Spotlight: The state of dams in Brazil

The number of dams in Brazil deemed to have "concerning" safety conditions has been reduced, as authorities and companies have taken steps to address the situation.

In 2022, a total of 122 dams across the country were classified as being concerning, down from 187 in 2021, according to an annual report prepared the water regulator ANA.

Source: ANA 

"The structures that cause concern do not necessarily represent a risk of rupture and are analyzed considering a set of information provided and in accordance with criteria established by each inspection body, which includes actions for management, maintenance and correction of anomalies," ANA said in a statement. 

Brazil ended last year with a total of 23,977 dams registered, which are used for irrigation, regulation of water flows, storing water supply for human consumption, electricity production, mining tailings and various other industrial uses.

The state of dams in the country is a highly sensitive topic, especially in the mining sector, following two major disasters in Minas Gerais state; one in 2015, after a tailings dam operated by Samarco Mineração collapsed, and in 2019, when the Brumadinho tailings dam operated by Vale failed, resulting in widespread environmental damage and causing hundreds of deaths.  

Since these tragedies, regulators have stepped up their surveillance of dams, despite some suffering budgetary problems.

"When we had the collapse of the tailings dams, at the time the ANM [mining regulator] had only three people that carried out inspections of dams. After that incident [Brumadinho in 2019], prosecutors in Minas Gerais filed a lawsuit forcing the government to hire 40 additional specialists to inspect dams," Ricardo Peçanha, the head of the workers’ union at ANM (ASANM), told BNamericas.

"We have seen the people hired to assess the conditions of the dams and we should reach around 64 professionals in this area, which is sufficient to inspect the 911 [tailings] dams that exist in the country," added Peçanha, underling that the mining regulator also uses technology to monitor tailing dams.

INCREASE IN ACCIDENTS 

Despite the decline in the number of dams classified as "concerning" last year, there was an increase in the number of accidents involving dams, with 24 reported last year according to ANA, up 85% compared with 2021. 

Despite that hike, no deaths were recorded. ANA states that accidents involve the structural integrity of the dam being compromised, resulting in partial or total collapse of the structure.

The funds invested in dam infrastructure and safety measures reached 113mn reais (US$23.5mn) last year, down from 128mn reais in 2021.

The full annual report on dam conditions published by ANA is available here, in Portuguese.

VALE'S LICENSE 

In a separate statement, Brazilian mining giant Vale announced that the Minas Gerais state environmental policy council, Semad, approved the operating license for the Torto dam at the Brucutu complex in Barão de Cocais and São Gonçalo do Rio Abaixo.

The dam will receive part of the tailings from the Brucutu plant. The complex has a tailings filtration plant, which processes most of the tailings from the site to remove water, allowing dry stacking of the material while also producing sand, thus reducing the volume deposited. 

The gradual start of operations at the Torto dam will allow Vale to increase production of agglomerates, such as iron ore pellets and briquettes.

"The improved product mix will enable higher price premiums for our production, contributing positively to our results. As previously reported, Vale expects to produce 36-40Mt of iron ore agglomerates in 2023 and 50-55Mt in 2026," the company said in a statement.