Project for filling tanks with treated sewage water stirs row

A Karnataka government project to fill several tanks with the secondary treated water from the polluted Bellandur lake here has stirred a controversy with a scientist and residents raising questions about it.

The scientific fraternity as well as, the residents of Anekal on the outskirts of the city have come out against the project, saying it would destroy their neighbourhood. They are apprehensive that even tertiary treated effluent dumped in the lake cannot remove the toxicants. Officials, however, said they would take steps to monitor toxin levels in the water every day.

Under the Rs 240 crore project, the Minor Irrigation department, the custodian of water bodies around the city, would supply the treated water from Bellandur lake to tanks in Kolar, Chikkaballapura and on the outskirts of Bengaluru urban district.

Spread over 1,000 acres near the infotech hub here, the Bellandur lake, the largest water body of Bengaluru, has been virtually reduced to the biggest septic tank receiving about 60 percent of the city's sewage. Nicknamed as "the burning lake", the Bellandur lake replete with sewage, chemical effluents and construction debris, drew national attention in January this year when a huge fire emanated from it, giving anxious moments to hundreds of residents living nearby.

It had also been in limelight earlier when the National Green Tribunal penalised two builders with a hefty penalty for encroaching its wetland and directed the state government to restore it at the earliest. The lake is in bad shape despite the tribunal pulling up the government and its various agencies for failing to prevent pollution and not doing enough to restore the lake to its pristine glory.

According to the present project, the Bengaluru Water Supply and Sewerage Board (BWSSB) will set up Sewage Treatment Plants (STP) to treat the effluents dumped in the lake and the treated water would be taken to the other water bodies. It involves setting up of pump houses to lift the treated water from the STPs and lay pipelines to fill these 69 lakes. Already, one STP had started functioning. Of the 69 lakes, 64 are in Anekal Taluk of Bengaluru urban district alone. Rest are in Bengaluru East and Kanakapura Taluk of Ramanagar district.

Minor Irrigation department Executive Engineer D Dayanand, who is in charge of the project, told PTI that it would not shift raw sewage but the secondary treated water, filtered by the BWSSB at its STPs at these lakes. "BWSSB will monitor the content of toxins in the water every day. They will regularly compare the raw water and treated water.The sample of treated water will remain at the BWSSB's lab at the site," he said. The treated water would be stored in a separate tank from where it would be pumped to the water bodies, Dayanand said.

These explanations, however, have not convinced the residents and others. Renowned scientist Dr T V Ramachandra from the Centre for Ecological Sciences in the prestigious Indian Institute of Science here is critical about the project. He said he had seen the quality of treated water (from the functional STP) and it was "as good as the raw sewage". "They had written to me also about the project. When I checked the quality of water, I found it is raw sewage only.

They claim that they were transferring the treated water. Unless they remove the nitrate, phosphate and heavy metals before transferring the water, people will have a long-term problem," he said. The residents in the project areas are equally worried as they fear it will not only pollute the groundwater but also lead to felling of trees for the work.

Deepanjali Naik, a member of citizens' group "Voice of Sarjapura" said fire catches in Bellandur lake because the water had a petrochemical mix. "Even tertiary treated effluent dumped in the lake cannot remove the toxicants. Yet, the government wants to dump the secondary treated water in our lakes. It will poison the groundwater in our area," she said.