Brazil’s National Mining Agency (ANM) said on Thursday that it would halt operations at 47 mining dams that failed to certify their stability, including at least 25 belonging to the world’s largest iron ore producer Vale SA.

The safety of Vale’s facilities have been under heavy scrutiny after one of its dam collapsed last year, releasing a torrent of mining waste that killed about 270 people. It was the second Vale dam to collapse in four years.

Last October, 54 Brazilian dams failed to certify their stability or file the stability paperwork altogether

Many of the same dams remain on the list and several new dams operated by Vale or its affiliates were added.

In a statement, Vale acknowledged that its Santana dam in the city of Itabira in Minas Gerais state had failed to register its declaration of stability.

That dam had been placed on a level 1 emergency alert in October last year and has been under 24-hour monitoring since then, Vale said. The company is planning to make structural improvements to the dam in the second half of the year, it said.

Vale said on Wednesday that it continues to institute improvements to its dam oversight system, with 78 of its structures successfully registering stability declarations, and it gave details on planned actions to improve safety at several dams.

Eight new structures had negative stability declarations and will also be put on level 1 emergency alert, Vale said.

Vale said the safety of people and communities downstream from its dams is a priority.

On Wednesday, it also said it was testing alternatives to tailings dams to boost production capacity at its Brucutu mining facility, which includes the Norte/Laranjeiras dam that failed to certify its stability.

Fonte: MINING.COM