Principal component, chemical, bacteriological, and isotopic analyses of Oued-Souf groundwaters (revised)

Oued-Souf City, located in the northwestern part of Algeria, has rapidly grown and been urbanized. The city and surrounding areas depend heavily on groundwater as a water source for drinking, as well as domestic, industrial, and agricultural uses. Comprehensively understanding the chemistry of the groundwater provides insight into the interaction of water with the environment and contributes to better overall resource management. The phreatic groundwaters are SO₄–Ca in character. These waters are hard with a high salinity, which poses a distinct danger for plants. Furthermore, major chemical elements in the water have concentrations above the values recommended by World Health Organization. The phreatic groundwaters display bacteriological germs in sampled waters, and high concentrations of nitrates were detected in the samples due to the absence of a formal sanitation network. In this work, stable and radioactive isotopes are used to understand the water origin of the phreatic groundwaters. The present isotopic study suggests that the groundwaters from the Oued-Souf phreatic aquifer are composed of two primary components, one from infiltrating recent rain waters and the other one from deep captive groundwaters. Herein, descriptive statistics, correlation matrices, and factor analyses were employed to understand the hydrochemistry of the groundwater in the phreatic aquifer in the Oued-Souf area.