Historically, both methods generally agree in terms of identifying impacted zones, but GeoTrax Survey™ often provides more context. For example, one energy firm compared GeoTrax Survey™, Laser-Induced Fluorescence (LIF), and soil samples and found that LIF sometimes produced false positives where GeoTrax Survey™ and soil borings showed no contamination. These false positives were viewed as a potential liability.
As another example, the image below provides a comparison of GeoTrax Survey™, TarGOST® (Tar-Specific Green Optical Screening Tool), and a traditional soil boring at a former tie treatment facility.
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The GeoTrax Survey™ images were able to map the vertical/horizontal extents of DNAPL related impacts across the imaging domain – impacted zones correlated with the more moderately electrically resistive anomalies (i.e., orange zones)
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Soil Boring 5 confirmed that there was a higher saturation of oil in the center of the orange zones (i.e., in the strongest part of the anomaly)
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TarGOST (TG) log detects shown below in orange graphical plots generally occurred within the same electrical anomalies, but the higher TarGOST® reflectance was generally limited to the top of Aestus’ orange anomalies (NOT supported by the soil boring)..