United States Court of Appeals 

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued September 19, 2017 Decided October 24, 2017

No. 16-1097

SIERRA CLUB, ET AL.,

PETITIONERS

v.

ENVIRONMENTAL PROTECTION AGENCY AND E. SCOTT PRUITT,

ADMINISTRATOR, U.S. ENVIRONMENTAL PROTECTION 

AGENCY,

RESPONDENTS

On Petition for Review of Agency Action of

the United States Environmental Protection Agency

Robert E. Yuhnke argued the cause and filed the briefs for 

petitioners.

Meghan E. Greenfield, Trial Attorney, U.S. Department 

of Justice, argued the cause for respondents. With her on the 

briefs were Jeffrey H. Wood, Acting Assistant Attorney 

General, and John C. Cruden, Assistant Attorney General at 

the time the brief was filed. Sue S. Chen, Trial Attorney, 

entered an appearance. 

Before: HENDERSON and GRIFFITH, Circuit Judges, and 

WILLIAMS, Senior Circuit Judge.
2

Opinion for the Court filed by Senior Circuit Judge

WILLIAMS.

WILLIAMS, Senior Circuit Judge: The petitioners—

environmental and community organizations—contend that 

the Environmental Protection Agency has violated the 

Administrative Procedure Act and the Clean Air Act by 

modifying, without notice and comment, its prior 

understandings of how to measure a proposed transportation 

project’s impact on ambient levels of PM2.5 and PM10. (The 

first is particulate matter 2.5 micrometers or less in diameter; 

the second is particulate matter 10 micrometers or less in 

diameter.) The parties agree that the modification would, at 

the margin, make it less likely than before that a project would 

run afoul of various legal restrictions on the affected projects. 

As petitioners see it, the EPA’s new viewpoint violates the 

Clean Air Act’s substantive requirements. 

For want of jurisdiction we do not reach the substance of 

either the APA or the Clean Air Act arguments. In the case of 

PM2.5, petitioners have shown no instance where the change 

would be likely to have any adverse effect on them or their 

members; they therefore lack standing. In the case of PM10,

the EPA’s new provisions are not binding on the agency or 

affected parties and therefore do not constitute “final action” 

within the meaning of the Clean Air Act provision on which 

petitioners rely for our jurisdiction, 42 U.S.C. § 7607(b)(1). 

* * *

Under the Clean Air Act, the EPA has established 

National Ambient Air Quality Standards (“NAAQS”) for 

various pollutants including PM2.5 and PM10. To prevent uses 

of federal money that would take an area out of compliance 

with the NAAQS, the Act bars federal instrumentalities from 

supporting projects that would tend to do so. The Act directs 
3

federal agencies not to supply funds for any project that “does 

not conform” to the applicable State Implementation Plan 

(“SIP”) (required of states in order to assure the 

implementation and maintenance of the NAAQS, 42 U.S.C. 

§ 7410), and defines conformity to the SIP as including 

assurance that the project will not

(i) cause or contribute to any new violation of any 

[NAAQS] in any area; 

(ii) increase the frequency or severity of any existing 

violation of any [NAAQS] in any area; or

(iii) delay timely attainment of any [NAAQS] . . . .

42 U.S.C. § 7506(c)(1)(B). 

EPA regulations governing “conformity” determinations 

for federally funded transportation plans possibly affecting 

PM2.5, PM10, or carbon monoxide substantially replicate this 

language. 40 C.F.R. § 93.116. (A separate set of regulations 

applies to federal actions other than highways and mass 

transit. See Determining Conformity of General Federal 

Actions to State or Federal Implementation Plans, 58 Fed. 

Reg. 63,214 (Nov. 30, 1993).) To define the conformity 

requirement’s scope, the regulations employ the Act’s 

classifications of areas with respect to “attainment” of the 

standard for a particular pollutant. Under the Act, an area of a 

state that fails to comply with a given NAAQS is rated 

“nonattainment”; one that formerly did not comply but now 

does, but has yet to satisfy some transitional criteria, is 

designated “maintenance.” An area is in “attainment” if it not 

only meets the standard but is not subject to the qualifications 

that would land the area in the “maintenance” category. 42 

U.S.C. § 7407(d)(1)(A)(i)-(ii), (3)(E). The regulation applies 
4

conformity requirements only to areas designated 

“nonattainment” or “maintenance.” 40 C.F.R. § 93.116(a). 

