Abstrakt

Interpretation of Groundwater Quality and Radon Estimation in the Selected Region of Bangalore North Taluk, Karnataka, India

Ravikumar P, Mohammad AM and Somashekar RK

Ca-Mg-HCO3 is the major hydrochemical facies in the study area, with cation facies belonging to Ca-Na (95.84%) and Ca-Mg (4.16%) and the anion facies being Cl-SO4-HCO3 (100%). The concentration of alkaline earths exceeded that of alkalies (viz., Ca+Mg > Na+K) and concentration of weak acids exceeded that of strong acid elements (viz., HCO3 > Cl + SO4). Indirect base-exchange reaction was noticed in 95.8% of the samples, which involved ion exchange of Ca2+–Mg2+ in water with Na+–K+ in rocks. Permanent/noncarbonate hardness was noticed in 95.84% of the samples due to higher total hardness values over total alkalinity. Radon activity in 87.5 % of the samples was higher than the EPA advised MCL value of 11.1 Bq/L. Due to higher water quality index (58.0 > WQI < to 137.8) in majority of the water samples, overall groundwater quality in the study area is categorized as unfit for human consumption, attributed to higher salinity, dissolved solids, hardness, etc. The groundwater samples are considered safe for irrigation purpose based on %Na and SAR values.