In the southern Indian city of Bangalore, where April temperatures can reach up to 39 degrees Celsius (103 degrees Fahrenheit), the arrival of cooling monsoon rain is something to be celebrated.
But recently, the rain has resulted in another, less welcome phenomenon: toxic foam.
The white puffy foam, which carries with it a variety of health problems for residents – as well as a pungent and inescapable stench – began spilling out of Varthur Lake, located near the city’s busy Whitfield Road intersection, Saturday.
A protective wire fence had been erected around the foamy banks of the lake and nearby rivers, but proved of little use as the winds picked up, carrying the foam above the fence and onto the streets.
Varthur Lake is the second largest lake in Bangalore, which before becoming India’s technology capital was known as the “city of lakes”.
“The frothing in the lake clearly shows there is mismanagement. There is a sustained flow of untreated sewage and industrial waste going into the lakes,” said TV Ramachandra, coordinator of the Energy and Wetlands Research Group, at the Indian Institute of Science in Bangalore.
“When sewage gets into the water body, nutrients, in the form of nitrogen and phosphorus go in too. The nitrogen is taken by the plants in the water, while the phosphorus gets trapped in the sediment. The rainfall and the high wind velocity churn the lakes, and the phosphorus that is trapped in the sediment is released, creating the foam,”added Ramachandra.
According to Ramachandra, the toxic foam can result in respiratory and skin problems, as well as more serious health implications.
“The underground water has also become contaminated. Our studies show it has a high level of nitrate, which is a carcinogen,” he said.
“There are also heavy metals and with vegetables grown in the downstream area of the lake, we have seen a higher content of metal in the food that enters into the city.”
Lake on fire
Unfortunately for residents, foam is not the only substance pouring forth from the city’s lakes.
Bellandur Lake – the city’s largest – made headlines in February when it erupted into flames.
“The lake was covered with plants which started drying. People were dumping waste on top of this and when they set fire to the waste and plastic, the dry plant bacteria also caught on fire,” explained Ramachandra, who has been studying the city’s lakes since 1997.
He believes the fire spread rapidly because of traces of petroleum in the water.
“We noticed the color of the fire was orange and yellow, and when we analyzed samples, we found there was a high level of hydrocarbon, which is found in petroleum products.”
Soon after the fire, India’s National Green Tribunal – a special government-backed tribunal created to handle environmental issues – banned the dumping of municipal waste in and around Bellandur Lake.
According to local media reports, Bengaluru’s Development Minister KJ George, met with concerned residents over the weekend and promised to provide a solution.
Ramachandra isn’t convinced, however. “There is a lack of sincerity. This problem could have been solved in two years. Unless there’s pressure from the judiciary, things don’t work.”