Geotechnical monitoring is playing an increasing role in improving tailings storage facility (TSF) safety, consequently allowing for earlier risk detection and more informed operational decisions, says monitoring services provider Terra Monitoring operations manager Schalk Prinsloo.

The company provides geotechnical data to support decision-making across a TSF’s life cycle, focusing on the supply, installation and management of instrumentation for long-term performance.

He adds that Terra Monitoring has been contracted across South Africa to support facility health and assist mines in meeting the Global Industry Standard on Tailings Management’s (GISTM’s) requirements at numerous TSFs.

Instrumentation is used to assess internal and surface behaviour, including vibrating wire piezometers to monitor pore water pressure and seepage, inclinometers to track lateral movement, and extensometers to measure deformation at depth.

“Additional survey-based or automated systems may be used to monitor surface displacement, with pore pressure, slope movement and deformation serving as key indicators of stability.”

Monitoring systems support trigger action response plans by activating alerts when thresholds are exceeded, supporting proactive decision-making and, despite real-time monitoring involving a short delay in data transmission, remaining an effective monitoring mechanism, adds Prinsloo.

Tailings Facility Risks

TSF risks are largely geotechnical and hydrogeological, and elevated pore water pressure can lead to slope instability and potential collapse, while seepage and internal erosion can weaken TSF structures.

Overtopping remains a risk where water balance is not controlled or during extreme rainfall; while liquefaction, foundation failure, deformation and external factors such as seismic activity can further contribute to instability, elaborates Prinsloo.

For overall TSF management, monitoring data is used to guide operational response, including interventions where required.

Tailings monitoring instrumentation has improved the understanding of pore pressure behaviour and phreatic surface movement, particularly on older or upstream facilities. He adds that instrumentation layouts are designed to meet “engineer-of- record” requirements, while proper installation and calibration ensure data quality.

However, Prinsloo highlights several challenges in implementing TSF monitoring systems across Africa.

“Remote locations often lack reliable power and connectivity, while cost pressures can limit instrumentation, particularly on older facilities. Gaps in technical understanding may affect data use, and environmental conditions can impact [on] instrument durability. Security risks, such as vandalism or illegal mining, can also damage infrastructure.”

Aligning with evolving regulatory requirements, where standards are not enforced consistently, also remains a challenge, he adds.

Nonetheless, technology in the TSF monitoring space is evolving, with remote and near-real-time systems using telemetry, and cellular and satellite networks to replace manual programmes.