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

Heading: Challenge to the First Step of the

Text: Designation Process First, Mississippi argues that the EPA acted arbitrarily in using 2008 to 2010 data for the first step of the two-step designation process (i.e., identifying violating monitors within a CBSA) even though the EPA possessed early-certified 2011 data from Tennessee. The 2009 to 2011 data showed no NAAQS violation at the Shelby County monitor. Accordingly, Mississippi argues, no violation should have been identified at the first step of the two-step designation process. But the EPA declined to evaluate Shelby County using the early-certified 2009 to 2011 data, instead using the 2008 to 2010 data. True, the EPA must adequately explain why it declined to rely on the early-certified 2011 data. See City of Waukesha, 320 F.3d at 248. But the agency did so. At the time of the final designations, the EPA had in its possession early-certified data from Mississippi and Tennessee, but not from Arkansas. In the first step of its two-step designation process, the EPA evaluates all air-quality monitors in a metropolitan area. Without 2011 Arkansas data, 35 the EPA did not have a full set of 2011 data for the Memphis CBSA. The EPA only had data from different time horizons—2008 to 2010 data for the Arkansas portion of the Memphis CBSA, and 2009 to 2011 data for the Tennessee and Mississippi portions of that same CBSA. The agency declined to rely on this mismatched dataset. Instead, the EPA opted to rely on the most recent matched dataset in its possession: the complete set of 2008 to 2010 data. We see no reason—and Mississippi provides none—to declare irrational the EPA’s conclusion that comparing data from the same time period would be more appropriate than analyzing data from different time periods in the same evaluation process. Cognizant of the substantial deference we owe the EPA in that highly technical evaluation, see Catawba Cnty., 571 F.3d at 41, we find the EPA was entitled to rely on a matched dataset instead of a mismatched one. Even assuming the EPA’s choice to rely only on matched datasets for the Memphis CBSA was reasonable (as we conclude it to be), Mississippi argues that the EPA’s approach nonetheless was arbitrary because the agency required a matched dataset for Memphis-area designations but allegedly relied on a mismatched dataset for Chicago-area designations. “[I]nconsistent treatment,” we have found, is a “hallmark of arbitrary agency action.” Id. at 51. There was no inconsistent treatment here, however. In both Chicago and Memphis, the EPA relied only on matched datasets in the designation process. With regard to the Chicago metropolitan area, Illinois early-certified its 2011 data. Wisconsin and Indiana—portions of which also lie in the Chicago metropolitan area—did not early-certify. Illinois’s early-certified data showed a violating monitor in the Chicago area. At the first step of the Chicago-area designation 36 process, the EPA relied on Illinois’s early-certified data, noted the violation, and thus proceeded to the second step’s multi-factor contribution analysis for all Chicago-area counties. Mississippi argues that, because the EPA only possessed early-certified data from Illinois, it used a mismatched dataset for Chicago’s designations. Consequently, Mississippi claims that the EPA took different approaches to dataset selection between Memphis and Chicago. Mississippi’s argument rests on a flawed understanding of the EPA’s designation process. At the first step of the process, a single violating monitor suffices to conclude the analysis and move to the second step. Though only Illinois had early-certified its data, that data showed a violating monitor. That was enough to terminate the first step of the process and move to the second step. It thus became irrelevant whether Wisconsin or Indiana data showed any violations: the EPA would proceed to the second step of the analysis regardless, based on the Illinois violation alone. The EPA therefore had a sufficient matched dataset of 2009 to 2011 data (albeit data from only one state, Illinois) to proceed to the second step of the designation process using 2009 to 2011 data alone. By contrast, the EPA had no matched dataset of 2009 to 2011 data in the Memphis area sufficient to complete the first step of the two-step process using that data alone. While data showing a single violating monitor are enough to end the first step and proceed to the second step, data showing all monitors in compliance would be needed to avoid proceeding to the second step’s multi-factor analysis—i.e., to terminate the two-step process at the first step. As a result, when Arkansas declined to early-certify its 2011 data, the EPA could not determine if the entire Memphis CBSA showed NAAQS compliance at all monitors for the 37 2009 to 2011 period; the agency lacked a sufficient 2009 to 2011 matched dataset with which to do so. The EPA then relied on the most recent matched dataset sufficient to complete the first-step analysis (the 2008 to 2010 data), just as the EPA selected the most recent matched dataset sufficient for the first-step analysis of the Chicago area. The EPA therefore acted in a consistent manner in both areas, each time using the most recent matched datasets sufficient to complete the first step of the two-step designation process.