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i16 February 2005 . AGE-NC Project No 97-0326 ' Page 2 of 5 21 WELL MONITORING AND EVACUATION ' On 23 September 2004 the depth to round water in monitoring wells MW-1 through MW-3 and P P g g g MW-7 through MW-9 was measured from the top of each well casing to the nearest 0 01-foot ' utilizing a Solinst water level meter Ground water elevation in each well was calculated by subtracting the measured depth to ground water from the surveyed casing elevation (Table 1) After water levels were measured, a Waterra inertia pump was used to purge each well Approximately 5 gallons of water(a minimum of three casing water volumes per well)were purged ' from single-level wells MW-2,MW-3,and MW-7,between 0 35 and 3 75 gallons were purged from multi-level wells MW-8A-D and MW-9A-D Ground water temperature,pH,and conductivity were measured at regular Intervals during purging using an Oakton water analyzer Purged ground water ' was containerized in properly labeled, Department of Transportation (DOT)-approved 55-gallon drums and stored on-site Field sheets and data are Included in Appendix B Free petroleum product was observed In well MW-1 A disposable bailer was used to purge the well until the product was not visible lie 2 2 COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES Water samples were collected from each purged well using a pre-cleaned inertia pump after allowing the wells to achieve a minimum 80% recovery of the pre-purge water volume Each water sample was transferred 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 California Department of Health Services (DHS)-certified analytical laboratory, for analysis The samples were analyzed for • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA Method 8015M, and • Benzene,toluene,ethylbenzene,and total xylenes(BTEX)and the fuel additives di-isopropyl ' ether(DIPE),ethyl tertiary-butyl ether(ETRE),methyl tertiary-butyl ether(MTBE),tertiary- amyl methyl ether (TAME), tertiary-butyl alcohol (TBA), 1,2-dibromoethane (EDB), 1,2-dichloroethane (1,2-DCA), methanol, and ethanol in accordance with EPA Method ' 8260B 1 ' Advanced GeoEnvironmental,Inc