The oil content on the shores of Awas beach in Alibaug, following the recent spill off the Mumbai coast, was significantly high.
While the bio-remediation process using the oil-zapper technology for Alibaug was completed on August 20, it will take about two months for the oil to degrade.
According to the soil testing analysis done by the Delhi-based The Energy and Resources Institute (TERI), the concentration of oil in the zero day sample of the sand was 60,000 parts per million (ppm). This is much higher than the internationally laid down permissible limit of 1,000 ppm applicable in the US and European nations.
“The oil content in Alibaug was very high,” said Banwari Lal, TERI scientist who spearheaded the bio-remediation process on two oil-contaminated sites of Alibaug and Navy Nagar. “It would have been very toxic had it come into contact with any organism. We are yet to ascertain the pesticide content; analysis for which is being done.”
At present, India does not have a permissible limit or standard spelt out for oil-soaked soil. However, the Central Pollution Control Board is working out on guidelines for the same that will be out in about three months.
Essentially, oil eating bacteria and nutrients are sprinkled into a 3-ft bioremediation pit consisting of oil-stained sand, sludge, plastic and tar balls from the shore.
The bacteria then help degenerate the oil. “The TERI team is collecting samples every week that will help compare the extent of oil degradation for both sites,” said Lal.