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Stantec <br /> SECOND QUARTER 2008 GROUNDWATER MONITORING REPORT <br /> Background and Previous Work <br /> July 7,2008 <br /> In May 2007, Stantec installed monitoring wells MW-1 through MW-3 at the locations shown on <br /> Figure 2. The groundwater monitoring wells were subsequently developed and sampled for <br /> TPHg; TPHd; TPHmo; benzene, toluene, ethylbenzene, and total xylenes (BTEX); and methyl <br /> tert-butyl ether(MTBE). Petroleum hydrocarbons as TPHd and TPHg were reported in the <br /> sample from well MW-1 at concentrations of 850 and 580 pg/L, respectively. No petroleum <br /> hydrocarbons or related constituents were reported in samples from the other two wells. The <br /> findings of this investigation are summarized in Stantec's report entitled, "Subsurface <br /> Investigation and Well Installation Report,"dated July 3, 2007 (SECOR, 2007a). <br /> 2.5 POST-INVESTIGATION GROUNDWATER MONITORING <br /> Monitoring wells MWA through MW-3 were first sampled in May 2007. During an October 2007 <br /> conference call between Ms. Wendy Cohen of the RWQCB, PG&E, and Stantec, Ms. Cohen <br /> suggested quarterly groundwater monitoring be implemented at the Site to confirm and <br /> document petroleum hydrocarbon impacts observed during the May 2007 groundwater <br /> monitoring event. <br /> Samples collected in May and November 2007 were prepared using silica gel prior to analysis <br /> of diesel- and motor oil-range extractable hydrocarbons. In their letter dated December 21, <br /> 2007, RWQCB staff requested that groundwater samples be analyzed without silica gel <br /> preparation. Subsequent groundwater samples collected at the Site have been analyzed <br /> without silica gel preparation. In correspondence dated May 5, 2008, RWQCB staff concurred <br /> with Stantec's recommendation, that PG&E perform an additional two quarters of groundwater <br /> monitoring (second and third quarters 2008) and requested that PG&E upload subsequent <br /> documents to-the Geotracker®online reporting system maintained by the State Water <br /> Resources Control Board. <br /> is i:\pg&e\french camp\groundwater monitoring\may 2008 monitoring\qmr rpt_fnl.doc 2.3 . <br />