The Bangalore Water Supply and Sewerage Board (BWSSB) on Thursday released 120 million litres of purified wastewater into Nayandahalli lake. Nayandahalli lake is the first waterbody in the city to be filled with tertiary treated water, the BWSSB claimed. Minister for Housing and Infrastructure Development V. Somanna inaugurated the project.
BWSSB officials said the water would be pumped into the lake from a nearby 60-MLD (million litres a day) tertiary treatment plant in the Vrishabhavati Valley near Mysuru Road.
The lake, which is spread over 15 acres, was developed by the Bruhat Bengaluru Mahanagara Palike (BBMP) recently. “Despite several steps taken by the BBMP, the lake is filled with polluted water, hence we have planned to release purified wastewater into the Nayandahalli lake,” an official said. “The work was completed at a cost of ₹2.52 crore by the BWSSB. It was carried out under deposit contribution from the BBMP,” the BWSSB said in a release.
Lake activists, who have welcomed the move, however, expressed a few concerns. “The project is good but the concern is whether the water will have all the nutrients. The BWSSB plant should be equipped with Biological Nutrient Removal technology, which is a process used for nitrogen and phosphorus removal from wastewater before it is discharged into the lake,” V. Ramprasad, co-founder and convener of Friends of Lakes, said. However, he added that this was not the first time a lake in the city was filled with treated sewage.
Mr. Ramprasad said the BWSSB should follow all the Central Pollution Control Board regulations when implementing the project. For this, a BWSSB official said, “We adhere to the latest guidelines of the CPCB norms on the phosphate and nitrate levels and the whole process will be scientific.”
