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' 08 November 2005 i AGE-NC Project No. 98-0481 ' Page 4 of 8 On 28 January 1999, two soil samples (SP-6 and SP-7) were collected from the stockpile of soil ' generated during the UST removal;the stockpile had been left to aerate since 1997. There were no reported detections of BTEX, TPH-g, or fuel oxygenating compounds in the soil samples. Insignificant levels of TPH-d were detected in samples SP-6 (3.5 mg/kg) and SP-7 (1.2 mg/kg). Also,low levels of metals were detected in the samples. Based on the soil sample analytical results, the SJCEHD concurred that no further action was required for the soil stockpile. Subsequently,the soil stockpile was apparently spread across the parcel. The laboratory analytical results for the stockpile soil samples were attached to the AGE-prepared Additional Site Assessment Work Plan, dated 22 February 2000. On 01 February 1999, during the repair of the product line, AGE utilized a hand auger to advance soil boring HA-1 for collection of two soil samples from beneath the area of the product line rupture; the soil samples were collected at depths of 6 feet bsg and 7.5 feet bsg utilizing a slide-hammer. Laboratory analysis detected low concentrations of BTEX, TPH-g, and MTBE in the samples (Table 2). Additional information and the laboratory analytical report were presented in the AGE- prepared Additional Site Assessment Work Plan, dated 22 February 2000. In March 2000, two soil borings (SB-3 and SB-4) were advanced at the site to assess petroleum ' impacts to ground water and further assess petroleum impacts to soil at the former fuel dispenser Iocation. As shown on Figure 2, borings SB-3 and SB-4 were located immediately north and northwest of the former fuel dispenser location. Soil Boring SB-3 was advanced to a depth of 23 feet ' bsg before encountering auger refusal; boring SB-4 was advanced to depth of 60 feet bsg. Soil samples were collected at 20 feet bsg in boring S13-3 and 50 and 60 feet bsg in boring SB-4, and a grab ground water sample was collected from boring SB-4. Laboratory analysis did not detect any BTEX compounds,TPH-d,TPH-g,or fuel oxygenating compounds in any of the soil samples or the ground water sample collected for analysis (Table 3). Additional information is presented in the AGE-prepared Preliminary Investigation and Evaluation Report, dated 28 August 2000. 2.4. REGIONAL SETTING The property is situated within the Great Valley Geomorphic Province of California, a large, ' elongate, 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. • ' Advanced GeoEnAronmental,Inc..