6 November 2015

Bento Rodrigues: a disastrous tailings dam failure in Brazil

Posted by Dave Petley

Bento Rodrigues

There are reports this morning of a disastrous tailings dam failure affecting the town of Bento Rodrigues in Brazil.  Current reports suggest that at least 15 people have been killed and as many as 45 more may be missing.

The mudslides that struck the town appear to have been generated by the collapse of the tailings dam associated with the Germano mine, owned by Samarco, which in turn is a joint venture between Vale of Brazil and BHP of Australia.  This is a Google Earth image of the setting, although note that this is a couple of years old:

Bento Rodrigues

Bento Rodrigues from Google Earth


The best gallery that I have seen is on the uol.com.br website, from which these images are taken.  The damage looks near apocalyptic:-

Bento Rodrigues

Bento Rodrigues talings dam failure via uol.com.br


Bento Rodrigues

Bento Rodrigues tailings dam failure via uol.co.br


In many ways this event is reminiscent of the dreadful tailings dam failure at Ajkai Timfoldgyar in Hungary in 2010, which I covered extensively at the time.  Back in 2009 I wrote about an academic study that had been published in a conference in Alberta that suggested that the frequency of tailings dam failures increases when commodities prices fall.  The peak in tailings dam failures occurs about two years after the peak in commodities prices.  I wrote:

The relationship between the peak in prices an the peak in accidents is ascribed by the authors to:

  1. The rush to mine quickly means that design and construction standards may be low;

  2. Rapid turn-over of key staff as new (presumably lucrative) opportunities arise during the boom;

  3. The boom drives the development of resources in areas that are known to be difficult;

  4. after the boom there are pressures to cut costs as commodity prices decline;

  5. The boom drives the use of inappropriate designs imported from other locations;

  6. There may be a lack of independent review, presumably to avoid the time delays and costs associated with this.

The prices of commodities are currently very low.  Iron ore commodities prices peaked in 2011.  It would be interesting to see images of the dam itself.