FOR PUBLICATION

UNITED STATES COURT OF APPEALS

FOR THE NINTH CIRCUIT

CENTER FOR COMMUNITY ACTION

AND ENVIRONMENTAL JUSTICE;

EAST YARD COMMUNITIES FOR

ENVIRONMENTAL JUSTICE; NATURAL

RESOURCES DEFENSE COUNCIL, INC.,

Plaintiffs-Appellants,

v.

BNSF RAILWAY COMPANY; UNION

PACIFIC RAILROAD COMPANY,

Defendants-Appellees.

No. 12-56086

D.C. No.

2:11-cv-08608-

SJO-SS

OPINION

Appeal from the United States District Court

for the Central District of California

S. James Otero, District Judge, Presiding

Argued and Submitted

April 8, 2014—Pasadena, California

Filed August 20, 2014

Before: Ferdinand F. Fernandez, N. Randy Smith,

and Mary H. Murguia, Circuit Judges.

Opinion by Judge Murguia
2 CTR. FOR CMTY. ACTION V. BNSF

SUMMARY*

Environmental Law

The panel affirmed the district court’s dismissal of an

action filed by environmental organizations under the citizensuit provision of the Resource Conservation and Recovery

Act, seeking to enjoin the emission from defendants’

railyards of particulate matter found in diesel exhaust.

The panel held that defendants’ emission of diesel

particulate matter did not constitute “disposal” of solid waste

within the meaning of RCRA. Accordingly, plaintiffs could

not state a plausible claim for relief under 42 U.S.C.

§ 6972(a)(1)(B). 

COUNSEL

David Pettit (argued), Melissa Lin Perella, and Morgan

Wyenn, Natural Resources Defense Council, Santa Monica,

California, for Plaintiffs-Appellants.

Mark B. Helm (argued), Henry Weissmann, and Leo

Goldbard, Munger, Tolles & Olson LLP, Los Angeles,

California; Patrick J. Cafferty, Jr., Munger Tolles & Olson

LLP, San Francisco, California; Kevin M. Fong, Pillsbury

Winthrop Shaw Pittman LLP, San Francisco, California;

Mark E. Elliott, Michael R. Barr, Margaret Rosegay, and

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

been prepared by court staff for the convenience of the reader.
CTR. FOR CMTY. ACTION V. BNSF 3

AmyE. Gaylord, Pillsbury Winthrop Shaw Pittman LLP, Los

Angeles, California, for Defendants-Appellees.

OPINION

MURGUIA, Circuit Judge:

In this case, we must decide whether the citizen-suit

provision of the Solid Waste Disposal Act (Resource

Conservation and Recovery Act (RCRA)), 42 U.S.C.

§§ 6901–6992k, may be used to enjoin the emission from

Defendants’ railyards of particulate matter found in diesel

exhaust. RCRA’s citizen-suit provision permits “anyperson”

to sue the owner or operator of a solid waste treatment,

storage, or disposal facility if the owner or operator “has

contributed or . . . is contributing to the past or present

handling, storage, treatment, transportation, or disposal of any

solid or hazardous waste which may present an imminent and

substantial endangerment to health or the environment.” 

42 U.S.C. § 6972(a)(1)(B). We conclude that Defendants’

emission of diesel particulate matter does not constitute

“disposal” of solid waste within the meaning of RCRA, and

that Plaintiffs therefore cannot state a plausible claim for

relief under § 6972(a)(1)(B). We therefore affirm the district

court’s judgment.

I.

Union Pacific Railroad and Burlington Northern Santa Fe

Railway Companies (collectively, “Defendants”) own and

operate sixteen railyards in the State of California. On or

near those railyards, various locomotive, truck, and other

heavy-duty vehicle engines emit tons of diesel particulate
4 CTR. FOR CMTY. ACTION V. BNSF

matter—small, solid particles found in diesel exhaust—into

the air. The California Air Resources Board (CARB) has

identified diesel particulate matter as a toxic air contaminant

with the potential “to cause cancer and other adverse health

problems, including respiratoryillnesses and increased risk of

heart disease.” The Environmental Protection Agency (EPA)

has similarly classified diesel exhaust as likely to be

carcinogenic to humans.

Plaintiffs are environmental organizations whose

members live in the vicinity of Defendants’ railyards.1 They

allege, citing CARB studies, that “over 1.8 million

Californians are at elevated [cancer] risk because of railyard

operations.” Plaintiffs further allege that “people living in

communities close to the source of [diesel particulate]

emissions, such as ports, railyards and intermodal transfer

facilities are likely to suffer greater health impacts and these

impacts will likely add to an existing health burden.” In

2005, according to Plaintiffs, Defendants’ railyards

collectively emitted over 160 tons of diesel particulate matter

into the air.

