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17 April 2000 <br /> AGE-NC Project No. 95-0100 <br />' Page 4 of 6 <br /> Fifty-five gallons of water were evacuated from well MW-1 and ten gallons of water(a minimum <br /> of 3 well-volumes per well) were evacuated from well MW-2, on the respective dates. <br />' Temperature,pH and conductivity of the purged water were measured at regular intervals in all wells <br /> with an ICM model 52200 water analyzer. Logs of the field data are included in Appendix C. Purged <br /> water was stored on-site in labeled 55-gallon drums. <br /> 2.5. COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES <br />' Water samples were collected from the purged wells using new disposable plastic bailers. Each water <br /> sample was transferred into three 40-m1 VOA vials containing 0.5 ml 18% HCl as a sample <br />' preservative. After collection, the samples were labeled and placed in a chilled container for <br /> transportation under chain-of-custody to McCampbell Analytical, Inc. (MAI), a California <br />' Department of Health Services (DHS)-certified analytical laboratory in Pacheco, California. Each <br /> sample was analyzed for: <br /> • Total petroleum hydrocarbons quantified as gasoline (TPH-g) by EPA Method 8015 <br /> Modified, <br /> • Volatile aromatic compounds -benzene, toluene, ethylbenzene and total xylenes (BTEX) by <br />' EPA Method 8020, with methyl tertiary-butyl ether (MTBE) and <br /> • Oxygenated fuel additives - di-isopropyl ether (DIPS), ethyl tertiary butyl ether (ETBE), <br />' MTBE,tertiary amyl'methyl ether(TAME)and tertiary butyl alcohol (TBA) by EPA Method <br /> 8260 Modified. <br /> 3.0. FINDINGS <br />' The soil profile was inferred from the field observations of the soil samples collected. Ground water <br /> elevation and flow direction were inferred from field data; fuel-hydrocarbon impact to ground water <br />' was assessed by laboratory analysis. <br /> 3.1. STRATIGRAPHY AND DEPTH TO GROUNDWATER <br /> Silty sand and silt with a tan color,was generally encountered from a depth of approximately 5 feet <br />' to 25 feet bsg, in the area of well MW-I. Interbedded clay and gravel strata were present at depths <br /> between 25 and 45 feet bsg. Sand was encountered at a depth of 55 feet bsg in the pilot boring for <br /> well MW-2. Below a depth of 55 .feet bsg, a silty clay was present in the soil boring established. <br />' Soil borings are depicted in Appendix A. <br /> Advanced GeoEnvironmental,Inc. <br />