Enforcement of Federal Pollution Control Laws
Congressional research reportApr 27, 2026
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Enforcement of Federal Pollution Control
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April 27, 2026
Congressional Research Service
https://crsreports.congress.gov
R48926
SUMMARY
Enforcement of Federal Pollution Control Laws
Congress has enacted an array of statutes designed to protect the environment and human health
from the impacts of pollution. These laws allow the government, and sometimes private parties,
to pursue enforcement actions against those who violate statutory requirements or prohibitions.
Whether and how the statutes are enforced informs how well they achieve Congress’s legislative
goals. Federal pollution control statutes generally require regulated entities to apply for, obtain,
and abide by permits to conduct certain activities involving potential discharges of pollutants to
the environment. These laws also typically have robust recordkeeping and reporting
requirements, which facilitate government oversight. The U.S. Environmental Protection Agency
(EPA) monitors compliance pursuant to its civil inspection and criminal investigation authorities.
R48926
April 27, 2026
Cassandra J. Barnum
Legislative Attorney
Kate R. Bowers
Supervisory Attorney
Andrew S. Coghlan
Legislative Attorney
EPA and the U.S. Department of Justice (DOJ) typically conduct enforcement actions on behalf
of the federal government. Many statutes also authorize “citizen suits”—lawsuits by nonfederal
actors seeking injunctive relief or penalties with respect to alleged violations. Enforcement
actions generally fall into one of three broad categories: administrative enforcement, civil judicial
enforcement, and criminal enforcement.
Administrative enforcement refers to actions taken by EPA outside the court system. Such actions can include orders to take
corrective action, withdrawal of permits, and imposition of penalties up to certain amounts. These actions require various
degrees of process; some corrective action orders can be issued based on an agency determination that a violation has
occurred, while permit withdrawals or money penalties typically follow a hearing where the accused has an opportunity to
submit evidence to a neutral adjudicator. Administrative enforcement actions are subject to judicial review, allowing courts to
determine whether agencies have acted within the scope of their statutory and constitutional authority. Exercising that power
of review, the Supreme Court recently held that administrative hearings may violate the Seventh Amendment right to trial by
jury, though the effect of that ruling on EPA’s administrative enforcement actions remains unsettled.
Civil judicial enforcement refers to lawsuits against alleged violators filed in federal court by the federal government or by
nonfederal actors, including state and local governments, private citizens, and advocacy groups. Plaintiffs must prove
violations by a preponderance of the evidence, and consequences can include both monetary penalties and injunctive relief
(often involving cleanup of polluted sites or actions to assure prospective compliance). Settlements of civil judicial actions
can be private, out-of-court agreements or can be formalized in a consent decree enforceable by a court. Civil judicial
enforcement cases initiated by nonfederal actors implicate an additional suite of legal considerations that arise under Article
III of the Constitution, which limits federal court jurisdiction to cases or controversies. Unlike the federal government, citizen
suit plaintiffs must demonstrate their “standing” to bring suit by showing that they have suffered a concrete and particularized
injury in fact that is fairly traceable to the alleged violation and redressable by available remedies.
Criminal prosecution is generally reserved for violations committed with a particular degree of intent, or mens rea. Various
environmental statutes criminalize violations committed negligently, knowingly, or willfully. Environmental laws prohibiting
“knowing violation” of a permit or regulatory requirement have led courts to consider whether defendants must be aware
only of their actions or also that their actions violate such requirements. The answer sometimes depends on the subject matter
of the law; courts have found that certain “public welfare offenses” involving hazardous devices or substances can require a
reduced showing of knowledge without offending due process, but courts have disagreed about whether the various
environmental laws fall within this category. Corporations may be liable for environmental crimes based on the actions of
their employees, and certain “responsible corporate officers” may be prosecuted for actions taken by subordinates. Applicable
criminal penalties include jail time, criminal fines, and special conditions of probation.
The executive branch enjoys broad discretion in its enforcement of environmental laws, subject to certain constitutional
constraints. Various policies govern EPA’s and DOJ’s exercise of that enforcement discretion, many of which vary widely
across presidential administrations. Supplemental environmental projects, in which a judicial settlement involves a
commitment to undertake a project benefiting the environment, have been a particular source of controversy in recent years.
To alter the terms of environmental enforcement, Congress may amend underlying statutes to redefine violations, change
who may enforce a statute, or change the penalties and remedies that may be imposed for statutory violations. Congress also
may use its appropriations power to increase or decrease funding for enforcement activities or conduct oversight on changing
enforcement policies and priorities across administrations.
Congressional Research Service
Enforcement of Federal Pollution Control Laws
Contents
Introduction ..................................................................................................................................... 1
Identifying Violations ...................................................................................................................... 4
Types of Federal Enforcement ......................................................................................................... 4
Administrative Enforcement ..................................................................................................... 5
Types of Administrative Enforcement Action ..................................................................... 5
Administrative Enforcement Procedures ............................................................................ 6
Review of Administrative Enforcement Actions ................................................................ 9
Administrative Enforcement and the Seventh Amendment ...............................................11
Civil Judicial Enforcement ...................................................................................................... 13
DOJ’s Role ........................................................................................................................ 14
Legal Standard, Burden of Proof, and Statute of Limitations ........................................... 15
Available Remedies .......................................................................................................... 15
Settlement Agreements and Consent Decrees ................................................................... 17
Citizen Suits ...................................................................................................................... 19
Criminal Enforcement ............................................................................................................. 24
Types of Criminal Provisions in Environmental Laws ..................................................... 25
Title 18 Criminal Offenses ................................................................................................ 26
The Mens Rea Requirement .............................................................................................. 27
Responsible Corporate Officers ........................................................................................ 34
Penalties ............................................................................................................................ 36
Enforcement Discretion and Agency Policy .................................................................................. 39
Enforcement Discretion, Generally ......................................................................................... 40
Limits on Enforcement Discretion .................................................................................... 40
Programmatic Nonenforcement ........................................................................................ 42
Enforcement Policies .............................................................................................................. 43
Strategic Enforcement Priorities ....................................................................................... 44
Supplemental Environmental Projects .............................................................................. 45
Considerations for Congress.......................................................................................................... 47
Changing Enforcement Policies and Priorities ........................................................................ 48
Enforcement by States and Citizens ........................................................................................ 49
Setting Penalties and Defining Remedies ............................................................................... 50
Responding to SEC v. Jarkesy ................................................................................................. 51
Tables
Table A-1. Selected Civil Penalty Provisions in Federal Pollution Control Laws ........................ 53
Table A-2. Selected Citizen Suit Provisions in Federal Pollution Control Laws .......................... 56
Table A-3. Selected Criminal Provisions of Federal Pollution Control Laws ............................... 59
Appendixes
Appendix. Selected Enforcement Provisions ................................................................................ 52
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Enforcement of Federal Pollution Control Laws
Contacts
Author Information........................................................................................................................ 62
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Introduction
Congress has enacted a number of statutes designed to safeguard the environment and human
health by maintaining the integrity of the nation’s land, air, and water. Whether Congress’s goals
for these laws are met depends in part on how the laws are enforced. Generally speaking, these
statutes, referred to herein as “federal pollution control statutes,” prohibit certain types of releases
of pollutants into the environment unless authorized by a permit.1 Such permitting regimes can
apply to various industrial, commercial, and personal activities that risk contaminating the
environment or endangering human health. Discharge of wastewater from industrial activity,
emission of airborne substances from smokestacks, and disposal of hazardous waste are just three
examples of regulated activity that generally can be undertaken only pursuant to a permit issued
under the relevant statutory authority.2 Conducting such prohibited activities without a permit or
in violation of the terms of a permit can give rise to a variety of enforcement actions under federal
pollution control laws. Those laws typically provide that enforcement can be against “any person”
in violation of the statute, where “person” is generally defined to include individuals,
corporations, state and local governments, and the federal government.3 The government or, in
some cases, private citizens can undertake enforcement.4 On the federal level, the U.S.
Environmental Protection Agency (EPA) enforces most of the pollution control statutes, either
alone or in conjunction with the U.S. Department of Justice (DOJ).5
This report provides an overview of what such enforcement entails. It begins with a brief
discussion of how the government uncovers and investigates environmental violations. A
fundamental difficulty for environmental enforcement is that environmental harm can be diffuse,
hard to detect, and harder still to trace back to a single source. Given these challenges, many
environmental laws require the regulated community to self-identify, obtain permits to operate,
and monitor their own operations for compliance with statutory, regulatory, or permit
requirements.6 Agency reviews of required reports, civil inspections, and criminal investigations
complement this self-policing regime.7 In light of the critical role self-reporting plays in these
regulatory regimes, several statutes have penalty provisions specifically targeting failure to
maintain required records or falsifying reports.8
1 See, e.g., Clean Water Act, 33 U.S.C. §§ 1251–1387; Clean Air Act, 42 U.S.C. §§ 7401–7671q. The various
enforcement provisions of laws addressed in this report are listed in Tables A1–A3, infra.
2 Id.; see also Resource Conservation and Recovery Act, 42 U.S.C. §§ 6901–6992. To varying degrees, jurisdictional
limitations within the federal pollution control statutes mean that not all such polluting activities implicate federal
statutory requirements. For example, the Clean Water Act prohibits certain discharges only to “waters of the United
States” and certain publicly owned treatments works. See 33 U.S.C. § 1319. Discharges to other water bodies may
nonetheless be subject to state or local regulation.
3 See, e.g., 33 U.S.C. § 1362(5). The federal government is typically a defendant in civil suits only when sued by a
private citizen, because the government generally cannot criminally prosecute or sue itself; certain administrative
remedies may nonetheless be available. See infra notes 47–48 and accompanying text; see also infra notes 137–139 and
accompanying text.
4 See “Citizen Suits,” infra.
5 Certain statutes addressed herein are enforced by other agencies—often but not always in conjunction with EPA—
such as the U.S. Coast Guard, for the Act to Prevent Pollution from Ships; the U.S. Department of Transportation and
Federal Aviation Administration (FAA), for the Hazardous Materials Transportation Act; or the U.S. Army Corps of
Engineers, for certain parts of the Clean Water Act.
6 See David M. Uhlmann, Prosecutorial Discretion and Environmental Crime, 38 HARV. ENV’T L. REV. 159, 197–98
(2014).
7 See “Identifying Violations,” infra.
8 See, e.g., 33 U.S.C. § 1319(c)(4); 42 U.S.C. § 6928(d)(3).
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Selected Pollution Control Law Names and Acronyms9
Act to Prevent Pollution from Ships (APPS)
Clean Air Act (CAA)
Clean Water Act (CWA)
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)
Emergency Planning and Community Right-to-Know Act (EPCRA)
Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA)
Hazardous Materials Transportation Act (HMTA)
Marine Protection, Research, and Sanctuaries Act (MPRSA)
Resource Conservation and Recovery Act (RCRA)
Safe Drinking Water Act (SDWA)
Toxic Substances Control Act (TSCA)
This report then addresses the legal enforcement mechanisms available under the federal
pollution control statutes: administrative actions, civil judicial suits by the government and by
private citizens, and criminal prosecutions.
•
•
•
Administrative enforcement refers to actions agencies take without going
through the courts, which can result in penalties, permit withdrawals, or orders to
do (or not do) certain things.10
Civil judicial enforcement refers to DOJ filing lawsuits in federal court by DOJ
on behalf of EPA to enforce statutory prohibitions or requirements or to compel
compliance with administrative orders; such lawsuits can result in financial
penalties or injunctive relief.11 The federal government may pursue civil judicial
enforcement actions under all the pollution control statutes, and several such laws
also allow private citizens to initiate civil judicial enforcement actions.12
Criminal enforcement is available under most pollution control statutes when
offenses are committed with a certain degree of intent, exposing violators to
criminal prosecution, fines, and potential prison time.13 While administrative and
civil judicial enforcement generally can result from unwitting conduct or
accidents, essentially resulting in a strict-liability regime,14 criminal penalties
typically apply in cases where violations are committed with a specific mental
state.15
Next, this report discusses the enforcement discretion that executive branch officials wield when
undertaking enforcement action and the policies that EPA and DOJ have adopted to guide the
9 This list, presented in alphabetical order, includes statutes referenced in this report and does not encompass every
potential federal statute governing pollution.
10 See “Administrative Enforcement,” infra.
11 See “Civil Judicial Enforcement,” infra.
12 Id.
13 See “Criminal Enforcement,” infra.
14 Pollution control laws typically define violations, and establish civil liability, without regard to the violator’s mental
state. See, e.g., 7 U.S.C. §§ 136a, 136l (FIFRA); 15 U.S.C. §§ 2614, 2615(a)(1), 2689 (TSCA); 33 U.S.C. § 300h-2(a)–
(c) (SDWA); id. §§ 1311(a), 1319(a)–(b) (CWA); id. §§ 1411(a)–(b), 1415(a) (MPRSA); 42 U.S.C. § 7413(a)–(b)
(CAA); id. § 6928(a)(3), (g), (h)(2) (RCRA); id. § 11045(b)(1)–(3) (EPCRA); see also Burlington N. & Santa Fe Ry.
Co. v. United States, 556 U.S. 599, 608 (2009) (noting that “CERCLA imposes strict liability for environmental
contamination”).
15 See “The Mens Rea Requirement,” infra.
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exercise of that discretion. While Congress enacts the laws governing pollution control, the
executive branch typically enjoys broad discretion with respect to when and how those laws are
enforced.16 Limited resources may preclude universal enforcement, and both the executive branch
and Congress, via its appropriations power, have a role to play in targeting enforcement efforts.17
The report concludes with several considerations for Congress, including options to address
changing executive branch enforcement policies and priorities, the role of enforcement by
nonfederal actors, the scope of available remedies and penalties, and the availability of
administrative enforcement in light of recent Supreme Court jurisprudence.
The pollution control statutes discussed in this report are a subset of the broader class of federal
environmental laws, which include wildlife protection measures such as the Endangered Species
Act,18 natural resource and land-use measures such as the Outer Continental Shelf Lands Act,19
and procedural measures such as the National Environmental Policy Act.20 This report focuses on
the pollution statutes listed in Table A-1, Table A-2, and Table A-3 as a framework for
discussion, but many of the issues discussed herein may be applicable to the wider canon of
federal environmental law.
Many pollution control laws authorize states to implement national standards pursuant to an EPAapproved state-law program that satisfy certain minimum federal requirements. Under this
“cooperative federalism” approach,21 state environmental protection agencies often take the lead
in issuing permits under federal pollution statutes, conducting inspections, and pursuing certain
enforcement measures under federal and state law.22 These pollution control statutes afford states
significant discretion in choosing how to structure and implement their programs, which can vary
considerably. While state agencies can play an important role in certain states’ enforcement
schemes, this report is limited in scope to enforcement of federal pollution control laws by the
federal government or through citizen suits in federal court.
This report also focuses on affirmative enforcement actions taken in response to alleged
violations of statutory or regulatory prohibitions or requirements. Some claims brought by private
individuals in citizen suits may allege that EPA is failing to perform a statutorily mandated duty.
Although this type of claim could fairly be characterized as a type of “enforcement,” such
lawsuits raise a unique set of legal considerations and are beyond the scope of this report.
Likewise, this report does not address remedial provisions of the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA) that apportion cleanup costs through a
no-fault liability scheme but do not proscribe conduct.23
16 See infra.
17 Id.
18 16 U.S.C. §§ 1531–1544.
19 43 U.S.C. §§ 1331–1356.
20 42 U.S.C. §§ 4321–4347.
21 See CRS Legal Sidebar LSB11309, Cooperative Federalism and the Clean Air Act: EPA’s Good Neighbor Interstate
Air Pollution Rule, by Kate R. Bowers (2025) (describing role of cooperative federalism in environmental law).
22 See Memorandum from Lawrence E. Starfield, Acting Assistant Adm’r, Off. of Enf’t and Compliance Assurance
(OECA), EPA, to Reg’l Adm’rs et al., Effective Partnerships Between EPA and the States in Civil Enforcement and
Compliance Assurance 1 (June 21, 2023), https://www.epa.gov/system/files/documents/202306/effectivepartnershipsbetweenepaandthestatesincivilenforcementandcomplianceassurance062123.pdf
[https://perma.cc/GKV4-GTU2].
23 For an overview of CERCLA’s remedial liability scheme, see CRS In Focus IF11790, Liability Under the
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), by Kate R. Bowers (2021).
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Identifying Violations
Enforcement begins with identifying violations, which can consist of unpermitted or otherwise
illegal pollution activity, pollution activity in violation of a permit, and recordkeeping violations,
among other things. EPA compliance-monitoring activity includes on-site inspections and off-site
review of data.24 Civil inspections consist of site visits to evaluate compliance by means of
observation, document review, interviews, and/or sampling activity.25 Inspection results, record
reviews, or civilian complaints indicating “serious, widespread, and/or continuing civil
violations” may trigger more in-depth civil investigations that can include enforceable written
information requests.26
EPA also has a Criminal Investigation Division, whose law enforcement officers are authorized
under federal law to carry firearms, serve and execute search and seizure warrants and other
forms of legal process, and make arrests.27 In conjunction with DOJ, any suspected criminal
violation can be opened as a matter before a federal grand jury, authorizing issuance of subpoenas
to compel documents and testimony.28
EPA can also learn of violations by way of tips, whether from whistleblower employees or from
the public.29 Certain statutes allow for awards up to a maximum dollar amount to tipsters whose
information results in successful enforcement actions,30 while the Act to Prevent Pollution from
Ships allows courts, in their discretion, to award whistleblowers up to half the amount of any civil
or criminal penalty imposed as a result of their information.31
EPA’s audit policy establishes conditions under which voluntary self-disclosure of violations can
result in civil penalty mitigation or a determination not to pursue a criminal case.32
Types of Federal Enforcement
Federal environmental enforcement falls into three broad categories: administrative enforcement,
civil judicial enforcement, and criminal enforcement.
24 Monitoring Compliance, EPA (Mar. 17, 2026), https://www.epa.gov/compliance/monitoring-compliance
[https://perma.cc/4PNE-YGH7].
25
Id.
26 Id.
27 See 18 U.S.C. § 3063.
28 See FED. R. CRIM. P. 6, 17.
29 See EPA, Report Environmental Violations, ENF’T & COMPLIANCE HIST. ONLINE, https://echo.epa.gov/reportenvironmental-violations [https://perma.cc/5UNF-869X] (last visited Apr. 27, 2026).
