Document ID: EPA-HQ-OW-2021-0602-0001
Agency: epa
Document Type: Proposed Rule
Title: Revised Definition of Waters of the United States
Posted Date: 2021-12-07T05:00Z

[Federal Register Volume 86, Number 232 (Tuesday, December 7, 2021)]
[Proposed Rules]
[Pages 69372-69450]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-25601]

[[Page 69371]]

Vol. 86

Tuesday,

No. 232

December 7, 2021

Part II

Department of Defense

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 Department of the Army, Corps of Engineers

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33 CFR Part 328

Environmental Protection Agency

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40 CFR Part 120

Revised Definition of ``Waters of the United States''; Proposed Rule

  Federal Register / Vol. 86 , No. 232 / Tuesday, December 7, 2021 / 
Proposed Rules  

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DEPARTMENT OF DEFENSE

Department of the Army, Corps of Engineers

33 CFR Part 328

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 120

[EPA-HQ-OW-2021-0602; FRL-6027.4-03-OW]

Revised Definition of ``Waters of the United States''

AGENCY: Department of the Army, Corps of Engineers, Department of 
Defense; and Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) and the Department 
of the Army (``the agencies'') are publishing for public comment a 
proposed rule defining the scope of waters protected under the Clean 
Water Act. This proposal is consistent with the Executive Order signed 
on January 20, 2021, on ``Protecting Public Health and the Environment 
and Restoring Science to Tackle the Climate Crisis,'' which directed 
the agencies to review the agencies' rule promulgated in 2020 defining 
``waters of the United States.'' This proposed rule would meet the 
objective of the Clean Water Act and ensure critical protections for 
the nation's vital water resources, which support public health, 
environmental protection, agricultural activity, and economic growth 
across the United States.

DATES: Comments must be received on or before February 7, 2022. Please 
refer to the SUPPLEMENTARY INFORMATION section for additional 
information on the public hearing.

ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-
OW-2021-0602, by any of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov/ 
(our preferred method). Follow the online instructions for submitting 
comments.
     Email: [email protected]. Include Docket ID No. EPA-HQ-OW-
2021-0602 in the subject line of the message.
    Instructions: All submissions received must include Docket ID No. 
EPA-HQ-OW-2021-0602. Comments received may be posted without change to 
https://www.regulations.gov/, including any personal information 
provided. For detailed instructions on sending comments and additional 
information on the rulemaking process, see the ``Public Participation'' 
heading of the SUPPLEMENTARY INFORMATION section of this document. Out 
of an abundance of caution for members of the public and our staff, the 
EPA Docket Center and Reading Room are open to the public by 
appointment only to reduce the risk of transmitting COVID-19. Our 
Docket Center staff also continues to provide remote customer service 
via email, phone, and webform. Hand deliveries and couriers may be 
received by scheduled appointment only. For further information on EPA 
Docket Center services and the current status, please visit us online 
at https://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT: Damaris Christensen, Oceans, Wetlands 
and Communities Division, Office of Water (4504-T), Environmental 
Protection Agency, 1200 Pennsylvania Avenue NW, Washington, DC 20460; 
telephone number: (202) 564-2281; email address: [email protected], and 
Stacey Jensen, Office of the Assistant Secretary of the Army for Civil 
Works, Department of the Army, 108 Army Pentagon, Washington, DC 20310-
0104; telephone number: (703) 459-6026; email address: 
[email protected].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Executive Summary
II. Public Participation
    A. Written Comments
    B. Virtual Public Hearings
III. General Information
    A. What action are the agencies taking?
    B. What is the agencies' authority for taking this action?
    C. What are the incremental costs and benefits of this action?
IV. Background
    A. Legal Background
    B. The Agencies' Post-Rapanos Rules
    C. Summary of Stakeholder Outreach
V. Proposed Revised Definition
    A. Basis for Proposed Rule
    B. Concerns With Alternatives
    C. Proposed Rule
    D. Implementation of Proposed Rule
    E. Publicly Available Jurisdictional Information and Permit Data
    F. Placement of the Definition of ``Waters of the United 
States'' in the Code of Federal Regulations
VI. Summary of Supporting Analyses
VII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review; 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act (PRA)
    C. Regulatory Flexibility Act (RFA)
    D. Unfunded Mandates Reform Act (UMRA)
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations

I. Executive Summary

    Congress enacted the Federal Water Pollution Control Act Amendments 
of 1972, Public Law 92-500, 86 Stat. 816, as amended, 33 U.S.C. 1251 et 
seq. (Clean Water Act or Act) ``to restore and maintain the chemical, 
physical, and biological integrity of the Nation's waters.'' 33 U.S.C. 
1251(a). In doing so, Congress performed a ``total restructuring'' and 
``complete rewriting'' of the existing statutory framework, seeking to 
better protect the quality of the nation's waters. City of Milwaukee v. 
Illinois, 451 U.S. 304, 317 (1981). Congress thus intended the 1972 Act 
to be a bold step forward in providing protections for the nation's 
waters.
    Central to the framework and protections provided by the Clean 
Water Act is the term ``navigable waters,'' \1\ defined in the Act as 
``the waters of the United States, including the territorial seas.'' 33 
U.S.C. 1362(7). This term establishes the extent of most federal 
programs to protect water quality under the Act--including, for 
example, water quality standards, impaired waters and total maximum 
daily loads, oil spill prevention, preparedness and response programs, 
state and tribal water quality certification programs, and dredged and 
fill programs--because such programs apply only to ``waters of the 
United States.''
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    \1\ To avoid confusion between the term ``navigable waters'' as 
defined in the Clean Water Act and its implementing regulations, 33 
U.S.C. 1362(7); 33 CFR 328.3 (2014), and the traditional use of the 
term ``navigable waters'' to describe waters that are, have been, or 
could be used for interstate or foreign commerce, 33 CFR 328.3(a)(1) 
(2014), this preamble will refer to the latter as ``traditional 
navigable waters'' or waters that are ``navigable-in-fact.''
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    As the Supreme Court presciently noted decades ago, defining this 
term requires the EPA and the U.S. Department of the Army (Army) 
(together, ``the agencies'') to ``choose some point at which water ends 
and land begins. Our common experience tells us that this is often no 
easy task: The transition from water to solid

[[Page 69373]]

ground is not necessarily or even typically an abrupt one. Rather, 
between open waters and dry land may lie shallows, marshes, mudflats, 
swamps, bogs--in short, a huge array of areas that are not wholly 
aquatic but nevertheless fall far short of being dry land. Where on 
this continuum to find the limit of `waters' is far from obvious.'' 
United States v. Riverside Bayview Homes, 474 U.S. 121, 132 (1985) 
(``Riverside Bayview'').\2\
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    \2\ The Supreme Court has twice more addressed the issue of 
Clean Water Act jurisdiction over ``waters of the United States.'' 
Solid Waste Agency of Northern Cook County v. U.S. Army Corps of 
Engineers, 531 U.S. 159 (2001) (``SWANCC''); Rapanos v. United 
States, 547 U.S. 715 (2006) (``Rapanos'').
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    In the nearly five decades since the Clean Water Act was enacted, 
the agencies have undertaken the challenge of developing and 
implementing a durable definition of the term ``waters of the United 
States'' that draws the line on the Riverside Bayview ``continuum'' 
consistent with the objective of the Act--to restore and maintain the 
chemical, physical, and biological integrity of the nation's waters--
based on science, and refined over the years by extensive experience in 
implementing the definition in the field. In 2020, however, the 
agencies issued a rule, called the ``Navigable Waters Protection Rule'' 
(NWPR), which substantially departed from prior rules defining ``waters 
of the United States.'' The earlier rules had been based on scientific 
concepts, implementation experience, and consideration of how the water 
quality implications of the definitions would advance the Clean Water 
Act's statutory objective. While the NWPR's interpretation of the 
statute and case law overlaps in some respects with those prior 
regulations--for example, its understanding that the statute authorizes 
the agencies to regulate waters beyond those that are navigable-in-
fact--it departed from prior regulations by diminishing the appropriate 
role of science and Congress's objective in the Clean Water Act. The 
NWPR provided less protection and could have allowed far more impacts 
to the nation's waters than any rule that preceded it.
    In response to President Joseph R. Biden Jr.'s Executive Order 
13990, 86 FR 7037 (January 25, 2021), which directed federal agencies 
to review certain regulations, EPA and the Army undertook a review of 
the NWPR. The agencies found that the NWPR did not appropriately 
consider the water quality impacts of its approach to defining ``waters 
of the United States,'' in contravention of Congress's objective in the 
Clean Water Act ``to restore and maintain the chemical, physical, and 
biological integrity of the Nation's waters,'' and that the rule's 
reduction in the scope of protected waters could have a potentially 
extensive and adverse impact on the nation's waters. The agencies' 
ongoing analyses of waters that fall outside of the Act's protections 
because of the NWPR support these findings.
    Following a federal district court decision vacating the NWPR on 
August 30, 2021, the agencies halted implementation of the NWPR and 
began interpreting ``waters of the United States'' consistent with the 
pre-2015 regulatory regime.3 4 Though EPA and the U.S. Army 
Corps of Engineers (Corps) are not currently implementing the NWPR, the 
agencies are aware that further developments in litigation over the 
rule could bring the rule back into effect. For these reasons, among 
others discussed more fully below, the agencies have decided that 
prompt replacement of the NWPR through the administrative rulemaking 
process is vital.
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    \3\ See Pascua Yaqui Tribe v. EPA, No. 20-00266 (D. Ariz. Aug. 
30, 2021); U.S. EPA, Current Implementation of Waters of the United 
States, https://www.epa.gov/wotus/current-implementation-waters-united-states.
    \4\ The ``pre-2015 regulatory regime'' refers to the agencies' 
pre-2015 definition of ``waters of the United States,'' implemented 
consistent with relevant case law and longstanding practice, as 
informed by applicable guidance, training, and experience.
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    In order to ensure necessary federal protections for the nation's 
waters, the agencies are proposing to exercise their discretion under 
the statute to return generally to the familiar pre-2015 definition 
that has bounded the Act's protections for decades, has been codified 
multiple times, and has been implemented by every Administration for 
the last 35 years, from that of Ronald Reagan through Donald Trump, 
which re-promulgated the pre-2015 regulations. See In re EPA & Dep't of 
Def. Final Rule, 803 F.3d 804, 808 (6th Cir. 2015). The pre-2015 
regulations were largely in place for both agencies in 1986 and are 
thus commonly referred to as ``the 1986 regulations.'' \5\
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    \5\ EPA and the Corps have separate regulations defining the 
statutory term ``waters of the United States,'' but their 
interpretations were substantially similar and remained largely 
unchanged between 1977 and 2015. See, e.g., 42 FR 37122, 37144 (July 
19, 1977); 44 FR 32854, 32901 (June 7, 1979). For convenience, the 
agencies in this preamble will generally cite the Corps' 
longstanding regulations and will refer to them as ``the 1986 
regulations,'' ``the pre-2015 regulations,'' or ``the regulations in 
place until 2015'' as inclusive of EPA's comparable regulations that 
were recodified in 1988 and of the exclusion for prior converted 
cropland both agencies added in 1993.
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    In this proposed rule the agencies are exercising their 
discretionary authority to interpret ``waters of the United States'' to 
mean the waters defined by the longstanding 1986 regulations, with 
amendments to certain parts of those rules to reflect the agencies' 
interpretation of the statutory limits on the scope of the ``waters of 
the United States'' and informed by Supreme Court case law. Thus, in 
the proposed rule, the agencies interpret the term ``waters of the 
United States'' to include: Traditional navigable waters, interstate 
waters, and the territorial seas, and their adjacent wetlands; most 
impoundments of ``waters of the United States''; tributaries to 
traditional navigable waters, interstate waters, the territorial seas, 
and impoundments that meet either the relatively permanent standard or 
the significant nexus standard; wetlands adjacent to impoundments and 
tributaries, that meet either the relatively permanent standard or the 
significant nexus standard; and ``other waters'' that meet either the 
relatively permanent standard or the significant nexus standard. The 
``relatively permanent standard'' means waters that are relatively 
permanent, standing or continuously flowing and waters with a 
continuous surface connection to such waters. The ``significant nexus 
standard'' means waters that either alone or in combination with 
similarly situated waters in the region, significantly affect the 
chemical, physical, or biological integrity of traditional navigable 
waters, interstate waters, or the territorial seas (the ``foundational 
waters''). With these amendments to the 1986 regulations, the proposed 
rule is within the proper scope of the agencies' statutory authority 
and would restore and maintain the chemical, physical, and biological 
integrity of the nation's waters.
    The proposed rule advances the Clean Water Act's statutory 
objective as it is based on the best available science concerning the 
functions provided by upstream tributaries, adjacent wetlands, and 
``other waters'' to restore and maintain the water quality of 
downstream foundational waters. By contrast, the agencies conclude that 
the NWPR, which this proposed rule would replace, and which found 
jurisdiction primarily under the relatively permanent standard, 
established a test for jurisdiction that did not adequately address the 
impacts of degradation of upstream waters on downstream waters, 
including traditional navigable waters, and was therefore incompatible 
with the objective of the Clean Water Act. While

[[Page 69374]]

the ``more absolute position'' taken by the NWPR ``may be easier to 
administer,'' it has ``consequences that are inconsistent with major 
congressional objectives, as revealed by the statute's language, 
structure, and purposes.'' County of Maui, Hawaii v. Hawaii Wildlife 
Fund, 140 S. Ct. 1462, 1477 (2020).
    In developing the proposed rule, the agencies also considered the 
statute as a whole, the scientific record, relevant Supreme Court case 
law, and the agencies' experience and expertise after more than 30 
years of implementing the 1986 regulations defining ``waters of the 
United States,'' including more than a decade of experience 
implementing those regulations consistent with the Supreme Court's 
decisions in Riverside Bayview, SWANCC, and Rapanos. The agencies' 
interpretation also reflects consideration of the statute as a whole, 
including section 101(b), which states that ``it is the policy of 
Congress to recognize, preserve, and protect the primary 
responsibilities and rights of States to prevent, reduce, and eliminate 
pollution, to plan the development and use (including restoration, 
preservation, and enhancement) of land and water resources.'' 33 U.S.C. 
1251(b). The proposed rule's limits appropriately draw the boundary of 
waters subject to federal protection by ensuring that where upstream 
waters significantly affect the integrity of waters and the federal 
interest is indisputable--the traditional navigable waters, interstate 
waters, and territorial seas--Clean Water Act programs would apply to 
ensure that those downstream waters are protected. And where they do 
not, the agencies would leave regulation to the states and tribes. The 
proposed rule's relatively permanent and significant nexus limitations 
are thus based on the agencies' conclusion that together, those 
standards are consistent with the statutory text, advance the objective 
of the Act, are supported by the scientific record and Supreme Court 
case law, and appropriately consider the policies of the Act. In 
addition, because the proposed rule reflects consideration of the 
agencies' experience and expertise, as well as updates in 
implementation tools and resources, it is familiar and implementable.
    While there are case-specific determinations that would need to be 
made under this proposed rule, that was also true under the NWPR and 
many other regulatory regimes where agencies must balance competing 
factors. The agencies, moreover, believe that a return to the pre-2015 
definition would provide a known and familiar framework for co-
regulators and stakeholders. In addition, the clarifications proposed 
here and the intervening advancements in implementation resources, 
tools, and scientific support (see section V.D.3.d of this preamble) 
would address some of the concerns raised in the past about timeliness 
and consistency of jurisdictional determinations under this regulatory 
regime.
    Through this rulemaking process, the agencies will consider all 
public comments on the proposed rule including changes that improve 
clarity, implementability, and long-term durability of the definition. 
The agencies will also consider changes through a second rulemaking 
that they anticipate proposing in the future, which would build upon 
the foundation of this proposed rule.

II. Public Participation

A. Written Comments

    Submit your comments, identified by Docket ID No. EPA-HQ-OW-2021-
0602, at https://www.regulations.gov (our preferred method), or via the 
other methods identified in the ADDRESSES section. Once submitted, 
comments cannot be edited or removed from the docket. EPA and the Army 
may publish any comment received to the public docket. Do not submit to 
EPA's docket at https://www.regulations.gov any information you 
consider to be Confidential Business Information (CBI) or other 
information whose disclosure is restricted by statute. Multimedia 
submissions (audio, video, etc.) must be accompanied by a written 
comment. The written comment is considered the official comment and 
should include discussion of all points you wish to make. EPA and the 
Army will generally not consider comments or comment contents located 
outside of the primary submission (i.e., on the web, cloud, or other 
file sharing system). For additional submission methods, the full EPA 
public comment policy, information about CBI or multimedia submissions, 
and general guidance on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets.
    Due to public health concerns related to COVID-19, the EPA Docket 
Center and Reading Room are open to the public by appointment only. Our 
Docket Center staff also continue to provide remote customer service 
via email, phone, and webform. Hand deliveries or couriers will be 
received by scheduled appointment only. For further information and 
updates on EPA Docket Center services, please visit us online at 
https://www.epa.gov/dockets.
    EPA and the Army continue to carefully monitor information from the 
Centers for Disease Control and Prevention (CDC), local area health 
departments, and our federal partners so that we can respond rapidly as 
conditions change regarding COVID-19.

B. Virtual Public Hearings

    Please note that because of current CDC recommendations, as well as 
state and local orders for social distancing to limit the spread of 
COVID-19, EPA and the Army cannot hold in-person public meetings at 
this time. The agencies are hosting virtual public hearings on 
Wednesday, January 12, 2022 from 10 a.m. to 1 p.m. Eastern Time; on 
Thursday, January 13, 2022 from 2 p.m. to 5 p.m. Eastern Time; and on 
Tuesday, January 18, 2022 from 5 p.m. to 8 p.m. Eastern Time.
    EPA and the Army will begin pre-registering speakers for the 
hearing upon publication of this document in the Federal Register. To 
register to speak at a specific session of the virtual hearing, please 
use the online registration forms available at:
    1. Wednesday, January 12, 2022--https://www.eventbrite.com/e/us-epa-and-department-of-the-army-wotus-public-hearing-tickets-211244667487.
    2. Thursday, January 13, 2022--https://www.eventbrite.com/e/us-epa-and-department-of-the-army-wotus-public-hearing-tickets-211258017417.
    3. Tuesday, January 18, 2022--https://www.eventbrite.com/e/us-epa-and-department-of-the-army-wotus-public-hearing-tickets-211274536827.
    The last day to pre-register to speak at each session will be, 
respectively, Friday, January 7, 2022; Monday, January 10, 2022; and 
Thursday, January 13, 2022. A day before each scheduled session, EPA 
and the Army will post a general agenda for the hearing that will list 
pre-registered speakers in approximate order at https://www.epa.gov/wotus/public-outreach-and-stakeholder-engagement-activities. People may 
also register to listen to the public sessions at the registration 
links above.
    To allow more time for speakers, the agencies may prerecord a video 
introduction and overview of the rule, which will be available on the 
EPA website above for viewing before the public hearings. EPA and the 
Army will make every effort to follow the schedule as closely as 
possible on the day of the hearing, but it is possible that the 
hearings will run either ahead of schedule or behind schedule.
    Each commenter will have three (3) minutes to provide oral 
testimony. EPA and the Army encourage commenters to

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provide the agencies with a copy of their oral testimony electronically 
by emailing it to [email protected]. EPA and the Army also recommend 
submitting the text of your oral comments as written comments to the 
rulemaking docket.
    The agencies may ask clarifying questions during the oral 
presentations but will not respond to the presentations at that time. 
Written statements and supporting information submitted during the 
comment period will be considered with the same weight as oral comments 
and supporting information presented at the public hearing.
    Please note that any updates made to any aspect of the hearing will 
be posted online at https://www.epa.gov/wotus/public-outreach-and-stakeholder-engagement-activities. While the agencies expect the 
hearing to go forward as set forth above, please monitor our website or 
contact [email protected] to determine if there are any updates. EPA and 
the Army do not intend to publish a document in the Federal Register 
announcing updates.
    If you require the services of a translator or special 
accommodations such as audio description, please pre-register for the 
hearing with [email protected] and describe your needs a week in advance 
of each session--respectively, by Wednesday, January 5, 2022; Thursday, 
January 6, 2022; and Tuesday, January 11, 2022. EPA and the Army may 
not be able to arrange accommodations without advanced notice.

III. General Information

A. What action are the agencies taking?

    In this action, the agencies are publishing a proposed rule 
defining ``waters of the United States'' in 33 CFR 328.3 and 40 CFR 
120.2.

B. What is the agencies' authority for taking this action?

    The authority for this action is the Federal Water Pollution 
Control Act, 33 U.S.C. 1251 et seq., including sections 301, 304, 311, 
401, 402, 404, and 501.

C. What are the incremental costs and benefits of this action?

    Because the agencies are not currently implementing the NWPR, the 
proposed rule would provide protections that are generally comparable 
to current practice; as such, the agencies find that there would be no 
appreciable cost or benefit difference. Potential costs and benefits 
would be incurred as a result of actions taken under existing Clean 
Water Act programs (i.e., sections 303, 311, 401, 402, and 404) that 
implement and follow this proposed rule. Entities currently are, and 
would continue to be, regulated under these programs that protect 
``waters of the United States'' under the Clean Water Act.
    The agencies prepared the Economic Analysis for the Proposed 
``Revised Definition of `Waters of the United States' '' Rule 
(``Economic Analysis for the Proposed Rule''), available in the 
rulemaking docket, for informational purposes to analyze the potential 
costs and benefits associated with this proposed action. The agencies 
analyze the potential costs and benefits against two baselines: The 
current status quo and the vacated NWPR. The analysis is summarized in 
section VI of this preamble. The agencies' primary estimate is that the 
proposed rule would have zero impact.

IV. Background

A. Legal Background

1. The Clean Water Act
    Before passage of the Clean Water Act, the nation's waters were in 
``serious trouble, thanks to years of neglect, ignorance, and public 
indifference.'' H.R. Rep. No. 92-911, at 753 (1972). Congress enacted 
the Federal Water Pollution Control Act Amendments of 1972, Public Law 
92-500, 86 Stat. 816, as amended, 33 U.S.C. 1251 et seq., with the 
objective ``to restore and maintain the chemical, physical and 
biological integrity of the Nation's waters.'' 33 U.S.C. 1251(a). The 
Act was intended to address longstanding concerns regarding the quality 
of the nation's waters and the Federal government's ability to respond 
to those concerns under existing law.
    Prior to 1972, the Federal government's authority to control and 
redress pollution in the nation's waters largely fell to the Corps 
under the Rivers and Harbors Act of 1899. While much of that statute 
focused on restricting obstructions to navigation on the nation's major 
waterways, section 13 of the statute made it unlawful to discharge 
refuse ``into any navigable water of the United States, or into any 
tributary of any navigable water from which the same shall float or be 
washed into such navigable water.'' 33 U.S.C. 407. In 1948, Congress 
enacted the Federal Water Pollution Control Act of 1948, Public Law 80-
845, 62 Stat. 1155 (June 30, 1948), to address interstate water 
pollution, and subsequently amended that statute in 1956, 1961, and 
1965. These early versions of the statute that eventually became known 
as the Clean Water Act encouraged the development of pollution 
abatement programs, required states to develop water quality standards, 
and authorized the Federal government to bring enforcement actions to 
abate water pollution. However, these authorities proved inadequate to 
address the decline in the quality of the nation's waters. See City of 
Milwaukee v. Illinois, 451 U.S. 304, 310 (1981).
    As a result, in 1972, Congress performed ``a `total restructuring' 
and `complete rewriting' of the existing'' statutory framework. City of 
Milwaukee, 451 U.S. at 317 (quoting legislative history of 1972 
amendments). The Clean Water Act, which was passed as an amendment to 
the Federal Water Pollution Control Act, was described by its 
supporters as the first truly comprehensive federal water pollution 
legislation. The ``major purpose'' of the Clean Water Act was ``to 
establish a comprehensive long-range policy for the elimination of 
water pollution.'' S. Rep. No. 92-414, at 95 (1971), 2 Legislative 
History of the Water Pollution Control Act Amendments of 1972 
(Committee Print compiled for the Senate Committee on Public Works by 
the Library of Congress), Ser. No. 93-1, p. 1511 (1971) (emphasis 
added). ``No Congressman's remarks on the legislation were complete 
without reference to [its] `comprehensive' nature.'' City of Milwaukee, 
451 U.S. at 318. In passing the 1972 amendments, Congress ``intended to 
repudiate limits that had been placed on federal regulation by earlier 
water pollution control statutes and to exercise its powers under the 
Commerce Clause to regulate at least some waters that would not be 
deemed `navigable' under the classical understanding of that term.'' 
United States v. Riverside Bayview Homes, 474 U.S. 121, 133 (1985) 
(``Riverside Bayview''); see also Int'l Paper Co. v. Ouellette, 479 
U.S. 481, 486 n.6 (1987).
    One of the Clean Water Act's principal tools to protect the 
integrity of the nation's waters is section 301(a), which generally 
prohibits ``the discharge of any pollutant by any person'' without a 
permit or other authorization under the Act. The terms ``discharge of a 
pollutant'' and ``discharge of pollutants'' are defined broadly to 
include ``any addition of any pollutant to navigable waters from any 
point source.'' 33 U.S.C. 1362(12). And ``navigable waters'' means 
``the waters of the United States, including the territorial seas.'' 
Id. at 1362(7). Although Congress opted to carry over the term 
``navigable waters'' from prior versions of the Federal Water Pollution 
Control Act, Congress broadened the definition

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of ``navigable waters'' to encompass all ``waters of the United 
States.'' Id. Indeed, in finalizing the 1972 amendments, the conferees 
specifically deleted the word ``navigable'' from the definition of 
``waters of the United States'' that had originally appeared in the 
House version of the Act. S. Conf. Rep. No. 92-1236, at 144 (1972). 
Further, the Senate Report stated that ``navigable waters'' means ``the 
navigable waters of the United States, portions thereof, tributaries 
thereof, and includes the Territorial Seas and the Great Lakes.'' S. 
Rep. No. 92-414, at 77 (1971), as reprinted in 1972 U.S.C.C.A.N. 3668, 
3742-43 (emphasis added). The Senate Report accompanying the 1972 Act 
also explained that ``[w]ater moves in hydrologic cycles and it is 
essential that the discharge of pollutants be controlled at the 
source.'' Id.
    The definition of ``waters of the United States'' affects most 
Clean Water Act programs--including water quality standards, impaired 
waters and total maximum daily loads, oil spill prevention, 
preparedness and response programs, the state and tribal water quality 
certification programs, National Pollutant Discharge Elimination System 
(NPDES) programs, and dredge and fill programs--because such programs 
apply only to ``waters of the United States.'' Some Clean Water Act 
programs are implemented by the Federal government, and others are 
implemented by state or tribal governments where the statute provides a 
direct grant of authority to the state or authorized tribe or provides 
an option for the state or authorized tribe to take on those programs. 
States and tribes may additionally implement, establish, or modify 
their own programs under state or tribal law to manage and regulate 
waters independent of the Clean Water Act.
    Under Clean Water Act section 303(d) and EPA's implementing 
regulations, states are required to assemble and evaluate all existing 
and readily available water quality-related data and information and to 
submit to EPA every two years a list of impaired waters that require 
total maximum daily loads (TMDLs). For waters identified on a 303(d) 
list, states establish TMDLs for all pollutants preventing or expected 
to prevent attainment of water quality standards. Section 303(d) 
applies to ``waters of the United States'' and ``non-jurisdictional'' 
waterbodies are not required to be assessed or otherwise identified as 
impaired; TMDL restoration plans likewise apply to ``waters of the 
United States.''
    Clean Water Act section 311 and the Oil Pollution Act (OPA) of 1990 
authorize the Oil Spill Liability Trust Fund (OSLTF) to reimburse costs 
of assessing and responding to oil spills to ``waters of the United 
States'' or adjoining shorelines. The OSLTF allows an immediate 
response to a spill, including containment, countermeasures, cleanup, 
and disposal activities. The OSLTF is not available to reimburse costs 
incurred by states or tribes to clean up spills and costs related to 
business and citizen impacts (e.g., lost wages and damages) for spills 
affecting waters not subject to Clean Water Act jurisdiction. EPA also 
lacks authority to take enforcement actions based on spills solely 
affecting waters not subject to Clean Water Act jurisdiction.
    The scope of facilities required to prepare oil spill prevention 
and response plans is also affected by the definition of ``waters of 
the United States.'' EPA-regulated oil storage facilities with storage 
capacities greater than 1,320 gallons (except farms) that have a 
reasonable expectation of an oil discharge to ``waters of the United 
States'' or adjoining shorelines are required to prepare and implement 
spill prevention plans. High-risk oil storage facilities that meet 
certain higher storage thresholds and related harm factors are required 
to prepare and submit oil spill preparedness plans to EPA for review. 
The U.S. Coast Guard and Department of Transportation also require oil 
spill response plans under their respective authorities. However, Clean 
Water Act section 311 spill prevention and preparedness plan 
requirements do not apply to a facility if there is no reasonable 
expectation that an oil discharge from a facility could reach a 
jurisdictional water or adjoining shoreline.
    Clean Water Act section 401 provides that a Federal agency cannot 
issue a permit or license for an activity that may result in a 
discharge to ``waters of the United States'' until the state or tribe 
where the discharge would originate has granted or waived water quality 
certification. As a result, section 401 certification provides states 
and authorized tribes an opportunity to address the proposed aquatic 
resource impacts of federally-issued permits and licenses. The 
definition of ``waters of the United States'' affects where federal 
permits are required and thus where section 401 certification applies.
    Under section 402 of the Clean Water Act, a National Pollutant 
Discharge Elimination System (NPDES) permit is required where a point 
source discharges a pollutant to a ``water of the United States.''
    The Clean Water Act section 404 permitting program addresses the 
discharge of dredged or fill material from a point source into ``waters 
of the United States,'' unless the activity is exempt from Clean Water 
Act section 404 regulation (e.g., certain farming, ranching, and 
forestry activities). Section 404 requires a permit before dredged or 
fill material may be discharged to ``waters of the United States.'' 
Where Clean Water Act jurisdiction does not apply, no section 404 
permits are required for dredged or fill activities in those waters or 
features.
    States and tribes play a vital role in the implementation and 
enforcement of these and other Clean Water Act programs. Section 101(b) 
of the Act established that ``it is the policy of Congress to 
recognize, preserve and protect the primary responsibilities and rights 
of States to prevent, reduce and eliminate pollution, to plan the 
development and use (including restoration, preservation, and 
enhancement) of land and water resources.'' 33 U.S.C. 1251(b). All 
states and 74 tribes have authority to implement section 401 water 
quality certification programs. Currently 47 states and one territory 
have authority to administer all or portions of the section 402 NPDES 
program for ``waters of the United States.'' All states and 46 tribes 
have established water quality standards pursuant to section 303 of the 
Act, which form a legal basis for limitations on discharges of 
pollutants to ``waters of the United States.''
    Moreover, consistent with the Clean Water Act, states and tribes 
retain authority to implement their own programs to protect the waters 
in their jurisdiction more broadly and more stringently than the 
Federal government. Under section 510 of the Clean Water Act, unless 
expressly stated, nothing in the Clean Water Act precludes or denies 
the right of any state or tribe to establish more protective standards 
or limits than the Clean Water Act.\6\ Many states and tribes, for 
example, regulate groundwater, and some others protect wetlands that 
are vital to their environment and economic

[[Page 69377]]

well-being but which may be outside the scope of the Clean Water Act.
---------------------------------------------------------------------------

    \6\ Congress has provided for eligible tribes to administer 
Clean Water Act programs over their reservations and expressed a 
preference for tribal regulation of surface water quality on 
reservations to ensure compliance with the goals of the statute. See 
33 U.S.C. 1377; 56 FR 64876, 64878-79 (December 12, 1991). In 
addition, tribes may establish more protective standards or limits 
under tribal law that may be more stringent than the federal Clean 
Water Act. Where appropriate, references to states in this document 
may also include eligible tribes.
---------------------------------------------------------------------------

    In 1977, Congress considered and rejected a legislative proposal 
that would have redefined and limited the waters subject to the Corps' 
permitting authority under section 404 of the Clean Water Act to only 
navigable-in-fact waters and their adjacent wetlands. In 1975, the 
Corps had extended the scope of ``waters of the United States'' to 
encompass, in a phased approach, non-navigable tributaries, wetlands 
adjacent to primary navigable waters, intermittent rivers, streams, 
tributaries, and certain other categories of waters. 40 FR 31325-31326 
(1975). In reaction to that broadened definition, Congress considered a 
proposal to limit the geographic reach of section 404, but it was 
defeated in the Senate and eliminated by the Conference Committee. H.R. 
Conf. Rep. No. 95-830, at 97-105 (1977). As the Supreme Court explained 
in Riverside Bayview, ``efforts to narrow the definition of `waters' 
were abandoned; the legislation as ultimately passed, in the words of 
Senator Baker, `retain[ed] the comprehensive jurisdiction over the 
Nation's waters exercised in the 1972 Federal Water Pollution Control 
Act. ' '' 474 U.S. at 136-137; see also 123 Cong. Rec. 26718 (1977) 
(remarks of Senator Baker: ``Continuation of the comprehensive coverage 
of this program is essential for the protection of the aquatic 
environment. The once seemingly separable types of aquatic systems are, 
we now know, interrelated and interdependent. We cannot expect to 
preserve the remaining qualities of our water resources without 
providing appropriate protection for the entire resource.'').
    Rather than alter the geographic reach of section 404 in 1977, 
Congress instead amended the statute by exempting certain activities--
for example, certain agricultural and silvicultural activities--from 
the permit requirements of section 404. See 33 U.S.C. 1344(f). The 
amendments also authorized the use of general permits to streamline the 
permitting process. See id. at 1344(e). Finally, the 1977 Act 
established for the first time a mechanism by which a state, rather 
than the Corps, could assume responsibility for implementing the 
section 404 permitting program, but only for waters ``other than'' 
traditional navigable waters and their adjacent wetlands. Id. at 
1344(g)(1). Three states have since assumed the section 404 program.
    The fact that a resource is a ``water of the United States'' does 
not mean that activities such as farming, construction, infrastructure 
development, or resource extraction, cannot occur in or near the 
resource at hand. The Clean Water Act exempts a number of activities 
from permitting or from the definition of ``point source,'' including 
agricultural storm water and irrigation return flows. See id. at 
1342(l)(2), 1362(14). As discussed above, since 1977 the Clean Water 
Act in section 404(f) has exempted many normal farming activities from 
the section 404 permitting requirement, including seeding, harvesting, 
cultivating, planting, and soil and water conservation practices, among 
other activities. Id. at 1344(f). The scope of ``waters of the United 
States'' does not affect these statutory exemptions.
    In addition, permits are routinely issued under sections 402 and 
404 of the Clean Water Act. The permitting authority, which is most 
often a state agency for the section 402 NPDES program and the Corps in 
the context of section 404, generally works with permit seekers to 
ensure that activities can occur without harming the integrity of the 
nation's waters.
    Effluent limitations serve as the primary mechanism in NPDES 
permits for controlling discharges of pollutants to receiving waters, 
and include technology-based effluent limitations and water quality-
based effluent limitations. These limits, which are typically numeric, 
generally specify an acceptable level of a pollutant or pollutant 
parameter in a discharge (for example, a certain level of bacteria). 
The permittee may choose which technologies to use to achieve that 
level. Some permits contain certain ``best management practices'' 
(BMPs) which are actions or procedures to prevent or reduce the 
discharge of pollution to ``waters of the United States'' (for example, 
stormwater control measures for construction activities).
    In issuing section 404 permits, the Corps or authorized state works 
with the applicant to avoid, minimize, or compensate for any 
unavoidable impacts to ``waters of the United States.'' Permit 
applicants show that steps have been taken to avoid impacts to 
wetlands, streams, and other aquatic resources; that potential impacts 
have been minimized; and that compensatory mitigation will be provided 
for all remaining unavoidable impacts. For most discharges that will 
have only minimal adverse effects, a general permit (e.g., a 
``nationwide'' permit) may be suitable. General permits are issued on a 
nationwide, regional, or state basis for particular categories of 
activities. While some general permits require the applicant to submit 
a pre-construction notification to the Corps, others allow the 
applicant to proceed with no formal notification. The general permit 
process eliminates individual review and allows certain activities to 
proceed with little or no delay, provided that the general or specific 
conditions for the general permit are met. For example, minor road 
construction activities, utility line backfill, and minor discharges 
for maintenance are activities in ``waters of the United States'' that 
can be considered for a general permit. States and tribes also have a 
role in section 404 decisions, through state program general permits, 
water quality certification, or program assumption.
    Under any regulation defining ``waters of the United States,'' 
property owners may obtain from the Corps jurisdictional determinations 
whether waters on their property are subject to the Clean Water Act. 
The Corps' regulations provide that a jurisdictional determination 
consists of ``a written Corps determination that a wetland and/or 
waterbody is subject to regulatory jurisdiction under Section 404 of 
the Clean Water Act (33 U.S.C. 1344) or a written determination that a 
waterbody is subject to regulatory jurisdiction under Section 9 or 10 
of the Rivers and Harbors Act of 1899 (33 U.S.C. 401 et seq.).'' See 33 
CFR 331.2. These jurisdictional determinations can be obtained at no 
charge to the property owners. See 33 CFR 325.1 (omitting mention of 
fees for jurisdictional determinations) and Regulatory Guidance Letter 
16-01 (2016) (stating that such determinations are issued as a ``public 
service'').
2. The 1986 Regulations Defining ``Waters of the United States''
    In 1973, EPA published regulations defining ``navigable waters'' 
broadly to include traditional navigable waters; tributaries of 
traditional navigable waters; interstate waters; and intrastate lakes, 
rivers, and streams used in interstate commerce. 38 FR 13528, 13528-29 
(May 22, 1973). The Corps published regulations in 1974 defining the 
term ``navigable waters'' to mean ``those waters of the United States 
which are subject to the ebb and flow of the tide, and/or are 
presently, or have been in the past, or may be in the future 
susceptible for use for purposes of interstate or foreign commerce.'' 
39 FR 12115, 12119 (April 3, 1974); 33 CFR 209.120(d)(1) (1974); see 
also 33 CFR 209.260(e)(1) (1974) (explaining that ``[i]t is the water 
body's capability of use by the public for purposes of transportation 
or commerce which is the determinative factor'').
    Several federal courts then held that the Corps had given ``waters 
of the

[[Page 69378]]

United States'' an unduly restrictive reading in its regulations 
implementing Clean Water Act section 404. See, e.g., United States v. 
Holland, 373 F. Supp. 665, 670-676 (M.D. Fla. 1974). EPA and the House 
Committee on Government Operations agreed with the decision in 
Holland.\7\ In Natural Resources Defense Council, Inc. v. Callaway, 392 
F. Supp. 685, 686 (D.D.C. 1975) (``Callaway''), the court held that in 
the Clean Water Act, Congress had ``asserted federal jurisdiction over 
the nation's waters to the maximum extent permissible under the 
Commerce Clause of the Constitution. Accordingly, as used in the 
[Federal] Water [Pollution Control] Act, the term [`navigable waters'] 
is not limited to the traditional tests of navigability.'' The court 
ordered the Corps to publish new regulations ``clearly recognizing the 
full regulatory mandate of the [Federal] Water [Pollution Control] 
Act.'' Id.
---------------------------------------------------------------------------

    \7\ EPA expressed the view that ``the Holland decision provides 
a necessary step for the preservation of our limited wetland 
resources,'' and that ``the [Holland] court properly interpreted the 
jurisdiction granted under the [Clean Water Act] and Congressional 
power to make such a grant.'' See section 404 of the Federal Water 
Pollution Control Act Amendments of 1972: Hearings Before the Senate 
Comm. on Pub. Works, 94th Cong., 2d Sess. 349 (1976) (letter dated 
June 19, 1974, from Russell E. Train, Administrator of EPA, to Lt. 
Gen. W.C. Gribble, Jr., Chief of Corps of Engineers). Shortly 
thereafter, the House Committee on Government Operations discussed 
the disagreement between the two agencies (as reflected in EPA's 
June 19 letter) and concluded that the Corps should adopt the 
broader view of the term ``waters of the United States'' taken by 
EPA and by the court in Holland. See H.R. Rep. No. 93-1396, at 23-27 
(1974). The Committee urged the Corps to adopt a new definition that 
``complies with the congressional mandate that this term be given 
the broadest possible constitutional interpretation.'' Id. at 27 
(internal quotation marks omitted).
---------------------------------------------------------------------------

    In response to the district court's order in Callaway, the Corps 
promulgated interim final regulations providing for a phased-in 
expansion of its section 404 jurisdiction. 40 FR 31320 (July 25, 1975); 
see 33 CFR 209.120(d)(2) and (e)(2) (1976). The interim regulations 
revised the definition of ``waters of the United States'' to include, 
inter alia, waters (sometimes referred to as ``isolated waters'') that 
are not connected by surface water or adjacent to traditional navigable 
waters. 33 CFR 209.120(d)(2)(i) (1976).\8\ On July 19, 1977, the Corps 
published its final regulations, in which it revised the 1975 interim 
regulations to clarify many of the definitional terms. 42 FR 37122 
(July 19, 1977). The 1977 final regulations defined the term ``waters 
of the United States'' to include, inter alia, ``isolated wetlands and 
lakes, intermittent streams, prairie potholes, and other waters that 
are not part of a tributary system to interstate waters or to navigable 
waters of the United States, the degradation or destruction of which 
could affect interstate commerce.'' 33 CFR 323.2(a)(5) (1978); see also 
40 CFR 122.3 (1979).\9\
---------------------------------------------------------------------------

