As part of efforts to treat water in contaminated borewells, the Bangalore Water Supply and Sewerage Board (BWSSB) is planning to install 168 treatment plants in the 110 villages that were newly-added to the city.
According to T Venkatraju, engineer-in-chief, BWSSB, of the 617 public water borewells located in the 110 villages, 168 were found to be contaminated.
“Therefore, we are planning to install treatment plants to ensure that the water, which is supplied, is not contaminated. As some of these borewells are situated in BBMP areas, we have already convened a meeting with Palike officials to discuss modalities of installing treatment plants,” Venkatraju explained.
The Karnataka High Court had taken suo motu cognizance of deteriorating groundwater levels in the city and had directed the Karnataka State Pollution Control Board (KSPCB) to check water quality in public borewells.
The KSPCB tested water from borewells on 22 parameters, including pH level, amount of dissolved solids, nitrates, fluorides, turbidity, sulphates, chlorides, phenol, total hardness, calcium cyanide ammonia, copper, zinc, iron, cadmium, manganese, lead, chromium and nickel. Water in 168 borewells, located in 64 villages, was found to be contaminated and non-potable.
Forty-eight of these borewells needed chloride treatment plants while 39 needed reverse osmosis plants to remove nitrates and other contaminants.
As many as 72 borewells needed de-fluoridation plants and disinfection units before they were declared as being potable.
Earlier, official sources had estimated the number of contaminated borewells to be 150.