Document ID: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-ca9-12-56467/USCOURTS-ca9-12-56467-0/pdf.json

Parties Involved:
Alameda Corridor Transportation Authority
Appellee
Coalition for a Safe Environment
Appellant
East Yard Communities for Environmental Justice
Appellant
Ray LaHood
Appellee
Victor Mendez
Appellee
Natural Resources Defense Council, Inc.
Appellant
Jeffrey Paniati
Appellee
State of California, Department of Transportation
Appellee
U.S. Department of Transportation
Appellee

Document Text:

FOR PUBLICATION

UNITED STATES COURT OF APPEALS

FOR THE NINTH CIRCUIT

NATURAL RESOURCES DEFENSE

COUNCIL, INC., a non-profit

corporation; EAST YARD

COMMUNITIES FOR ENVIRONMENTAL

JUSTICE, a non-profit corporation;

COALITION FOR A SAFE

ENVIRONMENT, a non-profit

corporation,

Plaintiffs-Appellants,

v.

U.S. DEPARTMENT OF

TRANSPORTATION; RAY LAHOOD, in

his official capacity as Secretary of

Transportation; STATE OF

CALIFORNIA, DEPARTMENT OF

TRANSPORTATION; VICTOR MENDEZ,

Administrator, Federal Highway

Administration; JEFFREY PANIATI, in

his official capacity as Acting

Deputy Director of the Federal

Highway Administration,

Defendants-Appellees,

ALAMEDA CORRIDOR

TRANSPORTATION AUTHORITY,

Real Party in Interest-Appellee.

No. 12-56467

D.C. No.

2:09-cv-08055-

JAK-MAN

OPINION

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2 NRDC V. USDOT

Appeal from the United States District Court

for the Central District of California

John A. Kronstadt, District Judge, Presiding

Argued and Submitted

May 14, 2014—Pasadena, California

Filed October 30, 2014

Before: John T. Noonan, Kim McLane Wardlaw,

and Raymond C. Fisher, Circuit Judges.

Opinion by Judge Wardlaw

SUMMARY*

Environmental Law

The panel affirmed the district court’s summary judgment

in favor of federal and state defendants in an action brought

by environmental groups alleging that the defendants violated

the Clean Air Act and the National Environmental Policy Act

by failing to properly evaluate and disclose the potential

environmental impact of a planned expressway connecting

the Ports of Los Angeles and Long Beach to the I-405

freeway.

Pursuant to the Clean Air Act (CAA), the states must

adopt a State Implementation Plan that provides for the

* This summary constitutes no part of the opinion of the court. It has

been prepared by court staff for the convenience of the reader.

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NRDC V. USDOT 3

implementation and maintenance of national air quality

standards. The CAA contains a “conformity” provision that

prohibits federal participation in any project that fails to

conform to an approved State Implementation Plan. The CAA

delegated to the Environmental Protection Agency(EPA) and

the U.S. Department of Transportation the duty to establish

procedures to assure conformity for transportation projects. 

Pursuant to that authority, the EPA promulgated regulations

mandating a “hot-spot analysis” for certain pollutants,

including PM2.5

- the pollutant at issue. In the course of the

expressway project’s approval process, the defendants

conducted an air quality Conformity Determination, which

involved a qualitative hot-spot analysis of existing

concentration of PM2.5

, and an Environmental Impact

Statement (EIS) as required by the National Environmental

Policy Act.

The panel held that the defendants were not required to

estimate PM2.5

increases within the area immediately adjacent

to the proposed expressway, and concluded that the

defendants’ Conformity Determination complied with the

CAA. Specifically, the panel held that the CAA’s statutory

phrase “any area” was ambiguous, and the governing

regulations did not decisively answer whether the CAA

required qualitative hot-spot analysis within the immediate

vicinity of the project area during the time period at issue, but

the EPA’s and Department of Transportation’s interpretation

of the regulations ̄permitting the type of analysis performed

here by the defendants ̄were entitled to considerable

deference. The panel further held that the defendants’

Conformity Determination was neither arbitrary nor

capricious.

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4 NRDC V. USDOT

Finally, the panel held that the EIS prepared by the

defendants took the requisite “hard look” at the freeway

project’s likely consequences and probable alternatives, and

therefore the EIS comported with the National Environmental

Policy Act.

COUNSEL

Adriano Martinez (argued), David Pettit, Natural Resources

Defense Council, Santa Monica, California; Robert E.

Yuhnke, Robert Yuhnke & Associates, Boulder, Colorado,

for Plaintiffs-Appellants.

J. David Gunter II (argued), Ignacia S. Moreno, David

Glazer, Norman Rave, United States Department of Justice,

Washington, D.C., for Defendants-Appellees.

Jocelyn Denise Thompson (argued), Sharon Rubalcava,

Shiraz D. Tangri, Marisa Blackshire, Alston & Bird LLP, Los

Angeles, California, for Real Party in Interest-Appellee.

