Southeast View of Building 916
Building 916 is the Emergency Generator Facility that once allowed the sump beneath two diesel generators to drain into an outdoor drainage ditch. A small trichloroethene (TCE) plume is downgradient of the facility. In addition, at least one electrical transformer on a former concrete pad adjacent to the building leaked cooling oil that contained polychlorinated biphenyls (PCB) into the surface soil.
The Travis AFB Groundwater Record of Decision selected Monitored Natural Attenuation (MNA) as the final groundwater remedy. The MNA monitoring network was established in 2015, and monitoring of the final groundwater remedy is ongoing. The West/Annexes/Basewide Operable Unit Soil Record of Decision selected land use and access restrictions as the final soil remedy, because the PCB concentrations in soil were below industrial cleanup levels but exceeded residential cleanup levels. The Air Force placed a land-use restriction on the property to ensure that it is not used for residential purposes without first addressing the PCB residue in the soil. The PCB concentration in the soil is low, so this chemical does not present an unacceptable risk to either local workers or the environment. Adherence to land use controls and access restrictions is evaluated annually.
Additional soil investigation at Site SD043 will be used to reassess the need to conduct additional remedial actions at this site, in order to remove the current LUCs.