2014-10-10_REVISION - C1996083 (5)

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seam lies between the Rollins Sandstone and the D -2 coal seam and varies in thickness from 9 to 22 feet. Longwall mining in the D -2 coal seam is complete. Longwall mining began in the B -2 coal seam with the approval of Permit Revision No. 8. Permit Revision No. 14 proposes to continue longwall mining in the B -2 seam between Terror Creek and Stevens Gulch, north of Highway 133. 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, 2.04.7, and Exhibit 3 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 proposed permit and adjacent areas are generally bounded by three (3) perennial streams. These streams are Stevens Gulch, Hubbard Creek and the North Fork of the Gunnison River and are located in the west, east and south areas of the permit area, respectively. Tributary to the perennial streams are the following intermittent and ephemeral streams: Stephens Draw, Freeman Gulch, A- Gulch, B- Gulch, C- Gulch, D- Gulch, Dove Gulch and Sheep Corral Gulch. Terror Creek and West Terror Creek, perennial streams, run roughly north /south through the central permit area. 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 discharge of the North Fork of the Gunnison River for the period of record (1934 -2012) is approximately 329,300 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 a calcium- bicarbonate type. Total dissolved solids concentrations at the downstream Bowie No. 2 monitoring point have ranged from approximately 50 milligrams per liter (mg /1) to approximately 692 mg/l over the life of the mine. Perennial streams Terror Creek, Hubbard Creek, and Stevens Gulch drain approximately 29, 57.5, and 8 square miles, respectively. Tributary drainages Stephens Draw, A- Gulch, B- Gulch, C- Gulch, D- Gulch, Sheep Corral Gulch, Iron Point Gulch, and Dove Gulch exhibit ephemeral and intermittent flow regimes. There are numerous stock ponds located in the permit and adjacent areas. All of the ponds are manmade and store less than 20 acre -feet of water that is generally intended for domestic livestock use. 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, and 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 the area. The groundwater associated with the alluvial deposits of the North Fork of the Gunnison River has been developed for domestic and agricultural uses. The localized groundwater resources associated with the alluvial deposits of Hubbard and Terror Creeks are not significantly developed. The groundwater associated with local colluvial deposits is recharged by snowmelt, Page 17 of 46