To ensure that excavation and materials handling operations did not result in excessive airborne PCB emissions from the site, PSARA also performed perimeter air monitoring in accordance with the Air Monitoring Plan (AMP), which is included as Appendix E of the WP. Perimeter air samples were collected and analyzed for PCBs using NIOSH Method TO-4. The air samples were submitted to DataChem Laboratories in Cincinnati, Ohio, for analysis. This section discusses the usability of the final verification soil data and the perimeter air quality data collected during the course of the remediation activities.

PSARA Technologies reviewed Heritage Laboratories' analytical data for 366 final verification soil samples collected from the LL Landfill and nearby Pelfree, Elliott, and Griffin properties. The primary purpose of PSARA's review was to evaluate whether the data quality objectives specified in Section 7 of the Post-excavation Verification SAP and the Quality Assurance Project Plan (QAPjP) for the Bloomington Sites were satisfied. Accordingly, 100 percent of the final soil verification data was reviewed to ensure that holding times were met, matrix spike recoveries were within acceptable ranges, and blank contamination, if any, did not adversely affect the final soil quality results. Moreover, the quality assurance (QA) objectives for precision, accuracy, representativeness, completeness, and comparability were evaluated as specified in the QAPjP. Although not required under the Post-excavation Verification SAP, PSARA also verified 10 percent of the final verification results from the associated raw data.

Heritage Laboratories provided QA data packages containing case narratives, analytical run logs, summary QC forms, chromatography, instrument calibration data, chains of custody, and certificates of analysis. All the samples were grouped into sample delivery groups by the laboratory. PSARA's review followed general procedures discussed in the "EPA Contract Laboratory Program National Functional Guidelines for Organic Data Review" dated February 1994. All data packages were evaluated for adherence to QC and QA criteria. Evaluations of the data packages were based on laboratory case narratives, summary QC forms for matrix spikes

1.(MS) and matrix spike duplicates (MSD) and surrogate recoveries, method blank data from the chromatography, instrument calibration data, Chain-of-custody records, and certificates of analysis, which included sample holding times and surrogate recovery data. Table 1 of Appendix I summarizes the pertinent laboratory QC data for the verification soil samples and any qualifications to the data set.

Based on PSARA's review of the soil data packages, the soil confirmation result for sample LL4753 failed to meet the internal laboratory QA/QC requirements and should be qualified as an estimated value. This verification soil sample was collected from a sidewall in Area 25. During the batch run that included this sample, the MS and MSD results were not reportable, and the laboratory control standard (LCS) exceeded the acceptable range. The final PCB dry-weight result for sample LL4753 was reported as 2.3 ppm, which was well below the cleanup criteria established for the site. No other verification soil samples were qualified during the data validation process. Consequently, there is a high level of confidence that all of the post-excavation verification soil analytical results are accurate in indicating that the remaining PCB concentrations in soil are below the cleanup objective(s) for the site. A discussion of the findings of the data validation review for the verification soil data is presented in Appendix I.

In addition, PSARA reviewed DataChem Laboratories' analytical data for 1,067 perimeter air samples collected during remediation of the LL Landfill site. Validation of the perimeter air samples was not required under the EPA-approved AMP and only the final certificates of analysis were provided to PSARA in the field. To further evaluate the quality of the perimeter air data, PSARA visited DataChem to review the raw data, which included the analytical run logs, chromatograms, and chemist's notes. In addition, PSARA contracted an independent laboratory, Environmental Standards, to prepare three blind, spiked polyurethane foam (PUF) cartridges. A letter from Environmental Standards documenting the spiking procedure and results is included in Appendix I. These three samples were labeled as perimeter air samples and included in a shipment from the project site to DataChem for analysis to evaluate their analytical performance. Table 2 of Appendix I summarizes the validation parameters for the perimeter air samples. A discussion of the findings of the data validation review for the perimeter air sample data is presented in Appendix I.