Determlning And Mapplng Dnapl Saturation Values From Nonlnvasive Gpr Measurements

With the possible application to fluid-flow modeling, saturation values of dense nonaqueous phase liquids<br>(DNAPLs) may be determined and mapped through the use of measurements acquited by noninvasive ground<br>penetrating radar (GPR). In 1991, a controlled injection of perchloroethylene @CE), a common DNAPL, was<br>performed by the University of Waterloo into an isolated, water-saturated, sandy aquifer at Canadian Forces Base<br>Borden. One of the geophysical techniques employed by the U. S. Geological Survey to monitor the location and<br>migration of the subsequent plume was 5OOMHz surface GPR acquited on a one meter grid spacing across the<br>nine meter by nine meter cell over a period of 340 hours. This paper describes how full-waveform GPR modeling<br>of these data for relative dielectric permittivity versus depth may be used to calculate and map spatial distributions of<br>DNAPL saturation over time using recursive solutions of the Bmggeman-Hark-Sen (BHS) mixing formula.