    \8\ Phase I, which was immediately effective, included coastal 
waters and traditional inland navigable waters and their adjacent 
wetlands. 40 FR 31321, 31324, 31326 (July 25, 1975). Phase II, which 
took effect on July 1, 1976, extended the Corps' jurisdiction to 
lakes and certain tributaries of Phase I waters, as well as wetlands 
adjacent to the lakes and certain tributaries. Id. Phase III, which 
took effect on July 1, 1977, extended the Corps' jurisdiction to all 
remaining areas encompassed by the regulations, including 
``intermittent rivers, streams, tributaries, and perched wetlands 
that are not contiguous or adjacent to navigable waters.'' Id. at 
31325; see also 42 FR 37124 (July 19, 1977) (describing the three 
phases).
    \9\ An explanatory footnote published in the Code of Federal 
Regulations stated that ``[p]aragraph (a)(5) incorporates all other 
waters of the United States that could be regulated under the 
Federal government's Constitutional powers to regulate and protect 
interstate commerce.'' 33 CFR 323.2(a)(5), at 616 n.2 (1978).
---------------------------------------------------------------------------

    In 1986, the Corps consolidated and recodified its regulatory 
provisions defining ``waters of the United States'' for purposes of 
implementing the section 404 program. See 51 FR 41216-17 (November 13, 
1986). These regulations reflected the interpretation of both agencies. 
While EPA and the Corps also have separate regulations defining the 
statutory term ``waters of the United States,'' their interpretations, 
reflected in the 1986 regulations, have been identical and remained 
largely unchanged from 1977 to 2015. See 42 FR 37122, 37124, 37127 
(July 19, 1977).\10\ EPA's comparable regulations were recodified in 
1988 (53 FR 20764, June 6, 1988), and both agencies added an exclusion 
for prior converted cropland in 1993 (58 FR 45008, 45031, August 25, 
1993). For convenience, the agencies in this preamble will generally 
cite the Corps' longstanding regulations and will refer to ``the 1986 
regulations'' as inclusive of EPA's comparable regulations and the 1993 
addition of the exclusion for prior converted cropland.
---------------------------------------------------------------------------

    \10\ Multiple provisions in the Code of Federal Regulations 
contained the definition of the phrases ``waters of the United 
States'' and ``navigable waters'' for purposes of implementing the 
Clean Water Act, 33 U.S.C. 1362(7), and other water pollution 
protection statutes such as the Oil Pollution Act, 33 U.S.C. 
2701(21). Some EPA definitions were added after 1986, but each 
conformed to the 1986 regulations except for variations in the waste 
treatment system exclusion. See, e.g., 55 FR 8666 (March 8, 1990); 
73 FR 71941 (November 26, 2008).
---------------------------------------------------------------------------

    The 1986 regulations define ``waters of the United States'' as 
follows (33 CFR 328.3 (2014)) \11\:
---------------------------------------------------------------------------

    \11\ There are some variations in the waste treatment system 
exclusion across EPA's regulations defining ``waters of the United 
States.'' The placement of the waste treatment system and prior 
converted cropland exclusions also varies in EPA's regulations.
---------------------------------------------------------------------------

    The term waters of the United States means:
    1. All waters which are currently used, or were used in the past, 
or may be susceptible to use in interstate or foreign commerce, 
including all waters which are subject to the ebb and flow of the tide;
    2. All interstate waters including interstate wetlands;
    3. All other waters such as intrastate lakes, rivers, streams 
(including intermittent streams), mudflats, sandflats, wetlands, 
sloughs, prairie potholes, wet meadows, playa lakes, or natural ponds, 
the use, degradation or destruction of which could affect interstate or 
foreign commerce including any such waters:
    a. Which are or could be used by interstate or foreign travelers 
for recreational or other purposes; or
    b. From which fish or shellfish are or could be taken and sold in 
interstate or foreign commerce; or
    c. Which are used or could be used for industrial purposes by 
industries in interstate commerce;
    4. All impoundments of waters otherwise defined as waters of the 
United States under this definition;
    5. Tributaries of waters identified in paragraphs (a)(1) through 
(4) of this section;
    6. The territorial seas;
    7. Wetlands adjacent to waters (other than waters that are 
themselves wetlands) identified in paragraphs (a)(1) through (6) of 
this section.
    8. Waters of the United States do not include prior converted 
cropland. Notwithstanding the determination of an area's status as 
prior converted cropland by any other federal agency, for the purposes 
of the Clean Water Act, the final authority regarding Clean Water Act 
jurisdiction remains with EPA. Waste treatment systems, including 
treatment ponds or lagoons designed to meet the requirements of Clean 
Water Act (other than cooling ponds as defined in 40 CFR 423.11(m) 
which also meet the criteria of this definition) are not waters of the 
United States.
    Note that these categories in the 1986 regulations may be referred 
to by this numbering system (for example, (a)(1) through (a)(8) waters) 
throughout this preamble. See sections I.C.3 and I.C.4 of the Economic 
Analysis for the Proposed Rule for a comparison of regulatory 
categories between the NWPR and this proposed rule.
3. U.S. Supreme Court Decisions
    The U.S. Supreme Court first addressed the scope of ``waters of the 
United States'' protected by the Clean

[[Page 69379]]

Water Act in United States v. Riverside Bayview Homes, 474 U.S. 121 
(1985) (``Riverside Bayview''), which involved wetlands adjacent to a 
traditional navigable water in Michigan. In a unanimous opinion, the 
Court deferred to the Corps' judgment that adjacent wetlands are 
``inseparably bound up with the `waters' of the United States,'' thus 
concluding that ``adjacent wetlands may be defined as waters under the 
Act.'' Riverside Bayview, 474 U.S. at 134, 139. The Court observed that 
the broad objective of the Clean Water Act to restore the integrity of 
the nation's waters ``incorporated a broad, systemic view of the goal 
of maintaining and improving water quality . . . . Protection of 
aquatic ecosystems, Congress recognized, demanded broad federal 
authority to control pollution, for `[w]ater moves in hydrologic cycles 
and it is essential that discharge of pollutants be controlled at the 
source.' '' Id. at 132-33 (citing S. Rep. 92-414). The Court then 
stated: ``In keeping with these views, Congress chose to define the 
waters covered by the Act broadly. Although the Act prohibits 
discharges into `navigable waters,' see CWA [sections] 301(a), 404(a), 
502(12), 33 U.S.C. [sections] 1311(a), 1344(a), 1362(12), the Act's 
definition of `navigable waters' as `the waters of the United States' 
makes it clear that the term `navigable' as used in the Act is of 
limited import.'' Id. at 133.
    The Court also recognized that ``[i]n determining the limits of its 
power to regulate discharges under the Act, the Corps must necessarily 
choose some point at which water ends and land begins. Our common 
experience tells us that this is often no easy task: The transition 
from water to solid ground is not necessarily or even typically an 
abrupt one. Rather, between open waters and dry land may lie shallows, 
marshes, mudflats, swamps, bogs--in short, a huge array of areas that 
are not wholly aquatic but nevertheless fall far short of being dry 
land. Where on this continuum to find the limit of `waters' is far from 
obvious.'' Id. at 132. The Court then deferred to the agencies' 
interpretation: ``In view of the breadth of federal regulatory 
authority contemplated by the Act itself and the inherent difficulties 
of defining precise bounds to regulable waters, the Corps' ecological 
judgment about the relationship between waters and their adjacent 
wetlands provides an adequate basis for a legal judgment that adjacent 
wetlands may be defined as waters under the Act.'' Id. at 134.
    The Court went on to note that to achieve the goal of preserving 
and improving adjacent wetlands that have significant ecological and 
hydrological impacts on traditional navigable waters, it was 
appropriate for the Corps to regulate all adjacent wetlands, even 
though some might not have any impacts on traditional navigable waters. 
Id. at 135 n.9. Indeed, the Court acknowledged that some adjacent 
wetlands might not have significant hydrological and biological 
connections with navigable waters, but concluded that the Corps' 
regulation was valid in part because such connections exist in the 
majority of cases. Id.
    The Court deferred to the Corps' definition of ``adjacent'': ``The 
term adjacent means bordering, contiguous, or neighboring. Wetlands 
separated from other waters of the United States by man-made dikes or 
barriers, natural river berms, beach dunes and the like are `adjacent 
wetlands.' '' The Court expressly reserved the question of whether the 
Act applies to ``wetlands that are not adjacent to open waters.'' Id. 
at 131 n.8.
    The Supreme Court again addressed the issue of Clean Water Act 
jurisdiction over ``waters of the United States'' in Solid Waste Agency 
of Northern Cook County v. U.S. Army Corps of Engineers, 531 U.S. 159 
(2001) (``SWANCC''). In SWANCC, the Court (in a 5-4 opinion) held that 
the use of ``isolated'' non-navigable intrastate ponds by migratory 
birds was not by itself a sufficient basis for the exercise of federal 
authority under the Clean Water Act. The Court noted that in Riverside 
Bayview it had ``found that Congress' concern for the protection of 
water quality and aquatic ecosystems indicated its intent to regulate 
wetlands `inseparably bound up with the ``waters'' of the United 
States' '' and that ``[i]t was the significant nexus between the 
wetlands and `navigable waters' that informed [the Court's] reading of 
the Clean Water Act'' in that case. Id. at 167.
    While recognizing that in Riverside Bayview it had found the term 
``navigable'' to be of limited import, the Court in SWANCC noted that 
the term ``navigable'' could not be read entirely out of the Act. Id. 
at 172. The Court stated: ``We said in Riverside Bayview Homes that the 
word `navigable' in the statute was of `limited import' and went on to 
hold that [section] 404(a) extended to non-navigable wetlands adjacent 
to open waters. But it is one thing to give a word limited effect and 
quite another to give it no effect whatever. The term `navigable' has 
at least the import of showing us what Congress had in mind as its 
authority for enacting the CWA: its traditional jurisdiction over 
waters that were or had been navigable in fact or which could 
reasonably be so made.'' Id. at 172 (internal citations omitted).
    The Court found that the exercise of Clean Water Act regulatory 
authority over discharges into the ponds, on the grounds that their use 
by migratory birds is within the power of Congress to regulate 
activities that in the aggregate have a substantial effect on 
interstate commerce, raised questions. Id. at 173. The Court explained 
that ``[w]here an administrative interpretation of a statute invokes 
the outer limits of Congress' power, we expect a clear indication that 
Congress intended that result,'' id. at 172, and that this is 
particularly true ``where the administrative interpretation alters the 
federal-state framework by permitting federal encroachment upon a 
traditional state power,'' id. at 173 (citing United States v. Bass, 
404 U.S. 336, 349 (1971)). The Court thus construed the Clean Water Act 
to avoid the constitutional questions related to the scope of federal 
authority authorized therein. Id. at 174.
    Five years after SWANCC, the Court again addressed the Clean Water 
Act term ``waters of the United States'' in Rapanos v. United States, 
547 U.S. 715 (2006) (``Rapanos''). Rapanos involved two consolidated 
cases in which the Act had been applied to wetlands adjacent to non-
navigable tributaries of traditional navigable waters. All members of 
the Court agreed that the term ``waters of the United States'' 
encompasses some waters that are not navigable in the traditional 
sense. Id. at 731 ((Scalia, J., plurality opinion) (``We have twice 
stated that the meaning of `navigable waters' in the Act is broader 
than the traditional understanding of that term, SWANCC, 531 U.S. at 
167, 121 S. Ct. 675, 148 L. Ed. 2d 576; Riverside Bayview, 474 U.S. at 
133, 106 S. Ct. 455, 88 L. Ed. 2d 419.'')).
    A four-Justice plurality in Rapanos interpreted the term ``waters 
of the United States'' as covering ``relatively permanent, standing or 
continuously flowing bodies of water,'' id. at 739, that are connected 
to traditional navigable waters, id. at 742, as well as wetlands with a 
``continuous surface connection'' to such water bodies, id. (Scalia, 
J., plurality opinion). The Rapanos plurality noted that its reference 
to ``relatively permanent'' waters did ``not necessarily exclude 
streams, rivers, or lakes that might dry up in extraordinary 
circumstances, such as drought,'' or ``seasonal rivers, which contain 
continuous flow during some months of the year but no flow during dry 
months.'' Id. at 732 n.5 (emphasis in original).
    Justice Kennedy's concurring opinion took a different approach that 
was based

[[Page 69380]]

in the Court's SWANCC opinion. Justice Kennedy concluded that ``to 
constitute `navigable waters' under the Act, a water or wetland must 
possess a `significant nexus' to waters that are or were navigable in 
fact or that could reasonably be so made.'' Id. at 759 (citing SWANCC, 
531 U.S. at 167, 172). He concluded that wetlands possess the requisite 
significant nexus if the wetlands ``either alone or in combination with 
similarly situated [wet]lands in the region, significantly affect the 
chemical, physical, and biological integrity of other covered waters 
more readily understood as `navigable.' '' Id. at 780. Justice 
Kennedy's opinion notes that to be jurisdictional, such a relationship 
with traditional navigable waters must be more than ``speculative or 
insubstantial.'' Id.
    The four dissenting Justices in Rapanos, who would have affirmed 
the court of appeals' application of the agencies' regulation to find 
jurisdiction over the waters at issue, also concluded that the term 
``waters of the United States'' encompasses, inter alia, all 
tributaries and wetlands that satisfy ``either the plurality's 
[standard] or Justice Kennedy's.'' Id. at 810 & n.14 (Stevens, J., 
dissenting). The four dissenting Justices stated: ``The Army Corps has 
determined that wetlands adjacent to tributaries of traditionally 
navigable waters preserve the quality of our Nation's waters by, among 
other things, providing habitat for aquatic animals, keeping excessive 
sediment and toxic pollutants out of adjacent waters, and reducing 
downstream flooding by absorbing water at times of high flow. The 
Corps' resulting decision to treat these wetlands as encompassed within 
the term `waters of the United States' is a quintessential example of 
the Executive's reasonable interpretation of a statutory provision.'' 
Id. at 788 (citation omitted).
    In addition to joining the plurality's opinion, Chief Justice 
Roberts issued his own concurring opinion noting that the agencies 
``are afforded generous leeway by the courts in interpreting the 
statute they are entrusted to administer,'' and the agencies thus have 
``plenty of room to operate in developing some notion of an outer bound 
to the reach of their authority'' under the Clean Water Act. Id. at 
758.
    Neither the plurality nor the concurring opinions in Rapanos 
invalidated any of the regulatory provisions defining ``waters of the 
United States.''
4. Post-Rapanos Appellate Court Decisions
    The earliest post-Rapanos decisions by the United States Courts of 
Appeals focused on which standard to apply in interpreting the scope of 
``waters of the United States''--the plurality's or Justice Kennedy's. 
Chief Justice Roberts anticipated this question and cited Marks v. 
United States, 430 U.S. 188 (1977) in his concurring opinion to Rapanos 
as applicable precedent. Marks v. United States provides that ``[w]hen 
a fragmented Court decides a case and no single rationale explaining 
the result enjoys the assent of five Justices, the holding of the Court 
may be viewed as the position taken by those Members who concurred in 
the judgments on the narrowest grounds.'' The dissenting Justices in 
Rapanos also spoke to future application of the divided decision. While 
Justice Stevens stated that he assumed Justice Kennedy's significant 
nexus standard would apply in most instances, the dissenting Justices 
noted that they would find the Clean Water Act extended to waters 
meeting either the relatively permanent standard articulated by Justice 
Scalia or the significant nexus standard described by Justice Kennedy. 
Rapanos, 547 U.S. at 810 & n.14 (Stevens, J., dissenting).
    Since Rapanos, every court of appeals to have considered the 
question has determined that the government may exercise Clean Water 
Act jurisdiction over at least those waters that satisfy the 
significant nexus standard set forth in Justice Kennedy's concurrence. 
None has held that solely the plurality's relatively permanent standard 
may be used to establish jurisdiction. Some have held that the 
government may establish jurisdiction under either standard. The 
Eleventh Circuit has held that only Justice Kennedy's standard applies. 
Precon Dev. Corp. v. U.S. Army Corps of Eng'rs, 633 F.3d 278 (4th Cir. 
2011); see also United States v. Donovan, 661 F.3d 174 (3d Cir. 2011); 
United States v. Bailey, 571 F.3d 791 (8th Cir. 2009); United States v. 
Cundiff, 555 F.3d 200 (6th Cir. 2009); United States v. Lucas, 516 F.3d 
316 (5th Cir. 2008); N. Cal. River Watch v. City of Healdsburg, 496 
F.3d 993 (9th Cir. 2007) (superseding the original opinion published at 
457 F.3d 1023 (9th Cir. 2006)); United States v. Robison, 505 F.3d 1208 
(11th Cir. 2007); United States v. Johnson, 467 F.3d 56 (1st Cir. 
2006); United States v. Gerke Excavating, Inc., 464 F.3d 723 (7th Cir. 
2006).
5. Post-Rapanos Implementation of the 1986 Regulations
    For nearly a decade after Rapanos, the agencies did not revise 
their regulations but instead determined jurisdiction under the 1986 
regulations consistent with the two standards established in Rapanos 
(the relatively permanent standard and the significant nexus standard) 
and by using guidance issued jointly by the agencies. See U.S. EPA & 
U.S. Army Corps of Engineers, Clean Water Act Jurisdiction Following 
the U.S. Supreme Court's Decision in Rapanos v. United States & 
Carabell v. United States (June 5, 2007), superseded December 2, 2008 
(the ``Rapanos Guidance'').
    Under the Rapanos Guidance,\12\ the agencies concluded that Clean 
Water Act jurisdiction exists if a water meets either the relatively 
permanent standard or the significant nexus standard. The agencies' 
assertion of jurisdiction over traditional navigable waters and their 
adjacent wetlands remained unchanged by Rapanos. Under the relatively 
permanent standard, the guidance stated that the agencies would assert 
jurisdiction over: Non-navigable tributaries of traditional navigable 
waters that typically flow year-round or have continuous flow at least 
seasonally; and wetlands that directly abut such tributaries. Id. at 4-
7. The guidance states that the agencies will determine jurisdiction 
under the significant nexus standard for the following waters: Non-
navigable tributaries that are not relatively permanent, wetlands 
adjacent to non-navigable tributaries that are not relatively 
permanent, and wetlands adjacent to but not directly abutting a 
relatively permanent non-navigable tributary. Id. at 8-12. The agencies 
generally did not assert jurisdiction over non-wetland swales or 
erosional features (e.g., gullies and small washes characterized by low 
volume or infrequent or short duration flow) or ditches (including 
roadside ditches) excavated wholly in and draining only uplands and 
that did not carry a relatively permanent flow of water. Id. at 11-12.
---------------------------------------------------------------------------

    \12\ The agencies note that the guidance ``does not impose 
legally binding requirements on EPA, the Corps, or the regulated 
community, and may not apply to a particular situation depending on 
the circumstances.'' Rapanos Guidance at 4 n.17.
---------------------------------------------------------------------------

B. The Agencies' Post-Rapanos Rules

    Since 2015, EPA and the Army have finalized three rules revising 
the definition of ``waters of the United States.''

[[Page 69381]]

1. The 2015 Clean Water Rule
    On June 29, 2015, EPA and the Army published the ``Clean Water 
Rule: Definition of `Waters of the United States,' '' 80 FR 37054 (June 
29, 2015). The 2015 Clean Water Rule's definition of ``waters of the 
United States'' established three categories: (A) Waters that are 
categorically ``jurisdictional by rule'' (without the need for 
additional analysis); (B) waters that are subject to case-specific 
analysis to determine whether they are jurisdictional; and (C) waters 
that are categorically excluded from jurisdiction. Id. at 37054. Waters 
considered ``jurisdictional by rule'' included (1) traditional 
navigable waters; (2) interstate waters, including interstate wetlands; 
(3) the territorial seas; (4) impoundments of waters otherwise 
identified as jurisdictional; (5) tributaries of the first three 
categories of ``jurisdictional by rule'' waters; and (6) waters 
adjacent to a water identified in the first five categories of 
``jurisdictional by rule'' waters, including ``wetlands, ponds, lakes, 
oxbows, impoundments, and similar waters.'' Finally, all exclusions 
from the definition of ``waters of the United States'' in the pre-2015 
regulations were retained, and several exclusions reflecting agency 
practice or based on public comment were added to the regulation for 
the first time.\13\
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    \13\ In February 2018, the agencies issued a rule that added an 
applicability date of February 6, 2020 to the 2015 Clean Water Rule. 
83 FR 5200 (February 6, 2018) (``Applicability Date Rule''). The 
Applicability Date Rule was challenged in several district court 
actions and on August 16, 2018--a mere six months after the rule had 
been issued--the rule was vacated and enjoined nationwide. See South 
Carolina Coastal Conservation League v. Pruitt, 318 F. Supp. 3d 959 
(D.S.C. Aug. 16, 2018); see also Puget Soundkeeper All. v. Wheeler, 
No. 15-01342 (W.D. Wash. Nov. 26, 2018) (vacating the Applicability 
Date Rule nationwide).
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2. The 2019 Repeal Rule
    On February 28, 2017, Executive Order 13778 ``Restoring the Rule of 
Law, Federalism, and Economic Growth by Reviewing the `Waters of the 
United States' Rule,'' directed EPA and the Army to review the 2015 
Clean Water Rule for consistency with the policy outlined in section 1 
of the order and to issue a proposed rule rescinding or revising the 
2015 rule as appropriate and consistent with law. 82 FR 12497 (March 3, 
2017). The Executive Order also directed the agencies to ``consider 
interpreting the term `navigable waters' . . . in a manner consistent 
with'' Justice Scalia's opinion in Rapanos. Id.
    Consistent with this directive, after notice and comment, on 
October 22, 2019, the agencies published a final rule repealing the 
2015 Clean Water Rule and recodifying the 1986 regulations without any 
changes to the regulatory text. 84 FR 56626 (October 22, 2019).
3. The 2020 Navigable Waters Protection Rule
    Three months later, on January 23, 2020, the agencies signed 
another final rule--the Navigable Waters Protection Rule: Definition of 
``Waters of the United States'' (NWPR)--that for the first time defined 
``waters of the United States'' based generally on Justice Scalia's 
plurality test from Rapanos. The NWPR was published on April 21, 2020, 
and went into effect on June 22, 2020. 85 FR 22250 (April 21, 2020). 
The NWPR interpreted the term ``the waters'' within ``the waters of the 
United States'' to ``encompass relatively permanent flowing and 
standing waterbodies that are traditional navigable waters in their own 
right or that have a specific surface water connection to traditional 
navigable waters, as well as wetlands that abut or are otherwise 
inseparably bound up with such relatively permanent waters.'' Id. at 
22273. Specifically, the rule established four categories of 
jurisdictional waters: (1) The territorial seas and traditional 
navigable waters; (2) tributaries of such waters; (3) certain lakes, 
ponds, and impoundments of jurisdictional waters; and (4) wetlands 
adjacent to other jurisdictional waters (other than jurisdictional 
wetlands). Id. at 22273.
    The NWPR defined the scope of each of these four categories. The 
territorial seas and traditional navigable waters were defined 
consistent with the agencies' longstanding interpretations of those 
terms. A ``tributary'' was defined as a river, stream, or similar 
naturally occurring surface water channel that contributes surface 
water flow to a territorial sea or traditional navigable water in a 
typical year either directly or indirectly through other tributaries, 
jurisdictional lakes, ponds, or impoundments, or adjacent wetlands. A 
tributary was required to be perennial or intermittent in a typical 
year. The term ``tributary'' included a ditch that either relocates a 
tributary, is constructed in a tributary, or is constructed in an 
adjacent wetland as long as the ditch is perennial or intermittent and 
contributes surface water flow to a traditional navigable water or 
territorial sea in a typical year. Id. at 22251. The definition did not 
include ephemeral features, which were defined as surface waters that 
flow only in direct response to precipitation, including ephemeral 
streams, swales, gullies, rills, and pools. Id.
    The NWPR defined ``lakes and ponds, and impoundments of 
jurisdictional waters'' as ``standing bodies of open water that 
contribute surface water flow in a typical year to a territorial sea or 
traditional navigable water either directly or through a tributary, 
another jurisdictional lake, pond, or impoundment, or an adjacent 
wetland.'' Id. A lake, pond, or impoundment of a jurisdictional water 
did not lose its jurisdictional status if it contributes surface water 
flow to a downstream jurisdictional water in a typical year through 
certain artificial or natural features. The NWPR also defined a lake, 
pond, or impoundment of a jurisdictional water inundated by flooding 
from a jurisdictional water in a typical year as jurisdictional. Id.
    As for wetlands, the NWPR interpreted ``adjacent wetlands'' to be 
those wetlands that abut jurisdictional waters and those non-abutting 
wetlands that are (1) ``inundated by flooding'' from a jurisdictional 
water in a typical year, (2) physically separated from a jurisdictional 
water only by certain natural features (e.g., a berm, bank, or dune), 
or (3) physically separated from a jurisdictional water by an 
artificial structure that ``allows for a direct hydrologic surface 
connection'' between the wetland and the jurisdictional water in a 
typical year. Id. at 22251. Wetlands that do not have these types of 
connections to other waters were not jurisdictional.
    The NWPR expressly provided that waters that do not fall into one 
of these jurisdictional categories are not considered ``waters of the 
United States.'' Id. Moreover, waters within these categories, 
including traditional navigable waters and the territorial seas, were 
not ``waters of the United States'' if they also fit within the NWPR's 
broad exclusions. See id. at 22325 (``If the water meets any of the[ ] 
exclusions, the water is excluded even if the water satisfies one or 
more conditions to be a [jurisdictional] water.'').\14\ The rule 
excluded groundwater, including groundwater drained through subsurface 
drainage systems; ephemeral features; diffuse stormwater runoff and 
directional sheet flow over upland; ditches that are not traditional 
navigable waters, tributaries, or that are not constructed in adjacent 
wetlands, subject to certain limitations; prior converted cropland; 
artificially irrigated areas; artificial lakes and ponds; water-filled 
depressions constructed or excavated in upland or in non-jurisdictional 
waters incidental to

[[Page 69382]]

mining or construction activity; pits excavated in upland or in non-
jurisdictional waters for the purpose of obtaining fill, sand, or 
gravel; stormwater control features constructed or excavated in upland 
or in non-jurisdictional waters; groundwater recharge, water reuse, and 
wastewater recycling structures constructed or excavated in upland or 
in non-jurisdictional waters; and waste treatment systems.
---------------------------------------------------------------------------

    \14\ The NWPR's exclusion for ditches, however, explicitly did 
not encompass ditches that are traditional navigable waters or 
jurisdictional tributaries. 33 CFR 328.3(b)(5).
---------------------------------------------------------------------------

4. Legal Challenges to the Rules
    Starting with the 2015 Clean Water Rule, the agencies' rulemakings 
to revise the definition of ``waters of the United States'' have been 
subject to multiple legal challenges.
    Multiple parties sought judicial review of the 2015 Clean Water 
Rule in various district and circuit courts. On January 22, 2018, the 
Supreme Court, in a unanimous opinion, held that rules defining the 
scope of ``waters of the United States'' are subject to direct review 
in the district courts. Nat'l Ass'n of Mfrs. v. Dep't of Def., 138 S. 
Ct. 617 (2018). Several of those district court cases remain 
pending.\15\ While the 2015 Clean Water Rule went into effect in some 
parts of the country in August 2015, due to multiple injunctions \16\ 
and later rulemakings, the 2015 Clean Water Rule was never implemented 
nationwide.
---------------------------------------------------------------------------

    \15\ See, e.g., North Dakota v. EPA, No. 15-00059 (D.N.D.); Ohio 
v. EPA, No. 15-02467 (S.D. Ohio); Southeastern Legal Found. v. EPA, 
No. 15-02488 (N.D. Ga.).
    \16\ See, e.g., North Dakota v. EPA, 127 F. Supp. 3d 1047 
(D.N.D. 2015) (preliminary injunction barring implementation of the 
2015 Clean Water Rule in 13 states); Georgia v. Pruitt, 326 F. Supp. 
3d 1356 (S.D. Ga. June 6, 2018) (same as to 11 states); Texas v. 
EPA, No. 3:15-cv-162, 2018 WL 4518230 (S.D. Tex. Sept. 12, 2018) 
(same as to 3 states). See section I.A of the Technical Support 
Document for the Proposed ``Revised Definition of `Waters of the 
United States''' Rule (``Technical Support Document''; located in 
the docket for this action), for a comprehensive history of the 
effects of the litigation against the 2015 Clean Water Rule.
---------------------------------------------------------------------------

    A number of pending cases involve claims against the NWPR. On 
August 30, 2021, the U.S. District Court for the District of Arizona 
remanded the NWPR and vacated the rule. Pascua Yaqui Tribe v. EPA, No. 
4:20-cv-00266, 2021 WL 3855977 (D. Ariz. Aug. 30, 2021). The court 
found that ``[t]he seriousness of the Agencies' errors in enacting the 
NWPR, the likelihood that the Agencies will alter the NWPR's definition 
of `waters of the United States,' and the possibility of serious 
environmental harm if the NWPR remains in place upon remand, all weigh 
in favor of remand with vacatur.'' Id. at *5. On September 27, 2021, 
the U.S. District Court for the District of New Mexico also issued an 
order vacating and remanding the NWPR. Navajo Nation v. Regan, No. 
2:20-cv-00602 (D.N.M. Sept. 27, 2021). In vacating the rule, the court 
agreed with the reasoning of the Pascua Yaqui court that the NWPR 
suffers from ``fundamental, substantive flaws that cannot be cured 
without revising or replacing the NWPR's definition of `waters of the 
United States.''' Slip. op. at 6. Six courts also remanded the NWPR 
without vacatur or without addressing vacatur.\17\
---------------------------------------------------------------------------

    \17\ Order, Pueblo of Laguna v. Regan, No. 1:21-cv-00277, ECF 
No. 40 (D.N.M. Sept. 21, 2021) (declining to reach issue of vacatur 
in light of the Pascua decision); Order, California v. Wheeler, No. 
3:20-cv-03005, ECF No. 271 (N.D. Cal. Sept. 16, 2021) (same); 
Waterkeeper All. v. Regan, No. 3:18-cv-03521, ECF No. 125 (N.D. Cal. 
Sept. 16, 2021) (same); Order, Conservation Law Found. v. EPA, No. 
1:20-cv-10820, ECF No. 122 (D. Mass. Sept. 1, 2021) (same); Order, 
S.C. Coastal Conservation League v. Regan, No. 2:20-cv-01687, ECF 
No. 147 (D.S.C. July 15, 2021) (remanding without vacating); Order, 
Murray v. Wheeler, No. 1:19-cv-01498, ECF No. 46 (N.D.N.Y. Sept. 7, 
2021) (same).
---------------------------------------------------------------------------

    At this time, 14 cases are pending challenging the agencies' rules 
defining ``waters of the United States,'' including the 2015 Clean 
Water Rule, 2019 Repeal Rule, and the NWPR.\18\ Some of these cases 
challenge only one of the rules, while others challenge two or even all 
three rules in the same lawsuit. See section I.A of the Technical 
Support Document for a comprehensive history of the effects of the 
litigation surrounding the 2015 Clean Water Rule, 2019 Repeal Rule, and 
the NWPR.
---------------------------------------------------------------------------

    \18\ Pascua Yaqui Tribe v. EPA, No. 20-00266 (D. Ariz.); 
Colorado v. EPA, No. 20-01461 (D. Colo.); Am. Exploration & Mining 
Ass'n v. EPA, No. 16-01279 (D.D.C.); Envtl. Integrity Project v. 
Regan, No. 20-01734 (D.D.C.); Se. Stormwater Ass'n v. EPA, No. 15-
00579 (N.D. Fla.); Se. Legal Found. v. EPA, No. 15-02488 (N.D. Ga.); 
Chesapeake Bay Found. v. Regan, Nos. 20-1063 & 20-1064 (D. Md.); 
Navajo Nation v. Regan, No. 20-00602 (D.N.M.); N.M. Cattle Growers' 
Ass'n v. EPA, No. 19-00988 (D.N.M.); North Dakota v. EPA, No. 15-
00059 (D.N.D.); Ohio v. EPA, No. 15-02467 (S.D. Ohio); Or. 
Cattlemen's Ass'n v. EPA, No. 19-00564 (D. Or.); S.C. Coastal 
Conservation League v. Regan, No. 19-03006 (D.S.C.); Puget 
Soundkeeper All. v. EPA, No. 20-00950 (W.D. Wash.); Wash. 
Cattlemen's Ass'n v. EPA, No. 19-00569 (W.D. Wash.).
---------------------------------------------------------------------------

5. 2021 Executive Order and Review of the Navigable Waters Protection 
Rule
    On January 20, 2021, President Biden signed Executive Order 13990, 
entitled ``Executive Order on Protecting Public Health and the 
Environment and Restoring Science to Tackle the Climate Crisis,'' which 
provides that ``[i]t is, therefore, the policy of my Administration to 
listen to the science; to improve public health and protect our 
environment; to ensure access to clean air and water; to limit exposure 
to dangerous chemicals and pesticides; to hold polluters accountable, 
including those who disproportionately harm communities of color and 
low-income communities; to reduce greenhouse gas emissions; to bolster 
resilience to the impacts of climate change; to restore and expand our 
national treasures and monuments; and to prioritize both environmental 
justice and the creation of the well-paying union jobs necessary to 
deliver on these goals.'' 86 FR 7037 (published January 25, 2021, 
signed January 20, 2021). The order ``directs all executive departments 
and agencies (agencies) to immediately review and, as appropriate and 
consistent with applicable law, take action to address the promulgation 
of Federal regulations and other actions during the last 4 years that 
conflict with these important national objectives, and to immediately 
commence work to confront the climate crisis.'' Id. at section 2(a). 
``For any such actions identified by the agencies, the heads of 
agencies shall, as appropriate and consistent with applicable law, 
consider suspending, revising, or rescinding the agency actions.'' Id. 
The order also revoked Executive Order 13778 of February 28, 2017 
(Restoring the Rule of Law, Federalism, and Economic Growth by 
Reviewing the ``Waters of the United States'' Rule), which had 
initiated development of the NWPR.
    In conformance with Executive Order 13990, the agencies reviewed 
the NWPR to determine if it is aligned with the principles laid out 
therein:
    Science: Science plays a critical role in understanding how to 
protect the integrity of our nation's waters. As discussed in detail 
below, see section V.B.3 of this preamble, the NWPR did not properly 
consider the extensive scientific evidence demonstrating the 
interconnectedness of waters and their downstream effects, thereby 
undermining Congress's objective to restore and maintain the chemical, 
physical, and biological integrity of the nation's waters. The NWPR's 
definition of ``waters of the United States'' does not adequately 
consider the way pollution moves through waters or the way filling in a 
wetland affects downstream water resources.
    Climate: Science has established that human and natural systems 
have been extensively impacted by climate change. Climate change can 
have a variety of impacts on water resources in particular. See 
Technical Support Document section III.C. For instance, a warming 
climate is already increasing precipitation in many areas (e.g., the 
Northeast and Midwest), while decreasing precipitation in other areas 
(e.g., the Southwest). Climate change can also increase the intensity 
of

[[Page 69383]]

precipitation events, including storms, and runoff from these storms 
can impair water quality as pollutants deposited on land wash into 
water bodies. Changes in streamflow, snowmelt timing, snowpack 
accumulation, and the size and frequency of heavy precipitation events 
can also cause river floods to become larger or more frequent than they 
used to be in some places. Climate change also affects streamflow 
characteristics like the magnitude and timing of flows, in part due to 
changes in snowpack magnitude and seasonality. As the climate continues 
to change, many historically dry areas are likely to experience less 
precipitation and increased risk of drought associated with more 
frequent and intense heatwaves, which can cause streams and wetlands to 
become drier, negatively affecting both water supplies and water 
quality. Lower streamflow and groundwater levels can also increase 
events such as wildfires, which can alter water quality and impact 
wetlands and their functions. A warming climate can also result in 
increased and more variable temperatures in streams, leading to fish 
kills and negatively affecting other aquatic species that can live only 
in colder water. Finally, rising sea levels associated with climate 
change are inundating low-lying wetlands and dry land and further 
contributing to coastal flooding and erosion.
    Although water resources are vulnerable to the effects of climate 
change, they perform a variety of functions that can help restore 
ecological function of other water resources in light of climate change 
(i.e., contribute to climate resiliency) and mitigate the negative 
effects of climate change on other water resources including 
traditional navigable waters, interstate waters, and the territorial 
seas. For instance, wetlands inside and outside of floodplains are 
well-known to store large volumes of floodwaters, thereby protecting 
downstream watersheds from potential flooding. Coastal wetlands can 
also help buffer storm surges, which are becoming more frequent due to 
climate change. Additionally, small streams are particularly effective 
at retaining and attenuating floodwaters. As natural filters, wetlands 
help purify and protect the quality of other waters, including drinking 
water sources--a function which is more important than ever as intense 
precipitation events spurred on by a changing climate mobilize 
sediment, nutrients, and other pollutants. Biological communities and 
geomorphic processes in small streams and wetlands break down leaves 
and other organic matter, burying and sequestering a portion of that 
carbon that could otherwise be released to the atmosphere and lead to 
continued negative effects on water resources.
    The NWPR did not appropriately acknowledge or take account of the 
effects of a changing climate on the chemical, physical, and biological 
integrity of the nation's waters. For example, its rolling thirty-year 
approach to determining a ``typical year'' does not allow the agencies 
flexibility to account for the effects of a rapidly changing climate, 
including positive trends in temperature, increasing storm events, and 
extended droughts (see section V.B.3.c of this preamble). The NWPR also 
excluded ephemeral streams and their adjacent wetlands in the arid West 
from the definition of ``waters of the United States.'' These aquatic 
systems are increasingly critical to protecting and maintaining 
downstream integrity as the climate in that region continues to get 
hotter and drier, but with altered monsoon seasons with fewer but more 
intense storms that contribute to flashy hydrology (i.e., higher runoff 
volume, leading to more rapidly rising and falling streamflow over 
shorter periods of time).
    Section V.A.2.c.iv of this preamble contains a discussion of how 
the agencies believe that climate change can be appropriately 
considered in implementing the proposed rule.
    Environmental Justice: The agencies recognize that the burdens of 
environmental pollution and climate change often fall 
disproportionately on population groups of concern (e.g., minority, 
low-income, and indigenous populations as specified in Executive Order 
12898). Numerous groups have raised concerns that the NWPR had 
disproportionate impacts on tribes and indigenous communities.\19\ The 
NWPR decreased the scope of Clean Water Act jurisdiction across the 
country, including in geographic regions where regulation of waters 
beyond those covered by the Act is not authorized under current state 
or tribal law (see section V.B.3.d of this preamble). Absent 
regulations governing discharges of pollutants into previously 
jurisdictional waters, population groups of concern where these waters 
are located may experience increased water pollution and impacts from 
associated increases in health risk.
---------------------------------------------------------------------------

    \19\ See, e.g., Tribal Consultation Comment Letter from 
President Jonathan Nez and Vice President Myron Lizer, Navajo 
Nation, October 4, 2021 (``The Navajo Nation relies greatly on all 
its surface waters, including ephemeral, intermittent, and perennial 
surface waters. The Navajo Nation currently lacks the resources to 
implement CWA permitting and other programs necessary to maintain 
and protect water quality and relies on the Agencies to fill that 
need. Therefore, any new WOTUS rule must not reduce the scope of the 
waters that the Agencies can protect, or it will have 
`disproportionately high and adverse human health or environmental 
effects' on the Navajo Nation.''), and Tribal Consultation Comment 
Letter from Clarice Madalena, Interim Director, Natural Resources 
Department, Pueblo of Jemez, October 4, 2021 (``The combination of 
these factors--[desert] hydrology and the geographic location of 
Native communities--means that the Navigable Waters Rule had the 
effect of disparately stripping Clean Water Act protections from 
areas with higher Native populations. This means that the Rule 
disproportionately harmed Native American communities. This 
discriminatory impact violates the principles of environmental 
justice'' (citations omitted). See, also, section V.B.3.d of this 
preamble and the Technical Support Document.
---------------------------------------------------------------------------

    Further, the NWPR categorically excluded ephemeral streams from 
jurisdiction, which disproportionately impacts tribes and population 
groups of concern in the arid West. Tribes may lack the authority and 
often the resources to regulate waters within their boundaries, and 
they may also be affected by pollution from adjacent jurisdictions.\20\ 
Therefore, the change in jurisdiction under the NWPR may have 
disproportionately exposed tribes to increased pollution and health 
risks.
---------------------------------------------------------------------------

    \20\ See supra at note 18.
---------------------------------------------------------------------------

    After completing the review and reconsidering the record for the 
NWPR, on June 9, 2021, the agencies announced their intention to revise 
or replace the rule. The factors the agencies found most relevant in 
making this decision are: The text of the Clean Water Act; 
Congressional intent and the objective of the Clean Water Act; Supreme 
Court precedent; the current and future harms to the chemical, 
physical, and biological integrity of the nation's waters due to the 
NWPR; concerns raised by stakeholders about the NWPR, including 
implementation-related issues; the principles outlined in the Executive 
Order; and issues raised in ongoing litigation challenging the NWPR. 
EPA and the Army concluded that the NWPR did not appropriately consider 
the effect of the revised definition of ``waters of the United States'' 
on the integrity of the nation's waters, and that the rule threatened 
the loss or degradation of waters critical to the protection of 
traditional navigable waters, among other concerns.

