The construction of the city’s fourth desalination plant at Perur, a few km away from the existing Nemmeli plant, is set to begin in January next year.
Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) is evaluating bids for the ₹5,000-crore project to build the plant with a capacity to treat 400 million litres a day (mld) of seawater. According to sources, the plant would come up in two streams of 200 mld. This would ensure that a minimum of 200 mld of treated water was produced at the plant even during the maintenance period.
The plant would conform to the environmental norms, including erosion management plan and safe disposal of brine into the sea. The production cost of treated water is estimated to be ₹33.52 per kilo litre in the new plant.
Water would be supplied to southern suburbs such as Tambaram, Chitlpakkam, Sembakkam, Mangadu and Valasaravakkam and other industrial areas. Nearly 22.67 lakh people would benefit from the project. The desalination plant would be commissioned by July 2026, said the officials.
Work in progress
Meanwhile, work on the third desalination plant of 150 mld capacity coming up on 10.5 acres of land at Nemmeli is apace. Officials said about 60% of the work has been completed so far. Of the 23 treatment units, construction of 18 structures is in progress.
“We have started dredging work to lay intake and outfall pipelines into the sea. There are plans to lay nearly 2,250 mm diametre intake pipeline for a distance of over 1 km into the sea. It will be sunk at a depth of 10 metre,” said an official. Though the offshore pipes were ready, the work has not been taken up because of rough sea conditions, the officials added.
The water board has completed work to lay pipelines for nearly 41 km of the total 47.35 km where it is planned to distribute treated water to nearly nine lakh residents. The third desalination plant would be functional by April next year.