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' 21 March 2001. AGE-NC Project No. 98-0432 Page 3 of 5 2.4. DRILLING/SAMPLING AND WELL DESIGN On 11 December 2000, two ground water monitoring wells and on 20 December 2000 one ground water extraction well were installed on-site. Drilling and sampling were performed using a truck- mounted CME 75-HT drill rig equipped with continuous flight 8-inch or 12-inch augers. The drill rig and two-man crew were provided by WestHaz Mat Drilling of Rancho Cordova, California. Soil samples were collected from pilot borings MW5 and MW6 at five-foot intervals, beginning at ten feet bsg, using a California split tube sampler loaded with three clean 2-inch by 6-inch brass ' sleeves. A 140-pound hammer was utilized to advance the sampler 18 inches; the number of blows required to advance the sampler over each 6-inch increment was recorded on the boring logs. All sampling equipment was washed in an Alconox solution and rinsed twice with water prior to each ' sampling run. Soil samples were collected for field screening and observations however,no samples were submitted for chemical analysis. 2.5. SOIL LOGGING During drilling, auger returns were monitored for the presence of organic vapor using an OVM. Auger returns were placed on plastic and stored on the eastern edge of the site, pending laboratory analysis. Duplicate soil samples were extruded from their sleeve and were screened for the presence of organic vapor using the OVM. The OVM readings were recorded on boring logs. The soil was then visually described in accordance with the Unified Soil Classification System (see boring-logs, Appendix A). 2.6. EQUIPMENT DECONTAMINATION The hollow stem augers were steam-cleaned prior to each boring advancement. Sampling tools and brass sleeves used for sample collection were thoroughly washed with a solution of Alconox and thoroughly rinsed with tap water prior to each sampling run. Following drilling activities, rinseate generated from decontaminating the equipment was placed in properly labeled 55-gallon drums and ' was stored on-site. ' 2.7. WELL COMPLETION Soil borings MW5 and MW6 were completed as conventional ground water monitoring wells with ' the same designations. Field numbering of the wells was determined prior to each well's installation 'to aide the PHS-EHD in field inspections. A summary of the construction details are depicted on the boring logs (Appendix A).