2009-06-15_GENERAL DOCUMENTS - C1982056 (2)

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• surface coal operations. On February 23, 2004 the Supreme Court rejected the petition for certiorari, seeking to have the High Court reverse the Citizens Coal Council v. Norton (03- 834) decision of the United States Court of Appeals for the District of Columbia Circuit of June 2004. In essence, the issue of surface subsidence caused by underground coal mining was not intended to be included in the definition of surface coal operations. Therefore, the unsuitability criteria, does not apply to this coal leasing action. No structures are present within the 100-year floodplain on this segment of Fish Creek. About a mile down the valley the downstream segments of Fish Creek and its associated floodplains have been undermined and subsided in the last five years. It is estimated that the gradient of Fish Creek has been increased by 0.6 percent as a result of the subsidence. As currently proposed the alignment of two long wall panels in the west half of section 19 are roughly perpendicular to Fish Creek. Fish Creek begins to flow northeast and parallel to the development mining along the edge of the long wall panels in the east half of section 19. Environmental Consequences: During subsidence which could range from 0 to 67 inches it would be expected that the floodplains and stream channel would subside an equal depth. In areas of the stream which may not subside (or minimally subside) initially, such as areas overlying the development mining (gateway) an undetermined amount of stream incision • (deepening) could be initiated. Erosion and scouring of the stream channel within these gateway areas can be expected and some disconnect with the active floodplain could result for an undetermined length. Because this possibility exists Twentymile Coal Company will need to establish stream cross sections, referencing the width of the stream and active floodplain and vertical height separating the channel and active floodplain; stream gradients and sinuosity will also need to be determined. No threat to human safety, life, welfare and property will result from modifying the coal lease and implementing the proposed action. Mitigative Measures: Same as for Surface Hydrology Name of specialist and date: Ole Olsen 5/17/06 INVASIVE, NONNATIVE SPECIES Affected Environment: Houndstongue, hoary cress (whitetop), Canada thistle, and other biennial thistles are known to occur in this area. There is the potential for noxious weeds, such as dalmatian and yellow toadflax, leafy spurge, knapweeds, perennial pepperweed and others, to exist and spread in these areas. Environmental Consequences: Since the proposed action is underground, it is not . anticipated that the proposed action would increase any invasive species establishment and production. Vehicular traffic associated with coal mining, as well as wind and water can