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• 2.04.7 <br />documentation exists for the more recently drilled holes. Many of the deeper <br />holes were drilled with mud, such that the static water level recorded should <br />be considered dubious at best. Any holes drilled with bentonite based mud <br />can greatly inhibit the hydrologic properties due to mud cake within the drill <br />hole. When air and foam are used as a drilling medium, the hydrologic <br />conditions of the in-situ rock are virtually unaffected, and observation of <br />subtle inflow or lost circulation zones are greatly enhanced. The progress <br />of these holes was monitored in the field and recorded by competent <br />personnel. <br />Drill holes 13, 15, 16, 25, 34B, 38, 39, 42, 49, 52, 54, and 55 were <br />completed as monitoring wells in the bedrock following exploration. Refer <br />to section 2.05.6 for further discussion of the deep bedrock groundwater <br />monitoring program. <br />Lower Perched Water Zone and Rollins Sandstone <br />A sufficient number of data points were obtained from the drill holes to plot <br />the potentiometric surfaces on the maps. As seen on Maps 10 and 11, the <br />potentiometric contours fit the geohydrological setting of the permit area in <br />that the saturated horizons (or potentiometric surface) gently dip northward, <br />following the structural attitude of the bedrock horizons. <br />The Rollins Sandstone in the permit and adjacent area is characterized as <br />dry along the outcrop and develops piezometric head as the formation dips <br />to the north. Monitoring well 34B is completed in the Rollins Sandstone. <br />The water level is under artesian conditions, approximately 170 feet above <br />the top of the formation. Somerset Mining Company has two wells <br />completed in the Rollins Sandstone (SC-1 & SC-2) and they are also <br />reported to be under artesian conditions (SMC permit section 2.04.7). <br />Mountain Coal Company has one well completed in the Rollins Sandstone <br />(SOM-128-H) which is also under artesian conditions (MCC 1994 AHR). <br />The quality of the water in the Rollins Sandstone is poor. The following table <br />presents typical values for selected chemical parameters from the water in <br />the Rollins Sandstone from the three mines referenced above: <br />• <br />PR-03 2.04 - 28 - 5/99 <br />