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NOW 4. Mr. Ron Rowe Page 2 will be performed by a C57 licensed drilling contractoriga direct to a maximush rig. The boring m depth of 40 feet located at the east end of the former tank pit will be advanced below ground surface (bgs), the historic low groundwater depth. The three peripheral borings will be drilled to first encountered groundwater, estimated at approximately 35 feet bgs. Based on San Joaquin County Groundwater Reports 1993 through 1996, the groundwater flow direction 0 is toward the east. The boring advanced in the former tank pit will be cored and logged continuously. Soil samples from all borings will be collected every 5 feet for logging and analytical purposes. Soil samples will be screened using a flame ionization detector (FID) to determine which samples will be submitted for laboratory analysis. The borings will then be backfilled with neat cement to the ground surface. Groundwater samples will be collected from the borings using a discrete sampling device. All drilling equipment will be steam cleaned prior to use to avoid cross contamination. Rinsate water generated by steam cleaning will be collected in appropriately labelled 55-gallon drums and temporarily stored onsite. Up to three (3) soil samples from each boring will be submitted to a state-certified laboratory and analyzed for TPHg using modified EPA method 8015, and BTEX and methyl tert-butyl ether (MTBE) using EPA method 8020. One soil sample from the central boring (collected from approximately 15 feet bgs) will also be analyzed for total lead using EPA method 6010 and for oxygenate additive compounds using EPA method 8260. In the event soil contamination extending to groundwater is evident beneath the former UST, up to two additional soil samples will be collected from the saturated zone and analyzed for the physical parameters hydraulic conductivity, porosity, bulk density and total organic carbon content. If two distinct soil lithologies are encountered in the saturated zone, then one sample will be collected from each. Up to four grab groundwater samples will be analyzed for TPHg, BTEX, and MTBE. Water samples collected from the boring located in the former tank pit and from the estimated downgradient (east) boring will also be analyzed for oxygenate compounds using modified EPA method 8260, as now required by PHSIEHD. All field and laboratory activities performed at the site will be conducted in accordance with the Quality Assurance/Quality Control Plan included in Attachment A. Field work will be Performed in accordance with the Health and Safety Plan included in Attachment B. Drilling permit applications and fees are included in Attachment C.