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Remediation Report - 152 East 11 th Street, Tracy, California Page 20 <br /> SAMPLING AND TESTING OF TREATED SOIL <br /> When the spread soil was free of any visual or olfactory indicators of hydrocarbons and it <br /> had been exposed to hot, sunny weather for an additional period of approximately one <br /> week, on October 04, 1996 it was sampled and tested in the manner described below <br /> Selection of Sampling Locations. <br /> Based on the statistical analyses of the results of samples taken from the stockpile of <br /> untreated soil, twelve random sampling locations were selected in the spread of aerated <br /> soil in the following manner The 450 ft by 81 ft spread was subdivided into a grid of 36 <br /> equally sized cells which formed a grid with each individual cell being identified by the row <br /> and column which contained it This arrangement is diagrammed on Figure 8, which <br /> shows the lettering and numbering scheme used to identify the individual cells Note that <br /> the total number of cells into which the spread was divided is greater than the calculated <br /> number of randomly distributed sampling locations needed to produce a statistically <br /> significant assessment of the condition of the treated soil <br /> To select cells from within which samples of the treated soil were to be recovered, a dice <br /> was repeatedly tossed to yield randomly paired sets of column letters and row numbers <br /> until a total of 12 cell were uniquely identified for sampling Within each selected cell, <br /> discrete sampling points were arbitrarily selected by tossing a sampling tube into it without <br /> consideration for the appearance, olfactory properties or any other characteristic of the <br /> soil therein The twelve cells in which sampling locations were randomly situated are <br /> identified on Figure 8 <br /> Sampling Procedure <br /> At each randomly selected sampling location a small pit was excavated so that its bottom <br /> was at least 3 in below the surface of the spread soil A clean, 2 in diameter, by 4 in <br /> long, brass sampling tube was then driven into the wall at the bottom of the sampling pit <br /> until the tube was completely filled with treated soil <br /> Following sample recovery, each sample tube was cleaned externally and its ends covered <br /> with aluminum foil and closed with tightly fitting plastic caps The caps were secured with <br /> adhesiveless tape Each sample tube was identified by the row and column number of the <br /> grid cell from which the sample that it contained had been recovered After being labeled <br /> accordingly for identification, the tubes were entered into chain-of-custody control and <br /> packed on chemical ice for transport to Chromalab's laboratory in Pleasanton, California <br />