C. Summary of Stakeholder Outreach

    EPA held a series of stakeholder meetings during the agencies' 
review of the NWPR, including specific meetings in May 2021 with 
industry, environmental organizations, agricultural organizations, and 
state associations. On July 30, 2021, the

[[Page 69384]]

agencies signed a Federal Register notice that announced a schedule for 
initial public meetings to hear from interested stakeholders on their 
perspectives on defining ``waters of the United States'' under the 
Clean Water Act and how to implement the definition. 86 FR 41911 
(August 4, 2021). The agencies also announced their intent to accept 
written pre-proposal recommendations from members of the public for a 
30-day period beginning on August 4, 2021, and concluding on September 
3, 2021. The agencies received over 32,000 recommendation letters from 
the public, which can be found in the pre-proposal docket (Docket ID 
EPA-HQ-OW-2021-0328). The agencies also announced their plans for 
future engagement opportunities, including geographically focused 
roundtables to provide for broad, transparent, regionally focused 
discussions among a full spectrum of stakeholders. The Federal Register 
notice articulated several specific issues that the agencies are 
particularly interested in receiving feedback on, including 
implementation of previous regulatory regimes; regional, state, and 
tribal interests; identification of relevant science; environmental 
justice interests; climate implications; the scope of jurisdictional 
waters such as tributaries, jurisdictional ditches, and adjacent 
features; and exclusions from jurisdiction.
    The agencies also have engaged state and local governments over a 
60-day federalism consultation period during development of this 
proposed rule, beginning with an initial federalism consultation 
meeting on August 5, 2021, and concluding on October 4, 2021. 
Additional information about the federalism consultation can be found 
in section VII.E of this preamble and in the report summarizing 
consultation and additional outreach to state and local governments, 
available in the docket (Docket ID No. EPA-HQ-OW-2021-0602) for this 
proposed rule. On September 29, October 6, and October 20, 2021, the 
agencies hosted virtual meetings with states focused on implementation 
of prior ``waters of the United States'' regulatory regimes.
    The agencies received input from a wide variety of states and local 
governments through virtual meetings, consultation letters, and 
recommendation letters submitted to the public docket. Many of these 
groups encouraged meaningful dialogue between the states, local 
governments, and the agencies, and identified implementation challenges 
with determining the jurisdiction of waters under the pre-2015 
regulatory regime. States and local governments stressed the need for 
guidance, training, and tools early in the process to help with 
implementing any revised definition of ``waters of the United States.'' 
A few also requested the agencies to consider a delayed effective date 
for revised definitions of ``waters of the United States'' to give 
state and local partners time to revise and develop new policies. Many 
state and local governments emphasized the variability of water 
resources across the United States and supported regionalized criteria 
for determining jurisdictional waters. Some of these groups noted the 
importance of strong Federal standards and the regulation of interstate 
waters, since pollutants from upstream states can enter waters within 
their borders.
    States and local governments held divergent views on the agencies' 
plans to revert to the pre-2015 regulatory regime, and on which water 
resources should be considered ``waters of the United States.'' Some 
supported the NWPR and recommended the agencies generally retain and 
revise that rule. These state and local entities believed that the NWPR 
provided a clear definition for ``waters of the United States,'' 
maintained a balance between federal and state jurisdiction, and 
appropriately excluded waters that should not be subject to the Clean 
Water Act. Others supported the agencies' current rulemaking efforts as 
they thought the NWPR was not protective enough and did not account for 
the complexities of the hydrologic cycle, importance of ephemeral 
waters, or the connections among waters on the landscape. State and 
local governments held differing opinions on how the criteria for 
jurisdiction of ephemeral streams, ditches, tributaries, and wetlands 
should be determined, and which resources should be included in the 
scope of the Clean Water Act.
    Several state and local governments recommended consideration of 
climate change and environmental justice concerns in any new rulemaking 
effort. Some emphasized that isolated wetlands and ephemeral streams 
are important in reducing flooding during extreme weather events and 
that the agencies should consider this importance in the rulemaking. 
Others acknowledged the impacts of climate change but stated that other 
programs and legislation are more appropriate ways to address climate 
change. Some state and local governments also noted that NWPR excluded 
wetlands that are important to minority and low-income communities and 
that future rulemaking needs to consider environmental justice issues.
    The agencies also initiated a tribal consultation and coordination 
process on July 30, 2021. The agencies engaged tribes over a 66-day 
tribal consultation period during development of this proposed rule 
that concluded on October 4, 2021, including two consultation kick-off 
webinars and meetings. The agencies received consultation comment 
letters from 24 tribes and three tribal organizations and held three 
leader-to-leader consultation meetings and two staff-level meetings 
with tribes at their request. The agencies anticipate that consultation 
meetings with additional tribes will be held with tribes during the 
rulemaking process. Many tribes and tribal organizations expressed 
support for the agencies' efforts to replace the NWPR. One tribe did 
not support the agencies' efforts to revise the definition of ``waters 
of the United States,'' stating tribal sovereignty concerns and 
concerns that the agencies might exceed the power of Congress under the 
Commerce Clause. Some tribes stated that the NWPR disadvantaged tribes 
because unlike states, many tribes lack the resources to enforce a 
definition of ``tribal waters'' that is broader than the definition of 
``waters of the United States.'' Several tribes also stated that they 
rely on the Federal government to permit discharges of pollutants into 
waters on their lands and do not have the resources to administer their 
own permitting programs. Some tribes spoke of the importance of 
protecting ephemeral streams, which were eliminated from jurisdiction 
under the NWPR, as well as for wetlands that were excluded under the 
NWPR. Several tribes spoke about the need to include ``waters of the 
tribe'' into the definition of ``waters of the United States'' Several 
tribes stated support for furthering environmental justice with the 
proposed rule, noting that the agencies failed to undertake an 
environmental justice analysis for the NWPR. Some tribes also supported 
the need to account for climate change in the definition of ``waters of 
the United States.'' Additional information about the tribal 
consultation process can be found in section VII.F of this preamble and 
the Summary of Tribal Consultation and Coordination, which is available 
in the docket for this proposed rule. On October 7, 13, 27, and 28, 
2021, the agencies hosted virtual dialogues with tribes focused on 
implementation of prior ``waters of the United States'' regulatory 
regimes.
    Consistent with the August 4, 2021 Federal Register notice, the 
agencies held six public meeting webinars on

[[Page 69385]]

August 18, August 23, August 25 (specifically for small entities), 
August 26, August 31, and September 2, 2021. At these pre-proposal 
webinars, the agencies provided a brief presentation and sought input 
on the agencies' intent to revise the definition of ``waters of the 
United States'' and the specific issues included in the outreach 
Federal Register notice described above. The agencies heard from 
stakeholders representing a diverse range of interests, positions, 
suggestions, and recommendations.
    The agencies have received a variety of recommendations during this 
pre-proposal outreach process. The agencies received broad support for 
robust stakeholder outreach and the development of a rule that is 
consistent with Supreme Court precedent. Stakeholders disagreed about 
whether states and tribes could or would fill any perceived gap in 
permitting introduced by the NWPR's decreased scope of jurisdiction, 
with some stakeholders providing examples of environmental harms caused 
by the NWPR. Some stakeholders expressed support for a science-based 
rule, including stakeholders who believed the NWPR did not adequately 
consider the agencies' scientific record. Most stakeholders who 
provided input supported a clear, implementable rule that is easy for 
the public to understand, and the agencies received feedback that the 
significant nexus standard and typical year analysis were challenging 
to implement under prior regulatory regimes.
    Many stakeholders also emphasized the importance of regional 
geographic variability across the United States, and some stakeholders 
suggested that the agencies consider regionally specific criteria for 
jurisdictional waters. Some stakeholders emphasized the importance of 
climate change considerations in any new rulemaking effort, while other 
stakeholders stated that climate change cannot be used as a tool to 
expand jurisdictional authority. Some stakeholders explicitly supported 
the consideration of impacts to minority and low-income communities in 
developing a revised definition of ``waters of the United States'' and 
asserted that the NWPR did not consider impacts to these communities.
    Stakeholders also provided feedback on which water resources should 
be considered jurisdictional as ``waters of the United States.'' For 
instance, some stakeholders supported a jurisdictional category for 
interstate waters, while others opposed such a category. Stakeholders 
differed in whether they supported the criteria for jurisdictional 
tributaries, wetlands, and ditches under the pre-2015 regulatory 
regime, 2015 Clean Water Rule, or NWPR. Some stakeholders suggested 
that the agencies should enhance clarity by using physical indicators, 
functional characteristics, or surface water flow as jurisdictional 
criteria. Some stakeholders asserted that the agencies should exclude 
most ditches from the definition of ``waters of the United States,'' 
while others stated that the agencies should instead include ditches as 
jurisdictional if they function as tributaries or have other 
connections to other hydrologic features in the watershed. Some 
stakeholders indicated that impoundments and ``other waters'' are not 
appropriate categories of jurisdictional waters, while others suggested 
regulating a broad spectrum of open waters.
    Stakeholders expressed different views about which exclusions are 
important and should be included in a revised definition of ``waters of 
the United States.'' Many stakeholders noted that the waste treatment 
system exclusion and prior converted cropland exclusion should be 
retained, and some stakeholders expressed support for other exclusions 
such as stormwater control features and artificial lakes and ponds. As 
described in section V.C.8 of this preamble, the agencies are proposing 
to retain the waste treatment system exclusion and prior converted 
cropland exclusion from the 1986 regulations and have specified in the 
preamble that certain other waters are generally not considered 
``waters of the United States.'' Stakeholders also had divergent views 
on whether ephemeral streams should be categorically excluded from the 
definition of ``waters of the United States'' or evaluated as 
tributaries. As described in section V.C.5 of this preamble, the 
agencies are not proposing to exclude ephemeral streams but are instead 
proposing that ephemeral streams that meet the significant nexus 
standard be jurisdictional as tributaries.
    The agencies have considered the input that they received as part 
of the consultation processes and other opportunities for pre-proposal 
recommendations. The proposed rule, discussed in section V of this 
preamble, seeks to balance the considerations and concerns of co-
regulators and stakeholders. The agencies welcome feedback on this 
proposed rule through a public hearing and the 60-day public comment 
period initiated through publication of this action. The agencies will 
consider all comments received during the comment period on this 
proposal, and this consideration will be reflected in the final rule 
and supporting documents.

V. Proposed Revised Definition

A. Basis for Proposed Rule

    In this proposed rule, the agencies are exercising their 
discretionary authority to interpret ``waters of the United States'' to 
mean the waters defined by the familiar 1986 regulations, with 
amendments to reflect the agencies' determination of the statutory 
limits on the scope of the ``waters of the United States'' informed by 
Supreme Court precedent. The agencies propose to interpret the term 
``waters of the United States'' to include: Traditional navigable 
waters, interstate waters, and the territorial seas, and their adjacent 
wetlands; most impoundments of ``waters of the United States''; 
tributaries to traditional navigable waters, interstate waters, the 
territorial seas, and impoundments, that meet either the relatively 
permanent standard or the significant nexus standard; wetlands adjacent 
to impoundments and tributaries, that meet either the relatively 
permanent standard or the significant nexus standard; and ``other 
waters'' that meet either the relatively permanent standard or the 
significant nexus standard.
    The proposed rule advances the Clean Water Act's statutory 
objective to ``restore and maintain the chemical, physical, and 
biological integrity of the Nation's waters,'' section 101(a), as it is 
based on the best available science concerning the functions provided 
by upstream tributaries, adjacent wetlands, and ``other waters'' to 
restore and maintain the water quality of downstream foundational 
waters. In developing the proposed rule, the agencies also considered 
the statute as a whole, relevant Supreme Court case law, and the 
agencies' experience and expertise after more than 30 years of 
implementing the longstanding 1986 regulations defining ``waters of the 
United States,'' including more than a decade of experience 
implementing those regulations consistent with the decisions in 
Riverside Bayview, SWANCC, and Rapanos collectively. This proposed 
interpretation also reflects consideration of provisions of the Act 
including section 101(b) which states that ``[i]t is the policy of the 
Congress to recognize, preserve, and protect the primary 
responsibilities and rights of States to prevent, reduce, and eliminate 
pollution, to plan the development and use (including restoration, 
preservation, and enhancement) of land and water resources'' because 
the limitations

[[Page 69386]]

reflect consideration of both the comprehensive nature and objective of 
the Clean Water Act and avoid assertions of jurisdiction that raise 
federalism concerns. Determining where to draw the boundaries of 
federal jurisdiction to ensure that the agencies achieve Congress's 
objective while preserving and protecting the responsibilities and 
rights of the states is a matter of judgment assigned by Congress to 
the agencies. The proposed rule's relatively permanent and significant 
nexus limitations appropriately draw this boundary by ensuring that 
where upstream waters significantly affect the integrity of the 
traditional navigable waters, interstate waters, and territorial seas, 
Clean Water Act programs will apply to ensure that those downstream 
waters are protected, and where they do not, the agencies will leave 
regulation to the states and tribes. These limitations are thus based 
on the agencies' conclusion that together those standards are 
consistent with the statutory text, advance the objective of the Act, 
are supported by the scientific record, and appropriately consider the 
objective in section 101(a) of the Act and the policy in section 
101(b). In addition, because the proposed rule reflects consideration 
of the agencies' experience and expertise, as well as updates in 
implementation tools and resources, it is familiar and implementable.
    For all these reasons, the proposed rule would achieve the 
agencies' goals of quickly and durably protecting the quality of the 
nation's waters. Quickly, because the regulatory framework is familiar 
to the agencies and stakeholders and supporting science is available 
along with confirmatory updates; and durably, because the foundation of 
the rule is the longstanding regulations amended to reflect the 
agencies' interpretation of appropriate limitations on the geographic 
scope of the Clean Water Act that is consistent with case law, the Act, 
and the best available science. The proposal would protect the quality 
of the nation's waters by restoring the important protections for 
jurisdictional waters provided by the Clean Water Act, including not 
only protections provided by the Act's permitting programs, but also 
protections provided by programs ranging from water quality standards 
and total maximum daily loads to oil spill prevention, preparedness and 
response programs, to the state and tribal water quality certification 
programs.
    The proposed rule is based on the agencies' interpretation of the 
Clean Water Act, and the proposed rule's protection of water resources 
advances both the goals of the Act and the goals identified in the 
Executive Order, including: Listening to the science; improving public 
health and protecting our environment; ensuring access to clean water; 
limiting exposure to dangerous chemicals and pesticides; holding 
polluters accountable, including those who disproportionately harm 
communities of color and low-income communities; and bolstering 
resilience to the impacts of climate change.
1. The Proposed Rule Is Within the Agencies' Discretion Under the Act
    The Clean Water Act delegates authority to the agencies to 
interpret the term ``navigable waters'' and its statutory definition 
``waters of the United States,'' and agencies have inherent authority 
to reconsider past decisions and to revise, replace, or repeal a 
decision to the extent permitted by law and supported by a reasoned 
explanation. Given the regulatory and litigation history described 
above, there can be little disagreement that both terms under the Clean 
Water Act are ambiguous and that therefore the agencies have generous 
leeway to provide the considered and reasonable interpretation of the 
terms provided in this proposal. Indeed, the Supreme Court has twice 
held that the Act's terms ``navigable waters'' and ``waters of the 
United States'' are ambiguous and, therefore, that the agencies have 
delegated authority to reasonably interpret this phrase in the statute.
    First, in Riverside Bayview, the Supreme Court deferred to and 
upheld the agencies' interpretation of the Act to protect wetlands 
adjacent to navigable-in-fact bodies of water, relying on the familiar 
Chevron standard that ``[a]n agency's construction of a statute it is 
charged with enforcing is entitled to deference if it is reasonable and 
not in conflict with the expressed intent of Congress.'' 474 U.S. at 
131 (citing Chevron U.S.A. Inc. v. Natural Resources Defense Council, 
Inc., 467 U.S. 837, 842-45 (1984)). Second, in Rapanos, all Justices 
found ambiguity in the terms--albeit to varying degrees. In his 
concurring opinion, Justice Kennedy referenced ``ambiguity in the 
phrase `navigable waters.' '' 547 U.S. at 780. So did the dissenting 
Justices. See id. at 796 (``[G]iven the ambiguity inherent in the 
phrase `waters of the United States,' the Corps has reasonably 
interpreted its jurisdiction[.]'') (Stevens, J., dissenting); id. at 
811-12 (``Congress intended the Army Corps of Engineers to make the 
complex technical judgments that lie at the heart of the present cases 
(subject to deferential judicial review).'') (Breyer, J., dissenting). 
The plurality also agreed that the term ``is in some respects 
ambiguous.'' Id. at 752.
    Ambiguity in a statute represents ``delegations of authority to the 
agency to fill the statutory gap in reasonable fashion.'' Nat'l Cable & 
Telecomm. Ass'n v. Brand X internet Servs., 545 U.S. 967, 980 (2005). 
As the Supreme Court explained in Riverside Bayview, Congress delegated 
a ``breadth of federal regulatory authority'' and expected the agencies 
to tackle the ``inherent difficulties of defining precise bounds to 
regulable waters.'' 474 U.S. at 134. And, in concurring with the 
Rapanos plurality opinion, Chief Justice Roberts emphasized the breadth 
of the agencies' discretion in defining ``waters of the United States'' 
through rulemaking, noting that ``[g]iven the broad, somewhat 
ambiguous, but nonetheless clearly limiting terms Congress employed in 
the Clean Water Act, the [agencies] would have enjoyed plenty of room 
to operate in developing some notion of an outer bound to the reach of 
their authority'' under the Clean Water Act. 547 U.S. at 758 (Roberts, 
C.J., concurring). Indeed, the agencies' interpretations under the Act, 
Chief Justice Roberts emphasized, are ``afforded generous leeway by the 
courts.'' Id.
    In addition, agencies have inherent authority to reconsider past 
decisions and to revise, replace, or repeal a decision to the extent 
permitted by law and supported by a reasoned explanation. FCC v. Fox 
Television Stations, Inc., 556 U.S. 502, 515 (2009) (``Fox''); Motor 
Vehicle Manufacturers Ass'n of the United States, Inc. v. State Farm 
Mutual Automobile Insurance Co., 463 U.S. 29, 42 (1983) (``State 
Farm''); see also Encino Motorcars, LLC v. Navarro, 136 S. Ct. 2117, 
2125 (2016) (``Agencies are free to change their existing policies as 
long as they provide a reasoned explanation for the change.''). Such a 
decision need not be based upon a change of facts or circumstances. A 
revised rulemaking based ``on a reevaluation of which policy would be 
better in light of the facts'' is ``well within an agency's 
discretion.'' Nat'l Ass'n of Home Builders v. EPA, 682 F.3d 1032, 1038 
& 1043 (D.C. Cir. 2012) (citing Fox, 556 U.S. at 514-15).
    As discussed further in section V.B.3 of this preamble, the 
agencies have reviewed the NWPR and determined that the rule should be 
replaced. The proposed rule properly considers the objective of the 
Act, is consistent with the text and structure of the Act and

[[Page 69387]]

Supreme Court precedent, and is supported by the best available 
science.
2. The Proposed Rule Advances the Objective of the Clean Water Act
    The proposed rule is grounded in the Act's objective ``to restore 
and maintain the chemical, physical, and biological integrity of the 
Nation's waters,'' 33 U.S.C. 1251(a). The proposed rule advances the 
Act's objective by defining ``waters of the United States'' to include 
waters that significantly affect the chemical, physical, or biological 
integrity of traditional navigable waters, interstate waters, and the 
territorial seas and waters that are relatively permanent or that have 
a continuous surface connection to such waters. Those limitations also 
ensure that the agencies will not assert jurisdiction where the effect 
is not significant. The proposed rule is supported by the best 
available science on the functions provided by upstream waters, 
including wetlands, to restore and maintain the integrity of 
foundational waters because it recognizes that upstream waters can have 
significant effects and enables the agencies to make science-informed 
decisions about such effects. The proposed rule thus retains the 
familiar categories of waters in the 1986 regulations--traditional 
navigable waters, interstate waters, ``other waters,'' impoundments, 
tributaries, the territorial seas, and adjacent wetlands--while 
proposing to add, where appropriate, a requirement that waters also 
meet either the significant nexus standard or the relatively permanent 
standard.
a. The Objective of the Clean Water Act To Protect Water Quality Must 
Be Considered When Defining ``Waters of the United States''
    A statute must be interpreted in light of the purposes Congress 
sought to achieve. See, e.g., Dickerson v. New Banner Institute, Inc., 
460 U.S. 103, 118 (1983). Thus, the agencies must consider the 
objective of the Clean Water Act in interpreting the scope of the 
statutory term ``waters of the United States.'' The objective of the 
Clean Water Act is ``to restore and maintain the chemical, physical, 
and biological integrity of the Nation's waters.'' 33 U.S.C. 1251(a). 
To thus adequately consider the Act's statutory objective, a rule 
defining ``waters of the United States'' must consider its effects on 
the chemical, physical, and biological integrity of the nation's 
waters. And--as the text and structure of the Act, supported by 
legislative history and Supreme Court decisions, make clear--chemical, 
physical, and biological integrity refers to water quality.
    The Act begins with the objective in section 101(a) and establishes 
numerous programs all designed to protect the integrity of the nation's 
waters, ranging from permitting programs and enforcement authorities, 
to water quality standards and effluent limitations guidelines, to 
research and grant provisions.
    One of the Clean Water Act's principal tools in protecting the 
integrity of the nation's waters is section 301(a), which prohibits 
``the discharge of any pollutant by any person'' without a permit or 
other authorization under the Act. Other substantive provisions of the 
Clean Water Act that apply to ``navigable waters'' and are designed to 
meet the statutory objective include the section 402 NPDES permit 
program, the section 404 dredged and fill permit program, the section 
311 oil spill prevention and response program, the section 303 water 
quality standards and total maximum daily load programs, and the 
section 401 state and tribal water quality certification process, as 
discussed above. Each of these programs is designed to protect water 
quality and, therefore, further the objective of the Act. The question 
of federal jurisdiction is foundational to most programs administered 
under the Clean Water Act. See section IV.A.1 of this preamble.\21\
---------------------------------------------------------------------------

    \21\ Additional provisions are also designed to achieve the 
Act's statutory objective and use its specific language, including 
the definition of ``pollution,'' which the Act defines as ``the man-
made or man-induced alteration of the chemical, physical, 
biological, and radiological integrity of water.'' 33 U.S.C. 
1362(19).
---------------------------------------------------------------------------

    Two recent Supreme Court Clean Water Act decisions, County of Maui, 
Hawaii v. Hawaii Wildlife Fund, 140 S. Ct. 1462, 1476 (2020) (``Maui'') 
and Nat'l Ass'n of Mfrs. v. Dep't of Defense, 138 S. Ct. 617, 624 
(2018) (``National Association of Manufacturers''), affirm that 
Congress used specific language in the definitions of the Act in order 
to meet the objective of the Act, that the definition of ``waters of 
the United States'' is fundamental to meeting the objective of the Act, 
and, therefore, that the objective of the Act must be considered in 
interpreting the term ``waters of the United States.''
    In Maui, the Supreme Court instructed that ``[t]he object in a 
given scenario will be to advance, in a manner consistent with the 
statute's language, the statutory purposes that Congress sought to 
achieve.'' 140 S. Ct. at 1476. The Court, in recognizing that 
Congress's purpose to `` `restore and maintain the . . . integrity of 
the Nation's waters' '' is ``reflected in the language of the Clean 
Water Act,'' also found that ``[t]he Act's provisions use specific 
definitional language to achieve this result,'' noting that among that 
definitional language is the phrase ``navigable waters.'' Id. at 1468-
69.\22\ Thus, in accordance with Maui, in interpreting the ``specific 
definitional language'' of the Clean Water Act, the agencies must 
consider whether they are advancing the statutory purposes Congress 
sought to achieve.
---------------------------------------------------------------------------

    \22\ The Court explained:
    The Act's provisions use specific definitional language to 
achieve this result. First, the Act defines ``pollutant'' broadly, 
including in its definition, for example, any solid waste, 
incinerator residue, `` `heat,' '' `` `discarded equipment,' '' or 
sand (among many other things). Sec.  502(6), 86 Stat. 886. Second, 
the Act defines a ``point source'' as `` `any discernible, confined 
and discrete conveyance . . . from which pollutants are or may be 
discharged,' '' including, for example, any `` `container,' '' `` 
`pipe, ditch, channel, tunnel, conduit,' '' or `` `well.' '' Sec.  
502(14), id., at 887. Third, it defines the term ``discharge of a 
pollutant'' as `` `any addition of any pollutant to navigable waters 
[including navigable streams, rivers, the ocean, or coastal waters] 
from any point source.' '' Sec.  502(12), id., at 886.
    Maui, 140 S. Ct. at 1469.
---------------------------------------------------------------------------

    In National Association of Manufacturers, the Court confirmed the 
importance of considering the objective of the Clean Water Act when 
interpreting the specific definitional language of the Act, and in 
particular when interpreting the definitional language ``waters of the 
United States.'' The Court identified section 301's prohibition on 
unauthorized discharges as one of the Act's principal tools for 
achieving the objective and then identified ``waters of the United 
States'' as key to the scope of the Act: ``Congress enacted the Clean 
Water Act in 1972 `to restore and maintain the chemical, physical, and 
biological integrity of the Nation's waters.' [33 U.S.C.] 1251(a). One 
of the Act's principal tools in achieving that objective is [section] 
1311(a), which prohibits `the discharge of any pollutant by any 
person,' except in express circumstances. . . . Because many of the 
Act's substantive provisions apply to `navigable waters,' the statutory 
phrase `waters of the United States' circumscribes the geographic scope 
of the Act in certain respects.'' 138 S. Ct. 617, 624. Thus, 
consideration of the objective of the Act is of particular importance 
when defining the foundational phrase ``waters of the United States.''
    Many other Supreme Court decisions confirm the importance of 
considering the Act's objective. When faced with questions of statutory 
interpretation on the scope of the Clean Water Act, many Supreme Court 
decisions begin with the

[[Page 69388]]

objective of the Act and examine the relevant question through that 
lens. See, e.g., PUD No. 1 of Jefferson Cty v. Washington Dep't of 
Ecology, 511 U.S. 700, 704 (1994) (interpreting the scope of Clean 
Water Act section 401 and finding that the Act ``is a comprehensive 
water quality statute designed to `restore and maintain the chemical, 
physical, and biological integrity of the Nation's waters,' '' that 
``[t]he Act also seeks to attain `water quality which provides for the 
protection and propagation of fish, shellfish, and wildlife,' '' and 
that ``[t]o achieve these ambitious goals, the Clean Water Act 
establishes distinct roles for the Federal and State Governments''); 
EPA v. California ex rel. State Water Resources Control Bd., 426 U.S. 
200, 203, 205 n.12 (1976) (``In 1972, prompted by the conclusion of the 
Senate Committee on Public Works that `the Federal water pollution 
control program . . . has been inadequate in every vital aspect,' 
Congress enacted the [Clean Water Act], declaring `the national goal 
that the discharge of pollutants into the navigable waters be 
Eliminated by 1985.''); Arkansas v. Oklahoma, 503 U.S. 91 (1992) 
(reviewing the scope of EPA's authority to issue a permit affecting a 
downstream state and finding that the Act ``anticipates a partnership 
between the States and the Federal Government, animated by a shared 
objective: `to restore and maintain the chemical, physical, and 
biological integrity of the Nation's waters' ''); S.D. Warren Co. v. 
Maine Bd. of Envtl. Protection, 126 S. Ct. 1843, 1852-53 (2006) 
(interpreting the scope of ``discharge'') (``Congress passed the Clean 
Water Act to `restore and maintain the chemical, physical, and 
biological integrity of the Nation's waters,' 33 U.S.C. [section] 
1251(a)''); Int'l Paper Co. v. Ouellette, 479 U.S. 481, 492-93 (1987) 
(``Congress intended the 1972 Act amendments to `establish an all-
encompassing program of water pollution regulation.' . . . The Act 
applies to all point sources and virtually all bodies of water, and it 
sets forth the procedures for obtaining a permit in great detail. . . . 
Given that the Act itself does not speak directly to the issue, the 
Court must be guided by the goals and policies of the Act in 
determining whether it in fact pre-empts an action based on the law of 
an affected State.'').
    Along with Maui and National Association of Manufacturers, these 
cases confirm that, for purposes of a rulemaking revising the 
definition of ``waters of the United States,'' the agencies must 
consider the rule's effect on the chemical, physical, and biological 
integrity of the nation's waters--i.e., the quality of those waters. 
The Supreme Court in Riverside Bayview explained the inherent link 
between the Act's objective and water quality: ``This objective 
incorporated a broad, systemic view of the goal of maintaining and 
improving water quality: As the House Report on the legislation put it, 
`the word ``integrity'' . . . refers to a condition in which the 
natural structure and function of ecosystems [are] maintained.' '' 474 
U.S. at 132 (citations omitted).
    Indeed, the Clean Water Act is replete with 90 references to water 
quality--from the goals set forth in furtherance of meeting the 
statutory objective to the provisions surrounding research, effluent 
limitations, and water quality standards. See, e.g., 33 U.S.C. 
1251(a)(2) (``[I]t is the national goal that wherever attainable, an 
interim goal of water quality which provides for the protection and 
propagation of fish, shellfish, and wildlife and provides for 
recreation in and on the water be achieved''), 1254(b)(6) (providing 
that the Administrator shall collect ``basic data on chemical, 
physical, and biological effects of varying water quality''), 
1311(b)(1)(C) (requiring permits to have limits as stringent as 
necessary to meet water quality standards), 1313(c) (providing that 
water quality standards ``shall be such as to protect the public health 
or welfare, enhance the quality of water and serve the purposes of this 
[Act]''). And Congress was clear that ``[t]he development of 
information which describes the relationship of pollutants to water 
quality is essential for carrying out the objective of the Act.'' S. 
Rep. No. 92-414 (1972), as reprinted in 1972 U.S.C.C.A.N. 3668, 3716. 
See also id. at 3717 (``Water quality is intended to refer to the 
biological, chemical and physical parameters of aquatic ecosystems, and 
is intended to include reference to key species, natural temperature 
and current flow patterns, and other characteristics which help 
describe ecosystem integrity. . . . The criteria will allow the 
translation of the narrative of the general objective of the Act to 
specific and precise parameters.''); id. at 3742 (``The Committee has 
added a definition of pollution to further refine the concept of water 
quality measured by the natural chemical, physical and biological 
integrity.''). As the Sixth Circuit explained shortly after the 1972 
enactment of the Clean Water Act: ``It would, of course, make a mockery 
of [Congress's] powers if its authority to control pollution was 
limited to the bed of the navigable stream itself. The tributaries 
which join to form the river could then be used as open sewers as far 
as federal regulation was concerned. The navigable part of the river 
could become a mere conduit for upstream waste.'' United States v. 
Ashland Oil & Transp. Co., 504 F.2d 1317, 1326 (6th Cir. 1974).
    To be clear, the agencies do not interpret the objective of the 
Clean Water Act to be the only factor relevant to determining the scope 
of the Act. Rather, in light of the precise definitional language of 
the definitions in the Act, the importance of water quality to the 
statute as a whole, and Maui and other Supreme Court decisions 
affirming that consideration of the objective of the Act is important 
in defining the scope of the Act, the agencies conclude that 
consideration of the objective of the Act for purposes of a rule 
defining ``waters of the United States'' must include substantive 
consideration of the effects of a revised definition on the integrity 
of the nation's waters. As discussed further below, the proposed rule 
properly considers and advances the objective of the Act because it 
focuses on the effects of upstream waters including wetlands on 
traditional navigable waters, interstate waters, and the territorial 
seas, and is supported by the best available science on those water 
quality effects.
b. The Proposed Rule Builds Upon the 1986 Regulations, Which Were 
Designed To Advance the Objective of the Act
    The 1986 regulations--which are substantially the same as the 1977 
regulations--represented the agencies' interpretation of the Clean 
Water Act in light of its objective and their scientific knowledge 
about aquatic ecosystems. The 1986 regulations were designed to advance 
the objective of the Act and are thus a reasonable foundation upon 
which to build the proposed rule. In this proposed rule, the agencies 
are exercising their discretionary authority to interpret ``waters of 
the United States'' to mean the waters defined by the familiar 1986 
regulations, with amendments to reflect the agencies' interpretation of 
the statutory limits on the scope of the ``waters of the United 
States'' informed by Supreme Court decisions and the scientific record.
    The best available science as discussed below confirms that the 
1986 regulations remain a reasonable foundation for a definition of 
``waters of the United States'' that furthers the water quality 
objective of the Clean Water Act. See Technical Support Document. This 
section describes the agencies' historic rationale for the 1986 
regulations and its regulatory categories

[[Page 69389]]

and describes the latest science that supports the conclusion that the 
categories of waters identified in the 1986 regulations, such as 
tributaries, adjacent wetlands, and ``other waters,'' provide functions 
that restore and maintain the chemical, physical, and biological 
integrity of traditional navigable waters, interstate waters, and the 
territorial seas.
    The agencies' historic regulations, which became the 1986 
regulations, were based on the agencies' scientific and technical 
judgment about which waters needed to be protected to restore and 
maintain the chemical, physical, and biological integrity of 
traditional navigable waters, interstate waters, and the territorial 
seas. For more than 40 years, EPA and the Corps recognized the need to 
protect ``the many tributary streams that feed into the tidal and 
commercially navigable waters . . . since the destruction and/or 
degradation of the physical, chemical, and biological integrity of each 
of these waters is threatened by the unregulated discharge of dredged 
or fill material.'' 42 FR 37121, 37123. The agencies further recognized 
that the nation's wetlands are ``a unique, valuable, irreplaceable 
water resource. . . . Such areas moderate extremes in waterflow, aid in 
the natural purification of water, and maintain and recharge the ground 
water resource.'' EPA, Protection of Nation's Wetlands: Policy 
Statement, 38 FR 10834 (May 2, 1973). In Riverside Bayview, the Supreme 
Court acknowledged that the agencies were interpreting the Act 
consistent with its objective and based on their scientific expertise:

    In view of the breadth of federal regulatory authority 
contemplated by the Act itself and the inherent difficulties of 
defining precise bounds to regulable waters, the Corps' ecological 
judgment about the relationship between waters and their adjacent 
wetlands provides an adequate basis for a legal judgment that 
adjacent wetlands may be defined as waters under the Act.

474 U.S. at 134.
    As the Corps stated in promulgating the 1977 definition, ``[t]he 
regulation of activities that cause water pollution cannot rely on . . 
. artificial lines, however, but must focus on all waters that together 
form the entire aquatic system. Water moves in hydrologic cycles, and 
the pollution of . . . part of the aquatic system . . . will affect the 
water quality of the other waters within that aquatic system.'' 42 FR 
37128. Thus, the proposed rule includes the categories long identified 
by the agencies as affecting the water quality of traditional navigable 
waters, interstate waters, and the territorial seas, including 
tributaries, adjacent wetlands, impoundments, and ``other waters.''
    For example, the agencies have long construed the Act to include 
tributaries as ``waters of the United States.'' The Corps explained in 
1977 that its regulations necessarily encompassed ``the many tributary 
streams that feed into the tidal and commercially navigable waters'' 
because ``the destruction and/or degradation of the physical, chemical, 
and biological integrity of each of these waters is threatened by the 
unregulated discharge of dredged or fill material.'' Id. at 37123.
    Construing ``waters of the United States'' to include tributaries 
of traditional navigable waters, interstate waters, the territorial 
seas, and impoundments of ``waters of the United States'' is consistent 
with the discussion of tributaries in the Act's legislative history. 
The Senate Report accompanying the 1972 Act states that ``navigable 
waters'' means ``the navigable waters of the United States, portions 
thereof, tributaries thereof, and includes the territorial seas and the 
Great Lakes.'' S. Rep. No. 92414, at 77 (1971), as reprinted in 1972 
U.S.C.C.A.N. 3668, 3742 (emphasis added). Furthermore, Congress 
recognized that Clean Water Act jurisdiction must extend broadly 
because ``[w]ater moves in hydrologic cycles and it is essential that 
[the] discharge of pollutants be controlled at the source.'' Id. 
Congress thus restated that ``reference to the control requirements 
must be made to the navigable waters, portions thereof, and their 
tributaries.'' Id. at 3743 (emphasis added).
    As discussed below and further in the Technical Support Document, 
the best available science supports the 1986 regulations' conclusions 
about the importance of tributaries to the water quality of downstream 
foundational waters: Tributaries provide natural flood control, 
recharge groundwater, trap sediment, store and transform pollutants 
from fertilizers, decrease high levels of chemical contaminants, 
recycle nutrients, create and maintain biological diversity, and 
sustain the biological productivity of downstream rivers, lakes, and 
estuaries.
    With the 1986 regulations, the agencies determined that wetlands 
adjacent to navigable waters generally play a key role in protecting 
and enhancing water quality: ``Water moves in hydrologic cycles, and 
the pollution of this part of the aquatic system, regardless of whether 
it is above or below an ordinary high water mark, or mean high tide 
line, will affect the water quality of the other waters within that 
aquatic system. For this reason, the landward limit of Federal 
jurisdiction under Section 404 must include any adjacent wetlands that 
form the border of or are in reasonable proximity to other waters of 
the United States, as these wetlands are part of this aquatic system.'' 
42 FR 37128; see also 38 FR 10834.
    In Riverside Bayview, the Supreme Court deferred to the agencies' 
judgment that adjacent wetlands provide valuable functions for 
downstream waters:

[T]he Corps has concluded that wetlands may serve to filter and 
purify water draining into adjacent bodies of water and to slow the 
flow of surface runoff into lakes, rivers, and streams and thus 
prevent flooding and erosion. In addition, adjacent wetlands may 
``serve significant natural biological functions, including food 
chain production, general habitat, and nesting, spawning, rearing 
and resting sites for aquatic . . . species.'' . . . [W]e cannot say 
that the Corps' judgment on these matters is unreasonable . . . .

