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INWO <br /> MO <br /> - ! <br /> r <br /> o From ground surface to 5 feet, samples were collected <br /> at approximate depths of 2 and 4-1/2 feet below <br /> grade. <br /> o From 5 to 10 foot depth interval, samples were <br /> a collected at approximate depths of 7 and 9--1/2 feet <br /> below grade. <br /> Since the vertical extent of soil contamination and proposed <br /> depth of excavation was limited to approximately 10 feet <br /> below grade, no samples were collected below a depth of <br /> 10 feet. <br /> A total of 186 discrete samples were collected which were <br /> composited in the laboratory to 12 samples for analysis. <br /> Each sample section represents one composite of 18 discrete <br /> samples (6 discrete samples in Secticn F) for each <br /> " <br /> 5-foot-thick portion. The extent of the sampling area was <br /> based on the previous sampling and site investigative work <br /> (Kaprealian, 1988, 1989) . <br /> The borings were drilled with 8-inch-diameter hollow-stem <br /> augers. Soil samples were obtained with a split spoon <br /> sampler and collected in clean stainless steel tubes. The <br /> samples recovered for chemical analysis were sealed with <br /> Teflon tape and plastic caps, and placed immediately into an <br /> iced cooler. The samples were then transported to a <br /> California-certified laboratory for analysis following proper <br /> chain of custody procedures. A description of drilling <br /> procedures and soil sampling protocol is included as <br /> Appendix A. <br /> 2.2 Analytical Methods -and Rgsult s <br /> For each 5-foot-thick portion in each sampling Section, <br /> (except in Section F) a total of 18 discrete samples <br /> representing approximately 450 cubic yards of -soil were <br /> composited in a California-certified laboratory for the <br /> required analysis. The composited soil samples were <br /> initially analyzed for TPH-D and TPH-G with BTEX distinction <br /> utilizing -EPA:Method-5030 and modified-EPA Method. 8020, - Soil <br /> samples with TPH-G and/or TPH-D levels greater than 1,000 ppm <br /> were additionally analyzed for sulfides in accordance with <br /> modified gaseous transfer EPA Method 376.2, and for acute <br /> ' aquatic toxicity.per Title 22 of the California Health and <br /> Safety Code.. Additionally, the 5- to 10-foot sample from <br /> Section A (with both TPH-G and TPH-D present in <br /> ..; concentrations greater than 1,000 ppm) , was analyzed for <br /> organic lead in accordance with. the BHS-LUFT Method. The <br /> results of the laboratory analysis are presented in Table 1. <br /> Copies of the,-,..official Laboratory Reports and Chain of . <br /> Custody Recors: included in Appendix B. <br /> 4 <br />