Simulating groundwater contaminant migration at Villa Farm lagoons

Abstract

agoons at Villa Farm near Coventry, UK were used for the disposal of industrial liquid waste after 1967. The lagoons were unlined and a leachate plume developed in the underlying thin sand aquifer. As part of a research programme into controls on the migration of landfill leachate, a twodimensional areal model describing the regional scale movement of chloride and phenol in the aquifer has been developed. Parameter ranges for advection, dispersion, degradation and adsorption have been established through model calibration, constrained by the results from previous laboratory studies. Linear representations of the adsorption and degradation processes are found to yield satisfactory results on the time and space scales adopted for the simulations. The model development has highlighted some important issues that have to be confronted when analysing the evolution of a plume based on short-term, late-time data. The uncertainty in the geometry of the aquifer on the simulated flow system has been examined using geostatistical methods.

Cyclic freeze–thaw as a mechanism for water and salt migration in soil

“…Péwé (1983) noted that determining the principles of water and salt transfer during the cyclic freeze-thaw is a way to control salinization. Due to the various factors influencing the freeze-thaw cycle and instrument limitations, a number of studies have been done in unfrozen soil such as farmland and groundwater (Rubin and James 1973;Rushton and Redshaw 1979;Mackay 2001;Almasri and Kaluarachch2007;Xu et al 2010;Jamin et al 2012;Chen et al 2014), but a little work has been done particularly on the effect of cyclic freeze-thaw on the water and salt migration. So it is urgent to answer the question that why the water and salt migrated during cyclic freezing and thawing and what is the mechanism.…”

Practical Implementation of New Particle Tracking Method to the Real Field of Groundwater Flow and Transport

“…Some studies (Brun et al, 2002;Mackay et al, 2001) have simulated leachate attenuation, biogeochemical processes, and the development of reduction-oxidation (redox) zones in a pollution plume downstream of the landfill. In these studies, the fundamental process was an advective-dispersive transport process for which Eulerian approaches have often been used to describe the concentration change due to advection and dispersion.…”

Precise numerical modelling of physical transport in strongly heterogeneous porous media

“…Studies of large-scale contaminant transport for a variety of field sites spanning a range of geological settings illustrate the difficulties of applying averaging to the assessment of contaminant distributions (e.g. Little et al 1996;Mackay et al 2001). Significant uncertainties are identified during the comparison of the results from the models with the observations.…”