ARCHIVED REPORTS_ANNUAL 2009 GROUNDWATER MONITORING AND SAMPLING REPORT

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Attachment C:Data Usability Summary and Laboratory Analytical Reports • Representativeness • Completeness • Comparability DATA USABILITY SUMMARY The following sections summarize the findings of the data evaluation process. Immediately following is a summary of the data verification and validation qualifiers used in the data evaluation: ualifier Description E Indicates the reported value is estimated due to associated quality control (QC) results. J Indicates the reported value is an estimated concentration detected between the method detection limit (MDL) and limit of quantitation(LOQ). A summary of qualified data is provided in Table C-1. Data validation reason codes for all qualified data are also presented and defined on Table C-1. Precision and Accuracy The precision and accuracy of field and laboratory QC samples were evaluated. The calculated relative percent differences (RPDs) for field duplicate and matrix spike/matrix spike duplicate (MS/MSD)pairs provided information on the precision of sampling and analytical procedures, and the RPDs for laboratory control sample/laboratory control sample duplicate (LCS/LCSD) pairs provided information on the precision of the analytical procedures. Evaluation of the percent recoveries (%Rs) of MS/MSDs, LCS/LCSDs, and surrogates provided information on accuracy. MS/MSDs One MS/MSD pair was collected during the field sampling event. All %Rs and RPDs were within acceptance criteria. LCS/LCSDs An LCS was analyzed with each analytical batch of samples. All LCS/LCSD %Rs were within the laboratory control limits with the exception of pyrene, which was slightly above the upper QC range. Pyrene was flagged E in sample MW-9-090116. Surrogates Surrogate recoveries were evaluated for all methods. The laboratory used three surrogates in the analysis of PAHS: nitrobenzene-d5, 2-fluorbiphenyl, and terphenyl-d14. PAH surrogate nitrobenzene-d5 was above QC limits for MS/MSD soil samples. However, nitrobenzene-d5 is not associated with the target PAHS; it was used to evaluate the overall system performance and not to qualify sample results. Orthoterphenyl was used as the surrogate for the TPH analysis. All other surrogates were within range.