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. Monitoring Well and Sparge Point Installation Report—Former Unocal Service Station#0187 July 15,2002 (Figure 2) Fieldwork was performed in accordance with GR's Site Safety Plan #240042 11, dated February 8, 2002 GR Field Methods and Procedures are included in Appendix A Underground Service Alert was notified prior to beginning site activities The wells were installed by Woodward Drilling, Inc (C57 # 710079), under SJCPHS-EHD permits #2882.1 and 428822 and City of Stockton encroachment permit 466869 Copies of the permits are included in Appendix B The one groundwater monitoring well and eight ozone microsparge wells were installed on February 11 through 19, 2002 Monitoring well boring U-26 was drilled to the depth of 120 feet bgs, and microsparge well borings SP-5A and SP-6A were drilled to the depth of approximately 111 feet bgs, SP-513 and SP-6B were drilled to a depth of 65 feet bgs, SP-1C and SP-3C were drilled to a depth of 45 feet bgs, and SP-5C and SP-6C were drilled to a depth of 40 feet bgs using a truck-mounted drill rig equipped with 8-inch diameter hollow-stem augers A GR geologist observed the drilling activities Soil samples were collected at five-foot intervals from well boring U-26 for description and preparation of a Iog, and possible chemical analysis Soil samples were collected at ten-foot intervals from microsparge well borings SP-5A and AP-6A for description and preparation of a log For microsparge well borings SPAC, SP-3C, SP-5B, SP-5C, SP-613 and SP-6C, soil samples were not collected Boring logs are included in Appendix C Locations of newly installed wells are shown on Figures 2 and 3 Copies of the Well Completion Reports are included in Appendix C Soil cuttings generated during drilling activities were stockpiled on-site, and were placed on and covered with plastic Composite disposal confirmation sample SP-1,2,3,4 was collected from the stockpiled soil cuttings(Table 1) Stockpile sampling procedures are presented in Appendix A Well Installation Groundwater monitoring well U-26 was constructed using 2-inch diameter Schedule 40 polyvinyl chloride (PVC) casing and 0 020-inch machine slotted screen material Well U-26 is screened from 110 to 120 feet bgs The annular space around the screen is packed with Lonestar #3 graded sand The sandpack is followed by a seal of bentonite chips, then neat cement to approximately 1-foot bgs The top of the well is protected by a vault box, locking well cap, and lock The vault box is installed flush with the ground surface, and is set in concrete The microsparge wells are constructed using 3/4-inch diameter Schedule 40 PVC casing and 2-inch diameter PVC microsparge screen material Microsparge wells SPAC and SP-3C are screened from 42 5 to 45 feet bgs, SP-5C and SP-6C are screened from 37 5 to 40 feet bgs, SP-513 and SP-6B are screened from 62 5 to 65 feet bgs, and SP-5A and SP-6A are screened from 107 5 to 110 feet bgs The annular space around the screens in each well is packed with Lonestar #2112 sand Above the sandpack, the sparge wells are constructed similar to monitoring well U-26 Well construction details are included with the boring logs in Appendix C Well Mon itonn Develo ment and Sampling The newly installed groundwater monitoring well was developed on March 11, 2002, by Woodward Drilling, Inc (C57 # 710079) On April 11, 2002, well U-26 was monitored and sampled by GR The well was checked for the presence of separate phase hydrocarbons (SPHs) No SPHs were observed in 24004211-1 4