London High Court Finds Mining Giant BHP Liable for 2015 Samarco Dam Collapse in Brazil

Landmark Ruling in London High Court

In a significant legal development, the High Court in London ruled on Friday, November 14, 2025, that mining giant BHP Group is liable for the devastating 2015 Samarco dam collapse in Brazil. Mrs Justice Finola O'Farrell delivered the judgment, concluding that BHP is responsible for the disaster that caused widespread environmental destruction and loss of life.

The ruling stems from a class action lawsuit brought by approximately 620,000 Brazilian claimants, including individuals, local governments, and businesses, represented by the law firm Pogust Goodhead. The claim is valued at up to £36 billion (approximately $48 billion USD), making it one of the largest civil claims ever lodged in England and Wales.

The Catastrophic Samarco Disaster of 2015

The disaster occurred on November 5, 2015, when the Fundão tailings dam, located near Mariana, Minas Gerais state, Brazil, suffered a catastrophic failure. The dam was operated by Samarco Mineração S.A., a joint venture equally owned by BHP and Brazilian mining company Vale S.A.

The collapse unleashed an estimated 40 to 45 million cubic meters of toxic iron ore tailings, a liquid mix of water, sands, and clays, into the environment. This torrent of sludge killed 19 people, destroyed entire villages such as Bento Rodrigues, and left thousands homeless. The toxic waste polluted the Doce River for an estimated 600 to 668 kilometers, eventually reaching the Atlantic Ocean. The environmental impact included the death of 14 tonnes of freshwater fish and the destruction of 80% of native vegetation along the river, cementing its status as Brazil's worst environmental disaster.

Basis of the Court's Decision

Mrs Justice O'Farrell's 222-page judgment found that the 'risk of collapse of the dam was foreseeable' and that there were 'obvious signs of contractive, saturated tailings and numerous incidents of seepage and cracking'. She concluded that continuing to raise the height of the dam when it was not safe to do so was the 'direct and immediate cause' of the collapse. The court determined that BHP was liable on two grounds under Brazilian law: strictly liable as 'polluters' under Articles 3(IV) and 14, paragraph 1 of Brazil's Environmental Law, and liable based on fault under Article 186 of the Brazilian Civil Code due to negligence, imprudence, and/or lack of skill.

The ruling highlighted BHP's 'extensive control' over Samarco, its assumption of responsibility for risk assessment, and its active participation in the tailings dam operations, which gave rise to a legal duty to avoid harm.

BHP's Response and Future Proceedings

Following the judgment, BHP announced its intention to appeal the decision, stating it would 'continue to defend this action'. The company also noted that many claimants in the London lawsuit have already received compensation in Brazil, suggesting this could significantly reduce the size and value of claims in the UK group action.

The current ruling addresses only the legal liability for the disaster. A second phase of the trial, focused on determining damages, is scheduled for October 2026, with further trials expected to conclude in 2028 or 2029.