Opinion ID: 772539
Heading Depth: 2
Heading Rank: 2

Heading: The selection of de minimis levels

Text: 24 Although EPA has the authority to exempt de minimis sources of PM-10, the selection of de minimis levels does not escape judicial scrutiny. We review a challenged de minimis exemption to determine whether the agency action is permissible. [U]nless [EPA] describes the standard under which [it] has arrived at this conclusion, supported by a plausible explanation, we have no basis for exercising our responsibility to determine whether [EPA's] decision is arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law . . . . American Lung Ass'n v. EPA, 134 F.3d 388, 39293 (D. C. Cir. 1998) (citations and quotations omitted); see Southwest Penn. Growth Alliance v. Browner, 121 F.3d 106, 117 (3d Cir. 1997) (record must demonstrate that agency has examined relevant data and articulated satisfactory explanation, rationally connecting facts found and choice made). EPA must cite information to explain why it exempted certain sources as de minimis, and [w]ithout data . . . we owe no deference to EPA's line-drawing. National Resources Defense Council, Inc. v. EPA, 966 F.2d 1292, 1306 (9th Cir. 1992). 25 We therefore defer to the agency's judgment only if EPA has provided a full explanation of its de minimis levels and its application of those levels to sources of pollution. 2 Once we have received that explanation, however, we owe deference to the agency's decision if it is a permissible interpretation of the statute. See Environmental Defense Fund, 82 F.3d at 467.
26 EPA designated as a de minimis source of PM-10 pollution in the Phoenix area any source that contributed less than one microgram per cubic meter of PM-10 to a location of expected annual exceedences, and less than five micrograms per cubic meter to a location of expected 24-hour standard exceedences. (To be considered de minimis, a source's PM-10 contribution had to contribute less than the amounts specified for both the annual and 24-hour standards.) 27 EPA eventually designated thirteen source categories as de minimis: industrial yards, surface mining, other industrial activities, fuel combustion, charbroiling, residential wood combustion, paved parking lots, locomotives, gasolinepowered on-road motor vehicles, diesel-powered on-road motor vehicles, airport ground support, major point sources, and other area sources (e.g. open burning, structural fires). Of these thirteen source categories, only four were unregulated in the FIP, either because the remaining nine were already controlled by existing control measures, or because no reasonably available control measures existed. The four sources of PM10 unregulated as de minimis were gas on-road motor vehicles, diesel on-road motor vehicles, locomotives, and airport ground support. 28 EPA adopted the de minimis thresholds from the federal new source review program for issuing permits to new stationary sources of pollution, including PM-10. See 40 C.F.R. 51.165(b). The new source review program applies to new sources of PM-10 pollution located in attainment areas. The de minimis levels in the program, however, were keyed to thenew sources' impact in nearby nonattainment areas. Ober challenges the use of the new source de minimis levels to establish de minimis thresholds in Phoenix's FIP. 29 In 1987, when EPA adopted the de minimis levels for the new source review program, the agency explained that the purpose of the thresholds was to enable the states to determine whether the modeled ambient impact of a new source or modification would significantly affect the air quality. 52 Fed. Reg. 24672, 24706 (1987). If the impact of a new source on PM-10 levels in a nonattainment area was below the specified thresholds, the impact was deemed insignificant, and no controls were required, because the source's impact would not be sufficient to cause or contribute to a NAAQS violation. Id. EPA would be required to make sure that the accumulated de minimis exemptions did not push the PM-10 levels in an area over the NAAQS. Id. at 24707. 30 EPA concluded that the de minimis levels for new sources of PM-10 would be applied to existing sources of PM-10 (such as those in this case) in 1994, relying on the inherent agency authority as described in Alabama Power : 31 [EPA] has the authority to exempt from regulation those source categories in the area which contribute only negligibly to ambient concentrations which exceed the NAAQS. The EPA believes the court's test for invoking the de minimis exemption authority would be satisfied in circumstances where a State demonstrates conclusively that, because of the small contribution of the source category's emissions to the nonattainment problem, the imposition of addi tional controls . . . on a particular source category in the area would not contribute significantly to the Act's purpose of achieving attainment of the NAAQS as expeditiously as practicable. 32 59 Fed. Reg. 41998, 42011 (1994). 33 EPA thus concluded that it will, in general, rely on the criteria applied under new source permitting programs (40 C.F.R. 51.165(b)) to determine when a source category contributes significantly to violations of the NAAQS in a PM-10 serious nonattainment area. Id. 3 The agency categorized PM10 pollution levels that were de minimis when generated by a new source of pollution as also de minimis when the pollution was generated by existing sources, such as the thirteen PM-10 sources considered de minimis in the Phoenix area. 34 EPA also concluded that it would be inappropriate to applythese de minimis standards automatically to every area that does not meet national air quality standards. Sources of de minimis amounts of PM-10 pollution would escape regulation only if the failure to regulate them would have little benefit on the affected area's air quality. EPA thus would decline to regulate de minimis sources of PM-10 only if the cumulative effect of controlling the pollution would not make the difference between attaining and not attaining clean air (the NAAQS) by the deadline set by the statute, December 31, 2000. See 42 U.S.C. S 7513(c)(2); 63 Fed. Reg. 15920, 15927 (de minimis categories cannot escape controls if such controls are needed for attainment).
