|
CAMBRIA
<br /> 2004 Well Installation During February 2004, Cambria installed one shallow offsite well
<br /> (MW-12) in the parking lot cast of the site and one deep onsite well (MW-13) Soil results indicate
<br /> that subsurface soil to the east of the existing UST complex is not impacted by TPHg, benzene,
<br /> toluene, ethylbenzene, xylenes (BTEX), or fuel oxygenates Cambria details this investigation in
<br /> our April 9, 2004 Site Investigation and First Quarter 2004 Groundwater Monitoring Report
<br /> Historical well and boring data is summarized in Table 1 Historical soil data is presented as
<br /> Appendix A
<br /> Groundwater Monitoring Program Wells MW-1 through MW-8, MW-12, MW-13, and VEW-2
<br /> are analyzed quarterly, well MW-9 is analyzed semi-annually, and wells MW- 10 and MW-1I are
<br /> analyzed annually for TPHg, BTEX, methyl tertiary butyl ether(MTBE), 1,2-dichloroethane (1,2-
<br /> DCA), and ethylene dibromide (EDB) Samples from all wells are also analyzed annually in the
<br /> third quarter for fuel oxygenates and wells MW-1, MW-2, MW-4, and MW-5 are analyzed
<br /> annually in the third quarter for ethanol
<br /> During the third quarter 2004 sampling event, TPHg was detected in wells MW-3, MW-4, MW-6
<br /> through MW-12, and VEW-2 at concentrations ranging from 87 to 120,000 ppb All TPHg
<br /> detections were flagged as having a discrete peak in the gasoline range Benzene was detected in
<br /> wells MW-7, MW-8, and VEW-2 at 40, 8 5, and 4,800 ppb, respectively MTBE was detected in
<br /> wells MW-4, MW-8, and MW-12 at concentrations of 22, 2 5, and 37 ppb, respectively Tertiary
<br /> butyl alcohol (TBA) was detected in wells MW-8 and MW-12 at concentrations of 13 and 9 9 ppb,
<br /> respectively 1,2-DCA was detected in wells MW-4, MW-12, and MW-13 at concentrations of
<br /> 0 85, 110, and 1 3 ppb respectively Historical groundwater monitoring data is presented as
<br /> Appendix B
<br /> Current depth to water beneath the site ranges from approximately 38 to 40 fbg Historically
<br /> (since groundwater monitoring began in 1990), groundwater beneath the site has been as deep as
<br /> approximately 60 tbg Groundwater flow is consistently towards the northeast
<br /> INTERIM REMEDIATION-- DPE
<br /> Soil analytical results trom borings B-3 (March 1990) and VEW-2 (duly 1990) indicated elevated
<br /> I
<br /> petroleum hydrocarbon concentrations from 15 to 50 fbg in the vicinity of the tormer UST
<br /> complex Aegis conducted extended soil vapor extraction (SVE) feasibility testing from wells
<br /> VEW-1, VEW-2, MW-3, and horizontal piping near the dispensers during late 1991 and early
<br /> 1992 Not all the data from this testing is available However, the available data suggest that
<br /> I
<br /> 0854 4
<br />
|