July 16, 2002

Dear Mr. Alcamo:

Tetra Tech EM Inc. (Tetra Tech) has prepared the enclosed data evaluation report for nonsplit samples collected by Tetra Tech during field sampling activities performed in Stout's Creek near the Asea Brown Boveri and Bennett's Dump sites on June 6, 2002. Viacom, Inc., is the responsible party for the sites. The enclosed data evaluation report summarizes polychlorinated biphenyl and total suspended solids analytical results for surface water samples collected in Stout's Creek near the sites. The full data package prepared by TriMatrix Laboratories, Inc., is not included in the enclosed report; however, sample analytical results, along with Tetra Tech's handwritten data qualifications, where warranted, are presented in the attachment to the data evaluation report.

1.0 INTRODUCTION

As requested by the U.S. Environmental Protection Agency (EPA) under the Response Action Contract (RAC) for Region 6, Contract No. 68-W6-0037, Work Assignment (WA) No. 944-ANLA-OSZZ, Tetra Tech EM Inc. (Tetra Tech) conducted field sampling activities near the Asea Brown Boveri (ARE) and Bennett's Dump sites in Bloomington, Indiana. Viacom, Inc. (Viacom; formerly CBS Corporation and Westinghouse Electric Corporation) is the responsible party for the sites. The project objectives were to conduct sampling and analysis of the West Fork and main branch of Stout's Creek in order to evaluate the potential polychlorinated biphenyl (PCB) impacts attributable to the ABB site as well as PCB concentrations adjacent to and downgradient of Bennett's Dump. As stated in Tetra Tech's EPA-approved revised field sampling plan dated June 20, 2002, Tetra Tech performed surface water sampling at a total of seven locations in Stout's Creek. The sampling locations are shown in the sampling plan.

This report discusses the usability of data collected from nonsplit surface water sampling activities conducted by Tetra Tech at the seven sampling locations on June 6, 2002. All nonsplit sampling activities and analytical procedures were conducted in accordance with the EPA-approved, multisite mini-quality assurance project plan (QAPP) dated December 13, 1999, and prepared under the RAC for Region 5.

All surface water samples collected by Tetra Tech were analyzed by TriMatrix Laboratories, Inc. (TriMatrix), of Grand Rapids, Michigan, for PCBs and total suspended solids (TSS). The full data package prepared by TriMatrix is not included in the enclosed report; however, sample analytical results, along with Tetra Tech's handwritten data qualifications, where warranted, are presented in the attachment to the data evaluation report.

The following sections describe the data usability review for the nonsplit surface water sample analytical results and Tetra Tech's conclusions about the overall quality and usability of the analytical data. Table 1 below summarizes the sampling location numbers, sampling location descriptions, and Tetra Tech sample identification numbers.

2.0 DATA USABILITY REVIEW

TriMatrix analyzed nonsplit surface water samples from Stout's Creek for PCBs using EPA Method 8082 and for TSS using EPA Method 160.2. Tetra Tech reviewed the usability of analytical data received from TriMatrix to evaluate whether (1) the data quality objectives specified in the mini-QAPP were satisfied and (2) the data generated are of sufficient quality for their intended use. Specifically, Tetra Tech evaluated all quality control (QC) criteria submitted by TriMatrix, holding times for sample analysis, and analytical result summary reports. Tetra Tech'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 required QC and quality assurance (QA) criteria. Evaluation of the data packages was based on laboratory case narratives, analytical run logs, summary QC forms, summary analytical results, all instrument and summary analytical calibration data, and sample holding times. If any inconsistencies were observed, a review of the raw data for accuracy was also conducted.

Trimatrix received the samples in three different coolers that did not contain temperature blanks. The temperatures of the three coolers were recorded at 12.4 to 14.9 øC, all outside the required temperature range of 4 ~ 2 øC. Because of the stability of PCBs, no qualifications are warranted.

Based on laboratory fortified sample analysis, matrix spike/matrix spike duplicate analysis, and surrogate recoveries, the accuracy and precision of laboratory procedures were acceptable for the PCB and TSS analyses.

The instrument and method blanks were free of contaminants.

Positive results for PCBs were confirmed by dual-column gas chromatographic analysis. Percent difference calculations between the concentrations reported for the two columns were checked at random and yielded acceptable results. The PCBs present in the surface water samples were poor matches to the unweathered PCBs in the laboratory standards. This was evident from the relatively large quantitative differences between the two columns and between the five peaks on each column used to determine the amount of each Aroclor. Because of these poor matches, the positive PCB results are flagged "J" to indicate that they are estimates.

The initial and continuing calibration results were acceptable. Although an occasional peak on column B was outside the acceptable limits during some continuing calibrations, the average results were acceptable. Furthermore, all initial and continuing calibration results for Aroclor 1248, the only reported PCB Aroclor detected in these samples, were completely within QC limits.

3.0 OVERALL DATA USABILITY

Based on the documents provided for review by Trimatrix, the TSS and PCB data submitted are acceptable for use as qualified.