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Appendix E.1:Data Usability Summary <br /> Naphthalene was found in field blank QA-0-080318 at a concentration of that found in sample SB-3-W- <br /> 080317 and was flagged E. <br /> Three sets of field duplicates, one soil and two groundwater,were taken during the sampling events. All <br /> %Rs were within the 50-percent RSD for soil and 30 percent for groundwater with the following <br /> exceptions: field soil duplicate pair samples SB-5-S-13-080318 and SB-5-SD-13-080318 had TPH, <br /> Clo-C36(95 percent), acenaphthlene(58 percent), and fluorene(54 percent)RPDs greater than the QC <br /> criteria and the results were qualified E. <br /> Chain-Of-Custody Forms <br /> Sample analytical results were evaluated for agreement with the chain-of-custody form. The evaluation <br /> indicated that all samples were received at the lab in the appropriate containers and in good condition <br /> with the chain-of-custody form filled out properly. <br /> Preservation and Holding Times <br /> Samples were preserved in the field as appropriate,were received at the laboratory within the acceptance <br /> temperature criterion of 4±2 °C, and were prepared and analyzed within specified holding times. Sample <br /> preservations,when required by the analysis,were less than the acceptance pH limit of 2. <br /> Reporting Limits <br /> Data reported for this sampling event were reported within the laboratory MDLs. The MDL represents <br /> the lowest concentration point where an analyte can be positively identified,but the quantitation is an <br /> estimate. The LOQ is the lowest concentration of an analyte in a sample that the laboratory can report <br /> with precision and accuracy. Analytes reported between the MDL and LOQ for this data set were <br /> qualified J as estimates. An initial dilution was necessary to perform the analysis due to sample matrix <br /> conditions in a few samples, and the reporting limits were adjusted accordingly. <br /> Benzo(b)fluoranthene and benzo(k)fluoranthene peaks were not resolved under certain sample analysis <br /> conditions and therefore the results were reported as benzo(b)fluoranthene. Both analytes were flagged E <br /> for the following samples SB-5-S-13-080318, SB-5-SD-13-080318, SB-10-S-18-080320,and SB-11-S- <br /> 16-080320. Due to the presence of an interferent ion,the retention time of acenaphthylene caused the <br /> reporting limit to be raised and samples SB-21-S-5-080327, SB-21-S-6-080327, SB-21-S-7.55-080327, <br /> SB-21-S-17-080327, SB-22-S-4.5-080327, and SB-22-S-6.5-080327 were flagged E. <br /> Completeness <br /> Completeness is defined as the number of valid results(i.e.,those not rejected)divided by the total <br /> number rejected. This evaluation of the data against the QC objectives concluded that the percentages of <br /> valid data for each method are 100 percent,with no data rejected for this investigation. <br /> Comparability <br /> The data evaluation determined that the data are comparable with other laboratory data for similar <br /> samples and sample conditions. The sample collection techniques,EPA test methods, detection limits, <br /> analytical laboratory,units of measure, and sample preparation procedures were selected to ensure data <br /> comparability on this project. <br /> SUMMARY <br /> SAIC's evaluation concluded that all analytical data contained in sample groups 1082250, 1082757, <br /> 1082732, 1082853, 1083265, 1083640, 1084091, 1084562, 1082249, 1082731, 1082756, 1082852, <br /> 1083271, 1083455, 1083631, 1084074, and 1084090 are usable as qualified for the purpose of <br /> determining chemical concentrations in soil and groundwater at the Mountain House Development <br /> Site#6 in Mountain House, California. <br /> E.1-5 <br /> ori i wi <br /> From Science to Snlutiens <br />