30 See, e.g., 42 U.S.C. § 7413(f) (CAA) (“The Administrator may pay an award, not to exceed $10,000, to any person
who furnishes information or services which lead to a criminal conviction or a judicial or administrative civil penalty
for any violation . . . under this section.”); 42 U.S.C. § 9609(d) (CERCLA) (authorizing $10,000 award to “any
individual who provides information leading to the arrest and conviction of any person for a violation subject to a
criminal penalty under this chapter”).
31 See 33 U.S.C. § 1908(a) (“In the discretion of the Court, an amount equal to not more than ½ of such fine may be
paid to the person giving information leading to conviction.”); see also id. § 1908(b)(2) (enforcing agencies may award
up to half of civil penalties to person giving information leading to penalty assessments).
32 See EPA’s Audit Policy, EPA (Oct. 8, 2025), https://www.epa.gov/compliance/epas-audit-policy
[https://perma.cc/WLP5-UTFP].
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Administrative Enforcement
In administrative enforcement actions, agencies exercise statutory authority to determine whether
violations have occurred and what statutorily authorized administrative remedies are appropriate
to address those violations. Agencies typically make these determinations using procedures that
are simpler and faster than civil litigation in federal court.33 By case volume, the vast majority of
EPA’s civil enforcement activity is administrative: the agency initiates more than 10 new
administrative enforcement actions for every new civil judicial enforcement action.34
EPA decides whether and how to exercise its administrative enforcement authority, but those it
targets can seek judicial review.35 Courts thus ensure that EPA acts within the bounds of its
statutory and constitutional authority. Courts also play an essential role in enforcing compliance
with EPA’s administrative directives: While EPA can issue administrative orders or assess
penalties, the agency’s main recourse against noncompliant entities is to bring suit.36
Types of Administrative Enforcement Action
Pollution control statutes authorize EPA to pursue three administrative enforcement responses to
suspected violations.
First, most statutes allow EPA to issue administrative compliance orders that direct entities to take
corrective actions necessary to cure alleged violations and remedy environmental harms, usually
within a specified time frame.37 This authority is often, though not always, predicated on a
finding that the violation in question poses an “imminent and substantial endangerment” to public
health or the environment.38 If a party fails to comply with EPA’s administrative orders, it may be
liable for civil penalties in a subsequent administrative or civil judicial enforcement action.39
33 See Todd S. Aagard, Agencies, Courts, First Principles, and the Rule of Law, 70 ADMIN. L. REV. 771, 786 (2018)
(noting that “agencies are able to create processes that, through specialization and routinization, make decisions with
greater speed and at lower cost than courts do”).
34 See EPA, ENFORCEMENT AND COMPLIANCE ASSURANCE ANNUAL RESULTS FOR FISCAL YEAR 2024, at 168 (2024),
https://www.epa.gov/system/files/documents/2025-03/eoy2024.pdf [https://perma.cc/CKC4-3S9W] (noting 60 new
complaints in civil judicial enforcement actions, as compared with new 987 complaints seeking administrative
penalties); EPA, ENFORCEMENT AND COMPLIANCE ASSURANCE ANNUAL RESULTS FOR FISCAL YEAR 2023, at 106 (2023),
https://www.epa.gov/system/files/documents/2025-03/eoy2023.pdf [https://perma.cc/32TS-SFSP] (noting 79 new
complaints in civil judicial enforcement actions, as compared with 912 complaints seeking administrative penalties).
Some commentators have observed that the ratio of administrative to civil judicial enforcement actions has grown
substantially in the first year of the second Trump Administration, though EPA’s most recent annual report does not
include comparative data on newly filed actions. See ENV’T INTEGRITY PROJECT, DECLINING ENVIRONMENTAL
ENFORCEMENT IN TRUMP’S SECOND TERM (2026), https://environmentalintegrity.org/wp-content/uploads/2026/02/
EIP_Report_2025EnvironmentalEnforcement_2.5.26.pdf [https://perma.cc/SHV5-9UHB].
35 See “Civil Judicial Enforcement,” infra.
36 Id.
37 See, e.g., 7 U.S.C. § 136k(a) (FIFRA); 33 U.S.C. § 1319(a)(3) (CWA); 42 U.S.C. § 6928(a)(1) (RCRA); id.
§ 7413(a)(1) (CAA), id. § 9606(a) (CERCLA), id. § 11045(a) (EPCRA).
38 See, e.g., 42 U.S.C. § 9606(a) (authorizing “such orders as may be necessary to protect public health and welfare and
the environment” when “an actual or threatened release of a hazardous substance” poses an “imminent and substantial
endangerment”); id. § 6973 (authorizing similar orders to respond to an “imminent and substantial endangerment”
related to solid or hazardous waste); id. § 7603 (authorizing similar orders to respond to an imminent and substantial
endangerment related to air pollution); id. § 300i(a) (authorizing similar orders to respond to an “imminent and
substantial endangerment” related to a contaminant that “is present in or is likely to enter a public water system”).
39 See infra notes 41 and 129 and accompanying text.
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Second, some statutes authorize EPA to withdraw certain permits from noncompliant
permittees.40
Third, most statutes authorize EPA to order payment of administrative penalties to punish and
deter noncompliance, including, in some cases, noncompliance with EPA’s own administrative
compliance orders.41 These statutes set maximum penalty amounts, which are adjusted for
inflation (see Table A-1).42 Current maximum penalties vary across statutes, but most are
between $20,000 and $70,000 per violation.43 EPA does not have to seek maximum penalties,
however, and many statutes identify factors that EPA must consider when determining
appropriate penalties in a given case.44 These statutory penalty factors may include, for example,
“the nature, circumstances, extent and gravity of the violation, or violations, and, with respect to
the violator, ability to pay, any prior history of such violations, the degree of culpability, and
economic benefit or savings (if any) resulting from the violation.”45 Statutory penalties are often
assessed for each day that a violation persists, but some statutes cap the aggregate penalties that
EPA can collect through administrative action and require the agency to bring a civil judicial
action to seek penalties that exceed those caps.46
The federal government is generally subject to requirements under pollution control statutes, and
EPA has statutory authority to issue administrative orders and assess administrative penalties
against federal facilities that violate the CAA, RCRA, and SDWA.47 EPA lacks that authority
under the CWA, TSCA, FIFRA, and EPCRA.48
Administrative Enforcement Procedures
The procedures that EPA must follow when bringing an administrative enforcement action
generally depend on the administrative remedy that the agency pursues. For instance, several
statutes authorize EPA to issue administrative compliance orders without first obtaining
information from violators or the public, or proving to a neutral adjudicator that a violation has
occurred. To illustrate, the CWA and CAA both authorize EPA to issue orders if the agency
believes, based on “any information available to” the Administrator, that a violation has
40 E.g., 33 U.S.C. § 1415(f); 42 U.S.C. § 6928(a)(3).
41 See, e.g., 7 U.S.C. § 136l(a)(1) (FIFRA); 15 U.S.C. §§ 2615(a)(2)(A), 2647(a) (TSCA); 33 U.S.C. §§ 1319(g)(2)(A)–
(B), 1321(b)(6)(B)(i)–(ii) (CWA); 42 U.S.C. §§ 6928(a)(3), 6928(c), 6928(h)(2) (RCRA); id. §§ 7413(d)(1), 7524(c)(1)
(CAA); id. § 9609(a) (CERCLA); id. § 11045(b)(1)–(2) (EPCRA).
42 Federal Civil Penalties Inflation Adjustment Act of 1990, Pub. L. No. 114-74, § 5, 104 Stat. 890, 891–92 (codified as
amended at 28 U.S.C. § 2461 note).
43 40 C.F.R. § 19.4, tbl. 1 (2025).
44 E.g., 15 U.S.C. § 2615(a)(2)(A)–(B); 33 U.S.C. § 1319(g)(3); 42 U.S.C. §§ 7413(e), 9609(a)(3).
45 33 U.S.C. § 1319(g)(3).
46 See e.g., 33 U.S.C. § 1319(g)(1)–(2) (capping CWA administrative penalties); 42 U.S.C. § 300h-2(c)(1)–(2) (capping
SDWA administrative penalties); cf. 42 U.S.C. § 7413(d)(1) (capping CAA administrative penalties at $200,000, unless
“the Administrator and the Attorney General jointly determine that a matter involving a larger penalty amount . . . is
appropriate for administrative penalty action”); accord id. § 7524(c)(1).
47 Overview of the Enforcement Process for Federal Facilities, EPA, (May 6, 2025),
https://www.epa.gov/enforcement/overview-enforcement-process-federal-facilities [https://perma.cc/4C9Q-Y6DQ].
48 Id.
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occurred.49 Similarly, RCRA authorizes EPA to issue orders if the Administrator “has reason to
believe” that violations have occurred.50
By contrast, when statutes authorize EPA to withdraw permits or order payment of monetary
penalties, they typically require the agency to provide an opportunity for the accused to submit
evidence at a hearing.51 Some of these statutes also require EPA to conduct its hearings in
accordance with the Administrative Procedure Act’s (APA’s) rules for “formal adjudications.”52
Those rules require trial-like adversarial proceedings before agency heads or administrative law
judges (ALJs), who weigh evidence, determine whether a violation occurred, and decide what
remedy is warranted53—powers that the Supreme Court has described as “functionally
comparable” to those exercised by Article III judges presiding over bench trials.54
EPA’s hearings are governed by the agency’s Consolidated Rules of Practice, which are codified
at 40 C.F.R. Part 22.55 These regulations establish procedures for the presentation of evidence,
including the examination and cross-examination of witnesses.56 They also designate ALJs as
presiding officers for hearings that are subject to the APA’s “formal adjudication” procedures and
regional judicial officers (RJOs) as the presiding officers for hearings that are not subject to those
procedures.57 RJOs and ALJs perform similar functions, but ALJs are subject to several APAmandated limits designed to ensure their impartiality.58 For instance, unlike RJOs,59 ALJs cannot
49 33 U.S.C. § 1319(a)(3); 42 U.S.C. § 7413(a)(1); see also Tenn. Valley Auth. v. Whitman, 336 F.3d 1236, 1241 (11th
Cir. 2003) (holding that the CAA’s “language and structure, in addition to agency practice, make clear that [compliance
orders under the CAA] are issued without any adjudication”).
50 7 U.S.C. § 136k; see also 42 U.S.C. §§ 6928(a)(1), 11045(a) (authorizing issuance of administrative orders without a
hearing under RCRA and EPCRA, respectively). But see 42 U.S.C. § 6991e (requiring EPA to provide an opportunity
for a hearing before issuing a compliance order addressing violations of RCRA’s requirements for underground storage
tanks); id. § 9613(k)(2)(B) (requiring EPA, as the President’s designee, to seek public comment before ordering a
remedial action under CERCLA to address releases of hazardous waste).
51 E.g., 7 U.S.C. 136l(a)(3); 33 U.S.C. §§ 1319(g)(2)(A), 1321(b)(6)(B)(i), 1415(a), (f); 42 U.S.C. §§ 300g-3(g)(B),
300h-2(c)(3). But see 42 U.S.C. § 6925(d) (authorizing EPA to revoke certain permits under RCRA without holding a
hearing).
52 E.g., 15 U.S.C. § 2615(a)(2)(A); 33 U.S.C. §§ 1319(g)(2)(B), 1321(b)(6)(B)(ii), 42 U.S.C. §§ 300j-6(b)(3), 6928(b),
7413(d)(2), 7524(c)(1), 9609(a)(2), (5), 11045(b)(2), 14304(e). The APA establishes baseline procedural requirements
that federal agencies must follow when taking various actions, including adjudication. 5 U.S.C. §§ 551(6)–(7), 554,
556–57. See also CRS Report R46930, Informal Administrative Adjudication: An Overview, by Ben Harrington and
Daniel J. Sheffner (2021).
53 5 U.S.C. §§ 556(b)–(c), 557(b).
54 Butz v. Economou, 438 U.S. 478, 481–82 (1978).
55 For summaries and interpretations of the Consolidated Rules of Practice, see EPA, GUIDE TO THE U.S.
ENVIRONMENTAL PROTECTION AGENCY’S ENVIRONMENTAL APPEALS BOARD (2025), https://www.epa.gov/system/files/
documents/2026-01/guide-to-the-eab-2025.pdf [https://perma.cc/C7EZ-JMHM] [hereinafter EAB GUIDE]; Joseph F.
Guida & Jean M. Flores, From Here to a Penalty: Anatomy of EPA Civil Administrative Enforcement, 43 TEX. ENV’T.
L.J. 129 (2013); Joseph J. Lisa, EPA Administrative Enforcement Actions: An Introduction to the Consolidated Rules of
Practice, 24 TEMP. J. SCI. TECH. & ENV’T. L. 1 (2005).
56 40 C.F.R. pt. 22, subpt. D.
57 40 C.F.R. §§ 22.3; 22.19; 22.22–22.24; see also EPA, Regional Judicial Officers, EPA ADMIN. ENFORCEMENT
DOCKETS (Apr. 17, 2026), https://yosemite.epa.gov/oa/rhc/epaadmin.nsf/e2d1f35fbb02bc3f8525753f006961b0/
7c1126a0949e9ab28525764f006dbae4!OpenDocument [https://perma.cc/LCM5-GBWL] (discussing the roles of ALJs
and RJOs under the Consolidated Rules of Practice).
58 5 U.S.C. §§ 554(d)(1)–(2), 557(d), 7521; see also Ramspeck v. Fed. Trial Exam’rs Conf., 345 U.S. 128, 130 (1953)
(discussing the APA’s legislative history and describing the statute’s protections for ALJs as a congressional response
to “complaint[s]” that early New Deal hearing examiners “were mere tools of the agency concerned and subservient to
the agency heads in making their proposed findings of fact and recommendations”).
59 KENT BARNETT ET AL., ADMIN. CONF. OF THE U.S., NON-ALJ ADJUDICATORS IN FEDERAL AGENCIES: STATUS,
(continued...)
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perform investigative or prosecutorial functions, cannot report to an employee who does,60 and
can be removed from their role “only for good cause established and determined by the Merit
Systems Protection Board on the record after opportunity for hearing before the Board.”61
Under the Consolidated Rules of Practice, EPA must establish liability by a “preponderance of the
evidence,” the “most common” burden of proof “in the civil law.”62 To carry that burden in an
administrative hearing, EPA must persuade the presiding ALJ or RJO “that a proposition is more
likely true than not true.”63
At least one pollution control law limits the time in which EPA can bring an administrative
enforcement action,64 but absent such a statute-specific limitation period, EPA’s authority to seek
administrative penalties is subject to the general statute of limitations codified at 28 U.S.C.
§ 2462.65 Under that law, “an action, suit or proceeding for the enforcement of any civil fine,
penalty, or forfeiture, pecuniary or otherwise, shall not be entertained unless commenced within
five years from the date when the claim first accrued.”66
In the environmental enforcement context, courts have held that a claim accrues at the time of the
violation, not when the government learns of that violation.67 The impact of this timing rule
depends, in part, on the nature of the violation at issue. Congress has defined some violations—
illegal ocean dumping, for example—to recur each day that the violation persists.68 For these
types of “continuing” violations, EPA can seek administrative penalties based on any conduct that
occurred within the past five years, even if the violative conduct began more than five years
ago.69 Conversely, courts have held that other violations—the failure to obtain a required CAA
SELECTION, OVERSIGHT, AND REMOVAL 1, 45–46 (2018), https://www.acus.gov/document/non-alj-adjudicators-federalagencies-status-selection-oversight-and-removal-final-report [https://perma.cc/VA6A-5972?type=image].
60 5 U.S.C. § 554(d)(1)–(2).
61 5 U.S.C. § 7521. The APA’s tenure protections for ALJs have been the subject of judicial scrutiny and courts are
divided on whether those protections are constitutional. Compare Decker Coal Co. v. Pehringer, 8 F.4th 1123, 1133–35
(9th Cir. 2021), Rabadi v. DEA, 122 F.4th 371, 374–77 (9th Cir. 2024), cert. denied, 145 S. Ct. 2846 (2025), Leachco,
Inc. v. Consumer Prod. Safety Comm’n, 103 F.4th 748, 764 (10th Cir. 2024), cert. denied, 145 S. Ct. 1047 (2025), and
Walmart, Inc. v. Chief Admin. L. Judge of Off. of Chief Admin. Hearing Officer, 144 F.4th 1315, 1342–48 (11th Cir.
2025) (holding that removal protections are constitutional), with Jarkesy v. SEC, 34 F.4th 446, 464 (5th Cir. 2022),
aff’d on other grounds and remanded, 603 U.S. 109 (2024), and VHS Acquisition Subsidiary No. 7 v. NLRB., 759 F.
Supp. 3d 88, 92–100 (D.D.C. 2024) (holding that removal protections are unconstitutional).
62 Concrete Pipe & Prods. of Cal., Inc. v. Constr. Laborers Pension Tr. for S. Cal., 508 U.S. 602, 622 (1993).
63 United States v. Watkins, 10 F.4th 1179, 1185 (11th Cir. 2021) (quoting United States v. Deleveaux, 205 F.3d 1292,
1296 n.3 (11th Cir. 2000)).
64 42 U.S.C. § 7413(d)(1) (limiting EPA’s administrative penalty authority under the CAA to actions where “the first
alleged date of violation occurred no more than 12 months prior to the initiation of the administrative action, except
where the Administrator and the Attorney General jointly determine that a matter involving a . . . longer period of
violation is appropriate for administrative penalty action”).
65 See 3M Co. v. Browner, 17 F.3d 1453, 1457 (D.C. Cir. 1994) (holding that an administrative action seeking penalties
is “an action, suit or proceeding” subject to 28 U.S.C. § 2462’s five-year limitations period).
66 28 U.S.C. § 2462. The same statute of limitations governs the civil judicial enforcement actions discussed later in
this report. See Coghlan v. Nat’l Transp. Safety Bd., 470 F.3d 1300, 1305 (11th Cir. 2006) (“Section 2462 encompasses
not only judicial proceedings, but also administrative proceedings that fall within the scope of its language.”).