Congress charged the EPA Administrator, with the 

concurrence of the Secretary of Transportation, with 

promulgating “criteria and procedures for demonstrating and 

assuring conformity in the case of transportation plans, 

programs, and projects.” 42 U.S.C. § 7506(c)(4)(B). For CO 

and PM, the EPA created a so-called “hot-spot” analysis. It 

specified that project sponsors (typically state departments of 

transportation) should combine the baseline concentration 

with the expected increment resulting from the project, and 

compare the sum with the concentration permitted by the 

NAAQS. 40 C.F.R. § 93.123(c)(1); see also 75 Fed. Reg. 

79,370, 79,370/3-79,371/1. 

In 2006, when the EPA first revised the hot-spot 

regulations to apply to PM2.5, the regulations said that the hotspot analysis “must be based on quantitative analysis 

methods” for projects of local air quality concern, including 

“[n]ew highway projects that have a significant number of 

diesel vehicles, and expanded highway projects that have a 

significant increase in the number of diesel vehicles.” 40 

C.F.R. § 93.123(b)(1), (b)(1)(i). But they also said that 

quantitative methods would not take effect “until EPA 

release[d] modeling guidance on this subject and announce[d] 

in the Federal Register that these requirements are in effect.” 

40 C.F.R. § 93.123(b)(4). Until then, rather vaguely described 

“qualitative” methods were to prevail. In fact, and of some 

importance for our analysis, the mandate to use quantitative 

methods took effect only after a two-year grace period 

following the EPA’s issuance of the preferred methodology in 

December 2010. See 40 C.F.R. § 93.111(a)-(b); 75 Fed. Reg. 

at 79,370/2. 
5

The EPA issued that guidance after employing notice and 

comment procedures specified by a settlement with 

environmental groups. See 75 Fed. Reg. 29,537, 29,538/1; 

see also Joint Appendix (“J.A.”) 299-302. It announced the 

release in the Federal Register. See 75 Fed. Reg. at 79,370/2. 

The Guidance essentially required a summing of monitored

PM on a specified extreme day (for the baseline) with the 

modeled PM increment for a specified extreme day (for the 

future). See Transportation Conformity Guidance for 

Quantitative Hot-spot Analyses in PM2.5 and PM10

Nonattainment and Maintenance Areas (EPA-420-B-10-040, 

Dec. 2010) (“2010 Guidance”), available at

nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=P1009HVH.TXT. 

(In some cases, the baseline was to be adjusted by an estimate 

of possible changes independent of the project. See 40 C.F.R. 

§ 93.123(c)(2); 2010 Guidance at § 8.3.3.) If the total (called 

the design value) was lower than the NAAQS, the project 

conformed. The rules for PM2.5 and PM10 differed simply in 

their identification of the extreme days to be evaluated. 

The 2015 Guidance—issued as we said without notice 

and comment—expressed an alteration of the EPA’s view of 

the proper methodology for the design value for both PM2.5 

and PM10. Given that we are not reaching the merits, and that 

all parties agree that at the margin the alteration tends to 

reduce the likelihood of a non-conformity finding, we need 

not describe the change. It essentially involved altering the 

designation of the extreme days for which the calculations 

were to be made. See Transportation Conformity Guidance 

for Quantitative Hot-spot Analyses in PM2.5 and PM10

Nonattainment and Maintenance Areas (EPA-420-B-15-084, 

Nov. 2015) (“2015 Guidance”), available at

nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P100NMXM.pdf. 

