PERTH (miningweekly.com) – Mining giant BHP Billiton on Friday reported that the tailings spill at its Samarco joint venture, in Brazil, was significantly less than initial estimates.
In its 60-day update since the November 5 incident, which claimed the lives of 17 people and left hundreds homeless, BHP and partner Vale noted that satellite assessment had indicated that the volume of tailings material released during the dam breach was about 32-million cubic metres.
It was estimated that about 85% of the released tailings was retained within 85 km of the Fundao dam.
The volume of tailings released was significantly less than the 50-million cubic metres estimated during the initial dam breach.
BHP said on Friday that Samarco had undertaken several activities to stabilise the released tailings and to prevent more material from entering the Rio Doce system, including constructing dikes to contain tailings and revegetation along the Gualaxo and Doce rivers.
Dredging of the Candonga hydroelectric dam was also planned, which was expected to improve water quality.
Meanwhile, water treatment facilities along the Rio Doce were operational and capable of treating water for human consumption and industrial and agricultural use. Work was also being performed by a number of organisations to control any ongoing impacts to hydroelectrical power plants from turbidity and sediment accumulation.
The dam burst is Brazil’s worst environmental disaster and government has sued BHP and Vale for $5-billion in damages.
Source: Mining weekly www.miningweekly.com