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Mr. Maurice Benson <br /> August 20, 2009 <br /> Page 4 <br /> the C-zone aquifer and that may remain in both saturated and unsaturated soil <br /> after the innovative technology is completed. <br /> Site P-8A is in the vicinity of the Emulsified Oil Substrate innovative technology <br /> currently in operation in the North Balloon. The in-situ pilot study will be in <br /> operation for a couple more months, followed by monitoring to observe the <br /> response of the system after shutdown. Post monitoring data from unsaturated <br /> and saturated soil and groundwater will help determine whether additional <br /> remedial actions are warranted to meet cleanup objectives and the protection of <br /> soil and groundwater from possible persistent sources. DTSC cannot support a <br /> NFA determination for Site P-8A until the in-situ technology has finished in the <br /> North Balloon and subsequent monitoring data from both unsaturated/saturated <br /> soil and groundwater demonstrate that no further remedial action is warranted for <br /> this area. <br /> 6. Page 1-3, Figure 1-1, Status of Soil Sites, DDJC-Sharpe; Similar to comment #2, <br /> DTSC recommends including the sampling confirmation data and relevant figures <br /> to show that the cleanup standards have been met at each TCE site <br /> recommended for NFA as Appendices to the report. DTSC cannot concur with a <br /> NFA determination at TCE sites with contaminant concentrations above the <br /> unrestricted use/unrestricted exposure levels and would require land use controls <br /> as part of the selected remedy if those standards are not achieved. <br /> 7. Page 2-1, section 2.0.1, Metal Sites; The Section implies that current industrial <br /> use cleanup standards for lead and chromium in soil are 1,000 mg/kg and 300 <br /> mg/kg, respectively. The industrial cleanup standard for lead has changed to <br /> 800 mg/kg and should be identified in the report as the current cleanup standard. <br /> Conclusions <br /> DTSC recommends that the Sharpe OU-2 ROD Amendment is modified to <br /> include figures and analytical data supporting DESJC's determination that soil <br /> cleanup objectives have been achieved at each of the metal and VOC sites. <br /> The ROD Amendment should identify that the soil sites with metal contamination <br /> over the unrestricted use/unrestricted exposure levels will require institutional <br /> controls in the form of LUCs. The LUCs are necessary for the metal sites and <br /> constitute an action of implementing, maintaining, monitoring, and enforcing the <br /> controls to prevent unacceptable risks and exposure pathways to human and <br />