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1 DRILLING QST drilled the soil borings using a track-mounted, continuous-flight hollow-stem auger drill rig The drill rig is owned and operated by a drilling company possessing a valid State of California C-57 license The borings were drilled under the direct supervision and guidance of ' an experienced QST geologist Prior to drilling, all borings were cleared with a hand auger to a depth of approximately 5 feet During drilling, the geologist logs each boring in accordance with the Unified Soil Classification System, noting soil color, relative density or stiffness, rmoisture content, odor (if obvious), and organic content (if present). All observations are recorded by the geologist on geologic boring logs. rDuring drilling, soil samples are collected at select intervals by driving a modified California split-spoon sampler, lined with new, thin-walled brass sleeves, through the center of and ahead of the hollow-stem augers In this way, a relatively undisturbed soil sample core is collected in the brass sleeves The brass sleeves are 1 5 inches in diameter and 6 inches in length The sampler is driven by a hydraulic hammer placed onto rods attached to the top of the sampler 1 Soil sample depth intervals are recorded by the geologist on the boring logs The brass sleeve containing the sample for laboratory analysis is covered at each end with Teflon sheeting, then with plastic end caps, and the end caps are sealed to the sleeve using organically inert duct tape that is free of any volatile organic compounds (VOCs) Finally, each sample is labeled, placed in cold storage, and transported, according to proper chain-of-custody procedures, to a state- certified laboratory for analysis f the remaining soil in the sampler is laced m a clean glass jar with a screw-type A portion o g P P hd and set in direct sunlight to enhance the volatilization of any VOCs present in the soil ' After approximately 15 minutes the sample is screened for VOCs using a photoionization detector (PID), and the PID measurements are noted on the boring logs. The PID provides qualitative data for use in selecting samples for laboratory analysis. All soil sampling equipment is cleaned between each sample collection event using an approved detergent and tap water solution followed by a tap water rinse Additionally, the drilling and soil sampling equipment is cleaned between borings to prevent cross- contamination The augers were steam-cleaned prior to arrival on site All soil cuttings r generated during drilling and sampling are collected and contained on site in wooden bins lined with visqueen pending laboratory analysis and proper disposal or recychng The borings are typically terminated upon penetrating a saturated soil horizon or when a predetermined interval of soil containing no evidence of contamination is penetrated This predetermined interval is typically based upon site-specific regulatory or client guidelines. As rpart of the workplan for this investigation, QST stated that groundwater samples would be collected if groundwater was found rOnce groundwater was found, QST drilled approximately 10 feet deeper and set a temporary 2-inch-diameter PVC groundwater monitoring well while raising the augers to expose the slotted portion of the casing A groundwater sample is collected by lowering a disposable r