The design, calibration, and operation of a laboratory-scale system to asse
ss the viability of detecting contaminants in soil based on changes in its
electromagnetic response are described. The complex permittivity measuremen
t device, permeation apparatus, and dielectric responses of soil specimens
measured before and after permeation with different CaCl2 solutions are dis
cussed. It is shown that the change in the complex permittivity of the soil
is best characterized in terms of the permittivity and loss factor at the
frequency of 250 MHz, since they exhibit a significant response to changes
in the pore-fluid chemistry. The laboratory system can be used routinely to
create soil samples permeated with a known contaminant at known concentrat
ions and then measure the complex permittivity of the contaminated soil sam
ples directly after permeation. The system is such that other factors (e.g.
, density and water content) which could influence the complex permittivity
can be carefully controlled, allowing the relationship between the type an
d level of contamination and dielectric behaviour of soils to be establishe
d.