Thirsty Chennai gets 550 MLD desalination plants

The nod was given during the last week of October.

The Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) has proposed a desalination plant with a capacity of 150 MLD in Nemmeli and another with a capacity of 400 MLD in Perur. The total estimate for the Nemmeli and Perur desalination plants is Rs 1,259 crore and Rs 3,912 crore, respectively.

The CRZ clearances were issued following a recommendation of the Expert Appraisal Committee (EAC) of the Ministry of Environment, Forests and Climate Change in May. The project area of the Nemmeli desalination plant, which would be based on seawater reverse osmosis technology, falls under CRZ-3, CRZ-1 (Inter-Tidal Zone) and CRZ-4 (Sea water area), while that of the Perur plant falls under CRZ-3 and CRZ-4, according to CMWSSB officials.

Though the Environment Ministry issued the CRZ clearances, it has specified certain conditions. Under the conditions, the CMWSSB should implement the shoreline erosion control and management plan framed by the State government, besides submitting an undertaking to the Tamil Nadu Coastal Zone Management Authority before starting the work on the plant stating that it would bear the full cost of environmental damage and restitution arising out of setting up the proposed 400 MLD and 150 MLD desalination plants. The CRZ clearances are also subject to obtaining No Objection Certificate from the Tamil Nadu Pollution Control Board for discharge of brine water into the sea after necessary safeguards. The CMWSSB should ensure that the structure of the plants aretsunami-resistant.

Though environmentalists and marine biologists have expressed concerns that the desalination plants could damage the ocean biodiversity, officials claimed that the plants would be built by adhering to State and central government norms and this would help mitigate the damage.

CMWSSB is already operating two desalination plants in Nemmeli and Minjur with a capacity of 100 MLD each. Due to water shortage in the city, water managers have brought down the supply from 830 MLD from 650 MLD. Of the 650 MLD, 200 MLD of drinking water is being supplied from Nemmeli and Minjur desalination plants.