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Tracy Cold Storage Soil Aeration Report Page:2 dust emissions. A log book was maintained to document the date and volume of soil added to the active aeration. .- A photoionization detector (PID) was used to periodically screen the aerating soil to monitor the levels of contaminants. These readings were used to evaluate the progress of the aeration program,and to redirect aeration efforts to areas where higher readings were obtained. When low PID readings were obtained throughout the pile, a sampling grid was established. A total of eight segments were delineated, seven containing approximately 200 cubic yards of soil each, and one containing approximately 122 cubic yards. Figure 1 shows the sampling grid that was established for the aerated soil. +� One two-point composite sample was collected from each of the eight segments on October 7, 1998. Two locations were selected within each of the eight segments. At each location a shallow excavation was advanced to remove between three and twelve inches of soil prior to collecting a �. sample. Each individual sample was collected by filling a brass sample container with soil, leaving no headspace. The ends of the sample container were sealed with plastic end caps, and the sample was labeled with the location, date and time, and placed into a cooler chilled to 4° Celsius. All samples were handled in accordance with strict chain of custody procedures and delivered to the analytical laboratory on the date of collection. Individual samples were composited by the laboratory prior to analysis. Samples were analyzed for gasoline and BTEX constituents using approved methodologies. Laboratory analytical data indicated no detectable levels of gasoline, benzene, toluene, or ethyl benzene in the samples collected from locations 1 through 6, and 8. Location 7 contained detectable levels of toluene, ethyl benzene and total xylenes. Total xylenes were also detected at `r levels between 5.6 gg/Kg and 19 µg/Kg in four of the samples, the remaining three were below the analytical detection limit. •.. Based on the results obtained from the sample collected at location 7, a second two-point composite sample was collected on October 16, 1998. The results of the second analyses indicated non detectable levels for all analyzed constituents. These data indicate that residual constituent levels continue to decline even without the benefit of active aeration. The results of these analyses are presented in Table 1 below. Analytical laboratory data sheets are attached to this letter report. To confirm that no contaminants were released to the native soils of the field, three discrete samples were collected from beneath the aerated soil on October 16, 1998. These samples were collected by using the bulldozer to remove aerated soil to expose the native materials in the vicinity of the initial "field" samples. Samples were collected within the top six inches of the former ground surface using the same collection, handling, and analytical methodology previously described. The results of these analyses indicate no detectable levels of any analyzed constituents. The results of these analyses are presented in Table 1 below. Analytical laboratory data sheets are attached to this letter report. �.r