Environment secretary Germano Vieira of Brazil's Minas Gerais state said the tailings dam at Vale SA's Gongo Soco iron ore mine has up to a 15% chance of bursting, following discussions with the miner and prosecutors, Reuters reported May 21.
The Gongo Soco mine is located about 64 kilometers from the Feijao iron ore mine, also in Brazil's Minas Gerais state, where a tailings dam disintegrated and killed hundreds of people in January.
A week earlier, the miner flagged a potential tailings dam collapse at the Gongo Soco mine, with rail freight and passenger train operations at a nearby rail line subsequently suspended.
In the newswire's report, Viera said a dam burst may be triggered by slippage in the embankment at the mine. "The breach of the embankment is going to happen," he said. "What we don't know is whether that breach will affect the dam."
As a preventive measure, Vale started building a concrete structure 6 kilometers downstream of the dam that could contain a large portion of the tailings.
In February, Vale was was ordered to evacuate about 500 people near the tailings dam at the Gongo Soco mine. The dam, which has been inactive since 2016, holds 6 million cubic meters of mine waste, according to mining regulator ANM.