OPINION

WARDLAW, Circuit Judge:

Natural Resources Defense Council, East Yard

Communities for Environmental Justice, and Coalition for a

Safe Environment (collectively “NRDC”) appeal the district

court’s grant of summary judgment in favor of the U.S.

Department of Transportation and other federal and state

defendants (collectively “Defendants”). NRDC argues that

Defendants violated the federal Clean Air Act (“CAA”) and

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NRDC V. USDOT 5

the National Environmental Policy Act (“NEPA”) by failing

to properly evaluate and disclose the potential environmental

impact of a planned expressway connecting the Ports of Los

Angeles and Long Beach to the I-405 freeway. We have

jurisdiction under 28 U.S.C. § 1291, and we affirm the district

court’s grant of summary judgment to Defendants.

I.

The Port of Los Angeles is our nation’s busiest container

port.1 Considered together with the adjacent Port of Long

Beach, this port complex is among the ten busiest in the

world, and it accounts for roughly forty percent of all

waterborne cargo that enters the United States. BILL

SHARPSTEEN, THE DOCKS 53-54 (2011). The port’s cargo

volume is projected to continue rising for decades.2

Although the ports are an economic boon for the Los

Angeles region, they also affect air quality in the surrounding

area, especially in the adjacent communities of San Pedro and

Wilmington. These impacts are projected to worsen with the

rise in container volume at the ports. The State Route 47

Expressway Project (“Project”) is one of several port-related

infrastructure projects designed to ease traffic congestion and

mitigate air pollution. If built, the Project will connect the

ports to the I-405 freeway via an elevated, 1.7 mile-long

1

Strategic Plan 2012-2017, THE PORT OF LOS ANGELES, at 1 (2012),

http://www.portoflosangeles.org/pdf/strategic_plan_2012_lowres.pdf(last

visited Sept. 24, 2014).

2

See Port Master Plan, THE PORT OF LOS ANGELES, at 9 (Feb. 2014),

http://www.portoflosangeles.org/planning/pmp/Amendment%2028.pdf

(last visited Sept. 24, 2014).

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6 NRDC V. USDOT

expressway. The Project’s sponsors, which are now the

Defendants in this litigation, assert that the Project will better

integrate the ports with the freeway system, thereby reducing

the need for surface-street travel by trucks carrying shipping

containers, and the pollution generated while they run idle at

traffic signals and railroad crossings.

In the course of the Project’s approval process,

Defendants conducted an air quality Conformity

Determination and an Environmental Impact Statement

(“EIS”). As one component of the ConformityDetermination

study, Defendants performed a qualitative “hot-spot” analysis

that measured existing concentrations of PM2.5, a type of fine

particulate matter, and estimated the Project’s likely impact

on PM2.5levels. Because there was no PM2.5receptor located

within the immediate vicinity of the Project, Defendants

based their qualitative hot-spot analysis on data from a

receptor five miles away from the project area. Defendants

released a draft Conformity Determination in November

2008. Following a round of comments and revisions, the

final Conformity Determination was issued in May 2009.

Meanwhile, Defendants prepared an EIS as required by

NEPA. The EIS process began in 2004, and Defendants

released a draft EIS in August 2007. The draft EIS prompted

numerous comments, including comments from NRDC, to

which Defendants responded at length. The comments also

spurred Defendants to conduct additional studies, such as a

Traffic Sensitivity Analysis and a Health Risk Assessment

that detailed the Project’s likely health impacts, including an

increased risk of cancer in the areas immediately adjacent to

the Project. Defendants released the final version of the EIS

in May 2009, and signed the Record of Decision in August

2009.

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NRDC V. USDOT 7

In November 2009, NRDC filed a complaint in the

Central District of California alleging that Defendants’

approval of the Project violated CAA, NEPA, and the

Administrative Procedure Act. At the district court’s request,

the parties briefed and argued cross-motions for summary

judgment. On June 29, 2012, the district court issued an

order granting summary judgment in Defendants’ favor. This

appeal follows.

II.

A district court’s decision on cross-motions for summary

judgment is reviewed de novo. Am. Civil Liberties Union of

Nev. v. City of Las Vegas, 466 F.3d 784, 790 (9th Cir. 2006). 

“We view the evidence in a light most favorable to the nonmoving party and decide whether there are any genuine issues

of material fact and whether the district court correctly

applied the substantive law.” FTC v. Stefanchik, 559 F.3d

924, 927 (9th Cir. 2009).

Under the Administrative Procedure Act, we must “hold

unlawful and set aside agency action, findings, and

conclusions found to be . . . arbitrary, capricious, an abuse of

discretion, or otherwise not in accordance with law.” 

5 U.S.C. § 706(2)(A). “Review under the arbitrary and

capricious standard is narrow, and we do not substitute our

judgment for that of the agency.” Barnes v. U.S. Dep’t of

Transp., 655 F.3d 1124, 1132 (9th Cir. 2011).

