Opinion ID: 187435
Heading Depth: 2
Heading Rank: 4

Heading: Application of the Nine-Factor Test

Text: As explained above, EPA uses nine factors  including things like air quality, population density, and traffic patterns  to determine the boundaries of areas contributing to nearby PM2.5 violations. See PM 2.5 Designations Rule, 70 Fed.Reg. at 947; see also supra at 28. State petitioners argue generally that EPA arbitrarily applied its nine-factor test by treating similarly situated counties differently without adequately explaining the allegedly divergent outcomes. In each of their challenges, petitioners seize upon discrete data points and ignore the very nature of the nine-factor test, which is designed to analyze a wide variety of data on a case-by-case basis, Holmstead Memo Guidance at 6. It is EPA's holistic assessment of numerous factors that drives the process  no single factor determines a particular designation. And although petitioners seek to paint a picture of systemwide inconsistencies, their challenges really amount to an attack on EPA's designations of a small group of New York counties. Although we address such individual challenges in Part VI, we conclude here that with respect to the system as a whole, EPA consistently applied its nine-factor test and adequately explained its decisions based on record evidence.
The first of the nine factors EPA uses to designate areas calls for the agency to consider how emissions levels contribute to nearby PM2.5 violations. In describing these levels, EPA characterizes a county's emissions as low, high, significant, insignificant, and so forth. State petitioners argue that EPA characterized county emissions inconsistently, providing further evidence that the designations were arbitrary. For example, petitioners claim it is manifestly arbitrary to designate as attainment counties with emissions levels EPA characterized as low based on weighted emissions scores of 9.4 (Sevier County, Tennessee) and 6.3 (Jasper County, Georgia), while designating as nonattainment counties with lower scores of 4.5 (Orange County, New York), 3.7 (Westchester County, New York), and 1.9 (Rockland County, New York). States' Opening Br. 34. As explained above, a weighted emissions score reflects only a county's share of a C/MSA's total emissions. Weighted emissions scores cannot be used in any meaningful way to compare emissions levels between counties in different C/MSAs. Because cumulative emissions scores for all counties within a C/MSA must total 100, areas with few counties (like the Athens, Georgia, MSA) will invariably have relatively larger county-level scores than areas with numerous counties (like the NY-NJ-CT-PA C/MSA), even though emissions levels in the smaller C/MSA may be lower. Likewise, petitioners argue that two instances in which EPA revised a county designation from nonattainment to attainment show that its characterization of emissions data and subsequent designations were arbitrary. EPA originally described the emissions levels in Woodford County, Kentucky, as significant and designated it as nonattainment. Technical Support Document § 6.4.3.3 (Factor 1). But EPA later concluded  without any change in emissions levels  that the county has relatively low emissions, id. (Justifications for Changes to EPA Recommendations Contained in the June 24, 2004, Letters to States), and revised its designation to attainment. These changes, petitioners argue, reflect the flawed manner in which EPA applied the first factor. But EPA adequately explained the change. After the initial designation, Kentucky submitted evidence that PM2.5 violations in nearby Fayette County were due to local sources, not emissions from Woodford County as originally thought. Id. Petitioners reply that EPA used the new data to explain the change in Woodford County's designation, not the change in EPA's assessment of emissions levels. To the extent that is even true, though, we can reasonably discern EPA's path. Given that the weighted emissions score is a rough estimate of a county's relative (and relevant) emissions in the first place, EPA simply interpreted the numeric score differently when the new data suggested its facial significance was inaccurate. In the same vein, petitioners contend EPA acted arbitrarily in revising its designation for Jasper County, Georgia. Finding significant emissions that potentially contribute to PM2.5 violations in other parts of the region, EPA originally designated the county as nonattainment. See id. § 6.4.2.2 (Factor 1). Data later submitted by Georgia, however, showed that emissions from a source in Jasper County were actually insignificant, prompting EPA to redesignate the county as attainment. See id. § 6.4.2.1 (Justification for Changes to EPA Recommendations Contained in the June 24, 2004, Letters to States); Letter from Ron Methier, Chief, Air Prot. Branch, Ga. Dep't of Natural Res., to Beverly Bannister, Dir., Air, Pesticides & Toxics Mgmt. Div., EPA Region 4, at 2 (Nov. 1, 2004). Far from being arbitrary, these revised designations demonstrate the reasonableness of EPA's case-by-case approach to applying the first factor.
