Geology and Stratigraphy of the East and West Firing Areas Lawrence Livermore National Laboratory Site 300

The purpose of this project is to gain a better understanding of the stratigraphy and geologic structure of the East and West Firing Areas, at Lawrence Livermore National Laboratory Site 300 (Figure 1). This analysis is designed to help better delineate hydrostratigraphic units (HSUs) in order to enhance the understanding of the fate and transport of contaminants in the subsurface. Specific objectives of the investigation include: (1) Evaluation of the stratigraphic relationships between the units that contain tritium in ground water that originates from Pit 7 and the Building 850 area in the vicinity of Doall Ravine; (2) The correlation of these units across the Elk Ravine Fault Zone; and (3) The correlation of these units between the Building 865, Pit 1, Pit 2, and Building 812 areas. These issues were raised by regulators at the Regional Water Quality Control Board in the review of the Pit 7 RI/FS (Taffet and others, 2005). The results of this investigation will assist Lawrence Livermore National Laboratory (LLNL) hydrogeologists to conduct work in a more focused and cost-effective manner. This document is submitted to fulfill contract obligations for subcontract B539658