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"E" Coal Seam to Middle Sandstone <br />• The Middle Sandstone is the first recognized aquifer above the "E" coal seam. It ranged from 210 feet to 310 feet <br />above the "E" coal seam. The Middle Sandstone is comprised of three (3) benches each extending over different <br />portions of the mine property. The mined bench (topmost) covers the largest part of the property and is the unit <br />monitored at RAG EC. It is believed that all tlree benches, when present are hydrologically interconnected and <br />behave as a unit. The monitored bench ranges from 50 feet thick in the south to 100 feet thick in the northeast part of <br />the property, as shown on the Middle Sandstone Structure and Isopach Map (Map 12). <br />"E" Coal Seam to the Twentvmile Sandstone <br />The Twentymile Sandstone is a regionally recognized unit and outcrops prominently at RAG EC. It is recognized as a <br />significant aquifer. The Twentymile ranges from 495 feet to 610 feet above the "E"coal seam. Much of the early <br />development of the No. 6 Mine will be south of the outcrop of the Twentymile and a large part of the first three (3) <br />panels will be beneath the partially saturated Twentymile Sandstone. Refer to the Lifaof--Mine Plan Map (Map 22) <br />and the Subsidence Map (Map 30) for information regarding the position of the Twentymile Sandstone relative to the <br />mining areas. <br />Site Specific Geolo <br />The site specific geology of the permit area can be best addressed graphically. A series of large geologic cross- <br />sections have been prepared utilizing geophysical logs. Thesasections show graphically the relationships between the <br />coal seams and enclosing strata. Particularly the major aquifers. Due to the sensitive technical information contained <br />on the cross-sections it is essential that this information be keptCONFIDENTIAL. The following is a listing of the <br />cross-sections and a brief description of their purpose: <br />• • Map 7A, Geologic Cross-Section A-A', this cross section depicts the geology from the "P" coal <br />seam down to the Trout Creek Sandstone in a line running west to east through the central portion <br />of the permit area. <br />• Map 7B, Geologic Cross-Section B-B', this cross section depicts the geology from the <br />Twentymile Sandstone down to the Trout Creek Sandstone in a line running North to South along <br />the Westem side of RAG EC's Permit boundary. <br />• Map 7C, Geologic Cross-Section C-C', this cross section depicts the geology from the First White <br />Sandstone down to the "C" coal seam in a line running North to South along the Westem side of <br />RAG EC's Permit Boundary. <br />RAG EC has included site specific geologic data within an exhibit of the permit application. The following reports <br />have been prepared as of the date of this application and are presented in the permit as Exhibit 8, Supplemental <br />Geological Information: <br />REPRESENTATIVE DRILL HOLE LOGS <br />Geologist's interpretation of representative drill hole logs found within the permit area. <br />Coal Seam Characteristics <br />Presented in Table 9, Characteristics of Mineable Class Seams and Enclosing Rocks, is a summary of the coal seam <br />• characteristics and geologic/engineering descriptions of the enclosing rocks. This table contains sensitive technical <br />data and it is requested that the contents be keptCONFIDENTIAL. <br />Permit Renewal No. 3 2.04-9 Revised 7/l0/00 <br />