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� v <br /> 0 <br /> A S 5 0 C I A T E S I N C <br />' 2_3 Groundwater Sampling and Analysis <br />' On February 7 and 8, 2002, a groundwater sample was collected from borings CPT-1 and CPT-2 <br /> A geoprobe water sampler was advanced to a depth of 93 feet At this depth, the screen was <br /> exposed and groundwater allowed to flow into the water sampler A clean reusable aluminum <br />' bailer was lowered into the water sampler to collect groundwater, retnved and groundwater <br /> transferred to the sample containers Sample containers were then labeled with sample <br /> identification, placed on ice, and shipped under chain-of-custody to Argon Laboratories <br /> tThe groundwater sample from bona s CPT-1 and CPT-2 were analyzed by Argon Laboratories <br /> for TPHg, BTEX, and oxygenates fuel additives Groundwater analytical results are summarized <br />' in Table 2, and laboratory data sheets are presented in Appendix B <br />' 3.4 SUBSURFACE CONDITIONS <br /> 331 Geology <br />' The CPT borings extend to a depth of 120 feet below ground surface At boring CPT-1, based on <br /> soil behavior types (SBT) as determined by the CPT logs, clays and clayey silts were encountered <br /> from the surface to a depth of approximately 30 feet From approximately 30 feet to <br /> approximately 60 feet stiff fine grained materials were primarily encountered along with thin <br /> layers of clay and silt From 60 feet to 120 feet, layers of clays, clayey silts, silts, and stiff fine- <br /> grained materials were primarily encountered At approximately 62 feet and 110 feet sandy silt <br /> was encountered <br />' 3_2 Hydrogeology <br /> A water level measurement was taken at boring CPT-1 on February 7, 2002 The water level was <br />' measured at a depth of 59 feet from the ground surface A summary of groundwater monitoring <br /> data is presented in Table 3 <br />' The site's underlying groundwater gradient could not be determined with a single measurement <br /> point, however regional groundwater flow is estimated to be eastward based on San Joaquin <br />' County Flood Control and Water Conservation District data (Lines of Equal Elevation of <br /> Groundwater, Fall 1997) <br />' 4.0 ANALYTICAL RESULTS <br /> 4.1 Soil Analytical Results <br /> ' Soil samples collected from boring CPT-1 and CPT-2 at depths of 50 and 91 feet bgs did not <br /> r contain concentrations of TPHg, benzene, ethylbenzene, toluene, ethylbenzene, and total xylenes <br /> above laboratory detection limits of 50 parts per billion (ppb), and 0 50 ppb, respectively <br /> W lwordpro117292117292 D 14epoM\!,.p_,nv doc 3 <br />