BHP report into Samarco disaster blames flaws in dam design

30th Aug 2016 07:14

(ShareCast News) - The Samarco dam disaster at a mine part-owned by BHP Billiton in Brazil last year that killed 19 people was caused by construction and design flaws , according to a review conducted by a panel of experts.The, report commissioned by BHP, said problems at the dam made it more unstable, causing "liquefaction" in the dam wall, the Daily Telegraph reported.BHP Billiton, and its partner Vale, have set aside up to $1.3bn (£1bn) to cover costs arising from the fatal accident that occurred at an iron ore mine in Brazil last year.The US law firm commissioned to publish the report, Cleary Gottlieb Steen and Hamilton, hired a panel of experts to work out why the dam collapsed. The panel, chaired by geotechnical engineer Norbert Morgenstern, used eyewitness accounts, advanced lab testing and computer modelling.The authors said the original design had to be changed, which used a type of sand designed to prevent a process known "liquefaction" - where soil loses its strength and stiffness when pressure is applied to it. "As part of this modification, a change in the design concept was also adopted and saturated conditions were permitted to develop in the sand," the report said.Dean Dalla Valle, BHP Billiton's Chief Commercial Officer, said the dam failure had a devastating impact."This important technical study will improve our understanding of what happened at Samarco. We have shared these findings so that the sector can learn from the dam failure and develop and implement further standards that can help prevent a similar event like this happening again," he said in a statement.He added that BHP Billiton had also conducted its own reviews of other significant dams at its operations and of its non-operated minerals joint venture arrangements."In the wake of this event, we have separately undertaken a comprehensive review of our significant dams, which has confirmed that those dams are stable. We will take a number of actions to further enhance risk management at these facilities." "We have looked comprehensively at tailings dam management and benchmarked to global leading practice. We have assessed our portfolio of dams against these global standards and are implementing actions to enhance the management of our dams."