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<br /> Navarra Site: Potable Water- upply Well Program Page 2 of 7
<br /> the releases of fuel hydrocarbons that occurred on the 7500 West Eleventh Street
<br /> property. The locations of the wells found are shown on Figure 1 that is attached. The
<br /> report included SJC's recommendation that, as a conservative check, a water-quality
<br /> monitoring program be initiated for six potable water supply wells on and in the
<br /> neighborhood of the Navarra Site. The wells specified in 2002 were those at 24195
<br /> Chrisman Road, 7500 West Eleventh Street, 7601 West Eleventh Street, 23950 Chrisman
<br /> Road, 23901 Chrisman Road and at the Carmelo Business Park.
<br /> Water-quality monitoring for the six specified potable water supply wells was initiated on
<br /> April 2, 2004 and a second monitoring round was performed on July 27, 2004. Based on
<br /> the findings from those two rounds that no analytes of concern were detected in samples
<br /> recovered from any of the six wells, which finding was consistent with the known
<br /> hydrogeology of the site, in our subsequent report, Groundwater-quality Monitoring
<br /> Report — July 25, 2004, Former Fueling Station, 7500 West Eleventh Street, Tracy,
<br /> California that was submitted to the SJCEHD on October 25, 2004, SJC recommended
<br /> that to conserve California Underground Storage Tank Cleanup Fund Program (USTCF)
<br /> funds, the potable water-quality monitoring program be discontinued at that time. A third
<br /> round of potable water-quality monitoring was conducted on October 28, 2004. That
<br /> round again demonstrated that water in all six potable water supply wells was free of any
<br /> analytes of concern. In our report, Groundwater-quality Monitoring Report - October 27,
<br /> 2004, Former Fueling Station, 7500 West Eleventh Street, Tracy, California, submitted to
<br /> the SJCEHD on December 18, 2004, we again recommended that to conserve public
<br /> funds, termination of the potable water supply monitoring program at the subject site.
<br /> In a meeting held on January 18, 2005 at SJCEHD offices in Stockton, SJC again
<br /> recommended termination of the potable water supply monitoring program, but the
<br /> recommendation was not approved by SJCEHD staff. At the same meeting, the SJCEHD
<br /> requested that the next round of potable water-quality sampling SJC actually expand the
<br /> analytical suite previously approved for that program to include analyses for ethylene
<br /> dibromide (EDB), 1,2 dichloroethane (1,2 DCA), ethanol and methanol, even though: 1)
<br /> several rounds of groundwater-quality monitoring at the site had demonstrated that no
<br /> detectable concentrations of EDB, 1,2 DCA or ethanol were present, either within or
<br /> beyond the plume of affected groundwater emanating from the 7500 West Eleventh
<br /> Street property when the analyses were performed by laboratory methods having Method
<br /> Detection Limits (MDLs) less than or equal to the maximum contaminant levels (MCL)
<br /> established by Title 22 of The California Code of Regulations (CCR); and 2) there was
<br /> no reason to believe that ethanol or methanol had been components of any of the fuels
<br /> stored in the underground tanks on that site. When the next round of groundwater-quality
<br /> monitoring was conducted over the period March 7 - 9, 2005, consistent with the known
<br /> geochemistry and history of the site, once again, no 1,2 DCA, EDB, ethanol or methanol
<br /> was detected in any of the samples recovered from the 27 groundwater-quality
<br /> monitoring wells included in that monitoring event, nor were any of those analytes found
<br /> in water recovered from any of the six potable water supply wells when they were
<br /> sampled on February 25, 2005
<br /> At the January 18,' 2005 meeting, SJCEHD staff also requested that SJC prepare a letter
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