67 E.g., 3M Co., 17 F.3d at 1460–63; accord United States v. Core Lab’ies, Inc., 759 F.2d 480, 482–84 (5th Cir. 1985);
see also Gabelli v. SEC, 568 U.S. 442, 447–48 (2013) (The “‘standard rule’ is that a claim accrues” under 28 U.S.C.
§ 2462 “when the plaintiff has a complete and present cause of action.” (quoting Wallace v. Kato, 549 U.S. 384, 388
(2007))).
68 33 U.S.C. §§ 1415(c), 1908(b).
69 See United States v. Midwest Generation, LLC, 720 F.3d 644, 647 (7th Cir. 2013) (noting that “Congress sometimes
writes regulatory statutes” so “that every day” of violation “is a fresh violation” of the statute).
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construction permit, for example—occur at a discrete point in time.70 Even if these violations are
never corrected, EPA must act within five years of the date of violation if it wants to secure
administrative penalties.71
Because 28 U.S.C. § 2462’s general limitations period applies only to actions seeking “fine[s],
penalt[ies], or forfeiture[s],” it does not limit injunctive remedies that require parties to take or
refrain from taking certain actions but that entail no monetary penalty or asset forfeiture and are
not punitive.72 Still, in litigation between private parties, courts typically withhold injunctive
relief if monetary penalties for the same underlying conduct are time-barred. While the Supreme
Court has never decided whether this rule—known as the concurrent remedies doctrine—applies
to the government, it has held that “an action on behalf of the United States in its governmental
capacity . . . is subject to no time limitation, in the absence of congressional enactment clearly
imposing it.”73 Heeding that admonition, circuit courts to consider the issue have held that the
federal government is not subject to the concurrent remedies doctrine.74 EPA thus generally
appears to be free to seek injunctive remedies even when 28 U.S.C. § 2462 precludes monetary
penalties.
Review of Administrative Enforcement Actions
The parties that EPA targets in administrative enforcement actions can challenge EPA’s authority
to act against them. When, where, and how they may do so depends on the type of enforcement
proceeding at issue, and, potentially, on the legal basis of their challenge.
Judicial Review of Administrative Compliance Orders Issued Without a Hearing
As noted above, several pollution control statutes authorize EPA to issue administrative
compliance orders without providing an opportunity for a hearing. For decades, lower courts
declined to review those orders unless and until EPA sued to enforce them.75 In Sackett v. EPA,
the Supreme Court rejected this approach, holding that recipients of EPA’s administrative
compliance orders could challenge those orders immediately under the APA rather than waiting
for EPA to bring suit.76
70 See, e.g., United States v. EME Homer City Generation, L.P., 727 F.3d 274, 284–85 (3d Cir. 2013) (holding that
violations of 42 U.S.C. § 7454(a) are complete when owners of major source of air pollution commence construction or
modification without a required permit in hand); accord United States v. Luminant Generation Co., L.L.C., 905 F.3d
874, 884 (5th Cir. 2018), reh'g en banc granted, 929 F.3d 316 (5th Cir. 2019); Midwest Generation, LLC, 720 F.3d at
647; Sierra Club v. Otter Tail Power Co., 615 F.3d 1008, 1015 (8th Cir. 2010); Nat’l Parks & Conservation Ass’n v.
Tenn. Valley Auth., 502 F.3d 1316, 1323 (11th Cir. 2007).
71 EME Homer City Generation, L.P., 727 F.3d at 284–85; Midwest Generation, LLC, 720 F.3d at 648; Otter Tail
Power Co., 615 F.3d at 1018; Nat’l Parks & Conservation Ass’n, Inc., 502 F.3d at 1323.
72 For a discussion of what constitutes a “penalty” within the meaning of 28 U.S.C. § 2462, see Kokesh v. SEC,
581 U.S. 455, 461–63 (2017).
73 E. I. Du Pont De Nemours & Co. v. Davis, 264 U.S. 456, 462 (1924).
74 Luminant Generation Co., 905 F.3d at 886–87; United States v. Telluride Co., 146 F.3d 1241, 1248–49 (10th Cir.
1998); United States v. Banks, 115 F.3d 916, 919 (11th Cir. 1997).
75 E.g., Sackett v. EPA, 622 F.3d 1139, 1143 (9th Cir. 2010), rev’d and remanded, 566 U.S. 120 (2012); Laguna
Gatuna, Inc. v. Browner, 58 F.3d 564 (10th Cir. 1995); S. Ohio Coal Co. v. Off. of Surface Mining, Reclamation &
Enf’t, 20 F.3d 1418 (6th Cir. 1994); S. Pines Assocs. by Goldmeier v. United States, 912 F.2d 713 (4th Cir. 1990);
Hoffman Grp., Inc. v. EPA, 902 F.2d 567 (7th Cir. 1990); Ross Incineration Servs., Inc. v. Browner, 118 F. Supp. 2d
837 (N.D. Ohio 2000); Sharp Land Co. v. EPA, 956 F. Supp. 691, 694 (M.D. La. 1996).
76 Sackett v. EPA, 566 U.S. 120, 131 (2012).
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Sackett concerned an EPA order requiring property owners to remedy alleged CWA violations by
conducting site restoration work.77 After receiving that order, the owners asked for an
administrative hearing, but EPA denied their request.78 The owners then brought suit under the
APA.79 The government argued that the suit was premature; the Supreme Court disagreed.80
The APA authorizes judicial review of (1) “final agency action” for which (2) “there is no other
adequate remedy in a court,” (3) so long as no other statute “preclude[s]” that review.81 According
to the Court, the property owners’ suit satisfied each of those conditions. EPA’s order was “final
agency action” because it both obliged the owners to restore their property and marked the
“‘consummation’ of [EPA’s] decisionmaking process,” which the agency demonstrated by
denying the hearing request.82 There was “no other adequate remedy in court” because the
property owners could not otherwise initiate suit themselves and because every day that they
waited for EPA to sue, “they accrue[d], by the Government’s telling, an additional $75,000 in
potential liability” for noncompliance.83 Finally, no other statute precluded judicial review
because “[n]othing in the [CWA] expressly” said so and any implied preclusive effect was
insufficient “to overcome the APA’s presumption of reviewability for all final agency action.”84
Agency and Judicial Review of Administrative Orders Issued After a Hearing
When ALJs and RJOs issue orders following hearings, EPA’s Consolidated Rules of Practice
allow aggrieved parties to seek review by the Environmental Appeals Board (EAB),85 a tribunal
of up to four EPA employees who are appointed by the EPA Administrator.86 The EAB reviews
matters “de novo,”87 which means that “it makes an independent determination without
deference” to the ALJs’ or RJOs’ “earlier analysis.”88 Pending EAB review, ALJ and RJO orders
are considered “interim” and have no binding effect.89 The EAB can then adopt, modify, or set
aside those interim orders,90 and its decisions are final and reviewable in federal court.91
77 Id. at 125.
78 Id.
79 Id.
80 Id. at 126–30.
81 5 U.S.C. §§ 701(a)(1), 704. See also CRS Legal Sidebar LSB10558, Judicial Review Under the Administrative
Procedure Act (APA), by Jonathan M. Gaffney (2024).
82 Sackett, 566 U.S. at 126–27.
83 Id. at 127–28.
84 Id. at 128–31.
85 40 C.F.R. § 22.30.
86 Changes to Regulations to Reflect the Role of the New Environmental Appeals Board in Agency Adjudications,
57 Fed. Reg. 5320 (Feb. 13, 1992); see also EAB GUIDE, supra note 55, at 2–3. No statute expressly authorizes the
EAB, leading some scholars to question whether the EAB is lawful. See William Funk, Is the Environmental Appeals
Board Unconstitutional or Unlawful?, 49 ENV’T L. 737 (2019).
87 De Novo, BLACK’S LAW DICTIONARY (12th ed. 2024).
88 EAB GUIDE, supra note 55, at 7.
89 40 C.F.R. § 22.27(c)(2), (d).
90 Id. § 22.30(f).
91 See, e.g., 42 U.S.C. § 11045(f)(1) (providing that “[a]ny person against whom a civil penalty is assessed under this
section [of the EPCRA] may obtain review thereof in the appropriate district court of the United States”); accord
15 U.S.C. § 2615(a)(3) (TSCA); 33 U.S.C. § 1319(g)(8)(A)–(B) (CWA); 42 U.S.C. § 300h-2(c)(6) (SDWA).
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Orders issued by ALJs and RJOs also become final if no one seeks EAB review within 45 days.92
In that case, EPA’s regulations state that the parties subject to the now-final order failed to exhaust
their administrative remedies and thus “waive[d] [their] rights to judicial review.”93 However, this
regulatory exhaustion requirement appears to have never been litigated, and if it were, it is
unclear if a court would give it controlling effect. Exhaustion of administrative remedies “is
required” when “Congress specifically mandates” it,94 but no statute mentions the EAB, let alone
directs parties to seek EAB review before judicial review.95 Absent a statutory mandate, the
doctrine of administrative exhaustion is prudential, and its application is committed to “sound
judicial discretion.”96
Even when an implied administrative exhaustion requirement is “fairly discernible” in statute,97
defendants in an enforcement action may still bypass agency proceedings and go directly to
federal district court if they contest an agency’s constitutional authority to proceed at all.98 Under
these circumstances, the Supreme Court has held that the harm from being subjected to an
unconstitutional agency proceeding is “‘a here-and-now injury’” that cannot be remedied once the
administrative proceeding is over and judicial review “kicks in.”99 The Court has also stressed
that when a litigant contests an agency’s “power generally” rather than “how that power was
wielded” in a particular case, its claims are generally “collateral” to administrative proceedings100
and “ill suited” to agency resolution.101 For these reasons, the Court has sometimes concluded
that certain constitutional challenges to agency authority are “not the type of claim Congress
intended to funnel through” generally applicable administrative proceedings.102
Administrative Enforcement and the Seventh Amendment
In recent years, some litigants have argued that administrative enforcement proceedings violate
the Seventh Amendment’s guarantee of trial by jury in “[s]uits at common law, where the value in
controversy shall exceed twenty dollars.” The Supreme Court considered that claim in SEC v.
Jarkesy, a case challenging the Securities and Exchange Commission’s (SEC’s) use of an inagency tribunal to levy administrative penalties for violations of antifraud provisions in securities
92 40 C.F.R. § 22.27(c).
93 Id. § 22.27(d).
94 McCarthy v. Madigan, 503 U.S. 140, 144 (1992) (emphasis added).
95 The statutory provisions that provide for judicial review of final EPA penalty orders, cited at note 91, supra, do not
mention the EAB or intermediate administrative appellate review generally. See also William Funk, Is the
Environmental Appeals Board Unconstitutional or Unlawful, 49 ENVTL. L. 737 (2019) (noting the absence of statutory
authorization for the EAB).
96 McCarthy, 503 U.S. at 144.
97 Thunder Basin Coal Co. v. Reich, 510 U.S. 200, 207 (1994) (quoting Block v. Cmty. Nutrition Inst., 476 U.S. 340,
351 (1984).
98 E.g., Axon Enter., Inc. v. FTC, 598 U.S. 175 (2023); Free Enter. Fund v. Pub. Co. Acct. Oversight Bd., 561 U.S. 477
(2010).
99 Axon Enter., 598 U.S. at 191 (quoting Seila L. LLC v. Consumer Fin. Prot. Bureau, 591 U.S. 197, 212 (2020)).
100 Id. at 193 (quoting Free Enter. Fund, 591 U.S. at 490).
101 ld. at 195 (quoting Carr v. Saul, 593 U.S. 83, 92 (2021)).
102 See id. at 184; Free Enter. Fund, 561 U.S. at 489–91 (allowing litigants to proceed first in district court with their
claims that removal protections afforded to certain inferior officers were unconstitutional). But see Elgin v. Dep’t of
Treasury, 567 U.S. 1, 17 (2012); Thunder Basin Coal Co. v. Reich, 510 U.S. at 216 (requiring administrative
exhaustion in cases where litigants raised both constitutional and nonconstitutional objections to agency action because
the agencies might dispose of the cases and afford complete relief on nonconstitutional grounds).
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laws.103 There, the Court applied a two-part test to determine whether administrative proceedings
were consistent with the Seventh Amendment.104
Because the Seventh Amendment jury right attaches to “[s]uits at common law”—i.e., legal
actions—the Court first asked whether SEC’s enforcement proceeding was “legal,” rather than
“equitable,” in nature.105 To parse the distinction between law and equity, the Court “consider[ed]
the cause of action and the remedy” sought106—though remedy was the “more important”
consideration107—and it asked whether the administrative proceeding was analogous to an action
that would have been heard in an 18th-century English court of law.108 If so, the jury right would
be implicated. If the proceeding was instead analogous to one that would have been heard in an
18th-century English court of equity, the jury right would not be implicated.109
While the historical distinction between law and equity is not always clear, the Court described
monetary penalties designed to punish and deter wrongdoing as “the prototypical common law
remedy.”110 On this basis alone, the Court concluded that SEC’s enforcement proceeding was
legal, rather than equitable,111 but the Court also stressed that the antifraud provisions in securities
laws “bore a close relationship” to “common law fraud,”112 further confirming the legal nature of
SEC’s enforcement proceeding.
Having concluded that SEC’s proceeding “implicate[d] the Seventh Amendment,” the Court next
asked whether the proceeding concerned “public,” rather than “private,” rights.113 If public rights
were at stake, the Court explained, then Congress could assign the proceeding to “an agency
tribunal without a jury, consistent with the Seventh Amendment.”114 While the Court has “not
definitively explained” the distinction between public and private rights,115 its “precedents have
recognized that the [public rights] doctrine covers matters ‘which arise between the Government
and persons subject to its authority in connection with the performance of the constitutional
functions of the executive or legislative departments.’”116 These include matters concerning
revenue collection, immigration, public lands, public benefits, and patents.117
That list is not exhaustive because Congress can create “new statutory public rights” and assign
their adjudication to agencies,118 but the Court cautioned that this congressional power is limited.
According to the Court, “[t]he public rights exception is, after all, an exception,” and practical
103 SEC v. Jarkesy, 603 U.S. 109, 115 (2024).
104 Id. at 121.
105 Id. at 122.
106 Id. at 123 (citing Tull v. United States, 481 U.S. 412, 417–18 (1987)).
107 Id. at 123 (quoting Tull, 481 U.S. at 421).
108 Id. at 122–23.
109 Id. For background on the concept of equity and equitable relief, see Sam Bray, A Student’s Guide to the Meanings
of “Equity,” REASON: VOLOKH CONSPIRACY (July 21, 2016, at 16:54 ET), https://reason.com/volokh/2016/07/21/astudents-guide-to-the-meanin/ [https://perma.cc/5DDQ-PZW6].
110 Jarkesy, 603 U.S. at 123.
111 Id. at 125.
112 Id. at 126.
113 Id. at 127.
114 Id.
115 Id. at 131 (quoting Oil States Energy Servs., LLC v. Greene’s Energy Grp., LLC, 584 U.S. 325, 334 (2018)).
116
Oil States, 584 U.S. at 334 (quoting Crowell v. Benson, 285 U.S. 22, 50 (1932)).
117 Jarkesy, 603 U.S. at 128–31.
118 See id. at 136–37 (quoting Atlas Roofing Co. v. Occupational Safety & Health Rev. Comm’n, 430 U.S. 442 (1977)).
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considerations “like increasing efficiency and reducing public costs are not enough to trigger”
it.119 Rather, Congress can “bypass the protection of the Seventh Amendment” only when it
creates statutory requirements with no common law antecedents. As an example, the Court cited
the Occupational Safety and Health (OSH) Act, a law whose requirements “resembled a detailed
building code” and were “‘unknown to the common law.’”120 The Court previously held that these
characteristics placed the OSH Act within the public rights exception.121 By contrast, the Court
held that securities fraud was “akin” to common law fraud and thus beyond Congress’s power to
assign to agency tribunals.122
It remains to be seen how Jarkesy’s two-step analysis will apply to administrative enforcement
proceedings under pollution-control statutes, but a recent decision by the U.S. Court of Appeals
for the Third Circuit suggests that at least some of those proceedings may concern public, rather
than private, rights. In Axalta Coating Systems v. FAA, the Third Circuit held that the FAA’s
proceedings to enforce the Hazardous Materials Transportation Act (HMTA) and impose
monetary penalties fell within the public rights exception.123 The court reasoned that the
underlying violation rested on “technical prescription[s]” that, like the requirements in the OSH
Act, brought no “common law soil with them.”124 While the HMTA defined “knowing” violations
by reference to two terms—“reasonable person” and “reasonable care”—with deep roots in the
common law tort of negligence, the court concluded that those terms were “relevant only to the
question whether the violating party knew of the violation” and thus did not control the public
rights analysis.125
Courts may conclude that other pollution control statutes with complex, highly technical
regulatory requirements likewise fall within the public rights exception.126 However, the law in
this area is evolving, and the Supreme Court has called for “close attention to the basis for each
asserted application of the [public rights] doctrine.”127 For now, at least, Jarkesy’s impact on
EPA’s enforcement authority remains unsettled.
Civil Judicial Enforcement
Every federal pollution control statute authorizes the federal government to sue alleged violators
in federal court, where juries (or in some cases, judges) determine liability, and where judges
119 Id. at 140.
120 Id.
121 See id. (discussing Atlas Roofing, 430 U.S. at 455).
122 Id. at 139.
123 144 F.4th 467, 471 (3d Cir. 2025).
124 Id. at 476 (quoting Jarkesy, 603 U.S. at 137). The prescriptions at issue in Axalta governed hazardous substance
“packagings for which retention of liquid is a basic function,” and required that those “packagings”
be capable of withstanding without leakage the greater of . . . [a]n internal pressure which produces
a gauge pressure of not less than 75kPa (11 psig) for liquids in Packing Group III of Class 3 or
Division 6.1; or 95 kPa (14 psig) for other liquids; or . . . [a] pressure related to the vapor pressure
of the liquid to be conveyed, determined by one of [three specified methods].
Id. at 477 (alterations in original) (quoting 49 C.F.R. § 173.27(c)(2)).
125 Id.
126 Cf. Tull v. United States, 481 U.S. 412, 420 (1987) (analogizing an action to enforce CWA Section 404 to an
“action in public nuisance” or “an action in debt” under the common law).
