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U Geological Technics Inc. Page 4 Additional Site Characterization Work Plan Project No.723.2 December 10,2007 2.1.3 Soil Sample Analyses The soil samples will be submitted to a State certified laboratory for the following analysis: • Benzene,toluene, ethyl benzene and xylene(BTEX)by EPA method 8021M or 8260 • Gasoline range petroleum hydrocarbons(TPH-G)by EPA method 8015M or 8260 The detection limits for these compounds are listed below. A Chain of Custody will be completed for all samples collected and tracked to ensure sample integrity. Detection Limits: BTEX TPH-G Soil(jig/K 3.0 1,000 2.2 Lateral Groundwater Plume Definition Four well sets consisting of an intermediate and deep well are proposed to define the extent of the groundwater plume to the northeast and southeast of the site. See Figure 2 for well locations. Wells MW-110/210, MW-111/211, MW-112/212 and MW 113/213 will be located approximately 500 feet north, 700 feet northeast, 900 feet east-northeast and 600 feet southeast of, respectively, the site. The boreholes for the wells in these locations will be advanced to a total depth of 100 feet bgs. 2.2.1 Borehole Drilling The borings will be drilled using an 8-inch outside diameter continuous flight hollow stem auger. Soil cuttings will be containerized in DOT approved 55-gallon steel drums and held on site pending disposal. 2.2.2 Soil Sampling Procedure The depth/intervals of soil sampling will vary among the proposed well sets: • Boring MW-210 will be sampled at five foot intervals from the surface to 75 feet bgs to confirm the lithology identified in!;the CPT-1 borehole location. The borehole will then be continuously sampled from 75 to 100 feet bgs. The depth of the well MW-210 screen will be targeted to intercept deeper sand layers that could act as a preferential pathway for contaminant transport. The MW-110 intermediate well boring will be free drilled to total depth. The screened interval of this well will be from 65 — 75 feet to intercept sand units identified in the CPT-1 borehole. If no significant sand layers are encountered below 75 feet, the screen of well MW-210 will be placed in the same interval as well MW-308 (89'). • Boring MW-211 will be sampled at five foot intervals from the surface to 70 feet bgs to confirm the lithology identified in the CPT-2 borehole location. The borehole will then be continuously sampled from 70 to 100 feet bgs. The depth of the well MW-211 screen will be targeted to intercept deeper sand layers that could act as a preferential pathway for contaminant transport. The MW-111 intermediate well boring will be free drilled to total depth. The screened interval of this well will also target intermediate sand layers