“When Congress has ‘explicitly left a gap for an agency

to fill, there is an express delegation of authority to the

agency to elucidate a specific provision of the statute by

regulation,’ and any ensuing regulation is binding in the

courts unless procedurally defective, arbitrary or capricious

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8 NRDC V. USDOT

in substance, or manifestly contrary to the statute.” United

States v. Mead Corp., 533 U.S. 218, 227 (2000) (quoting

Chevron, U.S.A., Inc. v. Natural Res. Def. Council, Inc.,

467 U.S. 837, 843-44 (1984)). Even if the agency has not

formally interpreted the statute, Chevron deference applies

when it has “promulgated a rule based on an implicit

interpretation of the statute.” Schleining v. Thomas, 642 F.3d

1242, 1246 (9th Cir. 2011). An agency’s interpretation of its

own regulation is “controlling unless plainly erroneous or

inconsistent with the regulation.” Auer v. Robbins, 519 U.S.

452, 461 (2000) (internal quotation marks omitted). 

III.

A.

The CAA mandates joint efforts between the federal

government and the states to combat air pollution. Under the

CAA’s statutory framework, the federal Environmental

Protection Agency (“EPA”) begins by establishing National

Ambient Air Quality Standards (“NAAQS”) for certain types

of pollutants. 42 U.S.C. § 7409. Then, the EPA designates

areas throughout the United States as “attainment,”

“nonattainment,” or “maintenance” for each type of pollutant

depending on whether these national standards have been

met. See 40 C.F.R. § 93.101 (defining these terms). For

PM2.5, the pollutant at issue here, the EPA has designated the

South Coast Air Basin—which encompasses the ports as well

as most of the greater Los Angeles area—as “nonattainment.” 

The details of NAAQS enforcement are left to the states, each

of which must adopt a State Implementation Plan that

provides for the implementation and maintenance of national

air quality standards. 42 U.S.C. § 7410(a)(1).

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NRDC V. USDOT 9

The CAA also contains a “conformity” provision that

prohibits federal participation in any project that fails to

conform to an approved State Implementation Plan. 

42 U.S.C. § 7506(c)(1). The statute defines “conformity” to

mean, in relevant part, that:

such activities will not—

(i) cause or contribute to any new violation of

any standard in any area;

(ii) increase the frequency or severity of any

existing violation of any standard in any area;

or

(iii) delay timely attainment of any standard

or any required interim emission reductions or

other milestones in any area.

Id. § 7506(c)(1)(B). The CAA does not define the term “any

area.” Instead, it delegates to the EPA and the U.S.

Department of Transportation (“DOT”) the duty to

“promulgate, and periodically update, criteria and procedures

for demonstrating and assuring conformity in the case of

transportation plans, programs, and projects.” Id.

§ 7506(c)(4)(B).

Acting pursuant to that authority, the EPA has

promulgated regulations that mandate a “hot-spot analysis”

for several air pollutants, including PM2.5. Hot-spot analysis

is described as

an estimation of likely future localized . . .

PM2.5 pollutant concentrations and a

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10 NRDC V. USDOT

comparison of those concentrations to the

national ambient air quality standards. Hotspot analysis assesses impacts on a scale

smaller than the entire nonattainment or

maintenance area . . . and uses an air quality

dispersion model to determine the effects of

emissions on air quality.

40 C.F.R. § 93.101. Project sponsors must carry out this hotspot analysis to ensure that the project does not “cause or

contribute to any new localized . . . PM2.5 violations, increase

the frequency or severity” of such violations, or “delay timely

attainment” of air quality goals. Id. § 93.116(a). When a

project’s sponsors conduct a hot-spot analysis, concentrations

“must be estimated and analyzed at appropriate receptor

locations in the area substantially affected by the project.” Id.

§ 93.123(c)(1).

Hot-spot analyses may be either qualitative or

quantitative. “Where quantitative analysis methods are not

available,” as was true of PM2.5 during the period at issue

here, the demonstration required by § 93.116(a) “must be

based on a qualitative consideration of local factors.” Id.

§ 93.123(b)(2). The parties agree that Defendants were

required to conduct a qualitative hot-spot analysis rather than

a quantitative analysis.

In March 2006, the EPA and DOT jointly published the

TransportationConformityGuidance for Qualitative Hot-spot

Analyses in PM2.5 and PM10 Nonattainment and Maintenance

Areas (“Conformity Guidance”). According to the EPA, all

qualitative PM2.5 analyses “should be completed” according

to the Conformity Guidance. 71 Fed. Reg. 12468, 12471

(Mar. 10, 2006). The Conformity Guidance does not define

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NRDC V. USDOT 11

“any area,” nor does it refer to “appropriate receptor

locations.” It does, however, provide a detailed methodology

for how project sponsors should conduct qualitative PM2.5

hot-spot analyses, and it features several examples of

permissible analyses.

