Nearly a year after three people died and 20 others were hospitalised following allegations of drinking contaminated water from public taps in Tamil Nadu’s Tambaram, the southern bench of the National Green Tribunal (NGT) has issued a series of stringent directives to prevent any recurrence of such incidents.

A bench comprising Justice Pushpa Sathyanarayana and expert member Prashant Gargava has instructed the Tamil Nadu Pollution Control Board (TNPCB) to carry out quarterly water quality audits and conduct systematic inspections of drinking water pipelines to ensure their structural integrity.

The tribunal emphasised that the preventive framework must be continuous and scientifically monitored to safeguard public health.

The NGT underlined the demographic and infrastructural stress faced by Tambaram Corporation, which has a population of over 10.11 lakh residents across 70 wards.

The bench in the notice stated that while the city has undergone rapid urbanisation, the development of underground sewerage systems (UGSS) and sanitation infrastructure has not kept pace.

Pointing to the existing coverage gaps, the tribunal observed that only 38 out of 70 wards are currently serviced by an underground sewerage network.

In the remaining areas, households rely on septic tanks and open drains, many of which discharge into stormwater drains or natural canals. This situation, the bench said, poses a persistent risk of cross-contamination – especially in localities where drinking water pipelines and sewer lines run parallel or intersect.

Although laboratory tests and post-mortem reports did not conclusively link the deaths last year to contaminated drinking water, the NGT stressed that systemic vulnerabilities remain.

“A locality with incomplete sewerage coverage and intermittent pipeline maintenance is perpetually at risk,” the bench noted, directing authorities not to ignore the structural deficiencies merely because contamination was not proven.

As part of its orders, the tribunal instructed the Tamil Nadu Water Supply and Drainage Board (TWAD) to begin preparing detailed project reports for extending underground sewerage systems to all remaining wards.

TWAD has also been asked to submit quarterly progress updates to the TNPCB.

The bench further directed the state government to ensure the timely release of sanctioned funds, expedite UGSS and STP projects, and continue community health surveillance, conduct health camps, and organise awareness programmes in vulnerable neighbourhoods.

Earlier, the Tambaram Corporation had denied that drinking water contamination was responsible for the deaths and maintained that adequate steps were being taken to ensure a clean water supply. The TNPCB supported the corporation’s stance.