The EPA administers the federal CAA (42 United States Code [U.S.C.] 7401 et seq.) to maintain the NAAQS that protect human health and to preserve the rural air quality in the region by ensuring the PSD Class I and Class II increments for SO2, NO2, and PM10 are not exceeded. The EPA has delegated this CAA authority to the State of Wyoming.
Wyoming regulates pollutants emitted into the air through the Wyoming Environmental Quality Act (W.S. 35-11-101 et seq.). Wyoming also is authorized by an approved SIP to administer all requirements of the PSD permit program under the CAA. In addition, the approved Wyoming SIP contains a number of programs that provide for the implementation, maintenance, and enforcement of the NAAQS, including a New Source Review program for minor source permitting that requires, among other things, an application of BACT for all new or modified sources, regardless of size or source category. Included, as well, are authorities for the control of particulate emissions, such as including fugitive particulate emissions from haul roads, access roads, or general facility boundaries. Wyoming also has been delegated the responsibility for operating an approved ambient air quality monitoring network for the purpose of demonstrating compliance with the NAAQS and the WAAQS.
NEPA requires that federal agencies consider mitigation of direct, indirect, and cumulative impacts during their preparation of an EIS (BLM Land Use Planning Manual 1601). Under the CAA, federal agencies must comply with SIPs regarding the control and abatement of air pollution. Before approval of RMPs or amendments to RMPs, the state director is to submit any known inconsistencies with SIPs to the governor of that state. If the governor of the state recommends changes in the proposed RMP or amendment to meet SIP requirements, the state director shall give the public an opportunity to comment on those recommendations (BLM Land Use Planning Manual, Section 1610.3-2.).
The USFS administers national forests, which include several wilderness areas that may be affected by direct impacts associated with development in the Bighorn Basin, such as the North Absaroka and Washakie Wilderness areas which have mandatory federal Class I designations. In addition, the Class II Cloud Peak Wilderness Area and the Bighorn National Forest should be included in the Planning Area analysis. As federal land managers, the USFS could act as a consultant to recommend that the BLM impact analysis results, or any future EPA- or state-administered PSD refined impact analysis results (if justified), trigger adverse impairment status. If the USFS determines impairment of wilderness areas, the BLM, the state, and/or the EPA might need to mitigate this predicted adverse air quality impact.
One area administered by the National Park Service with a mandatory federal Class I area designation, Yellowstone National Park, could be affected by direct impacts associated with emissions from sources in the Planning Area. As federal land managers, the National Park Service could act as a consultant to recommend that the BLM impact analysis results, or any future EPA- or state-administered PSD refined impact analysis results (if justified), trigger adverse impairment status. If the National Park Service determines impairment of National Park Service-administered Class I areas, the BLM, the state, and/or EPA might need to mitigate this predicted adverse air quality impact.