NRDC’s CAA claim turns on whether the statute’s use of

the phrase “any area” means that Defendants were required

to estimate PM2.5increases within the area immediately

adjacent to the proposed expressway. If Defendants were

required to do so, then it follows that their approval of the

Project was contrary to law and must be set aside. If not, then

their Conformity Determination complied with the CAA.

B.

1.

NRDC argues that the plain meaning of § 7506(c)(1)(B)

compels the conclusion that “any area” means “‘all’ or

‘every’ part of the ‘area’ affected by project emissions,” and

thus that Defendants were required to measure PM2.5

concentrations within the immediate vicinity of the Project. 

We agree that “read naturally, the word ‘any’ has an

expansive meaning.” Ali v. Fed. Bureau of Prisons, 552 U.S.

214, 219 (2008) (alterations and internal quotation marks

omitted). However, NRDC’s plain meaning argument

ignores a critical, obvious ambiguity in the phrase “any area”:

the word “area.”

On its own, the word “area” does not tell us whether

Defendants were required to measure PM2.5 concentrations

within the area immediately adjacent to the proposed

expressway or in any other “area.” The plain meaning of

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12 NRDC V. USDOT

“area” encompasses a wide variety of sizes. “Area” is

defined as “a region or part of a town, a country, or the

world,” “a space allocated for a specific purpose,” or “the

extent or measurement of a surface or piece of land.” NEW

OXFORD AMERICAN DICTIONARY 83 (3rd ed. 2010). 

Additionally, the statutory context does not allow us to

pinpoint the meaning of “area.” A different provision of the

CAA requires that states send the EPA “a list of all areas (or

portions thereof) in the State,” 42 U.S.C. § 7407(d)(1)(A), but

this usage of “area” appears to refer to entire air quality

regions, which often include multiple counties. Likewise, the

statutory section concerning State Implementation Plans

repeatedly uses the term “areas” to describe air quality

regions. E.g., id. § 7410(a)(2)(I). Thus, we are convinced

that the statutory phrase “any area” is ambiguous.

2.

Because Congress has not “directly spoken to the precise

question at issue,” Chevron, 467 U.S. at 842, we look to the

relevant agencies’ interpretations of the ambiguous phrase

“any area” during the period at issue in this appeal. NRDC

asserts that the EPA has adopted a regulatory interpretation

that supports its understanding of “any area,” and it argues

that EPA and DOT interpretations to the contrary are not

entitled to judicial deference.

NRDC’s argument begins with an EPA rule interpreting

the key statutory phrase “increase the frequency or severity

of any existing violation of any standard in any area.” 42

U.S.C. § 7506(c)(1)(B)(ii). According to the EPA’s

regulatory definition,

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NRDC V. USDOT 13

[i]ncrease the frequency or severity means to

cause a location or region to exceed a

standard more often or to cause a violation at

a greater concentration than previously

existed . . . .

40 C.F.R. § 93.101 (emphasis added). NRDC argues the term

“a location” refers to an area smaller than the project area,

such as the area immediately adjacent to the expressway. In

March 2010, nearly a year after the Defendants issued their

Conformity Determination, the EPA issued an amended rule

which “specifically clarifies that the term ‘any area’ in CAA

section 176(c)(1)(B) applies to anyportion of a nonattainment

or maintenance area, including the local area affected by a

transportation project.”375 Fed. Reg. 14,260, 14,276 (Mar.

24, 2010). NRDC argues that the EPA’s 2010 amendment to

40 C.F.R. § 93.116 confirms that the term “a location”

referred to an area smaller than the project area.

NRDC also points to the regulatory requirement that hotspot analyses estimate pollutant concentrations at

“appropriate receptor locations in the area substantially

affected by the project.” 40 C.F.R. § 93.123(c)(1). In

NRDC’s view, this provision’s use of the plural “locations,”

and its reference to “the area significantly affected by the

project,” impliedly interprets the CAA’s “any area”

requirement to mandate collection and analysis of data drawn

3

In explaining its amended rule, the EPA noted that “[i]n practice,

EPA’s regulations will ensure that any project that creates a new violation

or worsens an existing violation of the NAAQS in the local area affected

by the project (either by increasing the number of violations or the severity

of an existing violation) will not be found to conform.” 75 Fed. Reg.

14,260, 14,278 (Mar. 24, 2010).

