The Brihanmumbai Municipal Corporation (BMC) will set up three sewage treatment plants (STP) along Dahisar river and install sewage pipelines on the banks of Poisar river, along with nine STPs, as part of its water quality improvement program for Dahisar, Poisar and Oshiwara rivers.
Last week, the civic body floated tenders for the project, which is likely to take off in October.
Chief engineer of the stormwater drains department, VH Khandkar, said water quality improvement work includes “checking untreated sewage entering rivers, diverting this to an STP, constructing STPs where necessary, and channelling treated water back into the rivers”. “Work on checking the flow of sewage into the river by installing underground sewage lines on the bank, and constructing STPs will begin at Poisar river. Seventy per cent of the work for Dahisar river is complete. Work for Oshiwara river is in the pipeline.”
The Poisar river originates in Sanjay Gandhi National Park (SGNP) and meets the sea at Marve creek. The BMC will set up sewers along 17-km of its banks and nine STPs at a cost of Rs 45.28 crore. The civic body will also check the untreated sewage flowing through Abhishek nullah — which stretches from the Juhu Versova Link Road culvert to N Datta Road in Andheri — into Poisar, at a cost of Rs 1.41 crore.
The Dahisar river starts in the Tulsi lake in SGNP and meets the sea at Manori creek. The civic body will construct 3 STPs along 4.5-km of its banks. “The water in [Dahisar] river, that comes from SGNP where it is sourced, is in its purest form. However, it gets polluted on the way because of slums, toilets, and cattle stables. Where it is not possible to set up an STP on the banks of the river, we will intercept sewage at nullahs and divert these toward the STPs,” said Khandkar.
The STP at Kulupwadi nullah in Borivli will be able to treat 0.5 million litres of trash per day (MLD); one near SBI colony in Borivli will have a capacity of 1 MLD; and the one at Sanjat Nagar will treat 5 MLD.
The civic body has already mapped the cattle stables and slums along both rivers that generate sewage.
Apart from Dahisar, Poisar and Oshiwara, the BMC has been working on a separate water quality improvement project for Mithi river since June 2018, at a cost of over Rs 500 crore.
