Lessons Learned from the Two Major Tailings Dam Accidents in Brazil

The failures of the Mariana and Brumadinho tailings dams in Minas Gerais, Brazil, had severe environmental repercussions and caused many fatalities. What should or could have been done to prevent these kinds of accidents? This paper discusses the management practices, relevant legislation, and supervision of tailings dams in Brazil, as well as the possible causes of these dam breaks, and evaluates whether the measures taken by National Mining Agency (ANM) will prevent more such accidents. Intensive investigation of these accidents revealed some similarities and discrepancies. The failure mode for both tailings dams was liquefaction flow. Considering that many other tailings dams are in similar conditions, it is likely that further failures may occur, despite the measures taken by the ANM.