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' All bonngs were drilled using a truck-mounted B-61 HDX drill ng The drill ng and two- man crew were supplied by V & W Drilling of Rio Vista, California The borings were advanced using eight-inch diameter continuous flight hollow stem augers Auger returns were monitored dunng drilling activities for the presence of organic vapors using a photo- ionization detector (PID Thermo Environmental 580A, 10 0 eV, calibrated to isobutylene) ' Discrete sosamples coIlected in borings at five-foot intervals A 140-Ib hammer ' was used to advance a sampler loaded with three precieaned 2-inch by 6-inch brass sleeves The number of blows required to advance the sampler in 6-inch increments was recorded on the boring logs (See Appendix A) To avoid cross contamination, the hollow stem augers and drill bit were steam cleaned by the drill crew utilizing a portable decontamination unit, prior to dulling each boring Prior to the collection of each sample, the sampling equipment was decontaminated in a tri-sodium phosphate (TSP) solution and rinsed twice with water IFor each sample, the lead brass tube was removed and immediately covered with aluminum sheets, capped, sealed with tape, and logged under chain of custody procedures The samples were immediately placed in a chilled container Upon completion of drilling activities, the samples were transported and relinquished to Sparger Technology, Inc , a state certified analytical laboratory, for analysis Soil from the middle brass tube was extruded into i a plastic bag and screened for organic vapors using a photo-ionization detector (PID) The reading was recorded on the boring log, and the soil was described in accordance with the Unified Soil Classification System 3.2 Well Completion Bonngs 131, B2, B3, and B4 were completed as groundwater monitoring wells, designated MW-1, MW-2, MW-3, and MW-4, respectively The screened intervals in MW-1 is from 55 I feet to 75 feet, MW-2 and MW-3 from 54 feet to 74 feet, and MW-4 from 45 feet to 70 feet A typical well design is illustrated as Figure 4 Bonng B5 was grouted from 55 feet below ground surface to the surface with Portland cement I3.3 Well Surveying, Monitoring, and Sampling On February 15, 1994, the tops of the well casings were surveyed relative to an arbitrary datum of 100 00 feet established on site The datum point is located at the southwest comer of the structure located on site The elevation of each well casing top, depth to groundwater, and relative groundwater elevation for all wells is presented in Table 1 The relative groundwater elevations were calculated from these data A Solinst water level meter was used to measure depth to water in all monitoring wells on February 22, 1994 The water level in all wells were measured relative to each notched well- casing top After measuring depth to water in all wells, the wells were purged utilizing dedicated PVC Gww�.l Audit S.-Inc 6 L rry a Aum Aep..r Q(2"X17 S I