core of the Review Governance and Director of the International necessary level of independence and not be of the Standard was defined as including, but not process. Risk Governance Centre at L’Ecole Polytechnique subordinate to industry interests. It was also an limited to: Fédérale de Lausanne (EPFL), Switzerland. He is acknowledgement that no single stakeholder can 2.1 CO-CONVENERS also the President of the World Resources Forum solve the problem and that community and investor • a global and transparent consequence-based Association. trust in the mining sector needed to be restored in In an increasingly globalised world, many of the tailings facility classification system with the wake of a number of such high-profile disasters. challenges we face require a global response and appropriate requirements for each level of In addition, the tri-partite, co-convened, approach coordinated effort. Mining is one of those sectors classification broadened the range of perspectives and specialist that is particularly reliant on multi-stakeholder • a system for credible, independent reviews of The Scope and Governance document describes knowledge that could be drawn on to develop a engagement so that it can be undertaken responsibly tailings facilities the Chair as a: credible, technically sound, fit-for-purpose standard. and with minimal adverse impact on human life and the environment. • requirements for emergency planning and ‘Senior, respected person who will be seen as This introductory chapter: preparedness. independent. S/he will likely be a former employee The multi-partite, co-convened, model is not unique. of multilateral organisation, a former government • outlines the governance arrangements that were Shared power arrangements of this kind have been The full Scope and Governance document can be minister, or some other person with demonstrated put in place for the Review utilised on occasions in the past by the mining sector found on the Review website, here. The Terms of experience of chairing diverse groups to develop and other key actors, as a mechanism for developing Reference for the Chair and the Panel, which were policy or standards, ideally complemented with • documents the timeline and trajectory of the a consensus approach to contentious issues. For similarly co-developed and endorsed by the three co- senior (board level) experience in the private Review, from establishment through to the such a model to be successful it requires a nurturing, conveners, can also be found in this document. sector.’ finalisation of the Global Industry Standard adaptive and independent management approach 4 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 5
2.3 MULTI-STAKEHOLDER ADVISORY GROUP inviting a number of additional advisers to join. The AG members played a critical role in maintaining the 5. Contribution to GTR Papers full and final list of the members is provided below independence of the Review throughout the process Several of the AG members contributed to the A multi-stakeholder Advisory Group (AG) was (Table 1). and made several key contributions, both collectively GTR Papers, either as authors or co-authors, or by assembled by the co-conveners in spring 2019. and through bilateral and other engagements. The providing contacts for contributors. Following the first meeting in May, some members Note: Several proposed members could not accept main contributions were: of the AG raised concerns about the lack of sufficient 6. Bilateral discussions with the Expert Panel due to unavailability, and one was only able to representation from civil society and affected Throughout the process, AG members had the participate virtually due to inability to travel at the 1. May 2019 – First AG meeting communities. The Chair responded by collating opportunity to engage bilaterally with individuals time. The AG presented a list of individuals from which recommendations from the AG membership and then on the Expert Panel on matters relevant to their the Expert Panel was selected. respective disciplines. These discussions often 2. August 2019 – Second AG meeting led to concrete wording suggestions for specific Table 1. Composition of the Multi-stakeholder Advisory Group The AG rejected Draft 1 of the Standard and, Standard Requirements. as a result, the Panel reshaped and developed Draft 2 of the Standard on which the AG provided Name Organisation Title 2.4 EXPERT PANEL detailed comments. The Panel responded in kind Antonio Pedro UN Economic Commission for Africa Director: Central Africa and the resulting Draft 3 reflected much of the AG The Panel was selected by the Chair. The co- feedback. conveners and, as mentioned above, the AG, put forward a list of experts from which the Chair selected Brian Kohler IndustriALL Director – Health, Safety and Sustainability 3. November 2019 – Leveraging the AG network a shortlist. He then conducted virtual interviews The PMU sought the AG’s advice and expertise Universidade Federal de Juiz de Fora, with the shortlisted experts and selected the final Bruno Milanez Associate Professor in the execution of the public consultation Brazil panellists. workshops, including leveraging in-country Vice President: Science and Environmental Charles Dumaresq Mining Association of Canada contacts. Management The Panel comprised seven experts from a range 4. February 2020 – Third AG meeting of disciplines: geotechnical, social, environmental, Chris Sheldon* World Bank Practice Manager: Energy & Extractives The AG were provided with a post-consultation organisational behaviour and legal. This composition provisional draft ahead of an in-person meeting broadly reflected the requirements of the co- International Finance Corporation David Poulter Principal Mining Specialist in early February 2020. Members’ feedback conveners. (IFC) was integrated into the following iteration of the Director: Marine Studies Institute; UNESCO Standard which was then submitted to the co- Elaine Baker University of Sydney/GRID Arendal Chair: Marine Science conveners for consideration.
Günter Becker Munich Re Head of Mining Table 2. Composition of the Expert Panel Harvey McLeod Klohn Crippen Berger Vice President: Strategic Marketing Name Organisation Expertise Michael Davies Teck Resources Senior Advisor: Tailings & Mine Waste Emeritus Professor of Sociology, Australian Governance and organisational Prof Andrew Hopkins Secwepemc & Nuxalk Indigenous Member of Xat’sull (Soda Creek) First National University behaviour Nuskmata Mack Peoples Nation Director and Principal Geotechnical Dr Angela Küpper Tailings engineering International Cyanide Management President and Chair of the Board of Engineer, BGC Engineering Inc. Paul Bateman Code Directors Sustainable Minerals Institute (SMI), The Prof Deanna Kemp Community and human rights Payal Sampat Earthworks Director: Mining Programme University of Queensland Prof Dirk van Zyl University of British Colombia Tailings engineering Rebecca Campbell White & Case Partner: Global Head of Mining & Metals Senior Associate, Behre Dolbear; Director, International Union for Conservation Senior Programme Manager: Business and Steve Edwards Karen Nash Environmental & Social Performance, MDS Environment of Nature (IUCN) Biodiversity Programme Mining & Environmental Services Upmanu Lall Columbia Water Center Director Prof Mark Squillace University of Colorado Law School Legal Social performance * Note: Due to limited availability, in the latter part of the process Chris Sheldon was replaced by Sven Renner, Susan Joyce President, On Common Ground Consultants Manager of the World Bank’s Extractives Trust Fund. and Human Rights For more information on Panel members’ backgrounds, readers should refer to the Review website, link here. 6 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 7
of tailings management. Amongst other things, Figure 1 provides a visual representation of the main The Scope and Governance document describes the papers provide background on the intent and Box 2: Related Initiatives phases of the Review process. These were: the Expert Panel as: evolution the Standard, and, where appropriate, draw out key messages and recommendations for Underlining the urgent global response to (i) Commitment and inception: The co-conveners ‘Representatives: no more than 7 technical experts the industry and other actors that go beyond the the tragedy in Brumadinho and in parallel to committed to establishing a new standard on tailings with diverse range of disciplines (such as safety/ formal Requirements of the Standard. the Review, there are now a number of other management. As a result, the Global Tailings Review risk analysis, tailings, organisational behaviour, initiatives working towards the same objective. process was initiated, starting with the appointment • Consultation Report and publication of all (ex) regulator, community/social expert), selected They include: of an independent Chair, a multi-stakeholder Advisory submissions (with consent) – This report in accordance with a pre-determined minimum list Group and the formation of the Expert Panel. of qualifications.’ contains the specific suggestions, criticisms and • UNEA-4: United Nations Environment requests of the individuals and organisations Assembly Resolution on Mineral Resource (ii) Review and drafting: The second phase included that participated in the public consultation. The Governance; study trips by the Chair and members of the Expert The multidisciplinary nature of the Panel was a key summary and analysis of this feedback was Panel to Samarco, Brumadinho and Mount Polley, ingredient in delivering a trusted and credible standard prepared by an independent service provider • ICMM’s detailed technical guidance on tailings; and other mines in Brazil and Canada. The Expert underpinned by a holistic approach to tailings Traverse, who managed the online consultation • PRI’s Mining Safety and Tailings Initiative; Panel reviewed existing standards and practices management. effort. The Consultation Report also outlines how and developed a series of draft texts. The Advisory this feedback was addressed in the final version • Responsible Mining Initiative (RMI) 2020 report Group and the co-conveners subsequently provided 2.5 PROJECT MANAGEMENT UNIT of the Standard. In accordance with international on tailings management. feedback on these drafts. The full consultation draft best practice, and with the consent of those Day to day management was undertaken by the PMU • Establishment of a Global Research was completed towards the end of October 2019. comprising Antonia Mihaylova, Project Manager, who provided feedback, we have published the Consortium on Tailings. submissions on the Review’s website: www. and Audrey Hackett, Senior Advisor – Strategy and (iii) Public consultation: This was undertaken globaltailingsreview.org. Delivery. The PMU was likewise selected by the Chair More information about several of these both online and in person in a range of key mining based on a list of recommendations from the co- • Website – The www.globaltailingsreview.org initiatives can be found within this volume. jurisdictions. conveners. Key responsibilities of the PMU included: website has been the main source of information about the Review. Set up from the outset, the The multi-disciplinary approach to the development of (iv) Addressing public consultation feedback: This • coordinating the Standard development process – website is the repository of all governance the Standard provided layers of valuable reflection, but phase entailed integration of public consultation consolidating, reviewing and editing inputs from the documentation, published resources and news also added to the complexity of the effort. As a result, feedback, further engagement with the Advisory Panel updates. The website content was handled by the a number of iterations of the text were required, which Group and the development of another iteration of the • oversight and editing of other deliverables including Review’s PMU, with IT and graphic design support translated into timeline extensions. The timeline of the Standard. the GTR Papers and the Consultation Report provided by the ICMM. Review was extended twice in response to feedback received from the Advisory Group and the co- (v) Co-conveners’ consideration and endorsement: • day-to-day management, internal and external conveners. The work was completed in July 2020. In this final stage, the Standard and accompanying communications, planning and scheduling, documents were submitted to the co-conveners execution of public consultation workshops and 4. TIMELINE The final phase of the Review was extended, as it for discussion, negotiation, consideration and other events, and preparation of summary reports The Review process formally commenced in May coincided with the unprecedented global outbreak of endorsement. As noted above, this phase was amongst other tasks. 2019 following the appointment of an independent COVID-19 in early 2020 and the ensuing pandemic. extended by approximately two months due to the Chair (see above). A high-level retrospective timeline This resulted in a several month delay of the global pandemic at the time. of the development of Standard is provided in Figure finalisation and release of the final draft of the 3. DELIVERABLES 1, below. Standard. Below is a summary of the documents and resources The tragedy in Brumadinho required an immediate developed as part of the Review. response. The co-conveners’ original intent was to complete the process by the end of 2019 and to • The Standard – the main output of the Review launch the Standard on the one-year anniversary is the Global Industry Standard on Tailings of the tragedy. Some considered this timeline to be Management. It contains a preamble, 15 principles very ambitious and expressed fears that the time and 77 requirements organised under six topic pressures may unintentionally jeopardise quality. The areas, a glossary and tables in annex. counter-view was that a tight timeline reinforced the • The accompanying volume – Towards Zero Harm: urgency of the issue, maintained momentum and A Compendium of Papers prepared for the Global allowed all parties to stay focused on the ultimate Tailings Review (formerly Recommendations goal of the Review – to prevent catastrophic tailings Report) – a set of papers written from diverse facility failures. disciplinary perspectives that address a number of issues, challenges and developments in the area 8 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 9
PART B: them. The Requirements within Topic Area I are Co-conveners commitment ICMM commitment to establishing a new intended to be cross-cutting in terms of being Feb 2019 standard on tailings management OVERVIEW OF THE STANDARD addressed across all operational activities and ongoing throughout the tailings facility lifecycle. UNEP, PRI, ICMM co-convene the Global Mar 2019 Tailings Review (GTR) The Standard is directed at Operators1 and applies to Topic Area II requires Operators to develop knowledge facilities. It makes clear that extreme consequences about the social, environmental and local economic The Co-conveners select and appoint an to people and the environment from catastrophic context of a proposed or existing tailings facility, Apr 2019 independent Chair, Dr Bruno Oberle tailings facility failures are unacceptable. Operators and as part of this, to conduct a detailed site must have zero tolerance for human fatalities and characterisation. It asks for a multi-disciplinary First Advisory Group (AG) meeting to strive for zero harm to people and the environment May 2019 knowledge base to be developed and used by the support Chair in Expert Panel shortlist from the earliest phases of project conception. To Operator and key stakeholders in an iterative way Review and development be compliant with the Standard, Operators must to enable all parties to make informed decisions of consultation draft First Expert Panel (EP) meeting to kick off Jun 2019 use specified measures to prevent the catastrophic throughout the tailings facility lifecycle. These the review failure of tailings facilities and to implement best decisions will arise in the context of the alternatives practices in planning, design, construction, operation, analyses, the choice of technologies and facility Jul 2019 Series of EP meetings to prepare Draft 1 maintenance, monitoring, closure and post closure designs, emergency response plans, and closure and Chair conducts research studies of the Standard activities. Overall, conformance is expected where in Brazil and Canada post-closure plans, amongst others. there is no conflict with the legislative requirements of Second AG meeting to give feedback on Aug 2019 Draft 1 of the Standard the jurisdictions where facilities are located. Topic Area III aims to lift the performance bar for designing, constructing, operating, maintaining, EP develops Draft 2 of the Standard In accordance with the Review’s Scope and monitoring, and closing tailings facilities. Operators Sept 2019 Governance document, the Standard does not: AG gives feedback on are asked to demonstrate the ability to upgrade a Draft 2 online facility at a later stage to a higher consequence • contain detailed technical design criteria for tailings classification. For existing facilities, where upgrading Oct 2019 facilities EP develops Draft 3: the Consultation Draft is not feasible, the Operator must reduce the Consultation draft is translated consequences of a potential failure. Recognising in 6 languages • exclude or ban any technologies Nov 2019 Nov 15: Public Consultation Launch that tailings facilities are dynamic engineered • apply to riverine, deep sea and non-tailings related structures, Topic Area III requires the ongoing use Public consultation Public consultation: online and in country storage facilities of an updated knowledge base, consideration of (Kazakhstan, China, Chile, Ghana, South Dec 2020 Africa, Australia) • cover standards for rehabilitation of affected areas. alternative tailings technologies, the use of robust designs and well-managed construction and The Standard’s structure is logical, not chronological. operation processes to minimise the risk of failure. Review of feedback and development Jan 2020 Review of consultation feedback and develop- It is underpinned by an integrated approach to A comprehensive monitoring system must support of post-consultation draft ment of Post consultation draft (Draft 4) tailings management which was the overarching the full implementation of the Observational Method objective of the Panel. To give the Standard structure, and a performance-based approach must be taken Feb2020 Third AG meeting to give feedback on for the design, construction and operation of tailings Co-conveners meeting to give Draft 4 the Requirements are organised around six Topic feedback on Draft 4 Areas, 15 Principles and 77 specific Requirements. facilities. It is important to note that future development of Mar 2020 EP submits the Draft Standard to the Co-conveners consideration implementation protocols would further clarify Topic Area IV focuses on the ongoing management and endorsement Co-conveners for consideration expected levels of performance. and governance of a tailings facility. It provides for the designation and assignment of responsibility to Apr 2020 key roles in tailings facility management, including an Delay in discussions due to Topic Area I focuses on project-affected people. COVID 19 pandemic In order to respect human rights, including the Accountable Executive, an Engineer of Record and a Responsible Tailings Facility Engineer. Further, it sets May 2020 individual and collective rights of indigenous and tribal peoples, a human rights due diligence process standards for critical systems and processes, such Series of Co conveners meetings to as the Tailings Management System and independent discuss the Draft Standard and way ahead is required to identify and address those rights Jun 2020 that are most at risk from a tailings facility or its reviews, which are essential to upholding the integrity potential failure. To demonstrate this respect, project- of a tailings facility throughout its lifecycle. Cross- affected people, must be afforded opportunities for functional collaboration and the development of a Jul 2020 meaningful engagement in decisions that affect learning organisational culture that welcomes the
1. The Standard defines ‘Operator’ as: an entity that singly, or jointly with Figure 1: Global Industry Standard on Tailings Management Timeline other entities, exercises ultimate control of a tailings facility. This may include a corporation, partnership, owner, affiliate, subsidiary, joint venture, or other entity, including any State agency, that controls a tailings facility. 10 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 11
identification of problems and protects whistle- PART C: OBSERVATIONS AND A good example of how this process facilitated the As to be expected, there was both a lot of duplication blowers are also included. integration of a discrete topic is the approach taken and plenty of divergence in the views that were REFLECTIONS ON THE PROCESS by the Panel to the issue of climate change. Instead expressed. Naturally, individuals and organisations Topic Area V covers emergency preparedness of drafting a stand-alone requirement for Operators to within the same stakeholder group often made similar and response in the event of a tailings facility DECISION MAKING AND WAYS OF WORKING consider climate change impacts, the Panel identified comments while, conversely, different stakeholder failure. Operators must avoid complacency about multiple decision points where these impacts needed groups had different views across a broad range of the demands that would be placed on them in CO-CONVENERS to be addressed, along with other considerations. This issues. This required making iterative adaptations, the event of a catastrophic failure. The Standard The co-conveners had a series of meetings and approach ensures that climate change remains in looking for points of commonality, assessing the requires Operators to consider their own capacity, checkpoints throughout the process. The most scope for all risk management and review activities, practicality of proposals, and testing the logic and in conjunction with that of other parties, and to plan extensive engagements came at the beginning, in and that information is shared systematically across content of the Standard against the objectives of the ahead, build capacity and work collaboratively with the lead up to the public consultation, and towards the operation. Review on an ongoing basis. Overall, the majority of other parties, in particular communities, to prepare the end of the process during the consideration and the feedback was focused on a limited number of for the unlikely case of a failure. Topic Area V also endorsement phase. POST-CONSULTATION DECISION-MAKING specific controversial themes which are explored in outlines the fundamental obligations of the Operator more detail in the Global Tailings Review Consultation The Consultation Draft of the Standard was released in the long-term recovery of affected communities in Report released alongside this report. Each co-convener also presented their respective in mid-November 2019 and stakeholders were given the event of a catastrophic failure. positions on key issues formally as part of the public until the end of December to provide feedback. The consultation. All of the minor issues and a number of consultation process was conducted both online, and Topic Area VI requires public disclosure of more substantial disagreements were resolved in the in-person in several key mining jurisdictions globally. REFLECTIONS information about tailings facilities to support public resulting post-consultation iterations of the Standard. Respondents were asked to provide comments on accountability, while protecting Operators from the There are a number of reflections and lessons from Key points of divergence were left to be resolved individual Requirements and on the Standard more need to disclose confidential commercial or financial the Review process that are worth capturing for any during the negotiations amongst the co-conveners in generally, and were also invited to make suggestions information. The Standard concludes by requiring that future initiatives of this nature. The governance model, the final consideration and endorsement phase. for re-wording. Operators commit to transparency, and participate in the ambitious timeline and the multidisciplinary Panel global initiatives to create standardised, independent, were aspects of the Review that gave it external WITHIN THE PANEL The consultation responses were collated and industry-wide and publicly accessible information credibility, but, at the same time, made the process provided to the Panel on an ongoing basis throughout about tailings facilities. The general approach was to endeavour to reach particularly challenging. consensus on all issues. However, there were times the consultation period. Two weeks after the consultation closed, the Panel was provided with a when this was not possible. In these cases, the Chair Below are some key overarching takeaways from the single consolidated file containing all comments in a assumed responsibility for the final decision, taking Chair and PMU: EVOLUTION OF THE STANDARD account of both the views of the Panel member with structured way, based on ‘coding’ or categorisation of key terms and themes. Overarching and cross-cutting As mentioned above, there were a number of expertise in the area in question and the objectives of 1. Scope and governance. The scope of the comments were considered by the Panel at their first iterations of the Standard. However, there were certain the co-conveners. Review was frequently discussed throughout post-consultation in-person meeting. aspects on which the Panel remained firm in their the process and there were conflicting views intention to lift the performance bar for the industry as THE ‘OWNERSHIP’ DIVISION WITHIN THE PANEL between stakeholders concerning the breadth of Due to the volume of feedback, and in the interest a whole. As with any negotiated product, there were scope required to achieve the ultimate objective Each expert was assigned responsibility for a sub-set of saving time, each Panel member was tasked concessions and nuances added to the language of the Review. This made it difficult to maintain of Requirements that linked to their areas of expertise. with: (i) presenting a summary of the feedback on as it evolved. However, the intent of the Panel was focus on some of the detail of the proposed This work involved drafting the Requirements, the Requirements for which they had responsibility; generally respected, and the resulting Standard Requirements throughout the process. The Scope consulting on and addressing feedback from other and (ii) proposing a rewording if this was deemed contains, to one degree or another, ‘step-changes’ in and Governance document was intentionally members of the Panel. Some of this work was done necessary. These proposals were then discussed and all discipline areas. drafted by the co-conveners to allow for flexibility remotely, but at all key stages of the Review the full agreed by the full Panel. A triage process was applied to amend the parameters should public feedback Panel convened to examine all Requirements together. to facilitate decision-making. In addition, sub-groups of the Panel were formed to or the Chair’s assessment point to the need to problem-solve, engage bilaterally with the AG and adjust the scope. Ultimately, this allowed the Chair work on cross-cutting topics such as the integrated Triage process to addressing public and Panel to maintain control over the process. consultation feedback management system. 2. Schedule. The ambitious work plan from the outset, along with the dispersed geographical 1. Is the intent of this Requirement clear? While wordsmithing and improvements were spread of the Panel, proved challenging at a sometimes discussed bilaterally or in smaller working 2. Does the Panel want to keep or remove this number of critical junctures. The schedule also groups, when it came to finalising the Standard, every Requirement? forced part of the Review to be conducted in single edit to the text was collectively considered parallel to the drafting effort (e.g. the comparative and endorsed by all seven Panel members and the 3. Does the Panel want to keep it as is or reword Chair. This process, while time consuming, helped to it? maintain the integrated approach and delivered an end product which was coherent, technically sound and credible. 12 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 13
assessment of tailings management legislation 6. Translations. The translation period allowed under the freedom to think innovatively and not be 5. CONCLUSION across a number of mining jurisdictions). the revised pre-consultation schedule was two constrained by what had or had not worked in the The Review took just under a year and half to To address these challenges, strong project weeks. This proved to be insufficient for delivering past. However, and in connection with comments complete: from the public commitment by the three management controls were required. Technology technically-sound translations that reflected on the need for a common language among the co-conveners to jointly assemble an independent also played a big part in keeping people connected linguistic and structural nuances. The need to wait experts, one challenge which arose was to find a review on tailings management, up until the public and the information flowing. for translated versions also shrunk the amount of language that adequately covered the multitude launch of the Standard. Using an open and honest time available to in-country consultees to review of processes, systems and terminologies that 3. Challenges with logistics. Related to the point dialogue and consensus building throughout the the draft and engage with their constituencies. are used at an operational level across the world. above, the geographical spread often made it entirety of the process, the co-conveners managed to The draft Standard made it clear that the English To this end, the Panel took efforts to engage logistically challenging to accommodate the reach agreement and deliver the best possible product version should be considered as the definitive further with industry professionals across a range experts’ working times and availability. This to help improve the way tailings facilities are designed, version, and this was reiterated during the of disciplines to ensure that the Requirements proved particularly difficult in terms of arranging built, monitored, managed and closed. Looking ahead, consultation process. and Glossary terms were easily understood and in-person meetings. Having a quorum of 100 per it will be critical for all stakeholders involved to date aligned with currently accepted mining-industry cent also often led to delays even with virtual 7. Dealing with information asymmetry. A challenge to remain as committed during the next phase – the parlance. meetings. Early calendar sharing and the advance with taking a multi-stakeholder approach to implementation of the Standard. block-booking of dates allowed a level of certainty addressing an issue that is largely specific to one 10. Balancing the objectives of three disparate around some aspects of planning. industry is that, by definition, the industry was parties with distinct interests and perspectives. better placed to provide detailed technical input For the co-conveners, it was important that their 4. Managing the Advisory Group and co-conveners. on the draft Standard as it developed. This risked positions were respected and that their objectives The second AG meeting, in August 2019, was creating a perception from the outside that the were positioned in an amenable way so as to not scheduled so that it overlapped with one of the co- process was overly influenced by the industry exclude the other co-conveners. For the Chair, conveners’ checkpoints. The joint meeting, which who were seeking to self-police. To combat keeping the views of the co-conveners at the was attended by representatives from two of the this potential imbalance the Chair, in his role as back of mind throughout the process was vital three co-conveners, proved to be problematic facilitator, maintained consistent communication to ensure equitable representation of the co- due to this being perceived by some members of with all three parties. He also allowed additional conveners. the AG as undermining the independence of the time for the non-industry co-conveners to engage process. This was therefore the last combined within their respective constituencies, particularly meeting held. The timing and sequencing of on technical aspects, and made himself available meetings needed to be planned carefully so that as and when requested to discuss specific issues. information was shared evenly and participants were adequately informed in advance of key 8. Finding the right language within the Expert decision points. Panel. The multi-disciplinary composition was not without its challenges. As with the establishment 5. Managing the consultation process. Additional of any team, the Panel went through a period iterations during the pre-consultation of learning, adapting and familiarisation both drafting phase resulted in the delay of the with each other in terms of ways of working, consultation timeline. Unintentionally, this led and with those disciplines outside their area of to the consultation being conducted from mid- expertise. Over time, trust was built, and a working November until the end of December 2019, ‘language’ emerged through which all experts, coinciding with end-of-the-year processes and regardless of background, could engage. An seasonal holiday festivities. Some perceived example of this is the different interpretations this as a benefit and utilised the quieter period of the term ‘management systems’ which can to prepare a thorough submission; however, for imply different types of activities for the technical the in-person consultation it was impossible teams compared with the environmental and to visit a jurisdiction for more than three days, social teams. Much effort was therefore expended which made attendance for participants difficult in carefully clarifying the boundaries and the in some circumstances. Additional effort was areas of intersection between these different made around communications, and resources understandings. were drafted in to support invitations to the in-country consultations. Reminders were also 9. Finding widely understood terminology globally. issued to virtual participants to ensure the public As mentioned previously, independence was a consultation remained on their radar. core tenet of the Review. This gave the Panel 14 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 15
SETTING THE SCENE
CHAPTER II Upstream MINE TAILINGS 4 3 FACILITIES: OVERVIEW 2 1 AND INDUSTRY TRENDS Starter dyke: 1 Downstream The embankment design terms, upstream, Elaine Baker*, Professor, The University of Sydney, Australia and GRID Arendal, Arendal, Norway downstream and centreline, indicate the 4 Michael Davies*, Senior Advisor – Tailings & Mine Waste, Teck Resources Limited, Vancouver, Canada direction in which the embankment crest 3 moves in relation to the starter dyke at the Andy Fourie, Professor, University of Western Australia, Australia 2 base of the embankment wall. Gavin Mudd, Associate Professor, RMIT University, Australia 1 Kristina Thygesen, Programme Group Leader, Geological Resources and Ocean Governance, GRID Arendal, Norway Centreline Dyke: 2 to 4 or more 4 Dykes are added to raise the embankment. This continues throughout the operation 3 of the mine. 1. INTRODUCTION The tailings are most commonly stored on site 2 in a tailings storage facility. Storage methods for 1 This chapter provides an overview of mine tailings conventional tailings include cross-valley and paddock and mine tailings facilities. It illustrates why and (ring-dyke) impoundments, where the tailings are how mine tailings are produced, and the complexity behind a raised embankment(s) that then, by many Source: Vick, 1983, 1990 involved in the long-term storage and management definitions, become a dam, or multiple dams. of this waste product. The call for a global standard However, a tailings facility can have an embankment Figure 1. Common methods of tailings embankment construction for mine tailings management is a response to recent function like a dam during some portion of its life catastrophic facility failures. Mining companies, cycle but not during another (e.g. closure). For this governments and communities all recognise the Mine tailings management is a long-term process that mine closure, with expectations of improved land reason, it is more correct to refer to the entire tailings potential for unacceptable loss of life, livelihoods starts well before any tailings are produced (Figure 2). rehabilitation and comprehensive water management facility when discussing mine tailings. The tailings still and long-term environmental damage that can It can be difficult to estimate the ‘typical’ cost of planning (McCullough et al. 2018). A key take-out exist during all life-stages but the ‘dam(s)’ may not, as result from such failures. There are lessons to be building, operating and closing a tailings storage from Figure 2 is that by far the longest portion of a there may no longer be a function for embankment(s) learned from past failures but if we cannot integrate facility as it depends on many factors, but examples tailings life cycle (closure/post-closure) also occurs of that nature. these lessons throughout the industry, we will likely suggest up-front capital costs can be around 15 per at the time when the mine is not generating revenue. continue to witness these tragic events. The United cent of mine development, with ongoing operational For larger mining owners with multiple operations this Raised embankments can be constructed using Nations Sustainable Development Goals (SDGs) costs generally less than 5 per cent of the total cost of may be addressed through sharing of resources, but upstream, downstream or centreline methods (Figure should underpin the mining industry’s social licence to mine production. for most tailings facilities it is critical that the facility is 1) and even a combination thereof. The embankment operate, ensuring that benefits from mining to society sufficiently prepared for closure/post-closure through needs to be designed, constructed and operated to are not achieved at the expense of local communities There is increasing scrutiny being placed on investment during the operational phase. withstand the loading conditions expected during the or the environment. To realise this, the entire industry life of the mine, including post-closure. needs to commit to a standard of design, operation and innovation that solves the problem of tailings While impoundment storage of tailings slurry is facility failures. currently the most common storage method, tailings Exploration Construction Closure can also be deposited into a previously mined pit when available, filtered to produce dewatered stacked 2. MINE TAILINGS AND TAILINGS FACILITIES: AN tailings, placed underground after adding a binder OVERVIEW such as cement, or less commonly deposited into 5-25 5-10 2-4 20-100 5-50 Perpetuity rivers or offshore (though the latter is increasingly Mine tailings are the waste material that remains after limited due to jurisdictional and/or owner restrictions the economic fraction has been extracted from the on the use of such practices). The approach mineral ore. Tailings consist of a slurry of ground rock, taken in the design, construction, operation and Site selection, Operations Post closure and water and chemical reagents that remain after design and decommissioning of the tailings facility will depend on processing. The composition of mine tailings varies permitting many factors, including the owner’s own governance according to the mineralogy of the ore deposit and approach, government regulations, nature of the how the ore is processed. ore, the local topography and climate, site geology, Source: BHP, 2019; Mike Davies, 2020. seismic risk and cultural context. Figure 2. Life of a mine with a tailings storage facility – in average years *Member of the GTR Multi-stakeholder Advisory Group 16 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 17
Tailings, other than perhaps waste rock dumps in operating and maintaining traditional tailings facilities The precise number of active tailings storage facilities some instances, generally have the single largest are increasing. The largest facilities can have is currently unknown. Although incomplete, the Global mine site footprint, both spatially and temporally embankments designed to contain more than a billion Gold 21% Tailings Portal (see the chapters by Franks et al. and (Werner et al. 2020). This is but one of the reasons m3 of tailings. In 2016 it was estimated that more Barrie et al., this volume), which includes information why managing TSFs can be extremely complex. than 8 billion tonnes of tailings were produced from provided by publicly listed companies, currently The volume of waste material produced per unit the extraction of metals and minerals (Figure 3). The records 724 active tailings facilities. More than half of of commodity is increasing due to declining ore largest volume of tailings, 46 per cent, is produced these (364), were constructed in the last 10 years. The grades (Mudd 2007; 2010), so the challenges of from copper mining (Figures 4 and 5). Iron 9% actual total of tailings facilities in the world is likely at least an order of magnitude greater than the 724 noted above when all of the active and legacy (closed) facilities are taken into account (see Franks et al. Coal 8% this volume, who estimate there are approximately Commodities 8,500 sites world-wide or which around 3,250 are Copper Phosphate 4% active sites). Many of these other facilities may be Gold Lead – zinc 3% quite small and relatively inconsequential, but that Iron Ore Copper 46% Nickel 2% Coal Platinum Group Elements 1% presumptive assumption should be confirmed over Phosphate Bauxite 1% coming years. Lead-Zinc Uranium <1% Nickel Chromium <1% The growth in resource consumption as a result of Platinum Group Elements Waste rock Ore milled Molybdenum <1% Bauxite population increase and the continual expansion 72 000 000 000 18 800 000 000 Uranium Tin <1% of the global economy has seen a steady increase tonnes tonnes Chromium Vanadium <1% in the extraction of metals and minerals (Figure 6). Molybdenum Manganese <1% Mining of metal ores has grown on average by 2.7% Tin Niobium <1% per year since the 1970s, a reflection of the growth Vanadium Rare Earths <1% Manganese in infrastructure and manufacturing (International Lithium<1% Niobium Resource Panel [IRP] 2019). Metals and minerals are Ore produced Tailings Other minerals 1% Rare Earths essential to society and have a major impact on 11 Lithium 10 180 000 000 8 850 000 000 tonnes tonnes of the 17 Sustainable Development Goals (UNDP and Source: USGS, 2016; Mudd, 2020 UN Environment 2018). The reduction in poverty in many parts of the world is underpinned by mineral Figure 4. Percentage of global tailings volume per resources and the move towards a low carbon commodity in 2016 Source: USGS, 2016; Mudd, 2020 economy points towards increasing demand for metals. For example, the shift to renewable energy, Figure 3. Estimate of the volume of tailings and waste rock produced in 2016 in relationship to ore outlined in the scenarios developed to achieve the production (c.f. plastic waste weight and volume) Paris Climate Agreement target, requires increased use of many metals, including copper, lithium, cobalt, aluminium, iron, manganese and silver. Increased material efficiency and recycling may offset some of this demand, but for many currently important metals the projected demand far exceeds the current production rates (Giurco et al. 2019). 18 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 19
To obtain 20,1 million tonnes of copper approximately 14 913 million tonnes of rock is extracted from the ground: 30000
25000 Total rock material The non-economical 14 913 million fraction is normally 20000 tonnes Waste rock disposed of on the (non-economic) mine site. 10 804 million tonnes 15000
Million tonnes 10000
From the 14 913 million tonnes of rock, approximately 4 188 million 5000 tonnes is milled. The remaining 10 804 million tonnes is classified as non-economic and disposed of on-site. 5000 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 The milling process requires Ore material Water approximately 5 300 million tonnes of Year for milling for milling water (some of the water is reused in the 4 188 million 5 300 million milling process). tonnes tonnes Source: UN Environment Programme International Resource Panel Global Material Flows Database
Figure 6. The global extraction of metal ores (includes copper, iron, aluminium and other non-ferrous metals) from 1970 to 2017.
