ARCHIVED REPORTS_XR0012041 - Laserfiche WebLink

Home Browse Search

01 March 2002 AGE-NC Project No 95-0130 Page 8 of 10 between 30 and 35 feet bsg, 50 and 55 feet bsg, 70 and 77 feet bsg and 138 and 145 feet bsg, semi-permeable silty fine sand was observed at depths between 35 and 40 feet bsg, 45 and 50 feet bsg, 95 and 100 feet bsg and between 137 feet and 142 feet bsg, less permeable silty clay and clayey silt were observed at all other depths (Figures 3 and 4, Appendix B) • Saturated soil was encountered in MW-6 at a depth of 40 feet bsg, boring logs are included in Appendix B • TPH-g and BTEX-impacted soil was encountered from MW-6 at depths between 37 and 73 feet bsg, the greatest magnitude of impacted soil was encountered at 43 feet bsg (Table 1, Figure 9) • MTBE-impacted soil was encountered from MW-6 at depths between 37 and 43 feet bsg,the greatest magnitude of impacted soil was encountered at 43 feet bsg (Table 1, Figure 9) • AGE Installed five screen intervals at wells MW-6 and MW-7 identified as Intervals A, B, C, D and E at depths between 35 and 45 feet bsg (A), 50 and 55 feet bsg (B), 70 and 75 feet bsg(C), 100 and 110 feet bsg (D) and 125 feet and 142 feet bsg(E) Monitoring well details are summarized in Table 3 �. • TPH-g and BTEX-impacted ground water was encountered from MW-6 (B, C, D and E) at concentrations as lugh as 7,900 (MW-6B), the greatest benzene concentration was detected from MW-6B at a concentration of 2,200 Mg11 I • TPH-g and BTEX-Impacted ground water was encountered from MW-7 (B, C, D and E) at concentrations as high as 160,000,ug/l (MW-7B), the greatest benzene concentration was detected from MW-7B at a concentration of 38,000µg11 • MTBE-Impacted ground water was detected from MW-6 (B and C) and MW-7 (B) at concentrations between 35,ug/l and 420,ug/l, very minor MTBE-impacted ground water was detected from MW-7B and MW-7C at concentrations as high 2 8 ,ug/l • 1,2-DCA-impacted ground water was detected from MW-6B and MW-7B at concentrations of 37 kzg/l and 210 ,ug/l, respectively, very minor 1,2-DCA-impacted ground water was detected from MW-6C at a concentration of 1 1 ,ug/l • The estimated extent of on-site petroleum hydrocarbon-impacted soil is depicted in geologic cross sections B-B'and C-C'(Figures 9 and 10, respectively) Compilation of all laboratory data acquired to date shows that the more Intensely petroleum-Impacted soil is located between 15 and 50 feet bsg and significantly less Intensely petroleum-impacted soil-impact is located between 50 and 80 feet bsg • The estimated extent of on-site petroleum hydrocarbon-impacted ground water is summarized in Table 2 The greatest area of petroleum-Impacted ground water appears to be located at MW-7B (50 to 55 feet bsg), significant ground water-impact was detected at Advanced GeoEnvironmental,Inc i I