Chennai Metrowater has recently initiated a project to arrest discharge of untreated sewage into the city’s waterways by plugging sewage outfalls identified in various areas.
The water agency has identified 337 sewage outfalls in Cooum river, Adyar river and Buckingham canal. Of this, work has begun to plug 179 outfalls in various areas during the first phase of the project. Metrowater has identified such outfalls in areas such as Anna Nagar, Aminjikarai, Korukkupet, Tondiarpet, Pulianthope and Chintadripet.
The project has been taken up at a cost of Rs.150 crore provided under Infrastructure and Amenities Fund. Most of the identified outfalls were discharging sewage into the Buckingham canal. Cooum and Adyar rivers took the rest of the volume of untreated sewage through 150 outfalls.
Metrowater has initiated measures to strengthen the sewerage network to plug sewage outfalls within two years. “We are taking steps to provide connections to those who illegally discharge sewage into waterways. We will also identify areas where the sewer pipelines have limited carrying capacity,” said an official. Steps are afoot to improve the existing 218 pumping stations and establish new ones wherever required to pump sewage to treatment plants.
The water agency is also in the process of disconnecting illegal sewer connections across the city. “Chennai Corporation has given us a list of 3,000 such connections that released sewage into waterways. We have so far disconnected 2,000 illegal connections,” the official said.
According to a study undertaken by Metrowater two years ago, nearly 50 million litres of untreated sewage was estimated to be discharged into the waterways. Metrowater too had resorted to letting out sewage into the rivers owing to inadequate collection system in few locations and also in some heavily encroached places where sewer network maintenance was difficult, the study said.
The ongoing project aims to address such deficiencies and also intercept sewer lines and connect them to the nearest treatment plant. A detailed project report has been prepared proposing to plug 86 more outfalls in the second phase.
More sewage treatment plants are coming up in five places to treat sewage generated from the expanding city. At present, Chennai has a capacity to treat a total of 600 million litres (mld) of sewage. Work is on to build new plants at Koyambedu, Sholinganallur, Tiruvottiyur, Avadi and Tambaram with a total capacity to treat 237 mld.
The facilities would be ready next year.
Metrowater officials said that they are also co-ordinating with the Chennai River Restoration Trust and other nodal agencies to identify more outfalls and restore Cooum river.
