Tailing dams built with upstream lifting technique daily (see box for explanation) such as the ones that ruptured in Brumadinho and Mariana, in Minas Gerais state, have their days numbered. The mining companies will need to remove the waste from these dams and adapt them environmentally by August 15th, 2021.

This deadline was established by the National Mining Agency (ANM) on February 18th, less than a month after the tragedy in Brumadinho which led to 169 deaths and 141 disappearances. The goal is to eliminate this type of dam which is considered unsafe.

“Accidents put into question the effectiveness of this type of construction and whether the upstream lifting dams are really stable,” said ANM. It also mentioned the history of the three collapses: 2014, in Itabirito; 2015, in Mariana; and more recently, in Brumadinho – all of them in Minas Gerais state.

Other changes

On February 11th, other rules to prevent new tragedies from happening had already been announced by the agency. The mining companies will now be forced to inspect the lifting dams and send information to the government on a daily basis. Before this, reports on the dams used to be submitted every 15 days.

What are upstream lifting dams?
This type of dam gradually slopes up in the form of steps made of layers of waste (that which is not used in mining) that pile one on top of the other. It is as if it were the mining company’s waste deposit, which uses water and chemical products to wash the (iron) ore and then discards the sludge that is produced in this process.

This type of dam, which was popular in Brazil in the 1970s, is the simplest and cheapest way to store mining waste, but it is also the most outdated and unsafe.
QUESTIONS

1. According to a stipulation by the National Mining Agency, what should mining companies that have lifting dams NOT do?
a. Eliminate lifting dams.
b. Carry out daily inspections.
c. Send a report about the dam’s situation every fifteen days.
d. Forward information to the government everyday.

2. Do you think the measures announced by the government will help prevent new disasters?

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