Hydrochemical Evolution and Quality of Groundwater in a River-Dominated Area

ABSTRACT Groundwater chemistry of the Saharpada block of Keonjhar District, Odisha, is chiefly managed by alteration of the rockforming minerals present in the underground as well as by human activities. The water is alkaline and hard, but most of the chemical constituents are within allowable limits for drinking and domestic use. Ca2+, Mg2+, K+, Na+, HCO3− and F− are derived from the underlying basement granite, dolerite and their weathered soil. Na+, K+, Cl−, SO42−, NO3− and F− are anthropogenic substances being contributed by chaotic disposal of household and animal wastes, seepage from septic tanks, irrigation return flow, manures, fertilizers and soil amenders used in agriculture to increase crop production. HCO3−, which is the dominant ion, is a byproduct of mineral alterations and a result of the reaction between water and CO2 present in the atmosphere and soil zone. Commensurate with the chemical composition and population density, the quality of groundwater varies from good to moderate. It is recommended to reduce anthropogenic activities, adopt groundwater-recharge methods, check the groundwater chemistry intermittently and educate the public regarding the management of groundwater quantity and quality in the Saharpada block of Odisha.