Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG) Field Demonstration Report: Elmendorf Air Force Base, Alaska

摘要

A demonstration of the Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG) approach for assessing human health risk at weathered petroleum release sites was performed at a former underground storage tank (UST) release site at Elmendorf Air Force Base (EAFB), Alaska. The site, ST702/8, Military Airlift Command (MAC) Chalet (Building 31562), a recreational cabin, is impacted by diesel fuel. A total of ten soil samples were obtained at depths to 12 feet below the ground surface (bgs). The soil samples were analyzed for total petroleum hydrocarbons (TPH) as TPH gasoline range organics (GRO) and TPH diesel range organics (DRO), benzene, toluene, ethylbenzene, and xylenes (BTEX), polycyclic aromatic hydrocarbons (PAHs), and petroleum fractions. Six of the ten primary soil samples contained TPH DRO concentrations above the Alaska Method Two cleanup standard for petroleum migration to groundwater (250 mg/kg). RBSLs were calculated for a recreational and a commercial exposure scenario. For the recreational scenario, only one soil sample exceeded the Tier 1 total TPH RBSL (955 mg/kg). For the commercial exposure scenario four of the site soil samples contained TPH in concentrations that exceeded the Tier 1 total TPH RBSL for the subsurface soil indoor vapor inhalation pathway. Higher tier (Tier 2) risk evaluations are recommended for select data before any remedial actions are imposed.