|
Chevron Products Company d
<br />• Chevron Statton 99 5775 301 W _ Kelt1cmin Line Lodi CA � AuKust 25 2000
<br />quarterly during 1998, and monthly in 1999 and 2000 No detectable concentrations of
<br />hydrocarbons or fuel oxygenates have been reported in this well (City of Lodi and G -R)
<br />Quarterly Monitoring Data
<br />Quarterly groundwater monitoring and sampling of monitoring wells MW- I through
<br />MW -9 began in January of 2000 TPHg has been reported in monitoring wells MW -1,
<br />MW -3, MW -4, MW -5, and MW -6 at concentrations ranging from 150 to 51,000 ug/1
<br />In the most recent quarterly sampling event (second quarter 2000), TPHg was reported
<br />in monitoring wells MW -3, MW -5A, and EX -1 at concentrations of 220 ug/l, 67 ug/1,
<br />1,290 ug/l, respectively TPHg has not been reported in deep monitoring wells A
<br />shallow TPHg isoconcentration map is presented as Figure 6 The estimated area of
<br />TPHg impacted groundwater is presented in Figure 7 Historical groundwater
<br />monitoring data is presented as Attachment C
<br />Historically, benzene has been reported in monitoring wells MW -1, MW -3 MW -4, MW -
<br />5, MW -6, and EX -1 at concentrations ranging from 0 72 to 39,000 ug/l During the
<br />most recent quarterly sampling event, benzene was reported in monitoring wells MW -3,
<br />MW -5A, MW -6, and EX -I at concentrations of 8 3 ug/l, 0 73 ug/l, 0 57 ug/l, 455 ug/l,
<br />respectively Benzene has not been reported in the deep monitoring wells at the site A
<br />shallow benzene isoconcentration map is presented as Figure S The estimated area of
<br />benzene impacted groundwater is presented in Figure 9
<br />Concentrations of MtBE have been reported in monitoring wells MW- 1, MW -3, MW -4,
<br />MW -5, MW -6, MW -8, MW -9, and EX- I at concentrations ranging 1i om 2 75 to
<br />720,000 ug/1 During the most recent quarterly sampling event (July 24, 2000),
<br />concentrations of MtBE were reported in shallow and deep monitoi ing wells MW -3,
<br />MW -4, MW -5A, MW -5B, MW -6, MW -9, MW-IOB, MW -14, and EX -1 at reported
<br />concentrations of 30 ug/l, 1,900 ug/l, 810 ug/I, 170 ug/l, 3 5 ug/l, 5 8 ug/i, 2,100 ug/l,
<br />and 197,000 ug/l, respectively Shallow and deep MtBE isoconcentration maps are
<br />presented as Figures 10 and 11, respectively The estimated area of MtBE impacted
<br />groundwater is presented in Figure 12 The estimated area of MtBE impacted soil is
<br />shown on Figure 15
<br />Historical monitoring data from these wells indicate that groundwater at this site has
<br />been measured between 54 to 59 feet bgs Groundwater flow has generally been
<br />reported to the west-southwest, south, and southeast Quarterly monitoring and
<br />sampling is ongoing at the site Historical and recent groundwater monitoring and
<br />analytical data is summarized in Attachment C
<br />SUMMARY OF INTERIM REMEDIATION
<br />Interim remediation consisting of weekly pumping water from well EX- l was conducted
<br />by G -R from April 6 to June 29, 2000 During weekly well pumping, approximately
<br />2,635 gallons of water was removed from the site (G -R, July 2000)
<br />077 41991 043/FRP
<br />
|