Application of truncated plurigaussian method for the reactive transport modeling of a contaminated aquifer

Characterizing the spatial distribution of major lithofacies and their connectivity is a key aspect in the process of modeling contaminant transport in aquifers and also in characterizing the potential exposure pathways of contamination in the conceptual model of risk analysis. In heterogeneous aquifers, assignment of lithofacies-specific hydraulic and hydrochemical properties such as porosity, permeability, and sorption coefficient requires the knowledge of the layout of the lithofacies themselves. Plurigaussian simulation is a procedure derived from the truncated Gaussian model, used to simulate random sets, and, in particular, complex geological characteristics, expressed as categorical variables. Moreover, it allows to obtain geological representations conditioned to the input information. In this paper Truncated Plurigaussian simulation has been applied to reproduce the lithofacies geometry of a site whose level of contamination has already been studied. The study area, which belongs to a wide industrial district, presents a condition of contamination of soil and groundwater of difficult interpretation. In this context, the exact definition of the hydrogeological model allows to better interpret the complex phenomena of delay and reactive transport that can affect the remediation interventions.