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3.0 PROCEDURES �9 3.1 Monitoring Well Purge Procedures On September 27, 1994, a Solinst water Ievel meter was used to measure the depth to groundwater in the three monitoring wells(Table 1).After water levels were measured, PVC bailers were used to purge approximately 8 to 11 gallons of water from each monitoring well.Temperature, pH and conductivity were measured at one-gallon intervals using an ICM water analyzer. The purge water was placed in DOT-approved drums and stored on-site. Field data sheets are included in Appendix A. Due to the UST removal and installation r- procedures conducted on-site, quarterly monitoring was not performed during June 1994. TABLE 1 RELATIVE GROUNDWATER ELEVATIONS Arco Mini Mart 4511 Pacific Avenue, Stockton, CA Relative Depth to Groundwater Relative Groundwater Well Ging Elevation L No. Elevation 12/93 3194 9/94 12/93 3194 9/94 MW-1 99.07 52.08 49.69 52.31 46.99 49.38 46.76 MW-2 98.02 51.31 48.91 51.53 46.71 49.11 46.49 MW-3 98.66 51.74 49.36 51.91 46.92 49.30 46.75 AH measurements in leet 3.2 Groundwater Sample Collection Water samples were collected from each well using new disposable plastic bailers. Three 40- ml EPA vials were collected from each well. Two 1-liter amber bottles of water were also collected from MW-3. Samples were placed in a chilled container and transported under chain-of-custody to Western Environmental Science & Technology (WEST) in Davis. Each sample was analyzed for TPH as gasoline and BTE&X in accordance with EPA methods 8015m and 602, respectively. The sample from MW-3 was also analyzed for TPH as diesel. 4.0 FINDINGS 4.1 Groundwater Elevation and Gradient The relative groundwater elevations for the monitoring wells were calculated by subtracting the groundwater depth from the surveyed relative casing elevation (Table 1). Comparison ARM QPMaW._I.a C