1 Plaintiffs are the Center for Community Action and Environmental

Justice (CCAEJ), East Yard Communities for Environmental Justice

(EYCEJ), and Natural Resources Defense Council (NRDC). CCAEJ

proclaims itself to be “one of the oldest and most accomplished

environmental health and justice organizations in the nation”; its work

focuses on achieving environmental health and justice in Riverside and

San Bernardino Counties, California. Each of those counties is home to

one railyard or intermodal facility owned by Defendants. EYCEJ is

another California environmental health and justice organization. Its

membership base is located in East Los Angeles, where Defendants’

railyards are also located. NRDC is a national organization dedicated to

environmental justice and public health.
CTR. FOR CMTY. ACTION V. BNSF 5

Accordingto Plaintiffs,Defendants “have allowed and are

allowing [diesel particulate matter] to be discharged into the

air, from which it falls onto the ground and water nearby, and

is re-entrained into the atmosphere.” Plaintiffs acknowledge

that diesel particulate matter is initially emitted into the air as

diesel exhaust, but they contend that the solid particles in the

exhaust are “transported by wind and air currents onto the

land and water.” They allege that the particles are “inhaled

by people both directly and after the particles have fallen to

the earth and then have been re-entrained into the air by wind,

air currents and passing vehicles.”

II.

RCRA’s citizen-suit provision authorizes private persons

to sue “any person . . . who has contributed or who is

contributing to the past or present handling, storage,

treatment, transportation, or disposal of any solid or

hazardous waste which may present an imminent and

substantial endangerment to health or the environment.” 

42 U.S.C. § 6972(a)(1)(B). Invoking that provision, Plaintiffs

sued Defendants in the Central District of California, alleging

that diesel particulates constitute “solid waste and hazardous

waste,” the “handling, storage, treatment, transportation, or

disposal” of which Defendants have contributed or are

contributing to. In their complaint, Plaintiffs sought

injunctive and declaratory relief, asking the district court to

declare Defendants’ activities in violation of RCRA and order

Defendants to take certain control measures to reduce diesel

particulate emissions from their railyards.

Defendants moved to dismiss Plaintiffs’ complaint,

contending that Plaintiffs failed to state a claim under RCRA. 

Specifically, Defendants asserted that the provision of RCRA
6 CTR. FOR CMTY. ACTION V. BNSF

regulating air emissions, 42 U.S.C. § 6924(n), applies to air

pollutants resulting from the burning of fuel “only when the

fuel [itself] consists of or contains ‘solid’ or ‘hazardous’

waste, i.e., a discarded material.”2 All other air emissions,

according to Defendants, fall within the statutory and

regulatory scope of the Clean Air Act, the provisions of

which Plaintiffs do not and cannot invoke.3 Defendants

further argued that, even if Congress had intended RCRA to

apply in this context, Plaintiffs could not prevail because

Defendants did not emit diesel exhaust “into or on any land

or water,” and therefore were not “disposing” of solid waste

within the meaning of RCRA. See 42 U.S.C. § 6903(3)

(defining “disposal” to mean “the discharge, deposit,

injection, dumping, spilling, leaking, or placing of any solid

waste or hazardous waste into or on any land or water so that

[the waste] may enter the environment or be emitted into the

air or discharged into any waters”).

In response to Defendants’ motion to dismiss, Plaintiffs

argued that failing to apply RCRA to the diesel particulates

emitted at Defendants’ railyards would result in a “gap in the

2 Section 6924(n) requires the Administrator of the EPA to promulgate

“regulations for the monitoring and control of air emissions at hazardous

waste treatment, storage, and disposal facilities, including but not limited

to open tanks, surface impoundments, and landfills.” 42 U.S.C. § 6924(n).

3 The Clean Air Act’s citizen-suit provision is more limited than

RCRA’s. Under the Clean Air Act, individuals may bring suit only to

enforce the provisions of a permit or rules promulgated by the EPA. 

42 U.S.C. § 7604(a)(1). RCRA’s provision, by contrast, authorizes suits

against any person who “has contributed or who is contributing to the past

or present . . . disposal of any solid or hazardous waste which may present

an imminent and substantial endangerment to health or the environment,”

42 U.S.C. § 6972(a)(1)(B), whether or not the person sued is complying

with the terms of a permit or regulation.
CTR. FOR CMTY. ACTION V. BNSF 7

[Clean Air Act] when it comes to emissions from railyards.” 