End result: 20,1 million tonnes of copper At most mines, tailings are pumped Tailings The price of copper is variable. In 2016 the into large tailings dams, which remain after milling average price for 1 tonne of copper was ca. in situ in some form when the mine 4 109 million 3. TAILINGS FACILITY FAILURES commitment to the fundamentally sound design and 4 916 USD. The year’s production of 20,1 closes. The closure plan for a tailings tonnes operating concepts that were outlined in the review. million tonnes equates to 88 812 million USD dam varies from site to site. The UNEP Rapid Response Assessment on mine tailings safety (Roche et al. 2017) noted that in the At the same time, while failures do continue to occur, previous 10 years, significant failures of tailings and the rate and nature of those remain wholly facilities had been reported across the globe, Source: USGS, 2017; Mudd, 2008. unacceptable, on a per tonne basis the world’s largest including in jurisdictions with comprehensive facilities have performed well and are not contributing regulatory regimes. The key point is that despite Figure 5. The relationship between copper, waste rock, tailings and water usage – Global footprint of copper to these events. Further, an increasing number of numerous interventions, failures continue to occur production, 2016 countries have adopted governance programmes and at an unacceptable rate. Various groups around many owners, regulators, communities of interest the world have analysed and presented data on (COIs) and designers continue to advocate for their aspects of tailings facility failures, failure rates and use more broadly (e.g. Mining Association of Canada consequences (e.g. WISE 2019; WMTF 2019; Owen et [MAC] 2017; MAC 2019a). Finally, we can say that al. 2020) and all of these make useful contributions failure modes remain within a tight band of technical to highlighting the problem. The Global Tailings Portal root causes that have known engineering solutions (2020) provides a significantly updated database of (see below). tailings facilities and their consequence of failure. While not exhaustive, it illustrates the enormous Poor governance practices (operating or regulatory) volume of tailings that need to be safely managed. that contribute to failures can be addressed through more rapid adherence to frameworks like MAC’s In 2001 Davies reviewed tailings facility failures up Towards Sustainable Mining (see MAC 2019b) to that time and observed that all were predictable or, where a jurisdiction does not have a sound in hindsight and could have been prevented during governance model, the Global Industry Standard the design and/or operational phase. This is still on Tailings Management (‘the Standard’). When the case for the many failures that have occurred addressing the governance issues that can contribute in the intervening period, indicating that there to catastrophic failures, these frameworks are entirely has unfortunately not been sufficiently uniform consistent and are based upon the premise that 20 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 21
eliminating catastrophic failures is the ultimate goal. developed lacks the strength required for the • Focussing on single cause mechanisms may The Standard provides recommendations that In this respect there are similarities with how the loading conditions, inclusive of the slope of disguise a deeper underlying malaise, which address largely the owner/operator but also has clear mining industry approaches workplace safety. There the embankment. Where tailings are used for includes inadequate governance and inadequate requirements related to engagement of appropriate are likewise parallels with other industrial sectors, embankment construction and they are not or insufficient technical training of responsible design and independent review competence/capacity such as the airline, and hydroelectric industries, where sufficiently compacted, a very sudden loss of personnel. Achieving the goal of sound tailings commensurate with the subject facility. Though far the aim is also zero fatalities and zero major incidents strength called ‘liquefaction’ can occur and a facility governance towards a future with zero from a certainty, given the nature of the failures that that cause severe public and environmental impacts. catastrophic release of tailings can follow. catastrophic failures requires: (1) proper training in have occurred, it appears a logical conclusion that if personnel management, regulatory management, the recommendations in the Standard on governance In terms of what causes a tailings facility to fail, there The triggering mechanisms mentioned here are engineering principles, facility operation and other issues related to design, operation and review had are a number of design and/or operational flaws that certainly not exhaustive and there are many examples roles that are key to ensuring that a facility is been followed, many of the failures that occurred in can trigger a failure event. These triggers are well- of less well-recognised triggering events, such as designed and operated safely; and (2) management the past may not have happened, or at least would represented in the failure case history record and, as development of a sinkhole beneath the tailings facility systems to ensure that appropriate monitoring, have had less severe impacts. This observation is such, are well known and commensurately should sited in a karstic environment due to dissolution of surveillance and governance systems are in place necessarily speculative and is not intended in any way be able to be anticipated and addressed prior to any underlying limestone or dolomite (e.g. Yang et al. and are adequately resourced. to address any single incident, either explicitly noted failure event. These common triggers include: 2015) or the upstream failure of another structure, above or implied through connection. However, it • A single cause focus can also lead to the erroneous such as a beaver dam (e.g. McKenna et al. 2009) that broadly aligns with the published findings of incidents conclusion that solutions to ensuring stability are • Operating and/or regulatory failures of leads to a cascade failure event. and the examples of best practices from well- simple, e.g. ‘if failure occurs due to overtopping, all governance. A lack of attention to the key governed facilities that together were used to inform that is needed is monitoring of water levels’. Unless performance indicators that are required for the As evident from World Mine Tailings Failures (WMTF) the development process of the Standard; to that responsible personnel, including the designer, the facility to perform as intended can lead to any of database (2020), the number of tailings facility failure extent the conclusion appears well-justified. facility owner and the regulator, are adequately the common triggers that follow. While inadequate events is unacceptable to both the mining industry trained and suitably skilled to recognise an evolving designs have occurred, in the majority of all case and society in general. Whenever a failure occurs, problem, monitoring protocols alone may well histories available there was clearly a failure of there tends to be a rush to investigate whether other prove to be inadequate. 5. CONCLUSION either operating governance or regulatory oversight facilities have a similar flaw to that identified in the which was at odds with adequate tailings facility forensic investigation of the most recent failure, The mining industry is extremely good at determining management. Even the best designs may not be whatever that might be. As an example, in the the cause of tailings facilities failures, and to date able to withstand poor governance. aftermath of the failure of the Mount Polley tailings 4. PREVENTING TAILINGS FACILITY FAILURES there have been no unexplained failures reported. The facility in Canada, extensive field investigations were problem is that the events or conditions that lead to • Overtopping, where the capacity of a tailings facility The vast majority of active tailings facilities – and carried out around the world to determine if the failures, although clear in hindsight, have not always without a sufficiently sized spillway is insufficient to many that have been closed, – have operated possibility of the primary mechanism identified as been observed and/or are miscommunicated during safely store water during operational upsets and/ without any issues of concern for society. However, being responsible for this failure (in this case related the lead-up to the failure. There needs to be greater or extreme storm events. When this occurs in the the number of failures that continue to occur is to inadequate shear strength of the foundation soils) effort to identify high risk tailings facilities with a most extreme cases, water eventually overtops a rightfully deemed unacceptable by both those who could be a problem at other sites. Such reactive focus on preventing failures. Recent catastrophic low point on the facility perimeter, often resulting own/operate them and by society in general. As approaches can add some value but are prone to miss failures have increased community awareness of in significant erosion and perhaps even, ultimately, described above, there has been a wide variety a number of key issues: mining risk. Communities which may potentially be catastrophic release of tailings. of facilities across broad geographies that have impacted by the failure of a tailings facility deserve failed over the past 100 years (although record • Foundation failure, where the soil and/or rock • It is very rare that a tailings facility failure access to disclosure information that provides an keeping has been sporadic and incomplete). The beneath the tailings facility is not sufficiently strong is attributable to a single, isolated cause. understanding not only of the risk status of the specific causes and triggers for the documented to safely bear the imparted stresses from the Earthquake-induced failure may be an exception facility, but also the broader risks to communities failures have varied, but there are similarities in each weight of the overlying embankment that forms the to this statement, but even these failures are and the environment. Tailings facilities owners and case in terms of fundamental loss of governance retention portion of the facility. now avoidable, as evidenced by the excellent their regulators that do prioritise safety and provide at some point to the degree that a failure did performance of many large tailings facilities in appropriate risk information need to be acknowledged • Piping, which is initiated by excessive seepage occur. ‘Governance’, as used here, includes the Chile since the 1960s through many large seismic and rewarded for their combined efforts to operate through the embankment or the foundation of the responsibilities of the owner and/or operator, events including the very large (magnitude 8.8) existing facilities and/or design new ones with no tailings facility, which leads to sufficient erosion the core competencies of the designer, the core earthquake in 2010. Rather, forensic investigations credible failure modes. of embankment or foundation particles resulting competencies and role provided for any independent of tailings facility failures often point to a failure of in the development (sometimes very rapidly) of an senior review and the competency/capacity of the governance as well as technical issues. Focussing erosion void that may ultimately facilitate extremely regulatory processes within the jurisdiction of the on just the event that finally triggers a failure will rapid discharge of tailings and process water. This facility involved. Certainly not all of these aspects likely only serve to ensure that failures that are is a more common failure mode in conventional of governance were lacking for each incident, but more a function of poor governance will continue (non-tailings) water reservoirs but has occurred for in all cases systems and processes in at least one to happen. Good governance, for example the some tailings facilities as well. or more of those areas were insufficiently robust. management approaches outlined by MAC (2017; • Slope failure, including where tailings are used MAC 2019a), is clearly defined yet not universally to construct some or all of the tailings facility applied, as evidenced by the nature of failures that embankment(s). This type of failure can occur have continued to occur. where the material used for any embankment(s) 22 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 23
REFERENCES KEY MESSAGES BHP (2019). ESG Briefing: Tailings Dams June 2019. https://www.bhp.com/-/media/documents/media/ reports-and-presentations/2019/190607_esgbriefingtailingsdams.pdf?la=en Accessed 6 May 2020.
1. Mine tailings are currently an unavoidable waste product of mining. Davies M. P. (2020). Personal communication. May 2020.
Davies, M. P. (2001). Impounded mine tailings: what are the failures telling us? CIM Distinguished Lecture 2000- 2. There has been an increase in the volume of tailings produced for many 2001. The Canadian Mining and Metallurgical Bulletin 94(1052), 53-59. mineral commodities, due to increased demand for minerals and the continuing decrease in ore grade. Giurco, D., Dominish, E., Florin, N., Watari, T. and McLellan, B., (2019). Requirements for minerals and metals for 100% renewable scenarios. In Achieving the Paris Climate Agreement Goals. Teske, S. (ed.). Switzerland: Springer, 437-457. 3. The precise number of active tailings facilities is currently unknown, although initiatives are underway to determine both the location and Global Tailings Portal (2020). https://tailing.grida.no/
status of these facilities. IRP (2019). Global Resources Outlook 2019: Natural Resources for the Future We Want: Report of the International Resource Panel. United Nations Environment Programme. Nairobi, Kenya. 4. Responsible mine closure is integral to mining companies’ core business. IRP (2020). Global Material Flows Database. International Resource Panel. United Nations Environment 5. Mining conducted responsibly, is acknowledged as a key industry for Programme. https://www.resourcepanel.org/global-material-flows-database. Accessed 6 May 2020. achieving the United Nations Sustainable Development Goals (SDGs). Martín-Crespo, T., Gómez-Ortiz, D. and Martín-Velázquez, S., (2019). Geoenvironmental Characterization of Sulfide Mine Tailings. In Geochemistry. IntechOpen. 6. Failures of tailings facilities are continuing to be reported across the globe. McCullough, C.D., Harvey, B., Unger, B.C.J., Winchester, S., McCarthy, B. and Coetzee, J. (2018). From start to These failures are unacceptable to both the mining industry and society. finish–a perspective on improving sustainable development aspects of life-of-mine practices. From Start to Finish: Life of Mine Perspective, Spectrum, 24. 7. The triggers for failures of tailings facilities are well documented and McKenna, G., Keys, M., van Meer, T., Roy, L. and Sawatsky, L. (2009). The impact of beaver dams on the design understood and, as such, should be anticipated and addressed, starting and construction of reclaimed mine sites. Proceedings of the 24th Annual British Columbia Mine Reclamation at the design phase and continuously during operation through to closure Symposium, Williams Lake, BC, 2000. The Technical and Research Committee on Reclamation. (and beyond if necessary). MAC (2017). Third Edition of a Guide to Tailings Management, October 2017. Ottawa: Mining Association of Canada. https://mining.ca/documents/a-guide-to-the-management-of-tailings-facilities-version-3-1-2019/ 8. Communities potentially affected by mining hazards are entitled to information that allows an understanding of a broad range of risks, as well MAC (2019a). Developing an Operation, Maintenance and Surveillance Manual for Tailings and Water Management Facilities (Second Edition). Ottawa: Mining Association of Canada. https://mining.ca/our-focus/ as being informed about operator risk reduction strategies. tailings-management/
MAC (2019b). Towards Sustainable Mining. 2019 Highlights. Ottawa: Mining Association of Canada. https:// mining.ca/wp-content/uploads/2019/12/TSM-Booklet-EN-Web.pdf
Mudd, G.M. (2007). Global trends in gold mining: Towards quantifying environmental and resource sustainability. Resources Policy, 32(1),4 2-56.
Mudd, G.M. (2008). Sustainability reporting and water resources: a preliminary assessment of embodied water and sustainable mining. Mine Water and the Environment, 27(3), 136-144.
Mudd, G M. (2010). The Environmental Sustainability of Mining in Australia: Key Mega-Trends and Looming Constraints. Resources Policy, 35(2), 98-115.
Mudd G.M. (2020). Personal communication April 2020. 24 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 25
Owen, J.R., Kemp, D., Lèbre, É., Svobodova, K. and Murillo, G.P. (2020). Catastrophic tailings dam failures and disaster risk disclosure. International Journal of Disaster Risk Reduction, 42, p.101361. Pepper, M., Roche, C.P. and Mudd, G.M. (2014). Mining legacies—Understanding life‐of‐mine across time and THE SOCIAL space. In Proceedings of the Life‐of‐Mine Conference (pp. 449-465). Brisbane, Australia: Australasian Institute of Mining and Metallurgy. Roche, C., Thygesen, K., Baker, E. (eds) (2017). Mine Tailings Storage: Safety Is No Accident. A UNEP Rapid DIMENSION Response Assessment. Nairobi and Arendal: United Nations Environment Programme and GRID-Arendal.
UNDP and UN Environment (2018). Managing Mining for Sustainable Development: A Sourcebook. Bangkok: United Nations Development Programme.
USGS (2016). USGS Mineral Commodity Summaries 2016. https://www.usgs.gov/centers/nmic/mineral- commodity-summaries Accessed 6 May 2020.
USGS (2017). USGS Mineral Commodity Summaries 2017. https://www.usgs.gov/centers/nmic/mineral- commodity-summaries Accessed 6 May 2020.
Vick S.G. (1983). Planning, Design, and Analysis of Tailings Dams. John Wiley & Sons.
Vick S.G. (1990). Planning, Design, and Analysis of Tailings Dams. Vancouver: BiTech.
Werner, T. T., Mudd, G .M., Schipper, A. M. and Huijbregts, M. A .J. (2020). Global-Scale Remote Sensing of Mine Areas and Analysis of Factors Explaining Their Extent. Global Environmental Change, 60: doi.org/10.1016/j. gloenvcha.2019.102007, 10 p.
WISE (2019). Chronology of Major Tailings Dam Failures. World Information Service on Energy. https://www. wise-uranium.org/mdaf.html. Accessed May 2020.
World Bank (2016). What a Waste 2.0. A Global Snapshot of Solid Waste Management to 2050. https:// datatopics.worldbank.org/what-a-waste/trends_in_solid_waste_management.html. Accessed 6 May 2020.
WMTF(2019). World Mine Tailings Failures. https://worldminetailingsfailures.org/. Accessed 6 May 2020.
