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i The annular space between the casing and open hole of each well was filled from the top of the bentonite seal to the surface with a cement bentonite mixture under the direction of Michael Collins of the San Joaquin Co. EHD. All unused core material & drill cuttings were placed in sealed drums, clearly marked, and stored on site. The preserved cores were transferred under chain of custody to FGL laboratory with instructions to test for BTEX, (EPA 8020, ) and TPH-G, (EPA 8015M, ) using detection limits as required by the appropriate regulatory agencies. All three wells were equipped with precast surface vaults, and casing tops were sealed with expandable locking caps. The vault & casings were thoroughly grouted with concrete mix, and covered with a locking type traffic cover. On August 31, 1994, Del-Tech Geotechnical developed all three wells, marked casing tops for future reference, measured water levels, and took water samples as directed by WJH, & witnessed by Michael Collins, REHS, of the County EHD. Refer to APPENDIX H for field notes of that work. The properly preserved samples . were delivered to Sherwood laboratory under chain of custody with instructions to test for BTEX & TPH-G. A licensed surveyor, Siegfried & Associaties, determined the well head elevations for groundwater gradient measurements; a copy of their worksheet is included as APPENDIX I SUMMARY OF RESULTS OF ABOVE WORK: 1 . All soil samples taken & analyzed from MW-5, MW-6, & MW-7 were below detection limits for BTEX & TPH-G, indicating that the limits of the soil plume have been defined to the north, west, & south_ MW-1, located near the NE property line, revealed 25 mg/kg of benzene at 41 ' , and benzene, toluene, xylene, & TPH-G at 71' . No contamination was measured between those two depths, indicating that the groundwater, which is impacted at this location, has introduced the contamination into the soil The results of those soil analyzes are summarized on TABLE VIII ; the laboratory reports are included as APPENDIX F._ 2. All three wells revealed some contamination in the ground- water as summarized on TABLE IX showing that the "zero" line for the water has not been defined in any direction. PLATES XII & XIII are maps showing lines of equal concentration for benzene & TPH-G; they indicate that the plume extends off the property to the south & southeast_ The maps show that the plume has moved • southerly away from the site of the removed UST, following the direction of the hydraulic gradient measured to date from the 10