474 U.S. at 134-35 (citations omitted). The Supreme Court then 
unanimously held that ``a definition of `waters of the United States' 
encompassing all wetlands adjacent to other bodies of water over which 
the Corps has jurisdiction is a permissible interpretation.'' Id. at 
135.
    As discussed below and further in the Technical Support Document, 
the best available science supports the 1986 regulations' conclusions 
about the functions provided by adjacent wetlands to downstream 
traditional navigable waters, interstate waters, and the territorial 
seas, namely that adjacent wetlands provide valuable flood control and 
water quality functions including interruption and delay of the 
transport of water-borne contaminants over long distances, retention of 
sediment, prevention and mitigation of drinking water contamination, 
and assurance of drinking water supply.
    The 1986 regulations also included ``other waters'' based on their 
effects on water quality and their effects on interstate commerce. 42 
FR 37128. As discussed below and further in section IV.D of the 
Technical Support Document, the best available science also shows that 
``other waters''--such as depressional wetlands, open waters, and 
peatlands--can provide important hydrologic (e.g., flood control), 
water quality, and habitat functions which vary as a result of the 
diverse settings in which they exist across the country and which can 
have downstream effects on larger rivers, lakes, and estuaries, 
particularly when considered collectively with other non-floodplain 
wetlands on the landscape. The

[[Page 69390]]

functions that ``other waters'' provide include storage of floodwater, 
recharge of ground water that sustains river baseflow, retention and 
transformation of nutrients, metals, and pesticides, export of 
organisms to downstream waters, and habitats needed for aquatic and 
semi-aquatic species that also utilize streams.
    While the 1986 regulations are a reasonable foundation upon which 
to build the proposed rule, the agencies are exercising their 
discretionary authority to interpret ``waters of the United States'' to 
mean the waters defined by the familiar 1986 regulations, with 
amendments to reflect the agencies' interpretation of the statutory 
limits on the scope of the ``waters of the United States'' informed by 
Supreme Court decisions as discussed in section V.A.3 of this preamble.
c. The Proposed Rule Properly Considers the Objective by the Act 
Because It Is Informed by the Best Available Science on Water Quality
    As noted above, the agencies propose to interpret the term ``waters 
of the United States'' to include: Traditional navigable waters, 
interstate waters, and the territorial seas, and their adjacent 
wetlands; most impoundments of ``waters of the United States''; 
tributaries to traditional navigable waters, interstate waters, the 
territorial seas, and impoundments, that meet either the relatively 
permanent standard or the significant nexus standard; wetlands adjacent 
to impoundments and tributaries, that meet either the relatively 
permanent standard or the significant nexus standard; and ``other 
waters'' that meet either the relatively permanent standard or the 
significant nexus standard. The proposal is supported by the best 
available science on the functions provided by upstream waters, 
including wetlands, that are important for the chemical, physical, and 
biological integrity of foundational waters. The agencies' proposal is 
supported by a wealth of scientific knowledge. The scientific 
literature extensively illustrates the effects tributaries, wetlands 
adjacent to impoundments and tributaries, and ``other waters'' can and 
do have on the integrity of downstream traditional navigable waters, 
interstate waters, and the territorial seas. The relevant science on 
the relationship and downstream effects of streams, wetlands, and open 
waters has advanced considerably in recent years, and confirms the 
agencies' longstanding view that these waters can be subject to 
jurisdiction. A comprehensive report prepared by EPA's Office of 
Research and Development entitled ``Connectivity of Streams and 
Wetlands to Downstream Waters: A Review and Synthesis of the Scientific 
Evidence'' \23\ (hereafter the Science Report) in 2015 synthesized the 
peer-reviewed science. Since the release of the Science Report, 
additional published peer-reviewed scientific literature has 
strengthened and supplemented the report's conclusions. The agencies 
have summarized and provided an update on more recent literature and 
scientific support for this section in the Technical Support Document 
section II.
---------------------------------------------------------------------------

    \23\ U.S. Environmental Protection Agency, Connectivity of 
Streams and Wetlands to Downstream Waters: A Review and Synthesis of 
the Scientific Evidence (Final Report), EPA/600/R-14/475F (2015), 
available at https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=296414.
---------------------------------------------------------------------------

    Again, in the proposed rule, the agencies are not including all 
tributaries, adjacent wetlands, and ``other waters'' as jurisdictional 
waters. Rather, the agencies are concluding that proposing these 
longstanding, familiar categories of waters as subject to the 
relatively permanent or significant nexus jurisdictional standards is 
consistent with the best available science because waters in these 
categories can have significant effects on downstream foundational 
waters, and are therefore proposing to restore them from the 1986 
regulations. The agencies are also proposing to add the relatively 
permanent and significant nexus standards based on their conclusion 
that together those standards are consistent with the statutory text, 
advance the objective and policies of the Act, and are supported by the 
scientific record. Indeed, the agencies are not reaching any 
conclusions, categorical or otherwise, about which tributaries, 
adjacent wetlands (other than those adjacent to traditional navigable 
waters, interstate waters, or the territorial seas), or ``other 
waters'' meet either the relatively permanent or the significant nexus 
standard. Instead, the proposal enables the agencies to make science-
informed determinations of whether or not a water that falls within 
these categories meets either jurisdictional standard and is therefore 
a ``water of the United States,'' on a case-specific basis.
    The agencies also reiterate their previous conclusion that 
significant nexus is not a purely scientific determination. 80 FR 
37054, 37060 (June 29, 2015). As the agencies charged with interpreting 
the statute, EPA and the Corps must develop the outer bounds of the 
scope of the Clean Water Act and science does not provide bright line 
boundaries with respect to where ``water ends'' for purposes of the 
Clean Water Act. Riverside Bayview, 474 U.S. at 132-33. This section 
summarizes the best available science in support of the longstanding 
categories of the 1986 regulation, and in support of the proposed rule 
and the agencies' conclusion that the proposal advances the objective 
of the Clean Water Act. This section reflects the scientific consensus 
on the strength of the effects that upstream tributaries, adjacent 
wetlands, and ``other waters'' can and do have on downstream 
foundational waters. However, a significant nexus determination 
requires legal, technical, and policy judgment, as well as scientific 
considerations, for example, to assess the significance of any effects. 
Section V.D of this preamble discusses the agencies' approaches to 
making case-specific relatively permanent and significant nexus 
determinations under the proposed rule.
    Thus, while the agencies are not proposing to establish that any 
tributaries, adjacent wetlands (other than those wetlands adjacent to 
traditional navigable waters, interstate waters, and the territorial 
seas), or ``other waters'' are jurisdictional without the need for 
further assessment, they are proposing a rule that, based on the 
scientific record, identifies those categories of waters as subject to 
jurisdiction under the Clean Water Act under either the relatively 
permanent or significant nexus standard.
i. Tributaries Can Provide Functions That Restore and Maintain the 
Chemical, Physical, and Biological Integrity of Downstream Traditional 
Navigable Waters, Interstate Waters, and the Territorial Seas
    Tributaries play an important role in the transport of water, 
sediments, organic matter, nutrients, and organisms to downstream 
foundational waters. See Technical Support Document section IV.A. 
Tributaries slow and attenuate floodwaters; provide functions that help 
maintain water quality; trap and transport sediments; transport, store 
and modify pollutants; and sustain the biological productivity of 
downstream mainstem waters. Tributaries can provide these functions 
whether they are natural, modified, or constructed and whether they are 
perennial, intermittent, or ephemeral.
    All tributary streams, including perennial, intermittent, and 
ephemeral streams, are chemically, physically, and biologically 
connected to larger downstream waters via channels and associated 
alluvial deposits where water and other materials are concentrated, 
mixed, transformed, and transported. Streams, even where seasonally 
dry, are

[[Page 69391]]

the dominant source of water in most rivers, rather than direct 
precipitation or groundwater input to mainstem river segments. Within 
stream and river networks, headwater streams make up most of the total 
channel length. The smallest streams represent an estimated three-
quarters of the total length of stream and river channels in the United 
States.\24\ Because of their abundance and location in the watershed, 
small streams offer the greatest opportunity for exchange between the 
water and the terrestrial environment.
---------------------------------------------------------------------------

    \24\ The actual proportion may be much higher because this 
estimate is based on the stream networks shown on the U.S. 
Geological Survey (USGS) National Hydrography Dataset, which does 
not show all headwater streams.
---------------------------------------------------------------------------

    In addition, compared with the humid regions of the country, stream 
and river networks in arid regions have a higher proportion of channels 
that flow ephemerally or intermittently. For example, in Arizona, most 
of the stream channels--96% by length--are classified as ephemeral or 
intermittent. The functions that streams provide to benefit downstream 
waters occur even when streams flow less frequently, such as 
intermittent or ephemeral streams. For example, ephemeral headwater 
streams shape larger downstream river channels by accumulating and 
gradually or episodically releasing stored materials such as sediment 
and large woody debris.\25\ Due to the episodic nature of flow in 
ephemeral and intermittent channels, sediment and organic matter can be 
deposited some distance downstream in the arid Southwest in particular, 
and then moved farther downstream by subsequent precipitation events. 
Over time, sediment and organic matter continue to move downstream and 
influence larger downstream waters. These materials help structure 
downstream river channels by slowing the flow of water through channels 
and providing substrate and habitat for aquatic organisms.
---------------------------------------------------------------------------

    \25\ Videos of ephemeral streams flowing after rain events in 
the Southwest highlight how effective ephemeral streams can be in 
transporting woody debris (e.g., tree branches) and sediment 
downstream during the rainy season. See, e.g., U.S. Department of 
Agriculture, Agricultural Research Service, Multiflume Runoff Event 
August 1, 1990, https://www.tucson.ars.ag.gov/unit/WGWebcam/WalnutGulchWebcam.htm; U.S. Geological Survey, Post-fire Flash Flood 
in Coronado National Memorial, Arizona (August 25, 2011), https://www.youtube.com/watch?v=qJ8JxBZt6Ws; Santa Clara Pueblo Fire/Rescue/
EMS Volunteer Department, Greg Lonewolf, #4 Santa Clara Pueblo Flash 
Flood Event 01 Sept 2013 (April 14, 2017), https://www.youtube.com/watch?v=nKOQzkRi4BQ; Rankin Studio, Amazing Flash Flood/Debris Flow 
Southern Utah HD (July 19, 2019), https://www.youtube.com/watch?v=_yCnQuILmsM.
---------------------------------------------------------------------------

    Stream and wetland ecosystems also process natural and human 
sources of nutrients, such as those found in leaves that fall into 
streams and those that may flow into creeks from agricultural fields. 
Some of this processing converts the nutrients into more biologically 
useful forms. Other aspects of the processing store nutrients, thereby 
allowing their slow and steady release and preventing the kind of 
short-term glut of nutrients that can cause algal blooms in downstream 
rivers or lakes. Small streams and their associated wetlands play a key 
role in both storing and modifying potential pollutants, ranging from 
chemical fertilizers to rotting salmon carcasses, in ways that maintain 
downstream water quality. Inorganic nitrogen and phosphorus, the main 
chemicals in agricultural fertilizers, are essential nutrients not just 
for plants, but for all living organisms. However, in excess or in the 
wrong proportions, these chemicals can harm natural systems and humans. 
Larger rivers process excess nutrients much more slowly than smaller 
streams. Loss of nutrient retention capacity in headwater streams is 
known to cause downstream water bodies to contain higher concentrations 
and loads of nitrogen and phosphorus. In freshwater ecosystems, 
eutrophication, the enriching of waters by excess nitrogen and 
phosphorus, reduces water quality in streams, lakes, estuaries, and 
other downstream water bodies. One obvious result of eutrophication is 
the excessive growth of algae. Too much algae clouds previously clear 
streams, such as those favored by trout. Algal blooms not only reduce 
water column visibility, but the microbial decay of algal blooms 
reduces the amount of oxygen dissolved in the water, sometimes to a 
degree that causes fish kills. Fish are not the only organisms harmed 
by eutrophication: Some of the algae species that grow in eutrophic 
waters generate tastes and odors or are toxic--a clear problem for 
stream systems, reservoirs, and lakes that supply drinking water for 
municipalities or that are used for swimming and other contact-
recreational purposes. In addition, increased nitrogen and phosphorus 
and associated algal blooms can injure people and animals. Algal blooms 
can also lead to beach closures. In addition to causing algal blooms, 
eutrophication changes the natural community composition of aquatic 
ecosystems by altering environmental conditions.
    Recycling organic carbon contained in dead plants and animals is 
another crucial function provided by headwater streams and wetlands. 
Ecological processes that transform inorganic carbon into organic 
carbon and recycle organic carbon are the basis for every food web on 
the planet. In freshwater ecosystems, much of the recycling happens in 
small streams and wetlands, where microorganisms transform everything 
from leaf litter and downed logs to dead salamanders into food for 
other organisms in the aquatic food web, including salmon. Like 
nitrogen and phosphorus, carbon is essential to life but can be harmful 
to freshwater ecosystems if it is present in excess or in the wrong 
chemical form. If all organic material received by headwater streams 
and wetlands went directly downstream, the glut of decomposing material 
could deplete oxygen in downstream rivers, thereby damaging and even 
killing fish and other aquatic life. The ability of headwater stream 
ecosystems to transform organic matter into more usable forms helps 
maintain healthy downstream ecosystems.
    Microorganisms in headwater stream systems use material such as 
leaf litter and other decomposing material for food and, in turn, 
become food for other organisms. For example, fungi that grow on leaf 
litter become nutritious food for invertebrates that make their homes 
on the bottom of a stream, including mayflies, stoneflies, and caddis 
flies. These animals provide food for larger animals, including birds 
such as flycatchers and fish such as trout. The health and productivity 
of downstream traditional navigable waters, interstate waters, or the 
territorial seas depend in part on processed organic carbon delivered 
by upstream headwater systems.
    To be clear, the agencies recognize that SWANCC held that the use 
of ``isolated'' non-navigable intrastate ponds by migratory birds was 
not by itself a sufficient basis for the exercise of federal regulatory 
authority under the Clean Water Act. Consideration of biological 
functions does not constitute an assertion of jurisdiction over a water 
based solely on its use by migratory birds; rather, the agencies would 
consider biological functions for purposes of significant nexus 
determinations under the proposed rule only to the extent that the 
functions provided by tributaries, adjacent wetlands, and ``other 
waters'' significantly affect the biological integrity of the 
downstream traditional navigable waters, interstate waters, or the 
territorial seas. For example, to protect Pacific and Atlantic salmon 
in traditional navigable waters (and their associated commercial and 
recreational fishing industries), headwater streams must be protected 
because Pacific and

[[Page 69392]]

Atlantic salmon require both freshwater and marine habitats over their 
life cycles and therefore migrate along river networks, providing one 
of the clearest illustrations of biological connectivity. Many Pacific 
salmon species spawn in headwater streams, where their young grow for a 
year or more before migrating downstream, live their adult life stages 
in the ocean, and then migrate back upstream to spawn. Even where they 
do not provide direct habitat for salmon themselves, ephemeral streams 
may contribute to the habitat needs of salmon by supplying sources of 
cold water that these species need to survive (i.e., by providing 
appropriate physical conditions for cold water upwelling to occur at 
downstream confluences), transporting sediment that supports fish 
habitat downstream, and providing and transporting food for juveniles 
and adults downstream. These species thereby create a biological 
connection along the entire length of the river network and 
functionally help to maintain the biological integrity of the 
downstream traditional navigable water. Many other species of 
anadromous fish--that is fish that are born in freshwater, spend most 
of their lives in saltwater, and return to freshwater to lay eggs--as 
well as species of freshwater fish like rainbow trout and brook trout 
also require small headwater streams to carry out life cycle functions.
    Based on the importance of the functions that can be provided by 
tributaries to foundational waters, the agencies' proposal to interpret 
the Clean Water Act to protect tributaries where those tributaries meet 
either the relatively permanent standard or the significant nexus 
standard reflects proper consideration of the objective of the Act and 
the best available science.
ii. Adjacent Wetlands Provide Functions That Restore and Maintain the 
Chemical, Physical, and Biological Integrity of Downstream Traditional 
Navigable Waters, Interstate Waters, and the Territorial Seas
    Adjacent wetlands provide valuable flood control and water quality 
functions that affect the chemical, physical, and biological integrity 
of downstream foundational waters including interruption and delay of 
the transport of water-borne contaminants over long distances; 
retention of sediment; retention and slow release of flood waters; and 
prevention and mitigation of drinking water contamination and assurance 
of drinking water supply. See Technical Support Document section IV.B.
    Because adjacent wetlands retain sediment and augment streamflow 
via the gradual release of groundwater or water flowing just beneath 
the solid surface, wetland loss correlates with increased need for 
dredging and unpredictability of adequate streamflow for navigation. 
The Supreme Court has recognized the importance of the physical 
integrity of upstream tributaries in overcoming sedimentation hazards 
to navigation. United States v. Rio Grande Dam Irrigation Co., 174 U.S. 
690 (1899). Headwater wetlands are located where erosion risk is 
highest and are therefore best suited to recapture and stabilize 
manageable amounts of sediment that might enter traditional navigable 
waters, interstate waters, or the territorial seas. Adjacent wetlands 
naturally serve to recapture and stabilize sediment carried by streams 
and rivers in times when flood flow distributes water across a 
floodplain.
    Adjacent wetlands affect the integrity of downstream waters by 
retaining stormwater and slowly releasing floodwaters that could 
otherwise negatively affect the condition or function of downstream 
waters. The filling or draining of wetlands, including those that are 
close to the stream network, reduces water storage capacity in a 
watershed and causes runoff from rainstorms to overwhelm the remaining 
available water conveyance system. The resulting stream erosion and 
channel downcutting quickly drains the watershed as surface water 
leaves via incised (deeper) channels. Disconnecting the incised channel 
from the wetlands leads to more downstream flooding. As the adjacent 
wetlands remain disconnected, riparian vegetation and wetland functions 
are reduced. Because less water is available in groundwater and 
wetlands for slow release to augment streamflow during dry periods, the 
filling or draining of wetlands can make the timing and extent of 
navigability on some waterways less predictable during dry periods. 
Therefore, the filling or draining of adjacent wetlands, including 
headwater wetlands, can interfere with the ability to maintain 
navigability on the nation's rivers and harbors and can lead to 
flooding in larger downstream waters.
    The loss of wetlands adjacent to tributaries of navigable waters, 
interstate waters, and the territorial seas can also result in notable 
reductions in drinking water supply and quality. Over 225 million 
people are served by nearly 15,000 public water systems using surface 
water such as streams, rivers, lakes, tributaries, and surface-water 
storage impoundments as a primary source of water. Though drinking 
water supplied through public water supplies is regulated by the Safe 
Drinking Water Act, many water suppliers also rely on source water 
protection efforts, as the quality of the drinking water source is 
dependent on the protection of its upstream waters. Discharge of 
agricultural, industrial, sanitary, or other waste into any surface 
water may pose a public health risk downstream. For example, excessive 
upstream discharge may overwhelm a public water system filtration unit, 
allowing microbial pathogens into the drinking water system. EPA's 
Science Advisory Board cited drinking water contamination by pathogens 
as one of the most important environmental risks. Drinking water 
treatment to address microbial pathogens has little effect on many 
toxic chemicals, metals, and pesticides discharged into streams, 
drainage ditches, canals, or other surface waters. Conserving wetlands 
in source water protection areas can help protect water quality, 
recharge aquifers, and maintain surface water flow during dry periods.
    Adjacent wetlands have an important role in improving source water 
quality, due to their strategic location as buffers for other water 
bodies and their filtration of surface water. Detention of water and 
its associated constituents by wetlands allows the biochemical uptake 
and/or breakdown of contaminants, and the destruction of pathogens. A 
wide and dense distribution of adjacent wetlands protects and mitigates 
against contaminant discharges. The water detention capacity of 
adjacent wetlands also allows for the storage and gradual release of 
surface waters that may supply public water system intakes during times 
of drought. In either case, this detention substantially improves both 
the supply and quality of drinking water. For example, wetlands 
conservation is a crucial feature of the low-cost New York City 
municipal water system, which provides high-quality drinking water to 
millions of people through watershed protection, including of adjacent 
wetlands, of its source waters rather than extensive treatment.
    Based on the importance of the functions that are provided by 
adjacent wetlands to foundational waters, the agencies' proposal to 
interpret the Clean Water Act to protect adjacent wetlands where those 
adjacent wetlands meet either the relatively permanent standard or the 
significant nexus standard reflects proper consideration of the 
objective of the Act and the best available science.

[[Page 69393]]

iii. ``Other waters'' Can Provide Functions That Restore and Maintain 
the Chemical, Physical, and Biological Integrity of Downstream 
Traditional Navigable Waters, Interstate Waters, and the Territorial 
Seas
    ``Other waters''--examples of which include, but are not limited 
to, intrastate lakes, wetlands, prairie potholes, playa lakes, streams 
that are not tributaries, and natural ponds--can provide important 
functions which affect the chemical, physical, and biological integrity 
of downstream foundational waters. See Technical Support Document 
section IV.D. These functions are particularly valuable when considered 
cumulatively across the landscape or across different watershed/sub-
watershed scales and are similar to the functions that adjacent 
wetlands provide, including water storage to control streamflow and 
mitigate downstream flooding; interruption and delay of the transport 
of water-borne pollutants (such as excess nutrients and contaminants) 
over long distances; and retention of sediment. These functions can be 
important to the physical integrity of downstream foundational waters. 
For non-floodplain wetlands and open waters lacking a channelized 
surface or regular shallow subsurface connection, generalizations from 
the available literature about their specific effects on downstream 
waters are difficult because information on both function and 
connectivity is needed, and thus case-specific analysis of their 
effects on downstream waters is appropriate from both a scientific and 
policy perspective.
    ``Other waters'' individually span the gradient of connectivity 
identified in the Science Report; they can be open waters located in 
the riparian area or floodplain of traditional navigable waters, 
interstate waters, and the territorial seas (e.g., oxbow lakes) and 
otherwise be physically proximate to the stream network (similar to 
adjacent wetlands) or they can be open waters or wetlands that are 
fairly distant from the network. They can be connected to downstream 
foundational waters via confined surface or subsurface connections 
(including channels, pipes, and culverts), unconfined surface 
connections, shallow subsurface connections, deeper groundwater 
connections, biological connections, or spillage. They can also provide 
additional functions such as storage and mitigation of peak flows, 
natural filtration by biochemical uptake and/or breakdown of 
contaminants, and in some locations, high volume aquifer recharge that 
contributes to the baseflow in downstream waters. The strength of 
functions provided by ``other waters'' on downstream waters will vary 
depending on the type and degree of connection (i.e.., from highly 
connected to highly isolated) to downstream waters and landscape 
features such as proximity to stream networks and to ``other waters'' 
with similar characteristics that function as a group to influence 
jurisdictional downstream waters.
    Since the publication of the Science Report in 2015, the published 
literature has expanded scientific understanding and quantification of 
functions that ``other waters'' perform that affect the integrity of 
traditional navigable waters, interstate waters, and the territorial 
seas, particularly in the aggregate. The more recent literature (i.e., 
2014-present, as some literature from 2014 and 2015 may not have been 
included in the Science Report) has determined that non-floodplain 
wetlands can have demonstrable hydrologic and biogeochemical downstream 
effects, such as decreasing peak flows, maintaining baseflows, and 
performing nitrate removal, particularly when considered cumulatively.
    Oxbow lakes and other lakes and ponds that are in close proximity 
to the stream network, located within floodplain or riparian areas, or 
that are connected via surface and shallow subsurface hydrology to the 
stream network or to other ``waters of the United States'' also perform 
critical chemical, physical, and biological functions that affect 
downstream foundational waters. Like adjacent wetlands, these waters 
individually and collectively affect the integrity of downstream waters 
by acting as sinks that retain floodwaters, sediments, nutrients, and 
contaminants that could otherwise negatively impact the condition or 
function of downstream waters. They also provide important habitat for 
aquatic species to forage, breed, and rest.
    Some ``other waters'' are wetlands that are located too far from 
other jurisdictional waters to be considered ``adjacent.'' The specific 
distance may vary based on the characteristics of the aquatic resources 
being evaluated, but they are often located outside of the riparian 
area or floodplain, lack a confined surface or shallow subsurface 
hydrologic connection to jurisdictional waters, or exceed the minimum 
distances necessary for aquatic species that cannot disperse overland 
to utilize both the subject waters and the waters in the broader 
tributary network. Some ``other waters'' may be too removed from the 
stream network or from jurisdictional waters to have significant 
effects on downstream traditional navigable waters, interstate waters, 
or the territorial seas. However, particularly when considered in the 
aggregate, some ``other waters'' can, in certain circumstances, have 
strong chemical, physical, and biological connections to and effects on 
foundational waters. Sometimes it is their relative isolation from the 
stream network (e.g., lack of a hydrologic surface connection) that 
contributes to the important effect that they have downstream; for 
example, depressional non-floodplain wetlands lacking surface outlets 
can function individually and cumulatively to retain and transform 
nutrients, retain sediment, provide habitat, and reduce or attenuate 
downstream flooding, depending on site-specific conditions such as 
landscape characteristics (e.g., slope of the terrain, permeability of 
the soils).
    Based on the functions that can be provided by ``other waters'' to 
traditional navigable waters, interstate waters, and the territorial 
seas, the agencies' proposal to assess ``other waters'' to determine 
whether they meet either the relatively permanent standard or the 
significant nexus standard reflects proper consideration of the 
objective of the Act and the best available science.
    The agencies' use of the best available science to interpret the 
scope of ``waters of the United States'' is a change from the NWPR. In 
the NWPR's preamble, the agencies stated: ``While science informs the 
agencies' interpretation'' of the phrase ``waters of the United 
States,'' ``science cannot dictate where to draw the line between 
Federal and State or tribal waters, as those are legal distinctions.'' 
85 FR 22271, April 21, 2020; see also id. at 22314 (``the line between 
Federal and State waters is a legal distinction, not a scientific 
one''). In this proposal, the agencies agree that science alone cannot 
dictate where to draw the line defining ``waters of the United 
States.'' But science is critical to attaining Congress's objective to 
restore and maintain the chemical, physical, and biological integrity 
of the nation's waters: Only by relying upon scientific principles to 
understand the way waters affect one another can the agencies know 
whether they are achieving that objective. Drawing the line without 
regard to science risks nullifying Congress's objective altogether. And 
because the agencies believe that the definition of ``waters of the 
United States'' should advance the objective of the Act and that 
objective is focused on restoring and maintaining water quality, see 
section V.A.2 of this preamble, the best available science is of far 
more importance to the agencies' proposed

[[Page 69394]]

rule than it was in the NWPR. Moreover, the agencies have concluded 
that the NWPR was not informed by the science, but rather was 
inconsistent with the best available science in substantially important 
ways. See section V.B.3 of this preamble.
iv. The Significant Nexus Standard Allows for Consideration of the 
Effects of Climate Change on Water Resources Consistent With the Best 
Available Science
    The significant nexus standard allows for the agencies to consider 
a changing climate when evaluating if upstream waters significantly 
affect foundational waters. This is because the significant nexus 
standard is based on the science of the strength of the effects that 
upstream tributaries, adjacent wetlands, and ``other waters'' can and 
do have on downstream foundational waters, and so implementation of the 
standard can adapt to changing climatic conditions. For example, a lake 
that dries up from warming temperatures due to climate change and no 
longer has a surface hydrologic connection to downstream waters might 
become non-jurisdictional, whereas another lake that previously had 
limited surface hydrologic connectivity might have increased hydrologic 
connectivity with higher precipitation conditions under a changing 
climate.
    In addition, the significant nexus standard allows the agencies to 
consider the functions of streams, wetlands, and open waters that 
support the resilience of the chemical, physical, or biological 
integrity of traditional navigable waters, interstate waters, or the 
territorial seas to climate change. For example, as more intense and 
frequent storms and other shifts in precipitation cause floods to 
increase in frequency and volume in some areas of the United States, a 
significant nexus determination can evaluate the strength of the effect 
of runoff storage in wetlands, open waters, and headwater tributaries 
in mitigating increased flood risk associated with climate change in 
downstream foundational waters. In addition, as drought leads to 
decreased baseflows in foundational waters in other areas of the 
country, the transmission of flows into alluvial or regional aquifer 
storage through tributaries and wetlands can mitigate for these climate 
change-related conditions, and those benefits to downstream traditional 
navigable waters or interstate waters can be assessed as part of a 
significant nexus analysis. Changes in flow in tributaries caused by 
climate change will also be relevant to the relatively permanent 
standard, but that standard may not allow the agencies to take into 
account the contribution of upstream waters to the resilience of the 
integrity of downstream waters.
    As discussed in section V.C.10 of this preamble, the agencies 
believe that there are climate benefits that streams, wetlands, and 
open waters provide that are not related to restoring or maintaining 
the integrity of downstream traditional navigable waters, interstate 
waters, or the territorial seas, such as carbon sequestration. Those 
functions would not be considered under this rule because they are not 
directly related to the chemical, physical, and biological integrity of 
downstream waters. However, considering a changing climate when 
conducting jurisdictional decisions by considering on a case-by-case 
basis the functions of aquatic resources that contribute to the 
resilience of the integrity of downstream foundational waters to 
climate change is consistent with the policy and goals of the Clean 
Water Act, case law, and the policy goals of this administration as 
articulated in Executive Order 13990.
3. The Proposed Rule Establishes Limitations That Together Are 
Consistent With the Statutory Text, Supported by the Scientific Record, 
and Informed by Relevant Supreme Court Decisions
    In this proposed rule, the agencies are exercising their 
discretionary authority to interpret ``waters of the United States'' to 
mean the waters defined by the familiar 1986 regulations, with 
amendments to reflect the agencies' interpretation of the statutory 
limits on the scope of the ``waters of the United States'' informed by 
Supreme Court decisions. The proposed rule's relatively permanent and 
significant nexus limitations are based on the agencies' conclusion 
that together those standards are consistent with the statutory text, 
are supported by the scientific record, and appropriately consider the 
objective in section 101(a) of the Act and the policy in section 
101(b). Moreover, these fact-dependent, science-informed approaches to 
jurisdiction are not unique under the Clean Water Act.
    At the outset, the agencies think it is useful to lay out the areas 
where the agencies agree with the statutory interpretation and case law 
laid out in the NWPR. The agencies agree that ``[b]y the time the 1972 
amendments were enacted, the Supreme Court had held that Congress' 
authority over the channels of interstate commerce was not limited to 
regulation of the channels themselves but could extend to activities 
necessary to protect the channels,'' 85 FR 22263, April 21, 2020 
(citing Oklahoma ex rel. Phillips v. Guy F. Atkinson Co., 313 U.S. 508, 
523 (1941)), and that ``Congress had in mind a broader scope of waters 
subject to CWA jurisdiction than waters traditionally understood as 
navigable,'' id.; see also id. at 22267 (recognizing that ``[t]he 
plurality and Justice Kennedy both recognized the jurisdictional scope 
of the CWA is not restricted to traditional navigable waters'' in 
Rapanos). In fact, it would be impossible to achieve Congress's 
objective if the scope of authority were constrained to waters 
traditionally understood as navigable because those channels cannot be 
protected without protecting the tributaries that flow into them and 
wetlands adjacent to them. Cf. United States v. Ashland Oil & Transp. 
Co., 504 F.2d 1317, 1326 (6th Cir. 1974) (``It would, of course, make a 
mockery of [Congress's] powers if its authority to control pollution 
was limited to the bed of the navigable stream itself. The tributaries 
which join to form the river could then be used as open sewers as far 
as federal regulation was concerned. The navigable part of the river 
could become a mere conduit for upstream waste.''). The Supreme Court 
has explained both that the term ``navigable'' in the defined term 
``navigable waters'' has ``limited import,'' Riverside Bayview, 474 
U.S. at 133, and also that by using the term ``navigable,'' ``Congress 
had in mind as its authority for enacting the CWA[ ] [i]ts traditional 
jurisdiction over waters that were or had been navigable in fact or 
which could reasonably be so made,'' SWANCC, 531 U.S. at 172. As the 
agencies did in the NWPR, the agencies interpret this to mean that the 
object of federal protection is foundational waters, and that 
jurisdiction encompasses (and is limited to) those tributaries, 
wetlands, and open waters that are necessary to protect the 
foundational waters.\26\
---------------------------------------------------------------------------

    \26\ Unlike the NWPR, the agencies now interpret the 
foundational waters to include ``interstate waters.'' See section 
V.C.2 of this preamble.
---------------------------------------------------------------------------

    The agencies also agree that ``there must be a limit to that 
authority and to what water is subject to federal jurisdiction,'' 85 FR 
22263, April 21, 2020, that where to draw that limit is ambiguous, and 
that ``Congress, when it left ambiguity in a statute meant for 
implementation by an agency, understood that the ambiguity would be 
resolved, first and foremost, by the agency, and desired the agency 
(rather than the courts) to possess whatever degree of discretion the 
ambiguity allows,'' id. at 22264 (quoting Nat'l Cable & Telecomm. Ass'n 
v. Brand X

[[Page 69395]]

internet Servs., 545 U.S. 967, 982 (2005)). In determining that limit, 
the agencies generally continue to believe that the determination of 
jurisdiction with regard to wetlands adjacent to tributaries ``must be 
made using a basic two-step approach that considers (1) the connection 
of the wetland to the tributary; and (2) the status of the tributary 
with respect to downstream traditional navigable waters'' and that the 
concept of a ``connectivity gradient'' is useful. Id. at 22267, 22271. 
Similarly, for tributaries, the agencies agree that ``contribution of 
flow to and connection'' matters. Id. at 22267. At bottom, the agencies 
agree that the Supreme Court has indicated that the limit should relate 
to the ``significant effects'' of or ``significant nexus'' between that 
water and traditional navigable waters, interstate waters, and the 
territorial seas, id at 22263-64 (discussing Supreme Court case law, 
although as explained in section V.A.3.a of this preamble, the NWPR in 
fact removed the significant nexus test without considering an 
alternative approach to protecting waters that significantly affect 
downstream traditional navigable waters). Finally, the agencies agree 
that the Supreme Court has ``call[ed] into question the agencies' 
authority to regulate nonnavigable, isolated, intrastate waters that 
lack a sufficient connection to traditional navigable waters,'' id. at 
22269, and this proposal would not assert jurisdiction over such 
waters.\27\
---------------------------------------------------------------------------

    \27\ The NWPR criticized the agencies' prior practice as 
insufficiently attentive to the concerns raised by the Supreme Court 
in SWANCC regarding jurisdiction over the ``other waters'' category 
defined in (a)(3) of the regulatory definition that was at issue in 
SWANCC. Id. at 22264. This criticism is inaccurate. Cognizant of the 
Supreme Court's direction in SWANCC and to ensure that any assertion 
of authorities over (a)(3) waters is consistent with the Court's 
precedents, since SWANCC, the agencies have required that before 
exercising jurisdiction over an (a)(3) water field staff get 
approval from headquarters. 68 FR 1991 (January 15, 2003). As a 
practical matter, and as discussed in more detail below, section 
V.C.3 of this preamble, field staff have rarely, if ever, sought 
such approval and therefore the agencies have not asserted 
jurisdiction over (a)(3) waters. But (a)(3) waters can have 
significant effects on foundational waters and, when they do, 
jurisdiction is proper and would not implicate the constitutional 
concerns expressed by the Court in SWANCC for the reasons explained 
herein.
---------------------------------------------------------------------------

a. The Relatively Permanent Standard and the Significant Nexus Standard 
Together Advance the Objective of the Act
    The proposed rule's utilization of both the relatively permanent 
standard and the significant nexus standard gives effect to the Act's 
broad terms and environmentally protective aim as well as its 
limitations. See Rapanos, 547 U.S. at 767-69 (observing ``the evident 
breadth of congressional concern for protection of water quality and 
aquatic ecosystems'' and referring to the Act as ``a statute concerned 
with downstream water quality'') (Kennedy, J., concurring) (citations 
omitted); Riverside Bayview, 474 U.S. at 133 (``Congress chose to 
define the waters covered by the Act broadly.''). The agencies, 
however, are proposing that it is the significant nexus standard that 
advances the objective of the Act because it is linked to effects on 
downstream water quality while establishing a reasonable limitation on 
the scope of jurisdiction by requiring those links to be significant. 
The relatively permanent standard is administratively useful as an 
example of a subset of waters that will virtually always have the 
requisite nexus, but, on its own, is insufficiently protective to meet 
the objective of the Clean Water Act.
    The agencies have consistently construed Rapanos to mean that a 
water is jurisdictional under the Clean Water Act if it meets either 
the relatively permanent standard or the significant nexus standard. 
The NWPR, however, interpreted the statute to primarily find waters 
jurisdictional only if they met the relatively permanent standard, as 
specifically interpreted in the NWPR. The NWPR argued that it reflected 
both the plurality and Kennedy opinions, which it characterized as 
having ``sufficient commonalities . . . to help instruct the agencies 
on where to draw the line between Federal and State waters.'' 85 FR 
22268, April 21, 2020. The opinions have important differences, 
however. Justice Kennedy looked to the existence of a significant nexus 
between waters at issue and downstream traditional navigable waters, 
whereas the plurality held that ``waters of the United States'' is 
limited to ``relatively permanent'' waters connected to traditional 
navigable waters, and wetlands with a ``continuous surface connection'' 
with those waters. Rapanos, 547 U.S. at 742. Justice Kennedy rejected 
these two limitations in the plurality as ``without support in the 
language and purposes of the Act or in our cases interpreting it.'' Id. 
at 768; see also id. at 776 (``In sum the plurality's opinion is 
inconsistent with the Act's text, structure, and purpose.''). Yet the 
plurality's limitation of jurisdiction to ``relatively permanent 
waters'' and those with a ``continuous surface connection'' to those 
waters pervades the NWPR. See 85 FR 22338-39; 33 CFR 328.3(a), (c)(1), 
(c)(6), and (c)(12). The NWPR disregards the significant nexus 
standard, see generally 85 FR 22338-39; 33 CFR 328.3, and, in doing so, 
restricted the scope of the statute using limitations Justice Kennedy 
viewed as anathema to the purpose and text of the Clean Water Act.
    The agencies propose to reject the NWPR's interpretation as 
inconsistent with the objective of the Clean Water Act, the science, 
and the case law, and instead to propose an interpretation whereby if a 
water meets either standard, it falls within the protections of the 
Clean Water Act. This section first discusses why the significant nexus 
test is consistent with the Act and the best available science; then 
explains why the relatively permanent standard is administratively 
useful, but limiting the scope of jurisdiction to waters meeting the 
relatively permanent standard is insufficient to meet the objective of 
the Clean Water Act; and finally, explains that fact-based standards 
for determining Clean Water Act jurisdiction are reasonable and not 
unique to the definition of ``waters of the United States.''
i. The Significant Nexus Test Is Consistent With the Act and the Best 
Available Science
    The significant nexus standard advances the objective of the Act 
because it is linked to effects on downstream water quality while 
establishing a reasonable limitation on the scope of jurisdiction. The 
significant nexus standard reasonably effectuates the text of 33 U.S.C. 
1362(7), which defines ``navigable waters.'' The requirement that a 
significant nexus exist between upstream waters, including wetlands and 
``navigable waters in the traditional sense'' fulfills ``the need to 
give the term `navigable' some meaning.'' Rapanos, 547 U.S. at 779 
(Kennedy, J., concurring). With the significant nexus standard, the 
proposed rule is properly focused on protecting the foundational waters 
clearly protected by the Clean Water Act. The significant nexus is thus 
consistent with the text of the Act, with scientific principles and 
supported by the best available science, with the Act's legislative 
history, and with case law.
    Congress was focused on water quality when it enacted the Clean 
Water Act and established its objective, as discussed in section V.A.2 
of this preamble. The significant nexus standard is derived from the 
objective of the Act and thus also focused on water quality and 
specifically focused on the water quality of the foundational waters. 
As described more fully in section V.A.2.c of this preamble, supra, the

[[Page 69396]]

significant nexus standard is consistent with scientific principles 
about the aquatic ecosystem: Upstream waters can significantly affect 
the chemical, physical, and biological integrity of downstream 
traditional navigable waters, interstate waters, and the territorial 
seas. Therefore, assessing the effects that waters have on downstream 
foundational waters when considered, alone or in combination with other 
similar waters in a region, is a reasonable means of identifying those 
waters necessary to protect in order to advance the objective of the 
Act.
    A significant nexus analysis is consistent with the framework 
through which scientists assess a river system--examining how the 
components of the system (e.g., wetlands, tributaries), in the 
aggregate (in combination), in the region, contribute and connect to 
the river (significantly affect the chemical, physical, or biological 
integrity of foundational waters). Indeed, the significant nexus 
standard in the proposed rule reflects the type of analysis in the 
Science Report by describing the components of a river system and 
watershed; the types of physical, chemical, and biological connections 
that link those components; the factors that influence connectivity at 
various temporal and spatial scales; and methods for quantifying 
connectivity. The structure and function of rivers are highly dependent 
on the constituent materials stored in and transported through them. 
Most of these materials originate from either the upstream river 
network or other components of the river system and then are 
transported to the river by water movement or other mechanisms. 
Further, the significant nexus standard is supported by the Science 
Report's discussion of connectivity, a foundational concept in 
hydrology and freshwater ecology. See also Technical Support Document.
    Connectivity is the degree to which components of a system are 
joined, or connected, by various transport mechanisms and is determined 
by the characteristics of both the physical landscape and the biota of 
the specific system. Connectivity serves to demonstrate the ``nexus'' 
between upstream water bodies and the downstream traditional navigable 
water, interstate water, or the territorial sea and, while the 
scientific literature does not use the term ``significant'' in the same 
manner used by the Supreme Court, the literature does provide 
information on the strength of the effects on the chemical, physical, 
and biological functioning of the downstream water bodies that permits 
the agencies to judge when an effect is significant such that a water, 
alone or in combination, should be protected by the Clean Water Act in 
order to meet the objective of the Act. The Science Report presents 
evidence of connections for various categories of waters, evaluated 
singly or in combination, which affect downstream waters and the 
strength of those effects. The connections and mechanisms discussed in 
the Science Report include: Transport of physical materials and 
chemicals such as water, wood, sediment, nutrients, pesticides, and 
mercury; functions that jurisdictional adjacent waters perform, such as 
storing and cleansing water; and movement of organisms. Again, the 
significant nexus standard, under which waters are assessed alone or in 
combination for the functions they provide downstream, is consistent 
with the foundational scientific framework and concepts of hydrology.
    The agencies' use of scientific principles to determine the scope 
of ``waters of the United States'' is consistent with the Supreme 
Court's approach in Maui. The Court also looked to scientific 
principles to inform its interpretation of the Clean Water Act's 
jurisdictional scope, noting: ``[m]uch water pollution does not come 
from a readily identifiable source. See 3 Van Nostrand's Scientific 
Encyclopedia, at 5801 (defining `Water Pollution'). Rainwater, for 
example, can carry pollutants (say, as might otherwise collect on a 
roadway); it can pollute groundwater, and pollution collected by 
unchanneled rainwater runoff is not ordinarily considered point source 
pollution.'' 140 S. Ct. at 1471. The Court further observed that 
``[v]irtually all water, polluted or not, eventually makes its way to 
navigable water. This is just as true for groundwater. See generally 2 
Van Nostrand's Scientific Encyclopedia 2600 (10th ed. 2008) (defining 
`Hydrology').'' Id. at 1470. The Court then enumerated a series of 
factors relevant to determining whether a discharge is jurisdictional 
under the Act, many of which are scientifically based, including the 
nature of the material through which the pollutant travels and the 
extent to which the pollutant is diluted or chemically changed as it 
travels. Id. at 1476-77.
    In carefully considering the objective of the Act and the best 
available science, the proposed rule's incorporation of the significant 
nexus standard is consistent with the legislative history of the Clean 
Water Act. The Supreme Court has noted that ``some Members of this 
Court have consulted legislative history when interpreting ambiguous 
statutory language.'' Bostock v. Clayton County, Georgia, 140 S. Ct. 
1731, 1749 (2020). In Bostock, the Court stated further that ``while 
legislative history can never defeat unambiguous statutory text, 
historical sources can be useful for a different purpose: Because the 
law's ordinary meaning at the time of enactment usually governs, we 
must be sensitive to the possibility a statutory term that means one 
thing today or in one context might have meant something else at the 
time of its adoption or might mean something different in another 
context. And we must be attuned to the possibility that a statutory 
phrase ordinarily bears a different meaning than the terms do when 
viewed individually or literally. To ferret out such shifts in 
linguistic usage or subtle distinctions between literal and ordinary 
meaning, this Court has sometimes consulted the understandings of the 
law's drafters.'' Id. at 1750.
    Bills introduced in 1972 in both the House of Representatives and 
the Senate defined ``navigable waters'' as ``the navigable waters of 
the United States.'' See 2 Environmental Policy Div., Library of 
Congress, Legislative History of the Water Pollution Control Act 
Amendments of 1972 at 1069, 1698 (1973). The House and Senate 
Committees, however, expressed concern that the definition might be 
given an unduly narrow reading. Thus, the House Report observed: ``One 
term that the Committee was reluctant to define was the term `navigable 
waters.' The reluctance was based on the fear that any interpretation 
would be read narrowly. However, this is not the Committee's intent. 
The Committee fully intends that the term `navigable waters' be given 
the broadest possible constitutional interpretation unencumbered by 
agency determinations which have been made or may be made for 
administrative purposes.'' H.R. Rep. No. 92-911, at 131 (1972).
    The Senate Report stated that ``[t]hrough a narrow interpretation 
of the definition of interstate waters the implementation [of the] 1965 
Act was severely limited. Water moves in hydrologic cycles and it is 
essential that discharge of pollutants be controlled at the source.'' 
S. Rep. No. 92-414, at 77 (1971). The Conference Committee deleted the 
word ``navigable'' from the definition of ``navigable waters,'' broadly 
defining the term to include ``the waters of the United States.'' The 
Conference Report explained that the definition was intended to 
repudiate earlier limits on the reach of federal water pollution 
efforts: ``The conferees fully intend that the term `navigable waters' 
be given the broadest possible

[[Page 69397]]

constitutional interpretation unencumbered by agency determinations 
which have been made or may be made for administrative purposes.'' S. 
Conf. Rep. No. 92-1236, at 144 (1972).
    The significant nexus standard is also consistent with prior 
Supreme Court decisions, and with every circuit decision that has 
gleaned a rule of law from that precedent. For example, in Riverside 
Bayview, the Court deferred to the agencies' interpretation: ``In view 
of the breadth of federal regulatory authority contemplated by the Act 
itself and the inherent difficulties of defining precise bounds to 
regulable waters, the Corps' ecological judgment about the relationship 
between waters and their adjacent wetlands provides an adequate basis 
for a legal judgment that adjacent wetlands may be defined as waters 
under the Act.'' 474 U.S. at 134. In Rapanos, Justice Kennedy stated of 
the Court in Riverside Bayview ``the Court indicated that `the term 
``navigable'' as used in the Act is of limited import,' 474 U.S., at 
133, [and] it relied, in upholding jurisdiction, on the Corps' judgment 
that `wetlands adjacent to lakes, rivers, streams, and other bodies of 
water may function as integral parts of the aquatic environment even 
when the moisture creating the wetlands does not find its source in the 
adjacent bodies of water,' id., at 135.'' 547 U.S. at 779 (Kennedy, J., 
concurring). ``The implication,'' Justice Kennedy observed, ``was that 
wetlands' status as `integral parts of the aquatic environment'--that 
is, their significant nexus with navigable waters--was what established 
the Corps' jurisdiction over them as waters of the United States.'' Id. 
(emphasis added); see also id. at 780 (``[W]etlands' ecological 
functions vis-[aacute]-vis other covered waters are the basis for the 
Corps' regulation of them.''). The Court in SWANCC also characterized 
its decision in Riverside Bayview as informed by the ``significant 
nexus between the wetlands and `navigable waters.' '' 531 U.S. at 167.
    In Rapanos, Justice Kennedy reasoned that Riverside Bayview and 
SWANCC ``establish the framework for'' determining whether an assertion 
of regulatory jurisdiction constitutes a reasonable interpretation of 
``navigable waters,'' finding that ``the connection between a 
nonnavigable water or wetland and a navigable water may be so close, or 
potentially so close, that the Corps may deem the water or wetland a 
`navigable water' under the Act,'' and ``[a]bsent a significant nexus, 
jurisdiction under the Act is lacking.'' 547 U.S. at 767. Justice 
Kennedy also identified many of the same valuable functions of wetlands 
identified in the Science Report:

    Important public interests are served by the Clean Water Act in 
general and by the protection of wetlands in particular. To give 
just one example, amici here have noted that nutrient-rich runoff 
from the Mississippi River has created a hypoxic, or oxygen-
depleted, ``dead zone'' in the Gulf of Mexico that at times 
approaches the size of Massachusetts and New Jersey. Brief for 
Association of State Wetland Managers et al. 21-23; Brief for 
Environmental Law Institute 23. Scientific evidence indicates that 
wetlands play a critical role in controlling and filtering runoff. 
See, e.g., OTA 43, 48-52; R. Tiner, In Search of Swampland: A 
Wetland Sourcebook and Field Guide 93-95 (2d ed. 2005); Whitmire & 
Hamilton, Rapid Removal of Nitrate and Sulfate in Freshwater Wetland 
Sediments, 34 J. Env. Quality 2062 (2005).

