As many other semi-arid regions, the Cap Bon peninsula (N.E. Tunisia) shows a parallel increase in overexploitation and mineralization of groundwater resources. The study area is 45 km long and 17 km wide at the most and the Plio-quaternary aquifer extends over 475 km2 and its thickness varies between 30 and 150 m. Groundwater flows from NW, at the foot of a mountain range, to SE in the coastal plain.