A London judge ruled Friday that global mining company BHP Group is liable in Brazil’s worst environmental disaster when a dam collapse a decade ago unleashed tons of toxic waste into a major river, killing 19 people and devastating villages downstream.
High Court Justice Finola O’Farrell said that Australia-based BHP was responsible, despite not owning the dam at the time, finding its negligence, carelessness or lack of skill led to the collapse.
Anglo-Australian BHP owns 50% of Samarco, the Brazilian company that operates the iron ore mine where the tailings dam ruptured on Nov. 5, 2015.
Sludge from the burst dam destroyed the once-bustling village of Bento Rodrigues in Minas Gerais state and badly damaged other towns. Enough mine waste to fill 13,000 Olympic-size swimming pools poured into the Doce River in southeastern Brazil, damaging 600 kilometers (370 miles) of the waterway and killing 14 tons of freshwater fish, according to a study by the University of Ulster in the U.K. The river, which the Krenak Indigenous people revere as a deity, has yet to recover.
A decade later, legal disputes have prolonged reconstruction and reparations and the river is still contaminated with heavy metals. Even as Brazil tries to define itself as a global environmental leader while hosting the U.N. COP30 climate summit, advocacy groups say the dam collapse is a reminder of industry-friendly policies that have ecological protection.
Victims of the disaster called the ruling a historic victory in seeking justice.
“We had to cross the Atlantic Ocean and go to England to finally see a mining company held to account,” said Mônica dos Santos of the Commission for Those Affected by the Fundão Dam.
Gelvana Rodrigues, whose 7-year-old son, Thiago, was killed in a mudslide, celebrated the step forward and said she wouldn’t rest until those responsible are punished.
“The judge’s decision shows what we have been saying for the last 10 years: it was not an accident, and BHP must take responsibility for its actions,” Rodrigues said.
The judge agreed with lawyers representing 600,000 Brazilians and 31 communities in the class-action case who argued that BHP was heavily involved in the Samarco operation and could have prevented the disaster, but instead encouraged raising the dam to allow more production.
“The risk of collapse of the dam was foreseeable,” O’Farrell wrote in the 222-page decision. “It is inconceivable that a decision would have been taken to continue raising the height of the dam in those circumstances and the collapse could have been averted.”
BHP said that it plans to appeal.
The claimants are seeking 36 billion pounds ($47 billion) in compensation, though the ruling only addressed liability. A second phase of the trial will determine damages.
The case was filed in Britain because one of BHP’s two main legal entities was based in London at the time.
The trial began in October 2024, just days before the federal government in the South American country reached a multibillion-dollar settlement with the mining companies.
Under the agreement, Samarco — which is also half owned by Brazilian mining giant Vale — agreed to pay 132 billion reais ($23 billion) over 20 years. The payments were meant to compensate for human, environmental and infrastructure damage.
BHP had said the U.K. legal action was unnecessary, because it duplicated matters covered by legal proceedings in Brazil.
The judge ruled that those who were compensated in the settlement in Brazil could still bring claims, though they might be limited by any waivers they signed.
Brandon Craig, BHP’s president of Minerals Americas, said that nearly half of the claimants could be eliminated from the group because of settlement agreements they signed in Brazil.
BHP shares fell more than 2% on the London market after the ruling and the company said that it would update its financial provisions.
—Brian Melley, Associated Press