Brazil's water regulator ANA is raising the alarm on the structural integrity of more dams following the deadly January 2019 collapse of the Brumadinho tailings dam of miner Vale.
An ANA post-disaster report, which follows senate approval last week of a new safety law that increases oversight and fines, classified 156 dams across 22 states as being in critical condition, up 129pc from the 68 dams classified as critical the year before.
Driving the increase is a 135pc jump in on-site dam inspections by a state or federal official, from 920 in 2018 to 2,168 last year, the report said.
Minas Gerais state, which is a major mining state and accounts for about half of Vale's annual iron ore output, led the list with 40 of the 156 dams ranked in critical condition by the ANA. The state was home to the Brumadinho disaster last year that killed 270 people, and the November 2015 tailings dam break at Samarco's Mariana that killed 19.
According to ANA's report, Vale alone has 18 dams in Minas Gerais that are ranked as critical.
The critical list also included dams owned by aluminum producer Alcoa Aluminio, steel producer Arcelormittal Mineracao and fertilizer producer Mosaic Fertilizantes. The report also cited the 31.5MW Paranapanema hydroelectric plant owned by Italian utility Enel, 48MW Sao Domingos owned by Brazilian state-controlled utility Eletrosul and 130MW Montes Claro owned by Companhia Energetica Rio das Antas.
In a separate assessment, mining regulator ANM has identified 51 tailings dams that are currently classified as "at risk." This included four classified as "level three" which indicates a high likelihood of rupture. All four are located in Minas Gerais and three are owned by Vale.
Last week, the senate passed a bill that will stiffen prison sentences for those found guilty for dam accidents that result in the loss of life or environmental damage and raised fines to up to R1bn ($188mn) for companies in violation of safety regulations. In an earlier draft of the bill, fines were as high as R10bn for violations, but the lower house eased the penalties in the most recent version.
President Jair Bolsonaro is expected to sign the bill, but is likely to veto a clause that requires financial guarantees for all dams. This requirement could have a negative impact on state, local and federal governments, which operate and maintain many dams.