35 Ober objects to these agency conclusions. First, Ober rejects the agency's adoption of the de minimis levels from the new source program. Second, Ober argues that EPA's data is insufficient because EPA did not specify how much of a public health hazard is caused by each de minimis source of PM-10 pollution, or by the collective pollution generated by all the de minimis sources. Third, Ober contends EPA improperly focused only on the deadline and not on the relative benefit to the area's air quality when it exempted de minimis sources from controls. Ober maintains that EPA should require controls on de minimis sources even if the controls would not make the difference between timely attainment and nonattainment. We address each objection in turn. New source thresholds 36 When EPA adopted the PM-10 de minimis standards for the new source program, it codified those levels in a regulation after accepting and considering public comment. See 40 C.F.R. S 51.165(b); 52 Fed. Reg. 24672, 24705-07. EPA argues that the new source de minimis standards in place since 1987 were still appropriate seven years later, when in 1994 the agency stated its intention to use them for existing sources. Ober does not challenge EPA's establishment of these de minimis levels for the new source review program in 1987. Instead, Ober suggests that de minimis thresholds adopted by EPA for new sources of pollution are somehow inappropriate when those same de minimis thresholds are adopted for existing sources of pollution. 37 We see no evidence in the record that the de minimis levels should be different when the PM-10 pollution is caused by existing sources in the area, rather than by new sources located elsewhere. The new source program requires permits for sources of PM-10 pollution located outside nonattainment areas. But its de minimis levels are keyed to the source's impact on the air quality in nonattainment areas, reflecting theprojected amount of PM-10 pollution the new source will cause there. The de minimis thresholds in both the new source review program and in this case, therefore, are based on the source's contribution to the pollution in nonattainment areas. We conclude that it was permissible for EPA to adopt the PM-10 de minimis thresholds already in place in the new source review program. Public health 38 Ober faults EPA for not describing the precise public health effect of each of these small amounts of PM-10 pollution, as well as the effect of the collective pollution generated by all the de minimis sources. Because EPA's mandate is to protect the public health, Ober argues, it must specifically address the public health impact of exempting these sources from controls. 39 EPA is engaged in promulgating a federal implementation plan for Phoenix to bring the area into conformity with the NAAQS, defined by the statute as ambient air quality standards the attainment and maintenance of which in the judgment of the Administrator . . . are requisite to protect the public health. 42 U.S.C. S 7409(b)(1). Congress required that NAAQS must protect not only average healthy individuals, but also `sensitive citizens'--children, for example, or people with asthma, emphysema, or other conditions rendering them particularly vulnerable to air pollution. American Lung Ass'n, 134 F.3d at 389. By definition, then, a source of pollution that has only a de minimis effect on the effort to bring Phoenix in conformity with these air quality standards has only a de minimis effect on the public health, as the NAAQS themselves are set to protect the public health. Because the NAAQS are public health standards, we do not believe that EPA was required to analyze more specifically the effect of the de minimis sources on the public health, under the circumstances presented by this case. Attainment deadlines 40 Ober also claims that EPA's additional criterion for declaring a source de minimis, evaluating whether control of that source would result in attainment of the NAAQS by the deadline, was arbitrary. 41 EPA explains that after the FIP adopted the de minimis levels and identified existing sources that produced PM-10 pollution below those levels, the plan proposed not to regulate those de minimis sources if doing so would not bring the Phoenix area into compliance with NAAQS. In other words, EPA acknowledges that even the small amounts of pollutiongenerated by a de minimis source or sources would be controlled, if such control served the goal of attaining clean air by the deadline. 42 Requiring controls on de minimis sources if NAAQS will be met by the deadline serves to limit, not expand, the exemption of de minimis sources from controls. Further, using the deadline to determine whether controls must be imposed makes sense. The deadline is not an arbitrary date unrelated to air quality concerns. All the schedules and timetables for control of air pollution are keyed to the statutory deadline, which is a fundamental part of the federal implementation plan meant to ensure that national clean air standards are achieved as expeditiously as practicable. See National Resources Defense Council v. Browner, 57 F.3d 1122, 1127 (D.C. Cir. 1995) (describing incremental deadlines in Clean Air Act as intended to speed the attainment of clean air standards). EPA's mandate is to formulate implementation plans [that] provide for the attainment of the NAAQS as expeditiously as practicable, Ober I, 84 F.3d at 309 (emphasis added), but no later than the deadline of December 31, 2001. 43 In this case, the FIP concludes that the deadline will not be met even if these small sources of PM-10 were controlled. Under those circumstances, it is reasonable to decline to control the de minimis sources of pollution. See , e.g., Environmental Defense Fund, 82 F.3d at 466 (de minimis exemptions permissible where it seems eminently reasonable  for EPA to interpret Clean Air Act to require federal government to curtail only nonconforming activity that is likely to interfere with the attainment goals in a [state implementation plan]). 44 Ober characterizes the use of the attainment deadline as a measure of whether EPA will require controls on a de minimis source as fundamentally flawed, because it might result in unreasonably high de minimis thresholds. Ober posits that where air quality is at its worst, large amounts of pollution might remain unregulated as de minimis, because the area is so far from attainment by the deadline. 45 But EPA has not adopted an elastic ceiling for PM-10 de minimis levels. The de minimis threshold is set at, and will not exceed, one microgram per cubic meter for the annual standard, and five micrograms per cubic meter for the 24-hour standard, regardless of the general air quality level. EPA does, however, retain the flexibility to regulate amounts of PM-10 pollution that are even smaller than the de minimis levels, if their control would mean attainment by the deadline. This is a result Ober presumably would applaud. 4 46 We conclude that EPA acted permissibly in considering attainment deadlines in deciding whether to require con-trols on de minimis sources of PM-10 pollution.