Cameron-Cole was contracted to assess and develop corrective actions for a large petroleum contamination site located in Northwest Florida. The sources of contamination were two adjoining gasoline service stations that had releases of petroleum products. The gasoline plumes had spread beneath a four-lane highway and co-mingled. The resulting plume encompassed approximately four acres and exhibited dissolved concentrations of volatile organic aromatics that exceeded 100,000 parts per billion. Cameron-Cole conducted extensive pilot studies, including an aquifer performance test, in situ air sparging (AS) tests at various pressures and air injection rates, soil vapor extraction (SVE) tests, and a respiration test to evaluate bioremediation alternatives.

The data was compiled in a Preliminary Remedial Action Plan recommending in situ AS/SVE as the most feasible remediation strategy. Cameron-Cole designed and installed a single system, which would treat the entire contaminant plume. The remediation system utilized a 60-hp positive displacement blower with an after-cooler for air injection into four treatment zones which were cycled at various intervals. A 75-hp positive displacement blower with granular activated carbon filters was used to recover and treat the petroleum contaminants that were volatilized within the soil matrix. A grouting variance was obtained from the Water Management District to install twenty-eight 70-ft-deep, "nested" AS/SVE wells in common boreholes using hollow stem augers. The remediation system was installed in conjunction with the development of a new County Public Health Unit on the property and had AS/SVE treatment wells located within the courtyards of the building. A 180’ directional boring was installed beneath the highway to link the two areas of contamination to the common treatment system.  A variance was obtained from the Florida Department of Transportation to simultaneously install an 8"- and 4"-diameter casing beneath the highway using directional boring. The variance resulted in cost savings of tens of thousands of dollars in drilling costs for the client

The system reduced the areal distribution of the contamination by some 95% within the first 15 months of operation and following a required period of post-active remediation monitoring, an unconditional Site Rehabilitation Completion Order (SRCO) was issued by the Florida Department of Environmental Protection.