RIO DE JANEIRO—Brazil’s government on Feb. 18 banned new upstream mining dams and ordered the decommissioning of all such dams by 2021, targeting the type of structure that burst last month in the town of Brumadinho, killing hundreds of people.
Those dams, which hold mining byproducts, are cheaper to build but present higher security risks because their walls are constructed over a base of muddy mining waste rather than on solid ground.
