ARCHIVED REPORTS_WELL INSTALL AND QUARTERLY GROUNDWATER MONITORING REPORT 2008

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Well Installation and Quarterly Groundwater Monitoring Report Second Quarter 2008 _ 1950 West Fremont Street, Stockton, California On the behalf of TEC, Earth Tech, Inc. (Earth Tech) conducted a Preliminary Endangerment Assessment (PEA) investigation in January 2005 (first phase)and August 2006 (second phase)to address the findings and issues originating from DTSC's site inspection. The results of PEA investigation indicated elevated levels of chemicals exceeding the regulatory criteria, such as California Maximum Contaminant Levels (MCL),in the groundwater beneath the site. ' As presented in the Final Preliminary Endangerment Assessment Report (Final PEA Report) dated August 15,2007,the groundwater analytical data indicated the following: • Dissolved nickel was detected in groundwater at concentrations up to 0.794 milligrams per liter (mg/L), which is above the 0.1 mg/L California MCL for nickel. Groundwater with dissolved nickel concentrations exceeding the MCL is localized to the site. • N-Nitrosodimethylamine (MDMA) was detected in one grab groundwater sample at a ' concentration of 8.8 micrograms per liter (µg2) (or 8,800 nanograms per liter [ng/L]) in January 2005. Using a more appropriate NDMA analytical method with ultra-low detection limits, subsequent investigation at the same location in August 2006 showed a significantly lower concentration of 37.8 ng/L. The maximum NDMA detection in grab groundwater samples in August 2006 was 103 ng/L. The California Notification Level for NDMA is 10 ng/L. • Methyl tert-butyl ether (MTBE) was detected in several grab groundwater samples collected in August 2006 at relatively low concentrations (maximum of 16 µg/L). The California Primary MCL for MTBE is 13 µg/L. Locations where concentrations of nickel, NDMA and MTBE were previously found to exceed regulatory criteria are shown on Figure 3. The sampling locations where concentrations exceeding regulatory criteria were found are within the footprint of the building, which is currently occupied by an operating brewery. In a letter dated October 4, 2007, DTSC suggested that quarterly groundwater monitoring be conducted for a minimum period of one year and that the work plan for groundwater monitoring be submitted for rreview and approval. On the behalf of TEC, Earth Tech prepared and submitted the Groundwater Monitoring Work Plan (Work Plan), dated December 10, 2007 to DTSC for review and approval. The Work Plan was approved by DTSC on March 28,2008. ' Project 102790 2 July 2008