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I 13 April 2005 AGE-NC Project No 01-0827 ' Page 4 of 7 I2 3 QUARTERLY AND MONTHLY WELL MONITORING On 31 March 2005, the depth to ground water was measured in monitoring wells MW-1 through ' MW-6 and vapor wells VW-2d and VW-5d ' 2 3 1 Well Monitonng and Evacuation A Solmst water level meter was used to measure the depth to ground water in each well After water ' levels were gauged,a Wattera inertial tubing pump or dedicated disposable bailer was used to purge monitoring wells MW-6, and vapor wells VW-2d and VW-5d of a minimum of three casing-water ' volumes (between 8 and 20 gallons) of ground water Temperature, pH, and conductivity were measured at regular intervals during purging using an Oakton model water analyzer,while ORP in vapor well VW-2d adjacent to the IAS wells was measured Purged water from impacted wells was ' stored on-site in 55-gallon drums The field data sheets are included in Appendix B ' 2 3 2 Ground Water Sample Collection and Analysis After allowing wells to achieve a minimum 80% recovery of the pre-purge water volume, a water ' sample was collected using the disposable bailer The sample was transferred into three 40-milhliter(ml)EPA-approved volatile organic analysis(VOA)vials and a 1-liter amber container without preservative The samples were properly labeled, stored in a chilled container and ' transported under chain of custody to CTEL a California Department of Health Services (DHS)- certified analytical laboratory The samples were analyzed for ' • TPH-g in accordance with EPA Method 8015 Modified, BTEX and the fuel oxygenated compounds TBA, ETBE, TAME, MTBE, 1,2-DCA and ' EDB by EPA Method 8260 ' 3.0. FINDINGS Ground water flow directions and gradients were inferred from the field data collected on 31 March 2005 Contaminant impacts to groundwater were assessed from the laboratory analysis ofthe ground water samples collected The DO concentrations and ORP were determined from field data collected ' on 11 February and 31 March 2005 (Appendix B) • Advanced GeoEnvironmental,Inc.