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EPA Comments on the <br /> Draft Five-Year Review Report <br /> Defense Distribution Depot San Joaquin California, <br /> Sharpe Site,Lathrop,California <br /> March 2003 <br /> GENERAL COMMENT <br /> 1. It appears that the Five-Year Review Report(the Report)for the DDJC-Sharpe facility generally <br /> follows the Comprehensive Five-Year Review Guidance(EPA,2001). One of the specific <br /> comments that follow requests clarification that Guidance was followed, and one comment <br /> requests reconsideration of a decision to leave lead contamination in place at Site S-26. The other <br /> specific comments are generally requests for clarification to ensure the protectiveness of the <br /> remedies and the usefulness of the Report. <br /> SPECIFIC COMMENTS <br /> 1. Section 3.3.1,History of Contamination,Page 3-6: The first full sentence indicates that lead has <br /> been detected in groundwater,but the second sentence does not list lead as a frequently detected <br /> contaminant that may have originated at DDJC-Sharpe. Lead was detected in soils more <br /> extensively than chromium and was the only risk driver at several sites recommended for cleanup <br /> in the Record of Decision(ROD), so it is possible that lead will eventually appear in <br /> groundwater.Please clarify why lead is not listed among the groundwater contaminants that may <br /> have originated at DDJC-Sharpe. <br /> 2. Section 4.3.3.8,OU 2 Remedy Implementation(Metals),Page 4-29: This subsection discusses <br /> lead contamination left in place at a portion of Site S-26 due to logistical constraints.(railroad <br /> tracks),but it is not clear that this is protective. Since the decision was made to leave <br /> contamination in place in one portion-of Site S-26,there has been an increased interest in <br /> tracking areas of residual contamination through institutional controls (ICs)or other mechanisms <br /> and preventing complete exposure pathways to human and ecological receptors from such areas. <br /> In addition,the residual lead contamination exceeds levels that allow for unlimited use and <br /> unrestricted exposure, and as such will need to be evaluated in future statutory Five-Year <br /> Reviews. As part of the Five-Year Review process,please reconsider the decision to leave lead <br /> contamination in place above risk-based cleanup standards established in the ROD. Alternatively, <br /> please consider ICs or other mechanisms to ensure that the decision to leave residual lead <br /> contamination above risk-based cleanup standards is still protective for this portion of Site S-26. <br /> 1 <br />