BENGALURU: To meet the drinking water needs of residents, Bangalore Water Supply and Sewerage Board (BWSSB) has started supplying “blended water” to several areas of the city.
The board has been supplying 10 million litres of water daily from TG Halli reservoir blended with Cauvery water in the ratio of 1:20 to parts of south and west Bengaluru.
This is done due to the hard water quality in the reservoir.
BWSSB officials said this is the first time that blended water is being supplied. “The same will be done when water from Yettinahole reaches Bengaluru. We had invited a team of IISc researchers who conducted an audit of the water quality and suggested blending the water,” a senior BWSSB official said.
The water quality is hard as it has been stagnant for a very long time in the reservoir. The machines and pipelines, too, have not been in use for a long time. Now, even though the machines used to pump, treat and recycle water have been replaced and old underground pipelines have been changed, the hardness in water stayed even after treatment.
“As the flow of water continues and supply increases, the hardness will reduce and fresh water flow will increase. Over time, the blending will also come down. Bengalureans are used to the taste of treated Cauvery water so they are not able to distinguish between the taste of TG Halli reservoir water and Cauvery water now,” the official added.
The BWSSB has been supplying treated and blended water at no additional cost. At present, 1,450 MLD Cauvery water and 10 MLD of TG Halli reservoir water is supplied to Bengaluru. The present storage in the reservoir is 62 tmcft against the full capacity of 74 tmcft.
The government had stopped supply from TG Halli reservoir in 2012 after Cauvery Stage-4 was fully commissioned. However, with increasing water demand in the growing city, the government is working to restart supply from the reservoir which was inaugurated in 1933. It was built under the supervision of Sir M Visvesvaraya.
BWSSB Chairman Ram Prasath Manohar V said TG Halli has good water quality. It is certified by the IISc also. All efforts are being made to ensure that the plant is in running condition and the water is fully utilised.