Multivariate statistical analysis and numerical modelling for the hydrogeological and hydrochemical characterization of a closed MSW landfill: the case study of Vizzolo-Predabissi

This work aims at assessing the impact on groundwater resources of a leachate overflow occurred in the landfill of Vizzolo-Predabissi (Milan, Italy) after its closure. Hydrogeological sections, piezometric maps, spatio-temporal and multivariate analysis of hydrochemical data enabled to define a conceptual model and to build a groundwater flow model, solved and calibrated by means of MODFLOW-NWT and PEST. The results of the study pointed out that the leachate overflow produced an impulsive contamination, currently in attenuation, which behaved differently in areas with different redox characteristics.