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I ' 19 February 1996 w AGE-NC Protect No 95-0104 Page 3 of 4 MW-4 utilizing dedicated, disposable polyethylene bailers and new nylon ropes Sufficient sample ' was collected from each well to fill four 40-m1 EPA vials containing hydrochloric acid as a preservative for the samples Care was taken to ensure that no air bubbles were present in the VOAs after filling and capping Ground-water sample containers were labeled with the well designation, date, time, and samplers initials 3 3 LABORATORY ANALYSIS OF GROUND WATER SAMPLES After collection, each sample was logged on a chain-of-custody form, placed in a chilled container and transported to a Alpha Analytical Laboratones (AAL), a California state certified laboratory for analysis of hazardous materials Each sample was analyzed for TPH-g, volatile aromatics (benzene, toluene, ethyl benzene and xylene BTE&X) and halogenated volatile organic compounds (HVOCs) in accordance with EPA methods 5030, 602, and 601, respectively 4.0. FINDINGS 4 1 RELATIVE GROUND WATER ELEVATION AND GRADIENT The relative elevation of ground water on 25 January 1996 is depicted in Figure 3 Between October 1995 and January 1996, ground water elevation rose approximately 4 03 feet in MW-1, 4 25 feet in MW-2, 4 15 feet in MW-3, and 4 20 feet in MW-4 IIn January 1996,the ground water gradient at the site was calculated to be 0 005 ft/ft (approximately 26 feet per mile) directed N 12° W (Figure 3) In October 1995, the gradient was calculated to be 0 0013 ft/ft (approximately 7 feet per mile) directed N 71°E Between October 1995, and January 1996, ground water flow direction beneath the site rotated approximately 31° from the northeast toward the northwest 4 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES During the January 1996 sampling, TPH-g was detected in MW-1 at 360 pg/l (parts per billion ppb) Analytical results of TPH-g and BTE&X in ground water are summarized in Table 2 The laboratory report and chain-of-custody are included in Appendix B Halogenated volatile organic compounds(HVOCs)were detected m samples collected from each well Iduring the January 1996 sampling event at concentrations ranging from 41 ppb (1,1,1- Trichloroethane in MW-3) to 420 ppb (1,2-dichloroethane in MW-1) Analytical results of HVOC analysis are summarized in Tables 3 through 6 The laboratory report and chain-of-custody form are I