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\| Photo Credit: B. Jothi Ramalingam

In a bid to upgrade the city’s ageing sewer infrastructure in core areas, Chennai Metrowater is evaluating bids for a project to improve the sewer network in three zones covered by the Nesapakkam sewage treatment plant.

While the water agency is seeking a phased, STP-wise overhaul in core areas, residents demand a comprehensive modernisation of water supply and sewer infrastructure to address recurring leaks and drinking water contamination. Work order is likely to be issued in two months, officials said.

In the first phase, the sewerage system in parts of Teynampet and Kodambakkam and Adyar zones, which was created nearly five decades ago and suffered a significant strain over the years as sewage generation outnumbered the capacity, would be improved.

The water agency has planned to replace nearly 324.19 km long stoneware pipelines in the existing sewage collection system with larger cast iron or double wall corrugated pipelines of diameters ranging from 150 millimeters to 500 mm. Another 51.71 km major sewage pipelines would be replaced with 1000 mm dia pipes.

The Rs.800 crore project, which would be taken up under Asian Development Bank assisted Chennai Climate Resilient Water Supply and Sewerage Project, also includes rehabilitation of 39 sewage pumping stations.

Residents of Kodambakkam and T.Nagar said the project must be expedited to end the chronic issues of sewage mixing with drinking water. They pointed out that old pipelines in areas like Kodambakkam Akbarabad have become inadequate to handle the increased sewage generated by rapid growth of apartment complexes.

S.Gopi, secretary, Kodambakkam Subramania Nagar Civic Welfare Association, said sewer machines are deployed periodically to desilt the network. Improving the capacity of sewer pipelines and ensuring round-the-clock operation of sewage pumping stations during rainy days would address recurring issues.

North Chennai residents also highlighted the dire need to extend the scheme to chronically affected areas, including Kodungaiyur, Korukkupet and R.K.Nagar. T.K.Shanmugam, president, Federation of North Chennai Residents’ Welfare Association, said some of the households in Gandhi Nagar, Kodungaiyur have stopped using underground sumps for fear of sewage contamination of drinking water. The water agency must prioritise rehabilitation of both water and sewer network in core areas to prevent such issues.

Officials said a detailed project report is being prepared for existing network in core areas covered under Kodungaiyur, Koyambedu and Perungudi STPs. Besides installing odour control systems in sewage pumping stations, the water agency plans to lay sewer lines using trenchless technology to reduce inconvenience to residents and quicker restoration of roads.

A centralised SCADA monitoring system would be integrated with sewage pumping stations and STP to monitor operations. The project, which would be completed in three years, has been designed to suit the projected population in 2060. At present, nearly 715 mld of sewage is treated in STPs across the city.

Published - July 22, 2026 05:30 am IST