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' 03 May 2000 ' AGE-NC Project No 95-0184 Page 2 of 4 ' 22 COLLECTION OF GROUND WATER SAMPLES Water samples were collected from each purged well using new disposable bailers Each sample was ' transferred into 40-m1 EPA-approved VOA vials containing 0 5 ml 18% hydrochloric acid as a sample preservative The sample from MW-4 was also transferred into a 1-liter amber bottle without ' preservative The sample containers were labeled,placed in a chilled container and transported under chain-of-custody to McCampbell Analytical, Inc (MAI) in Pacheco, California, a California Department of Health Services (DHS)-certified analytical laboratory The samples were analyzed ' for • Total petroleum hydrocarbons quantified as gasoline (TPH-g) In accordance with EPA ' Method 5030/8015m, - • Volatile aromatic hydrocarbons benzene, toluene, ethylbenzene and xylenes (BTEX) with ' methyl tertiary-butyl ether(MTBE) In accordance with EPA Method 60218020, and • Volatile organic compounds and fuel oxygenates (di-isopropyl ether [DIPE], ethyl tertiary- butyl ether [ETBE], tertiary-amyl methyl ether [TAME] tertiary butanol [TBA] and MTBE) in accordance with EPA Method 8260 ' The 1-liter sample from MW-4 was also analyzed for total petroleum hydrocarbons quantified as diesel (TPH-d) in accordance with EPA Method 8015m 3 0. FINDINGS Ground water elevation and flow direction were calculated from field data, hydrocarbon-impact to ground water was inferred from laboratory analysis of the ground water samples 3 1 RELATIVE GROUND WATER ELEVATION AND GRADIENT ' The average depth to ground water at the site was 31 32 feet below the well casing tops during the February 2000 monitonng event Ground water elevation increased an average of 0 51 feet between November 1999 and February 2000 Ground water was approximately 23 6 feet above the screened interval In monitoring wells MW-1 and MW-3 Ground water was approximately 12 to 114 feet above the screened Interval In MW-4, VW-2B and VW5C, 8 5 feet above the screen In MW-7, 3 8 feet above the screen In VW-3 and 2 1 feet above the screen in VW-4 Ground water was within the screened interval of well VW-5B only Ground water elevations In deeper wells were similar to elevations calculated for the shallower wells at the site Vapor well VW-5 was installed at an angle of approximately 15° from vertical and therefore was not used for calculating the ground water Advanced GcoEniironmental,Inc