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{ 2.1 Geologic Conditions This section is unchanged from the Work Plan dated 1 August 2006. 2.2 Hydrogeologic Conditions I! This section is unchanged from the Work Plan dated 1 August 2006. ,-� 3.0 PURPOSE OF INVESTIGATION Previous work at the site involved installation of four groundwater monitoring wells and six bore holes, all advanced to 50 ft. bsg, to investigate possible contamination from underground diesel and waste oil storage tanks. Contamination from these USTs, as evidenced by groundwater samples from on-site wells MW-I, MW-2 and MW-3, has dropped to relatively minor levels and continues to decline. MW-3 has been free of �u contamination since M ch 2002. MW-4,just off the eastern edge of the property, �ED4� 1�2t14q�<k7„ evidenced contamination from gasoline, BTEX and oxygenates. Contamination levels have decreased somewhat,but BTEX and 1,2 DCA are consistently above the California primary maximum contaminant levels for drinking water. The primary focus of the proposed investigation is to investigate the vertical extent of contamination from the - '' USTs, and the lateral and vertical extent of contamination from gasoline, BTEX and oxygenates. Advanced GeoEnvironmental, Inc. (AGE), conducted an extensive investigation of the Pacific Pride site immediately south of California Tank Lines, using cone penetrometer testing (CPT)to a depth of 125 ft. bsg. The proposed investigation at California Tank Lines will also use CPT to 125 ft. bsg. This will allow developing sections using lithology from both sites, and may provide greater insight into contaminant pathways affecting the sites. 'i 4.0 DISCUSSION Proposed boring locations are shown on Figure 3. A total of four CPT borings, one west ofMW-2, one on the sidewalk east ofMW-2 and north ofMW-4, one west ofMW-1, and one on the east side of S. El Dorado street, east of AM-4, will be advanced. Soil and/or water samples will be taken adjacent to each of the four CPT borings, and adjacent Yb P$ l� 3