In considering the critical aspects required to improve tailings dam safety, the following subjects are addressed in this Bulletin: Corporate and Management Commitment, Education and training of company staff, Critical aspects relating to the design of a tailings dam, Critical aspects to be considered when designing for and implementing the final closure of a tailings dam, Risk management, The essential need for regular external audits and Some notes on the positive role that is played by industry regulators. The conclusion reached in the document is that diligent attention to these critical aspects will result in improved awareness and a lowering of safety incidences for tailings dams.
This document provides guidelines for implementing risk-informed decision making in a dam safety program. The intended audience is federal agencies that own or regulate dams. The guidelines could also be applied to non-federally owned or regulated dams that can impact federally owned or regulated facilities; however, this would require the cooperation and involvement of the non-federal dam owner.
The purpose of this document is to identify FEMA resources and services that are applicable to support dam hazard risk mitigation, preparedness, response or recovery. The goal is to view the various directorates and programs within FEMA to determine the eligibility or applicability of the resources or services they offer and how they may address your identifed needs.
This paper reviews the progressive growth of awareness, adoption and practices with respect to geotechnical risk in mining in Australia over the last four decades, with a particular focus on underground mining. Initial experience in the 1980s was drawn from other high-risk industries such as nuclear and petrochemical sectors, and whilst the mining industry recognised the issue of a changing hazard and risk environment, it did not change practices significantly. Subsequent growth in understanding of the evolving discipline of risk management, coupled with major changes in mining legislation to a more enabling legislative framework, have led to a far more risk-aware industry where risk assessment and risk management practices have become a fundamental component of the overall mining management systems. In underground mining, geotechnical risk is at, or close to, the top of the risk priority list for proactive mine management today. The recognition of what are referred to as core risks associated with particular mining methods was a further development in the maturity of the industry management systems, with implications for all levels of management, right from feasibility through to design, planning and operations. One of the problems with the growth of risk-based management practices in Australia is that because we do so many risk assessments and develop so many hazard plans, we have, in some cases, become too blasé about them and do not give due recognition and priority to the ongoing management of important risks with the potential for serious consequences through lack of attention to detail and lack of integration of risk management into the mine management system. In an effort to overcome this issue and place higher priority on the most critical risks facing a mining operation, the International Council of Mining and Metals (ICMM) Critical Control Management (CCM) system, for focusing on the most critical risks, and then directing more attention to the actual control practices required to manage them, has been a valuable trend in recent years. In the Australian coal sector over the last 10 years, the industry-funded RISKGATE system has also been an extremely useful documentation of industry experience and a tool to assist operators either investigate incidents or plan risk assessments on new topics or areas. Geotechnical topics make up at least three of the 18 major topic areas covered by RISKGATE. This paper will briefly outline how RISKGATE operates and is applicable to the industry in the geotechnical space.
Risk management is a key component of any effective corporate tailings governance framework. Uncertainty is inherent to a mining company's business activities and may present both risk and opportunity. An integrated risk-based approach assists management in identifying, evaluating, prioritising and managing key risks to the achievement of the mining company's strategic objectives, as well as opportunities to enhance performance and value. Corporate risk management frameworks are typically designed to manage risks at the enterprise or operational level with specific definitions for consequence and likelihood. Challenges can develop in accurately ranking tailings-related risks when utilising an operational-level corporate risk management framework. This paper highlights various corporate risk management approaches and discusses some key considerations when developing a tailings risk management framework and governance model.
Rio Tinto Iron Ore operates 16 different mine operations in the Pilbara region of Western Australia. Across these operations, there could be more than 100 operational open pits at any given time. This poses a considerable challenge for the effective management of geotechnical risks with finite resources. There are also a number of external legislation and internal compliance requirements that need to be adhered to. A number of standardised systems and tools have been developed by the geotechnical teams to manage the geotechnical risks and this paper introduces the different components of Rio Tinto Iron Ores geotechnical management System (GMS). The GMS covers the complete process, from the geotechnical design of a slope, through implementation to verification of performance and feedback to the design engineer. The focus of the paper will be on the Geotechnical Risk and Hazard Assessment Management System (GRAHAMS) which is used to assess and document the safety and economic geotechnical risk assessments of different slope areas. A number of reports and visual summaries of the risk assessments are available in the system, offering leaders the opportunity to identify areas of elevated risk and allocate resources accordingly. Details of realised risks (geotechnical hazards) are also captured and GRAHAMS provides a process to communicate the hazard and relevant controls to operational personnel. The GRAHAMS system was recently enhanced, moving from a Microsoft Access front-end to a web-based platform. This will enable a number of system improvements to further increase its effectiveness.
Risk-Informed Decision-Making (RIDM) is a method of dam safety evaluation that uses the likelihood of loading, system response given the loading, and consequences of failure to estimate risk. This risk estimate can be used to inform decisions regarding dam safety investments. This approach has many benefits including a greatly improved understanding of the safety of the dam and identifying dam safety vulnerabilities that have not been identified using standards-based evaluation techniques. This website includes dam safety guidelines to evaluate consequences of failure and is intended for use on water dams.
AngloGold Ashanti (AGA) has developed a concept to integrate geotechnical input into long-term mine planning using a block model approach referred to as a geotechnical model for rapid integration (GMRi). The GMRi is a simple spatial collection of rock mass data integrated with empirical evaluations, numerical modelling results and monitoring data for a specific mine plan. In this paper, the value of using the GMRi to manage geotechnical risk and identify opportunities associated with ground support design, stress-induced damage, design stope spans and total extraction is demonstrated. The GMRi concept allows for the rapid evaluation of spatially distributed geotechnical data and identifies areas of risk and opportunity, demonstrated at two recent underground studies completed at AGAs Australian operations.
Investor confidence is largely driven by a mining companys ability to deliver on the guaranteed return on investment. Thus, robust due diligence processes, functioning as part of a mining companys corporate governance, become essential tools to identify hazards that can impact production, assess the associated risks and introduce controls to manage the risks. The geotechnical practitioner is tasked to manage one of the biggest risks on the mine; that of a rock mass instability. Since an instability, or collapse, need not be large to have a significant impact on production, the challenge is to develop an optimised life-of-mine design with a risk management plan that suits the risk requirements of the mining company and investors, whilst meeting acceptable, minimum safety standards. The concept of a Geotechnical Review Board has been adopted in the industry as a vehicle to provide assurance that the geotechnical risks on a mine have been identified and are being properly managed. The review relies on external parties providing appraisals of the design and processes, and experienced oversight of the active operations. In general, these reviews tend to have a unique style; often a combination of the current, visible, critical issues on the mine and issues deemed as important by either the reviewer or a third party. Coupled with the challenge of fluidity in modern planning environments, the geotechnical practitioner is often still faced with uncertainty in the level of geotechnical risk associated with any given mine plan. This paper introduces a geotechnical risk assessment tool that has been developed for use as a leading indicator within AngloGold Ashantis international operations. The authors aim to provide the reader with insight into how the tool can be utilised to understand a mines ability to proactively identify and manage geotechnical hazards, by exploring the following components: