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stratigraphic interval of approximately 500 to 600 feet above the Rollins Sandstone. These coal seams are, in ascending order, the A-Seam, the B- I Seam, the B-2 Seam, the C-Seam, the D-1 Seam, the D-2 Seam, the E- I Seam, the E-2 Seam and the F-Seam, The B-2 and D-2 Seams are mineable within the permit area. The D-2 Seam overlies the Rollins Sandstone by 350 to 450 feet, and it ranges in thickness from about 8 to 16 feet. The B-2 coal seam lies between the Rollins Sandstone and the D-2 coal seam and varies in thickness from 9 to 22 feet. Once longwall mining in the D-2 coal seam was finished, and with the approval of Permit Revision No. 8, longwall mining began in the B-2 coal seam. Hydrology - Detailed information regarding the surface and groundwater hydrology in and adjacent to the Bowie No. 2 Mine permit area is provided within Sections 2_04.5 and 2.04.7 of the permit application document. A brief summary is provided below, and the summary is derived from the information presented in permit application Sections 2.04.5 and 2.04.7. The permit and adjacent areas are generally bounded by three (3) perennial streams. These streams are Terror Creek, Hubbard Creek and the North Fork of the Gunnison River, and the streams are located west, east and south of the permit area, respectively. Tributary to the perennial streams are the following intermittent and ephemeral streams: Freeman Gulch, Stephans Draw, A-Gulch, B-Gulch, C-Gulch, D-Gulch, Dove Gulch and Sheep Corral Gulch. The specific locations of these streams are depicted on permit application Map No. 9. The North Fork of the Gunnison River drains an area of approximately 526 square miles. The average annual yield of the North Fork of the Gunnison River from October 1993 to September 1994 was approximately 330,500 acre-feet. The quantity and quality of this river is influenced significantly by agricultural and municipal uses. Near Somerset, Colorado, the water in the North Fork of the Gunnison River is acalcium-bicarbonate type, and total dissolved solids concentrations range from approximately 100 milligrams per liter (mg/1) to approximately 400 mg/I. Terror Creek is a perennial stream which drains approximately 29 square miles, and Hubbard Creek is a perennial stream which drains approximately 35 square miles. Freeman Gulch is a significant drainage which is tributary to Hubbard Creek. Freeman Gulch exhibited flow during the snowmelt period of Spring 1995, and may be considered an intermittent stream. Stephans Draw is also an intermittent stream, and Stockpond P-1 is located along Stephans Draw. The drainages of A-Gulch, B-Gulch, C-Gulch, D-Gulch, Sheep Corral Gulch and a portion of Dove Gulch probably exhibit ephemeral flow regimes. Originally, a portion of Dove Gulch was considered perennial. However, in Permit Revision No. 10, BRL is contending that Dove Gulch is ephemeral. Permit Revision No. 10 is currently under review. There are twelve (12) stock ponds located in the permit and adjacent areas. These include Pond P-I, mentioned above, and all of the ponds are manmade. The ponds collect spring season runoff, and any available seep water. Groundwater in the area is located within the alluvial deposits along the North Fork of the Gunnison River and Hubbard and Terror Creeks, within the steep sloped colluvial deposits found within some of the drainages, in perched water zones located within the lenticular sandstones of the Mesa Verde formation and in the Rollins Sandstone. The Rollins Sandstone is a recognized aquifer in [he area. 13