For a week now, unidentified persons have been dumping toxic oil sludge in protected mangroves located behind the huge Slum Rehabilitation Authority (SRA) complex at Mahul near Chembur.

Deepak Koli (name changed on request), 69, who lives with his family beside the SRA complex first informed the forest department about the dumping. "Around 15 trucks have been dumping oil sludge on mangroves for the past week. The dumping goes on for over three hours," he said.

His son said the area swamped by the oil sludge is home to small crabs, fish and other aquatic life that comprise the regular catch of local fishermen. "So much sludge is poured that several trees are damaged. We step in this wetland each day to catch fish and crabs," said Koli's son.

On Friday, officials from the forest department's mangrove cell inspected the area and collected samples of the sludge.  "A significant portion has been affected. It smells like petroleum and the tidal flushing will push it further into the mangrove swamps," said Seema Adgaonkar, range forest officer, mangrove cell.

According to a Bombay high court order of October 2005, regardless of ownership of the land, all construction taking place within 50m on all sides of all mangroves shall be forthwith stopped and no development permission shall be granted in mangrove areas.