One in every three dams belonging to mining company Vale could cause significant human and environmental losses in the event of a collapse like the one in Brumadinho, last Friday (25th). So far, 84 people died, and another 276 are still disappeared.
According to the National Agency of Waters (ANA), Vale owns 175 dams around the country, 56 of which considered of "high-risk potential." The classification accounts for possible human losses, as well as social, economic and environmental damages in the case of a collapse. Brumadinho's dam was in this category.
However, there are more high-risk dams than the number of barriers that Vale announced it would be closing.
Vale's CEO Fabio Schvartzman said that ten dams in Minas Gerais would be deactivated. All of them use a model that uses "steps" built as the tailings pile up.
This model, used in Brumadinho and Mariana, is cheaper but it's considered less safe.
Vale didn't comment on the number of dams that the government classified as high risk.
ANA's classification uses data from 2017. The agency considers not only the potential damage but also the risk of accidents in a given dam, evaluating technical features and maintenance.
With these criteria, there are 1,124 dams considered to be in high risk of accidents in Brazil, according to ANA. None of them belongs to Vale. Vale owns 99 medium-risk dams, two low-risk dams and other 74 unclassified.
But the Brumadinho dam was considered one with low risk of accidents.
Other 50 Vale dams in the high-risk categories are located in Minas Gerais, and five are in Pará. As a whole, Brazil has 2,986 dams classified as high risk.
Translated by NATASHA MADOV