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Attachment B:Data Usability Summary and Laboratory Analytical Results(January 2008) • Comparability DATA USABILITY SUMMARY The following sections summarize the findings of the data evaluation process. The 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). R Indicates the result is rejected because of deficiencies in the ability to meet QC criteria and cannot be used for decision making. U Indicates the analyte was analyzed for,but not detected above the level of the associated value. A summary of qualified data is provided in Table B-1. Data validation reason codes for all qualified data are also presented and defined on Table B-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 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. MSIMSDs Project-specific MS/MSDs were collected with the groundwater samples. All MS/MSD samples were within QC range,with the following exceptions: MW6-W-080129MS and MW6-W-080129MSD had benzo(a)pyrene(46 and 54 micrograms per liter [gg/L]), indo(1,2,3-cd)pyrene(67 gg/L), and benzo(g,h,i)perylene(54 and 64 gg/L)below the acceptance criteria. Associated samples MW-2-W- 080129 MW-3-W-080129,MW-5-W-080129,MW-6-W-080129,MW-6WD-W-080129, and MW-7-W- 080129 will be flagged E for specific analytes. LCS/LCSDs A LCS was analyzed with each analytical batch of samples. All LCS/LCSD%Rs were within the laboratory control limits. Surrogates All surrogates were within QC criteria. Representativeness Representativeness was assessed through the evaluation of the equipment blank sample, chain-of-custody forms,preservation, and holding times. The reported results were also compared to the laboratory's MDLs and LOQs.