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10/10/00 TUE 17:06 FAX 1 916 861 0430 SECOR-SACRAMENTO
<br />Chevron Products Company 3
<br />Fo r v on H9- 75 V+ ne lifomia
<br />Between December of 1999 and February of 2000, five additional monitoring wells
<br />(MW -5A, -6, -7, -8A, and MW -9 [now renamed as MW -9A]), four soil vapor extraction
<br />wells (VE -1 through VE -4), one groundwater extraction well (EX -1), and two soil
<br />borings (SB -2 and SB -3) were installed by V&W Drilling (G -R, Monitoring Well
<br />Installation Report, dated March 30, 2000). Soil samples collected from the borings
<br />were reported fo contain concentrations of TPHg, benzene, and MtBE up to 1,740
<br />mg/kg, 446 mg/kg, and 100 mg/kg, respectively. The highest concentrations were
<br />reported in samples from borings EX -1 and VE -1 located in the area of the former
<br />USTs. Groundwater samples collected from the monitoring and extraction wells were
<br />reported to contain concentrations of TPHg, benzene, MtBE, ETBE, and TAME
<br />ranging up to 51,000 ug/l, 39,000 ug/l, 720,000 ug/l, 18,000 ug/l, and 6,000 ug/l,
<br />respectively.
<br />Between June 14 and July 7, 2000, ten groundwater monitoring wells (MW -5B,
<br />MW -8B, MW- l0A and B, MW -11A and B, MW -12A and B, MW -13, and
<br />MW-14/EX-2) were drilled and installed at the site by Cascade Drilling. Monitoring
<br />wells MW -5B, MW -8B, MW -1 OB, MW -1113, and MW -12B were drilled and completed
<br />to approximately 90 feet bgs. Monitoring wells MW -10A, MW -11A, MW -12A,
<br />MW -13, and MW-14/EX-2 were drilled and completed to approximately 65 feet bgs_
<br />Concentrations of petroleum hydrocarbons and fuel oxygenates were not reported in
<br />soil samples collected from monitoring wells MW -5B, MW -8B, MW-l0A and 13,
<br />• MW -11A and B, MW -12A and B, and MW -13. MtBE was reported at a concentration
<br />of 0.189 mg/kg in the sample collected from 65 feet bgs in monitoring well
<br />MW- l 4/EX-2.
<br />•
<br />TPHg and benzene, toluene, ethyl -benzene, and xylenes (BTEX compounds) were not
<br />reported in groundwater samples collected from monitoring wells NW -513, MW -8B,
<br />MW- l0A and B, MW -11A and B, MW -12A and B and, MW -13_ Benzene was
<br />reported in monitoring well MW-14/EX-2 at a concentration of 1.02 ug/1. MtBE was
<br />reported in monitoring wells MW -5B, MW -10B, and MW-14/EX-2 at concentrations of
<br />160, 5.2, and 1,100 ug/l, respectively. Concentrations of ETBE were reported in
<br />monitoring we]Is MW -5B and MW -i 4/EX-2 at concentrations of 14 and 120 ug/l,
<br />respectively. Ethanol was detected in monitoring wells MW -1 OB and MW -12B at
<br />concentrations of 1,400 and 2,000 ug/l, respectively.
<br />Additionally, sampling of the municipal well located approximately 350 feet southwest
<br />of the site was initiated in 1996 (San Joaquin Co. Public Works Department, Frank
<br />Beeler, verbal communication, July 2000). The well was sampled annually in 1996 and
<br />1997, quarterly during 1998, and monthly in 1999 and 2000. No detectable
<br />concentrations of hydrocarbons or fuel oxygenates have been reported in this well (City
<br />of Lodi and G -R).
<br />077,41991.04319-5775 W p! 0090o.doc
<br />Q 004
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