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r� <br /> . Work Plan for So,l and Groundwater Assessment 2 <br /> Chevron U S A. Products Company, 575 West Grantline Road, Tracy, CA February 14, 1995 <br /> TASK 2 SOIL BORINGS/SOIL SAMPLING <br /> Groundwater Technology will drill four soil borings at the locations shown on Figure 1 <br /> (Attachment 1) using a truck-mounted drill rig equipped with 8-inch-diameter hollow-stem augers <br /> The borings will be drilled to approximately 20 feet below ground surface (BGS) to accommodate <br /> groundwater monitoring well installation <br /> i <br /> i <br /> Soil samples will be collected from each sod boring at 5-foot intervals beginning at 5 feet BGS using <br /> a split-spoon sampler lined with 2-inch-diameter by 6-inch-long brass sample tubes The <br /> hollow-stem augers will be steam cleaned before drilling, and sampling equipment will be cleaned <br /> between each sampling interval Each sod sample will be screened for hydrocarbon vapors using a <br /> photoionization detector (PID) Soils encountered during drilling will be logged using the Unified Soil <br /> Classification System by a Groundwater Technology field geologist, working under the supervision of <br /> a California registered geologist One sample tube from each sampling interval will be sealed with <br /> aluminum foil, capped, taped, labeled, and placed on ice in an insulated container Based on field <br /> observations, selected soil samples from each borehole will be analyzed by a State-certified <br /> analytical laboratory for benzene, toluene, ethylbenzene and xylenes (BTEX), and total petroleum <br /> hydrocarbons-as-gasoline (TPH-G) <br /> All sod generated through drilling will be placed on and covered with plastic sheeting on site pending <br /> characterization and disposal Water generated by steam cleaning will be contained in a <br /> steam-clean trailer and temporarily stored on site in Department-of-Transportation (DOT) approved <br /> 55-gallon drums <br /> TASK 3 GROUNDWATER MONITORING WELL INSTALLATION/DEVELOPMENT <br /> Groundwater monitoring wells will be constructed of 2-Inch-diameter blank polyvinylchloride (PVC) <br /> casing and 0 020-inch-slot PVC well screen The well screen will be installed approximately 5 to ten <br /> feet above and ten feet below the water table A sand filter pack will be placed within the annulus of <br /> each well from the bottom of the boring to approximately 2 feet above the top of the well screen <br /> The annulus will be sealed with approximately 2 feet of bentonite on top of the sand, and a portland <br /> cement/bentonite grout to the surface Well construction specifications will be adjusted according <br /> to field conditions, if required The well heads will be protected by a locking cap and a traffic-rated, <br /> watertight street box set in concrete <br /> Prior to groundwater monitoring and sampling, the monitoring wells will be developed by surging <br /> and bailing to remove fines from the well and sand pack The wells will be developed until well <br /> water is visibly clear Development water will be stored in a DOT-approved purge water trailer and <br />. hauled to a Chevron refinery for recycling <br /> 01385GA WKP <br /> PE110 <br /> GROUNDWATER <br /> ❑ TECHNOLOGY , <br />