Kolkata metro corridor to get new cooling system, save 180 million litres water every year

Hindustan Times

2 days ago

KOLKATA: India's oldest metro corridor in Kolkata has decided to shift from traditional water-cooled chillers to air-cooled chillers, a move that would help it annually save around 180 million litres of water, enough to fill over 70 Olympic-sized swimming pools. Out of the 15 underground stations in the Blue Line, the cooling system of 11 stations will be changed from water-cooled chillers to air-cooled chillers. (Wikimedia Commons/Chinakpradhan)
'In a bid to preserve groundwater, we are going to introduce a new type of cooling system in Kolkata Metro Railway's Blue Line, the oldest metro corridor in India. We are shifting from the traditional water-cooled chillers to air-cooled chillers,' said a senior official of the Metro Railway in Kolkata.
The Blue Line of the Metro Railways is a 3.4 km stretch between Esplanade and Bhowanipore (Now Netaji Bhavan station) and was commissioned on October 24, 1984. It now runs between Kavi Subhash and Dakshineshwar, covering a stretch of 31.3 km.
'Out of the 15 underground stations in the Blue Line, the cooling system of 11 stations will be changed from water-cooled chillers to air-cooled chillers. This will save 180 million litres of ground water every year,' said the official.
Officials stated that tenders have already been opened and are being evaluated.
The work is scheduled to commence in 2026 and is expected to be completed by 2029. The Union government has already sanctioned ₹150 crore for this.
A study published in the international journal Springer Nature in 2022 reported that a significant trough had formed in Kolkata due to the over-withdrawal of groundwater. The study also revealed that water level was declining by 33 cm every year at the centre of the trough and by around 11 cm per year towards the periphery. The report also said the gradual lowering of groundwater levels was triggering subsidence in the city.
'The depletion of Kolkata's groundwater has been arrested over the past decade since the city has reduced its dependency on groundwater and relies primarily on surface water. 180 million litres is not a huge amount, especially for a large city like Kolkata. But whatever little we can give back is always welcome,' said Abhijit Mukherjee, professor at Environmental Science and Engineering at IIT Kharagpur.