O Mariana's disaster occurred on November 5, 2015 and was the greatest environmental tragedy in the history of Brazil.
The accident was caused by the collapse of the Fundão Dam, used to store the iron ore tailings explored by the Samarco company.
The event caused the destruction of the environment, contamination of the river, the soil and a death toll of 19 people.
Disaster
On November 5, 2015, at 4:20 pm, the Fundão Dam did not contain the 55 million cubic meters of mud it stored inside and burst.
The mud arrived in just 15 minutes at the small town of Bento Rodrigues, located 8 km from the dam, with a population of 620 inhabitants. This city disappeared under the mud and today only the rubble of what used to be houses remains.
For 16 days, the mud followed the 853 km bed of the Doce River and reached the riverside towns, causing a shortage of water, a decrease in fishing, trade and tourism.
The mud reached the watershed on November 21 and the waste spread over a radius of 80 kilometers causing serious damage to the local industry.
In all, 39 municipalities in Minas Gerais and Espírito Santo, where 1.2 million people live, live in these cities and have had their lives affected. Two thousand more hectares of land were flooded and rendered useless for planting.
Samarco and Mariana's disaster
Samarco is a Brazilian iron ore extraction and processing company created in 1977 and managed by the Brazilian company Vale and the Anglo-Australian company BHP Billiton.
The company generates three thousand direct jobs and around 3.4 thousand indirect jobs in Brazil and had a profit of 2.2 billion reais in 2014.
The company innovated the exploration of iron ore using “ore pipelines”, that is, tunnels to transport the material extracted from the mountains of Minas Gerais.
Likewise, Samarco specializes in manufacturing iron ore pellets and reached production of 30.5 million tons per year in 2014.
To extract iron ore it is necessary to separate it from the earth and dispose of the residues. In this process, companies must adapt these wastes in appropriate dams following safety standards.
After the disaster, the company claimed that it strictly followed the rules and that the dams periodically underwent government inspections.
However, it is suspected that several environmental licenses and inspections have been approved as an exchange of favors from the company to politicians interested in financing their campaigns elections.
The company was fined by IBAMA (Brazilian Environmental Institute) in R$ 250 million, however, in 2017 it had only paid about 1% of this amount.
Environmental impacts of the Mariana disaster
The environmental consequences of the Mariana disaster were so severe that researchers are still looking for answers to understand the effects of the action and how nature can recover.
The mud and mining residues traveled more than 600 km to reach the Atlantic Ocean, where they resulted in environmental impacts to the marine ecosystem, especially the coral reefs.
During the mud avalanche, most fish died and as a result 26 species disappeared from the area. Meanwhile, land animals such as small mammals and amphibians were buried under the mud. Trees near river stretches were uprooted by the force of water or were submerged.
The mud also prevented photosynthesis from phytoplankton, the base of the aquatic food chain, and contaminated fish and other organisms. The affected rivers still had changes in their physical characteristics, such as decreased depth, destruction of riparian forest and burial of springs.
The soil was contaminated by the mud flow, making it infertile and preventing the development of plant species. The chemical composition of the soil has changed and it is not known how and how long it will take to recover.
Many researches indicate that the restoration of the area is impossible. So, the biodiversity site was irreversibly lost, with severe environmental consequences for nature and the human population that depended on natural resources.
Mariana's tragedy numbers
| Amount of Mud | 62 million m3 |
|---|---|
| Affected Cities | 41 |
| fatal victims | 19 |
| homeless families | 600 |
| Destroyed Vegetation | 1469 hectares |
| dead fish | 14 tons |
| Unemployment Index in the Region | 23,5% |
| Legal Proceedings Against Samarco, Vale and BHP | 22 |
| Environmental Recovery Forecast | Year 2032 |
Economic impact of the Mariana disaster
The Mariana disaster left thousands of fishermen jobless. In Linhares (ES), fishing has been prohibited since 2015.
With the stoppage of Samarco, the state of Espírito Santo was affected, as the company accounted for 5.8% of Espírito Santo's GDP and generated 20 thousand direct and indirect jobs.
Cities in the south of Espírito Santo, such as Guarapari and Anchieta, saw their revenue decrease drastically and several suppliers lost their biggest customer.
Lawsuits against Samarco
After the environmental disaster, the Public Ministry filed a lawsuit against the mining companies responsible for the Fundão Dam.
One of the ways found to repair the damage and speed up those affected was to create the Renova Foundation. This entity comprises civil, government and mining company representatives who work together to find a solution to the Mariana tragedy.
On June 26, 2018, a new agreement was reached between the miners and the Public Ministry. This included changes in the board of the Renova Foundation, the production of independent technical reports and the constitution of local commissions to assess the progress of the recovery programs.
However, this decision suspends the 20 billion reais lawsuit that was being filed against the miners, as well as another one from 2017, in the amount of 155 billion reais.
Recovery of Rio Doce
On September 20, 2018, a research task force was launched to measure the environmental impacts caused by mud contamination.
Called "Rio Doce Mar", this is a collaborative project between 24 research institutions coordinated by the Federal University of Espírito Santo (Ufes).
The researchers will collect data to assess the level of intoxication in water, sediment, vegetables and fish. Every six months, reports will be prepared with results pointing out possible solutions to the problems found.
Read more:
- ecosystem
- Environmental impacts
- Water pollution
