Approval and Promulgation of Implementation Plans; Wisconsin

The EPA is proposing to approve revisions to Wisconsin's State Implementation Plan (SIP) regarding the control of nitrogen oxide (NO<INF>X</INF>) emissions. On August 29, 2003, the EPA published a final rulemaking approving the emission averaging program for existing sources subject to the state's rule limiting NO<INF>X</INF> emissions in southeast Wisconsin. By its submittal dated May 25, 2004, the Wisconsin Department of Natural Resources requested that EPA approve modifications to existing requirements regarding the control of NO<INF>X</INF> emissions in the Wisconsin SIP. The SIP revisions modify language to clarify which sources are eligible to participate in the NO<INF>X</INF> emission averaging program. In addition, the revision creates a separate categorical emission limit for new combustion turbines burning biologically derived gaseous fuels. The request is approvable because it meets the requirements of the Clean Air Act. Wisconsin held a public hearing on the submittal on August 6, 2003. In the final rules section of this Federal Register, EPA is approving the SIP revision as a direct final rule without prior proposal, because EPA views this as a noncontroversial revision and anticipates no adverse comments. A detailed rationale for the approval is set forth in the direct final rule. If no adverse comments are received in response to this proposed rule, no further activity is contemplated in relation to this proposed rule. If EPA receives adverse comments, EPA will withdraw the direct final rule and address all public comments received in a subsequent final rule based on this proposed rule. EPA will not institute a second comment period on this action. Any parties interested in commenting on this action should do so at this time.