Analytical Groundwater Quality Assessment for Drinking and Agriculture Purposes in Al-Jouf Region, Kingdom of Saudi Arabia

Kingdom of Saudi Arabia (KSA) primarily relies depends mainly on groundwater for drinking and irrigation purposes. The study was therefore aimed to identify groundwater quality in Al-Jouf Region, KSA using water quality index (DWQI). In addition, investigating the hydro-chemical characteristics that control the groundwater quality. Groundwater samples were collected from 150 groundwater wells at a 300-500 m depth and subjected for chemical analysis. The values of chemical constituents were compared with the KSA and World Health Organization (WHO) standards for drinking and irrigation purposes. The results indicated that, the concentrations of ions were within the ranges of KSA for drinking water and WHO. Based on DWQI data, for drinking water about 23.9% of the wells were within poor water category (III), while 9.91% was very poor water within (IV) group, 45.6% is good water of group (II) and 20.5% is excellent water within category (I). Regarding the evaluation of water quality, the estimated DWQI values for the 150 well waters in Al-Jouf, region ranged from 40.7 to 319. About 23.9% of wells were considered poor water “class (III)”, 9.9% were very poor water “class (IV)”, 45.6% were good water for drinking or “class (II), and 20.53% were excellent water. The result shows that the groundwater possess moderate to high salinity hazards with low to medium sodium hazards. The piper diagram showed that cations were decreasing as follow: Na+>Ca2+>Mg2+, while the anions were decreasing as follow Cl− > HCO3− > SO42−>CO32-. The SAR values varied from 0.68 to 15.43; while Kelly’s ratio (KR) ranged between 0.32 to 4.02. The calculated IWQI values of all wells revealed that water was moderate type in which its value was between 22 to -27.