ARCHIVED REPORTS_XR0005438 - Laserfiche WebLink

Home Browse Search

13 December 1999 AGE-NC Project No 95-0173 ' Page 3 of 5 ' 3 1 RELATIVE GROUND WATER ELEVATION AND GRADIENT M During the October 1999 monitoring event, depths to ground water in wells MW-1 through MW-12, ' VW-1,VW-2, AW-1B and AW-2B were measured between 24 40 and 26 87 feet below the tops of well casings, ground water elevations were calculated to be between 15 78 feet and 16 83 feet below mean sea level Ground water elevation at the site decreased an average 1 60 feet between the July and the October 1999 ground water monitoring events The ground water elevation data for MW-1 through MW-12 during the October 1999 ground water monitoring event is depicted in Figure 3 Ground water flow direction for the area bound by wells MW-1 through MW-8 and MW-12 was generally toward the east-northeast at a gradient of 0 003 ft/ft, or approximately 15 feet per mile (Figure 3), ground water flow direction for the area bound by wells MW-9,MW-10 and MW-11 was generally toward the north-northeast at a gradient of 0 003 ft/ft Ground water was approximately 24 and 34 feet above the screen intervals at AW-1B and AW-213, respectively, therefore these wells are "drowned" and yield samples more representative of deeper screened ground water Due to the low gradient at the site, slight variations in ground water measurements or changes of recharge/discharge of the local ground water could greatly modify ground water flow direction 3 2 LABORATORY RESULTS OF GROUND WATER SAMPLES A total of fifteen ground water samples were submitted to a DHS-certified laboratory in October 1999 TPH-g was detected in water samples collected from wells MW-1 through MW-4, MW-6, MW-9, MW-12, VW-1, AW-IB, and AW-2B at concentrations ranging up to 260,000 micrograms per liter(ug/1) TPH-d was detected in water samples collected from wells MW-1 through MW-4, MW-6,MW-9,MW-11,MW-12,VW-1,AW-1B, and AW-2B at concentrations ranging up to 9,800 ,ugll, however, the laboratory reported that the diesel chromatograms for the samples did not have typical diesel characteristics BTEX compounds were detected in ground water samples collected from wells MW-1 through MW- 4, MW-6, MW-7, MW-9, MW-10, VW-1, AW-IB, and AW-2B at concentrations ranging as high as 67,000,ug/1(toluene, VW-1) The greatest benzene concentration was detected from well AW-1B at a concentration of 20,000 ,ug/l MTBE was detected in ground water samples collected from wells MW-2,MW-3,MW-4 and VW-1 utilizing EPA Method 8260 at concentrations as high as 85 ,ug/l,TBA was detected from wells MW- IAdvanced Geo E nviron mental,Inc