127 Jarkesy, 603 at 131.
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interpret the law, assess civil penalties, and craft injunctive relief.128 These laws generally permit
suits to enforce substantive statutory requirements or to compel compliance with the terms of
EPA-issued administrative orders.129
DOJ’s Role
“Except as otherwise authorized by law,” the Attorney General and her designees have sole
authority to “supervise all litigation to which the United States, an agency, or officer thereof is a
party.”130 Because no statute gives EPA independent litigating authority, EPA must refer cases to
DOJ to bring a civil judicial enforcement action.131 EPA’s referrals typically go to DOJ’s
Environment and Natural Resources Division (ENRD), which handles much of the department’s
environmental enforcement caseload.132
As a matter of policy, ENRD sues to enforce a statute only when asked to do so by the agency
charged with administering that statute.133 EPA’s referral is thus a precondition for civil judicial
enforcement action under most pollution control laws. However, EPA’s referral alone does not
guarantee a lawsuit. ENRD acts on most EPA referrals,134 but DOJ’s Office of Legal Counsel
(OLC), which issues legal opinions that are binding on the executive branch,135 has long
maintained that the Attorney General ultimately decides whether to bring litigation on behalf of
the United States.136
128 See generally Balt. & Carolina Line v. Redman, 295 U.S. 654, 657 (1935) (noting that, “in the absence of express or
implied consent to the contrary, issues of law are to be resolved by the court and issues of fact are to be determined by
the jury under appropriate instructions by the court”); see also Tull, 481 U.S. at 425 (noting the “constitutional right to
a jury trial to determine . . . liability on . . . legal claims”); id. at 427 (holding that Congress can, and typically does,
assign civil penalty determinations to judges).
129 See, e.g., 33 U.S.C. § 1319(d) (authorizing penalties in civil suits under the CWA against “any person who violates
any order issued by the Administrator”); 42 U.S.C. § 7413 (authorizing civil actions against any person who violates “a
requirement or prohibition of any . . . order . . . issued, or approved under” the CAA).
130 28 U.S.C. § 519; see also 28 U.S.C. § 516 (“Except as otherwise authorized by law, the conduct of litigation in
which the United States, an agency, or officer thereof is a party, or is interested, and securing evidence therefor, is
reserved to officers of the Department of Justice, under the direction of the Attorney General.”).
131 When it was debating the 1977 Amendments to the Clean Air Act, Congress considered granting EPA authority to
represent itself in civil litigation. S. REP. NO. 95-127, at 52 (1977). It “decided against such a transfer of representation
authority primarily on the strength of the personal commitment” by the Attorney General to “remedy” perceived
shortcomings in DOJ’s representation of EPA. Id. at 52–53. See also Memorandum of Understanding Between
Department of Justice and Environmental Protection Agency, 42 Fed. Reg. 48942 (Sep. 26, 1977) (discussing the roles
and responsibilities in cases that EPA refers to DOJ).
132 See 28 C.F.R. § 0.65 (2025) (DOJ regulations outlining ENRD’s responsibilities); see also U.S. Dep’t of Just., Just.
Manual § 5-1.200 (2024) [hereinafter Just. Manual] (authorizing ENRD “to exercise the functions and responsibilities
undertaken by the Attorney General in the Memorandum of Understanding dated June 15, 1977, between the
Department and the EPA”).
133 Just. Manual, supra note 132, § 5-12.111.B.
134 See Memorandum from Jeffrey Bossert Clark, Assistant Att’y Gen., Env’t & Nat. Res. Div., to ENRD Section
Chiefs & Deputy Section Chiefs, Enforcement Principles and Priorities n.17 (Jan. 14, 2021), https://www.justice.gov/
enrd/media/1412026/dl?inline [https://perma.cc/Y32K-XFEN] (noting that ENRD returns referrals to EPA only “on
occasion” after “thoroughly review[ing] such referrals”).
135 28 U.S.C. §§ 511–513; 28 C.F.R. § 0.25; Exec. Order No. 12146, §§ 1-401–1-402, 44 Fed. Reg. 42657 (July 18,
1979).
136 See The Att’y Gen.’s Role as Chief Litigator for the United States, 6 Op. O.L.C. 47, 48 (1982) (“[A]bsent clear
legislative directives to the contrary, the Attorney General has full plenary authority over all litigation, civil and
criminal, to which the United States, its agencies, or departments, are parties.”); see also United States v. Sandstrom,
22 F. Supp. 190, 191 (N.D. Okla. 1938) (holding that after a “case was referred to the Department of Justice,” the
(continued...)
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With exceptions not relevant here,137 DOJ generally does not sue other federal agencies. This
position reflects OLC’s long-held view that “‘lawsuits between two federal agencies are not
generally justiciable’” because agencies ultimately report to the President and “a lawsuit
involving the same person as both plaintiff and defendant” lacks adversity necessary to trigger
federal court jurisdiction.138 OLC has also opined that intra-executive branch suits raise
separation of powers concerns, since judicial resolution of agency disputes could constrain the
President’s constitutional authority “to supervise his subordinates and resolve disputes among
them.”139 Thus, while federal agencies are generally subject to requirements in pollution control
statutes, as a practical matter, they are generally not subject to civil judicial enforcement actions
by the federal government.
Legal Standard, Burden of Proof, and Statute of Limitations
The legal standard, ultimate burden of proof, and statute of limitations in civil judicial
enforcement actions mirror the standard, burden, and limitations period in administrative
enforcement hearings: liability is generally strict,140 negating the need to establish a defendant’s
knowledge or intent; the parties must prove the elements of their case by a preponderance of the
evidence; and suits for monetary penalties are subject to 28 U.S.C. § 2462’s five-year time-bar.141
Available Remedies
Pollution control statutes generally authorize the federal government to sue for monetary
penalties. Under most of these statutes, the government can seek penalties for the first time in a
civil judicial enforcement action,142 but under TSCA, FIFRA, and the Marine Protection,
Research, and Sanctuaries Act, DOJ can sue only to compel payment of EPA-assessed
administrative penalties.143
Civil judicial penalties are capped at an inflation-adjusted, daily maximum amount and are
assessed for each day that a violation persists.144 These maximum daily penalties are equal to or
higher than corresponding administrative penalties and are not subject to the aggregate limits that
referring agency “ceased to have any control over the same,” and the “Attorney General was not bound by the
recommendation of the” referring agency).
137 Exceptions to the general rule against interagency suit include suits involving independent agencies that are
insulated from presidential control and suits where the government plaintiff is not the real party in interest. For
examples of the former, see Bijal Shah, Executive (Agency) Administration, 72 STAN. L. REV. 641 (2020); for an
example of the latter, see United States v. Interstate Com. Comm’n, 337 U.S. 426 (1949).
138 Auth. of Dep’t of Hous. & Urban Dev. to Initiate Enf’t Actions Under the Fair Hous. Act Against Other Exec.
Branch Agencies, 18 Op. O.L.C. 101 (1994) (quoting Nuclear Regul. Comm’n’s Imposition of Civil Penalties on the
Air Force, 13 Op. O.L.C. 131, 138 (1989)).
139 INS Rev. of Final Order in Emp. Sanctions Cases, 13 Op. O.L.C. 370, 371 (1989).
140 See sources cited supra note 14.
141 See Ramirez v. T&H Lemont, Inc., 845 F.3d 772, 778 (7th Cir. 2016) (noting that “unless the governing statute . . .
specifies a higher burden, or the Constitution demands a higher burden because of the nature of the individual interests
at stake, proof by a preponderance of the evidence will suffice” in federal civil cases).
142 See 33 U.S.C. § 1319(d) (CWA); 42 U.S.C. § 300h-2(a)–(b) (SDWA); id. § 6928(g) (RCRA); id. § 7413(b) (CAA);
id. § 11045(b)(3) (EPCRA).
143 See 7 U.S.C. § 136l(a)(1) (FIFRA); 15 U.S.C. § 2615(a)(4) (TSCA); 33 U.S.C. § 1415(a) (MPRSA).
144 See, e.g., 33 U.S.C. § 1319(d) (CWA); 42 U.S.C. § 300h-2(a)–(b) (SDWA); id. § 6928(g) (RCRA); id. § 7413(b)
(CAA); id. § 11045(b)(3) (EPCRA).
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Congress set for some administrative penalties.145 As with administrative penalties, many statutes
provide factors for courts to consider when determining appropriate penalty amounts.146
Monetary penalties aside, two statutes authorize suits for seizure of certain substances. Under
FIFRA, the government can seek judicial permission to “seize[] for confiscation” a “pesticide or
device” that is adulterated, misbranded, unregistered, mislabeled, or improperly marketed.147
Similarly, TSCA authorizes suits “for seizure of an imminently hazardous chemical substance or
mixture.”148
Courts can also issue case-specific injunctive orders requiring parties to take or refrain from
taking certain actions.149 Injunctions can be preliminary or permanent. Preliminary injunctions
remain in place while a suit is pending, generally to maintain the status quo during litigation.150
Permanent injunctions are issued only after a final determination on the merits of a case.151
Some environmental statutes authorize injunctive relief,152 but even without such statute-specific
authorization, federal courts can issue injunctions under the general equitable authority conferred
by the Judiciary Act of 1789.153 That authority allows courts to craft injunctive relief so long as
that relief is consistent with “express and implied statutory limitation[s]”154 and falls “within the
broad boundaries of traditional equitable relief” available at the time of the founding.155
To obtain an injunction, a plaintiff must demonstrate
(1) that it has suffered an irreparable injury; (2) that remedies available at law, such as
monetary damages, are inadequate to compensate for that injury; (3) that, considering the
145 Maximum penalty amounts are provided in the statutory sections cited in note 144, supra. For current, inflation-
adjusted maximum penalties, see 40 C.F.R. § 19.4, tbl. 1.
146 See, e.g., 33 U.S.C. § 1319(d) (penalty considerations under the CWA); 42 U.S.C. § 7413(e) (penalty assessment
criteria under the CAA); 49 U.S.C. § 5122(a) (penalty considerations under the HMTA). While civil liability does not
turn on a defendant’s mental state, evidence of a defendant’s negligence or malign intent may be relevant to
determining civil penalty amount. E.g., 33 U.S.C. § 1319(g)(3). See also United States v. Harford Sands, Inc., 575 F.
Supp. 733, 735 (D. Md. 1983) (“While the defendant’s lack of knowledge . . . may affect its culpability and therefore
the amount of a civil penalty which would be appropriate, those sections of the [CWA] which the defendant is charged
with violating do not require that the violation be ‘willful’ or ‘knowing.’”); 33 U.S.C. § 1321(b)(7)(D) (providing for
higher civil penalties when violations result from “gross negligence or willful misconduct”).
147 7 U.S.C. § 136k(b)–(c).
148 15 U.S.C. § 2606(a)–(b)
149 CRS Report R46902, Nationwide Injunctions: Law, History, and Proposals for Reform, by Joanna R. Lampe (2021).
150 See Lackey v. Stinnie, 604 U.S. 192, 200 (2025) (“The purpose of a preliminary injunction is merely to preserve the
relative positions of the parties until a trial on the merits can be held.” (quoting Univ. of Tex. v. Camenisch, 451 U.S.
390, 395 (1981))).
151 As one scholar explained, the term “permanent injunction” is misleading because “[s]o-called ‘permanent
injunctions’ may be explicitly time limited, as when they are phased out after a year or two. And even if an injunction
is ostensibly permanent, the court may dissolve or modify it at any time.” Samuel Bray, The Purpose of the Preliminary
Injunction, 78 VAND. L. REV. 809 (April 2025).
152 See, e.g., 33 U.S.C. § 1319(b) (authorizing “civil action[s] for appropriate relief, including a permanent or
temporary injunction”); accord 15 U.S.C. §§ 2616(a)(1)(A)–(D), 2622(d) (TSCA); 42 U.S.C. § 6928(a) (RCRA); id.
§ 7413(b) (CAA).
153 See Trump v. CASA, Inc., 606 U.S. 831, 841 (2025) (noting that the Judiciary Act of 1789 “is what authorizes the
federal courts to issue equitable remedies” (quoting S. Bray & E. Sherwin, Remedies 442 (4th ed. 2024))).
154 Armstrong v. Exceptional Child Ctr., Inc., 575 U.S. 320, 327 (2015); see also Miller v. French, 530 U.S. 327, 340
(2000) (holding that courts “should not construe a statute to displace courts’ traditional equitable authority absent the
‘clearest command,’ or an ‘inescapable inference’ to the contrary” (quoting Califano v. Yamasaki, 442 U.S. 682, 705
(1979), and Porter v. Warner Holding Co., 328 U.S. 395, 398 (1946))).
155 CASA, Inc., 606 U.S. at 846 (quoting Grupo Mexicano de Desarrollo S.A. v. All. Bond Fund, Inc., 527 U.S. 308,
322 (1999)).
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balance of hardships between the plaintiff and defendant, a remedy in equity is warranted;
and (4) that the public interest would not be disserved by a[n] . . . injunction.156
The Supreme Court has stressed that injunctions are “extraordinary” relief and are not “granted as
a matter of course.”157 Even so, the Court has noted that “[e]nvironmental injury, by its nature,
can seldom be adequately remedied by money damages and is often permanent or at least of long
duration, i.e., irreparable.”158 While this does not create a “presumption” in favor of injunctive
relief in environmental cases, it does mean that “the balance of harms will usually favor the
issuance of an injunction to protect the environment.”159
Commonly sought injunctions in environmental cases include orders requiring defendants to
clean up polluted sites or take actions to ensure prospective compliance with statutory obligations
or administrative orders.160
Court-issued injunctions are enforceable through contempt orders.161 Parties held in contempt
may be subject to fines or imprisonment.162
Settlement Agreements and Consent Decrees
If the parties in a civil judicial enforcement action agree to terms, they can voluntarily resolve
their dispute through settlement. EPA has a say in whether to settle cases,163 but as with the
decision to bring suit, OLC maintains that ultimate settlement authority rests with DOJ.164
Broadly speaking, settlements may take one of two forms. First, litigants can memorialize their
agreement in an out-of-court settlement. When this happens, the parties often stipulate to
voluntary dismissal of the underlying enforcement action, and the court lacks continuing
156 Monsanto Co. v. Geertson Seed Farms, 561 U.S. 139, 156–57 (2010). A plaintiff that seeks a preliminary injunction
before liability is resolved must also show that it is likely to succeed on the merits of its claim. Winter v. Nat. Res. Def.
Council, Inc., 555 U.S. 7, 20 (2008).
157 Id. at 165.
158 Amoco Prod. Co. v. Vill. of Gambell, 480 U.S. 531, 545 (1987).
159 Id.
160 See, e.g., Meghrig v. KFC W., Inc., 516 U.S. 479, 484 (1996) (holding that a “plain reading” of RCRA’s remedial
scheme authorizes courts to issue “a mandatory injunction, i.e., one that orders a responsible party to ‘take action’ by
attending to the cleanup and proper disposal of toxic waste, or a prohibitory injunction, i.e., one that ‘restrains’ a
responsible party from further violating RCRA”); Interfaith Cmty. Org. v. Honeywell Int’l, Inc., 399 F.3d 248, 264 (3d
Cir. 2005) (affirming a district court’s entry of permanent injunction under RCRA requiring the defendant to excavate
and dispose of contaminated waste); U.S. Pub. Int. Rsch. Grp. v. Atl. Salmon of Maine, LLC, 339 F.3d 23 (1st Cir.
2003) (affirming a district court’s entry of permanent injunction requiring operational changes at a commercial fish
farm to ensure prospective compliance with the CWA); United States v. Deaton, 332 F.3d 698, 713 (4th Cir. 2003)
(affirming district court’s injunctive order requiring defendant to take remedial action to restore wetlands filled in
violation of the CWA); EPA v. Env’t Waste Control, Inc., 917 F.2d 327, 331–32 (7th Cir. 1990) (affirming district
court’s injunction requiring defendants to permanently close a landfill to address RCRA violations); Gordon-Darby
Holdings, Inc. v. N.H. Dep’t of Safety, Comm’r, No. 25-CV-508-LM-AJ, 2026 WL 207187, at *19 (D.N.H. Jan. 27,
2026) (granting a motion for preliminary injunction and ordering a state agency “to take all steps necessary to resume
and ensure the continued implementation and enforcement of” the state’s “vehicle inspection and maintenance
program” as required under the CAA).
161 11A WRIGHT & MILLER’S FEDERAL PRACTICE & PROCEDURE § 2960 (3d. ed. 1998). See also Nken v. Holder,
556 U.S. 418, 428 (2009) (noting that an injunction “directs the conduct of a party . . . with the backing of [the court’s]
full coercive powers”).
162 See 18 U.S.C. § 401 (authorizing courts to punish “contempt of [their] authority”).
163 See Memorandum of Understanding Between Department of Justice and Environmental Protection Agency, 42 Fed.
Reg. 48943 (Sep. 26, 1977) (“The settlement of any case in which [DOJ] represents [EPA] . . . shall require
consultation with and concurrence of both the [EPA] Administrator and the Attorney General.”).
164 The Att’y Gen.’s Role as Chief Litigator for the United States, 6 Op. O.L.C. 47, 59–60 (1982).
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jurisdiction to compel compliance with the terms of the settlement agreement.165 A party seeking
to enforce those terms would have to bring a separate suit akin to a breach of contract action, with
the settlement agreement serving as the underlying contract.
Alternatively, settling parties can ask the court to incorporate their settlement terms in an order
called a consent decree.166 If the court agrees to do so, the resulting consent decree “is subject to
the rules generally applicable to other judgments and decrees.”167 Thus, as with other judgments,
consent decrees can be modified or vacated only with leave of the court;168 courts retain
jurisdiction to monitor compliance with, and enforce, consent decrees;169 and courts can hold
noncompliant parties in contempt.170 Parties to a consent decree can ask the court to enforce its
terms, but a consent decree is generally “not enforceable directly or in collateral proceedings by
those who are not parties to it.”171
DOJ will seek entry of a consent decree in “an action to enjoin discharges of pollutants” only
after “persons (natural or corporate) who are not named as parties to the action” have a 30-day
opportunity to comment on the proposed decree.172 After DOJ considers those comments, which it
must also file with the court, the department either withdraws the proposed decree or asks that the
court enter it.173
Before entering a consent decree, a court must determine for itself if the parties’ proposed terms
are “reasonable,” “faithful to the . . . objectives” of the statute that gave rise to the suit, “and fair
(both procedurally and substantively).”174 Because this inquiry is “guided by the general principle
that settlements are encouraged,” courts generally defer to the parties’ proposed terms.175 That
deference is heightened “in very complex and technical regulatory contexts,” where “the
165 See FED. R. CIV. P. 41(a)(1)(A)(ii) (allowing plaintiffs to voluntarily dismiss an action without a court order by
filing “a stipulation of dismissal signed by all parties who have appeared”); see also Kokkonen v. Guardian Life Ins.
