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_ .._ w rag�!i On S - �' _ - - ,miss. •Yr l 1.9 METH D .1 Soil Sampling andon aminati n Reduction Soil borings and soil sampling will be performed under the direction of a Delta engineer or geologist. The soil borings will be advanced using a :ruck-mounted drill rig utilizing hollow-stem augers. To reduce the chances of cross-contamination between boreholes,all down-hole drilling equipment will be cleaned between borings. To reduce cross-contamination between samples, the split-barrel sampler will be washed in a soap solution and double rinsed between each sampling event. Soil sampling will be done in accordance with ASTMA586-84. Using this procedure, a two-inch O.D.split-barrel Sampler or a two-inch I.D.California-type sampler is driven into the soil by a 140- f pound weight falling 30 inches. After an initial set of six inches,the number of blows required to ' drive the sampler an additional 12 inches is known as penetration resistance, or the KN"'<falue. The N value is used as an empirical measure of the relative density of cohesionless soi:; and the consistency of cohesive soils. Upon recovery, a portion of the soil sample will be place+ into a glass jar and sealed for later screening with a portable photoionization detector. Another portion of the soil sample will be used f'- for classification and description. That part of the soil sample collected ir, brass tubes within the California-type sampler will be stored at approximately 4°C for transport to the laboratory. r , 12 Soil la Ifica!'Fnn As the samples are obtained in the field,they will be classified by a geologist/engineer in accordance with ASTM:D ,2488-84_ Representative portions of the samples will then be returned to the E laboratory for further examination and for verification of the field classification. Logs of the 1 £ f boring•,.indicating the depth and identification of the various strata, the N value, water-level information and pertinent information regarding the method of maintaining and advancing the bore hole will be made. E 1.3 Soll-Sauml rggnin _r oi. Ph i niza i n Insiterinr M h d After soil-sample jars have been brought to room temperature, the head-space vapors of the soil- r sample jars will be screened with a portable photoionizatien detector equipped with a 10.2 eV lamp calibrated to benzene for direct reading in parts per million(ppm).The sample-jar lid will b.,opened and_the-.probe-imm..e_diately_placed within the head space of the jar. The highest observed reading -------.. !aa will be recorded. - - - - i; ins.