Laserfiche WebLink
• 2.04.7 <br />and Terror Creek drainages. Hydrologic testing in similar material performed <br />by Colorado Westmoreland Inc. (CWI) during development of their Steven's <br />Gulch well field showed that yields from these sources are moderate (27 <br />gpm at Steven's Gulch well field), with transmissivity values ranging from 187 <br />to 230 sq. ft. per day, and storage coefficient of 0.0002. Water from wells <br />penetrating this lithotype are classified as sodium bicarbonate (Brooks, <br />1983). Recharge is accomplished from precipitation and run-off, and water <br />is discharged from seeps or springs. Although similar in some respects, <br />these areas do not fulfill the requirements of being Alluvial Valley Floor <br />areas. <br />Several years of water table monitoring in the CWI wells installed in the <br />Steven's Gulch indicated the water level in this aquifer is below the local <br />streambed for most of the year, and therefore the streams are recharging the <br />aquifer. <br />The areas of the colluvial-alluvial sediments in Hubbard Creek and Terror <br />Creek lie below the coal seam to be mined. Protection of these sediments <br />is provided by limited extraction zones under the Creeks and assuring the <br />projected extent of subsidence is 100-feet from the centerline of the Creeks. <br />Mesaverde Formation -Perched Groundwater <br />All of the mines in the region report a similar experience as that observed at <br />the Bowie No. 2 Mine. The Mesaverde formation does not contain extensive <br />aquifers. Typically, the formation is dry or the rock units are of such low <br />permeability they yield insufficient water for sustained use. Even the <br />extensive Rollins Sandstone, the recognized aquifer in the region, is highly <br />cemented and a low producer. <br />Groundwater occurrences within the Mesaverde Formation have been <br />interpreted from monitoring holes and logs run during the exploration drilling <br />process (refer to Geology Map 07). From the monitoring holes, water quality <br />samples were obtained and static water levels or potentiometric elevation <br />data were noted. In addition, file research was done on the logs of the <br />exploration drill holes to detect static water levels noted during drilling or <br />logging. From the available information, two saturated horizons within the <br />PR-04 2.04 - 24 - 10/00 <br />