ARCHIVED REPORTS_PHASE II ENVIRONMENTAL SITE ASSESSMENT

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WGR • Soulthwest, Inc. South Ditch bank, and B-17 and B-18 were located in areas where old vehicles were observed during the Phase I. The Phase 11 work plan allowed for relocation of borings if deemed necessary or advantageous due to actual field conditions encountered during siting of the borings. Two of the proposed borings, B-11 and B-13, were relocated. B-11 was relocated approximately 30 feet west because field observations revealed the original location to have a concrete surface which would have likely impeded the downward migration of potential contaminants. The new location was centrally located in an area mapped as a former depression. B-13 was relocated approximately 50 feet north because the planned location was inaccessible due to the presence of a large scrap metal stockpile. The new location of B-13 was also an area where metal processing and storage has occurred adjacent to the railroad spur where materials may have also been loaded. 8.0 FIELD ACTIVITIES 8.1 Exploratory Excavation • On May 8, 2008 several areas along the banks of the South Ditch near the eastern portion of the site were excavated using a backhoe contracted through ENV Environmental International of Richmond, California. The exploratory excavation work was conducted to provide preliminary information regarding the lateral and vertical extent of the embedded automotive debris observed in the surficial soil. The backhoe excavation was directed in the field based on visual observations of the surface and subsurface conditions that were encountered. Eighteen separate excavations were made, and the approximate areas of excavation are depicted on Figure 2. As shown, seven excavations were made along the north bank of the ditch (N-1 through N-7) and nine were made along the south bank (S-1 through S-9). Additionally, two excavations were made along the chain-link fence adjacent to the opposite side of the road that extends along the south side of the ditch (F-1 and F-2). The excavations ranged from one to three feet deep and extended a maximum of 610 feet west of the east site boundary on the north bank and 980 feet west of the east site boundary on the south bank. The excavations determined that the automotive debris is typically about six inches thick along the north bank,with a maximum thickness of approximately one foot found in excavation N-4 (see Figure 2). Along the south bank the debris is also typically about six • inches thick, with an approximately two-foot-thick zone in the areas of S-2 and S-3. The 704. PRI.05 17 July 21, 2008