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' 03 March 2004 • AGE-NC Project No 01-0827 ' Page 3 of 6 ' On 09 January 2004, a Solmst water level meter was used to measure the depth to ground water in monitoring wells MW-1 through MW-6 and vapor wells VW-1, VW-2d, VW-3 and VW-5d After water levels were gauged,a dedicated disposable bailer or waterra bailer was used to purge the wells ' of a minimum of three casing-water volumes (approximately 8 to 20 gallons) of ground water Temperature, pH, and conductivity were measured at regular intervals during purging using an Oakton model water analyzer Purged water from impacted wells was stored on-sate in 55-gallon ' drums The field data sheets are included an Appendix A ' 2 2 2 Ground Water Sample Collection and Analysis Water samples were collected from the monitoring wells and vapor wells using new disposable ' bailers after allowing the wells to achieve a minimum 80%recovery of the pre-purge water volume Each sample was transferred into three 40-m1 EPA-approved volatile organic analysis (VOA) vials and one 1-later amber bottle The samples were stored in a chilled container and transported under ' chain-of-custody to CalTech Environmental Laboratory (CTEL) a DHS-certified analytical laboratory The samples were analyzed for • Total petroleum hydrocarbons quantified as gasoline and diesel (TPH-g/TPH-d) in accordance with EPA Method 8015 Modified, Y Benzene, toluene, ethylbenzene and total xylenes(BTEX) compounds and fuel oxygenated compounds-tertiary butanol(TBA),di-isopropyl ether(DIPE),ethyl tert butyl ether(ETRE), tert amyl methyl ether (TAME), methyl-tertiary butyl ether (MTBE), 1,2-Dichloroethane ' (1,2-DCA), ethylene dibromade (EDB), ethanol and methanol by EPA Method 8260 ' 3.0. FINDINGS AGE determined contaminant impact to ground water was assessed from the laboratory analysis of ' the ground water samples collected on 17 December 2003 and 09 January 2004 ,ground water flow direction and gradient from the field data collected on 09 January 2004, the DO concentrations and ORP were determined from field data collected on 17 December 2003 and 14 January 2004, ' respectively (Appendix A) ' 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION On 09 January 2004, depths to ground water in monitoring wells MW-1 through MW-6 and vapor wells VW-1, VW-2d, VW-3 and VW-5d ranged from 22 24 to 24 12 feet below the tops of the • casings (btoc), the water table was approximately 8 to 15 feet above the screened intervals of wells ' MW-1 through MW-5 and VW-2d, VW-3 and VW-5d and 35 feet above the screened interval of well MW-6 (Table 1)