Abstract |
The 4,600-acre McChord Air Force Base (AFB) is located in Pierce County, Washington. The site contains a 22-acre parcel of land, referred to as the Site 54 Washrack Treatment Area (WTA), which contains weapon and aircraft maintenance facilities. From 1957 to 1985, several site areas, including Sites 54 and 60, were identified as waste spill and disposal areas. Floating fuel was identified as underlying a 300,000-square-foot area of the site, which resulted from unrecorded spills. The ROD addresses remediation of the excavated soil and the NAPL-contaminated ground water at Site 54. The primary contaminants of concern affecting the soil and ground water are VOCs; organics, including oils; and metals, including lead. The selected remedial action for the site includes excavating, consolidating, and treating fuel-contaminated soil onsite with ex-situ bioremediation, then backfilling the treated soil into an onsite trench; installing passive subsurface extraction trenches to collect LNAPLs, with onsite separation using fuel skimmers; and transporting the recovered fuel offsite in drums to either a recycling facility. |