Rulemaking on Section 126 Petitions From New York and Connecticut Regarding Sources in Michigan; Revision of Definition of Applicable Requirement for Title V Operating Permit Programs

In today's action, EPA is revising one element of a final rule published on January 18, 2000, regarding petitions filed by four Northeastern States under section 126 of the Clean Air Act (CAA). The petitions seek to mitigate interstate transport of nitrogen oxides (NO<INF>X</INF>), one of the main precursors of ground-level ozone pollution. The final rule partially approved the four petitions under the 1-hour ozone national ambient air quality standard, thereby requiring certain types of sources located in 12 States and the District of Columbia to reduce their NO<INF>X</INF> emissions. Subsequently, the U.S. Court of Appeals for the District of Columbia Circuit issued a decision on a related EPA regulatory action, the NO<INF>X</INF> State implementation plan call (NO<INF>X</INF> SIP Call), that has relevance to the Section 126 Rule. Although the court decision did not directly address the State of Michigan, the reasoning of the court regarding the significance of NO<INF>X</INF> emissions from sources in two other States called into question the inclusion of a portion of Michigan in the area covered by the NO<INF>X</INF> SIP Call. In response, the EPA is removing that portion of Michigan, known as the "coarse grid" portion, from the NO<INF>X</INF> SIP Call. The Section 126 Rule is based on many of the same analyses and information used for the NO<INF>X</INF> SIP Call and covers part of Michigan. Thus, in light of EPA's response to the court ruling on the NO<INF>X</INF> SIP Call, EPA is also withdrawing its section 126 findings and denying the petitions under the 1-hour ozone standard with respect to sources located in the coarse grid portion of Michigan. The EPA has not identified any existing section 126 sources located in the affected portion of the coarse grid. The EPA is also revising the definition of the "applicable requirement" for title V operating permit programs by providing expressly that any standard or other requirement under section 126 is an applicable