Id. at 777-78.
    The agencies are mindful of the Supreme Court's decision in SWANCC 
regarding the specific Commerce Clause authority Congress was 
exercising in enacting the Clean Water Act. The Court noted that the 
statement in the Conference Report for the Act that the conferees 
``intend that the term `navigable waters' be given the broadest 
possible constitutional interpretation,'' S. Conf. Rep. No. 92-1236, at 
144 (1972), signifies Congress's intent with respect to its exertion of 
its commerce power over navigation and no more. In light of the 
ambiguous nature of the phrase ``waters of the United States,'' the 
agencies have found the legislative history concerning the intent of 
Congress regarding the scope of the Act's protections under its power 
over navigation confirms the reasonableness of the proposed rule. The 
rule would ensure that all waters that either alone or in combination 
significantly affect the integrity of traditional navigable waters, 
interstate waters, or the territorial seas are protected under the 
Clean Water Act. The Supreme Court has long held that authority over 
traditional navigable waters is not limited to either protection of 
navigation or authority over only the traditional navigable water. 
Rather, ``the authority of the United States is the regulation of 
commerce on its waters . . . [f]lood protection, watershed development, 
[and] recovery of the cost of improvements through utilization of power 
are likewise parts of commerce control.'' United States v. Appalachian 
Electric Power Co., 311 U.S. 377, 426 (1940); see also Oklahoma ex rel. 
Phillips v. Guy F. Atkinson Co., 313 U.S. 508, 525-526 (1941) (``[J]ust 
as control over the non-navigable parts of a river may be essential or 
desirable in the interests of the navigable portions, so may the key to 
flood control on a navigable stream be found in whole or in part in 
flood control on its tributaries. . . . [T]he exercise of the granted 
power of Congress to regulate interstate commerce may be aided by 
appropriate and needful control of activities and agencies which, 
though intrastate, affect that commerce.''). Again, to quote the Sixth 
Circuit after the 1972 enactment of the Clean Water Act: ``It would, of 
course, make a mockery of [Congress's] powers if its authority to 
control pollution was limited to the bed of the navigable stream 
itself. The tributaries which join to form the river could then be used 
as open sewers as far as federal regulation was concerned. The 
navigable part of the river could become a mere conduit for upstream 
waste.'' United States v. Ashland Oil & Transp. Co., 504 F.2d 1317, 
1326 (6th Cir. 1974). The significant nexus standard included in the 
proposed rule remains well within the bounds of SWANCC.
ii. The Relatively Permanent Standard Is Administratively Useful, but 
Insufficient To Meet the Objective of the Clean Water Act
    The agencies also conclude that federal protection is appropriate 
where a water meets the relatively permanent standard. Waters that meet 
this standard are an example of a subset of waters that will virtually 
always have the requisite connection to downstream traditional 
navigable waters, interstate waters, or the territorial seas, and 
therefore properly fall within the Clean Water Act's scope. However, 
the relatively permanent standard is insufficient as the sole standard 
for geographic jurisdiction under the Clean Water Act as it is 
inconsistent with the Act's text and objective and runs counter to the 
science.
    Science supports that tributaries of traditional navigable waters 
with relatively permanent, standing, or continuously flowing water and 
wetlands and relatively permanent open waters with continuous surface 
connections to such relatively permanent waters perform important 
functions that either individually or cumulatively with similarly 
situated waters in the region have substantial effects on the chemical, 
physical, or biological integrity of downstream foundational waters. 
See Technical Support Document section IV.A. For example, perennial and 
seasonally intermittent tributaries contribute consistent flow to 
downstream foundational waters, and with that flow export nutrients, 
sediment, and food resources, contaminants, and other

[[Page 69398]]

materials that can both positively (e.g., by contributing to downstream 
baseflow, providing food for aquatic species, contributing to 
downstream aquatic habitat) and negatively (e.g., if exporting too much 
sediment, runoff, or nutrients or if exporting pollutants) affect the 
integrity, including the water quality, of those larger downstream 
waters. In addition, wetlands with a continuous surface connection to 
such relatively permanent waters can attenuate floodwaters, trap 
sediment, and process and transform nutrients that might otherwise 
reach downstream traditional navigable waters, interstate waters, or 
the territorial seas. The relatively permanent standard is useful 
because it generally requires less information gathering and assessment 
and because it focuses on flow and includes wetlands with a continuous 
surface connection. As such, while both the significant nexus and 
relatively permanent standards require fact-specific inquiries before 
determining whether a water is a ``water of the United States,'' the 
relatively permanent standard will generally require less assessment.
    Standing alone as the sole test for Clean Water Act jurisdiction, 
the relatively permanent standard is insufficient. The standard's 
apparent exclusion of major categories of waters from the protections 
of the Clean Water Act, specifically with respect to tributaries that 
are not relatively permanent (such as ephemeral streams) and adjacent 
wetlands that do not have a continuous surface water connection to 
other jurisdictional waters, is inconsistent with the Act's text and 
objective and runs counter to the science demonstrating how such waters 
can affect the integrity of downstream waters, including traditional 
navigable waters, interstate waters, and territorial seas. The NWPR, 
for example, excluded federal jurisdiction over the many ephemeral 
tributaries that regularly and directly provide sources of freshwater 
to the sparse traditional navigable waters in the arid Southwest, such 
as portions of the Gila River.
    As discussed in section V.A.2.c of this preamble, there is 
overwhelming scientific information demonstrating the effects ephemeral 
streams can have on downstream waters and the effects wetlands can have 
on downstream waters when they do not have a continuous surface 
connection. The science is clear that aggregate effects of ephemeral 
streams ``can have substantial consequences on the integrity of the 
downstream waters'' and that the evidence of such downstream effects is 
``strong and compelling.'' Science Report at 6-10, 6-13. EPA's Science 
Advisory Board (SAB) Review of the draft Science Report explained that 
ephemeral streams ``are no less important to the integrity of the 
downgradient waters'' than perennial or intermittent streams. Letter 
from SAB to Gina McCarthy, Administrator, EPA (Oct. 17, 2014) (``SAB 
Review'') at 22-23, 54 fig. 3. The agencies also find no exclusion of 
waters that are not relatively permanent in the text of the statute. 
Rapanos, 547 U.S. at 770 (``To be sure, Congress could draw a line to 
exclude irregular waterways, but nothing in the statute suggests it has 
done so.'') (Kennedy, J., concurring).
    The science is also clear that wetlands may significantly affect 
downstream waters when they have other types of surface connections, 
such as wetlands that overflow and flood jurisdictional waters or 
wetlands with less frequent surface water connections due to long-term 
drought; wetlands with shallow subsurface connections to other 
protected waters; or other wetlands proximate to jurisdictional waters. 
Such wetlands provide a number of functions, including water storage 
that can help reduce downstream flooding, recharging groundwater that 
contributes to baseflow of downstream rivers, improving water quality 
through processes that remove, store, or transform pollutants such as 
nitrogen, phosphorus, and metals, and serving as unique and important 
habitats including for aquatic species that also utilize larger 
downstream waters. See, e.g., Science Report at 4-20 to 4-38. For 
example, adjacent, interdunal wetlands separated from the Atlantic 
Ocean only by beach dunes would not meet the relatively permanent 
standard, but provide numerous functions, including floodwater storage 
and attenuation, storage and transformation of sediments and 
pollutants, and important habitat for species that utilize both the 
wetlands and the ocean, that significantly affect the Atlantic Ocean 
(both a traditional navigable water and territorial sea).
    In addition, the agencies see no basis in the text or the science 
to exclude waters from Clean Water Act jurisdiction based solely on the 
continuous surface connection requirement. As discussed in section 
V.A.2.a of this preamble, the objective of the Act is to restore and 
maintain the water quality of the nation's waters. Nowhere does the Act 
refer to a continuous surface connection, and the imposition of such a 
limitation would not account for the science regarding how upstream 
waters and wetlands affect downstream foundational waters. As discussed 
above in this section and in the Technical Support Document, the 
science supports that wetlands and open waters that lack a continuous 
surface connection to relatively permanent waters can individually and 
cumulatively have more than a speculative or insubstantial effect on 
the chemical, physical, and biological integrity of traditional 
navigable waters, interstate waters, or the territorial seas. As a 
scientific matter, the agencies agree with Justice Kennedy that the 
Clean Water Act intends to protect waters that do not meet the 
relatively permanent standard, where such waters have a significant 
nexus. Rapanos, 547 U.S. at 773-74 (``Needless to say, a continuous 
connection is not necessary for moisture in wetlands to result from 
flooding--the connection might well exist only during floods.'') 
(Kennedy, J., concurring); see also id at 775 (``In many cases, 
moreover, filling in wetlands separated from another water by a berm 
can mean that floodwater, impurities, or runoff that would have been 
stored or contained in the wetlands will instead flow out to major 
waterways. With these concerns in mind, the Corps' definition of 
adjacency is a reasonable one, for it may be the absence of an 
interchange of waters prior to the dredge and fill activity that makes 
protection of the wetlands critical to the statutory scheme.'').
    While the relatively permanent standard is administratively useful 
and includes waters that have important effects on downstream water 
quality, the standard excludes many waters that properly fall within 
the Act's protections. As a result, the proposed rule's incorporation 
of both Rapanos standards represents a reasonable interpretation of 
broad and ambiguous statutory text and a permissible way for the 
agencies to fulfill their congressionally delegated responsibility to 
interpret ``waters of the United States'' in a manner that advances the 
objective of the Act.
iii. Fact-Based Standards for Determining Clean Water Act Jurisdiction 
Are Reasonable
    Finally, while a fact-dependent jurisdictional analysis of whether 
a water meets either the relatively permanent standard or the 
significant nexus standard does not necessarily provide categorical 
certainty, case-specific determinations of the scope of Clean Water Act 
jurisdiction are not unique. In the Supreme Court's most recent 
decision addressing a question about the jurisdictional scope of the 
Clean Water Act, although not the scope of ``waters of the United 
States,'' the Court established a standard for

[[Page 69399]]

determining jurisdiction that, like the significant nexus standard, 
does not establish bright lines marking the bounds of federal 
jurisdiction and instead requires an inquiry focused on the specific 
facts at issue and guided by the purposes Congress sought to achieve 
under the Act. In Maui, the Supreme Court considered whether discharges 
to groundwater that reach navigable waters are jurisdictional under the 
Act and thus subject to the Act's section 402 permitting program. The 
Court held that ``the statute requires a permit when there is a direct 
discharge from a point source into navigable waters or when there is 
the functional equivalent of a direct discharge.'' Maui, 140 S. Ct. at 
1476. The Court explained that ``[w]e think this phrase best captures, 
in broad terms, those circumstances in which Congress intended to 
require a federal permit.'' Id. The Court further explained that, in 
applying its broadly worded standard, ``[t]he object in a given 
scenario will be to advance, in a manner consistent with the statute's 
language, the statutory purposes that Congress sought to achieve.'' Id. 
The Court recognized that the difficulty with its approach was that 
``it does not, on its own, clearly explain how to deal with middle 
instances,'' but reasoned that ``there are too many potentially 
relevant factors applicable to factually different cases for this Court 
now to use more specific language.'' Id. The Court enumerated a series 
of factors relevant to determining whether a discharge is the 
``functional equivalent'' of direct discharge, including the time 
between when the discharge occurs and when the pollutants reach the 
navigable water, the distance the pollutants travel to the navigable 
water, the nature of the material through which the pollutant travels, 
the extent to which the pollutant is diluted or chemically changed as 
it travels, the amount of pollutant entering the navigable waters 
relative to the amount of the pollutant that leaves the point source, 
the manner by or area in which the pollutant enters the navigable 
waters, and the degree to which the pollution (at that point) has 
maintained its specific identity. Id. at 1476-77.
    The Supreme Court's ``functional equivalent'' standard has several 
key characteristics in common with the significant nexus standard and 
the agencies' approach in the proposed rule. Both standards require an 
analysis focused on the specific facts at issue in a particular 
instance. The ``functional equivalent'' standard requires consideration 
of facts related to the discharge at issue, the geologic substrate 
through which the discharges travels, the location and nature of the 
receiving water, and other factors. Likewise, the significant nexus 
standard requires consideration of scientific principles of upstream 
functions and effects on the integrity of downstream waters and facts 
related to the specific waters at issue. Indeed, the agencies have 
proposed a list of factors that would be considered when assessing 
whether waters ``significantly affect'' foundational waters that is 
similar in nature to the factors identified by the Court for making a 
``functional equivalent'' assessment. See section V.C.10 of this 
preamble. The relatively permanent standard also requires inquiry into 
specific facts about particular tributaries and wetlands, although the 
inquiry generally requires less information gathering and assessment 
than the significant nexus standard. The Court in Maui also explicitly 
rejected EPA's suggested approach which established a bright line that 
categorically excluded all discharges to groundwater regardless of 
whether they reached navigable waters and instead adopted the 
``functional equivalent'' analysis. 140 S. Ct. at 1474-75. Likewise, 
the significant nexus standard also does not necessarily establish 
bright lines with respect to determining which waters have a sufficient 
impact on downstream traditional navigable waters, interstate waters, 
or the territorial seas, in contrast to the NWPR which categorically 
excluded all ephemeral waters in spite of their impact on the chemical, 
physical, and biological integrity of downstream foundational waters.
    Finally, both the functional equivalent standard and the 
significant nexus standard should be applied while keeping in mind the 
purposes of the Act. As the Court explained in Maui, ``[t]he underlying 
statutory objectives also provide guidance. Decisions should not create 
serious risks either of undermining state regulation of groundwater or 
of creating loopholes that undermine the statute's basic federal 
regulatory objectives.'' Id. at 1477. Likewise, Justice Kennedy 
explained that when assessing the existence of a ``significant nexus'' 
between wetlands and navigable waters, ``[t]he required nexus must be 
assessed in terms of the statute's goals and purposes.'' Rapanos, 547 
U.S. at 779.
    The agencies recognize that in both Rapanos and Maui the Supreme 
Court was clear that the agencies could promulgate regulations that 
further refine the case-specific jurisdictional tests. The agencies' 
goal with this proposed rule is to return to the familiar and 
longstanding framework that will ensure Clean Water Act regulatory 
protections, informed by relevant Supreme Court decisions. The agencies 
also anticipate developing another rule that builds upon the regulatory 
foundation of this rule with the benefit of additional stakeholder 
engagement and which could, among many issues, consider more 
categorical approaches to jurisdiction.
b. The Proposed Rule Reflects Full and Appropriate Consideration of the 
Water Quality Objective in Section 101(a) and the Policies Relating to 
Responsibilities and Rights of States and Tribes Under Section 101(b) 
of the Act
    The proposed rule reflects consideration of the statute as a whole, 
including the objective of the Act and the policies of the Act with 
respect to the role of states and tribes. As discussed in section 
V.A.2.a of this preamble, the agencies must consider the objective of 
the Clean Water Act in interpreting the scope of the statutory term 
``waters of the United States.'' In this proposed rule, the agencies 
also consider the entire statute, including section 101(b) of the Clean 
Water Act, which provides that it is Congressional policy to preserve 
the primary responsibilities and rights of states ``to prevent, reduce, 
and eliminate pollution, to plan the development and use . . . of land 
and water resources, and to consult with the Administrator with respect 
to the exercise of the Administrator's authority'' under the Clean 
Water Act. 33 U.S.C. 1251(b). Determining where to draw the boundaries 
of federal jurisdiction to both ensure that the agencies achieve 
Congress's objective while preserving and protecting the 
responsibilities and rights of the states is a matter of judgment 
assigned by Congress to the agencies.
    The agencies find that the proposed rule both advances the 
objective of the Act in section 101(a) and respects the role of states 
and tribes in 101(b).\28\ The proposed rule appropriately draws the 
boundary of waters subject to federal protection by extending, and 
limiting, it to the protection of upstream waters that significantly 
affect the integrity of waters where the federal interest is 
indisputable--the traditional navigable waters, interstate waters, and 
territorial seas. Waters that do not implicate federal interest in 
these foundational

[[Page 69400]]

waters are left entirely to state and tribal protection and management.
---------------------------------------------------------------------------

    \28\ While Clean Water Act section 101(b) does not specifically 
identify tribes, the policy of preserving states' sovereign 
authority over land and water use is equally relevant to ensuring 
the primary authority of tribes to address pollution and plan the 
development and use of tribal land and water resources.
---------------------------------------------------------------------------

    The scope and boundaries of the proposed definition therefore 
reflect the agencies' considered judgment of both the Act's objective 
in section 101(a) and the Congressional policy relating to states' 
rights and responsibilities under section 101(b). In several key 
respects, the agencies' consideration and weighing of these provisions 
in this rulemaking differs from the agencies' approach in the NWPR. 
Those differences and the bases for them follow.
i. Consideration of Sections 101(a) and 101(b) in the NWPR
    In promulgating the NWPR, the agencies gave predominant weight to 
consideration of the policy in section 101(b), citing it frequently in 
its rationale for the rule generally. For example, the agencies stated: 
``The agencies interpret the policy of Congress, set forth in section 
101(b), as relevant to all aspects of the implementation of the CWA, 
both implementing federally-established standards as well as the scope 
of waters subject to such standards and regulatory programs.'' 85 FR 
22269, April 21, 2020. The agencies also opined on the relationship 
between its consideration of section 101(a) and 101(b): ``In developing 
an appropriate regulatory framework for the final rule, the agencies 
recognize and respect the primary responsibilities and rights of States 
to regulate their land and water resources as reflected in CWA section 
101(b). The oft-quoted objective of the CWA to `restore and maintain 
the chemical, physical, and biological integrity of the Nation's 
waters,' . . . must be implemented in a manner consistent with 
Congress' policy directives to the agencies.'' Id. The NWPR ultimately 
concluded that the rule ``appropriately balances . . . the objective of 
the Act and the policy of Congress set forth in CWA sections 101(a) and 
101(b), respectively.'' Id. at 22277.
    Beyond relying on section 101(b) for the agencies' overall approach 
to the rulemaking, the NWPR relied specifically on section 101(b) as a 
basis for the rule's line-drawing between jurisdictional and non-
jurisdictional waters. For example, with regard to tributaries, the 
agencies stated that limiting jurisdiction to waters that contribute 
surface flow to traditional navigable waters in a typical year ``better 
balances the CWA's objective in section 101(a) with the need to respect 
State and tribal authority over land and water resources as mandated by 
Congress in section 101(b).'' Id. at 22287. The agencies contended, 
moreover, that excluding ephemeral waters from jurisdiction 
``respect[s] State and Tribal land use authority over features that are 
only episodically wet during and/or following precipitation events.'' 
Id. at 22319. With regard to wetlands, the agencies similarly relied 
upon ``limitations on federal authority embodied in CWA section 
101(b)'' as a justification for excluding subsurface hydrologic 
connectivity as a basis for determining what constitutes an adjacent 
wetland. Id. at 22313.
ii. Consideration of Sections 101(a) and 101(b) in Developing the 
Proposed Rule
    The agencies have carefully considered sections 101(a) and 101(b) 
as well as the agencies' analysis and application of these provisions 
in promulgating the NWPR. As discussed below, based on the text of 
section 101(b), the structure of section 101 and the Act as a whole, 
Supreme Court precedent, and the history of federal water pollution 
laws enacted by Congress up through the 1972 Amendments, the agencies 
believe that the proposed rule reflects fuller and more appropriate 
consideration of sections 101(a) and 101(b) than the agencies undertook 
in promulgating the NWPR.
    As a threshold matter, the agencies agree that the policy in 
section 101(b) is both important and relevant to the agencies' defining 
an appropriate scope of ``waters of the United States.'' Consistent 
with the text of the statute and as emphasized by the Supreme Court, 
federal jurisdiction under the Clean Water Act has limits. As explained 
above, Clean Water Act jurisdiction encompasses (and is limited to) 
those waters that significantly affect the indisputable federal 
interest in the protection of the foundational waters that prompted 
Congress to enact the various incarnations of the Act--i.e., 
traditional navigable waters, interstate waters, and the territorial 
seas. And consistent with the section 101(b) policy, where protection 
(or degradation) of waters do not implicate this federal interest, such 
waters fall exclusively within state or tribal regulatory authority, 
should they choose to exercise it.
    The agencies' considered view at this time differs, however, in 
certain important respects from how the NWPR considered section 101(b). 
As the above statements make clear, section 101(b) was not simply a 
relevant consideration for the NWPR, but a key lynchpin of both the 
overall regulatory approach and the rule's specific definitions of 
jurisdictional waters. In the agencies' view, the better reading of 
section 101(b) does not support the heavy weight accorded to it by the 
NWPR for either its overall approach nor its specific definitions.
(1) The Text of Section 101(b)
    First, the agencies believe that the NWPR's reading of section 
101(b) fails to align with the better reading of the text of section 
101(b). For example, the agencies stated in support of the NWPR that 
``[i]n developing an appropriate regulatory framework for the final 
rule, the agencies recognize and respect the primary responsibilities 
and rights of States to regulate their land and water resources as 
reflected in CWA section 101(b).'' 85 FR 22269, April 21, 2020 
(emphasis added). However, this appears to be a restatement of the 
first sentence of section 101(b), which actually states:

    It is the policy of the Congress to recognize, preserve, and 
protect the primary responsibilities and rights of States to 
prevent, reduce, and eliminate pollution, to plan the development 
and use (including restoration, preservation, and enhancement) of 
land and water resources, and to consult with the Administrator in 
the exercise of his authority under this Act.

    The NWPR read this provision as essentially agnostic (or even in 
opposition) to preventing pollution and meeting the objective of Act. 
See, e.g., 85 FR 22270, April 21, 2020 (``States are free to evaluate 
the most effective means of addressing their waters and may weigh the 
costs and benefits of doing so.''). The agencies believe the better 
reading of this provision is found in the text of section 101(b), as a 
recognition of states' authority to ``prevent, reduce, and eliminate 
pollution'' and provide support for the Administrator's exercise of his 
authority to advance the objective of the Act. Indeed, section 101(b)'s 
text is plainly focused on environmental protection (``prevent, reduce, 
and eliminate pollution,'' ``including restoration, preservation and 
enhancement[] of land and water resources'').
    Section 101(b) further recognizes the very important role that the 
states play in achieving the Act's objective. ``Pollution'' is a 
defined term in the Act that means ``man-made or man-induced alteration 
of the chemical, physical, biological, and radiological integrity of 
water'' (section 502(19)) and has a broader scope than the ``discharge 
of a pollutant'' subject to regulatory jurisdiction under the Clean 
Water Act (e.g., nonpoint sources of pollution). The agencies believe 
that Congress's use of the broad term ``pollution'' in section

[[Page 69401]]

101(b) indicates that the policy in this section is intended to 
recognize and preserve, among other things, states' authority to 
prevent, reduce, and eliminate all kinds of pollution, including 
pollution falling outside the scope of federal regulatory authority. 
Importantly, this includes all non-point sources, which indisputably 
may (and do) significantly affect the integrity of foundational waters. 
The agencies' proposed definition of ``waters of the United States'' 
does not implicate, let alone impinge, on such state authorities.
    The first sentence of section 101(b) also refers to states' 
``primary'' role in preventing, reducing, and eliminating pollution--a 
word that is not incompatible with overlapping federal and state 
authority over waters which, under the proposed rule, implicate core 
federal interests. Thus, the text of section 101(b) need not be read, 
and in the agencies' view is best not read, as a general policy in 
favor of preserving for states a zone of exclusive regulatory authority 
based on federalism principles ``to choose whether or not to regulate'' 
regardless of the impact of those decisions on achievement of the Act's 
objective. See 85 FR 22270, April 21, 2020.
    In developing the proposed rule, the agencies also considered the 
language in section 101(b) referring to states' rights and 
responsibilities ``to plan the development and use (including 
restoration, preservation, and enhancement) of land and water 
resources.'' Planning the development, use, and protection of land and 
water resources is indisputably a traditional state function (e.g., 
zoning, allocation and administration of water rights, exercise of 
eminent domain, preservation of lands and waters). Congress's 
recognition of the states' primary role in this domain does not state 
or even suggest a policy to limit Clean Water Act jurisdiction over 
waters, as would be covered under the proposed rule, implicating the 
core federal interest in protecting traditional navigable waters, 
interstate waters and the territorial seas.
    Indeed, any implication to the contrary is dispelled by the 
remainder of section 101(b), which, among other things, expressly 
recognizes states' role in administering the federal permitting 
programs under section 402 of the Act:

    It is the policy of Congress that the States manage the 
construction grant program under this Act and implement the permit 
programs under sections 402 and 404 of this Act. It is further the 
policy of the Congress to support and aid research relating to the 
prevention, reduction, and elimination of pollution, and to provide 
Federal technical services and financial aid to State and interstate 
agencies and municipalities in connection with the prevention, 
reduction, and elimination of pollution.

    Thus, in the agencies' view, the text of section 101(b) as a whole 
reflects not a general policy of deference to state regulation to the 
exclusion of Federal regulation, but instead a policy focused on 
preserving the responsibilities and rights of states to work to achieve 
the objective of the Act by preventing, reducing and eliminating 
pollution generally, including, but not limited to, through their 
authority over any source of pollution subject to state law, consulting 
with the Administrator in the exercise of his Clean Water Act 
authority, and implementing the Act's regulatory permitting programs, 
in partnership and with technical and financial support from the 
Federal government.
    In the preamble to the NWPR, the agencies criticized prior 
statements they had made as taking an unduly narrow view of section 
101(b) ``as limited to implementation of the Act's regulatory programs 
by States and State authority to impose conditions on `waters of the 
United States.''' 85 FR 22269, April 21, 2020. As indicated above, the 
agencies now view the policy in section 101(b) as encompassing a broad 
understanding of states' roles in preventing, reducing, and eliminating 
pollution, and as explained above, the proposed rule reflects due 
consideration of this provision.
    The agencies' interpretation and consideration of section 101(b) in 
this rulemaking is consistent with Supreme Court precedent. The Supreme 
Court has described, on numerous occasions, section 101(b) as creating 
a partnership between the federal and state governments, in which the 
states administer programs under federally mandated standards and are 
allowed to set even more stringent standards. See Arkansas v. Oklahoma, 
503 U.S. at 144 (describing ``partnership between the States and the 
Federal government'' to meet 101(a) objective of Federal government 
setting pollutant discharge limitations and States implementing water 
quality standards for water bodies themselves); Int'l Paper Co. v. 
Ouellette, 479 U.S. at 489-90 (explaining 101(b) as allowing Federal 
government to delegate administration of point source pollution permits 
to states and allowing states to establish more stringent discharge 
limitations than federal requirements); City of Milwaukee, 451 U.S. at 
341 (describing 101(b) as creating ``shared authority between the 
Federal Government and the Individual States'' that allows for the 
states to set more stringent standards than necessary by federal law); 
Colorado Public Interest Group, 426 U.S. at 16, n.13 (describing 101(b) 
as providing states authority to develop permit programs and 
establishing standards more stringent than the Clean Water Act).
(2) Relationship Between Sections 101(a) and 101(b)
    The agencies have also carefully considered the policy in section 
101(b) as it relates to the Act's objective in section 101(a) and have 
reconsidered how the agencies considered these two provisions in 
promulgating the NWPR.
    In the preamble to the final NWPR, the agencies stated: ``The oft-
quoted objective of the CWA to `restore and maintain the chemical, 
physical, and biological integrity of the Nation's waters,' . . . must 
be implemented in a manner consistent with Congress' policy directives 
to the agencies.'' 85 FR 22269, April 21, 2020. As discussed above, the 
agencies gave section 101(b) predominant weight, and relied upon it as 
the basis for the rule's line-drawing between jurisdictional and non-
jurisdictional waters. Upon further review and reconsideration, while 
the agencies agree with the view in the NWPR that section 101(b) is 
relevant to a rulemaking defining ``waters of the United States'' (and 
have given the provision due consideration, as discussed above), the 
agencies are giving greater weight to section 101(a) than did the NWPR, 
and conclude that section 101(b) is better read as supporting 
Congress's objective in the Clean Water Act than in tension with it.
    The Clean Water Act's structure makes clear that section 101(a) is 
the foundational purpose of the statute that must be achieved. First, 
section 101(a) is the opening section of the statute and is labelled 
the ``objective'' of the Act. The agencies interpret its placement and 
its simple, declarative, and overarching statement as a powerful 
expression by Congress that merits significant weight in defining the 
scope of jurisdiction for all of the Clean Water Act's regulatory 
programs. In contrast, section 101(b) is one of four Congressional 
policies contained in section 101; the other three relate to seeking to 
ensure foreign countries take action to prevent, reduce, and eliminate 
pollution; reducing paperwork, duplication, and government delays; and 
state authority to allocate quantities of water within their 
jurisdictions. See 33 U.S.C. 1251(c), (f) and (g). The agencies believe 
that the prominently placed and single expression of the Act's 
overarching objective in section 101(a) merits greater weight in the 
agencies' decision-making than one of the four Congressional

[[Page 69402]]

policies expressed in section 101 which, while important, appear 
subordinate to the objective--particularly given the statutory text and 
structure.
    The remainder of the Act's text also demonstrates how important 
this objective was to Congress. As the NWPR accurately stated, the 
objective in section 101(a) is ``oft-quoted'' 85 FR 22269, April 21, 
2020. In the Clean Water Act itself, Congress refers to the objective 
of the Act approximately a dozen times, including in sections 122, 217, 
301, 302, 304, 305, 308, 318, 402, 405, 505, 516, 518, 601, and 603. 
The repeated reference to section 101(a) highlights the importance of 
the Act's objective to the statute as a whole, supporting the agencies' 
giving significant weight to this provision. Section 101(b), in 
contrast, is not referred to elsewhere in the Act.
    Indeed, while the NWPR read section 101(b) in isolation from the 
rest of the Clean Water Act, reviewing the statute as a whole reveals 
that Congress itself gave direction to the agencies on how it expected 
them to achieve section 101(a)'s objective and implement section 
101(b)'s policy. Following section 101, the remainder of the Act 
provides extensive and detailed instruction on how Congress expected 
its objective, goals, and policies to be met through the Act. 
Specifically, with regard to its objective and goals in section 101(a), 
Congress laid out a series of detailed programs (e.g., the section 303 
water quality standards program, the section 402 discharge elimination 
program, and the section 404 dredge and fill program) designed to meet 
that objective. So too, Congress gave detailed instructions on how it 
intended to apply its policy of preserving the primary role of the 
states. Specifically, as referenced explicitly in section 101(b), it 
authorized states to implement the key permitting programs under 
sections 402 and 404 of the Act--i.e., their authority to assume 
administration of the federal regulatory program for discharges of 
pollutants under sections 402(b) and 404(g). The Clean Water Act 
likewise delineates a role for states in implementing numerous other 
Clean Water Act programs central to achieving the Act's objective, 
including the water quality standards program and impaired waters and 
total maximum daily load program in section 303. Section 401 grants 
primary authority to states and authorized tribes to grant, deny, or 
waive certification of proposed federal licenses or permits that may 
discharge into ``waters of the United States'' within their borders. 
And under section 510, unless expressly stated, nothing in the Clean 
Water Act precludes or denies the right of any state or tribe to 
establish more protective standards or limits than the Act. As 
described above, the Clean Water Act further assigns exclusive 
authority to the states to regulate non-point sources.
    Thus, the agencies choose not to read the policy of section 101(b) 
as essentially a free-floating instruction or license for the agencies 
to interpret or implement other sections of the Act in a manner that 
impedes achievement of its overall objective, in particular 
definitional provisions like ``waters of the United States'' which are 
central to administration of the entire statute and therefore achieving 
that objective. To the contrary, Congress itself defined the contours 
of how it expected the agencies to both achieve its object in section 
101(a) and implement its policy in section 101(b) through the rest of 
the provisions of the Act. Notably, a narrow definition of ``waters of 
the United States'' would not uniformly boost state authority, as the 
NWPR suggested, as that definition is foundational to the scope of all 
of these programs in which the states are assigned authority. Indeed, 
with regard to section 401, a narrow definition would actually limit 
states' ability to protect waters within their borders.
    Finally, section 101(a) has also been ``oft-quoted'' by the courts, 
including the U.S. Supreme Court. See, e.g., National Association of 
Manufacturers, 138 S. Ct. at 624 (``Congress enacted the Clean Water 
Act in 1972 `to restore and maintain the chemical, physical, and 
biological integrity of the Nation's waters.' 33 U.S.C. 1251(a).''); 
see supra section V.A.2 of this preamble (summarizing Supreme Court 
case law surrounding the Act's statutory objective).
    The agencies' careful balancing of 101(a) and 101(b) in the 
proposed rule is also informed by and consistent with the Court in 
SWANCC, which noted that ``Congress chose to `recognize, preserve, and 
protect the primary responsibilities and rights of States . . . to plan 
the development and use . . . of land and water resources. . . .' 33 
U.S.C. [section] 1251(b). We thus read the statute as written to avoid 
the significant constitutional and federalism questions.'' U.S. 531 at 
174. Justice Kennedy further explained in Rapanos: ``In SWANCC, by 
interpreting the Act to require a significant nexus with navigable 
waters, the Court avoided applications--those involving waters without 
a significant nexus--that appeared likely, as a category, to raise 
constitutional difficulties and federalism concerns.'' 547 U.S. at 776. 
Likewise here, the proposed rule--by limiting jurisdiction only to 
those waters that significantly affect the integrity of waters where 
the federal interest is indisputable (traditional navigable waters, 
interstate waters, and the territorial seas)--would avoid 
constitutional and federalism concerns.
    In sum, taking into account the prominence, text, repeated 
statutory references to section 101(a), the Supreme Court's 
highlighting of the central importance of this provision, and the fact 
that the vast majority of the rest of the Clean Water Act is primarily 
aimed towards meeting this objective, the agencies accord this section 
significant weight, and greater weight than the due consideration it 
has given section 101(b) in developing the proposed rule.
(3) Statutory History
    Finally, in considering sections 101(a) and 101(b) for purposes of 
interpreting the scope of ``waters of the United States,'' the agencies 
believe it is important to consider the statutory history that gave 
rise to this structure. Indeed, the agencies recognize that in passing 
the Federal Water Pollution Control Act Amendments of 1972, Congress 
was not acting on a blank slate--it was amending existing law that had 
primarily provided for states to establish water quality standards for 
a subset of waters. Water Quality Act of 1965, Public Law 89-234, 79 
Stat. 903 (1965). Congress found the previous statute's focus on 
states' establishment and administration of water quality standards 
insufficient for the task of upgrading and protecting the quality of 
America's waters because states were lagging in establishing such 
standards and there was ``an almost total lack of enforcement.'' S. 
Rep. 92-414, S. Rep. 92-414 (1971) at 3671, 72. The Clean Water Act was 
enacted to address these shortcomings after ``two of the important 
rivers [in the Sixth] circuit, the Rouge River in Dearborn, Michigan, 
and the Cuyahoga River in Cleveland, Ohio, reached a point of pollution 
by flammable materials in the last ten years that they repeatedly 
caught fire.'' United States. v. Ashland Oil & Transp. Co., 504 F.2d 
1317, 1326 (6th Cir. 1974).
    With the 1972 Amendments, Congress adopted an entirely new approach 
to water pollution control--a prohibition of discharges of pollutants 
unless authorized by the Act and a new, comprehensive, federal 
regulatory scheme grounded in technology-based effluent standards 
applied uniformly across industries of the same type. ``The Committee 
recommends the change to effluent limits as the best available 
mechanism to control water pollution.

