ARCHIVED REPORTS_QUARTERLY REPORT - SECOND QUARTER 2008

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, 1 In September 2001, six Hydropunch groundwater samples were collected and analyzed for VOCs from three locations (Haley & Aldrich, 2001b). The full results of the Hydropunch project were presented in the November 2001 Interim Remedial Action Plan (Haley & Aldrich, 2001 c). Pre-remediation tests were performed in the fall of 2001 (Haley & Aldrich, 2001b). This work included an analysis of general chemistry and indicators of natural attenuation in groundwater samples, aquifer tests at monitoring well MW-3B, and well testing on the two inactive water supply wells at the facility. Data from the first half of 2002 showed reduced groundwater concentrations in wells MW-3B and MW-413 that historically had the highest levels of carbon tetrachloride and chloroform. To address this change in site conditions, Haley & Aldrich re-evaluated remediation plans and, with concurrence from RWQCB, implemented a groundwater extraction pilot test program (Haley & Aldrich, 2002). The pilot test was designed to evaluate the efficacy of utilizing groundwater extraction to remediate portions of the aquifer known to be most impacted with carbon tetrachloride and chloroform. The pilot test was concluded in April 2003. Interpretations of the test results were presented in the Pilot Test Report (Haley & Aldrich, 2003a), and in the 2003 Annual Groundwater Monitoring Report (Haley&Aldrich, 2003b). In July 2003, an application for a WDR was submitted to the RWQCB for a proposed Hydrogen Release Compound (HRC) injection pilot test. The RWQCB adopted the WDR in October 2003 (California RWQCB, 2003). Subsequently, the HRC injection pilot test was placed on hold and the feasibility of other remedial technologies were evaluated during 2004. A Waste Discharge Requirements (WDR) for a Granular Zero Valent Iron (GZVI) pilot test was applied for and approved by the RWQCB in October 2004 (Order no. R5-2004-0160). In August 2004, monthly baseline sampling was started in support of the GZVI pilot study (Haley & Aldrich, 2005). In April and May of 2005, two new monitoring wells, MW-9B and MW-10B, were installed in accordance with the WDR to monitor the results of the GZVI pilot test. Hydraulic fracturing and GZVI injections were conducted on 12 April through 16 April, and 16 May 2005. A Pilot Study Evaluation Report was submitted to the RWQCB in May 2006. A Remedial Action Plan was submitted to the RWQCB in February 2007. In October 2007, the RWQCB granted conditional approval for a recirculation pilot study. This groundwater recirculation system, consisting of a pair of injection/extraction wells and one new monitoring well,was installed in May 2008. 1.2 Hydro eog logy The geology underlying the French Camp Elevator site consists of thick intervals(individual units are up to 50 feet thick) of fine-grained sediment(predominantly silt and clay), separated by occasional lenses of silty sand, sand, and/or gravel (up to 20 feet thick). This formation extends to a depth of at least 180 feet bgs. The sand lenses are generally semi continuous across the site 4