ARCHIVED REPORTS XR0003466 - Laserfiche WebLink

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The results of the laboratory analysis of soil samples are summarized in Table 1 , while the official laboratory reports and chain of custody records are included in Appendix C. 3 .0 DISCUSSION OF RESULTS Nineteen soil samples were analyzed for hydrocarbon constituents . The results of the field activities and laboratory analyses of soil samples collected during this investigation are discussed below. • Ground water was encountered at a depth of approximately 18 feet below grade an Boring B-1 . Subsequent borings were drilled to a maximum depth of 16 . 5 feet. • Soil types encountered during drilling and sampling generally consisted of silty clay from below the asphalt surface to a depth of 7 to 13 feet grade, underlain by sandy salt to silty sand. Poorly graded sand was encountered at depths of 13 to 18 feet below grade in those borings drilled to sufficient depths . • TOG was not detected above reported detection limits in any of the soil samples analyzed from Borings B-1 or B-2 an the vicinity of the underground waste oil tank. • TPH-G was detected in Borings B-6 and B-7 at depths of 10 to 11 feet below grade at concentration of 4 . 6 and 300 parts per million (ppm) . BTEX constituents were additionally detected in Borings B-8 , B--9, and B-10 at depths of 10 to 15 feet below grade. 4 .0 FINDINGS AND CONCLUSIONS The findings and conclusions of this preliminary site assessment are summarized below. • Since soil samples cannot be collected directly beneath the existing dispenser islands and service station building from vertical borings , the extent of hydrocarbons in the subsurface soil above stabilized ground water at these locations cannot be fully assessed at this time. • Based on the results of this preliminary assessment, significant concentrations of petroleum hydrocarbon constituents appear to be limited to the southwestern is 3