Modelling landfill liner performances

The design of landfill bottom barrier systems on the basis of their performances requires the modelling of the pollutant transport processes, while taking into consideration both advective and dispersive-diffusive phenomena. This modelling can be developed in the context of an environmental and health risk assessment, which allows the specific vulnerability of the site to be taken into account. A calculation procedure, based on closed-form analytical solutions, which can be considered suitable for a second-level risk analysis type, according to the ASTM and USEPA classifications, is presented in this paper. This procedure, although based on a very simple and intuitive conceptual model, is able to provide useful indications for design choices, at least in the preliminary dimensioning phase of a project.