Contamination of coastal aquifers from intense anthropic activity in south-weastern Sicily, Italy

Abstract

This study was conducted in western Sicily, in the Marsala and Castelvetrano-Campobello di Mazara coastal plain area. The economy of the area is mainly based on intense farming of specific agricultural crops (citrus, grapes, olives and others in greenhouses). These activities require a substantial and growing amount of water drawn, essentially, from local aquifers. In summers, water demand increases due to high population density. In order to satisfy this demand, numerous wells were drilled throughout the area, in some cases with a density of 10 wells / km2. The uncontrolled groundwater exploitation in the last 10 years has resulted in a drastic decrease in water well levels, consequently allowing extensive seawater intrusion. The main aquifer is a sandy-calcarenitic, plio-pleistocenic complex, interbedded with clayey-marly layers in the lower layers. Multi-layered aquifers are present with the upper layers unconfined. Related studies are also being conducted in this area including monitoring of over 100 wells to better define potential groundwater resources. More specifically, the authors of this study, who are part of the U.O. 4.17 of the Gruppo Nazionale Difesa dalle Catastrofi Idrogeologiche (G.N.D.C.I) (National Defense Group for Hydrogeologic Catastrophes) of the Consiglio Nazionale delle Ricerche (C.N.R.) (National Research Council), are completing a “Pollution Vulnerability Map” of all aquifers in south-western Sicily (1:50.000 scale) using the zoning method for homogeneous areas (G.N.D.C.I.-C.N.R. method). This map is a valid instrument for all authorities governing the management and protection of groundwater resources in the area.