K. Abbaspour et al., A contaminated site investigation: comparison of information gained from geophysical measurements and hydrogeological modeling, J CONTAM HY, 40(4), 2000, pp. 365-380
The investigation of contaminated sites is usually a long and expensive pro
cess. It is therefore desirable to use a combination of methodologies in an
integrative approach that can reduce redundant information gathering. The
objective of this study was to examine the usefulness of 2 non-intrusive ex
ploration techniques in a contaminated site investigation. Borehole positio
ning based on geophysical measurements was compared to positioning based on
the Bayesian expert system for flow-field modeling. The goal set at the fi
eld site was the assessment of the type and load of contaminants transporte
d from the landfill site to the adjacent aquifer and the extent of leachate
plumes within the groundwater. The two methods made different demands on i
nformation gathering and were found to be complementary. The geophysical ap
proach focused attention on the waste compartments at the site and on mixin
g plumes in the adjacent aquifer but could not, without prior information,
provided information on the flow field. The Bayesian approach to flow-field
modeling determined areas of greatest model uncertainty at the model bound
aries. The model highlighted areas of greatest uncertainty that might other
wise have been overlooked and provided information on the most likely mean
direction of the leachate plumes, it was concluded that both methods contri
bute to a site investigation and should be used before additional drilling
is carried out. (C) 2000 Elsevier Science B.V. All rights reserved.