Bengaluru’s biggest lake, the Bellandur lake, started frothing again on Tuesday after overnight rain, The Indian Express reported. In some places, the thick froth rose to almost 10 feet. The toxic froth is produced as a result of untreated sewage water flowing into the lakes.

“We have issued notices to all concerned parties to respond to who released the water without treatment,” Karnataka Pollution Control Board chief Laxman told NDTV.

The weather office said Bengaluru got an average of 4 cm rain due to the southwest monsoon in the last few days. Weather experts expect the downpour to continue for the next four days.

Bellandur Lake is infamous for the gigantic clouds of froth that accumulate on its surface, spilling over into roads. In May, the National Green Tribunal said the city administration’s sheer callousness and indifference had forced the lake to become the “largest septic tank of the city”.

In April 2017, the tribunal had ordered the Karnataka government to shut down all industrial units around the Bellandur lake. It also announced a Rs 5-lakh penalty for anyone found dumping waste in and around the lake.

Yamuna spills toxic foam

The Yamuna river overflowed with thick foam and filth on Monday after Haryana opened its Hathinikund barrage, reported The Indian Express. The foul-smelling toxic froth is made of residential and industrial waste.

Immersion of idols in the river on the occasion of Ganesh Chaturthi further worsened the situation. According to the Central Pollution Control Board guidelines, non-biodegradable idols cannot be immersed in the river. However, the authorities have failed to keep this under check.