An insured’s consultant had conducted a site assessment at a Florida gas station and proposed large-scale soil excavation and disposal in conjunction with an air sparge system to address groundwater contamination.  Although contaminant levels in soil exceeded the state’s Soil Cleanup Target Levels and dissolved phase contaminants exceeded the Natural Attenuation Default Concentrations (NADCs), Roux suggested that the consultant conduct additional soil testing; this time to determine site-specific leachability values for contaminants in soil by analysis using the Synthetic Precipitation Leaching Procedure (SPLP) laboratory extraction method.

Based on the SPLP results, it was apparent that most of the soil did not represent a risk to groundwater.  Based on these findings, a work plan was prepared and approved by the Florida DEP to remove limited quantities of soil followed by a natural attenuation monitoring program for groundwater.

Following the limited soil hot spot removal activities, dissolved phase levels quickly decreased to below the NADCs, and within 18 months all contaminants were below the GCTLs.  Following a short period of additional monitoring, site closure was achieved within little more than two years.  Total savings for the cleanup was approximately $500,000 in comparison with the original soil excavation / air sparge plan.