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Background: To briefly summarize the PEA, IAS-09 was an unpaved road approximately 7,300 feet long that provided access to the Landfill Area in the western portion of Rough and Ready Island (RRI). Research into the history of IAS-09 indicated that oil containing organochlorine pesticides(OCPs) had been applied to the road in order to control dust and insects. Environmental investigations specific to IAS-09 were conducted by the US Navy starting in 1992 and continuing through 1999. The results of the Navy investigations completed in 1992 and 1995 indicated that OCPs in soil were the only contaminant of concern at IAS-09. Subsequent studies in 1998 focused on defining the nature and extent of OCPs in soil at IAS-09. The conditions at IAS-09 were discussed in March and July 2010 at meetings between the Port's consultant and representatives of the DTSC and CVRWQCB.As a result of these discussions,ERS agreed to perform limited soil sampling at IAS-09 to fill data gaps and evaluate the current state of OCPs in soil.No additional ground water investigation was requested and none was proposed. This plan was submitted to DTSC as a Technical Memorandum dated August 11,2010.Sampling was completed on August 12. The results of the 2010 sampling did not reveal OCPs in soil at concentrations exceeding screening levels, despite the fact that some of the areas sampled had previously yielded some of the highest concentrations of OCPs in soil at IAS-09.The 2010 results were consistent with the 1996 results in that the concentrations in the southern portion of IAS-09 were generally higher than those in the northern portion, where a majority of the results were below detection limits in 2010. All of the 2010 results were lower than the 1996 results. The PEA offered the explanation that OCPs had degraded under natural conditions, and cited a reference in support of this hypothesis. The PEA concludes that OCPs are no longer present in soil at concentrations exceeding applicable screening levels, so no further action on OCPs in soil is necessary. The PEA states on Page 22: "No pesticide[s] or PCBs have ever been detected in the 54 samples collected from wells within 30 feet of the boundaries of IAS-09." This is documented on Table 9 of the PEA. To further elaborate, there are 12 wells listed on Table 9 with analytical results for Pesticides and PCBs. All 12 are located 30 feet or less from IAS-09, some as close as 15 feet. Nine of these wells have at least four quarters of data with no detections of OCPs. This includes wells RRI-W121 and RRI-W122, which are located 15 feet away from IAS-09 in the southernmost portion of IAS-09 where some of the highest OCP concentrations in soil were found,both in 1996 and 2010. There is no evidence of a dissolved OCP plume in ground water, and abundant evidence for its absence. If there are no ground water impacts in the area of highest concentrations, it is extremely unlikely that those impacts would be observed in an area where concentrations of that same contaminant are much lower. Response to Comments: This letter will not respond to the seven general comments provided by the CVRWQCB;as noted in the letter, some of these have already been addressed.This memorandum is in response to the Page 2 of 4 e r C