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ATTACHMENT A <br /> FIELD AND LABORATORY PROCEDURES <br /> Soil Sampling During Excavation <br /> Soil samples will be collected by advancing 2-inch-diameter brass sample liners into <br /> undisturbed soil, or soil removed from an excavation by a backhoe bucket. Soil samples for <br /> chemical analysis were retained in the brass liners, labeled, and capped with Teflon sheets, <br /> and plastic end caps. The samples will then be sealed in zip-lock bags, placed on ice, and <br /> transported to the laboratory accompanied by the appropriate chain-of-custody <br /> documentation. <br /> Organic Vapor Procedures <br /> Soil samples collected during excavation will be analyzed in the field for ionizable organic <br /> compounds using a photo-ionization detector(PID)with a 10.2 eV lamp or a flame ionization <br /> detector (FID). The test procedure will involve measuring approximately 30 grams from an <br /> undisturbed soil sample, placing this subsample in a clean glass jar, and sealing the jar with <br /> aluminum foil secured under a ring-type threaded lid. The jar will be warmed for <br /> approximately 20 minutes (in the sun),then the foil will be pierced and the head-space within <br /> the jar will be tested for total organic vapor, measured in parts per million as benzene (ppm; <br /> volume/volume). The instrument will be calibrated prior to drilling using a 100-ppm <br /> isobutylene standard (in air) and a sensitivity factor of 55 which relates the photo-ionization <br /> potential of benzene to that of isobutylene at 100 ppm. The results of the field testing will be <br /> noted on the boring logs. PID and FID readings are useful for indicating relative levels of <br /> contamination, but cannot be used to evaluate hydrocarbon levels with the confidence of <br /> laboratory analyses. <br /> Laboratory Procedures <br /> Selected soil samples collected from the excavations will be analyzed by a California state- <br /> certified laboratory for the presence of total petroleum hydrocarbons calculated as gasoline, <br /> benzene, toluene, ethylbenzene, and xylenes and MtBE using modified EPA Methods 8015 <br /> and 8020. In addition, selected soil samples collected from the area of the former waste oil <br /> 9200391A/WPLAN A- 1 August 27, 1996 <br />