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. Site History Canepa's Car Wash(Pacific Avenue) Page 6 of 7 1n a letter dated October 2, 2002 Condor requested annual monitoring of monitor wells MW-5, MW-6, MW-7, and the destruction of monitor wells MW-8 and MW-10. In a letter dated February 4, 2003, the SJCEHD indicated that the monitoring frequency for monitor wells MW-5, MW-6, MW-7, and MW-10 could be reduced to annually (with the annual event to be conducted in the third quarter) and that monitor well MW-8 could be destroyed. The SJCEHD also indicated that installation of a monitor well in the vicinity of former monitor well MW-8 and a down-gradient monitor well was required following development of the property that the MW-8 was located on. Monitor well MW-8 was destroyed by Condor on April 11, 2003. Condor conducted quarterly monitoring activities at the site on January 14 and 15, 2003. Laboratory analytical results of the groundwater samples indicated concentrations of petroleum hydrocarbon constituents consistent with historical data. At the request of Mr. Jeffrey Wong of the SJCEHD, groundwater monitoring for gasoline oxygenates/additives was reinitiated during the first quarter of 2003. 1,2-DCA and TBA were detected in groundwater samples collected from MW-3 and MW-11 at concentrations of 190 pg/L and 15 µg/L, respectively. The groundwater sample analytical results for MW-12D continued to indicate a trend of lower contaminant concentrations since the initial sampling event for this well conducted on October 25, 2001, The SVE system was temporarily removed from service for modifications on January 31, 2003. Condor conducted second quarter 2003 groundwater monitoring activities at the site on April 17 and 18, 2003. Laboratory analytical results of the groundwater samples indicated that concentrations of petroleum hydrocarbon constituents were generally consistent with historical data. Groundwater elevation data indicated that the groundwater gradient was consistent with historical groundwater gradients. The SVE system continued to be out of service for modifications, pending approval by the SJCEHD of the RAP submitted by Condor for the site. Condor conducted annual groundwater monitoring activities during the third quarter 2003 at the site on July 25, August 1, and August 4, 2003. Laboratory analytical results of the groundwater samples indicated that concentrations of petroleum hydrocarbon constituents were generally consistent with historical data. For the first time in the monitoring history of deep monitor well MW-12D, none of the contaminants of concern were detected at or above the laboratory reported detection limits. TBA and TAME were detected in the sample collected from MW-3 for the first time (110 and 1.3 µg/L, respectively). The concentration of MTBE detected in the groundwater sample collected from MW-3 is consistent with an increasing trend for that contaminant in that well. Groundwater elevation data indicated that the groundwater gradient was consistent with historical groundwater gradients. The SVE system continued to be out of service for modifications, pending approval by the SJCEHD of the RAP submitted by Condor for the site. Condor conducted fourth quarter 2003 groundwater monitoring activities at the site on November 9, 2003. Four of the site monitor wells historically used to estimate groundwater gradient/elevation were not utilized during the monitoring even. Water level data from wells MW-2 and MW-11 were significantly different than water levels from nearby wells and were believed to be erroneous. MW-5 and MW-10 had been paved over and were not relocated and restored until November 10. Laboratory analytical results of the groundwater samples indicated that concentrations of petroleum hydrocarbon constituents were generally consistent with historical data. No constituents of concern were detected in the samples . collected from monitoring well MW-9 and deep monitoring well MW-12D. The concentration of MTBE detected in the sample collected from monitor well MW-3 nearly doubled and is consistent with an