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i ' 01 February 2006 AGE-NC Project No 99-0657 ' Page 2 of 5 ' 22 COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES Ground water samples were collected from each purged well using the Waterra inertia pump and ' dedicated tubing after allowing the wells to achieve a minimum 80%recovery of the pre-purge water volume Each water sample was transferred into one 1-liter amber bottle without sample preservative and into three 40-milliliter (ml) volatile organic analysis (VOA) vials containing 0 5 ml 18% ' hydrochloric acid solution as a sample preservative After collection, the samples were properly labeled, placed in a chilled container, and transported under chain of custody to Cal Tech Environmental Laboratories (CTEL), a State of California Department of Health Services (DHS)- certified analytical laboratory, for analysis The samples were analyzed for • Total petroleum hydrocarbons quantified as gasoline (TPH-g) and diesel (TPH-d) in ' accordance with EPA Method 8015 Modified, and • Benzene, toluene, ethyl-benzene, and total xylenes (BTEX) and the fuel additives di- isopropyl. ether (DIPE), ethyl tertiary-butyl ether (ETBE), methyl tertiary-butyl ether (MTBE), tertiary-amyl methyl ether (TAME), tertiary-butyl alcohol (TBA), 1,2-dichloroethane (1,2-DCA), and 1,2-dibromoethane (EDB) in accordance with EPA Method 8260B ' 3.0. FINDINGS ' The ground water elevation,flow direction,and gradient were determined from field data collected on 08 November 2005, the contaminant impact to ground water was quantified by the laboratory analytical data 1 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION ' At the time of the November 2005 sampling event, depths to ground water ranged from 36 51 feet (MW-7)to 39 94fect(MW-9)below the tops of the well casings Ground water elevation at the site ' averaged approximately 6 1 feet above mean sea level (MSL), indicating an increase in average ground water elevation of approximately 0 2 feet since the last monitoring event in August 2005 During this monitoring event, the ground water levels in the wells were at least six feet below the ' tops of the well screens, indicating that the wells are screened properly to yield representative shallow ground water samples ' Ground water flow was inferred to be flowing toward the southwest under a hydraulic gradient of • approximately 0 004 foot/foot (ft/ft) This flow direction remains consistent with the previous ' Advanced GeoEnvironmental,Inc