SITE INFORMATION AND CORRESPONDENCE

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1r,/ `or, Case Closure Summary Page 2 Leaking Underground Fuel Storage Tank Program III Release and Site Characterization Information (continued) Maximum Documented Contaminant Concentrations -- Before and After Cleanup Contaminant Soil (ppm) Water (ppm) Contaminant Soil (ppm) Water (ppm) Before After Before After Before After Before After TPH (Gas) NA NA NA NA Xylene .200 <0.005 <0.0005 <0.0005 TPH (Diesel) 13000 150 19 <.05 Ethylbenzene .470 <0.005 <0.0005 <0.0005 Benzene <.005 <0.005 <0.0005 <0.0005 Oil &Grease NA NA NA NA Toluene .097 <0.005 <0.0005 <0.0005 Heavy Metals NA NA NA NA MTBE NA <0.005 <0.0005 <0.0005 Comments:The before soil contaminant concentrations are from a sample collected at the time of the UST removal in 1995. The after soil contaminant concentrations are from SB1 at 19 feet below grade, collected on 11/21/05. The before groundwater contaminant concentrations are from a geoprobe.grab sample (SB-3) beneath the former UST and dispenser. The after groundwater contaminant concentrations are from MW-3 located approximately 10 feet outside the excavated area and downgradient of the former UST and dispenser. 300 cubic yds. of contaminated soil was removed to 19 feet bgs and approximately 18,874 gal.of water was pumped from the excavation. The soil sample results at 19 feet bgs were below detection limits. 3 MWs were installed and sampled for three times from Feb. 2006 to Jan. 2007. Analytical results for soil and groundwater from all 3 MWs were below detection limits. NA means not analyzed. IV. Closure Does completed corrective action protect existing beneficial uses per the Regional Board Basin Pian? Yes Does completed corrective action protect potential beneficial uses per the Regional Board Basin Plan?Yes Does corrective action protect public health for current land use?Yes Site management requirements: NA Should corrective action be reviewed if land use changes?Yes Monitoring/Vapor wells decommissioned: No Number Decommissioned: 0 Number retained: 3 List enforcement actions taken: NOR sent to RPs List enforcement actions rescinded: NA V. Local Agency Representative Data Name: Margaret Lagorio Title: Program Coordinator Unit IV, REHS Signature: Date: /a-? IO 7 VI. Central Valle Regional Water QualityControl Board RB Notification [ Date Submitted to RB: Response Date: RB Staff: J. Barton Response: Title: Eng. Geologist VII. Additional Comments, Data, etc. This document and the related CASE CLOSURE LETTER,Shall be retained by the lead agency as part of the official site file.