ARCHIVED REPORTS SOIL AND GROUNDWATER INVESTIGATION REPORT

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' Appendix D.1:Data Usability Summary (0.013 gg/L), and pyrene(0.011 µg/L) in this equipment rinsate blank. In addition,equipment blank QA-R-070312 also had detected amounts of phenanthrene(0.013 gg/L), anthracene (0.010 µg/L), pyrene(0.010µg/L), and acenaphthylene(0.015 pg/L). The presence of these analytes in the equipment rinsate may indicate that the decontamination procedure was not adequately performed or there was a ' source of introduced contamination to the samples. Consequently,these samples were qualified E. Chain-Of-Custody Forms ' Sample analytical results were evaluated for agreement with the chain-of-custody form. Based on the evaluation, all samples were received at the lab in the appropriate containers and in good condition with the chain-of-custody form filled out properly. ' Preservation and Holding Times Samples were preserved in the field as appropriate, were received at the laboratory within the acceptance temperature criterion of 4±2 °C, and sample preservations—when required by the analysis—were less than the acceptance pH limit of 2. The samples were prepared and analyzed within specified holding times. ' Reporting Limits Data reported for this sampling event were reported within the laboratory MDLs. The MDL represents the lowest concentration point where an analyte can be positively identified,but the quantitation is an ' estimate. The LOQ is the lowest concentration of an analyte in a sample that the laboratory can report with precision and accuracy. Analytes that were reported between the MDL and LOQ for this data set were qualified J as estimates. Laboratory Fuel Notes for TPH-d Analysis The laboratory made several notes on the observed chromatogram patterns for groundwater samples ' analyzed for TPHd. Groundwater samples CPL-087-W-070313, SB-37-W-070313, SB-41-W-070312, SB-40-W-070312, QA-R-070312, and SB-39-W-070312 had observed TPHd patterns that include#2 fuel diesel and an additional pattern that elutes later in the diesel-carbon range. Completeness Completeness is defined as the number of valid results (i.e., those not rejected) divided by the total number rejected. Evaluation of the data against the QC objectives indicated that the percentages of valid ' data for each method are 100 percent, with no data rejected for this investigation. Comparability The data evaluation determined that the data are comparable with other laboratory data for similar samples and sample conditions. The sample collection techniques,EPA test methods, detection limits, analytical laboratory, units of measure,and sample preparation procedures were selected to ensure data ' comparability on this project. SUMMARY SAIC's evaluation concluded that all analytical data are usable as qualified for the purpose of determining chemical concentrations in soil and groundwater at the Tracy Byron Road site in Tracy, California. Data associated with SDGs for this sampling event were qualified for LCS/LCSD recoveries,MS/MSD recoveries, surrogate recoveries, field blank contamination, and results reported between the laboratory MDL and LOQ. Qualified data with applicable reason codes are shown in Table D-1. Analytical data collected in support of this investigation are considered precise, accurate,representative, ' complete, and comparable, and they may be used for their intended purposes unless noted otherwise. ' Page D.1-4 Jr: ` From Science to Solutions