Mumbai: First sewage tunnel to treat Mithi water completed

The total length of the tunnel is 6.70 km, with an average depth of about 15 metres

The Brihanmumbai Municipal Corporation (BMC) has completed work on the first phase of the underground sewage tunnel under the ongoing Mithi River Rejuvenation Project to improve the water quality of Mithi River. An event to mark the ‘breakthrough' of the first phase of the sewage tunnel was held at Kurla Park on Tuesday.

The tunnel is being constructed from Bapat nullah and Safed Pul nullah to the Dharavi Sewage Treatment Plant. The total length of the underground sewage tunnel is 6.70 km, with an average depth of about 15 metres. Of this, the first phase covered 1.8 km. The entire work will be completed in three phases. The second phase of the project will be taken up at Kanakia Zillion (SCLR Junction), Sahar-Kurla Road and the third phase at Bapat nullah. The project will have a total capacity to transport 400 million litres of sewage per day and currently, it will handle 168 million litres of non-monsoon flow per day.

The excavation for the second phase will start from Kurla Park and be completed at the Santacruz-Chembur Link Road Junction shaft on Lal Bahadur Shastri Road, Sahar-Kurla Road. The length of the second phase will be 1.80 km. The final phase, which is 3.10 km long, will be excavated from the Santacruz-Chembur Road Junction shaft to Bapat nullah. Sewage transported through the tunnel will be treated at the plant at Dharavi and then released into the creek at Mahim Nature Park. The project will help keep the Mithi River clean, BMC officials claimed. This is the smallest diameter sewage tunnel in India, with an inner diameter of 2.60 metres and an outer diameter of 3.20 metres. A total of five shafts have been proposed for tunnel alignment. The project was started on October 1, 2021, and will be completed in 48 months, by September 30, 2025. "So far, 43 per cent of the project has been completed," said a BMC official.