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The geologic structure of the permit area exhibits an attitude of N66'W, with a 3 to 5- degree dip <br />to the northeast. There is one identified fault located in the southwest corner of the permit area. <br />The fault trends approximately N55'W and it dips 70 to 80 degrees to the northeast. The throw <br />of the fault ranges from 7 to 30 feet, with the downside located on the south side of the fault. <br />The coal in the area is situated within Mesaverde formation which contains interbedded <br />sandstones, mudstones, shales, siltstones and coal beds. The Mesaverde formation lies upon the <br />Rollins Sandstone Member of the Iles formation and below the Wasatch formation. The coal <br />bearing member of the Mesaverde formation locally contains up to nine (9) coal seams. These <br />seams are located within a stratigraphic interval of approximately 500 to 600 feet above the <br />Rollins Sandstone. These coal seams are, in ascending order, the A -Seam, the B- I Seam, the <br />B -2 Seam, the C -Seam, the D -1 Seam, the D -2 Seam, the E- I Seam, the E -2 Seam and the <br />F -Seam. <br />The B -2 and D -2 Seams are mineable within the permit area. The D -2 Seam overlies the Rollins <br />Sandstone by 350 to 450 feet, and it ranges in thickness from about 8 to 16 feet. The B -2 coal <br />seam lies between the Rollins Sandstone and the D -2 coal seam and varies in thickness from 9 to <br />22 feet. Longwall mining in the D -2 coal seam is complete. Longwall mining began in the B -2 <br />coal seam with the approval of Permit Revision No. 8. Permit Revision No. 13 proposed to <br />continue longwall mining in the B -2 seam between Terror Creek and Stevens Gulch, north of <br />Highway 133. <br />Hydrology - <br />Detailed information regarding the surface and groundwater hydrology in and adjacent to the <br />Bowie No. 2 Mine permit area is provided within Sections 2.04.5 and 2.04.7 of the permit <br />application document. A brief summary is provided below, and the summary is derived from the <br />information presented in permit application Sections 2.04.5 and 2.04.7. <br />The proposed permit and adjacent areas are generally bounded by three (3) perennial streams. <br />These streams are Stevens Gulch, Hubbard Creek and the North Fork of the Gunnison River and <br />the streams are located in the west, east and south areas of the permit area, respectively. <br />Tributary to the perennial streams are the following intermittent and ephemeral streams: <br />Stephens Draw, Freeman Gulch, A- Gulch, B- Gulch, C- Gulch, D- Gulch, Dove Gulch and Sheep <br />Corral Gulch. The specific locations of these streams are depicted on permit application Map <br />No. 9. <br />The North Fork of the Gunnison River drains an area of approximately 526 square miles. The <br />average annual yield of the North Fork of the Gunnison River from October 1993 to September <br />1994 was approximately 330,500 acre -feet. The quantity and quality of this river is influenced <br />significantly by agricultural and municipal uses. Near Somerset, Colorado, the water in the <br />North Fork of the Gunnison River is a calcium- bicarbonate type, and total dissolved solids <br />concentrations range from approximately 100 milligrams per liter (mg /1) to approximately 400 <br />mg /l. <br />8 <br />