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amec­� <br /> AMEC will collect two soil samples from each boring within the upper 10 feet to obtain data for <br /> possible use in a health risk assessment(HRA). AMEC will also collect soil samples from <br /> depths corresponding to the depth where affected soil was encountered at the Tracy Rail Yard <br /> (approximately 15 to 20 feet bgs). If affected soil is observed in a soil boring, samples of <br /> affected soil will be targeted. Two soil samples also will be collected below visibly-affected soil, <br /> with the deeper sample put on hold pending analysis of the shallower sample collected below <br /> affected soil. If no visually affected soil is identified, soil samples will be collected at depths of <br /> approximately 5, 10, 15 and 20 feet bgs. Soil samples will be collected in butyrate sleeves, or <br /> equivalent, sealed with Teflon sheets, end caps, and silicon tape. <br /> Grab groundwater samples will be collected from each boring following installation of a <br /> temporary well consisting of 1-inch-diameter polyvinyl chloride (PVC) blank casing and 5 feet <br /> of 0.01-inch slot well screen. The outer drive casing will be retracted approximately 2 to 5 feet <br /> to expose the PVC screen to the water bearing-unit while maintaining a surface seal. The <br /> groundwater sample will be collected using a peristaltic pump and will be decanted into the <br /> appropriate containers provided by the laboratory. In general, a grab groundwater sample will <br /> not be collected if affected soil is observed in the soil core. <br /> AMEC will advance additional step-out borings if stained soil is observed during drilling <br /> activities or analytical results indicate that the lateral extent of affected soil or groundwater has <br /> not been defined. The location of potential step-out borings will be determined based on <br /> results of the primary sampling activities. AMEC will employ the drilling and sampling methods <br /> described herein when advancing step-out borings and collecting additional samples. <br /> All soil and groundwater samples will be stored in ice-cooled chests until delivery to a <br /> California-certified analytical laboratory in accordance with AMEC chain-of-custody protocols. <br /> Soil cuttings, decontamination water, and purge water will be placed in 55-gallon drums. The <br /> drums will be temporarily stored at a nearby Chevron-owned property (990 Beechnut Street) <br /> pending analysis and disposal by CEMC. <br /> 4. 2 ANALYTICAL METHODS <br /> Soil samples will be analyzed for TPH quantified as crude oil (TPHc; carbon range C10 to Cas) <br /> using U.S. Environmental Protection Agency (U.S. EPA) Method 8015, BTEX using U.S. EPA <br /> Method 8260, and PAHs using U.S. EPA Method 8270C with selective ion monitoring (SIM). <br /> Soil sample analytical data will be reported on a dry-weight basis. <br /> AMEC Geomatrix, Inc. <br /> X:\16000s\161130\4000\OffSiteEastWP 061511\1 txt,cvrs,Itrs\text.docx 5 <br />