As per the report, given to the panel, the samples that were lifted from Kalindi Kunj and ITO bridge by the CPCB had a phosphate concentration of 0.51 mg/litre.
Recently, media outlets had carried out a series of photographs depicting devotees offering prayers while standing in a waist-deep toxic froth during the Chhath Puja celebrations in a river at Kalindi Kunj in October.
This lead to the National Green Tribunal appointing a committee comprising of the Central Pollution Control Board (CPCB) as well as the Delhi Pollution Control Board to submit reports on the condition of the Yamuna.
As per the report, given to the panel, the samples that were lifted from Kalindi Kunj and ITO bridge by the CPCB had a phosphate concentration of 0.51 mg/litre. It is quite high from the normal range which is between 0.005 to 0.05mg/litres.
To control the pollutant the panel members will examine the causes in detail and will also issue specific instructions. According to the Yamuna panel, approximately 90% of domestic wastewater flows into the Yamuna. The river already has a high concentration of laundry chemicals and detergent in it.
A committee member told HT that the phosphate compound presence is largely due to household wastewater. The froth is not seen almost throughout the year. It can be seen when there is turbulence in the water downstream which leads to a churning effect that brings all the pollutants up resulting in the froth.
The report also said that when the river is normally flowing then the phosphoric compounds settle on the river bed. However, when the water is released to reduce the pollution load, turbulence causes a lot of churning leading to the formation of the froth. The NGT committee comprises of retired expert member BS Sajwan and former Delhi chief secretary Shailaja Chandra. The panel was constituted in order to formulate an action plan to rejuvenate the Yamuna.
Experts claim that during festivals like Chhath, extra water gets released from Wazirabad barrage which goes down to the Okhla barrage. The water flows into the river from a height and thus froth is formed due to the churning.
Thus, the main contributor to the froth visible at the Yamuna river ghats during the Chhath celebrations was high phosphate concentration. Yamuna Pollution Control Committee reported that these emerged largely from household waste.