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CAMBRIA <br /> appears to flow radially outward from well MW-2 at an approximate hydraulic r <br /> gradient ranging from 0 01 to 0 04 <br /> • Groundwater samples collected from wells MW-2 through MW-4, MW-7, and MW-9 <br /> contained TPHg concentrations ranging from 165 to 20,400 ppb Wells MW-2, <br /> MW-4, MW-7, and MW-9 contained benzene concentrations ranging from 4 84 to <br /> 1,160 ppb MTBE (by EPA Method 8020) was reported in wells MW-2 through <br /> MW-4 and MW-7 through MW-9 at concentrations ranging from 17 8 to 633 ppb <br /> The groundwater sample from MW-2 was also analyzed by EPA Method 8260A and <br /> did not contain MTBE (<1 00 ppb) This indicates that the EPA Method 8020 <br /> analysis for MTBE was a false positive result <br /> • Well MW-8 contained 6 31 ppb 1,2-D►chloroethane 1,2-Dichloroethane and EDB <br /> were not detected in any of the other wells A chemical concentration map is <br /> presented on Figure 2 <br /> Quarterly Sampling <br /> • Groundwater samples were analyzed for total purgeable hydrocarbons as gasoline (TPHg) by <br /> EPA Method 8015 (Modified) and benzene, toluene, ethylbenzene, xylenes (BTEX) and <br /> methyl tertiary butyl ether (MTBE) by EPA Method 8020 Well MW-2 was also analyzed <br /> for MTBE by EPA Method 8260A All wells were analyzed for EDB and 1,2-Dichloroethane <br /> (1,2-DCA) by EPA Method 8260A <br /> Chemical analytical data are presented in a summary table in Blaine's groundwater <br /> monitoring report (Appendix A) Additional groundwater analytical data are summarized in <br /> Table 1 <br /> Conclusions and Recommendations <br /> Hydrocarbon and MTBE concentrations are within the historical norm for this site Some <br /> wells showed a slight increase in hydrocarbon concentration, which appears to correlate with <br /> the higher groundwater elevations noted this quarter Cambria completed additional site <br /> investigation fieldwork in March 2000 We've prepared a report documenting the March <br /> 2000 fieldwork and expect to issue it within a week of this report We recommend well <br /> MW-8 be sampled again next quarter for 1,2-DCA to confirm the detection this quarter <br /> 0778 2 <br />