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14 NRDC V. USDOT

from the project’s immediate vicinity. Finally, NRDC cites

the EPA’s 1997 response to a public comment on proposed

hot-spot rules. In this response, the EPA noted that some

commenters had proposed that “a project should be allowed

to make a violation worse in a place not frequented by the

public if it improves air quality and eliminates violations

where public exposure is more likely.” 62 Fed. Reg. 43,780,

43,798 (Aug. 15, 1997). The EPA, however, rejected this

view, explaining that

Clean Air Act section 176(c)(1)(B) states that

transportation projects must not cause or

contribute to any new violation of any

standard in any area, or increase the frequency

or severity of any existing violation of any

standard in any area. It is not public exposure

to a violation of a standard that the Clean Air

Act language prohibits; it prohibits any

violation of any standard in any area. The

conformity rule cannot override the Clean Air

Act to make exceptions that create new or

worsen existing violations.

Id.

NRDC’s arguments, while not without merit, fail to

persuade us that during the period at issue in this appeal the

EPA interpreted “any area” in the manner NRDC proposes. 

First, that 40 C.F.R. § 93.101 refers to “a location or region”

does not persuade us that the “area” referenced is the area

immediately adjacent to the expressway as opposed to the

broader project area. Although the EPA clarified the term

“any area” in its 2010 amendments to mean “any portion of

a nonattainment or maintenance area, including the local area

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NRDC V. USDOT 15

affected by the transportation project,” the EPA did not

clearly indicate that this interpretation should apply

retroactively. 75 Fed. Reg. at 14,276; cf. Kankamalage v.

INS, 335 F.3d 858, 862 (9th Cir. 2003) (observing that a

regulation may not apply retroactively unless it

“unambiguously directs retroactive application”).

Nor do we find the language of 40 C.F.R. § 93.123(c)(1)

particularly relevant. To begin with, it is not clear from the

language or structure of this provision whether its

“appropriate receptor locations” requirement applies to all

hot-spot analyses or only the more rigorous quantitative

analyses. Section 93.123(c)(1) is listed as one of several

“General requirements,” but § 93.123(b)(2) explicitly carves

out an exception for qualitative analyses, which “must be

based on a qualitative consideration of local factors.” The

EPA’s own statements and publications also indicate that the

“appropriate receptor locations” provision is inapplicable to

qualitative hot-spot analyses. The qualitative Conformity

Guidance says nothing about “receptors” or “appropriate

receptor locations.” In a 2010 response to public comments,

the EPA noted that it “intends to describe appropriate

receptor locations in its forthcoming quantitative PM hot-spot

guidance.” 75 Fed. Reg. 14,260, 14,282 (Mar. 24, 2010)

(emphasis added). The EPA’s recent quantitative Conformity

Guidance made good on this promise. See EPA,

Transportation Conformity Guidance for Quantitative Hotspot Analyses 113-15 (Nov. 2013) (defining and explaining

appropriate receptor locations).

Finally, the EPA’s 1997 response does not settle the

matter. The response does not discuss hot-spot analysis,

much less the proper application of qualitative PM2.5 hot-spot

analysis. In addition, the response simply reiterates “that

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16 NRDC V. USDOT

transportation projects must not cause or contribute to any

new violation of any standard in any area, or increase the

frequency or severity of any existing violation of any

standard in any area.” 62 Fed. Reg. at 43,798. It does not

interpret the term “any area” or state that the term refers to an

area immediately adjacent to a transportation project. Thus,

the 1997 response does not establish the meaning of the term

“any area” at the time the Defendants issued their Conformity

Determination.

Therefore, the governing regulations do not decisively

answer whether the CAA required qualitative hot-spot

analysis within the immediate vicinity of the project area

during the time period at issue.

3.

The EPA and DOT’s ConformityGuidance implicitly, but

authoritatively, fills this void by interpreting these ambiguous

regulations to permit the type of analysis Defendants

performed here. Although the ConformityGuidance does not

explicitly interpret terms such as “any area,” “a location,” or

“appropriate receptor locations,” the methodological

examples it sets forth make clear that a qualitative PM2.5 hotspot analysis may be performed by analyzing data from an

existing air qualitymonitor in a location similar to the project

area, even if that monitor is not located within the immediate

vicinity of the new project. Because this interpretation is not

“plainly erroneous or inconsistent with the regulation,” Auer,

519 U.S. at 461, we must afford it considerable deference.

The ConformityGuidance, which the two agencies jointly

published in March 2006, was “developed . . . to help state

and local agencies meet the [regulatory] hot-spot analysis

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NRDC V. USDOT 17

requirements.” Conformity Guidance at 2. Indeed, it states

that “future qualitative PM2.5. . . hot-spot analyses should be

based on today’s new guidance.” Id.; see also 71 Fed. Reg.

at 12471 (referring to the Conformity Guidance and stating

that “[q]ualitative PM2.5 hot-spot analyses should be

completed according to joint EPA and DOT guidance”). The

Conformity Guidance “highlights two methods for

completing qualitative PM2.5 . . . analyses,” including one in

which the project sponsor compares the project location to

“another location with similar characteristics.” Conformity

Guidance at 17. The comparison method “involves

reviewing existing highway or transit facilities that were

constructed in the past and built in locations similar to the

proposed project and, whenever possible, near an air quality

monitor (a ‘surrogate’) to allow a comparison of PM2.5. . . air

quality concentrations.” Id.

