BENGALURU: The Bangalore Water Supply and Sewerage Board (BWSSB) is on its way to increase supply of water treated with zero-bacteria technology to significantly reduce dependency on Cauvery water or borewells. The board is already sending three lakh litres of zero-bacteria treated sewage water daily to IT major Wipro, and has set an aim to treat one crore litre of water treated with the zero-bacteria technology.
The sewage water is categorised as black water (which comes from sanitary lines) and grey water (discarded from bathrooms, kitchens and domestic use). BWSSB Chairman Ram Prasath Manohar said the demand for treated water has increased in Bengaluru from 60,000 litres to six million litres per day (MLD) over a decade and the board is treating 1,200 MLD of sewage water.
Water experts have said this initiative can significantly reduce pressure on Cauvery and borewell water for secondary purposes like bathing, washing, cleaning vehicles, gardening, AC maintenance and other non-potable functions by 50 per cent.
Water expert and environment professional Vishwanath Shrikantaiah said that 440 MLD of treated water from KC Valley was filling up tanks in Kolar, while 260 MLD of treated water from HN Valley was filling up tanks in Bengaluru Rural, Chilkkaballapur and Anekal.
This arrangement is for agricultural purposes, although the treated water is also supplied for lake rejuvenation and for industry use, he said. “Currently, 1,470 MLD of Cauvery water is supplied to Bengaluru through pipes, and under Cauvery stage V, additional 775 MLD of water will be supplied. If we put all our Sewage Treatment Plants (STPs) to good use, recharge the ground, and protect our lakes, we can reduce stress on Cauvery water by 50 per cent.”