Yang, Y.Y., Xu, Y.S., Shen, S.L., Yuan, Y. and Yin, Z.Y., (2015). Mining-induced geo-hazards with environmental protection measures in Yunnan, China: an overview. Bulletin of Engineering Geology and the Environment, 74(1), 141-150. 26 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 27
THE SOCIAL DIMENSION
function of position, privilege, and perspective. Our The Standard’s Glossary defines a ‘stakeholder’ as CHAPTER III experience of working in the area of mining and social any affected or interested party, located anywhere, performance is that there are often differences in with an interest in any aspect of tailings facility SOCIAL PERFORMANCE AND how actors understand and interpret a supposedly management. Social performance work, by contrast, ‘common’ event. Reconciling the professional and the primarily involves engaging with a local set of SAFE TAILINGS MANAGEMENT: personal, the cultural and the commercial, and the stakeholders, many of whom will be directly affected differences between local and global understandings by operational activities. These stakeholders have a A CRITICAL CONNECTION of ‘development’ and ‘disaster’ is, we would argue, the distinctly situated set of rights, interests, obligations essence of social performance work. and entitlements that cannot be de-linked from the Susan Joyce*, President, On Common Ground Consultants Inc context within which they are ascribed and exercised Deanna Kemp*, Professor and Director, Centre for Social Responsibility in Mining, Sustainable Minerals Institute, This chapter explains how and why social (Joyce 2019). University of Queensland, Australia performance work is critical to tailings facility management. It describes the logic that underpins The place-based focus of social performance the inclusion and integration of social performance differentiates this practice domain from: elements throughout the Standard, and our work to 1. INTRODUCTION: IS SOCIAL PERFORMANCE ensure that these elements were stabilised during the • public relations, which is primarily concerned with RELEVANT TO TAILINGS FACILITIES? Box 1: Global Industry Standard on Tailings Management Glossary definition of ‘catastrophic various rounds of consultation and feedback. It also protecting and enhancing a company’s reputation provides our perspective on what is needed to ensure The starkest indicator of a catastrophic tailings failure’ • government relations, which is concerned with the effective participation of social performance in the facility failure is loss of human life. There is no more maintaining a certain equilibrium with the state, and devastating outcome. If a tailings facility has a A tailings facility failure that results in material Standard’s implementation into the future. significant flow failure in a locality where people live or disruption to social, environmental and local • investor relations, which focuses on assuring work, where protections are absent, and local capacity economic systems. Such failures are a function 1.1 DEFINING SOCIAL PERFORMANCE investors that they will profit financially from their engagement with the company. to respond is low, tragedy is likely to unfold. While the of the interaction between hazard exposure, We use the term ‘social performance’ to refer to how loss and damage from a catastrophic failure can be vulnerability, and the capacity of people and a company handles its commitments, interactions While a mining company’s supply chain raises an forensically documented, quantified and classified, systems to respond. Catastrophic events and activities as they relate to local communities. The important set of social performance and human the lived experience for affected people is one of typically involve numerous adverse impacts, at practical tasks involved in this work include, amongst rights considerations, social performance in mining is trauma and distress. These considerations provided different scales and over different timeframes, other things: scoping and overseeing applied, field- largely anchored to the point of extraction. It is here the backdrop to our work as communities and social including loss of life, damage to physical based, studies and surveys; gaining access to land; that waste is generated and stored, and where tailings performance specialists on the Expert Panel for the infrastructure or natural assets, and disruption negotiating agreements, compensating for loss and facilities are located. Global Industry Standard on Tailings Management to lives, livelihoods, and social order. Operators disruption; mitigating and managing impact and (the ‘Standard’). may be affected by damage to assets, disruption benefit streams; and ensuring that project-affected to operations, financial loss, or negative impact people receive timely and accessible information and Preventing loss of life and responding to worst to reputation. Catastrophic failures exceed the that their grievances are investigated and remedied 2. WHERE DO THE ‘SOCIAL’ ELEMENTS FEATURE case scenarios involves anticipating what might capacity of affected people to cope using their where needed. Effective social performance practice IN THE STANDARD? unfold under different circumstances. This requires own resources, triggering the need for outside prioritises respect for human rights, harm avoidance Social performance spans all six Topic Areas of the an understanding of the social norms, rules and assistance in emergency response, restoration and equitable benefit sharing. protocols that would apply in the event of a failure and recovery efforts. Standard, with specialist components defined in 14 (18 per cent) of the Standard’s 77 Requirements, event. This knowledge offers the much needed insight This arena of work is often mischaracterised as with a further 18 Requirements (23 per cent of the into people’s ownership and use of land and territory, a one-dimensional activity encompassed solely Standard) requiring operators to integrate social systems of social and political organisation, livelihood by the concept of ‘community engagement’. This performance inputs into processes, systems and systems, and human exposure to credible failure and ecological significance and the associated loss characterisation misses the vital role that the social decisions about tailings facility management. modes and potential impacts. It follows, therefore, and trauma from this event was catastrophic for their performance function can play in using field-based that this knowledge must be available to developers, communities, with lasting effect. data to influence how a mining project is configured The first sub-section below describes the placement regulators and local people before a facility is built, and managed throughout its lifecycle. Community and position of the specialist, and more obvious, and before a failure occurs. Early access to data and Some dam specialists have argued that the Mount engagement remains a priority but equating social social performance components. The second sub- information may even enable decisions that entirely Polley event should not be described as catastrophic performance work with relational work ‘outside the section draws connections between these and other avoid the possibility of harm to people. because the consequences of the failure did not fence’ does not adequately describe this field of parts of the Standard. As we explain, the level of depth meet the necessary threshold in the engineering practice (Kemp 2010). Social performance work also and breadth in this Standard differentiates it from A catastrophic tailings facility failure is not solely Consequence Classification tables. In their view, involves engaging internally within companies, to other voluntary standards and schemes relating to defined by loss of life. Though lives were not lost at any application of the descriptor ‘catastrophic’ influence how mining takes place. Such work, done either tailings management or social performance. Mount Polley, traditional custodians characterised where lives were not lost serves no function other properly, involves relational, scientific, organisational the tailings facility failure at this operation as than to invoke unnecessary emotion. By contrast, and legal dimensions, with the latter anchored in catastrophic. First Nations groups have expressed, we argue that the way a tailings facility failure is instruments of international human rights law. quite publicly, that the damage to places of cultural described or classified must be understood as a
*Member of the GTR Expert Panel 28 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 29
2.1 SPECIALIST SOCIAL PERFORMANCE Monitoring of the Tailings Facility, may appear to be an 2.2 EMBEDDED INTERDISCIPLINARY Topic IV, Management and Governance requires the COMPONENTS exclusively technical section, written for engineers and CONNECTIONS establishment of a tailings governance framework and tailings facility specialists. However, while this section confirms the Environmental and Social Management Four social performance Requirements are bundled The Standard embeds social performance in ways is certainly weighted to this audience, it does not System (ESMS) as an integral component (8.2). under Topic I Affected Communities. The upfront that may not appear obvious on first pass. For exclude other disciplines, and in fact encompasses a This topic nominates one or more Accountable positioning of these components provides a strong instance, in Topic II, Integrated Knowledge Base, the range of social performance elements. For example, Executive(s) as responsible for, amongst other signal that the catastrophic failure of a tailings Standard calls for social performance knowledge to following the provision requiring the operator to matters, avoiding or minimising the consequences facility is a salient human rights issue, and requires be included in early technical decisions given that consider additional steps to minimise consequences of a tailings facility failure for local people (8.4). respect for human rights, including human rights these decisions determine, to a large extent, how (5.7), the Standard requires the operator to follow Other requirements include multi-disciplinary risk due diligence, from the very outset of a project and a facility will affect people and the environment. international standards if involuntary resettlement is assessments (10.1), and the review (10.2) and audit throughout the tailings facility lifecycle (1.1)1. Typically, this knowledge is not generated until the pursued to achieve this aim (5.8). (10.3) of the ESMS as it relates to the tailings facility. regulatory approvals or environmental permitting The Standard also requires operators to work stage, which is often not early enough to support Another important feature of the Standard is that it Accountable Executives will need to rely on social to obtain and maintain free, prior and informed key decisions about tailings facility management. includes requirements for both risk reduction and performance knowledge and expertise in order to consent from indigenous and tribal peoples, Decoupling the generation of social knowledge from consequence minimisation. Operators are required discharge their duty to minimise adverse social where circumstances warrant it (1.2). Meaningful regulatory requirements, and ‘front end loading’ that to reduce risk, which includes both probability and consequences (8.4). In the same way, the Standard engagement (1.3) is fundamental to the Standard’s process, means that mine planners and tailings facility consequences, to as low as reasonably practicable specifies that a Responsible Tailings Facility Engineer goal of achieving zero harm to people, as is the designers are better placed to minimise negative (ALARP). They are also expected to decouple (RTFE) should liaise not only with operations and requirement for an operational-level, non-judicial consequences to people and the environment from these two concepts and to think solely about the mine planners, but also with social and environmental grievance mechanism that effectively handles issues the very outset of project planning. Early access to consequences of the event, without considering teams on matters that are relevant to the tailings relating to the tailings facility and its potential failure information may even enable planners to identify the probability of that event occurring; that is, facility (8.5). This may include, for instance, being (1.4). The sharing of information to support these and sensitive or ‘no go’ areas, potentially saving time, to take additional reasonable steps to minimise involved in processes of stakeholder engagement other local-level processes is explicitly required. resources and unnecessary conflict down the track. consequences to people and the environment. This, and information sharing, responding to grievances in effect, reinforces the requirement to reduce risk to or concerns about the facility, or changes in Social performance components also feature To provide a specific example: under Topic II, ALARP, but compels Operators to consider impacts to downstream land use about which the RTFE may not prominently in Topic II, Integrated Knowledge Base. Knowledge Base, the multi-criteria alternatives people and the environment as a priority. be immediately aware. These changes could include, Under this topic, social, environmental, and local analysis (3.2) should be iterative and apply diverse for instance, an increase or decrease in human economic considerations are packaged together, criteria for the selection of sites, technologies and Topic V, Emergency Preparedness and Recovery settlements, the influx of artisanal miners into areas given the often inextricable link between these management strategies (e.g. upstream, downstream, is critically important from a social performance identified in the dam breach analysis as potentially aspects at the operational level. The Standard centre line, in-pit and so forth). Having robust and perspective. Requirement 13.1 anticipates impacted, or damage to downstream engineering requires that knowledge is developed from the relevant information available means that social meaningful engagement with employees and measures through community activity. In this way, the outset of project planning, and that operators build performance can contribute to deliberations and contractors in the development of Emergency social performance footprint extends well beyond the an understanding of the context within which a actively influence outcomes. Successive reviews of Preparedness and Response Plans, and ‘locks more ‘obvious’ elements of the Standard. tailings facility exists or may exist in the future (2.1). alternatives will flag the need for more granular or in’ the role of project-affected people in the co- This must include knowledge of downstream areas. different data and information, with each stage of the development of community-focused emergency Public accountability for tailings facilities must Similarly, the knowledge base provisions include a analysis building on new inputs. Through this iterative preparedness measures. Requirements 14.1 to respond to a set of discernible local-level concerns requirement to understand human exposure and process, in conjunction with other disciplines, social 14.5 cover the long-term recovery of people and for public health and safety. While the documents vulnerability in the event of a credible flow failure (2.4). performance inputs can be scaled up as options are the environment in the event of a catastrophic listed under Topic VI, Public Disclosure and narrowed down. failure event – a topic that is not covered in any Access to Information will likely be in the hands Operators are also required to conduct impact other tailings or social performance standard. of other functions, such as external affairs assessments and develop mitigation plans where Throughout the Standard, social performance is and legal, many of these concerns fall within material adverse impacts are anticipated (3.3). These positioned as integral to tailings facility management. Requirement 14.1 asks operators to take reasonable the purview of social performance. Regularly assessments are to be updated, both periodically This includes a series of requirements under Topic steps, before a failure event, to meaningfully engage publishing and updating information (15.1) and and when there is a material (adj.) change to the III, Design, Construction, Operation and Monitoring with public sector agencies and other organisations responding to reasonable requests for additional tailings facility or the social, environmental and local of the Tailings Facility. For instance, numerous that would participate in medium- and long-term information (15.2) is fundamental to meaningful economic context (3.4). Such changes may include, social performance aspects from Topic II, Integrated social and environmental post-failure response engagement at the local-level, and for generating for instance: the closure or commencement of Knowledge Base, would be used to inform the strategies. These agencies are likely to be quite trust across the stakeholder spectrum. another major project; a radical change in land use Consequence Classification. Topic III also includes different to the first responder groups engaged for (e.g. from farming to an urban settlement); water or requirements to use social management (6.1) and Requirement 13.1. Requirements 14.2 to 14.5 apply 2.3 GAPS AND OMISSIONS food shortages following a major climatic event (e.g. social monitoring (7.1) systems in the management after a catastrophic failure and would involve post hoc drought or flood); increased in or out-migration; or a of a tailings facility, as appropriate to the data and The Standard sets a new benchmark for integrating impact assessments, and stakeholder engagement major conflict or security event. information that becomes available. The Expert social performance considerations into a deeply to develop and implement plans that enable the Panel carefully built these types of evidence-based technical area. Nonetheless, there are some aspects participation of affected people in restoration and Topic III, Design, Construction, Operation and interconnections throughout the Standard, as an that were not fully resolved by the Expert Panel and recovery works and ongoing monitoring activities. underlying logic. at this point are not integrated into the Standard. For instance, the Standard does not confirm the rights of 1. Numbers in parentheses refer to the relevant requirement of the Standard. 30 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 31
project-affected people to participate in tailings-related 3. WHAT IS DIFFERENT ABOUT THIS STANDARD? Table 1. Voluntary standards: social performance strengths and opportunities to strengthen decisions that affect their lives. This language sat In its initial phase of work, the Expert Panel was uncomfortably with some tailings facility specialists, tasked with reviewing international standards and Social performance reflecting the gap that still exists in understanding Standard Scope Opportunities to strengthen guidelines about tailings facilities to understand strengths how social performance work supports rather than coverage of our respective disciplinary areas. We were undermines technical decision-making. The essence Tailings Tailings-specific standard. Requirements to No requirement to respect also tasked with reviewing standards and guidelines of the concept (i.e. ‘participation’) is addressed, such Management Facility focused. Supported by understand community human rights with reference to within our own areas of specialisation for coverage as through the glossary definition for ‘meaningful Protocol, as part the Guide to the Management of expectations about the UNGP. No requirement for of tailings facilities. This process of review continued engagement’. In our view, this need not have been of MAC’s Towards Tailings Facilities, and the guide tailings facility participation of project-affected throughout the Standard drafting process. While there a contested term, and will be one of a number of Sustainable Mining to Developing and Operation, management through people in decisions about are many voluntary standards and schemes in active concepts that is likely to become part of the Standard (TSM) scheme. Maintenance, and Surveillance local-level engagement. public safety. No coverage use, we focused on those in which a connection was as it evolves. Manual for Tailings and Water Requires community of long-term recovery after a expected or was identified. These are listed in Table 1. Management Facilities. engagement in failure. No requirements for It is also the case that we were not always familiar, emergency planning. public disclosure. The best example of a voluntary standard that is or comfortable, with the terminology and concepts beginning to forge some connections between tailings Position Statement Tailings-specific position Nil. No coverage. Excludes used in other disciplinary areas, and other disciplines facility management and social performance can be Tailings Governance statement. ICMM Principle 9 on Social adjusted some of their language to account for found in the Tailings Management Protocol and the Framework, ICMM. Performance. our preferences and understandings. For instance, Indigenous and Community Relationships Protocol for the use of ‘material’ in a sustainability reporting Standard for Comprehensive sustainability Focus on preventing Few explicit cross references the Mining Association of Canada’s (MAC’s) Towards sense is well established, whereas to engineers, Responsible standard with a waste-specific harm to people and the between social performance Sustainable Mining scheme. Both of these protocols ‘material’ is a physical substance or object. Finding Mining, Initiative for chapter and social performance environment. Disciplinary and tailings facilities. No were updated following the Mount Polley failure. Key agreement on these terms was often difficult. In Responsible Mining chapters. Applies site-wide. depth within chapters. coverage of long-term aspects of social performance are addressed in the our view, deep and sustained engagement between Assurance. recovery after a failure or tailings-specific protocol, with some cross reference experts from different disciplines would help to build public disclosure in the Waste to the community-specific protocol. That said, social mutual understanding in other similarly complex and and Materials Management performance is not integrated to the degree that contested topic areas. The imperative created by the Chapter. No coverage of waste has been achieved in the Standard. In regard to the Standard to move beyond comfortable disciplinary or tailings in the Human Rights numerous other sustainability standards that we ‘streams’, and engage in interdisciplinary work is a Chapter. reviewed, but that are not in the table, our principal significant undertaking, with potential upsides for observation is that the connections between the International Comprehensive social and Focus on minimising No substantive cross- people and the environment and ultimately mining technical aspects of tailings facility management and Finance environmental performance risk to people and the references between social companies themselves. social performance are absent. Corporation’s (IFC) standards. Applies project-wide. environment. Disciplinary performance and tailings Environmental and depth and systems facilities. Acknowledging the challenges, our priority in this In this sense, we confirm that, from a social Social Performance focus. process has been to put forward a workable and performance perspective, the ‘step change’ in the Standards, IFC. technically accurate Standard that included critical Global Industry Standard on Tailings Management is social performance components that were well TSM Indigenous Applies site-wide. Broad Disciplinary depth. Use of tag clause: ‘…including that it connects leading practice social performance integrated with the technical aspects of the standard. and Community focus on building local-level Includes a list of tailings- those associated with tailings to the topic at hand and demonstrates the criticality While we certainly support the version of the Standard Relationships relationships, and managing related issues that may management (as applicable)’, of integrating social performance into this high-stakes that has been endorsed by the co-conveners, we are Protocol, Mining impacts and benefits throughout be of interest to people but few substantive points of field of practice. There is no equivalent standard in also of the view that it should not be regarded as Association Canada the mine lifecycle. at the local-level. connection back to the Tailings this respect. an immutable document, but rather, as the basis for (MAC). Management Protocol. interdisciplinary discussion that will continue to evolve The International Broad focus on building Disciplinary depth. Across the ICMM’s full suite over time. Council on Mining local-level relationships, and Reference to a range of ‘social performance’ and Metals’ social managing impacts and benefits of leading practice documents, few explicit performance- throughout the mine lifecycle. standards. connections are made between related principles, social performance and tailings performance facilities. standards, guidance materials and tools. Key messages
32 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 33 1. Mining companies should avoid equating the social performance function solely with community engagement, and work to strengthen the scientific, organisational and legal dimensions of this function.
2. Senior management should ‘hard-wire’ social performance into operational management practices to maximise the value of the function. 4. WHAT WAS INVOLVED IN INTEGRATING SOCIAL work to estimate life and loss in the external context. specialists will remain unconvinced that social for peer-learning, and career development, remain PERFORMANCE INTO THE STANDARD? Instead, they should expect to work in an environment performance knowledge is relevant to the prevention relatively limited. 3. Companies should review whether operational-level social performance functions are where social performance knowledge and expertise is of catastrophic failure and the safe management of We use the analogy of a ‘push-pull’ dynamic to ‘fit-for-purpose’ (i.e. appropriate to both the tailings facility and the local context) and available to them when they, and others, need it. tailings facilities. Thus, despite what the Standard The field of social performance has many points of describe our efforts at integrating social performance adequately resourced. requires on paper, it is possible that critical data entry. Anecdotal evidence suggests that practitioners into the Standard. A ‘push’ dynamic occurs Social performance specialists should likewise expect about the social and local economic context will not have a diversity of qualifications and experience, when a producer or supplier works to convince a that they will have access to the resources they need be documented, and that information about social which can range from geology to environment, and consumer to use their product or service. A ‘pull’ 4. A high- level of interdisciplinary effort is required to support the safe management of to commission and conduct the necessary studies change over time will become de-linked from tailings from health services to security and policing. Some dynamic occurs once a consumer is convinced and tailings. and build accurate and accessible information. It facility management. Our aim has been to bring social will have knowledge gaps in the technical aspects of begins to request that service because they see is sometimes the case that financial and human performance to the forefront of the conversation mining, whereas others will have gaps in technical inherent value in it. In this section, we take social resources are available, but that the lead time for about the safe management of tailings facilities, and aspects of social performance. Locally hired performance as an available service, and tailings 5. Managers at all levels of a mining company should maintain a willingness to engage in conducting studies is inadequate. Studies conducted to make the connection between social performance practitioners may have deep knowledge of the facility engineers, specialists and other accountable and promote cross-disciplinary conversations on specialist topics such as tailings facility in remote areas with difficult transportation routes, and technical aspects as explicit as possible. In doing context, but no formal training in either mining or persons as potential consumers of that expertise management, and actively support inter-disciplinary work. across language groups, and in situations where so, we seek to extend what is currently understood to social performance. Yet, there are few structured and knowledge. We sought to create an inherent ‘pull’ consent is required to proceed with data collection, be ‘best practice’ in this arena. professional development pathways that enable social for social performance, to avoid social performance need to be scheduled and planned to ensure that performance practitioners to address competency practitioners having to routinely justify their role at the adequate time is allowed, with in-built flexibility and gaps.2 At the time of writing, several university-based operational level. contingencies. postgraduate programs had been disbanded due to 5. DOES THE SOCIAL PERFORMANCE FUNCTION low enrolments. Short courses and specialised The inclusion of social performance aspects in the NEED TO BE STRENGTHENED? All these factors need to be considered in making this forums are available but tend not to form part of a Standard was logical for some stakeholders, and knowledge available for the purposes of supporting If the Standard is immediately taken up, there will professional or formal qualification. The social the composition of the Expert Panel suggests that safe tailings facility management. The outcome likely be a shortage of qualified and experienced aspects of mining have gained increased visibility at its inclusion was part of the ambition from the very required by the Standard will not be achieved if the professionals to meet demand. This problem industry conferences; however, the emphasis tends outset of the GTR. Nonetheless, we encountered social performance function is unable to furnish exists across multiple disciplines, including in mine towards showcasing company activities and strongly held arguments from some of those who engineers and other specialists with quality data, engineering and other specialist areas. In some achievements, rather than reflecting the needs of the made public submissions, some members of the information and analysis. The Standard seeks to companies, work will be required to build both cohort for professionalisation. advisory group, and others from within industry, address this by ‘front-end loading’ the study process social performance competency and organisational that social performance should be removed from by insisting that social performance knowledge is built functionality to support the Standard. In this section, While there is a need to strengthen the competency the Standard or relegated to guidance material. The from the outset of project planning (alongside other we consider some of the challenges that need to be of social performance practitioners, there is a parallel reason given for excising social performance from types of knowledge), and pulled into the decision- overcome for social performance to contribute to the need to strengthen competencies in other disciplines. the Standard was that it diverted attention away from making process, as needed, throughout the tailings ongoing success of the Standard. Practitioners and leaders from other disciplines the physical integrity of tailings facility and detracted facility lifecycle. that are active in the company-community interface from the important task of preventing catastrophic 5.1 CHALLENGES AT THE PROFESSIONAL should understand how social performance relates failures. Our argument that context is crucial to Leading companies already require the early LEVEL to their work. For instance, tailings facility specialists preventing catastrophic outcomes and minimising development of a robust knowledge base to use in would ideally understand what is involved in a social consequences was not accepted by all. As a result, we Social performance emerged as a specialized field their engagement processes, studies, and planning baseline, an impact assessment and a human rights found ourselves working to make the case that social in mining more than 20 years ago. Initially referred and management processes. One area where even due diligence process, and in turn what they might performance is critical to preventing catastrophic to as ‘community relations’ (Zandvliet and Anderson leading companies may not have ventured is in utilise as outputs from these processes. Where failures. 2009; Kemp and Owen 2013), the field has developed re-thinking the composition of Independent Tailings social performance competency is built across an in response to evolving stakeholder expectations Review Boards (ITRBs). Most ITRBs are comprised of organisation it can harness collective capability Take the example of the process of determining the and international standards. Leading companies engineers and other technical specialists as needed to meaningfully engage project-affected people, consequence classification for a facility. Ideally, when have progressively incorporated these standards for specific site conditions. With the Standard’s focus communicate about risks and consequences, dam designers classify a facility, they call upon social into their corporate policy frameworks. Most social on the context in which a facility is located, we would avoid or mitigate impacts, and contribute to safe performance knowledge and expertise in determining performance practitioners are site-based, reflecting expect that the ITRB will, from time to time, include tailings facility management over the long term. potential loss of life and other consequences across the grounded and characteristically place-based social performance in their review processes. This Interdisciplinary work involves both deep disciplinary health, social, cultural, infrastructure and economic nature of the work. This means, however, that may involve, for instance, a review of the operator’s expertise, and a structured approach to working categories in their tables. Engineers should expect these practitioners tend to have relatively limited assessment of human exposure and vulnerability to across disciplines on cross-cutting issues. that information about human exposure is available opportunities to interface with the global initiatives confirm that it interfaces adequately with the dam and accurate, and that expertise is on hand to assist that are defining best practice in their field. The nature breach analysis. As an important line of defence, the 5.2 STRUCTURAL AND SYSTEMIC ISSUES with deliberations about the classification, should of the work also means that specialists spend much ITRB should be ‘pulling’ social performance into the this be necessary. They should also expect that the of their time engaging externally and can become Researchers have raised issues about how companies review processes whenever circumstances warrant. information is appropriate to the site and the context disconnected from the business. Opportunities are configuring their social performance functions and in which they are operating, recognising that in some In practice, the push-pull dynamic that we describe cases, significant effort will be required to collect and here is fluid and can range from open collaboration collate that information. Engineers should not assume 2. While there have been various attempts to do so, social performance to a more reluctant, even combative, type of competencies have not been systematically defined at an industry level – that they have this knowledge, or just rely on guess- engagement. There is a risk that some technical either for social performance generalists or those who may be working in a sub-field such as indigenous relations or resettlement. 34 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 35
whether they are ‘fit-for-purpose’ (Owen and Kemp 6. CONCLUSION: WHAT LIES AHEAD FOR SOCIAL 2017). It is common, for instance, for projects that PERFORMANCE IN THIS ARENA? KEY MESSAGES involve resettlement, or mining on indigenous peoples’ The Standard is a next generation regulatory lands, to have limited access to specialist expertise. framework, in which social performance is integrated, Where expertise is procured from other sectors, not separated, from consequential decisions at specialists are not always ‘on-boarded’ in terms of 1. Mining companies should avoid equating the social performance function the operational level. Social performance is not understanding the technical aspects of mining, such symbolically positioned alongside the technical solely with community engagement, and work to strengthen the scientific, as the design and operation of tailings facilities. It is aspects of tailings management, but rather, organisational and legal dimensions of this function. essential that social performance expertise is geared positioned to influence outcomes. If the Standard to the mining project, and the context in which it is is broadly adopted, effort will be needed to increase situated. This same logic applies to tailings facilities. 2. Senior management should ‘hard-wire’ social performance into operational industry capacity in social performance. Industry Expertise must be geared towards the facility, the capacity is currently low, and specialist knowledge management practices to maximise the value of the function. local operating context and the expectations of and expertise are not widely available. Moreover, the affected and interested stakeholders. position of the social performance function within 3. Companies should review whether operational-level social performance corporate hierarchies may not be aligned to the task. Another consideration is alignment with the Appropriate organisational structures, disciplinary functions are ‘fit-for-purpose’ (i.e. appropriate to both the tailings facility Standard’s goal of zero harm to people. Global mining diversity and an inclusive approach to managing risk companies are readily prioritising strategies aimed and the local context) and adequately resourced. to people and the environment are keys to ‘moving at enhancing their reputation and demonstrating the needle’ to a level that satisfies stakeholder ‘benefit’. However, a predominant focus on building 4. A high-level of interdisciplinary effort is required to support the safe expectations in this arena. up reputation can inadvertently skew an operator’s management of tailings. focus towards appearance, rather than performance. The challenging process of getting to an agreed The Standard has a clear focus on risks to people, standard reflects the tensions present across the rather than risk to the operator’s reputation. Consider 5. Managers at all levels of a mining company should maintain a willingness industry between disciplines, and with different a mine with a tailings facility in a context where stakeholder groups. There have been constructive to engage in and promote cross-disciplinary conversations on specialist an urban majority realises benefits through direct conversations during the Global Tailings Review employment, business opportunities, and community topics such as tailings facility management, and actively support inter- and some progress made towards building investment, while downstream settlements carry the mutual understanding. We hope that the current disciplinary work. burden of risk in terms of the potential consequences appetite for difficult conversations continues into of failure. The Standard aims to avoid this scenario by the future. Tailings facilities require precision in requiring operators to focus on both probability and design, construction and management. As complex consequences. An enhanced corporate reputation engineered structures, they must apply robust design may be the outcome of such measures, but it should criteria to maintain physical integrity throughout their not be the driver. lifecycle. At the same time, there is a recognition that both engineered structures and human systems are Finally, we observe that the social performance fallible. The Standard supports industry efforts to function is at a disadvantage in terms of its position move beyond purely technical solutions to bolster in most corporate hierarchies. Over the past few safeguards, enhance public accountability, and years, many of the largest mining companies have position the goal of zero harm to people and the brought their social performance functions under environment, with zero tolerance for human fatality as communications or external affairs, and many are a clear priority. now represented at the executive and board level under this banner. We see the function being re- orientated towards reputation-enhancing initiatives that have little bearing on how a mining complex is designed or configured, including how waste is managed and how tailings facilities are designed and operated. The priority should be on installing a social performance function with the resources and influence it needs to operate effectively. As we have outlined, this should involve the social performance function being ‘pulled’ into decisions on the basis that interdisciplinary work is critical to preventing catastrophic failure, rather than the function having to ‘push’ its way into conversations in order to contribute to operational decisions. 36 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 37
THE SOCIAL DIMENSION
REFERENCES Joyce, S. (2019). Challenges and strategies for meaningful rights-holder participation in company- CHAPTER IV commissioned HRIA. In Götzmann, N. (ed.) (2019), Handbook on Human Rights Impact Assessment. Edward Elgar: Cheltenham, UK. LESSONS FOR MINING
Kemp, D. (2010). Community relations in the global mining industry: exploring the internal dimensions of FROM INTERNATIONAL externally orientated work. Corporate Social Responsibility and Environmental Management, 17 (1), 1-14. DISASTER RESEARCH
Owen, J.R. and Kemp, D. (2017). Extractive Relations: Countervailing Power and the Global Mining Industry. Deanna Kemp*, Professor and Director, Centre for Social Responsibility in Mining, Sustainable Minerals Institute, Greenleaf Publishing/Routledge: Sheffield, UK. University of Queensland, Australia Zandvliet, L. and Anderson, M. (2009). Getting It Right: Making Corporate-Community Relations Work. Routledge: Oxfordshire.
