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A composite sample of soil cuttings generated during drilling, was collected and analyzed by <br /> Mc Campbell Analytical of Pacheco, California, for reactivity, corrosivrty, and ignitability <br /> (Title 22) to facilitate disposal. <br /> Upon amval to the laboratory, the samples' condition was checked and any nonconformaties <br /> were noted Copies of signed laboratory reports and sample condition forms are presented in <br /> Appendix C of this report <br /> 2.4 Well Construction <br /> Vadose zone observation wells were installed in the two soil borings The wells were <br /> constructed using two inch schedule 40 PVC pipe and 0 02 inch slotted PVC well screen j <br />' The screen length in each well is 25 feet, with a total well depth of 30 feet <br /> Lonestar sand #3 was used to fill the annular space surrounding the well screens, from the <br /> well base to one foot above the top of the screen Each well was sealed using a one foot <br /> thickness of 3/8 inch bentonite pellets, followed by a Portland cement slurry to within six <br /> inches of the sidewalk Tightly fitted locking caps, protected by flush mounted curb boxes <br /> were used to prevent tampering. <br /> 2.5 Disposal of Contaminated Materials <br /> Drill cuttings from the boreholes are stored in 55-gallon drums located at the site in the <br /> basement Decontamination liquids were contained in 55-gallon drums, as they were <br /> produced, and stored on-site. Soil samples not selected for analyses were placed into the <br /> drum with the drill cuttings to await disposal Used sample sleeves will be disposed of with <br /> the drill cuttings. Stockpiled cuttings and water are currently being profiled and scheduled <br /> for disposal at appropriate facilities. <br /> 3.Q Results <br /> 3.1 Site Geology <br /> During drilling activities conducted beneath the Lindsay Street sidewalk, three distinct soil <br /> layers were encountered The upper layer consisted of imported fill material, emplaced upon <br /> removal of three and replacement of one 25,000 gallon underground storage tanks at the site <br /> This fill was composed of sands, silts, and gravels and was noted to extend to approximately <br /> 18 feet below grade Native soils were encountered underlying this fill layer, which consisted <br /> NIV09-08-94/UST/94-0142 nbr <br />