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1 29 December 1999 AGE-NC Project No 98-0465 Page 2 of 9 xylenes (BTEX) were detected at concentrations up to 0 29 mg/kg, methyl tertiary butyl ether (MTBE)was detected in soil samples at concentrations up to 0 54 mg/kg Analytical results of soil samples collected during tank removal activities are summarized in Table 1 Laboratory analysis of three grab ground water samples collected beneath the former UST areas detected dissolved TPH-g at concentrations up to 5,900 µg/1 (micrograms per liter), BTEX compounds were detected in grab ground water samples at concentrations up to 0 29 4g11, methyl tertiary butyl ether(MTBE)was detected in grab ground water samples at concentrations up to 0 54 µg/1 Analytical results of soil samples collected during tank removal activities are summarized in Table 2 23 REGIONAL GEOLOGIC SETTING The property is situated within the Great Valley Geomorphic Province of California, a large, elongate, north-northwest trending, asymmetric structural trough The Great Valley Province has been filled with thick sequences of sediment ranging in age from Jurassic to Recent, creating a nearly . flat-lying alluvial plain, extending from the Tehachapi Mountains in the south to the Klamath Mountains in the north The western and eastern boundaries of this province are comprised of the California Coast Range and the Sierra Nevada, respectively Rocks composing the basement complex of the province have not been completely defined but are believed to be metamorphic and igneous in origin The northern and southern portions of the Great Valley Province have been designated the Sacramento and San Joaquin Valleys, respectively Based on the General Soil Map from the San Joaquin County Soil Survey, published by the United States Department of Agriculture Soil Conservation Service in 1992, the site area is within the Jackson-Hallenbeck-Stockton (JHS) association The JHS soils are located within basins, and generally consist of moderate to poorly drained fine textured soils The soils are generally derived from both marine and non-marine sediment, and are generally formed in alluvium derived from mixed rock sources The Modesto, Riverbank, Turlock Lake Formations and overlying recent alluvium are the principal source of domestic ground water to the 13,500 square-mile San Joaquin Valley Ground Water Basin (Basin 5-22) This basin is drained primarily by the San Joaquin River The nearest surface water feature in the vicinity of the property is the Smith Canal located approximately 1,000 feet south of the site Advanced Geo Environmental,Inc