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Geo(ogica[T'echnics Inc. Page 2 Shawver WP Add. g Project No.757.2 July 28, 1999 100 feet bgs. A SimulProbe sampling tool will be used to collect soil and soil-pore water samples from this boring. This borehole will be grouted up and a monitoring well (MW- 1)will be installed in a borehole adjacent to S13-101. 2. To define the lateral extent of contamination, it is proposed that three boreholes be drilled to a depth of±80 feet below grade. These borings will be named MW-2, MW-3 and SB- 1 and will be located to the east, the south and the west of the former waste oil tank. See Figure 1: Site map for boring locations. The close proximity of the shop will prevent drilling immediately north of the tank. 2.1 Soil Boring Soil boring permits will be secured as necessary and the local regulatory agency will be notified 48 hours prior to commencing work. The subsurface will be cleared of underground utilities by notifying Underground Service Alert. Deep Boring The deep soil boring will be drilled using an 8-inch outside diameter, continuous flight, hollow stem auger owned and operated by V&W Drilling (C57# 720904). The boring will be drilled to a depth of approximately 100 feet bgs, the lowest groundwater level reported on San Joaquin County Flood Control and Water Conservation District maps (for 1978). Soil samples will be collected at five-foot intervals as described in Section 2.2. In addition, two soil and soil-pore water samples will be collected from this boring, using a SimulProbe sampling tool, at depth of approximately 80 and 100 feet bgs. This procedure is also described in Section 2.2 Upon collection of the bottom hole sample the boring will be closed by a neat cement grout tremied into the borehole. Shallow Borings These boreholes will be drilled using an 8-inch outside diameter, continuous flight, hollow stem auger owned and operated by V&W Drilling (C57# 720904). The expected depth to groundwater is approximately 60 to 65 feet below ground surface, based on data from San Joaquin County Flood Control and Water Conservation District for 1990. The boring, MW-1, will be drilled through the center of the excavation, next to SB-101, to a depth of approximately 80 feet bgs. This boring will be free drilled due to its proximity to SB-101. A monitoring well will be installed in this borehole as described in section 2.3. The borings for MW-2 and MW-3 will be drilled to the east and south, respectively, of the former tank pit. The borings will be advanced to a depth of approximately 80 feet bgs. Soil samples will be collected at five-foot intervals as described in Section 2.2. A monitoring well will be installed in these boreholes as described in section 2.3. Soil boring S13-1 will be drilled to the west of the former tank pit and extend to the capillary fringe, approximately 65 feet bgs. Soil samples will be collected at five-foot intervals as described in Section 2.2 2.2 Soil Sampling Procedure Soil samples will be collected for geological and analytical evaluation at 5-foot intervals in S13-101, MW-2, MW-3 and S13-1. A boring log providing sediment description using the