How much sewage is released into Kolkata wetlands: NGT asks State

Waste dump?:A part of the East Kolkata Wetlands.- FILE PHOTO  

The National Green Tribunal (NGT) has asked the West Bengal Government to furnish details on the amount of waste water and sewage released into the East Kolkata Wetlands (EKW) on the eastern fringes of the city.

The order was issued after several city based activists filed a petition to the NGT expressing concern over the inadequate amount of wastewater and sewage released into the wetlands which will adversely affect the unique organic sewage treatment system and the livelihoods of nearly 1 lakh local fishermen of the area.

The EKW, which spans over an over an area of about 125sq km, comprises of salt marshes and meadows as well sewage farms and shallow ponds used to cultivate fish. It was recognised as wetlands of international importance under the Ramsar Convention on Wetlands in August, 2002. The Ramsar Convention is an inter-government treaty to ensure conservation and wise use of wetlands.

“We direct the Respondent No.9, the Irrigation Department of the Government West Bengal to furnish the status report of Bantala Lock Gate (on the eastern fringes of the city) with specific reference to its height (level of sewage) as compared to the wetland…” stated the NGT order.

The EKW plays a crucial role in refining the city’s sewage and wastewater as the local fishermen channel them into shallow ponds where within a few days the organic compounds of wastewater are biologically degraded. The process takes place by means of sunlight and micro organisms living in the ponds. The micro organisms such as planktons also serve as food for the fishes cultivated by the locals. Kolkata generates about 750 million litres of waste water and sewage every day.

In the petition the activists pointed out that in order to ensure that adequate amount of sewage reaches the wetlands the level of sewage at the lock gate in Bantala under the Kolkata Municipal Corporation (KMC) need to be 9 feet but it has been “reduced to 8feet.” The city sewage, through a network of 61 km of underground canals, accumulates at the Bantala lock gate and from there is released into the wetlands by two open canals.

The activists are also apprehensive that the prohibition on release of untreated wastewater into wetlands under the Central Wetland (Conservation and Management) Rules, 2010 will further aggravate the situation. “There should be an exception for EKW in terms of releasing untreated sewage and wastewater into the wetlands. Otherwise the fragile ecosystem will sustain further damage,” Dhruba Das Gupta, a researcher on the EKW and one of the petitioners told The Hindu .

According to the Section 4(3) of the Central Wetland (Conservation and Management) Rules, 2010 “discharge of untreated waters and effluents from industries cities or towns and other human settlements” is prohibited.

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Printable version | Apr 21, 2021 8:26:43 PM | https://www.thehindu.com/news/cities/kolkata/How-much-sewage-is-released-into-Kolkata-wetlands-NGT-asks-State/article14515025.ece

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