# United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Ar gued February 20, 2014 Decided May 9, 2014

No. 13

- 1069

N ATIONAL A SSOCIATION OF M ANUFACTURERS , P ETITIONER

v.

E NVIRONMENTAL P ROTECTION A GENCY AND G INA M C C ARTHY , A DMINISTRATOR , EPA, R ESPONDENTS

A MERICAN L UNG A SSOCIATION , ET AL ., I NTERVENORS

Consolidated with 13

- 1071

On Petitions for Review of Final Rule of the United States Environmental Protection Agency

William L. Wehrum Jr. argued the cause for petitioner. With him on the briefs were Andrea Bear Field

, Allison D. Wood

, Lucinda Minton Langworthy

, Roger R. Martella Jr.

, Timothy K. Webster

, Joel F. Visser

, Rachel L. Brand

, Sheldon Gilbert , and Quentin Riegel

.

Eric G. Hostetle r , Attorney, U.S. Department of Justice, argued the cause for respondents. With him on the brief were2

Robert G. Dreher , Acting Assistant Attorney General, and John T. Hannon

, Steven E. Silverman

, David P.W. Orlin

, Brian L. Doster
, Geoffrey L. Wilcox , Attor neys, U.S. Environmental Protection Agency.

Peter Zalzal

, John D. Walke

, Nicholas Morales

, and David S. Baron were on the brief for intervenors Environmental Defense Fund, et al. in support of respondents.

Before: T ATEL , B ROWN , and K AVANAUGH , Circuit Judges

. Opinion for the Court filed by Circuit Judge K AVANAUGH

.

K AVANAUGH , Circuit Judge : In 2013

, EPA tightened the primary National Ambient Air Quality Standards, or NAAQS, for fine particulate matter. The National Association of Manufacturers and ot her industry groups challenge that decision

. Consistent with the general principle that the Clean Air Act gives EPA substantial discretion in setting the NAAQS, w e deny the petition s for review

.

I

The Clean Air Act requires EPA to establish N ational A mbient A ir Q uality S tandar d s for six common air pollutants

. 42 U.S.C. § § 7408(a)(1), 7409(a)

- (b). Each NAAQS consists of four components: (i) the “ indicator ,” or regulated pollutant; (ii) the “level,” or allowable concentration of the pollutant; (iii) th e “averaging time,” which is the tim e period over which pollutant concentration measurements are average d ; and (iv) the “ form ,” which refers to the way that compliance with the leve l will be determined within the averaging time (for example, that the level not be exceeded more than once per3
year)

. See American Farm Bureau Federation v. EPA , 559 F.3d 512, 516 (D.C. Cir. 2009). “ Primary ” NAAQS

– the standards at issue in this case

– must be set at a level that EPA determines is “ requisite to protect the pub lic health” with “an adequate margin of safety.” 42 U.S.C. § 7409(b)(1). The Supreme Court has interpreted “requisite” to mean “sufficient, but not more than necessary.” Whitman v. American Trucking Associations , Inc. , 531 U.S. 457, 473 (2001) (internal quotation mark omitted)

. After EPA establishes the NAAQS, the States assume primary responsibility for implementing and enforcing the standards. See 42 U.S.C. § 7407(a). 1

To ensure that the NAAQS take account of current science, the Clean A ir Act directs EPA to review the standards at least once every five years. See id. § 7409(d).

One pollutant regulated under the NAAQS program is particulate matter

. The term “particulate matter” is a shorthand for a variety of substances that form part icles in the ambient air. So

- called “ f ine particles”

– the kind of particulate pollution at issue in this case

– are produced mainly by a utomobiles and power plants

. See American Farm Bureau Federation , 559 F.3d at 515

. In 1971, EPA first set NAAQS for particulate matter

. Several times since then, t he agency has considered whether to revise those stand ards. See i d. at 516

- 17. T he most recent revision process began in 2007

. B y 2013, both EPA and the Clean Air Sci entific Advisory Committee ultimately determined that the then

- existing standards for particulate
matter w ere not sufficiently pro tective of public health, based