In both 2010 and 2015, the guidance documents further 

explained that, pursuant to 40 C.F.R. § 93.105(c), an 
6

interagency consultation process “must be used to develop a 

process to evaluate and choose models and associated 

methods and assumptions to be used in PM hot-spot 

analyses.” 2015 Guidance, § 2.3; 2010 Guidance, § 2.3. This 

consultation process requires that the state department of 

transportation sponsoring a project work with the EPA, the 

Department of Transportation, and relevant state agencies 

during the design and implementation of the hot-spot analysis. 

After the state department of transportation completes its 

analysis, it submits it to the Department of Transportation for 

a final conformity determination. 40 C.F.R. § 93.104; 2015 

Guidance, § 2.9.2.

* * *

We find that petitioners lack standing to challenge the 

2015 Guidance regarding PM2.5, and that we have no statutory 

jurisdiction under 42 U.S.C. § 7607(b)(1) to rule on their 

PM10 claim because the 2015 Guidance imposes no binding 

norm. 

PM2.5. The environmental organizations assert standing 

on the basis of the additional exposure to pollutants that they 

believe the change from the 2010 to the 2015 Guidance will 

inflict on their members. See Nat’l Envtl. Dev. Ass’n’s Clean 

Air Project v. EPA, 752 F.3d 999, 1005 (D.C. Cir. 2014). 

Specifically, they point to possible effects on the legal 

viability of three highway projects—I-70 East in Colorado, 

South Mountain Freeway in Arizona, and I-710 in California. 

Their difficulty lies in their having failed to adduce evidence 

that the change will have any effect on any of the projects. 

See Lujan v. Defenders of Wildlife, 504 U.S. 555, 560–561 

(1992); Sierra Club v. EPA, 292 F.3d 895, 898 (D.C. Cir. 

2002). 
7

The first two—I-70 East in Colorado and South Mountain 

Freeway in Arizona—are not located in a nonattainment or 

maintenance area for PM2.5, so for these projects the 

regulations require no PM2.5 hot-spot analysis. That ends the 

matter as to those projects. 

The third project, I-710 in California, is within a 

nonattainment zone for PM2.5. But petitioners have made no 

showing that the 2015 methodology will be used by the I-710 

project sponsors or that applying that methodology would 

make any difference. The only evidence in the record with 

regard to the I-710 project’s conformity analysis is a 2012 

draft Environmental Impact Study (“EIS”). J.A. 245-58. That 

study was not based on either the 2015 or the 2010 

methodology: It was drafted in the two-year grace period 

between the EPA’s release of guidance for use of quantitative 

methods and the date on which their use became obligatory. 

See 40 C.F.R. §§ 93.111(b), 93.123(b)(4); J.A. 257. And it 

obviously preceded release of the 2015 Guidance—in fact by 

more than three years. 

A supplemental draft EIS was released for the I-710 

project in July 2017. Even if this post-filing development 

could alter our standing analysis, see Wheaton College v. 

Sebelius, 703 F.3d 551, 552 (D.C. Cir. 2012) (“[S]tanding is 

assessed at the time of filing . . . .”), it too would be of no help 

to petitioners. The supplemental draft EIS explains that no 

quantitative hot-spot analysis has yet been conducted for 

PM2.5 and that the I-710 project sponsors are in the process of 

developing the methodology they will use: “The PM hotspot 

analysis protocol is under development, and the interagency 

consultation process regarding this protocol has been 

initiated.” See California State Department of Transportation 

& Los Angeles County Metropolitan Transit Authority, I-710 

Corridor Project Recirculated Draft Environmental Impact 

Report/Supplemental Draft Environmental Impact Statement 
8

and Section 4(f) Evaluation, p. 3.13-15, available at

http://www.dot.ca.gov/d7/env-docs/docs/RDEIR_SDEIS%

20July%202017.pdf. But nothing appears to suggest that the 

project will fall in that critical margin between the 2010 and 

the 2015 methods.

Thus petitioners have failed to establish that the 2015 

PM2.5 methodology will be used or that its use would result in 

a conformity determination different from the one that would 

have resulted if the 2010 methodology had applied—the latter 

a point counsel for petitioners conceded at oral argument. 

Oral Argument 7:30-7:47.

