ARCHIVED REPORTS XR0001951 - Laserfiche WebLink

Home Browse Search

. 14 May 2004 AGE-NC Project No 97-0312 Page 4of5 No other target analytes were detected at or above laboratory reporting levels in the ground water samples collected this quarter The laboratory reports (MAI Lab IDs 0403245-001 through 0403245-007) and chain-of-custody forms are included In Appendix B Analytical results of water samples collected during the first quarter 2004 are summarized on Tables 2 and 3 The analytical results of all water samples are summarized on Tables 4 and 5 Figures 4 and 5 Illustrate the areal extent of TPH-g- and 1,2-DCA-Impacted ground water 4.0. DISCUSSION AND CONCLUSIONS Based upon data collected from the site, AGE concludes • Ground water elevation Increased approximately 3 05 feet at the site between the December 2003 and March 2004 monitoring events The Inferred ground water flow direction was generally toward the northeast The ground water gradient was approximately 0 001 ft/ft across the site • During the March 2004 monitoring event TPH-g was detected In the water sample collected from monitoring well UST-5 Toluene and xylenes were detected in the sample collected from well UST-2 MTBE was detected in the sample collected from well UST-6 The reported concentrations of toluene, xylenes and MTBE were below the DHS Maximum Contaminant Levels (MCL) for the respective analyte • During the March 2004 monitoring event 1,2-DCA was detected in samples collected from well UST-5 and UST-6 The maximum concentration of 1,2-DCA was detected in the sample collected from well UST-5 at 390 µg/1 The detected concentrations were above the DHS MCL of 0 5 µg/1 • PCE was detected In the sample collected from well UST-7 The detected concentration was below the DHS MCL of 5 0 µg/1 • Methylene chloride was detected In samples collected from wells UST-4,UST-6,UST-7 and the large domestic well The reported concentrations were below the DHS MCL of 5 µg/1 • The reported concentrations and lateral extent of analytes of concern have remained relatively stable during the past three years of monitonng Based on the analytical results of the ground water sample collected from UST-7, the vertical extent of petroleum hydrocarbon-Impacted ground water at the site appears to be limited to the uppermost hydrogeologic zone The source of the PCE detected in UST-7 is unknown to AGE and may be from an off-site source Advanced GeoEnvironmental,Inc