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Workplan for Monitoring Well Installation Flag City New West#1003,6437 West Banner Street,Lodi,California Page 3 November 9, 2005-Apex,New West, SJCEH, and the CVRWQCB had a meeting discussing the site and future work. January 9, 2006-The SJCEHD issued a letter requiring clarity as to the owner and operator of the site for the clean up fund, stating additional sampling was needed for the NPDES permit, requiring Apex to conduct a pumping test, and to evaluate other remedial alternatives. January 2006 -To determine the source of the release at the site,New West performed an enhanced tracer test at the site. No deficiencies with the underground fueling system were detected during the enhanced tracer test. No source of a release at the New West site has been determined. March 30, 2006 -Apex,New West, SJCEH, and the CVRWQCB had a meeting discussing the site and future work. It was decided that additional wells and interim remediation is needed at the site. March 30, 2006—Apex prepared and submitted an Interim Remediation Plan Letter including a proposal to submit a workplan for additional wells at the site. April 4, 2006—Interim remediation was initiated using weekly 4,800 gallon batch extraction events from well EW-4 as approved by SJCEHD (Appendix A). MONITORING WELL INSTALLATIONS Based on current soil and groundwater conditions (Tables 1 through 3) and as illustrated on Figures 3 through 7, Apex proposes to install seven additional monitoring wells as shown on Figure 8 (MW-3C,MW-7A, MW-7B,MW-8A, MW-8B, MW-9B, and MW-9C). The placement of these new wells will provide lateral and vertical definition information and provide additional information regarding the nature and number of sources in the vicinity and assess the possibility of commingled plumes. Offsite wells will be installed on private properties and right- of-entry agreements will have to be contracted prior to well installation. Depth to groundwater is approximately 14 feet below ground surface(bgs) and all wells will be installed using a hollow stem auger drill rig. All wells will be constructed using Schedule 40 PVC and 0.020 slotted schedule 40 PVC screen. A zone wells will be installed within the first zone to a total depth of 25-feet bgs and screened from 5-to 25-feet bgs. B zone wells will be installed in the second zone to a total depth of 50-feet bgs and screened from 40 to 50 feet bgs. C zone wells will be installed in the Rocky's upper zone to a total depth of 75-feet bgs and screened from 70-to 75- feet bgs. Total depth may be modified pending subsurface conditions. The annular space between the well screen/casing and the borehole will be backfilled with a#3 Monterey sand pack from total depth to 1-foot above the screened interval, followed by 2-feet of hydrated bentonite and Portland cement to the surface. The well casings will be protected with locking expansion caps and traffic-rated vault boxes.