1. INTRODUCTION partial explanation. The approach pivots away from conceptualising disaster as a spatially and time- When there is a major industrial disaster, there are bound event, and towards seeing the broader context a number of common reactions. People express as a potential cause of the disaster, and not simply shock or anger, empathise with victims, and applaud as the backdrop against which disaster plays out. Re- rescue efforts. Losses and damages are calculated, framing disasters in this way has important practical and forensic investigations ensue. Many people implications, as it significantly broadens the focus of will ask how the disaster happened. However, while efforts to prevent catastrophic outcomes in the future. legal charges may be laid against individuals and organisations, and moral disapproval expressed In this chapter I draw on this body of work to towards those seen as responsible for the disaster, demonstrate the value of viewing tailings disasters rarely do we insist that investigators look beyond as resulting from a set of factors and forces that immediate events and probe for deeper underlying produce conditions of vulnerability that create or causes. In the aftermath of a disaster – and before contribute to disasters, rather than a disaster being public interest wanes – popular media tends to centre attributable solely to the hazard; or in the case of a on the drama, the tragedy, and the crimes of those tailings facility, the failure of an engineered structure. who failed to fulfil their corporate responsibilities. I also examine the challenges associated with mobilising forensic, broad-based research to conduct This sequence mirrors what has occurred after this form of analysis, and explore the implications for devastating failures of mine tailings facilities. Most the global mining industry of viewing disasters from recently, the world expressed shock at the torrent a perspective that includes people’s vulnerability as a of sludge that wiped out villages and ecosystems causal factor. in Brazil, watched in horror as the death count of employees and community members rose, and The first part of the chapter defines ‘disaster’ and empathised with the families whose lives and ‘disaster risk’, and then reviews developments in livelihoods were shattered. Forensic studies of the international disaster research and practice. I then tailings facilities were commissioned, examining briefly elaborate five principles that define this their design, integrity and stability. The decisions contemporary approach to understanding and that immediately preceded the failures and the explaining disasters. In the concluding section I reflect sudden release of slurry were also scrutinised and on the benefits of taking a broad-based approach flaws exposed. As prosecutors identified who was to analysing disaster risk in mining and discuss the responsible, fines were issued, damages paid, and challenges associated with changing how the industry charges instituted against corporate executives. views – and therefore seeks to explain – the causes of a tailings disaster. There is a growing movement in contemporary disaster research that asks not only why a particular A key aim of the chapter is to demonstrate that event occurred, but why it resulted in disaster. This social, cultural, political and historical factors must approach pushes towards a deeply structural and be considered if the goals of the Global Industry systemic analysis on the basis that conventional Standard on Tailings Management (the ‘Standard’) investigations of catastrophic events provide only a are to be realised. Deeply technical knowledge from
*Member of the GTR Expert Panel 38 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 39
the physical sciences is crucial to the safe design, disasters are, in fact, created and are not at all a 3.1 DISASTER EVENTS AS CONDITIONED BY construction, management, and closure of tailings Box 1: The Components of Disaster Risk natural outcome. This way of thinking about disaster SOCIAL PROCESSES facilities. However, while such knowledge is essential, is encapsulated in the Sendai Framework for Disaster According to Oliver-Smith and Hoffman (2002), it is not sufficient for understanding and addressing The foundational definition of ‘disaster risk’ is Risk Reduction (2015–2030), which was adopted by disasters do not just happen. Rather, they occur the myriad underlying causes that give rise to tailings DR = H x V. This formulation (Blaikie et al. 1994) member states in early 2015 at the World Conference through the interaction of two factors: the presence facility disasters. The Standard has succeeded in represents disaster risk (DR) as a function of on Disaster Risk Reduction held in Sendai, Japan and of a human population and a potentially destructive positioning other, non-technical considerations as hazard exposure (H) and people’s vulnerability to endorsed by the UN General Assembly later that same agent. Both of these elements, and the relationship relevant to risk reduction (e.g. local-level engagement, hazard (V). Later versions (Wisner et al., 2003), year.4 The first goal of the framework is to ensure that between them, are in turn embedded in broader organisational management systems and internal include other elements, such as people’s capacity disaster risk reduction policy and practice is based on natural, economic and social processes. Oliver- culture), but further shifts in the mining industry’s to cope (C), which is linked to the concept of understanding of people’s vulnerability to hazards, and Smith and Hoffman (2002) approach disasters as approach will be required to achieve the ultimate goal ‘disaster resilience’. how that vulnerability comes about. The framework processes that reach backwards in time and space, of preventing catastrophic tailings facilities failures. also recognises the constructive role that the private and that are linked to issues that exist beyond the site, DR = ______H X V sector can play in this arena. and beyond the decisions and actions of those who C were implicated in immediate events. They note that The Sendai Framework applies to a full range of 2. DEFINITION AND KEY INTERNATIONAL the roots of disasters also track forward in time, to disaster risks, including small and large-scale INSTRUMENTS impact on future loss of assets and income; political disasters, frequent and infrequent events, rapid and are major long-term consequences for people and the mobilisation (e.g. growth of opposition to large- The outcomes associated with recent tailings dam slow-onset disasters, as well as tectonic, climatic, environment. It is these ‘disastrous’ failures that have scale mining); and the time it takes for social and failures are commonly described as ‘catastrophic’. technological, engineered, chemical, and biological garnered public attention and provided the impetus environmental systems to recover from disaster. This term features prominently on the Global Tailings hazards and risks. In effect, the framework recognises for commissioning a global review of the industry’s Review (GTR) website. The ICMM likewise states that smaller, isolated and remote mining communities approach to managing tailings facilities. From this perspective, tailings dam failures become that it is committed to achieving ‘the safe and secure can be devastated by a tailings facility failure and, in disasters when people are directly harmed by a failure management of tailings facilities that prevents effect, experience a ‘disaster’. As the UNDRR definition indicates, contemporary (e.g. through loss of life or shelter, serious damage catastrophic failures’ (emphasis added). disaster studies are mainly concerned with hazards to property) and/or there are significant impacts The Sendai Framework also recognises that disasters and hazardous events that cause, or have the on places to which people have attached value, In common parlance, ‘disaster’ and ‘catastrophe’ are not limited to sudden events, and can involve, for potential to cause, significant harm and disruption to significance or meaning. These can include places of are often used interchangeably, although they instance, chronic impacts – such as the long-term people, either directly or indirectly.3 In a similar vein, economic, ecological, cultural and spiritual meaning have different etymological roots, with the term health effects of tailings dust or water contamination. Oliver-Smith and Hoffman (2002, p.4), in the opening and value. This perspective positions tailings disasters catastrophe tending to signal a more far reaching, or By contrast, the mining industry’s current focus is on chapter to their volume Catastrophe and Culture, as imbued in a history and politics, and embedded in permanent, disruption.1 In this chapter I have opted tailings facility failures that take the form of sudden define disaster as: a range of issues that exist beyond the time and place to use ‘disaster’ as the key term, largely because it is and acute events, rather than other types of failures that the disaster occurred. grounded in an established literature, utilised by global that have slow-moving and chronic impacts. The A process/event combining a potentially destructive bodies, and embedded in international instruments of Sendai Framework also recognises that industrial agent/force from the natural, modified or built Contemporary scholars argue that, while disasters policy and practice. disasters can arise from compound interactions, environment, and a population in a socially and may be triggered by natural phenomena (e.g. such as those associated with climate change. For a economically produced condition of vulnerability, earthquakes, cyclones), the impact of these The United Nations Office of Disaster Risk Reduction tailings facility, this includes the compounding effects resulting in a disruption of the customary relative hazardous events is a function of socially constructed (UNDRR), defines a disaster as: of extreme weather events, both in contributing satisfactions of individual and social needs for physical conditions (Santos and Milanez 2017). For example, to the failure of facilities and in exacerbating the survival, social order and meaning. whether or not people living downstream from A serious disruption of the functioning of a community consequences of these failures. a tailings facility have escape routes, access to or a society at any scale due to hazardous events From this perspective, disasters are defined not only transport, or dwellings that can withstand an interacting with conditions of exposure, vulnerability by hazards that carry the potential for loss of life, inundation from a flow failure is mainly determined by and capacity, leading to one or more of the following: injury or damage, but also by those processes that 3. FIVE PRINCIPLES OF CONTEMPORARY the societal context, including economic and political human, material, economic and environmental losses set hazards in motion, exposing them to people and DISASTER RESEARCH processes at different scales. Likewise, these same and impacts.2 places. processes determine where people live and work, their This section elaborates on five principles that access to information, and their level of protection and According to this definition, a cyclone that remains characterise contemporary developments in Since the 1990s, the United Nations (UN) has preparedness, and therefore who is most vulnerable to off-shore in an unpopulated area is not a disaster; it international disaster research. For each principle, been working to change the prevailing paradigm or ‘at risk’ from a tailings facility failure. only warrants this label once it makes landfall and I note the relevance to tailings facilities, and potential of disaster research by challenging the notion of a causes widespread damage. If we apply the same implications for the mining industry. ‘natural disaster’. A new way of conceiving of disaster Most research about tailings facility failures focuses approach to the mining industry, structural failures to and disaster risk is now embedded in international on the engineered structure and the properties tailings facilities become disasters when there instruments of the UN. This perspective holds that
1. In engineering, the term ‘catastrophic failure’ is often used to describe ‘a rapid and irreversible structural failure’. This is a narrower formulation that 3. This is not to discount the significance of impacts on other types of characterises the failure event itself, rather than its consequences. populations (e.g. the widespread loss of wildlife as a result of a massive 2. See: UNDRR’s knowledge platform for disaster risk reduction, wildfire) but that is not the primary focus of disaster studies, or of this 4. The Sendai Framework follows the Hyogo Framework, which was the PreventionWeb. https://www.preventionweb.net/terminology/view/475 chapter. global blueprint for disaster risk reduction efforts between 2005 and 2015. 40 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 41
of the materials stored in it, and why the facility vulnerability and people’s capability to cope under understanding the root causes of disaster, but rather, introduce the PAR model here not as a replacement failed to contain water and waste. More recently, adverse conditions is socially produced, it is also the a model for analysing how people become vulnerable for studies of the engineered structure, or studies some research has focused on how organisational case that disaster risk is unevenly distributed across to a hazard. This model helps to bring into frame other of organisational factors, but as a complement that factors contributed to failure, with several studies the social spectrum. It is important to recognise, root causes of disaster, aside from the precursors and might help to build a more complete picture of why a concluding that organisational structure and culture however, that vulnerability to a hazard is not solely factors driving and mobilising the hazardous event. I tailings disaster unfolded. had a significant role to play. However, contemporary defined by poverty and disadvantage. Even though disaster research would go further than this and also disasters so often affect this demographic, people can examine the ways in a broader set of off-site and be vulnerable to a hazard in many different ways, and The progression of vulnerability supra-organisational factors interacted to produce for different reasons, not just because they are poor. the conditions of disaster. This approach does not deny the significance of the hazard, the engineering or In applying the notion of vulnerability to disaster 1. Root Causes 2. Dynamic Pressures 3. Unsafe Conditions Disaster Hazards organisational factors of a facility failure, but reminds studies, Wisner et al. (2003) include a temporal Limited Lack of: Fragile physical • Tectonic us that engineered structures and organisations are dimension whereby vulnerability is measured in access to: • Local institutions environment: created by people whose decisions and actions are terms of loss and damage to past, present and future • Climatic • Power • Skills and training • Dangerous • Technological shaped and constrained by the context in which they livelihoods. Vulnerable individuals and groups are • Structures • Local investment location • Engineered operate. This broader context includes processes those who would find it hardest to reconstruct their • Resources • Local markets • Unprotected • Chemical • Press freedom buildings and • Biological of governance, law, regulation, policy, enforcement, lives and livelihoods, and to recover in the aftermath Ideologies: • Ethical standards in infrastructure cultural attitudes towards risk, and a range of micro of a disaster. The same factors in turn make them • Political systems public life and macro power structures. more vulnerable to the effects of subsequent or • Economic Fragile local RISK compound hazards. The word ‘livelihood’ is important systems Macro-forces: economy: • Rapid population • Livelihoods at risk Hazard x Focusing on the broader context of a disaster in this definition, with Wisner et al. referring to the growth • Low income Vulnerability highlights that: (i) social and political systems command that an individual, family or social group • Rapid urbanisation create hazards and the entities that manage them, has over their income and the bundles of resources • Arms expenditure Social vulnerability: and (ii) these systems place different people at that they can use or exchange to satisfy their needs. • Debt repayment • Groups at risk schedules • Lack of local different levels of risk from the same hazard. These resources may include information, knowledge, • Deforestation institutions The risk status of different groups of people, and social networks, and legal rights, as well as land • Decline in soil their experience of a hazard or a disaster event, is and other tangible and intangible assets. For these productivity Public actions: differentiated on the basis of social attributes such reasons, understanding livelihoods is critical to • Lack of preparedness as wealth, class, race, ethnicity, language, gender, understanding vulnerability. • Endemic disease age, education, health, and immigration or citizen status. Contemporary disaster research demands Most contemporary disaster research now defines that developers, states and other ‘producers’ of disaster risk in terms of hazard and vulnerability. hazard examine these factors and understand how These factors are considered to be interdependent Figure 1. The Pressure and Release (PAR) Model. Adapted from Wisner et al. (2003). they contribute to disaster risk and occurrence. in the sense that exposure to a hazard reflects how social relations of production unfold in territory In short, disasters, should always be seen as a and geography, including within and across mining The PAR model represents disaster risk as the assumptions, ideology, and established knowledge reflection of existing social and political processes, landscapes. In short, vulnerability to disaster is interaction of ‘hazard’ and ‘vulnerability’, with disaster systems that they have become ‘invisible’ or ‘taken rather than as exceptional events that sit outside what characterised by a range of social, economic, being the ‘crunch point’ between these two sides of for granted’. These underlying causes are usually a society may consider to be ‘normal’. political and cultural conditions that increase the equation. The model is weighted to the left, as it is connected to the function (or dysfunction) of the state people’s propensity to experience loss and harm. It designed to promote an examination of vulnerability at and other economic and political systems that reflect 3.2 VULNERABILITY AS A POWERFUL is increasingly common for people’s capabilities to different depths and scales. This model was originally the exercise and distribution of power. EXPLANATORY VARIABLE be factored into the equation; that is, their ability to designed to examine vulnerability in the face of natural manage a hazard and cope under adverse conditions. Contemporary disaster research positions the hazards. Nonetheless, in evaluating the disaster risk of The second link in the chain of causality are ‘dynamic This reflects an increasing focus on ‘resilience’ and vulnerability of people as a key determinant a tailings facility, the model helps to identify the links pressures’, which serve to translate or ‘channel’ represents a distinct point of convergence between of whether an event becomes a disaster. The between the impact of a failure, and those processes generalised root causes into specific ‘unsafe human development and disaster research. commonplace meaning of vulnerability is the that generate conditions of vulnerability. conditions’. These dynamic pressures can include, propensity or predisposition of an individual or group for example, migration or patterns of production and 3.3 THE PRESSURE AND RELEASE MODEL of people to suffer damage and loss, including loss The PAR model traces the connections that link consumption. Dynamic pressures are not always of life, livelihood and property or other assets. For the The search for deeper explanations as to why a disaster with a series of social processes that negative, but in certain circumstances will manifest purposes of disaster research, vulnerability refers to disasters unfold has led to the development of models produce vulnerability. This series starts with deeply as ‘unsafe conditions’. These conditions may include those social characteristics and conditions that place based on analysing people’s vulnerability in specific structural, generalised and often distant ‘root causes’. people having to live or work in hazardous locations, people at risk in terms of their ability to anticipate, hazardous situations. The Pressure and Release These causes are ‘distant’ from the disaster in one or survive through dangerous or precarious work. The respond to, and recover from a hazard event (Oliver- (PAR) Model (Wisner et al. 2003) is useful in this or more ways: spatially (arising in a distant centre ‘crunch point’ – the disaster – comes when those Smith et al. 2016). As argued above, insofar as regard (Fig. 1). The PAR is not a complete model for of economic or political power); temporally (based conditions combine with a hazardous event in a in the past); or by being so bound up with cultural specific time and place. 42 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 43
3.4 CONTEXT AS POTENTIALLY CAUSAL TO understand the engineering aspects of a top event, of those losses. This may include, for example, and synthesises different types of knowledge. DISASTER focusing only on this aspect can create blind spots in identifying that a loss of housing structures is due to Oliver-Smith et al. (2016) describe this process as other areas. poor building standards, or that loss of agricultural broadening the ‘circle of knowledge’. They also note Despite the utility and availability of the PAR and products is due to planting in the flood zone. However, that an absence of collaboration between natural, other similar models, the dominant initial response The root causes of vulnerability, and therefore to prevent a disaster, strategies must go further than physical and social scientists has been a hindrance following tailings-related disasters has been to disaster, will always be entangled with underlying calculating loss and damage and attributing impact to mainstreaming a more integrated approach to commission studies to identify why the facility failed, problems that are embedded in a society’s history, to immediate cause. There must be an examination disaster research. rather than inquire why and how people, or things politics, structure, culture, organisation, and the nature of why people were exposed to the hazard, and they value, where made vulnerable to the failure. For of human-environmental relations. These factors will why conditions of vulnerability existed in the first Researchers, practitioners and advocates who argue example, following the 2014 Mount Polley disaster in play out in each and every location where a tailings place. The purpose of identifying deep causal chains for a deeper examination of vulnerability as a root Canada, the provincial government, with the support facility is situated. While there may be similarities and linkages is to identify which issues might be cause of tailings facility disasters continue to make of two First Nations, commissioned an independent between cases and contexts, differences must also be addressed by either long or short-term controls, and the point that their approach is not a replacement investigation on the cause of the dam breach. understood. thus warrant proactive investment. for technical investigations, or a diversion from the Investigators attributed the cause of the disaster to important work of engineers and other technical flaws in the original site characterisation and other The aim of delving into these aspects is to identify Understanding the underlying root cause of specialists. What they argue is that their approach is technical failures (Morgenstern et al. 2015). An the features of a host context that cultivate and vulnerability, particularly multi-generational complementary and, in fact, essential to supporting investigation by the British Columbia Chief Inspector energise the drivers that manifest in patterns of vulnerability, is not straightforward. Some aspects the industry’s goals of sustainable development of Mines (2015) focused on organisational factors vulnerability. When these patterns are affected by a of the social environment are easily recognised, and disaster prevention. Demonstrating to industry that contributed to the dam failure. Neither study hazard event, or multiple hazard events, they combine such as people living in adverse economic situations the value of understanding a diverse set of root considered why First Nation, and sites of importance to produce disaster. Identifying the specific features in hazard-prone zones (e.g. flood plains of rivers, causes for these disasters, beyond the engineered were at risk, as these broader considerations were not of each situation – at multiple scales of analysis – earthquake prone areas). However, there are a myriad structure, needs experts who are willing to work within the scope of either review. requires a shift from an exclusive focus on the facility of less obvious political and economic factors that across conventional boundaries. Moving beyond and its failure, to a more inclusive focus that also contribute to vulnerability to disaster. These factors these boundaries also requires engagement with For the more recent 2019 Bruhmidino disaster in examines the context in which laws, policies and relate to the manner in which assets, rights, income, stakeholder groups to create an environment that is Brazil, the operator (Vale SA) commissioned two other frameworks for resource extraction, human and access to resources (such as critical information conducive to transformative work. studies. First, there was a technical review, which rights protection and environmental safeguards are and data) are disclosed and distributed. People may concluded that a series of design and engineering negotiated, developed and governed. also experience various forms of discrimination flaws created the conditions for failure (Robertson et in the allocation of protections and availability of al. 2019). Second, an examination of the organisation 4. BENEFITS OF EXPANDING THE FRAME OF 3.5 DEEPER INVESTIGATION AS CRITICAL TO safeguards, including priorities in development, and in concluded that a series of internal factors, such as REFERENCE PREVENTION disaster relief and recovery efforts. corporate culture, faulty information sharing, and a The five principles discussed above are transforming skewed compensation structure, had a significant Understanding different modes of causality is critical It is the less obvious factors that link a tailings facility international disaster research and practice and role to play in the failure (Nasdaq 2020). In PAR for guiding decisions about investing in proactive and its associated risks to broader social and political are helping to prioritise disaster prevention and risk terms, these studies focussed on the hazard and the disaster prevention and risk reduction measures. processes. While addressing underlying root causes is reduction. The emphasis on disaster prevention is hazard-producing entity, rather than also examining Around the world, the amount of investment in unlikely to be the responsibility of a mining company, it mirrored in the stated aims of the GTR and those why people and significant sites were vulnerable to proactive strategies is eclipsed by the expenditure is nonetheless a developer’s responsibility to support of the ICMM and many of its members. However, a large-scale tailings facility failure, how they were associated with reacting to disaster through and stimulate the generation of knowledge about the stronger leadership is required to embed this affected, what is needed to support recovery, and how emergency response and recovery efforts after the context and conditions in which they have chosen approach in the mining industry, given the dominance this situation might be averted in future. Ideally, a third fact (Kyte 2015). Billions of dollars are committed to build and operate a mine and a tailings facility. A of the engineering approach and the inclination to study would be commissioned, bringing these broader to assist in emergency response efforts globally, commitment to knowledge building is vitally important contain the investigative frame, rather than open it up. issues into focus. but relatively little investment in research and for developers to know what will be disrupted through programmatic interventions to avert future disasters. their decisions and actions, and to demonstrate how According to Andrew Maskrey (2016, p. 5), coordinator Brief background descriptions in the academic This is also the case in disasters involving natural and they are preventing or mitigating potential harm. of the bi-annual UN Global Assessment Report (GAR) literature of the Samarco disaster (Demajorovic industrial hazards. For instance, the value of BHP and on Disaster Risk Reduction at the UNDRR: 2019; Santos and Milanez 2017) provide a sense of Vale’s financial investment in the Renova Foundation, 3.6 DISASTER RESEARCH AS INTER- the deep historical issues that accompany technical an independent entity designed to support the long- DISCIPLINARY WORK Transforming the direction of disaster research in a failure. Contributing factors included, for instance: term recovery of affected communities, is likely to way that reveals the social construction of risk could weaknesses in state and voluntary regulation, eclipse what might have been required to avert the Given the complex processes leading to disaster risk contribute to a profound re-definition of disaster ritualised licencing processes, structural asymmetries disaster in the first place. and occurrence, it stands to reason that it is beyond risk management. This includes understanding that favoured developers, weak state enforcement the capability of any single group or discipline to that historical processes operating at different capacity, lack of public participation, and limitations Building the case for addressing the underlying analyse the full array of causes and effects that could asynchronous spatial and temporal scales configure of public accountability in the absence of disclosure. causes of disaster is a complex and multi-layered be associated with a disaster. Disaster research must the specific circumstances in which disaster occurs. In light of these findings, the industry’s propensity to undertaking. Any call for investment must quantify be a broad-based, collaborative and interdisciplinary focus on the technical hazard is akin to conducting disaster impacts, their spatial and social distribution, undertaking that provides opportunities for a The way disaster is framed makes a difference to a narrowly scoped ‘Bow Tie’ analysis of the top event and the potential for loss and damage. The multiplicity of disciplines to engage at depth, while whose interpretations of events are included or and removing other factors. While it is critical to proposition must then address the immediate causes also creating opportunities for work that combines excluded in accounts of disasters (Rajan, 2003). 44 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 45
The aim of the UNDRR is to open the frame of 5. CONCLUSION: LOOKING TO THE FUTURE reference, and to challenge convention. The ICMM If the goal is to prevent catastrophic tailings facility KEY MESSAGES was established to play a similar role; that is, to extend failures, there is little value to be had from confining the industry’s frame of reference towards sustainable the industry’s attention to a facility focus, in isolation development, and challenge conventional wisdom. from considering people’s vulnerability to that hazard. From a UNDRR perspective, disasters must no longer 1. Mining companies could improve their ‘contextual intelligence’ by paying Yet, in response to recent events, the preference of be viewed as a single event, but a pivot around which some in the industry has been to narrow in on the greater attention to the social, environmental and local economic context multi-scalar, multi-stakeholder, and multi-disciplinary facility, and advocate for other causes of disaster to in which a project is situated, and the project’s effects on that context. analysis should be conducted, and preventive and be excluded from the field of vision. If this approach is remedial strategies developed. Until we take account maintained, tailings dam disasters are likely to affect of multiple perspectives, and tackle a variety of 2. Including vulnerability as a relevant factor in root cause analysis would human populations and the places they value in ever underlying causes, patterns will re-occur, and the more profound ways. A broader and deeper analysis is support mining companies to account for the structural and systemic same problems will emerge, again and again. needed – one that seeks to prevent disaster through aspects of disaster risk. a comprehensive understanding of the hazard and Casting a broader analytical net is increasingly conditions of vulnerability. This type of analysis would important given that new risks (and new connections help to ensure that industry efforts to manage risk 3. Mining companies could consider utilising other relevant frameworks, between risks) are emerging in ways that have not are appropriate to each and every context in which a been previously anticipated. In the context of climate such as the Sendai Framework for Disaster Risk Reduction 2015-2030. tailings facility is located. It would also demonstrate change, the world is experiencing an ever-growing to a concerned public that the mining industry is number of cascading and systemic risks across 4. Better enabling of social specialists to contribute to tailings risk committed to understanding the full extent of its global and local systems for which predictive models disaster potential. management (e.g. through participation in interdisciplinary processes) do not yet exist. We have seen the burgeoning use of tailings facilities over the past decade, a trend could help mining companies to avoid harm. Looking to the future, the Standard can play an which is likely to be maintained as demand grows, important role in promoting this shift in thinking. the mining industry expands, and grades continue to Currently, the Standard does not specify, for instance, 5. Both public and private sector actors should consider broadening the decline. We are also seeing an expansion of mining that matters of vulnerability should be included in into remote and often sensitive locations, meaning ‘circle of knowledge’ on disaster prevention, to include the natural, physical root cause analysis, or that incident investigation that tailings facilities will increasingly be situated in should include structural and systemic considerations and social sciences, and the lived experiences of affected people. complex landscapes that are characterised by a high that reach beyond the immediate proximity of the co-occurrence of risk factors (Owen, et al., 2019). failure and consider the context in which the facility is situated. Incorporating such requirements into future The UNDRR has challenged the public and private iterations of the Standard, in line with the shifts that sectors to think in new and creative ways about are now well under way in contemporary international development and disaster risk. For mining, a shift disaster policy and practice, would assist the industry in perspective would align with existing corporate to better reconcile its dual potential for human commitments to international frameworks such as development and disaster. The way in which the the UN Guiding Principles on Business and Human mining industry proceeds will be a defining feature of Rights, and the UN Sustainable Development Goals. its own future, and that of the communities in which it These and other internationally agreed frameworks operates. are interconnected and interdependent in ways that the mining industry has yet to fully acknowledge. There is potential, for instance, for companies to integrate disaster risk reduction into development planning through these instruments. Mining companies could commit to a more coherent implementation of international instruments to which they already subscribe, and consider engaging with other frameworks, such as the Sendai Framework, that will help to establish linkages in far more explicit ways. 46 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 47
REFERENCES Blaikie, P., Terry C., Davis, I., and Wisner, B. (1994). At Risk: Natural Hazards, People’s Vulnerability, and Disasters. London and New York: Routledge. MANAGEMENT British Colombia Chief Inspector of Mines (2015). Mount Polley Mine Tailings Storage Facility Breach: Investigation Report of the Chief Inspector of Mines. https://www2.gov.bc.ca/gov/content/industry/mineral- exploration-mining/further-information/directives-alerts-incident-information/mount-polley-tailings-breach/ mount-polley-investigation. OF TAILINGS:
Demajorovic, J., Lopes, J., Santiago, A. (2019). The Samarco dam disaster: a grave challenge to social license to operate discourse. Resources Policy, 61, 273-282. PAST, PRESENT Kyte, R. (2012). From disaster response to disaster prevention, TEDxSendai (English). https://www.youtube. com/watch?v=cWYcXhMhJF4. Maskrey, A. (2016). Preface. In Forensic Investigations of Disasters (FORIN): A Conceptual Framework and Guide AND FUTURE to Research, Integrated Research on Disaster Risk. Oliver-Smith, A., Alcantara-Ayala, I., Burton, I and Lavell, A. (eds). http://www.irdrinternational.org/wp-content/uploads/2016/01/FORIN-2-29022016.pdf
Santos, R.S. and Milanez, B. (2017). The construction of the disaster and the ‘privatization’ of mining regulation: reflections on the tragedy of the Rio Doce Basil, Brazil. Vibrant: Virtual Brazilian Anthropology, 14(2), 127-149. http://www.ufjf.br/poemas/files/2016/06/Santos-Milanez-2017-The-construction-of-the-disaster-and-the- privatization-of-mining-regulation.pdf
Morgenstern, N., van Zyl, D. and Vick, S. (2015). Independent Expert Engineering Investigation and Review Panel Mount Polley Tailings Storage Facility Breach. https://www.mountpolleyreviewpanel.ca/
Nasdaq (2020). ‘Brazil’s Vale dam disaster report highlights governance shortcomings’. https://www.nasdaq. com/articles/brazils-vale-dam-disaster-report-highlights-governance-shortcomings-2020-02-21
Oliver-Smith, A. and Hoffman, S. (2002). Culture and Catastrophe: The Anthropology of Disaster (eds). Oxford: School of American Research Press.
