Kolkata: Five days after residents first suspected water contamination at a New Town housing complex — triggering a spate of hospitalisation — more families temporarily moved out on Friday after videos circulating on residents' WhatsApp groups showing insects floating in tap water.
Residents alleged that the authorities were yet to identify the exact source of contamination. The New Town Kolkata Development Authority (NKDA), meanwhile, has advised the facility management to install a dedicated chlorinator at the underground reservoir to ensure continuous disinfection. Officials said the reservoirs were not chlorinated for at least three years. The advisory also called for thorough cleaning, followed by super-chlorination and flushing of the entire internal supply network, including all 141 overhead reservoirs.
"Stagnant water was noticed in valve chambers. The manhole and the sewer line near the underground reservoirs should be diverted immediately," a KMDA official said.
The authorities are inspecting the sewerage pipeline, which is less than a metre from the overhead reservoir connection line, to check for breaches. The officials are also examining whether seepage linked to a rise in the water level of the Bagjola canal — flowing just outside the boundary wall — contributed to the contamination. According to KMDA officials, the proximity between the internal storage system and sewage lines near the canal violates standard separation norms.
"We don't think there will be any immediate solution. We have two flats here. The tenant has already moved to a relative's place, and we are planning to return to our native home in Bankura as my wife was seriously ill due to the infection. My two daughters who work in New Town will shift to a friend's place for now," said Sudhir Mondal, a retired civil engineer and resident of E Block.
NKDA detected coliform bacteria in the internal storage system and said contamination was found at the entry point of the underground reservoirs. However, till Friday evening, the officials did not trace the source.
"One resident shared a video of an insect swimming in tap water even after cleaning. It means the breach isn't plugged yet," said Neha Gupta, who shifted to her in-laws' home in Assam with her ailing children.