Because, according to Plaintiffs, both the Clean Air Act and

RCRA are intended to apply to mobile sources of air

pollution—including diesel particulate emissions—the two

laws can and should be “harmonized” to fill the regulatory

gap that Plaintiffs contend otherwise results.

The district court granted Defendants’ motion and

dismissed Plaintiffs’ complaint with prejudice. In its order,

the court concluded that the Clean Air Act, and not RCRA,

applies to the emissions from Defendants’ railyards and that

any “gap” that might exist between the two statutory schemes 

“was created through a series of reasoned and calculated

decisions by Congress and the EPA.” As an “independent

reason” for granting the motion to dismiss, the district court

noted that Plaintiffs failed to state a claim under RCRA

because, even if RCRA does apply, “diesel exhaust is not a

‘solid or hazardous waste.’ ” Plaintiffs timely appealed the

district court’s order.

III.

We review de novo a district court’s order granting a

motion to dismiss under Federal Rule of Civil Procedure

12(b)(6). We accept as true the factual allegations in the

complaint and construe those allegations in the light most

favorable to the nonmoving party. Hinds Invs., L.P. v.

Angioli, 654 F.3d 846, 849–50 (9th Cir. 2011). “To survive

a motion to dismiss, a complaint must contain sufficient

factual matter, accepted as true, to ‘state a claim to relief that

is plausible on its face.’ ” Ashcroft v. Iqbal, 556 U.S. 662, 678

(2009) (quoting Bell Atl. Corp. v. Twombly, 550 U.S. 544,

570 (2007)). We will uphold a district court’s decision to

dismiss “where there is either a lack of a cognizable legal
8 CTR. FOR CMTY. ACTION V. BNSF

theory or the absence of sufficient facts alleged under a

cognizable legal claim.” Hinds Invs., 654 F.3d at 850.

To survive a motion to dismiss under RCRA’s citizen-suit

provision, Plaintiffs must plausibly allege that Defendants

have contributed or are contributing to “the past or present

handling, storage, treatment, transportation, or disposal of any

solid or hazardous waste which may present an imminent and

substantial endangerment to health or the environment.” 

42 U.S.C. § 6972(a)(1)(B). In other words, Plaintiffs must

allege, based on a cognizable legal theory, (1) that

Defendants have contributed to the past or are contributing to

the present handling, treatment, transportation, or disposal of

diesel particulate matter; (2) that diesel particulate matter is

a “solid waste”; and (3) that the solid waste that Defendants

emit “maypresent an imminent and substantial endangerment

to health or the environment.”

In their complaint, Plaintiffs allege that Defendants

“dispose” of solid waste—specifically, diesel particulate

matter—by allowing the waste to be “transported by wind

and air currents onto the land and water near the railyards.” 

According to Plaintiffs’ allegations, the particulates are then

“inhaled by people both directly and after the particles have

fallen to the earth and then have been re-entrained into the air

by wind, air currents, and passing vehicles.” They contend

that Defendants violate RCRA by failing to “limit or control

the amount of [diesel particulate matter] generated on and by

the railyards.” Plaintiffs’ allegations, however, even if true,

do not establish that Defendants “dispose” of solid or
CTR. FOR CMTY. ACTION V. BNSF 9

hazardous waste as the term “disposal” is defined under

RCRA.4

Under RCRA, “disposal” means

the discharge, deposit, injection, dumping,

spilling, leaking, or placing of any solid waste

or hazardous waste into or on any land or

water so that such solid waste or hazardous

waste or any constituent thereof may enter the

environment or be emitted into the air or

discharged into any waters, including ground

waters.

42 U.S.C. § 6903(3). Although that definition does not

plainly state whether emissions of solid waste into the air fall

within its scope, it does provide sufficient contextual clues

for us to conclude that they do not. See Food & Drug Admin.

v. Brown & Williamson Tobacco Corp., 529 U.S. 120, 132

(2000) (“The meaning—or ambiguity—of certain words or

phrases may only become evident when placed in context.”). 

4 Plaintiffs do not allege that Defendants contribute or contributed to the

“handling,” “storage,” “treatment,” or “transportation” of solid waste. 

Despite Plaintiffs’ contention at oral argument that they had also alleged

that Defendants contributed to the “handling” of solid waste within the

meaning of § 6972(a)(1)(B), we find nothing in the record to support that

assertion. Indeed, in opposing Defendants’ motion to dismiss, Plaintiffs

stated that “[t]he heart of this case is that Defendants’ railyards contribute

to the disposal of a solid hazardous waste—diesel particulate matter—that

may present an imminent and substantial endangerment to the health of

Plaintiffs’ members.” We therefore focus solely on the question whether

the emission of diesel particulate matter by way of diesel exhaust from

Defendants’railyards constitutes “disposal” within the meaning ofRCRA. 

