Case background: In November 2015, the Fundão tailings dam, near Mariana, in the state of Minas Gerais, Brazil, collapsed, claiming the lives of 19 people, and spilling toxic waste over 600 kilometres. Thousands of people were displaced from their homes as villages and farms were submerged in the mine waste. The collapse of the Mariana dam resulted in a lasting ecological damage and has been considered Brazil’s worst ever environmental disaster.  

The Mariana dam was owned and operated by a Brazilian company, Samarco Mineracao SA, jointly owned by Vale SA and BHP Brazil. The collapse of the dam was said to be caused by drainage and design flaws.  

The Mariana case has been addressed through extensive litigation in Brazil and through R$20bn worth compensation schemes. However, many of these legal proceedings remain pending until today and some have been stayed, including the main R$155bn civil public action (a form of collective action in Brazil), that has been stayed since 2017. 

Initiation of UK proceedings: In 2018, over 200,000 Brazilian citizens filed a group action before the High Court of England against the parent companies of BHP Brazil, BHP England and BHP Australia, whose headquarters sits in London. BHP Brazil was not named as a party to these proceedings. The claimants asked compensation for the losses they suffered over the collapse of the dam. They based their lawsuit against the defendants under Brazilian law – claiming strict liability as indirect polluters under environmental law, fault-based liability under the civil code, and liability as controlling shareholders under the corporate law.  

Court decisions: On November 9, 2020, the High Court of Justice dismissed the case, declaring that it has no jurisdiction, principally, due to the legal proceedings taking place in parallel in Brazil.   

The claimants appealed on the decision to decline jurisdiction, and eventually, on July 8, 2022, the Court of Appeal overturned the previous ruling and declared that the case can proceed in the UK. The Court of Appeal denied the defendants claims that, considering the proceedings underway in Brazil, allowing the case to proceed in the UK would amount to an abuse of process. After conducting a thorough and lengthy assessment of the ongoing proceedings and compensation schemes in Brazil, the Court concluded that full redress was not available to all the claimants in the Brazilian proceedings as many of them were excluded from the scope of the main pending R$155bn civil public action. The Court also found that the Brazilian proceedings do not address the liability of the defendants in the proceedings before the English Court, i.e. the parent companies, and thus, the degree of overlap between the Brazilian and English proceedings is limited. The Court denied the defendant’s request to stay the proceedings, noting that a final decision in the ongoing Brazilian proceedings, if they resume, is unlikely for another decade. Therefore, pausing the English Court proceedings until the Brazilian case concludes would greatly harm the claimants’ ability to seek relief and disrupt efficient justice administration 

In December 2022, BHP sought to have Vale SA brought into the case to potentially share in any damages should they be found liable. Vale SA initially challenged the jurisdiction of the English Court. However, on August 7, 2023, the High Court dismissed Vale’s jurisdictional challenge, thereby requiring Vale to join the case as a third party.  

By February 2023, which was set as the cut-off date for claimants to opt into the proceedings, more than 500,000 claimants joined the proceedings, setting the overall number of plaintiffs at 720,000 and the potential damage at $£ 36bn, the largest collective action in world history.  

The case is now scheduled for trial to be commenced in October 2024.