Yamuna foam returns at Kalindi Kunj; DJB plans pre-Chhath defoaming

White foam has returned across stretches of the Yamuna near Kalindi Kunj.

The Delhi Jal Board plans to spray chemical defoaming agents in the coming weeks before Chhath. The measure has been used since 2022 to reduce visible foam, which forms when soap-like surfactants in polluted water are churned at the nearby Okhla barrage.

Foam becomes more persistent as temperatures fall because bubbles are more stable in winter. Pollutants can enter the river through untreated domestic sewage, industrial discharge and dhobi ghats. Decomposing water hyacinth can also release foam-forming compounds.

A TERI study commissioned by the Delhi government identified poorly functioning sewage treatment plants and common effluent treatment plants among the concerns behind excessive froth. During the October-December 2025 anti-froth drive, the DJB used 48,000 kg of defoaming chemicals over 63 days.

Bhim Singh Rawat of the South Asia Network on Dams, Rivers and People said spraying defoamers addresses the visible symptom but does not resolve the pollutants entering the river.