Type curves for estimating the potential impact of stabilized waste disposal sites on groundwater

This paper presents analytical solutions for estimating the potential impact of waste disposal sites (landfills) on groundwater. The solutions yield estimates of the average groundwater concentrations in an aquifer located below the landfill, and of the pollutant flux at the interface between a mineral barrier and the aquifer. Several source boundary conditions are considered: a constant source concentration, an exponentially decreasing source concentration, and a source concentration that is controlled by the diffusive release of pollutants from the waste. The latter is of particular relevance to the case of stabilized-waste landfills. The solution for the case of stabilized-waste is compared to two numerical models, and developed in terms of dimensionless variables that are combinations of the real model parameters. These variables are then used to generate type curves for estimating peak aquifer concentrations. An example application of the proposed type curves illustrates their usefulness for evaluating the performance of stabilized-waste landfills, in terms of potential impact, for different landfill designs.