Co. of Am., 511 U.S. 375, 380–82 (1994) (holding that courts have no inherent authority to enforce settlements terms
that are not included in a court order).
166 Rufo v. Inmates of Suffolk Cnty. Jail, 502 U.S. 367, 378 (1992); see also Buckhannon Bd. & Care Home, Inc. v. W.
Va. Dep’t of Health & Hum. Res., 532 U.S. 598, 604–05 (2001) (noting that a court-ordered consent decree, like a
“judgment on the merits,” creates a “judicially sanctioned change in the legal relationship of the parties”).
167 Rufo, 502 U.S. at 378.
168 If a party to a consent decree wants a court to modify or repeal that decree, it must file a motion under Federal Rule
of Civil Procedure 60(b), which allows courts to “relieve a party or its legal representative from a final judgment, order,
or proceeding” if the order “has been satisfied, released, or discharged,” is “based on an earlier judgment that has been
reversed or vacated,” is “no longer equitable,” or for “any other reason that justifies relief.” Fed. R. Civ. P. 60(b)(5)–
(6); see also Rufo, 502 U.S. at 378 (holding that consent decrees are subject to Rule 60(b)).
169 Beckett v. Air Line Pilots Ass’n, 995 F.2d 280, 282 (D.C. Cir. 1993) (noting “the well-established principle that a
trial court retains jurisdiction to enforce its consent decrees”).
170 See Spallone v. United States, 493 U.S. 265, 276 (1990) (“In selecting a means to enforce the consent judgment, the
District Court was entitled to rely on the axiom that ‘courts have inherent power to enforce compliance with their
lawful orders through civil contempt.’” (quoting Shillitani v. United States, 384 U.S. 364, 370 (1966))).
171Blue Chip Stamps v. Manor Drug Stores, 421 U.S. 723, 750 (1975).
172 28 C.F.R. § 50.7(a)–(b).
173 Id. § 50.7(b); see also Just. Manual, supra note 132, § 5-12.620.B.
174 City of Bangor v. Citizens Commc’ns Co., 532 F.3d 70, 93 (1st Cir. 2008) (quoting United States v. Charles George
Trucking, Inc., 34 F.3d 1081, 1084 (1st Cir. 1994)); accord United States v. North Carolina, 180 F.3d 574, 581 (4th
Cir. 1999); United States v. Oregon, 913 F.2d 576, 580 (9th Cir. 1990). To assess reasonableness and fairness, courts
consider “the basic legality of the decree,” “whether the terms of the decree, including its enforcement mechanism, are
clear,” “whether the consent decree reflects a resolution of the actual claims in the complaint,” and “whether the
consent decree is tainted by improper collusion or corruption of some kind.” SEC v. Citigroup Glob. Mkts., Inc.,
752 F.3d 285, 295 (2d Cir. 2014).
175 North Carolina, 180 F.3d at 581.
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settlement has been advanced for entry as a decree by a government actor committed to the
protection of the public interest and specially trained and oriented in the field,”176 so courts are
particularly unlikely to reject proposed consent decrees in government-led environmental
enforcement actions. That said, a court presented with a proposed consent decree “is not merely a
rubber stamp,”177 and judges sometimes refuse to enter decrees proposed by the government.178
Citizen Suits
Most of the federal pollution control statutes include citizen suit provisions that authorize
nonfederal parties to act as private attorneys general by suing other private parties or government
actors to address alleged violations of a statute. At the federal level, citizen suit provisions
originated in the Clean Air Act Amendments of 1970 and were intended as a way to
(1) supplement enforcement in light of agencies’ limited resources to assure compliance and
(2) encourage the executive branch to take action where appropriate.179 While citizen suits can
take several forms, this report focuses on the use of citizen suits as private enforcement actions,
that is, to address violations of pollution control requirements.180
Most major federal environmental statutes include a citizen suit provision, but some do not. Table
A-2 lists the citizen suit provisions in major federal pollution control statutes.
Elements of Citizen Suits
While the exact wording of citizen suit provisions varies from statute to statute, many provisions
share a common formulation.
Plaintiffs and defendants. In general, citizen suit provisions allow suits by “any citizen” or “any
person,” which is defined to include state and local governments.181 Plaintiffs may file lawsuits
176 United States v. Comunidades Unidas Contra La Contaminacion, 204 F.3d 275, 280 (1st Cir. 2000).
177 Citigroup Glob. Mkts., 752 F.3d at 293.
178 See, e.g., EEOC v. Int’l Ass’n of Bridge, Structural & Ornamental Ironworkers Loc. 580, No. 25-44-CV, 2026 WL
392327, at *5 (2d Cir. Feb. 12, 2026) (affirming district court’s refusal to enter proposed consent decree).
179 S. REP. NO. 91-1196, at 36–39 (1970) (“Government initiative in seeking enforcement under the Clean Air Act has
been restrained. Authorizing citizens to bring suits for violations of standards should motivate governmental agencies
charged with the responsibility to bring enforcement and abatement proceedings.”); see also STAFF OF S. COMM. ON
PUBLIC WORKS, 93RD CONG., A LEGISLATIVE HISTORY OF THE CLEAN AIR ACT AMENDMENTS OF 1970, at 214 (Comm.
Print 1974) (letter from Nixon Administration to Sen. Jennings Randolph, Chair, Senate Committee on Public Works);
Natural Res. Def. Council, Inc. v. Train, 510 F.2d 692, 727–30 (D.C. Cir. 1974) (reproducing comments on the Senate
floor by Sen. Muskie and Sen. Hart and statement by Ramsey Clark). For further discussion of the legislative history of
federal citizen suit provisions, see Robert D. Snook, Environmental Citizen Suits and Judicial Interpretation: First
Time Tragedy, Second Time Farce, 20 W. NEW ENG. L. REV. 311, 316–20 (1998). For a discussion of the state-law
origins of citizen suit provisions, see James R. May, The Availability of State Environmental Citizen Suits, 18 NAT.
RES. & ENV’T 53, 55 (2004); Scott W. Stern, Standing for Everyone: Sierra Club v. Morton, Supreme Court
Deliberations, and a Solution to the Problem of Environmental Standing, 30 FORDHAM ENV’T L. REV. 21, 88–97
(2019); Susan George, William J. Snape, III, & Rina Rodriguez, The Public in Action: Using State Citizen Suit Statutes
to Protect Biodiversity, 6 U. BALT. J. ENV’T L. 1, 17–25 (1997).
180 As noted in the Introduction, discussion of the legal issues arising in so-called “mandatory duty” suits—where a
citizen sues a federal agency for failure to take a required action under one of the applicable laws—is beyond the scope
of this report.
181 See, e.g., 42 U.S.C. § 7602(e) (CAA); 33 U.S.C. §§ 1362(5), 1365(g) (CWA); 42 U.S.C. § 9659 (CERCLA);
15 U.S.C. § 2619 (TSCA).
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against “any person,” which includes the federal government and other governmental entities to
the extent permitted by the Eleventh Amendment.182
Violations. Citizen suits generally may allege that a defendant has violated a statute or
enumerated sections of a statute, as well as a regulation, a permit, order, or limitation issued
thereunder.183 This includes allegations that a federal facility violated pollution-control
standards.184
Notice and timing requirements. Many statutes limit the availability of citizen suits by requiring
that putative plaintiffs first notify defendants and EPA of their intent at least a specified length of
time before filing a lawsuit, thereby giving the alleged violator an opportunity to come into
compliance with the statute and EPA an opportunity to take action.185 For example, the CWA
citizen suit provision requires that plaintiffs provide at least 60 days’ notice of the alleged
violation to the EPA Administrator, the state in which the alleged violation occurred, and the
alleged violator(s) before filing a suit alleging violations of the statute.186
Government involvement. Several mechanisms provide for additional notification to the federal
government and an opportunity for government involvement in litigation. First, citizen suit
provisions generally bar private enforcement actions if EPA or a state has undertaken and is
“diligently prosecuting” a civil or criminal action to address the same violations.187 In such cases,
however, a citizen plaintiff may intervene in the federal or state enforcement action.188 Second,
EPA generally may intervene as a matter of right in citizen suits.189 Third, in addition to the notice
requirements described above, plaintiffs must also notify the federal government after filing a
complaint and after finalizing a proposed consent decree.190 The court may not enter (i.e.,
approve) a consent decree any earlier than 45 days after EPA and DOJ are notified; during that
window, the United States may comment on or object to the proposed consent decree.191
182 E.g., 42 U.S.C. § 7604(a)(1) (CAA); 33 U.S.C. § 1365(a)(1) (CWA); 42 U.S.C. § 9659(a)(1) (CERCLA); 15 U.S.C.
§ 2619(a)(1) (TSCA). The Eleventh Amendment bars federal courts from construing their judicial power to allow suits
against states by citizens of another state or by foreign states or their citizens or subjects. U.S. CONST. amend. XI; Libr.
of Cong., Overview of Eleventh Amendment, Suits Against States, CONSTITUTION ANNOTATED,
https://constitution.congress.gov/browse/essay/amdt11-1/ALDE_00013675/ (last visited Apr. 27, 2026).
183 See, e.g., 42 U.S.C. § 7604(a)(1) (CAA), (a)(3); 33 U.S.C. § 1365(a)(1) (CWA); 42 U.S.C. § 9659(a)(1) (CERCLA);
15 U.S.C. § 2619(a)(1) (TSCA).
184 In its report accompanying the CAA amendments that added the citizen suit provision, the Senate Committee on
Public Works noted that authorizing citizen suits against the government was important because federal facilities
“generate considerable air pollution” and “have been notoriously laggard in abating pollution and in requesting
appropriations to develop control measures.” S. REP. NO. 91-1196, at 37 (1970).
185 See, e.g., 42 U.S.C. § 7604(b); 33 U.S.C. § 1365(b); 42 U.S.C. § 9659(d); 15 U.S.C. § 2619(b)(1); Gwaltney of
Smithfield, Ltd. v. Chesapeake Bay Found., 484 U.S. 49, 60 (1986); S. REP. NO. 91-1196, at 37 (1970). Some citizen
suit provisions impose more restrictive timing requirements. A citizen suit to challenge the adequacy of a CERCLA
cleanup may not be filed until after a cleanup is completed, and persons may not challenge a removal action at a site
where a longer-term remedial action is planned. 42 U.S.C. § 9613(h).
186 33 U.S.C. § 1365(b)(1). For citizen suits alleging violations of Sections 306 (relating to National Standards of
Performance) or 307(a) (relating to standards for discharges of toxic pollutants), plaintiffs must still provide notice but
may file a lawsuit immediately after doing so. Id. § 1365(b).
187 E.g., 42 U.S.C. § 7604(b)(1)(B); 33 U.S.C. § 1365(b)(1)(B); 42 U.S.C. § 9659(d)(2); 15 U.S.C. § 2619(b)(1)(B).
188 E.g., 42 U.S.C. § 7604(b)(1)(B); 33 U.S.C. § 1365(b)(1)(B); 15 U.S.C. § 2619(b)(1)(B). The CERCLA citizen suit
provision does not have a comparable mechanism for citizen plaintiff intervention. 42 U.S.C. § 9659.
189
E.g., 42 U.S.C. § 7604(c)(2); 33 U.S.C. § 1365(c)(2); 42 U.S.C. § 9659(g); 15 U.S.C. § 2619(c)(1).
190 E.g., 42 U.S.C. § 7604(c)(3); 33 U.S.C. § 1365(c)(3).
191 Id.
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Remedies. Depending on the statute at issue, litigants who are successful may obtain injunctive
relief, recover litigation costs, and (in more limited instances) secure civil penalties to be paid to
the U.S. Treasury.192 Citizen suits are intended to redress harm to the environment, rather than to
individuals, resulting from statutory violations.193 Plaintiffs may be able to pursue state-law tort to
vindicate private interests and address personal injury, property damage, or economic loss.194
Citizen suit provisions expressly preserve rights and remedies under other laws, including state
tort laws.195
Article III Limitations on Citizen Suits
The Supreme Court has recognized various restraints on the availability of citizen suits under
Article III of the Constitution, which limits the scope of federal court jurisdiction to adjudicating
“Cases” and “Controversies.”196 The doctrine of standing, which generally refers to a litigant’s
right to have a court rule upon the merits of particular claims for which that litigant seeks judicial
relief, derives from this limitation.197
While citizen suit provisions confer jurisdiction on federal courts to hear private enforcement
claims, they do not confer standing on plaintiffs to bring suit.198 Instead, litigants who wish to file
a citizen suit must meet the basic Article III standing requirements by showing that (1) they have
suffered an injury in fact that is (2) fairly traceable to the allegedly unlawful actions of the
opposing party and (3) likely redressable by a favorable judicial decision.199 In the environmental
context, plaintiffs typically must demonstrate that they themselves have been harmed or
anticipate harm as a result of the violation and that such harm could be addressed by a court
order, such as an injunction directing the defendant to stop ongoing pollution. Additionally, courts
have developed a set of “prudential” standing principles, including that a litigant may not assert
the rights of third parties not before the court, seek redress for a generalized grievance, or assert
an interest that does not fall within the zone of interests arguably protected or regulated by the
statute or constitutional provision underlying the litigant’s claims.200 Article III also requires that
“an actual controversy must exist not only at the time the complaint is filed, but through all stages
192 E.g., 42 U.S.C. § 7604(a) (authorizing injunctive relief and civil penalty awards), (d) (allowing litigation costs);
33 U.S.C. § 1365(a) (authorizing injunctive relief and civil penalty awards), (d) (allowing litigation costs); 42 U.S.C.
§ 9659(c) (authorizing injunctive relief and civil penalty awards), (f) (allowing litigation costs); 15 U.S.C. § 2619(a)(1)
authorizing courts to “restrain” relevant violations), (c)(2) (allowing litigation costs).
193 See Barry Breen, Citizen Suits for Natural Resource Damages: Closing a Gap in Federal Environmental Law,
24 WAKE FOREST L. REV. 851, 870 (1989).
194 See Mark Latham, Victor E. Schwartz, & Christopher E. Appel, The Intersection of Tort and Environmental Law:
Where the Twains Should Meet and Depart, 80 FORDHAM L. REV. 737, 750–758 (2011); Albert C. Lin, The Unifying
Role of Harm in Environmental Law, 2006 WISC. L. REV. 897, 905–911 (2006).
195 E.g., 42 U.S.C. § 7604(e); 33 U.S.C. § 1365(c); 42 U.S.C. § 9659(h); 15 U.S.C. § 2619(c)(3); see also S. REP. NO.
91-1196, at 38 (1970).
196 U.S. CONST. art. III, § 2.
197 See Libr. of Cong., Overview of Standing, CONSTITUTION ANNOTATED,
https://constitution.congress.gov/browse/essay/artIII-S2-C1-6-1/ALDE_00012992/ (last visited Apr. 27, 2026).
198 See, e.g., Middlesex Cnty. Sewerage Auth. v. Sea Clammers, 453 U.S. 1, 16 (1981).
199 TransUnion LLC v. Ramirez, 594 U.S. 413, 423 (2021).
200 Bennett v. Spear, 520 U.S. 154, 162 (1997); Allen v. Wright, 468 U.S. 737, 750–51 (1984). The Court has said this
zone-of-interests test is a prudential standing requirement that can be modified or abrogated by Congress. See Bennett,
520 U.S. at 164–165. For example, the Court held that ESA’s citizen suit provision expanded the zone of interests
protected by the statute to economic as well as environmental interests, reasoning that the ESA’s provision that “any
person may commence a civil suit” constituted “an authorization of remarkable breadth,” including in comparison to
some other citizen suit provisions, and also noting that the provision’s purpose of encouraging private enforcement
supported a conclusion of expanded standing. Id.
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of the litigation.”201 If the controversy existing at the time a lawsuit was filed is no longer “live”
due to a change in the law or in the status of the parties involved, the case is considered moot, and
federal courts must generally decline to hear (or continue to preside over) it.202
Initially, courts interpreted Article III requirements generously toward environmental plaintiffs,
concluding that plaintiffs have satisfied the injury-in-fact requirement by alleging that challenged
conduct threatened aesthetic harm, harm to their interest in observing or studying certain animals,
or widespread harm shared by many others.203 While those harms are still recognized today,
beginning in the 1980s, the Supreme Court took a more demanding approach to standing,
particularly in citizen suits.204 The Court’s 1992 decision in Lujan v. Defenders of Wildlife
articulated the current, more stringent standard for the “injury in fact” prong of Article III
standing.205 In Lujan, the Court ruled that affidavits that an organization’s members intended to
travel internationally to observe endangered species were insufficient to establish standing to
challenge a policy excluding overseas projects from certain Endangered Species Act
requirements.206 The affidavits included statements that the members had previously traveled to
observe endangered species and expressed a general intent to do so in the future, but did not
identify concrete plans or a specific time when the members intended to travel again.207
Explaining that it was “substantially more difficult” to establish standing if a plaintiff “is not
himself the object of the government action or inaction he challenges,” the Court reasoned that
the affiants’ intent to return to the development sites, without a description of concrete plans,
could not support a finding of “actual or imminent” injury.208
Other cases have addressed Article III as it relates to the timing of violations alleged in citizen
suits. In general, the Court has held that citizen suits may proceed only where there are continuing
(rather than past) violations, but that the voluntary cessation of unlawful conduct after a lawsuit
has been filed does not suffice to moot the case because, absent a showing to the contrary, the
defendant could resume the unlawful conduct.209 Similarly, with respect to the redressability
prong of the Article III standing test, the Court has ruled that civil money penalties and certain
forms of injunctive relief do not establish redressability for past violations because any remedy
for past violations amounts to “vindication of the rule of law” rather than remediation of
plaintiffs’ own injuries.210 The Court has further held that the injunctive relief sought by the
plaintiffs—providing for inspection authority and compelling the production of compliance
reports—would not remediate a past wrong, and the plaintiffs had not alleged an ongoing or
201 Kingdomware Techs., Inc. v. United States, 579 U.S. 162, 168 (2016) (quoting Already, LLC v. Nike, Inc., 568 U.S.
85, 90–91 (2013)).
