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LITHOLOGICAL LOGGING A field geologist will log all boreholes using ASTM standard procedures and techniques. Soil samples are taken at five foot intervals and used to describe the color, moisture, sorting, grain size, and any other pertinent soil characteristics observed. The blow counts of the hammer used to drive the split-spoon are noted on the logs, which indicates the relative density of the soil. Blow counts will also be used to determine when sample refusal has occurred. A maximum of 50 hammer blows are allowed per six inches of sample recovery before abandoning a sampling attempt. Soil color is determined by using a condensed version of the Geological Society of America Rock or MunsellTM Soil Color Chart. Color of the soil is measured by comparing a sample of the soil to the color-chips reproduced on photographic paper. Textural properties of the soil are determined by using field charts. Sorting is determined by observing the gram-size distribution of the soil sample through a hand lens and comparing the distribution to a sorting chart from Folk(1974). Grain size is determined by comparing grains of soil to a plastic grain-size chart produced by American Stratigraphic, Inc. Grains of soil are placed on the chart and viewed through a hand lens, which allows the geologist to directly compare the grains of soil to pictures of grains that range in size from very coarse sand to very fine sand. This method produces accurate and reproducible results. All this information is written on the boring log form and the soil will then be classified using the Unified Soil Classification System. In addition, the geologist will check the drill cuttings to observe changes in lithology and use the core samples to confirm the changes. These changes are noted on the boring log and used to determine the stratigraphy (layering) of the soil. All boring logs are reviewed and signed by a California Registered Geologist. EQUIPMENT DECONTAMINATION When sampling is to occur, a restricted work zone will be established. Only qualified team members, as outlined in Appendix A (HASP), will be permitted to enter this zone. A decontamination area and a clean zone are established at the perimeter of the restricted work zone for preparation and breakdown of sampling appurtenances. The decontamination area is established to contain decontamination rinsate solution for subsequent disposal. Racks are used to steam-clean equipment (e.g. backhoe bucket, augers, etc.) and 5-gallon buckets are set up to decontaminate smaller pieces of equipment such as hand auger and split spoon samplers. Equipment is decontaminated by the following procedures: Loose dirt is brushed off the equipment with a steel-bristle brush,and; • After removing the loose dirt, equipment is steam cleaned with a high pressure steam cleaner to remove any remaining dirt. C-3