Mining company employees knew about cracks in a dam that later collapsed and killed 19 people, a court has heard.
British and Australian-owned BHP has previously claimed its board of directors was unaware the stability of the Mariana Dam in Brazil was compromised when it caused Brazil’s worst environmental disaster.
But the High Court in London heard that at least two BHP employees were aware of a ‘serious’ incident that victims say caused the dam’s collapse.
The disaster unleashed more than 50million cubic metres of toxic waste into the River Doce on 5 November 2015, killing 19 people as well as the unborn child of one of the survivors.
Two communities were decimated by the tsunami of mud and the slimes polluted more than 700 kilometres of the river until it reached the Atlantic Ocean.
Around 640,000 victims are currently suing BHP at the High Court, with law firm Pogust Goodhead estimating compensation for the victims could reach £36bn if successful.
The current trial is assessing the mining giant’s responsibility for the collapse, as the dam was owned in a 50/50 joint venture between BHP and Brazilian-owned Vale called Samarco.
In a document setting out its defence, BHP said: ‘Of the causes [of the collapse] identified… the only two of which the BHP Brazil appointees to the Board of Directors had any knowledge prior to the collapse was the failure of the main underdrain in 2009 and the plugging of the spillway galleries.’
Giving evidence, BHP risk auditor Max Wetzig admitted he did know about the existence of cracks in the dam from a November 2014 report.
The court heard Mr Wetzig did not mention he was aware of the issue in his witness statement, but said in evidence: ‘I must add that I got aware of those cracks appearing at the setback by having read the report.’
Asked by Alain Choo Choy KC, representing the claimants, when he saw the report Mr Wetzig said: ‘During the course of the audit or perhaps prior to fieldwork.’
The report recommended the cracks should be ‘filled in as quickly as possible’ and a stability analysis carried out, which Mr Wetzig said he recalled.
But the engineer admitted he did not remember receiving a ‘stability analysis’ or details about inspections of the cracks. He told the court this should have been forwarded by BHP Brazil’s Iron Ore department for use in the audit.
Asked if the auditor Dr Vinod Garga asked for these to be done, Mr Wetzig said: ‘I don’t recall that Dr Garga reviewed information on stability. I do not recall him having recommended further stability analysis.’
He added: ‘I do not have the competence to determine if a stability analysis is required after an incident of this nature.
‘Of course I had appreciation that there had been a serious incident and I must add that I pursued information in relation to the resolution or actions taken by Samarco in regard to that incident.’
Mr Choo Choy said: ‘Well, there’s no evidence that you were shown any stability analysis.’
According to a report after the dam’s collapse, the cracking was in the same place the ground became so saturated with water it started to liquify, which the claimants say was one of the causes of the dam’s collapse.
Mr Wetzig also told the court he later received a study signed by Dr Garga which said the recommendations in the report had been made, and told the court he put ‘full reliance’ on Dr Garga to assess the dam’s safety.
Previously the judge heard Guilherme Campo Ferreira, another member of BHP Brazil’s risk team, had also been sent the 2014 report relating to the cracks.
Mr Ferreira was responsible for monitoring the risks relating to the dam’s design and was asked on an internal assessment whether all the recommendations to ensure the dam’s safety had been carried out – which included filling the cracks.
He marked this step as ‘pass’, however the court heard this recommendation was never carried out.
The court also heard that before the audit was carried out, Mr Wetzig received an email from expert Dr Andrew Robertson raising concerns the dam was being operated outside safe parameters.
Dr Robertson told Mr Wetzig Samarco had ‘pushed the dam to limits of operating tolerances that are beyond what I consider appropriate. And continue to do so.’
Asked if he was concerned about these comments, Mr Wetzig said his role was ‘accompanying Dr Garga with my experience in risk assessment and assurance to make sure he followed the process.’
The trial continues.
