Iron ore miner Vale said external auditors have refused to renew stability certificates for its 13 dams and four dikes in Brazil following the dam collapse at the Brumadinho mine in Minas Gerais in January this year.
Vale said the loss of the stability consideration declarations at the structures would not reduce Vale’s safety or impact the company’s iron ore and pellet production (estimated at 307–322 million tonnes).
The auditors reevaluated available data from the structures in question and “considered new interpretations for calculating safety factors in their analyses, with the adoption of new constitutive models and more conservative resistance parameters,” according to Vale.
Seven upstream dams among the listed structures to not receive renewals were inactive dams that had already been evacuated in line with the company’s Emergency Action Plan for Mining Dams.
These include the Sal Superior dam at the Gongo Soco mine; the B3/B4 dams at Mar Azul; Vargem Grande at the Vargem Grande complex; and Forquilha I, II, III and Grupo dams at the Fabrica complex.
“Vale reiterates that its priority is the safety of all its structures and, consequently, of the population and workers downstream. The production from these sites will only be resumed once the safety of the structures is assured,” the company said.
Further, Vale disclosed the First Court of Nova Lima’s decision to freeze its funds to the tune of 1 billion reais ($365.23 million) to set aside remediation for those affected by the evacuation of its Vargem Grande dam.
Vale has been under intense government since the January 25 tailings dam collapse resulted in one of the worst environmental disasters in the South American country’s history.
It led to the confirmed deaths of 217 people with 87 more still missing as of March 30, according to Latin American news agency Prensa Latina.
The event occurred just over two years after a similar tailings-based incident in the same region at a Vale-BHP Samarco joint venture project in November 2015, which killed 19 people and caused extensive environmental damage.