CHENNAI: As many as 43 water samples collected from Zone 11 between May 26 and August 12 tested positive for E.coli, including 36 samples collected from Metro Water facilities, according to a health department report tabled at the council meeting on Friday.
E. coli is an indicator of faecal contamination, and drinking water standards stipulate that the bacteria should not be detectable in a 100-ml sample. The report lists 46 samples as “bacteriologically not satisfactory”, of which 43 were explicitly recorded as E. coli-positive.
However, it does not mention the total number of samples tested during the period, and therefore does not indicate what proportion of the total samples from the zone failed the tests.
Three wards accounted for more than half of the E. coli-positive samples. Ward 145 recorded 10, followed by Ward 148 with nine and Ward 147 with six. Together, the three wards accounted for 25 of the 43 positive samples. Wards 143, 152 and 153 recorded four positive samples each, while Wards 151, 150 and 155 recorded three, two and one respectively.
The samples were collected from households, tanks and public facilities. Two samples linked to the Chinna Porur UCHC tested positive.
A Metro Water sample collected from a tank at an Amma Unavagam in Ward 148 also tested positive on July 21. Two tanks in Nerkundram returned positive results on June 9 and June 23 respectively. Displaying the report at the council meeting, Zone 11 chairman V Rajan raised concerns over the health risks posed by contaminated drinking water and sought similar testing across all 15 zones.
Speaking to TNIE, Rajan said a water tank supplying Wards 145 and 148 was located in neighbouring Zone 10 and claimed that contamination had been detected there as well. Ward 78 councillor C Velu said Metro Water had not paid GCC the charges for restoring roads dug up for its works.
Commissioner GS Sameeran said Metro Water was carrying out works worth around Rs 3,600 crore under the Vada Chennai Valarchi Thittam and was dependent on funds from CMDA to meet the road-cut restoration charges. As CMDA was facing financial crunch, payments had not been made, he said.