Chevron Products Company 3
<br />Chevron Station 49-5775 361 W Kctdcnian Lane Lodi CA August 25 2000
<br />• of TPHg, benzene, MtBE, ETBE, and tertiary amyl methyl ether (TAME) ranging up to
<br />11,000 ug/l, 6,800 ug/l, 62,000 ug/I, 2,400 ug/l, and 780 ug/l, respectively
<br />In October of 1999, G -R continuously monitored the groundwater elevations at the site
<br />over a three-day period (G -R, Offsite Source Survey, dated November 2, 1999) The
<br />results of the study indicated that groundwater elevations fluctuate in dally cycles
<br />corresponding to the operation of nearby City of Lodi Municipal Well # 12, located
<br />approximately 350 feet southwest of the site
<br />Between December of 1999 and February of 2000, five additional monitoring wells
<br />(MW -5 through MW -9), four soil vapor extraction wells (VE- I through VE -4), one
<br />groundwater extraction well (EX -1), and two soil borings (SB -2 and SB -3) were
<br />installed by V&W Drilling (G -R, Mointoting WellInslallculo1! Repoil, dated March 30,
<br />2000) Soil samples collected from the borings were reported to contain concentrations
<br />of TPHg, benzene, and MtBE up to 1,740 mg/kg, 446 mg/kg, and 100 mg/kg,
<br />respectively The highest concentrations were reported in samples from borings EX -I
<br />and VE -1 located in the area of the former USTs Groundwater samples collected from
<br />the monitoring and extraction wells were reported to contain concentrations of TPHg,
<br />benzene, MtBE, ETBE, and TAME ranging up to 51,000 ug/l, 39,000 ug/I, 720,000
<br />ug/l, 18,000 ug/l, and 6,000 ug/1, respectively
<br />Between June 14 and July 7, 2000, ten groundwater monitoring wells (MW -513, MW -
<br />is 8B, MW- IOA and B, MW -1 IA and B, MW -12A and B, MW -l3, and MW -14) were
<br />drilled and installed at the site by Cascade Drilling Monitoiing wells MW -5B, MW -813,
<br />MW- I OB, MW -1113, and MW -12B were drilled and completed to approximately 90 feet
<br />bgs Monitoring wells MW -10A, MW -1 IA, MW -12A, MW -13, and MW -14 were
<br />drilled and completed to approximately 65 feet bgs Concentrations of petroleum
<br />hydrocarbons and fuel oxygenates were not reported in soil samples collected from
<br />monitoring wells MW -5B, MW -8B, MW -I OA and B, MW 1 I and B, MW -12A and B,
<br />and MW -13 MtBE was reported at a concentration of 0 189 mg/kg in the sample
<br />collected from 65 feet bgs in monitoring well MW -14
<br />TPHg and benzene, toluene, ethyl -benzene, and xylenes (BTEX compounds) were not
<br />reported in groundwater samples collected from monitoring wells MW -513, MW -8B,
<br />MW -10A and B, MW -1 IA and B, MW -12A and Band, MW -13 Benzene was reported
<br />in monitoring well MW -14 at a concentration of 1 02 ug/l MtBE was reported in
<br />monitoring wells 1\4int-5B, MW- IOB, and MW -14 at concentrations of 160, 5 2, and
<br />1,100 ug/l, respectively Concentrations of ETBE were reported in monitoring wells
<br />MW -513 and MW -14 at concentrations of 14 and 120 ug/l, respectively Ethanol was
<br />detected m monitortng wells MW- I OB and MW -12B at concentrations of 1,400 and
<br />2,000 ug/l, respectively
<br />Additionally, sampling of the municipal well located approximately 350 feet southwest of
<br />the site was initiated in 1996 (San Joaquin Co Public Works Department, Frank Beeler
<br />verbal communication July 2000) The well was sampled annually In 1996 and 1997,
<br />077 41991 0411FRP
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