Nemmeli desalination plant’s production capacity to be improved this month end by replacing RO membranes

Chennai Metrowater plans to improve desalination plant capacity, reduce production cost, and resolve issues for better water supply.

The production capacity of Nemmeli desalination plant will be improved by this month end once the work to replace part of reverse osmosis membranes is completed. This summer, Chennai Metrowater plans to draw more water from the city’s reservoirs, which is available in abundance.

Currently, Chennai is supplied with 1,013 million litres of water a day (mld). Of this, desalination plants contribute nearly 139 mld. The three desalination plants have a combined total capacity of 360 mld.

The water agency plans to use freshwater sources and reduce production cost of desalinated water this season and also complete ongoing maintenance works and resolve issues. The production cost of one kilo litre of desalinated water is ₹46, noted officials.

At the 150 mld Nemmeli desalination plant, about 80 mld is being produced based on the requirement from residential areas. Besides zones 12, 13, 14 and 15, desalinated water is also supplied to Tambaram corporation. It would be stepped up once there is an increase in demand, said officials.

The water agency is looking to improve the water production up to 85 mld at the Nemmeli desalination plant, which has a capacity to treat 110 mld, by this month end. It is now supplying nearly 58.51 mld of desalinated water to southern parts of Chennai and pipeline from Veeranam tank is also interlinked to offset dip in water supply.

Officials of the Metrowater said of the 7,056 RO membranes, which are crucial for producing freshwater in the plant, about 4,100 membranes have been replaced with those imported from the U.S. Every year, at least 15% of the membranes need to be changed to maintain the quality of drinking water. The plant will be operated to its full capacity from August once the remaining membranes are replaced.

A little further away, about 30% of the work has been finished to build the city’s fourth desalination plant at Perur along East Coast Road. While it is designed to produce 400 mld, the plant would be ready to supply 200 mld of water by March 2026, noted officials.