Appraisal of ground water quality in and around Kolar and Malur taluks of south-eastern Karnataka, India

Atotal of 16 bore well samples were collected from Kolar and Malur taluks and analyzed for physico-chemical and irrigation water quality parameters. Electrical conductivity values indicated that 37.5% of the analyzed water samples were under permissible and doubtful categories and were unsuitable for drinking and irrigation purpose. Total hardness values classified 37.5% of the samples as very hard waters while 81.25% of the samples were non-saline (< 1000 mg L−1) in nature based on total dissolved solids (TDS) levels. Among cations, concentration of alkaline earth metals (Ca+Mg) was dominant over alkali metals (Na+K). Among anions, weak acidic anion (HCO2) concentration was dominant over strong acidic anion concentration (Cl+SO4) in 81.25% of the samples. Majority of the samples were suitable for irrigation purpose based on SAR (Sodium Absorption Ratio) and percent sodium values. WQI (Water Quality Index) values ranged from 7.56 to 24.69 (mean: 14.8) in the study area, which demonstrated their suitability for domestic and other utilitarian purposes. Fluoride content was above the BIS standard limit of 1.5 mg L−1 at Dhanamatanahally, Challahally, Garudnahally, Kolar West and Mangasandra places, which is a matter of concern in view of the health hazards of fluoride