Laserfiche WebLink
' 06 November 2002 <br /> AGE-NC Project No 95-0137 <br /> ' Page 5 of 7 <br /> ' where M= cumulative mass recovered (kg) <br /> C = soil-vapor concentration (kg/m') <br /> Q =extraction flow rate (M3/hr) <br /> ' t= operational period, in hours <br /> The estimated mass of hydrocarbons removed was based on laboratory analysis of soil-vapor <br /> samples, the flow rate and operational time The operational time for the quarter was divided Into <br /> three time periods The mass of extracted hydrocarbons was calculated for each time period using <br /> average Influent soil-vapor sample hydrocarbon concentrations and average air flow rates The <br /> ' operational results are summarized on Table 1 <br /> A total of 35 2 kg, 80 5 lbs or 12 4 gallons hydrocarbons as gasoline were removed and destroyed <br /> ' by the SVE network between 13 June and 19 September 2002 The volume and mass calculations <br /> are attached In Appendix',1,41 3 <br /> ' 3 4 GROUND WATER GRADIENT AND FLOW DIRECTION <br /> ' Depths to ground water during September ranged from 21 56 to 22 61 feet below the well casing <br /> tops The relative ground water elevations ranged from 76 92 feet(MW-4) to 77 04 feet (MW-5), <br /> decreasing an average of one foot over the second quarter 2002 (Table 4) <br /> ' A contoured ma of ground water elevations Infers an outward-radiating flow pattern, fro a <br /> p � g P > <br /> ' northerly flow at the eastern portion of the site to a northwest flow at the western portion(FigureAl <br /> the hydraulic gradient was very gentle, ranging from 0 001 foot/foot on the western part of the site <br /> to less than 0 0004 foot/foot on the northern part <br /> 1 <br /> 3 5 ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br /> ' Laboratory analytical results of ground water samples from monitonng wells MW-1 through MW-5 <br /> are provided for the third quarter 2002 monitoring events <br /> 1 TPH-g was detected in four of the five ground water samples collected from the site, at <br /> concentrations ranging from non-detection in sample MW-5 to 1,700µg/1 in samples MW-2,TPH-d <br /> ' was detected in all of the ground water samples at concentrations ranging from 340 gg/l in samples <br /> MW-4 to 4,500 µg/1 in MW-3 <br /> ' BTEX compounds were detected in water sample collected from mor_itonng wells MW-1 through <br /> MW-4 at concentrations as high as of 47 µg/1, 5 1µg/1, 96 µg/1 and 51 µg/l, respectively(MW-2) <br /> 'v <br /> Advanced Geo Environmental,Inc <br /> 1 <br />