Kolkata: High levels of coliform bacteria were detected in the internal water reservoir system of E Block at the Shukhobrishti housing complex in New Town. Residents believe that stored contaminated water triggered a wave of illness that left more than 300 people suffering from diarrhoea and stomach infections over the past three weeks. Residents said the tap water supply, which was suspended, will resume from Thursday morning. But its use will be limited to toilet and flushing purposes.
NKDA officials confirmed on Wednesday that laboratory tests on samples collected from multiple flats, overhead and underground reservoirs in the affected block revealed significant bacterial presence within the complex's internal storage system. However, they maintained that the main supply line feeding New Town remained uncontaminated.
"There was no contamination in the water supplied by NKDA. The problem appears to lie within the housing's internal storage infrastructure. High levels of coliform were found in the reservoirs and even in kitchen outlets of some affected flats," an NKDA official said. The findings followed mounting complaints from residents of E Block, many of whom reported recurring cases of acute diarrhoea since last month. Several residents required hospitalisation, prompting civic authorities to conduct an on-site inspection and collect water samples on Tuesday.
While emergency cleaning operations are underway, officials admitted that the exact source of contamination is yet to be identified. NKDA's public health engineering wing began deep-cleaning the underground reservoirs and overhead tanks, particularly in E Block where bacterial presence was confirmed.
Residents, however, said the crisis was far from over. With water supply temporarily suspended during the clean-up, many families were struggling to manage daily needs. "We have been forced to carry water in buckets from the ground floor to the upper floors," said Neha Gupta, a resident whose daughter fell ill. "Authorities have said water supply will resume on Thursday morning. But a circular has been issued saying even after the supply resumes, we can use the water only for toilet and flushing purposes. We cannot use it for drinking, cooking, brushing, bathing or washing dishes until further orders."
Abdul Karim, another resident, raised concerns about possible structural vulnerabilities in the internal pipeline network. He said the pipeline carrying water from the underground reservoir to overhead tanks runs adjacent to sewerage lines. "If there is even a small breach in that pipeline, contamination is possible. Cleaning alone is not enough. The exact source must be identified immediately," Karim said.
NKDA officials indicated long-term maintenance lapses within the housing complex may have contributed to the situation. "It appears the internal storage system, especially in E Block, was not properly maintained for years. We are conducting deep cleaning on humanitarian grounds, but regular upkeep is the responsibility of the housing management," an official said.