ARCHIVED REPORTS_XR0012025 - Laserfiche WebLink

Home Browse Search

08 July 1999 AGE-NC Project No 95-0130 Page 4 of 5 ' 4.0. DISCUSSION AND CONCLUSIONS Based upon data collected during the March 1999 monitoring event, AGE concludes • Ground water was inferred to be flowing toward the northeast in the area containing wells MW-1 through MW-5 and flowing toward the northeast at a calculated gradient of 0 007 ' Wft,or approximately 37 feet per mile (Figure 3) 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 iGround water flow direction in the area bound by wells V W-1 C, VW-2A and VW-3A appeared to have a southwesterly gradient and was contrary to surrounding ground water ' flow direction bound by wells MW-1 through MW-5 Ground water elevations calculated from VW-1C, VW-2A and VW-3A were not utilized to contour ground water elevations in Figure 3 ' • Between the December 1998 and March 1999 ground water monitoring events, ground water elevation increased an average 1 79 feet at the site, a trend of increasing ground water elevations has been observed at the site at least since January 1995 • Theround water g surface elevation at the site is approximately 12 feet to 23 feet above the ' slotted screen intervals in wells MW-1 through MW-5 and approximately 4 feet to 10 feet above the slotted screen intervals in wells VW-1C, VW-2A and VW-3A Therefore these wells are "drowned", and yield samples representative of deeper screened ground water ' • TPH-g was detected in water samples collected from wells MW-I through MW-5, VW-1 C, VW-2A and VW-3A at concentrations as high as 240,000 ug/1, respectively The laboratory ' noted unmodified or weakly modified gasoline was significant at each sample • MTBE was detected in wells MW-2, MW-3, VW-I C,VW-2A and VW-3A at concentrations ranging as high as 4,400 ,ug/l • RIPE was detected in a water sample collected from MW-2 at a concentration of 1 7 ,ug/1, TBA was detected in a water sample collected from well MW-3 at a concentration of 47,ug/l • BTEX compounds were detected in wells MW-I through MW-5,V W-1 C,VW-2A and VW- 3A at concentrations ranging as high as 41,000 kcg/l (benzene and toluene, VW-1C) • From December 1998 to March 1999, a substantial increase in dissolved petroleum hydrocarbon concentrations were detected in samples from wells MW-1, MW-2, MW-3 and MW-4 (Table 2) Conversely, a substantial decrease in dissolved hydrocarbons were observed from well MW-5 • The elevated concentrations of petroleum hydrocarbons detected in samples collected from Advanced GeoEwswonmental,Inc