Nitrate and fluoride levels in ground waters of Davanagere Taluka in Karnataka.

The quality of ground water supplies in Davanagere Taluk, situated in central part of Karnataka has been investigated with respect to pH, dissolved solids, chlorides, nitrates and fluorides. The levels of pH, dissolved solids and chlorides were found within the safe limits as prescribed by BIS, for more than 95% of the samples. Out of the 61 different borewell samples analysed, selected from different areas of Davanagere taluk, 26% of the samples are found to contain fluorides less than 0.50 PPM (lower safe limit prescribed by BIS) and 11.5% of the samples are found to contain more than 1.5 PPM of fluorides (higher safe limit prescribed by BIS). Further, it was also found during study that, 16.00% of the borewell samples analyzed, were found to contain more than 100.00 PPM of nitrates (measured as NO3 mg/L, safe limit prescribed by BIS). The values of fluorides and nitrates observed in different samples were in the range of 0.19 - 2.06 PPM and 0.08 - 308 PPM, respectively.