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substantial changes to cleanup standards and monitoring requirements
<br /> after the ROD has been finalized. Since leachability studies may result
<br /> in significant changes to ROD-based cleanup standards, why were such
<br /> leachability studies not performed before the ROD was finalized? At a
<br /> minimum, the work plan must include a detailed description of the
<br /> evaluation process that will be performed based on the leachability test
<br /> results to determine whether cleanup standards and/or groundwater
<br /> monitoring warrant revision. Also, by proposing such changes to the ROD
<br /> after it has been finalized, DDJC may be extending the RD/RA schedule.
<br /> Does the RD/RA schedule allow sufficient time for the ROD to be modified
<br /> and approved by the regulatory agencies?
<br /> 2. Table 9-1, Required Reporting Limits for Contaminants of Concern
<br /> Soil reporting limits for certain analytes listed in Table 9-1 exceed
<br /> the soil cleanup standards specified in the Site-Wide Comprehensive ROD,
<br /> Section 9 . In addition, the list of groundwater and soil analytes in
<br /> Table 9-1 is incomplete relative to the ROD-based groundwater monitoring
<br /> standards (ROD, Table 9-7) and ROD-based soil cleanup standards (ROD,
<br /> Section 9) . Table 9-1 must be modified to be fully consistent with the
<br /> ROD. Soil reporting limits must not exceed ROD-based soil cleanup
<br /> standards. The following inconsistencies were noted:
<br /> * Soil reporting limits in Table 9-1 exceed soil cleanup standards
<br /> specified in the ROD (Section 9) at one or more sites for the
<br /> following analytes: PCB-1260, arsenic, lead, simazine, linuron,
<br /> carbofuran, methiocarb, 2,4-D, 2,4,5-T, phorate, ronnel and 2,4-
<br /> dinitrophenol;
<br /> * Soil analytes missing from Table 9-1 (but listed in ROD, Table 9-
<br /> 7) : 2-butanone, carbaryl, dicamba, 1,2-DCE, diuron, ethylbenzene,
<br /> TCE, acetone, toluene, heptachlor epoxide, aldrin, 2-hexanone,
<br /> xylenes, 4-methyl-2-pentanone, selenium, monuron and total PAHs;
<br /> and
<br /> * Groundwater analytes missing from Table 9-1 (but listed in ROD,
<br /> Table 9-7) : 2-butanone, carbaryl, dicamba, 1,2-DCE, diuron,
<br /> ethylbenzene, .*TCE, acetone, PCE, toluene, heptachlor epoxide,
<br /> dioxins/furans, aldrin, 2-hexanone, xylenes, 4-methyl-2-pentanone,
<br /> and monuron.
<br /> 3 . Section 4.2.3 .5.4, SWMU 8 Design Data Collection Plan, page 4-12
<br /> For Geoprobe holes GE053, GE055, and GE056, additional leachability test
<br /> samples should be collected at 15 feet bgs, for the following reasons:
<br /> a. It will provide a greater range of contaminant concentrations for
<br /> the leachability assessment than what is currently proposed. A
<br /> greater range of leachability values appear warranted because the
<br /> data would enable better quantification of the concentration
<br /> threshold in Fills 2 and 3 from which a threat to groundwater
<br /> exists, particularly if cleanup standards may be revised.
<br /> 2
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