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i+rievron u mil. r-rouuci5 Wmpdrly, IV3 VYBSS I IUl Jl, IIkluy, VM +•+ ++•� "" <br /> TASK 2. SOIL BORINGS/SOIL SAMPLING <br /> Groundwater Technology will drill two soil borings at the locations shown (Figure 1, Attachment 1) <br /> using a truck-mounted drill rig equipped with 8-inch-diameter hollow-stem augers The borings will <br /> be drilled to approximately 25 feet below ground surface (BGS) to accommodate groundwater <br /> monitoring well installation "` <br /> Sod samples will be collected from each soil boring at 5400t 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 hollow- <br /> stem augers will be steam cleaned before drilling, and sampling equipment will be cleaned between <br /> each sampling interval Each soil 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 sod 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 (CPH-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 steam- <br /> clean trader and temporarily stored on site in Department-of-Transportation (DOT) approved 55- <br /> 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 10 feet <br /> 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 The well heads will be protected by a locking cap and a <br /> traffic-rated, watertight street box set in concrete Figure 2 shows construction details of a typical <br /> monitoring well <br /> Prior to the next scheduled groundwater monitoring and sampling event, the groundwater monitoring <br /> wells will be developed by surging and bailing to remove fines from the well and sand pack <br />