Safeguarding Tailings Dams at the Climate Brink

Tailings dams, structures used to store mining waste, face increasing risks due to climate change. Intensified rainfall,more frequent extreme weather events,and thawing permafrost threaten the stability of these dams,potentially leading to catastrophic failures with devastating environmental and human consequences. A recent study published in Science highlights the urgent need for enhanced monitoring, improved design standards, and proactive risk management strategies to safeguard these critical infrastructure components.

Tailings are the byproducts of mineral ore processing, frequently enough containing fine particles of rock and chemical processing reagents. These materials are mixed with water to form a slurry, which is then pumped into engineered dams. Globally, there are an estimated over 3,000 tailings storage facilities, many of which are located in seismically active regions or areas prone to extreme weather.

Climate change exacerbates the risks associated with tailings dams in several ways. Increased precipitation can saturate the dam structure, raising pore water pressure and reducing its shear strength. This makes the dam more susceptible to landslides and breaches. Conversely, prolonged droughts can dry out the tailings, making them more prone to wind erosion and dust generation, posing health hazards to nearby communities. The International Council on Mining and Metals (ICMM) emphasizes the importance of considering climate change impacts in tailings facility design and management.

Thawing permafrost, particularly in northern regions, presents a unique challenge. As permafrost thaws, the ground beneath and within tailings dams can become unstable, leading to subsidence and potential dam failure. This is a growing concern for mining operations in Arctic and subarctic environments.

The Science study, authored by Wei-Bo Ma and colleagues, underscores the need for a multi-faceted approach to tailings dam safety. This includes:

• Enhanced Monitoring: Implementing real-time monitoring systems to track pore water pressure, ground deformation, and meteorological conditions.
• Improved Design Standards: Adopting more conservative design standards that account for climate change projections and potential extreme events. CDM Smith provides resources on best practices in tailings dam safety.
• Proactive Risk Management: developing comprehensive risk management plans that identify potential failure scenarios and outline mitigation measures.
• Independent Audits: Conducting regular, independent audits of tailings dam safety by qualified experts.
• Community Engagement: Engaging with local communities to ensure they are informed about the risks and involved in decision-making processes.

Recent tailings dam failures, such as the Brumadinho disaster in Brazil (2019) and the Jurei dam collapse (2019), serve as stark reminders of the potential consequences of inadequate tailings dam management.These events resulted in significant loss of life, environmental damage, and economic disruption.

Addressing the challenges posed by climate change requires a collaborative effort involving mining companies, governments, researchers, and local communities. Investing in robust tailings dam safety measures is not only an ethical imperative but also a crucial step towards ensuring the long-term sustainability of the mining industry.