Improving the safety of tailings dams

Linda Spies, senior geotechnical engineer at SRK Consulting.

Mining executives today require more assurance that their tailings dams are safe, with controls becoming much stricter. Greater transparency id also being demanded by other stakeholders such as investors and communities, said Linda Spies, SRK Consulting senior geotechnical engineer.

“After several hundred lives were lost in two well-publicised tailings dam failures in Brazil in 2015 and 2019, awareness of tailings dam risks has been raised within the mining industry and in the public eye globally. These latest failures were especially significant insofar as senior management at the mining companies were for the first time being implicated directly with charges of manslaughter and environmental damage.

“This meant that the discussion was more holistic and valuable, enriched with insights from these various perspectives. This is vital in promoting innovation, safety and environmental and social responsibility in the design, operation and closure of tailings dams," she said.

Spies was speaking at the Southern African Institute of Mining and Metallurgy (SAIMM) conference focusing on tailings dams. While the tone of the event was serious in light of recent failures, there was also an optimism flowing from the showcasing of best practice in the field and how this was being successfully applied. In her own case study presentation on a lined tailings dam at a South African platinum mine, she highlighted the complexities introduced by the liner requirement – and how good drainage design and quality assurance were an important part of the solution.

Continued application of the latest technologies

Among the key issues discussed at the conference was whether upstream tailings dams should be allowed – as this was one of the commonalities in the recent Brazilian failures. High-level input was given in a panel discussion by senior leaders from a mining company, a law firm and an insurance firm, including technical opinions from tailings industry expert and specialist geotechnical engineer Adriaan Meintjes, a partner and corporate consultant from SRK.

Tailings is rightly receiving considerable attention from a combined engineering and scientific perspective and will continue to do so in the future, said Sheila Imrie, SRK principal hydrogeologist and numerical modeller.

“The continued application of the latest technologies by the industry’s top experts is critical. Industry must also ensure that sufficiently detailed research, monitoring and numerical modelling informs the future design and current management of tailings dams," she said.