It is unacceptable that tailings dam failures are reported to be about ten times more frequent than water dams on a ratio basis, says geotechnical engineering company Geotheta CEO Ian Hammond, particularly in terms of loss of life, livelihood or environmental damage.
“Tailings facilities can and must be designed, operated and closed to ensure that the facilities do not cause any severe consequences from failure. In South Africa, we need to adopt a new approach to hazard classification and adapt our designs accordingly.”
This means that the professional engineers overseeing the facilities must account for more stringent, more severe and more appropriate factors in the design, monitoring, surveillance and closure aspects of the tailings storage facilities and their appurtenant structures, he tells Mining Weekly.
Hammond notes that, aside from more stringent requirements being introduced – where appropriate – more transparency is required. This, he suggests, should include third-party reviews, independent review boards, regular testing and modelling, proper financial allocations and diligent monitoring, as well as cooperation among the investors, owners, engineers and operators.
“Investors have a responsibility to ensure that they invest in facilities and structures that do not adversely impact on life and the environment. They also need to ensure that the people managing their investments are doing enough to guarantee that the present rate of failure, and the rate of lives lost, are dramatically reduced. They can and should set these onerous safety and environmental conditions as a precedent before investments are made.”
Further, Hammond notes that, while both upstream and downstream tailings storage facility configurations require significant care in terms design, operation, surveillance and closure, upstream tailings require a lot more effort in terms of care and surveillance.
“Upstream tailings certainly have economic merits, however, the facility needs to be safe at the same time. Our role as professional engineers is to ensure safe and economic solutions and structures for clients. This is achieved through understanding, measurement, modelling, communication and continuous execution of our designs,” he explains.
Geotheta is involved with the professional design, construction supervision, surveillance and closure aspects of tailings storage facilities. The company has several professional engineers and engineers-in-training working for the company as employees or consultants.
The company also does general geotechnical engineering investigations and designs – which enables it to pursue all aspects of tailings storage facility design – using sound engineering judgment and advanced software. Geotheta uses the software to analyse data, model facilities and review the consequences of failure for many clients, including several mining majors.
“We approach each project with the view that, if our investigations and design processes lead to simplicity and understanding, then we are on the right path. If things get too complicated as we progress, then we know that we have taken a wrong turn and need to go back and re-evaluate,” Hammond tells Mining Weekly.
He notes that, since investors and industry stakeholders are, of late, more aware of the risks of tailings facilities, larger budgets are being allocated to investigate and resolve tailings-related issues to improve performance while reducing risks.
“While we have industry codes in South Africa, we are going to need to learn to deal with more stringent internationally accepted codes if we are going to satisfy the broader investor concerns,” he stresses.
“There is a new level of professionalism dawning and we are going to have to step up to the plate on this,” he concludes.