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Additional Soi Ciroundwater Investigation Work Plan
<br /> Raymond Investment Corporation
<br /> May 19,2006
<br /> Page 2
<br /> Report, dated June 1, 2004. In the report, Condor recommended preparing a work plan for the installation
<br /> of three groundwater monitoring wells and initiating quarterly groundwater monitoring at the Site. In a
<br /> letter dated July 7, 2004, SJCEHD directed the preparation and submittal of a work plan for the
<br /> installation of three groundwater monitoring wells at the Site. Condor prepared the Monitoring Well
<br /> Installation Work Plan, dated August 11, 2004 that was approved by SJCEHD in a letter dated August ,..
<br /> 25, 2004Condor installed three shallow groundwater monitoring wells (MW-I, MW-2, and MW-3) on
<br /> Septe`mbe'r 23 and 24, 2004Condor prepared the Monitoring Well Installation Preliminary Report and
<br /> Monitoring Well Destruction Work Plan, dated October 12, 2004;that described the installation of MW-3
<br /> and the discovery of grout inside the well casing. Condor recommended that MW-3 should be properly
<br /> destroyed and a replacement well (MW-3R) be installed approximately ten feet south of MW-3. In a
<br /> letter dated October 21, 1004,the SJCEHD approved the destruction of MW-3 and the installation of
<br /> MW-3R. Monitoring well MW-3 was properly destroyed and MW-3R installed on October 26, 2004. All
<br /> field and analytical activities involved in the installation, development, and sampling of monitoring wells
<br /> MW-1, MW-2, and MW-3R and the destruction of monitoring well MW-3R are described in Condor's
<br /> Monitoring Well Installation Report, dated December 15,2004.
<br /> Quarterly groundwater .monitoring was initiated after the wells were installed. Groundwater samples
<br /> were analyzed for TPH-G,TEPH-D, TEPH-MO, and total extractable petroleum hydrocarbons quantified
<br /> as kerosene (TEPH-K);- benzene, .toluene, ethyl benzene, total xylenes (BTEX); and gasoline
<br /> oxygenates/additives. The gasoline oxygenates/additives include methanol, ethanol, tcrtiary-butanol
<br /> (TBA), methyl tertiary-butyl ether(MTBE), di-isopropyl ether(DIPE), ethyl tertiary-butyl ether (ETBE),
<br /> tertiary-amyl methyl ether(TAME), 1,2-dichloroethane (1,2-DCA), and EDB.
<br /> On November 8, 2004, February 4, 2005, May 4, 2005, August 16, 2005, and November 18, 2005,
<br /> monitoring events were conducted by Condor. The groundwater elevation in the monitoring wells ranged
<br /> from approximately -18.5 to -21.0 feet. The general groundwater gradient for the Site was approximately
<br /> ? 0.005 ft/ft to the east-northeast. None of the analytical constituents were detected at or above the
<br /> laboratory reported detection limits in the groundwater samples collected from monitoring wells MW-1,
<br /> MW-2, and MW-3R during the November 2004, February 2005, and November 2005 groundwater
<br /> monitoring events. On May 4, 2005, TPH-G and TEPH-D were detected in the groundwater sample
<br /> collected from MW-1 at concentrations of 170 micrograms per liter (p.g/L) and 110 p.g/L, respectively.
<br /> Ori August 16, 2005, TPH-G and TEPH-D. were detected at 92 µg/L and 82 .gg/L, respectively, in the
<br /> - groundwater sample collected from monitoring well MW-2. No other analytical constituents were
<br /> detected at or above the laboratory reported detection limits in the samples collected from those wells on
<br /> those dates.
<br /> Based on historic groundwater monitoring data for the Site through the third quarter of 2005, Condor
<br /> recommended consideration for Site closure in the Third Quarter Groundwater Monitoring Report, dated
<br /> October 5, 2005. In a telephone conversation on October 27, 2005, Ms. Victoria McCartney of the
<br /> SJCEHD indicated that she would review the Site for potential closure and requested that groundwater
<br /> monitoring continue while the potential for closure was evaluated. Ms. McCartney subsequently
<br /> recommended.a reduction in sampling of monitoring well MW-3R from quarterly to annually in her letter
<br /> dated i February 22, 2006.
<br /> On March 9, 2006, the average groundwater elevation in the monitoring wells was -17.4 feet; the
<br /> estimated groundwater gradient for the Site was 0.006 ft/ft to the east-northeast. Monitoring wells MW-1
<br /> CONDOR
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