ARCHIVED REPORTS_XR0005327 - Laserfiche WebLink

Home Browse Search

• 20 August 2002 AGE-NC Project No. 95-0185 Page 3 of 4 ' The relativeound water iter elevation at the site ranged from 36.68 feet(MW-2)to 36.70 feet(MW-1). The ground water flow direction determined during this monitoring event was toward the southwest with a hydraulic gradient of 0.00025 feet/feet. The relative ground water elevations at the site are contoured on Figure 3. 3.2. GROUND WATER ANALYTICAL RESULTS ' TPH-d was detected in ground water samples collected from wells MW-1 through MW-4 at concentrations of 3,700 micrograms per liter (ug/1), 1,300 µg/l, 680 µg/l, and 450,000 Rg/l, ' respectively. TPH-g was detected in ground water sample MW-1 and MW-4 at concentrations of 180 gg/l and 9,000 µg/1, respectively. Benzene and ethylbenzene were detected in the ground water sample from well MW-4 at concentrations as high as 3.5gg/l, and toluene was detected in sample MWA at a concentration of 0.83 gg/l. '• MTBE was detected ins le MW-4 b EPA Method 8260B at a �P y concentration of 3.4 gg/l. ' No other target analytes were detected in the analyzed samples. Current and previous analytical results are sunmTkuized in Tables 2 and 3. The laboratory report(MAI Laboratory I.D.Nos. 0206382- 01 to 04),quality control and quality assurance data(QA/QC)and chain-of-custody form are included ' in Appendix B. ' 4.0. CONCLUSIONS Based on the data collected during this monitoring period, AGE concludes. • Ground water flow at the site, was toward the southwest at hydraulic gradient of ' approximately 0.00025, which is nearly horizontal. The hydraulic gradient suggested that ground water flow rate during the.lune 2002 monitoring event was slow. • The concentrations of TPH-d and TPH-g in well samples MW-1 through MW-3 remained --_.—stable since theAast-monitoring-event;=however; TPH-&decrease&and=TPH=g=increased""`+- - significantly in sample MW-4. • Various BTEX compounds were detected in samples MW-1 and MW-4 at concentrations below the DHS' Maximum Contaminant Levels.(MCL) for drinkingwater. MTBE has been detected sporadically,in samples from well MW-4 since monitoring began - ' in 1997; the detected MTBE concentrations since October•1997 have been below the MCL. Advanced GeoEnvironmental,Inc.