ARCHIVED REPORTS_XR0005066 - Laserfiche WebLink

Home Browse Search

' 27 June 2002 AGE-NC Project No. 98-0520 ' Page 5"of 8 3.1. SOIL PROFILE A general subsurface stratigraphy was developed for the site based on the well-log soi I.descriptions, supplemented by boring logs from the Preliminary Investigation and Evaluation Report and the ' .Quarterly Report-Fourth Quarter 1999, dated 25 April 2000. Based on the boring log descriptions, three soil layers were defined: ' The uppermost layer (Layer l) consisted of approximately 20 feet of yellowish to brownish green, generally unconsolidated, fine to medium sand. ` ' The second layer(Layer 2)was identified between 15 feet and approximately 20 feet,below surface grade(bsg), and appears to be an approximately 15-foot thick clayey silt;towards the north,the soil ' appears to transition into a sandy silt or silty sand with clay. Beneath former USTs No. 1 and 2,a ' discontinuous lense of green to olive gray fine sand was identified near the top of layer 2. ' The third layer(Layer 3),below 35 feet bsg, appears to be an olive green to brown,unconsolidated coarse to pebbly sand;this layer was defined on the basis of the two deepest soil borings(MW-6 and B-1) located at the former USTs' No. 1 and 2, respectively(Figure 2). Geologic cross sections are provided in Figures 3 and 4; boring logs are'provided in Appendix A. , 3.2. FIELD EVIDENCE OF HYDROCARBON-IMPACTED SOIL - ' The OVM detected organic vapor above background in soil sample duplicates.MW-6-35,MW-8-20 and MW-9-20; the maximum organic vapor concentration detected was 72 parts per million(ppm) from sample MW-9-20. Additionally,a strong petroleum hydrocarbon-like odor was detected from ' samples MW=6-35 and MW-9-20 and -25, a moderate hydrocarbon-like odor .detected from MW-8-20, and a slight odor from MW-6-40 and -50, MW-8-30 and -35, MW-9-30 and -35, and ' MW-10-20, 25 and 30. PID data is included on the boring logs (Appendix A). ' 3.3, RESULTS OF SOIL SAMPLE ANALYSIS No petroleum hydrocarbon compounds were detected in any of the' sail`samples analyzed from boring MW-10. TPH-g was'detected in soil sample MW-8-30 and MW-9-20 at concentrations of 15 and 130 milligrams per kilograms (mg/kg), respectively. TPH-.d was detected in soil sample MW-6-35 and MW-9-20 at concentrations of 1.2 and 150 mg/kg,respectively. In addition,TPH-mo ' was detected in sample MW-9-20 at 10 mg/kg. Advanced GeoEnvironmentai,Inc.