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EPA Comments DD-Tracy Draft"Project Closeout Plan(Remedial Action Report),SWMU 6, SWMU 20,and SWMU 27 Small Excavation Sites and SWMU 4 Wet Season Controls"dated March,2001 GENERAL COMMENTS 1, The summary tables for SWMUs 6, 20 and 27 (Tables 4-2A,4-213, and 4-2C) show results that are marked with a less than symbol (<),indicating the results are"not detected above the practical quantitation limit",according to the notes in the tables. However, the practical quantitation limits (PQLs)on the analytical reports for these results in Appendix F are less than the posted results in the tables. The posted results appear to be reporting limits, apparently elevated due to correction for moisture content, based on the data in Appendix F. For example, in SWMU 6, sample location DP0091, the PQLs presented in Appendix F for the ROD-defined chemicals of concern (1.5 to 10 ug/kg) are less than the posted reporting limits(1.9 to 13 ug/kg). It is unclear why the summary tables (Tables 4-2A,B, and C) state that the results with the less than symbol are less than the PQL when Appendix F shows the results to be less than reporting limits higher than the PQLs. Please clarify the use of PQL versus reporting limits in the tables. 2. The reporting limits for sample DP0091 are all greater than the soil cleanup standards. This raises the issue of whether the cleanup goals were met at SWMU 6 because DP0091 was a confirmation sample collected to demonstrate that contamination was removed in the southern portion of the excavation. Since the reporting limits for the Site-Wide Comprehensive Record of Decision(ROD)-defined chemicals of concern exceed the ROD-specified soil cleanup standards,it is not clear why or how this sample was used to demonstrate that contamination was removed from the southern portion of the excavation. Please provide an explanation in the text justifying the usability of this data and how it was used to make remedial decisions, such as stopping excavation. SPECIFIC COMMENTS 1. Section 4.3.2,page 4-6,sixth paragraph,third sentence. This sentence states that the results for the soil samples analyzed by DI-WET were compared to groundwater concentrations requiring evaluation presented in the ROD. The ROD presents groundwater concentrations requiring evaluation but does not specify the use of those concentrations to evaluate soil concentrations that exceed the ROD-specified soil cleanup standards. Please discuss the regulatory basis for the use of groundwater concentrations requiring evaluation to evaluate soils above ROD-specified soil 1