CHENNAI: After several delays, decks are cleared for the 400 million litres per day (MLD) mega desalination plant at Perur, Nemmeli, in Kancheepuram district, along East Coast Road. The Expert Appraisal Committee (EAC) of Ministry of Environment, Forests and Climate Change has recommended grant of Coastal Regulation Zone (CRZ) clearance.At its 190th meeting on May 8, the EAC reconsidered the project proposed by Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) at an estimated cost of `3,912.16 crore. The project site falls in CRZ-3 and CRZ-4 area.
The CRZ clearance was recommended after an expert team visited the project site and submitted the report, albeit certain conditions. Metro water 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 (TNCZMA) prior to starting work on the plant stating that it should bear the full cost of environmental damage and restitution arising due to setting up of the proposed 400 MLD desalination plant.
The desalination plant, which is based on reverse osmosis process, should be tsunami-resistant for which the plant site will be raised 6.5 metres above the last level affected by Tsunami. Also, the plant should be shifted towards landward side to reduce environmental impact. At the earlier meeting in November, 2017, EAC had granted CRZ clearance for 150 MLD desalination plant, but deferred the 400 MLD plant which is just 600 metres away from the smaller plant. The committee noted that there was significant erosion in Nemmeli beach arising due to the 100 MLD desalination plant commissioned there.
Marine biologists warn that desalinisation could take a heavy toll on ocean biodiversity; as such facilities’ intake pipes essentially vacuum up and inadvertently kill millions of plankton, fish eggs, fish larvae and other microbial organisms that form the base of the marine food chain. S Janakarajan, a former professor at Madras Institute of Development Studies and president of South Asia Consortium of Inter-Disciplinary Water Studies (SaciWATERs), said the 400 MLD plant is probably the largest desalination plant in South Asia and would trigger ecological disaster.
Promised measures to minimise harm
• Metro water shall implement the shoreline erosion control and management plan of State govt
• Metro water should give an undertaking to TNCZMA that it would bear full cost of environmental damage and restitution arising due to setting up of the proposed plant
• The plant will be tsunami-resistant and the site will be 6.5 metres above the last level affected by tsunami
• Sea water intake head will be located at a distance of about 1,150 metres from shoreline