2007-11-16_REVISION - C1981041 (6)

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The Roadside operation mined the Cameo coal seams found in the Mount Garfield Formation of the Mesaverde Formation of sandstones, coal and shales. The Mount Garfield Formation is an example of the transitory nature of many oceanic transgressions and regressions from the Cretaceous geologic period. The Mount Garfield Formation ranges in thickness from 472 to 536 feet in the permit area and consists of three coal zones intertonguing with three prominent sandstone members. From the top to the base, the formational sequence is as follows: the Carbonera coal seam, (stratigraphic marker of the top of the Mount Garfield sequence), a 64-foot sandstone/shale sequence, the Cameo coal seam, 9 to 12 feet thick, Rollins sandstone member, about 114 feet thick, another shale/sandstone sequence, followed by the cliff-forming Palisade sandstone which is 139 feet thick. Beneath the Palisade sandstone member, named for the town nearby, is the Palisade coal seam and then the Sego sandstone which forms the base of the Mount Garfield Formation. The stratigraphic column can be found in Exhibits 14, 24 and 40 of the permit application. The Cameo coal seam was the zone of interest at the Roadside Mines. Of the three coal seams in the Bookcliffs Mount Garfield Formation, only the "B" and "C" Cameo seams are recognized as economically recoverable. The Cameo "B" seam was the primary seam extracted, and was mined via the North Portals on the west side of the Colorado River and the South Portals on the east side of the river. The South Portals were permanently idled in January, 1997. Some limited mining of the "C" seam occurred through the North Portals in late 1998 and 1999. The Cameo "B" seam in the permit area varies in thickness from a minimum of four feet to a maximum of eleven feet, with an average minable thickness of six feet. The coal has been classified as bituminous, with a low sulfur and high ash content. Coal extraction ceased on December 2, 1999, and the operator submitted official notice of permanent cessation of operations in March 2000. Further information on the geology of the permit area can be found in Tab 6, Volume 2,of the permit application. Groundwater Hydrology The water table in the Roadside permit area is controlled by a combination of local precipitation, topography, stratigraphy and geologic structure. The nature of the rock strata in the upper portion of the Mesaverde Formation creates a discontinuous water table. Localized perched aquifers are found in the coal overburden which measures between 0 to 1900 feet in thickness. Groundwater moves slowly through and between these perched aquifers via the network of interconnected sandstone lenses. The strata in the Roadside Mine area dip NE beneath the Colorado River. The Cameo Coal Seam outcrops at approximately the location and elevation of the South Portals and dips at approximately 3 degrees beneath the river to the northeast. The seam where mined at the North Portals is below the elevation of the river, but "cross dip" from the river. The entire sequence of Mesaverde that overlies the Cameo coal zone, behaves as a single hydrologic unit. The water table in the permit area and adjacent area can be directly correlated to its elevation relative to the Colorado River. Rock formations and alluvium below the level of the river are gravity-fed and are saturated with water from the river. Due to the clastic differentiation and lensing of sandstones and shales in the area together with the low permeability of the rock, the strata above the zone of saturation act to confine the body of groundwater. Therefore, the water table is located at approximately the same elevation as the Colorado River. Permit Renewal No. 5 9 November 16, 2007