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Pyrene and Fluoranthene in soil at MW-4. In our opinion, the detection of Chrysene is attributed to a low background concentration of PAH in the site soils. The current data shows ND for all wells except MW-2 at 0.4 mg/I of Ni and MW-4 at 0.3 of Ni and 0.08 mg/I of V. Although, there were ND concentration of Ni and V in the ground water samples of the baseline report, there were, however, soluble Threshold limit concentration (STLC) concentrations of Ni and V were found in the soil of the baseline samples. A review of the pertinent sections of the Appendix B of Dames and Moore's baseline report (see Appendix D of this report) reveals the following: Ni was found at STLC levels of 0.44 mg/I at 0.5 feet deep and 0.70 mg/I at 10 feet deep within borings MW-1B and A respectively. V was found at STLC levels of 0.510 mg/I at 0.5 feet deep and 1.06 mg/I at 10 feet deep within borings MW-1B and A respectively. Ni was also found at STLC levels of 0.84 mg/I at 10 feet deep within boring MW-1B/10.0. Ni was found at STLC levels of 0.46 mg/I at 0.5 feet deep and 0.38 mg/I at 10 feet deep within borings MW-2B and MW-2A respectively. V was found at STLC levels of 2.11 mg/I at 10 feet and 0.84 mg/I at 0.5 feet deep within borings MW-2B and MW-1B respectively. Ni was found at STLC levels of 0.29 mg/I at 0.5 feet deep and 0.46 mg/I at 10 feet deep within boring MW-4B at two depth intervals (0.5' and 10' deep respectively). In addition, Ni was found at STCL level of 0.36 mg/I at 0.5 feet deep within boring MW-4A. V was found at STLC level of 0.558 mg/I at 0.5 feet deep and 1.21 mg/I at 10 feet deep within boring MW-4B at two depth intervals (0.5' and 10' deep respectively). In addition, V was found at STLC level of 0.866 mg/I at 0.5 feet deep within boring MW-4A. In view of the above, it is amply clear that pre-existing STLC (leachable) concentrations of both Ni and V had existed in various depths within the site's soils, hence, establishing a pathway for Ni and V to gradually desorb from the site's sediments to the aquifer. In addition, a review of the published literature from the University of California, Davis, Kearney Foundation Special Report, March 1996, reveals that Nickel in California soils may range from about 7 to 140 mg/kg, average about 40-70 mg/kg. The presence of Nickel and Vanadium is interpreted as a natural background given the regional geology and source of the alluvial sediments underlying the site. The very low concentrations observed in groundwater are not considered unusual compared to the background data of both regional soils and pre-existing conditions established by Dames and Moore's report. In our opinion, further work is not warranted at this time. TRE recommends that all four monitoring wells be permanently closed in place by submitting a well destruction application to the SJCEHEY 10