Ex-Situ ISCO – Dry Cleaning Facility / Brownfield, GA
Overview
Site is a former dry cleaner, extensive fill to depths of 12-17’ present. GW depth is 20-25’. PCE mixed with non-halogenated VOCs present from an unknown source (drain or rear storage).
Treatment included ex-situ treatment of impacted soils in highest concentrations areas behind building (>20,000 ppb of PCE). Excavation and landfilling of peripheral areas and ISCO injection inside building.
Treatability findings identified MF with metakaolin stabilizers for ex-situ blending and KPM for soil blending/wetting bed in base of excavation and injection.
A total of 970 tons of impacted soils were excavated and 200 tons were pre-treated ex-situ using MF for VOC oxidation. After treatment, soils were hardened and stabilized using metakaolin prior to TCLP analysis.
Injection was performed inside the building at 8’-16’ using a 2-3% solution of potassium permanganate. Injection was performed on a tight grid spacing with a 2-3 foot spacing. Approximately 180 injection points were utilized.
Confirmatory soil samples collected inside building and on the base and sidewalls indicated target treatment goals were met or exceeded.
A series of 10-15 side-by-side bucket auger borings are being advanced to remove and treat remaining impacted soil adjacent to foundation. KPM- gravel wetting beds will be created in the bottom 1-2’ of the borings for long term deeper soil & GW treatment, if
needed.
