BENGALURU: The Bangalore Water Supply and Sewerage Board (BWSSB) plans to upgrade 20 of its Sewage Treatment Plants (STPs), in the light of the National Green Tribunal’s order on the need for better treated water to be discharged by these plants.The move will benefit the environment as the treated water is being utilized for recharge of groundwater, apart from numerous non-potable purposes.
V Gangadhar, Chief Engineer, Waste Water Management, BWSSB, said, “We plan to upgrade 20 of the 32 STPs we maintain. Those selected are the older ones and were commissioned at the time of the Cauvery Water Supply Scheme Stage-IV, Phase-I.”Funds will not be a constraint as the government had already earmarked nearly Rs 1,500 crore for STPs in its 2019-20 budget, he said.
The Indian Institute of Science will be ready with a concept report in two months, Gangadhar said, adding that this would be followed by the Detailed Project Report.STPs to be upgraded are the Raja Canal at Hennur Road that treats up to 40 Million Litres Per Day ( MLD), one at KR Puram (treats 20 MLD), Nagasandra (treats 20 MLD) and Mylasandra (75 MLD).
According to the Tribunal’s revised norms issued on May 3, 2019, these are the new standards for effluents released in the treated water: the level of biochemical oxygen demand (oxygen needed for survival of aquatic life) in the treated sewage has been set at 10 mg per litre, from earlier 20 mg/l; COD (Chemical Oxygen Demand) and total nitrogen, which earlier had no limit are restricted to 20 and 10 mg/litre respectively; total suspended solids have to be less than 50 mg/l, from the earlier 100 mg/l.