In January, a mining tailings dam collapsed at Brumadinho in Brazil killing more than 300 people – we posted about it in Mining’s human cost, Mining operator ‘knew collapsed dam was at risk’ and Another mining disaster. Last month, the company responsible warned that another mining waste dam could collapse and hundreds of people have been evacuated from their homes:
Brazilian mining giant Vale said Saturday [March 23] that communities in the southeastern state of Minas Gerais have been ordered to evacuate after independent auditors found that one of its dams could collapse at any moment.
On Friday, the company raised the level of risk at a mining waste dam in the city of Barao de Cocais to three, the highest grade. According to Brazil’s mining and energy secretary, level three means that “a rupture is imminent or already happening.”
The news comes nearly two months after another Vale-operated dam in the nearby city of Brumadinho collapsed, unleashing a wave of toxic mud that contaminated rivers and almost certainly killed about 300 people.
The contamination of rivers with mining waste, or tailings, which contain high levels of iron-ore and other metals is of great concern and can last for years or even decades, experts say. Small residues of iron oxide eventually fall at the bottom of the riverbed and are brought up to the surface each time it rains heavily.
Brazilian environmental group SOS Mata Atlantica said Friday it had proof of water contamination in the large Sao Francisco river as a result of the Brumadinho dam collapse. Hundreds of municipalities and larger cities such as Petrolina, 1,400 kilometers (870 miles) from Brumadinho, get drinking water from the Sao Francisco.
SOS Mata Atlantica was among the environmental groups that studied the impact of another dam rupture also in Minas Gerais in 2015. The accident killed 19 people and thousands of fish and left 250,000 people without drinking water. Three years later, experts say the water in the nearby Doce River is still unfit for consumption.
Last week, safety alerts were issued for three more dams. This week, the Wall Street Journal reported that safety inspectors had refused to guarantee the stability of many more.
Brazilian mining giant Vale says a total of four of its dams could collapse at any moment: https://t.co/aj2NsVzfbz via @YahooNews— Bryan Harris (@bryanhimself) March 28, 2019
Brazilian villages evacuated after warnings of mine tailings dam collapse https://t.co/LldVqOeYLF #Brazil #mining #Vale— Payal Sampat (@payalsampat) March 25, 2019
EDIT 7.4.19 Investors overseeing $80 trillion in assets pressure miners over tailings safety:
Ethical investors working on a global standard for tailings dams have written to 683 listed resource companies, including major miners, asking for information to be made public within 45 days about every facility they control.
"It is essential that investors can establish a clear line of sight on which company has which tailings facility and how that facility is being managed. The current disclosures from companies are largely inadequate," Adam Matthews, director of ethics and engagement for the Church of England Pensions Board, said in a statement.
