Toxic foam floats in the Yamuna river, during sunset in New Delhi.

A view of the polluted Yamuna River, in New Delhi.

Toxic foam floats on the surface of Yamuna River at Kalindi Kunj, in New Delhi. The national capital is battling with toxic water after a spike in ammonia content in the Yamuna riv...

Toxic foam floats on the surface of Yamuna River at Kalindi Kunj, in New Delhi. The national capital is battling with toxic water after a spike in ammonia content in the Yamuna riv...

Toxic foam floats on the surface of Yamuna River at Kalindi Kunj, in New Delhi. The national capital is battling with toxic water after a spike in ammonia content in the Yamuna riv...

A fisherman prepare to catch fish at Yamuna River as toxic foam floats on its surface, at Kalindi Kunj in New Delhi.

Fishermen throw their net for fishing at the Yamuna River as toxic foam floats on its surface owing to pollution, at Kalindi Kunj in New Delhi.

Fishermen throw their net for fishing at the Yamuna River as toxic foam floats on its surface owing to pollution, at Kalindi Kunj in New Delhi.

Untreated sewage water is released in river Gomti, as seen on World Environment Day, in Lucknow. The theme for World Environment Day 2020 is biodiversity.

Gomti river covered with Hyacinth and other waste material near Hardinge bridge, as seen on World Environment Day, in Lucknow.

Washermen wash clothes along the Yamuna River, in New Delhi.