TPH Impacted Soils

Location: North Central Indiana
Scope: Fractionation Analysis to Establish Site-specific Closure Levels

TecServ was retained by a prospective purchaser of a large manufacturing facility for the initial objective of Underground Storage Tank (UST) Closures oversight. During the UST removals, visual and olfactory evidence of a release was observed in the excavation.

The default site characterization methods for petroleum releases as defined in the Indiana Department of Management’s (IDEM) Risk-Integrated System of Closure (RISC) were employed. The results indicated a release to soils and groundwater above default industrial closure levels for total petroleum hydrocarbons (TPH) in both soils and groundwater. In fact, if the impacted soils were to be managed using default the industrial closure criterion, the extent of the impact would result in a remedial effort that would have exceeded $500,000.

TecServ employed a strategy whereupon IDEM’s pertroleum fractionation method was used to establish site-specific closure levels based upon the surrogate toxicity calculations. This evaluation resulted in establishing a site-specific closure criterion for TPH as 4,125 mg/Kg, more than four times greater than IDEM’s default industrial closure criterion.

This approach allowed for the transaction to be closed and manufacturing operations to begin unencumbered. The implementation of this management approach was embraced by the IDEM as one of the first projects to successfully utilize remedial strategies outlined in the agency’s new TPH fractionation guidance.