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�r..r Sol-* Work Plan for Additional Site Assessment 3 7-Eleven Store#21756,853 E.Yosemite Ave.,Manteca,CA October 27, 1999 IT Corporation will conduct a technical review of the pertinent information associated with the site, Underground Service Alert(USA)will be contacted and requested to notify the local utility companies to mark the location of underground utilities surrounding the site. TASK 2: SOIL. BORINGS/SOIL SAMPLING IT Corporation will drill three soil borings at the locations shown on Figure 2 using a rotary drilling rig equipped with 8-inch-diameter hollow-stem augers. The borings will be drilled to approximately 25 feet below ground surface(BGS)depending on first encountered groundwater, and will be used to characterize and delineate the extent of adsorbed petroleum hydrocarbons and oxygenates adjacent to the former UST pit and product lines. It is anticipated that groundwater will be encountered approximately 17 feet BGS based on previous site assessments. Soil samples will be collected from each soil boring at 5-foot intervals to total depth of the boring beginning at 5 feet BGS using a split-spoon sampler lined with 2-inch-diameter by 6-inch-long brass sample tubes. Drilling equipment will be steam cleaned before drilling, and sampling equipment will be cleaned between each sampling interval. Each soil sample will be screened for hydrocarbon vapors using a flame/photo-ionization detector(FID/PID). Soils encountered during drilling will be logged using the Unified Soil Classification System by an IT Corporation field geologist, working under the supervision of a California registered geologist. One sample tube from each sampling interval will be sealed with teflon sheets, capped, taped, labeled, and placed on ice in an insulated container. An estimated two soil samples from each boring will be analyzed by a State-certified analytical laboratory for BTEX, MTBE, and TPH-G by EPA methods 8020/8015 modified and for MTBE and other oxygenates by EPA Method 8260. All soil generated through drilling will be placed in Department of Transportation (DOT)-approved 55-gallon drums pending characterization and disposal. Water generated by steam cleaning will be temporarily stored on site in DOT-approved 55-gallon drums pending characterization and disposal. TASK 3: WELL CONSTRUCTION/DEVELOPMENT/GAUGING/SAMPLING A groundwater monitoring well will be constructed in each boring of 2-inch diameter Schedule 40 poly- vinyl-chloride (PVC) casing with flush threads and 0.020-inch-slot well screen. The well screen for each monitoring well will be installed from approximately 10 to 25 feet BGS. A sand filter pack will be placed around the well screen to a maximum height of 2 feet above the top of the screen. The well will be sealed with hydrated bentonite to approximately 5 feet BGS, followed by a neat-cement grout to grade containing a mixture of 95 pounds of Portland Type I/II cement to 5 gallons of clean water. The wellhead will be protected at the surface by a locking, expandable cap and traffic-rated street box(with 21756wkp.LTR