What the Court Decided
In a landmark ruling, the BHP Group has been found legally liable by the UK’s High Court for the collapse of the Mariana dam disaster (also known as the Fundão dam collapse) in Brazil. Judgment was handed down on 14 November 2025, with Justice Finola O’Farrell declaring that BHP’s involvement in the joint venture that owned the dam meant it owed a duty of care—one it breached through foreseeable and preventable risk.
The Disaster: What Happened in Brazil
On 5 November 2015, the Fundão tailings dam owned by Samarco — a joint venture between BHP (50 %) and Vale — failed in the state of Minas Gerais, Brazil. The collapse released over 40 million cubic metres of mining waste, destroyed the village of Bento Rodrigues, killed 19 people and spread toxic sludge along the Doce River for hundreds of kilometres. The ruling emphasised that the risk of collapse was “foreseeable” and that the decision to raise the height of the dam despite warning signs was a “direct and immediate cause” of the disaster.
Why This Case Went to the UK
Although the disaster occurred in Brazil, the case was brought in the UK because BHP had a legal entity based in London at the time, enabling claimants to seek redress through UK courts. Representing around 600,000 Brazilians from 31 communities, the class-action lawsuit is seeking up to £36 billion (~US$47 billion) in compensation.
What the Judgment Means
- The court has established liability but has not yet determined the final compensation amount. A second phase will assess damages.
- The decision is widely seen as a precedent-setting moment for holding multinational companies accountable in foreign jurisdictions for environmental harm.
- BHP said it plans to appeal the judgment, arguing the UK proceedings duplicate legal processes already taking place in Brazil.
Impact on Brazil and Beyond
For the affected Brazilian communities, many of whom have been waiting nearly a decade for accountability and full restitution, this ruling represents a significant step. One local resident whose son died in the collapse called it “what we have been saying for the last 10 years: it was not an accident, and BHP must take responsibility.”
Environmentally, the disaster remains a stark reminder of the long-term damage mining failures can inflict — contamination of waterways, destruction of habitats and disruption of Indigenous communities.
What Comes Next
- The next phase will determine how much BHP must pay in compensation.
- The outcome may influence how mining firms manage risk and liability internationally.
- The case may push legal and regulatory reforms regarding tailings dam safety and corporate oversight globally.
- For Brazil’s regulatory and remediation frameworks, the judgment may increase pressure for stronger enforcement and faster recovery for affected populations.
