Opinion ID: 2804920
Heading Depth: 3
Heading Rank: 2

Heading: Challenge to the EPA’s Response to Comments

Text: Next, Indiana argues that the EPA failed to adequately respond to its comments about the impact of Milwaukee, Wisconsin’s emissions on the violation at the Zion monitor. According to the source apportionment modeling submitted by Indiana, the Milwaukee area contributed over 5 ppb to the Zion violation, while Lake, Porter, and Jasper Counties contributed 4 ppb, 2 ppb, and 0.5 ppb, respectively. See Letter from Ind. Dep’t of Envtl. Mgmt. to EPA, Enclosure 1 at 13–14 (Apr. 13, 2012). This, Indiana maintains, produced the “inconsistent and unfounded” result of nonattainment designations for the Indiana counties but an attainment designation for the Milwaukee area. Id. at 14. As an initial matter, we note that, because the Milwaukee area is not a single county but rather is a metropolitan area made up of five counties, Indiana’s argument is premised on an apples-to-oranges comparison. More important, we have no basis for finding the EPA’s designations inconsistent given that Indiana’s modeling—which was limited to meteorological linkages and therefore fell short of a full analysis—did not establish that Milwaukee “contributed to” the Zion violation under the agency’s five-factor analysis. By contrast, after conducting its full five-factor analysis, the EPA found that Lake and Porter Counties did contribute. Accordingly, the EPA’s determination regarding the Milwaukee metropolitan area was neither unreasonable nor inconsistent with its determination regarding the Indiana counties. We also find that the EPA did adequately respond to Indiana’s comments about its modeling results, although without mentioning Milwaukee specifically. Indeed, the modeling was one of the factors that led the EPA to reconsider its designation of Jasper County. See Chicago Area 44 Designations at 21 (describing Jasper County’s 0.5 ppb contribution as “not significant”). But the EPA simply disagreed with Indiana’s premise that 2 ppb and 4 ppb were insufficient contributions when considered as part of the five-factor test, for reasons that were reasonable and well explained. See id. at 18 (“In keeping with EPA’s ozone contribution levels used to select states that should be covered in regional emission control programs, 2 ppb to 4 ppb ozone concentration contributions are considered to be significant ozone contributions.”).