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08 September 2009 AGE -NC Project No. 03-1055 Page 14 of 19 depicted on Figure 13. The vertical extent of impacted ground water at the former Tracy Diner site appears to be limited to the water table as evidenced by the generally non -detect, deep screened (between 30 feet and 35 feet bsg) ground water monitoring wells MW -13 and MW -14. Based on the extensive commingling of the former Chevron and Tracy Diner plumes (Figure 12), determination of the remaining dissolved TPH-g mass is not feasible without including former Chevron contamination. Therefore, AGE did not calculate a remaining dissolved TPH-g mass at the site. Utilizing Figure 12, however, it appears the soil excavations conducted in 2000 and 2003, greatly reduced the dissolved mass on the former Tracy Diner site. 4.2. ESTIMATED TIME TO COMPLIANCE Graphs illustrating the concentration hydrocarbons from ground water analysis at the site were generated to analyze trends in the reported data over time. These graphs were also used to estimate when dissolved petroleum hydrocarbon concentrations at the site will be in compliance with the CVRWQCB water quality objective for TPH-g of 5 µg/1. The CVRWQCB water quality objective for TPH-g is a taste and odor threshold, or the concentration at which TPH-g will not impart an undesirable taste or odor in ground water, or other edible products of aquatic origin. Based on trend analysis ofanalytical data verses time and linear regressions, the estimated compliance date for wells MW -6 and MW -8 is projected to be in April 2011. Well MW -1 I was omitted from estimated compliance determinations because the impact observed in this well is the result of the former Chevron release. Trend graphs illustrating groundwater analysis over time and estimated date of compliance are included in Appendix F. 5.0. SENSITIVE RECEPTOR SURVEY As part of the leak investigation at the closed former Chevron site, approximately 40 feet west of the former Tracy Diner property, a well search was conducted by Gettler-Ryan, Inc (GRI). Results of the GRI well search were presented in the report entitled Well Search for Former Chevron Service Station #9-0959, 103 H" Street, Tracy, California (Well Search) and dated 21 January 1997; the above referenced report is provided as Appendix K. According to the GRI Well Search, 14 wells were located within 'h -mile of the former Chevron. Seven of the 14 wells were identified as municipal wells, two were identified as domestic wells, three were identified as ground water monitoring wells, one was identified as an agricultural well, and one well did not have an identified use. Well locations are shown on the Well Search Figure 1 Advanced GeoEnvironmental, Inc.