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in a rigid cooler filled with ice and chilled to approximately 4° Celsius for transport to the analytical laboratory. Soil borings were backfilled with a mixture of cement and hydrated bentonite chips and capped with asphalt,concrete,gravel,or soil to match the existing grade. 4.0 LABORATORY TESTING A chain-of-custody was completed for the soil and groundwater samples collected during field activities, which were subsequently delivered under chain-of-custody to Curtis & Tompkins, Ltd. of Berkeley, California. Curtis & Tompkins, Ltd. is certified by the State of California to perform analysis of soil and groundwater samples for the presence of TPH-DRO, VOCs, OCPs, and RCRA-8 Metals. Collected soil samples were analyzed for the presence of VOCs using EPA Method 8260B, TPH-DRO using EPA Method 8015B,OCPs using EPA Method 8081A, and RCRA 8 Metals utilizing EPA Method 6010B and 7470A/7471A. A copy of the laboratory report and chain-of-custody are attached as Appendix A. Relevant data from the laboratory testing of samples collected during this investigation are summarized in Table 1. 5.0 SUMMARY OF RELEVANT FINDINGS The following findings are based upon field observations and measurements, review of analytical data, comparison of analytical results with applicable regulatory levels, and comparative evaluation of contaminant concentrations with known environmental conditions of the surrounding area. 5.1 Field Investigation Findings The following findings are based upon field observations and measurements: • Soils encountered at the subject property consisted predominantly of silty sand to roughly 10 to 14 feet bgs then grading to a fine-grained sand and clay mixture. • No visible staining and/or olfactory indications of impacted soils were noted during drilling activities in any of the borings advanced at the subject property. • Groundwater was encountered in seven of the ten borings advanced at the subject property between 16.5 and 20 feet bgs. No sheen or odor was noted in groundwater samples collected from the site. 5.2 Laboratory Results Analytical results for soil and groundwater samples collected from this investigation are summarized in Table 1. Reported concentrations reviewed from the laboratory report were compared to the US Environmental Protection Agency, Regional Screening Levels (RSLs) as well as the California Regional Water Quality Control Board, San Francisco Bay Region in Screening for Environmental Concerns at Sites with Contaminated Soil and Groundwater; Volume 1: Summary Tier 1 Lookup Tables, December 2013, Table B, shallow soil(! 3MBGS), Table D, Deep Soil(>3MBGS)— Water is not a Current or Potential Source of Drinking Water ("Environmental Screening Levels" [ESLs]for Industrial Soils). The ESLs were used as a comparative general reference. Zions First National Bank Limited Subsurface Investigation 9 f�UC�la Valentine Properties—Manteca, California % I _