Oliver-Smith, A., Alcantara-Ayala, I., Burton, I and Lavell, A. (2016). Forensic Investigations of Disasters (FORIN): A Conceptual Framework and Guide to Research, Integrated Research on Disaster Risk. http://www. irdrinternational.org/wp-content/uploads/2016/01/FORIN-2-29022016.pdf
Owen, J.R., Kemp, D., Lebre, E. Svobodova, K. and Perez Murillo, G. (2019). Catastrophic tailings dam failures and disaster risk disclosure. International Journal of Disaster Risk Reduction. https://www.sciencedirect.com/ science/article/pii/S2212420919306648
Robertson, P., de Melo, L., Williams, D., and Ward Wilson, G. (2019). Report of the Expert Panel on the Technical Causes of the Failure of Feijão Dam I. http://www.b1technicalinvestigation.com/
Sendai Framework for Disaster Risk Reduction 2015 – 2030. (2015). https://www.unisdr.org/we/coordinate/ sendai-framework
United Nations Guiding Principles on Business and Human Rights (UNGPs) (2011). https://www.ohchr.org/ documents/publications/guidingprinciplesbusinesshr_en.pdf
United Nations Sustainable Development Goals (SDGs) (2011). https://sustainabledevelopment.un.org/
Wisner, B., Blaikie, P. Cannon, T and Davis, I. (2003). At Risk: Natural Hazards, People’s Vulnerability and Disasters, 2nd ed., London: Routledge. 48 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 49
MANAGEMENT OF TAILINGS: PAST, PRESENT AND FUTURE
and data from various elements and disciplines relationships with those items that were originally CHAPTER V that affect the system. This is precisely what allows included in the system’. significant progress compared to compartmentalised, MINE TAILINGS – single-discipline, linear approaches. A SYSTEMS APPROACH This chapter introduces the systems approach to Box 1: Factors in complex socio-technical tailings management including the systems that systems that have the potential to have an Angela G. Küpper*, Director, Principal Geotechnical Engineer, BGC Engineering, Canada produce tailings, and the systems associated with adverse impact on safety Dirk van Zyl*, Professor of Mining Engineering, Norman B. Keevil Institute of Mining Engineering, University of the design, management and operations of tailings British Columbia facilities. All of this is seen as part of the broader 1. Performance is an emergent property of a John F.H. Thompson, PetraScience Consultants, Canada community and environmental realities at and near complex socio-technical system. It is impacted mine sites. by the decisions of all the actors– politicians, managers, safety officers and work planners – not just the front-line workers alone 2. SYSTEM CHARACTERISTICS 1. INTRODUCTION Progress in tailings management requires taking 2. Sub-optimal performance is usually caused by into consideration that tailings are part of a complex There have been tailings facility failures since the A socio-technical system includes several groups multiple contributing factors, not just a single system. There is more complexity to managing inception of placing tailings on land in facilities versus of people at multiple levels who are involved in catastrophic decision or action. tailings than can be handled by simple linear cause- the practice until about 100 years ago of directly performing a technological task to produce an and-effect approaches, and therefore a systemic placing all tailings into watercourses. Over the past expected result. A socio-technical system has the 3. Sub-optimal performance can result from a lack approach is required. The tailings system needs 100 years, the amount of tailings produced has following features (Durand 2006): of vertical integration (i.e., mismatches) across to balance important components, which can be continued to increase as global ore grades decline levels of a complex socio-technical system, not both interconnected and competing, such as: risk and the economics of mining drive towards larger Interaction – elements of a system interact just from deficiencies at any one level. management, societal expectations regarding risk operations. While the number of failures per tonne of performing actions on other elements while being and environmental performance, tighter regulatory tailings produced on an annual basis has declined, the subject to actions by other elements. The system 4. The lack of vertical integration is caused, in requirements, economic expectations from investors, number and nature of facility failures remains wholly includes feedback loops. part, by a lack of feedback across levels of a and capital, operational and closure costs. The unacceptable. The recent failures of tailings facilities complex socio-technical system. Actors at each communities living near a mine, their livelihoods and have turned the public and technical spotlights • Comprehensiveness – a system cannot be reduced level cannot see how their decisions interact well-being, are a central consideration necessitating on tailings management at mines and the mining to the sum of its parts. There are specific properties with those made by actors at other levels, so the an increased level of systemic risk management industry in general. In the last six years, major failures to each subset of the system. threats to safety are far from obvious before an at tailings facilities. Further, tailings facilities will at Mount Polley, Samarco, Cadia and Brumadinho accident. exist essentially in perpetuity making them not only • Organisation – refers to both the structure and have led to a loss of confidence in the mining industry complex systems to manage but entities that once operation of a system designed to achieve a goal to manage the risk of tailings facility failures. Given 5. Work practices in a complex socio-technical developed will exist for generations. Managing the and assures the functions and processes of a the communication age upon us, failures that may system are not static. They will migrate over changes that will occur to the facility over those system. have happened a few decades ago that only received time under the influence of a cost gradient generations is part of the system management regional attention, if any, are occurring in front of a • Complexity – systems have complexity that can driven by financial pressures in an aggressive challenge. global audience. have several characteristics: competitive environment and under the influence of an effort gradient driven by the Significant progress has already been made in These failures have resulted in a renewed focus on - new and dynamic system properties can emerge psychological pressure to follow the path of addressing these challenges, with corporations the impact on lives and on the importance of tailings least resistance. and investors increasingly taking longer term views - a complex system can change its organisation management relative to a potential failure, as well on social, environmental and economic objectives without external influences as the financial and reputational impact to mining 6. The migration of work practices can occur at relative to mining, and to tailings management in - sensitivity to conditions and constraints influence companies. Mining is an essential industry to our multiple levels of a complex socio-technical particular. The drive towards responsible mining subsequent dynamics and adaptability modern world – it is not an optional industry or one system, not just one level alone. needs to incorporate a systems approach to tailings - temporal dynamics can produce events that that is likely to reduce in its importance to people facilities that is designed to prevent significant change the system dynamics in the future. As such, it has become increasingly 7. Migration of work practices causes the system’s failures. clear that tailings facilities are important elements - there is uncertainty in intricately organised defences to degrade and erode gradually over of mining operations and their safety must be systems time, not all at once. Sub-optimal performance According to Garbolino, Chéry and Guarnieri (2019, considered within a larger framework in order to - it is difficult to predict the evolution of a complex is released by a combination of this migration in p.1), the advent of the systemic approach, which improve overall tailings risk management. The silver system. work practices and a triggering event, not just by considers phenomena and problems as systems, lining of the crisis created by the high-profile tailings an unusual action or an entirely new, one-time ‘heralded a turning point in the history of science and failures is the enhanced opportunity to improve According to Garbolino, Chéry and Guarnieri (2019, threat to safety. its application to the organisation, and to production’. practices in the area of tailings management so this p.7), unpredictability in a complex system ‘can be By recognising that all components of a system are essential industry can continue with far less impact to reduced by taking into account those elements Source: Rasmussen (1997) as summarised in interconnected, the systemic approach highlights the communities where mining takes place. that were originally excluded from the system, but Donovan et al. (2017). emerging behaviour and links knowledge, expertise which are subsequently found to have strong causal *Member of the GTR Expert Panel 50 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 51
Rasmussen (1997) has argued that in complex constraints may contribute to failure. There are 4. TAILINGS PRODUCTION, OPERATIONS AND socio-technical systems, risk management must be real constraints on mining companies including: Box 2: Investigating Failures in Complex Systems MANAGEMENT done in a cross-disciplinary manner and requires a market and political pressures, schedule and The production and management of tailings can be system-oriented approach, since safety is impacted budget considerations, development and We can all work on letting a post-Newtonian ethic thought of as part of a larger system consisting of by decisions, behaviours and actions of actors across engagement of a high-quality workforce, and of failure emerge if we embrace systems thinking several interconnected systems. Although much can all levels of a work system (see Box 1). establishment of systems to help maintain the more seriously than we have before. In a post- be said about this larger system, this chapter focuses stability of tailings operations. Newtonian ethic, there is no longer an obvious relationship between the behavior of parts in on the systems and the aspects of these systems that 2. A series of small decisions can have a large the system (or their malfunctioning, for example most directly affect tailings. This encompasses: 3. HOW COMPLEX SYSTEMS FAIL impact (‘decrementalism, or small steps’) – ‘human errors’) and system-level outcomes. Many of the decisions that are made over time in • Mine-related factors – the location and nature of The terms of reference of recent failure investigation Instead, system level behaviors emerge from the tailings management do not necessarily result in resources, and the landscape in which they occur. panels were narrowly focused on the immediate multitude of relationships, interdependencies major changes; in most cases they present small These variables determine the location and type of technical causes of the failure events. Valuable and interconnections inside the system, but incremental changes. However, a series of small, mine, and ultimately the amount and character of learnings emerged from these investigations. cannot be reduced to those relationships or apparently unrelated decisions may in the long- the tailings. These characteristics are inflexible, and However, although there are always immediate interconnections. In a post-Newtonian ethic, term significantly impact outcomes if their system they constrain the system. technical reasons for tailings facilities failures, the we resist looking for the ‘causes’ of failure or impacts are misunderstood or neglected. overarching technical and governance reasons that success. System-level outcomes have no clearly • Processing plant characteristics – these affect allowed the situation to get to the point of failure 3. Misunderstanding of interdependencies traceable causes as their relationships to effects the physical and chemical nature of the tailings are, in most cases, the root cause of the failure (see (‘sensitive dependence on initial conditions’) are neither simple nor linear. produced. Hopkins, this volume). For example, while it may be – An incomplete understanding of system • Tailings facility planning, design and operation. true that a flood event caused the overtopping that conditions that are interrelated can have Source: Dekker 2011, p. 201 lead to the facility failure – what was the flaw in the significant impacts on outcomes due to a series • Tailings facility governance and oversight (inclusive governance process that led to the planner, operator, of decisions that misunderstand and neglect of independent review and the regulatory system). A critical governance concept that must be addressed designer, reviewer and regulator failing to notice the the interdependencies. Anyone who is involved in the safe design, construction, operations and • Mine operation, governance and social lack of system capacity for either storing this flood with a tailings facility may be unaware of the closure of tailings facilities is normalisation of performance. event or passing it safely through an adequately interdependencies of some decisions as they may deviance (Dekker 2011; Pinto 2014; Vick 2017). designed and constructed spillway? While overtopping have an incomplete understanding of how they • Local and regional social and environmental In summary ‘normalisation of deviance suggests may have been the immediate technical cause of the are related to the specific tailings system at that system. that the unexpected becomes the expected, failure event, a series of poor decisions were involved site. which becomes the accepted’ (Pinto 2014, p.377). that were most assuredly part of the root cause of Combining all these layers and contextual factors 4. Models may not be reliable (‘unruly technology’) Vick (2017) describes three tailings facility and that event. effectively defines the overall tailings system, which – Parameter uncertainties can be included in conventional water dam projects where this concept both affects and is affected by these broader systems evaluations before a decision is made. However, was demonstrated. In these cases, the failure modes An important consideration for the overall and cannot be adequately conceived or managed the models may not always be reliable. Despite were recognised but not adequately acted upon due management of tailings is how to characterise and without taking account of this context. our best attempts, there can be unknowns that to a normalisation of deviance: repeated deviations work towards understanding and preventing systems are not effectively evaluated due to incomplete from intended performance became accepted as failures, whether these relate to the physical system, The community and its social, cultural and economic information or other factors. Models may not normal, deviations were rationalised, and warning the communication system, the management system framework are critical elements of the overall system. capture everything that could go wrong and there signs were ignored. The accepted deviances allowed or any other component of the overall system. The environmental system upstream and downstream is a danger that the ‘calibrations’ may not be the failure triggers to go unrecognised. Another of the tailings facility is also a critical component. A correct. related human-issue concern are the hierarchical In his book Drift into Failure, Sidney Dekker defined ore deposit – the prospective mine – will be models that are prevalent in companies/society that (2011) describes five elements that together may 5. Failure to benefit from available governance located within a broad landscape, where people may limit communication that can prevent root causes characterise this ‘drift to failure’, meaning the multiple and other systems (‘contribution of protective live and pursue a variety of activities. Further, mines of failures (e.g., where concerns are not raised out factors that have been derived from evaluating many structure’) – There are many regulations, can exist over many decades and even more than of fear of retribution), or simply structures that allow systems failures. These elements are listed below; the management procedures, governance measures, a century so what may start as a remote site for a the strongest personalities to dominate the decision- terminology used by Dekker is inside the parentheses. institutional knowledge, etc. in place that can mine can evolve into a mine with many interfaces making process. provide support in maintaining systems integrity. with people and their economic and/or recreational 1. Constraints impacting decision-making These measures and procedures must be pursuits. Traditionally, a new or established mine In reviewing possible ways of preventing failure of (‘scarcity and competition’) –Three types of identified and applied in the day-to-day approach interfaces with the social, cultural and economic complex systems, Dekker (2011) suggests that the constraints have been recognised in complex to the management of complex systems. landscape through national and regional government inclusion of diversity can reduce the overall chances for systems: economic boundary, safety boundary regulators on one hand, and communities and These concepts indicate the difficulty of analysing drifting into failure. Diversity impacts the five elements and workload boundary. Economic pressure to civil society on the other hand. Many aspects of a systems failures using a linear cause-and-effect identified above and results in a much more resilient reach higher efficiencies will push the system’s proposed mine will come under scrutiny – access, Newton/Descartes approach (Box 2). While it is a outcome. Safety-critical organisations are complex operations closer to the workload and safety energy and water use, potential effects on local challenge to find the ‘immediate technical cause of a adaptive systems. These organisations must pay attention boundaries. If economic pressure wins it may livelihoods and traditional culture and heritage, failure’, it is much more difficult to find the cause of to diversity that brings a larger number of perspectives result in borrowing from safety to accomplish biodiversity and the environment. Among these, failure of the entire complex system. resulting in a wider range of possible outcomes. the efficiency. Decision-making within these the siting of the tailings facility and the associated 52 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 53
risks – real and perceived – are critically important and gold. No tailings are produced in the leaching processed and then are conveyed to a tailings storage This inner circle includes the typical day-to- and perhaps an important decision in terms of the process, but the leached rock represents volumes of facility, which in itself is part of a complex system. day activities that involve the planning, design, relationship between the value from the mine for waste rock, some of which may contain significant The tailings facility system, as other parts of the mine construction and operations functions and the society and the potential impacts that value entails. concentrations of deleterious elements both inherent operations system, includes both a technical and a important interactions between these groups. The Once in production, concerns and opposition among to the waste and added during processing. governance system, which are intimately connected. inner circle can be more complex in larger operations local people may decrease or increase depending on This is the system that is most directly related to – and involve more ‘boxes’, but the key issues remain performance and the relationship between the mine The metal concentration and mineralogy of the ore and has the most influence on – reducing the risk of similar. The main sub-systems that form the inner and the communities. constrain the processes used to extract the mineral or failure of the tailings facility. This section describes circle system are described below. metal of interest. Detailed assessment of the defined the tailings facility system, starting from its most local An understanding of this broader system is required ore body generates extensive data on the mineralogy, components and expanding into the broader systems. Planning from the start of a project and effective interactions concentrations of all elements (including those that The Planning work for a tailings facility involves with the broader system need to be maintained for may be deleterious to humans or the environment), 6.1 THE TAILINGS FACILITY PLANNING, DESIGN several aspects. One of the main activities involves the long term. This is the overarching system that and the physical properties of the rocks. These data AND OPERATION (THE INNER CIRCLE) determining the volume of tailings and water that needs to be continuously recognised, respected and are used to design the mine and processing facilities requires deposition and containment with time and Tailings facilities are distinct from infrastructure improved upon. and assess detailed economic feasibility. In addition, consequently the required rate of rise of the tailings projects where a design is done according to pre- these data are used to evaluate the tailings that will facility. It also involves defining the construction established planning parameters, followed by The remainder of this chapter focuses on the more be produced, and to assess how the tailings volumes process to meet the storage requirements according construction to implement the design, supported by local, mine specific tailings systems and how they and character may change over time due to variability to the design. For example, some of the important a quality assurance / quality control process (QA/QC) can be improved to minimise the risk of failures of of the ore body and the related adjustments to the considerations are the availability of construction until the project is complete. Tailings facility projects, tailings facilities. The local systems, which interact processing plant. materials (borrow material, tailings, overburden, by contrast, require continual involvement of the as an operation-wide system, include both tailings as waste rock or other mine waste), access from the planning, design, construction, QA/QC, and operations part of the mine and processing plant system, and the While the volume and character of tailings are strongly material source to the construction area, location functions, all linked to the overall mining development, tailings facility as a system in itself. influenced by the type of ore deposit, including its of tailings and water lines, as well as recycle water and undertaken in a dynamic environment with metal concentration and mineralogy, mining and facilities. For larger operations, the Planning function changes due to ore variability, processing plant issues processing options also influence tailings (see also may include several teams such as mine planning and market pressures. In other words, a tailings Williams, this volume). For example, new ore sorting and tailings planning, or short-term planning and 5. TAILINGS AS PART OF THE MINE AND facility is a highly integrated dynamic system with a technologies deployed on shovels or conveyer long-term planning. Material quality, quantity and PROCESSING PLANT SYSTEM high degree of complexity. belts at the mine may remove rock with low metal availability schedule have a profound impact on The production and processing of tailings relates concentrations prior to crushing or grinding, hence design and construction and, in some cases, safety The diagram in Figure 1 provides an idealised to the orebody, the ore processing and extraction decreasing the material that is fully processed and the of a tailings facility. For this reason, planners need depiction of common elements of the local system technology, and the overall mine infrastructure. resulting amount – and, in some cases, properties – to work in effective collaboration with geologists, (‘inner circle’) that represents the fundamental circle of tailings that are produced. Processing technologies mineral processing engineers and geotechnical of activities for the development and operation of a Many of the major metals used by society occur in that can have a significant impact on tailings engineers (both the designers and the monitoring tailings facility: tailings facility planning, design and specific types of ore deposits defined by geological, properties include the degree of ore grinding, the team) to support the safe construction and operation operations, and the relationships between these geometric and mineralogical characteristics. Each flotation process, the use of thickeners or centrifuges of a tailings facility. Involvement of the designers at activities. For simplicity, inputs and outputs of this deposit type has a range of distinct chemical and to decrease the water content of tailings, and the use an earlier stage allows cost savings: for example, system are not illustrated. physical properties. The nature of the ore deposits of additives such as flocculants and coagulants. by developing a design that seeks to optimise the largely determines how they are mined (e.g., at use of available materials and the site development surface or underground), how the ore is processed, Traditionally, ore processing technology tended schedule, and by piggy-backing on geology drilling and the scale of the mining operation (e.g. tonnes of to be exclusively focused on maximising recovery programmes for geotechnical characterisation of PLANNING ore treated by the plant per day). These factors also and minimising costs, however currently there is overburden materials and tailings facility foundation. determine the amount of waste rock and tailings that an increasing trend of taking into consideration the Finally, planning that does not take closure will be produced by the mine, and the mineralogical, resulting tailings properties. There are examples of DATA considerations into account will almost never lead chemical and physical nature of the tailings. secondary processing that both enhance recovery and to an integrated tailings facility concept. All tailings optimise tailings properties. Governance decisions facilities will spend more of its lifecycle in the closed DESIGN OPERATION Major ore deposits contain metals in concentrations are evolving into a bigger picture business analysis configuration than in operation, so commensurate that range from a few parts per million (ppm) to more of the system that considers optimising not only attention to this condition during the planning stage MONITORING than 65 per cent, with the remainder of the mined recovery but also tailings management operations, is paramount to the safety of the tailings facility rock following removal of metal-bearing minerals facility construction and closure, and environmental throughout its lifecycle. constituting waste rock and/or tailings. In some management. CONSTRUCTION cases, metal can be recovered by direct leaching of Design broken or fragmented rock piles, a process known Source: Küpper 2019 The Engineer of Record (EOR) is responsible for as ‘heap leaching’. This is restricted to near-surface the design of the tailings facility, which is a critical 6. TAILINGS FACILITY DEVELOPMENT AND ore deposits where surficial weathering has changed element of the safety of the facility. Fundamental MANAGEMENT AS A SYSTEM Figure 1. Simplified diagram of the ‘inner circle’ of the mineralogy allowing leach solutions to capture the tailings facility system elements supporting a ‘solid blue’ robust design the metals of interest, most commonly copper, nickel After the processing plant, tailings may be further are shown in the diagram of Figure 2: get the 54 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 55
geology ‘right’, get the soil mechanics ‘right’, get the a design that is calibrated to the site conditions Construction and Operation necessarily inform all aspects of the planning and hydrology ‘right’, and get the implementation ‘right’. and performance; (2) adjust this design as the site In some cases, construction of the starter dyke, if operating phases for the facility. To accomplish this, the EOR team needs to have both conditions evolve; and (3) bring to the system a depth there is one, is carried out by a contractor. However, competency and experience commensurate with of understanding of the design assumptions, design when construction of the starter dyke is complete, All the people involved in the inner circle of work need the specific requirements of the project. Further, it is intent, uncertainties and an appreciation of the risks Construction and Operations often become the same to understand the purpose, importance and potential necessary to have an appropriate level of competent of each structure and how they are managed in the as these activities are taken care of by the mine consequences of their work. This is regardless of and credible review that is independent of the design. An effective and balanced collaboration operations. This merger of functions increases the whether they are in planning, design, construction, EOR and the facility owner – this review is further among the Design, Planning, Operations and complexity of the system and the interaction between operation, or are involved in obtaining the data (for described in the ‘outer circle’ following in this chapter. Monitoring functions can reduce costs and manage its parts. Operations is affected by Planning, for example, instrumentation monitors, surveyors, drillers Effective collaboration with Planning, Operations risks to the integrity of the tailings facility. example, as material availability may affect the rate of and geo-professionals on site investigation or in the and Monitoring is critical for the EOR to: (1) produce construction. Operations can also influence Planning; laboratory). Moreover, their practical knowledge and for example, by providing feedback and contributing observations need to be considered in planning and to make future plans more realistic and better suited designing the tailings facility. This is important for to tailings facility operation and safety. An important improving the quality of the work and the safety of the interaction between Design and Operations occurs facility. through QA. Beyond checking the QC programme, QA should have sufficient understanding of the design 6.2 THE TAILINGS FACILITY GOVERNANCE AND Get the soil mechanics right, e.g.: Get the geology right, e.g.: to assess whether construction meets the design OVERSIGHT SYSTEM (THE OUTER CIRCLE) • Solid understanding of fundamental • Definition of the stratigraphy, intent and to identify whether there is a need to adjust Tailings facilities are also part of a management soil behaviour, including pore material types and mineralogy the design to the observed site conditions, including pressure responses • Definition of structural geology system that relates to the various layers of materials. Operations interacts with the other sub- • Appropriate site investigation, field • Understanding of the geomorphology governance and oversight. This system includes and laboratory testing, correctly and how it affected the nature, systems of the inner circle, but also with the physical company personnel, consultants, regulators, and local interpreted distribution and properties of the environment; for example, having to manage high geological units in the area and non-local communities. The diagram in Figure 3 • Factors of safety consistent with precipitation events by adjustments to the normal uncertainties in geology, material • Understanding of the hydrogeology, (below) provides an idealised representation of operations. behaviour, mobilized shear its boundary conditions and seasonality common elements of a tailings facility management strengths, acceptable strain levels system and the relationships between these elements. • Appropriate use of analytical tools At the centre of the inner circle is the data system Again, for simplicity, the fundamental drivers – input required for all the sub-systems to work adequately. and output – of this system are not illustrated. This The quality of the work product is only as good as ‘outer circle’ provides support and oversight to enable the quality of the data that the work is based on. The participants in the inner circle to get their best work data system includes the geological data and model, done. This circle also provides important ‘end goals’ geotechnical data (e.g., borehole logs, sampling, test for the inner circle and links to the broader systems. results, instrumentation readings, etc.), planning data, The outer circle is formed by senior management, construction QA/QC and as-built data, monitoring independent reviewers, regulators and communities data, operational data, and social and environmental that provide oversight of the tailings facility. The blue data. It is essential to have complete, detailed Get the hydrology right, e.g.: Get the implementation right, e.g.: shading in the diagram in Figure 3 emphasises that • Develop a design that is practical and accurate data that are easily accessible to all • Understanding of the the entire system must be supported by high quality, and implementable without major parties involved and that are geo-referenced where precipitation data and the accessible data. Like the inner circle, each rectangular relationship between surface challenges for the site conditions appropriate. Data integrity is critical. water and hydrogeology (materials, technology, personnel, box of the outer circle is a system in itself; however, • Selection of the design criteria climate) in the case of the outer circle, these systems involve • Produce quality documents that Another essential element of the tailings planning and the design flows more complexity. • Appropriate use of modern adequately communicate the process is the use of risk assessments. These analytical tools design • Support construction in the field are employed throughout the design process and with appropriate Quality Assurance
Source: modified after Küpper 2019
Figure 2. Simplified diagram of elements of the design of a tailings facility 56 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 57
operation, maintenance, and closure of tailings and who can work collaboratively with others in the facilities. Discharging this role effectively, requires a system. Their work also needs to be based on high comprehensive understanding of the planning and quality, accessible, data, and information sharing. COMMUNITY engineering necessary to build, operate, maintain, and ultimately close tailings facilities. Ideally, regulators 6.3 THE COMPLETE TAILINGS FACILITY should also be in a position to set up a professional LOCAL SYSTEM PLANNING inspection and enforcement programme capable of For the tailings facility system to work well and identifying problems and making sure those problems for risks to be adequately managed, not only it is are corrected promptly before they increase the risk of necessary to have competent and experienced DATA catastrophic failures. personnel leading all the functions represented by the SENIOR ‘boxes’ in the diagram in Figure 3 but the interaction MANAGEMENT DESIGN OPERATION REGULATORS Community involvement between the boxes needs to be cooperative and Communities also have an important role to play effective. MONITORING in participating as stakeholders who bring diversity of input and accountability to the system. The Integration and communication across the overall community brings a diversity of perspectives, tailings system are fundamental. Risk assessments CONSTRUCTION providing a broader context of the local environment support the overall work of the tailings system by and areas of most concern to them. These helping communicate and provide clarity on the contributions should be incorporated into the system. requirements and the uncertainties, and by allowing INDEPENDENT See Box 3 for a community-society perspective. REVIEW risk mitigation across all elements of the system. Risk assessments form part of the basis for risk-informed decision making for follow-up action to manage risk. Source: Küpper 2019 Box 3: A community-society role In addition to be an element of the risk management Figure 3. Simplified diagram of the ‘inner circle’ and ‘outer circle’ of the tailings facility system framework, risk assessments are a powerful tool to Communities are also proxies for society in help individuals in all functions of the tailings system general and therefore can play an important role recognise the risk elements, the inter-dependencies, in tailings management. Mining has historically and the potential impact of their decisions on been driven towards a ‘Net Present Valuation’ The oversight provided by the outer circle includes is one where the senior management understand that the tailings facility, while supporting vertical and for commodity development which is a logical the governance of the mining company, local and their role in governance is to facilitate and encourage horizontal integration across the system. approach for the orebody evaluation. However, general, as well as through its board of directors. a flow of information in all directions that will meet for the perpetual legacy of tailings facilities this The governance system includes risk management the needs of the safety culture required for the tailings Leadership throughout the entire tailings system is a false premise as there is no discounting and technical and operational reviews provided facility management. is required to create, implement and maintain a of future risks by present risk transference or by independent reviewers and auditors. The other culture of quality, safety and transparency. Continuity vice versa. Consequently, tailings management important elements are the regulatory system and Independent Review of personnel is another key element of tailings requires a much broader view, which takes the community, which provide oversight of the tailings Independent technical review of the design, storage facilities stewardship. It is invaluable to have account of how the true cost of a commodity facility. The main sub-systems that form the outer construction, operation and closure of tailings institutional memory and people in the system who includes the cost of tailings management. circle are described below. facilities is an important element of risk management. are well calibrated to site conditions, local materials Society, as driven by its communities, sets values The independent review also helps identifying and practices, and who will mentor others as part of a for raw materials through consumptive patterns Senior Management opportunities for improvement. The expertise well laid out succession plan. The cult of personality, and if those patterns were to insist on more Senior managers are responsible for development and of the reviewers relates to the specific technical where decisions are owned by the loudest voices life-cycle investment in mine tailings as part continuous improvement of tailings stewardship and aspects of the tailings facility site, material and or the most senior opinion, is to be avoided and of the cost of a mined commodity, one of the governance throughout the company’s operations, design characteristics. The quality of reviews is challenged by the healthy organisation – one that significant barriers existing in many parts of the including the implementation of audits, conformance directly affected by the information presented to the sees all individuals and all information as part of the world to improved tailings management could be reviews and independent technical reviews. Senior reviewers, the core competency of the reviewers overall management of a safe facility. overcome. managers can support building a quality and safety relative to the nature of the facility being reviewed, and culture. They interact with other senior managers, by the nature of the communications. The safety of tailings facilities can only be improved Source: Michael P. Davies, personal communicate with the executive and board on tailings by each person in the system, no matter which role communication matters, and are typically actively involved in national Regulators they play. This entails being technically competent, and international tailings activities. It is essential This term encompasses all relevant public sector understanding what needs to be achieved and why, that senior management be receptive to input from agencies. At the highest level, regulators are having a view of the causes and consequences, and the team at all levels when concerns are raised. Past responsible for legislation, regulations and guidelines The outer circle, again similarly to the inner circle, producing detailed and accurate data to support examples of retribution to individuals approaching that ideally support the entire system without stifling needs competent people in all functions (see each other’s work, within a culture where effective, senior management and/or fear of such reprisals creativity and technical development by being too Evans and Davies, this volume) who understand collaborative relationships promote quality work. have left senior management uninformed and ill- prescriptive. Regulators have a unique position the importance of their work for the overall system equipped for decision making. A healthy organisation of independent oversight of the construction, 58 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 59
• minimises impact to the environment, including is the management of occupational health and safety. fauna, flora, hydrological resources, air and water By approaching occupational risk management as a quality system, the industry has involved engineering, process technology, information technology, ergonomics, • has adequate foundation conditions for a stable sociology and psychology to build a positive cultural structure, along with sufficient storage capacity for change in the workplace supported by tools that lead COMMUNITY tailings to a decrease in occupational accidents. Key features • is located at a relatively short distance from the of the systemic approach are demonstrated in the processing plant, and modern management of occupational health and PLANNING safety that are familiar in the mining industry • is feasible for closure in a manner consistent with (see Box 4). future land use by the local communities. DATA The interaction with the social and environmental SENIOR Box 4: Systemic approach features in the MANAGEMENT DESIGN OPERATION REGULATORS system during construction, operations and closure of a tailings facility includes many important aspects, modern management of occupational health and safety MONITORING such as: environmental monitoring and management (with modification of plans and designs, and implementation of remedial measures as required); • Vertical integration – there is support to safety CONSTRUCTION open lines of communication with communities; from all levels within the organisation. assessment and management of social impacts; • Horizontal integration – all groups within the management and communication of risks; and organisation participate in safety programmes INDEPENDENT regulatory compliance and regulatory oversight. and safety training. REVIEW • Knowledge from individuals in all levels within MINE OPERATION SYSTEM the organisation is respected and integrated 7. RECOGNISING AND MANAGING TAILINGS into improved procedures, policies, etc. ‘Safety FACILITIES AS A SYSTEM SOCIAL AND ENVIRONMENTAL SYSTEMS shares’ are common and frequent. The tailings facility system is complex and typically • Information is gathered, valued, and compiled Source: Küpper 2019 involves many people in different groups with to improve the organisation through continued different objectives and different responsibilities. The education, awareness, and knowledge sharing; Figure 4. Simplified diagram of the elements of the tailings storage facility system importance of treating it as a system comes from the this includes access to knowledgeable Note: Each rectangular box in this diagram represents a system in itself. need to align the objectives and responsibilities from specialists inside and outside the organisation all areas of the system, such that sound stewardship and use of a wide variety of monitoring is achieved. technologies. 6.4 THE MINING OPERATIONS SYSTEM site selection process must consider and optimise a Several organisations within the mining industry • There is a clear understanding of the role of variety of aspects related to: the physical and social everyone at all levels within the organisation The tailings facility system is an integral part of the have recognised that tailings must be managed as a environment within which the facility is located; in improving safety by taking personal mine operations system (Figure 4). It is affected by the system. The Mining Association of Canada (MAC) has parameters from the ore body; the processing plant; responsibility for individual actions as well as mine and the processing plant (as discussed above) been one of the pioneers in the governance of tailings the conveyance system; the design, construction the actions of others, and by implementing while at the same time enabling the functioning of facilities as a system. Its publications in this area and operation of the facility; and its closure and correct procedures, use of adequate these operations. It is also a critical component of the (MAC 2019 and 2018, for example) have been helpful final land use. Some of these items have competing equipment, developing positive attitudes, and overall mine infrastructure, personnel and governance in promoting awareness and the implementation of a requirements and the optimisation process is not seeking continuous improvement. system. systemic approach to governance of tailings facilities. simple. Techniques, such as risk assessments, The Global Tailings Review further reinforces and • Governance support is provided, including multiple account analyses and others, can be used to 6.5 THE SOCIAL AND ENVIRONMENTAL broadens this perspective. through the continuous updating of support the process. However, most importantly, it is SYSTEM regulations. necessary that specialists from all these areas work Some mining companies have also recognised the As Figure 4 also shows, the tailings facility and the in collaboration, sharing the same goals, to achieve a need for a systemic approach for the technical and mine operations system are in turn embedded into solution that appropriately considers all the relevant operational aspects of tailings facilities and have larger social and environmental systems. This overall elements. established tailings stewardship programmes aimed Most mining companies have developed a solid system is complex, intricate, and governance happens at a more effective risk management of their facilities. safety culture; thus, the systemic approach and its at many levels with several groups of people involved. Ideally, the selected site: implementation would be familiar. The same type of An example of an area where the mining industry has processes, level of effort and emphasis can be applied The selection of the tailings facility site is an activity • minimises impact to people, their culture and used the systemic approach with significant success successfully to tailings facilities risk management. where the interaction with the broader social and livelihood environmental system is particularly critical. The 60 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 61
8. THE PATH FORWARD • Development and implementation of a robust data 9. CONCLUSION management system where all data relative to A path forward to the improvement of the safety It has become increasingly clear that tailings facilities geology, hydrology, materials, volumes, schedule, of tailings facilities would involve a deeper are important elements of mining, an essential designs, specifications, surveys, photographs, understanding and a broader implementation of a industry, and that the safety of tailings facilities as-builts, reports, instrumentation, monitoring systemic approach, along with an improvement of must be managed within a larger framework in order data, etc., are easily accessible and available in an the technical knowledge related to tailings facilities to improve overall risk management and to renew efficient, timely and practical manner to the entire across the entire system. confidence in tailings facility management. Tailings organisation. Data accuracy and data integrity are facilities are a highly integrated dynamic system with a must. There is a varied level of awareness within the a high degree of complexity. Therefore, risk must mining industry in regard to a tailings facility being a • Consistent use and application of risk assessments be managed using a system-oriented approach in a system and the requirement to be managed as such. and risk management principles with program cross-disciplinary manner, since safety is impacted Moreover, there have been varied levels of success priorities being informed by these assessments. by decisions, behaviours and actions of actors across in managing tailings facilities using a systemic all levels of the system. This chapter has provided • Clear understanding of the role of everyone at all approach. However, anywhere within this spectrum, an overview of the elements needed to incorporate a levels within the organisation in improving safety of improvements could be made for continuing systemic approach to effective tailings management. the tailings facility by adopting correct procedures, improvement to the management of these facilities. adequate equipment, positive attitudes, and continuous improvement approaches. A systemic approach to tailings facilities should include understanding the system for a specific • Transparency in internal and external site and managing this system by considering the communications and a supportive culture such intricacies of complex systems. The approach that problems can be aired and addressed in a should involve identifying all elements that directly or constructive manner. indirectly affect the system and addressing all these • Establishment of tailings as a career path in the elements and their interaction in a governance system organisation and within the mining industry with (structure and operation) that promotes collaboration well-defined objectives, technical knowledge towards the common goal of tailings facility safety. and experience expectations, and with growth Management of tailings facilities benefits from opportunities. applying a multi-disciplinary perspective. It can also benefit from recognising that complex systems are • Clear succession plans, with candidates identified, dynamic, so adaptability needs to be promoted along for all key roles in the organisation related to with a robust approach to handling of uncertainty. tailings management. • A strong governance framework that supports and The specifics of implementing a systemic approach reinforces all the above. will vary in each case, however some common elements include: With the concepts mentioned above in mind, a management framework can be developed such • Vertical integration from the worker level to the that tailings management is supported by effective board of directors, where there is support for and communication, underpinned by an accessible and understanding of the measures, activities and robust data management, flow of information and attitudes required for safe tailings management. adequate levels of knowledge and experience. A • Horizontal integration, with all groups within the management structure that includes embedded operation supporting tailings facility safety as one monetary and non-monetary incentives to support of their key objectives. the alignment of the objectives and promotes vertical and horizontal integration is more likely to minimise • Knowledge integration from all levels within the the risk of catastrophic failures of tailings facilities, operation – from workers to the C-suite. Knowledge improve efficiency and reduce unnecessary costs. is gathered, respected and integrated into improved Leadership and personality traits from individuals at plans, designs, operational procedures and policies. all levels within complex socio-technical systems can • Information gathered and compiled to improve the also affect the outcome. These factors need to be organisation and support continued education, managed to promote the best culture and the best awareness, knowledge sharing, including access to outcome for the work system. knowledgeable specialists, inside and outside the organisation. 62 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 63
REFERENCES KEY MESSAGES Dekker, S. (2011). Drift into Failure: From Hunting Broken Components to Understanding Complex Systems. Burlington Vt: Ashgate.
