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California ional Water Quality Cont Board
<br /> l \' Central Valley Region .�.,. i,�
<br /> vKarl E. Longley,ScD,P.E.,Chair "
<br /> Linda S.Adams Arnold
<br /> �c ,rGn.t.Io, Sacramento Main Office Sch AArnold er
<br /> Lnnr�nuurara/ 11020 Sun Center Drive 0200. Rancho Cordova.California 95670,6114
<br /> Phone(916)464-3291 •FAX(916)464-4645 27 SCO VEGovernor
<br /> mauar
<br /> http./hrww.walerboards.ca.@ov/centralvalley �
<br /> 3 May 2007 rRaY 1 1 200?
<br /> Ms. Jennifer Sedlachek pE9po/TI1 N>yfq�r
<br /> ExxonMobil Oil Corporation CF
<br /> 4096 Piedmont Ave, #194
<br /> Oakland, CA 94520
<br /> REPORT REVIEW, MARLER PROPERTY (AKA JH GRIFFIN MOBIL SERVICE),
<br /> 75 E. ALPINE AVENUE, STOCKTON, SAN JOAQUIN COUNTY
<br /> I reviewed the Well Installation and Risk Assessment (Report), received 30 April 2007 and
<br /> submitted by your consultant ETIC Engineering Inc (ETIC). The Report documents the
<br /> installation, sampling, and analyses of five onsite borings/monitoring wells (MW-1 through
<br /> MW-5) and ten soil vapor wells (V1 through V10) at the Site. Soil, groundwater, and soil vapor
<br /> samples were submitted for laboratory analyses, including petroleum hydrocarbons,
<br /> polychlorinated biphenyls, volatile organic compounds, semi-volatile organic compounds,
<br /> metals, moisture content, and porosity. All soil vapor results were non-detect at detection
<br /> limits below the San Francisco Bay Regional Board Environmental Screening Levels (ESLs)
<br /> for shallow residential soils. Maximum soil and groundwater results are reported in the
<br /> following table:
<br /> Sample TPHg' TPHdz B3 T4 E5 X6 MtBE' 1,2- O&Ga Metals10
<br /> DCA'
<br /> Soil" 23,400 1,200 15.8 735 259 23,400 0.0515 0.0068 53.3 As, 3.41
<br /> & 3.86
<br /> Groundwater12 120,000 6,000 15,000 49,000 2,900 17,000 1,100 11 <4.713 As, 24;
<br /> Cd, 1.3;
<br /> Pb, 10,
<br /> 1=Total Petroleum Hydrocarbons as gasoline 2=Total Petroleum Hydrocarbons as diesel 3=benzene 4=toluene
<br /> 5=ethylbenzene 6=xylenes 7=methyl ten-butyl ether 8=1,2-dichlorethane 9=oil and grease
<br /> 10=MW-1 metals above ESLs or Regional 5 Water Quality Goals;As=arsenic,Cd=cadmium, Pb=lead
<br /> 11=soil results in milligrams per kilogram, or mg/kg 12=groundwater results in micrograms per Liter,or ug/L 13=non-detect
<br /> The Report soil boring logs identified sands, silts and clays to 45 feet in depth. Depth to water
<br /> varied from 32.99 to 34.65 feet below the top of well casings. Groundwater flow direction was
<br /> towards the east-northeast at 0.004 ft/ft (head loss between wells in feet per horizontal
<br /> distance in feet, McJunkin, 1995).
<br /> California Environmental Protection Agency
<br /> pia Recycled Paper
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