Mumbai civic body to stop sewage discharge into Powai Lake from October 1

The Brihanmumbai Municipal Corporation BMC has completed the work to intercept and divert all 20 sewage outfalls flowing into Powai Lake and sewage discharge into the lake will be completely stopped from Thursday October 1 the civic body said on WednesdayThe 20 sewage flows have been intercepted and diverted to sewage treatment plants STPs with 18 flows along Adi Shankaracharya Marg being diverted to the Bhandup sewage treatment plant through gravitybased systems Two other sewage flows near Perugate on the northern side of Powai Lake have been diverted to the Filterpada STPThe work involved laying a total of 3056 metres of new sewer lines Additional Municipal Commissioner Projects Abhijit Bangar inspected the project site on Wednesday and reviewed the status of the work and the next steps He directed officials to complete the remaining associated works within the stipulated timeline and according to the required quality standardsBMC completes interception of 20 sewage outfallsThe civic body said the measures are part of its efforts to conserve and rejuvenate Powai Lake and address water pollution caused by sewage entering the lakePowai Lake was created in 1891 and has a total water spread of 223 hectares The lake has a circumference of around 66 km while its catchment area extends over approximately 600 hectares Its waterholding capacity is around 5455 million litres The lake water is used for nonpotable purposesThe BMC said increasing urbanisation around Powai and the daily discharge of around 18 million litres of sewage into the lake have contributed to water pollution The civic bodys Sewerage Projects and Mumbai Sewerage Disposal Project departments inspected the 20 sewage outfall points entering the lakeOf these 18 outfall points are located along Adi Shankaracharya Marg while two are at Perugate on the northern side of the lakeThe nonmonsoon sewage flow from Adi Shankaracharya Marg has now been diverted to the Bhandup STP through the existing sewer network Restoration of trenches dug during the work is currently in progressNew 8 million litre STP planned at PowaiThe BMC is also constructing an 8 million litre per day capacity modern and fully automated sewage treatment plant at the site of a disused sewage pumping station in PowaiThe Mumbai Sewerage Disposal Project is undertaking the construction Once operational the facility will scientifically treat sewage and release 8 million litres of treated water back into Powai LakeAccording to the tender schedule the project is due to be completed by December 2028 However the BMC is making efforts to complete the sewage treatment plant by May 2027Once the facility becomes operational 8 million litres of sewage will be diverted to the new plant while the remaining 8 million litres will be sent to the Bhandup STPBMC removes 85 per cent of water hyacinthThe BMC is also carrying out continuous work to remove water hyacinth from the surface of Powai Lake Two harvester machines are currently being used for the operationThe estimated quantity of water hyacinth in the lake is 24000 metric tonnes As of September 29 the civic body had removed 20340 metric tonnes or 85 per cent of the estimated quantityBangar said the presence of sewage had adversely affected the water quality of Powai Lake which is an ecologically sensitive ecosystemldquoSince Powai Lake is an ecologically sensitive ecosystem it is extremely important to maintain its water quality and prevent sewage from entering the lakerdquo stated BangarHe said the sewage flows had therefore been intercepted and diverted to sewage treatment plantsBangar also explained that the increase in organic content in the lake water has contributed to extensive growth of water hyacinth While the BMC is regularly removing the plant using harvesting equipment its natural growth rate is significantly higher resulting in its repeated growthHe said stopping sewage inflow is expected to reduce the spread of water hyacinth Although sewage inflow has currently been stopped organic content remains in the existing lake waterldquoTo improve the water quality a special initiative will soon be undertakenrdquo Bangar said adding that the civic body would study available biological technologies and begin implementing suitable measures within the next one to two monthsThe sewage interception work began in August 2025 and was completed in 13 months which Bangar described as a significant achievement for the Sewerage Projects departmentDeputy Municipal Commissioner Special Engineering Shashank Bhore Chief Engineer Sewerage Projects Sanjaykumar Pandav Chief Engineer Mumbai Sewerage Disposal Project Rajendra Parab and officials from the concerned departments were present during the inspection