1. Tailings facilities are complex entities that operate as a system within Durand, D. (2006). La systémique. France: Presses Universitaires de France.
the broader context of mining operations, their external societal and Donovan, S-L., Salmon, P., Lenné, M., Horberry, T. (2017). Safety leadership and systems thinking: application and environmental settings, and their potential to last in perpetuity. evaluation of a Risk Management Framework in the mining industry. Ergonomics, 60:10, 1336-1350.
2. Tailings facilities are complex systems that need to be managed with a Garbolino, E., Chéry, J.-P., Guarnieri, F. (2019). The systemic approach: concepts, method and tools. In Safety Dynamics: Evaluating Risk in Complex Industrial Systems, Guarnieri, F. and Garbolino, E. (eds). Switzerland: systemic approach for effective risk management Springer.
3. Although there are always immediate technical reasons for tailings Küpper, A.G. (2019). ‘Tailings Dams’, 2019 Distinguished Lecture Program, Geological Engineering: University of British Columbia, Canada. facilities failures, the overarching technical and governance factors that allowed the facilities to approach a critical state are, in most cases, the MAC (2019). A Guide to the Management of Tailings Facilities, Version 3.1. February 2019. Ottawa: Mining root cause of the failure. Association of Canada. https://mining.ca/documents/a-guide-to-the-management-of-tailings-facilities- version-3-1-2019/
4. The systematic management approach for tailings facilities involves MAC (2018). Developing an Operation, Maintenance and Surveillance Manual for Tailings and Water Management vertical and horizontal integration of all functions (planning, design, Facilities. November 2018. Ottawa: Mining Association of Canada. https://mining.ca/documents/oms-guide- second-edition-2019/ construction, operation, management, oversight) that operate and collaborate within a broader framework. Pinto, J.K. (2014). Project management, governance and the normalization of deviance. International Journal of Project Management. 32, 376-387.
5. The resulting management framework must be supported by effective Rasmussen, J. (1997). Risk Management in a Dynamic Society: A Modelling Problem. Safety Science, 27 (2-3), communication, transparent and robust data management, and 183-213. information flows that builds knowledge and experience. Success also Vick, S.G. (2017). Dam safety risk – from deviance to diligence. Proc. GeoRisk 2017, American Society of Civil requires leadership, appropriate incentives and a culture of performance. Engineers. 19-30, GSP282.
6. Ultimately, the framework and resulting systems management has to be based on leadership that drives a culture of system-level performance. 64 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 65
MANAGEMENT OF TAILINGS: PAST, PRESENT AND FUTURE
is because the costs of closing and rehabilitating the tailings dewatering, density and shear strength, and CHAPTER VI resulting tailings facility are discounted by the NPV maintaining a safe, stable and non-polluting tailings accounting approach and are not considered to be storage (see Box 1). THE ROLE OF TECHNOLOGY significant. Instead, the NPV approach prioritises the minimisation of short-term capital costs (Williams 2014). While the best practices in the industry have AND INNOVATION IN IMPROVING Box 1: Limitations of the NPV Approach moved beyond the NPV approach, with a growing number of owners and jurisdictions now embracing TAILINGS MANAGEMENT The use of NPV and an artificially high Discount true full-life economics, there remains a substantive Factor result in apparent cost savings in tailings David John Williams Professor of Geotechnical Engineering, Director of the Geotechnical Engineering Centre, portion of global tailings practice that still uses the management in the short-term, but at the price and Manager of the Large Open Pit Project, School of Civil Engineering, The University of Queensland NPV approach. of increasing operational and capital costs, and unintended cumulative detrimental impacts This way of thinking leads to tailings being stored over time, and ever-increasing closure and as a slurry in surface facilities that are often initially rehabilitation risks and costs in the long-term. too small, leading to high rates of rise, and creating This is particularly the case in flat terrain, such 1. INTRODUCTION large and growing body of guidance documents on wet and soft tailings deposits that store excessive as much of Australia, where there is limited free best or leading tailings management practice. An amounts of water. Operating costs tend to blow While there is no ‘silver bullet’ to cover all tailings in storage in valleys, resulting in containment walls Appendix to the chapter lists the more significant of out, and the risk of tailings run-out on loss of all climatic, topographic and seismic settings, much extending around an increasing proportion of these documents. containment increases. The wet and soft tailings can be learnt from recent high-profile and well- the tailings storage perimeter as they are raised, can also be difficult and expensive to rehabilitate, documented tailings facility failures which, while rare, making high facilities too costly. As a result, due to the challenge of capping a ‘slurry like’ tailings. continue to occur at an unacceptably high frequency facility heights are limited, and tailings storage This is contrary to good practice, which aims in terms of both industry and societal expectations. 2. CONVENTIONAL TAILINGS MANAGEMENT footprints grow ever larger. A rethink is also required about the way in which many to optimise tailings management by improving The conventional approach to tailings storage is to view tailings management in terms of economics, thicken the tailings just to the extent that they can be relying on a net present value (NPV) approach with pumped using robust centrifugal pumps by pipeline a high discount factor, rather than a whole-of-life to a surface tailings facility, where the tailings are economics approach. There is scope for the further deposited sub-aerially (that is, above water and on the development and implementation of new tailings surface) forming a beach. management technologies and innovations, and for Inefficient water & process chemical recovery Slurry-like: No the use of different economic models. Change is Centrifugal pumps sufficient The forms of tailings containment and method of Extensive water management Tailings slurry particle/particle most readily achieved in new mining projects and interaction, saturated, construction and facility raising varies from region to Containment required (typically segregating) hence change in tailings management for the mining High runoff & potential seepage no effective stress region. Upstream construction, using tailings where Rehabilitation difficult (soft & wet) industry as a whole will be generational. Clay mineral-rich possible, is widely employed in southern Africa, Low CapEx and OpEx, but high rehab. cost Australia and the south-west of the USA, which have tailings stuck here For context, this chapter first describes conventional in common a dry climate. Centerline and downstream tailings management, arguing that applying NPV construction, by contrast, is usually employed in wet accounting to tailings management supports the Improved water & process chemical recovery Thickened tailings and/or high seismic regions. While the necessity Positive displacement &/or diaphragm pumps (dewatered, ideally non-segregating) transportation of tailings as a slurry to a facility, with for centreline or downstream construction is Discharge management required (steeper beach) insufficient consideration being given to the potential Reduced water management understandable in wet climates, the choice between risks and long-term costs of this method of storage. Some containment required upstream construction and other geometries is not While this conventional management approach Some runoff & seepage potential Paste tailings so obvious. It seems that this is more a function of Rehabilitation difficult (soft & wet) can be the optimal NPV and life-cycle choice for a (Dewatered, ideally non-bleeding) past experience and established regional practices, High CapEx and OpEx, and high rehab. cost given operation, there is often a divergence when Pumpable which vary and are difficult to change. Sand facilities, a whole-of-life approach is fully considered. The cycloned and/or compacted, are widely employed in constraints under which a conventional surface Non-pumpable South America and Canada, now usually raised by the Efficient water & process chemical recovery tailings facility must operate are also described. ‘Wet’ filter cake centreline or downstream methods. Rockfill and/or Transportable by truck or conveyor The chapter then outlines the key causes of the Minimal water management (near-saturated) roller compacted concrete facilities are finding favour unacceptable consequences of tailings facility failures Minimal containment required for high tailings facilities in the deep valleys of the Negligible seepage losses Soil-like: Particle/ and the threats posed to industry, regulators and Andes in South America. Progressive rehab. possible particle interaction, society by such failures. Alternative approaches to Stable tailings mass ‘Dry’ filter cake effective stresses tailings management are described in the main body (85 to 70% saturated) and suction, shear 2.1 NET PRESENT VALUE ACCOUNTING Very high CapEx and OpEx, but low rehab. cost of the chapter. Issues relating to the closure and strength APPLIED TO TAILINGS MANAGEMENT rehabilitation of tailings facilities are also discussed.
There is a commonly held perception that Source: After Williams 2017; adapted from Davies and Rice 2004 The chapter draws on the author’s own research, the transporting tailings as a slurry to a facility is the most work of other researchers active in this area, and a economic approach. However, to a large extent this Figure 1. Tailings Continuum from slurry-like to soil-like as they dewater 66 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 67
Figure 1 shows five different tailings treatment • the need to manage, store, and recycle, when In Chile, by contrast, the climate is dry, but the In western portions of British Columbia, the climate is options, the advantages and disadvantages of each possible, supernatant tailings water topography and seismicity are extreme. Prior to wet, the topography extreme and earthquake loading option, and the relative levels of capital (CapEx), 1965, the majority of Chilean mining companies, can be high, if infrequent. In continental Canada, the • the need to minimise the risk of the release of operational (OpEx) and rehabilitation expenditure (which at the time, mainly operated in Central Chile, climate is dry but seasonal, the topography low relief, tailings and tailings water through overtopping, required for each option. It can be seen that the NPV above Santiago) employed cycloning to form a sand and the seismicity low. Brazil has an extreme wet tailings storage embankment instability, or approach, which prioritises the minimisation of CapEx facility that was constructed upstream. However, season and high topographic relief, but low seismicity. excessive seepage and OpEx over the minimisation of rehabilitation a magnitude 7.4 earthquake in 1965 caused a The 2015 Fundão and 2019 Brumadinho tailings costs, favours what is often the least desirable option • the need to meet discharge water quality licence liquefaction failure of the cycloned, upstream tailings facility failures in Brazil were influenced by the wet from a long-term management perspective. conditions facility at El Cobre Mine, resulting in more than 200 season rainfall and the high topographic relief. fatalities. This failure occurred in a decade when world • the need to maximise the tailings settled dry Most tailings can be thickened mechanically, some copper production, particularly in Chile, increased 3.2 NATURE OF TAILINGS density, and hence minimise wall raising and the to a paste or filter cake consistency. However, clay significantly. required tailings storage volume Tailings are typically mainly silt-sized (0.002 to mineral-rich tailings, such as coal tailings, mineral 0.06 millimetres in size) but may also contain sand- sands tailings, tailings from some oxide ores, and • the need to facilitate upstream wall raising, where The failure resulted in almost immediate industry- sized particles (0.06 to 2 millimetres in size) and clay- residue from the processing of bauxite, nickel laterite appropriate initiated changes to tailings facility construction in sized particles or clay minerals (finer than 0.002 mm). and oil sands, are difficult to dewater mechanically, Chile. These included: • the need to rehabilitate the tailings storage on Tailings particles can also have a range of specific particularly where the unstable, moisture-reactive closure to a safe, stable and non-polluting structure gravities, ranging from as low as 1.8 for coal-rich sodium smectite clay mineral is present, even in small • using dozers to flatten the downstream slope to in perpetuity, and to achieve some post-closure tailings to 4.5 for iron-rich tailings. This compares proportions. As a consequence, dewatering tailings to about half (from an angle of repose of wet sand of land use or ecological function. with a specific gravity of about 2.65 for normal a paste or by filtration has conventionally been seen about 2.5 horizontal to 1 vertical to about 4 to 1), mineral matter. The variable particle size and specific as too capital intensive and too expensive to operate, also inducing compaction 3.1 SETTING OF THE MINE SITE gravity of tailings particles result in hydraulic sorting and as being difficult to scale-up for large production • moving from upstream to downstream and down the tailings beach on conventional sub-aerial rates. The long-term benefits of reduced storage Tailings management is typically easier, at least centreline construction deposition. volume occupied by tailings paste or filter cake, and physically, in dry climates, where advantage can be the relative ease of capping ‘soil-like’ tailings have taken of desiccation (that is, drying by exposure to • the installation of centralised cyclone stations The presence of clay minerals in tailings, even in been discounted, as have the potential for a higher the wind and sun) to naturally dewater, increase the • in some instances, the installation of a ‘temporary’ small proportions, can limit sedimentation and level future land use and/or improved ecological density of the tailings and strengthen the tailings. upstream liner to limit seepage from the slimes into consolidation, and water recovery. Tailings can be function. However, on desiccation in a dry climate, sulphidic the sand facility, and hypersaline due to the chemistry of the ore and/ and otherwise potentially contaminating tailings can or the process water; acidic due to the presence of oxidise, potentially leading to acidic and otherwise • limiting the percentage of fines in the sand facility sulphides and/or acidic process water; or alkaline as contaminated seepage and runoff. On the other hand, to a maximum of about 20 per cent. 3. CONSTRAINTS UNDER WHICH A a consequence of caustic processing, such as for the limited rainfall in a dry climate will reduce the CONVENTIONAL TAILINGS STORAGE MUST bauxite, nickel laterite and oil sands. transport of any contaminants that are generated. The Chilean regulators followed the industry some OPERATE Unrelated to water transport, fugitive dust generation years later with Decrees in 1970 and 2016 (see Box 2). 3.3 CONVENTIONAL SUB-AERIAL TAILINGS Conventional tailings storage remains the optimal from tailings in arid climates is a significant SLURRY DISPOSAL AND STORAGE solution for a wide-range of existing and proposed contributor to off-site impacts in many regions. facilities. However, conventional tailings storage is The conventional approach to tailings disposal and Box 2: Tailings facility performance in Chile not ideal for every site. For those locations where High topographic relief provides ‘free storage’ in storage, supported by the NPV approach, is to thicken conventional facilities are both false economics and valleys, requiring a facility of limited width, but also the tailings just to the extent that they can be pumped Since 1965, Chilean tailings facilities have poor technical choices, there is a series of constraints results in a high embankment to create the storage for using inexpensive and robust centrifugal pumps increased in height to 200 metres or higher. There that counter their use. The constraints under which the facility, leading to initially high rates of rise and the by pipeline to a surface tailings storage, where the are currently about 740 tailings facilities in Chile, a conventional surface slurried tailings storage must need to divert steam flows. High seismicity can also tailings are deposited sub-aerially forming a beach. of which about 100, mostly downstream sand operate include the following (Williams 2014): dictate design, such as in Chile, which experiences facilities with a dozed downstream slope, are about 40 per cent of global seismicity. Conventional sub-aerial tailings slurry disposal to a active; about 470, mostly former upstream sand • the climatic, topographic, seismic and geological surface tailings storage involves the processes of facilities, are inactive; and about 170, mostly settings Different combinations of these aspects may beaching, hydraulic sorting of particles down the former upstream sand facilities, are abandoned. dominate in particular geographical areas. For beach according to their particle size and specific • the nature of the tailings, and potential The active Chilean downstream sand tailings example, in much of Australia, apart from the humid gravity, settling of particles, consolidation, desiccation contaminants, including sulphides, salinity, facilities have performed well since 1965, due and cold West Coast of Tasmania and the seasonally if exposed to the sun and wind, and loading by an radioactivity, cyanide, etc., and how these may to improved construction methods. The large wet tropics, the climate is dry, the topography upstream raise or cover placed for rehabilitation change during the mine life number of inactive or abandoned Chilean sand generally flat (which limits the height of tailings purposes. Beaching and hydraulic sorting are best tailings facilities have also performed well since • the tailings production rate and solids facilities but not their extent) and the seismicity assessed on the beach. Settling involves very large 1965, as they have drained down in the dry concentration which must be accommodated, and generally low. The same is generally the case for deformation and little strength gain, consolidation Chilean climate. how these change during the mine life southern Africa and the South-West of the United involves large deformation and significant strength States of America (USA). 68 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 69
gain, and desiccation involves some deformation and substantial strength gain. Loading the tailings Box 3: Constraints of the Limit Equilibrium method 10-8 beach could cause ‘bow-wave’ failure of tailings with Best I Category I projects a desiccated surface crust, requiring that loading Category II projects The calculated factor of safety does not warrant Category III projects be progressive on a broad front, which will result in 10-7 strength gain in the tailings as they drain over time. a precision of more than one decimal place. The II Category IV projects Limit Equilibrium method also assumes that all Data from real- 10-6 3.4 KEY CAUSES OF TAILINGS FACILITY points along the critical failure surface are at world projects FAILURES the same state (of failure), notwithstanding that brittle, cemented or bonded tailings resulting 10-5 Tailings facilities continue to fail at an unacceptably from desiccation and oxidation may be at high rate of about two per year (Rico et al. 2008). different failure states. Recent high profile failures in Brazil in 2015 and 2019 10-4 resulted in significant fatalities and involved major III mining companies. (the higher variability for closure reflects the fact 10-3 that closure is in perpetuity, nominally 10,000 years, Most tailings facilities that fail have marginal stability, IV and most tailings facility failures involve ‘water’, requiring gross projections from available earthquake Poor Annual Probability of Failure Annual 10-2 making drainage, clay cores and water management data in most cases). The undrained shear strength key. Many tailings are potentially liquefiable, either estimate for tailings may be ±50 per cent, while the under earthquake or static loading, although not all estimated drained friction angle for tailings may be 10-1 fail since the facility usually has adequate stability. ±3 degrees. There is clearly a need to use conservative Further, tailings in the embankment shell of centerline values in design and to carry out sensitivity analyses, 1 and downstream facilities that have been placed with but this has not always been the case in practice. compaction and drainage (as in Chile and Canada), have been shown not to be susceptible to liquefaction. The relationship between the calculated factor of 0.5 1.0 1.5 2.0 ‘safety’ and the corresponding probability of ‘failure’ Another cause of tailings facility failure can be a weak Factor of Safety foundation layer (often unidentified, possibly moving must also be understood, particularly as it relates to the standard of design and construction. This is from over- to normally-consolidated on progressive Source: Adapted from Silva et al. 2008 raising). illustrated in Figure 2 (adapted from Silva et al. 2008). The figure shows that poor design and construction Figure 2. Relationship between calculated factor of safety and corresponding probability of failure, as it to a factor of safety of 1.5 corresponds to a very relates to standard of design and construction Many tailings facilities that fail have been constructed -1 upstream. Equally, there are many traditional tailings high and unacceptable probability of failure of 10 . facilities that have used the upstream method of By contrast, best design and construction, also to construction that are fully resistant to all external a factor of safety of 1.5, corresponds to a very low -6 While considerable work has been devoted to risk loads and will provide excellent operating and closure probability of failure of 10 , at the level of acceptability assessment, there is relatively little guidance on the Box 4: Implications for Tailings Facility design stability. Nonetheless, use of upstream construction generally adopted for aircraft travel. acceptability of risk. Whitman (1984) attempted to takes a higher level of design, independent review and Clearly, tailings facilities can be built to a While attractive to many, the use of limit-equilibrium plot the annual probability of failure against lives operating discipline than some facilities are afforded similar margin of safety as water facilities, at a factors of safety are, at best, a guide and should lost and dollars lost (in 1984 $). Key findings from and unless all of the key elements of strong design, probability of failure of about 10-4. If this were not be the sole discriminator for the security of a this analysis are reproduced in Figure 3. Whitman review and operating practices can be assured, done, it would prevent many tailings facility tailings facility. Alternative approaches, for example assigned bubbles to represent different activities and upstream facilities do present a higher risk than failures, and the associated loss of life, damage deformation evaluations, may be far more appropriate types of infrastructure such as civil aviation (assigned centreline or downstream facilities. to infrastructure, and environmental harm. for many facilities. Further, depending upon the an ‘acceptable’ annual probability of failure of about 10-6), water facilities (at about 10-4), buildings (at In relation to the design of tailings facilities, reliance parameters used, a factor of safety of 1.1 can be between 10-5 and 10-4), foundations (at between 10-3 has traditionally been placed on stability analyses associated with a facility presenting zero risk of harm and 10-2), mine pit slopes (at about 10-1), and shipping carried out using the deterministic Limit Equilibrium to society, whereas one with a much higher computed (at between 10-3 and 10-2). Whitman also added method, typically with a single set of design value (above 1.5) may present a high risk of harm. possibly upper bounds for ‘acceptable’ and ‘marginally parameters (see Box 3). The key parameters include How a facility will strain under load (brittle versus acceptable’. To Whitman’s plot has been added the the annual rainfall, which typically varies from 50 to ductile), along with the nature of the input parameters, wide range for tailings facilities (from 10-4 to 1), 200 per cent of the average annual rainfall. The site are but two key reasons why the factor of safety is not based on the high tailings facility failure rates and seismicity has a variability of perhaps ±20 per cent as useful a tool as many consider it to be. consequences. Implications for tailings facility design for operations to perhaps ±50 per cent for closure are given in Box 4. 70 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 71
in Chile following an earthquake-induced tailings Water recovery from the tailings storage itself is facility failure in 1965 that killed more than 200 generally limited to the recovery of supernatant water1 Lives lost people, and in Brazil following the Brumadinho (the water that pools at the end of the tailings beach), 10-2 10-1 100 101 102 103 104 tailings facility failure in 2019 that killed 270). although seepage through the wall may also be collectable. Other tailings water is lost to entrainment 10-0 3.6 ALTERNATIVE APPROACHES TO TAILINGS within the tailings, evaporation from the decant pond2 Marginally accepted MANAGEMENT and wet tailings, and seepage into the foundation and through the embankment. ‘Leading’ or ‘best’ current practice in tailings Accepted 10-1 management has been documented in numerous Mine In order to maximise the recovery of supernatant pit guidance documents, guidelines and handbooks water from the tailings storage, good design, slopes Merchant shipping (see the Appendix to this chapter). Conventional construction and management of the water return storage methods can be a ‘best practice’ for the ‘Geisers’ system is required. This should include the planning TAILINGS DAMS right site conditions, but for many sites, alternative 10-2 Mobil drill rigs and implementation of tailings disposal to direct technologies would be a better option. Alternatives to supernatant water to the decant pond, minimising current tailings management practices are described Foundations the size of the decant pond and the rapid return of in several of these documents. Super tankers supernatant water to minimise evaporation losses, -3 Fixed drill rigs and maintaining the decant pumps and water return 10 Can The following sections consider a range of alternative vey LN pipelines. Canvey refineries G tailings management options, most of which use st or ag currently available technology (Williams 2015). e The overall tailings water recovered as a proportion The innovative aspects of these technologies lies of the total water used in processing is typically 50 -4 mainly in their application to tailings management. 10 Dams to 60 per cent for tailings disposal as a slurry. This Sound management practices are also essential for increases to 60 to 70 per cent for tailings disposal as Canvey recommended conventional tailings deposition.