The government concedes that petitioners have 

established injury for purposes of standing to challenge the 

revised PM10 hot-spot methodology. Oral Argument 21:30-

22:06. We have no reason to doubt the concession, but we 

need not address the question in view of our lack of statutory 

jurisdiction over the PM10 claims. See Ruhrgas AG v. 

Marathon Oil Co., 526 U.S. 574, 585 (1999) (“[A] federal 

court [may] choose among threshold grounds for denying 

audience to a case on the merits.”). Even if we were to find 

that petitioners have standing to challenge the PM10

provisions, that finding would not create standing to challenge 

those for PM2.5. Standing is not evaluated “in gross.” Lewis 

v. Casey, 518 U.S. 343, 358 n.6 (1996); see also Davis v. 

FEC, 554 U.S. 724, 733–34 (2008); DaimlerChrysler Corp. v. 

Cuno, 547 U.S. 332, 352 (2006).

Because petitioners have not identified “any concrete 

application” of the 2015 PM2.5 methodology “that threatens 

imminent and concrete harm to the interests of their 

members,” see Summers v. Earth Island Inst., 555 U.S. 488, 

494-95 (2009), we hold that they lack standing as to that 

aspect of the 2015 Guidance. 
9

PM10. Under the Clean Air Act, this Court has 

jurisdiction over a petition for review of any “nationally 

applicable regulations promulgated, or final action taken, by 

the Administrator under this chapter . . . .” 42 U.S.C. 

§ 7607(b)(1) (emphasis added). In the absence of final agency 

action, we lack jurisdiction to hear an administrative 

challenge. Dalton Trucking, Inc. v. EPA, 808 F.3d 875, 879 

(D.C. Cir. 2015); Portland Cement Ass’n v. EPA, 665 F.3d 

177, 193 (D.C. Cir. 2011). 

In a case under the Clean Air Act, “the term ‘final action’ 

is synonymous with the term ‘final agency action’ as used in 

Section 704 of the APA.” Indep. Equip. Dealers Ass’n v. 

EPA, 372 F.3d 420, 428 (D.C. Cir. 2004). For a purported 

guidance document, the basic question is “whether the 

challenged agency action is best understood as a non-binding 

action, like a policy statement or interpretive rule, or a binding 

legislative rule.” Ass’n of Flight Attendants-CWA, AFL-CIO 

v. Huerta, 785 F.3d 710, 716 (D.C. Cir. 2015). “Policy 

statements ‘are binding on neither the public nor the agency,’ 

and the agency ‘retains the discretion and the authority to 

change its position . . . in any specific case.’” Id. (quoting 

Syncor Int’l Corp. v. Shalala, 127 F.3d 90, 94 (D.C. Cir. 

1997)). 

In resolving the issue, we typically consider (1) “the 

actual legal effect (or lack thereof) of the agency action in 

question on regulated entities”; (2) “the agency’s 

characterization of the guidance”; and (3) “whether the 

agency has applied the guidance as if it were binding on 

regulated parties.” Nat’l Mining Ass’n v. McCarthy, 758 F.3d 

243, 252-53 (D.C. Cir. 2014). 

In their claim that the change in the PM10 methodology is 

binding on project sponsors and on the relevant agencies, 
10

petitioners disregard both the plain language of the Guidance 

and the way it has been administered.

In both 2010 and 2015, the EPA explained that the 

recommended PM10 methodology was just that—a 

recommendation. The Guidance explicitly states that the EPA 

was open to considering better, alternative methods:

More advanced methods of calculating a PM10 design 

value, such as combining modeled and monitored 

concentrations on a quarterly basis, may be considered on 

a case-by-case basis by the EPA Regional Office, OTAQ

[Office of Transportation Air Quality], and OAQPS

[Office of Air Quality Planning and Standards]. Any 

alternative methods for calculating PM10 design values 

must be evaluated and chosen through the process 

established by each area’s interagency consultation 

procedures (40 C.F.R. § 93.105(c)(1)(i)).

