On July 11, 2011, EPA published a Supplemental Notice of Proposed Rulemaking (SNPR) that proposes Federal Implementation Plans (FIPs) for Iowa, Kansas, Michigan, Missouri, Oklahoma, and Wisconsin to address emissions identified as significantly contributing to nonattainment and interference with maintenance of the 1997 8-hour ozone National Ambient Air Quality Standards (NAAQS) in downwind states and the transport requirements with respect to the relevant NAAQS. EPA is proposing to include these states in the Cross-State Air Pollution Rule (CSAPR) ozone season NOx program. Five of these states - Iowa, Kansas, Michigan, Missouri, and Wisconsin - are also included in the fine particulate control program of the CSAPR, requiring year-round (not just summertime) NOx reductions.

As part of this notice, EPA is also providing an opportunity for public comment on

  1. The conclusion that emissions from these states significantly contribute to downwind nonattainment or interfere with maintenance of the 1997 ozone NAAQS in other states, and
  2. The decision to use the final CSAPR programs as the FIPs to address these emissions

EPA is also taking comment on the

  1. State ozone season NOx emission budgets,
  2. Data inputs (e.g. corrections to heat input values for particular units) used in applying allocations, and
  3. Application of the new unit set-aside methodology and resulting set-asides.

EPA has stated that they provided ample opportunity for comment on the methodologies for establishing the state budgets, allowance allocations, and for establishing the set-asides and will not take comment on those items. Comments must be received on or before August 22, 2011.

Wisconsin Contribution
The analysis for the final CSAPR identifies Wisconsin as a state that significantly contributes to nonattainment or interferes with maintenance of the 1997 annual PM2.5 NAAQS, 2006 24-hour PM2.5 NAAQS, and 1997 ozone NAAQS. Wisconsin is only considered to have a significant contribution for a newly-identified maintenance receptor in Allegan County, MI. The methodology used to analyze significant contribution and its application to Wisconsin is described in the preamble to the final CSAPR and in associated documents in the public docket for this rule. In this SNPR, EPA is requesting comment specifically on whether there are errors in the Agency's application of the CSAPR methodologies with respect to Wisconsin's significant contribution to nonattainment and interference of the 1997 ozone NAAQS.