Multiphase Saturation Determination by Application of Digital Image Analysis

Unsaturated soil is frequently contaminated with non-aqueous phase liquids (NAPLs) as the result of surface spills, leakage from underground storage tanks (USTs) or from waste disposal sites. The effectiveness of digital image analysis at measuring the transient saturations of liquids in unsaturated soil was investigated. Multiple fluid spills using water and sunflower oil were simulated in the laboratory in a soil cross section. Digitized slides of the spills were then analyzed with the image analysis software EASI/PACE{reg_sign}. Using this technique, various saturation intensities were measured. In addition, mass conservation was utilized to verify the accuracy of digital image analysis for the multiple fluid system. The utilization of digital image analysis, provides an inexpensive method that has the potential to generate large quantities of transient saturation data. The generation of such data would allow the determination of important parameters needed to predict the fate of contaminant movement through soil.