MINING giant BHP is legally responsible for a deadly dam collapse in Brazil, the High Court ruled today.

More than 600,000 individuals, municipal governments, businesses and indigenous groups brought legal action against the firm over the collapse of the Fundao dam in November 2015.

The collapse unleashed more than 40 million cubic metres of toxic waste into the Doce River, killing 19 people, and has been described as the country’s worst environmental disaster.

The judge ruled that the risk of the dam’s collapse was “foreseeable” and there had been “obvious signs of contractive, saturated tailings and numerous incidents of seepage and cracking.”

Ms Justice O’Farrell said that by August 2014, BHP knew or should have known that the dam’s internal drainage was inadequate.

This phase of proceedings addressed legal liability, while a second phase will look at damages.

Poghust Goodhead, representing those seeking damages, previously valued the claims at £36 billion.

The firm’s chief executive, Alicia Alinia, said the ruling “sends an unmistakable message to multinational companies around the world: You cannot disregard your duty of care and walk away from the devastation you caused.”

Fionna Smyth, interim director of campaigns, policy and international programmes at War on Want, said: “It finally looks like the communities and Indigenous groups affected by the collapse of the Fundao dam in Brazil will see justice.

“Lessons must be learnt from this disaster. We need effective mechanisms to protect human rights everywhere — including a legally binding UN treaty on business and human rights — which would hold corporations to account when they fail to prevent human rights abuses and environmental harms.”  

BHP said it intends to appeal the decision and that it had supported “extensive remediation and compensation efforts” in Brazil.

BHP and Vale share ownership of Samarco, the company that operates the mine where the dam ruptured. BHP argued that all three parties had already entered settlement in Brazil worth $32 billion (£24bn) last year.

Brandon Craig, BHP’s president of Minerals Americas, said: “The court has upheld releases provided in Brazil and 240,000 claimants in the UK group action who have already been paid compensation in Brazil have signed full releases.

“We believe this will significantly reduce the size and value of claims in the UK group action.”