Annual Probability of ‘Failure’ Annual a high-density slurry. 3.7 ACHIEVING PHYSICAL STABILITY AND 10-5 E 3.8 ON-OFF TAILINGS CELLS st Other im WATER RECOVERY VIA DEWATERING at LNG ed TAILINGS As an alternative to in-plant dewatering, desiccation U S studies D and harvesting of black coal tailings in ‘on-off’ a Achieving physical stability of tailings via dewatering Commercial m tailings cells has been employed at a number of aviation s (how dry is possible, and how dry is dry enough) 10-6 mines, including at Charbon Coal Mine in New must be balanced against the need to ensure their 10-4 10-5 10-6 10-7 10-8 10-9 10-10 South Wales since 1990 (see Figure 4). This method geochemical stability. The latter requires maintaining can be effective provided that the tailings are $ Lost the tailings near-saturated and preferably permanently deposited in thin sub-layers, preferably no more under water, requiring a permanent impoundment and Source: Adapted from Silva et al. 2008 than 600 milimetres thick, since desiccation by solar water supply. and wind action drops off exponentially with depth. Figure 3. Acceptability of failure Sufficient time (of the order of several weeks) must The recovery of water in-plant is the most effective also be allowed for desiccation of each sub-layer means of maximising water return for recycling and before further sub-layers are added, to a maximum the retention of any residual process chemicals. depth of about 3 metres, and before the full depth of Tailings are conventionally thickened prior to disposal 3.5 CONSEQUENCES FOR INDUSTRY • an instantly ‘social media-connected’, although not dried tailings is harvested. This necessitates a large to a surface tailings storage. The slurry concentration necessarily well-informed, community number of cells covering a large footprint -although As a result of the unacceptably high rate and severe achievable by conventional thickeners varies with probably no larger a footprint than would ultimately consequences of ongoing tailings facility failures, • major investors, such as the Church of England, the type of tailings, typically ranging from 25 per be needed for a conventional surface slurried tailings there has been a loss of trust and confidence in the BlackRock and the United Nations-supported cent solids by mass for coal tailings and alumina facility. The harvested dried tailings can be co- industry’s ability to safely manage tailings. While the Principles for Responsible Investment international residue (red mud), and up to 40 to 50 per cent solids deposited with coarse wastes, so that ultimately there vast majority of tailings facilities do not fail, the failure network (PRI) for metalliferous tailings. Smaller diameter high rate rate is still beyond that deemed acceptable to both the is no dedicated tailings storage facility. • insurers, who are making cover more difficult and high compression thickeners raise the solids industry and society. Further, the very clear lessons to obtain and more expensive, leading to self- concentration further, but with less torque than from failures indicate that there is an ability to reduce insurance by major mining companies and creating conventional thickeners. the rate of failures considerably towards a goal of difficulties if not near impossibility for mid-tier zero catastrophic incidents. The track record to date, mining companies in securing cover however, has created threats to the mining industry’s financial and social licences to operate, coming from: • regulators, who are imposing stricter requirements 1. Supernatant water is the water that pools at the end of the tailings beach. (for example, outlawing upstream construction 2. The decant pond is the body of supernatant (process) water that has separated from the tailings solids, plus any rainfall runoff collected on the tailings facility. (Department of Industry 2016, p.110). 72 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 73
Red mud has a specific gravity of about 3.0 and is to a depth of about 300 mm. Amphirolling or scrolling difficult to densify due to it forming a loose ‘card- can increase the dry density to about 0.9 tonnes per house’ structure of low permeability. Without farming, cubic metre, and dozing can increase it further to 1.3 the dry density achieved is typically limited to about to 1.4 tonnes per cubic metre. 0.7 tonnes per cubic metre, and desiccation is limited Source: Author Source: Insufficient desiccation Full-depth drying Dumping
Figure 4. On-off coal tailings cells, employing solar and wind drying, harvesting and disposal with coarse reject
3.9 THICKENING – IS THERE A PRACTICAL • Some drying and strengthening of the tailings LIMIT? or residue surface is required to allow safe and efficient amphirol operation. If conventional thickening and slurry disposal fails to achieve adequate settling and consolidation • Too heavy a bearing pressure from the amphirol and supernatant water recovery, secondary (inline) and/or too soft a tailings or residue surface leads Author Source: flocculation3 can be applied just prior to tailings to bogging of the amphirol. An amphirol will only Figure 5. Amphirol or scroller on red mud Figure 6. D6 Swamp Dozer on red mud discharge to re-flocculate conventionally thickened achieve minimal consolidation or compaction of tailings that have been shear-thinned by pumping. the tailings or residue since its bearing pressure is 3.11 PASTE TAILINGS dewatering facility is located close to the discharge low. point, possibly on a mobile skid that can be moved. Paste thickeners raise the percentage of solids to The practical limit to thickening is considered to be a Underground tailings paste backfill will generally reach • An amphirol should: between 45 per cent (for red mud) and 75 per cent for consistency that is just pumpable by inexpensive and its intended destination under gravity, provided that robust centrifugal pumps. However, this consistency metalliferous tailings. The relative consistencies of - essentially ‘float’ over the tailings or residue the angle between the discharge and final points is will vary with the particle size distribution of the high-density thickened slurry and high and low slump surface steeper than 45 degrees. tailings and, particularly, with the clay mineral type and paste metalliferous tailings are illustrated in Figure 7. - create trenches down the tailings or residue proportion. The overall tailings water recovery as a percentage beach to facilitate the drainage of surface water Pumping paste tailings to a surface tailings storage of the total water used in processing increases to requires piston pumps, which are about an order of 3.10 ‘FARMING’ OF TAILINGS - maximise the tailings or residue surface area about 80 per cent for tailings disposal as a high slump magnitude more expensive than centrifugal pumps, exposed to evaporation and strengthening, and paste, and to 85 to 90 per cent for tailings disposal Some forms of wet and soft tailings, particularly cost more to operate, and are more sensitive to - expose undesiccated tailings or residue on as a low slump paste. However, to date the practical clay-rich tailings or process residue, may benefit from variable input feeds. Also, piston pumps discharge a further farming. applications of paste tailings have typically been ‘farming’ by the use of equipment such as an amphirol ‘toothpaste-like’ consistency, which requires that the limited to gravity deposition in-pit or as a cemented or scroller, and/or later by a D6 Swamp Dozer. discharge point be constantly moved. However, paste Farming is widely applied to red mud in Australia, and • An amphirol should not over-shear the tailings or underground backfill. residue by excessive or repeated farming; about tailings can be delivered under gravity as underground has been trialled on other tailings, including on coal backfill (usually with cement added) or into a pit if the tailings and fly ash in Australia, and oil sands tailings four amphirol passes is optimal. in Canada. A D6 Swamp Dozer has a bearing pressure of about An amphirol (shown in Figure 5, Williams 2014) has a 35 kilopascals and can be used once the tailings very low bearing pressure of 3 to 5 kilopascals and is or residue has gained sufficient shear strength and used first. The principles of tailings or residue farming bearing capacity to safely support it (see Figure 6). by amphirol are as follows: A dozer could be used after amphirolling or simply after the tailings or residue has desiccated naturally • The tailings or residue can be poured to a thickness on exposure. Dozing improves the already desiccated of 700 to 900 mm, up to three times the thickness if tailings by compaction, leading to a further increase in surface desiccation only was allowed. dry density and shear strength. Source: Author Source: High density slurry High slump paste Low slump paste 3. Flocculation is a process widely used in mineral processing whereby small particles in suspension are aggregated to make larger clusters (flocs) that are more easily separated than the original particles. Figure 7. Consistency of thickened and paste tailings 74 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 75
3.12 FILTRATION AND DRY STACKING Filtration of tailings can be achieved by vacuum, belt 3.13 BRIQUETTING rejects into a material that is transportable by truck press, plate and frame, or screw (although screw has been practiced in British Columbia. This results in If a consistency greater than is readily pumpable Briquetting has been shown in trials to be very filters have not been taken up for tailings) methods. a compactable material that can be used to develop by centrifugal pumps is desirable, filtration may be effective in dewatering ultra-fine black product coal While centrifuging and filtration can produce a cake stable stacks that more resemble a conventional mine preferable to producing paste tailings. Centrifuges or (Williams 2012). This technology can also potentially of similar moisture content or the percentage of waste dump than a tailings facility. belt press filters can produce a ‘wet’ filter cake, while be applied to tailings. In the trials, ultra-fine product solids, the greater pressures imposed by filtration will plate and frame or screw filtration can produce a ‘dry’ coal that was initially at 40 to 45 per cent total create a ‘structure’ that makes the filtration cake more The pumped co-placement of combined coal tailings filter cake. The filter cake can then be transported by moisture content was dewatered to about 15 per ‘permanent’, more readily transportable by conveyor and coarse coal rejects has been practiced at a truck or conveyor. Centrifuged filter cake may still flow, cent total moisture content (85 per cent solids) by or truck without inducing flow, and more manageable numerous coal mines in Australia and Indonesia, while dry filter cake can be compacted. squeezing the slurry between two rollers under very (see Figure 8). since this method was first introduced at Jeebropilly high stress (of the order of 50 megapascals). The Coal Mine in the Ipswich Coalfields of South-East very high stresses imposed over very limited duration Queensland in about 1990. resulted in further dewatering of the briquettes formed, in a dry atmosphere, to about 2 to 5 per cent Pumped co-disposal in-pit at Jeebropilly Coal Mine is total moisture content (95 per cent solids). The air- shown in Figure 11 (Morris and Williams 1997; 1999). dried briquettes can re-wet in a humid atmosphere, Unfortunately, in order to avoid pipeline blockages, the but only to about 15 per cent of total moisture content, combined washery wastes are pumped at a low 25 to and they retain their ‘briquette’ lumpy structure. This 30 per cent solids and at high velocity (up to 4 m/s). sequence of drying and re-wetting is illustrated in This results in the unintended segregation of most of Figure 10. However, the high initial CapEx and high the fines and the generation of an undesirable flat (at OpEx of briquetting have discouraged its application to about a 1 in 100 slope) fines beach (mostly tailings) either ultra-fine black product coal or tailings. beyond the desirable steep upper coarse-grained beach (at about a 1 in 10 slope). In addition, the 3.14 CO-PLACEMENT OF TAILINGS AND COARSE- inclusion of the coarse rejects results in high pump GRAINED WASTE Source: Author Source: and pipeline wear. Centrifuged (wet cake) Filtered (dry cake) Co-placement of fine coal (tailings) rejects and coarse Figure 8. Consistency of centrifuged and filtered tailings
Dry tailings filter cake better lends itself to dry as shown in Figure 9 for coal tailings. It is essential 50 stacking, although even then compaction may be to avoid confusion around the nomenclature adopted required to form a stable stack, and to limit oxygen for these filtered tailings: although termed ‘dry’, 45 ingress and rainfall infiltration into potentially they do retain moisture after processing and when contaminating tailings in order to minimise placed. The more correct term would be ‘unsaturated’ 40 contaminated seepage. Dry stacking, sometimes stacked tailings, but the existing terminology is well- 35 involving compaction, has found most favour in dry established and should be understood by most in the climates such as northern Chile. Dry tailings filter cake industry. 30 can also be co-disposed with coarse-grained wastes, 25
20 Initial drying on briquetting to ~15%
15 Total Moisture Content ( ) Total Moisture Content 10 Partial re-wetting 5 Further atmospheric drying to 2-5 0 0.01 0.1 1 10 100 1000 10000 100000 1000000
Matric Suction (kPa) Source: Author Source: Belt press filter Conveying Co-disposal in spoil piles Filtered ultra-fine: drying curve Briquetted ultra-fine: drying data Briquetted ultra-fine: wetting data Figure 9. Belt press filtering of coal tailings, transportation of filter cake and coarse reject by conveyor, and end-dumping in spoil piles S W
Figure 10. Briquetting trial on ultra-fine black product coal 76 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 77
compressibility and a permeability that is lower than that of waste rock alone, but higher than that of Box 5: Challenges of closing conventional tailings alone. tailings facilities
3.18 REDUCED TAILINGS PRODUCTION Post-closure, surface tailings facilities are required to remain physically and chemically While it is not the major focus of this chapter, it should stable in perpetuity, which can be mutually be noted that more attention is now being paid to exclusive objectives. Some conventional wet Source: Author Source: finding ways of reducing tailings production. This is in tailings facilities have soft tailings deposits that Figure 11. Pumped co-disposal of combined coal tailings and coarse coal rejects response to the ever-increasing production of tailings, are difficult and expensive to physically cover and due to decreasing ore grades and increasing demand rehabilitate, particularly at the end of the mine for minerals. Another driver has been the rising cost life when it is no longer producing revenue and 3.15 PIT TAILINGS STORAGE haul truck or conveyor. This method has also been of energy and other mining and processing inputs. construction equipment is being demobilised. employed in the wet tropics to encapsulate potentially The primary focus of innovation has been on coarse Storing tailings in completed pits is gaining favour, Further, the presence of wet and soft tailings acid forming tailings and waste rock behind a robust particle or dry processing. New technologies that are particularly as permitting of new surface tailings at some locations will limit the future land use containment of more benign waste rock constructed being applied to facilitate these alternatives include storages meets with increasing community opposition. potential of the tailings storage. On the other in compacted layers. ore sorting using magnetic resonance technology, and This option can be attractive when pit backfilling does hand, their high degree of saturation will limit the ‘precision mining’. not sterilise potential future ore reserves. It can be very oxidation of any sulphides present in the tailings. 3.17 ‘PASTE ROCK’ AND ‘ECOTAILS/GEOWASTE’ attractive financially as it eliminates the need for the construction of a containment structure and does not Another approach has been to combine filtered require further thickening of the tailings. It also fills tailings with waste rock. Examples include: 4. CLOSURE CONSIDERATIONS • water covers are appropriate for wet climates as the void, albeit with wet and soft tailings that are very Surface tailings storage closure should be developed effective oxygen barriers difficult to rehabilitate. • ‘Paste Rock’, patented by Golder Associates, which with community input and address the agreed post- has been trialled in Canada for mine waste covers • water-shedding soil covers are appropriate in moist mining land use. Irrespective of the use(s) agreed A challenge with implementing this option is that the (Wilson et al. 2008) climates to promote rainfall runoff and limit net upon, considerations for all facilities entering their rate of rise will be high in-pit due to its small footprint, percolation of rainfall • ‘EcoTails/GeoWaste’, patented by Goldcorp, which closure phase will include: particularly in the early stages. It is also difficult to incorporates filtered tailings and screened or • store and release soil covers, which store manage the supernatant water due to the steep pit crushed waste rock (Burden et al. 2018). • facility geotechnical instability – Tailings are wet season rainfall, releasing it through slopes limiting access to pumps, and the reduced expected to drain down on cessation of deposition, evapotranspiration during the dry season to sustain evaporation of water by sun and wind (by up to 2-fold The practical and economic challenges that must but may be recharged by high rainfall (in the revegetation, are appropriate for dry or seasonally compared with surface ponds). This will severely be overcome to promote the combination of filtered absence of a spillway) dry climates to sustain vegetation and limit net limit dewatering, consolidation and strengthening tailings and waste rock include: percolation of rainfall. of the tailings through desiccation. Consolidation • facility erosional instability, particularly in a dry of the tailings will be high and ongoing, causing the climate if the slope is flattened and topsoiled • Minimising the extent to which the tailings must In seasonally dry climates, store and release covers tailings surface to ‘dish’, reflecting the shape of the be dewatered, in order to save costs, while not • differential tailings settlement, affecting slope are more robust than rainfall-shedding covers since pit. A further disadvantage could be the potential for compromising the stability of the tailings/waste profile and drainage they better sustain vegetation and limit erosion. Store the contamination of any groundwater resources rock mixture. and release covers require a base sealing layer to limit surrounding the pit, if contaminated pit water rises • poor water quality (saline, and/or acidic, or alkaline), the breakthrough of rainfall infiltration, and may take above the surrounding groundwater level. In addition, • Minimising the crushing or screening of the waste after a lag: advantage of the natural tailings beach slope to direct the stability of underground mining operations in the rock to allow mixing with the filtered tailings and clean excess rainfall infiltration towards a collection vicinity may be jeopardised. A further consideration is transportation. The top-size of the waste rock for - ponded water, and in any spill ponding below the point, avoiding breakthrough into the underling that, in a dry climate, a final pit lake over tailings will conveying is about 200 to 300 mm, while coarser- tailings facility tailings. inevitably contain water of increasingly poor quality grained waste rock can be trucked. - emerging at low points around toe, and/or due to the concentration of salts and contaminants • Achieving adequate mixing of the filtered tailings - infiltrating to any groundwater resource. Any soil cover over tailings is necessarily relatively through net evaporation. and waste rock. This is unlikely to occur on a thin, and hence is prone to breakthrough. Also, all conveyor or on dumping from a haul truck, but Box 5 summarises the challenges involved in closing soil covers have some ‘store and release’ function. 3.16 WASTE LANDFORMS may be achieved by a number of drop points into facilities containing wet and soft tailings deposits. Historically, soil covers were limited in thickness and Integrated waste landforms are being employed in hoppers along a conveyor line. were placed primarily to support revegetation. Over Australia, particularly at coal and iron ore projects, The rehabilitation of tailings can range from direct time, an increase in cover thickness was seen as an • Compaction of the mixture may be required to including new projects. This involves either the revegetation of benign tailings, to soil covers, and also ‘improvement’. Rainfall-shedding covers followed the produce a stable deposit, although this could be construction of a robust containment for thickened water covers, depending on the climatic setting. The approach taken to cover landfills, but are prone to restricted to the perimeter of the emplacement. tailings using waste rock, or the co-disposal of Global Acid Rock Drainage [GARD] Guide (INAP 2009) failure in dry or seasonally dry climates due to erosion. mixtures of filtered tailings, and waste rock or coarse- recommends that the choice between cover types Too thin a cover lacks the capacity to store rainfall The benefits of combining filtered tailings and waste grained processing wastes, delivered by combined based on climatic conditions should be guided by the infiltration, can dry out during prolonged dry periods, rock can include improved geotechnical parameters, pumping (such as for coal washery wastes), or by following considerations (Figure 12): and can be punctured by erosion. Store and release including increased shear strength, reduced 78 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 79
Without proper management, differential contour and downslope drains on tailings facility consolidation settlement of tailings can disrupt embankment slopes concentrate rainfall runoff and 0.125 any constructed surface drainage features on a are prone to failure due to overtopping and piping tailings cover, particularly as they are gently sloping failure. 50 (typically less than one per cent). This will also result
0.25 in surface ponding of rainfall runoff on the tailings, The reality is that in many regions in the world, few recharging and exacerbating seepage. However, the surface tailings storages have been successfully 125 hydraulic conductivity (permeability) is generally low rehabilitated, due to the associated costs, with
0.5 due to the fine-grained particle size of most tailings, reprocessing and in-pit storage being increasingly Permafrost 250 and particularly those that contain clay minerals or considered as alternatives. As argued above, the Annual Precipitation (mm) Thermal Covers sulphides that hardpan. Consequently, consolidation conventional cost-based approach to surface tailings Latitudinal Region (freeze thaw effects) 1 can be slow and difficult to predict, and clay mineral- storage rehabilitation is often at odds with the 500 -8ºC rich tailings may remain under-consolidated. potential for value-added rehabilitation, as described Polar in Table 1 (Williams 2019). A focus on the costs 2 1000 1.5ºC The treatment of the side slopes of a tailings facility of tailings storage rehabilitation by operators and is often given only limited attention. While slope regulators discourages rehabilitation activities post- Sub-polar Water Covers 4 2000 flattening will increase geotechnical slope stability, closure, which in turn is likely to lead to increased Water Shedding Covers Infiltration Control Low Permeability Oxygen Barriers 3ºC it may not be required for this purpose. A downside impacts over time, exacerbating the situation. Boreal Potential Evapotranspiration Ratio Organic Covers of slope flattening is that it will likely increase the By contrast, identifying and realising potential 8 (erosion) 4000 potential for erosion due to the increased slope opportunities for value-added rehabilitation and post- 6ºC catchment and runoff, particularly if erodible topsoil is closure land uses sets the rehabilitation budget and is Cool Temperate 16 Store and Release placed on the slope to facilitate revegetation. Further, a potential win for all stakeholders. 8000 (sustainability of 12ºC Warm Temperate vegetation) Sub-tropical Table 1. Conventional cost-based rehabilitation versus value-added rehabilitation 32 24ºC Tropical 16000
Super- Perarid Arid Semi- Sub- Humid Per- Super Conventional Cost-Based Rehabilitation Value-Added Rehabilitation arid arid humid humid humid Production rules Post-closure ‘value’ is identified upfront Rehabilitation is seen by operator and Examples of post-closure value include: Source: INAP 2009 regulator as a ‘cost’ • Re-processing of tailings to extract metals of value, Operator discounts cost over time, Figure 12. Choice of cover related to climate depositing the residual tailings in-pit and reducing the discouraging rehabilitation rehabilitation liability covers gained popularity for dry climates but have a layer makes it difficult for roots to extract deep Infrastructure such as power lines and • Industrial land use not always been well designed and constructed. A drainage, leading to a wetting-up of the cover and buildings are stripped for little financial gain • Renewable energy– solar, wind and pumped storage, composite cover is seen by regulators to be ‘better’, increased risk of breakthrough. Rehabilitation is limited to ‘smoothing’ and delivered to the grid via mine transmission lines but by operators to be more costly. ‘greening’ (where sustainable) Exposure to the atmosphere of potentially acid • Agriculture and/or fishery impoundment Tree death (when tree roots reach contaminated generating or otherwise potentially contaminating • Tourism and heritage (older the better) tailings) and/or blow-down of shallow-rooted trees, tailings may require that they be maintained under due to roots spreading laterally across a compacted water, preferably from disposal onwards. The Post-closure land use and function are limited ‘Value’ sets rehabilitation budget layer or contaminating tailings, can threaten the downside is that this will leave slurry tailings soft and integrity of a cover over tailings. However, excluding wet. In wet climates and valley topographies, it may Operator is threatened with loss of financial Potential wins for operator, future land user and Government tree growth is unsustainable. To address these issues, be possible to maintain the tailings underwater in and social licences to operate use may be made of shallow-rooted plants or plants perpetuity, provided that the stability of the facility’s that can survive on toxic tailings and/or take-up containment embankment can be assured. In dry contaminants. climates and in flat terrain, the focus will need to be on 4.1 BARRIERS TO IMPLEMENTATION OF adoption of alternative tailings management. minimising rainfall runoff over exposed contaminating INNOVATIVE TAILINGS MANAGEMENT Barriers to the implementation of innovative tailings management include the following: Store and release covers are designed to have tailings and the net percolation of rainfall that would Conventional slurried tailings deposition remains a sustainable tree, shrub and grass cover to transpire transport contaminants. Alternatively, potentially best practice option for many sites. However, the • The continued reliance on NPV accounting and moisture. There is an optimal store and release contaminating tailings could be placed in a completed industry currently has a range of options beyond the use of a high discount factor (typically 6 to 10 growth medium thickness, of the order of 1.5 to pit or underground mine and maintained underwater, this conventional approach and for those where per cent, which is three to five times the consumer 2 m. Too thin a layer does not store sufficient rainfall or contaminants could be removed by additional conventional deposition and storage is not the best price index). This approach favours tailings infiltration delivered by the climate, while too thick processing, such as desulphurisation. option. This begs the question of what is stopping 80 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 81
management options that are cheap in the short- natural resistance to doing things differently to the term (particularly for CapEx), and delays necessary way they are usually done in those jurisdictions. KEY MESSAGES expenditure on rehabilitation. These factors together are likely to exacerbate impacts and blow- Tailings facilities can be built to a similar margin of out rehabilitation costs. safety to that of water dams, at a probability of failure of about 10-4. This would prevent many tailings facility 1. If tailings facilities were built to a similar margin of safety to water dams, • Alternative tailings management options, such failures, and the associated loss of life, damage to as mechanical dewatering and co-disposal, are this would prevent many tailings facility failures. infrastructure, and environmental harm. It would also seen as too costly. This view is reinforced by NPV restore the industry’s financial and social licences accounting. 2. There is a commonly held perception in the mining industry that to operate. The implementation of existing and new • There are perceived and real technical difficulties technologies to tailings management could help to transporting tailings as a slurry to a facility is the most economic associated with mechanical dewatering and co- eliminate the risks posed by a subset of conventional approach, but this fails to factor in the true cost of closing and storage (for example, high clay mineral content, and tailings facilities, possibly removing them altogether. handling coarse-grained wastes). Such technologies include: rehabilitating the resulting tailings facility. • Uncertainty – and perceived higher risk – of new • optimising in-plant dewatering of tailings, approaches also serve to discourage innovation. 3. A rethink is required about the way in which tailings management is particularly by thickening or filtration costed. A substantial portion of global tailings practice still uses the Net Underlying all of this is an inherent resistance to • ‘farming’ deposited tailings that consolidate poorly Present Value (NPV) approach with a high discount factor. What is needed change, which is often disguised as unsubstantiated • dry stacking of filtered tailings claims about perceived high costs, perceived technical is a whole-of-life cost approach. obstacles, and perceived uncertainty. • co-disposal of tailings and coarse-grained waste • in-pit tailings disposal, particularly if final pit lakes 4. In practice, not enough tailings facilities have been successfully containing water of diminishing quality can be rehabilitated, due to the difficulty of capping a ‘slurry-like’ (wet and soft) CONCLUSIONS avoided by complete back-filling tailings deposit and the excessive cost involved, particularly at a time when Tailings management must take into account the • integrated waste landforms that re-combine tailings nature of the tailings and, importantly, the climatic, and coarse-grained wastes the mine is no longer producing revenue. topographic and seismic settings of the mine. The • reduced tailings production through coarse or dry ongoing rate of tailings facility failures is unacceptable 5. The implementation of existing and new technologies to tailings processing to both industry and society, and there is a need to management could help to eliminate the risks posed by the nature of restore trust and confidence in the industry’s ability • value-added tailings rehabilitation post-closure. to safely manage tailings. A rethink is required about conventional tailings facilities that have been responsible for the failures the way in which tailings management is costed. As discussed, there are several barriers to the that have occurred, possibly removing them altogether. Too many jurisdictions continue to rely largely on implementation of innovative tailings management a net present value (NPV) approach with a high where they are indicated by site-specific conditions, discount factor, rather than a whole-of-life cost particularly where existing facilities are concerned. 6. A fundamental barrier to the implementation of innovative tailings approach. There is scope for the further development Change will be more readily achieved in new mining management at those sites that would benefit from these technologies is and implementation of new tailings management projects and hence change in tailings management people’s resistance to change, which is often disguised as unsubstantiated technologies and innovations, and for the use of for the mining industry as a whole will necessarily be different cost models, but this must overcome the generational. claims about perceived high costs, technical obstacles and uncertainty.
