How tailings dam decommissioning in Brazil is generating business opportunities

The efforts of mining companies with operations in Brazil to close their tailings dams will generate strong demand for services and solutions in the coming years, according to an expert.

"Today in Brazil we have a total of 21 structures considered as dams, both for the disposal of mining tailings and industrial residues. None of these are 100% decommissioned and what we’re doing are the rehabilitation of the reservoirs, and safety in general, to bring these dams in line with the global standard," Mônica Moncada, senior geotechnical engineer at Alcoa Alumínio, the Brazilian subsidiary of US aluminum giant Alcoa, told BNamericas. 

The pace of dam decommissioning in Brazil have accelerated because of legislation and risk-mitigation strategies.

"When you decommission a structure, a dam, you reduce the costs that a dam generates for the company, such as maintenance. In addition, there is a reduction of liability risks," said Moncada.

The country has seen two major disasters due to tailings dam collapses in recent years. In 2015, it was one owned by iron ore pellet maker Samarco, a Vale-BHP joint venture, in Mariana, Minas Gerais state. Then a second collapse took place in 2019 in Brumadinho at an iron ore mine owned by Vale, which is Brazil’s largest mining company. 

The disasters caused around 300 deaths and led to massive environmental damage.

After these tragedies, the federal government forced miners to decommission all tailings dams by the first quarter of this year. However, companies failed to meet this deadline and requested more time, citing technical difficulties.

Earlier this year miners signed an agreement with the authorities to extend the timetable and the decommissioning process is now moving forward on a case-by-case basis.

This week Vale announced a commitment to adapt all its 48 tailings dams, including dykes and drained piles, to the Global Industry Standard for Tailings Management (GISTM) by 2025.

Adherence to GISTM means improved inspection, monitoring and information transparency, as well as a continuous evaluation through independent audits, the company said in a statement. 

Since 2019, Vale has invested around 5bn reais (US$970mn) in its decommissioning program. Of the 30 structures that have used the construction method with elevations upstream, nine have been eliminated and three more are expected to be decommissioned this year.

Vale expects progress with the program to reach 40% at year-end.