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SECOND QUARTER 2003
<br /> GROUNDWATER MONITORING REPORT
<br /> AND ADDITIONAL ASSESSMENT REPORT
<br /> JAMAR OIL DISTRIBUTION
<br /> JUNE 2003
<br /> A typical, extrapolated drawdown plot taken for time over distance was used at this site because of
<br /> the fairly isotropic and uniform lithology encountered in drilling EW-1. This environment has the
<br /> hydrogeologic parameters apparent or observed that can be incorporated into the standard
<br /> conditions for capture zone modeling, as shown in Table 4 for 30, 60, 100 and 365 days at
<br /> distances of 10, 50 and 100 feet.
<br /> Groundwater Analysis of EW-1
<br /> Groundwater samples were collected in EW-1 on May 22, 2003 before the APT, after the APT was
<br /> concluded and again on May 23, 2003. The groundwater samples from EW-1 were analyzed for
<br /> TPH G, TPH D, BTEX, 1,2 DCA, EDB, and fuel oxygenates using EPA Methods 8015M and
<br /> 8260B, respectively. The analyses were conducted by SunStar Laboratories Inc., a California
<br /> State-certified laboratory, in accordance with state guidelines and EPA protocol.
<br /> Using EPA Method 8015 M, TPH G ranged from 38,000 µg/l to 45,000 µg/l and TPH D ranged
<br /> from 5,300 µg/1 to 6,940 µg/l. Using EPA Method 8260B, MTBE was detected in EW-1 at 25,000
<br /> micrograms per liter (µg/1), 29,000 µg11 and 22,000 µg/1, respectively. 1,2-DCA was detected in all
<br /> three samples at 480 µg/1, 600 µg/1, and 490 µg/l, respectively. Benzene was detected at 27,000
<br /> µg/l, 26,000 µg/1, and 24,000 ug/l, respectively. Toluene, ethylbenzene, and total xylenes were
<br /> also reported at varying levels. EDB was not detected in any of the three samples.
<br /> A copy of the laboratory report with COC documentation is included in Appendix F.
<br /> Evaluation of the APT
<br />' Groundwater capture of the impacted area appears to be attainable from EW-1 at a pump rate of
<br /> 2.5 to 3 gallons per minute, which is an optimal range for pumping based on existing conditions at
<br /> the site. This pump rate and predicted drawdown indicate that pump and treat is a viable remedial
<br /> option at this site. The analytical results of groundwater before, after and on the following day of
<br /> this one day test indicated neither a decline nor an appreciable increase in concentrations of
<br /> dissolved constituents of petroleum hydrocarbons. This seems to show that EW-1 is placed in the
<br /> r.
<br /> heart of the impacted groundwater plume and is optimally located for a pump and treat operation.
<br /> The similar horizontal hydraulic conductivities from around wells MW-1 and EW-1, the average
<br /> pump yield from the APT, and the groundwater influence shown in MW-1, MW-2 and MW-4 all
<br /> seem to indicate that groundwater influence could extend as far as the recently installed multiple
<br /> zone wells,MW-6A, MW-6B, MW-7A and MW-7B.
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