ARCHIVED REPORTS XR0007786 - Laserfiche WebLink

Home Browse Search

rl * 26 May 1998 AGE-NC Project No 95-0142 Page 2 of 4 22 GROUND WATER SAMPLE COLLECTION Water samples were collected from each purged well (MW-4, MW-5, VW-I through VW-4) using new, clean, disposable plastic bailers Immediately upon retrieval, the samples were transferred into EPA-approved 40-m1 VOA vials containing 0 5 milliliters 18%hydrochloric acid as a preservative The vials were then labeled and placed in a chilled container The samples were transported in under chain-of-custody to McCampbell Analytical, Inc , (MAI) in Pacheco, California for analysis Each sample was analyzed as follows • By EPA Method 8015 M for total petroleum hydrocarbons quantified as gasoline (TPH-g), • By EPA Method 8020 for volatile aromatic compounds(benzene,toluene, ethyl-benzene and total xylenes BTE&X) and • By EPA Method 8260m for oxygenated fuel additives methyl-tert-butyl ether (MTBE) tertiary butyl alcohol(TBA),di-isopropyl ether(DIPE),ethyl tertiary butyl ether(ETBE)and tertiary amyl methyl ether (TAME) 23 PURGED GROUND WATER DISPOSAL On 14 April 1998, three drums of previously purged ground water, approximately 120 gallons total, were collected by Nor Cal Oil of Turlock, California, for final disposal at a licenced treatment facility A copy of the generators manifest is Included in Appendix B 3.0 FINDINGS 3 1 GROUND WATER GRADIENT AND DIRECTION Depth to ground water at the site ranged from 32 02 feet to 33 05 feet below the well casing tops Between December 1997 and March 1998 the average ground water elevation increased approximately 6 5 feet During the March 1998 monitoring event, the inferred ground water flow direction varied from east to northeast, away from well VW-3, and the hydraulic gradient was calculated to be approximately 0 007 ft/ft The relative ground water elevation data Is depicted In Table 1 The relative elevation of ground water surface at the site Is illustrated on Figure 3 • Advanced CeoEnviron mental.Inc