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CJS� <br /> 3.1.2 Collecting Drill Cuttings GEOMATRIX <br /> The field geologist/engineer may observe drill cuttings from the drilling fluid return for - <br /> ' lithologic information to supplement discrete sampling. Sampling and logging cuttings will be <br /> performed as follows: <br /> ' 1. The height of the drilling table above ground surface, lengths of the drill bit, sub <br /> and drill collars, and length of drill rods should be taken into account in calculat- <br /> ing the depth of penetration. <br /> ' 2. In mud rotary drilling, a small-diameter, fine mesh hand screen will be used to <br /> obtain a sample of the cuttings from the borings by holding the screen directly in <br /> the flow of the drill fluid return line. In air rotary drilling, cuttings will be <br /> collected after discharge from the cyclone. <br /> ' 3. In rotary drilling, a composite sample may be obtained from the return line by <br /> leaving the screen in place during the time it takes the driller to advance the boring <br /> ' to a preselected depth. <br /> 4. In rotary drilling, the travel time for cuttings to reach the surface may be estimated <br /> ' each time the driller adds a new length of drill rod by timing the first arrival of <br /> cuttings after circulation is resumed. This travel time can be used along with the <br /> depth of penetration to estimate the start and finish of each 5-foot sampling <br /> ' interval. <br /> ' 3.2 LOGGING OF EXPLORATORY BORINGS <br /> The observations of the field geologist/engineer will be recorded on a BORING LOG OR <br /> ' WELL LOG at the time of drilling. The drill rig operator and the field geologist/engineer will <br /> discuss significant changes in material penetrated, drilling conditions, hydraulic pressure, <br /> ' drilling action, and drilling fluid circulation rate. The field geologist/engineer will be present <br /> during drilling of soil borings and will observe and record such changes by time and depth. <br /> Drill cuttings and core samples will be observed in the field. A lithologic description will be <br /> ' recorded on the BORING LOG using the Unified Soil Classification System (USCS) as <br /> ' described in the American Society of Testing and Materials (ASTM) Standard D 2488-90. <br /> This description will include the USCS soil type, ;rain sizes and estimated percentages of <br /> ' DRILLING AND DESTRUC7Ot1 OF SOIL BORINGS Pave 44 6 <br /> 'JSC'?R0T0-DD.7Y7 REVTSICN DATE:MARCH I DD-4 <br />