The extent of an oil spill seen at Balikpapan Bay, East Kalimantan, Indonesia
By Wilda Asmarini and Bernadette Christina Munthe
JAKARTA (Reuters) - A coal ship that dropped anchor off the coast of the Indonesian port city of Balikpapan on Borneo island was likely to blame for an oil spill, after dragging a pipeline more than 100 meters and causing it to crack, an energy ministry official said.
Indonesia declared a state of emergency this week after the spill and fire killed five fishermen. The environment ministry said the oil covered an area of nearly 13,000 hectares and had polluted 60 km of coastal ecosystems, including mangrove wetlands and marine mammal habitats.
"We suspect the pipe was dragged by the ship that caught fire," Oil and Gas Director General Djoko Siswanto told reporters on Thursday.
"At the time it was bad weather, so they had to drop anchor," Siswanto said, noting it was an area where ships were not supposed to anchor.
Siswanto did not identify the vessel, but said it was a coal ship with a Panama flag.
Balikpapan is a bustling mining and energy hub, sitting on a shipping lane serving one of Indonesia's biggest thermal coal mining regions.
Pertamina had at first said initial tests showed the oil was marine oil used in boats, but on Wednesday said a cracked 20-year-old underwater pipeline linked to its refinery in Balikpapan was the source.
By Tuesday night, around 70 cubic meters of spilled oil had been contained by a team from several oil companies operating in the area and government agencies, the environment ministry said.
Thick clumps of oil were still visible in some areas on Thursday, but "much less than the several days prior," Environment Minister Siti Nurbaya said in a statement.
The ministry, which is responsible for supervising the cleanup and compensation claims, had asked Pertamina to contain the remaining oil and help affected members of the community, Nurbaya said.
Oil and Gas Director General Siswanto said the spill had been stopped and "the remains of the oil spill are still being cleaned up". He did not estimate how much oil had spilled.
The spill had reduced the operational capacity of the Balikpapan oil refinery, a Pertamina official said.
A second smaller undamaged pipeline running next to the broken pipe was being used to deliver crude to the refinery, with additional oil supplied via tankers, Siswanto said.
Some green groups have criticized Pertamina for not taking responsibility for the spill.
Siswanto said Pertamina had been late in announcing the source of the oil, but said the government was investigating the company that owned the vessel suspected of breaking the state company's pipeline.
The vessel owners would be questioned and could be charged over the deaths resulting from the spill, he said.
"It depends on who was to blame. It depends on the investigation," he said.
(Reporting by Wilda Asmarini and Bernadette Christina Munthe; Writing by Fergus Jensen, editing by David Evans)