Underground sewage lines in Chennai to be revamped with bank funding

Chennai: Decades-old underground sewerage system in the core city zones under the Chennai Corporation will soon get a makeover, as the State government has proposed to implement a project with the help of Asian Development Bank (ADB) to identify bottlenecks and rectify them.

According to TNUIFSL (Tamil Nadu Urban Infrastructure Financial Services Limited), a detailed project report will be prepapred to improve the existing sewerage system (174 sq km) at Tondiarpet, Royapuram, Thiru Vi Ka Nagar, Anna Nagar, Teynampet, Kodambakkam and Adyar.

Additionally, a supervisory control and data acquisition (SCADA) system will be developed to monitor sewer lines remotely across the city covering 426 sq km.

“The detailed project report will be completed by the end of the current financial year. Based on the design, works will be carried out to replace or improve the old sewer lines,” an official said.

The official pointed out that most sewer lines in the core city zones are more than 50 years old and some were constructed during the British era. “But, only 24 of the 42 local bodies, which merged with Chennai Corporation as extended zones in 2011, have underground sewer lines that were constructed after the merger,” he added.

Presently, Chennai Metropolitan Water Supply and Sewerage Board (Metro Water) maintains around 5,200 km of underground sewage lines, of which 1,223 km were constructed before 1978.

Meanwhile, the State government has been discussing with various line departments to constitute a technical committee to adopt innovative concepts for planning, design, and implementation while constructing the new network.

A recent CAG report recommended an institutional mechanism for ensuring coordination of all line departments, along with availability of worksite and all mandatory clearances before awarding tenders, while implementing UGSS.

The report also stated that as of March 2019, only 52 per cent of the sewage generated was collected by the existing sewerage system, leaving the remaining 48 per cent uncollected. Further, only 88 per cent of the collected sewage was treated before being discharged.