Borewells will be sunk at different places as directed by Karnataka State Pollution Control Board to collect the groundwater for testing. The water will be tested for 20 parameters. At present, the water is treated twice before pumping it to the city.

The pre-chlorination treatment is being done at T G Halli while post-chlorination treatment is done at the Tavarekere reservoir. BWSSB uses alum, lime and chlorine for water treatment.

It has already issued a pre-tender notification to invite bids from water testing laboratories.

A BWSSB official said, “We are exploring the possibility of installing an ultra-filtration plant or reverse osmosis filtration plant to treat water that is being supplied from T G Halli.” T G Halli reservoir was the major source of water supply to the city till the Cauvery projects were commissioned.

At present 60 million litres daily (MLD) from the reservoir is added to the Cauvery water supplied to the city.