ARCHIVED REPORTS_XR0008128 - Laserfiche WebLink

Home Browse Search

. 13 September 2001 ' AGE-NC Project No 95-0128 Page 5 of 7 ' 3 2 GROUND WATER ELEVATION AND GRADIENT ' The ground water elevation on 02 July 2001 ranged from 17 23 to 18 20 feet below mean sea level (msl) The average ground water elevation during this monitoring event was approximately 0 15 feet lower than the average ground water elevation during the April 2001 monitoring event The depth ' to ground water and ground water elevation data is summarized in Table 1 The ground water table occurred within the screened intervals of the shallow screened wells The screened intervals in monitoring wells MW-1 to MW-3, MW-11B and MW-12B are currently drowned Ground water was determined to be flowing to the northeast on site to north-northeast off site(Figure 3) at a gradient of 0 003 feet/feet on-site and 0 005 feet/feet off-site 33 ANALYTICAL RESULTS FROM GROUND WATER SAMPLES TPH-g was detected in samples MW-4, MW-5 and VW-1 at concentrations of 13,000 µg/l, • 2,100µg/1 and 2,100 µg/1, respectively Samples MW-2, MW-4, MW-5 and VW-1 also contained TPH-d at concentrations of 120 µg/l, 2,500 µg/1, 700µg/1 and 180 ,ug/l, respectively TPH-g and TPH-d were not detected in the remaining samples Benzene was detected in samples MW-2, MW-4, MW-5 and VW-1 at concentrations of 0 70 ,ug/1, 11 µg/l, 32,ug/l and 34µg/l, respectively The remaining BTEX compounds were only detected in the same samples at concentrations ranging up to 560 4g/1 of xylenes in MW-4 MTBE was detected by EPA Method 8020 In ground water samples MW-2, MW-3,MW-5, MW-8, MW-11A, MW IB, MWI2A, MW-12B and VW-1 at concentrations ranging from 7 8 µg/l In MW-3 to 610 4g/1 in MW-11B (off-site) MTBE was also quantified by EPA Method 8260 Modified In ground water samples MW-2, MW-3, MW-4, MW-5, MW-6, MW-8, MW-11A/B, MW12A/B, MW-15 and MW-16 at concentrations ranging from 2 3 µg/l in MW-6 to 640µg/1 In MW-11B Of the remaining fuel oxygenates, ETBE was detected in sample MW-16 at 14µg/1 and TBA was detected in sample MW-5 at 24µg/1 The analytical results are summarized on Tables 2 and 3 The laboratory reports for the quarterly monitoring event(MAI Laboratory ID No 71704 to 71710 and 71970 to 71970), quality assurance and quality control (QA/QC) reports and the chain-of-custody form are Included in Appendix C Dissolved MTBE is displayed on a scaled site plan (Figure 4) • Advanced GeoEnviroamental Inc