Bangalore, May 6, DHNS: It is not just the borewells in Bangalore City that have high levels of contamination. Over two lakh borewells across the State have recorded high levels of fluoride, nitrate, total hardness and pH (potential hydrogen) values, a study conducted last year has revealed.

The Karnataka Rural Water Supply and Sanitation Agency (KRWSSA) collected post-monsoon samples of borewell water and conducted a test for the first time in the country in November last year.

Six laboratories in Bangalore, Mysore, Belgaum, Chitradurga, Bellary and Dharwad collected 1,98,860 samples and tested 1,45,860. As many as 24,948 samples had contamination of pH, total hardness, chloride, fluoride, nitrate, iron, etc.

KRWSSA Director Dr P Boregowda said he was planning a second round of pre-monsoon sampling by May 10, after which an overall view of groundwater contamination in the State would be established.

“We understood with the first phase of borewell water testing that the deeper you sink a borewell, the chances of contamination only rise. In many places, borewells have touched the static level of groundwater that will yield harmful results in future,” he said.

The agency, which will be known as State Water and Sanitation Mission (SWSM), has identified 59,000 habitations, including areas that do not come under its jurisdiction, for the second round of pre-monsoon quality checks.

KRWSSA has mobilised over 1,000 block resource persons and cluster resource persons to conduct water sampling testing at field levels and later send samples with high contamination to designated laboratories for further testing.

Dr Boregowda said that after the pre-monsoon reports on contamination, a comprehensive plan would be drawn to create awareness among people about the consequences of drinking contaminated water. “We cannot outrightly ask them to stop using water from a particular borewell; we will have to provide an alternative and then educate them,” he said.

Since colour coding chemical contents help identify contamination better, the agency will paint borewells in different colours indicating that their water is non-potable. In order to provide an alterative source, if a borewell has high fluoride content, then defluoridation methods will be adopted. If the contamination level is high, then RO (reverse osmosis) will be incorporated to provide drinking water.

Rainwater harvesting will also be encouraged among villagers, added Boregowda.