TheConformityGuidance then provides several examples

of permissible comparisons. Two of these examples suggest

that a project can conform even if it increases PM2.5

concentrations in the area immediately surrounding the

project, and even if the surrogate is in violation of NAAQS. 

In Example A, a project sponsor plans to build a bus terminal

that will “significantly increase diesel bus traffic at the

project’s location.” Id. at 27. The project sponsor measures

PM2.5 emissions in “the vicinity” of a similar, already-existing

bus terminal. Id. The project sponsor also uses a “nearby”

air monitor to determine existing air-quality conditions. Id.

The “similar” bus terminal’s PM2.5 emissions violate NAAQS

standards. Id. However, because the new bus terminal will

include “mitigation measures,” the project sponsor concludes

that the new terminal will conform. Id. In Example B, the

project sponsor plans to modify a highway interchange

“connecting a primary route to an interstate” which will be

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18 NRDC V. USDOT

used by a “significant number of diesel vehicles.” Id. at 28. 

The project sponsor collects air quality information from the

project’s “location.” Id. The project is found to meet the

conformity hot-spot requirements because “any increase in

the emissions due to traffic changes associated with the

project[] would be offset by decreases in the emissions from

the transportation facility.” Id.

Only one published decision has addressed the

Conformity Guidance, but it is well-reasoned and highly

instructive. In Audubon Naturalist Society of the Central

Atlantic States, Inc. v. U.S. Department of Transportation,

524 F. Supp. 2d 642 (D. Md. 2007), environmental advocacy

groups challenged the PM2.5 hot-spot analysis for a highway

project, in part because the project sponsor used an existing

air monitor located outside the immediate vicinity of the

proposed highway. Id. at 701. The district court held that the

regulations governing qualitative PM2.5 hot-spot analyses are

ambiguous and that the Conformity Guidance is entitled to

Auer deference as a reasonable interpretation of those

regulations. Id. at 697–99. The court then noted that the

Conformity Guidance explicitly recommends the “monitor

comparison method,” in which data from “another location

with similar characteristics” is used to project the likely

impact of the new project. Id. at 700. Ultimately, the court

upheld the project sponsors’ analysis, reasoning that the

Conformity Guidance neither mentions a distance

requirement nor requires installation of new air monitors;

rather, it only requires project sponsors to use nearby air

monitors at “locations similar to the proposed project.” Id. at

701 (quoting Conformity Guidance at 17).

We also note that the Federal Highway Administration

(“FHWA”), an agencywithin the DOT, has published several

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NRDC V. USDOT 19

examples of permissible qualitative PM2.5 hot-spot analyses. 

According to FHWA’s website, these are analyses that “could

be replicated in other areas of the country.”4 Two of these

examples—the Woodrow Wilson Bridge and Prairie Parkway

projects—are of particular interest. In the Woodrow Wilson

Bridge hot-spot analysis, the project sponsor based its

estimated PM2.5 concentrations on a surrogate air monitor

twenty miles away from the project site.5 Because the

estimated traffic levels for the Woodrow Wilson Bridge

project were similar to the traffic levels at the surrogate

monitor, and because the surrogate did not violate PM2.5

standards, the sponsor concluded that the project would not

violate PM2.5standards. Id. at 21. Similarly, in the Prairie

Parkway hot-spot analysis, the project sponsor based its

estimated PM2.5 concentrations on a surrogate air monitor

roughly ten miles away from the project site.6 Traffic levels

near the surrogate were similar to estimated traffic levels for

the project, and the surrogate did not violate PM2.5standards.

Id. at 23. Thus, the sponsor concluded that Prairie Parkway

project would not violate PM2.5standards. Id. While we

acknowledge that these examples are less authoritative than

the Conformity Guidance—in part because the studies

4 FHWA, Examples of Transportation Conformity Practices,

http://www.fhwa.dot.gov/environment/air_quality/conformity/practices/

(last visited Sept. 24, 2014).

5 Woodrow Wilson Bridge PM2.5 Conformity Analysis, at 15 (Oct. 2006),

http://www.fhwa.dot.gov/environment/air_quality/conformity/practices/

woodrow_wilson.pdf (last visited Sept. 24, 2014).

6 Fine Particulate Matter (PM2.5

) Project Level Hot-Spot Analysis:

Prairie Parkway Study, ILL. DEP’T OF TRANSP. 9 (Jan. 4, 2008),

http://www.fhwa.dot.gov/environment/air_quality/conformity/practices/

prairie_parkway.pdf (last visited Sept. 24, 2014).

