New Delhi: As devotees Tuesday prepared to take a “holy” dip in the Yamuna for the Chhath Puja celebrations, a thick layer of white foam greeted them. It did not deter the women from wading into the dense layers of foam. They went about their prayers, accepting the toxic Yamuna foam as a part of their annual rituals.
“This froth has become a part of our Chhath Puja now,” said Reena Devi, bejewelled by the white foam at the Kalindi Kunj barrage.
The Delhi Jal Board (DJB) officials told ThePrint that the agency has been sprinkling anti-foam chemicals in the river water to ensure the white foam would dissipate.
“Over the last week, we have been spraying a diluted anti-foam chemical to clear the foam in the Yamuna River ahead of the Chhath celebrations. This solution is completely safe for humans,” said a DJB official on the condition of anonymity.
But such last-minute measures are merely an eyewash.
The river sees high pollution levels. A toxic mix of untreated sewage from households and chemicals from industries disintegrates, forming a film of toxins over the river.
Experts pointed out that temporary measures such as spraying the anti-foam chemicals cleared only the visible foam on the surface, but the river water remained polluted.
Exposure to such high levels of toxins could cause severe problems such as skin infections and rashes, dizziness, and itching of the eyes.
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What makes the Yamuna foam
Senior scientists from the Delhi Pollution Control Committee (DPCC) said that the froth over Yamuna waters is a mix of mainly chemical and organic waste. While these pollutants are present in the river year-long, they become more prominent post-monsoon—October and November—when the water levels in the river subsides.
“Two primary ingredients cause the frothing—phosphates and surfactants. Their source is untreated sewage from households and industries. After monsoon, when the water levels in the river decrease, it enhances the activity of surfactants, increasing foam formation,” a senior DPCC scientist said.
Surfactants, chemical compounds that reduce tension between liquids, are a primary ingredient in detergents and soaps that result in lathering. Phosphates are a common pollutant found in sewage and wastewater.
Under usual water flow, this froth would get washed away. However, post-monsoon, when the waste levels reduce, the stagnant river becomes the perfect ground for the lather to form and accumulate.
Vimlendu Jha, a Delhi-based environmentalist, said that the annual froth in Yamuna is only the “tip of the iceberg”. He said that the high pollution levels in the Yamuna prove the government’s incompetence in handling environmental issues in the capital.
“The foam over Yamuna is only more visible and prominent during October-November because of low water levels. Below this foam layer are high levels of toxins, which are extremely dangerous for any living being. The Delhi government claims that all the sewage released into the river gets treated, but looking at the pollutants in the river, we can tell a false narrative is being peddled,” Jha said.
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Yamuna pollution in Delhi
In a recent report released in October this year, the DPCC analysed the pollution levels at eight locations in Delhi and found that the river water failed to meet the standards of dissolved oxygen (DO), faecal coliform, and biochemical oxygen demand (BOD)—all indicators of how clean or polluted the water in a river is.
The assessment showed that the river progressively became more polluted as it flowed into the city. For instance, in Palla, where Yamuna enters Delhi, the pollution was at its lowest, with the DO levels at roughly 5 mg/l. When the river reached the last station, the levels became nil. The report highlighted that at the last of the monitoring stations in Delhi, in Asgarpur, the BOD levels were roughly 15 times higher than the standard 3 mg/l.
DO is the amount of oxygen dissolved in a water body, and its levels indicate the health of the river and the ability of life to survive in it.
The report showcased the presence of high faecal coliform, which depicts the presence of untreated sewage, in the discharge from 16 drains that enter Yamuna. In September this year, the faecal coliform levels in Yamuna peaked at 4,900,000 MPN (most probable number)/100ml. According to the DPCC, this was 1,900 times higher than the standard of 2,500 units and 9,800 times the desired limit of 500 units.
“The foam visible in the Kalindi Kunj area is due to polluted water pushed (into the Yamuna) from Uttar Pradesh. Delhi has made arrangements to clean up the river water ahead of Chhath Puja,” said Delhi environment minister Gopal Rai at a press conference last week.
Experts said that the absence of ample flooding in the river over the last few years is one of the reasons for such high pollution accumulation in Yamuna. Flooding flushes out debris and pollutants.
The natural flow of Yamuna has stopped for several years now, said environmental activist Diwan Singh. “Flooding is a natural function the river performs to rid itself of pollutants and toxins. Without flooding, the status of Yamuna comes down to a drain,” he said.
(Edited by Madhurita Goswami)
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