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'—tl� —�• Bi'P? <br /> e •_ <br /> y.r <br /> r <br /> 13F3� <br /> 1 .. <br /> 1,0 N�PE 01)5 <br /> {i I,1 moil Sam�iln�and Contaminntlon Reduct[on <br /> Soil borings and soil sampling was performed under the direction of a Delta engineer or geologist. The <br /> soil borings were advanced using a truck-mounted drill rig utilizing hollow-stem augers. <br /> To reduce the chances of cross contamination between boreholes,all down-hole drilling equipment were <br /> cleaned between each soil boring. To reduce cross contamination between samples, the split-barrel <br /> sampler was washed in a soap solution and double rinsed between each sampling event. <br /> Soil sampling was done in accordance with ASTM 1586.94. Using this procedure, a 2-inch outside- <br /> diameter split-barrel sampler or a 2-inch inside-diameter California-type sampler is driven into the soil by <br /> a 140-pound weight falling 30 inches. After an initial set of 6-inches the number of blows required to <br /> drive the sampler an additional 12 inches is known as penetration resistance, or the "N"value. The N <br /> value is used as an empirical measure of the relative density of cohesionless soils and theconsisten <br /> cy of <br /> cohesive soils. <br /> Upon recovery, a portion of the soil sample was placed into a glass jar and sealed for later screening <br /> with a photoionisation detector (PID). Another p <br /> ,cz (p ) portion of the soil sample was used for classification <br /> and description. That part of the soil sample collected in brass tubes within the California-type sampler <br /> was stored at approximately 4oC for transport to the laboratory. <br /> 1.2 Soil Cinssldcation <br /> As the samples are obtained in the field, they were classified by the crew chief/geologist in <br /> accordance <br /> with ASTIvI D24&WW. Representative portions of the samples were returned to the laboratory for further <br /> E.� examination and for verification of the field classification. bogs of the borings indicating the depth and ' <br /> identification of the various strata, the N value, water-level information and pertinent information <br /> regarding the method of maintaining and advancing the bore hole were made. <br /> ` 1.3 SOILSamnle ScrgeninaNu Photolonization Detector Method <br /> After soil-sample jars have been brought to room temperature, the head-space vapors of the soil-sample <br /> jars were screened with an hNu photoionization detector equipped with a I0.2 eV lamp calibrated to <br /> benzene for direct reading in parts per million (ppm). The sample-jar lid will be opened and the hNu <br /> _ - probe irnmediately placed within the head space of-the-jar.-The highest observed reading was recorded----------- <br /> T <br />