SITE INFORMATION AND CORRESPONDENCE_CASE 2 FILE 2

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Shell Oil Sites Page 3 2494 Fremont Street,Stockton Access to the property to the north of this site has not been obtained so the ground water investigation in that direction has not been conducted. Shell is to continue their site investigation. 2375 Grant Line,Tracy EHD agrees with Shell that the methyl tert butyl ether(MTBE) detected in samples from monitoring well MW-4, appears to be from the 2360 West Grant Line Road (7-Eleven) site located directly south (down-gradient) of the Shell site. However,water from MW-1 has the highest MTBE concentrations and that contamination appears to be from an on-site source. Since the Highway 205 on-ramp is located directly north and down-gradient of MW-1, additional investigation to define the lateral extent down-gradient of the contamination and to determine the total mass of the plume may be difficult. Shell agreed to explore the possibility of conducting a dual- site groundwater treatment with 2360 West Grant Line Road and/or providing a model of the contamination to evaluate the potential for migration and impact. Shell will.submit a monitoring well installation/contamination investigation report by the end of this month Qune 2005). <1011 Main Street,Manteca EHD was informed that Cambria had created a site model and the results did not support site closure. EHD recommended that Cambria use good professional judgment to support why the model may not be correct. Cambria agreed to prepare a site closure report (discussed in the Tri- Regional Board Staff Recommendations dated April 16,2004). 341 Main Street,Ripon A closure report for this site was provided at the meeting. 7700 Moreland Street,Stockton Eight monitoring wells have been installed to investigate the MTBE in the soil and groundwater. The lateral extent of the shallow contamination has been defined. An EHD permit has been issued for the installation of a deeper monitoring well to investigate the vertical extent of the contamination. Quarterly groundwater monitoring/sampling of the monitoring wells will continue to demonstrate that the MTBE concentrations in the groundwater are still declining. Analysis for methanol,ethanol,EDB and 1,2-DCA will be performed on the water samples to determine if these contaminants are present in the groundwater.. 6131 Pacific Avenue,Stockton There has been a lack of progress at this site with focus on minor contamination in offsite lateral wells rather than remediation of the major onsite contaminant problem. EHD has directed that interim remediation of the on-site source area soil contamination be performed,but to date interim remediation has not been performed. It was discussed that dual phase extraction should be performed as interim remediation and that language should be included in the Corrective Action Plan to be submitted by September 9,2005, that if DPE is successful it will be the alternative for the final remedial action. 3725 Trace Blvd,Tracy An SCM is to be prepared for this site. Further delineation of the contamination may be required. Quarterly groundwater monitoring/sampling of the monitoring wells will continue to demonstrate that the MTBE concentrations in the groundwater are still declining. Analysis for methanol, ethanol, EDB and 1,2-DCA will be performed on the water samples to determine if these contaminants are . present in the groundwater. The Record Title Owner information should be updated if ownership of the facility has changed. i a