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3.0 DRILLING PROCEDURES Drilling was done with a truck-mounted direct-push Geoprobe boring rig on May 11, 1998. Five borings were drilled, ranging from 26 to 37 feet in depth. As directed by PHS/EHD, two borings were continuously sampled from 21 to 26 feet; otherwise, samples were usually collected at 5-foot intervals. Each sample was collected in a 2-foot-long plastic sleeve, screened for organic vapors with a photo-ionization detector (PID), described on the boring log, cut,into shorter sections, capped, and placed into a cooled ice chest for preservation. The first boring (GP-1, Figure 2) was drilled through a conductor casing that had been previously set into the former UST cavity at a depth of 15 feet. The first sample was collected at 20 feet, and the boring was continuously sampled to 26 feet (Appendix A). The boring was terminated at a depth of 36 feet, where no evidence of contamination was detected. All other borings were drilled into native soil, and sampling began at approximately 15 feet. All borings except GP-1 were grouted to the surface with a bentonite-cement grout when drilling was completed. 4.0 GROUNDWATER MONITORING PROCEDURES Groundwater monitoring took place on May 12. Upon an-ival at the site, Upgradient personnel opened the wells and allowed them to equalize with air pressure. Well KF-3 was particularly difficult to open, because the well cover has been bent out-of-round (probably by vehicular traffic) and can no longer be screwed shut. Approximately 15 minutes after opening, the depth to groundwater was measured with a Solinst water level meter. The water depths are shown in Table I and Appendix B. A two-stage submersible pump was then used to purge the wells of standing water, which was deposited in a 55-gallon drum. During purging, the temperature, pH, and conductivity of the water were measured at 4 to 5-gallon intervals with a Corning Checkmate meter until these parameters stabilized (see Appendix B). To prevent cross-contamination, the pump was washed in a TSP solution between wells. The water samples were collected with a disposable plastic bailer and placed in 40-ml vials. The vials were labeled and logged and placed in a cooled ice chest. 5.0 RESULTS 5.1 Stratigraphy Three distinct layers underlie the site in the upper 35 feet. The shallowest layer consists of brown to gray or blue clayey silt or silty clay. This layer extends to a depth of approximately 21 feet in most borings and was exposed in the sidewalls of the tank excavation during the UST removal (Figures 3 and 4). In three of the five Geoprobe borings, samples from this layer emit moderate to strong gasoline odors. 4