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with air unless circulation is lost. A chemical analysis of the water medium, if <br />utilized, will be obtained. <br />Drilling and Sample Collection Methods <br />Overburden materials are generally sampled by utilizing one or more of the following three <br />methods: continuous cores, cuttings or chips, and highwall or outcrop grab samples. <br />Barrett et al. (1980), Dollhopf et al. (1981), MDSL (1983), Harrington (1983), WDEQ <br />(1985), and USDI-OSMRE (1985b) all recommend that a combination of continuous core and <br />drill cutting locations be utilized for baseline overburden assessment studies. <br />Continuous coring is utilized primarily during the first phase of a sampling program to <br />accurately identify and document structure and stratigraphy. Subsequently, during Phase <br />II, rotary drilled chip samples are preferred to confirm chemical and physical trends <br />because sampling is faster and more economical. 8a rth et al. (1981) recommends chip <br />sampling for shallow overburden or where strata is homogenous. Harrington (1983) showed <br />overburden analyses results obtained from cores and cuttings to be similar when drilling <br />fluids and other variables were controlled. Dollhopf et al. (1981) relied exclusively on <br />chip sampling for all of their selective handling studies. Peabody Coal Company (1987) <br />showed lithologic descriptions and saturation percentages to be similar from a twinned <br />hole location. <br />Peabody proposes to drill and collect samples from four chip sample holes (Sites A, B, C, <br />and D) within the projected Wadge coal recovery area as shown on the enclosed map. <br />Overburden thickness at Sites A, B, C, and D will be approximately 40, 50, 60, and 110 <br />feet, respectively. Chip samples will be collected on two-foot vertical increments from <br />the soil surface to the top of coal. Core samples will be collected where ground water is <br />encountered or where circulation of cuttings is restricted. <br />The core and chip samples will be described in the field by the driller and subsequently <br />by a geologist or soil scientist. Standard geologic description information such as <br />lithology, color, hardness, grain size, boundary conditions, wetness, and presence of <br />fractures, pyrites, gypsum, and carbonates will be included. The chip samples and cores <br />will be packaged in six mil polyethylene by two-foot increments and placed in standardized <br />boxes for shipment to the lab. At the lab, chip samples and cores will be air dried, <br />split or composi ted according to lithologic or stratigra phic sequence, crushed to pass a <br />10 and/or 20mesh sieve, and bagged For storage. <br />4 <br />