BWSSB plans nine sewage treatment plants on lakebeds to stop floods, pollution

The BWSSB is preparing a plan to set up nine sewage treatment plants (STPs) on lakebeds and is looking for suitable spots for their installation.

The project, which could be taken up as part of the flood mitigation plans, will focus on waterbodies in the city’s northern and eastern parts.

"If we could treat the water and transport it from Bengaluru to the surrounding districts, it would benefit both the city and neighboring areas,” reasoned a senior Bengaluru Water Supply and Sewerage Board (BWSSB) official.

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The official pointed to multiple complaints of sewage getting discharged into the lakes, acknowledging the immediate need to address the issue since the lake ecosystem gets polluted.

“Ideally, every lake should have an STP," explained another official. “However, since the investment is huge and the BWSSB has limited resources, it is proposing 10 Intermediary Sewage Pumping Stations (ISPS).”

Since setting up STPs is capital-intensive, the official reasoned that having one at every lake would be impossible. “We, therefore, proposed a few ISPSs to ensure sewage reaches the closest STP,” the official added.

Even as experts welcomed the idea to set up new STPs, they cautioned that not monitoring them will make the project useless.

"There is a need to be transparent and put the data out in the public. The data should be monitored, and measures be put in place based on the readings," said Raghavendra B Pacchapur, programme manager, ActionAid Association India.

ActionAid's report highlighted issues with 13 out of 31 sewage treatment plants in Bengaluru. These plants either provided inaccurate data or had no recorded readings.

According to Pacchapur, the new STPs must incorporate advanced technology and ensure the tertiary treatment of water. He emphasised the importance of tertiary treatment for water reuse.

The BWSSB plans to undertake the project with financial assistance of Rs 1,000 crore from the World Bank.

This funding is part of the flood mitigation grant for Bengaluru. While Bengaluru is expected to receive Rs 3,000 crore, the remaining Rs 2,000 crore is allocated for strengthening the stormwater drain (SWD) network and rejuvenating lakes.