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I h"� KLEINFELDER' The oxygenates MTBE, DIPE, ETBE, and TAME (only analyzed from MW-DIS-15) showed non-detectable concentrations afor above the laboratory reporting limits. I This quarter MW-DIS-9 was sampled due to a recent groundwater flow direction shift towards the east. The groundwater flow direction had previously been towards the southeast. MW-DIS-9 is located directly east of the former UST's and remediation facility. The sample collected from MW-DIS-9 showed non-detectable concentrations of TPH-g, BTEX, TBA, 1,2-DCA and EDB. Due to the recent groundwater flow direction shift towards the east (recorded during the fourth quarter 2004), Kleinfelder requested from Def Monte and was granted permission to conduct a water well survey within a 2,000-foot radius of the site to evaluate whether any new wells have been installed and are pumping. DWR has been contacted to collect and review the available records pursuant to the request. At this time there are no records available from the DWR to accompany this report. At the time when records become available, the information will be forwarded to Del Monte and included in the next quarterly report. The seasonal fluctuations of groundwater elevations may be linked to naturally occurring rainfail/recharge, and/or groundwater extraction practices near the site. In areas of such flat gradients, slight changes in groundwater elevations can affect the groundwater flow directions. The groundwater elevation range at the site typically is less than a foot. GROUNDWATER TREATMENT SYSTEM OPERATION The soil vapor extraction system installed by CH2M Hill was replaced by Kleinfelder during 2003 with an air sparging (AS)/high vacuum soil vapor extraction (SVE)/ozone injection system. The ozone injection system began consistent operation within the I downgradient portion of the plume in September 2003. The system has only been inoperable during periods of system maintenance and enhancements. i During the second quarter on June 30, 2005, air samples were collected for the performance evaluation of the catalytic oxidizer. The laboratory results showed inlet f concentrations of TPH-g and benzene concentrations at 2,100 ppmv and 12 ppmv, ? respectively. The outlet results showed TPH-g and benzene concentrations of 15 ppmv and non-detect, respectively. The volumes of TPH-g and benzene estimated removed this quarter reflects an increase over last quarter and previous quarters. The destruction efficiency of the catalytic oxidizer was calculated at 99%. The total estimated pounds of TPH-g removed during Kleinfelder's operation of the system is t approximately 22,623 pounds (per date of the sampling). Photoionization detector (PID) readings were recorded from VE-1, VE-2, VE-3, VE-4, } VE-5, and the mainline before and after the reducer on April 14, April 29, May 27, and June 30, 2005. The PID readings ranged in concentrations from 345 ppm to 899 ppm in the VE samples, and 360 ppm to 890 ppm in the mainline samples. i r f 12280.MONIST05R8031JZ:ly Page 2 of 15 ©2005, Kleinfelder, Inc. July 25,2005