Nearly 50 pc of city’s sewage discharge remains untreated: CAG report

The report stated that as of March 2019, only 52% of the sewage generated in CMA was collected by the existing sewerage system, leaving the remaining 48% uncollected. “The fact that 48% of the waste remained uncollected, was an indicator of the enormity and seriousness of the issue. Further, only 88 per cent of the collected sewage was treated before discharged,” the report said. The report pointed out that the water quality in the rivers such as Adyar and Cooum, and streams such as Buckingham Canal and Otteri Nullah Canal remained largely unchanged since 2006-2007 despite substantial investment and increase in the sewerage network and that this was a poor outcome of sewage management. “As a result of unjustified delays in award of tender, lack of effective coordination with the line departments to ensure availability of work site and inadequate planning, the projects to plug sewage outfalls into rivers have not succeeded, even four to seven years after sanction,” the report said.

Also, an estimated 242.73 MLD of raw sewage enters storm water drains and mixes with water bodies, according to the report. The plugging of sewage outfall into water bodies, being executed under the Chennai Rivers Restoration Trust (CRRT), remained unachieved even four years after the scheduled date. The report added that the underground sewerage system was provided in only 11 of the 42 newly-added areas as on November 2019. Only 60 per cent of the Chennai Metropolitan Area has a sewer network. Pointing out the delay in completing the projects, the report said that after a delay of four years and 11 EOTs (extension of time) granted to the contractor due to delay on his part, all works under Porur UGSS were completed by October 2016. The project, however, could not be commissioned till date (May 2020) due to delay in completion of pumping main works and terminal pumping station forming part of Ramapuram UGSS.