Assessing groundwater quality in northern Algeria using geochemical and index approaches

This study aims to enhance understanding of the hydrogeochemical behavior of the aquifer by utilizing a water quality index in conjunction with hydrogeochemical analysis. The focus is on identifying the factors that control its chemical composition and influence its suitability for domestic use. Water samples were collected from twenty boreholes and analyzed for major ions, pH, and electrical conductivity during the dry and wet seasons. During the wet season, the water quality index indicated generally good chemical quality, with an average score of 96.12. This was categorized as Excellent (5%), Good (55%), and Poor (40%). In contrast, the dry season showed a slight deterioration in water quality, with an average score of 102.57, reflecting a distribution of Excellent (10%), Good (35%), and Poor (55%). Boreholes located in the western and central parts of the aquifer exhibited better chemical quality compared to those in the eastern part, which are considered unsuitable for human consumption due to their poor quality. The mineralization process is primarily attributed to the dissolution of dolomitic and evaporitic formations, resulting in various chemical facies. The dominant facies identified were calcium and magnesium bicarbonate (85%), followed by sodium bicarbonate (7.5%), calcium sulfate (5%), and sodium chloride (2.5%). This study underscores the critical need for sustainable management practices to protect groundwater quality in the Mitidja plain amid ongoing environmental challenges. Addressing these issues is essential for ensuring safe drinking water availability for local communities.