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Ms. Margaret Lagorio,SJCEHD January 5,2005 <br /> Work Plan for Additional Site Assessment and Project No. 2033-15600-01 <br /> Evaluation of Remedial Alternatives <br /> Joe's Truck Plaza,Lathrop,California <br /> Page 5 <br /> • Contract with a California-licensed well driller (C-57 license) to install the <br /> proposed wells. <br /> • Update the site-specific Health and Safety Plan. <br /> • Secure permits from SJCEHD to perform the drilling and well construction <br /> activities. <br /> • Mark the proposed well locations and notify Underground Service Alert at least <br /> 48 hours in advance of the scheduled field activities. <br /> • Secure a permit to discharge extracted water to the sanitary sewer during <br /> feasibility testing. <br /> • Secure a permit from the San Joaquin Valley Unified Air Pollution Control <br /> District (SJVAPCD) to discharge treated soil vapor to the atmosphere during <br /> feasibility testing. <br /> Task 2: Soil Borings and Monitoring Well Installation Activities <br /> Drilling Activities <br /> Three borings (MW-9 through MW-11) will be drilled to the base of Sand A <br /> (approximately 15 feet bgs), and one boring (MW-8)will be drilled to the base of Sand B <br /> (approximately 40 feet bgs). These borings will all be completed as monitoring wells, as <br /> described below. All borings will be advanced using a truck-mounted drilling rig <br /> equipped with 8-inch diameter hollow-stem augers. To advance the boring for well <br /> MW-8, a 12-inch diameter boring will be advanced approximately 5 feet into the fine- <br /> grained material at the base of Sand A (approximately 20 feet bgs), and a steel conductor <br /> casing will be installed and cemented in place. The 8-inch diameter augers will be <br /> advanced through this conductor casing to complete the well boring. The proposed <br /> monitoring well locations are shown on Figures 2 and 3. <br /> The initial 5 feet of each boring will be advanced with hand tools, air knife, or water <br /> knife to reduce the possibility of damaging underground utilities. At a minimum, soil <br /> samples from each boring will be collected at 5-foot intervals during drilling using a <br /> California-type, split-spoon sampler, fitted with three pre-cleaned brass tubes. The <br /> sample tubes will be filled by drilling to the desired sampling depth, then driving the <br /> sampler ahead of the augers. After retrieving the sampler, the ends of the bottom-most, <br /> intact tube from each sample interval will be lined with Teflon TM sheets, capped, and <br /> sealed. Each sample will then be labeled, placed in a resealable plastic bag, and stored in <br /> an ice-chilled cooler. The samples will remain chilled and strict chain-of-custody <br /> procedures will be followed from the time the samples are collected until the time the <br /> samples are relinquished to the laboratory. <br /> K:Uoe's Truck Plaza\Work PlansUoes workplan 010505.doc <br />