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` Phase 11 Environmental Site Assessment Report-Executive Sununary
<br /> 1025 East Main Street,Stockton,San Joaquin County,California
<br /> Page 6
<br /> ►. angular rock]; slightly moist, medium stiff, dark brown clay at 4 to 5 feet bgs [95% clay and 5% coarse
<br /> sand].
<br /> 1
<br /> ` Boring 3 -Poorly graded gravel and slightly moist brownish gray clay at 0 to 2.5 feet bgs [40% clay and
<br /> 60% angular rock]; slightly moist reddish brown gravelly clay at 2.5 to 4 feet bgs [60% clay and 40%
<br /> angular rock]; slightly moist reddish brown clay at 4 to 7 feet bgs [85% clay and 15%coarse sand].
<br /> 4
<br /> Boring 4 - Poorly graded gravel and slightly moist brownish gray clay at 0 to 2 feet bgs [45% clay and
<br /> 55% angular rock]; slightly moist reddish brown gravelly lean clay at 2 to 4 feet bgs [65% clay and 35%
<br /> Langular rock]; slightly moist, medium stiff dark brown clay at 4 to 5 feet bgs [85% clay and 15% coarse
<br /> sand].
<br /> 4.2 SOIL HAND AUGER SAMPLES
<br /> There was approximately 2 to 3 feet of aggregate base rock present in the western portion of the property
<br /> (rail spurs). A breaker bar was used in order to reach the subsurface sampling depths. A significant
<br /> ` amount of aggregate base rock (3-4 feet bgs) was also present at the former Western Pacific Railroad
<br /> tracks located on the eastern portion of the property. Surface soil samples collected from the former
<br /> WPRR tracks were prepared in the field by separating out aggregate from soil materials before
<br /> transferring soil to the sampling jars. In some areas of the depot's perimeter, non-native sandy soil at the
<br /> surface 0 to 2 feet bgs and native soils was observed at 2-3 feet bgs at the time of soil sampling.
<br /> 5.0 LABORATORY ANALYTICAL RESULTS
<br /> All laboratory analytical results are summarized in Tables 3 through 6, below, and Figures 4 through 7,
<br /> Appendix A. In addition, laboratory analytical reports, certificates of analyses, and chain of custody
<br /> records are provided in Appendix B.
<br /> 5.1 SOIL SAMPLES
<br /> L 5.1.1 Metals
<br /> Rail Spurs
<br /> r L
<br /> Figure 4, Appendix A and Table 3 (following page) summarize the laboratory analytical results for lead
<br /> and arsenic.. Lead was detected in surface soil samples RS 1-0, 2-0, 3-0, and 4-0 at 39, 100, 61, and 370
<br /> mg/kg, respectively. Arsenic was detected in surface samples RS 1-0, 2-0, 3-0, and 4-0 at 5.1, 9.0, 5.3,
<br /> and 13 mg/kg, respectively. Lead was detected in subsurface samples RS 1-1, 2-1, 3-1.5, and 4-3 at 42,
<br /> 130, 120, and 250 mg/kg, respectively; and arsenic was detected in the same subsurface samples at 8.2,
<br /> 4 11, 11, and 17 mg/kg,respectively.
<br /> Former Western Pacific Railroad Tracks
<br /> Lead was detected in surface samples WP 1-0 and WP 2-0 at 350 and 94 mg/kg,respectively; and arsenic
<br /> Lwas detected in the same samples at 40 and 11 mg/kg,respectively. Subsurface samples from Borings 133
<br /> and 134 yielded the following results: lead was detected in subsurface samples B 3-3 and B 4-3 both at 24
<br /> mg/kg; and arsenic was detected in samples B 3-3 and B 4-3 at 32 and 10 mg/kg,respectively. Please see
<br /> Figure 6,Appendix A,and Table 3, for a summary of analytical results.
<br /> Depot Building
<br /> Lead was detected in surface soil samples DSE-0, DNE-0,DN-0,DNW-0,DSW-0, and DS-0 at 500,200,
<br /> L 160, 250, 240, and 840 mg/kg, respectively. Lead was detected in subsurface soil samples DSE-2, DN-
<br /> 1.5, DNW-2, and DSW-2 at 96, 40, 45, and 36 mg/kg, respectively. Results are summarized in Figure 5,
<br /> L
<br /> w
<br /> Lt.J CONDO
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