Pollutant Migration through Liner Underlain by Fractured Soil

Abstract

A new, simple, semi‐analytic technique for modeling contaminant migration through an unfractured clayey liner underlain by fractured soil (or rock) and an aquifer is described. The model is implemented on a microcomputer and allows consideration of advective‐diffusive‐dispersive transport through the liner (including sorption, where appropriate), advective‐dispersive transport through the fractures, matrix diffusion from the fractures into the adjacent soil, sorption on the fracture surface and in the soil matrix, and finite mass of contaminant in the landfill and dilution in the aquifer. The application of the model is illustrated by considering migration from a hypothetical landfill separated from an underlying aquifer by fractured till. Consideration is given to impact without a liner and with a reworked till as a compacted clay liner underlain by fractured till. The results obtained by modeling migration through the compacted liner and fractured till are compared with what would be obtained using approximate approaches that consider either the liner alone or consider the full thickness to be fractured.