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PQWV <br /> EPA Comments on the <br /> Draft Operable Unit 2 Metals Remedial Action Report, <br /> Site 5-26,Area 6, DDJC Sharpe Site,Lathrop, California <br /> October 2007 <br /> SPECIFIC COMMENTS <br /> 1. Section 5.3.5,Page 5-3: Groundwater standards have changed since the Record of <br /> Decision(ROD) was signed but this is not reflected in the text. The text in this section <br /> refers to the"drinking water action level of 15 micrograms per liter(ug/L) for lead or the <br /> maximum contaminant level (MCL) of 100 ug/L total chromium. However, 15 ug/L is <br /> now the primary California and Federal MCL for lead, and the California primary MCL <br /> for chromium is 50 ug/L (the Federal MCL is still 100 ug/L). Please revise the text to <br /> recognize these changes in the MCLS for lead and chromium. Note thara change in ROD <br /> standards is not being suggested, only an accurate reflection of what these values <br /> currently represent. <br /> I <br /> MINOR COMMENTS <br /> 1. Table 2-1, Chronology of Events for DDJC-Sharpe Site 5-26, Area 6, Page 2-1 and <br /> Table 5-2, Result of Total and Soluble Metals Analysis for Excavation <br /> Confirmation,Page 5-5: The event listed for January 2007 on Table 2-1 indicates there <br /> was collection of an attenuation sample for the confirmation location exceeding the <br /> chromium attenuation criterion of 50 ug/L; however, according to Table 5-2, all <br /> confirmation samples had non-detect results for chromium. There was an exceedance of <br /> the attenuation criterion for lead. Confirmation sample AREA6HE-07NS had a <br /> concentration of 613 ug/L, which exceeded the attenuation criterion for lead of 150 ug/L. <br /> Please revise Table 2-1 to include this information <br /> 1 <br />