16h20, 5th of November of 2015: This is the exactly time of the burst of a tailing-pond dam at an iron ore mine owned by Samarco (a joint venture between Vale SA and BHP Billiton) in the state of Minas Gerais (MG), Brazil.
The volume of 62 million cubic meters of mineral sludge took 40 minutes to reach the location of Bento Rodrigues, a subdistrict of Mariana-MG, destroying 82% of the buildings in the location and killing 17 people (and 2 are still missing). Seven other villages and districts that are located nearby were hit with minor damage.
Few hours later, the mud reached the Rio Doce River, which basin has a drainage area of about 86.715 square kilometers, flowing down about 600 kilometers until reaches the Atlantic Ocean spreading for around 168 square kilometers.
The total of 1.5 thousands hectares of vegetation was devastated, at least 11 tons of dead fish were removed from the Rio Doce River and 35 cities were affected by the cut off of water supply, leaving around 400 000 people with no drinking water for a week.
An independent group of scientists GIAIA released the first results of water quality analysis presenting levels of manganese, arsenic, lead, iron and aluminium higher than the limit established by the National Environmental Council – CONAMA (in portuguese, Conselho Nacional de Meio Ambiente).
The accident was described as the biggest environmental disaster in Brazil’s history by the Brazil president Dilma Rousseff during the COP21 (France, 2015).