Brazil has ordered the immediate closure of 47 mining dams that
failed to certify their stability, with more than half of them belonging to
Vale (NYSE: VALE), whose Córrego do Feijão iron ore mine’s tailings suffered a
catastrophic failure in January last year, killing at least 270 people.
The deadly incident, the second dam collapse in a Vale mine
in less than four years, led to serious production stoppages, pledges by the
company to reconstruct or decommission many of its other waste storage facilities
and the firing of a number of executives.
Regulations released in August required Vale, which lost its spot as the world’s top iron producer to Rio Tinto (ASX, LON, NYSE: RIO) earlier this year, to “decharacterize” or modify some small internal dikes at nine dams similar to the one that burst in January 2019. The new directives also forced the decharacterization of some drained stack structures owned by the miner, which are a different kind of commonly used tailings dam.
The decharacterization process is part of the last phase of
the decommissioning of a dam. It refers to the treatment of a structure so
that it does not present dam characteristics and can be reincorporated
to the environment.
By October, 54 Brazilian dams had either not certified their
stability or failed to file the required paperwork altogether. Many of those
structures are the ones closed down today, but the list also includes others operated
by Vale or its affiliates.
Earlier this week, the iron ore giant had reported in a file
to the Brazilian securities exchange commission (CVM) that three of its dams were
at higher risk of collapsing.
Dams in Brazil are labelled at risk levels, ranging from 1
to 3, in which level 3 indicates a structure is likely to collapse.
Vale said the dams to raise their risk level from 1 to 2
included the B3/B4 dam at its Mar Azul mine, the Doutor dam at its Timbopeba
mine, as well as its Sul Inferior dam at its Gongo Soco mine. The risk level
increased during the time period of September 2019 to March 2020, Vale said.
More to come …