The Groundwater Resources of the Morainic Amphitheatre: A Case Study in Piedmont

Abstract

Problem statement: The risk of groundwater pollution and preservation of groundwater quality of these resources are extremely important topics, particularly at the present time in which water is becoming a limitative factor for land development. In this context the main objective of this study was the evaluation of the pollution vulnerability of groundwater in the Ivrea Morainic Amphitheatre (IMA), situated in the North-West of Piemonte. Approach: The case study required the application of the combined approach SINTACS and GNDCI-CNR Basic Method. SINTACS, used only for the evaluation of vulnerability in the plain covered by alluvial materials, was not considered for the hilly area due to lack of sufficient data, necessary to assign values to the seven required SINTACS parameters. Instead the GNDCI-CNR Basic Method was used, based on a survey of hydrogeologic complexes. The hydrogeologic study had identified an unconfined aquifer in the plain area, situated in the fluvial permeable sediments. Moreover the study had identified a confining bed which separates the aquifer from a deep confined aquifer. Analysis of water table aquifer flow patterns and groundwater quality had led to the characterization of some relationships between different aquifers. Results: Vulnerability map showed an important difference between the water table aquifer and the glacial tills aquifers. The first one had a very high vulnerability, due especially to the small depth of middle-high permeable sediments in the water table. The second one, on the contrary, had a low degree of vulnerability. Conclusion: The vulnerability map must be a fundamental component of an overall groundwater protection scheme: Springs in moraines and the confined aquifer in the plain, which was not affected by groundwater contamination, had better characteristics for drinking water designations.