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On August 8, 1998, a work plan was prepared for six monitoring wells. On October 2, 1998, SJCEHD approved the six monitoring wells requested in the work plan and required two additional monitoring wells to 70 feet below ground surface (bgs). In March and April of 1999, six monitoring wells and one deep soil boring were installed by JJW Geosciences (JJW). On August 30 and 31, 1999, two monitoring wells (MW-7 and MW-8) were installed to 110 feet bgs. On March 16, 2000, SJCEHD requested that the vertical and lateral extent of the documented contamination be further evaluated, and additional monitor wells be installed. JJW submitted a workplan and a workplan addendum on May 12, 2000, and July 31, 2000, in response to the SJCEHD directive. The workplan outlined the additional site assessment, monitor well installation, and replacement of the compromised monitor well MW-7 required by SJCEHD. SJCEHD approved the workplan on August 30, 2000. JJW completed direct push water sampling and analysis on April 6, 2001 to evaluate the site for monitor well placement. On May 2, 3, and 4, 2001, a soil boring with interval water sampling (SB2), and four additional monitoring wells (MW-9 to MW-12) were installed. MW-7 was abandoned and replaced by MW-7A. Monitor well MW-3 was damaged in 2002 due to construction activities at the adjoining business and could no longer be sampled. After approval from SJCEHD, MW-3 was abandoned by overdrilling and grouting with cement from the bottom, using tremie pipe, to the surface on October 8, 2004. In September and October, 2004, twenty sparge points, ranging in depth from 37 feet bgs to 130 feet bgs, were installed at twelve locations in and around the petroleum contamination plume. In November and December, 2004, the sparge points were plumbed to an ozone generating system installed at the subject site. Ozone sparging was initiated on December 1, 2004. The SJCEHD recommended, in a letter dated March 18, 2008, modifying the sampling regimen of groundwater monitoring wells MW-4, MW76, MW-9, MW-10, and MW-12 to annual sampling events from the current quarterly sampling schedule. Soil Vapor Survey Upon approval of this workplan, JJW will forward a permit application and appropriate fee to San Joaquin County Environmental Health Department (SJCEHD) for approval and permitting purposes, if required. We will indicate the chosen well driller's license number and prepare a site-specific health and safety plan. Following permit issuance, we will obtain utility clearance through Underground Service Alert. We will also schedule a grout inspection with San Joaquin County at least 24 hours in advance of the proposed investigative activities, if required. JJW GEOSCIENCES Inc.