River foaming in Tamil Nadu? TVK minister blames soap and shampoo

Tamil Nadu Environment Minister VK Rajiv has attributed foam formation in rivers, including the Noyyal river in Tiruppur, to the use of soap and shampoo, sparking criticism amid longstanding concerns over industrial pollution in the state’s water bodies. The minister made the remarks after inspecting effluent treatment infrastructure at the Kasipalayam Common Effluent Treatment Plant in Tiruppur.

The minister’s comments have drawn attention because the Noyyal, which flows through Coimbatore, Tiruppur and Karur districts, has repeatedly faced allegations of pollution from effluents of textile dyeing units and other waste discharges.

According to reports, Rajiv inspected the treatment infrastructure and praised the functioning of textile dyeing effluent treatment facilities in Tiruppur. He also assured dyeing mill owners that steps would be taken to address their demands. To a question about the foaming in Noyyal river, the minister said, “It can happen when water from bathrooms or sewage mixes with the river. The soap and shampoo we use can also cause it. When water falls down from a height, it happens.”

The minister’s remarks on soap and shampoo have prompted questions about the extent to which domestic wastewater and industrial effluents contribute to the foaming. While detergents can contribute to foam formation, the phenomenon can also be associated with untreated sewage, industrial wastewater and the turbulence caused by heavy rainfall or water releases.

Reacting to the minister’s statement, PMK president Anbumani Ramadoss criticised Rajiv and said that the discharge of waste into rivers was a known cause of foaming. “Even children know that the foaming of rivers such as the Noyyal is caused by the discharge of waste,” Anbumani said.

He alleged that textile dyeing effluents from Coimbatore, Tiruppur and Karur districts were being discharged into the Noyyal, and pointed to the longstanding pollution of the Orathuppalayam dam, which farmers have protested against.

Anbumani also cited foaming in the Thenpennai near Kelavarapalli dam, attributing it to waste discharged into the river in Karnataka. He said he had inspected both rivers several times and urged authorities to prevent effluent discharge.

Questioning the circumstances in which Rajiv made his remarks, Anbumani said the minister had praised the functioning of textile effluent treatment facilities and assured mill owners that their demands would be addressed before attributing river foaming to soap and shampoo.

He called for urgent action to stop textile effluents, municipal sewage, solid waste and other pollutants from entering Tamil Nadu’s rivers and water bodies, urging the minister to take concrete steps to protect them.

A persistent issue across the state

River foaming has been reported repeatedly in Tamil Nadu, particularly in the Noyyal and Thenpennai rivers.

In July 2018, white foam was reported in the Noyyal near Aathupaalam in Coimbatore. Environmental activists blamed effluents from industrial units and alleged that authorities had failed to prevent pollution.

In December 2019, the Noyyal was reported to be foaming again near the Poosaripalayam bridge in Coimbatore. The incident renewed concerns over the discharge of industrial effluents and sewage into the river.

Chennai’s coastline also witnessed thick white foam in October and November 2019, particularly near Pattinapakkam and Foreshore Estate. Reports linked the phenomenon to sewage and effluents entering the sea through the Adyar river, with rainfall and turbulence contributing to the frothing.

The Thenpennai river, also known as the South Pennar, has witnessed similar incidents near the Kelavarapalli dam in Krishnagiri district. In 2020, the National Green Tribunal took up the issue and directed a joint committee to investigate the sources of pollution and recommend remedial measures. The committee’s report to the NGT recorded concerns about industrial effluents, domestic sewage and poor water quality.

Foaming at Kelavarapalli dam was reported again in July 2022 and October 2024. During the October 2024 incident, foam reportedly rose to around 10 feet on a road near the dam following heavy rainfall and water releases. Officials cited pollution in water entering Tamil Nadu and turbulence as possible contributing factors.

River foam forms when air becomes trapped in water containing substances that reduce surface tension, allowing bubbles to form and persist. These substances include surfactants, which are present in detergents and shampoos but can also enter rivers through industrial wastewater and other discharges.

Domestic sewage can contain detergents, oils, phosphates and organic matter. Industrial wastewater may contain surfactants and other chemicals that promote foaming. When such substances enter a river, they can make bubbles more stable, allowing foam to accumulate on the surface.

Rainfall and increased water flow can intensify the phenomenon. Turbulence and aeration mix air into the water, while heavy rain can wash accumulated pollutants into rivers. Dams, spillways and other locations where water churns or falls can further increase bubble formation.

Foam associated with sewage or industrial effluents may also contain harmful chemicals, pathogens or other contaminants. Testing for surfactants, phosphates, organic pollutants, heavy metals and microbiological contamination can help determine the nature and severity of the pollution.