The use of groundwater in Bouhmama area for drinking and irrigation purposes has increased progressively over the past decade. The water quality of the aquifer has been significantly altered by anthropogenic activity, such as the extensive use of chemical fertilizers. This research intends to enhance our understanding of the hydrogeochemical function of the Mellagou aquifer in the Bouhmama area in northeastern Algeria. It contributes to the identification of the phenomena affecting the mineralization and the mechanisms of salinization of groundwater. A total of 15 groundwater samples were collected during the rainy seasons in 2022 distributed in the study area. In order to performed the results obtained this study used hydrochemical diagram (Piper, Schoeller, Stiff, Stabler, and Wilcox diagrams), thermodynamic models (saturation indexes), and statistical method (PCA). Three chemical facies with a predominance of the calcic bicarbonate facies reflect the influence of intercalations within the bicarbonate sedimentary formations. Groundwater mineralization is mainly governed by the dissolution and the precipitation of minerals (gypsum and halite, calcite and dolomite), Base Exchange, and anthropogenic activities. The results acquired by PCA show that the variables controlling water mineralization are Cl^-, Na⁺, and K⁺.