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<br /> 31 October 2005
<br /> AGE-NC Project No 03-1080
<br /> Page 4 of 10
<br /> sample BI-15 at a concentration of 0 51 mg/kg TPH-g- and TPH-d-range hydrocarbons were
<br /> 1 detected in ground water sample BI-GW at concentrations of 2,100 µg/1 and 7,200 µg/l,
<br /> respectively, in addition, ethylbenzene, xylenes, MTBE, and 1,2-DCA were detected in sample
<br /> B 1-GW at concentrations of 7 9µg/1 and 63 µg/1, 18µg11,and 2 7µg/l,respectively No constituents
<br /> ' of concern were detected in grab ground water samples collected from borings 132 and 133 Analytical
<br /> results of soil and grab ground water samples are summarized in Tables 2 and 3, respectively
<br /> 1 3.0. SOIL PROPERTIES
<br /> ' From surface grade to approximately 10 feet bsg, dark to light brown silty sand was encountered in
<br /> all three bore holes(B 1 through 133),characteristically,the material was fine-grained,poorly graded,
<br /> and moist This material extended to 15 feet bsg in B 1,while gray-brown clayey silt and silt with low
<br /> plasticity,low to moderate consistency,and low toughness were encountered in 132 and 133 at 15 feet
<br /> bsg At 19 5 feet bsg, a thin layer of moist, orange-brown and gray-brown fine-grained soil was
<br /> encountered in borings 131, B2, and 133 This material was characterized by low plasticity, low to
<br /> moderate consistency, and low toughness At approximately 20 feet bsg, a layer of light brown and
<br /> orange-brown, fine- and medium-grained silty sand and clean sand was identified At 25 feet bsg,
<br /> ' . a distinctive layer of orange, dark brown,and gray-brown clay and clay with silt was encountered
<br /> This clay had low plasticity, moderate to high consistency, and low to moderate toughness At
<br /> 30 feet bsg in all three borings, gray and orange-brown silty sand and sandy silt were encountered
<br /> ' This material extended to 35 feet bsg in 132 and 133 At 35 feet bsg in 131, orange-brown silty clay
<br /> of moderate plasticity and consistency and low toughness was identified At 40 feet bsg in B 1,gray-
<br /> brown silt with low plasticity and moderate consistency and toughness was encountered Soil boring
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<br /> ' logs are provided in Appendix D Cross-sections A-A'and B-B' (Figures 3 and 4,respectively)were
<br /> constructed to exhibit the general llthology beneath the site
<br /> " 4.0. PETROLEUM HYDROCARBON - IMPACTED SOIL AND GROUND WATER
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<br /> ' During dispenser upgrade In January 2003, a total of eleven soil samples were collected from the r
<br /> dispenser area and analyzed, laboratory analysis detected petroleum hydrocarbons in the samples
<br /> collected from dispenser D 1 (6,100 mg/kg TPH-g,8,500 mg/kg TPH-d, 11 mg/kg ethylbenzene,and
<br /> ' 137 mg/kg xylenes) and dispenser D4 (110 mg/kg TPH-d, 0 005 mg/kg toluene, and 0 006 mg/kg
<br /> xylenes), and from soil stockpile SP2A-2B (0 019 mg/kg MTBE and 0 16 mg/kg TBA)
<br /> ' In August 2004, soil bonngs B1 through 133 were advanced at the dispenser area,ten soil samples
<br /> and three grab ground water samples were collected and analyzed for petroleum hydrocarbons
<br /> TPH-g, TPH-d, and xylenes were detected in a soil sample collected from boring 131 at 15 feet bsg
<br /> (B1-15) at concentrations of 250 mg/kg, 190 mg/kg, and0 51 mg/kg, respectively TPH-g, TPH-d,
<br /> ethylbenzene, and xylenes were detected in the ground water sample collected from boring 131
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<br /> ' Advanced GeoEnvironmental,Inc
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