E. Coli Detected in 43 Drinking Water Samples Across Chennai's Zone 11

As many as 43 drinking water samples collected from Zone 11 between May 26 and August 12 tested positive for E. coli contamination, according to a health department report presented at the Chennai Corporation council meeting on Friday.

The report showed that 36 of the contaminated samples were collected from Chennai Metro Water facilities. In total, the health department listed 46 samples as "bacteriologically not satisfactory", with 43 explicitly testing positive for E. coli. The presence of E. coli is a primary indicator of faecal contamination, while standard drinking water norms stipulate that the bacteria should not be detectable in a 100-ml sample.

The report did not state the total number of water samples tested across the zone during this period, leaving the overall failure rate unclear. The tested samples were drawn from households, storage tanks, and various public facilities across the locality.

More than half of the contaminated samples came from three specific wards. Ward 145 recorded 10 positive samples, Ward 148 recorded nine, and Ward 147 recorded six, together accounting for 25 of the 43 positive results. Additionally, Wards 143, 152, and 153 recorded four positive samples each, while Ward 151 recorded three, Ward 150 recorded two, and Ward 155 recorded one.

Contamination was detected at several public installations. Two samples linked to the Chinna Porur Urban Community Health Centre (UCHC) tested positive. A Metro Water sample taken from a tank at an Amma Unavagam in Ward 148 tested positive on July 21, and two separate water tanks in Nerkundram returned positive results on June 9 and June 23.

Zone 11 chairman V Rajan presented the report at the council meeting to raise alarms over the public health risks posed by contaminated drinking water, urging the civic body to conduct similar testing across all 15 zones of the city. Rajan noted that a water tank supplying Wards 145 and 148 is located in neighbouring Zone 10, where he claimed contamination had also been found.