ARCHIVED REPORTS_XR0008078 - Laserfiche WebLink

Home Browse Search

' 08 July 2003 • AGE-NC Project No 96-0229 ' Page 3 of 5 ' Ground water elevations were calculated to be between 19 27 feet(MW-5)and 20 97 feet(MW-12) below mean sea level (MSL), the ground water elevation Increased an average of 1 07 feet between the November 2002 and the February 2003 ground water monitoring events The ground water ' surface elevation at the site was within the screened Intervals of wells MW-2 through MW-10A, MW-1I and MW-12 but was approximately 17 and 19 feet above the screen Intervals in wells MW-1 and MW-1 OB, respectively The ground water elevation data for MW-2 through MW-12 during the February 2003 ground water monitoring event is depicted and contoured In Figure 3, elevation data for deep-screened wells MW-1 and MW-I OB were not used to determine ground water gradient because these elevations may be representative of deeper ground water conditions ' The general ground water gradient at the site was calculated to be approximately 0 004 fl/fl or less, or approximately 21 feet per mile, and inferred to be flowing towards the northeast 3 2 LABORATORY RESULTS OOF GROUND WATER SAMPLES iA total of thirteen ground water samples were submitted to McCampbell Analytical Inc (MAI) a DHS-certified laboratory in Atwater, California ' TPH-g was detected In water samples collected from wells MW-1,MW-2,MW-3,MW-6 and MW-9 at concentrations between 2,800 micrograms per liter(µg11) in well MW-9 and 76,000µg/l in well MW-2 BTEX constituents were detected in ground water samples collected from the same wells at a maximum concentration of 16,000 µg/1 (xylene, MW-6), the highest benzene concentration was detected in sample MW-1 at a concentration of 4,400 µg/1 MTBE was detected by EPA Method 8260B in ground water samples collected from wells MW-1, MW-6, MW-7, MW-9, MW-IOA,MW-IOB and MW-11 at a maximum concentration of 660 µg/1 (MW-6), 1,2-DCA was detected in samples collected from wells MW-1 and MW-10B at concentrations of 110 µg11 and 0 71 µg11, respectively No other constituents of concern were detected above laboratory reporting limits in the analyzed Isamples Previous and current analytical results of ground water monitoring well samples are summarized in Tables 3 and 4 The laboratory reports (MAI Work Order 0302345) and chain-of- custody forms are presented in Appendix C • Advanced GeoEnvironmentai,Inc I