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20 NRDC V. USDOT

themselves were conducted by state agencies—FHWA’s

endorsement providesfurther indication that Defendants were

permitted to rely on a surrogate air monitor outside the

immediate vicinity of the project. See United States v. Mead

Corp., 533 U.S. 218, 234 (2001) (“[A]n agency’s

interpretation maymeritsome deference whatever its form.”);

J.G. v. Douglas Cnty. Sch. Dist., 552 F.3d 786, 797 n.8 (9th

Cir. 2008) (“Although a state agency’s interpretation of

federal law is not entitled to deference, the Secretary’s

approval of that agency’s interpretation is due some deference

because it shows a federal agency’s interpretation of the

federal statute that it is charged to administer.” (citation

omitted)).

NRDC offers no persuasive reason why we should not

rely upon these agency interpretations. Having already

concluded that the language of the CAA and the hot-spot

regulations are ambiguous, we address NRDC’s three

remaining arguments: that the CAA delegates interpretive

authority to the EPA, not FHWA; that the agencies’

interpretations were not adopted through notice-and-comment

rulemaking; and that FHWA’s application of the Conformity

Guidance represents an inconsistent and unexplained change

in policy. NRDC’s first remaining objection makes little

sense. The EPA and DOT, to whom Congress expressly

delegated interpretive authority, jointly published the

ConformityGuidance on which Defendants relied. 42 U.S.C.

§§ 7506(c)(4)(B);EPA, Transportation ConformityGuidance

for Quantitative Hot-spot Analyses 1 (Nov. 2013). Moreover,

FHWA—which performed the hot-spot analysis here and

published examples of permissible qualitative analyses on its

website—is an agency within the DOT that reports to the

Secretary of Transportation.

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NRDC V. USDOT 21

NRDC’s second objection fares no better. We afford

Auer deference to an agency’s interpretation of its own

regulations regardless of whether that interpretation was

adopted through notice-and-comment rulemaking. See, e.g.,

Chase Bank USA, N.A. v. McCoy, 131 S. Ct. 871, 881 (2011)

(deferring to agency’s interpretation of its own regulation that

was advanced in an amicus brief).7

NRDC’s third remaining argument, its objection to the

agency’s purported change in policy, is more properly

analyzed as a challenge to this particular Conformity

Determination, not as a challenge to the agency’s general

interpretation of the permissible methodology for conducting

qualitative hot-spot analyses. We therefore turn to the review

of the Conformity Determination before us.

C.

Having concluded that the agencies’ interpretation of the

appropriate hot-spot analysis governs, it is clear that

Defendants’ Conformity Determination was neither arbitrary

nor capricious.

Defendants performed a qualitative PM2.5 hot-spot

analysis using the comparison method described in the

Conformity Guidance. Defendants chose the North Long

Beach air monitoring station, located roughly five miles away

from the far end of the project, as a surrogate because its

PM2.5 concentrations were “representative of the project

7 NRDC’s reliance on High Sierra Hikers Ass’n v. Blackwell, 390 F.3d

630 (9th Cir. 2004), is misplaced. High Sierra Hikers stands for the

uncontroversial—but inapposite—proposition that an informal agency

interpretation is not entitled to Chevron deference. Id. at 648.

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22 NRDC V. USDOT

area.” To reach this determination, Defendants compared the

North Long Beach station to a second monitoring station

located closer to the project area.8 They found that annual

average daily traffic, trucks as a percentage of all traffic, and

PM2.5 concentrations at the closer station were all similar to

those at the North Long Beach station, and therefore

concluded that “the North Long Beach station reflects the

same traffic conditions as at the project location, and the

monitoring data are shown to be representative of ambient air

quality for the project area.”

Defendants then used the North Long Beach PM2.5 data as

a baseline to estimate the Project’s likely impacts on PM2.5

concentrations. Defendants projected that although the

Project might increase total vehicle miles traveled in

comparison to the no-build alternative, this impact would be

offset by faster vehicle speeds and reduced traffic congestion. 

As a result, Defendants concluded, “PM2.5 emissions of the

build alternatives would be the same or less than the No Build

alternative,” and “[b]ased on the current ambient PM2.5

concentrations in the project area, the project is not expected

to have [a] significant localized PM2.5 concentration increase

when compared to the No Build alternative.” Thus, because

the Project would not cause a new PM2.5 violation, increase

the severity of an existing violation, or delay the

implementation of national air quality standards for PM2.5,

Defendants concluded that the Project conforms to statutory

and regulatory requirements.

Defendants’ Conformity Determination using this

comparison method was a reasonable application of the EPA

8 This closer station was not chosen for the hot-spot analysis because it

was relatively new and thus lacked extensive historical data.

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NRDC V. USDOT 23

and DOT’s Conformity Guidance. The Conformity

Determination compares favorably to the hot-spot analysis

approved in Audubon, as well as to the Woodrow Wilson

Bridge and Prairie Parkway analyses endorsed by the FWHA. 

