When the D.C. Circuit Court of Appeals stayed the implementation of the Cross-State Air Pollution Rule, or Transport Rule, 76 Fed.Reg. 48208 (August 8, 2011), on December 30 of last year, it did not address the U.S. Environmental Protection Agency's (USEPA) late December addition of five states (Iowa, Michigan, Missouri, Oklahoma and Wisconsin) and proposal for inclusion of a sixth state (Kansas). USEPA issued a Notice of Intent on February 6, 2012, that it will not require these additional states to implement the Transport Rule prior to resolution of the appeals of the rule that led to the court's stay. 77 Fed.Reg. 5710, 5711 (Feb. 6, 2012).

During the comment period after proposal of the Transport Rule, USEPA, in response to comments, collected additional data from states and sources and conducted additional and updated analyses of states' impacts on downwind ozone and fine particulate matter monitors. As a result, USEPA issued a supplemental notice of final rulemaking (SNFR) on December 27, 2011, that added Iowa, Michigan, Missouri, Oklahoma and Wisconsin to coverage under the Transport Rule because of the impacts of emissions from those states on downwind monitors. 76 Fed.Reg. 80761 (Dec. 27, 2011). Additionally, USEPA proposed a federal implementation plan (FIP) for Kansas for the same reason.

These actions were not included in the appeals of the Transport Rule and so were not encompassed by the court's stay of the Transport Rule. However, acknowledging that implementation of the Transport Rule in these few states would be impracticable, USEPA has determined that it will treat the rules covering these states "in the same manner as the underlying Transport Rule. . . . EPA does not expect covered sources under the SNFR to comply with the provisions of that rule for the duration of the Court's stay." 77 Fed.Reg. at 5711.