To improve safety, mitigate risks and create a state of readiness for any eventuality among internal and external stakeholders related to tailings facilities, mines are developing comprehensive knowledge bases that integrate insights from multiple disciplines.

This interdisciplinary approach is key to complying with the Global Industry Standard on Tailings Management (GISTM) and to developing and using a knowledge base to guide decisions, according to SRK Consulting senior environmental scientist Kavandren Moodley.

“Principle 2 of the GISTM specifically requires mines to develop an interdisciplinary knowledge base, while Principle 3 specifies that all elements of that knowledge base – social, environmental, local economic and technical – must be considered in decision-making throughout the tailings facility’s life cycle,” said Moodley. He emphasised that risk mitigation decisions must respect the rights of project-affected people – which involves meaningful engagement on an ongoing basis through to closure.

Engagement is priority

“This aspect is highlighted in the very first principle of the GISTM, where human rights, specifically the right to access to information is the focus,” he noted. “Gathering indigenous knowledge about the area from the community and providing capacity building and information about tailings management are therefore important parts of the knowledge base that a mine develops.”

The approach is leading to a closer integration of elements such as engineering considerations with environmental, social and governance (ESG) factors such as climate change, as well as the emergency preparedness and response plans (EPRPs) that are put in place by mines. While a ‘multidisciplinary’ approach draws on knowledge from different disciplines, its value is still limited by those disciplines keeping to their own lanes. An interdisciplinary approach, by contrast, goes further by analysing and synthesising the links between disciplines into a coherent whole.

“For instance, the GISTM calls for a breach analysis that models where tailings will flow in the case of a tailings facility breach – so that the inundation zone can be predicted,” he said. “This in turn informs decisions about the technical design of the tailings facility and where it is located, decisions about environmental and socio-economic risks associated with the inundation zone, as well as the mine’s engagements with nearby affected people.”

Lisl Pullinger, who collaborated with SRK on GISTM projects, noted that an important part of developing the socio-economic part of the knowledge-base is determining the presence of vulnerable people in the inundation zone and working with the community relations and emergency response teams.  “This ensures that specific plans are developed to support vulnerable groups in case of an emergency,” she added.

In addition, it is paramount to understand both the number of people potentially affected by a breach as well as the value of private, public and community assets in the inundation zone. “This information provides a scientific baseline, included in the knowledge base from which mining companies can make informed decisions about tailings design and management,” Pullinger said.

Bruce Engelsman, partner and principal engineer at SRK Consulting further highlighted that the knowledge base impacts dramatically on the assumptions taken when a breach analysis is undertaken. “A poor technical knowledge base and uncertainty leads to conservative assumptions which, in turn, leads to larger inundation areas from a hypothetical breach. This means a larger community to consult with and the need for more comprehensive emergency preparedness and response planning.”

Buy-in and disclosure

This implies that the consultation process with affected people must generate sufficient buy-in from stakeholders such as local communities regarding the technical solutions proposed by engineers and scientists, said SRK Consulting associate partner and principal civil engineer Justin Walls.

“For example, the most commercially feasible option for siting, or even closing, a tailings facility may in fact not align with the community’s expectations or preferences for a specific land use – and this needs to be ascertained as early as possible in the design process,” said Walls.

Pullinger added that transparency is another key focus of the GISTM, not only to investors through publishing specific information, but also to local affected communities. “Sharing an integrated knowledge base and being able to solicit interdisciplinary input into key messages about tailings design, management and risk ensure that messaging remains consistent between stakeholder groups. This is a key component in building trust with local stakeholders and increasing investor confidence.”

Planning for emergency

The knowledge base also guides the emergency planning, and the short-term, medium-term and long-term aspects of an emergency response – each of which demands the involvement of other stakeholders such as municipal emergency services, national government departments or specialised rescue agencies. Andries Fourie, senior technologist at SRK Consulting, pointed out that working with district or metropolitan municipalities is part of GISTM compliance, even though many of these bodies may not be sufficiently resourced to play their role in a long-term EPRP.

“In these cases, some mines have even stepped in with assistance programmes to identify the gaps in municipal capacity – and to actively help to address those shortcomings,” said Fourie. “The GISTM requires this level of collaboration as an essential aspect of preparing adequately for the prospect of a tailings dam failure.”

He also noted the proactive approach to GISTM taken by organisations like Mine Rescue Services (MRS). Supported by South African mining companies, MRS has put itself forward in a primary responder role in the event of tailings dam failure, he said, and is prepared to provide support for these possible events.  

Years of ESG experience

SRK Consulting partner and principal environmental scientist Franciska Lake emphasised that the GISTM builds on what has been learned through years of ESG practice. While the fieldwork and analysis required to assess the environmental and socio-economic impacts is standard practice in the sector, the GISTM now sharpens the focus on the impacts of possible dam failure.

“This means being very thorough with assessing the baseline situation to inform the knowledge base within the inundation zone – such as affected people at risk, or which biodiversity-sensitive areas exist could be impacted by a tailings dam failure,” said Lake. “The industry has considerable experience in these fields which can contribute to GISTM compliance, however the standards require an effective integration of the different disciplines.”

She pointed out that a well compiled knowledge base can facilitate improvements to the safety and management of both existing and new tailings dams – with the siting of new facilities being particularly important.

Engelsman noted that tailings storage facilities are ever evolving. “A thorough knowledge base requires compilation of knowledge at hand, as well as meticulous planning and development to improve the knowledge base, as technical knowledge base improvement is time consuming and costly,” he added.

Living asset

“The knowledge base should not be static, but is rather a living asset that mines can expand and adapt in line with the developments on and around the mine site,” she said.

Lake also highlighted the importance of designing a tailings facility with closure in mind, and how the GISTM provides valuable additional guidance for this priority. For new operations, therefore, the standards should be applied from the concept stage to gain the best advantage. Moodley concurred, emphasising that interdisciplinary collaboration in these early stages were the most effective way of balancing engineering, financial, socio-economic and environmental imperatives.

“In choosing an optimal site for a tailings dam, for example, a fatal flaw in any one of these factors will rule out that option,” he argued. “It is essential to find out very early which sites are unacceptable, and whether the risks can be mitigated to an acceptable level.”

Risk and uncertainty

From a technical perspective, the GISTM is attempting to reduce risk by managing uncertainty, according to Engelsman. Much of this uncertainty, he argued, resides at the boundaries of disciplines – highlighting the need for better integration within the knowledge base.  

“On the ground, mining operations are often quite compartmentalised, which make integration of knowledge difficult in practice,” he explained. “Consultants in fact play a very important role in helping clients to bridge these disciplinary boundaries on their mines; certainly SRK’s range of in-house disciplines and our interdisciplinary approach is a significant benefit in this respect.”

Design philosophy

Given the lengthy operating lives of tailings facilities, the knowledge base also represents a vital tool as a paper trail for the approaches, plans and actions of the owner and operator over time, argued Roanne Sutcliffe, principal environmental engineer at SRK Consulting.

“It allows for the design philosophy of the facility to be followed in detail – right up to the point where mine closure is being considered,” said Sutcliffe. “During the tailings facility’s life, there may be changes in legislation and standards, for instance, which have guided decisions in the past. A knowledge base helps practitioners to understand the strategies and the thinking behind decisions at any given time.”

To comply with the closure aspects of the GISTM, considerable work is now being undertaken retrospectively, she added, whereas closure work should ideally be initiated from the tailings facility’s inception and carefully documented. The knowledge base needs to capture this information on an ongoing basis, providing the necessary information for those accredited agencies and individuals who will in future conduct GISTM audits.