The Bento Rodrigues dam disaster is considered to be worse environmental incident in the history of mining in Brazil.[1] On November 5, 2015, two iron oretailings dams of Samarco ( a joint-venture between Vale S.A. and BHP Billiton) collapsed. [2] The mud containing by-products of mining flowed down, destroying completely Bento Rodrigues, a sub-district of Mariana, and invaded other neighbouring cities, such as Barra Longa, causing at least six casualties, and destroying at least 200 homes. The mud reached the Rio Doce, contaminated the water, and compromised the water supply of cities in Minas Gerais and Espírito Santo that lay by the river. Several species of fish died to the low oxygen levels in the water, and up till today scientists could not estimate the total environmental impact.