Froth in Yamuna: What causes it and why it is dangerous?
The visuals of devotees taking a dip in the froth-filled waters of the Yamuna river sent chills down the spine of the residents of Delhi and worried environmentalists. The frothing also led to political war of works between the ruling Aam Aadmi Party (AAP) government in Delhi and nearby states.
While the BJP leaders alleged that the AAP government did not allow Chhath celebrations on the Yamuna banks to hide the "pathetic" state of the river, the AAP's Gopal Rai and Raghav Chadha blamed the governments in Uttar Pradesh and Haryana for the frothing in the river.
The 22-kilometre stretch of the Yamuna between Wazirabad and Okhla, which is less than 2 per cent of its length of 1,370 kilometres from Yamunotri to Allahabad, accounts for around 80 per cent of the pollution load in the river.
What is froth formation?
This is a phenomenon that takes place on many lakes and streams. Foam bubbles are produced when organic matter decomposes. These foam-producing molecules have one end that repels water and another that attract water and they work to reduce the surface tension on the surface of the water. These foam bubbles are lighter than water, so they float on the surface as a thin film that gradually accumulates.
What causes the froth?
The presence of phosphates and surfactants in untreated sewage from Delhi, Haryana and Uttar Pradesh is a major reason behind frothing in the river, according to experts. While these two components comprise of 1 per cent, the remaining 99 per cent is air and water.
AAP leader and Delhi Jal Board Vice Chairman Raghav Chadha said that the waste material falls from a height at the Okhla barrage which leads to the formation of foam.
What are the sources of pollution that cause foam formation?
Untreated sewage may contain soap-detergent particles. The other sources are industrial effluents, organic matter from decomposing vegetation and presence of filamentous bacteria.
The pollution from sugar and paper industries in Uttar Pradesh that travel through the Hindon canal also causes pollution in the Yamuna.
What are the health hazards?
Short-term exposure can lead to skin irritation and allergies. If ingested, these chemicals may cause gastrointestinal problems and diseases like typhoid. Long term exposure to heavy metals in industrial pollutants can cause neurological issues and hormonal imbalances.
The war of words
Raghav Chadha claimed that Haryana and Uttar Pradesh have been releasing around 155 million gallons of untreated waste water. While the Delhi government has been working to upgrade its sewage treatment plants to meet the revised standards of the Delhi Pollution Control Committee (DPCC), Uttar Pradesh and Haryana should do their bit in keeping the river clean, he said.
BJP MP Manoj Tiwari, who rode a boat in the foam-covered Yamuna, alleged that the AAP government did not allow Chhath Puja on its banks because it wanted to cover up the frothing in the river caused by high pollution load.
Reacting to it, Environment Minister Gopal Rai blamed the BJP-led Haryana government for the toxic foam in the river and said leaders of the saffron party here should seek answers from the neighbouring state.
On an average, 24 out of the 35 sewage treatment plants (STPs) in the national capital did not meet the prescribed standards for wastewater over the last one year, according to government data.