76% of Dharavi sewage treatment plant for Mithi river complete, to start running in July 2027

The sewage treatment plant (STP) at Dharavi is seen as key to reducing pollution in Mumbai's Mithi river. Seventy-six per cent of the Brihanmumbai Municipal Corporation project has been completed, and work is moving faster than scheduled. Construction is targeted for completion by May 2027, and the plant is planned to be commissioned in July 2027.

Additional Municipal Commissioner (Projects) Abhijit Bangar visited the project site and reviewed the construction, mechanical and electrical works. The treatment tanks, pumping station, sewage lines, sludge treatment system and other basic facilities were also inspected.

Work on the Dharavi plant, part of the Mumbai sewage project, began on July 5, 2022. Because of limited space, the 418 MLD plant is being built over several storeys.

Sewage from the Bapat Nala and Safed Pul areas currently flows into the Mithi. It will now be collected through underground tunnels and brought to the Dharavi treatment centre. About 168 MLD of sewage will be treated this way, reducing the volume of dirty water discharged directly into the river.

The plant will use Sequential Batch Reactor (SBR) technology. All 418 MLD of sewage will receive primary and secondary treatment. Of this, 209 MLD will get a further, tertiary level of treatment. Sludge will be treated to Class A standard. Electricity will also be generated from the biogas produced during treatment.

Work is under way on 10 units under the project's liquid line. The trash rack is complete and 75 per cent of the influent pumping station is done. Machinery is planned to be installed at this pumping station from December 2026. The SBR unit is 99 per cent complete, and the air blower building is ready.

The Maharashtra Coastal Zone Management Authority (MCZMA) has permitted construction of the double tunnel and the receiving shaft. The treated water will be disposed of as recommended by the National Institute of Oceanography (NIO).

During the visit, Bangar directed that work on the launching shaft of the double tunnel be completed by the end of November 2026. He also asked for the compound wall and internal roads to be finished. He said structures affected by the project would be rehabilitated through the concerned department. The liquid line that carries out secondary treatment is targeted for completion by February 2027.

About 688 workers are currently employed at the site every day. Stressing quality, safety and speed, Bangar asked for construction to be completed by May 2027. The target is to commission the plant by July 2027.

Once operational, the plant will raise Mumbai's sewage treatment capacity and help reduce the volume of untreated sewage released directly into the Mithi. Pollution in the river is expected to fall as a result.