The organisations and people cleaning up the oil spill along the Chennai coast in Tamil Nadu have completed more than 90% of the work, the Centre said on Saturday. More than 65 tonnes of sludge was removed from the affected areas till February 2, since the oil spill off Kamarajar Port on January 28, PTI reported.

“There is a vast difference between the quantity of the oil spilled and the sludge recovered because the oil gets coagulated and becomes puffy when it is recovered with water and sand,” an official government statement said. The remaining work is expected to be completed in the next couple of days, the Centre said, adding that the Coast Guard was continuing to coordinate operations.

Tamil Nadu Chief Minister O Panneerselvam took stock of the operation at Ennore Port on Sunday. More than 5,700 people helped to clean up the sludge, he said, adding that all affected areas would be cleared of the spillage within a couple of days, ANI reported. “This is an extraordinary situation,” he said.

Panneerselvam also assured fishermen that their livelihood would be safeguarded. “The Centre and state government are working in close coordination...We will compensate fishermen for their loss,” he said, though he denied any impact on marine flora and fauna and said the fish caught from these regions were found suitable for consumption.

Meanwhile, the Indian Oil Corporation has begun to treat the waste sludge collected from the beaches through bioremediation – a natural process that involves the use of microbes to clean the contaminated soil where the waste is being stored. SK Puri, the deputy general manager of IOC’s Faridabad-based research facility, said the sludge will be treated in a 2,000-sq-m and 1.5-ft-deep pit near the Kamarajar Port. Special nutrients will also be added to the pit to treat the sludge. “We spread the collected sludge and safely treat it,” Puri said.

The incident has spiralled into an ecological disaster. The spill, which officials had earlier claimed was no more than 10 tonnes of oil and in a restricted area, has now spread from Ennore to Mahabalipuram – a distance of 72 km – along the Tamil Nadu coast. At least 70 tonnes of oil spilled into the ocean, affecting life along the coast and hitting marine life, some species of which are endangered like the Olive Ridley turtles that are breeding right now.