[[Page 69403]]

With effluent limits, the Administrator can require the best control 
technology.'' S. Rep. 92-414 at 3675. Congress further indicated that 
the Clean Water Act was intended to ``restore Federal-State balance to 
the permit system. Talents and capacities of those States whose own 
programs are superior are to be called upon to administer the permit 
system within their boundaries. The Administrator is to suspend his 
activity, insofar as the permit system is concerned, in these States.'' 
Id. . Congress also viewed the prohibition on discharges of pollutants 
unless authorized under the Act as ``establish[ing] a direct link 
between the Federal government and each industrial source of discharge 
into the navigable waters.'' Id. Thus, Congress viewed the Clean Water 
Act as a change from previous laws that centered on states and state 
water quality standards to a system based on a prohibition of 
discharges of pollutants to waters unless permitted in accordance with 
a federal regulatory scheme and technology standards established by 
EPA. States and tribes play a vital role in the implementation and 
enforcement of the Clean Water Act and the proposed rule proposes 
limitations after carefully considering how best to identify those 
waters for which protections were better left to the states.
    Thus, in passing the 1972 Amendments, Congress itself acted to 
rebalance its approach to protecting water quality--shifting from a 
statutory scheme dependent on state action to one rooted in a federal 
foundation, providing a uniform floor of water quality protection and 
leaving space for states to choose whether to regulate more 
stringently. See Dubois v. U.S. Dep't of Agriculture, 102 F.3d 1273, 
1300 (1st Cir. 1996) (``Simply put, the CWA provides a federal floor, 
not a ceiling, on environmental protection.''). Yet, in interpreting 
section 101(b) as serving to limit the scope of the Federal 
government's authority in favor of state authority, the NWPR turned 
Congress's scheme in the 1972 Amendments--in which it purposefully 
sought to give the Federal government a greater role in water quality 
protection--on its head. Unlike the NWPR, which did not consider the 
Act's statutory history in its read of section 101(b), the agencies 
here interpret section 101(b) in the context of this history and 
Congress's deliberate choice to restructure the statute to move away 
from its previous reliance on state-led water pollution control.
    The Supreme Court has also long recognized that Congress, in 
enacting the Clean Water Act, ``intended the 1972 Act amendments to 
`establish an all-encompassing program of water pollution 
regulation.''' Int'l Paper Co. v. Ouellette, 479 U.S. 481, 492-93 
(1987); see, e.g., PUD No. 1 of Jefferson Cty v. Washington Dep't of 
Ecology, 511 U.S. 700, 704 (1994) (interpreting the scope of Clean 
Water Act section 401 and finding that the Act ``is a comprehensive 
water quality statute designed to `restore and maintain the chemical, 
physical, and biological integrity of the Nation's waters,''' that 
``[t]he Act also seeks to attain `water quality which provides for the 
protection and propagation of fish, shellfish, and wildlife,''' and 
that ``to achieve these ambitious goals, the Clean Water Act 
establishes distinct roles for the Federal and State Governments''); 
EPA v. California ex rel. State Water Resources Control Bd., 426 U.S. 
200, 203, 205 n.12 (1976) (``In 1972, prompted by the conclusion of the 
Senate Committee on Public Works that `the Federal water pollution 
control program . . . has been inadequate in every vital aspect,' 
Congress enacted the [Clean Water Act] declaring `the national goal 
that the discharge of pollutants into the navigable waters be 
Eliminated by 1985.''). In the context of the scope of ``waters of the 
United States,'' the Court stated that Congress ``intended to repudiate 
limits that had been placed on federal regulation by earlier water 
pollution control statutes and to exercise its powers under the 
Commerce Clause to regulate at least some waters that would not be 
deemed `navigable' under the classical understanding of that term.'' 
Riverside Bayview, 474 U.S. 121, 133. More recently, the Supreme Court 
in Maui noted that:

    Congress' purpose as reflected in the language of the Clean 
Water Act is to ```restore and maintain the integrity of the 
Nation's waters,' '' [section] 101(a), 86 Stat. 816. Prior to the 
Act, Federal and State Governments regulated water pollution in 
large part by setting water quality standards. See EPA v. California 
ex rel. State Water Resources Control Bd., 426 U.S. 200, 202-203, 96 
S.Ct. 2022, 48 L.Ed.2d 578 (1976). The Act restructures federal 
regulation by insisting that a person wishing to discharge any 
pollution into navigable waters first obtain EPA's permission to do 
so. See id., at 203-205, 96 S.Ct. 2022; Milwaukee v. Illinois, 451 
U.S. 304, 310-311, 101 S.Ct. 1784, 68 L.Ed.2d 114 (1981).

140 S. Ct. at 1468.
    With respect to states' responsibilities and rights under section 
101(b), Justice Kennedy in Rapanos cited state amici briefs which 
``note[d], among other things, that the Act protects downstream States 
from out-of-state pollution that they cannot themselves regulate.'' 547 
U.S. at 777. Indeed, the Supreme Court has recognized that this is an 
important aspect of the Clean Water Act's passage. City of Milwaukee 
involved alleged discharges of inadequately treated sewage from 
Milwaukee, Wisconsin sewer systems directly into Lake Michigan, which 
also borders Illinois. The Supreme Court noted that prior to passage of 
the Clean Water Act, these discharges would have had to be resolved 
through litigation, in which the courts must apply ``often vague and 
indeterminate nuisance concepts and maxims of equity jurisprudence.'' 
451 U.S. at 317. The Clean Water Act, however, replaced this 
unpredictable and inefficient approach with ``a comprehensive 
regulatory program supervised by an expert administrative agency.'' Id.
    Yet, an overly narrow definition of jurisdictional waters--such as 
that under the NWPR (including the NWPR's removal from jurisdiction the 
longstanding category of interstate waters) --threatens a return to 
pre-1972 days excluding from federal protection waters that 
significantly affect foundational waters and risks removing from the 
statutory scheme instances of interstate pollution the 1972 amendments 
were designed to address. In response to concerns expressed by 
commenters regarding protection of downstream states from out-of-state 
pollution, the agencies in the NWPR simply stated: ``The CWA provides a 
number of opportunities for the EPA to mediate disputes among states, 
though the remedies available for cross-boundary water pollution 
disputes over non-jurisdictional waters depends upon the parties and 
the issues of the case. As they do today, under the final rule remedies 
for pollution disputes among states that do not implicate CWA sections 
319(g), 401, or 402 would likely derive from federal common law under 
the Supreme Court's original jurisdiction. Remedies for disputes 
between a state and a public or private party would likely derive from 
state or federal common law and be heard by state or federal courts.'' 
NWPR, Response to Comments, Topic 1 Legal Arguments at 26. But 
directing states and other parties to utilize state or federal common 
law to resolve such disputes overlooks ``Congress' intent in enacting 
the [1972] Amendments . . . to establish an all-encompassing program of 
water pollution regulation,'' City of Milwaukee, 451 U.S. at 318, and 
that ``the need for such an unusual exercise of lawmaking by federal 
courts disappears'' when Congress passes legislation that ``speak[s] 
directly'' to the question at issue, as Congress did in

[[Page 69404]]

passing the Clean Water Act. Id. at 317-18.
    By proposing regulations interpreting the Act to cover waters that 
meet the relatively permanent standard or the significant nexus 
standard, the agencies have reasonably interpreted the Act to protect 
those waters necessary to protect the integrity of downstream 
traditional navigable waters, interstate waters, and the territorial 
seas while leaving regulatory authority over all other waters 
exclusively to the states. This interpretation respects the statutory 
history that gave rise to the Act and gives effect to the comprehensive 
nature of the Clean Water Act, its objective, and the many programs 
affected by the scope of ``waters of the United States'' designed to 
meet that objective, along with other important policies of the Act, 
while ensuring that states have sole authority over waters with no or 
insignificant connection to the foundational waters clearly protected 
by the Clean Water Act.
(4) The Definitions of Jurisdictional Waters in the Proposed Rule 
Reflect Appropriate Consideration of Sections 101(a) and 101(b) of the 
Act
    As discussed elsewhere, the proposed rule includes definitions of 
tributaries, adjacent wetlands, and ``other waters'' that meet the 
relatively permanent or significant nexus standards (see section V.C of 
this preamble). The proposed rule advances the Act's objective by 
helping restore and maintain the chemical, physical, and biological 
integrity of traditional navigable waters, interstate waters, and 
territorial seas--waters of longstanding and indisputable federal 
interest--by protecting them from degradation of upstream waters that 
significantly affect them. At the same time, consistent with section 
101(b), the proposed rule recognizes, preserves, and protects states' 
rights and responsibilities subject to the policy in section 101(b) of 
the Act by leaving within their purview all waters that do not 
significantly affect the foundational waters of paramount federal 
interest. The specific jurisdictional lines in the proposed rule 
demarcating jurisdictional from non-jurisdictional waters therefore 
bear a relationship to the nature and extent of federal and state 
interests at play; this line-drawing highlights the agencies' 
deliberate and due consideration of sections 101(a) and 101(b) in 
developing the proposed rule.
    The agencies believe that the jurisdictional line-drawing reflected 
in the proposed rule better aligns with these statutory provisions than 
the NWPR. As noted previously, the preamble to the final NWPR cited 
section 101(b) as a justification, in part, for its specific 
definitions of jurisdictional tributaries and adjacent wetlands. One of 
the most environmentally significant decisions in the NWPR was its 
categorical exclusion of all ephemeral streams from Clean Water Act 
jurisdiction. The agencies cited section 101(b) as a basis for this 
exclusion as ``respecting State and Tribal land use authority over 
features that are only episodically wet during and/or following 
precipitation events.'' 85 FR 22319. The agencies' explanation, 
however, does not link the agencies' line-drawing to the text or 
purpose of section 101(b). Nor do the agencies, at this time, see any 
linkage between the flow regime of ephemeral waters and the nature or 
extent of state authorities referenced in section 101(b). Indeed, as 
discussed elsewhere, available science unequivocally demonstrates that 
ephemeral tributaries can implicate the important federal interest in 
the protection of the integrity of traditional navigable waters, 
interstate waters, and territorial seas. Likewise, in categorically 
excluding ephemeral waters, the agencies in the NWPR cite section 
101(a), but again do not explain how their decision relates to or 
advances the Act's objective. 85 FR 22277, April 21, 2020. In contrast, 
informed by the policy in section 101(b) and the Act's objective in 
section 101(a), the proposed role appropriately distinguishes between 
jurisdictional and non-jurisdictional tributaries based on whether a 
tributary implicates core federal interests, in which case it is 
covered by the rule, or fails to do so, in which case its protection 
and management is left to states and tribes.
    The NWPR similarly relied upon section 101(b) as a basis for its 
definition of adjacent wetlands, in particular the decision to exclude 
from consideration subsurface hydrologic connection between a wetland 
and an adjacent water when determining jurisdiction, stating: 
``[B]alancing the policy in CWA section 101(a) with the limitations on 
federal authority embodied in CWA section 101(b), the agencies are 
finalizing the definition of `adjacent wetlands' that does not include 
subsurface hydrologic connectivity as a basis for determining 
adjacency.'' Id. at 22313. Again, the NWPR does not explain how 
excluding consideration of subsurface hydrologic connections relates to 
or derives from section 101(b), and the agencies do not now discern 
such a linkage. And as with the definition of tributaries, the NWPR 
does not explain how this choice relates to or advances the objective 
of the Act. In contrast, the proposed rule's approach to adjacent 
wetlands, like its approach to jurisdictional tributaries, gives due 
consideration to the policy in section 101(b) and the objective in 
section 101(a) by tethering jurisdiction to whether the wetland 
implicates foundational waters with a demonstrated federal interest.
4. The Proposed Rule Is Both Familiar and Implementable
    The agencies have extensive experience implementing the 1986 
regulations. In addition, the scientific and technical information 
available to inform the significant nexus analysis and identify waters 
that meet the relatively permanent standard has markedly improved over 
time and become more easily available since the agencies first started 
implementing both standards. The agencies are taking comment on a range 
of implementation options discussed in section V.D of this preamble 
that would further inform the public as to the agencies' intended 
practice for asserting jurisdiction under the proposed rule.
    Since the Court's decision in Rapanos, the agencies have gained 
more than a decade of experience implementing the 1986 regulations 
consistent with the relatively permanent standard and the significant 
nexus standard under three different presidential Administrations, 
beginning with the Rapanos Guidance issued in 2007. Even after the 
agencies promulgated the 2015 Clean Water Rule, they continued to 
implement the 1986 regulations consistent with the Rapanos Guidance in 
certain states in response to court decisions enjoining the 2015 Clean 
Water Rule in various parts of the country.
    The agencies repromulgated the 1986 regulations in the 2019 Repeal 
Rule and implemented those rules nationwide until June 22, 2020, when 
the NWPR became effective. The agencies explained that with the 2019 
Repeal Rule, they intended to ``restore the regulatory text that 
existed prior to the 2015 Rule'' and that the agencies would 
``implement the pre-2015 Rule regulations informed by applicable agency 
guidance documents and consistent with Supreme Court decisions and 
longstanding agency practice.'' 84 FR 56626, October 22, 2019. The 
agencies concluded that ``[the] final rule will provide greater 
regulatory certainty and national consistency while the agencies 
consider public comments on the proposed [2020 Rule].'' Id. at 56660. 
To further justify a return to the 1986 framework, the agencies noted 
that ``[t]he agencies, their

[[Page 69405]]

coregulators, and the regulated community are . . . familiar with the 
pre-2015 Rule regulatory regime and have amassed significant experience 
operating under those pre-existing regulations. Agency staff in 
particular have developed significant technical expertise in 
implementing the 1986 regulations.'' Id. The 2019 Repeal Rule would 
thus ``provide greater certainty by reinstating nationwide a 
longstanding regulatory framework that is familiar to and well 
understood by the agencies, States, Tribes, local governments, 
regulated entities, and the public.'' Id. at 56661. Indeed, a number of 
regulators and regulated parties alike expressed support for returning 
to the pre-2015 regulations, as implemented following SWANCC and 
Rapanos, due in part to their experience and familiarity with that 
regime.\29\
---------------------------------------------------------------------------

    \29\ See, e.g., comments submitted by American Water Works 
Association (August 13, 2018) (Docket ID: EPA-HQ-OW-2017-0203-
15559); comments submitted by North Dakota's Department of 
Agriculture (July 25, 2018) (Docket ID: EPA-HQ-OW-2017-0203-15541); 
comments submitted by the Office of the Governor of Utah (August 9, 
2018) (Docket ID: EPA-HQ-OW-2017-0203-15202) (``Recodification of 
the regulations that existed prior to the 2015 Rule will provide 
continuity and certainty for regulated entities, States, the 
agencies' staff, and the American public.'').
---------------------------------------------------------------------------

    Further, in responding to comments asserting that the agencies 
should not return to the pre-2015 regulatory regime because that regime 
would reduce regulatory certainty compared to the 2015 Clean Water Rule 
due to the prior regime's reliance on case-specific significant nexus 
determinations, the agencies explained that ``[f]ollowing the Supreme 
Court's decisions in SWANCC and Rapanos . . . the Corps published a 
guidebook to assist district staff in issuing approved jurisdictional 
determinations. In particular, the guidebook outlines procedures and 
documentation used to support significant nexus determinations. This 
guidebook has been and continues to be publicly available and will 
continue to serve as a resource in issuing jurisdictional 
determinations under this final rule.'' \30\ Id. at 56660. Even after 
the NWPR's June 22, 2020 effective date, the agencies continued to 
implement the 2019 Repeal Rule consistent with the Rapanos Guidance in 
Colorado until April 2021 due to litigation barring implementation of 
the NWPR in that state.
---------------------------------------------------------------------------

    \30\ For convenience, EPA decisions on jurisdiction are referred 
to as jurisdictional determinations throughout this document, but 
such decisions are not approved jurisdictional determinations as 
defined and governed by the Corps regulations at 33 CFR 331.2.
---------------------------------------------------------------------------

    In addition to the past three presidential Administrations, courts 
have also found that the 1986 regulations, implemented consistent with 
the Rapanos standards, provide an appropriate regulatory framework by 
which to implement the Act. Indeed, in staying the 2015 Rule 
nationwide, the Sixth Circuit found that returning to the ``familiar, 
if imperfect, pre-Rule regime'' was the best path forward pending 
judicial review of the 2015 Rule. In re EPA & Dep't of Def. Final Rule, 
803 F.3d 804, 808 (6th Cir. 2015). In doing so, the court recognized 
that it needed to reinstate the pre-2015 regulatory regime--not the 
1986 regulations alone--to properly preserve the status quo. See id. at 
806 (finding that ``the status quo at issue is the pre-[2015 Rule] 
regime of federal-state collaboration that has been in place for 
several years, following the Supreme Court's decision in Rapanos''). 
Likewise, in vacating the NWPR, the Arizona district court reinstated 
the pre-2015 regulatory regime, noting that the regime ``is familiar to 
the Agencies and industry alike.'' See Pascua Yaqui Tribe, 2021 WL 
3855977, at *5.
    The agencies acknowledge that a return to the pre-2015 regime would 
result in the need for case-specific analyses for certain 
jurisdictional determinations, potentially raising some timeliness and 
consistency issues that the agencies' rules in 2015 and 2020 were 
designed, in part, to reduce. However, the NWPR both fails to advance 
the Act's statutory objective and introduces new implementation 
uncertainties, including its own case-specific typical year analysis 
for most categories of jurisdictional waters. In contrast, the proposed 
rule is both consistent with the Act's statutory text and purposes and 
is longstanding and familiar to regulated parties and regulators alike. 
Moreover, all definitions of ``waters of the United States'' require 
some level of case-specific analysis, and implementation of the 
proposed rule will be aided by improved and increased scientific and 
technical information and tools that both the agencies and the public 
can use to determine whether waters are ``waters of the United States'' 
(see section V.D of this preamble). Accordingly, the agencies have 
concluded the proposed rule is consistent with the Clean Water Act and 
the best available science as well as familiar and implementable.
    Through the various rulemakings and court decisions relating to the 
definition of ``waters of the United States'' since the Rapanos 
decision in 2006, the agencies have continued implementing the 1986 
regulations consistent with the Rapanos standards nationwide or in 
numerous states across the country for various periods of time. This 
experience has allowed the agencies to further develop expertise in 
implementing this regime. The agencies, most often the Corps, have made 
hundreds of thousands of Clean Water Act approved jurisdictional 
determinations since the issuance of the 2008 Rapanos Guidance. Of 
those, approximately 36,000 have required a case-specific significant 
nexus determination. The agencies have made such determinations in 
every state in the country as well as in the U.S. territories.
    With field staff located in 38 Corps District offices and 10 EPA 
regional offices, the agencies have over a decade of nationwide 
experience in making decisions regarding jurisdiction under the 1986 
regulations consistent with the relatively permanent standard and the 
significant nexus standard as interpreted by the Rapanos Guidance. 
These individual determinations have been made affirmatively for waters 
ranging from an ephemeral stream that flows directly into a traditional 
navigable water used extensively for recreational boating and fishing, 
to wetlands directly touching a perennial tributary, to an intermittent 
stream that provides flow to a drinking water source, to a group of 
floodplain wetlands that provide important protection from floodwaters 
to downstream communities alongside the traditional navigable water, to 
headwater mountain streams that provide high quality water that 
supplies baseflow and reduces the harmful concentrations of pollutants 
in the main part of the river below. The agencies have also made many 
findings of no jurisdiction under the 1986 regulations when they 
concluded the waters in question did not meet either the relatively 
permanent standard or the significant nexus standard as implemented by 
the Rapanos Guidance. This includes individual determinations for a 
small non-relatively permanent stream without any adjacent wetlands 
miles from the nearest downstream traditional navigable water, for a 
small wetland adjacent to a non-relatively permanent water that 
together did not have a case specific significant nexus under the 
guidance, and for a roadside ditch constructed in and draining uplands 
that lacked relatively permanent flow.
    Through this experience, the agencies developed wide-ranging 
technical expertise in assessing the hydrologic flowpaths along which 
water and materials are transported and transformed that determine the 
degree of chemical, physical, or biological connectivity and effects to 
downstream

[[Page 69406]]

waters. The agencies have also become deeply familiar with the 
variations in climate, geology, and terrain within and among watersheds 
and over time that affect the functions (such as the removal or 
transformation of pollutants) performed by streams, open waters, and 
wetlands for downstream traditional navigable waters, interstate 
waters, or the territorial seas. The Corps can complete jurisdictional 
determinations at no charge to the landowner or project proponent upon 
their request.
    The agencies utilize many tools and many sources of information to 
help support decisions on jurisdiction, including U.S. Geological 
Survey (USGS) and state and local topographic maps, aerial photography, 
satellite imagery, soil surveys, National Wetland Inventory maps, 
floodplain maps, watershed studies, scientific literature and 
references, and field work. As discussed further in section V.D.3.d of 
this preamble, these tools have undergone significant technological 
advances, and become increasingly available, since the Rapanos 
decision. For example, USGS and state and local stream maps and 
datasets, aerial photography, gage data, watershed assessments, 
monitoring data, and field observations are often used to help assess 
the contributions of flow of tributaries, including intermittent and 
ephemeral streams, to downstream traditional navigable waters, 
interstate waters, or the territorial seas. Similarly, floodplain and 
topographic maps from federal, state, and local agencies, modeling 
tools, and field observations can be used to assess how wetlands are 
storing floodwaters that might otherwise affect the integrity of 
downstream waters. Further, the agencies utilize the large body of 
scientific literature regarding the functions of tributaries, including 
tributaries with ephemeral, intermittent, and perennial flow, and of 
wetlands and open waters to inform their significant nexus analyses. In 
addition, the agencies have experience and expertise from decades of 
making decisions on jurisdiction that considered hydrology, ordinary 
high water mark (OHWM) and its associated indicators (see section 
V.C.9.d of this preamble), biota, and other technical factors in 
implementing Clean Water Act programs. The agencies' immersion in the 
science, along with the practical expertise developed through case-
specific determinations across the country for more than a decade, have 
helped the agencies determine which waters have a significant nexus and 
where to draw boundaries demarking the ``waters of the United States.''
    Regulated entities and other interested parties also have 
significant experience with the 1986 regulations and the two Rapanos 
standards. While the agencies have been developing their expertise in 
implementing this regime, so have state and tribal co-regulators and 
regulated entities that may be subject to the Act's reach, including 
technical consultants that advise regulated entities on whether they 
may be subject to Clean Water Act requirements, and interested citizens 
who may play an important role in the Act's permitting process.
    Due in part to the familiarity of this regime, the proposed rule 
would not undermine significant reliance interests in an alternative 
regime, including the NWPR. The Supreme Court has held that agencies' 
changes in position do not require any reasons ``more substantial than 
those required to adopt a policy in the first instance.'' FCC v. Fox 
Television Stations, Inc., 556 U.S. 502, 514 (U.S. 2009). The Court 
acknowledges that if an agency's ``prior policy has engendered serious 
reliance interests,'' the agencies must not ignore them, but must 
provide a reasoned explanation for disregarding facts and circumstances 
that underlay or were engendered by the prior policy. Id. at 515. 
However, the Court emphasizes that even in the case of serious reliance 
interests, further justification is not required ``by the mere fact of 
policy change.'' Id. at 516.
    The proposal does not implicate serious reliance interests because, 
first, the agencies are proposing to codify a rule similar to the 
definition currently being implemented nationwide. Therefore, no 
stakeholders are currently relying on the implementation of an 
alternative definition, including the NWPR. As discussed in section VI 
of this preamble, the proposed rule would restore a regime that is 
generally comparable to current practice, and there would be no 
appreciable cost or benefit difference between the proposed rule and 
the regulatory regime that the agencies are currently implementing. 
Second, members of the public, states, and tribes have been aware that 
the agencies might reconsider the NWPR for nearly a year and have had 
many opportunities to share their views with the agencies. President 
Biden indicated on his first day in office, following the issuance of 
Executive Order 13990, that this administration would be reviewing the 
NWPR and deciding whether to revise or replace the rule. See section 
IV.B.5 of this preamble. On June 9, 2021, the agencies announced their 
intention to revise or replace the rule. The agencies subsequently 
embarked on an extensive stakeholder outreach process, including public 
meetings and state and tribal consultation. See section IV.C of this 
preamble. The agencies received over 32,000 recommendation letters from 
the public during its pre-proposal outreach. Third, the NWPR was only 
in effect for 14 months and was subject to multiple legal challenges 
during that entire time. Finally, as discussed in this section, members 
of the public are familiar with the proposed rule's regulatory 
framework thereby minimizing the potential disruption of a change. 
Regardless, even if serious reliance interests were at issue, which 
they are not, this proposed rule provides a thorough and reasoned 
explanation for the changed definition of ``waters of the United 
States.''
    For all of these reasons, the agencies are now once again proposing 
to return the definition of ``waters of the United States'' to its 
longstanding and familiar definition reflected in the 1986 regulations, 
amended to reflect the agencies' current view of the limitations on 
their jurisdiction informed by relevant Supreme Court decisions.

B. Concerns With Alternatives

    In promulgating a rule to repeal existing regulations, agencies 
must address and consider alternative ways of achieving the relevant 
statute's objectives and must provide adequate reasons to abandon those 
alternatives. Motor Vehicle Mfrs. Ass'n v. State Farm Mut. Auto. Ins. 
Co., 463 U.S. 29, 48 (1983). As discussed below, the agencies have 
thoroughly considered alternatives to the proposed rule and have 
concluded that the proposed rule is the best path forward to meet the 
agencies' goals to promulgate a rule that advances the objective of the 
Clean Water Act, is consistent with Supreme Court decisions, is 
supported by the best available science, and promptly and durably 
restores vital protections to the nation's waters. The agencies have 
reconsidered the policies, interpretations, and conclusions of the NWPR 
and for the reasons articulated in this preamble are changing their 
approach. FCC v. Fox Television Stations, Inc., 556 U.S. 502, 515 
(2009).
1. 2015 Clean Water Rule
    The agencies are not proposing to repromulgate the 2015 Clean Water 
Rule. While the proposed rule utilizes the best available science in 
support of the conclusion that the proposed rule would advance the 
objectives of the Act, the proposed rule is not, as aspects of the 2015 
Rule were, based on categorical significant nexus determinations. 
Rather, the proposed rule restores the

[[Page 69407]]

longstanding and familiar categories of the 1986 regulations and 
proposes jurisdictional limitations based on both the relatively 
permanent standard and the significant nexus standard.
    The 2015 Clean Water Rule, while designed to advance the objective 
of the Clean Water Act, is not the best alternative to meet the policy 
goals of the agencies: To promptly restore the protections of the 
longstanding regulations and avoid current and future harms to 
important aquatic resources, consistent with the best available science 
and the agencies' determination of the statutory limits on the scope of 
the ``waters of the United States.'' In particular, the procedural 
status of the 2015 Rule in light of the complex litigation surrounding 
it means that re-adoption of the rule would not meet the agencies' 
policy goal of promptly ensuring necessary protections for the nation's 
waters.
    Indeed, litigation over the 2015 Rule previously led to different 
definitions of ``waters of the United States'' being in effect in 
different parts of the country. At this time, the 2015 Clean Water Rule 
remains subject to preliminary injunctions barring implementation of 
the rule in roughly half the states in the country. See section I.A of 
the Technical Support Document for more information on the status of 
the definition of ``waters of the United States'' in effect at 
different times across the country based on the litigation over the 
2015 Rule.
2. 2019 Repeal Rule
    As discussed in section V.A of this preamble, the agencies agree 
with the concept in the 2019 Repeal Rule of returning to the pre-2015 
regulatory framework as a means of restoring a longstanding and 
familiar regulatory regime. Indeed, like the 2019 Repeal Rule, the 
proposed rule seeks to return generally to the longstanding regulations 
that existed prior to the 2015 Clean Water Rule.\31\ Unlike the 2019 
Repeal Rule, however, the proposed rule would restore those regulations 
with necessary limitations to ensure the definition of ``waters of the 
United States'' reflects consideration of the agencies' statutory 
authority under the Clean Water Act and of relevant Supreme Court 
decisions.
---------------------------------------------------------------------------

    \31\ 2019 Repeal Rule, Response to Comments at 9 (``The agencies 
find that reinstating the longstanding and familiar pre-2015 Rule 
regulatory regime will provide regulatory certainty in this interim 
period . . . .''), 15 (``[T]his final rule to recodify the 1986 
regulations will provide greater regulatory certainty and nationwide 
consistency while the agencies consider public comments on the 
proposed revised definition of ``waters of the United States.'').
---------------------------------------------------------------------------

    Additionally, the agencies have significant concerns regarding the 
legal rationale underpinning the 2019 Repeal Rule. In particular, the 
agencies are concerned that the interpretation of relevant Supreme 
Court case law in the 2019 Repeal Rule is flawed and thereby led to an 
erroneous assessment of the legality of the 2015 Clean Water Rule. See, 
e.g., 84 FR 56638-52, October 22, 2019. The agencies' reading of the 
Clean Water Act in the 2019 Repeal Rule is also inconsistent with the 
agencies' considered interpretation, at this time, of the Act. For 
these reasons, the agencies find that the 2019 Repeal Rule is not an 
appropriate alternative to the proposed rule.
3. NWPR
    The agencies have also evaluated the NWPR as an alternative to the 
proposed rule. After carefully considering the NWPR in light of the 
text, objective, and legislative history of the Act, Supreme Court case 
law, the best available scientific information, and the agencies' 
experience in implementing the NWPR for over a year, the agencies do 
not believe the NWPR is a suitable alternative to the proposal.
a. The NWPR Fails To Advance the Objective of the Clean Water Act
    The agencies do not consider the NWPR to have advanced the 
statutory objective of the Clean Water Act, which the Supreme Court 
recently emphasized is an important aspect of defining the 
jurisdictional scope of the Act. See, e.g., Maui, 140 S. Ct. 1462, 
1468-69 (emphasizing the importance of considering the Clean Water 
Act's objective when determining the scope of the Act and finding that 
``[t]he Act's provisions use specific definitional language to achieve 
this result,'' including the phrase ``navigable waters''). Consistent 
with the Supreme Court's opinion in Maui, a rule defining ``waters of 
the United States'' must consider its effects on the chemical, 
physical, and biological integrity of the nation's waters. And--as the 
text and structure of the Act, supported by legislative history and 
Supreme Court decisions, make clear--chemical, physical, and biological 
integrity refers to water quality.
    The agencies do not view the objective of the Clean Water Act as 
the only factor relevant to determining the scope of the Act. Rather, 
the agencies have concluded that consistent with the text, structure, 
and legislative history of the Act, as well as Maui and the other 
Supreme Court decisions addressing ``waters of the United States,'' and 
with general principles of administrative law, the agencies must give 
substantial consideration of the effects of a revised definition of 
``waters of the United States'' on the integrity of the nation's 
waters.
    The agencies view the failure of the NWPR to advance the Act's 
objective as an important factor in their choice not to propose a rule 
based on the NWPR. One critical example of the NWPR's failure to 
advance the objective of the Act is its removal of the significant 
nexus test without considering an alternative approach to protecting 
waters that significantly affect downstream traditional navigable 
waters. The significant nexus inquiry reflects and furthers the 
objective of the Clean Water Act by allowing for a scientific 
evaluation of the effect of wetlands, tributaries, and other features 
on downstream waters. For that reason, evolving forms of this inquiry 
have been present in Riverside Bayview, SWANCC, and Justice Kennedy's 
concurring opinion in Rapanos. The NWPR ``eliminate[d]'' the 
significant nexus test, 85 FR 22325, April 21, 2020, and failed to 
replace it with an alternative approach that furthered the objective of 
the Act.
    To be clear, the Supreme Court's interpretations of the scope of 
``waters of the United States'' do not require adoption of a 
significant nexus test. The Supreme Court has held that its 
interpretation of a statutory term only binds the agency in future 
rulemakings if it has stated that ``its construction follows from the 
unambiguous terms of the statute and thus leaves no room for agency 
discretion.'' Brand X internet Services, 545 U.S. at 982. The term 
``waters of the United States'' is no such ``unambiguous term.'' 
``Waters of the United States'' can be subject to many interpretations 
and the agencies have ``generous leeway'' in interpreting it. Rapanos, 
547 U.S. at 758 (Roberts, C.J., concurring in the judgment.)
    While the agencies were not bound to adopt the significant nexus 
standard, the failure of the NWPR to adopt any standard for 
jurisdiction that adequately addresses the effects of degradation of 
upstream waters on downstream waters, including traditional navigable 
waters, fails to advance the Act's objective. For example, the NWPR 
categorically excluded ephemeral features without appropriately 
considering scientific information about their important effects on the 
integrity of downstream traditional navigable waters. In addition, in 
limiting the scope of protected wetlands to those that touch or 
demonstrate evidence of a regular surface water connection to other 
jurisdictional waters, the NWPR failed

[[Page 69408]]

to appropriately consider the many effects of other categories of 
wetlands on downstream waters. For example, an ephemeral stream that 
flows directly into the Rio Grande (a traditional navigable water) and 
an adjacent wetland separated from the Mississippi River (a traditional 
navigable water) by an artificial levee and that lacks a direct 
hydrologic surface connection to the river in a typical year are non-
jurisdictional under the NWPR but have significant effects on 
traditional navigable waters.
    The NWPR's assertion that it considered the objective of the Act 
because Clean Water Act and non-Clean Water Act state, tribal, and 
local efforts ``collectively pursue the objective'' does not reflect 
consideration of the objective as intended by Congress. The agencies 
contended in adopting the NWPR that the drastic reduction in the scope 
of Clean Water Act jurisdiction pursues the objective of the Act 
because it would be combined with the Clean Water Act's non-regulatory 
programs as well as state, tribal, and local efforts. The NWPR 
explained: ``The CWA's longstanding regulatory permitting programs, 
coupled with the controls that States, Tribes, and local entities 
choose to exercise over their land and water resources, will continue 
to address the discharge of pollutants into waters of the United 
States, and the CWA's non-regulatory measures will continue to address 
pollution of the nation's waters generally. These programs and measures 
collectively pursue the objective of restoring and maintaining the 
chemical, physical, and biological integrity of the nation's waters.'' 
85 FR 22269, April 21, 2020.
    The agencies agree with the NWPR's position that the Clean Water 
Act's non-regulatory measures, such as grantmaking and technical 
assistance authorities, advance the objective the Act. However, the 
agencies do not view these authorities as limiting the scope of 
``waters of the United States,'' or as relevant to determining whether 
a definition of ``waters of the United States'' advances the objective 
of the Act. The non-regulatory Clean Water Act programs that the NWPR 
cites complement and support the permitting programs at the core of the 
Act, as opposed to limiting its scope. For example, the NWPR cited the 
Act's provisions to address pollution into key waters in its 
discussion, including the Great Lakes, 33 U.S.C. 1258, the Chesapeake 
Bay, see id. at 1267(a)(3), Long Island Sound, see id. at 
1269(c)(2)(D), and Lake Champlain, see id. at 1270(g)(2). These 
resources are ``waters of the United States'' to which regulatory 
programs apply, and the technical assistance and grants in the cited 
sections assist states and others in achieving the requirements of the 
Act, but do not limit the regulatory programs' scope.
    The agencies disagree, however, with NWPR's assertion that the 
rule's reduction in regulatory scope achieved the objective of the Act 
based in part on the impacts of non-Clean Water Act programs. As 
discussed in section V.A.3.B of this preamble, the Clean Water Act's 
fundamental innovation in 1972 was ``to establish an all-encompassing 
program of water pollution regulation,'' Int'l Paper Co. v. Ouellette, 
479 U.S. 481, 492-93 (1987). The definition of ``waters of the United 
States'' establishes the scope of that program. The agencies therefore 
believe it is appropriate to consider whether the definition of the 
scope of waters to which the Act's water pollution regulations apply 
helps to achieve that objective. Thus, the NWPR's statement that the 
rule ``pursues'' the objective of the Act if Clean Water Act and non-
Clean Water Act programs are viewed in ``combination,'' is not 
consistent with the better reading of text and structure of the Act, 
its legislative history, or Supreme Court decisions concerning the 
effect of enactment of the Clean Water Act in 1972, nor does it fulfill 
the agencies' obligation to consider the objective of the Act by 
assessing the water quality effects of revising the definition of 
``waters of the United States.''
    In sum, based on the text, structure, and history of the statute, 
the relevant and available science, Supreme Court case law, and the 
agencies' technical expertise and experience, the agencies have 
determined that the NWPR is not a suitable alternative to the proposed 
rule because it fails to achieve the objective of the Act. The NWPR 
does not establish either the significant nexus test or an alternative 
standard that advances the objective of the Clean Water Act by 
protecting waters, including upstream ephemeral tributaries and 
wetlands, where they have a significant effect on the integrity of 
downstream traditional navigable waters, interstate waters, and the 
territorial seas and does not appropriately value the importance of 
federal programs in achieving the objective of the Act.
b. The NWPR is Inconsistent With the Best Available Scientific 
Information
    The NWPR's exclusion of major categories of waters from the 
protections of the Act, specifically in the definitions of 
``tributary'' and ``adjacent wetlands,'' runs counter to the scientific 
record demonstrating how such waters can affect the integrity of 
downstream waters. Specifically, its categorical exclusion of ephemeral 
features and large categories of wetlands is inconsistent with the 
scientific record before the agencies. In addition, the NWPR's limits 
on the scope of protected wetlands to those that touch or demonstrate 
evidence of a regular surface water connection to other jurisdictional 
waters were counter to the ample scientific information demonstrating 
the effects of wetlands on downstream waters when they have other types 
of connections.
    First, the definition of the term ``tributary'' in the NWPR 
categorically excluded ephemeral streams from the regulatory 
protections of the Act, contrary to scientific information emphasizing 
the vital role these streams can play in protecting the integrity of 
downstream waters. The science is clear that aggregate effects of 
ephemeral streams ``can have substantial consequences on the integrity 
of the downstream waters'' and that the evidence of such downstream 
effects is ``strong and compelling,'' as discussed above. Science 
Report at 6-10, 6-13. EPA's SAB Review of the draft Science Report 
explains that ephemeral streams ``are no less important to the 
integrity of the downgradient waters'' than perennial or intermittent 
streams. SAB Review at 22-23, 54 fig. 3. While in the arid Southwest, 
features flow into downstream waters less frequently than they do in 
the wetter East, the Science Report emphasizes that short duration 
flows through ephemeral streams can transport large volumes of water to 
downstream rivers. Science Report at 6-10. For instance, the report 
notes that ephemeral streams supplied 76% of flow to the Rio Grande 
following a large rainstorm. Id. at 3-8. The SAB Review emphasizes that 
the ``cumulative effects'' of ephemeral flows in arid landscapes can be 
``critical to the maintenance of the chemical, physical, and biological 
integrity'' of downstream waters. SAB Review at 22.
    Similarly, the NWPR's definition of ``adjacent wetlands'' excluded 
many categories of wetlands that can play a vital role in protecting 
the integrity of waters to which they are connected, including 
traditional navigable waters. In defining ``adjacent wetlands,'' the 
NWPR limited the scope of wetlands protected by the Clean Water Act's 
regulatory programs to those that either abut or have evidence of 
certain surface water connections to other protected waters in a 
typical year. 85 FR 22340, April 21, 2020. Specifically, the rule

[[Page 69409]]

encompassed wetlands that (i) abut, meaning to touch, another 
jurisdictional water; (ii) are flooded by a jurisdictional water in a 
typical year; (iii) are separated from a jurisdictional water only by a 
natural feature, such as a berm, which provides evidence of a direct 
surface hydrological connection with that water; or (iv) are separated 
from a jurisdictional water only by an artificial structure so long as 
that structure allows for a direct hydrologic surface connection 
between the wetlands and the water in a typical year. Id. As with the 
tributary definition, the NWPR stated that the definition of ``adjacent 
wetlands'' is ``informed by science.'' Id. at 22314. Yet the NWPR's 
limits on the scope of protected wetlands to those that touch or 
demonstrate evidence of a regular surface water connection to other 
jurisdictional waters were counter to the ample scientific information 
before the agencies demonstrating the effects of wetlands on downstream 
waters when they have other types of surface connections, such as 
wetlands that overflow and flood jurisdictional waters or wetlands with 
less frequent surface water connections due to long-term drought; 
wetlands with shallow subsurface connections to other protected waters; 
or other wetlands proximate to jurisdictional waters. See Rapanos, 547 
U.S. at 786 (Kennedy, J., concurring in the judgment) (``[g]iven the 
role wetlands play in pollutant filtering, flood control, and runoff 
storage, it may well be the absence of a hydrologic connection (in the 
sense of interchange of waters) that shows the wetlands' significance 
for the aquatic system.'') Id. at 786.
    Indeed, the overwhelming scientific information before the agencies 
weighs decisively against proposing the definition of ``adjacent 
wetlands'' in the NWPR. Available scientific information demonstrates 
the significant effects of categories of newly excluded wetlands on the 
chemical, physical, and biological integrity of downstream traditional 
navigable waters. For example, whereas the NWPR provided that wetlands 
flooded by jurisdictional waters are only protected if the flooding 
occurs in a ``typical year,'' the Science Report stated that wetlands 
that are ``rarely'' or ``infrequently'' flooded by streams and rivers 
can be ``highly connected'' to those waters and have ``long-lasting 
effects'' on them. Science Report at 4-39. The Science Report noted 
that effects ``critical to maintaining the health of the river'' result 
from large floods that provide ``infrequent connections'' with more 
distant wetlands. Id. Reflecting these concerns, the October 16, 2019 
SAB Draft Commentary on the proposed NWPR stated that the narrow 
definition of ``adjacent wetlands'' in the NWPR as it was proposed 
``departs from established science.'' The agencies have weighed these 
statements and in light of the information about the importance of 
``infrequently'' flooded wetlands to downstream waters, the agencies 
believe that the NWPR's exclusion of wetlands that lack the limited, 
specific types of surface water connections to other jurisdictional 
waters in a typical year lacked scientific support.
    The SAB's assessment of the NWPR proposal recognized that the 
proposed rule was not consistent with the scientific information in the 
record, including the Draft Science Report that the SAB had previously 
reviewed. SAB Commentary on the Proposed Rule Defining the Scope of 
Waters Federally Regulated Under the Clean Water Act (February 27, 
2020). The 2020 SAB Commentary emphasized that the proposal does not 
``fully incorporate the body of science on connectivity'' that the SAB 
had reviewed in the Draft Science Report and offers ``no scientific 
justification for disregarding the connectivity of waters accepted by 
current hydrological science.'' Id. at 2.
    The NWPR stated that the ``agencies' decisions in support of this 
final rule have been informed by science.'' 85 FR 22288, April 21, 
2020. For example, the scientific information that the NWPR cited as a 
basis for excluding ephemeral tributaries is the concept of a 
``connectivity gradient.'' Id., citing the SAB Review. The NWPR 
referred to the SAB Review's recommendation that the agencies recognize 
that connectivity occurs along a gradient allowing for variation in 
chemical, physical, and biological connections. Id., citing the SAB 
Review at 3. The NWPR asserted that there is a ``decreased'' likelihood 
that waters with ``less than perennial or intermittent'' flow, i.e., 
ephemeral streams, will affect the chemical, physical, and biological 
integrity of downstream waters. Id.
    Upon careful review, however, the agencies have concluded that the 
NWPR's conclusion takes the SAB's recommendation out of context and is 
inconsistent with the information in the SAB Review as a whole. The 
agencies recognize that the SAB explained that the connectivity 
gradient the NWPR cited was just a hypothetical example \32\ meant to 
illustrate just one aspect of connectivity--hydrological, or physical 
connectivity--and sheds no light on the many other ways that features 
connect to and affect downstream waters. According to the SAB itself, 
the only scientific information the agencies provided in support of 
categorically excluding ephemeral features does not fully represent the 
discussion in the cited SAB Review and runs counter to key elements of 
the scientific record before the agencies. Id.
---------------------------------------------------------------------------

