ARCHIVED REPORTS_XR0005711 - Laserfiche WebLink

Home Browse Search

02 November 2001 . AGE-NC Project No 95-0173 Page 4of8 20 and 21 June 2001, the contaminant impact to ground water was assessed from the ground water laboratory data From field and laboratory data collected at the SVE remediation system between 01 April and 30 June 2001, AGE deter mined the average TPH-g concentration, the average flow rate and calculated the approximate mass and volume of hydrocarbons removed 4 1 GROUND WATER ELEVATION AND GRADIENT During the June 2001 ground water monitoring event, depths to ground water in the monitoring wells were measured between 24 05 and 26 57 feet below the tops of well casings, ground water elevations were calculated to be between 15 43 feet and 16 54 feet below mean sea level Ground water elevation at the site decreased an average 0 72 feet between the March 2001 and the June 2001 ground water monitoring events The ground water elevation data for the June 2001 ground water monitoring event is depicted in Figure 3 Ground water flow diiection at the site was inferred to be toward the northeast at a gradient of 0 005 ft/ft or less, or appi ox i mate ly 26 feet per mile (Figure 3) 42 LABORATORY RESULTS OF GROUND WATER SAMPLES A total of sixteen giound water samples were submitted to a DHS-certified laboratory for analysis TPH-g was detected in ground water samples collected from wells MW-1, MW-2, MW-3, MW-4, MW-6,MW-9,MW-13,AW 1 A,AW-1B,AW-2A and AW-213 at concentrations as high as 220,000 micrograms per liter (µg/l), the greatest TPH-g concentrations were detected in the sample from AW-lA BTEX compounds weie detected in ground water samples collected from wells MW-1, MW-2, MW-3, MW-4, MW-6, MW-13, AW-IA, AW-1B,AW-2A and AW-2B at concentrations as high as 50,000 µg/1 (toluene, AW-IA) The greatest benzene concentration was detected from AW-lA at a concentration of 20,000µg/l MTBE was detected in thesam round water les collected fiom wells MW-5 and MW-11 at g P concentrations as high as 1 4 ,ug/l, DIPE was detected in a sample collected from well MW-5 at a concentration of 0 36 µg/l, 1,2-DCA was detected in samples collected from wells MW-2, MW-3, MW-4 and MW-5 at concentrations as high as 20 ,ug/1 No other fuel oxygenated compounds were detected in any other ground water samples Previous and current analytical results of ground water monitoring well samples are summarized in Tables 2 and 3, the estimated extent of dissolved petroleum hydrocarbons is depicted in cross sectional view C-C' (Figure 5) The laboratory reports Advanced GeoEnvironmental,Inc