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Groundwater was not encountered during removal of the USTs at the site. Groundwater depth data collected from monitoring wells MW-1 through MW-3 located on an adjacent property in June, July, August, and November 1994, indicate groundwater flow directions varied from south-southwest to northwest during this time frame. This information was previously communicated to you by Mill Creek Associates. FIELD WORK On March 15, 1995 Ground Zero, under the supervision of Linda Turkatte of San Joaquin Co. PHS/EHD, observed Spectrum Exploration of Stockton, California (C57 512268) drill one soil boring (HP-1) along the downgradient edge of the former used-oil UST cavity adjacent to the loading dock and one boring (HP-2) at the former lube oil UST location near the eastern property boundary (Figure 1). The borings were advanced to just above first encountered groundwater using a drill rig equipped with 8-inch diameter hollow-stem augers. Depth to groundwater was determined from the monitoring wells located on the adjacent property on the day of drilling. Groundwater was encountered at a depth of approximately 24 feet below ground surface. Once the borings were drilled to just above groundwater, a hydropunch probe was advanced into the groundwater bearing zone. Two hydropunch attempts were made in boring HP-1. Neither of these were successful due to a complete lack of water influx into the hydropunch tool, presumably as a result of the fine grained soil type. Based on the lack of observable evidence of hydrocarbons in the soil in this boring, and due to the fine grained soil type, the workplan was verbally amended with the approval of PHS/EHD such that a groundwater sample would not be required at this location. A groundwater sample was collected from within the hydropunch tool in boring HP-2 from a depth interval of 26-28 feet below grade. During drilling, soil samples were collected at 5 foot intervals for logging purposes. Logs of borings are included as Attachment A. Upon completion the borings were backfilled to grade using a cement/bentonite slurry. The groundwater sample from HP-2 was shipped to Argon Laboratories of Ceres, California (DOHS Cert. #1873) for analysis of total petroleum hydrocarbons as gasoline (TPHg); benzene, toluene, ethylbenzene, and xylenes (BTEX); total petroleum hydrocarbons as diesel (TPHd); total petroleum hydrocarbons as kerosene (TPHk); and heavy hydrocarbons using EPA Method 8015. Laboratory and chain-of-custody reports are included as Attachment B. Analytical results are summarized in Tam 1. All field activities were conducted in accordance with the Quality Assurance/Quality Control Plan previously submitted with our workplan. SOIL AND GROUNDWATER CONDITIONS Stiff, elastic silt was encountered in boring HP-1 from a depth of approximately 1 to 5.3 feet bgs. This was underlain by an approximately 5 foot thick poorly graded sand and a silty sand from approximately 10.5 to 15 feet bgs. Below these sandy intervals a very stiff to hard elastic silt was encountered to total depth of 25.5 feet.