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KLEINEELDER Soil samples were collected by drilling to immediately above the sampling g depth A modified ' California split-spoon sampler lined with three brass or stainless steel tubes was driven into the undisturbed soil beneath the augers Upon removal from the sampler, the bottom tube was immediately sealed with Teflon sheeting and plastic caps, labeled, logged on a chain of custody, and placed into an Iced cooler for transport to the analytical laboratory 3 2 GENERAL SITE HYDROGEOLOGY The soil encountered in each of the borings consisted of sand from the ground surface to approximately 15 feet below ground surface. The sand was underlain by a sandy silt to a depth of approximately 20 feet. A moderately dense silty clay was observed in each of the borings from approximately 20 feet to nearly 25 feet In the monitoring wells, the clay was underlain by interbedded sands and silts to a depth of 50 feet Groundwater was encountered in monitoring well MW-1 and MW-3 at approximately 40 feet, and in MW-2 at approximately 36 feet. Water rose in each of the borings prior to construction suggesting that semi-confined or slow recharge conditions may occur 3.3 QUALITATIVE FIELD SCREENING To provide a qualitative indication of the presence volatile organic constituents in the soil and to monitor concentrations in the breathing zone, a photoionization detector (PID) was used to screen the samples in the field The PID was equipped with a 10 6 eV lamp and measured total ionizable compounds in parts per million by volume (ppmv) relative to an Isobutylene calibration standard Qualitatively, the PID readings correlated well with the quantitative data supplied by the laboratory. Analyzed samples with PID readings less than 100 ppmv either did not contain detectable concentrations of petroleum hydrocarbons or contained concentrations near the detection limits The PID readings are presented with the analytical data on Table 1 For the protection of the field crew, the PID also was used to measure the total ionizable concentrations in the breathing zone prior to and while drilling of the borings No consistent readings were noted in the breathing zone above I ppmv while drilling the borings 24-220152-Do01FR12-105 (1993) Page 5 of 18 July 27, 1993 Copyright 1993 Kleinfelder, Inc