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Second Quarter 2005 Quarterly Groundwater Monitoring Report
<br /> Raymond Investment Corporation,Stockton,CA
<br /> Page 2
<br /> GROUNDWATER ELEVATIONS AND GRADIENT ,
<br /> The average groundwater elevation in the monitoring wells was -18 49 feet, an increase of approximately - ; -
<br /> 1 70 feet since the previous sampling event conducted on February 4, 2005 The estimated groundwater
<br /> gradient for the Site was 0 0049 ft/ft to the east and is shown on Figure 3, attached Monitoring well
<br /> groundwater elevation data are presented in Table 1, below Historic groundwater elevation data are
<br /> presented in Table A, attached
<br /> _. Table 1
<br /> Groundwater Elevation Data (May 4,2005)
<br /> TOC Screened Depth to Groundwater j
<br /> Well LD Elevation' Interval &sGroundwater ElevationZ
<br /> MW-1 1635 - 32-47 3475 -1840
<br /> MW-2 1652 32-47 3503 -18 51
<br /> MW-3R 1 15 78 32-47 - 3435 - -18 57
<br /> TOC Elevation referenced to NAVD88 vertical datum V
<br /> Groundwater Elevation Elevations are measured from the top of the well casings and are referenced to the benchmark indicated
<br /> above
<br /> All measurements are in feet
<br /> LABORATORY ANALYTICAL RESULTS
<br /> Groundwater samples collected from the monitoring wells were analyzed for benzene, toluene, ethyl
<br /> benzene, total xylenes (BTEX) and gasoline additives/oxygenates by EPA Method 826013, total
<br /> petroleum hydrocarbons quantified as gasoline (TPH-G) and total extractable petroleum hydrocarbons
<br /> • quantified as kerosene (TEPH-K), motor oil (TEPH-MO), and diesel (TEPH-D) by EPA Method 8015B
<br /> Gasoline oxygenates/additives include methanol, ethanol, tertiary-butanol (TBA), methyl tertiary-butyl
<br /> ether (MTBE), di-isopropyl ether (DIPE), ethyl tertiary-butyl ether (ETBE), tertiary-amyl methyl ether
<br /> (TAME), 1,2-dichloroethane (1,2-DCA), and 1,2-dibromoethane (EDB) Groundwater samples were
<br /> analyzed by Argon Laboratories, Inc of Ceres, California The current groundwater sample laboratory
<br /> analytical results are presented in Table 2, below Historic groundwater monitoring data are presented in
<br /> Table A, attached r -
<br /> Table 2
<br /> Groundwater Sample Analytical Results (May 4, 2005)
<br /> Sample I D Sample Date B T E X TPH-G TEPH Oxygenates r
<br /> (gg/L) (pg/L) (µg/L) (ug/L) (µg/L) (pg/L) (>tg/L) ba
<br /> 3849E-MW 1-5/4/05 514/05 <0 5 <0 5 <05 < 10 170* 0 <05—<50
<br /> Wim`
<br /> 3849E-MW2-5/4/05 514105 <0 5 <05 <05 < 10 <50 <50-<250 <0 5—<50
<br /> 3849E-MW3R-5/4/05 5/4/05 <0 5 <0 5 <0 5 < 1 0 <50 <50-<250 <0 5—<50
<br /> Notes
<br /> *Chromatographic pattern does not match typical gasoline standard Heavier than gas-range hydrocarbons detected
<br /> Unit Conversions pg/L=micrograms per liter=parts per billion(ppb)
<br /> Analytical
<br /> B,T,E,X=benzene,toluene,ethyl benzene,total xylenes
<br /> TPH-G=total petroleum hydrocarbons,quantified as gasoline
<br /> TEPH=total extractable petroleum hydrocarbons quantified as kerosene(K),diesel(D),and motor oil(MO)
<br /> • Oxygenates=methanol,ethanol tertiary-butanol(TBA),methyl tertiary-butyl ether(MTBE),di-isopropyl ether(DIPS),ethyl tertiary-butyl ether
<br /> (ETRE),tertiary-amyl methyl ether(TAME),1,2-dichloroethane(1,2-DCA),and 1,2-dibromoethane(EDB)
<br /> t� CONDOR
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