How the Mariana dam collapse lawsuits unfolded

Fundão dam collapses near Mariana, Minas Gerais, killing 19 people

Brazil settlement signed in Brasília

Definitive settlement (repactuação) for reparation of the Fundão dam collapse. Samarco, Vale and BHP Billiton Brasil agreed a settlement of about 170 billion reais, described by Vale as 100 billion reais paid in instalments over 20 years to public authorities, 32 billion reais of performance obligations by Samarco and 38 billion reais already spent. The Minas Gerais government described 132 billion reais in new resources.

Supreme Federal Court president approves the settlement

Homologation of the settlement (as reported). InfoMoney reported that the court's president signed the homologation of the agreement. Agência Brasil reported that on 9 April 2025 the court unanimously found no irregularities in the homologation decision when judging five appeals filed by entities that are not parties to the case.

English High Court liability judgment

Municipio de Mariana v BHP Group (UK) Ltd and BHP Group Ltd [2025] EWHC 3001 (TCC), first stage judgment. The court decided key liability issues. As summarised by the Court of Appeal and BHP, it held BHP liable as a polluter under Brazilian environmental law and at fault under the Brazilian Civil Code, rejected liability under Brazilian corporate law, found the claims not time barred, and upheld the validity of releases signed by claimants compensated in Brazil. Entitlement and quantum are for later stages.

High Court costs order, including interest on costs and 43 million pounds on account

Court of Appeal refuses BHP permission to appeal liability

Municipio de Mariana v BHP Group (UK) Ltd [2026] EWCA Civ 502. Permission to appeal was refused on strict liability, fault-based liability and all three limitation grounds. The only ground proceeding was BHP's appeal on interest on pre-judgment costs, for which the High Court had given permission, and the court ordered that appeal expedited. The judgment refers to a further trial in the second half of 2027 into 2028 dealing with outstanding issues including quantum.