Management of dams requires the use of experienced dam engineers and other competent personnel familiar with all relevant basic principles, technical guidelines, articles and manuals. This requires appropriate qualifications, registrations and adequate knowledge and experience relevant to the type of dam and the task required.
Engineering services in Queensland must comply with the Professional Engineers Act 2002 which requires a registered professional engineer of Queensland (RPEQ) to undertake or directly supervise an engineering service. Attributes in addition to RPEQ are recommended for personnel responsible for dam safety management. Inputs are often required from non -engineering technical specialists, such as geologists. Supervising these inputs in the context of meeting the Professional Engineers Act 2002 should be considered.
A matrix of skills for dam safety management personnel has been prepared as part of the Queensland dam safety management guideline and subject to extensive stakeholder feedback in its preparation. The matrix consists of a list of roles typically required for dam safety management and, for each role, a corresponding set of recommended core attributes.
— OR —
Ryan Singh, Jiri Herza, James Thorp, Michael Ashley
Performance-based risk-informed decision making is an underlying principle of the Global Industry
Standard on Tailings Management (GISTM). While owners make significant efforts to align with this
principle, commonly used risk assessment and management practices in the mining industry have largely been based on the HSE principles, which consider more frequent, lower consequence incidents.
As a result, the existing risk assessment frameworks do not provide the owners with a comprehensive understanding of the risk profiles of their tailings storage facilities (TSFs). Without the understanding of a facility’s risk profile, the owners cannot appreciate how changes to their facility, processes and operational activities may impact the risk profile. A large step-change in thinking is therefore required in risk assessment practices for the owner to align their TSF management with GISTM requirements.
Beyond risk assessments, the mining industry has other valuable concepts to manage the safety of their tailings management practices, such as Critical Controls, however, commonly used risk assessment and management practices do not incorporate these concepts.
This paper explores commonly used risk assessment practices and the concepts of Critical Controls. It proposes how these concepts can be linked, with Critical Controls being embedded in the risk assessment process. The outcomes of linking these concepts result in an estimation of the effectiveness of the Critical Controls and how they can be improved to demonstrably reduce the risk presented by a TSF. A case study has been included to demonstrate the benefits of linking risk assessment with Critical Controls and how owners can readily identify deficiencies and efficiently manage the risk profiles of their facilities.
Olle Wennstrom, Andrew White
Over the last few years tailings dams have come under increased scrutiny, partly due to two highly publicised TSF failures in South America, but also because of several other incidents in Australia and elsewhere in the world. As investors came under pressure to positively impact the projects they financed, the Global Industry Standard on Tailings Management (GISTM) was released in August 2020.
Topic 5 of GISTM, “Emergency response and long-term recovery”, comprises Principle 13: “Prepare for emergency response to tailings facility failures” and Principle 14: “Prepare for long-term recovery in the event of catastrophic failure”. The topic further introduces the term “Emergency Preparedness and Response Plan” (EPRP).
This paper explains what the term “Emergency Preparedness” means and how the owner/operator of a mine can achieve it. The paper also delivers a concept for long-term recovery planning.
Reena Ram, Siraj Perera, Mark Pearse, John Pisaniello, Shane McGrath, Joanne Tingey-Holyoak, Peter Hill
Dam construction in Victoria commenced in the 1850s and there are over 8,000 dams currently regulated by the Department of Environment, Land, Water and Planning (DELWP). Dam ownership spans across state owned water utilities and local government authorities to privately owned hydro-electricity generators and farmers.
Victoria was one of the first states in Australia to adopt risk-informed principles in the management and regulation of dam safety. A recent review of the State’s dam safety regulatory framework included a comparative analysis of Victoria’s dam safety arrangements with other regulatory regimes within Australia and overseas, including a total of 16 jurisdictions. A similar review was conducted in 2010.
The objective of the 2019 review was to examine the effectiveness of dam safety regulation in managing dam safety risks in Victoria and to assess the extent that dam safety regulation was consistent with good practice so that improvement opportunities could be identified.
This paper discusses the processes adopted in comparing various regulatory models, identification of good international practices and opportunities to achieve improved public safety outcomes for dam owners and regulators. In particular, it outlines how the State’s journey in progressively reducing dam safety risks over the years can be further strengthened.
David Reid, Andy Fourie, Riccardo Fanni, Cristina Vulpe, Alexandra Halliday
Recent failures of a number of tailings storage facilities (TSFs) has highlighted the need for better
governance and operational management of these structures. One means to improve their safety is clearly better and more focussed monitoring. Significant efforts are underway in this area, with a number of technologies being deployed. In particular, the monitoring of deformations through a variety of means (direct, satellite inferred) is increasingly being applied. While deformation monitoring to warn against failure has a long history in geotechnical engineering, some aspects of the rapid triggering and resulting flow of some TSFs may not be amenable to deformation monitoring, in the sense that actionable warning of an impending failure is not assured.
To examine this issue, a series of numerical models of an idealised TSF are carried out. This idealised TSF is brought to failure by means of a rising phreatic surface – often referred to as the constant shear drained (CSD) stress path. Deformations of the outer slope and crest of the numerical model – i.e. those that could be monitored for a real TSF – are tracked and analyses for the models carried out. It is seen that under CSD loading distinct deformation patterns indicative of impending failure are not always clear. Rather, minimal deformations and indeed swelling of the crest is seen leading to failure. The importance of recognising the minimal pre-failure deformation patterns that may manifest with a rising phreatic surface is noted.
Thomas Ridgway, Nic Polmear, Hugh Tassell
All industries, inclusive of the dams and tailings industry use some form of monitoring and reporting to confirm items or services are functioning properly or correct. In engineering, we seek to use both manual and automated systems to both qualifiably and quantifiably define the suitability of a process or structure/item. As the dams industry continues to evolve with technology and with ongoing developments in stewardship expectations for both water dams and tailings dams the industry is beginning to move into automation of their instrumentation systems. This process has recently been undertaken at a mine in NSW with the development of both a near real-time survey monitoring and visualisation system as well as a monthly photographic assessment system. This paper will set out the process undertaken to assess the surveillance monitoring requirements for the mine, details of the design, implementation of a near real-time monitoring system and the difficulties associated with the work.