ARCHIVED REPORTS_LIMITED PHASE 2 SOIL REPORT

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CRA MEMORANDUM Page 2 All samples were properly delivered on ice, and stored by the laboratory at the required temperature (<6°C). 3.0 Laboratory Method Blank Analyses Method blanks are prepared from a purified matrix and analyzed with investigative samples to determine the existence and magnitude of sample contamination introduced during the analytical procedures. For this study, laboratory method blanks were analyzed at a minimum frequency of 1 per 20 investigative samples and/or 1 per analytical batch. All method blank results were non-detect, indicating that laboratory contamination was not a factor for this investigation. 4.0 Surrogate Spike Recoveries-Organic Analyses In accordance with the methods employed, all samples, blanks, and QC samples analyzed for organics are spiked with surrogate compounds prior to sample extraction. Surrogate recoveries provide a means to evaluate the effects of laboratory performance on individual sample matrices. All samples submitted for volatile organic compound (VOC), polychlorinated biphenyl (PCB) and organochlorine pesticide analysis were spiked with the appropriate number of surrogate compounds prior to sample extraction. Surrogate recoveries were assessed against the associated control limits. All surrogate recoveries met the above criteria with a few exceptions. Where high recoveries were found the associated non-detect results would not have been impacted and the associated sample detections were qualified as estimated due to the implied high bias. Where low recoveries were found the associated sample results were qualified as estimated due to the implied low bias. A summary of the qualifications is presented in Table 4. 5.0 Laboratory Control Sample(LCS)Analyses LCS and/or laboratory control sample duplicates (LCSD) are prepared and analyzed as samples to assess the analytical efficiencies of the methods employed, independent of sample matrix effects.The relative percent difference (RPD) of the LCS/LCSD recoveries is used to evaluate analytical precision. For this study, LCS/LCSD were analyzed at a minimum frequency of 1 per 20 investigative samples and/or 1 per analytical batch. Organic Analyses The LCS/LCSD contained the compounds specified in the method. All LCS recoveries and RPDs were within the associated control limits, demonstrating acceptable analytical accuracy and precision with the exception of one high recovery. The associated sample results were non-detect and would not have been impacted by the implied high bias. No qualification of the data was deemed necessary. EQUAL EMPLOYMENT OPPORTUNITY EMPLOYER