ARCHIVED REPORTS_XR0008069 - Laserfiche WebLink

Home Browse Search

J ' 09 August 2000 AGE-NC Project No 96-0229 Page 3 of 5 y I water gradient at the site was calculated to be approximately 0 002 ft/ft or approximately 11 feet per mile and directed towards the north-northeast The ground water surface elevation at the site is approximately 7 feet to 8 feet above the slotted screen Intervals in wells MW-3 and MW-4 and approximately 25 feet to 27 feet above the slotted screen Intervals In wells MW-1 and MW-10B 3 2 LABORATORY RESULTS OF GROUND WATER SAMPLES A total of eleven ground water samples were submitted to a DHS-certified laboratory TPH-g was ' detected in water samples collected from wells MW-1, MW-2, MW-3, MW-6, MW-7, and MW-8 at concentrations ranging between 230 micrograms per liter (,ug/1) and 70,000 Ag/l IBTEX compounds were detected In ground water samples collected from wells MW-1, MW-2, MW-3, MW-4, MW-6, and MW-7 at concentrations ranging between 0 54 4g/1 and 7,000 µg/1 (xylene, MW-2) The greatest benzene concentration was observed at MW-1 at a concentration of 3,400/cg/1 MTBE was detected utilizing EPA Method 8020 In ground water samples collected from wells MW-1, MW-3, MW-6, MW-7, MW-8 and MW-l0A at concentrations ranging as high as 310 1ugl1 MTBE was confirmed utilizing EPA Method 8260 In samples collected from wells MW-1, MW-2, MW-3,MW-5, MW-6, MW-7, MW-8 and MW-10A at concentrations ranging as high as 230,ug/l, TBA was detected in ground water samples collected from wells MW-4, MW-7 and MW-8 at concentrations of 8 1 ug/l, 16,ug/l and 75,ug/l,respectively No other fuel oxygenated additives were Idetected above laboratory reporting limits from the analyzed samples Analytical results of the ground water samples are summarized In Table 2 The laboratory reports (Castle Analytical Laboratory Reference No 2965 and McCampbell Analytical Inc I D No 35307 through 35317), QA-QC data and chain-of-custody forms are Included as Appendix B 4.0. SUMMARY AND CONCLUSIONS IThe Implications from the findings of the April 2000 investigation are • Ground water monitoring data collected In the area of wells MW-1 through MW-10 Indicated a ground water flow direction generally toward the north-northeast at a gradient of 0 002 ft/ft This flow direction appears to be prevailing for the area Due to the low hydraulic gradient - — at the site, slight variations In ground water measurements or changes of recharge/discharge of the local ground water could greatlymodlfy_ground water flow-direction • Monitoring wells MW-1 and MW-IOB are "drowned", and may not yield representative IAdvanced GeoEnvironmental,Inc 1