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Ms. Vicki McCartney November 15, 2006 Page 2 of 3 As previously approved, based on field observations and PID measurements, at least three soil samples per boring will be submitted for laboratory analysis. These soil samples should include those collected at the approximate depth of the bottom of the former UST(15 feet below sub-grade), at the groundwater table interface (i.e., capillary fringe), and at the total depth of the soil borings. Additional soil samples may be submitted for analysis, if required to adequately characterize the site. Field observations and sample selection will be reviewed with the EHD hazardous materials inspector, prior to sample submittal to the lab. As previously approved, the soil samples will be sealed with Teflon° film and plastic end caps, labeled, packaged in an iced cooler, and transported with chain-of-custody documentation to a state of California-certified hazardous waste testing laboratory for analysis. Each of the soil samples will be analyzed on a standard turn-around time for TPH- as-gasoline and BTEX by EPA Method 8021 B/8015M or 8260B, and for MTBE, DIPE, ETBE, TAME, TBA and 1,2-DCA by EPA Method 8260B. From all three soil borings, groundwater samples will be collected from the boreholes using 3/4-inch diameter PVC temporary wells. The temporary wells will consist of 15 feet of flush- threaded and machine-slotted (0.020-inch) well screen spanning approximately five feet above and ten feet below the depth of static groundwater. Blank PVC casings will thread into the tops of the well screens and extend to the surface. Neither a sand pack nor a well seal will be installed in the temporary wells. As previously approved, prior to groundwater sampling, the temporary wells will be purged of at least three casing volumes using a bailer. During purging, groundwater temperature, pH and electrical conductivity will be recorded to evaluate the stability of these parameters. Once the groundwater in the temporary wells is purged and recharged to at least 90% of its original groundwater column thickness, the groundwater samples will be collected. As previously approved, each of the groundwater samples will be collected using decontaminated polyethylene bailers and laboratory-supplied containers. The sample containers will be labeled, packaged in an iced cooler, and transported with chain-of-custody documentation to a state of California-certified hazardous waste testing laboratory for analysis. The laboratory will analyze the groundwater samples for TPH-as-gasoline and BTEX by EPA Method 8021B/8015M or 8260B, and for MTBE, DIPE, ETBE, TAME, TBA and 1,2-DCA by EPA Method 8260B. As previously approved, upon completion of the groundwater sampling at each location, the temporary wells will be removed and the boreholes will be sealed with neat cement grout, using a tremie pipe. The surface will be restored with asphalt or concrete patches.