BTEX Remediation

Retail Gas Station in Florida 






Acceptance into the Florida State cleanup program, was the driver for remedial action at this petroleum contaminated (gasoline) site in Northwest Florida. The dense clay nature of the subsurface lithology rendered conventional remedial methods (sparge and vent, dual phase extraction, etc.) ineffective. When excavation reached the vertical limits of the equipment and stained soils and OVA sampling indicated remaining contamination, an in-situ chemical oxidation process the Cool-Ox® Process, a Technology based upon the controlled production of hydrogen peroxide in-situ, was selected to complete site remediation. After one application, post treatment results revealed that the cumulative total BTEX concentrations were reduced by 82%. Based on the results of the first application, a second application was approved and conducted. The current cumulative total BTEX concentrations have been reduced by 95%, over a 7-year monitoring period.


Type of Site: Retail Gasoline Station

Location: Jackson County, FL

Contaminants: BTEX

Work Scope: Inject Cool-Ox® Reagent

Media Treated: Soil & Groundwater

Soil Type: Clayey Sand to Sandy Clay to Dense Clay; LS @ 80'

Groundwater Depth: 10 fbgs

Remedial Objectives (Phase 1): Reduce GW concentration to GCTL’s

Pre Map_edited.jpg

Application Method: DPT Probe Rig

Area Treated: 6,000 and 1,660 square Feet

Vertical Interval: 10 to 25 and 10 to 75 feet bgs

Injection Point (IP) Spacing: 7 feet

Media Volume Treated: 3,667 and 1,640 cubic yards

Number of Injection Points: 122 and 46

Cool-Ox® Volume: 17,778 and 7,956 gallons

Cool-Ox® per IP: 90 and 173 gal

Post Map.png

The blue area on the site map depicts the extent of the groundwater contaminant plume prior to the first ISCO injection. Groundwater samples collected after the injection events revealed that the contaminant plume had shrunk.


Because of the significant reductions in contaminant concentrations, the site was placed in Post Remedial Action Monitoring Status pending determination of natural attenuation activity.