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1 <br /> • <br /> During the April 1997 site investigation, Enviros drilled a soil boring (SB-2)in the vicinity of the <br /> former waste oil tank. In accordance with Enviros' December 23, 1996 Site Investigation Work <br /> Plan, which was approved by SJCPHS/EHD on December 30, 1996, soil and groundwater <br /> samples from this boring were analyzed for cadmium, chromium, lead, nickel, zinc, oil and <br /> grease, HVOCs (which include chlorinated hydrocarbons), and SVOCs (which include PCP and <br /> PNAs). Note that PCB and creosote analyses were not conducted. The soil samples from SB-2 <br /> contained detectable concentrations of chromium, lead, nickel, zinc, and oil and grease. No <br /> chlorinated hydrocarbons, PNAs, or PCP were detected in soil. The groundwater sample from <br /> SB-2 contained detectable concentrations of chromium, nickel, zinc, and naphthalene. The <br /> chromium, nickel, and zinc levels were below California MCLs. No chlorinated <br /> hydrocarbons, PNAs other than naphthalene, or PCP were detected in groundwater. <br /> Based on these results, Cambria does not propose additional soil sampling for waste oil <br /> constituents. Because the concentrations of metals (chromium, nickel, and zinc) detected in <br /> groundwater beneath the site were below California MCLS, additional groundwater analyses for <br /> these constituents is not warranted. Cambria concurs with SJCEHD that additional groundwater <br /> sampling for naphthalene, PCBs, and creosote is warranted. This is proposed below. <br /> • Discussion of Fue; O;ryganElas <br /> It has been established that the Shell station at this site ceased operation in 1974, prior to the <br /> introduction of fuel oxygenates into gasoline. Therefore, any release that may have occurred at <br /> the former Shell site would not be a source of fuel oxygenates, and the oxygenates that have been <br /> identified in groundwater beneath the site must have originated from another source. Because <br /> their presence beneath the site is not related to Shell's activities, Shell respectfully declines to <br /> further investigate or characterize this fuel oxygenate release and proposes to discontinue all <br /> oxygenate analyses (including MTBE). <br /> Revised Groundwater Monitoring Program <br /> Cambria recommends monitoring and sampling wells S-1 through S-4 quarterly and wells S-5 <br /> and S-6 annually. Since no petroleum constituents except fuel oxygenates have been detected in <br /> wells S-5 and S-6, there is no reason to monitor them more frequently than annually. As stated <br /> above, Shell declines to monitor the fuel oxygenate plume because it did not originate as a result <br /> Shell's operations at the subject site, which ceased in 1974. Cambria recommends that <br /> groundwater samples from all wells be analyzed for TPHd, TPHg, BTEX, and 1,2-DCA. In <br /> s <br /> 0943 4 <br />