Household waste water main contributor to Yamuna froth: Report
High phosphate concentration, largely from household waste water, was the major contributor to the layers of froth seen at some ghats of river Yamuna during the Chhath festival earlier this month, the Yamuna pollution control committee was told.
After images of devotees offering prayers in waist-deep froth in the river at Kalindi Kunj were carried by media outlets, the NGT-appointed committee had asked the Delhi Pollution Control Committee as well as the Central Pollution Control Board (CPCB) to submit a report on the condition of water.
“In the samples lifted by the CPCB from Kalindi Kunj and ITO Bridge, it was found that the phosphate concentration was 0.51 mg/litre, which is several times higher than the normal range of 0.005 to 0.05mg/litres,” as per a report submitted to the panel.
The panel member said it will examine the causes in detail and issue specific directions to control this pollutant. As per the Yamuna panel, at least 90% of domestic waste water in the city flows into the Yamuna, which has a high content of detergent and laundry chemicals.
“The presence of phosphate compounds in the river is largely from household waste water. This (the froth) is not seen for most part of the year, however, when there is turbulence in the water downstream, there is a churning effect and these pollutants are thrown up resulting in froth,” a committee member, who did not wish to be named, said.
When the river is at its normal flow, the phosphoric compounds settle on the river bed, however, when more water is released to reduce the pollution load in it, the turbulence causes a churning of water, which throws up these pollutants thus forming layers of froth, the report said.
The NGT committee comprises former Delhi chief secretary Shailaja Chandra and retired expert member BS Sajwan. The panel was constituted to look into issues plaguing the Yamuna and to prepare an action plan to rejuvenate the river.
According to experts, during festivals like Chhath, extra water is released from the Wazirabad barrage, which goes down to the Okhla barrage and from there into the river. Since the water falls into the river from a height, it causes churning and the froth develops.
Manoj Misra, Yamuna Jiye Abhiyan, said, “We get to see this phenomenon every year after monsoon when there is a dip in temperature and the white bubbles from detergents and phosphate compounds float on the surface of the Yamuna. During festivals, extra water is released into the river to make it relatively cleaner for devotees who come to offer prayers. However, the water falling from a height results in a foam covering on the river.”