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6. If SVOCs, PAH% studio PCBs are detected and are determined to pose an unacceptable risk or threat to ground water above drinking water MCLs, then IIOEILLNL will follow the CERCLA process to propose and assess remedial alternatives, and select and implement a remedy m mitigate the risk andlor threat to ground water. Forexample, a Focused Feasibility Study would be prepared that proposes remedial alumetives and a medy would be selected to address these constituents in an Amendment to the GSA ROD. Data Evmluarion: Because SVM.c and PAHs were not detected above their analytical reporting limits and concentrations of PCBs in all soil samples were helow regulatory screening levels these constituents do not pose an unacceptable risk or threat to ground water above drinking water MCI . Additionally, PCBs were not detected in ground wader above their respective RLs. Therefore, remedial actions are not warranted. 6. Summary and Conclusions The characterieadio t activities summarized in this "I'cehnial Memorandum provide sufficient data to deLLxmine a path fowled for regulatory closure of the Eastern GSA Bonds Burial 'I'much area. The results ofthese activities were reps ned at the January 21 , 2015 RPM meeting. Because SVOC or PA1 is were not detected in any of the soil samples collected in the Emern GSA debris burial trench area above the aaytical method reporting limits, DOE and the regulatory agencies served that the investigation of SVO(:s and PAR; in the Eastern GSA debris burial trench area is considered complete, and no further action for these constituents is needed. The PCB analytical data for samples collected in the Eastern GSA debris burial trench area indicate that: While PCBs were detected above the RL in some soil samples, mncentmtions were below EPA's residential and industrial soil RSLs and the MCL-based Protection of Ground Water SSLs, including samples collected near medal debris encountered in the boreholes. Therefore, these constituents do not pose an unacceptable risk or impact to ground wader above Miffs. • The lateral and vertical extent of PCBs in rude urfnce soil is hounded by non-detections, or evidence of native material. PCBs were not detected above the RL in any ground water samples collected firm wells located near smaller do ergradienl from the boreholes in which the PCBs were detected. Therefore, DOE and the regulatory agencies agreed that the investigation of PCBs to the Eastern GSA debris burial trench area is considered complete, and no lumber action for these constituents is needed. As agreed to at the January 21, 2014 RPM mecfing, the sampling meflmds and data am presented in this 'I'edmical Memommlum and provided to the regulatory agencies for review and comment. Once approved, this Technical Memorandum will the included as an appendix m the Final Close Out Repot for the Eastern GSA. 19