BMC completes final breakthrough of 5.8-km sewage tunnel in western suburbs, 90% work done

The Brihanmumbai Municipal Corporation (BMC) has completed 90 per cent of the Priority Sewage Tunnel Phase-1 project, which it took up to strengthen the sewage system in the western suburbs. The final "breakthrough" of the underground tunnel was successfully completed on Friday.

The tunnel is 5.8 km long. It is being built from the Don Bosco School junction in Borivali to the new Malad pumping station coming up at Malvani in Malad. The civic body aims to complete the entire project by July 31, 2027.

The main aim of the project is to treat Mumbai's sewage properly. It also seeks to improve the quality of water discharged into the sea and rivers, curb water pollution and reduce the load on the sewage system. The work is being carried out through the Mumbai Sewerage Project department.

The tunnel was excavated from the new Malad pumping station towards the Don Bosco School junction. It has been built using the segmental lining technique and has an internal diameter of 3.2 metres. Its sewage-carrying capacity is 1,182 million litres a day. The project includes five shafts, three drop shafts and six screen chambers.

Sewage arriving at the four pumping stations of Gorai, Shimpoli, Charkop and Malad will now flow through this tunnel. This will reduce the need for these stations, and savings are expected in their maintenance and repair costs. Sewage management will become more effective and will also help protect the environment.

Rising sewage volumes in six areas of the western suburbs, Dahisar, Borivali, Gorai, Charkop, Malad and Kandivali, are putting pressure on the existing sewer lines. In some places, the capacity of these lines is falling short. The new underground tunnel will increase sewage-carrying capacity and ease the burden on the older lines. The civic body plans to complete the remaining work on schedule and commission the system by July 2027.