Five years after the Brumadinho dam collapse: Evaluation of water quality based on combined analysis of land use and environmental data

• Published in: The Science of the total environment 2024-12, Vol.957, p.177619, Article 177619
• Main Authors: Mello, Caio C.S., Leão, Monica M.D., Amorim, Camila C.
• Format: Article
• Language: English
• Subjects: Dam rupture impacts; Post-disaster assessment; Water quality
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.177619

The collapse of the dam in the Paraopeba River watershed in 2019 triggered significant concerns regarding water quality in the region. This study aimed to assess, five years after the disaster, the effects on water quality and understand the underlying factors of environmental pressure contributing to the observed changes. To perform the evaluation, the study utilized surface water quality data pre-disaster (2012–2018) and post-disaster (2019–2023), environmental data regarding the identification of high-polluting potential industries operating in the region of interest, and land use for the watershed as a combined evaluation. Nonparametric statistical tests Kruskal-Wallis, complemented by Dunn's, were employed to assess the significance of changes in water quality parameters post-collapse. The results indicate a relatively stable baseline scenario of land use dominated by agriculture and pasture, with minor changes observed in forest cover and urban development. However, post-collapse assessments showed significant variations in water quality parameters, with turbidity exceeding conformity levels by up to 68 % (over 100 NTU), dissolved iron (Fe) by up to 70 % (over 0.3 mg.L–1), manganese (Mn) by up to 91 % (over 0.1 mg.L–1), dissolved aluminum (Al) by up to 83 % (over 0.01 mg.L–1), and lead (Pb) by up to 26 % (over 0.01 mg.L–1). Statistical tests suggested possible effects of the dam collapse on turbidity, pH, dissolved Fe, Mn, and dissolved Al. Temporal analysis showed constant effects on water quality, with notable increases in dissolved Fe and Mn concentrations observed upstream post-disaster and persistent impacts downstream. New mining activities licensed after 2019 may have contributed to the deterioration of water quality, highlighting the relevant relationship of anthropogenic activities and the environmental disaster in the Paraopeba River watershed. [Display omitted] •5 years post-disaster: water quality in Paraopeba river still reflects its impacts.•Water quality is also deteriorated in upstream regions of the collapse.•Land use and industries data were used in an integrated assessment.•Levels of DO, pH, Fe, Mn and Al shows a possible effect related to the disaster.