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Map ID MAP FINDINGS <br /> Direction <br /> Distance EDR ID Number <br /> Elevation Site Database(s) EPA ID Number <br /> DEFENSE DISTRIBUTION DEPOT SAN JOAQUIN SHARPE SITE (Continued) 1000368504 <br /> sites, monitoring for burrowing owls at two metals sites, and documents no <br /> further action decisions at eight other TCE silesl . LUCs may also be <br /> established for OU 1 in the forthcoming amendment to the OU 1 ROD. <br /> Consequently, LUCs may be a component of the overall remedial strategies for <br /> both OU 1 and OU 2 to ensure protection of human health and the <br /> environment. The OU 2 ROD identified 14 TCE sites that required further <br /> Investigation and/or remediation using in situ volatilization (ISV) (now more <br /> commonly referred to as soil vapor extraction [SVE]). After the OU 2 ROD was <br /> signed, two additional TCE sites (P-2B and P-4C) were identified as requiring <br /> further investigation. All but one (Site P-5A) of the 16 TCE sites has been <br /> Investigated and/or remediated in accordance with the OU 2 ROD remedy. The <br /> results of recent investigations indicated that a residual TCE source area <br /> exists at Site P-5A; therefore, as of April 2010, Site P-5A is being remediated <br /> using SVE In accordance with OU 2 ROD requirements. The purpose of including <br /> the TCE sites in this ROD amendment is to formalize no further action decisions <br /> at Sites P-1 D, P-1 E, P-1 F, P-3A, P-4A, P-4C, P-6A, and P-8A and to establish <br /> LUCs at Sites P-1A, P-1 B. PAC, P-1 G, P-2A, P-213, P-413, and P-5A. LUCs are <br /> necessary at these eight TCE sites to protect a hypothetical residential <br /> receptor potentially exposed to residual VOC concentrations via the vapor <br /> Intrusion pathway. No threats to the environment were identified at the TCE <br /> sites. At Site P-5A, the need for LUCs will be re-evaluated following <br /> completion of the SVE remedial action. In addition, because of the potential <br /> for vapor Intrusion from volatilization from shallow (A Zone) groundwater <br /> plumes, LUCs may be established for groundwater in the forthcoming amendment to <br /> the OU 1 ROD. The OU 2 ROD also identified 14 areas with total lead and/or <br /> chromium concentrations that required further investigation and/or remediation <br /> using excavation with off-site disposal. These 14 metals areas were <br /> consolidated Into five metals sites (S-3, S-261 S-30, S-33/29, and S-36). Three <br /> of the five metals sites were investigated and did not require remediation <br /> because the concentrations of total lead and chromium reported at those sites <br /> did not exceed the OU 2 ROD cleanup standards. At the two remaining sites, soil <br /> was excavated until total lead and chromium confirmation sample results were <br /> less than cleanup standards. However, LUCs are necessary at the five metals <br /> sites to protect human health, because the total lead and chromium cleanup <br /> standards at the Sharpe Site are based on current and potential future <br /> industrial land use; the site Is not approved for unlimited use and <br /> unrestricted exposure (e.g., residential use). In addition, an ecological risk <br /> evaluation of burrowing owls concluded that concentrations of total lead at a <br /> few individual sample locations at Sites S-3 and S-26 exceed effect-based soil <br /> screening levels; therefore, annual monitoring at these two sites is necessary <br /> to protect burrowing owls. The OU 2 ROD did not document the administrative <br /> measures used to ensure that use of the TCE and metals sites remains <br /> protective; therefore, this ROD amendment describes the administrative <br /> implementation of the LUC remedial component associated with protecting human <br /> health at eight of the TCE sites and the five metals sites. LUCs are measures <br /> that help minimize the potential for human and ecological receptor exposure to <br /> contamination by restricting activity, use, and/or access to property with <br /> residual contamination. This ROD amendment thereby enhances the remedy <br /> identified In the OU 2 ROD by formally adding LUCs and the associated <br /> mechanisms that will prohibit development for uses such as schools, child care <br /> facilities, playgrounds, and residential housing at eight of the TCE sites and <br /> the five metals sites. In addition, annual monitoring at two of the metals <br /> sites is added in this ROD amendment to ensure burrowing owls do not inhabit <br /> Site S-3 or Site S-26, The Defense Logistics Agency (DLA), the lead agency, <br /> and the United States Environmental Protection Agency (EPA) Region 9 select <br /> this ROD amendment in concurrence with the California Environmental Protection <br /> Agency, Department of Toxic Substances Control (DTSC) and Regional Water <br /> TC4755450.2s Page 21 <br />