Laserfiche WebLink
1 16 rune 2004 <br /> • AGE-NC Project No. 98-0497 <br /> ' Page 3 of 4 <br /> ' 3.2• ANALYTICAL RESULTS FROM GROUND WATER SAMPLES <br /> .The analytical results from the 12 March 2004 ground water sampling event are as follows: <br /> 1 • TPH-g was detected in well MW-1 at a concentration of 8,400 micrograms per liter(gg/l). <br /> The laboratory report noted that the detected concentration was mostly in the diesel range; ' <br /> ' • TPH-d was detected in MW-1 at a concentration of 78,000 µg/1; <br /> • BTEX compounds and MTBE were not detected in the five ground water samples analyzed; <br /> 1 f, <br /> Laboratory results of water samples analyzed for petroleum hydrocarbons are summarized in <br /> ' Table 2. Copies of the laboratory reports for the quarterly monitoring event (CTEL Project No <br /> CT214-0403121), QA/QC reports and chain-of-custody form are in Appendix B. <br /> 1 4.0. SUMMARY AND CONCLUSIONS <br /> ' The findings of the 12 March 2004 ground water monitoring event include the following: <br /> • Measured ground water elevation was approximately 39.8 feet below MSL, and was within <br /> t the screened interval of each monitoring well. Ground water flow direction near the former <br /> UST location was to the southeast with an average gradient of 0.002 ft/ft. Historically,flow <br /> direction at the site has been toward the east or has had no observable gradient. <br /> tContamination by TPH-g and TPH-d was encountered in the ground water sample collected <br /> and analyzed from MW-1. The detected concentrations of TPH-d in samples collected from <br /> MW-1 have fluctuated significantly during the past nine monitoring events. <br /> 1 • No analytes of concern were detected in samples collected from wells MW-2 through MW-5. <br /> • The TPH-g- and TPH-d-impacted ground water plume appears to be limited to the former <br /> ' UST area immediately surrounding MW-1. The inferred areal extent of hydrocarbon- <br /> impacted ground water is illustrated in Figure 4. <br /> 1 <br /> 5.0. RECOMMENDATIONS <br /> Based on the results of this and previous investigations, AGE recommends: <br />' Performance of a monitoring and sampling event of the ground water well network with the <br /> preparation of a Corrective Action Plan. <br />' Advanced GeoEnvironmental <br />