SITE INFORMATION AND CORRESPONDENCE_CASE 2

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i Case Closure Summary Page 2 Leaking Underground Fuel Sto age Tank ProgF�m i III Release and Site Characterization Information (continued) I Maximum Documented Contaminant Concentrations - -Before and After Cleanup Contaminant Soil Sol! Water Water Con aminant Soil Soil Water Water i Before After Before After Before After Before After (Ppm) (Ppm} {ppm) (PPm) TPH(Gas) 2.4 1 <1.0 0.120 <0.05 MTBE 2.7 <0.005 0.44 0.0006 TPH (diesel) 6.2 <1.0 0.17 <0.05 TBA 24 <0.025 <0^005 <0.005 Benzene 0.0065 <0.005 0.0032 <0.0005 1,2- CA ---- <0.005 <0.005 Toluene 0.054 <0.005 0.009 <0.0005 EDB ---- <0.005 ---- <0.005 Ethylbenzene ND <0.005 0.001 <0.0005 Oxygenates ND <0.005 <0.005 <0.005 Xylenes 0.0065 <0.005 0.0077 <0.0005 Soil Before from February 1999 tank removal. Water Before from soil probe grab water samples in January 2001. Soil After from installation of the monitoring wells in January 2002. Water After from monitoring wells 11107102. Excavation and transportation of the potentially contaminated soil appeared to adequately remediate most of the soil contamination. MTBE and petroleum hydrocarbon chemicals appeared in grab water samples, but were not detected in monitoring well samples (with the exception of one occasion for NITBE at concentration of 0.0006 ppm). No private wells were found within 2,000-foot radius. Calculation of the mass remaining in the soil using highest analytical results. Beneficial uses of groundwater are protected, now and in the futu e. Iv. Closure Does completed corrective action protect existing beneficial uses per the Regional Board Basin Plan? Yes Does completed corrective action protect potential beneficial use per the Regional Board Basin Plan? Yes Does corrective action protect public health for current land use? Yes Site management requirements: none Should corrective action be reviewed if land use changes? Yes Monitoring wells decommissioned: Yes Number Decommissioned: 3 Number retained: 0 List enforcement actions taken: NOR List enforcement actions rescinded: None V. Local Agency Representative Data Name: Donm Heran Title: Director of Environmental Health Signature: Date: VI. Central Valley Regional Water Quality Control Board (RB) Notification Date Submitted to RB: Response Date: March 17, 2004 RB Staff: James L. BartonResponse: Concurrence with No Further Action Status Title: Assoc Eng Geologist VII. Additional Comments, Data, etc. Monitorin welEs were all destroyed under permit and inspection. 9 This document and the related CASE CLOSURE LETTER Shall be retained by the lead agency as part of the official site file. (08124193) Exhibit N Page 2 of 2