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aIM —4 7 9' r ; L i" inn After obtaining an access permit from Crestwaod i-Iospital,WC MW 11 was installed on 17 April 1991 in the parking lot of the hospital. 1,11v well was compacted 44 feel bgs with 4-inch- April diameter PVC casing; the screen is 20 fret long. This well define.- :extent of the petroleum hydrocarbon plume in the downgrtdient(northeast)direction. 3.3 WELL COMPLETION DETAILS With the exception of PSV 1 and PSV2,the annular space in the boreholes was packed with�S Lonestar sand to 1-2 feet above the top of the screen. A bentonite plug 1-2 feet thick was laaced on top of the sand pack,and the remainder of the annular space was backfilled to the surface with a cement-bentonite grout. The wells were completed at the surface with a locking expansion cap, and all of the wells were secured at the surface inside 14-inch-diameter water-tight steel traffic boxes. A well tag containing p:rtinent information about the well construction,owner,and well number was placed in the traffic box for each well. Well construction details are included in the well logs(Appendix B)and are detailed in accompanying figures. Wells PSV1 and PSV2 were completed as cluster wells; each boring contains two 1-inch-diame- ter screens and casings installed at different depths. The vertical intervals between the deeper and shallower screens were filled with cement-bentonite grout to prevent direct air flows be tweet,these two monitored zones. 3.4 SOIL SAMPLING ing in Undisturbed soil samples were collected at 5-foot intervals aring n calchlborehlole are indicat- ed ndic accord- ance - ance with EA standard protocols(Appendix A). sample depths i ed in the boring logs(Appendix B). Soil samples were delivered, under chain of custody, to Pace Laboratories,certified by the Cali- fornia Department of Health Services(DHS)for hazardous materials analysis. The samples were analyzed for total petroleum hydrocarbons(TPH) as gasoline by DHS-modified EPA Method 8015 and for benzene7 toluene,xylenes,and ethylbenzene(BTXE)by EPA Method 8020. 3.5 WELL DEVELOPMENT All new wells,except vapor monitoring wells PSV 1 and PSV2 and vapor extraction wells V2 and V4,were developed following EA standard protocols(Appendix A). The wells were surged with a vented surge block for about 15 minutes and then purged using a submersible pump; the procedure was repeated three times,or until the water was relatively clear and free of sand and silt and sediment from the well's bottom was removed. 8 e5?f�•N179471iun4lR+ .