2008-06-09_REVISION - C1980007 (3)

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Chapter 3 Ground Water Direct and indirect effects on ground water from Alternative 3 would be the same as Alternative 2. Cumulative ~:ffects Because indirect and direct effects on surface water and ground water are expected to be short-teen, cumulative impacts from the proposed action are not anticipated. Drainage, sediment control and surface water monitoring requirements of the DRMS Performance Standards will also help to assure prevention of surface water impacts by providing a regulatory framework for development of interim mitigation measures. Future resource development (coal exploration and leasing, methane gas development) in this portion of the North Fork drainage will undergo environmental analysis and permitting, thereby limiting any unforeseen future cumulative effects. Consistency with Forest Plan and Other Laws In Alternative 2 and Alternative 3, design criteria state "drilling water (less than 10 acre- feet per year for shaft and MDW) will be obtained from MCC's non-tributary water in the mine or Minnesota Creek. This quantity of water is within the GMUG's blanket consultation with USFWS for depletion associated with the Upper Colorado River System." The following restriction with respect to water resources was found to be applicable to Alternative 2 and Alternative 3 after applying the unsuitability criteria stipulated in the amended LRMP dated September 1991. for the GMUG National Forests: All alternatives are consistent with the Clean Water Act and Forest Plan standards for water resources. The stipulations for water resources in Alternative 2 and Alternative 3 are also consistent with the FS Region 2 Water Conservation Practices Handbook and Ground Water Management FSM: 2880. Geology Affected Environment The analysis area. includes the Deer Creek Shaft anal MDWs, and lies within the Dry Forlc of Minnesota Creek and portions of the Deep Creek watershed. Elevations in the area range from approximately 6,700 feet above mean sea level (amsl) near the southwest coiner (Sec. 8, T14S, R90W) to approximately 9,120 feet amsl near the southeast conger (Sec. 1, T14S, R90W). Lion Mesa is the predominant topographic feature in the area at just over 8,100 feet. Lion Mesa is located in the southwest corner of the project area and is drained by Deer Creek to the north. Topography consists of small mesas (less than 100 acres) dissected by drainage channels which have been incised by intermittent and perennial streams. Slopes within the drainages are characterized by irregular topography, in which cliffs and shelves are underlain by resistant sandstone and the intervening slopes are underlain by fine-grained material. The Deer Creek Shaft and MDW area lies in the project areaonia-Somerset coal field. The commercial coal beds occur in the Mesaverde Group of Late Cretaceous age. The Mesaverde is underlain by the Mancos Shale of Late Cretaceous age. In the eastern part of the area, the Mesaverde is overlain by the Wasatch and also Ohio Creek formations of Paleocene and Eocene age. Regionally, the bedrock sequence dips three to four degrees toward the north- northeast. Surficial deposits consist of colluviuin (slopewash) on the slopes and alluvium in the larger stream valleys. Regional topography displays abundant evidence of mass wasting of several types. Landslides and rockfalls are common, and landslides are often accompanied by subsequent creep within the slide mass. Mass • • • 68 Deer Creek Ventilation Shaft and E Seain Methane Drainage Wells FEIS