Remediation Solution
Remediation Approach
Technology
Media Treated
Industry
Contaminant Type
Contaminant of Concern
Location
LNAPL contamination at a former oil refinery in southern Indiana reached depths of 18.5 feet in silty and sandy clay geology (12–32 ft below ground surface). Substantial free product presence in the low-permeability subsurface required pre-injection extraction to reduce LNAPL saturation before full-scale chemical treatment.
Four vacuum extraction events were conducted prior to full-scale injection to reduce LNAPL saturation. Sodium persulfate activated with caustic was injected through 122 screened injection wells (15–35 ft below ground surface) totaling approximately 86,430 gallons. A vacuum truck was operated simultaneously during injection for continued hydraulic management.
Following one treatment round, 83% LNAPL reduction was achieved across injection wells and 67% reduction in monitoring wells within the injection area at the former oil refinery in southern Indiana. Benzene concentrations decreased 18% site-wide, with continued monitoring underway to assess whether additional treatment rounds are needed. The treatment program involved four pre-injection vacuum extraction events to reduce LNAPL saturation, followed by delivery of approximately 86,430 gallons of caustic-activated sodium persulfate through 122 screened injection wells from 15 to 35 feet below ground surface in silty and sandy clay geology. Simultaneous vacuum truck operation during injection provided hydraulic management throughout treatment.
Superfund ISTR Under Strict Air Emission Limits
Bioremediation for PFAS
High-Profile ISTR of Historic Chemical Disposal Impacts
