Opinion ID: 2804920
Heading Depth: 4
Heading Rank: 1

Heading: HYSPLIT Modeling

Text: The Texas Petitioners challenge the EPA’s use of HYSPLIT modeling on three fronts. First, they argue that the EPA could not legitimately use HYSPLIT modeling at all because HYSPLIT “cannot measure ozone formation or transport.” State & County Br. 45. Second, they contend that the EPA arbitrarily treated Wise County differently by using HYSPLIT modeling to designate it as nonattainment while using historic wind patterns to designate other allegedly similar counties as attainment. And third, they argue that, even among other counties that the EPA subjected to HYSPLIT modeling, it arbitrarily treated Wise County worse because the respective HYSPLIT models demonstrated that wind moved through those other counties—each of which the EPA designated as attainment—more frequently than it moved through Wise County. We address each argument in turn. First, we find no merit in the Texas Petitioners’ conclusory argument that the EPA erred by using HYSPLIT modeling at all because HYSPLIT modeling “cannot measure ozone formation or transport. See State & County Br. 45–46. Indeed, we rejected a materially indistinguishable challenge in ATK Launch Systems, 669 F.3d at 339, a case involving the EPA’s 2006 fine particulate matter NAAQS designations. See id. at 334. We did so there because the EPA had taken “reasonable steps to ensure that the ‘HYSPLIT’ model’s limitations were considered.” Id. at 339 (quotation mark omitted). Here too, the EPA took reasonable steps to account for HYSPLIT’s limitations by evaluating the 53 source-apportionment modeling and historical wind data that the Texas Commission submitted during the comment period. See Final Dallas–Fort Worth Area Designations at 14–20, 23. Because “[o]zone and ozone precursors can be transported to an area from sources in nearby areas or from sources located hundreds of miles away,” see 2008 Designations Rule, 77 Fed. Reg. at 30,088, the EPA reasonably concluded that HYSPLIT modeling, as a more precise measurement of the path taken by air masses containing ozone precursors, was useful in determining whether wind moving through Wise County could have transported emissions to the areas with the violating monitors. Second, we find no merit in the Texas Petitioners’ argument that the EPA’s use of HYSPLIT modeling to designate Wise County as nonattainment amounts to arbitrarily disparate treatment. At the outset, it bears repeating that this Court has expressly sanctioned the EPA’s use of a holistic, multi-factor, totality-of-the-circumstances test for making NAAQS determinations, see ATK Launch Sys., 669 F.3d at 336; Catawba Cnty., 571 F.3d at 39, and we have twice iterated that, when using a multi-factor test, “ ‘discrete data points’ are not determinative” because isolating any one discrete consideration “ ‘ignores the very nature of the . . . test, which is designed to analyze a wide variety of data on a case-by-case basis.’ ” ATK Launch Sys., 669 F.3d at 336 (quoting Catawba Cnty., 571 F.3d at 39) (emphasis added; alteration omitted)). Indeed, because the EPA’s “holistic assessment of numerous factors . . . drives the process,” we have recognized that “no single factor determines a particular designation.” Id. For this reason, the EPA could have subjected Wise County to arbitrarily disparate treatment only if it treated genuinely “similar counties” dissimilarly. Id. (emphasis in original). Given “significant” differences among counties, “a direct one-to-one comparison of the data,” including the methods 54 used to measure such data, could be “inappropriate” or even “illogical.” Id. at 337. As noted, the EPA conducted a HYSPLIT analysis in areas where it “believed [HYSPLIT] could provide additional insight into whether [the] area[] contribute[s] to nonattainment.” Resp’t’s Br. 110 n.47. The EPA reasonably determined that Wise County was one such area because Dallas–Fort Worth “experiences light wind speeds and winds from variable directions,” making HYSPLIT’s more sophisticated evaluation of wind patterns “a more useful tool than annualized wind patterns.” EPA Response to Pet. for Reconsideration from Devon Energy Corp. at 12. According to the EPA, this more refined analysis was not necessary for all areas of the country, particularly those in which “there was not significant debate over whether [they] should be included” in a nonattainment area. See Resp’t’s Br. 111. The EPA’s decision to use HYSPLIT analysis in one area but not in another fits comfortably within the agency’s “technical expertise,” Catawba Cnty., 571 F.3d at 41, and the EPA’s explanation for the differing treatment was rational. Moreover, although the Texas Petitioners direct this Court to other attainment areas that were not evaluated using HYSPLIT modeling—specifically, Orange County and Cattaraugus County in New York—the “significant” differences between Wise County and those counties “make a direct one-to-one comparison of the data underlying the analyses inappropriate.” ATK Launch Sys., 669 F.3d at 337. For instance, the EPA justified its Orange County attainment designation, in