A long-pending proposal of the Bangalore Water Supply and Sewerage Board (BWSSB) to upgrade old sewage treatment plants (STPs) has now gained fillip as Chief Minister Basavaraj Bommai, in his maiden budget, announced that 20 old STPs would be rejuvenated and modernised by the BWSSB at a cost of ₹1,500 crore.
BWSSB’s chief engineer (waste water management) B.C. Gangadhar admitted that the proposal had been in the pipeline for a couple of years. It was first proposed to not just prevent water pollution, but also included modifications to reduce the presence of biological nutrients in the water bodies.
Experts have for long stated that the one of the main reasons for overgrowth of microphytes and macrophytes, such as algae and water hyacinth, is the presence of biological nutrients (phosphorus, potassium and nitrates) that flow unhindered and untreated into the water bodies.
Mr. Gangadhar said that of the 35 STPs operated and maintained by the BWSSB, 20 were around 15 to 20 years old, such as the plants at Kadubeesanahalli, Hebbal, Ulsoor, K.R. Puram, Vrushabhavathi valley etc. They were established as per the prevailing parameters set by the Central Pollution Control Board (CPCB). The National Green Tribunal (NGT) has now revised the parameters that required change of equipment and processes of waste water treatment in the old STPs, he said.
“The Indian Institute of Science (IISc) prepared the concept note based on the new NGT parameters. We are now in the process of preparing the detailed project report. The same is expected to be ready in two months’ time,” he said.
With the limited scope for civil work, the work on upgrading and modernising the equipment in the STPs will be taken up this year itself, he added.