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20 September 2007 AGE-NC Project No. 97-0300 Page 5 of 6 form, and place into a dry cooler (room temperature). Subsequently, all of the collected soil vapor samples will be delivered to a State-certified laboratory for analysis of the chemical constituents listed in Section 2.2. After collection of the sample, soil vapor from the polyethylene tubing will be monitored for the presence of volatile organics using a photo-ionization detector(PID)pre-calibrated to isobutylene. 3.2. CPT DRILLING AND GRAB GROUND WATER SAMPLE COLLECTION Based on 1,2-DCA impact encountered from wells MW-4 and MW-5R(screened 60 to 70 feet bsg) and based on the sandy-silty sand content of soil samples previously observed at these depths, CPT soil borings will be advanced to target depths of approximately 70 feet bsg utilizing a 25-ton truck- mounted CPT drill rig equipped with 2-inch diameter hollow-stem rods. Each CPT soil boring will utilize a hydraulic ram to advance a cone penetrometer to the desired depth. Soil parameters such as cone bearing, sleeve friction, friction ration and pore water pressure will be measured and recorded as the cone penetrometer is advanced to depth.Rinseate generated during drilling activities will be containerized in properly labeled DOT-approved 55-gallon drums, and stored on-site in an area lacking public access. A second soil boring will be located adjacent the first CPT boring for ground water sample collection.Based on CPT findings,discrete grab ground water samples will be collected in selected saturated intervals of porous and permeable material, and at depths between 60 and 70 feet bsg. A HydroPunch sample tool will be pushed into the specified zone,then withdrawn approximately three feet to expose an inlet screen. The interior of the sampling tool fills with water and a 1-inch outer diameter(O.D.) stainless steel bailer will be lowered and utilized to extract a ground water sample. Following sample collection, the samples will be placed in laboratory-supplied containers and transported under chain-of-custody to a DHS-certified laboratory. Ground water samples will be collected utilizing three 40-m1 EPA-approved volatile organic analysis(VOA)vials. Ground water sample containers were labeled with the well designation, date, time, and sampler's initials. Each ground water sample will be logged on a chain-of-custody form, placed in a chilled container and transported to a California Department of Health Services (DHS)-certified laboratory for analysis for 1,2-DCA. Proposed soil boring locations are illustrated on Figure 2. 3.3. EQUIPMENT DECONTAMINATION All sampling tools used for sample collection will be thoroughly rinsed with clean water after being washed with a solution of Alconox.All down-hole drilling and sampling equipment will be pressure washed prior to starting the boring. All rinseate generated during drilling activities will be Advanced GeoEnvironmental,Inc.