The sight of Delhites taking a dip in the Yamuna every year on the occasion of Chhath Puja, knee-deep in the toxic foam and offering their prayers, is something we see on an annual basis. But what really causes these dangerous frothy wastes to form in the river? How dangerous is it for the people coming in its contact? We answer all your questions here.
What is the froth that is formed in the river?
A thin layer of foam is always formed in rivers as a natural consequence of decomposition as part of its ecosystem. Dead and decaying plants upon decomposition do not simply dissolve in the water but break its surface tension to create bubbles which leads to the natural froth formation.
But the toxic foam that is much more visible in the Yamuna is due to a separate, more worrisome reason. Untreated sewage effluents have a high level of phosphate molecules in them which then gets discharged into the river. This is the main reason for the frothing.
Why does it occur specifically during the winter months?
Detergents containing pollutants like surfactants and phosphates are released from homes and industries. Most of it is untreated to remove toxicity. During the winter months, the flow in the river is significantly less. This means that the toxins do not get sufficiently diluted. This causes the foam to thicken and accumulate significantly more during the onset of winter.
How detrimental is it to the people who come into its contact?
The toxic phosphates cause the growth of algae in the water. This in turn cuts off oxygen from dissolving in the river. Marine life is harmfully affected as a result which affects the quality of water. Doctors have warned that those coming in direct contact with the froth may experience skin irritation but the long term ramifications are yet to be studied.
Who has been tasked with keeping the water body clean in Delhi?
There is a point of conflict as to who is to blame for this regular occurrence. The foam has only been seen downstream of the Okhla region. The Delhi Jal Board, which comes under the Delhi government, defends itself citing the reason that had the effluents from Delhi were to blame then the foam would have been seen all across the stretch. The Okhla barrage is instead maintained by the irrigation department of Uttar Pradesh government. This has meant that no particular authority has owned responsibility for the situation.