2015 Guidance, § 9.3.4; 2010 Guidance, § 9.3.4. 

Contrary to petitioners’ assertions, this is not a case in 

which the guidance document signals that the agency “will not 

be open to considering approaches other than those 

prescribed” therein. See Gen. Elec. Co. v. EPA, 290 F.3d 377, 

384 (D.C. Cir. 2002); see also McLouth Steel Prod. Corp. v. 

Thomas, 838 F.2d 1317, 1321 (D.C. Cir. 1988). We said of 

the guidance at issue in Appalachian Power Co. v. EPA, 208 

F.3d 1015 (D.C. Cir. 2000), that “from beginning to 

end . . . [it] reads like a ukase. It commands, it requires, it 

orders, it dictates.” Id. at 1023. This is no ukase. As the 

quoted passage shows, it affirmatively invites the affected 

agencies to consider and apply improvements. 

The EPA’s vow to remain flexible was not just talk, as 

shown by its conduct under identical language in the 2010 
11

Guidance. In August 2014, as part of the interagency 

consultation process, the EPA and the project sponsors for the 

I-70 East and South Mountain Freeway projects discussed 

how to properly perform the hot-spot analysis required by 40 

C.F.R. § 93.123. See J.A. 195-97, 225-26. In two 

substantially contemporaneous communications with the 

project sponsors, the EPA explained that it had “recently 

provided technical assistance for another project” and that 

now “[a]nother option is available” for calculating the PM10

design value. J.A. 197, 227. “Based on implementation of 

the PM Hot-spot guidance to date,” the EPA said that it 

“believe[d] that there is further flexibility in what air quality 

monitoring data is used for design value calculations for PM 

hot-spot analyses” and that the relevant project sponsors could 

adopt “a slightly revised methodology for PM10 design value 

calculations.” J.A. 197, 227. The new possibility was 

ultimately to appear as the key novelty in the 2015 Guidance. 

On its face and as applied, the 2015 changes to the PM10

methodology are not binding. Petitioners contend that we 

should nonetheless find that the 2015 Guidance is a legislative 

rule because it purports to change another legislative rule. We 

agree, of course, that an amendment to a legislative rule must 

itself be legislative. Huerta, 785 F.3d at 718; Am. Mining 

Cong. v. Mine Safety & Health Admin., 995 F.2d 1106, 1109 

(D.C. Cir. 1993). But petitioners are mistaken in their 

premise that the 2010 Guidance was itself a legislative rule. 

As we have just discussed, the 2010 PM10 methodology 

was not applied with unyielding rigidity; instead, the EPA 

modified its approach over time. And while the release of the 

Guidance in 2010 had the effect of triggering the effective 

date of the requirement that project sponsors use quantitative 

(as opposed to qualitative) methods to perform the hot-spot 

analysis, that consequence flowed from the issuance of the 

Guidance, not its substance. 
12

Petitioners counter that the 2010 Guidance must be a 

legislative rule because it was promulgated with notice and 

comment. Even if petitioners were right that full APA 

procedures were used in the release of the 2010 Guidance (a 

point the EPA contests), an agency’s decision to embrace 

additional process cannot convert a guidance document into a 

legislative rule. See Am. Tort Reform Ass’n v. OSHA, 738 

F.3d 387, 394 (D.C. Cir. 2013). The EPA makes a host of 

guidance documents available for public comment. See 

Significant Guidance Documents, available at

https://www.epa.gov/laws-regulations/significant-guidancedocuments. That doesn’t transform them into legislative 

rules. Petitioners’ theory, if adopted, would discourage 

agencies from pursuing the very public engagement they seek. 

In short, the PM10 design value methodology found in the 

2015 Guidance “does not express a final agency action, and so 

we lack jurisdiction under the Clean Air Act, 42 U.S.C. 

§ 7607(b), to consider” it. See Am. Petroleum Inst. v. EPA, 

684 F.3d 1342, 1354 (D.C. Cir. 2012).

* * *

Because the petitioners lack standing with respect to the 

revised PM2.5 methodology and because we lack jurisdiction 

under the statute for their challenge to the revised PM10

methodology, the petition for review is

Dismissed.