Engineers fear more catastrophes await, as the world confronts a swelling volume of muddy mine tailings, contained by more and larger dams. Some rise to nearly the height of the Eiffel Tower and hold back enough waste to fill Australia’s Sydney Harbor. “The consequences of a failure are getting much bigger,” says Priscilla Nelson, a geotechnical engineer at the Colorado School of Mines.
In response, scientists, governments, environmentalists, and miners are searching for safer ways to handle the tainted mud. Some are trying to simply inventory the world’s tailings dams—estimates of the number range from 3500 to 21,000—and identify those most at risk of failure. A few have called for a ban on one common but failure-prone design. Others are working on regulatory and management fixes. “The mining industry,” says Joseph Scalia, a geotechnical engineer at Colorado State University, “is realizing they can’t just spend as little as possible and the problem is going to go away.”
Many groups are also pushing for regulatory and management reforms. After the 2019 Brazilian disaster, investment funds worth more than $10 trillion helped bring together officials from industry, government, and the investor group Principles for Responsible Investment to create a set of global guidelines for tailings dam construction. Earlier this month, the coalition issued its plan, calling for stiffer engineering standards for new dams. It also urges top mining executives, rather than lower level staff, to be responsible for tailings safety, and for independent experts to review companies’ waste plans.
Source: Science Mag
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