Surface and Groundwater Quality, in the Mixing Area, using Hydrochemical and Statistical Methods, in the Valley of Low Djemaa — Zitouna Basins, Algeria

Surface and groundwater of low Djemaa- Zitouna basins were sampled to study the hydrochemical processes that control the water chemistry. Temperature, pH, EC, major and trace element concentrations were measured. The data obtained were used to determine the hydrochemical facies and to perform statistical analyses (correlation matrix, dendrogram of Q-mode cluster analysis). The corrosiveness or scale forming tendencies and saturation indexes were evaluated in order to assess the corrosive potential and the quality of the groundwater in the mixing area. Two main hydrochemical types (SO 4 2− -Ca 2+ -Mg 2+ and Ca 2+ -HCO 3 2− ) were identified. Based on Langelier index, surface water samples show scale forming with a non-corrosive character, whereas groundwater samples are slightly scale forming and corrosive. On the other hand, the Ryznar stability index of all samples shows stable waters and a slight tendency for scale dissolving. It also shows that calcite precipitation and dolomite dissolution driven by gypsum dissolution is the main factor controlling the water chemistry of the coastal aquifer.