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I. 4 ACTIVITIES CONDUCTED Three monitoring wells and eight shallow soil borings were advanced on the site. The three groundwater monitoring wells were installed on November 25, 2003. The monitoring wells were designated MW-1, MW-2, and MW-3; and the eight soil borings were designated B-1 through B-8. (see Plate 3). Additionally, groundwater samples were collected from the three monitoring wells and the domestic water supply well on site, and a geophysical survey was conducted to assess the possibility of an underground storage tank (UST) being located near the western portion of the site. 4.1 MONITORING WELL INSTALLATION AND SAMPLING 4.1.1 Permitting and Pre-Field Activities Kleinfelder's "Revised Workplan, Limited Soil and Groundwater Investigation, Schmiedt Property/Tri-Ag Services, Inc. Facility, Manteca, California" dated May 23, 2003 was submitted to the Regional Water Quality Control Board (RWQCB), and San Joaquin County Environmental Health Division (EHD) for review and permitting. The monitoring well installation permit approval was obtained prior to initiating fieldwork. The boring locations were marked in white paint and Underground Service Alert (USA) was notified prior to drilling activities. For a copy of the boring permit, please refer to Appendix A. 4.1.2 Monitoring Well Installation Three monitoring wells were installed at the site. One upgradient well (MW-1) was located near the eastern edge of the site, one crossgradient well (MW-2) was located near the northern edge of the site, and one downgradient well (MW-3) was located near the western edge of the site. The soil borings were advanced using a truck-mounted drill rig equipped with 8-inch diameter hollow stem auger. Soil samples were collected at 5-foot intervals beginning at the surface for logging purposes and possible laboratory analysis. Samples were collected by advancing the boring to a point immediately above the desired sampling depth and then driving a 2-inch diameter Modified California Split-Spoon Sampler, lined with three 6-inch long stainless steel tubes into the undisturbed soil. The sampler was then removed from the bottom of the boring. The ends of the bottom (third) tube were covered with Teflon film and sealed with tight fitting plastic caps. The soil samples were collected from the surface (0-12 inches), and 5-, 10-, 15-, 20-, and 25-foot intervals below the ground surface for lithologic classification. Select sample intervals were submitted for laboratory analyses. In accordance with the workplan the sample intervals included the surface, 5, and 10 foot intervals (with the exception of MW-3 from which the 10-foot sample interval was not analyzed but instead put on hold). The samples were submitted to FGL Environmental of Stockton, California. FGL Environmental is certified by State of California Department of Health Services (DHS) for the requested analyses. I. 27125.E01 / STO4R181 C) 2004 Kleinfelder, Inc. KLEINFELDER 2825 East Myrtle Street, Stockton, CA 95205-4794 (209) 948-1345 (209) 948-0621 fax Page 7 of 23 February 13, 2004