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3.1.2 Collecting Drill Cuttings The field geologist/engineer may observe drill cuttings from the drilling fluid return for litholagic information to supplement discrete sampling.'Sampling and logging cuttings will be ' performed as follows: 3 1. The height of the drilling table above ground surface, lengths of the drill bit, sub and drill collars, and length of drill rods should be taken into account in calculating the depth of penetration. 2. In mud rotary drilling, a small-diameter, fine mesh hand screen will be used to obtain a sample of the cuttings from the borings byjholding the screen directly in the flow of the drill fluid return line. In air rotary drilling, cuttings will be collected after L discharge from the cyclone. 3. In rotary drilling, a composite sample may be obtained from the return line by leaving the screen in place during the time intakes the driller to advance the boring to a preselected depth. 4. In rotary drilling, the travel time for cuttings to reach the surface may be estimated each time the driller adds a new length of drill rod by timing the first arrival of cuttings after circulation is resumed. This travel time can be used along with the depth of penetration to estimate the start and finish of each 5-foot sampling interval. 3.2 LOGGING OF EXPLORATORY BORINGS The observations of the field geologist/engineer will be recorded on a BORING LOG OR WELL LOG at the time of drilling. The drill rig operator and the field geologist/engineer will discuss significant changes in material penetrated, drilling conditions, hydraulic pressure, drilling action, and drilling fluid circulation rate. The field geologist/engineer will be present during drilling of soil borings and will observe and record such changes by time and depth. Drill cuttings and core samples will be observed in the field. A lithologic description will be recorded on the BORING LOG using the Unified Soil Classification System (OSCS) as described in the American Society of Testing and Materials (ASTM) Standard D 2488-90. This description will include the USCS soil type, grain sizes and estimated percentages of each, moisture content, color according to the Munsell color charts (Kollmorgen'Instruments Corp.), plasticity for fine-grained materials, consistency, and other.pertinent information, such as degree DRILLING AND DESTRUCTION OF SOIL BORINGS Page 4 of 6 PHOTO-DD.doo REVISION DATE:MARCH 096 DD-4