Laserfiche WebLink
43. Section 5.2.1 <br /> Contrary to the title of this section, the text does not elaborate on the extent of <br /> contamination. <br /> Corrective Action: Include a discussion of the extent of contamination. <br /> 44. Section 5.2.6 <br /> The text implies that there are smaller plumes of other contaminants, however, it <br /> does not explain "nature and extent." Further, the text states that Contaminant <br /> Areas 5 and 6 "are not judged to be sources of significant groundwater plumes." <br /> However, given that the on-Base investigations have not been completed, this <br /> statement is premature. <br /> Corrective Action: Describe the nature and extent of other contamination. Delete <br /> the text which indicates that some conclusion has been made regarding the <br /> significance of these sources. <br /> 45. Section 5.2.8 <br /> The text in this section states "metals of concern detected in groundwater samples <br /> were found to be irregularly distributed in most areas of the Base" and also "elevated <br /> total metal concentrations were always associated with observed brown, turbid water <br /> samples." However, recently collected non-turbid groundwater total metals analyses <br /> indicate elevated arsenic levels immediately downgradient of selected SWMUs. <br /> Therefore, the text in this section is not accurate. <br /> Corrective Action: Revise the text to more accurately reflect recent groundwater <br /> data. <br /> 46. Section 5.2.14 <br /> The text states "arsenic, chromium, and lead found in the unfiltered groundwater <br /> samples taken on the depot are not found in the filtered samples taken on the depot . <br /> . W. This text is not accurate. Arsenic and chromium have been found in filtered <br /> samples taken on the depot. <br /> Corrective Action: Delete this sentence. <br /> 47. Section 5.3.1 . <br /> The text erroneously indicates that dieldrin may have an off-Base source. Further, <br /> the text states that metals may be naturally occurring. The ROD should not promote <br /> these speculative scenarios when more recent information indicates that elevated <br /> levels of dieldrin and arsenic are immediately downgradient of selected SWMUs. <br /> Also, this assertion of an off-Base source seems to contradict text in Section 6.3.7. <br /> EPA/R9 June 7, 1993 12/40 <br />