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E <br /> ATTACHMENT A <br /> FIELD AND LABORATORY PROCEDURES <br /> Exploratory Drilling <br /> The soil boring for the groundwater monitoring well will be drilled using 8-inch hollow-stem <br /> auger drilling equipment to a depth of approximately 20 feet bgs (first groundwater is <br /> expected to be at approximately 7 feet bgs). Borings will be logged by a SECOR <br /> International Incorporated geologist using the Unified Soil Classification System and standard <br /> geologic techniques. Soil samples for logging will be collected at 5 -foot depth intervals using <br /> a California-modified split-spoon sampler. The sampler will be driven a maximum of <br /> 18 inches using a 140-pound hammer with a 30-inch drop. All soil samples for chemical <br /> analysis will be retained in brass liners, capped with Teflon squares and plastic end caps, and <br /> sealed in clean zip-lock bags. The samples will be placed on ice for transport to the laboratory <br /> accompanied by chain-of-custody documentation. All down-hole drilling and sampling <br /> equipment will be steam-cleaned following the completion of the soil boring. Down-hole <br /> sampling equipment will be washed in an alconox solution between samples. <br /> Organic Vapor Procedures <br />` Soil samples collected at 5-foot depth intervals during drilling will be analyzed in the field for <br /> ionizable organic compounds using a photo-ionization detector (PID) with a 10.2 eV lamp or <br /> a flame ionization detector (FID). The test procedure will involve measuring approximately <br /> 30 grams from an undisturbed soil sample, placing this subsample in a sealed container (either <br /> a zip-lock bag or a mason jar). The container will be warmed for approximately 20 minutes <br /> (in the sun), then the head-space within will be tested for total organic vapor, measured in <br /> parts per million as benzene (ppm; volume/volume). The instrument will be calibrated prior to <br /> drilling using a 100-ppm isobutylene standard (in air) and a sensitivity factor of 55 which <br /> relates the photo-ionization potential of benzene to that of isobutylene at 100 ppm. The <br /> results of the field testing will be noted on the boring logs. PID and FID readings are useful <br /> for indicating relative levels of contamination, but cannot be used to evaluate hydrocarbon <br /> levels with the confidence of laboratory analyses. <br /> l <br /> i <br /> 76007-044-01/WpIm A - 1 11/03/98 <br />