202 Id.; Liner v. Jafco, 375 U.S. 301, 306 n.3 (1964).
203 Sierra Club v. Morton, 405 U.S. 727, 734 (1972); United States v. Students Challenging Regul. Agency Procs.
(SCRAP), 412 U.S. 669, 687–88 (1973); Japan Whaling Ass’n v. Am. Cetacean Soc’y, 478 U.S. 221, 230 n.4 (1986);
see also Ann E. Carlson, Standing for the Environment, 45 UCLA L. REV. 931, 939-42 (1998).
204 See Cassandra Stubbs, Is the Environmental Citizen Suit Dead? An Examination of the Erosion of Standards of
Justiciability for Environmental Citizen Suits, 26 N.Y.U. REV. L. & SOCIAL CHANGE 77, 82–83 (2001); Carlson, supra
note 203, at 938.
205 504 U.S. 555 (1992).
206 Id. at 563–64.
207 Id.
208 Id. at 564. A plurality of the Court also found that the plaintiffs had not satisfied the Article III redressability
requirement. Id. at 571.
209 Gwaltney v. Chesapeake Bay Found., 484 U.S. 49, 56–63 (1987); Friends of the Earth, Inc. v. Laidlaw Env’t Servs.
(TOC), Inc., 528 U.S. 167, 173–74, 189 (2000).
210 Steel Co. v. Citizens for a Better Env’t, 523 U.S. 83, 106 (1998).
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imminent violation.211 By contrast, in the case of a continuing violation, civil money penalties
may “afford redress to citizen plaintiffs who are injured or threatened with injury as a
consequence of ongoing unlawful conduct”—even though they are payable to the U.S. Treasury
and not to plaintiffs—insomuch as they “encourage defendants to discontinue current violations
and deter them from committing future ones.”212
One example of recent litigation in the citizen suit arena focused on the traceability component of
the Article III standing test and the degree to which plaintiffs must trace specific injuries (as
opposed to injuries of a certain type) to alleged statutory violations.213 In Environment Texas
Citizen Lobby, Inc. v. ExxonMobil Corp., the district court found that the plaintiffs had standing
and had established traceability for 3,651 days of permit violations at a Texas refinery, applying
the requirement that the plaintiffs show that each alleged violation “(1) causes or contributes to
the kinds of injuries they allege and (2) has a specific geographic or other causative nexus such
that the violation could have affected their members.”214 After a divided panel of the U.S. Court
of Appeals for the Fifth Circuit, the full Fifth Circuit ordered rehearing en banc, vacated its earlier
panel opinions, and, almost two years later, issued a short per curiam opinion affirming the
district court’s ruling without addressing standing.215 The Supreme Court declined to take up the
case after the Fifth Circuit’s fractured holding, and the peculiar procedural history of the case
means there is no precedential decision on the standing question in the Fifth Circuit.216 As a
result, there is still legal uncertainty regarding the traceability showing plaintiffs must make.217
Additional Constitutional and Policy Considerations
Some critics of the citizen-suit model have expressed concerns that citizen suits may violate
separation-of-powers principles and infringe on powers delegated to the executive branch in
Article II of the Constitution by permitting private citizens to exercise an enforcement function
vested solely in the executive branch.218 Critics of citizen suits also assert that citizen suits allow
211 Id. at 108.
212 Friends of the Earth, 528 U.S. at 187–88.
213 Env’t Tex. Citizen Lobby, Inc. v. ExxonMobil Corp., 123 F.4th 309 (5th Cir. 2024) (mem.); 47 F.4th 408, 417, 419
(5th Cir. 2022).
214 Env’t Tex. Citizen Lobby, Inc. v. ExxonMobil Corp., 524 F. Supp. 3d 547, 555 (S.D. Tex. 2021).
215 Env’t Tex. Citizen Lobby, Inc., 47 F.4th 408; Env’t Tex. Citizen Lobby, Inc., 123 F.4th 309.
216 ExxonMobil Corp. v. Env’t Tex. Citizen Lobby, Inc., No. 24-982, 145 S. Ct. 2845 (June 30, 2025) (mem.) (denying
certiorari).
217 On the same day that it denied the cert petition in ExxonMobil Corp. v. Environment Texas Citizen Lobby, the
Supreme Court also declined to review the U.S. Court of Appeals for the Ninth Circuit’s holding in a different case that
environmental plaintiffs could file a CWA citizen suit in federal court to enforce state law requirements that had been
incorporated into Washington State’s Industrial Stormwater General Permit, and which were broader than federal
requirements. Port of Tacoma v. Puget Soundkeeper All., No. 24-350, 145 S. Ct. 2849 (June 30, 2025) (mem.). That
case turned on the specific language of the CWA’s citizen suit provision, and its applicability to other statutes is
unclear.
218 See Friends of the Earth, 528 U.S. at 197 (Kennedy, J., concurring) (noting that “[d]ifficult and fundamental
questions are raised when we ask whether exactions of public fines by private litigants, and the delegation of Executive
power which might be inferable from the authorization, are permissible in view of the responsibilities committed to the
Executive by Article II of the Constitution of the United States”); id. at 209 (Scalia, J., dissenting) (cautioning that
“[b]y permitting citizens to pursue civil penalties payable to the Federal Treasury, the [CWA] . . . turns over to private
citizens the function of enforcing the law,” empowering plaintiffs to “[act] as a self-appointed mini-EPA”); see also
Brief of Richard Epstein and Jeremy Rabkin as Amici Curiae in Support of Plaintiff United States of America, United
States v. DTE Energy Co., No. 10-cv-13101, 2020 WL 10730046 (E.D. Mich. Dec. 30, 2020); Charles S. Abell,
Ignoring the Trees for the Forests: How the Citizen Suit Provision of the Clean Water Act Violates the Constitution’s
Separation of Powers Principle, 81 VA. L. REV. 1957 (1995).
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private litigants to dictate enforcement priorities without the oversight and accountability that
accompany government enforcement and that citizen suits do not necessarily result in meaningful
environmental improvement.219
Advocates for citizen suits argue that such suits provide a necessary backstop where the
government lacks the resources to fully enforce environmental laws, to buffer against varying
levels of enforcement across administrations, or where regulated entities have undermined the full
federal implementation of environmental statutes.220 They also argue that the statutory provisions
authorizing citizen suits include various mechanisms authorizing the executive branch to “protect
its policy and strategy choices,” whether by engaging in its own enforcement action and thus
barring the availability of a citizen suit, intervening in a citizen suit or participating as an amicus
curiae, or commenting on a proposed citizen suit consent decree.221 According to some scholars,
these limitations also ensure that the President retains control over the enforcement of federal
laws consistent with the Take Care Clause.222 To date, while some individual Supreme Court
Justices have expressed concerns regarding the constitutionality of citizen suits, the Court as a
whole has not indicated a willingness to consider these issues.223
Criminal Enforcement
Many environmental statutes authorize criminal penalties for certain violations, which can result
in jail time for individuals, as well as potential criminal fines and restitution for both individuals
and corporations.224 As a consequence, the government carries a heavier burden of proof in
criminal cases than in administrative or civil judicial enforcement matters and must prove the
defendant’s guilt beyond a reasonable doubt.225 Criminal prosecutors within DOJ, whether in the
U.S. Attorneys’ Offices or ENRD, bring criminal cases under the pollution control laws on behalf
of the federal government.226 A felony criminal case typically begins when prosecutors obtain an
indictment from a grand jury upon a finding of probable cause that an offense has been
219 E.g., Jonathan H. Adler, Stand or Deliver: Citizen Suits, Standing, and Environmental Protection, 12 DUKE ENV’T
L. & POL’Y F. 39, 43, 49–50 (2001) (arguing that citizen suit litigation strategy may favor easier victories over those
that would bring greater environmental benefit, and noting that the vast majority of CWA citizen suits are filed against
private industry, even though municipal facilities cause more pollution).
220 James R. May, Now More Than Ever: Trends in Environmental Citizen Suits, 10 WIDENER L. REV. 1, 5–10, 30
(2003); Adler, supra note 219, at 43.
221 Jeffrey G. Miller & Brooke S. Dorner, The Constitutionality of Citizen Suit Provisions in Federal Environmental
Statutes, 27 J. ENV’T L. & LITIG. 401, 454–55 (2012).
222 Stephen M. Johnson, Private Plaintiffs, Public Rights: Article II and Environmental Citizen Suits, 49 KAN. L. REV.
383, 399–402 (2001). See also Miller & Dorner, supra note 221; Robin Kundis Craig, Will Separation of Powers
Challenges “Take Care” of Environmental Citizen Suits? Article II, Injury-in-Fact, Private “Enforcers,” and Lessons
from Qui Tam Litigation, 72 U. COLO. L. REV. 93, 171 (2001).
223 See Friends of the Earth, 528 U.S. at 197 (Kennedy, J., concurring); id. at 209 (Scalia, J., dissenting).
224 For a concise history of the development of federal environmental crimes, see Joshua Ozymy & Melissa Jarrell
Ozymy, The Politics of the Criminal Enforcement of the U.S. Clean Air Act, 47 WM. & MARY ENV’T L. & POL’Y REV.
197, 201–03 (2022).
225 In re Winship, 397 U.S. 358, 364 (1970) (“Lest there remain any doubt about the constitutional stature of the
reasonable-doubt standard, we explicitly hold that the Due Process Clause protects the accused against conviction
except upon proof beyond a reasonable doubt of every fact necessary to constitute the crime with which he is
charged.”).
226 See Just. Manual, supra note 132, § 5-11.104.
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committed.227 For misdemeanors, grand jury involvement is not required and prosecutors may
commence a case by filing a charging document referred to as an information.228
A criminal violation consists of certain “elements,” meaning the different components of the
offense that the government must prove.229 Such elements in an environmental crime can include
an act (e.g., the defendant discharged a pollutant), a particular factual situation related to the
statutory requirement (e.g., the discharge is from a “point source” or to the “ambient air” or in
violation of a permit), a mental state (e.g., the defendant acted negligently, knowingly, or
willfully), a jurisdictional fact (e.g., the discharge was to a “water of the United States”), or a
result (e.g., a person was endangered).230
Types of Criminal Provisions in Environmental Laws
Much of the conduct that can result in civil penalties under the pollution statutes can give rise to
criminal liability as well, though as a general matter criminal penalties are reserved for offenses
committed with a certain degree of knowledge or intent.231 Broadly, environmental crimes under
the pollution statutes can arise from illegal discharges,232 false recordkeeping,233 failure to make
required reports,234 and tampering with equipment,235 among others.236 Examples of criminal
pollution control law offenses and penalties can be found in Table A-3. The statutes vary
structurally, but most include penalties for violating both statutory requirements and regulatory
requirements promulgated pursuant to statutory authority.237 Some statutes also impose criminal
227 See FED. R. CRIM. P. 7; Branzburg v. Hayes, 408 U.S. 665, 687 (1972); see also CRS Infographic IG10084,
Proceedings in Federal Criminal Cases: From Initiation to Indictment, by Cassandra J. Barnum (2025).
228 See Fed. R. Crim. P. 7, 58.
229 See 1 WAYNE R. LAFAVE, SUBSTANTIVE CRIMINAL LAW § 1.2(c) (3d ed. 2025) (“The totality of these various
items—conduct, mental fault, plus attendant circumstances and specified result when required by the definition of a
crime—may be said to constitute the ‘elements’ of the crime.”).
230 See 33 U.S.C. § 1319(c) (CWA discharges in violation of a permit); 42 U.S.C. § 7413(c)(4) (CAA negligent release
of hazardous substance resulting in endangerment).
231 See “The Mens Rea Requirement,” infra; see also Joseph Brennan et. al., Environmental Crimes, 62 AM. CRIM. L.
REV. 563, 566 n.15 (2025) (noting “overlapping civil, criminal, and administrative penalties” in FIFRA, TSCA, CWA,
RCRA, and CERCLA). EPA policies have articulated factors for determining whether to pursue a violation criminally
or civilly, including egregiousness, deceptive or misleading conduct, chronic noncompliance, and the need for
immediate injunctive relief. See, e.g., Memorandum from David M. Uhlmann, Assistant Adm’r, OECA to EPA Reg’l
Couns. & Deputies et al., Strategic Civil-Criminal Enforcement Policy, at 6 (Apr. 17, 2024), https://www.epa.gov/
system/files/documents/2024-04/strategic-civil-criminal-enforcement-policy-april-2024.pdf [https://perma.cc/UWP6PBTZ]; see also Just. Manual, supra note 132, § 5-11.1112 (noting parallel civil and criminal proceedings may be
appropriate “when in the course of a civil case the government receives evidence of deliberate violations of the law
meriting criminal prosecution or when a criminal investigation uncovers evidence of an on-going violation causing
environmental contamination that should be stopped quickly through an injunctive action”).
232 See, e.g., 33 U.S.C. § 1319(c) (CWA).
233 See, e.g., 42 U.S.C. § 7413(c)(2)(A) (CAA).
234 See, e.g., 42 U.S.C. § 9603(b) (CERCLA).
235 See, e.g., 42 U.S.C. § 7413(c)(2)(C) (CAA).
236 See Table A-3.
237 See, e.g., 42 U.S.C. § 7413(c)(1) (prohibiting knowing violation of various CAA statutory requirements, “including
a requirement of any rule, order, waiver, or permit promulgated or approved under such sections or subchapters”).
These requirements can be very specific, such as the work practice standard in CAA regulations requiring wetting of
asbestos-containing materials during renovation, 40 C.F.R. § 61.145(c)(3), or very broad, such as the CAA imposition
on owners or operators of stationary sources of a “general duty” to “identify hazards which may result from such
releases using appropriate hazard assessment techniques, to design and maintain a safe facility taking such steps as are
necessary to prevent releases, and to minimize the consequences of accidental releases which do occur.” 42 U.S.C.
§ 7412(r)(1).
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penalties for violating any condition of a permit issued pursuant to the pertinent regulatory
regime.238 Certain offenses apply only to specific categories of people or employees,239 while
others apply to any person or organization.240
Violations of any particular statute can be part of a course of conduct that implicates multiple
laws.241 Acts that violate more than one law can sometimes be charged under each law violated.242
Title 18 Criminal Offenses
Other offenses in the criminal code can overlap with environmental crimes, and prosecutors often
charge defendants with violating environmental statutes as well as various, generally applicable
prohibitions codified in Title 18 of the U.S. Code.243 For example, falsifying a required discharge
monitoring report to conceal illegal discharges from regulatory agencies could constitute a
violation of the CWA, which prohibits knowingly making “any false material statement,
representation, or certification” in any document “filed or required to be maintained” under the
act.244 An initial offense is punishable by two years’ imprisonment (or four for a subsequent
offense).245 The same conduct could also potentially violate a number of prohibitions in Title 18,
238 See, e.g., 42 U.S.C. § 6928(d)(2)(B) (prohibiting treatment, storage, or disposal of hazardous waste “in knowing
violation of any material condition or requirement of such permit”).
239 For example, the CAA regulations governing the handling of asbestos apply to “the owner or operator of a
demolition or renovation activity.” 40 C.F.R. § 61.145(a). Only a person who meets that definition can be prosecuted
for violating those regulations under 42 U.S.C. § 7413(c). See United States v. Pearson, 274 F.3d 1225, 1231 (9th Cir.
2001) (articulating “substantial control” test to determine whether a person constitutes an owner or operator as “ability
to direct the manner in which work is performed and the authority to correct problems”). See also 7 U.S.C.
§ 136l(b)(1)(B) (under FIFRA, offense limited to “commercial” pesticide applicators or distributors); 42 U.S.C.
§ 9603(b) (under CERCLA, offense limited to “person in charge”).
240 See, e.g., 42 U.S.C. § 6928(d) (RCRA prohibitions apply to “any person”); 33 U.S.C. § 1319(c) (CWA prohibitions
apply to “any person”). Enforcement of environmental crimes against corporations is subject to the Department-wide
corporate enforcement policy adopted by DOJ in March 2026, which governs corporate prosecutions by all components
of the Department (with certain exceptions for the Antitrust Division). See DOJ, CORPORATE ENFORCEMENT AND
VOLUNTARY SELF-DISCLOSURE POLICY (2026), https://www.justice.gov/dag/media/1430731/dl?inline
[https://perma.cc/DJ28-HWWY]. That policy generally instructs prosecutors not to pursue criminal cases against
corporations that have “voluntarily self-disclosed misconduct,” “fully cooperated with the Department’s investigation,”
and “timely and appropriately remediated the misconduct,” unless certain “aggravating circumstances” exist. Id. at 2.
241 See Joshua Ozymy & Melissa Jarrell Ozymy, Exploring Charging and Sentencing Patterns in U.S. Clean Air Act
Criminal Prosecutions, 61 NAT. RES. J. 229, 235–37 (2021) (collecting data on cases charged under more than one
environmental statute).
242 Conduct can be charged as violating more than one law without being unconstitutionally multiplicitous as long as
each crime requires proof of at least one unique element. See Blockburger v. United States, 284 U.S. 299, 304 (1932)
(“The applicable rule is that, where the same act or transaction constitutes a violation of two distinct statutory
provisions, the test to be applied to determine whether there are two offenses or only one, is whether each provision
requires proof of a fact which the other does not.”).
243 See Ozymy & Ozymy, supra note 241, at 239, tbl. 2 (reporting that 21% of CAA cases from 1983 to 2019 include
false statement charges; 18% include conspiracy charges). One example of a case implicating multiple categories of
offenses was United States v. Moss, 872 F.3d 304, 305 (5th Cir. 2017) (“A fatal welding accident occurred on an
offshore oil platform in the Gulf of Mexico in November 2012. Three years after that incident, the government indicted
the owner and operator of the platform and several oil platform contractors, charging criminal violations of the Outer
Continental Shelf Lands Act (OCSLA), 43 U.S.C. §§ 1331, et seq., and the Clean Water Act, 33 U.S.C. §§ 1251 et seq.,
as well as involuntary manslaughter. 18 U.S.C. § 1112.”).
244 33 U.S.C. § 1319(c)(4).
