Mumbai: BMC issues work order for Priority Sewerage Tunnel between Borivali, Malad

Mumbai: The BMC has issued a work order to design, build, and commission an underground Priority Sewerage Tunnel-1 of 5.8 km between Borivali and Malad.

While the project's estimated cost is around 571 crores, the ambitious project has already received clearance from the Union Ministry of Environment and Forests (MoEF) and the Ministry of Climate Change. The project has also received final clearance and working permission from the chief conservator of the forest, said the civic official. 

The Mumbai Sewerage Disposal Project (MSDP) is an ambitious project under which the Greater Mumbai Municipal Corporation (MCGM) plans to construct two tunnels, a sewerage pumping station at Dahisar and a wastewater treatment facility in Versova.

The total cost of MSDP is around Rs. 2,000 crores. A part of this project is the Priority Sewerage Tunnel-1, which will run from the Don Bosco school in Borivali (West) to the Wastewater Treatment Facility (WwTE) at Malad.

An underground sewerage tunnel will be constructed to carry sewerage from nullahs as well as pumping stations together into the sea at Erangal, Malad (West). It will take three years to complete the project. 

The project needed a coastal regulation zone and forest clearance for a patch of mangroves in Malad. While starting the process of getting all the clearances, the BMC had appointed consultants to study and prepare tenders for Malad WwTF.

"Since we have received all the required clearance, a work order has been issued to a contractor to design and build a tunnel with the segment lining method. The length of the sewer tunnel will be around 5.8 km, while the inner diameter is 3.2 metres."

"The tunnel will be 15 to 16 metres below the ground. The project will also increase the quality and reliability of wastewater collection, treatment, and disposal through affordable and sustainable technologies over a 25-year period, which is expected to be completed by 2025," said the civic official. 

The sewage disposal system of city 130 years old

The sewage disposal system of the city is more than 130 years old. This system consists of a 1,830 km long sewer network. The daily collection of sewage is about 1,700 million litres.

The sewage collected is disposed of in the sea through marine outfalls at Colaba, Worli, and Bandra and creeks through the lagoons at Versova, Bhandup, and Ghatkopar. The sewage collected at Malad is disposed of in Malad Creek after preliminary treatment.