Hydrochemical and statistical study of karstic spring waters of Bejaia coastal area (North Algeria)

Karstic spring waters of the coastal area of Bejaia represent important sources of drinking water. The present study covers the identification of the geochemical processes responsible of the mineralization of spring waters and their characterization. Forty-two water samples were collected from six important springs within the study area then analyzed according to major ions. In addition to traditional diagrams, Piper, Gibbs and scatter diagrams, multivariate statistical analyses, namely principal component analysis (PCA) and hierarchical cluster analysis (HCA), were applied. Hydrochemical parameters such as temperature (T), pH, and electrical conductivity (EC) of the samples were measured on site, and major ion analysis (Ca2+, Mg2+, Na+, K+, HCO3−, SO42−, and Cl−) was conducted in the laboratory. Results showed three different geochemical groups of samples: (1) The first group, characterized by water flowing through fractures of Jurassic limestone (Toudja, Aiguades and Cascade), was lowly mineralized and had Ca–HCO3 water type. (2) The second group was highly mineralized (samples from Derguina spring), characterized by Ca–Mg–HCO3-SO4water type, indicating that waters are flowing through Triassic evaporitic formations. (3) The third group, which represents samples from Source Bleue and Minena springs, was moderately mineralized and had Ca–Mg–HCO3 water type with important concentrations of SO42−. The water of this group might be the result of an interaction between both limestone and evaporite within abnormal contacts.