See Ravell v. United States, 22 F.3d 960, 962 n.2 (9th Cir. 1994)

(declining to consider a claim raised for the first time at oral argument).
10 CTR. FOR CMTY. ACTION V. BNSF

Our conclusion in that respect is consistent with other

provisions of RCRA, and it does not conflict with the

statute’s purposes or its statutory and legislative histories. 

See, e.g., Carson Harbor Vill., Ltd. v. Unocal Corp., 270 F.3d

863, 877 (9th Cir. 2001) (noting that courts resort to

legislative history “even where the plain language is

unambiguous, ‘where the legislative history clearly indicates

that Congress meant something other than what it said’ ”

(quoting Perlman v. Catapult Entm’t, Inc. (In re Catapult

Entm’t, Inc.), 165 F.3d 747, 753 (9th Cir. 1999))).

A.

We begin with RCRA’s text. See Safe Air for Everyone

v. Meyer, 373 F.3d 1035, 1041 (9th Cir. 2004). We note first

that RCRA’s definition of “disposal” does not include the act

of “emitting.” Instead, it includes only the acts of

discharging, depositing, injecting, dumping, spilling, leaking,

and placing. That “emitting” is not included in that list

permits us to assume, at least preliminarily, that “emitting”

solid waste into the air does not constitute “disposal” under

RCRA. See 2A Norman J. Singer & J.D. Shambie Singer,

Sutherland Statutes &StatutoryConstruction § 47:23 (7th ed.

2012) (noting that expressio unius est exclusio alteriusstands

for the proposition that when Congress expresses meaning

through a list, a court may assume that what is not listed is

excluded).

The text of § 6903(3) is also very specific: it limits the

definition of “disposal” to particular conduct causing a

particular result. By its terms, “disposal” includes only

conduct that results in the placement of solid waste “into or

on any land or water.” 42 U.S.C. § 6903(3). That placement,

in turn, must be “so that such solid waste . . . may enter the
CTR. FOR CMTY. ACTION V. BNSF 11

environment or be emitted into the air or discharged into any

waters, including ground waters.” Id. We therefore conclude

that “disposal” occurs where the solid waste is first placed

“into or on any land or water” and is thereafter “emitted into

the air.”

The solid waste at issue here, however, at least as it is

characterized in Plaintiffs’ complaint, is not first placed “into

or on any land or water”; rather, it is first emitted into the air. 

Only after the waste is emitted into the air does it then travel

“onto the land and water.” To adopt Plaintiffs’ interpretation

of § 6903(3), then, would effectively be to rearrange the

wording of the statute—something that we, as a court, cannot

do. Reading § 6903(3) as Congress has drafted it, “disposal”

does not extend to emissions of solid waste directly into the

air.

Other provisions of RCRA further support that

conclusion. The term “release,” for example, which is

defined in the section of RCRA governing underground

storage tanks, includes “spilling, leaking, emitting,

discharging, escaping, leaching, or disposing . . . into ground

water, surface water or subsurface soils.” 42 U.S.C.

§ 6991(8) (emphasis added). “[W]hen Congress includes

particular language in one section of a statute but omits it in

another section of the same Act, it is generally presumed that

Congress acts intentionally and purposely in the disparate

inclusion or exclusion.” Barnhart v. Sigmon Coal Co., 534

U.S. 438, 452 (2002) (internal quotation marks omitted). 

That Congress knew how to define “disposal” to include

emissions, but nonetheless chose not to, counsels against our

reading into the definition of “disposal” conduct that

Congress must have intended to exclude from its reach.
12 CTR. FOR CMTY. ACTION V. BNSF

United States v. Power Engineering Co., 191 F.3d 1224

(10th Cir. 1999), which Plaintiffs cite for the proposition that

“aerosolized solid waste would not lose its character as solid

waste simply because it was disposed of through the air,” is

not to the contrary. In Power Engineering, the Tenth Circuit

decided the question whether defendant Power Engineering

Company was subject to certain financial assurance

provisions of Colorado’s RCRA State Implementation Plan. 

Id. at 1227–28. Power Engineering had been discharging

hexavalent chromium and other hazardous materials into the

soil on its facility’s site, and the materials had then leaked

into the groundwater and made their way into waters of the

Platte River. Id. at 1229, 1231. The court concluded that

disposing of the hazardous mist onto the soil constituted

illegal “disposing of hazardous wastes.” Id. at 1231. 

