Officials Say No E.Coli in Anna Nagar Drinking Water, But There Is Foul Smell

CHENNAI: The Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) has said that repeated tests of drinking water supplied to residents of M Block, 8th Street, Anna Nagar, found no traces of E.coli, even as it acknowledged complaints of foul smell in the water.

The clarification came following a DC report published on September 3, titled “Anna Nagar residents flag E.coli in drinking water”. According to the area engineer-VIII, a complaint about foul-smelling drinking water was received from residents through the M Block Residents’ Association on August 4.

Following the complaint, officials inspected the premises and checked the quality of water supply on site. The total dissolved solids (TDS) was recorded at 220 ppm, while the residual chlorine level was 2.2 ppm, both within permissible limits, the official said.

A water sample was subsequently collected and sent for bacteriological examination. The laboratory report received on August 11 was satisfactory, with E.coli not detected. However, as residents continued to complain about foul smell, the CMWSSB flushed the water main on August 10. Officials said the water mains in the locality were old and partially choked and that flushing was carried out to remove accumulated deposits, clean the pipeline and improve the quality of water.

As a further measure, the water supply was checked again on August 14 and samples were collected from several locations in the affected area. The laboratory results received on August 20 found no E.coli in any of the samples tested.

The water distribution network was also inspected to check the possibility of cross-contamination from nearby sewer or storm-water drainage lines. No source of such contamination was identified during the inspection, the official said.

The CMWSSB also noted that a private laboratory test and its own laboratory examination had confirmed the absence of E.coli. Subsequent samples collected from multiple locations in the affected area were also found to be bacteriologically satisfactory.

Regarding the persistent foul smell, residents were advised to ensure proper cleaning and periodic maintenance of their underground and overhead water storage tanks. Officials said prolonged storage and accumulation of deposits inside storage tanks could trigger unpleasant odour.

The CMWSSB said necessary measures, including site inspections, water quality testing, bacteriological examinations, flushing of the old water main and testing of samples from multiple locations, had already been undertaken. The latest test results, it reiterated, showed no E.coli contamination in the samples tested.