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May -22. 2000 1 :47PM TUSD_FACILITIES _ No.4044 P. 2/14 former undmvow,nd storage tank{UST}.The other bore shall be vertical, 15 to 20 feat northeast fi of n location of tine UST.However, if field observations indicate that signiicauat conation are present at the site, selected probe borings may be advanced to greater depths or to ground water,or additional probe borings may be advanced. All required San Joaquin Couody FHS permits and fees must be secured prior to start of work. Proposed probe locations are illustrated in Figure 3. Area of boring shall be first investigated by a qualified underground utility location fim. Only when areas are deemed free of underground utilities shall boring begin. Site-specific health and safety plan must be submitted to San Joaquin County PHS_ Soil samples will be collected from each probe boring;grab ground water samples will be collected from two borings where ground water is encountered. Total depth of probe borings will be based on field observations and field screening using an organic vapor meter(OW)equipped with a photo-ionization detector. Soil samples will be collected from the probe boring at five-foot intervals from ground surface to the total depth of the 20-foot boring. .Probe boring will be advanced using van-mounted Geoprobe direct-push probing unit equipped with 1.25-inch probing rods. The Geoprobe advances soil probe borings using a hydraulic or pneumatic hamine7r to drive soil and ground water sampling tools to specific depths. Soil samples will be collected using Geoprobe push-driven 2-inch diameter discrete and/or continuous come samplers fitted with four six-inch brass sleeves or a two-foot long Teflon sleeve. Upon removal from the sampler,the sample sleeve is separated with a clean soil knife. The exposed ends of the sleeve will be covered with Teflon sheets, capped and sealed with tape. Soil samples will be field screened for the presence of volatile organic compounds wing an OVM. Following sample collection,each preswa d sample sleeve will be labeled with the boring location,depth,time,and sampler's initials.Appropriately sealed and labeled samples will be placed in a chilled container under ice and pending transportation to a DHS-carOed laboratory. For the collection of grab ground water sample,a soil probe boring will be advanced to the fop of the ground water table as identified by collection of a saturated soil sample. Once ground water has been encountered,a Geoprobe push-driven water sampling device will be advanced two to three feet into the water bearing zone.A grab ground water sample will be collected using a Geoprobe water sampling assembly fitted with a pre- cleaned one-inch 0.01 slotted temporary well screen. The ground water sample will be extracted by lowering a Teflon bailer through the hollow center of the push rods into the screen section.The sample will be collected in laboratory-supplied,40-ml VOA vials containing 0.5-m1 of hydrochloric acid as sample preservative. The labeled vials and bottles will be placed in a chilled container under ice pending transportation to a DHS- certified laboratory.