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Quik Stop Market No 121 CCI Project No 12118-2 Page 2 formaldehyde Groundwater samples were collected from the site wells in accordance with CCI's Groundwater Sampling Protocol (Appendix A) The groundwater purged from each well and equipment rinse water were placed a 55-gallon drum and left at the site A summary of the groundwater purge data is presented in Table 1 Groundwater Sampling As previously mentioned, CCI sampled ten wells for the quarterly sample round Prior to groundwater sampling, CCI measured the depth to groundwater using an electronic sounding tape and field-checked the wells for the presence of free-floating product by collecting a sample in a clear acrylic bailer Free-floating product was not observed, however slight-to-moderate product odor was noted in wells MW-3 and RW-1 Each well was purged of stagnant water prior to the collection of a sample It should be noted that the water table has dropped approximately 2 feet from the levels reported during the July 2002 sample round Monitoring wells MW-1, MW- 7 and MW-8 were dry this quarter Normal field measurements, including pH, conductivity, water temperature and dissolved oxygen, 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) Iabeled, (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 Table 1 Laboratory Analysis The groundwater samples were submitted to STL San Francisco (STL), 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), using 8015M and 8021B Test Methods and for fuel oxygenates, including methyl tertiary butyl ether (MTBE), using EPA Prep Method 5030B and EPA Test Method 8260B In addition, water samples from wells MW- 3, RW-1 and MW-12 were analyzed for acetone and formaldehyde Summary of Laboratory Results Six of the seven shallow groundwater monitoring wells (A-aquifer) were sampled and found to be impacted with petroleum hydrocarbons or MTBE Monitoring well MW-11, located on the northeast side of the site, was reported to be free of detectable TPHg/BTEX and fuel oxygenates { Figures 2A and 3)