Contrary to Plaintiffs’ contentions, Power Engineering did

not involve disposal of solid waste “through the air,” and so

does not support the proposition that Plaintiffs attribute to it.5

Plaintiffs additionallycontend that, because RCRA has an

“air emissions” provision, see § 6924(n), “emitting” must fall

within the statute’s reach and therefore may form the basis of

a citizen suit under § 6972(a)(1)(B). Plaintiffs read § 6924(n)

as proof that both RCRA and the Clean Air Act extend to air

emissions. Because that is so, Plaintiffs continue, the two

5 Plaintiffs cite United States v. Apex Oil Co., No. 05-CV-242-DRH,

2008 WL 2945402 (S.D. Ill. July 28, 2008), for a similar proposition, but

that case is likewise inapposite. In Apex Oil, the vapors were disposed of

onto the land, after which they leaked into groundwater and were released

into the air. Citizens Against Pollution v. Ohio Power Co., No. C2-04-

CV-371, 2006 WL 6870564 (S.D. Ohio July 13, 2006), yet another case

that Plaintiffs cite, is the only case that supports their interpretation. 

Because we find the reasoning of Citizens Against Pollution contrary to

RCRA’s text and legislative history, we decline to rely on it.
CTR. FOR CMTY. ACTION V. BNSF 13

statutory schemes should be “harmonized” in a way that

“give[s] effect to both.” Plaintiffs suggest that we

“harmonize” the two laws by reading RCRA’s definition of

disposal to include emissions of solid waste from Defendants’

railyards.

We are not persuaded. Section 6924(n) of RCRA requires

the EPA to promulgate regulations “for the monitoring and

control of air emissions at hazardous waste treatment,

storage, and disposal facilities, including but not limited to

open tanks, surface impoundments, and landfills, as may be

necessary to protect human health and the environment.” 

Although that section clearly contemplates that certain air

emissions will fall within RCRA’s regulatory reach, it does

not provide a private right of action. And § 6972(a)(1)(B),

RCRA’s citizen-suit provision, does not permit individuals to

bring suit to enforce § 6924(n). Thus, the fact that RCRA

permits the EPA to regulate air emissions is not to say that it

provides “any person,” by way of its citizen-suit provision, a

private right of action with respect to those emissions. 

Indeed, as noted earlier, the very existence of § 6924(n)

suggests that Congress, by not including “emitting” in the

actions prohibited under § 6972(a)(1)(B), intended to exclude

it.

Thus, we preliminarily conclude—based on the statute’s

wording considered alone and in context—that emitting

diesel particulate matter into the air does not constitute

“disposal” as that term is defined under RCRA. To the extent

that the definition of “disposal” is ambiguous on this point,

see Citizens Against Pollution, 2006 WL 6870564, at *5

(reaching a different conclusion), the statutory and legislative

histories of both RCRA and the Clean Air Act resolve that

ambiguity. We turn to those histories.
14 CTR. FOR CMTY. ACTION V. BNSF

B.

When the Clean Air Act was enacted in 1963, it left the

task of controlling air pollution largely to the states. See

Clean Air Act, Pub. L. No. 88-206, 77 Stat. 392 (1963). It

was not until 1970, after a comprehensive overhaul of the

Act, that Congress adopted a national system of air quality

standards, emission limits, and other requirements seeking to

“preven[t] and control . . . air pollution at its source.” Clean

Air Act Amendments of 1970, Pub. L. No. 91-604,

§ 101(a)(3). The 1970 amendments required the federal

government, by way of the newly created EPA, to establish

National Ambient Air Quality Standards (NAAQS) for

pollutants that adversely affect public health and welfare, as

well as to establish national emission standards for

“hazardous air pollutants.” §§ 108–09, 112, 84 Stat. 1676,

1678–80, 1685–86. The 1970 amendments also required

states to submit “State Implementation Plans” to “provid[e]

for implementation, maintenance, and enforcement” of the

NAAQS. § 110(a)(1), 84 Stat. at 1680.

