SÃO PAULO — When the dam at the iron ore mine in Mariana burst more than a month ago, killing at least 15 people, it was quickly described as Brazil's worst ecological disaster ever. The 40 billion liters of toxic mud unleashed in the central state of Minas Gerais, destroyed houses, roads, and left many sensitive areas heavily polluted, as the so-called "mud tsunami" traveled more than 600 kilometers to the Atlantic Ocean.

Mining company Samarco, which controlled the dam, has taken some measures since the Nov. 5 collapse. But the response has been piecemeal, and came only after the company — a joint-venture owned by Vale and the Anglo-Australian BHP Billiton — was pressured to do so by the Brazilian Justice Department, local authorities, environmental organizations and the prosecutor's office.

Samarco's actions have been mostly aimed at limiting the impact caused by the toxic mud. The company has, for instance, distributed millions of liters of clean water and installed a containment boom in the Atlantic to prevent the mud from spreading farther into the ocean.

But the concrete actions to try and ease the damage and destruction only came after urgent calls by environmental officials in the neighboring coastal state of Espirito Santo, where the mud was flowing. Officials demanded that Samarco deploy a helicopter over affected areas, distribute water to the cities dependent on the Rio Doce river, send a team to assess the impact of the mud on the ground and check the quality of the river's water.

More actions and measures followed, but in almost every case had to be forced upon the company. Two weeks after the dam collapsed, Samarco announced it was rescuing the fish in the Rio Doce river, with fishermen taking them and transporting them to fish farms, where they will be kept until it becomes possible to repopulate the polluted river. But looking back again, the company only did so three days after the Justice department ordered it.

Another action the mining company was pressured into taking was to aid indigenous populations whose lives depended on the Rio Doce river. Only after five days of protesting were the indigenous people given 44,000 liters of water.

In at least one instance, the company took action before any judicial decision: Samarco indeed took care of operations to widen the river's mouth, three days before a court decision would have obliged it to do so. Later though, it is the Justice department that demanded that booms be installed in the Atlantic so as to contain the torrent of mud pouring into the ocean.

This decision however was ridiculed by Hernani Lima, professor at the Federal University of Ouro Preto, who said the attempt at containment amounted to a "joke." The booms installed are designed to stop the spread of oil, which floats on water, whereas mud doesn't. Samarco has not responded to Folha's request for comment on these issues.

For Maria Dalce Ricas, director of Mining Association of Environmental Defense, delays in reacting have taken a huge toll. Once the mud had reached the Rio Doce river, there was indeed very little that could avoid the damage.