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a 1 5 1 3 <br /> 1 24 April 2003 <br /> AGE-NC Project No 95-0144 <br /> ' Page 2 of 4 <br /> ' On 20 February 2003, depth to water was measured in the fifteen ground water monitonng wells at <br /> the site, and ground water samples were collected from three of the wells (MW-2, MW-4 and <br /> MW-5) in accordance with the revised monitoring schedule established at a 25 September 2002 <br /> ' meeting with the EHD <br /> 2 1 WELL MONITORING AND PURGING <br /> A Sohnst water level meter was used to measure the depth to ground water in fourteen monitoring <br /> wells at the subject site relative to the tops of the well casings The ground water elevation, flow <br /> direction and hydraulic gradient were determined from these data(Table 1) <br />� After depth to water measurements were recorded, wells MW-2, MW-4 and MW-5 were purged <br /> using new, disposable plastic bailers Approximately three casing-water volumes of water <br /> (approximately 13 to 13 5 gallons) were removed from the purged wells Temperature, pH and <br /> conductivity of purged water were measured at regular purge-volume intervals using an Oakton <br /> water analyzer The recorded field data and logs are included in Appendix A All purged water was <br /> • stored in 55-gallon DOT-approved drums on-site <br /> ' 2 2 COLLECTION OF GROUND WATER SAMPLES <br /> Water samples were collected from each purged monitoring well using new disposable bailers after <br /> allowing the wells to achieve a minimum 80% recovery of the pre-purge water volume Samples <br /> were transferred into 40-m1 EPA-approved VOA vials containing 0 5 ml 18%hydrochloric acid as <br /> a sample preservative and into 1-liter amber bottles without preservative The samples were labeled, <br /> stored on ice and transported under chain-of-custody to McCampbell Analytical, Inc (MAI), a <br /> California Department of Health Services (DHS)-certified analytical laboratory Each sample was <br /> analyzed for <br /> TPH-g, TPH-d and TPH-mo in accordance with EPA Methods 5030/8015 and 3550/$015, <br /> respectively, and <br /> BTE&X and methyl tertiary-butyl ether(MTBE) in accordance with EPA Method 8021B, <br /> 3.0. FINDINGS <br /> ' Ground water elevation and flow direction were inferred from field data, hydrocarbon-impact to <br /> • ground water was quantified from laboratory analysis of the ground water samples <br /> I <br /> Advanced GeaEnvironmental,far- <br /> I <br />