Toxic foams seen floating in river Yamuna have become a not so rare occurrence in Delhi and one of the reasons blamed for it is the discharge of chemicals from soaps and detergents to the water from households.
According to an official of the Central Pollution Control Board, the primary reason behind the formation of the toxic foam in the Yamuna high phosphate content in the wastewater because of detergents used in dyeing industries, dhobi ghats and households.
These detergents and other organic matter gets deposited in the riverbed when the river is flowing normally.
When water falls from a height on reaching a barrage, it leads to turbulence and churning which causes froth.?
Earlier this year, the National Green Tribunal (NGT) had in January accepted recommendations of a two-member expert panel which had suggested directing the Delhi government to issue orders "prohibiting sale, storage and transportation and marketing of detergents which do not conform to the revised BIS standards".
The NGT had also directed to launch awareness campaigns about the harmful effect of using substandard soaps and detergents.
On Monday, the Delhi Government banned the sale, storage, transportation, and marketing of soaps and detergents not conforming to the latest BIS standards in the national capital.
Yamuna has been one of the most polluted rivers in India thanks to the unchecked discharge of both sewage and industrial waste to the waterbody for many years.
Though the quality of the water and oxygen level in the Yamuna had substantially improved last year during the first lockdown, it began deteriorating after the restrictions were lifted.?
In January, the Delhi government had prepared a nine-point action plan to prevent frothing in the Yamuna river due to the discharge of untreated sewage in the river. The plan, approved by the Delhi Pollution Control Committee (DPCC), lays down targets to be achieved by various agencies, including the Delhi Jal Board (DJB), Delhi Development Authority (DDA) and municipal corporations, to prevent the discharge of untreated wastewater in the river.?
According to the plan, Haryana and Uttar Pradesh have been asked to upgrade their sewage treatment plants (STPs) to standards prescribed by the DPCC for treating the wastewater entering the Yamuna through Najafgarh drain and Hindon cut canal.
Last month, the Master Plan Delhi 2041 had proposed identifying specific locations for permitting agriculture on the floodplains of the Yamuna.
In January 2015, the NGT had banned farming on the Yamuna floodplains, saying the vegetables grown there were "highly contaminated" and their consumption could lead to cancer.
In July 2019, a two-member panel appointed by the NGT to monitor pollution in the river recommended that farmers may be allowed to grow crops and vegetables but with regular and constant watch on metal content and pesticides levels in the harvested produce.