As explained in greater detail in Part VI, EPA Region 1 used a bright-line test to determine which counties within a C/MSA would be designated as attainment. The test worked like this: EPA Region 1 ranked each of its counties from highest to lowest according to their weighted emissions scores. Starting from the top of the list, EPA Region 1 added each county's score and stopped when the sum hit 80%. Counties above the 80% cut-off point were presumed to be nonattainment; those below were designated as attainment, provided they did not have a violating monitor and were not among those recommended for nonattainment status by a state. See Technical Support Document § 6.1.1 (Factor 1). State petitioners argue that application of this 80% test led to inconsistent area designations, and they are right in one instance. Rockland County, New York, which is not in EPA Region 1 and was designated as nonattainment, would have been designated as attainment under the 80% test. Such an inconsistency is evidence of an arbitrary designation, but as Part VI explains, EPA's mistaken designation of Rockland County is an aberration, and petitioners fail to identify any other designation that might have changed had EPA applied the 80% test elsewhere. Nothing about the way EPA Region 1 applied the first factor reveals a fundamental problem with EPA's evaluation of emissions in potentially contributing areas.
Under the second of the nine factors, which looks to air quality, EPA uses monitoring data to compute a design value to describe the concentration of ambient PM2.5 in a county. See supra at 30. The agency then compares the design value to the annual NAAQS to help determine whether the county is violating PM2.5 standards or contributing to violations nearby. See id.; EPA Br. 14. State petitioners argue that EPA arbitrarily designated some counties as nonattainment despite their relatively low design values and other counties as attainment despite their higher design values. For example, EPA designated Hardin County, Kentucky, as attainment even though its design value of 14.1 was higher than the 12.5 design value for Westchester County, New York, which was designated as nonattainment. See Technical Support Document § 6.4.3.2 (Factor 2); id. § 6.2.2 (Factor 2). As EPA explained, however, design values alone do not determine designations based on contribution. Indeed, they are merely one component, albeit an important one, of a complex process that ultimately yields designations. Petitioners' argument ignores the multiple factors EPA uses in making case-by-case assessments of counties' contributions to nearby violations. See Holmstead Memo Guidance at 4. Some areas, like Hardin County, may have relatively high design values but still fall short of violating the annual PM2.5 standard of 15 micrograms per cubic meter. And many such counties are not contributing areas because they have low rankings for other factors like population, traffic, and emissions levels. See, e.g., Technical Support Document § 6.4.3.2 (explaining Hardin County's attainment designation). The three areas state petitioners use as examples of inconsistent treatment  Nassau, Suffolk, and Westchester Counties in New York  may have had lower design values when compared to other attainment areas, but each ranked high for emissions levels, population, and number of commuters, all of which support the determination that they contributed to nearby violations. See id. § 6.2.2. In short, EPA had ample evidence upon which it based its designation of these counties as nonattainment, despite their relatively low design values.
EPA takes account of the distance between a power plant and a violating monitor to help determine whether an area's meteorological features (the sixth factor) and its particular geography and topography (the seventh factor) will increase the likelihood that emissions from the plant will contribute to a violation. State petitioners argue that EPA used this distance inconsistently. For example, the agency designated Clearfield County, Pennsylvania, as attainment even though it has a power plant 60 miles from a violating monitor. See id. § 6.3.4.2 (Discussion). By contrast, EPA designated Orange County, New York, as nonattainment even though its power plant is 50 miles from the closest violating monitor. See id. § 6.2.2. But EPA never placed the type of weight on the distance factor that petitioners' argument assumes. Although EPA considered the distances, it weighed other factors as well. For example, Orange County has very high emissions levels, and meteorological data show winds blowing from the county toward violating monitors elsewhere. See id. Clearfield County, on the other hand, has mountainous terrain and other geographic features limiting emissions travel. See id. § 6.3.4.2 (Discussion). Petitioners claim that the attainment designation for Jasper County, Georgia, demonstrates inconsistency because it has a power plant 45 miles from the nearest violating monitor. But the plant's emissions are relatively insignificant, and other factors  such as low population and few commuters  support the county's designation. See id. § 6.4.2.1 (Justification for Changes to EPA Recommendations Contained in the June 24, 2004, Letters to States); Letter from Ron Methier to Beverly Bannister at 2. Once again, seizing upon a single factor misapprehends the purpose of the nine-factor test.
Finally, petitioners compare weighted emissions scores, design values, population density, number of commuters, and population growth for four attainment counties (Lee County, Alabama; Russell County, Alabama; Sevier County, Tennessee; and Fulton County, Ohio) with the same data for one nonattainment county  New York's Orange County  to illustrate that EPA applied the nine factors inconsistently, rendering the designation process unpredictable and arbitrary. See Technical Support Document §§ 6.4.2.5, 6.4.6.2, 6.5.4.9. Although this argument acknowledges, where the others do not, that EPA considers how the various factors might work together, it fails for two reasons. First, as we have already explained, see supra at 31-32, comparisons of weighted emissions scores between counties in different C/MSAs are meaningless. And second, even though Orange County ranked relatively low on some factors, which might suggest it was a good candidate for an attainment designation, it also has emissions levels of PM2.5, SO2, and NOx that far exceed the levels of the four attainment counties petitioners point to. See Technical Support Document § 6.2.2. Orange County's designation, which is adequately justified, is yet another illustration of the case-by-case analysis that the Designations Rule calls for and the nine-factor test achieves.