part, on its finding that “the density of [Orange County’s] emissions and vehicle usages are not of the level of the other counties in the CSA that are in New York’s proposed New York–Northern New Jersey–Long Island, NY-NJ-CT nonattainment area.” New York-Northern New Jersey-Long 55 Island, NY-NJ-CT Nonattainment Area Designations for the 2008 Ozone NAAQS at 16 (emphasis added). In contrast, the EPA justified its nonattainment designation of Wise County, in part, based on the “[t]he close proximity of [Wise County’s] comparatively high emissions to violating monitors.” Final Dallas–Fort Worth Area Designations at 23 (emphasis added). Similarly, the EPA designated Cattaraugus County as attainment not only because “it is in the prevailing downwind direction from” the nearest violating monitor but also because “other monitors representative of Cattaraugus County, as well as the rest of upstate New York, are attaining the ozone standard.” See Attainment Status for Jamestown, New York and the Remainder of Upstate New York at 6 (emphasis added). But in the Dallas–Fort Worth area, seven violating monitors surrounded Wise County and some of the monitors—including one located one-half mile from Wise County’s border—reported levels of ambient ozone higher than anywhere else in the United States. Because “the core reason for the disparate designations” did not, as the Texas Petitioners would have it, reflect an “inconsistent approach to meteorology,” Industrial Br. 19, the EPA did not arbitrarily and capriciously treat Wise County differently by evaluating its wind patterns using HYSPLIT modeling instead of prevailing wind patterns. Third, when Wise County is compared to other counties for which the EPA used HYSPLIT modeling, it is clear that the EPA did not arbitrarily subject Wise County to disparate treatment. The Texas Petitioners point to four other counties—York, Dauphin and Lawrence Counties in Pennsylvania and Roane County, Tennessee—each of which the EPA designated as attainment notwithstanding HYSPLIT modeling demonstrated that air moved through them to violating monitors more frequently than through Wise County. 56 But again, a holistic look at why the EPA designated these counties attainment but designated Wise County nonattainment demonstrates that the EPA did not act arbitrarily or capriciously. For example, York and Dauphin Counties are both near Lancaster County, which houses all violating monitors in the area. Because Lancaster County “is served by a single-county transportation-planning agency,” the EPA concluded that there were “strong jurisdictional arguments” for designating Lancaster as “a single county nonattainment area” and, accordingly, designating all other counties in the vicinity—including York and Dauphin—as attainment. See Pennsylvania Area Designations for the 2008 Ozone NAAQS at 29–31. In contrast, Wise County is part of the Dallas–Fort Worth CSA (which means it is presumptively included in the Dallas–Fort Worth nonattainment area) and is also part of the Dallas–Fort Worth metropolitan planning organization (which implements programs and projects to reduce emissions across all included counties). In other words, jurisdictional and regional planning concerns—not differing approaches to HYSPLIT modeling data—drove the EPA’s conclusion that York and Dauphin Counties should be designated as attainment while Wise County should be designated as nonattainment. The Texas Petitioners’ comparisons of Wise County to Roane County, Tennessee, and Lawrence County, Pennsylvania, fare no better. Roane County is “geographically separated from the nearest county with a violating monitor” by approximately thirty miles and the ozone levels in the county between Roane and the next county with a violating monitor are in attainment. Resp’t’s Br. 122. The monitor in Lawrence County reports ozone levels that, at 0.066 ppm, are well below the EPA’s NAAQS 0.075 ppm threshold. 57 Moreover, the county with a violating monitor nearest to Lawrence County—Allegheny County—is not adjacent to Lawrence County. In contrast to both Roane County and Lawrence County, Wise County is adjacent to multiple counties reporting severe NAAQS violations, the closest of which is located a mere half mile from the Wise County line. The dispositive principle that the Texas Petitioners try to, but ultimately cannot, avoid is that under the EPA’s holistic analysis, “discrete data points” like the data from HYSPLIT modeling “are not determinative, because elevating them ignore[s] the very nature of the [holistic] test, which is designed to analyze a wide variety of data on a case-by-case basis.” ATK Launch Sys., 669 F.3d at 336 (quotation mark omitted). Based on the foregoing analysis, we cannot say that, had the EPA declined to evaluate Wise County’s wind patterns using HYSPLIT modeling, Wise County “would not have been designated nonattainment.” Industrial Br. 19. Because none of the areas discussed by the Texas Petitioners is truly “similarly situated” to Wise County, and because the EPA fully and rationally supported its use of HYSPLIT modeling for Wise County, it did not act arbitrarily or capriciously.