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l02 March 2000 AGE-NC Project No 98-0452 Page 2 of 5 3 1 DRILLING AND SAMPLING On 23 November 1999, three soil borings were advanced at the site Boring MW-1, MW-2, and MW-3 were advanced using a CME-75 drill ng All three borings were advanced to a depth of 25 feet below surface grade (bsg) using 8-inch diameter hollow-stem augers The drill ng and two-man crew were supplied by Mitchell Environmental Drilling of Sacramento, California Auger returns generated by drilling were placed on plastic sheeting and stored on site pending laboratory analysis Soil samples were collected ahead of the dnll bit using a split-tube sampler loaded with three I pre-cleaned 2-inch by 6-inch brass sleeves The samples were collected at five-foot intervals, beginning at 5 feet bsg in borings MW-1, MW-2, and MW-3 using a 140-pound hammer to advance the sampler 18 inches The number of blows required to advance the sampler in 6-inch increments was recorded on the boring logs Sampling equipment was washed in an Alconox solution and rinsed with water prior to each sampling run to avoid cross-contamination IFor each sample,both ends of the leading sleeve were covered with Teflon sheets, capped and sealed with tape The samples were labeled, stored on ice and transported under chain-of-custody to • McCampbell Analytical, Inc (MAI), a State of California Department of Health Services (DHS)- certified analytical laboratory 32 LOGGING The soil sample duplicates were utilized for field characterization The soil was screened for the presence of organic vapor using an organic vapor meter equipped with a photo-ionization detector (PID Thermo Environmental 580A, 10 OeV, calibrated to isobutylene), and the readings were recorded on the boring logs Soil was visually described in accordance with the Unified Soil Classification System (Bonng Logs, Appendix A) 33 WELL AND BORING COMPLETION I Borings MW-1, MW-2, and MW-3 were completed as ground water monitoring wells using two- inch diameter PVC casing with 0 020-inch slotted screen installed from 25 feet to 5 feet bsg with blank casing extending to the surface The filter pack (No 3 Lonestar sand) was installed from 25 Ifeet to approximately 3 feet bsg The wells were then developed using a surge block to settle the sand pack A nominal 2-foot bentonite pellet plug was then installed above the filter pack and hydrated The wells were then grouted to near the surface with portland cement Water-tight, traffic-rated well boxes were then installed over the wells The ground water monitoring well design is presented in • Figure 4 Advanced GeoEnvironmental,Inc I