Oil mop-up in last stage
Getting a move on - Raigad operations end, work in Mumbai 70 per cent complete. Oil-eating bacteria will be used to break down contamination on Colaba shore. Water, soil, mangrove studies continue. State claims Rs 3 crore in damages from ship’s owners.mumbai Updated: Aug 25, 2010 02:09 IST
Seventeen days after the oil spill caused by the collision between merchant vessels MSC Chitra and Khalijia 3, clean-up operations were nearing an end. Officials said they were 70 per cent complete in Mumbai, while the clean-up in Raigad was over.
The Maharashtra Pollution Control Board (MPCB) paid Rs 65 lakh as advance for the operation to four collectorates — Rs 10 lakh to Mumbai city, Rs 15 lakh to suburban Mumbai, Rs 10 lakh to Thane and Rs 30 lakh to Raigad.
On August 7, 800 tons of oil spilled into the ocean as the ships collided, spreading to the mangroves of Navi Mumbai, Uran and Alibaug as well as the shores of Sasvane, Kihim, Rewas and Mandwa in Raigad.
“Spots such as Awas beach at Alibaug and the Elephanta Caves have been cleaned up,” said S. Sonawane, Raigad collector.
In Mumbai, the clean-up is complete near Mahul jetty and part of INS Kunjali at Colaba. The state government granted permission to The Energy and Resources Institute (TERI) to carry out bioremediation using the ‘oil zapper’ technology at Kunjali. The technology was also used at Awas.
Bioremediation involves the sprinkling of oil-eating bacteria and nutrients into a pit filled with oil-stained sand, sludge, plastic and tar balls from the shore. The bacteria break down the oil. “Bioremediation will clean up the sand at Colaba,” said Valsa Nair Singh, state environment secretary.
“At Awas, it will take two months for the oil to degrade,” said Banwari Lal, the TERI scientist who developed the technology. “We will test soil samples every week.”
A team of experts was called to examine the canisters carrying ammonium phosphate that fell off the Chitra. Of the 2,000 canisters on board, 110 washed up at Elephanta and 250 at Alibaug.
The government sent a Rs 3-crore claim to the Chitra’s owners for the costs incurred and for the ecological harm done.
The amount was calculated with the help of the International Tanker Owners’ Pollution Federation Limited, a not-for-profit organisation established by ship owners to promote effective responses to spills of oil, chemicals and other hazardous substances.
“We took into account the cleaning operations, the man hours put in, transportation, laboratory bills and disposal of waste,” said Nair Singh.
MPCB Regional Director B.B. Wade said no phosphate gas was detected at Kunjali. “No oil traces were found in the sea or the beach. Instead, tar balls have started accumulating on the shore. They can be cleaned through bioremediation,” he said.
To avoid an overlap into the analysis of the ecological effects of the spill, scientists from the National Institute of Oceanography (NIO) and National Environmental Engineering and Research Institute (NEERI) will submit their reports in three stages — a one-month interim report, a ‘rapid report’ in three months and a comprehensive report within six months to a year — to the MPCB. The Bombay Natural History Society will submit its rapid assessment on the impact on mangroves by November.
NIO will study the impact on water quality, sediments and marine life. NEERI will conduct a risk assessment on mangrove losses, the socio-economic impact and damage to the coast and habitat.