1 Under the NAAQS program, EPA also establishes a “secondary” set of standards “requisite to protect the public welfare.” 42 U.S.C. § 7409(b)(2). The secondary NAAQS are not at issue in this case.4

on an “increased confidence in the association between
exposure ” to particulate matter and “ s erious public health effects.” National Ambient Air Quality Standards for Particulate Matter, 78 Fed. Reg. 3086, 3120 (Jan. 15, 2013)

. In reaching that conclusion , EPA explained that several key epidemiological studies had reported statistically signific ant associations between adverse health effects and particulate matter exposure at concentrations between 12.8 and 14.8
μ g/m 3

. See id. at 3106

- 08, 3135 Fig. 4. In 2013, EPA therefore issued a Final Rule revising the level of the annual standa rd for parti culate matter emissions from 15 .0 μ g/m 3 to 12.0 μ g/m 3

, a level slightly lower than the lowest concentration s reported as causing adverse health effects in
t h e epidemiological studies analyzed by EPA. See id. at 316 2

- 6 4.

EPA’s Final Rule also revised the f orm of the standard t o eliminate a provision that had allowed certain areas to demonstrate compliance based on the averaged results from multiple monitori ng sites. EPA reasoned that the averaging provision , called “spatial averaging,” could result in a standard that was not sufficiently protective of sensitive individuals living in areas with high particulate ma tter concentrations. See id. at 3124

- 26.

Finally, EPA amended regulations regarding the monitors used to measure concentrations of p articulate matter in the air

. The amended regulations require the installation of additional monitors near heavily trafficked roads in urban areas where more than 1 million people live

. See id. at 3238

- 41

.
Petitioners here challenge EPA’s Final Rule purs uant to Section 307(b)(1) of the Clean Air Act

. See 42 U.S.C. § 7607(b)(1) , 7607(d)(9)

. Citing the arbitrary and capricious standard of review, p etitioners argue that EPA’s revisions to5

the level and form of the particulate matter NAAQS were unreasonable . Petitioners also contend that EPA acted unreasonably by amending the monitoring network provisions

. Petitioners further assert that EPA acted unreasonably by promulgating the Final Rule without first issuing certain implementation documents that petiti oners contend are necessary to en able compliance with the Rule. We address tho se arguments in turn.

II

In the 2013 Rule, EPA l ower ed the level of the particulate matter NAAQS from 15 .0 μ g/m 3 to 12.0 μ g/m 3

. EPA did so after it considered a broad array of scientific
sources, as well as the views of EPA staff and the Clean Air Scientific Advisory Committee

. S ee 78 Fed. Reg. at 3106

- 21 ; Letter from Dr. Jonathan M. Samet, Chair, Clean Air Scientific Advisory Committee, to Lisa P. Jackson , EPA Administrato r i

- ii (Sept. 10, 2010)

. EPA selected the 12.0
μ g/m 3 level because it was somewhat below the lowest long

term mean concentration shown by certain key epidemiologic studies to cause adverse health effects

. See 78 Fed. Reg. at 3158

- 59, 3161. EPA follow ed a similar approach in earlier particulate matter NAAQS revisions , and we upheld those EPA decisions

. See American Farm Bureau Federation v. EPA , 559 F.3d 512, 526

- 27 (D.C. Cir. 2009) (EPA “reasonably decided to address long

- term exposure with an annual s tandard somewhat below the long

- term mean concentrations in the ACS and Six Cities studies”); American Trucking Associations, Inc. v. EPA , 283 F.3d 355, 372 (D.C. Cir. 2002) (upholding particulate matter NAAQS where “EPA ultimately set the standard just be low the range of mean annual [particulate matter] concentrations observed in studies showing a statistically significant association between fine particulate matter and health effects”)

.6

Petitioners raise several arguments about EPA’s decision

.

First , p etitioners assert that EPA “prejudged” the outcome of the review process by failing to request comment on whether to revise the NAAQS at all. Although it is true that EPA did not specifical ly ask for comments on whether revision was necessary

, the preambl e to EPA’s N o tice of Proposed R ulemaking request ed comments on “all issues” related to the agency’s proposal to lower the level of the particulate matter NAAQS

. See National Ambient Air Quality Standards for Particulate Matter, 77 Fed. Reg. 38,890, 38,899 (June 29, 2012) . That broad request necessarily

enco mpassed the question of whether any revision of the particula te matter NAAQS was warranted. Moreover , when EPA requested comments on how to revise the NAAQS, regulated entities could have responded by disputing the premi se that revisions were required in the first place

. Indeed,

some p etitioners did just that by submitting comments advocating retention of the 2006 NAAQS. See Comments of Util ity Air Regulatory Group at 7

- 8 (Aug. 31, 2012)

. EPA’s notic e sufficed.

