Court of Appeal upholds High Court ruling on strict liability, clearing way for damages phase in major group claim
The Court of Appeal has refused BHP permission to appeal against key liability findings arising from the 2015 Mariana dam collapse in Brazil, reinforcing a High Court ruling that exposed the mining group to one of the largest collective damages claims ever pursued in the English courts.
In Municipio de Mariana v BHP Group Ltd [2026] EWCA Civ 502, Lord Justice Fraser rejected BHP’s attempt to challenge findings made by Mrs Justice O’Farrell following the extensive liability trial concluded last year.
The litigation concerns the collapse of the Fundão tailings dam near Mariana, in southeastern Brazil, on 5 November 2015. Nineteen people died, entire communities were destroyed and vast quantities of mining waste contaminated the Doce River system.
Hundreds of thousands of Brazilian claimants including individuals, businesses, municipalities and public authorities brought proceedings in England against BHP. The claims allege that BHP, through its joint venture Samarco with Vale, bore responsibility for the disaster under Brazilian law.
In November 2025, the High Court held that BHP could be held liable as a “polluter” under Brazilian environmental legislation. BHP subsequently sought permission to appeal on several grounds, including alleged errors concerning causation, foreseeability, knowledge of dam risks and the interpretation of Brazilian environmental law.
The Court of Appeal rejected those submissions in firm terms.
Delivering judgment, Lord Justice Fraser said: “I do not consider it to be reasonably arguable that the trial judge was wrong to hold that BHP are strictly liable as polluters under Article 3(IV) of the Environmental Law.”
The Court of Appeal’s ruling is significant because it endorses the High Court’s interpretation of strict liability under Brazilian environmental legislation and sharply limits BHP’s ability to revisit factual and legal findings reached after the lengthy liability trial. In refusing permission to appeal, the court made clear that the proposed grounds did not come close to meeting the threshold required for appellate intervention.
Lord Justice Fraser emphasised that Mrs Justice O’Farrell’s conclusions were firmly rooted in the evidence presented during the proceedings. “Her findings were not unsupported by evidence; on the contrary, there was ample evidence before her to justify her findings,” he said.
He also dismissed submissions that the trial judge had failed properly to engage with BHP’s defence arguments. “There is simply no basis for any claim that the trial judge ‘failed to engage’ with BHP’s case,” Fraser LJ said, adding that the judge had considered the competing evidence but ultimately preferred the claimants’ case.
Claimant firm Pogust Goodhead described the ruling as “a further victory” for those affected by the collapse. The litigation will now move toward the damages phase, expected to begin in 2027, where the scale and assessment of compensation are likely to become the central focus of the proceedings.