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1 I 0 08 October 2003 AGE-NC Project No. 98-0504 Page 4 of 7 Soil samples were collected from the soil borings at five-foot intervals beginning,at 5 feet bsg in borings MW-1 and MW-3 and at 15 feet bsg in boring MW-2. The samples were collected with a California-modified split spoon sampler.loaded with three clean, 2-inch by 6-inch brass sleeves. A 140=pound hammer was used 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. Sampling equipment was washed in an Alconox solution and rinsed with water prior to each sampling run to minimize cross-contamination. For each sample,both ends of the leading or other selected sleeve were covered with Teflon sheets, capped and sealed with tape., 3.2. SOIL LOGGING After sample preservation, soil was extruded from the remaining sleeves and screened for the presence of organic vapor. The soil was also described in accordance with the Unified Soil Classification System. Soil boring logs exhibiting soil profiles are depicted in Appendix B. 3.3. MONITORING WELL INSTALLATION AND DEVELOPMENT Pilot borings MW-1 through MW-3 were completed as ground water monitoring wells using two-inch diameter PVC casing with 0.020-inch slotted screen installed from 25 to 45 feet bsg in borings MW-1 through MW-3 with blank casing extended to the surface. A filter pack (No. 3 Lonestar sand) was installed from approximately 23 to 45 feet bsg in wells MW-1 through MW-3. A nominal 2- to 3-foot bentonite chip plug was then installed above the filter pack and hydrated. Afterwards, the remaining annular space was backfilled to within six inches of surface grade with portland'cement, and a traffic-rated well box (8-inch diameter) was installed over each well in accordance with San Joaquin County regulations.Monitoring well design specifications are depicted in Appendix B. 3.4. GROUND WATER DEVELOPMENT AND SURVEY ACTIVITIES On 07 April 2003, ground water well development activities were performed at the site in order to increase water flow into the well and to minimize the amount of fine-grained sediment drawn into the well during pumping or bailing. The water level and the total well depth in each monitoring well were measured relative to the tops of the well casings using a Solinst water level meter. After water levels and total depths were measured, a steel bailer was used to purge five gallons from each well casing. Advanced GeoEnvironmental,Inc.