ESA was retained to address an asphalt millings and diesel fuel discharge resulting from a vehicle accident. A triaxle dump truck hauling asphalt millings overturned and caught fire. Asphalt millings discharged to an adjacent retention pond and surface soil surrounding the pond. The fuel tanks on the truck ruptured and diesel fuel discharged to the surface soil surrounding the retention pond. The impacted areas of the asphalt millings and diesel fuel were distinct and did not overlap.
The construction company that built the retention pond reported to ESA that the pond was constructed with an asphalt millings liner. Differentiating between the asphalt millings of the liner and the discharge from the dump truck would be impracticable.Prior to conducting any remedial actions, ESA contacted the NJDEP to discuss the situation.
Upon approval from NJDEP, asphalt millings were excavated from the retention pond and from the surficial soils along the bank, and post-excavation soil samples were collected from along the bank. ESA also collected post-excavation soil samples from the area of the diesel fuel discharge. Because of the presence of the asphalt millings liner, post-excavation sediment samples from the bottom of the pond and surface water samples were not collected.
Laboratory results for the post-excavation soil samples in the area of the asphalt millings discharge were reported as non-detect and no further remediation was required. Laboratory results for the post-excavation soils in the area of the diesel fuel discharge indicated that benzo(a)pyrene (BaP) exceeded the NJDEP residential direct contact soil remediation standard (RDCSRS), non-residential direct contact soil remediation standard (NRDCSRS) and the default impact to ground water soil screening level (IGWSSL).
Typically, additional remedial activities are required to address these concentrations of BaP remaining in the soil. However, ESA evaluated the data and applied compliance averaging to demonstrate that the average concentration of BaP met the applicable NJDEP soil remediation standards and no further remedial action was required. This saved the client the costs associated with remobilization to the site, heavy equipment to re-excavate the soil, soil disposal, and re-sampling. A groundwater investigation was conducted and, after two clean rounds of groundwater samples, an area of concern-specific Response Action Outcome was issued for the case.