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I ' 30 June 2003 • AGE-NC Project No 98-0433 ' Page 2 of 4 ' 2 2 GROUND WATER SAMPLE COLLECTION Prior to the collection of ground water samples,the depth to ground water was re-measured In each ' well to ensure that a minimum of 80% of the initial water volume had recharged Water samples were then collected from each well using a disposable plastic bailer In addition,a water sample was collected from the domestic well(DW-1)on the site by allowing the well pump to operated for one ' minute, then collecting a water sample from a dedicated sample tap The water from each monitoring well was transferred into three chilled 40-m1 volatile organic ' analysis (VOA) vials containing 0 5 ml hydrochloric acid (18%) as a sample preservative and one 1-liter amber bottle without preservative,water from the domestic well was poured directly into the ' sample contamers from the dedicated sample tap After collection,the samples were labeled and placed in a chilled container for transportation under ' chain-of-custody to Cal Tech Environmental Laboratories, Inc (CTEL), a state of California Department of Health Services-certified analytical laboratory Each sample was analyzed for ' • Total petroleum hydrocarbons quantified as gasoline and diesel (TPH-g and TPH-d) in accordance with EPA Method 8015 Modified and • Benzene,toluene,ethyl benzene and total xylene(BTEX)and the fuel additives methyl butyl ' ether(MTBE), tertiary butyl alcohol (TBA), di-isopropyl ether (RIPE), ethyl tertiary butyl ether (ETBE), tertiary amyl methyl ether (TAME), ethylene dibromide (EDB), 1,2- ' dichloroethane (1,2-DCA), in accordance with EPA Method 8260 Modified ' 3.0. FINDINGS ' Ground water elevations were determined by subtracting the measured depths--to-water from the surveyed casing elevations Ground water flow directions were determined by contouring the water elevations on a scaled site plan(Figure 3) The impact of the unauthorized release on ground water ' was quantified by laboratory analysis of samples collected during the quarter ' 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION ' Depth to ground water in well without free product on 14 May 2003,ranged fro 78 to 25 42 feet below well casing tops The ground water elevations at the site ranged from feet (MWXto • 33 69 feet(MW-6)above mean sea level(msl) The data indicates an average decrease of the ground ' water elevation in most wells of 0 89- feet since the previous quarterly momtormg event Advanced GeoEnviron mental,Inc I