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Page 2 West Lauffer Road February 29,2008 referenced Phase I study included recommendations for the collection of soil samples from the tank area for laboratory analysis. Further, we understand that our Phase I report was submitted to the San Joaquin County Environmental Health Department as part of a tentative map review process. The County prepared a letter dated March 27, 2006 indicating that Phase II soil sampling/testing in the vicinity of the diesel tank was required. hi April 2006, our firm collected several near-surface soil samples in the vicinity of the above-ground diesel tank; the locations of the soil samples are shown on Plate 2 and the results are summarized on Table I. Laboratory analysis revealed that some of the samples contained diesel at concentrations above the laboratory reporting limits.Z Our site observations and the sampling results generally indicated that the extent of diesel-impacted soils was limited. However, considering the planned residential redevelopment of the property,we indicated that remedial removal of contaminated soils was warranted. We understand that the above-ground diesel tank was removed and initial excavation of diesel-impacted soils was in late 2007. Subsequently, we were contacted to perform clearance soil sampling. SOIL SAMPLING AND ANALYTICAL TESTING On January 3, 2008, our representative performed reconnaissance of the remedial excavation within the vicinity of the former above-ground diesel fuel tank, and we collected shallow soil samples at the locations shown on Plate 2 (S9 through S14). The soil samples were collected in brass sleeves and secured with Teflon tape and plastic end caps. Each sample was assigned a discrete sample number, placed on ice, and transported with chain-of- custody documentation to a State-certified laboratory for analysis for total petroleum hydrocarbons (TPH) as diesel, and select samples for benzene, toluene, ethyl-benzene, and xylenes (BTEX). The results of the soil analyses are summarized on the attached Table 1. Copies of the laboratory report and chain-of-custody documentation also are attached. Based the January 2008 sampling data and our site observations, it appeared that elevated concentrations of diesel-range petroleum hydrocarbons were present at some of the limits of the initial remedial excavation; we recommended additional remedial excavation. Further excavation within the former tank area was performed on February 8, 2008; our representative observed the additional excavation activities and collected additional soil samples at the final limits of the excavation. The February soil sampling locations are shown on Plate 2, and the laboratory results are summarized on Table 1. Upon completion of the remedial soil removal, soils at the limits of the excavation did not exhibit diesel staining or odor. 2 Raney Geotechnical,Inc.;"Soil Sampling and Laboratory Analysis,Vicinity of Above-Ground Fuel Tank, APN 001-030-04,West Lauffer Road,Thornton,California";April 24,2006;Reference No.2836-001.