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FIELD ACTIVITIES ' Geoprobe Soil Sampline ' On April 1, 2002, Kleinfelder obtained a boring permit for the Geoprobe locations from EHD. Additionally, Underground Services Alert (USA) was notified 48 hours prior to advancing probe borings. ' On April 3, 2002, 18 Geoprobe borings (B-1 through B-18) were advanced in the vicinity of the three former bulk liquid fertilizer tank farm structures. In addition, one background Geoprobe ' boring (B-G) was advanced away from the tank farm areas, approximately 150 feet from the northern and eastern site boundaries. Geoprobe borings were advanced from ground surface to approximately 5.5 feet below ground surface (bgs). Geoprobe boring locations are shown on Plate 2. En-Prob Environmental Probing of Oroville, California advanced the Geoprobe borings. During sampling, an experienced geologist collected soil samples for laboratory analysis. Soil samples ' were obtained from the borings by advancing a Geoprobe core sampler. This consisted of a hollow rod with plastic tubing inside. The probe was driven/pushed at the desired depth, while the soil sample was collected and contained inside the plastic tubing. Once the sample was brought to the surface, the desired sample was obtained, and the ends of the tubing were sealed with Teflon tape and plastic caps. In each of the 19 Geoprobe boring, soil samples were collected from approximately ground surface to 0.5 feet below ground surface (bgs), 1 to 1.5 feet bgs, 3 to 3.5 feet bgs, and 5 to 5.5 feet bgs. A total of 76 soil samples were collected. The soil ' sample containers were labeled and placed in an iced cooler, and later transferred to the laboratory for analysis. ' To reduce the potential for cross-contamination between the probe borings, sampling equipment was cleaned prior to advancing each boring. The borings were backfilled with a cementlbentonite grout to surface grade upon completion of the sampling. Mr. Jeff Wong of San ' Joaquin County Environmental Health Division approved the grouting method. A copy of Kleinfelder's field protocol is included in Appendix A. ' GPS Mappine On May 6, 2002, Kleinfelder mapped the site and Geoprobe boring locations with a Trimble Global Positioning System (GPS) equipped with differential correction. This system is accurate to within 3 feet. GPS was used to accurately show sample locations, "foot prints" of the three former tank farm structures and other site features. Plate 2 was created from the GPS data. ' LABORATORY ANALYSIS ' The 76 soil samples from the 19 Geoprobe borings were transported under chain-of-custody documentation and transferred on April 4, 2002, to a representative of Sequoia Analytical, in Sacramento, California. Initially, only the two shallowest samples (0 to 0.5 and 1 to 1.5 feet bgs) ' were analyzed. The two remaining deeper samples (3 to 3.5 and 5 to 5.5 feet bgs) were placed on hold, pending results of the shallower samples. After reviewing results from the two shallowest depths, Kleinfelder requested that the remaining samples be analyzed for the selected constituents (April 29, 2002). ' 23485060-1\SAC2R335 Page 2 of 5 July 30,2002 Copyright 2002 Kleinfelder,Inc. KLEINFELDER 3077 Fite Circle, Sacramento, CA 95-827-1835-- 19161 366-1701 (916)366-7013 fax —