Second , p etitioners challenge EPA’s weighing of the scientific evidence

. Among other things, petitioners argue that EPA applied inconsistent peer

- review standards and afforded disproportionate weight to certain studies finding statistically s ignificant associations between particulate matter exposure and adverse health effects. Under the arbitrary and capricious standard, we exercise great deference when we evaluate claims about competing bodies of scientific research. See City of Waukesha v. EPA , 320 F.3d 228, 247 (D.C. Cir. 2003). Here, we can be brief: P etitioners simply have not identified any way in which EPA jumped the rails of reasonableness in examining the science. EPA offered reasoned explanations for how it approached and weigh ed the7
evidence, and why the scientific evidence supported revision of the NAAQS.

Third

, according to petitioners, EPA did not respond when petitioners’ comments cited certain studies that supported retention of the existing particulate matter NAAQS. EPA admittedly did not directly address ev ery study that petitioners cite d to the agency . B ut our precedents do not require as much , and EPA acted within its discretion in this case in addressing the more significant comments

. See Northside Sanitary Land fill, Inc. v. Thomas , 849 F.2d 1516, 1519 (D.C. Cir. 1988) (“C omments must be significant enough to step over a threshold requirement of materiality before any lack of agency response or consideration becomes of concern .”) (alteration omitted) ; see also C i ty of Waukesha , 320 F.3d at 257 (an agency “need not address every comment”) (internal quotation mark omitted)

.

III

In the Final Rule, EPA also amend ed the form of the particulate matter standard by eliminating “spatial averaging

. ” Citing the arbitrary and capricious standard, petitioners challeng e EPA’s decision as unreasonable.

With s patial averaging, certain areas can demonstrate compliance with emission standards by averaging results from multiple monitoring sites within that area

. In 1997, EPA firs t adopted spatial averaging in the particulate matter NAA QS

. See National Ambient Air Quality Standards for Particulate Matter, 62 Fed. Reg. 38,652, 38,671

- 72 (July 18, 1997). In the 2006 NAAQS, EPA retained spatial averaging , but the agency restricted t he circumstances under which spatial averaging could be used due to concerns that spatial averaging might allow greater exposures for sensitive populations. See National Ambient Air Quality Standards for8
Particulate Matter, 71 Fed. Reg. 61,144, 61,165

- 67 (Oct. 17, 2006). In the 2013 NAAQS, EPA eliminated spatial averaging altogether

. See 78 Fed. Reg. at 3124

- 27

.

Pe titioners contend that EPA acted unreasonably by eliminating spatial averaging. Their claim rests on EPA’s supposed failure to explain e mpirically why the constraints imposed on spatial averaging in the 2006 NAAQS no longer suffice d to p rotect against exposure hazards. That argument misunderstands the nature of our review

. For example, w hen EPA revises the level of the NAAQS

, this Court does “not ask why the prior NAAQS once was ‘requisite’ b ut is no longer up to the task

. ” Mississippi v. EPA , 744 F.3d 1334, 1343 (D.C. Cir. 2013) . Rather, the only inquiry is “whether EPA’s proposed NAAQS is ‘requisite.’” Id. In othe r words, we do
not assign “presumptive validity” to the prior NAAQS; the question is whether EPA reasonably explains the current standards. Id. So it is with the form of the standards as well.

EPA here fulfilled its obligation to reasonably explain its decision not to employ spatial averaging

. As the agency stated , spatial averaging would enable some portions of a compliance area

– particularly those areas where sensitive individuals are likely to live

– to exceed the NAAQS for periods of time. See 78 Fed. Reg . at 3124

- 27. EPA reasonably concluded that allowing those excess emissions under all the circumstances here was inconsistent with EPA’s goal of ensuring that the NAAQS provide requisite protection for all individuals. Id. ; see also id. at 3168.

