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Canepa's Car Wash 6230 Pacific Avenue Stockton,CA Third Quarter Groundwater Monitoring Report,July 2005 Page 5 of 8 TREATMENT SYSTEM STATUS UPDATE • Installation of the pump and treat system and upgraded SVE system was completed in September 2004 The City of Stockton Municipal Utilities District (MUD) authorized the initiation of discharge of treated groundwater on October 28, 2004 Groundwater extraction and treatment, with subsequent discharge to the sanitary sewer began November 1, 2004 The system was voluntarily shut down in February due to exceedance of the discharge limit for MTBE set forth in the MUD groundwater discharge permit Corrective action was undertaken and the equipment was restarted on April 6, 2005 During the third quarter 2005, the system remained in normal operation during the months of May, June, and July with periodic scheduled shutdowns by Condor technicians for system maintenance Several unscheduled, automatic shutdowns by the system's built-in safety features also occurred, generally related to blown fuses and high water levels in the storage tank The system was inadvertently shut down the evening prior to the third quarter 2005 monitoring event when a vehicle backed into the enclosure gate, damaged piping on the air stripper, and tripped the system's emergency shut-off switch The system was put back into operation by Condor representatives on July 29, 2005 and has been running normally since then MASS REMOVAL AND DESTRUCTION CALCULATIONS The system was operating for approximately 1,342 hours between April 15, 2005 and July 28, 2005, or approximately 53% of the time The effects of the system auto shutdowns, and the accidental shutdown, and system maintenance shutdowns referred to in the previous section are reflected in the subsequent mass removal and destruction calculations Operational and efficiency data are included in Attachment D Aqueous Phase Mass Removal The groundwater treatment system has removed petroleum hydrocarbons from 348,873 gallons of groundwater during the third quarter of 2005 Groundwater treatment system samples and associated data were collected to comply with the Self-Monitoring Sample Program of the MUD Groundwater Discharge Permit, as well as to monitor the operational efficiency of the system and the consumption of carbon (Attachment D) Groundwater is pumped from the subsurface via extraction wells MW-1 and MW-11 MW-1 has contributed approximately 95% of the total groundwater influent into the treatment system The concentrations of BTEX, TPH-G, and MTBE detected in samples collected from MW-1 have been increasing as anticipated and discussed above A total of 705,313 gallons have been treated by the system as of July 28, 2005 Calculations indicate that approximately 71 pounds of gasoline have been removed from the groundwater at the Site during the third quarter of 2005 Furthermore, an approximate total of 160 pounds of gasoline have been removed since the system was made operational A calculation worksheet is included in Attachment D ' Vapor Phase Quantification Methodology Soil vapor mass removal and destructive efficiency calculations are made using the following methodology - Field photo-ionization detectors (PID) measurements are collected weekly and laboratory samples are collected and analyzed monthly - The data is compiled and a correction factor is calculated between corresponding PID measurements and laboratory analytical results The correction factor is then applied to the PID measurements so they more accurately . represent projected laboratory results on a weekly basis CONDOR