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1 Additional Site Assessment and Sod Vapor Extraction Test, second Quarter 2002 Groundwater Monitoring Data 4 7-Eleven lnc,Store 21756,853 E Yosemite Avenue Manteca California August 5,2002 ' 55 Well Construction/Surveying On April 3, 2002, groundwater monitoring well MW-4 was installed in a 30-foot-deep 8-Inch-diameter ' boring at the location shown on Figure 2 The groundwater monitoring well was constructed of 2-Inch-diameter, Schedule 40 polyvinyl chloride casing with flush threads, and 0 020-inch-slot well screen The well screen was installed from 15-30 feet bg Sand was placed in the well annulus from the bottom of ' the borehole to approximately 2 feet above the top of the well screen The well annulus was sealed with approximately 2 feet of bentonite pellets saturated in place on top of the sand pack, and neat-cement grout to the ground surface The wellheads are protected at the surface by locking, watertight well caps and traffic-rated street boxes (with watertight bolted lids) set in concrete Well construction details are shown on the drill logs in Appendix A ' Following Installation, the monitoring well was developed by hand bailing to remove fine-grained sediments from the well and filter pack On April 2, 2002, two-dual nested sparge/vent wells (SPV-1 and SPV-2) were installed in 29-foot-deep 10- inch-diameter borings at the locations shown in Figure 2 The wells were constructed of 2-inch-diameter, Schedule 40 polyvinyl chloride casing with flush threads, and 0 020-Inch-slot screen The sparge well screen was installed from 2429 feet bg Sand was placed in the deep well annulus from the bottom of the borehole to the top of the well screen The sparge well annulus was sealed from 22-24 feet bg with approximately 2 feet of bentonite pellets saturated in place on top of the sand pack ' The SVE well screen was installed from 12-22 feet bg Sand was placed in the shallow well annulus from the bottom of the screen to approximately 2 feet above the top of the screen The SVE well annulus was sealed with approximately 2 feet of bentonite pellets (saturated in place) on top of the sand pack, overlain ' by neat-cement grout to near ground surface The wellheads are protected at the surface by locking, watertight well caps and traffic-rated street boxes(with watertight bolted lids) set in concrete Well ' construction details are shown on the drill logs in Appendix A The top of casing and rim of the box of well MW-4 will be surveyed for horizontal position and elevation ' relative to mean sea level datum Wellhead elevation Information will be included in subsequent groundwater monitoring and sampling reports 60 RESULTS OF SOIL SAMPLE ANALYSES Table 2 summarizes the laboratory analytical results for the soil samples collected on April 1 through 3, 2002 No analytes were detected above laboratory reporting limits in any of the samples collected for analysis Copies of laboratory reports and chain-of-custody documents are included in Appendix C ' 21756SAR doc