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 a health-environmental risk analysis, which allows the specific vulnerability of the site to be taken into account. A calculation procedure, based on a closed-form analytical solution, which can be considered a second-level risk analysis type, according to the ASTM and USEPA classifications, is presented in this essay. This procedure, although based on a very simple and intuitive conceptual model, is able to furnish useful indications for design choices, at least in the preliminary dimensioning phase of a project. Moreover, it can also be used in the probabilistic field when the variability of the parameters influences the results to a great extent.