SITE INFORMATION AND CORRESPONDENCE (2)

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Data Usability Summary 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 with 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. Sample results in this data set were qualified J for concentrations reported between the MDL and LOQ. Completeness Completeness is defined as the number of valid results(i.e.,those not rejected)divided by the total number rejected. Based on this evaluation of the data against the QC objectives,the percentages of valid data for each method and matrix are 100 percent. Comparability Based on the data evaluation, it was concluded 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. SUMMARY Based on SAIC's evaluation, all analytical data are usable as qualified for the purpose of determining chemical concentrations in groundwater at the site. Data reported in laboratory report 1013540 for this sampling event were qualified E for results associated with equipment blank contamination or LCS and MS/MSD%Rs above upper control limits. Sample results were qualified J for concentrations reported between the MDL and LOQ. Qualified data with applicable reason codes are shown in Table B-1. Unless noted otherwise,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.