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results of field screening suggest that soil and/or groundwater is impacted in the primary boreholes, three additional borings (secondary borings) will be drilled adjacent to the south, west, and north property lines and samples of the soils and groundwater will be collected (Figure 2). The boreholes will be drilled using a drill rig equipped with 8 or 10-inch O.D. hollow-stem, continuous-flight augers. The exact number and location of the boreholes may change based on conditions encountered during the field activities. The exploratory borings will be drilled to first encountered groundwater to facilitate soil and groundwater sample collection. Samples of the subsurface soils will be collected at intervals no greater than 5 feet using a 2-inch or 2 ,h-inch I.D. split spoon sampler, a standard penetration sampler, or a continuous coring device. All drill bits, drill rods, augers, etc. will be steam-cleaned prior to each use. The following procedures will be employed when collecting and handling soil samples: 1. Prior to sampling, the split spoon sampler (or equivalent) and sample liners will be thoroughly washed with a solution of Alconox or non-phosphate TSP and rinsed with potable water. 2. The samples will be retained in the sample liners with the ends covered with aluminum foil or Teflon sheets and plastic end caps. 3. Each sample will be labeled using waterproof ink with the job name, job number, boring number, sample depth, date collected, and the initials of the person who collected the sample. 4. A description of the soil sample will be entered on a boring log form by the field geologist. This description will include soil classification (ASTM D-2487-83), color, moisture content and consistency (in relative terms), and estimated degree of hydrocarbon content as measured using a photoionization detection (PID) meter. 5. Immediately after sample collection and labeling, the samples will be sealed in a plastic bag and placed in a sturdy ice chest. The temperature in the ice chest will be maintained at or below 4°C. 6. When the ice chest is full (or contains all the samples which will be stored in it), a completed chain of custody form will be inserted and the chest will be closed and sealed. Groundwater grab samples will be collected from each borehole in the upper portion of the first water- bearing zone. Two-inch diameter PVC well screen and casing will be inserted into each borehole to allow groundwater sampling and water level measurements. The well screen will be 5 to 10 feet in length and will extend across the water table surface. A filter sock will be placed over the well screen to control turbidity in the groundwater samples. The groundwater samples will be collected by lowering a bailer through the casing immediately after the borehole is drilled and the augers are removed from the hole. The bailer contents will be carefully transferred into the appropriate sample containers. The groundwater samples will be submitted for chemical analyses to a State of California-certified laboratory (Chromalab, San Ramon). The well screen and casing will remain in each borehole until the water level in each borehole has stabilized (but not for a period longer than 24 hours per San Joaquin County requirements). Once the water cca/9-30-92/8913a/JAWP13 8