Councillors Flag Severe Drinking Water Contamination Across Chennai Zones

Councillors raised serious concerns over faecal contamination of drinking water and the mounting public health risk across Greater Chennai Corporation (GCC) zones during the Council meeting on Friday.

Valasaravakkam Ward Committee Chairperson V. Rajan submitted a report to Mayor R. Priya, revealing that 44 informal water samples tested positive for E. coli and were classified as bacteriologically unsatisfactory. The findings highlighted severe contamination issues in several western neighbourhoods of the city.

According to the data analysed by experts between May 26, 2026, and August 12, 2026, a ward in Nerkundram recorded the highest concentration with 12 positive samples, making up 27.3% of the total analysed cases. Four wards in Nerkundram, along with Chinna Nolambur, Alwarthirunagar, and Maduravoyal, collectively accounted for 68.2% of the contaminated samples.

The contaminated samples were collected from a variety of sources, including Metrowater supply lines, reverse osmosis (RO) units, open wells, and borewells. Affected locations included Ippasi Street, Mandaveli Street, Mookambigai Nagar, Kadambadi Street, Vallalar Street, and Jai Balaji Nagar in Ramapuram.

To ensure water safety and neutralise bacterial threats like E. coli, residual chlorine levels must be maintained at 0.2 parts per million at the tail ends of the distribution network, including household taps. However, the effectiveness of chlorination depends on free residual chlorine levels, contact time, and water temperature.

Concerns were also raised regarding other parts of the city. MDMK councillor S. Jeevan warned that public health risks remained high across north Chennai due to contaminated water supply. DMK councillor Parithi Elamsurithi stated that sewer networks had sustained damage in areas close to Metrorail construction sites, including Purasawalkam, resulting in sewage mixing with drinking water.

Responding to the council, GCC Commissioner G.S. Sameeran confirmed that the civic body had taken up the matter with the Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) to trace contamination points, carry out repairs, and enhance chlorination.

Metrowater stated that measures are under way to secure safe drinking water across the city and advised residents experiencing contamination issues to register complaints on the helpline 45674567.