The central government’s sanction of Rs 800 crore to the Karnataka government under the Atal Mission for Rejuvenation and Urban Transformation (AMRUT) to mitigate pollution of the city’s lakes has left many lake experts and members of lake rejuvenation action groups in the city worried.
According to union environment minister, Prakash Javadekar, out of the Centre's grant of Rs 800 crore, Rs 500 crore has been allocated for laying down a 74-km trunk sewage pipeline, while Rs 162 crore has been provided to construct four sewage treatment plants (STPs) in Bellandur lake.
He noted that 1,280 million litres per day (MLDs) of sewage are generated in Bengaluru, while the sewage treatment capacity of the city is only 721 MLD, out of which, only 600 MLDs of sewage are actually treated. He added that out of a total of 520 STPs, only 137 are non-functional.
While lake experts and lake action groups don’t deny this, they fear that the state government’s plans to have a centralised sewage treatment plant might send money down the drain.
Ecological sciences professor, TV Ramachandra, from the Indian Institute of Science, says that a centralised model will starve other lakes in the city.
“This is a short-term treatment plan and would not only fail in a few years’ time but also starve other lakes of water as all the treated water would be diverted to Bellandur Lake. A decentralised model, where STPs are installed for every local area, will work more efficiently. That’s what has been done in areas around Jakkur Lake and it is working very well. The government should learn from its successful projects,” he said.
Ramprasad, a convenor of Friends of Lakes, said that a centralised STP has always failed.
“They are suggesting four 150-MLD capacity STPs in Bellandur lake. Anything more than 80-120 MLD capacity has always failed, and then the whole untreated sewage is going to flow into the lake and the situation will go back to square one,” said Ramprasad. He added that the motive behind sanctioning big sewage plants is for contractors to make money, and said that when such plants fail, there would be little effort put into repairing it.
Ramprasad also added that such large plants will face issues with power supply, since power bills can run up to about Rs 6 lakh to run a 10 MLD plant for a month. “Imagine a 150 MLD plant then,” he said.
“If smaller treatment plants are made on upper lakes (numerous smaller upstream lakes around the bigger lower lake), then local citizens will make sure that they are maintained and performing well. If one of them fail, then the extent of damage would not be as bad when a huge plant stops working,” he said.