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3. 0 PROCEDURES ' 3. 1 Drilling and Sampling Borings B17 and B18 and monitoring well MW-5 were drilled on August ' 25 and 26, 1993 . The 2-man drilling crew and truck-mounted drill rig equipped with 8-inch-diameter hollow-stem augers were provided by West Hazmat Drilling Co. of Rancho Cordova, California. In order to investigate the northern extent of soil contamination in the ' vicinity of 14W-4 , boring B17 was drilled at an angle of 300 from vertical and bottomed at a depth of 38 feet, approximately 5 feet north of the sidewalk on the south side of Harding Way (Figure 2) . ' Boring B18 investigated the southern extent of the contamination detected in MW-4 , and was continuously cored from a depth of 20 to 40 feet. The core was screened for volatile organic vapors using a portable photo-ionization detector (PID model OVA-580A calibrated ' to isobutylene) and the readings were recorded on the boring log. Samples were collected from the core at approximately 5-foot intervals, and -each sample was packed into a 6-inch brass tube, ' capped, and sealed. A center line was then scribed down the core, and the core was described on the boring log in accordance with the Unified Soil Classification System. Mr In MW-5 and B17 , soil samples were collected- at 5-foot intervals, starting at a depth of 20 feet. A 140-pound down-hole hammer was used to advance a split-tube sampler loaded with three brass sleeves. The number of blows required to advance the sampler 18 inches was recorded on the boring log (Appendix A) . Samples were screened for volatile organic vapors using a PID and the readings ' were recorded on the boring log. The ends of the sample tube were then covered with sheets of aluminum foil, capped, and sealed with tape. Samples were labelled, logged on the boring log and chain of custody form, and placed on ice until delivery to McCampbell Analytical for analysis. Soil in the middle and upper tubes was extruded and described on the boring log. To avoid contamination of subsequent samples, the tubes and sampler were then triple-rinsed in a phosphate solution; the augers were steam-cleaned between borings. 3 .2 Well Completion MW-5 was completed by the installation of . 020-inch slotted PVC casing from 60 feet to 40 feet. The well was manually developed for approximately 20 minutes to tighten the sand pack, which settled approximately 1. 5 feet. Details of the well design are shown on the boring log. Borings B17 and B18' were grouted with a slurry of ' Portland cement from total depth to surface. 3 . 3 Well Monitoring and sampling The elevation of MW-5 was surveyed on August 27, 1993 . The top of the casing was surveyed relative to the casing in MW-1. A permanent ' 4