3D geological model to assess the fate of contaminant transport in groundwater: the case study of Maruzzella Landfill (Caserta, Italy)

Abstract

In order to assess the potential risk of aquifer pollution in an alluvial plain area used as a landfill, a detailed geological and hydraulic model of the subsoil was realised. The chosen area is represented by the transfer site for solid urban waste called "Maruzzella", in the lower plain of the Volturno River. The analysis of lithostratigraphic data allowed a 3D reconstruction of the subsoil, which was subsequently implemented thanks to a hydrostratigraphic characterization. Through the use of GIS, the calculation grids necessary for the characterization of the flows have been built, elaborated through the use of ModFlow with three different 3D models of the subsoil with increasing degrees of geological simplification. The dispersion models created with ModFlow made possible to establish the dispersive dynamics that predominate or coexist in relation to permeability and temporal progression considering different stress periods, respectively equal to 3650 days and 7300 days. The comparison of the geological scenarios highlighted the real dispersive processes, thus underlining the importance of a detailed knowledge of the stratigraphic architecture of the subsoil.