The Conformity Guidance makes clear that Defendants were

permitted to use a surrogate air monitor, and this monitor’s

distance from the Project—about one mile from the near end

of the Project, and five miles from the far end—was well

within the ranges approved in Audubon and the Woodrow

Wilson and Prairie Parkway examples. In addition,

Defendants used a second air monitor to verify that the North

Long Beach station was representative of air quality in the

project area, further bolstering the accuracy of their

qualitative analysis.

IV.

Under NEPA, federal agencies must prepare an EIS when

considering “major Federal actions significantly affecting the

quality of the human environment.” 42 U.S.C. § 4332(C). 

Federal regulations require that the EIS “provide full and fair

discussion of significant environmental impacts,” 40 C.F.R.

§ 1502.1, as well as “state how alternatives considered in it

and decisions based on it will or will not achieve the

requirements of [NEPA] and other environmental laws and

policies,” id. § 1502.2(d). The EIS’s discussion of

alternatives “should present the environmental impacts of the

proposal and the alternatives in comparative form, thus

sharply defining the issues and providing a clear basis for

choice among options by the decisionmaker and the public.” 

Id. § 1502.14.

Generally, our review is limited to whether the EIS

contains “a reasonably thorough discussion of the significant

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24 NRDC V. USDOT

aspects of the probable environmental consequences.” City

of Carmel-by-the-Sea v. U.S. Dep’t of Transp., 123 F.3d

1142, 1150 (9th Cir. 1997) (internal quotation marks

omitted). “Once satisfied that a proposing agency has taken

a ‘hard look’ at a decision’s environmental consequences, our

review is at an end.” Id. at 1151 (alterations and internal

quotation marks omitted). NRDC contends that Defendants

violated NEPA because their EIS failed to address whether

the potential increase in PM2.5 concentrations would violate

2006 NAAQS standards and failed to fully disclose the

Project’s likely effects on public health.

Contrary to NRDC’s argument, the EIS did not

impermissibly rely on outdated air quality standards. In

2006, the EPA updated the NAAQS standard for PM2.5,

cutting the maximum permissible level to 35 micrograms per

cubic meter. 71 Fed. Reg. at 61,144 (Oct. 17, 2006). These

new standards did not go into effect for transportation

conformity purposes until December 2010, over a year after

the Conformity Determination was completed. See 75 Fed.

Reg. 14260, 14262 (Mar. 24, 2010) (“Transportation

conformity for the 2006 PM2.5 NAAQS does not apply until

December 14, 2010.”).

Further, Defendants correctly contend that the EIS was

forthright in discussing the new standard. For example, the

EIS acknowledged that even though PM2.5levels were below

the old NAAQS standard in the two preceding years, “the

current federal 24-hour PM2.5standard of 35 [micrograms per

cubic meter] was exceeded each year in the past 3 years.” 

The EIS also discussed at length the results of Defendants’ air

quality study, and concluded that any localized increase in

PM2.5 would be offset by reduced vehicle congestion and

idling in the project area as a whole. The EIS also

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NRDC V. USDOT 25

incorporated Defendants’ response to NRDC’s comment on

this point. Defendants noted that according to the results of

the air quality study, “the project will not adversely affect the

human environment by contributing to increased PM2.5

concentrations in the study area or delay attainment of the

NAAQS regardless of whether the study area is subject to the

existing or revised 24-hour NAAQS.”

In addition, Defendants’ EIS adequately disclosed the

Project’s likely health effects. The EIS included a Health

Risk Assessment that was subject to the public comment and

review process. In the Health Risk Assessment, Defendants

disclosed that the Project would lead to increased PM10 and

PM2.5 concentrations in the immediate vicinity of the Project,

and how those increased concentrations could have adverse

health effects for local residents. The Health Risk

Assessment also acknowledged that this type of

transportation project usually leads to increased PM2.5

concentrations in the area immediately adjacent to the project.

Defendants also conducted detailed studies based on

2006-2007 meteorological data, where theyestimated cancerand other health-risk increases at thousands of residences,

schools, parks, and other areas in the immediate vicinity of

the Project. Defendants explained the study results with

color-coded diagrams illustrating the precise locations where

adverse health effects would be the greatest. They also

included statistical discussions and tables illustrating that

roughly 97% of the adverse health affects would be due to

diesel particulate matter concentrations. Additionally,

Defendants determined that a heating, ventilation, and air

conditioning retrofit program for residences within the

vicinity of the significant impact zone would be a feasible

mitigation measure.

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26 NRDC V. USDOT

Because we are satisfied that Defendants took a “hard

look” at the Project’s likely consequences and probable

alternatives, see Carmel-by-the-Sea, 123 F.3d at 1151, we

agree with the district court that the EIS comported with

NEPA requirements.

V.

Defendants’ConformityDetermination did not violate the

CAA, nor did their EIS violate NEPA. Accordingly, we

AFFIRM the district court’s grant of summary judgment.

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