Of particular relevance to this case, the legislative history

leading up to the 1970 amendments suggests that Congress

considered, but ultimately did not adopt, a provision that

would have required the EPA to adopt national standards for

emissions from locomotives. See Hearings Before the

Subcommittee on Air and Water Pollution of the Committee

on Public Works, 91st Cong. 139 (1970) (testimony of Robert

H. Finch) (describing the provisions of Senate Bill 3229,

which would have “authorize[d] the Department to establish

national standards for the control of emissions from . . .

locomotives” and noting that although “locomotives . . . are

not major sources of air pollution at this time . . . , we support

the principle of making them subject to emission controls”). 
CTR. FOR CMTY. ACTION V. BNSF 15

Congress also recognized, but similarly opted not to address,

the environmental problem arising from diesel emissions

from heavy-duty trucks and buses. See, e.g., id. at 65

(testimony of John Middleton) (noting that “beginning

January 1, 1970, . . . all new diesel engines will necessarily

comply with a smoke emission standard” but that “[t]he

serious problem is what do you do with the used diesel

vehicle or the used gasoline-fueled vehicle?”).

Six years later, Congress enacted RCRA in an effort to

“solv[e] the problems associated with the 3–4 billion tons of

discarded materials generated each year, and the problems

resulting from the anticipated 8% annual increase in the

volume of such waste.” H.R. Rep. No. 94-1491, at 2 (1976)

(Conf. Rep.).6 The law was intended to “eliminat[e] the last

remaining loophole in environmental law, that of unregulated

land disposal of discarded materials and hazardous wastes.” 

Id. at 4. As its name suggests, the law was intended to

provide “two possible solutions” to the “discarded materials

problem”: (1) “resource conservation[, achieved] by reducing

the amount of waste generated,” and (2) “resource [recovery],

achieved by reclaiming valuable materials from the waste and

thereby reducing the volume to be disposed of.” Id. at 10.

By its terms, RCRA thus governs the disposal of

“discarded materials,” including “solid waste.” The law also

governs “hazardous waste,” which is “a solid waste, or

combination of solid wastes, which because of its quantity,

concentration, or physical, chemical, or infectious

characteristics may” cause, contribute to, or “pose a

6 RCRA was enacted as an amendment to the Solid Waste Disposal Act,

which was originally enacted in 1965. See SolidWaste Disposal Act, Pub.

L. No. 89-212, 79 Stat. 997 (1965).
16 CTR. FOR CMTY. ACTION V. BNSF

substantial present or potential hazard” to human or

environmental health. 42 U.S.C. § 6903(5). RCRA provides

for solid and hazardous waste management, which are “the

systematic [control or] administration of activities which

provide for the collection, source separation, storage,

transportation, transfer, processing, treatment, and disposal

of” solid and hazardous wastes. 42 U.S.C. § 6903(7), (28). 

When RCRA was enacted in 1976, it did not include a

provision regulating air emissions from solid or hazardous

waste disposal facilities.

In 1977, against the backdrop of RCRA’s enactment the

year before, Congress again significantly overhauled the

Clean Air Act. The 1977 overhaul was made in an effort to

provide additional guidance on matters like best available

control technologies, unregulated pollutants, and other issues

that had gone unaddressed in prior versions of the Act. See

H.R. Rep. No. 95-564 (1977) (Conf. Rep.). As part of the

1977 revision, Congress added two provisions relevant to this

case.

The first was a provision requiring the EPA to conduct a

railroad emissions study. In response to industry

recommendations that Congress consider “[f]ederal

regulation of air pollutants emitted from railroad rolling

stock,” Congress requested that the EPA conduct a study to

assess (1) “the extent to which emissions from railroads are

a national problem,” (2) “state of the art of control

technology,” and (3) “the kinds of regulations of emissions

currentlyimposed on railroads byState and local authorities.” 

S. Rep. No. 95-127, at 93 (1977); see also Clean Air Act

Amendments of 1977, Pub. L. No. 95-95, § 404, 91 Stat. 685,

793–94 (calling for a railroad emissions study).
CTR. FOR CMTY. ACTION V. BNSF 17

The second was a series of provisions establishing what

is known as the “indirect source review program.” Those

provisions prohibited the federal government from regulating

any “indirect source,” or any “facility, building, structure,

installation, real property, road, or highway which attracts, or

may attract, mobile sources of pollution,” with the exception

of those that are federally assisted, owned, or operated. Pub.

L. No. 95-95, § 108(e), 91 Stat. at 696. The indirect source

review program permits, but does not require, a state to

regulate indirect sources as part of that state’s Clean Air Act

implementation plan. Id.7

In this case, neither party disputes

that Defendants’ railyards are “indirect sources” within the

meaning of the “indirect source review program” provision.

