Snaking through residential areas, and even between large commercial buildings that symbolise ‘hi-tech Bengaluru’, storm water drains leave an unpalatable stench in their wake. They have turned into cesspools of filth and sewage.

Despite frequent complaints, can a machine record the smell to start the process of taking legal action?

This is the challenge before the Karnataka State Pollution Control Board (KSPCB), which has started the process of quantifying and monitoring odour.

After a direction from the task force on Bengaluru’s air pollution, Regional Officers will be asked to identify areas where odour is overwhelming. “We have a machine to measure Volatile Organic Compounds (VOC), which constitute odour. But, this will be the first time and we are not sure what kind of readings it can take in case of a drain,” said D.R. Kumaraswamy, Chief Environment Officer – 3 of KSPCB, who is in charge of co-ordinating the exercise.

The machine, he says, is more than 100 times less sensitive than the human nose. “We may have to put it really close to the drain to get some kind of reading,” he said. Only one such machine is available with the department, to monitor industries in Peenya.

M. Madan Gopal, Additional Chief Secretary of Environment, Forests and Ecology, believes an attempt has to be made to rein in the odour – for an environment point of view as well as sociologically. “We monitor these smells coming from distilleries and pharmaceutical industry as it makes life difficult for villages nearby and even cause health disorders. Since a lot of residents have complained, odour must be treated as a pollutant,” he said.

No escaping the smell

In the congested bylanes and ramshackle housing of Viveknagar and Ejipura, an urbanised ‘sangam’plays out: two large drains carry putrid discharge emanating from central Bengaluru. Even half a kilometre away, the drains make their presence felt.

Babu T., a tailor whose shop faces the drain, says though he has lived in the area for more than four years, the stench gets the better of him. “On days that the smell is particularly bad, I leave the shop and go for a walk…It seems to get worse every year,” he says.

While many living close to drains may have ‘got used’ to the smell, Vijaya Kumari, who shifted to Okalipuram – where the Vrishabhavathy ‘river’ starts to take shape – barely a month ago, can only sigh: “Some days, I don’t even feel like eating. It is a disgusting smell,” she said.

At V. Nagenahalli in the north of the city, Rajanna V., a retired government employee, says the drain close to his house – which seems to be born out of the toilets of north Bengaluru and flows towards Hebbal Valley – makes the air seem heavy, acidic, much like having a ‘pile of manure’ close by.

In the east, the froth of Bellandur carries the acidic nausea in the area populated with IT parks. In the south, the whiff of Vrishabhavathy at its peak flow is an olfactory assault on residents of Kengeri and surrounding areas as well as motorists along Mysuru Road.

Quantifying odour

Are foul smelling gases pollutants? How much odour is ‘permissible’?

KSPCB officials, who are hopeful of finally quantifying fetid gases, believe that they may not be able to ‘legally’ pursue departments to contain the flow of sewage that causes bad odour. “We have standards for carbon, sulphur, nitrogen-based pollutants and even noise and dust. But, there is no national standard for bad odour,” says Ramachandra, Chairperson, KSPCB.

Similarly, an environmental officer also believed that ‘odour’ is a ‘secondary pollutant’ born out of water pollution. “Both the Air Act and Water Act (under which KSPCB functions) cover issues of primary pollutants. However, odour is a secondary pollutant and a by-product of some other type of pollution,” he said.