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Preliminary Investigation and Evaluation Report— California Cedar Products Laboratory quality control analyses included method blanks, matrix spikes, and surrogate spikes These data were reviewed by RAB Consulting, which verified the following • The method blanks did not contain any of the analytes, and • The analytical results for the matrix spike samples and matrix spike duplicate samples were within acceptable recovery ranges for BTEX (Wagner, 1992) 4.0 Discussion of Findings The objective of this sal and ground water investigation was to characterize the extent of diesel released in the soil and to ascertain if groundwater had been impacted in the vicinity of the former UST T2 The findings are illustrated - g strated on the two geologic cross-sections located on Figure 3- Subsurface Probe Map and presented on Figure 4- Geologic Cross-Sections Cross-Section A-A' illustrates the Northwest to Southeast Profile (ground water downgradient) and Cross-Section B-B' illustrates the Southwest to Northeast Profile (cross-gradient) Cross-Section A-A' Cross-Section A-A' illustrates that the diesel occurs in sand at elevated concentrations of 6,900 mg/Kg to a depth of approximately 18 feet bgs Diesel concentrations decrease both horizontally and vertically from this point At 18 feet bgs at 62, diesel is 9 3 mg/Kg and at 18 feet at B4, diesel is ND At 61 , lower diesel concentrations of 170 mg/Kg are detected in the sand at 23 feet bgs and 14 mg/Kg in the clay at 25 feet bgs and ND at 30 feet bgs The impermeable clay at 24 5 feet bgs re-directs the diesel horizontally and a concentration of 410 mg/Kg is detected at B2 at 23 feet bgs and a concentration of 220 mg/Kg is detected at B4 at 23 bgs RAB Consulting 8