Panel of experts say excess water played a part in dam collapse
A panel of four experts appointed by Vale’s legal advisers reported that the tailings dam failure at one of Vale’s mines in the Brazilian town of Brumadinho was partially triggered by “a persistently high water level” that caused the dam to lose its strength. The dam failure killed at least 255 people.
Reuters reported that the team of experts wrote in the report that was released on Dec. 12 that there was no warning that the dam was unstable, and that no seismic activity or explosions in the area were recorded on the day the dam burst in late January.
The Brumadinho disaster came less than four years after another dam collapse at a joint venture between Vale and BHP Group in the same region, an accident that experts also blamed on water weakening the solid materials composing the dam so that they behave more like a liquid - a phenomenon known as liquefaction.
While prior experience indicates that tailings dams rarely collapse because of a single cause, the disaster in the town of Brumadinho was facilitated by several factors, including poor internal drainage and intense rain that helped cause the excess of water, the four-expert panel said.
Vale and its top executives at the time of the disaster have been assailed by politicians and prosecutors for failing to prevent the disaster despite what critics say were ample warning signs, but the panel’s report said there were “no apparent signs of distress prior to failure.”
Simultaneously, the Wall Street Journal reported that German prosecutors have opened an investigation into Tüv Süd, which certified the failed dam as safe days prior to its collapse.
Brazilian authorities are in the midst of a separate probe that may also end in criminal charges against the Vale, 13 of its employees and the German inspector.
Police said the parties presented fake documents backing the stability of the dam and could face up to 18 years in jail if found guilty.
Photo: mine tailings after the collapse of the tailings dam in Brumadinho. Shutterstock.