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THIRD QUARTER,2001 GROUNDWATER MONITORING REPORT JAMAR OIL DISTRIBUTION JANUARY 2002 Groundwater Analyses On September 28, 2001, depths to groundwater were measured from the top of the well casings (TOC)using an electronic water level indicator The groundwater elevations recorded by GHH are summarized in Table 1 Each monitoring well was purged by pumping at least three well volumes of water Conductivity,temperature and pH were monitored while the wells were being purged Purging data were recorded on field data sheets, which are included in Appendix A Samples were collected from each monitoring well using new disposable bailers Groundwater samples were analyzed for TPH G,BTEX, 1,2-DCA,EDB and fuel oxygenates using EPA Methods 8015 Modified, 8020 and 8260B,respectively The analyses were conducted by Acculabs,Inc of Davis, California, a California State certified laboratory, in accordance with state guidelines and EPA protocol Copies of the laboratory reports with COC documentation are included in Appendix B The analytical data are summarized in Figure 5 and in Table 2 SUMMARY Groundwater Flow and Gradient Based on depth to groundwater measurements taken on September 28,2001, the depths to groundwater range from 62 56 feet below ground surface bgs in monitoring well MW-1 to 62 90 feet bgs in MW-4 All groundwater elevations were measured to the nearest 0 01-feet relative to the surveyed top of casing elevation The elevations are based on the survey conducted by JPCA on August 30, 2000 The survey on August 30, 2000 was completed by setting the corner of the cement sidewalk on the southeastern comer of the store as the benchmark with an assumed elevation of 30 feet Based on the surveyed casing elevations and the measured depth to water on September 28, 2001, the groundwater elevations range from -34 22 feet in MW-5 to-34 39 feet in MW-4 The direction of groundwater flow has been calculated to be trending to south-southeas th a hydraulic gradient of approximately 0 001-feet/feet across the site as sho F Calculated groundwater elevations are summarized in Table 1, and shown on Figure 4 Groundwater Analytical Results TPH G was detected in all wells this quarter at concentrations of 100,000 micrograms per liter (Ezg/l), 8,000 pg/l, 19,000,ag/l, 18,000 /.cg/l and 180 µg/l in samples from MW-1,MW-2,MW-3, MW-4,and MW-5,respectively 4