SITE INFORMATION AND CORRESPONDENCE

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Quarterly Monitoring Report, July 2000 Canepa's Car Wash (Pacific Avenue) Page -2 gasoline (TPH-G), and methyl tertiary-butyl ether (MTBE) were present at the former location of the fuel dispenser islands. Prior to granting approval of installation of the new SVE system, the Underground Storage Tank Clean-Up Fund indicated the need for additional investigation. Condor subsequently conducted the installation and sampling of two soil borings adjacent to the SVE well array. The investigation included soil vapor screening using a Simulprobe sampling device in soil vapor collection mode. The results indicated high levels of volatile organic compounds were present in the soil vapor at the site. The laboratory analytical results of the soil and groundwater samples collected during the investigation are presented in Report — Soil and Groundwater Investigation, dated June 12, 1998. Operation of the SVE system has continued since its initiation on March 15, 1999 . Due to a directive from the Underground Storage Tank Cleanup Fund (USTCF), laboratory analyses of groundwater samples for gasoline oxygenates/additives by EPA Method 8260 was discontinued beginning with the October 1999 quarterly groundwater monitoring event. The USTCF indicated that analysis by EPA Method 8260 is not warranted based on historical groundwater laboratory analytical results. Commencing with the October 1999 quarterly groundwater monitoring event, laboratory analyses of groundwater samples for gasoline oxygenates/additives is limited to MTBE using EPA Method 8020 or 802113. 10 QUARTERLY GROUNDWATER MONITORING - JULY 2000 On July 10 and 11 , 2000 a Condor representative collected groundwater samples from the eight monitor wells and one soil vapor extraction well at the site (see Figure 3 , Appendix A, for well Iocations). The sampling order was as follows: MW-8, MW-5, MW-4, MW-6, MW- 1 , MW-7, MW-3, MW-2, and SV-4. 3.1 GROUNDWATER MONITORING OBSERVATIONS AND PARAMETERS The static water level in each well was measured to the nearest 0.01 -foot with a battery-operated, flat tape, water-level meter. A clean, single-use, polypropylene, disposable bailer was lowered into each well to check for floating product, petroleum odors, and sheen. Floating product was not observed in any of the monitor wells during the groundwater sampling. The surface of the groundwater table was above the top of the well screens, however. Olfactory observations were: • A moderate petroleum hydrocarbon odor detected in the groundwater sample collected from MW- 1 . • A slight petroleum hydrocarbon odor detected in the groundwater samples collected from MW-2, MW-3 , MW-7, and SV-4. • Petroleum hydrocarbon odors were not noted in any of the other groundwater samples. SV-4 and monitoring wells MW-2, MW-4, MW-5, MW-6, and MW-8 were purged using new, disposable bailers. Monitor wells MW4 , MW-3 , and MW-7 were purged with Redi-Flow submersible pumps that were decontaminated prior to use. Approximately three well casing volumes of water were purged from each well (see the Groundwater Monitoring Field Forms in Appendix B). The purged water from each well was discharged to the washwater mixing pit. 3.2 GROUNDWATER SAMPLING The groundwater samples obtained from monitor wells MW-2, MW-4, MW-5, MW-6, MW-8, and SV-4 were collected by gently draining the groundwater from each bailer with a bottom-emptying device directly into two 40-milliliter glass vials. r L � coNooa