12 February 2024

Mining waste threatens biodiversity conservation


According to an Australian study, 29 percent of mining tailings storage facilities are located in or near protected areas. With significant risks to the environment

by Matteo Cavallito


Nearly one-third of the world’s mining waste is stored in or near protected areas. This is reported in a study by the University of Queensland in Brisbane, Australia, which highlights the risks involved. “Mine tailings contain the waste and residue that remains after mineral processing, and the storage facilities built to contain it are some of the world’s largest engineered structures,” Bora Aska, a researcher at the Sustainable Minerals Institute at the same university and co-author of the research, explains in a statement. “Our findings,” she adds, “suggest that mine wastes threaten biodiversity within protected areas all over the world, including 8 active tailings storage dams in Australian protected areas, recognised by the International Union for the Conservation of Nature.”

29% of storage facilities are located near protected areas

“The potential biodiversity impacts globally due to tailings are mostly unknown,” the study states. “Here we assess the spatial coincidence between 1,721 disclosed tailings storage facilities and currently protected areas (PAs) and other conservation priorities (Key Biodiversity Areas and remaining intact ecosystems).” In short:

Nine percent of storage facilities are located within PAs, half of which were established after the PA was designated,” the study explains. “Another 20% of storage facilities are within 5 km of a PA, indicating even larger risks posed by upstream facility failures.”

In short, the data, which emerged thanks to information made public by companies listed on the push of the Mining and Tailings Safety Initiative, a program launched by the UN and the Church of England Pension Fund, highlight an open problem. Despite international commitments to protect biodiversity, in fact, storage facilities continue to spring up within protected areas and the phenomenon shows an increasing trend.

From mining tailings, risks to the environment

According to scholars, tailings pose a serious risk to the environment and people. The study, moreover, recalls how the failure of storage facilities has caused significant environmental disasters over the years. These include, for example, the collapse of the Samarco Dam in Brazil, which in 2015 killed 19 people swept away by a wave of waste.

But also the tragedy in Brumadinho, also in Brazil, which in 2019 cost the lives of 270 people also killed by a dam collapse. Also destroying 133 hectares of Atlantic forest and 70 hectares of protected areas downstream.

The memory of these events, of course, calls into question today the need for better management of the residuals also in view of their likely growth in the future. “Total tailings production is predicted to increase significantly in the next 30 years due to the growing demand for energy transition metals and declining ore grades,” explains Laura Sonter, professor at the University of Queensland and co-author of the paper. “Considering the current global distribution of tailings storage facilities and their failure rate, the consequences for biodiversity could be devastating.”

Protecting biodiversity

The issue is obviously crucial. The impact of human factors on the conservation of plant and animal species is receiving increasing attention. So much so that some observers have begun to refer to climate change and biodiversity loss as genuine “twin crises.”

Today, the research explains, “it is unsurprising that biodiversity factors are rarely included when assessing and categorizing the risks posed by new and existing tailings storage facilities. Greater transparency and a holistic consequence-based approach, supported by data, monitoring and new technologies are needed to drive reform at local, national and regional levels.”