245 Id.
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including the general false statement statute and several obstruction-of-justice provisions, all of
which carry higher penalties.246
The false report could also, if more than one person were involved, violate 18 U.S.C. § 371,
which prohibits conspiracies to commit any offense against the United States, as well as
conspiracies to “defraud the United States, or any agency thereof in any manner or for any
purpose.”247 Courts have said the latter type of conspiracy includes conduct that interferes with or
obstructs a lawful government function (a so-called “Klein conspiracy”).248 In a conspiracy
charge, the government must prove that there was an agreement between at least two people to
commit an offense against or defraud the United States and at least one “overt act” in furtherance
of that agreement.249 There is no requirement, however, that the government prove the underlying
substantive offense was completed to obtain a conviction for conspiracy.250
Generally applicable criminal provisions may facilitate enforcement of environmental laws that
implicate more traditional criminal acts.251 For example, fraudulent abuses of the renewable
biofuel credit program may violate CAA regulations but also constitute wire fraud.252
The Mens Rea Requirement
In general, criminal penalties apply for offenses involving a culpable state of mind, or mens
rea.253 Reflecting the “familiar proposition that ‘[t]he existence of a mens rea is the rule of, rather
than the exception to, the principles of Anglo-American criminal jurisprudence,’” courts usually
246 See 18 U.S.C. §§ 1001 (false statements; five years’ imprisonment maximum), 1505 (obstruction of a pending
proceeding, five years’ imprisonment maximum), 1512 (obstruction of an official proceeding, 20 years’ imprisonment
maximum), 1519 (destruction, alteration, or falsification of records in federal investigations, 20 years’ imprisonment
maximum).
247 18 U.S.C. § 371.
248 See United States v. Klein, 247 F.2d 908 (2d Cir.1957) (articulating conspiracy to defraud by obstructing lawful
government function principle); United States v. Overholt, 307 F.3d 1231, 1247 (10th Cir. 2002) (“One of the alleged
objects of the conspiracy was ‘to defraud the United States by impeding, impairing, obstructing, and defeating the
lawful function of the United States Environmental Protection Agency and the United States Department of
Defense.’”).
249 See United States v. Lewis, 435 F. App’x 486, 488–89 (6th Cir. 2011) (“To convict Lewis of conspiracy to defraud
under 18 U.S.C. § 371, the government was required to prove (1) that Lewis and VanSickle and Wolfe agreed to violate
the False Statements Act and the Safe Water Drinking Act and to obstruct EPA’s enforcement of its regulations by
rigging injection wells to falsify EPA tests, (2) that Lewis knowingly and intentionally entered the agreement, and (3)
that Lewis, VanSickle, or Wolfe committed one or more overt acts ‘constituting actual participation in the
conspiracy.’”).
250 LAFAVE, supra note 229, § 12.1(a) (“The agreement constitutes the act, while the intention to thereby achieve the
objective is the mental state; it is not necessary that the objective have been realized.”).
251 See David M. Uhlmann, Prosecutorial Discretion and Environmental Crime, 38 HARV. ENV’T L. REV. 159, 184
(2014) (noting “inclusion of Title 18 charges incorporates the traditional ‘badges of criminality’ that prosecutors
emphasize when exercising discretion” and that “judges are more familiar with (and more receptive to) Title 18
charges”).
252 See United States v. Davanzo, No. 2:15-CR-00141 (M.D. Fla. Oct. 1, 2015) (defendants engaged in fraudulent sale
of renewable biofuel credits under EPA’s Renewable Fuel Standard program charged with wire fraud and money
laundering).
253 See CRS Report R46836, Mens Rea: An Overview of State-of-Mind Requirements for Federal Criminal Offenses, by
Michael A. Foster (2021); Morissette v. United States, 342 U.S. 246, 250–51 (1952) (in criminal case, “relation
between some mental element and punishment for a harmful act is almost as instinctive as the child’s familiar
exculpatory ‘But I didn’t mean to’”).
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interpret laws without any explicit mens rea requirement to require that a person act with some
degree of intent in order to incur criminal liability.254
Certain laws include negligent offenses, generally meaning that the offender acts without
exercising the requisite degree of care.255 Knowledge is the most common mental state specified
in environmental laws, and generally means awareness of the conduct at issue, that is, the conduct
is not the result of mistake or accident.256 Other statutes impose criminal penalties where a person
acts willfully, generally meaning the person is aware the conduct is illegal and acts with intent to
break the law.257
Negligence
Negligence, a concept central to tort law, generally means the failure to exercise due care.258
Negligent conduct rarely gives rise to criminal liability, but certain federal laws do impose
criminal penalties for negligent conduct, including the CWA and the CAA.259 Under these
provisions, when a person fails to exercise the requisite due care, and illegal discharges or other
pollution events result, criminal liability can arise even absent any intent to cause those events.260
The CWA authorizes criminal fines and up to one year of imprisonment for two categories of
offenders: first, any person who “negligently violates” a series of statutory requirements or permit
conditions,261 and second, any person who “negligently introduces into a sewer system or into a
publicly owned treatment works any pollutant or hazardous substance which such person knew or
reasonably should have known could cause personal injury or property damage,” or who makes
such a negligent discharge in violation of permits or local requirements, and thereby causes the
254 United States v. U.S. Gypsum Co., 438 U.S. 422, 436 (1978) (quoting Dennis v. United States, 341 U.S. 494, 500
(1951)); see also id. at 438 (noting “generally disfavored status” of strict liability offenses and stating that “far more
than the simple omission of the appropriate phrase from the statutory definition is necessary to justify dispensing with
an intent requirement”). Whether such a violation requires any intent element may depend on the court considering the
particular case. Compare United States v. Mast, 938 F.3d 973, 977 (8th Cir. 2019) (“Because neither the statutory
language nor the legislative history indicates an intent to dispense with a mental state requirement as an element of
§ 668dd(f)(2), courts may not treat the statute as setting out a strict liability offense; some mental state is required.”)
with United States v. Blow, No. 2:25PO2, 2025 WL 1699832, at *6 (E.D. Va. June 17, 2025) (“Other courts have
grappled with whether § 668dd(f)(2) includes a mental state element. This Court finds that the statute does not,
meaning that the Government need not prove that Blow acted with a specific mental state to convict him of violating
§ 668dd(f)(2).”).
255 See, e.g., 33 U.S.C. § 1319(c)(1); 42 U.S.C. § 7413(c)(4).
256 See Karen M. Hansen, “Knowing” Environmental Crimes, 16 WM. MITCHELL L. REV. 987 (1990) (noting most
environmental statutes “target for criminal liability certain conduct that is engaged in ‘knowingly’” and citing FIFRA,
TSCA, CWA, RCRA, CAA, CERCLA, and EPCRA).
257 See, e.g., 42 U.S.C. § 300h-2(b)(2)(2).
258 See Negligence, BLACK’S LAW DICTIONARY (12th ed. 2024) (defining negligence as tort action grounded in “failure
to exercise the standard of care that a reasonably prudent person would have exercised in a similar situation”).
259 See 33 U.S.C. § 1319(c)(1) (negligent discharges to waters or treatment facilities); 42 U.S.C. § 7413(c)(4) (negligent
endangerment by release of hazardous air pollutants). Though it does not invoke negligence by name, the Hazardous
Materials Transportation Act imposes criminal penalties on any person who “knowingly” tampers with hazardous
waste labels, packaging materials, or vehicles transporting hazardous waste, and states a person acts knowingly when
“a reasonable person acting in the circumstances and exercising reasonable care would have that knowledge[.]”
49 U.S.C. § 5124(b)(1)(B). Other examples of laws criminalizing negligent conduct include the Lacey Act, 16 U.S.C. §
3373(d)(2) (knowingly transacting in wildlife when in the exercise of due care one should know the wildlife had been
illegally taken, possessed, transported, or sold), and the seaman’s manslaughter statute, 18 U.S.C. § 1115 (negligence
by vessel captains or employees resulting in loss of life).
260 See Stacey P. Geis, An Accident Waiting to Happen: Prosecuting Negligence-Based Environmental Crimes, 59 U.S.
ATT’YS BULL. 33 (July 2011).
261 33 U.S.C. § 1319(c)(1)(A).
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facility to violate a permit condition.262 The statute does not define “negligently,” but courts have
generally interpreted this provision to employ an “ordinary negligence” standard—that is,
factfinders must determine whether the defendant failed to “exercise the degree of care that
someone of ordinary prudence would have exercised in the same circumstance.”263
The CAA authorizes criminal fines and up to a year of imprisonment for “[a]ny person who
negligently releases into the ambient air” certain hazardous substances, “and who at the time
negligently places another person in imminent danger of death or serious bodily injury.”264 Courts
have not addressed in published opinions what “negligently” means in the context of this
provision, but at least one court has given jury instructions defining the term as “failure to
exercise the degree of care that someone of ordinary prudence would have exercised in the same
circumstances.”265 Several cases charged under this provision have involved defendants
disturbing, or causing the disturbance of, asbestos-containing materials in the course of
renovation or demolition projects, resulting in the exposure of workers to inhalation of highly
toxic asbestos fibers.266
Knowledge
Many environmental crimes require proof that the defendant acted “knowingly.”267 Courts have
grappled with the question of what the government must prove to establish a “knowing” violation
under a variety of environmental statutes.268 The Supreme Court has said that, “unless the text of
the statute dictates a different result, the term ‘knowingly’ merely requires proof of knowledge of
the facts that constitute the offense.”269 Courts generally disfavor so-called “mistake of law”
defenses to “knowing” offenses, in recognition of the traditional principle that “ignorance of the
law is no excuse.”270 In other words, not knowing about or misunderstanding a prohibition does
not excuse violating it.
262 Id. § 1319(c)(1)(B). Penalties for both negligent violations double for subsequent convictions. Id. § 1319(c)(1).
263 United States v. Ortiz, 427 F.3d 1278, 1283 (10th Cir. 2005) (interpreting Clean Water Act phrase “negligently
violates” in 33 U.S.C. § 1319(c)(1)(A)); see also United States v. Pruett, 681 F.3d 232, 242 (5th Cir. 2012)
(“[33 U.S.C.] § 1319(c)(1)(A) requires only proof of ordinary negligence,” that is, “failure to exercise the standard of
care that a reasonably prudent person would have exercised in a similar situation”); United States v. Hanousek, 176
F.3d 1116, 1120–21 (9th Cir. 1999) (same); United States v. Maury, 695 F.3d 227, 257–58 (3d Cir. 2012) (noting a
“slowly expanding body of law from our sister circuits which indicates that simple or ordinary negligence may be the
appropriate standard of mens rea under § 1319(c)(1)” and finding district court did not err in jury instructions to that
effect).
264 42 U.S.C. § 7413(c)(4). The penalty doubles for subsequent convictions. Id. One commentator has observed that the
use of “negligently” in reference to both the release and the endangerment makes it “necessary to show that the alleged
violator violated a duty to prevent the release and a duty to foresee that a release would endanger someone.” John
Armstrong West, Negligent Violations of the Environmental Laws: What Standard for Criminal Prosecution?, 20 N.
KY. L. REV. 167, 178 (1992).
265 Court’s Instructions to the Jury at 23, United States v. Hylton, No. 06-cr-299 (W.D. Okla. Aug. 20, 2007), Dkt. No.
62.
266 See, e.g., United States v. Miller, No. 1:15-CR-00163 (D.D.C. Nov. 10, 2015); United States v. Morales, No. 2:21CR-00199 (D. Nev. July 14, 2021); United States v. Pilling, No. 4:22-CR-00282 (D. Idaho Dec. 14, 2022).
267 The negligent and willful offenses discussed herein are the exceptions to this rule.
268 See United States v. Atl. States Cast Iron Pipe Co., No. 03-852, 2007 WL 2282514, at *22–39 (D.N.J. Aug. 2, 2007)
(reviewing cases), aff’d sub nom., United States v. Maury, 695 F.3d 227 (3d Cir. 2012).
269 Bryan v. United States, 524 U.S. 184, 193 (1998).
270 United States v. Int’l Mins. & Chem. Corp., 402 U.S. 558, 562 (1971); see also United States v. Hansen, 262 F .3d
1217, 1253 (11th Cir. 2001) (CERCLA requires proof defendant knew of the release, but not proof he knew of the
requirement to report it).
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Where a statutory violation is predicated on a legal requirement, the distinction between fact and
law can blur. For example, where the CAA imposes penalties on “any person who knowingly
violates any requirement” of the act, does that mean that the person has to be aware of the facts
constituting the offense (for example, that they are causing the release of asbestos), or does the
person also need to be aware that the CAA imposes certain requirements for how to handle
asbestos and that the person’s conduct violates those requirements?271 Where RCRA prohibits
knowingly transporting hazardous waste to an unpermitted facility, does the defendant need to
know that the facility is unpermitted, or just that he is transporting hazardous waste to that
facility?272 In this vein, the Court has recognized that in some statutes, it can be unclear “how far
down the sentence the word ‘knowingly’ is intended to travel[.]”273
The Court has taken different approaches to this issue depending on context. For example, in a
case of a law prohibiting use of food stamps “in any manner not authorized” by the statute or
regulations, the Court held that “there is a legal element in the definition of the offense”274 and
that to allow conviction without proof of knowledge that the stamps were being used in an
unauthorized fashion “would be to criminalize a broad range of apparently innocent conduct.”275
The Court has viewed the matter differently, however, with respect to certain “public welfare
offenses.”276 Such cases involve “dangerous or deleterious devices” or “obnoxious waste
materials” where “the probability of regulation is so great that anyone who is aware that he is in
possession of them or dealing with them must be presumed to be aware of the regulation.”277 On
this basis, the Court affirmed the conviction of a defendant charged with shipping corrosive acids
in violation of a law imposing criminal penalties for “knowingly violating” applicable regulations
where he had shipped the acids without identifying them as the regulations required, irrespective
of his knowledge of those regulations.278 In more recent decisions, the Court has also looked to
statutory penalties to inform its analysis, with “severe penalties counsel[ing] in favor of a strong
scienter requirement” and against application of the public welfare offense doctrine.279
Lower courts differ in how they have applied the public welfare doctrine to modern pollution
statutes, with analyses varying from statute to statute. Courts have tended to agree that RCRA and
CERCLA, which regulate hazardous waste, are public welfare statutes and do not require proof of
271 42 U.S.C. § 7413(c)(1); see also United States v. Weintraub, 273 F.3d 139, 146 (2d Cir. 2001) (holding that the
phrase “knowingly violated” in the CAA “may plausibly be read to require either knowledge that the conduct in
question violated the law or knowledge of the facts and circumstances that amount to a violation, without specific
knowledge of the law”).
272 42 U.S.C. § 6928(d)(1).
273 Liparota v. United States, 471 U.S. 419, 424 n.7 (1985) (quoting WAYNE R. LAFAVE & AUSTIN W. SCOTT, JR.,
CRIMINAL LAW § 27 (1972)).
274 Id. at 426 n.9.
275 Id. at 426; see also id. at 426–27 (“Such a reading would also render criminal a nonrecipient of food stamps who
‘possessed’ stamps because he was mistakenly sent them through the mail due to administrative error, ‘altered’ them by
tearing them up, and ‘transferred’ them by throwing them away.”).
276 Morissette v. United States, 342 U.S. 246, 255–56 (1952).
277 United States v. Int’l Mins. & Chem. Corp., 402 U.S. 558, 565 (1971). By contrast, Court held in another case that
gun ownership is sufficiently widespread and lawful so as not to trigger a presumption of awareness of regulation.
Staples v. United States, 511 U.S. 600, 608 (1994).
278 Int’l Mins. & Chem. Corp., 402 U.S. at 559. The law, since repealed, subjected anyone who “knowingly violated”
Interstate Commerce Commission regulations to criminal penalties. See 18 U.S.C. § 834(f) (repealed 1979).
279 Ruan v. United States, 597 U.S. 450, 60 (2022); accord United States v. X-Citement Video, Inc., 513 U.S. 64, 72
(1994); Rehaif v. United States, 588 U.S. 225, 232 (2019).
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the defendant’s knowledge of legal requirements.280 The same is largely true with respect to the
CAA,281 but courts considering the CWA have diverged more widely with respect to whether it is
a public welfare statute.282 In some cases, courts have framed their analysis of a given law in
terms of the substance at issue rather than the law more broadly; a court might determine that a
reasonable person would be aware that asbestos is a heavily regulated substance, for example,
irrespective of whether a violation of the CAA is categorically a public welfare offense.283
Regardless of whether a particular offense requires proof of the defendant’s awareness of a legal
requirement, courts generally recognize “mistake-of-fact” defenses to statutes with a “knowing”
mens rea element. The mistake-of-fact defense allows a defendant to be acquitted if a jury finds
he was genuinely mistaken about an element of the offense, such as a hypothetical “transporter
280 See, e.g., United States v. Laughlin, 10 F.3d 961, 965 (2d Cir. 1993) (observing, in prosecution for violation of
RCRA, 42 U.S.C. § 6928(d)(2)(A), “When knowledge is an element of a statute intended to regulate hazardous or
dangerous substances, the Supreme Court has determined that the knowledge element is satisfied upon a showing that a
defendant was aware that he was performing the proscribed acts; knowledge of regulatory requirements is not
necessary”); see also United States v. Dean, 969 F.2d 187, 192 (6th Cir. 1992); United States v. Self, 2 F.3d 1071,
1089–91 (10th Cir. 1993); United States v. Baytank (Houston), Inc., 934 F.2d 599, 612 (5th Cir. 1991); United States v.
Dee, 912 F.2d 741, 745 (4th Cir. 1990); United States v. Hoflin, 880 F.2d 1033, 1038 (9th Cir. 1989); United States v.
