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i k9 KI_EINFELDER 6 CONCLUSIONS AND RECOMMENDATIONS i On December 8 and 9, 2005, seven down gradient monitoring wells were purged and sampled. Water samples obtained from each location were submitted for chemical analysis. Based on the data obtained during our assessment, the following conclusions and recommendations have been formulated: 1. The groundwater gradient at the site was estimated to be east/southeast and relatively flat at 0.0006 ft./ft. 2. Groundwater samples from seven monitoring wells (MW-DIS-11 S, MW-DIS-11 D, MW-DIS-12, and MW-DIS-13, MW-DIS-14S, MW-DIS-14D, and MW-DIS-15) did not contain TPH-g, BTEX, TBA, and EDB at or above the laboratory reporting limits. Concentrations of 1,2-DCA were detected in MW-DIS-11S, MW-DIS-12, MW-DIS-14S, and MW-DIS-15. The 1,2-DCA concentration in MW-DIS-11S increased from 8 ug/Lthe previous quarter to 22 ug/Lduring the fourth quarter, but still reflected a lower overall concentration versus the. same reporting period last year. The concentrations of 1,2-DCA detected in MW-DIS-12, MW-DIS-14S, and MW-DIS-15 remained similar to or decreased slightly compared to previous results. The additional oxygenates MTBE, DIPE, ETBE, and TAME were not detected at or above the laboratory reporting limits in MW-DIS-15. 3. Kleinfelder recommends that monitoring of the site be continued in accordance with the "Groundwater Monitoring Frequency Decision Tree" at this time. However, TPH-g, BTEX, EDB, TBA, and Oxygenates (MW-DIS-15 only) have not been detected in MW-DIS-11S, MW-DIS-11D, MW=DIS-12, MW-DIS-13, MW- DIS-14S, MW-DIS-14D, or MW-DIS-15 for at least the past four consecutive quarters. We recommend TBA, EDB and the oxygenates be discontinued in accordance with the Groundwater Monitoring Frequency Decision Tree. TPH-g and BTEX are constituents of concern within the source area and should continue to be monitored for in the groundwater samples. Concurrence from the San Joaquin County Environmental Heath Division should be obtained prior to discontinuing the analyses. 4. A copy of this report should be submitted by Del Monte, Inc. to the San Joaquin County Environmental Heath Division and the Central Valley Office of the State of California Regional Water Quality Control Board for their review and consideration. This report is subject to the limitations in Chapter 7 of this report. i 12280.M0NIST06R0701CD:Iv Page 12 of 14 0 2006 Kleinfelder, Inc. February 16,2006