Suitability of groundwater quality for its drinking and agricultural use near Koira region of Odisha, India

Groundwater samples were collected from five different locations for a period of 1 year covering the three seasons, i.e., summer, monsoon and winter for analysis of various physico-chemical parameters and calculation of different water quality indices. The average ionic concentrations of cations: calcium (Ca²⁺), magnesium (Mg²⁺), sodium (Na⁺), iron (Fe²⁺), potassium (K⁺) and anions: chloride (Cl⁻), sulphate (SO₄²⁻), carbonate (CO₃²⁻), bicarbonate (HCO₃⁻), fluoride (F⁻) in the study area are in the order of Ca²⁺  > Mg²⁺  > Na⁺ > Fe²⁺  > K⁺ and Cl⁻ > SO₄²⁻ > CO₃²⁻ > HCO₃⁻ > F⁻, respectively. Water quality index (WQI) in the area indicates that, water samples were in the class of good to poor quality for drinking purpose. During summer and post-monsoon, the water quality was good (WQI = 88, 92) and during monsoon it was poor category (WQI = 114.6). Correlation study between WQI and physico-chemical parameters showed higher WQI values, mainly due cations, such as Ca²⁺, Mg²⁺, Fe²⁺ (r = 0.761, 0.695, 0.664, respectively) and anion, such as Cl⁻ (r = 0.827, p = 0.06). A good positive correlation among total dissolved solid with bicarbonate ion (r = 0.986) and Ca²⁺–Mg²⁺ (r = 0.98) was obtained. The multiple linear regression (MLR) study depicts that Ca²⁺, Mg²⁺, Cl⁻, F⁻ parameters were good at predicting WQI. Furthermore, calculation of water quality indices, such as sodium adsorption ratio (SAR), magnesium absorption ratio (MAR), soluble sodium percentage (SSP), sodium percent (Na%), Kelly’s ratio (KR) depicts the fitness of water for agriculture.