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Quik Stop Market No 121 CCI Project No 12118-2 Page 3 zn well RW-1 Each well was purged of stagnant water prior to the collection of a sample It should be noted that the water table was found to be very low Of the twelve wells sampled, six wells were found to have 1 5 to 2 feet of water Normal field measurements, including pH, conductivity, and water temperature, were periodically recorded during the purging process A sample was collected when these parameters stabilized to within 10% of each other After the groundwater was purged from each well, the groundwater samples were (a) collected with a clean disposable bailer, (b) transferred to appropriate laboratory-supplied bottles, ( c) labeled, (d) logged on a chain-of-custody form, and (e) placed in a chilled ice chest for transportation to a state-certified laboratory Monitoring well purge data are summarized in data Table 1 Laboratory Analysis The groundwater samples were submitted to STL ChromaLab (ChromaLab), a state-certified laboratory located in Pleasanton, California, for chemical analysis The laboratory employed methods approved by the California Regional Water Quality Control Board (CRWQCB) and the EPA The groundwater samples were analyzed for total petroleum hydrocarbons as gasoline (TPHg) and benzene, toluene, ethylbenzene and total xylenes (BTEX) and fuel oxygenates including methyl tertiary butyl ether (MTBE), using EPA Prep Method 5030B and EPA Test Method 8260B Summary of Laboratory Results Five of the nine shallow groundwater monitoring wells (A-aquifer) were sampled and found to be impacted with petroleum hydrocarbons or MTBE Monitoring well MW-1, located on the northwest side of the site (Figure 2), near the intersection of Union Road and West Louise Avenue, was reported to contain TPHg at a concentration of 320 micrograms per liter (ug/L), no detectable BTEX compounds and MTBE at 120 ug/L Monitoring well MW-2, also located on the north side of the site, was reported to be free of detectable TPHg/BTEX and fuel oxygenate compounds Monitoring well MW-3, located on the southeast side of the property, was reported to be free of detectable TPHg and BTEX compounds However, those compounds may be masked by the high detection limits used by the laboratory Monitoring well MW-3 was reported to contain MTBE at a concentration of 66,000 ug/L Recovery well RW-1, located near the east side of the fuel tanks, was also reported to be free of detectable TPHg and BTEX compounds Once again, high detection limits used by the laboratory may be masking some of those compounds RW-1 was reported to have 110,000 ug/L MTBE Monitoring well MW-4, screened from 33 to 43 feet in the A-aquifer, was reported to contain 38,000 ug/L MTBE Monitoring well MW-5, located on the southwest side of the site, was reported to contain 320 uglL TPHg and 100 ug/L MTBE Monitoring wells MW-2, MW-7, MW-11 and MW-12 were all reported to be free of detectable petroleum hydrocarbons this quarter