IV

Petitioners also challenge EPA’s new requirement that States place monitors near heavily trafficked roads in large metropolitan areas

.9

U nder the NAAQS program , States must develop and operate (subject to EPA approval) monitoring networks to

measure concentrations of the six NAAQS pollutants in the air

. See 42 U.S.C. §§ 761 9, 7410(a)(2)(B); 40 C.F.R. pt. 58. EPA uses the d ata from tho se networks for several purposes, including for research and for determining compliance with air quality standards.

As part of the review process for the 2013 particulate
matter NAAQS revision, EPA proposed adding a new, “ near

road ” component to the particulate matter monitoring network
t o “ better understand the potential health impacts ” of particulate matter exposures around heavily trave led roads. 77 Fed. Reg. at 39,009. In the Final Rule, EPA adopted that approach , concluding that requiring “ a modest network ” of

near

- road compliance particulate matter monitors “ is
necessary

. . . including for comparison t o the NAAQS.” 78 Fed. Reg. at 3238. The Rule require s approximately 50 new monito rs to be installed near heavily travel ed roads in large metropolitan areas. Id. at 3238

- 41.

Petitioners challenge that decision on substantive and procedural grounds. On the substantive side, petitioners contend that near

- road monitor ing will make the NAAQS for particulate matter overly stringent . As petitioners see it, near

road monitoring will generate data from areas with unrepresentatively high particulate matter c oncentrations. EPA responds that the goal here was to ensure that the NAAQS represent real

- world conditions. The point of the NAAQS program is to safeguard the quality of the “ambient air,” which is defined as the “portion of the atmosphere

, external to buildings, to which the general public has access.” 42 U.S.C. § 7409(a); 40 C.F.R. § 50.1(e). That definition obviously includes near

- road areas. Therefore

, EPA explained that monitoring near

- road areas

– and not just non

-10

near

- road areas

– w as important in order to obtain an accurate, area

- wide picture of ambient air quality. It stated : “I gnoring monitoring results from [near

- road] areas (or not monitoring at all) would abdicate this responsibility. Put another way, monitoring in such areas does not make the standard more stringent, but rather affords requisite protection to the populations, among them at

- risk populations, exposed to fine particulate in these areas.” 78 Fed. Reg. at 3240.

In the context of this statutory scheme that grant s EPA substantial discretion

, EPA’s decision and explanation are at least reasonable.

On the procedural side , petitioners maintain that EPA did
not afford them an opportunity to comment generally on near

road monitoring, and specifically on EPA’s decision to use

near

- road data for complia nce purposes, not simply for research. But EPA’s proposal mentioned using near

- road monitors for many purposes, including “collec tion of NAAQS comparable data”

– in other words, to assess compliance. 77 Fed. Reg. at 39,009. That statement sufficed to put regulated entities on notice regarding the possible u ses of near

- road data. P etitioners themselves had no problem und erstanding the scope of the issues up for consideration; several petitioners submitted comment s opposing the use of near

- road monitors for compliance purposes. See, e.g.

, Comments of Util ity Air Regulatory Group at 54

- 55 (Aug. 31, 2012 ) (“[B]ecause reliance on near

- road monitors to judge compliance would be unreasonable, the Agency does not have an adequate basis to require states to incur the cost to install and operate them.”).

Petitioners also suggest that EPA improperly relied on data from a Census Bureau study without providing opportunity to comment on the study. Petitioners have filed a11
petition for reconsideration with EPA raising their objections on that issue. We therefore do not address that challenge at this time. See Utility Ai r Regulatory Group v. EPA

, 744 F.3d 741 , 746

- 47 (D.C. Cir. 2014)

.

V

Finally, petitioners argue that EPA should not have issued, or at least should not require compliance with, the 2013 NAAQS without first providing States and regulated parties certain impl ementation guidance

. We disagree. The NAAQS sets a clear numerical target specifying the maximum levels of emissions in the State s . Under the law, States will devise implementation plans to meet that target. Nothing in the law dictates additional guida nce from EPA at this point.

* * *

We have considered all of petitioners’ arguments. We deny the petition s for review.

So ordered.