MELBOURNE (Reuters) - Much less sludge was spilled than first estimated from a dam burst at a Brazilian iron ore mine last November which killed 17 people, co-owner BHP Billiton (BHP.AX)(BLT.L) said on Friday.
Satellite assessments showed about 32 million cubic meters of sludge was released into the Rio Doce river, BHP said, citing information from mine operator Samarco, its joint venture with Brazil's Vale (VALE5.SA).
"The amount of tailings released is therefore significantly less than some initial estimates which were in excess of 50 million cubic meters," BHP said. The early estimates suggested the mine tailings could have filled more than 20,000 Olympic-sized swimming pools.
The dam burst left hundreds homeless in Brazil's worst environmental disaster for which the government is seeking 20 billion reais ($5 billion) in damages and seeking to hold BHP and Vale responsible for any amount that Samarco cannot pay.
The latest Samarco report showed about 85 percent of the sludge stayed within 85 km (53 miles) of the burst dam, while the recovery effort has found fish alive in the Rio Doce in a 670 km (416 mile) stretch of the river out to where it flows into the Atlantic Ocean.
"They were able to detect fish living in areas affected by the turbidity plume as well as in unaffected tributaries of the Rio Doce," BHP said.
Companies in charge of water supply have also been able to treat water from the river up to drinking standards and for use in industry and on farms, while Samarco and other companies are working to limit harm from sediment in the river at hydroelectric plants.
Reporting by Sonali Paul; Editing by Himani Sarkar