    \32\ The figure cited is captioned in part as ``Hypothetical 
illustration of connectivity gradient and potential consequences to 
downstream waters.'' SAB Review at 54 (emphasis added). Nowhere in 
its review does the SAB review indicate that this is the actual or 
only connectivity gradient.
---------------------------------------------------------------------------

    The NWPR also stated that the line it draws between regulated and 
non-regulated wetlands, which excludes large categories of wetlands 
previously covered by the Act, is ``informed by science.'' 85 FR 22314, 
April 21, 2020. The NWPR cited statements from the SAB Review to the 
effect that wetlands situated alongside other waters are likely to be 
connected to those waters, whereas ``those connections become less 
obvious'' as the distance ``increases.'' Id., citing the SAB Review at 
55; see also id. at 22314, citing the SAB Review at 60 (``[s]patial 
proximity is one important determinant [influencing the connections] 
between wetlands and downstream waters''). In addition, the NWPR cited 
a statement in the Science Report that explained, ``areas that are 
closer to rivers and streams have a higher probability of being 
connected than areas farther away.'' Id. at 22314, citing the Science 
Report at ES-4.\33\
    Despite these citations, the NWPR's definition of adjacent is not 
based on proximity, but instead on factors that are distinct from 
proximity--e.g., a ``direct hydrologic connection,'' or a ``continuous 
surface [water] connection.'' See id. at 22340. Thus, the NWPR's 
definition of ``adjacent wetlands'' may exclude wetlands a dozen feet 
away from jurisdictional waters (therefore proximate under any 
reasonable interpretation of the term) if they are separated by a levee 
that does not convey flow in a typical year, but include wetlands much 
further away so long as they are inundated by flooding from the 
jurisdictional water in a typical year.
c. The NWPR Is Difficult To Implement and Yields Inconsistent Results
    In addition to the above concerns, the agencies' experience 
implementing the NWPR for over a year made clear that foundational 
concepts underlying much of the NWPR are confusing and difficult to 
implement in the way the NWPR required. While any rule that draws lines 
between jurisdictional waters and

[[Page 69410]]

non-jurisdictional waters will involve some implementation challenges, 
the agencies have found the challenges imposed by the NWPR to be 
impracticable in important respects. Based on the agencies' experience, 
the NWPR does not ``provide[] clarity and predictability for Federal 
agencies, States, Tribes, the regulated community, and the public.'' 
See 85 FR 22252, April 21, 2020. More importantly, the challenges that 
the NWPR imposes to establish jurisdiction for features that it appears 
to define as jurisdictional and that significantly affect the integrity 
of downstream waters further undermine the NWPR's viability as an 
alternative to the proposed rule.
i. ``Typical Year'' Metric
    The ``typical year'' is a concept fundamental to many of the NWPR's 
definitions. Id. at 22273. Under the rule, tributaries and lakes, 
ponds, and impoundments of jurisdictional waters are only 
jurisdictional if they have certain surface water connections with a 
traditional navigable water or territorial sea at least once in a 
typical year. 33 CFR 328.3(c)(6), (12). Two categories of wetlands only 
meet the adjacency test for jurisdiction if they have a surface water 
connection with other jurisdictional waters once in a typical year. Id. 
at (c)(1). As a scientific matter, the concept of ``typical year 
conditions,'' including precipitation normalcy, may be relevant to 
ensuring that certain surface water connections in natural streams are 
not being observed under conditions that are unusually wet or dry. In 
terms of implementation, the concept of precipitation normalcy is valid 
in certain contexts, such as to inform determinations as to the 
presence of a wetland. However, in many important contexts, available 
tools, including the tools the NWPR recommends, cannot reliably 
demonstrate the presence of surface water connections in a typical 
year, which are a necessary element of most categories of 
jurisdictional waters under the NWPR. However, ``typical year 
conditions'' are often irrelevant to the extent of flow in many human-
altered streams, including effluent-dependent streams, and the NWPR did 
not explain why human-altered hydrology should be subject to the same 
typical year requirement as natural streams. These challenges undermine 
the NWPR's claim that it enhances the ``predictability and consistency 
of Clean Water Act programs . . .'' See 85 FR 22250, April 21, 2020.
    Identifying the presence of a surface water connection in a typical 
year can be difficult and sometimes impossible, as such connections are 
often not apparent from visual field observation alone. For example, on 
the day of a visit to an intermittent stream that flows only several 
months or several weeks a year, it is very unlikely that an observer 
would see a surface water connection to a downstream jurisdictional 
water. Similarly, though many ponds or wetlands may be frequently 
inundated, those in arid areas may be inundated only a few times every 
year, and sometimes the inundation occurs on a single day or within a 
matter of hours. While these waters satisfy the NWPR's jurisdictional 
test, agency staff would probably not be able to determine that they 
do, given how unlikely they would be to observe it. The difficulty of 
finding in a field visit the direct hydrologic connections under any 
interpretation of typical year permissible under the NWPR is 
exacerbated by the fact that the NWPR discourages reliance on field 
indicators. See, e.g., id. at 22292 (``The agencies . . . conclude that 
physical indicators of flow, absent verification of the actual 
occurrence of flow, may not accurately represent the flow 
classifications required for tributaries under this rule.'').
    Given the insufficiency of visual field observations to assess the 
presence of a surface water connection as specified in the NWPR, agency 
staff must often expend substantial time and resources to try to obtain 
ancillary data to determine flow conditions at a particular site in a 
typical year. Hydrologic modeling tools and advanced statistical 
analyses could be employed where sufficient flow data are available, 
but often data needed to conduct such an analysis is limited or lacking 
altogether, especially for smaller streams. Few streams across the 
country have hydrologic gages that continuously measure flow, as most 
such gages are located on larger rivers with perennial flow.
    For the same reasons that agency staff are unlikely to witness the 
specific surface water connections required under the NWPR during a 
site visit in dry regions or during the dry season, available aerial 
photographs, which are often taken just once per year or once every 
other year, are also very unlikely to capture evidence of this surface 
water connection between a stream and a downstream traditional 
navigable water or territorial sea. High-resolution satellite imagery 
can potentially provide additional coverage, but availability and 
usability vary across the country, depending on access, update 
intervals, cloud cover, and land cover (i.e., vegetation or trees that 
obscure aerial views of stream channels, requiring the use of advanced 
tools to detect features of interest or the presence of water). 
Moreover, as the NWPR acknowledges, ``characteristics of tributaries 
may not be visible in aerial photographs'' taken during periods of 
``high shrub or tree cover,'' 85 FR 22299, April 21, 2020. New 
satellites are expected to surmount some of these issues in the future, 
but as this information is not yet available, regulators could not use 
it to inform jurisdictional decisions under the NWPR. Although any 
definition of ``waters of the United States'' requires the use of 
remote tools like interpretation of aerial or satellite imagery, the 
NWPR made it more challenging to use these resources because of that 
rule's typical year criteria and the burden of proof to demonstrate 
that the requirement is met.
    The same difficulties create challenges in detecting surface 
hydrologic connections that meet the NWPR's definition of ``adjacent 
wetlands'' or ``lakes and ponds, and impoundments of jurisdictional 
waters.'' Demonstrating that a wetland, lake, pond, or impoundment is 
inundated by flooding once in a typical year would require a field 
visit or a high-quality aerial photograph or satellite image coinciding 
with the exact time that the hydrologic connection (flooding) occurs 
from a tributary to a wetland, lake, pond, or impoundment. The NWPR's 
standard of inundation by flooding in a typical year is not tied to any 
more commonly calculated flood interval, such as flood recurrence 
intervals, and the agencies are not aware of any tool capable of 
collecting the type of inundation data the NWPR requires. Determining 
that inundation by flooding occurs in a typical year is therefore 
extremely difficult, and sometimes impossible. Demonstrating that an 
artificial feature allows for a direct hydrologic surface connection 
between a wetland and a tributary in a typical year poses similar 
obstacles, requiring either auspiciously timed field visits, aerial 
photography, or high-resolution satellite imagery, or data that the 
agencies may not be able to access, such as construction plans or 
operational records for an artificial levee.
    The NWPR suggests the agencies ``will generally use'' precipitation 
data from the National Oceanic and Atmospheric Administration (NOAA) to 
help determine the presence of a surface water connection in a typical 
year, see 85 FR 22274, April 21, 2020, but the methodology described in 
the NWPR preamble for determining precipitation in a typical year makes 
it difficult to use these data to inform jurisdiction. NOAA 
precipitation totals over the three

[[Page 69411]]

months prior to a site observation are compared to precipitation totals 
observed over the preceding 30 years to determine if rainfall was 
wetter than normal, drier than normal, or normal (``typical''). Using 
the methodology in the preamble of the NWPR, only 40% of observations 
over a rolling 30-year period of record are considered ``normal,'' 
while 30% of observations are considered to be ``wetter than normal'' 
and 30% of observations are considered to be ``drier than normal.'' If 
surface water flow was observed during normal or dry conditions, the 
agencies can have higher confidence that the surface water observations 
represent flow in a ``typical year.'' However, if flow was observed 
during the 30% of conditions that are ``wetter than normal,'' the 
surface water observations do not reveal whether flow would occur 
during a typical year. And if flow was not observed, precipitation data 
from the previous three months do not indicate whether flow might occur 
in that particular water feature under typical year conditions at a 
different point in the year. Therefore, if a site visit is conducted 
when surface water flow is not present, the agencies' suggested 
approach for evaluating whether a feature meets the typical year test 
often does not provide meaningful and relevant information upon which 
the agencies could reasonably rely to make accurate determinations of 
jurisdiction. Under any regulatory regime, the agencies use a weight of 
evidence approach to determine jurisdiction, but the NWPR typical year 
requirement places onerous and in many instances arbitrary constraints 
on the data that can be used as evidence.
    Use of NOAA precipitation data to assess whether surface water flow 
occurs in a typical year for purposes of the NWPR presents other 
implementation challenges. The data rely on reports from weather 
stations that are sometimes at a different elevation from the site in 
question, or far away from the site, so that their indications as to 
whether precipitation at a given site is normal, wetter than normal, or 
drier than normal can be inaccurate. More importantly, the typical year 
concept as applied to the NWPR does not account for the increasing 
number of recurrent heatwaves, droughts, storms, and other extreme 
weather events in many parts of the country, which can have profound 
impacts on local and regional streamflow. Although the concept of 
``typical year'' in the NWPR factors in long-term climatic changes over 
time to some degree by considering a thirty-year rolling period of 
data, see 33 CFR 328.3(c)(13), the NWPR does not allow the agencies 
flexibility to consider other time intervals when appropriate to 
reflect effects of a rapidly changing climate, including positive 
trends in temperature, increasing storm events, and extended droughts. 
In response to more rapid recent changes in climate, NOAA has developed 
alternative approaches for estimating climate normals, including 
seasonal averages computed using shorter, annually-updated averaging 
periods for temperature (10-year seasonal average) and total 
precipitation (15-year seasonal average). The rolling thirty-year 
approach to determining typical year in the NWPR does not allow the 
agencies to use these updated methods.
    The NWPR notes that the agencies can look to sources of information 
other than site visits, aerial photographs, and precipitation data to 
assess whether a feature has surface water flow in a typical year. It 
identifies the Web-based Water-Budget Interactive Modeling Program, 
Climate Analysis for Wetlands Tables, and the Palmer Drought Severity 
Index, 85 FR 22275, April 21, 2020, but all of these only look at 
climate-related conditions generally and have well documented 
limitations. These methods, which provide information useful in many 
other contexts, often do not specifically answer the jurisdictional 
questions established by the NWPR. For example, they do not address 
whether surface water flow might connect a particular stream to a 
downstream traditional navigable water or territorial sea, whether a 
particular wetland is inundated by or connected to a jurisdictional 
water as required under the NWPR, or how uncertainties associated with 
their application at different locations and in different months affect 
the accuracy of condition estimates. Precipitation is an important 
factor but other information is also relevant to streamflow and surface 
water connections in particular waters, including the abundance of and 
contributions of flow from wetlands, upgradient streams, and open 
waters in the watershed, evapotranspiration rates, water withdrawals 
including groundwater pumping, and other climatic conditions. Yet 
collecting this information from a variety of sources and interpreting 
it can be extremely time- and resource-intensive and may require 
special expertise that in many cases may not be feasible given 
available agency staff and resources. While the agencies have 
substantial experience using a weight of evidence approach to determine 
jurisdiction, the ``typical year'' requirement makes it significantly 
more difficult to interpret available data and narrows the scope of 
data that can be used to determine jurisdiction.
    Finally, the challenges presented by determining the presence of 
surface water flow in a typical year are even greater when evaluating a 
tributary at a distance from the downstream traditional navigable water 
or territorial sea. Even streams that flow perennially or 
intermittently often travel many miles prior to reaching the closest 
traditional navigable water or territorial sea, meaning many downstream 
reaches may need to be assessed. Under the NWPR, any ephemeral reaches 
along that pathway that do not carry surface water flow once in a 
typical year would render all upstream waters non-jurisdictional. Id. 
at 22277. The need to assess lengthy tributary systems pursuant to this 
provision of the rule imposes an extraordinarily high burden of proof 
on the agencies to assess surface water flow in a typical year along 
the flow path, and the longer the pathway, the less feasible the 
analysis.
ii. Determining Adjacency
    The NWPR provides that wetlands are ``adjacent'' when they: (1) 
Abut a traditional navigable water or territorial sea; a tributary; or 
a lake, pond, or impoundment of a jurisdictional water; (2) are 
inundated by flooding from one of these waters in a typical year; (3) 
are physically separated from one of these waters only by a natural 
berm, bank, dune, or similar natural feature; or (4) are physically 
separated from one of these waters only by an artificial dike, barrier, 
or similar artificial structure so long as that structure allows for a 
direct hydrologic surface connection between the wetlands and the water 
in a typical year, such as through a culvert, flood or tide gate, pump, 
or similar artificial feature. Id. at 22338; 33 CFR 328.3(c)(1). In 
practice, agency staff have found several of these criteria for 
adjacency extremely difficult to implement in certain circumstances.
    First, agency staff have found it difficult to distinguish between 
natural and artificial barriers for purposes of determining adjacency. 
The NWPR for the first time establishes separate tests for adjacency 
depending on whether the barrier between the wetland and jurisdictional 
water is ``natural'' or ``artificial''; if a barrier is artificial, it 
must allow for a direct hydrological surface connection in a typical 
year in order for a wetland to be adjacent, whereas no such showing is 
necessary for natural barriers. 33 CFR 328.3(c)(1)(iv). However, many 
barriers between wetlands and jurisdictional

[[Page 69412]]

waters were built decades or even a century earlier, and determining 
whether they were originally natural or artificial can be extremely 
challenging, even if inspected in person, as artificial features that 
are left alone often naturalize over time. It sometimes requires 
extensive research into historical records, and those records may not 
be available at all. Furthermore, some barriers may be both artificial 
and natural. Artificial levees and other barriers are frequently built 
on top of natural berms. Given the distinct regulatory consequences 
that flow from whether a barrier is ``artificial'' or ``natural,'' the 
NWPR requires the agencies to make determinations that are difficult or 
in some cases not possible.
    The artificial barrier provision also leads to absurd results. For 
example, under the fourth way to meet the adjacency definition, a 
wetland may be jurisdictional if it is separated from a jurisdictional 
water by an artificial structure, such as a levee, that allows for a 
direct hydrologic surface connection in a typical year through a 
culvert. However, the same wetland would not be jurisdictional if there 
was no levee present, even if there was a direct hydrological surface 
connection in a typical year through a culvert (assuming the wetland 
did not meet another criterion for adjacency). The NWPR therefore 
establishes that certain wetlands with a direct hydrologic surface 
connection to a jurisdictional water are only jurisdictional due to the 
presence of an artificial barrier. This discrepancy bears no 
relationship to the actual connections between the features at issue 
and makes no scientific or practical sense.
    Finally, the provision establishing that a wetland is ``adjacent'' 
if a jurisdictional water inundates it by flooding in a typical year is 
also extremely difficult to implement. See 33 CFR 328.3(c)(1)(ii). 
Inundation by flooding in a typical year is not a metric that is 
normally recorded either by implementing agencies or the regulated 
community. Available models generally focus on flood recurrence 
intervals, which do not necessarily correspond to the likelihood of 
inundation by flooding in a given or typical year. Indeed, the NWPR 
acknowledges that inundation by flooding in a typical year could 
correspond to a variety of flood recurrence intervals depending on 
location, climate, season, and other factors. 85 FR 22311, April 21, 
2020. Given the absence of existing records of inundation by flooding, 
determining whether inundation by flooding has occurred in a typical 
year is extremely difficult in many circumstances.
    Compounding the challenge, the NWPR provides that wetlands can be 
jurisdictional if they are inundated by flooding from a jurisdictional 
water in a typical year--but inundation in the other direction, from 
the wetlands to the jurisdictional water, is not grounds for 
jurisdiction. Not only is there no compelling scientific or legal basis 
for distinguishing between inundation of the wetland as opposed to 
inundation from the wetland, see Riverside Bayview, 474 U.S. at 134 
(upholding the Corps' assertion of jurisdiction over ``wetlands that 
are not flooded by adjacent waters [but] may still tend to drain into 
those waters''), but determining whether the limited available 
photographs or other evidence of inundation reflects flooding in one 
direction as opposed to another compounds the difficulty in evaluating 
whether this standard is met. The same challenges apply to determining 
whether lakes, ponds, or impoundments of jurisdictional waters are 
inundated by flooding in a typical year, one basis for demonstrating 
Clean Water Act jurisdiction over these features. 85 FR 22338, April 
21, 2020; 33 CFR 328.3(c)(vi).
iii. Ditches
    Among other requirements, the NWPR provides that a ditch \34\ is 
jurisdictional as a tributary if it was originally built in a tributary 
or adjacent wetland, as those terms are defined in the NWPR, and 
emphasizes that the agencies bear the burden of proof to determine that 
a ditch was originally constructed in a tributary or adjacent wetland. 
33 CFR 328.3(a)(2), (c)(12); 85 FR 22299, April 21, 2020. In other 
words, in order to find a ditch jurisdictional, the agencies must 
demonstrate that a ditch was (1) originally constructed in a stream (2) 
that, at the time of construction, had perennial or intermittent flow 
and (3) a surface water connection to a downstream traditional 
navigable water or territorial sea (4) in a ``typical year.'' 
Alternatively, the agencies must show that a ditch was (1) originally 
constructed in a wetland (2) that either abutted or had certain surface 
hydrologic connections to a jurisdictional water (3) in a ``typical 
year,'' in order to demonstrate that the ditch is jurisdictional. 
Americans have been building ditches, straightening streams, and 
draining wetlands for hundreds of years. Therefore, to determine 
whether a ditch is jurisdictional under the NWPR, the agencies must 
address all of the implementation challenges discussed in the preceding 
sections involved in determining surface water connections and wetland 
adjacency in a typical year--but often for ditches built fifty, one 
hundred, or several hundred years ago. To the extent that sparse 
evidence is available to demonstrate a surface water connection in a 
typical year for tributaries using tools available today, evidence is 
even more difficult to find when looking so far back in time. States 
have approached the agencies seeking assistance in assessing the 
jurisdictional status of ditches, but the agencies are often unable to 
provide significant help given the burdens imposed by the NWPR's ditch 
definition.
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    \34\ Ditches perform many of the same functions as natural 
tributaries. For example, like natural tributaries, ditches that are 
part of the stream network convey water that carries nutrients, 
pollutants, and other constituents, both good and bad, to downstream 
traditional navigable waters, interstate waters, and the territorial 
seas.
---------------------------------------------------------------------------

    The NWPR also provides that ditches are jurisdictional if they 
relocate a tributary, as that term is defined in the rule, 85 FR 22341, 
April 21, 2020, 33 CFR 328.3(a)(2), (c)(12), but this standard as 
defined is also often extremely difficult to assess. The NWPR explains 
that a relocated tributary is ``one in which an entire portion of the 
tributary may be moved to a different location.'' 85 FR 22290, April 
21, 2020. In other words, the NWPR appears to require a ditch to divert 
100% of the tributary's flow to meet the ``relocate a tributary'' test. 
While prior rules have defined relocated tributaries as jurisdictional, 
the requirement that the entire portion be relocated is new and has 
created significant implementation challenges. As a practical matter, 
when a tributary is relocated it often reroutes just a portion to the 
ditch. Assessing whether a ditch relocated 100% of a tributary's flow, 
however, as opposed to 80% or 50% of its flow, is extremely difficult 
and may not be possible in some circumstances. By establishing a 
jurisdictional standard that is extremely difficult to meet, the NWPR 
effectively removes from the protections of the Clean Water Act large 
numbers of ditches that function as tributaries and that significantly 
affect the integrity of downstream traditional navigable waters, 
interstate waters, and the territorial seas. As is the case with 
tributaries, lakes and ponds, impoundments, and wetlands, the NWPR's 
impracticable approach to ditches makes it extremely difficult to find 
that many waters subject to the NWPR are actually jurisdictional, 
further undermining the viability of the

[[Page 69413]]

NWPR as an alternative to the proposed rule.
d. The NWPR Has Significantly Reduced Clean Water Act Protections Over 
Waters
    The failure of the NWPR to achieve the objective of the Act, as 
well as its inconsistency with science and the challenges it presents 
in implementation, have had real-world consequences. The agencies have 
found that substantially fewer waters are protected by the Clean Water 
Act under the NWPR compared to previous rules and practices. It is 
important to note that the definition of ``waters of the United 
States'' affects most Clean Water Act programs designed to restore and 
maintain water quality--including not only the NPDES and dredged and 
fill permitting programs, but water quality standards, impaired waters 
and total maximum daily loads, oil spill prevention, preparedness and 
response programs, and the state and tribal water quality certification 
programs--because such programs apply only to ``waters of the United 
States.'' While the NWPR was enacted with the expressed intent to 
decrease the scope of federal jurisdiction, the agencies now believe 
the actual decrease in water resource protections has been more 
pronounced than the qualitative predictions in the NWPR preamble and 
supporting documents anticipated and acknowledged to the public. This 
data supports the agencies' conclusion that the NWPR is not a suitable 
alternative to the proposed rule.
i. Jurisdictional Determination and Permitting Data Show a Large Drop 
in the Scope of Waters Protected Under the Clean Water Act.
    Through an evaluation of jurisdictional determinations completed by 
the Corps between 2016 and 2021,\35\ EPA and the Army have identified 
consistent indicators of a substantial reduction in waters protected by 
the NWPR (see Technical Support Document section III.B.ii for 
additional discussion on methods and results of the agencies' 
analyses). These indicators include an increase in the number and 
proportion of jurisdictional determinations completed where aquatic 
resources were found to be non-jurisdictional, an increase in 
determinations made by the Corps that no Clean Water Act section 404 
permit is required for specific projects, and an increase in requests 
for the Corps to complete approved jurisdictional determinations (AJDs) 
rather than preliminary jurisdictional determinations (PJDs), which 
treat a feature as jurisdictional. These trends all reflect the narrow 
scope of jurisdiction in the NWPR's definitions. Additionally, the 
agencies believe these indicators account for only a fraction of the 
NWPR's impacts, because many project proponents do not need to seek any 
form of jurisdictional determinations for waters that the NWPR 
categorically excludes, such as ephemeral streams, and the Corps does 
not have purview over such projects and does not track them. A closer 
look at each of these indicators will help demonstrate some of the more 
pronounced impacts of the NWPR on foundational waters of this country 
than was identified for the public in the NWPR and its supporting 
documents. As explained in detail above, when a water falls outside the 
scope of the Act, that means, among other things, that no federal water 
quality standards will be established, and no federal permit will be 
required to control the discharge of pollutants or fill into such 
waters. And by virtue of the fact that the NWPR's scope means that for 
many waters entities do not even need to seek a jurisdictional 
determination, it is impossible to fully understand the scope of 
degradation to foundational waters caused by the NWPR's definition.
---------------------------------------------------------------------------

    \35\ A jurisdictional determination is a written Corps 
determination that a water is subject to regulatory jurisdiction 
under section 404 of the Clean Water Act (33 U.S.C. 1344) or a 
written determination that a water is subject to regulatory 
jurisdiction under section 9 or 10 of the Rivers and Harbors Act of 
1899 (33 U.S.C. 401 et seq.). Jurisdictional determinations are 
identified as either preliminary or approved, and both types are 
recorded in determinations through an internal regulatory management 
database, called Operation and Maintenance Business Information 
Link, Regulatory Module (ORM2). This database documents Department 
of the Army authorizations under Clean Water Act section 404 and 
Rivers and Harbors Act section 10, including permit application 
processing and jurisdictional determinations. This database does not 
include aquatic resources that are not associated with a 
jurisdictional determination or alternatives to jurisdictional 
determinations (such as delineation concurrences or ``No 
jurisdictional determination required'' findings, where the Corps 
finds that a jurisdictional determination is not needed for a 
project), or permit request or resource impacts that are not 
associated with a Corps permit or enforcement action. An approved 
jurisdictional determination (AJD) is an official Corps document 
stating the presence or absence of ``waters of the United States'' 
on a parcel or a written statement and map identifying the limits of 
``waters of the United States'' on a parcel. A preliminary 
jurisdictional determination (PJD) is a non-binding written 
indication that there may be ``waters of the United States'' on a 
parcel; an applicant can elect to use a PJD to voluntarily waive or 
set aside questions regarding Clean Water Act jurisdiction over a 
particular site and thus move forward assuming all waters will be 
treated as jurisdictional without making a formal determination.
---------------------------------------------------------------------------

    Consistent with Executive Order 13990, EPA and Army staff have 
reviewed jurisdictional determinations as recorded in the Corps' 
internal regulatory management database, referred to as the ORM2 
database (see supra note 30), to identify any noticeable trends in 
jurisdictional determinations under the past recent rules defining 
``waters of the United States.'' The agencies found within the AJDs 
completed under the NWPR, the probability of finding resources to be 
non-jurisdictional also increased precipitously. Of the 9,399 AJDs 
completed by the Corps during the first twelve months in which the NWPR 
was in effect,\36\ the agencies found approximately 75% of AJDs 
completed had identified non-jurisdictional water resources and 
approximately 25% of AJDs completed identified jurisdictional 
waters.\37\ Conversely, when the 1986 regulations and applicable 
guidance were in effect during the previous five years (including 
following the 2019 recodification of those regulations), significantly 
more jurisdictional waters were identified in AJDs than compared to the 
first twelve months of the NWPR. During similar 1-year calendar 
intervals when the 1986 regulations and applicable guidance were in 
effect, approximately 27% to 45% of AJDs completed identified non-
jurisdictional aquatic resources, with percentages varying between each 
of the different periods, and 55% to 72% of AJDs identified 
jurisdictional resources.\38\

[[Page 69414]]

The change from a range of 27% to 45% non-jurisdictional AJD findings 
prior to the NWPR to 75% non-jurisdictional findings following issuance 
of the NWPR indicates that significantly fewer waters are protected by 
the Clean Water Act under the NWPR (see Technical Support Document 
section III.B.ii for additional discussion).
---------------------------------------------------------------------------

    \36\ These AJDs were completed by the Corps between the NWPR's 
effective date of June 22, 2020 and June 21, 2021.
    \37\ This excludes drylands and waters identified as being 
jurisdictional only under section 10 of the Rivers and Harbors Act. 
In addition, under the NWPR, a single AJD in the Corps' database can 
include both affirmative and negative jurisdictional determinations. 
Under prior regulatory regimes, the Corps' database was structured 
such that a single AJD could be either affirmative, or negative, but 
not both. To account for this change in the structure of the 
database, a NWPR jurisdictional determination that includes both 
affirmative and negative jurisdictional resources was normalized and 
counted as two separate AJDs, one affirmative and one negative. The 
total number of AJDs considered after this process was carried out 
was 9,399. Prior to this normalization, the total number of AJDs 
considered was 7,769. More details on this can be found in the 
Technical Support Document section III.B.ii.
    \38\ The time periods evaluated were June 22, 2016 to June 21, 
2017; June 22, 2017 to June 21, 2018; and December 23, 2019 to June 
21, 2020. The date ranges here constitute periods of time when the 
1986 regulations (including the 2019 Repeal Rule's recodification of 
those regulations) and applicable guidance were in effect 
nationally. Because the proposed rule is marking a return to prior 
longstanding practice, 2015 Clean Water Rule determinations were 
left out of this analysis.
---------------------------------------------------------------------------

    When evaluating the effect of the NWPR on the number of 
jurisdictional individual aquatic resources (as opposed to the AJDs 
completed), the agencies found a similar significant reduction in 
protections. Within the first twelve months of implementation of the 
NWPR, the Corps documented the jurisdictional status of 48,313 
individual aquatic resources or water features through AJDs completed 
between June 22, 2020, and June 21, 2021; of these individual aquatic 
resources, approximately 75% were found to be non-jurisdictional by the 
Corps. More specifically, 70% of streams and wetlands evaluated were 
found to be non-jurisdictional, including 11,044 ephemeral features 
(mostly streams) and 15,675 wetlands that did not meet the NWPR's 
revised adjacency criteria (and thus are non-jurisdictional under the 
NWPR). Ditches were also frequently found to be non-jurisdictional 
(4,706 individual exclusions), which is likely the result of the 
narrowed definition of a relocated tributary under the NWPR. By 
comparison, only 45% of aquatic resources were found to be non-
jurisdictional during similar year-long calendar intervals between 2016 
and 2020 under the 1986 regulations implemented consistent with Supreme 
Court case law.\39\ The agencies anticipate that this increase in non-
jurisdictional determinations, to a level of approximately 75% of water 
bodies being non-jurisdictional under the NWPR as opposed to only 45% 
under the prior regulations, would reduce the integrity of the nation's 
waters.
---------------------------------------------------------------------------

    \39\ Based on the average annual percentage of non-
jurisdictional findings.
---------------------------------------------------------------------------

    Of particular concern to the agencies is the NWPR's 
disproportionate effect on arid regions of the country, which are 
dominated by ephemeral stream systems. The Corps' data show that in New 
Mexico, of the 263 streams assessed via AJDs in the first twelve months 
of implementation of the NWPR (i.e., between June 22, 2020, to June 21, 
2021), 100% were found to be non-jurisdictional ephemeral 
resources.\40\ In Arizona, of the 1,525 streams assessed in AJDs in the 
first year of implementation of the NWPR, 1,518, or 99.5%, were found 
to be non-jurisdictional ephemeral resources. While the Corps found 
high percentages of streams in Arizona to be non-jurisdictional between 
2016 and 2020, the NWPR resulted in a ten-fold increase in the total 
number of individual resources documented as non-jurisdictional in 
AJDs.
---------------------------------------------------------------------------

    \40\ These non-jurisdictional ephemeral resources are 
predominantly ephemeral streams, but a small portion may be swales, 
gullies, or pools.
---------------------------------------------------------------------------

    For example, the average annual number of individual stream 
resources considered in AJDs in Arizona between 2016-2020 was 147 (of 
which 138 were determined non-jurisdictional), compared to 1,525 stream 
reaches assessed under the NWPR (of which 1,521 were determined non-
jurisdictional accounting for all exclusions). The number of stream 
reaches assessed in Arizona also dominated the number of evaluations 
completed nationally under the NWPR, which is incongruent with the 
geographic extent of water resources in this country. The number of 
stream reaches assessed in Arizona constituted 9% of the total stream 
reaches assessed nationally and 13% of the ephemeral reaches assessed 
nationally over the first twelve months in which the NWPR was 
implemented.\41\ This increase in the number of streams assessed and 
found to be non-jurisdictional in Arizona under the NWPR highlights the 
disproportionate impacts this rule had on water resource protection in 
this state and in similar arid regions of this country.
---------------------------------------------------------------------------

    \41\ There were a total of 16,787 stream reaches assessed via 
AJDs nationwide between June 22, 2020 and June 21, 2021.
---------------------------------------------------------------------------

    The number of individual stream reaches considered under PJDs also 
declined precipitously in these states under the NWPR, while many more 
streams were evaluated and determined to be non-jurisdictional through 
AJDs. As mentioned previously, project proponents who request an AJD 
obtain an official Corps document stating the presence or absence of 
``waters of the United States'' on a parcel or a written statement and 
map identifying the limits of ``waters of the United States'' on a 
parcel. In contrast, an applicant can elect to use a PJD to voluntarily 
waive or set aside questions regarding Clean Water Act jurisdiction 
over a particular site and thus move forward assuming all waters will 
be treated as jurisdictional without making a formal determination. 
There are time savings and sometimes cost savings associated with 
requesting a PJD in lieu of an AJD. However, proportionally fewer PJDs 
being requested under the NWPR indicate that fewer project proponents 
are requesting that aquatic resources on their project site be treated 
as if they are jurisdictional.
    In Arizona, the annual average number of individual stream reaches 
considered under PJDs and similar alternatives to AJDs between 2016 to 
2020 was 941, while under the NWPR in 2020-2021 it was only 45.\42\ 
When looking at the total number of individual streams reaches over 
time, under the NWPR Arizona experienced an approximate 95% decrease in 
individual stream reaches being considered via PJDs and a 9-fold 
increase in individual stream reaches being considered via AJDs, 
compared to pre-2015 regulatory practice. Similar metrics for New 
Mexico show an 84% decrease in individual streams being considered via 
PJDs and a 28-fold increase in individual streams being considered via 
AJDs under the NWPR. Based on averages for non-jurisdictional streams 
from 2016-2020 compared to non-jurisdictional streams under the NWPR, 
there has been a 10-fold increase in non-jurisdictional findings for 
streams in Arizona and a 36-fold increase in non-jurisdictional 
findings for streams in New Mexico following implementation of the 
NWPR. Compounding resource losses, eliminating these streams from 
jurisdiction under the NWPR also typically eliminated jurisdiction over 
wetlands which otherwise might meet adjacency criteria.
---------------------------------------------------------------------------

    \42\ The AJD values associated with the NWPR fall outside of the 
95% confidence interval calculated for annual data from 2016-2020. 
Note that in New Mexico and Arizona, the 2015 Clean Water Rule was 
never implemented due to litigation stays. The PJD values associated 
with the NWPR do not fall outside of the 95% confidence interval 
calculated for annual data from 2016-2020; this is likely a product 
of scale. See the Technical Support Document section III.B.ii for 
more analysis.
---------------------------------------------------------------------------

    The NWPR also significantly reduced the number of Clean Water Act 
section 404 permits required for dredging and filling activity 
nationwide. The Corps has identified at least 368 projects from June 
22, 2020 to June 21, 2021 through its ORM2 database that would have 
needed a Clean Water Act section 404 permit pre-NWPR, but no longer did 
under the NWPR's definition of ``waters of the United States.'' \43\ 
Moreover, in comparing 2020-2021 to similar annual data from 2016 to 
2020 from

[[Page 69415]]

implementation of the 1986 regulations consistent with Supreme Court 
case law, there was on average an increase of over 100% in the number 
of projects determined to not require section 404 permits under the 
Clean Water Act due to activities not occurring in ``waters of the 
United States'' or activities occurring in waters that were deemed no 
longer ``waters of the United States'' due to the NWPR. The number of 
projects that did not require a section 404 permit under the NWPR was 
likely much greater than these numbers indicate because project 
proponents did not need to notify the Corps if they had already 
received an AJD that concluded waters in the review area were not 
``waters of the United States,'' and because many project proponents 
may not have sought a jurisdictional determination or applied for a 
permit at all if they believed their aquatic resources were non-
jurisdictional under the NWPR. Many projects could have occurred 
without consultation with the Corps due to the NWPR's narrow definition 
of ``waters of the United States'' and expansive non-jurisdictional 
categories. Therefore, while the Corps' ORM2 data shed light on the 
trend and magnitude of impacts to the scope of jurisdiction under the 
NWPR, it is fair to assume that these impacts are a significant 
underestimate.\44\
---------------------------------------------------------------------------

    \43\ This tracking method only applies when 100% of jurisdiction 
is lost under NWPR (i.e., if even 1 aquatic resource out of 100 that 
is proposed to be impacted remains jurisdictional, this method is 
not used). Additionally, this tracking method has not been 
implemented uniformly across the United States, and is likely under-
representative even for those cases in which 100% of jurisdiction 
was lost under the NWPR.
    \44\ Requests for AJDs and the jurisdictional dispositions of 
the aquatic resources evaluated as part of those AJDs are imperfect 
measures of activities that might affect those jurisdictional or 
non-jurisdictional aquatic resources. The AJD data in the Corps ORM2 
database generally contain only records for situations in which 
landowners or project proponents have requested jurisdictional 
determinations from the Corps or that are associated with an 
enforcement action, and thus do not represent all aquatic resources 
that exist within the United States. The proportion and specific 
types of aquatic resources evaluated for jurisdiction via AJDs 
varies both geographically and also from year to year. In addition, 
the ORM2 data collected from AJDs conducted under different 
regulatory regimes have some metrics that are not directly 
comparable. Notwithstanding these limitations, the volume of ORM2 
data on AJDs and associated aquatic resources is quite large and is 
tracked in a reasonably accurate fashion, and thus provides a 
reasonable estimate of overall trends and conditions on the ground. 
It represents the best data available to the agencies at this time.
---------------------------------------------------------------------------

ii. States and Tribes Did Not Fill the Regulatory Gap Left by the NWPR
    Some stakeholders have argued that the diminished scope of ``waters 
of the United States'' would not necessarily reduce protections for 
waters as a practical matter, because states, tribes, and local 
entities may regulate discharges even in the absence of Clean Water Act 
regulation. See section V.A.3.b of this preamble. This perspective is 
consistent with the NWPR's emphasis that, in the face of a narrower 
scope of ``waters of the United States,'' ``the controls that States, 
Tribes, and local entities choose to exercise over their land and water 
resources . . .'' would help to achieve the objective of the Act. 85 FR 
22259, April 21, 2020. Yet while some states and tribes regulate 
``waters of the state'' or ``waters of the tribe'' more broadly than 
the federal government under their own laws, many newly non-
jurisdictional waters under the NWPR were in states and on tribal lands 
that do not regulate waters beyond those covered by the Clean Water 
Act. Under the NWPR, discharges into these waters could have occurred 
without any restriction.
    As discussed in the Economic Analysis for the Proposed Rule, many 
states and tribes do not regulate waters more broadly than the Clean 
Water Act requires. Economic Analysis, Chapter II; NWPR Economic 
Analysis at 30-31. Contrary to the predictions made in the NWPR 
Economic Analysis, during the year in which the NWPR was in effect, the 
net change made by states was deregulatory in nature. Two states which 
had previously protected state waters beyond the scope of ``waters of 
the United States'' removed these expansive protections, whereas no 
states that had previously lacked these broader protections established 
them. See NWPR Economic Analysis at 39-41 (estimating that certain 
states are likely to continue their current permitting practices for 
dredged and fill material) and the Economic Analysis for the Proposed 
Rule Chapter II (indicating that two of those states sought to reduce 
the scope of state clean water protections after the NWPR was 
finalized, and none of them sought to expand protections.).
    The agencies understand that revising state regulations and/or laws 
takes time and the agencies do not know how some states might have 
responded if the NWPR had been in place for more than a year, but the 
agencies have no basis to expect that more states that currently lack 
protections beyond the NWPR federal floor would have established them. 
Indeed, the External Environmental Economics Advisory Committee (E-
EEAC) has stated that the model that the NWPR used to forecast state 
responses to that rule was overly optimistic with respect to the 
likelihood that states would address a federal regulatory gap, in part 
based on the agencies' failure to fully consider states' responses to 
past changes to the definition of ``waters of the United States'' 
(i.e., only two states directly changed regulations in response to the 
decision in SWANCC that the use of ``isolated'' non-navigable 
intrastate ponds by migratory birds was not by itself a sufficient 
basis for the exercise of federal authority under the Clean Water Act, 
and the agencies' significant resulting change in implementation of the 
Act). See E-EEAC Report on the Repeal of the Clean Water Rule and its 
Replacement with the Navigable Waters Protection Rule to Define Waters 
of the United States (WOTUS) 5-6, available at https://www.e-eeac.org/wotusreport.
    The agencies are also not aware of any tribes that expanded their 
clean water protections to compensate for a reduction in protections 
under the NWPR. During the agencies' tribal consultation and 
coordination for this rulemaking process, tribes overwhelmingly 
indicated that they lack the independent resources and expertise to 
protect their waters and therefore rely on Clean Water Act protections. 
See section IV.C of this preamble and the Summary of Tribal 
Consultation and Coordination, available in the docket for this 
proposed rule. This feedback is consistent with the concerns expressed 
during the NWPR rulemaking process. See, e.g., 85 FR 22336-22337, April 
21, 2020 (``many Tribes may lack the capacity to create a tribal water 
program under tribal law, to administer a program, or to expand 
programs that currently exist. Other tribes may rely on the Federal 
government for enforcement of water quality violations'').
    Given the limited authority of many states and tribes to regulate 
waters more broadly than the Federal government, the narrowing of 
federal jurisdiction would mean that discharges into the newly non-
jurisdictional waters would in many cases no longer be subject to 
regulation, including permitting processes and mitigation requirements 
designed to protect the chemical, physical, and biological integrity of 
the nation's waters. The agencies have heard concerns from a broad 
array of stakeholders, including states, tribes, scientists, and non-
governmental organizations, that corroborated the agencies' data and 
indicated that the NWPR's reduction in the jurisdictional scope of the 
Clean Water Act would cause significant environmental harms. Ephemeral 
streams and their associated wetlands, wetlands that do not meet the 
NWPR's revised adjacency criteria, and other aquatic resources not 
protected by the NWPR provide numerous ecosystem services. The absence 
of protections for such resources and any subsequent unregulated and 
unmitigated impacts to such resources would have caused cascading, 
cumulative, and substantial downstream harm, including damage

[[Page 69416]]

connected to water supplies, water quality, flooding, drought, erosion, 
and habitat integrity, thereby undermining the objective of the Clean 
Water Act (see section V.A.2 of this preamble). See Pascua Yaqui v. 
EPA, no. 4:20-cv-00266, slip op. at 9-10 (citing evidence that the 
agencies and plaintiffs provided of a ``substantial reduction in waters 
covered under the NWPR'' as demonstrating ``the possibility of serious 
environmental harm'' that weighed in favor of vacating the rule.); see 
also Navajo Nation v. Regan, no. 2:20-cv-00602, slip op. at 6-7 (citing 
the same reduction particularly ```an increase in determinations by the 
Corps that waters are non-jurisdictional,' including excluded ephemeral 
resources, `and an increase in projects for which CWA Section 404 
permits are no longer required,''' as weighing in favor of vacatur).
    In conclusion, the agencies do not believe the NWPR is a suitable 
alternative to the proposed rule because it failed to advance the 
objective of the Act, including through its elimination of the 
significant nexus standard and the absence of any alternative standard 
that would protect the chemical, physical, and biological integrity of 
the nation's waters; it is inconsistent with scientific information 
about protecting water quality; its implementation proved confusing, 
difficult, and often infeasible; and it drastically reduced the numbers 
of waters protected by the Clean Water Act, including waters that 
affect the integrity of downstream traditional navigable waters, 
interstate waters, and the territorial seas.

