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' Site History Canepa's Car Wash(Pacific Avenue) ' Page 8 of 9 • results of the groundwater samples indicated that with the exception of MW-1, concentrations of petroleum hydrocarbon constituents were generally consistent with historical data Contaminant concentrations in the sample collected from MW-1 increased sharply relative to the previous monitoring event due to active pumping drawing contamination to the well Contaminant concentrations in the sample collected from MW-3 decreased relative to the previous monitoring event Contaminant concentrations in the sample collected from MW-11 increased slightly relative to the July 2004 monitoring event (groundwater samples were not collected from MW-11 during the October 2004 groundwater monitoring event) Groundwater elevation data indicated that a cone of depression had formed at the location of MW-1 Monthly sampling and reports submitted to MUD, as required by the Groundwater Discharge Permit, for the months of November and December 2004, and January 2005 indicated that none of the contaminants of concern were detected at or above the laboratory reported detection limits A Condor representative conducted the groundwater monitoring activities for the second quarter of 2005, ' on April 13, 2005 The representative made field observations at the I1 site monitoring wells (MW-1 through MW-7, and MW-9 through MW-12D) and at one soil vapor extraction well (SV-4) Depth to water measurements were collected from MW-1 through MW-7, MW-9 through MW-12D, and SV4 MW-1 and MW-11 were used for groundwater extraction related to the operation of the groundwater treatment system The results and analyses of the second quarter groundwater monitoring event showed that the cone of depression around MW-1 had a greater radius of influence than measured during the previous quarter Concentrations of MTBE decreased in the pumping wells, MW-1 and MW-11, while the concentration increased in MW-3 The data collected from the groundwater extraction and treatment system indicated that the system continued to remove hydrocarbons at a steady rate and from a radius of influence that was larger than that reported during the first quarter 2005 The SVE system had removed ' approximately 40 pounds of gasoline during the second quarter of 2005 and 9,760 pounds of petroleum hydrocarbons from the soil since the SVE system was placed into service on November 1, 2004 The laboratory analytical data for the final discharge sample collected on February 16, 2005 indicated that I none of the contaminants of concern were detected at or above the laboratory reported detection limits except for MTBE, which was detected at a concentration of 120 µg/L This concentration of MTBE exceeded the discharge limit set forth in the MUD groundwater discharge permit, and the system was shut down Corrective action was undertaken and the equipment was restarted as of April 6, 2005 Condor representatives conducted the groundwater monitoring activities for the third quarter of 2005 on July 28, 2005 The representatives made field observations at the 11 site monitoring wells (MW-1 through MW-7, and MW-9 through MW-12D) and at one soil vapor extraction well (SV-4) Depth to water measurements were collected from MW-1 through MW-7, MW-9 through MW-12D, and SV-4 MW-I and MW-11 were used for groundwater extraction related to the operation of the groundwater treatment system Concentrations of MTBE at MW-i were the highest ever measured at the monitoring well, while concentrations of MTBE at MW-3 have been increasing over the previous sampling events None of the contaminants of concern were detected at or above the laboratory reported detection limits in monitoring wells MW-4 through MW-7, MW-9, MW-10, and MW-12D All other measurements and laboratory data were generally consistent with previous quarters and trends The system operated approximately 1,332 hours between April 15, 2005 and July 28, 2005, which is 53% of the time, whereas the total operational hours for the system since it began operating (November 1, 2004) through July 28, 2005 has been 2,969 hours, which is 46% of the time The groundwater treatment system removed petroleum hydrocarbons from approximately 348,873 gallons of groundwater during the third quarter of 2005, and a total of approximately 705,313 gallons have been treated by the system as of July 28, 2005 The average groundwater pumping rate between April 15, 2005, and July 28, 2005, was approximately 4 35 gallons per minute Condor estimates that approximately 71 pounds of gasoline have