From Issue Sustainuary 2016: Planning For A Sustainable Future
Towards the end of last year, Brazil experienced a devastating mining disaster, that destroyed one of its most important rivers.
A dam burst at an iron ore mine, releasing 50 million tonnes of iron ore waste containing high levels of toxic heavy metals and other toxic materials in one of the largest and most important rivers in Brazil, Rio Doce. The government is currently suing Vale and BHP Billiton, mining giants that funded Samarco, the joint venture whose dam fell apart.
When the dam collapsed, 40 to 62 cubic metres of the water and sediment—residue from iron ore extraction—slid down a mountainside. “The scale of the environmental damage is the equivalent of 20,000 Olympic swimming pools of toxic mud waste contaminating the soil, rivers and water system of an area covering over 850 kilometres,” according to a UN special rapporteur from the U.N.’s Office of the High Commissioner for Human Rights. The collapse killed 12 people, devastated and destroyed the nearby village of Bento Rodrigues, left 500 people homeless, and left 200 villages with about a quarter of a million people without a potable water supply.
This environment disaster will also cause very serious long term damage. Brazil’s environmental officials have said that the damages to aquatic flora and fauna could last a generation.The contaminated water from the Rio Doce River, which flows into the Atlantic Ocean threatens endangered sea turtles and dolphins. Aloysio da Silva Ferrão Filho, a researcher at the Oswaldo Cruz Foundation, emphasized the gravity of the situation by stating that “The entire ecosystem is under threat and the impacts can even reach the marine food chain, possibly even the Abrolhos coral reefs, which are quite sensitive to sedimentation of inorganic material”.
The causes for this disaster are still unknown. During the Paris climate conference, Brazilian President Dilma Rousseff blamed this disaster on the “irresponsible action of a company,” referring to Samarco, which operates on the location of the dam and is the joint venture of the two mining giants, Vale of Brazil and BHP Billiton of Australia. Brazil is currently suing the companies for $7.2 billion. While BHP Billiton has aided Brazil in the operation Noah’s Ark, it has denied statements that the residue and waste are toxic. “The tailings that entered the Rio Doce were comprised of clay and silt material from the washing and processing of earth containing iron ore, which is naturally abundant in the region” stated a BHP representative. According to a spokesperson from Samarco, the company using drones and piezometers to monitor the dam’s surface marks and nothing seemed to indicate an anomaly.
Others wonder if the government could have done more to prevent this tragedy. The National Department of Mineral Production, responsible for checking the safety of dams, did not closely monitor the Rio Doce dam because it was considered a low risk dam. Marilene Ramos, the president of the Brazilian government’s environment agency stated, “We have to revise our safety criteria.”
Brazil’s Senate has decided to create a temporary commission to review dam safety legislation. Brazilians hope that the current trial will uncover evidence that will explain why they overlooked the potential danger of the dam, and what were the mistakes were made. Though investigators claim to have not found anything out of the ordinary, “It is not possible for a dam to be that safe and a few months later have a disaster of this magnitude,” said Carlos Pinto, an environmental prosecutor.