ARCHIVED REPORTS XR0001704 - Laserfiche WebLink

Home Browse Search

l 28 April 2000 • AGE-NC Project No. 95-0109 Page 3 of 4 increase of ground water elevation between January and March 2000. Ground water elevation contours,based upon data collected on 22 March 2000, are depicted in Figure 3. The inferred ground water flow direction is toward the south. Ground water elevations are summarized on Table 1. 3.2. MICROBIOLOGICAL ACTIVITY IN GROUND WATER General and selective subpopulations increased in MW-9 and decreased in MW-14. Nutrient concentrations generally remained stable.Nutrient concentrations remain below optimal for ongoing bioremediation. Field measurement for indicators of microbiological activity are summarized on Table 2; microbiological and physicochemical analytical results are summarized on Table 3. The laboratory report (A. Keith Kaufman April 6, 2000) and chain-of-custody form are included in Appendix B. 3.3. PETROLEUM HYDROCARBON-IMPACTED GROUND WATER Petroleum hydrocarbons were detected in ground water samples from seven of the fifteen wells . sampled. TPH-g concentrations ranged up to 2,300 parts per billion (ppb; reported as micrograms per liter). Benzene, toluene, ethylbenzene and xylenes were detected at concentrations as high as 58 ppb, 22 ppb, 18 ppb and 150 ppb, respectively. The highest concentrations were detected in samples collected from MW-4,MW-9 and MW-14. Petroleum hydrocarbons were not detected in the samples collected from MW-2, MW-6, MW-7, MW-10, MW-11, MW-12, MW-13 and EW-1. The results of analysis by EPA Method 8015m/602 for the January 2000 monitoring event are presented on Table 4. Historical analytical results by EPA Method 8015m/602 are summarized.in Table 5. Graphs illustrating the concentrations of TPH-g and benzene over time are presented in Appendix C. TBA was detected in the sample collected from MW-9 at a concentration of 9.2 ppb. Other oxygenated compounds were not detected in the samples collected. 1,2-Dichloroethane (1,2-DCA) was detected in MW-1,MW-3,MW-4,MW-5,MW-8,MW-9 and MW-14 at concentrations as great as 69 ppb. Seven additional analytes, detected by EPA Method 8260, are noted in Table 6. 1,2-DCA was detected by EPA Method 601 at similar concentrations to that of EPA Method 8260. Other analytes were not detected by EPA Method 601. The laboratory report (MAI Laboratory I. D. Nos. 33868 through 33882) and chain-of-custody forms are included in Appendix B. . 4.0. DISCUSSION AND CONCLUSIONS Based upon data collected from the site, AGE finds: i Advanced CeoEnvironmental,Inc.