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• 07 March 2000 <br /> AGE-NC Project No. 98-0432 <br /> Page 3 of 6 <br /> 2.3. GROUND WATER DEPTH MEASUREMENT AND PURGING <br /> On 19 January 2000, a Solinst water level meter was used to measure the depth to ground water in <br /> ' each well relative to the top of the well casing. After ground water depth measurements were <br /> collected, monitoring wells were purged using a two-stage submersible pump. <br /> ' Nine gallons of water(a minimum of 3 well-volume) was evacuated from wells MW-1, MW-3 and <br /> MW-4. Only three gallons of water(1 well-volume) were evacuated from well MW-2, which went <br /> dry at that point of the purging process. <br /> Temperature, pH and conductivity of the purged water were measured at regular purge-volume <br /> intervals in all wells. These field data were measured with an ICM model 52200 water analyzer. <br /> ' <br /> -Logs of the field data are included inAppendix B. Purged water was stored.on-site in labeled 55- <br /> gallon drums. <br /> 2.4. COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES <br /> Water samples were collected from each well using a new disposable plastic bailer. Each water <br /> sample was transferred into three 40-m1 EPA-approved VOA vials containing 0.5 ml 18%.HCI as <br /> a sample preservative and into one 1-liter amber bottle without preservative. After collection, the <br /> samples were labeled and placed in a chilled container for transportation under chain-of-custody to <br /> PET. Each sample was analyzed for: <br /> TPH-g and TPH-d by EPA Method 8015 Modified and <br /> - BTEX and MTBE by EPA Method 8260 Modified <br /> ' `2.5. MONITORING WELL SURVEY <br /> On 18 February 2000, a California state-licensed survey engineer from Baumbach & Piazza, Inc. <br /> surveyed a reference point on the top of the casing of each ground water monitoring well at the site <br /> to the-nearest 0.01-foot relative to the City of Manteca BM463 at 33.758 feet above mean sea level ; <br /> ' (msl). The results of the monitoring well survey are contained in Table 1. The surveying report <br /> (Baumbach & Piazza) is presented-in Appendix C. <br /> • 3.0. FINDINGS <br /> Ground water elevation and flow direction were inferred from field data; fuel-hydrocarbon impact <br /> to ground water was assessed by laboratory analysis. Soil in the area east of well MW-4 was found <br />