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SEC ® R
<br /> Mr Wong
<br /> July 3, 2003
<br /> Page 2
<br /> Subsurface Conditions The upper eight feet bgs was composed of fill material, including, gravels,
<br /> concrete, and very dark brown sandy clay material Soil texture from approximately eight feet bgs to
<br /> 45 feet bgs, was dominantly sand with some silt A layer of clay was encountered at approximately
<br /> 45 feet bgs to 48 feet bgs, overlaying with clayey sand and sand with clay from approximately 48 feet
<br /> bgs to 68 feet bgs First groundwater was encountered at 53 feet bgs The boring log with well
<br /> construction details is included as Attachment C
<br /> Sod Sampling and Analysis Soil samples were collected at 5-foot intervals in the soil boring
<br /> Three soil samples from the boring were selected from at 30 feet bgs, 50 feet bgs, and 65 feet bgs
<br /> (MW4-30, MW4-50, and MW4-65) and were sent under chain-of-custody to a state-certified
<br /> laboratory for chemical analysis Samples submitted for chemical analysis were analyzed for total
<br /> petroleum hydrocarbons as gasoline (TPHg), benzene, toluene, ethylbenzene, xylenes (BTEX),
<br /> methyl tertiary butyl ether(MtBE), ethyl tertiary butyl ether (EtBE), tertiary amyl methyl ether (TAME),
<br /> tertiary buyl alcohol (TBA), and di-isopropyl ether (DIPE) Samples submitted for analysis were
<br /> below laboratory detection limits for all constituents A copy of the laboratory analytical reports and
<br /> chain-of-custody documentation are included as Attachment D
<br /> Groundwater Sampling and Analysis Groundwater monitoring well (MW-4) will be developed,
<br /> gauged, and sampled by Gettler-Ryan during the 3`d Quarter 2003 Groundwater monitoring and
<br /> sampling results will be presented in the Chevron Groundwater Monitoring Report (3Q03)
<br /> • Monitoring Well Survey On June 16, 2003 Morrow Surveying of West Sacramento, California,
<br /> surveyed MW-4, relative to mean sea level and with an accuracy value of 0 001 foot
<br /> SENSITIVE RECEPTOR SURVEY
<br /> Water Supply Wells were located using Geotracker, a State Water Resources Control Board
<br /> (SWQCB) state Geographic Information Systems (GIS), by contacting local water purveyors, and by
<br /> performing a DWR Water Well Drillers Report file review The results are included in Table 1 and
<br /> shown on Figure 3 Geotracker identified four public water wells located nearby the site 1
<br /> Additionally, municipal water suppliers California Water Service, the City of Stockton, and Bogetti
<br /> Enterprises Inc were contacted for well information Two domestic water wells (well Ids s and 1),
<br /> two municipal water wells (well IDs 10 and M2), and one industrial water well (well ID 1) were found
<br /> within 2,000-feet of the site Six additional municipal water wells, located over 2,000-feet to the west
<br /> and north of the site are included in Figure 3 are referenced in Geotracker as near the site
<br /> ' 1
<br /> DWR Well Survey A 2,000 foot radius DWR well survey was performed by a SECOR
<br /> representative on June 10'h, 2003 DWR Water Well Drillers Reports found within the vicinity of the
<br /> site are included in Attachment E i
<br /> Door to Door Well Search A SECOR representative performed a 500-foot radius door-to-door well
<br /> search Five businesses, a public library, and approximately ninety-five residences were contacted
<br /> during the well survey Approximately 50 residences were not available at these locations, an
<br /> envelope was placed in the doorway containing a blank water supply well location survey form in
<br /> Spanish and English, explanation letter, and a self-addressed and stamped envelope As of June
<br /> 24, 2003, nine surveys from domestic residences have been received, signed copies of the Water
<br /> Zhevron1962581REP0RTSISAR_2003 doc SECOR Intematronal Incorporated
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