Evaluation of the petroleum technology-based dry soil barrier

Many contaminated subsurface sites cannot be economically decontaminated due to the limitations in the existing technology. The most viable approach in such cases is to prevent further spread of contamination. Therefore, in parallel to remediation efforts, innovative technologies are needed to retard or prevent the advancement of contamination plumes into the environment. This paper aims at investigating the feasibility of an innovative approach for preventing the movement of liquid contaminants toward groundwater using commercially available oil and gas technology and equipment. The concept involves using either vertical or horizontal wells for dry air circulation through a targeted subsurface layer to lower, by evaporation, and then maintain the water saturation well below the minimum saturation required for flow of liquids. Drying increases the liquid storage capacity of the soil layer and therefore, the soil will tend to retain rather than transmit the liquids. Dry soil barrier (DSB) provides a nonphysical confinement, active monitoring and leak detection, and high potential for integration with other remediation technologies. However, it would greatly benefit from proof of concept to gain acceptance. An experimental study was undertaken to evaluate the feasibility of the soil-drying concept. Several issues including the influence of the soil characteristics on drying profile and liquid retention have been investigated. The results have provided the knowledge base for soil drying processes and fluid infiltration in porous media. The experimental results indicated that dry soil has a significant potential as barrier.