The accumulation of foam in the Uyyakondan canal near Kuzhumayi Amman Temple has triggered concern among residents over the discharge of untreated effluents into the water body.

The frothing was noticed after the heavy downpour on Monday, with residents observing changes in the colour and odour of the water in the Uyyakondan canal and the nearby stretch of the Kudamurutti River near the temple. Thick patches of white foam floating along the canal raised fears of worsening pollution in the water body.

Residents alleged that the canal continues to be contaminated by effluents, sewage discharge, and dumping of solid waste. The presence of water hyacinth in several stretches has further clogged the waterway, aggravating stagnation and pollution. They also complained of a pungent smell emanating from the canal, indicating possible chemical contamination. Children, unaware of the health hazard, were seen playing in the foam along the canal banks.

A similar frothing incident had been reported after rains last year, and residents said the issue has recurred repeatedly during monsoon spells. “Chemical effluents are allegedly released into the water body during rain so that they go unnoticed. This has been happening frequently. Though several petitions have been submitted, no concrete steps have been taken either to identify the source of pollution or prevent contamination. Authorities should identify and plug the points where effluents enter the canal,” said K.C. Neelamegam, an environmental activist.

The Uyyakondan canal irrigates more than 32,000 acres and feeds over 36 irrigation tanks across Tiruchi and nearby districts. However, the canal, particularly along its 15-km stretch through the city, has faced severe pollution for decades, with sewage reportedly entering the water body at multiple locations.

Despite measures initiated by the Corporation in recent years, residents alleged that untreated sewage continues to mix with the canal water at several points and that long-term preventive measures remain inadequate.