One-hundred-sixty-one unauthorised colonies located on the Zone O of the Yamuna floodplains are yet to get no-objection certificates from landowning agencies for construction of sewage lines to treatment plants, leading to its discharge in the Yamuna river, Delhi environment department informed National Green Tribunal (NGT). The government said it was making concerted efforts to expedite the process.

The submission, made on behalf of the Delhi chief secretary, said 472 colonies were yet to be connected to a sewage treatment plant (STP). Of these, work in 206 colonies is underway and has a deadline of December 2025, but there has been no progress in 161 colonies.

”Out of 472 unauthorised colonies, colonies, 311 will be connected to decentralised STPs or be provided a proper sewerage network. There are 161 unauthorised colonies where NOC is still awaited from the forest department, ASI, DDA,” it read.

NGT was hearing a plea filed in December 2022 over illegal sewage dumping in drains in Vasant Kunj. The tribunal had sought the status of trapping sewage and steps taken by the government to curb illegal dumping.