It might look like cotton and marshmallow, but the wall of foam billowing from Bellandur Lake in India is highly-polluted and toxic.
Residents of Bangalore were confronted on Tuesday with a mountain of froth that in some places reached 10ft high.
The nightmarish scenes were caught on film next to the lake in southern India’s Karnataka State, which chemicals and sewage have turned into a 900-acre septic tank.
This is the huge flow of toxic foam that has risen from a lake polluted with sewage and is overflowing onto nearby roads
One resident in their car is confronted by the mountain of froth which had spilled over the top of a 10ft fence
In the video, a gigantic mass of what looks like snow can be seen pouring out of the lake and into nearby streets, as a river carrying the foam flows in the background.
Local media report that the foam mountain has spilled over a 10ft-high fence and into crowded nearby streets while cars and motorbikes pass by.
A local resident named Seema told reporters that people had been travelling to take selfies with the foam, despite the fact that it is known to be toxic and emits an awful smell.
‘Sheer callousness and indifference’: the green court blamed the Karnataka government for its failure to tackle the decades-old problem
Despite looking at first glance like snow, the foam is reportedly highly-toxic and emitting an awful smell
And it gets worse. The Bellandur foam is highly flammable and can turn the lake into an inferno with only the slightest trigger.
The Bellandur made headlines in February last year when it began ‘breathing fire and smoke’ as the foam ignited.
Witnesses observed huge flames coming from the lake and heavy black smoke engulfed the local area.
The lake caught fire once again in January this year, and this time it took a 5000-strong army unit seven hours to put out the flames.
A local resident said people have travelled to the lake to take selfies with the sludgy foam, despite the fact it is contaminated with sewage
The foam is reportedly caused by untreated sewage diverted from the nearby Agara and Iblur lakes entering the Bellandur, as well as the large-scale dumping of illegal waste on the riverbed, which is often set alight.
When the lake caught fire in 2015, it was the result of chemical waste which had been illegally thrown into the water.
The authorities failed to set up a plant to treat the sewage and other pollutants, and instead ammonia, phosphate and oxygen have mixed, causing the foam to rise.
Three other lakes – Yemalur, Varthur and Byramangala – have also emitted a dense froth in recent months
It is caused by a chemical reaction between ammonia, phosphate and oxygen and displaced by heavy rainfall
Local media reported that in June the green court ordered the Karnataka government to take action and condemned the ‘sheer callousness and indifference’ that had destroyed the lake.
Reports suggest a sewage treatment plant is expected to be built at the Bellandur by 2020, and Seema said more than £5.2 million had been earmarked to help save the lake from pollution.
For over two decades the people of Bangalore have witnessed their lakes come alive after heavy rainfall.
As well as the Bellandur, three others lakes – Yemalur, Varthur and Byramangala – have emitted heavy froth recently.