Hydrogeochemical characterization and assessment of water suitability for drinking and irrigation in crystalline rocks of Mothkur region, Telangana State, South India

Abstract The present study confers the chemical quality of groundwater and surface water of Mothkur region, Telangana State, for drinking and irrigational purposes. Mothkur region is geologically occupied by the Archaean crystalline terrain. Most of the population depends on groundwater for their daily needs especially for drinking, house needs and irrigation purposes. For this reason, twenty-five groundwater and five surface water samples were collected and analysed for pH, electrical conductivity, total dissolved solids (TDS), total hardness (TH) bicarbonate (HCO3 −), chloride (Cl−), sulphate (SO4 2−), fluoride (F−), calcium (Ca2+), magnesium (Mg2+), sodium (Na+) and potassium (K+). The results are evaluated and compared with WHO and BIS water quality standards. Based on obtained results 32%, 20%, 28% and 4% of groundwater samples are not recommended for drinking with reference to the concentrations of fluoride, TDS, TH and Cl−, respectively. Base-exchange indices and meteoric genesis indices classified 67% and 33% of the water sources as the Na+–HCO3 − type and deep meteoric water percolation type, respectively. Piper trilinear diagram for geochemical classification indicates 44% and 60% of groundwater and surface water samples of Ca2+–Na+–HCO3 − type and 29% belong to Na+–HCO3 − types. Multivariate graphical methods have been carried out using the United States Salinity Laboratory diagram, Wilcox diagram, sodium adsorption ratio, per cent sodium (%Na), residual sodium carbonate and permeability index which indicate that majority of groundwater samples are useful for irrigation purposes