ARS recently completed a field pilot test at an Army facility in Tennessee to evaluate the use of Pneumatic Fracturing integrated with proppant injection within a loess (silts and clays) formation to facilitate the installation and operation of SVE to treat the vadose zone. Field activities included the fracturing of three locations in a triangular orientation about 100 feet from one another and the subsequent injection of a ceramic proppant using either a slurry delivery technique or dry-media injection method.

After the fracturing and proppant injection, an air flow extraction test was conducted by the site consulting engineering firm. The results indicated an increase in extraction flow rate through the loess material of approximately 50-100%. A Vacuum ROI increase of approximately 200-300% relative to baseline testing was also observed. Overall, the field data indicate the dry-media injection of proppant in conjunction with Pneumatic Fracturing is an effective process for enhancing the permeability of a difficult formation.