Cellphone videos from Yamuna -- showing people taking dips in the toxic foam -- were widely circulated.
Delhi blamed Uttar Pradesh and Haryana today as toxic foam turned the Yamuna river white, affected water treatment plants and hit the water supply in the national capital. Attributing the foam to "untreated" chemicals and detergents released into the river from the two states, Delhi Jal Board Vice Chairman Raghav Chadha said repeated appeals to treat the water before it is released into Yamuna have gone unheard.
Today, cellphone videos from Yamuna banks -- showing people making Chhath puja offerings and taking dips in the toxic foam -- were widely circulated.
Mr Chadha said the photos were from Okhla barrage, which is under the Irrigation Department of the Government of Uttar Pradesh.
"It is important to understand from where the foam in the Yamuna comes from. Actually, 154 MGD of water comes at the Okhla barrage. Out of this, 105 MGD of water is released by Haryana government into Yamuna, which comes from the Najafgarh drain. At the same time, 50 MGD of Ganga water is sent by Uttar Pradesh from Shahdara drain," Mr Chadha said.
"This water also contains many types of industry dirt, chemicals, detergents. And when water is released from a height, then foam is generated in the water," he added.
The Delhi government, he said, has appealed to the governments of Haryana and Uttar Pradesh many times that the water be treated and only clean water discharged into the river.
"There are many technologies which prevent the formation of foam... such technology were also sent by the Delhi government to the Uttar Pradesh government... Many suggestions were given to the Uttar Pradesh government to deal with pollution but till date no solution has been found," he added.
On Sunday, pumping from Sonia Vihar, Bhagirathi, Wazirabad, Chandrawal and Okhla water treatment plants was affected, the Delhi Jal Board had said.
The dip in the river during Chhath puja, meanwhile, became a flashpoint between Delhi's ruling am Aadmi Party and the opposition BJP.
As the Delhi Disaster Management Authority (DDMA) prohibited Chhath Puja on the banks of the Yamuna this year in view of the toxic water, the BJP accused the Delhi government of issuing bans instead of addressing the problem.
BJP MP Parvesh Verma said he would defy the ban and challenged Chief Minister Arvind Kejriwal to stop him if he can.
Earlier today, BJP MP Manoj Tiwari took a boat ride in the river. "The Delhi government bans people from coming to ghats but makes false claims of cleaning it. The Supreme Court should take a suo -motu cognisance on this matter," he told reporters.