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The augers were then advanced to 15 , bgl, at which point the decontaminated sample chamber was lowered into the hole and driven from 15 ' to 1616" . When the barrel was retrieved and Opened, only 411 of very wet silty clay was recovered. Steve Sasson, REHS from the San Joaquin County EHD had arrived on location earlier, and requested that another core be taken in an effort to obtain sufficient material for analysis . The core was not preserved. The augers were advanced to 171 bgl , and a clean core barrel was lowered into the well and driven to 1716" . The sample chamber was retreived and laid on a clean surface. It was opened by the geologist and recovery consisted of 6" of wet, sandy silty clay. The sample was sealed, labeled and preserved pending transport to the laboratory for analysis . A weighted tape was run in the well and measured water at 11 ' bgl . The augers were then advanced to 25 ' bgl for completion. 411 OD schedule 40 PVC casing was run into the hole and landed at 25 ' below grade . The bottom 20 ' consisted of shop made . 020" slots; the top 5 ' was blank. The annulus from bottom to 3 ' was (• packed with 9 sacks of #2/12 washed sand; one sack of bentonite pellets was placed on top of the sand, and the remaining annular space was filled with cement . The top was fitted with a precast "Christy" type box, which was thoroughly grouted in place . The 4" casing was cut off about 6" above the bottom of the box, and was sealed with an expandable locking cap. The surface was fitted with a preformed traffic cover. Refer to PLATE II for a schematic diagram of the well completion. Preserved samples were delivered to FGL laboratory under chain of custody with instructions to analyze for BTEX (EPA 8020, ) & TPHg (EPA 8015M. ) The sample at 171 was also to be screened for MTBE . The results of those analyses, summarized on TABLE A, reveal that all samples were below detection limits . Copies of the laboratory sheets, QA/QC, and custody chain are included as EXHIBIT A. On May 15, 1996, the well was developed, purged and sampled by Del-Tech Geotechnical Support Services under the direction of a representative of the San Joaquin County EHD . Details of that work are included as EXHIBIT B, along with copies of the labora- tory worksheets and chain of custody. The results of those analyses, summarized on TABLE I , reveal that the water samples were below detection limits for BTEX, MTBE, and TPHg. Elevations of the casings and their locations were determined by 2