Intensive exploitation effects on the alluvial aquifer of the Catania plain (Eastern Sicily, Italy)

The growth of an industrial area in the eastern part of the Catania Plain in Sicily has caused an intensive exploitation of groundwater, with negative consequences on its hydrodynamic equilibrium and water quality degradation. In this work, the eastern portion of the plain, located between Mt. Etna and the Hyblean Plateau, is analysed by means of lithological characteristics from boreholes and resistivity data which have permitted the reconstruction of the geometrical relations within the deposit and its thickness varations. The granulometric variability of the alluvial deposits (sand, silt and gravel) and the relative permeability is characteristic of a typical multilayered aquifer system that is unconfined in the upper part and partially confined in its lower portion. It rests on a clayey marine substratum whose morphology is affected by buried tectonic structures controlling the aquifer thickness. The piezometric surface shows a pronounced depression caused by the falling of the groundwater level by about 2 m year–1 since 1962 due to pumping from industrial wells. This has also induced infiltration of poor quality water from the overlying polluted aquifer, while deep test holes have caused further pollution of the aquifer owing to chloride water contained in sandy lenses within the underlying marine clays