Performance-Based In Situ Groundwater Bioremediation of TCE and Excavation of PCB Impacted Soil, Sites SS014 and SS015, Scott AFB, IL

In-Situ Groundwater Remediation – Enhanced Bioremediation (SS-14)

To remediate chlorinated solvent contaminated groundwater in three distinct hot spots, we designed, installed, and operated an in-situ groundwater remediation system that involved injecting EOS® substrate, bacterial culture, and amendments to promote bio-augmentation and bio-stimulation.  We also injected sodium bicarbonate buffer solution to maintain pH conditions conducive to microorganism growth.  The system included an initial injection as well as a second injection 18 months later to enhance bio-stimulation.  Insight performed pre and post-injection performance sampling by monitoring groundwater at 39 wells.  We performed the following:

  • Prepared Remedial Action Work Plan, QAPP, SSHP, Waste Management Plan, and CQC Plan
  • Prepared remedial design documents
  • Installed 296 DPT injection wells at 3 different groundwater depth zones and 68 permanent remediation injection wells to target three separate hot spot areas
  • Injected 280,000 gallons of an emulsified oil substrate (EOS®)/sodium bicarbonate buffer solution, 320 liters of KB-1® bacterial culture, and anaerobic chase water (EHC®)
  • Monitored injection pressures, times and volumes
  • Performed maintenance of remedial systems and post-injection performance sampling
  • Achieved average 70% TCE decrease after initial 4-month injection event, prepared remedial action reports

Soil Excavation and Transportation & Disposal (SS-15)
To address PCB-contaminated soil at a transformer site, we performed a deep excavation, removing over3,500 tons of impacted soil, including areas along utility lines.  Our work at SS-15 included:

  • Excavated soil to as deep as 20 feet bgs, including up to 15 feet below the water table
  • Performed hydraulic containment measurements by pumping out/dewatering excavation cavities below water table and rainfalls events
  • Satisfied both CERCLA and TSCA requirements
  • Collected 100 post-excavation soil samples to verify impacted soil above cleanup limits had been excavated
  • Used field test kits to analyze soil samples for PCBs, allowing real-time in-field decision-making
  • Performed waste characterization  and managed T&D of soil to an approved offsite disposal facilities

Contract Value $3.5 Million