The plant at Nemmeli

CHENNAI: The capacity of Nemmeli desalination plant that supplies drinking water to southern parts of the city has dropped to 60% from its estimated daily generation of 100 million litres, sources said. The reason being the intake pipeline drawing water from the sea into the plant is choked.

Officials in the know said the massive intake pipeline could have choked due to rising marine pollution. “The reason for inlet clogging could be due to marine organisms or other pollutants. The biochemical oxygen demand in the water is also high close to the plant, which could be due to pollution,” an official said.

Metro water has approached NIOT scientists to conduct a water intake analysis to find a solution. The Nemmeli plant that works on reverse osmosis technology is one of the two plants in the city with a capacity of 100MLD each. The two power intensive plants can produce around 80 million litres each on any given day. Usually, the plants contribute to around 38% (160MLD) of the total 525MLD supplied to the city. Now, the shortfall in Nemmeli’s capacity might affect city’s drinking water supply. The plant caters to areas like Adyar, Velachery, Besant Nagar, Sholinganallur, ECR, Neelankarai, Kottivakkam, Perungudi, Palavakkam and Thiruvanmiyur.

Experts said unlike the external intake structures to draw water at the Kalpakkam power plant, the Nemmeli plant’s intake pipeline is submerged at a depth of about six to eight metres making periodic maintenance difficult.

While a metro water official confirmed that the Nemmeli plant was not working in its full capacity the water agency’s managing director Prabhu Shankar could not be reached for a comment.

