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a. Foot notes to these tables indicate that the practical quantitation <br /> limits (PQLs) for some compounds, as presented in the QAPP, are greater than <br /> the cleanup limit (cleanup standard) . For SWMU 6, the cleanup limits for <br /> Heptachlor and Lindane are 1.5 and 1.7 ug/kg, respectively, while the <br /> QAPP-based PQLs for these compounds are 2.0 and 3.0 ug/kg, respectively. <br /> For SWMU 20, the cleanup limit for Dieldrin is 2 ug/kg, while the QAPP-based <br /> PQL for this compound is 3.0 ug/kg. Finally, for SWMU 27, the cleanup limit <br /> for MCPA is 5,000 ug/kg, while the QAPP-based PQL for this compound is <br /> 25, 000 ug/kg. As discussed during the March 3 technical meeting, DDJC-Tracy <br /> (ICF Kaiser) will attempt to find another laboratory which has established <br /> lower PQLs for these compounds. EPA expects that PQLs for all target <br /> analytes to be at least as low as the ROD-based cleanup limits for each <br /> analyte. Otherwise, how will DDJC-Tracy be able to demonstrate that <br /> ROD-based cleanup standards have been met? <br /> b. Also, it is not clear from Tables 3-1 and 3-3, why two PQLs apply to <br /> some analytes (e.g. , for Heptachlor, the QAPP-based PQL is 2.0 ug/kg, while <br /> the PQL listed in Table 3-1 is 1.5 ug/kg) . Each analyte should have only <br /> one PQL. <br /> 12. Section 5.1.2, Second Round Sampling, page 5-2 <br /> This section describes the approach for collecting soil <br /> samples for DI WET analysis if soil cleanup standards have not been met and <br /> critical structures may be compromised. This section should be expanded to <br /> explain that if an excavation cannot be continued because of impacts to <br /> critical structures, then an Explanation of Significant Differences (ESD) is <br /> needed to document and explain this change to the ROD. <br /> 4 <br />