Application of hydrochemical and preliminary geophysical surveys within the study of the saltwater uprising occurring in the Oltrepò Pavese plain aquifer

The shallow aquifer of the Oltrepò Pavese plain sector is naturally polluted with Na-Cl rich waters, coming from the deep marine substrate at the base of the alluvial aquifer. This phenomenon is localised along an important, buried tectonic discontinuity known as the Vogherese Fault. Groundwater hydrochemical assessment was undertaken: for water sampling and analysis it encompassed, electrical conductivity logs within wells and continuous monitoring of electrical conductivity and piezometric levels of other wells. VLF-EM profiles across the Vogherese Fault were undertaken over the entire investigated area for an expeditious assessment of buried conductive bodies that could be connected to the saltwater uprising (tectonic discontinuities). Moreover, resistivity depth-soundings and one resistivity profiling were undertaken.