CHENNAI: In a move that is likely to threaten the local environment, the Union Environment Ministry has allowed a proposal to set up a desalination plant inside the eco-sensitive zone of Gulf of Mannar Marine National Park. The project will be coming up at Kuthiraimozhi village in Kadaladi Taluk of Ramanathapuram, from where the boundary of the marine park is a mere 25 metres away.
The plant, to be set up by the Tamil Nadu Water and Drainage (TWAD) Board, will produce 60 million litres of freshwater per day (MLD). In the process, it will discharge a whopping 42 MLD of brine (water with high salt concentration) into the sea for at least two months a year, which could wreak havoc on reefs, seaweed, and the overall ecosystem.
Despite this concern, the ministry’s expert committee has granted clearance for the project. In its earlier meeting, the expert committee had asked the TWAD Board to shift the proposed project away from the marine park. It even suggested a merger of the proposed plant with another in Alanthalai.
The Board, however, insisted on building a new plant as it wanted to use a new technology – Counter Flow Reverse Osmosis (CFRO) – instead of the conventional process, to increase the recovery rate of drinking water from seawater to 64 per cent from the current 45 per cent. The quantum of brine is also reduced from 98.42 MLD to 42 MLD.
The Board has also promised to create artificial lagoons to collect the brine and thereby reduce its infusion into the sea. The surplus flow will be used by the Tamil Nadu Salt Corporation Limited or private salt pans owners in the nearby areas. Considering these measures, the expert panel recommended clearance for the project. The condition being, the TWAD Board explore the possibility of zero brine discharge.
Brine discharge into the sea during the two months when the salt pans are non-operational must not exceed 42 MLD, the panel has said. The EAC asked the TWAD Board to earmark `10.05 crore under Corporate Environment Responsibility for the activities to strengthen bird habitat and migratory bird conservation in the affected area around the project. Installation of artificial reefs was also suggested.