21 per cent of Mumbaikars not connected to sewage network; BMC is bridging gap, say officials

The sewage treatment plant in Colaba. File pic/Shadab Khan

About 21 per cent of Mumbai's population is still not connected to its sewage network. According to officials, the total length of the network is 2070 km, but only 79.40 per cent of the population has access to it. The Brihanmumbai Municipal Corporation (BMC) is attempting to connect the entire city to the sewage network and has decided to also appoint a consultant to prevent waste from entering stormwater drains, creeks and nullahs. This will also help increase the rainwater-carrying capacity of these channels.

A civic official said, "The existing sewage network serves 85.43 per cent of Mumbai's area. After creating a 100 per cent network, sewage can be diverted to
treatment plants."

Anand Pendharkar, environmentalist

An official from the BMC's sewage department said that in 2016-17, the civic body launched the Mumbai Sewerage Improvement Programme under which 77.52 km of a proposed 93.68 km of sewage lines has been laid. "Work on 12.51 km is ongoing while that of 3.65 km of pipeline will start soon," the official said.

As phase 2 of the project, 143.19 km of sewer lines was proposed. Out of this 23.80 km has been completed, 34.27 km is in progress. The upsizing of 5.87 km of sewer lines is also in the pipeline.

"The BMC working on appointing a consultant to prepare a detailed project plan for diverting dry weather flow [the average amount of sewage that flows into a sewer or wastewater treatment plant during a period without rain] from major nullah to prevent sea and creek pollution," said an official.

"This will help to reduce the additional load on nullahs," the official added.

Hazards of untreated waste

Environmentalist Anand Pendharkar said, "Untreated sewage mixing with the nullah, creek and sea water is not only an environmental hazard but also dangerous for humans."

He added, "Though untreated sewage mixes with groundwater, there are many borewells and wells in use, so the BMC needs to complete this project on a war footing.

Preventing sewage from entering nullahs will help increase their capacity to carry rainwater."

2070 km
Total length of Mumbai's sewage network

‘BMC can but won't'

Highlighting the dangers of untreated sewage, D Stalin, another environmentalist, said. "The BMC claims there is a lack of space in slums to create a sewage network. It can create underground sewage lines with micro tunnelling without disturbing ground-level structures. However, the civic body doesn't have the will to do this."