Environmental Law | Corporate Litigation | South America

Introduction: When the Ruin of a River Becomes a London Case

In a momentous ruling, a UK High Court judge has held the mining giant BHP Group legally responsible for the catastrophic 2015 collapse of the Fundão tailings dam in Mariana, Brazil — an event widely regarded as Brazil’s worst-ever environmental disaster. The judgment brings decades of environmental damage, loss of life, and community suffering into the spotlight, and underlines a stark message: transnational corporations may not escape accountability simply by keeping their disasters abroad.

The Mariana Disaster: A Tailings Wall That Broke

• On 5 November 2015, the Fundão dam — operated by Samarco, a joint venture between BHP and Brazilian miner Vale — ruptured, releasing tens of millions of cubic metres of toxic mining sludge. (Wikipedia)
• The flood killed 19 people, wiped out the village of Bento Rodrigues, and displaced hundreds more. (CRBC News)
• The tailings spread far beyond local communities: the sludge contaminated about 600 kilometres of the Doce River, devastating the ecosystem, destroying fish stocks and harming Indigenous and riverside populations. (ABC News)

What the UK Court Ruled: Liability and Legal Basis

• High Court Justice Finola O’Farrell found that BHP was liable even though it did not directly own the dam, because of its operational control and strategic involvement through Samarco. (JURIST)
• On the basis of Brazilian environmental law, the court held BHP strictly liable as a “polluter” — meaning it must pay regardless of intent. (Law Gazette)
• In addition, BHP was found negligent under Brazil’s civil code: the judge concluded that BHP knew (or should have known) about warning signs — such as seepage or cracks in the dam — and that it continued raising the dam’s height unsafely. (serlecourt.co.uk)
• Justice O’Farrell determined the collapse was “reasonably foreseeable”, criticizing BHP’s decisions to expand production even as technical risks mounted. (CRBC News)

Scale of the Claim & Who Is Involved

• The legal action is enormous: more than 620,000 claimants — individuals, businesses, municipalities, and Indigenous communities — have joined the UK group lawsuit. (serlecourt.co.uk)
• Lawyers estimate potential compensation could reach £36 billion. (CRBC News)
• Some claimants already received compensation in Brazil through a settlement with Samarco, BHP, and Vale. The UK court upheld many of those “releases,” which may reduce the total number of future claims. (bhp.com)

Environmental and Human Impact: More Than Just Mone

• The disaster’s toll goes beyond economic loss. Entire communities were disrupted, traditional ways of life destroyed, and ecosystems poisoned. (PBS)
• The Doce River, central to many communities culturally and spiritually, was transformed by the sludge flow, which killed aquatic wildlife and contaminated water sources. (CRBC News)
• Victims and representatives have described the ruling as a historic vindication. For many, it’s a kind of long-overdue justice. (ABC News)

BHP Responds: Defense and Future Risk

• BHP has announced it intends to appeal the decision. (bhp.com)
• The company argues that compensation already paid in Brazil should significantly reduce its liability in the UK. (Law Gazette)
• BHP says repatriating all further claims would be unjust and that Brazil remains the “most appropriate avenue” for remediation. (Law Gazette)
• Meanwhile, the UK court has scheduled a second-phase trial (from October 2026) to assess damages, and a third stage (possibly by 2028) to resolve individual claims. (bhp.com)

Why This Case Matters — Globally

1. Corporate Accountability Across Borders
   The ruling underscores that multinational companies can be held liable in their home or listed jurisdictions for environmental disasters that occur abroad. (JURIST)
2. Precedent for Transnational Litigation
   With hundreds of thousands of claimants, this case could embolden similar cross-border group actions against corporations responsible for environmental harm.
3. Environmental Law & Strict Liability
   The court’s application of Brazilian environmental law in a UK court highlights how national environmental protections can empower global litigation.
4. Long Road to Justice
   While this decision establishes liability, meaningful compensation will depend on complex, multi-year proceedings. The affected communities may finally see accountability — but only if the full legal process plays out.

Conclusion: A Landmark for Justice, but Not the End

The UK High Court’s decision marks a turning point in environmental litigation: BHP cannot sideline its responsibility by pointing to geographic or corporate distance. The judgment delivers a powerful message: when corporations bear profits abroad, they may also face accountability in foreign courts.

But this is only the beginning. The path to reparations for the survivors, the contaminated river, and devastated communities remains long and uncertain. As the world watches, the case could reshape how we think about cross-border justice, corporate duty, and environmental redemption.