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1 <br />' 22 April 2002 <br /> AGE-NC Project No 98-0511 <br /> Page 4 of 7 <br />' 3.0. FINDINGS <br /> Shallow site stratigraphy and ground water elevation and flow direction were determined from field <br /> data Hydrocarbon-Impact to soil and ground water was Inferred from laboratory analysis of the soil <br /> and ground water samples <br /> 1 3 1 SOIL PROFILE <br /> A general subsurface soil profile was developed for the site based on the bonng-log soil descriptions, <br /> supplemented by boring logs from two Additional Site Assessment Report dated 03 April 2000 and <br /> 30 November 2000 The soils were grouped Into four units separated by distinct, approximately <br /> 2-foot-thick clay layers Cross-sections are provided in Figures 3 and 4, a copy of the boring logs are <br /> included In Appendix C <br />' The upper 13 feet bsg of soil consisted dominantly of yellowish brown to olive,silty to medium sand <br /> (Unit 1) with the exception of the fill material in the former excavation, which was described as <br />'. poorly-graded backfill material of sand, silt and clay to a depth of approximately 20 feet bsg <br /> Underlying the surface sand was an approximately 2-foot thick,apparently laterally continuous clay <br /> layer(Clay 1),which in tum overlies a silt layer with interfingenng lenses of sand from the north and <br /> west sides of the site (Unit 2), Unit 2 shows apparent thickening towards the north and west <br /> Below approximately 20 feet bsg,the soil layers appear to dip gently towards the north and west,an <br />' apparent dip of approximately 0 05°was measured on a 2-foot thick,continuous clay layer(Clay 2) <br /> at the base of Unit 2 <br /> Unit 3 is a gently-Inclined unit underlying Clay 2 which thickens towards the north and west, it Is <br /> dominantly composed of sand on the south and east portions of the site, but appears to transition to <br /> silt towards the north and west portions Unit 4 appears to be composed of silt with thin, <br /> discontinuous clay and sand lenses <br />' 32 FIELD EVIDENCE OF HYDROCARBON-IMPACTED SOIL <br /> The OVM detected organic vapor above background in soil sample duplicates B-5-40 and B-5-50, <br /> B-6-15 through B-6-35, and B-9-15 through B9-25 The maximum organic vapor concentration <br /> detected from each boring was 69 parts per million(ppm)from sample B-5-50,74 ppm from B-6-15 <br /> and 175 ppm from B-9-20 Additionally, a strong petroleum hydrocarbon-like odor was detected <br />' from samples B-5-5 and B-9-20 and slight hydrocarbon-like odor was detected from samples B-5-50 <br /> and B-9-25 <br /> Advanced Gen Environmental,Inc <br />