Hayes Int’l Corp., 786 F.2d 1499, 1503 (11th Cir. 1986); United States v. MacDonald & Watson Waste Oil Co.,
933 F.2d 35, 50 (1st Cir. 1991). But see United States v. Johnson & Towers, Inc., 741 F.2d 662, 669 (3d Cir. 1984)
(“[I]n order to convict each defendant the jury must find that each knew that Johnson & Towers was required to have a
permit, and knew that Johnson & Towers did not have a permit.”). With respect to CERCLA, see, e.g., Laughlin,
10 F.3d at 966–967 (“In accordance with our interpretation of ‘knowingly’ in RCRA, discussed supra, we find that
section 9603(a) does not demand knowledge of the regulatory requirements of CERCLA; it demands only that
defendant be aware of his acts.”); United States v. Buckley, 934 F.2d 84, 88 (6th Cir. 1991); United States v. Greer,
850 F.2d 1447, 1450–51 (11th Cir. 1988).
281 Compare United States v. Alghazouli, 517 F.3d 1179, 1193 (9th Cir. 2008) (“[T]he CAA is a public welfare statute
dealing with harmful substances.”), United States v. Ho, 311 F.3d 589, 606 (5th Cir. 2002) (“knowingly” in CAA
means knowledge of facts, not law, in part because “the CAA as a whole is a public welfare statute”), and United States
v. Buckley, 934 F.2d 84, 88 (6th Cir. 1991) (applying International Minerals to CAA), with United States v.
Weintraub, 273 F.3d 139, 151 (2d Cir. 2001) (applying International Minerals to asbestos offense under CAA, but
limiting holding to asbestos cases and reserving judgment on whether CAA is more broadly a public welfare offense).
282 Compare United States v. Weitzenhoff, 35 F.3d 1275, 1286 (9th Cir. 1993) (“The criminal provisions of the CWA
are clearly designed to protect the public at large from the potentially dire consequences of water pollution and as such
fall within the category of public welfare legislation. International Minerals rather than Liparota controls the case at
hand.”) (citation omitted), United States v. Hopkins, 53 F.3d 533, 538–39 (2d Cir. 1995) (applying “presumption of
regulation” reasoning to the CWA); United States v. Sinskey, 119 F.3d 712, 716 (8th Cir. 1997) (holding that
“knowingly violates” language in the CWA does not require knowledge that acts violate the CWA or a permit, in part
because the CWA is a public welfare law), and United States v. Wilson, 133 F.3d 251, 263–264 (4th Cir. 1997) (“Even
though the materials involved in this case, fill and native soil from a wetland, may not be inherently deleterious, the
Clean Water Act is, as a general matter, largely concerned with pollutants that are inherently deleterious.”), with United
States v. Ahmad, 101 F.3d 386, 391 (5th Cir. 1996) (holding that illegal discharges under the CWA are not public
welfare offenses because they are “felonies punishable by years in federal prison” and “‘dispensing with mens rea
would require the defendant to have knowledge only of traditionally lawful conduct’” (quoting Staples, 511 U.S. at
618)); see also Hanousek v. United States, 528 U.S. 1102 (2000) (mem) (Thomas, J., dissenting) (“Although provisions
of the CWA regulate certain dangerous substances, this case illustrates that the CWA also imposes criminal liability for
persons using standard equipment to engage in a broad range of ordinary industrial and commercial activities. This fact
strongly militates against concluding that the public welfare doctrine applies.”).
283 See Weintraub, 273 F.3d at 149 (“Unlike the generic category of ‘guns’ in Staples, the category of ‘asbestos’ is
easily sufficient to trigger an expectation of regulation in a reasonable person and to distinguish in his or her mind
innocent from wrongful conduct.”); United States v. Rubenstein, 403 F.3d 93 (2d Cir. 2005) (quoting favorably
language from Weintraub that “no one can reasonably claim surprise that asbestos is regulated and that some form of
liability is possible for violating those regulations” and rejecting argument from Hasidic defendants that their lack of
knowledge was reasonable “by virtue of their insular lives”). This approach reflects the principle emphasized in
Liparota, Staples, and X-citement Video that scienter requirements are of particular import where a statute could
criminalize a subtype of “apparently innocent” conduct—like using a food stamp, owning a gun, or transporting
explicit material.
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who relied in good faith upon a recipient’s fraudulent certificate”284 or the defendant who argued
he believed he was discharging water instead of gasoline.285
Willful Blindness
Courts typically allow prosecutors to prove the knowledge element of criminal offenses by
demonstrating that the defendant was “willfully blind” to the operative facts.286 The Supreme
Court has articulated the standard as consisting of two requirements: “(1) The defendant must
subjectively believe that there is a high probability that a fact exists and (2) the defendant must
take deliberate actions to avoid learning of that fact.”287 Such a showing establishes a state of
mind that “surpasses negligence and recklessness” because a willfully blind defendant “can
almost be said to have actually known the critical facts.”288
Willful blindness can be proved by circumstantial evidence, as in one RCRA case where the
defendant, who was knowledgeable of hazardous waste disposal requirements, hired an
inexperienced contractor to remove hazardous chemical waste.289 The court found “a jury could
reasonably infer that [the defendant’s] failure to make proper inquiry and to provide a proper
manifest were tantamount to willful blindness to the ultimate destination and disposal of the
waste.”290
Certain environmental statutes specify that willful blindness constitutes knowledge. For example,
the CAA and TSCA provide that, “in proving a defendant’s possession of actual knowledge,
circumstantial evidence may be used, including evidence that the defendant took affirmative steps
to be shielded from relevant information.”291 RCRA includes nearly identical language with
respect to its “knowing endangerment” offense.292
284 United States v. Speach, 968 F.2d 795, 796 (9th Cir. 1992) (citing United States v. Hayes Int’l Corp., 786 F.2d
1499, 1504 (11th Cir.1986)).
285 See Ahmad, 101 F.3d at 393; Wilson, 133 F.3d at 262 (“Congress intended that the defendant have knowledge of
each of the elements constituting the proscribed conduct even if he were unaware of their legal significance. This
interpretation would not carry with it the corollary that the defendant’s ignorance of his conduct’s illegality provides
him a defense, but would afford a defense for a mistake of fact.”); United States v. W. Indies Transp., 127 F.3d 299,
310 (3d Cir. 1997) (“The purpose of adding the word ‘knowingly’ is to insure that no one will be convicted for an act
done because of mistake, accident, or other innocent reason”).
286 See, e.g., United States v. MacDonald & Watson Waste Oil Co., 933 F.2d 35, 52 (1st Cir. 1991) (approving of jury
instruction that the element of knowledge in RCRA prosecution could be satisfied by proof of willful blindness).
287 Global-Tech Appliances, Inc. v. SEB S.A., 563 U.S. 754, 769 (2011).
288 Id.; see also United States v. Buckley, 934 F.2d 84, 88 (6th Cir. 1991) (in CAA prosecution for asbestos violations,
approving jury instruction that “the government could establish Buckley’s knowledge by showing that Buckley closed
his eyes to obvious facts or failed to investigate when aware of facts which demanded investigation”); United States v.
Hopkins, 53 F.3d 533, 542 (2d Cir. 1995) (affirming use of willful blindness jury instruction where defendant “had
studiously avoided confirming the tampering” and had told an employee responsible for sampling, “I know nothing, I
hear nothing”).
289 United States v. Wasserson, 418 F.3d 225, 238 (3d Cir. 2005).
290 Id.; see also United States v. Hayes Int’l Corp., 786 F.2d 1499, 1504 (11th Cir. 1986) (“It is common knowledge
that properly disposing of wastes is an expensive task, and if someone is willing to take away wastes at an unusual
price or under unusual circumstances, then a juror can infer that the transporter knows the wastes are not being taken to
a permit facility.”).
291 42 U.S.C. § 7413(c)(5)(B); see also 15 U.S.C. § 2615 (incorporating CAA provisions into TSCA).
292 42 U.S.C. § 6928(f) (“[I]n proving the defendant’s possession of actual knowledge, circumstantial evidence may be
used, including evidence that the defendant took affirmative steps to shield himself from relevant information.”).
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Willfulness
Several criminal provisions of the pollution statutes use the term “willfully.” Examples include
the SDWA prohibition on violating “any requirement of an applicable underground injection
control program” (which, when “such violation is willful,” is subject to criminal penalties);293 the
HMTA prohibition on “willfully or recklessly violating” the statute or any regulatory requirement
thereunder;294 and the TSCA provision that any person who “knowingly and willfully” violates
that law and thereby knowingly “places an individual in imminent danger of death or serious
bodily injury” is subject to enhanced penalties.295
Crimes predicated on “willful” misconduct generally require prosecutors to prove not just that
defendants knew of the factual underpinnings of the violation, but also that “the defendant acted
with knowledge that his conduct was unlawful.”296 The government is not generally required to
prove that the defendant knew the precise statutory or regulatory provision being violated; rather,
it suffices for the government to prove that the defendant was generally aware his actions were
illegal.297 The Supreme Court has held that certain “highly technical” statutes, such as particular
tax offenses and financial crimes, “‘carv[e] out an exception to the traditional rule’ that ignorance
of the law is no excuse and require that the defendant have knowledge of the law.”298 In such
cases, the Court has required prosecutors to prove the defendant’s knowledge of particular
statutory requirements.299
At least one court has declined to apply that “highly technical” exception to an environmental
statute: in United States v. Overholt, the U.S. Court of Appeals for the Tenth Circuit held that a
SDWA prohibition on willful violation of an underground injection control program requirement
required the government to prove only that the defendant knew his conduct was unlawful—not
that he knew the specific requirement being violated.300 The court found that, notwithstanding the
complexity of environmental regulation, the general principles underlying the public welfare
offense doctrine weighed against a heightened mens rea requirement. In that vein, the court wrote
that “we strongly doubt that as the federal government has sought to protect the environment by
imposing more and more restrictions on those handling dangerous chemicals, Congress has
intended to reduce the burden on such persons to inform themselves of what the law requires.” 301
293 42 U.S.C. § 300h-2(b)(2)(2).
294 49 U.S.C. § 5124(a).
295 15 U.S.C. § 2615(b)(2)(A). TSCA uses a “knowing or willful” standard for non-endangerment offenses. Id.
§ 2615(b)(1) (emphasis added).
296 Ratzlaf v. United States, 510 U.S. 135, 137 (1994); see also 49 U.S.C. § 5124(c) (for purposes of the HMTA, “a
person acts willfully when—(1) the person has knowledge of the facts giving rise to the violation; and (2) the person
has knowledge that the conduct was unlawful.”).
297 See Bryan v. United States, 524 U.S. 184, 191 (1998).
298 Id. at 195 (quoting Cheek v. United States, 498 U.S. 192, 201 (1991)); see also Ratzlaf, 510 U.S. at 149.
299 Cheek held a “willful” criminal tax offense required proof the defendant knew the particular requirement being
violated, 498 U.S. at 201; Ratzlaf dealt with a law prohibiting willfully structuring financial transactions to avoid
reporting requirements, and held the law required proof that the defendant knew not only of the fact that he was
structuring transactions to avoid reporting, but also of the specific law making such structuring illegal, 510 U.S. at 149.
300 United States v. Overholt, 307 F.3d 1231, 1246 (10th Cir. 2002).
301 Id.
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Corporate Intent
The U.S. Code generally, and various pollution control laws specifically, define “person” to
include corporations.302 Because corporations cannot have a “mental state” as such, courts have
analyzed corporate mens rea by reference to vicarious liability—the principle that corporations
can be responsible for the acts of their employees acting in the scope of their employment with
the intent to benefit the corporation.303 This principle applies to knowledge as well as acts: where
an employee acts knowingly, for example, that knowledge can be imputed to the corporation.304
In some cases, there might be no single employee within an organization who has knowledge of
the full set of facts underlying the offense.305 Some courts have recognized a “collective
knowledge” doctrine, allowing prosecutors to aggregate the knowledge of various employees and
impute the totality of that knowledge to the organizational defendant.306 Other courts have been
wary or critical of this approach.307
Responsible Corporate Officers
The “responsible corporate officer” (RCO) doctrine has allowed for certain corporate officers and
employees to be convicted for offenses committed by other employees of the corporation under
some circumstances. The doctrine derives from two Supreme Court cases arising under food and
drug safety laws: United States v. Dotterweich308 and United States v. Park.309 These cases
involved high-level corporate officers being convicted for strict liability drug and food safety
offenses, respectively, without any proof the individual defendants knew of the violations. The
Court’s rationale was that the defendants were in a position to prevent the violations by virtue of
their corporate authority and that, in keeping with the public welfare offense doctrine, it was fair
to assume that where statutes aim to protect the public from certain dangers, Congress intended to
302 See 1 U.S.C. § 1 (“In determining the meaning of any Act of Congress, unless the context indicates otherwise . . .
the words ‘person’ and ‘whoever’ include corporations, companies, associations, firms, partnerships, societies, and
joint stock companies, as well as individuals[.]”); see also, e.g., 42 U.S.C. § 7602(e) (CAA); 33 U.S.C. § 1362(5)
(CWA); 42 U.S.C. § 6903(15) (RCRA).
303 See, e.g., United States v. MacDonald & Watson Waste Oil Co., 933 F.2d 35, 42 (1st Cir. 1991); United States v.
Oceanic Illsabe Ltd., 889 F.3d 178, 195 (4th Cir. 2018); United States v. Ionia Mgmt., 555 F.3d 303, 309 (2d Cir.
2009). The employee need not be solely motivated to benefit the corporation; some degree of intent is enough. See
Oceanic Illsabe, 889 F.3d at 197 (“As long as the corporate agent intends, at least in part, to benefit his employer, the
corporate entity can be criminally liable, even if the agent is also acting for his own benefit.”); United States v. AgostoVega, 617 F.3d 541, 553 (1st Cir. 2010).
304 See United States v. Philip Morris USA Inc., 566 F.3d 1095, 1118 (D.C. Cir. 2009) (“Because a corporation only
acts and wills by virtue of its employees, the proscribed corporate intent depends on the wrongful intent of specific
employees.”)
305 See David M. Uhlmann, The Pendulum Swings: Reconsidering Corporate Criminal Prosecution, 49 U.C. DAVIS L.
REV. 1235, 1280 (2016) (“Corporations compartmentalize knowledge and subdivide operational duties to promote
corporate efficiency.”).
306 See United States v. Bank of New England, N.A., 821 F.2d 844, 856 (1st Cir. 1984) (“[A] corporation cannot plead
innocence by asserting that the information obtained by several employees was not acquired by any one individual who
then would have comprehended its full import. Rather the corporation is considered to have acquired the collective
knowledge of its employees and is held responsible for their failure to act accordingly.” (quoting United States v.
T.I.M.E.–D.C., Inc., 381 F. Supp. 730, 738 (W.D. Va. 1974))).
307 See, e.g., Philip Morris USA Inc., 566 F.3d at 1122 (“Like Defendants and other courts, we are dubious of the legal
soundness of the “collective intent” theory.”); see also Mark Rush et al., Corporate Responsibility: Who Could Be
Subject to a Corporation’s Criminal Liability?, 39 E. MIN. L. FOUND. § 10.04 (2018) (describing circuit split).
308 320 U.S. 277 (1943).
309 421 U.S. 658 (1975); see United States v. MacDonald & Watson Waste Oil Co., 933 F.2d 35, 51 (1st Cir. 1991)
(“The seminal cases regarding the responsible corporate officer doctrine are” Dotterweich and Park).
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burden those with the opportunity to prevent the hazard rather than “to throw the hazard on the
innocent public who are wholly helpless.”310 Such statutes allow for conviction, the Court held in
Park, where the government proves “the defendant had, by reason of his position in the
corporation, responsibility and authority either to prevent in the first instance, or promptly to
correct, the violation complained of, and that he failed to do so.”311
Since Dotterweich and Park, the RCO doctrine has evolved primarily in the context of
environmental enforcement actions.312 When Congress amended the Water Pollution Control Act
(now known as the CWA) in 1972, it included a provision to the effect that, for purposes of the
act’s criminal penalties provision, the word “person” included “any responsible corporate
officer.”313 In 1977, two years after Park was decided, Congress similarly amended the CAA to
add “responsible corporate officer” to the act’s definition of “person” for purposes of criminal
enforcement.314 According to the Senate committee report accompanying that amendment, the
provision was “based on a similar definition in the enforcement section of the Federal Water
Pollution Control Act. The committee intends that criminal penalties be sought against those
corporate officers under whose responsibility a violation has taken place, and not just those
employees directly involved in the operation of the violating source.”315
The application of the RCO doctrine in the environmental context is complicated by the fact that
Dotterweich and Park dealt with strict liability FDCA offenses, while the modern pollution
statutes have explicit scienter requirements. Courts have taken differing approaches to the
questions of what mental state RCOs must have to be criminally liable for the acts of corporate
employees and how that mental state can be proven. A number of courts have held that statutes
with “knowing” mens rea standards require proof of actual knowledge or willful blindness on the
part of any defendant and that juries may not infer knowledge solely on the basis of the RCO’s
corporate position and responsibility.316 The Third Circuit has suggested that such an inference
310 Dotterweich, 320 U.S. at 285.
311 Park, 421 U.S. at 673–674.
312 See Katrice Bridges Copeland, The Crime of Being in Charge: Executive Culpability and Collateral Consequences,
51 AM. CRIM. L. REV. 799, 809 (2014) (“In the twenty years following the Park decision, the overwhelming majority of
responsible corporate officer prosecutions were based on violations of environmental laws rather than the FDCA.”);
Martin Petrin, Circumscribing the “Prosecutor’s Ticket to Tag the Elite”- A Critique of the Responsible Corporate
Officer Doctrine, 84 TEMP. L. REV. 283, 290 (2012) (“The RCO doctrine’s most important field of application,
however, has become liability under environmental statutes on both the federal and state level.”). The doctrine has been
applied primarily in criminal matters but has been used in civil cases as well. See Utah Physicians for a Healthy Env’t
v. Diesel Power Gear LLC, 374 F. Supp. 3d 1124, 1137 (D. Utah 2019) (“Although the Tenth Circuit has not spoken on
this issue, a number of other courts have held responsible corporate officers can be held liable in CAA and Clean Water
Act civil enforcement actions, despite the absence of specific language to that effect in the citizen enforcement
provisions.”).
313 Federal Water Pollution Control Act Amendments of 1972, Pub. L. No. 92-500, § 2, 86 Stat. 816, 860 (codified at
33 U.S.C. § 1319(c)(6)).
314 Clean Air Amendments Act of 1977, Pub. L. No. 95-95, § 111, 91 Stat. 685, 705 (codified at 42 U.S.C.
§ 7413(c)(6)).
315 S. REP. NO. 95-127, at 51 (1977); see also United States v. Hagerman, 525 F. Supp. 2d 1058, 1067 (S.D. Ind. 2007)
(prison exposure for RCOs incentivizes compliance with
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