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

Heading: the 2008 ozone naaqs and the epa’s

Text: 2008 GUIDANCE On March 12, 2008, the EPA promulgated new primary and secondary NAAQS for ambient ozone, 2 a component of urban smog. See 2008 Designations Rule, 77 Fed. Reg. at 30,089. Even though ozone is an “essential presence in the atmosphere’s stratospheric layer,” it becomes harmful at ground level and “can cause lung dysfunction, coughing, wheezing, shortness of breath, nausea, respiratory infection, and in some cases, permanent scarring of the lung tissue.” S. Coast Air Quality Mgmt. Dist. v. EPA, 472 F.3d 882, 887 (D.C. Cir. 2006) (quoting Henry A. Waxman, An Overview of the Clean Air Act Amendments of 1990, 21 ENVTL. L. 1721, 1758 (1991)). It also “has a broad array of effects on trees, 2 “Primary” NAAQS exist to protect the “public health,” 40 C.F.R. § 50.2(b), and they ensure the safety of “sensitive” populations such as asthmatics, children and the elderly. See National Ambient Air Quality Standards (NAAQS), EPA, http://www.epa.gov/air/criteria.html (last updated Oct. 21, 2014). “Secondary” NAAQS exist to protect the “public welfare,” 40 C.F.R. § 50.2(b), and they prevent harms like decreased visibility and damage to animals, crops, vegetation and buildings. See National Ambient Air Quality Standards (NAAQS), EPA, http://www.epa.gov/air/criteria.html (last updated Oct. 21, 2014). 8 vegetation, and crops and can indirectly affect other ecosystem components such as soil, water, and wildlife.” Mississippi v. EPA, 744 F.3d 1334, 1340 (D.C. Cir. 2013). Because ozone forms at ground level when “ozone precursors”—specifically, nitrous oxides (NOx) and volatile organic compounds (VOCs)—react with sunlight, NAAQS compliance largely depends on reducing emissions from ozone-precursor producers like power plants, industrial compounds, motor vehicles and combustion engines. See 2008 Designations Rule, 77 Fed. Reg. at 30,089. Complicating this task is that ozone and ozone precursors travel easily through the atmosphere, which can result in NAAQS violations hundreds of miles away from the source of the ozone precursors. See id. Both the EPA’s 2008 primary and secondary ozone NAAQS reduced the maximum allowable daily average eight-hour level of ozone from 0.08 parts per million (ppm) to 0.075 ppm. See National Ambient Air Quality Standards for Ozone, 73 Fed. Reg. 16,436, 16,436–37 (Mar. 27, 2008). By setting these new NAAQS, the EPA triggered the states’ responsibility to submit their initial designations. See 42 U.S.C. § 7407(d)(1)(A). To assist this process, the EPA issued a guidance titled “Area Designations for the 2008 Revised Ozone National Ambient Air Quality Standards” [hereinafter 2008 Guidance] on December 4, 2008, which included several matters relevant to the instant petitions. First, the 2008 Guidance instructed states on the quality of data it expected them to consider. Specifically, it recommended that the states “identify violating areas using the most recent three consecutive years of quality-assured, certified air quality data.” 2008 Guidance at 2. The 2008 Guidance also informed the states that “[i]n general, [NAAQS] violations [will be] identified using data from . . . monitors that 9 are sited and operated in accordance with [EPA regulations located at] 40 C.F.R. Part 58.” Id. Second, the 2008 Guidance provided instruction for establishing geographic boundaries around nonattainment areas, noting first that the “EPA believes it is important to examine ozone-contributing emissions across a relatively broad geographic area.” 2008 Guidance at 3. Accordingly, the 2008 Guidance recommended that if an air-quality monitor reports a NAAQS violation, the state should consider using the Core Based Statistical Area (CBSA) or Combined Statistical Area (CSA) in which the monitor is located as the “presumptive” boundary. 3 Id. If the violating monitor is not in a CSA or CBSA, the 2008 Guidance recommended using the county in which the violating monitor is located as the presumptive boundary. Id. 3 A CBSA is defined by the Office of Management and Budget (OMB) as: [A] statistical geographic entity consisting of the county or counties associated with at least one core (urbanized area or urban cluster) of at least 10,000 population, plus adjacent counties having a high degree of social and economic integration with the core as measured through commuting ties with the counties containing the core. See Standards for Defining Metropolitan and Micropolitan Statistical Areas, 65 Fed. Reg. 82,228, 82,238 (Dec. 27, 2000). A CSA is formed by two or more adjacent CBSAs if there is sufficient “employment interchange” between them. Id. In other words, CSAs and CBSAs are both roughly equivalent to a “metropolitan” area. See generally id. at 82,235–36. Throughout this opinion, we use the term “metropolitan area” to refer to the CSA or CBSA, as defined in the 2008 Guidance. See 2008 Guidance at 3 & n.2. 10 The 2008 Guidance made plain, however, that CSAs, CBSAs and county lines were merely presumptive boundaries, recognizing that “area-specific analyses . . . may support nonattainment area boundaries that are larger or smaller than the presumptive area starting point.” Id. Stressing that “each potential nonattainment area should be evaluated on a case-by-case basis,” the 2008 Guidance instructed the states to consider nine factors when determining a nonattainment area’s borders. See id. at 2, Attach. 2. These include (1) air-quality data; (2) emissions data (such as location of emissions sources and contribution to ozone concentrations); (3) population density and degree of urbanization (including commercial development); (4) traffic and commuting patterns; (5) population growth rates and patterns; (6) meteorology (such as weather and air-transport patterns); (7) geography and topography (such as mountain ranges or other air-basin boundaries that could affect ozone dispersion); (8) jurisdictional boundaries (such as counties, air districts, existing nonattainment area boundaries and regional planning authority boundaries) and (9) the level of control of emissions sources. See id. Attach. 2. The 2008 Guidance stated that the EPA planned to consider these same factors, “along with any other relevant information,” in determining whether to modify the states’ initial designations. Id.