The area affected by an oil spill in Balikpapan Bay, East Kalimantan, has widened although it remains unclear what exactly is causing the spread, an official has said.

Widodo Pranowo, the head of the marine and coastal area data laboratory of the Fisheries and Maritime Affairs Ministry, said on Friday that the area polluted by the oil spill in had widened to 20,000 hectares from 12,987 hectares.

“There is a possibility that the source of the leak has not been perfectly sealed. But also there is a possibility that the spill has been thinning and drifting away with the currents,” he said as quoted by Kompas newspaper.

The oil spill reportedly came from a broken pipe belonging to state-owned oil and gas company Pertamina.

Widodo, who examined the oil spill area through satellite imaging, said more thorough research was needed to determine the cause of the spread.

Pertamina says it has deployed four cleaner teams and 15 cleaner ships to clean up the bay.

Yudi Nugraha, Kalimantan regional manager of social responsibility and communications at Pertamina said the company had utilized a variety of techniques and equipment for cleaning the oil spill, from vacuum trucks, to oil booms and oil spill dispersant (OSD).

“To clean the waters of the beach, we’re using oil skimmers and tug boats,” Yudi added.

“We’ve dispatched no fewer than 1,000 people to clean up the oil spill. We also have the support of volunteers from various civil society groups, students, community members and environmental activists,” he said.

MR Karliyansyah, director general of pollution control in the Environment and Forestry Ministry, said Pertamina promised to have the spill cleaned by April 9. (gis/ahw)