A historic release from an aboveground storage tank (AST) at this facility affected soils within the fenced portion of the facility and in a nearby field. At the time, affected soils in the nearby field (off-site) were excavated and confirmation soil sampling and analysis was performed. Total Petroleum Hydrocarbons - Diesel Range Organics (TPH-DRO) was detected at concentrations exceeding its action level (10.0 milligrams per kilogram [mg/kg]) in the confirmation soil samples.
Soil Remediation Project Work
To better define the area of impact, AGES collected additional soil samples in the nearby field. TPH-DRO was detected above the specified action level (10.0 mg/kg) in three (3) surface soil samples at concentrations ranging from 12 mg/kg to 14 mg/kg.
To assess portions of the facility inside the fence line, AGES collected additional soil samples from several soil borings. Samples were collected with the use of a Geoprobe®. Concentrations of TPH-DRO ranged from non‑detect to 190 mg/kg.
During meetings with the KYDEP, it was determined that the TPH action level of 10 mg/kg was not appropriate for this site and the USEPA Region 9 action levels for PAHs would apply. Soil removal would only be required if PAH action levels were exceeded, or if TPH levels exceeded 100 mg/kg.
After the meeting, AGES collected additional soil samples from within the fenced portion of the facility for analysis of PAHs. Samples were collected in the locations of previous TPH detections. All PAH results for samples collected within the fenced area were below action levels. Because no PAHs were detected inside the facility fence line, a soil removal action level of 100 mg/kg for TPH was selected for the site. Based on this action level, one (1) soil sample required excavation and proper disposal.
Soil Removal Action
Excavated soil was loaded directly into trucks and transported to a licensed landfill. After the excavation was complete, it was backfilled with gravel and the site was restored to original conditions. To confirm that all TPH-affected soil was removed, the AGES field representative collected a total of five (5) confirmation soil samples, consisting of four (4) excavation sidewalls and one (1) excavation floor samples. To ensure sample integrity, all samples were handled and shipped in accordance with strict chain-of-custody procedures. To prevent cross-contamination, disposable, sterile, one-use sampling equipment was used. All results were below the applicable action level and no further action was required.
Application of constituent-specific action levels significantly reduced the scope of remedial action required.