IN001 – Pneumatic Fracturing
Active Manufacturing Facility, Northern Indiana
This case study presents a successful application of Pneumatic Fracturing (PF)-enhanced soil vapor extraction system in an active manufacturing facility in Indiana. The site was contaminated with trichloroethylene (TCE) resulting from historic plant activities. TCE had been detected at concentrations as high as 17,000 µg/L and 25 mg/kg in the groundwater and soils, respectively. The site is underlain by low-permeability glacial till consisting mainly of sand, silt and clay.
Pneumatic fracturing of “tight” subsurface soils serves to increase the bulk air permeability by creating a dense inter-connected fracture network. The technology can effectively enhance (or, in many cases, enable the implementation of) conventional remediations such as soil vapor extraction, multi-phase extraction and air sparging by improving the induced airflow and mass transfer rate of the contaminants.
Prior to the full-scale implementation, ARS conducted a PF/SVE pilot test at the site to evaluate the effect of the PF by comparing the results of the post-fracturing SVE test to that of a previously performed and unsuccessful extraction test prior to ARS’ involvement. Throughout the post-fracturing SVE pilot test, significant vacuum radius of influence was observed in the majority of the monitoring points in the area. Vacuum was observed in monitoring wells as far as 35 feet from the extraction point.