Hydrochemical assessment and groundwater quality of Koysinjaq area in Kurdistan Region-Iraq

Groundwater quality and quantity are important factors for controlling water management. The importance of the hydrochemical analysis underlies the fact that the chemistry of the ground water can directly be rated with the source of water, climate, and geology of the region. The study includes the hydrochemical characterization of groundwater in Koysinjaq area, Kurdistan Region, to achieve their chemistry, quality, suitability for drinking, irrigation, and industry purposes. Forty groundwater samples were collecting during two periods (spring season and fall season). The physicochemical parameters, namely pH, electrical conductivity (EC), dissolved oxygen (DO), total dissolved solids (TDS), total inorganic carbon (TIC), major cations and anions, and trace elements, were analyzed to evaluate the present groundwater quality as well as the possible source of ions in the groundwater. The chemical composition of water is based primarily on the minerals which have dissolved in it and modified by ion-exchange equilibrium. The hydrochemical composition reflects the hydrogen carbonate water type as Ca-Mg-HCO3, Ca-Mg-Na-HCO3, and Ca-Mg-SO4-HCO3 water type for the groundwater samples. All water samples have low sodium hazard (sodium absorption ration SAR < 9) and most of the groundwater samples has < 1.5 meq/L residual sodium carbon (RSC), which is good quality and suitable for using in irrigation for all types of soils. Geochemical modeling used to determine saturation Index and speciation of water samples calculated by using hydrogeochemical equilibrium model. Most groundwater samples were saturated for calcite and dolomite, whereas unsaturated for gypsum and halite.