7. Change is more likely to be achieved in new mining projects than existing operations. Hence, change in tailings management for the industry as a whole will necessarily be generational. 82 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 83
REFERENCES Williams, D.J. (2014). An alternative whole-of-life approach to tailings management. Proceedings of Life-of-Mine 2014, 16-18 July 2014, Brisbane, Australia. 285-298. ANCOLD (2012). Guidelines on Tailings Dams – Planning, Design, Construction, Operation and Closure. Canberra: Australian National Committee on Large Dams. Williams, D.J. (2015). Towards the elimination of conventional surface slurried tailings storage facilities. Proceedings of Tailings and Mine Waste Management for the 21st Century, Sydney, Australia, 27-28 July 2015, Burden, R., Wilson, G.W, Williams, D.J. and Jacobs, M. (2018). The shear strength of filtered tailings and 11-23. waste rock blends. Proceedings of Tailings and Mine Waste 2018, 29 September to 1 October 2018. Keystone, Colorado. 347-355. Williams, D.J. (2017). Future Tailings Management. Proceedings of Tailings 2017, Santiago, Chile, 12-14 July 2017, 8 p. CDA (2013). Dam Safety Guidelines. Toronto: Canadian Dam Association. Williams, D.J. (2019). Obstacles to effective mine closure, rehabilitation and relinquishment. Proceedings of CDA (2020). Application of Dam Safety Guidelines to Mining Dams. Toronto: Canadian Dam Association. Tailings and Mine Waste 2019, 17-20 November 2019. Vancouver, Canada. 1271-1286. Davies, M.P. and Rice, S. (2004). An alternative to conventional tailing management – ‘dry stack’ filtered tailings. Wilson, G.W., Wickland, B. and Miskolczi, J. (2008). Design and Performance of Paste Rock Systems for Proceedings of Tailings and Mine Waste 2004. 10-13 October 2004. Vail, Colorado. 411-422. Improved Mine Waste Management. Proceedings of Fifth International Seminar on the Management of Rock Dumps, Stockpiles and Heap Leach Pads.5-6 March 2008. Perth, Australia. 107-116. International Network for Acid Prevention [INAP] (2009). Global Acid Rock Drainage Guide. www.gardguide.com.
Department of Industry (2016) Tailings Management. Leading Practice Sustainable Development Program for the Mining Industry. Australian Government: Canberra. www.industry.gov.au/data-and-publications/leading- practice-handbook-tailings-management. APPENDIX – GUIDANCE ON BEST OR LEADING • EPA (1994). Technical Report – Design and TAILINGS MANAGEMENT Evaluation of Tailings Dams MAC (2019). Developing an Operation, Maintenance, and Surveillance Manual for Tailings and Water Management Global references to best or leading tailings • SANS 10286 (1998). Code of Practice for Mine Facilities, Version 3.1. Ottawa: Mining Association of Canada. management include (but are not limited to): Residue Deposits • GARD Guide (2009) USEPA (1994). Technical Report – Design and Evaluation of Tailings Dams. Washington DC: United States • ICOLD bulletins: Environmental Protection Agency. • ANCOLD (2012) Guidelines on Tailings Dams - 44: Bibliography: Mine and Industrial Tailings • Leading Practice Handbook: Tailings Management ICMM (2016). Position Statement – Tailings Management. London: International Council on Mining & Metals. Dams and Dumps (1982) (2016) https://www.icmm.com/position-statements/tailings-governance - 44a: Bibliography: Mine and Industrial Tailings Dams and Dumps (1989) • CDA (2013). Dam Safety Guidelines ICOLD (from 1982). Various bulletins on tailings storage. Paris: International Committee on Large Dams. - 45: Manual on Tailings Dams and Dumps (1982) • CDA (2020) Application of Dam Safety Guidelines to Morris, P.H. and Williams, D.J. (1997). Co-disposal of washery wastes at Jeebropilly Colliery, Queensland, - 74: Tailings Dam Safety – Guidelines (1989) Mining Dams. Canadian Dam Association Australia, Transactions IMM, A: Mining Industry. 106:A25-A29. - 97: Tailings Dams – Design of Drainage (1994) • Mining Association of Canada [MAC] (2019). - 98: Tailings Dams and Seismicity – Review and Developing an Operation, Maintenance, and Rico, M., Benito, G., Salgueiro, A.R., Díez-Herrero, A. and Pereira, H.G. (2008). Reported tailings dam failures. Recommendations. (1995) Surveillance Manual for Tailings and Water Journal of Hazardous Materials, 152(2): 846-852. Management Facilities - 99: Dam Failures Statistical Analysis (1995) Shokouhi, A. and Williams, D.J. (2015). Settling and consolidation behaviour of coal tailings slurry under - 101: Tailings Dams – Transport, Placement and • UN (2014). Safety guidelines and good practices for continuous loading. Proceedings of Tailings and Mine Waste 2015. 26-28 October 2015. Vancouver, BC, Canada. Decantation (1995) tailings management facilities. 1-11. - 103: Tailings Dams and the Environment – • ICMM (2016). Tailings Management. Review and recommendations. (1996), • ICMM (2019). Global Tailings Review. Silva, F., Lambe, T.W. and Marr, W.A. (2008). Probability and risk of slope failure. Journal of Geotechnical and - 104: Monitoring of Tailings Dams – Review and Geoenvironmental Engineering, ASCE, 134(12): 1691-1699. recommendations (1996) - 106: A Guide to Tailings Dams and SANS 10286 (1998). Code of Practice for Mine Residue Deposits. South African Bureau of Standards. Impoundments – Design, construction, use and ACKNOWLEDGEMENTS rehabilitation (1996) United Nations (2014). Safety guidelines and good practices for tailings management facilities. United Nations The authors wish to thank Michael Davies, Senior Economic Commission for Europe. - 121: Tailings Dams: Risk of dangerous Advisor – Tailings & Mine Waste, Teck Resources occurrences – Lessons learnt from practical Limited, for his helpful comments on an earlier draft of Whitman, R.V. (1984). Evaluating calculated risk in geotechnical engineering. ASCE Journal of Geotechnical experience (2001) this chapter. Engineering, 110(2): 143-188. - 139: Improving Tailings Dam Safety – Critical Aspects of Management, Design, Operation and Williams, D.J. (2012). Some mining applications of unsaturated soil mechanics. Geotechnical Engineering, 43(1), Closure (2006) 83-98. 84 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 85
MANAGEMENT OF TAILINGS: PAST, PRESENT AND FUTURE
single raise construction methods are the next most CHAPTER VII Box 1: Data limitations common. In-pit/natural landform and dry-stacked There may be incentives for companies to under- are the least common construction methods. While LESSONS FROM TAILINGS report on parameters such as the existence of upstream facilities currently make up 37 per cent of past stability issues, and to that extent the analysis total reported number of facilities, they have declined FACILITY DATA DISCLOSURES and data presented herein should be considered from a peak of 85 per cent of facilities constructed in conservative. The failure of tailings facilities also 1920-1929 to 19 per cent of new facilities in 2010- Daniel M. Franks, Professor & Program Leader, Governance and Leadership in Mining, Sustainable Minerals has the effect of contributing to under-reporting by 2019. However, there is variation across commodities. Institute, The University of Queensland, Australia the very fact that in some cases those facilities no Martin Stringer, W.H. Bryan Mining & Geology Research Centre, Sustainable Minerals Institute, The University of longer exist and thus their characteristics are not Analysis of the incidence of past stability issues Queensland, Australia disclosed. reveals strong trends across tailings facility raise Elaine Baker*, Professor, The University of Sydney, Australia and GRID Arendal, Arendal, Norway types and other parameters.3 Upstream and hybrid Rick Valenta, Professor & Director, W.H. Bryan Mining & Geology Research Centre, Sustainable Minerals The method used to request information facilities are the most likely to have reported a past Institute, The University of Queensland, Australia disclosure on tailings facilities from publicly-listed stability issue when normalised against the frequency Luis A. Torres-Cruz, Senior Lecturer in Geotechnical Engineering, School of Civil and Environmental Engineering, contemporary companies has produced a dataset of each raise type, with 18 per cent of active upstream University of the Witwatersrand, South Africa that is likely more representative of active tailings facilities reporting ‘notable stability concerns’ or failure Kristina Thygesen, Programme Group Leader, Geological Resources and Ocean Governance, GRID Arendal, facilities, omitting some closed facilities and the to be ‘confirmed or certified as stable’ at some point Norway large number of abandoned facilities for which in their history. The normalised prevalence of past Adam Matthews†, Director for Ethics & Engagement for the Church of England Pensions Board & Co-Chair of the there is no longer an owner responsible. There is stability issues reported by active upstream facilities Global Mining & Tailings Safety Initiative, United Kingdom also a possibility that the survey under-samples is twice that of downstream facilities and six times as John Howchin† Secretary General of the Council on Ethics for the Swedish National Pension Funds & Co-Chair less diligent companies, with lower governance many as dry-stack facilities. No active in-pit/natural of the Global Mining and Tailings Safety Initiative, Sweden standards, who failed to respond to the disclosure landform facilities reported a past stability issue. Stephen Barrie, Deputy Director for Ethics & Engagement for the Church of England Pensions Board, United request. These observations are consistent with analyses Kingdom of tailings facility failures, which show a greater The dataset does not include information from prevalence of failure for upstream facilities than for companies that are not publicly listed, such as other raise types (ICOLD and UNEP 2001).4 state-owned entities, privately-owned companies, and many mid-sized and junior companies, Taller and larger facilities (by volume) are also more 1. INTRODUCTION AND SUMMARY OF FINDINGS can be generated from the current dataset, they contributing to an under-representation of facilities likely to have reported a past stability issue, although represent a significant advancement of the science on In this chapter we report on lessons derived from an in countries such as China and Chile, and potentially facilities over 100m in height show fewer issues, tailings facilities. analysis of the most comprehensive global survey an over-representation of larger facilities. perhaps due to higher standards of construction. of tailings facilities ever undertaken. The data are The relationship with seismic hazard is complex. As Although the dataset does not capture all tailings derived from information disclosures by publicly seismic hazard increases, facilities are initially less facilities (see Box 1), it does represent 30 per cent listed companies, following a request by the Church mineral production as reported by the United States likely to have reported a stability issue, which may be of contemporary global commodity production, with of England Pensions Board and the Council on Ethics Geological Survey mineral commodity summaries. explained by the lower proportion of upstream and 83 per cent of the market capitalisation of publicly of the Swedish National Pension Funds. The request hybrid facilities in this fraction or the possibility that listed companies in the industry responding to the was made on behalf of the Investor Mining and Planned generation of tailings over the coming five facilities are built to higher standards of construction disclosure request. This significant representation 3 Tailings Safety Initiative, a group of 112 investors that years is 2.5 billion m per year for the reporting in earthquake prone regions. However, at locations of of active facilities makes it possible to scale trends represent US$14 trillion in assets under management. companies, with the total planned tailings under high and very high seismic hazard, the likelihood of a within the data to generate global estimates for some 3 The information disclosures reveal new data on 1743 storage expected to be 56.2 billion m , which facility reporting a past stability issue increases. parameters. unique tailings facilities, containing 44.54 billion m3 of represents a 26 per cent increase in tailings under waste material.1 storage over this five-year period. When scaled to Hybrid, upstream, downstream and centreline Our analysis finds that the number of tailings facilities 3 global mineral production we estimate 11.1 billion m tailings facilities were found to be associated with has significantly increased over time. The number of The chapter analyses this unique dataset for the first of additional tailings is expected to require storage in a significantly higher consequence of facility failure facilities doubled between 1955 and 1969 (14 years), time, presenting findings across a range of topics, tailings facilities per year over the coming five-year than those for dry-stack, single raise and in-pit/natural doubled again between 1969 and 1989 (20 years) including facility construction method, consequence period (14.4 billion t). Baker et al. (this volume) used landform facilities, as determined by company- and again between 1989 and 2020 (31 years). We of failure, the number of facilities that have reported mineral production and ore grades for a wide range project the total number of active tailings facilities at least one past stability issue, volume of tailings of commodities to estimate an annual output of 8.85 worldwide to be around 3,250 and the total number 3. We refer to stability issues throughout the chapter as synonymous under storage, and the rate of uptake of alternative billion t of tailings for 2016. with geotechnical stability, acknowledging that the geochemical stability of active, inactive and closed facilities around technologies to dewater tailings and reduce of tailings is a critically important issue, but not one addressed by the 8,500. This estimate is calculated by scaling the disclosures. geotechnical risk. While the findings presented here Of the reported tailings facilities, the upstream number of facilities reported in the dataset to global 4. In their analysis of tailings facility failures ICOLD and UNEP (2001:20) are only the beginning of the potential insights that construction method is the most common, followed find a greater prevalence of failures for upstream facilities, though they by downstream construction. Centreline, hybrid,2 and qualify this by stating: ‘The [stability] incidents must be reviewed in terms of the number of particular dam types in operation. The upstream method is the oldest and most commonly used method of tailings dam construction.’ 1. For a sense of scale, if this volume were spread evenly across an area the Elsewhere, ICOLD and UNEP (2001:24) argue that ‘In general, dams built by size of Manhattan island, it would be higher than all the skyscrapers. 2. The term ‘hybrid’ facility is used here to refer to facilities where multiple the downstream or centreline method are much safer than those built by the raise methods are utilised in the same facility over time. upstream method, particularly when subject to earthquake shaking.’ * Member of the GTR Multi-stakeholder Advisory Group † PRI Co-convener 86 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 87
commissioned modelling during facility design and or Board Chair. A follow-up letter was sent on April • All 23 out of 23 publicly listed members of the and Tailings Safety Initiative, GRID-Arendal compiled construction.5 Given that upstream facilities have 17, setting an extended deadline of June 7, 2019 for International Council on Mining and Metals (ICMM) the data into a database for analysis. The individual been considered by ICOLD and UNEP (2001) as less the disclosure (CoE and Swedish Council on Ethics, publicly disclosed. company disclosures were compiled independently by safe than downstream and centreline facilities, it 2019b). Correspondence was sent to a total of 727 two additional research teams from The University of could be expected that the construction of these companies, representing publicly listed mining, as well The proportion of market capitalisation of the Queensland and The University of the Witwatersrand, facilities is avoided in locations where the potential as oil and gas companies. The later were included due respondents was calculated on 4 November 2019 and shared with the GRID-Arendal team for consequence of failure is high, however, this does not to the potential exposure to tailings from oil sands using the Thomson Reuters Eikon financial data cross-checking, comparison and data-cleaning. A appear to be the case. operations and joint ventures. platform. searchable online database of the disclosures was published by GRID-Arendal on the 24th of January The removal of water from tailings to generate A specialist Environmental, Social and Governance In December of 2019 and January of 2020, a 2020, as the Global Tailings Portal (http://tailing.grida. thickened, paste or filtered tailings is an important (ESG) financial services provider was commissioned compilation of the disclosed data was sent to each no). innovation in tailings practice that has been identified to compile the list of companies and distribute the reporting company for verification. The majority of by a significant number of authors as having the letter requesting disclosure. The list of companies disclosing companies responded to this extra request, The S&P Global Metals and Mining Industry database potential to improve geotechnical and geochemical was generated using the Global Industry Classification resulting in 86 per cent of the entries of the dataset was used to assign individual mine site mineral stability (Nguyen and Boger 1998; Boger 2009; Standard.6 An additional 88 small and mid-market being subject to this additional layer of verification. production to the active tailings facility entries. The Boger et al. 2006; Jewell and Fourie 2006; Davies companies not listed in the above codes were added A full list of the companies that were contacted and most recent S&P Global production figures (2018) et al. 2011; Franks et al. 2011; Edraki et al. 2014). by investor participants in the initiative. the status of their disclosure is publicly available and were used.7 All tailings production was assigned to the Tailings dewatering has been identified as a priority published on the Investor Mining and Tailings Safety primary commodity of the operation. Global mineral by individual mining companies and peak industry The request specified that companies should report Initiative website (CoE and Swedish Council on Ethics, production figures from the United States Geological bodies (see for example, ICMM 2019). Analysis of all tailings facilities where the company has any 2019c). The version of the dataset analysed in this Survey (USGS), Mineral Commodity Summaries the disclosures shows that the uptake of filtered and interest, through subsidiaries, partnerships, joint chapter was current as at February 26, 2020. (2019, reporting 2018 data) were used to calculate in-situ dewatering of tailings has not significantly ventures both incorporated and unincorporated, and the representativeness of the dataset as a function increased over recent decades. any other enterprises of whatever legal form. All joint Due to duplicate reporting by multiple owners, the of global production and to project a global estimate venture partners were requested to report on jointly disclosures were corrected for analysis to represent of tailings production and number of facilities.8 The The findings reported here complement those from owned facilities, even if the reporting company was only unique tailings facilities. Where there were tailings facility dataset represents an average of analyses of individual tailings facility failures, such as not the operating partner. discrepancies in the reported data by multiple owners 30.2 per cent of global commodity production. The those reported by Morgenstern et al. (2015; 2016) and of the same facility, we prioritised data for analysis relatively high sample rate provides confidence in the Robertson et al. (2019), and the analysis of datasets Of the 727 companies contacted: which were disclosed by the operating companies. global representativeness of the dataset for active of multiple tailings facility failures, such as those Where the ownership of the facility was a separate tailings facilities. reported by ICOLD and UNEP (2001), Azam and Li • 339 responded (representing 47 per cent of the joint-venture company, we prioritised the data (2010), and Bowker and Chambers (2017). companies contacted) reported by the owner with the highest ownership The tailings production (as stored in tailings facilities) share. In the case of 50/50 joint ventures, we for each mine was calculated by using the annual • 187 of these companies confirmed they did not prioritised the data of the owner by alphabetical order. average of the planned tailings storage in five-years, have tailings facilities (representing 55 per cent of which was reported by the companies. Production 2. BACKGROUND AND METHODS those responding and 26 per cent of all companies) Each ‘tailings facility’ in the dataset represents a data is available in the S&P database for a range On April 5, 2019, the Church of England (CoE) • 152 confirmed they did have tailings facilities. unique tailings structure. In some cases, tailings of commodities (bauxite, coal, cobalt, copper, Pensions Board and the Council on Ethics of the facilities may consist of multiple structures. This diamonds, gold, iron ore, lanthanides, lead, lithium, Swedish National Pension Funds, on behalf of 112 As of March 2020, 45 of the companies that generated a second type of duplicate in the raw molybdenum, nickel, niobium, palladium, phosphate, investors, representing US$14 trillion in assets under confirmed exposure to tailings facilities had not data that is relevant for calculations of volume. platinum, potash, silver, tin, uranium, zinc). For management, wrote to Board Chairs and Chief published their disclosure on a website or asked for Companies that reported facilities with multiple commodities where production data is not available Executive Officers of listed extractive companies and extra time to complete their disclosure. structures sometimes reported the same total volume from the S&P Global database or cannot be matched requested specific disclosure on tailings facilities and planned volume for multiple data entries. In our with USGS production data (alumina, aluminium, (CoE and Swedish Council on Ethics, 2019a). The For the mining sector specifically: calculations of volume, duplicate data have been borates, chromite, ferrochrome, ferromanganese, disclosure questions were developed in consultation corrected by evenly distributing the reported volume ferrovanadium, ilmenite, manganese, rutile, tantalum, with independent technical advisors, the ICMM • 45 out of the 50 largest mining companies by against the number of structures that make up the titanium, vanadium, oil sands, refineries, smelters, Secretariat and four mining companies. Barrie et market capitalisation in the world responded facility. It is also worth noting that ‘tailings facilities’ in power plants), which represents 16 per cent of the al. (this volume) provide a full list of the disclosure the dataset include tailings production at mines, but reported active facilities, the average coverage of • 83 per cent of the industry by market capitalisation questions. The letter requested that the responses be also tailings, slimes, ash and other wastes produced the other commodities (30.2%) was used to project responded uploaded to the company website, signed by the CEO at mineral processing and smelting facilities. the global estimate. The number of tailings facilities • 60 per cent of the industry by market capitalisation was estimated by projecting the proportion of global publicly disclosed With funding support from the United Nations production represented by the mines in the tailings 5. A tailings dam breach analysis is conducted by a dam safety professional Environment Program (UNEP) and the Investor Mining to identify and characterise threats to public safety and the environment. The results are typically presented as inundation and deposition maps 6. Companies in the following sub-industry codes were contacted: oil and 7. Except bauxite, where the most recent production data available in the and used to classify the consequence of a potential failure of a facility, as gas drilling, oil and gas exploration and production, integrated oil and gas, S&P Global database was 2016. well as to assist in emergency planning, dam safety management, failure coal and consumable fuels, fertilizers and agricultural chemicals, aluminium, 8. USGS commodity summaries do not include artisanal and small-scale mitigation planning, and mine closure and dam decommissioning planning diversified metals and mining, copper, gold, precious metals and minerals, mining production, for which extraction is commonly of placer deposits with (Martin et al. 2019). silver, steel, and construction materials. consequent low production of tails. 88 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 89
facility dataset for active mines. If a constant sample 3. FINDINGS 3.2 NUMBER OF FACILITIES AND THEIR number has significantly increased over time as rate is assumed between active, inactive and closed MANAGEMENT illustrated by Figure 2, which shows the number of 3.1 TAILINGS PRODUCTION facilities then an estimate can also be calculated for tailings facilities by decade of construction. A total of 1743 unique facilities are reported in the the total number of facilities. A total of 44.54 billion m3 of tailings is currently under dataset (725 of which are currently active). This storage by the facilities disclosed in the dataset. Data on seismic hazard were derived from the Global Expected generation of tailings over the coming five Seismic Hazard Assessment Program (Zhang et al. years is 2.52 billion m3 per year for the reporting 1999) which provides a global dataset of seismic risk companies (2019-2023), with a 26 per cent increase based on Peak Ground Acceleration risk estimates. in tailings under storage over this five-year period to 3 Data on wind was sourced from Global Wind Atlas 56.2 billion m at January 2024. When these numbers 300 (2017), and data on precipitation sourced from Fick are scaled to represent global mineral production we and Hijmans (2017). estimate 11.1 billion m3 (14.4 billion t) 9 of additional tailings will require storage per year over the coming 250 five-year period.10 This annual estimate of worldwide increase in tailings requiring storage (see Figure 1) is 200 higher than the global tailings production estimates reported by Baker et al. (this volume), who used mineral production and ore grades to estimate 8.85 150 billion t of tailings produced per year in 2016 for a range of commodities. 100
50
Phosphate 1% decade constructed per of facilities Number Copper 41% 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020 Gold 37% Coal 4% Construction year Iron Ore 40% Nickel 21% Bauxite 27% Figure 2. Tailings facilities by decade of construction Platinum 76% Note: shading indicates active facilities U308 12% Zinc 31% Diamonds 65% The number of tailings facilities doubled between (2000) cite a global estimate of 3,500 tailings facilities, Molybdenum 28% 1955 and 1969 (14 years), doubled again between while Yin et al. (2011) cite 12,000 facilities just in Silver 39% 1969 and 1989 (20 years) and again between 1989 China. Other researchers have estimated as many as Lanthanides 10% and 2020 (31 years). The largest reported facility by 18,000 facilities (Brown and Elliott 2019). However, tailings under storage is 1.56 billion m3. The largest the methods for determining the aforementioned Lead 24% Reported in database active tailings storage facility by volume of tailings estimates are unknown, and it is not clear whether Palladium 40% Extrapolated to world production under storage is 1.19 billion m3. The mean facility they refer to active, inactive, closed, or abandoned Lithium 74% % Percentage of production covered volume for all facilities is 26.3 million m3 and for facilities. Potash 22% active-facilities-only is 43.7 million m3, which may indicate an increase in individual facility volume over Companies reported that most facilities keep full and 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 time. complete engineering records (85 per cent), have an Worldwide tailings storage increase per year, km3 (extrapolated from reported planned storage) accompanying closure plan (93 per cent), and include We estimate that the total number of active tailings long-term monitoring in their closure plans (87 per facilities worldwide is around 3,250 and the total cent). Oversight of the management of the facilities Figure 1. Tailings storage increase per year for a range of commodities as reported in the dataset and number of active, inactive and closed facilities is predominantly undertaken jointly by both external extrapolated to world production is 8,500. This estimate was calculated using the engineering specialists and in-house professionals reported number of facilities projected to global (72 per cent), followed by external-only (20 per cent) 9. Tailings production by weight calculated assuming the modal average of commodity production using USGS mineral and internal-only oversight (6 per cent). For around tailings bulk density reported by 20 companies as part of the disclosures commodity production estimates. Due to the data two per cent of the facilities (46 in total) it was not 3 (1.3 t/m ). The reprocessing and reclamation of tailings (a type of negative considerations outlined in Box 1 it is important to clear whether they were under any kind of engineering production of tailings) was not considered in the calculation of expected future tailings production. note that this is a conservative estimate that does oversight. Three of these facilities reported a past 10. This estimate does not include tailings that are not stored in a tailings not include abandoned facilities. Davies and Martin stability issue. facility (e.g. tailings backfill and heap leach pads). 90 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 91
3.3 CONSTRUCTION METHODS While upstream facilities make up 37 per cent of total reported facilities, they have declined from a peak of Figure 3 shows the total number of tailings facilities in 85 per cent of new facilities in 1920-1929 to 19 per the database, categorised by raise type. The upstream cent of new facilities in 2010-2019 (see Figure 4). construction method is historically the most common, 120 Downstream Upstream facilities make-up 43 per cent of facilities followed by downstream construction. Centreline, that are inactive, closed or reclaimed. In the past hybrid, and single raise construction methods are the twenty years the number of new downstream and in- 100 next most common. In-pit/natural landform and dry- pit/natural landform facilities have risen sharply, while stacked are the least common facility types.11 the number of new upstream facilities has declined. 80
60 Upstream
40 In-pit/landform Single raise Centreline 600 20 Hybrid Dry-stack Number of facilities constructed per decade constructed per of facilities Number 500 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020
400 Construction year
300 Figure 4. Number of facilities constructed per decade by raise type
200 Number of facilities Number
100 200 200 200 North America Europe Asia 150 500 (29%) 150 64 (4%) 150 268 (15%) Dry-stack Other In-pit/landform Centreline Hybrid Single raise Downstream Upstream 100 100 100
50 50 50
0 0 Figure 3. Tailings facilities by raise type 200 200 200 South America Africa Oceania Note: shading indicates active facilities 150 306 (18%) 150 311 (18%) 150 294 (17%)
100 100 100 Number of facilities Number 50 50 50 The relative frequency of facility construction and South America when compared to Africa and methods varies by continent, which is due to a range Oceania. This may partly reflect different regulatory 0 of factors, including commodity, ore type, climate, approaches; for example, upstream facilities were seismic hazard, topography, and governance (see banned in Chile following the La Ligua earthquake in Other Other Other Hybrid Hybrid Hybrid Dry-stack Dry-stack Dry-stack
Figure 5). Upstream facilities now represent a 1965 and the collapse of the El Cobre tailings facilities, Upstream Upstream Upstream Centreline Centreline Centreline Single raise Single raise Single raise Single relatively low number of active facilities in North which resulted in the deaths of more than 200 people. Downstream Downstream Downstream
In-pit/landform In-pit/landform In-pit/landform
Figure 5. Distribution of tailings facility raise type by continent12 11. For data analysis purposes Modified Centreline facilities were categorized together with Centreline facilities. Operations that produce Note: shading indicates active facilities paste or thickened tailings were classified by companies by the facility raise type, rather than whether the tailings themselves have been dewatered. A small number of Central Thickened Discharge facilities were reported in the 12. Countries are assigned to continents according to dataset, but not enough to undertake meaningful analysis. https://www.geonames.org/countries/. 92 TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW TOWARDS ZERO HARM – A COMPENDIUM OF PAPERS PREPARED FOR THE GLOBAL TAILINGS REVIEW 93
The volume of tailings under storage also varies dry-stack and other facilities (see Figure 6). The same facility is not recorded. This may have the effect rate of instability over a normalised period of time; with facility construction methods. Upstream highest median volume of tailings stored per facility of undercounting the prevalence of stability issues however, they do enable the comparison of general facilities contain the highest total volume of tailings are hybrid facilities (18.3 million m3), followed by for facilities prone to experiencing them. Due to this stability trends between facility types. under storage, followed by downstream, hybrid and centreline (7.3 million m3) and upstream limitation, the findings are not a calculation of the centreline, single raise, in-pit/natural landform, (5.9 million m3).
20 20 % of active facilities % of all facilities Standard error due to sampling
) 15 15 3