SITE INFORMATION AND CORRESPONDENCE FILE 2

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�,. .i > Karen Petryna Equiva Services,LLC Page 4 Action item: Harlin Knoll to send letter to Shell stating that horizontal and vertical extent of contamination must be defined. i Completed: June 22, 2001. 4445 N Pgrshine Contamination is not currently evident in the groundwater at this site. However,the well screens for monitoring wells MW-1,MW-2 and MW-3 are currently submerged. The screen lengths are no known;therefore the significance of the submerged screens is also unknown. Additionally,a concentration of petroleum hydrocarbons has been detected in groundwater samples from Exxon well,MW-8,which is adjacent to the Shell property. It is not known at this time if the contamination is coming from Exxon or Shell. Because of this concern,the work plan that was previously submitted by Cambria is no longer viable. Therefore,the workplan must be modified to include a plan for determining the source of the contamination. The new work plan should consider the screen intervals of Shell's current monitoring wells avhi h includes all soi ti addition, Harlin Knoll requested that Cambria should include a summary, result for samples collected during UST removal and MW installation,with the work plan. Action item: Cambria to submit a new workplan to the County. 3725 Tracy Boulevard Harlan Knoll has approved the workplan. A recent increase in concentration of TPH as gasoline, as well as benzene,toluene,ethylbenzene and xylenes, suggests a possible new release. A monitoring well should be placed in the street next to the property in order to evaluate this possibility,but the City of Tracy is reluctant to issue the encroachment permit. Action item: Equiva/Cambria to provide a City of Tracy contact to Harlan Knoll so that he can call the City of Tracy with a request to allow the installation of the monitoring well in the street. 420 W Kettleman Lane There is a MtBE soil problem that needs to be remediated, and groundwater monitoring needs to continue to confirm or disprove possible methanol/ethanol contamination. Soil vapor extraction is a potential solution to the soil problem. Cambria will be submitting report to the County and RWQCB July 29 that includes a the results of the installation of five soil borings,CPT borings and the installation of monitoring wells MW-6 and MW-10. After the report has been submitted, Cambria will submit a soil vapor extraction(SVE)work plan. Action item: Cambria to submit investigation report and SVE work 620 Charter Wav Additional investigation is required to define the lateral and vertical extent of groundwater contamination in the 50-to 80-foot depth. Cambria suggested installing a monitoring well in the adjacent Best Western parking lot but anticipates problems with access agreements. The County will send a letter to Shell directing them to submit a revised workplan that defines the extent of groundwater contamination to the northeast.