Mapping the Norman, Oklahoma, Landfill Contaminant Plume Using Electrical
Geophysics
By Robert J. Bisdorf and Jeffrey E. Lucius
ABSTRACT
The lateral extent of the electrically conductive portion of the contaminant
plume emanating from the Norman Landfill was mapped using electrical geophysical
measurements. EM induction and DC resistivity methods measured the apparent
electrical resistivity of the subsurface. Both methods show an area of low
resistivity indicating poor ground water quality in the alluvium, presumably
due to leachate from the Norman Landfill. This area extends from the southwest
side of the main landfill mound toward the Canadian River for no more than
about 200 meters. Cross section and depth-slice maps made from the interpretation
of the DC resistivity soundings and maps of measured resistivity from the
EM measurements illustrate the lateral extent of the landfill contamination
and show that the contaminate plume, which is about 9m thick, does not appear
to extend into the bedrock. The EM induction method proved to be an easy and
efficient procedure for rapidly determining the lateral extent of the leachate
plume. The DC resistivity method, although more time consuming, provided better
vertical resolution of the resistivity distribution.