It has been two months since the preliminary reports on the oil sludge dumped on the protected mangroves in Mahul were filed, but the territorial forest department and the mangrove cell are yet to restore the site to its original state.
In February, unidentified persons had dumped the oil sludge behind the Mahul Slum Rehabilitation Authority (SRA) complex. A month later, locals found oil sludge dumped once again in another part of the contiguous mangrove swamps. Officials from the forest department said the pollutant seemed to be a byproduct from petroleum companies.
"The mangrove cell is short on manpower to clean the area alone. With the National Environmental Engineering Research Institute's (NEERI) support, we will undertake the physical removal of the sludge from the site and look at rejuvenating the area," said N Vasudevan, chief conservator of forests, mangrove cell. "Since it is a contiguous area, a lot of the sludge had spread across, but it has not entered the creek water in large quantities and is unlikely to enter the food chain."
NEERI, which had filed a report on the sludge and analysed its contents (see box), has recommended bioremediation, in which microbial action is used to break down the matter and clean it up.
Activists, however, said the authorities have failed to investigate why sludge was dumped on two different places in that particular area.
"Since the area is away from public glare, the dumping could have taken place at Mahul to reclaim it for development. This modus operandi has been used at several mangrove swamps in the city," said Stalin D, director (projects), Vanashakti, a non-governmental organisation.