A serious incident has occurred at Samarco Mineração’s iron ore operation in Minas Gerais, southeast Brazil. Fundão and Santarem dams, which hold back waste water from mining operations, ruptured on the afternoon of Thursday 5 November.

"First and foremost, our thoughts are with the Samarco employees, contractors, their families and the local community of Bento Rodrigues that has been devastated by the flooding. We are deeply concerned for their welfare. We still don’t know the full extent of the situation but we are working to better understand the circumstances," Andrew Mackenzie, CEO of BHP Billiton said in a statement on 6 November.

Australian mining company BHP Billiton and Brazilian company Vale are 50% shareholders in the joint venture Samarco which operates the facility.

Samarco stated that it has fully implemented its Emergency Action Plan on Dams along with relevant institutions such as the Fire Department, Military Police and others. It says it is mobilising every effort to prioritise the care of the people who were working in or living near the dams, in addition to containing environmental damage. Operations at its Germano unit has stopped.

The number of victims and those missing has not been confirmed and the cause and full extent of the incident is as yet unknown.
Samarco says it performs its own inspections, according to the Federal Law of Dam Safety and has operations teams working in 24-hour shifts. The company added that all dams have the appropriate operational licences and at their last inspection, which took place in July 2015, the regional environmental office indicated that the dams were all in a "safe condition".

The Samarco operation in Brazil has an annual production capacity of more than 21M tonnes of iron ore pellets and 1M tonnes of concentrates. There are four dam structures: Germano, Fundão, Santarem and Cava de Germano. Samarco says the waste is inert and consists mostly of silica (sand) from the iron ore processing and presents "no chemical that is harmful to health".

Unconfirmed reports suggest that 600 people have had to be evacuated, 16 people have died and more than 45 are still missing.