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Quarterly Monitoring July 2441 and Sensitive Receptor Survey Report Canepa's Car Wash(Pacific Avenue) Page 3 • Restarting of the soil vapor extraction system by June 5, 2001 • Implementation of the additional site investigation by June 11, 2001, and • Submittal of a work plan describing the methodology to identify the source of the groundwater mounding at the site and a report of a sensitive receptor survey with 2,000-foot radius of the site by August 5, 2001 In a letter to Mr Wong dated May 14, 2001 Condor requested extensions of the due dates for the four project deliverables referenced above to June 4, July 5, July 25 and August 20, 2001, respectively In a letter dated May 18, 2001 Mr Wong approved the extensions 3.0 QUARTERLY GROUNDWATER MONITORING —JULY 2001 On July 19 and 20, 2001 a Condor representative collected groundwater samples from the eight monitor wells at the site (see Figure 2, Appendix A, for well locations) The monitor wells were sampled in the following order MW-b, MW-4, MW-5, MW-8, MW-2, MW-7, MW-1, and MW-3 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 No floating product or sheen was 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 A strong petroleum hydrocarbon odor was detected in the groundwater samples collected from MW-1 and MW-2 Petroleum hydrocarbon odors were not noted in any of the other groundwater samples Monitor wells MW-1 and MW-6 were purged with a Grundfos Redi-Flo 11 submersible pump, which was decontaminated prior to use in each well The remaining monitor wells were purged with disposable bailers A new bailer was used for each monitor well 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 facility washwater mixing pit r3 2 GROUNDWATER SAMPLING The groundwater samples were collected by filling three 40-milliliter glass vials with groundwater directly from the pump discharge tubing at a reduced rate or from the bottom of the bailer The sample containers were labeled, placed in a cooler chilled with ice, and delivered, in accordance with chain-of= custody procedures, to GeoAnalytical Laboratories, Inc in Modesto, California, for analyses 4.0 GROUNDWATER MONITORING RESULTS 4 1 GROUNDVVATER ELEVATION CONTOURS On July 19, 2001 the depth to groundwater was measured in each monitor well prior to the collection of groundwater samples The average depth to groundwater was approximately 34 0 feet below the well measuring points on top of the well casings, slightly below the ground surface The average depth to groundwater increased approximately 1 9 feet since the previous monitoring event conducted in April 2001 The groundwater elevations ranged from 20 53 to 21 50 feet below mean sea level (bmsl) The groundwater elevation contour map (Figure 2, Appendix A) indicates groundwater mounding in the V.611tw �� CONDOR