April 19: The National Green Tribunal today asked the state pollution control board to issue a notice to the Calcutta Municipal Corporation about the pollution in Adi Ganga and take "appropriate action" if the civic body is found to be at fault.

The board functions under the environment ministry, which is headed by Calcutta mayor Sovan Chatterjee.

The board had more than a year back slapped a notice on the civic body for polluting Adi Ganga (also called Tolly's Nullah) following an order of the tribunal but did not fine the authorities.

The eastern zonal bench of the tribunal - comprising Justice W.S. Wangdi and expert member Ranjan Chatterjee - today asked the board to issue a fresh notice as nothing had been done to stop the discharge of effluent from 57 outlets into the waterway in compliance with an earlier order.

Environment activist Subhas Datta, based on whose petition the tribunal has issued the orders, told Metro that the chief secretary had on May 17, 2015, submitted before the bench through an affidavit that a detailed project report (DPR) on diverting the 57 outlets was ready and work would start soon. The affidavit was prepared based on inputs from the civic body.

"The DPR is yet to be finalised," Datta said. "The outlets fall within the area of the civic body, which is the designated agency to prepare the DPR and take steps to prevent the release of effluents into Adi Ganga.... So, the bench directed the board to notify the civic body and take appropriate action."

The pollution control board has also been asked to ascertain the extent of water pollution in Adi Ganga at various points and file a status report about the condition of the outflow channels.

The board's earlier reports pointed out that effluent being discharged into the waterway were rich in faecal colliform bacteria and had almost "zero" dissolved oxygen.

The bench also asked the central agencies whose representatives attended the hearing - the National Mission for Clean Ganga and the environment, forest & climate change ministry - why they could not fund the restoration of the entire 75km stretch of Adi Ganga, instead of just 15km. The lawyer representing the agencies sought time to file a detailed response.

The board lawyer said they had sent a notice to the civic body. The lawyer representing the civic body said his client was finalising the DPR.