SITE INFORMATION AND CORRESPONDENCE

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Geomatrix These concentrations will be compared to results of samples collected from monitoring wells MW-9 and MW-24 in September 2008. Hydraulic Control Review of historical water level data suggest that shallow zone groundwater levels beneath the site vary seasonally with water levels declining during the summer months (April through September)and recovering during the winter months(October through March). Groundwater level measurements were collected monthly from May through November 2007 when groundwater elevations are not highly influenced by recharge. Potentiometric surface maps were prepared for the shallow and intermediate zones based on the March, September, October, and November 2007 water level elevation data(Figures 3 through 10). Hydraulic control will be demonstrated by the presence of a depression in shallow zone groundwater below the site in the summer months. If hydraulic control is not apparent within 5 years after phytoremediation has been implemented (anticipated to be in July 2008), then a remedial alternative will be implemented at the site. As mentioned previously, the mound that was observed in shallow groundwater beneath the Facility in September 2007 is attributed to the leak in the main irrigation line. Data collected in October(Figure 7) and November(Figure 9) after the leak was repaired indicate that groundwater levels are decreasing in the area were the groundwater mound was previously observed. Groundwater levels will continue to be monitored on a monthly basis during 2008, and a hydraulic control demonstration will be included in the Second Semiannual and Annual 2008 Groundwater Monitoring Report that will be submitted by December 1, 2008. In addition,a pressure test will be conducted on the main irrigation line to verify its integrity prior to placing it back in service for 2008. 5.0 MONITORING WELL MW-30 INSTALLATION Monitoring well MW-30 will be installed approximately 350 feet east of monitoring well MW-27 (Figure 2) within the City of Stockton street right-of-way at the intersection of Old Spanish Drive and Rogue Drive. The well will have similar construction to the other shallow zone monitoring wells in the vicinity. It is anticipated that the well will be installed to a depth of approximately 30 feet bgs, with 15 feet of well screen. Proposed well construction is summarized on Figure 23. It is anticipated that groundwater samples will be collected from monitoring well MW-30 during the first semiannual 2008 groundwater monitoring event scheduled for March 2008. 1.15000s,5352 000V h,v 5352-148 d. 18