Vale’s internal October report placed the Brumadinho dam within an “attention zone,” saying that “all prevention and mitigation controls” should be applied.
A failure could cost the company $1.5 billion and had the potential to kill more than a hundred people, the report said. The dam was marked for decommissioning.
Nine other dams in Brazil, out of 57 that were studied, were also placed in the “attention zone,” according to the report.
A separate Vale report dated Nov. 15, 2017, also seen by Reuters, states that any structure with an annual chance of failure above 1 in 10,000 should be brought to the attention of the chief executive and the board.