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C A M B R I A <br /> samples collected from shallow wells MW-2, MW-4 through MW-6, MW-8, and RW-IA <br /> contained MTBE (by EPA Method 8260A) at concentrations ranging from 23 3 to <br /> 191,000 ppb Shallow wells MW-7 and MW-9 through MW-11 were sampled for MTBE <br /> by EPA Method 8020 only, with the only detection 1n well MW-7 of 3 90 ppb TAME <br /> was detected in wells MW-5 and RW-IA at concentrations of 3,490 and 2,830 ppb, <br /> respectively These data are shown on the chemical concentration map (Figure 2) and <br /> are summarized in the table in Blaine's monitoring report (Appendix A) Additional <br /> analytical data are summarized on Table 1 <br /> • Separate phase petroleum hydrocarbons were not present in well RW-IA this quarter <br /> • From March through June 1999, weekly groundwater extraction (GWE) was performed <br /> on well RW-IA Beginning in July 1999, GWE occurs bi-weekly During each GWE <br /> event, approximately 5,000 gallons of water is purged by a vacuum truck and transported <br /> to the Martinez Refining Company for recycling As of November 22, 1999, <br /> approximately 103,043 gallons of water have been removed from RW-IA These data <br /> are presented on Table 2 <br /> Groundwater samples collected from deep monitoring wells MW-12 through MW-14 did <br /> not contain detectable concentrations of TPHg, benzene, MTBE, or other fuel <br /> oxygenates <br /> • TPHg, benzene, MTBE, and fuel oxygenates were not detected in the groundwater <br /> samples collected from the CalTrans irrigation well nor in any of the domestic wells, with <br /> the exception of the Warman well sampled downhole, which contained 299 ppb TPHg <br /> The laboratory analytical results are summarized in the table in Blaine's monitoring <br /> report (Appendix A) Additional analytical data are summarized on Table l <br /> Quarterly Sampling <br /> Groundwater samples from all wells were analyzed for total purgeable hydrocarbons as <br /> gasoline (TPHg) and methanol according to EPA Method 8015 (Modified), benzene, toluene, <br /> ethylbenzene, xylenes (BTEX), and methyl tertiary butyl ether (MTBE) according to EPA <br /> Method 8020 Groundwater samples from wells MW-2 through MW-6, MW-8, MW-12 <br /> through MW-14, RW-IA, the CalTrans well, and the domestic wells were also analyzed for <br /> fuel oxygenates (ethanol, TBA, MTBE, ETBE, DIPE, and TAME) by EPA Method 8260A <br /> 241-0783 2 <br />