Scenarios of environmental deterioration in the Paraopeba River, in the three years after the breach of B1 tailings dam in Brumadinho (Minas Gerais, Brazil)

Rafaella Gouveia Mendes; Renato Farias do Valle Junior; Maytê Maria Abreu Pires de Melo Silva; Gabriel Henrique de Morais Fernandes; Luís Filipe Sanches Fernandes; Teresa Cristina Tarlé Pissarra; Marília Carvalho de Melo; Carlos Alberto Valera; Fernando António Leal Pacheco

doi:10.1016/j.scitotenv.2023.164426

Scenarios of environmental deterioration in the Paraopeba River, in the three years after the breach of B1 tailings dam in Brumadinho (Minas Gerais, Brazil)

Sci Total Environ. 2023 Sep 15:891:164426. doi: 10.1016/j.scitotenv.2023.164426. Epub 2023 May 24.

Authors

Rafaella Gouveia Mendes¹, Renato Farias do Valle Junior², Maytê Maria Abreu Pires de Melo Silva³, Gabriel Henrique de Morais Fernandes¹, Luís Filipe Sanches Fernandes⁴, Teresa Cristina Tarlé Pissarra⁵, Marília Carvalho de Melo⁶, Carlos Alberto Valera⁷, Fernando António Leal Pacheco⁸

Affiliations

¹ Federal Institute of Triângulo Mineiro (IFTM), Uberaba Campus, Geoprocessing Laboratory, Uberaba, MG 38064-790, Brazil.
² Federal Institute of Triângulo Mineiro (IFTM), Uberaba Campus, Geoprocessing Laboratory, Uberaba, MG 38064-790, Brazil. Electronic address: renato@iftm.edu.br.
³ Federal Institute of Triângulo Mineiro (IFTM), Uberaba Campus, Geoprocessing Laboratory, Uberaba, MG 38064-790, Brazil. Electronic address: mayte@iftm.edu.br.
⁴ Center for Research and Agro-environmental and Biological Technologies (CITAB), University of Trás-os-Montes e Alto Douro, Ap. 1013, 5001-801 Vila Real, Portugal. Electronic address: lfilipe@utad.pt.
⁵ Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista (UNESP), Via de Acesso Prof. Paulo Donato Castellane, s/n, Jaboticabal, SP 14884-900, Brazil. Electronic address: teresa.pissarra@unesp.br.
⁶ Secretaria de Estado de Meio Ambiente e Desenvolvimento Sustentável, Cidade Administrativa do Estado de Minas Gerais, Rodovia João Paulo II, 4143 Bairro Serra Verde - Belo Horizonte, Minas Gerais, Brazil. Electronic address: marilia.melo@meioambiente.mg.gov.br.
⁷ Coordenadoria Regional das Promotorias de Justiça do Meio Ambiente das Bacias dos Rios Paranaíba e Baixo Rio Grande, Rua Coronel Antônio Rios, 951, Uberaba, MG 38061-150, Brazil. Electronic address: carlosvalera@mpmg.mp.br.
⁸ Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista (UNESP), Via de Acesso Prof. Paulo Donato Castellane, s/n, Jaboticabal, SP 14884-900, Brazil; Center of Chemistry of Vila Real (CQVR), University of Trás-os-Montes e Alto Douro, Ap. 1013, 5001-801 Vila Real, Portugal. Electronic address: fpacheco@utad.pt.

PMID: 37236470
DOI: 10.1016/j.scitotenv.2023.164426

Abstract

The collapse of B1 dam at the Córrego do Feijão mine of Vale, S.A., located in the Ferro-Carvão stream watershed (Brazil), released 11.7 Mm³ of tailings rich in iron and manganese, and 2.8 Mm³ entered the Paraopeba River 10 km downstream. Seeking to predict the evolution of environmental deterioration in the river since the dam break on January 25, 2019, the present study generated exploratory and normative scenarios based on predictive statistical models, and proposed mitigating measures and subsides to ongoing monitoring plans. The scenarios segmented the Paraopeba into three sectors: "anomalous" for distances ≤63.3 km from the B1 dam site, "transition" (63.3-155.3 km), and "natural" (meaning unimpacted by the mine tailings in 2019; >155.3 km). The exploratory scenarios predicted a spread of the tailings until reaching the "natural" sector in the rainy season of 2021, and their containment behind the weir of Igarapé thermoelectric plant located in the "anomalous" sector, in the dry season. Besides, they predicted the deterioration of water quality and changes to the vigor of riparian forests (NDVI index) along the Paraopeba River, in the rainy season, and a restriction of these impacts to the "anomalous" sector in the dry season. The normative scenarios indicated exceedances of chlorophyll-a in the period January 2019-January 2022, but not exclusively caused by the rupture of B1 dam as they also occurred in areas not affected by the accident. Conversely, the manganese exceedances clearly flagged the dam failure, and persist. The most effective mitigating measure is likely the dredging of the tailings in the "anomalous" sector, but currently it represents solely 4.6 % of what has entered the river. Monitoring is paramount to update the scenarios until the system enters a route towards rewilding, and must include water and sediments, the vigor of riparian vegetation, and the dredging.

Keywords: Dredging; Environmental deterioration; Monitoring; Riverine ecosystem; Statistical forecasts; Water quality.