So, by 1977, the regulation of emissions from

locomotives and railyards was governed solely by the Clean

Air Act. However, under its indirect source review program,

the Clean Air Act prohibited federal regulation of sources like

Defendants’ railyards, leaving regulation of emissions from

those sources entirely to the states. RCRA, for its part,

included no provision regulating air emissions and, indeed,

did not even contemplate the disposal of material into the air;

according to its stated purpose, RCRA was limited to

7 A House Report from 1977 documents a few of the reasons that federal

regulation ofindirect sources of pollution was considered so controversial

at that time: (1) indirect sources do not pollute and therefore shouldn’t be

subject to the Clean Air Act; (2) indirect source control should not be

required before automobile pollution is fully controlled; (3) EPA has no

express statutory authority over indirect sources; (4) “[i]ndirect source

controls are veiled land use controls”; (5) indirect source controls will

only delay development and construction, contributing to unemployment,

inflation, and recession; and (6) indirect source controls will promote

urban sprawl. H.R. Rep. No. 95-294, at 220–21 (1977).
18 CTR. FOR CMTY. ACTION V. BNSF

regulating “land disposal.” See H.R. Rep. No. 94-1491, at 4

(1976) (Conf. Rep.).

That changed in 1984, when Congress amended RCRA to

include a provision regulating air emissions from certain

sources. That provision requires the EPA to “promulgate

such regulations for the monitoring and control of air

emissions at hazardous waste treatment, storage, and disposal

facilities.” Hazardous and Solid Waste Amendments of 1984,

Pub. L. No. 98-616, § 201(n), 98 Stat. 3221, 3233. A Senate

Report summarizing the 1984 amendments sheds some light

on Congress’s intent as to the scope of the emissions

provision:

There is a considerable body of

information indicating that emissions into the

air from hazardous waste facilities pose a

significant threat to health and the

environment. Emissions of volatile chemicals

from treatment, storage and disposal of wastes

have been estimated to be of a similar

magnitude as emissions of the same

compounds from industrial processes. Studies

of hazardous waste surface impoundments

and landfills report that significant quantities

of hazardous constituents in the wastes may

be emitted into the air. . . .

Proposals to regulate emissions from

hazardous waste facilities have been

published on several occasions since the

passage of [RCRA] in 1976. Final regulations

have never been issued. The Agency also has

authority to regulate emissions of hazardous
CTR. FOR CMTY. ACTION V. BNSF 19

air pollutants under the Clean Air Act, but its

performance under that Act has been

appallingly slow.

S. Rep. No. 98-284, at 63 (1983). Thus, with the 1984

amendments, Congress created the first (and only) overlap

between RCRA and the Clean Air Act: regulation of

emissions of hazardous air pollutants from “hazardous waste

treatment, storage, and disposal facilities.”

Congress most recently overhauled the Clean Air Act in

1990. See Clean Air Act Amendments of 1990, Pub. L. No.

101-549, 104 Stat. 2399. During that process, Congress

amended the Act to require the EPA to promulgate

regulations “containing standards applicable to emissions

from new locomotives and new engines used in locomotives.” 

See § 222(a), 104 Stat. at 2500.8 The amended statute

expressly prohibits the states from doing the same: “No State

or any political subdivision thereof shall adopt or attempt to

enforce any standard or other requirement relating to the

control of emissions from . . . [n]ew locomotives or new

 

8

 The provision further states,

Such standards shall achieve the greatest degree of

emission reduction achievable through the application

of technology which the Administrator determines will

be available for the locomotives or engines to which

such standards apply, giving appropriate consideration

to the cost of applying such technology within the

period of time available to manufacturers and to noise,

energy, and safety factors associated with the

application of such technology.

§ 222(a), 104 Stat. at 2500.
20 CTR. FOR CMTY. ACTION V. BNSF

engines used in locomotives.” § 222(b), 104 Stat. at 2502.9

Pursuant to its legislative directive, the EPA promulgated the

“New Locomotive Rule,” 63 Fed. Reg. 18978 (Apr. 16,

1998), and has since promulgated additional rules that apply

to emissions from heavy-duty vehicle engines and nonroad

vehicles. See, e.g., 66 Fed. Reg. 5002 (Jan. 18, 2001)

(Heavy-Duty Highway Rule); 73 Fed. Reg. 37096 (June 30,

2008) (Updated New Locomotive Rule).

Thus, in 1990, regulation of emissions from locomotives

and railyards, which are indirect sources subject to the

indirect source review program, remained governed by the

provisions of the Clean Air Act. By way of the Act’s 1977

and 1990 amendments, regulation of locomotives and

locomotive engines was left exclusively to the EPA, and

regulation of railyards, as indirect sources of air pollution,

was expressly (although permissively) left to the states. 

RCRA applied to neither. The only overlap between the

Clean Air Act and RCRA was in the regulation of emissions

from “hazardous waste treatment, storage, and disposal

facilities.”

