Five dams used to store mining waste are at “extreme” risk of causing environmental damage if they fail, according to a review by BHP, the world’s biggest mining company.
BHP said in a presentation on Friday that four tailings dams in Australia and one in the US were ranked at the highest level of risk, and had the potential to cause serious damage to the local environment and cause scores of deaths in the case of a collapse.
The company revealed the results of a risk assessment into its dams after two high-profile fatal dam failures in Brazil that collectively killed hundreds of people.
In a presentation to investors, the mining company said 16 of its 67 tailings dams which hold mining byproducts were “high risk”. The risk relates to the damage which would be caused to the environment and to human life if they collapsed.
The company said the “extreme risk” rating given to five of its dams means more than 100 people would be killed and there would be major environmental and economic and structural damage.
In 2015 a dam in Brazil, which was being run with BHP in a joint venture, collapsed killing 19 people and devastating the local environment.
The company said it had a range of controls to manage the risk, including surveillance and monitoring. BHP said in its presentation: “The dam risk review identified no immediate concerns regarding dam integrity. Subsequently we have undertaken dam safety reviews which provide assurance statements on dam integrity.”