* * * * *

The statutory and legislative histories help to resolve any

textual ambiguities in at least two ways. First, they make

clear that RCRA, in light of its purpose to reduce the volume

of waste that ends up in our nation’s landfills, governs “land

disposal.” The Clean Air Act, by contrast, governs air

9 The legislative history suggests that Congress enacted the prohibition

on state regulation in light ofthe “unconstitutional burdens” that such state

efforts “would impose . . . on interstate commerce.” 136 Cong. Rec. H 12,

848 (daily ed. Oct. 26, 1990) (statement of Rep. Dingell).
CTR. FOR CMTY. ACTION V. BNSF 21

pollutants. To that end, the histories confirm our reading of

the RCRA’s text.

Second, the histories further clarify that Defendants’

railyards, as “indirect sources” of air pollution, are excluded

from regulation under both statutory schemes. As we

explained, when RCRA was amended in 1984 to include the

emissions provision on which Plaintiffs rely here, the Senate

Committee on Environment and Public Works noted that the

EPA “has authority to regulate [these emissions] under the

Clean Air Act, but its performance under that Act has been

appallingly slow.” S. Rep. No. 98-284, at 63 (1983). Thus,

the emissions that Congress intended to be governed by the

newly enacted RCRA provision were also, at that time,

governed by the Clean Air Act. Defendants’ railyards,

however, as indirect sources, fell outside the scope of the

Clean Air Act, and therefore must also be excluded from

RCRA’s regulatory reach.

The upshot of that conclusion, of course, is that emissions

such as those at issue here—emissions from indirect sources

like railyards—fall entirely outside the ambit of federal

regulation. On one hand, the Clean Air Act’s indirect source

review program prohibits federal regulation of emissions

from indirect sources; on the other, RCRA, as we interpret it,

likewise does not extend to these emissions. Plaintiffs,

relying on the Supreme Court’s decision in Morton v.

Mancari, take issue with the regulatory “gap” that results and

invite us to fill that gap by “harmonizing” the two statutory

schemes. See 417 U.S. 535, 551 (1974) (“When there are two

acts upon the same subject, the rule is to give effect to both if

possible.” (internal quotation marks omitted)). For two

reasons, we decline the invitation.
22 CTR. FOR CMTY. ACTION V. BNSF

First, the Supreme Court in Morton announced a rule

disfavoring “repeal[s] byimplication,” reiterating instead that

the legislature’s intent to repeal must be clear. Id. at 550. “In

the absence of some affirmative showing of an intention to

repeal, the only permissible justification for a repeal by

implication is when the earlier and later statutes are

irreconcilable.” Id. Under Morton, where two laws govern

the same conduct, a court must identify the degree to which

the two laws “irreconcilably conflict”; only where an

irreconcilable conflict occurs will the court consider the later

law to have impliedly repealed the earlier one. But where, as

here, there is no overlap between the two laws, Morton’s rule

simply does not apply.

But, Morton aside, the second reason we decline to fill the

regulatory “gap” that Plaintiffs contend exists is because we

agree with the district court that any “gap” is the product of

a careful and reasoned decision made byCongress that we are

not at liberty to disturb. The statutory and legislative

histories make clear that Congress, having identified specific

reasons for its decision, intended to exclude indirect sources

from federal regulation. And its reasons for doing so, see

H.R. Rep. No. 95-294, at 220–21, are no less applicable under

RCRA than they are under any other federal law. Congress

was entitled to leave the regulation of indirect sources to the

states, and we defer to its reasoned judgment in doing so.

IV.

We conclude that, by emitting diesel particulate matter

from their railyards and intermodal facilities, Defendants do
CTR. FOR CMTY. ACTION V. BNSF 23

not “dispose” of solid waste in violation of RCRA.10 That

conclusion, in our view, follows relatively clearly from

RCRA’s text; however, to the extent that its text is

ambiguous, RCRA’s statutory and legislative histories

resolve that ambiguity. Thus, Plaintiffs fail to state a

plausible claim for relief under § 6972(a)(1)(B). We

therefore AFFIRM the district court’s judgment.

10 Because we conclude that Defendants do not “dispose” ofsolid waste

in violation of RCRA, we need not reach the parties’ arguments about

whether diesel particulate matter is indeed “solid waste” under 42 U.S.C.

§ 6903(27). Likewise, we do not reach the question whether diesel

particulate matter, if it is a solid waste, “present[s] an imminent and

substantial endangerment to health or the environment.” § 6972(a)(1)(B).