C. Proposed Rule

    The agencies are proposing to restore the longstanding, familiar 
1986 regulations, with amendments to reflect the agencies' 
determination of the statutory limits on the scope of the ``waters of 
the United States'' informed by Supreme Court case law. Therefore, this 
proposed rule retains the structure of the agencies' 1986 definition of 
``waters of the United States,'' and the text of that definition where 
revisions are not warranted. Continuity with the 1986 regulations will 
minimize confusion and provide regulatory stability for the public, the 
regulated community, and the agencies, while protecting the nation's 
waters. Each aspect of the proposed rule will be discussed in more 
detail below.
    The implementation section V.D of this preamble identifies features 
that the agencies have, as a matter of practice, generally not asserted 
jurisdiction over and the agencies propose to continue implementing the 
regulations consistent with that longstanding interpretation and 
practice. In addition, the agencies note that Congress has exempted or 
excluded certain discharges from the Clean Water Act or from specific 
permitting requirements. The proposed rule also would not affect any of 
the exemptions, including exemptions from section 404 permitting 
requirements provided by section 404(f), such as those for normal 
farming, ranching, and silviculture activities. 33 U.S.C. 1344(f); 40 
CFR 232.3; 33 CFR 323.4. The proposed rule would not affect the 
existing statutory or regulatory exemptions or exclusions from section 
402 NPDES permitting requirements, such as for agricultural stormwater 
discharges and return flows from irrigated agriculture, or the status 
of water transfers. 33 U.S.C. 1342(l)(1), (l)(2); 33 U.S.C. 1362(14); 
40 CFR 122.3(f), 122.2. In addition, where waters are covered by the 
Clean Water Act, the agencies have adopted measures to simplify 
compliance with the Act such as general permits and tools for 
expediting the permitting process (e.g., mitigation banks, in-lieu fee 
programs, and functional/conditional assessment tools). The agencies 
intend to continue to develop general permits and simplified procedures 
to ensure that projects, particularly those that offer environmental or 
public benefits, can proceed with the necessary environmental 
safeguards while minimizing permitting delays.
    The agencies have highlighted areas throughout the proposal where 
they are seeking comment on specific aspects of the revised definition 
of ``waters of the United States'' and implementation of that 
definition. The agencies are also generally seeking comment from the 
public on all aspects of this proposal to support development of the 
final rule.
1. Traditional Navigable Waters
    The proposed rule retains the provision in the 1986 regulations 
that defines ``waters of the United States'' to include ``all waters 
that are currently used, or were used in the past, or may be 
susceptible to use in interstate or foreign commerce, including all 
waters which are subject to the ebb and flow of the tide.'' 33 CFR 
328.3(a)(1) (2014); 40 CFR 122.2 (2014); 40 CFR 230.3(s)(1) (2014). 
Such waters are often referred to as ``traditional navigable waters.'' 
With respect to traditional navigable waters, the text of the 1986 
regulations and the text of the NWPR are identical. The agencies are 
not proposing to amend this longstanding text defining ``traditional 
navigable waters.''
    The NWPR maintained the categories of traditional navigable waters 
and the territorial seas in the definition of ``waters of the United 
States,'' but consolidated these two categories into a single paragraph 
in the regulatory text in order to streamline the text. 85 FR 22280, 
April 21, 2020. Because the 1986 regulations kept the traditional 
navigable waters provisions and the territorial seas provisions 
separate, this proposed rule does as well. The agencies are seeking 
comment, however, on whether it would be useful to similarly streamline 
the proposed rule by consolidating the traditional navigable waters, 
interstate waters, and the territorial seas provisions into one 
provision since under the 1986 regulations and the proposed rule the 
jurisdictional status of the other categories of waters relies on their 
connection to a traditional navigable water, interstate water, or the 
territorial seas (and, where required, meeting either the relatively 
permanent or the significant nexus standard). The agencies also seek 
comment on whether consolidation would cause confusion regarding the 
consistency of the proposed rule with the 1986 regulations, because 
such a change would require corresponding changes to cross references 
and the numbering of other provisions.
    Supreme Court decisions have not questioned the inclusion of 
traditional navigable waters in the definition of ``waters of the 
United States.'' E.g., SWANCC, 531 U.S. 159, 172 (``[t]he term 
`navigable' has at least the import of showing us what Congress had in 
mind as its authority for enacting the CWA: Its traditional 
jurisdiction over waters that were or had been navigable in fact or 
which could reasonably be so made.'').
    The agencies also are making no changes to their longstanding 
guidance on traditional navigable waters for purposes of Clean Water 
Act jurisdiction. Waters will continue to be considered traditional 
navigable waters, and thus jurisdictional under this provision of the 
proposed rule, if they:
     Are subject to section 9 or 10 of the Rivers and Harbors 
Act of 1899;
     have been determined by a federal court to be navigable-
in-fact under federal law;
     are waters currently being used for commercial navigation, 
including commercial waterborne recreation (for example, boat rentals, 
guided fishing trips, or water ski tournaments);
     have historically been used for commercial navigation, 
including commercial waterborne recreation; or

[[Page 69417]]

     are susceptible to being used in the future for commercial 
navigation, including commercial waterborne recreation.

    See ``U.S. Army Corps of Engineers Jurisdictional Determination 
Form Instructional Guidebook, Appendix D, `Traditional Navigable 
Waters''' (hereinafter, ``Appendix D''). The NWPR also continued use of 
Appendix D, stating ``because the agencies have not modified the 
definition of `traditional navigable waters,' the agencies are 
retaining Appendix D to help inform implementation of that provision of 
this final rule.'' 85 FR 22281, April 21, 2020.\45\ However, after the 
NWPR was promulgated the agencies issued a coordination memo that 
created some confusion. ``U.S. Environmental Protection Agency (EPA) 
and U.S. Army Corps of Engineers (Corps) Process for Elevating and 
Coordinating Specific Draft Determinations under the Clean Water Act 
(CWA)'' (hereinafter ``TNW Coordination Memo''). The memorandum 
established an implementation process by which the agencies elevate to 
their headquarters for coordination certain case-specific and stand-
alone Clean Water Act traditional navigable water determinations 
concluding a water is ``susceptible to use'' solely based on evidence 
of recreation-based commerce. Id. On November 17, 2021, the TNW 
Coordination Memo was rescinded. Regardless of any confusion caused by 
the TNW Coordination Memo, the Supreme Court has been clear that 
``[e]vidence of recreational use, depending on its nature, may bear 
upon susceptibility of commercial use.'' PPL Montana v. Montana, 565 
U.S. 576, 600-01 (2012) (in the context of navigability at the time of 
statehood and quoting Appalachian Elec. Power Co., 311 U.S. at 416 
(``[P]ersonal or private use by boats demonstrates the availability of 
the stream for the simpler types of commercial navigation''); Utah, 283 
U.S. at 82 (fact that actual use has ``been more of a private nature 
than of a public, commercial sort . . . cannot be regarded as 
controlling'')).
---------------------------------------------------------------------------

    \45\ Appendix D is an attachment to the U.S. Army Corps of 
Engineers Jurisdictional Determination Form Instructional Guidebook 
that was published in 2007 concurrently with the 2007 Rapanos 
Guidance, available at https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll11/id/2316. The Rapanos Guidance was 
updated in 2008, but Appendix D has remained unchanged since 2007. 
Appendix D notes (at page 1) that ``EPA and the Corps are providing 
this guidance on determining whether a water is a `traditional 
navigable water' for purposes of the Rapanos Guidance, the Clean 
Water Act (CWA), and the agencies' CWA implementing regulations.'' 
Appendix D operates in tandem with the Rapanos Guidance, along with 
other agency resources, to assist in guiding field implementation of 
Clean Water Act jurisdictional determinations.
---------------------------------------------------------------------------

2. Interstate Waters
    The proposed rule would restore the longstanding categorical 
protections for interstate waters, regardless of their navigability, 
that were established by the earliest predecessors to the 1972 Clean 
Water Act and remained in place until the promulgation of the NWPR. 
Interstate waters are waters of the several states and therefore 
unambiguously ``waters of the United States.'' Categorical protection 
of interstate waters is the interpretation of the Clean Water Act that 
is most consistent with the text of the statute, including section 
303(a), its purpose and history, Supreme Court case law, and the 
agencies' charge to implement a ``comprehensive regulatory program'' 
that protects the chemical, physical, and biological integrity of the 
nation's waters.
    Until 1972, the predecessors of the Clean Water Act explicitly 
protected interstate waters independent of their navigability. The 1948 
Water Pollution Control Act declared that the ``pollution of interstate 
waters'' and their tributaries is ``a public nuisance and subject to 
abatement.'' 33 U.S.C. 466a(d)(1) (1952) (codifying Pub. L. 80-845 
section 2(d)(1), 62 Stat. 1156 (1948)). Interstate waters were defined 
without reference to navigability: ``all rivers, lakes, and other 
waters that flow across, or form a part of, State boundaries.'' 33 
U.S.C. 466i(e) (1952) (codifying Pub. L. 80-845 section 10(e), 62 Stat. 
1161 (1948)).
    In 1961, Congress broadened the 1948 statute and made the pollution 
of ``interstate or navigable waters'' subject to abatement, retaining 
the definition of ``interstate waters.'' 33 U.S.C. 466g(a) (1964) 
(codifying Pub. L. 87-88 section 8(a), 75 Stat. 204, 208 (1961)). In 
1965, Congress required states to develop water quality standards for 
``interstate waters or portions thereof within such State.'' 33 U.S.C. 
1160(c)(1) (1970) (codifying Pub. L. 89-234 section 5, 79 Stat. 903, 
907 (1965)); see also 33 U.S.C. 1173(e) (1970) (retaining definition of 
``interstate waters''). In the 1972 Act, Congress abandoned the 
``abatement'' approach initiated in the 1948 statute in favor of a 
focus on permitting for discharges of pollutants.
    The NWPR asserted that Congress' replacement of the term 
``navigable or interstate waters'' with ``navigable waters'' in 1972 
was an ``express rejection'' of the regulation of interstate waters as 
an independent category, reflecting Congress' intent to protect 
interstate waters only to the extent that they are navigable. 85 FR 
22583, April 21, 2020. In support of its rationale, the NWPR cited the 
order of the U.S. District Court for the Southern District of Georgia 
remanding the 2015 Clean Water Rule. Id.; citing Georgia v. Wheeler, 
418 F. Supp. 3d 1336 (S.D. Ga. 2019). That order found that the 
categorical inclusion of interstate waters exceeds the agencies' 
authority under the Clean Water Act because it ``reads the term 
navigability out of the CWA,'' and would assert jurisdiction over 
waters that are not navigable-in-fact and otherwise have no significant 
nexus to any other navigable-in-fact water. Id. at 1358-59. The court 
also found the standard overly broad because it would result in Clean 
Water Act jurisdiction over tributaries, adjacent waters, and case-by-
case waters based on their relationship to non-navigable interstate 
waters. Id. at 1359-60.
    The agencies view the interpretation of the agencies' authority 
over interstate waters articulated in the NWPR and in Georgia v. 
Wheeler as inconsistent with both the text and the history of the Clean 
Water Act, as well as Supreme Court case law. While the term 
``navigable waters'' is ambiguous in some respects, interstate waters 
are waters that are clearly covered by the plain language of the 
definition of ``navigable waters.'' Congress defined ``navigable 
waters'' to mean ``the waters of the United States, including the 
territorial seas.'' The Supreme Court has recognized that ``the power 
conferred by the Commerce Clause [is] broad enough to permit 
congressional regulation of activities causing air or water pollution, 
or other environmental hazards that may have effects in more than one 
State.'' Hodel v. Virginia Surface Mining & Reclamation Ass'n, 452 U.S. 
264, 282 (1981). Interstate waters are, by their very nature, waters of 
the ``several States,'' U.S. Const. section 8, and, consequently, 
waters ``of the United States.'' The Clean Water Act reflects Congress' 
recognition that the degradation of water resources in one state may 
cause significant harms in states other than that in which the 
pollution occurs.
    In addition, the text of the 1972 Act specifically addresses 
``interstate waters'' regardless of their connection to navigability. 
The 1972 statute retains the term ``interstate waters'' in 33 U.S.C. 
1313(a), a provision added in 1972, which provides that pre-existing 
water quality standards for ``interstate waters'' remain in effect 
unless EPA determined that they were inconsistent with any applicable 
requirements of the pre-1972 version of the Act. That plain language is 
a clear indication that Congress

[[Page 69418]]

intended the agencies to continue to protect the water quality of 
interstate waters without reference to their navigability. Excluding 
``interstate waters'' as an independent category of Clean Water Act 
jurisdiction disregards the plain language of section 303(a).
    The Supreme Court has concluded that the 1972 amendments ``were not 
merely another law `touching interstate waters,' '' but rather 
``occupied the field through the establishment of a comprehensive 
regulatory program supervised by an expert administrative agency.'' 
City of Milwaukee v. Illinois, 451 U.S. 304, 317 (1981). Thus, the 1972 
amendments superseded the federal common law of nuisance as a means to 
protect interstate waters in favor of a statutory ``all-encompassing 
program of water pollution regulation,'' id. at 318, and they did not 
curtail the scope of protected waters.
    Even if the text and history of the statute and Supreme Court case 
law interpreting the Act do not unambiguously resolve the issue, the 
situation addressed by the Supreme Court in the City of Milwaukee cases 
highlights the reasonableness of the agency's interpretation that the 
Clean Water Act protects interstate waters. The City of Milwaukee 
litigation involved alleged discharges of inadequately treated sewage 
from Milwaukee, Wisconsin sewer systems directly into Lake Michigan, 
which also borders Illinois. As the Supreme Court noted, prior to 
passage of the Clean Water Act, these discharges would have had to be 
resolved through litigation, in which the courts must apply ``often 
vague and indeterminate nuisance concepts and maxims of equity 
jurisprudence.'' Id. at 317. The Clean Water Act, however, replaced 
this unpredictable and inefficient approach with ``a comprehensive 
regulatory program supervised by an expert administrative agency.'' Id. 
The Court in Arkansas v. Oklahoma also stated in the context of an 
NPDES permit for a discharge of pollutants to interstate waters that 
while the Clean Water Act may place some limits on downstream states' 
participation in the permitting process, those limits ``do not in any 
way constrain the EPA's authority to require a point source to comply 
with downstream water quality standards.'' 503 U.S. at 106.
    The potential for interstate harm, and the consequent need for 
federal regulation, is particularly clear with respect to water bodies 
that span more than one state. The alternative interpretation would 
leave interstate waters that do not fall within any other provisions in 
the definition of ``waters of the United States'' without federal 
protection and parties in different states to resolve concerns about 
upstream discharges in non-jurisdictional waters through litigation 
using ``often vague and indeterminate nuisance concepts and maxims of 
equity jurisprudence.'' City of Milwaukee, 451 U.S. at 317; 85 FR 
22286, April 21, 2020. Restoration of longstanding protections for 
interstate waters, regardless of whether they are navigable-in-fact, 
would enable the agencies to efficiently and effectively address 
interstate water quality issues. The agencies interpret interstate 
waters to encompass all waters that Congress has sought to protect 
since 1948: all rivers, lakes, and other waters that flow across, or 
form a part of, state boundaries. Pub. L. 80-845, sec. 10, 62 Stat. 
1155, at 1161 (1948). These waters need not meet the relatively 
permanent standard or significant nexus standard. See Technical Support 
Document section I.B. for further discussion of interstate waters.
    Interstate waters may be streams, lakes or ponds, or wetlands. 
Under this provision of the proposed rule, consistent with the pre-2015 
regulatory regime, the agencies would consider lakes, ponds, and 
similar lentic (or still) water features, as well as wetlands, crossing 
state boundaries jurisdictional as interstate waters in their entirety. 
For streams and rivers, including impoundments, the agencies would 
determine the upstream and downstream extent of the stream or river 
crossing a state boundary or serving as a state boundary that should be 
considered the ``interstate water.'' One method of determining the 
extent of a riverine ``interstate water'' is the use of stream order. 
Stream order is a common, longstanding scientific concept of assigning 
whole numbers to indicate the branches of a stream network. Under this 
method, for rivers and streams the ``interstate water'' would extend 
upstream and downstream of the state boundary for the entire length 
that the water is of the same stream order. For interstate waters that 
are lakes and ponds or wetlands, the entire lake, pond, or wetland 
could be considered the interstate water through the entirety of its 
delineated extent. The agencies are requesting comment on this approach 
or others for implementing the interstate waters provision of the 
proposed rule. For instance, if a water serves as the state boundary, 
the entire length of the river that serves as the boundary could be 
considered the appropriate extent of the interstate water.
    The agencies are seeking comment on whether interstate waters 
should encompass waters that flow across, or form a part of, boundaries 
of federally recognized tribes because these waters flow across, or 
form a part of, state boundaries. See Public Law 80-845, sec. 10, 62 
Stat. 1155, at 1161 (1948). In comments submitted to the agencies as 
part of the tribal consultation and coordination process for this 
proposed rule, several tribes and tribal organizations stated that 
interstate waters should include waters that border upon or traverse 
tribal lands, both between and from state to tribe (or vice versa) and 
between and from one tribe to another (in instances where tribal lands 
are adjacent to each other). The agencies are also interested in 
comments on whether and how to identify what constitutes a tribal 
boundary for purposes of interstate waters under the Clean Water Act, 
for example, boundaries associated with the term ``Indian country'' as 
defined at 18 U.S.C. 1151 or reservation boundaries.
3. Other Waters
    The agencies are proposing to retain the ``other waters'' category 
from the 1986 regulations in the definition of ``waters of the United 
States,'' but with changes informed by relevant Supreme Court 
precedent. Under the 1986 regulations, ``other waters'' (such as 
intrastate rivers, lakes, and wetlands that are not otherwise 
jurisdictional under other sections of the rule) could be determined to 
be jurisdictional if the use, degradation, or destruction of the water 
could affect interstate or foreign commerce. The proposed rule amends 
the 1986 regulations to delete all of the provisions referring to 
authority over activities that ``could affect interstate or foreign 
commerce'' and replace them with the relatively permanent and 
significant nexus standards the agencies have developed based on their 
best judgment and relevant Supreme Court case law. The proposed rule 
provides that ``other waters'' meet the relatively permanent standard 
if they are relatively permanent, standing or continuously flowing 
bodies of water with a continuous surface connection to a traditional 
navigable water, interstate water, or the territorial seas. The 
proposed rule also provides that ``other waters'' meet the significant 
nexus standard if they, either alone or in combination with similarly 
situated waters in the region, significantly affect the chemical, 
physical, or biological integrity of a traditional navigable water, 
interstate water, or the territorial seas. Thus, the proposed rule 
would provide for case-specific analysis of waters not addressed by any 
other provision of the definition to determine whether they are 
``waters of the United

[[Page 69419]]

States'' under the relatively permanent or significant nexus standards. 
In light of agency guidance discussed below, the agencies have not in 
practice asserted jurisdiction over ``other waters'' based on the 1986 
regulations' provision since SWANCC. Section V.D of this preamble 
solicits comment on this practice and other implementation approaches 
for this provision of the proposed rule.
    The text of the 1986 regulations reflected the agencies' 
interpretation at the time, based primarily on the legislative history 
of the Act, that the jurisdiction of the Clean Water Act extended to 
the maximum extent permissible under the Commerce Clause of the 
Constitution. SWANCC did not invalidate the 1986 regulations' ``other 
waters'' provision or any other parts of the 1986 regulations' 
definition of ``waters of the United States.'' Based on that case and 
subsequent Supreme Court decisions, the agencies conclude that 
asserting jurisdiction over non-navigable, intrastate ``other waters'' 
based solely on whether the use, degradation, or destruction of the 
water could affect interstate or foreign commerce pushes the scope of 
the Clean Water Act beyond the limitations intended by Congress. The 
proposal is consistent with many of the concerns the agencies 
identified in guidance issued in 2003 (discussed further below). In 
addition, the proposed rule reflects consideration of the principles 
the NWPR identified as foundational to the Court's opinion in SWANCC. 
See 85 FR 22265, April 21, 2020 (``the reasoning in the SWANCC decision 
stands for key principles related to federalism and the balancing of 
the traditional power of States to regulate land and water resources 
within their borders with the need for national water quality 
regulation.'').
    The proposed rule would replace the interstate commerce test with 
the relatively permanent and significant nexus standards because, as 
discussed in section V.A of this preamble, those standards are 
consistent with the text of the Clean Water Act, advance the objective 
of the Act, and are consistent with relevant decisions of the Supreme 
Court. Waters that do not fall within one of the more specific 
categories identified in the proposed rule may still meet either the 
relatively permanent or significant nexus standard. For example, a lake 
that is not a tributary and is not a wetland may have a continuous 
surface connection to a traditional navigable water, and the ``other 
waters'' provision as proposed would allow for such a water to be 
evaluated for jurisdiction. This is consistent with Supreme Court 
precedent. As the Rapanos plurality concluded, ``relatively permanent, 
standing or continuously flowing bodies of water,'' 547 U.S. at 739, 
that are connected to traditional navigable waters, id. at 742, and 
waters with a ``continuous surface connection'' to such water bodies, 
id. (Scalia, J., plurality opinion), are ``waters of the United 
States'' under the relatively permanent standard. And as Justice 
Kennedy concluded, SWANCC held that ``to constitute `navigable waters' 
under the Act, a water or wetland must possess a `significant nexus' to 
waters that are or were navigable in fact or that could reasonably be 
so made.'' Id. at 759 (citing SWANCC, 531 U.S. at 167, 172).
    The agencies note that in 2003, they issued a Joint Memorandum 
regarding SWANCC. See 68 FR 1991, 1995 (January 15, 2003) (``SWANCC 
Guidance''). In the guidance, the agencies stated that in view of 
SWANCC, neither agency would assert Clean Water Act jurisdiction over 
isolated waters that are both intrastate and non-navigable, where the 
sole basis available for asserting Clean Water Act jurisdiction rests 
on the factors listed in the ``Migratory Bird Rule.'' In the preamble 
to the 1986 regulations, the agencies had stated that ``waters of the 
United States'' include waters ``[w]hich are or would be used as 
habitat by birds protected by Migratory Bird Treaties,'' as well as 
waters ``[w]hich are or would be used as habitat by other migratory 
birds which cross state lines.'' 51 FR 41216-17 (November 13, 1986). 
That preamble language became known as the ``Migratory Bird Rule.'' In 
addition to ending use of the ``Migratory Bird Rule,'' the SWANCC 
Guidance also stated that, cognizant of the Supreme Court's direction 
in SWANCC, with respect to all waters subject to the ``other waters'' 
provision, ``field staff should seek formal project-specific 
Headquarters approval prior to asserting jurisdiction over such waters, 
including permitting and enforcement actions.'' 68 FR 1996 (January 15, 
2003). The Rapanos Guidance ``[did] not address SWANCC nor does it 
affect the Joint Memorandum regarding that decision issued by the 
General Counsels of EPA and the Department of the Army on January 10, 
2003.'' Rapanos Guidance at 4 n.19. As a result of the SWANCC 
Guidance's directive to field staff, field staff have not in practice 
sought Headquarters approval and the agencies have not asserted 
jurisdiction over waters based on the ``other waters'' provision of the 
1986 regulations since then.
    The ``other waters'' provision in the 1986 regulations contains a 
non-exclusive list of water types that could be jurisdictional under 
this provision if they are not jurisdictional under the other 
provisions of the definition: ``[a]ll other waters such as intrastate 
lakes, rivers, streams (including intermittent streams), mudflats, 
sandflats, wetlands, sloughs, prairie potholes, wet meadows, playa 
lakes, or natural ponds.'' The agencies are not proposing to change 
this language. Rather, the agencies are proposing to replace the 
Commerce Clause-based standard for determining jurisdiction with the 
relatively permanent and significant nexus standards. It is important 
to note that the list of water types does not reflect a conclusion that 
these waters are necessarily jurisdictional; rather the list is simply 
meant to inform the public of types of waters that can be 
jurisdictional if they meet the requisite test (under the proposal, 
either the relatively permanent standard or the significant nexus 
standards), even though they do not fall within the other provisions of 
the proposed rule. The list led to confusion in the past when it was 
sometimes incorrectly read as an exclusive list. There has also been 
confusion about some of the listed water types; for example, the list 
includes intermittent streams and was meant to allow for jurisdictional 
evaluation of intermittent streams that do not fall within the other 
categories (such as intermittent streams that are not tributaries to a 
traditional navigable water, interstate water, or territorial sea but 
which under the 1986 regulations could affect interstate commerce and 
under the proposed rule could meet the significant nexus standard) and 
not to imply that intermittent streams were not jurisdictional under 
the tributary provision of the 1986 regulations.
    The agencies are seeking comment on whether it would be helpful to 
the public to delete the list of water types or to otherwise provide 
more clarity to the list of water types in the regulation. For 
instance, the agencies could delete the list of water types in the 
``other waters'' provision of the 1986 regulations and simply state in 
the rule that the ``other waters'' category includes ``all other 
intrastate waters (including wetlands)'' that meet either the 
relatively permanent standard or the significant nexus standard. 
However, removing the list of water types would not be meant to imply 
that any of the water types listed in the 1986 regulations are not 
subject to jurisdiction under this provision of the proposed rule if 
they meet either the relatively permanent standard or the significant 
nexus standard. The agencies

[[Page 69420]]

also solicit comment on whether the final rule should add or delete 
particular water types from the list.
    In the NWPR, the category of waters most analogous to the ``other 
waters'' category was the category for lakes, ponds, and impoundments 
of jurisdictional waters that met certain tests. Because those 
limitations on the scope of jurisdiction were not related to the 
effects of other waters on the water quality of foundational waters, 
the agencies are proposing an approach based in the relatively 
permanent and significant nexus standards.
4. Impoundments
    The proposed rule retains the provision in the 1986 regulations 
that defines ``waters of the United States'' to include impoundments of 
``waters of the United States'' with one change. Waters that are 
determined to be jurisdictional under the ``other waters'' provision 
would be excluded from this provision under the proposed rule.
    The Supreme Court has confirmed that damming or impounding a 
``water of the United States'' does not make the water non-
jurisdictional. See S.D. Warren Co. v. Maine Bd. of Envtl. Prot., 547 
U.S. 370, 379 n.5 (2006) (``[N]or can we agree that one can 
denationalize national waters by exerting private control over 
them.''). While the definition of ``waters of the United States'' was 
not before the Court in S.D. Warren, the Court's conclusion supports 
the agencies' longstanding interpretation of the Clean Water Act that a 
``water of the United States'' remains a ``water of the United States'' 
even if it is impounded, as reflected in the 1986 regulations and 
continued in this proposal. The Ninth Circuit has similarly found that 
``it is doubtful that a mere man-made diversion would have turned what 
was part of the waters of the United States into something else and, 
thus, eliminated it from national concern.'' United States v. Moses, 
496 F.3d 984, 988 (9th Cir. 2007), cert. denied, 554 U.S. 918 (2008).
    The agencies are proposing to exclude impoundments of waters that 
are determined to be jurisdictional under the ``other waters'' 
provision. This proposal is practical: as discussed in sections V.C.5 
and 7 below, the agencies are proposing that the ``tributaries'' 
category not include tributaries of ``other waters'' and the adjacent 
wetlands category not include wetlands adjacent to ``other waters.'' 
This change reflects the agencies' consideration of the jurisdictional 
concerns and limitations of SWANCC and Rapanos. The agencies have 
concluded that a provision that authorizes consideration of 
jurisdiction over tributaries that meet the relatively permanent or 
significant nexus standard when assessed based simply on connections to 
``other waters'' would have too tenuous a connection to traditional 
navigable waters, interstate waters, or the territorial seas. The 
proposed rule retains the provisions of the 1986 regulations under 
which tributaries and adjacent wetlands to impoundments may be 
determined to be jurisdictional. The proposed change ensures that the 
impoundment of an ``other water'' does not change the jurisdictional 
status of tributaries or adjacent wetlands to it. This change reflects 
the agencies' consideration of the jurisdictional concerns and 
limitations of SWANCC and Rapanos. To be clear, an impoundment of an 
``other water'' could still meet the relatively permanent standard or 
the significant nexus standard under the ``other waters'' provision; 
the impoundment simply would not retain its jurisdictional status under 
this impoundment provision.
    Impoundments of jurisdictional waters were not addressed in the 
Rapanos decision and thus were not directly addressed by the agencies 
in the Rapanos Guidance. Under the proposed rule and pre-2015 practice, 
impounding waters can create traditional navigable waters, even if the 
waters that are impounded are not themselves traditional navigable 
waters. In addition, under the proposed rule impounding a water can 
create a relatively permanent water, even if the water that is being 
impounded is a non-relatively permanent water. For purposes of 
implementation, relatively permanent waters include waters where water 
is standing or ponded at least seasonally.
    In the NWPR, the agencies changed their longstanding position that 
impoundments of jurisdictional waters remain jurisdictional and added 
new requirements for impoundments of jurisdictional waters to be 
considered ``waters of the United States.'' Specifically, under the 
NWPR, impoundments of jurisdictional waters had to either contribute 
surface water flow to a downstream jurisdictional water in a typical 
year or be inundated by flooding from a jurisdictional water in a 
typical year. In support of the NWPR's position that impounding a 
jurisdictional water could potentially create a non-jurisdictional 
feature, the agencies stated that ``the agencies are aware of no 
decision of the Supreme Court that has ruled that the indelibly 
navigable principle applies to all waters of the United States, 
although the principle does apply to certain traditional navigable 
waters or any decision that would prohibit the United States from 
consenting to defederalization of a water by a lawfully issued section 
404 permit.'' 85 FR 22303, April 21, 2020.
    The agencies disagree that jurisdiction over impoundments of 
``waters of the United States'' reflects application of the principle 
of indelible navigability. The indelible navigation principle is 
applicable to Rivers and Harbors Act jurisdiction, not Clean Water Act 
jurisdiction, and holds that sudden or man-made changes to a water body 
or its navigable capacity do not alter the extent of Rivers and Harbors 
Act jurisdiction, and thus the area occupied or formerly occupied by 
that water body will always be subject to Rivers and Harbors Act 
jurisdiction even when the area is no longer a water.\46\ The agencies 
are not aware of any statement relying on that concept as the 
justification for its longstanding position that impoundments of 
``waters of the United States'' remain ``waters of the United States'' 
for Clean Water Act purposes, absent a legally authorized change of 
jurisdictional status under a Clean Water Act permit (such as a section 
404 permit authorizing creation of an excluded waste treatment system).
---------------------------------------------------------------------------

    \46\ This principle has been incorporated in the Corps' 
definition of ``navigable waters of the United States'' for purposes 
of the Rivers and Harbors Act: ``A determination of navigability, 
once made, applies laterally over the entire surface of the water 
body, and is not extinguished by later actions or events which may 
impede or destroy navigable capacity.'' 33 CFR 329.4. The rule is 
expanded upon in 33 CFR 329.9 and 329.13: ``an area will remain 
`navigable in law,' even though no longer covered with water, 
whenever the change has occurred suddenly, or was caused by 
artificial forces intended to produce that change.'' EPA has no such 
regulations for purposes of implementing the Clean Water Act.
---------------------------------------------------------------------------

    In departing from the agencies' longstanding position regarding the 
jurisdictional status of impoundments, the NWPR also stated that the 
agencies were unaware of any judicial decision ``that would prohibit 
the United States from consenting to defederalization of a water by a 
lawfully issued section 404 permit.'' 85 FR 22303, April 21, 2020. As 
noted above, the agencies recognize that a lawfully issued section 404 
permit, with any accompanying appropriate and practicable mitigation, 
can authorize filling of a ``water of the United States'' such that it 
is no longer a ``water of the United States.'' The ``impoundment'' 
provision of the definition of ``waters of the United States'' simply 
retains jurisdiction over ``waters of the United States'' that are 
naturally or artificially impounded. If the impoundment occurs pursuant 
to a section 404 permit and the permit

[[Page 69421]]

authorizes the removal of the resulting impoundment from jurisdiction, 
such as in the case of the creation of a waste treatment system 
excluded from the ``waters of the United States'' by regulation, the 
impoundment would no longer be jurisdictional pursuant to this 
provision. On the flip side, an impoundment of a water that is not a 
``water of the United States'' could become jurisdictional if, for 
example, the impounded water becomes navigable-in-fact and is thus 
covered under the traditional navigable waters provision of the rule.
    Asserting Clean Water Act jurisdiction over impoundments also 
aligns with the scientific literature, as well as the agencies' 
scientific and technical expertise and experience, which confirm that 
impoundments have chemical, physical, and biological effects on 
downstream waters through surface or subsurface hydrologic connections. 
See Technical Support Document section IV.C. Indeed, berms, dikes, and 
similar features used to create impoundments typically do not block all 
water flow. Even dams, which are specifically designed and constructed 
to impound large amounts of water effectively and safely, generally do 
not prevent all water flow, but rather allow seepage under the 
foundation of the dam and through the dam itself. See, e.g., 
International Atomic Energy Agency (``All dams are designed to lose 
some water through seepage.''); U.S. Bureau of Reclamation (``All dams 
seep, but the key is to control the seepage through properly designed 
and constructed filters and drains.''); Federal Energy Regulatory 
Commission 2005 (``Seepage through a dam or through the foundations or 
abutments of dams is a normal condition.''). Further, as an agency with 
expertise and responsibilities in engineering and public works, the 
Corps extensively studies water retention structures like berms, 
levees, and earth and rock-fill dams. The agency has found that all 
water retention structures are subject to seepage through their 
foundations and abutments. See, e.g., U.S. Army Corps of Engineers 1992 
at 1-1; U.S. Army Corps of Engineers 1993 at 1-1; U.S. Army Corps of 
Engineers 2004 at 6-1.
    That said, there may be circumstances where an impoundment 
authorized under a section 404 permit completely and permanently severs 
surface or subsurface hydrologic connections. See ``U.S. Army Corps of 
Engineers Jurisdictional Determination Form Instructional Guidebook,'' 
at 58. The agencies are considering whether there are certain types of 
impoundments--such as the example in the preceding sentence--that 
should be assessed under the ``other waters'' provision of the 
regulation. The agencies are seeking comment on this approach and 
accompanying implementation issues.
5. Tributaries
    The proposed rule retains the tributary provision of the 1986 
regulations, updated to reflect consideration of relevant Supreme Court 
decisions. The 1986 regulations defined ``waters of the United States'' 
to include tributaries of traditional navigable waters, interstate 
waters, ``other waters,'' or impoundments. The proposed rule defines 
``waters of the United States'' to include tributaries of traditional 
navigable waters, interstate waters, impoundments, or the territorial 
seas if the tributary meets either the relatively permanent standard or 
the significant nexus standard. The agencies solicit comment on all 
aspects of the tributary provision in this proposed rule.
    The 1986 regulations include tributaries to interstate waters. 
Since interstate waters, like traditional navigable waters and the 
territorial seas, are foundational waters protected by the Clean Water 
Act, the agencies are proposing to protect them in a similar manner by 
providing that tributaries that meet either the relatively permanent 
standard or the significant nexus standard in relation to an interstate 
water are jurisdictional under the proposed rule. Ample scientific 
information makes clear that the health and productivity of rivers and 
lakes, including interstate waters, depends upon the functions provided 
by upstream tributaries. As discussed in section V.A.2.c of this 
preamble, tributaries, adjacent wetlands, and ``other waters'' that are 
relatively permanent or that have a significant nexus to downstream 
waters, including interstate waters, have important beneficial effects 
on those waters, and polluting or destroying these tributaries, 
adjacent wetlands, or ``other waters'' can harm downstream 
jurisdictional waters.
    The agencies are proposing to delete the cross reference to ``other 
waters'' as a water to which tributaries may connect to be determined 
``waters of the United States.'' This change reflects the agencies' 
consideration of the jurisdictional concerns and limitations of SWANCC 
and Rapanos. The agencies have concluded that a provision that 
authorizes consideration of jurisdiction over tributaries that meet the 
relatively permanent or significant nexus standard when assessed based 
simply on connections to ``other waters'' would have too tenuous a 
connection to traditional navigable waters, interstate waters, or the 
territorial seas. Rather, any such streams that are tributaries to 
jurisdictional ``other waters'' could be assessed themselves under the 
``other waters'' category to determine if they meet the relatively 
permanent or significant nexus standard. Thus, a tributary to, for 
example, a lake that meets the significant nexus standard under the 
``other waters'' provision could not be determined to be jurisdictional 
simply because it significantly affects the physical integrity of the 
lake; rather, the tributary would need to be assessed under the ``other 
waters'' provision for whether it significantly affects a traditional 
navigable water, interstate water, or the territorial seas.
    Additionally, the agencies are proposing to add the territorial 
seas to the list of waters to which tributaries may connect to 
constitute a jurisdictional tributary because the territorial seas are 
explicitly protected by the Clean Water Act and are a type of 
traditional navigable water. The agencies are unaware of a legal basis 
for the 1986 regulation's failure to include the term ``territorial 
seas'' in the original tributaries provision of the rule. The proposed 
rule clarifies that tributaries to the territorial seas where they meet 
either the relatively permanent standard or the significant nexus 
standard fall within the definition of ``waters of the United States.'' 
The territorial seas are explicitly covered by the Clean Water Act and 
they are also traditional navigable waters, so it is reasonable to 
protect tributaries to the territorial seas that meet either the 
relatively permanent standard or the significant nexus standard for the 
same reasons as tributaries to traditional navigable waters are 
covered.
    Finally, the agencies are retaining the 1986 regulations' coverage 
of tributaries to impoundments, updated to include the requirement that 
the tributaries meet either the relatively permanent or significant 
nexus standard. As discussed above, the agencies' longstanding 
interpretation of the Clean Water Act is that a ``water of the United 
States'' remains a ``water of the United States'' even if it is 
impounded. Since the impoundment does not ``defederalize'' the ``water 
of the United States,'' see S.D. Warren at 379 n. 5, the agencies 
similarly interpret the Clean Water Act to continue to protect 
tributaries that fall within the tributary provision of the proposed 
rule upstream from the jurisdictional impoundment.
    The agencies' longstanding interpretation of tributary for purposes

[[Page 69422]]

of Clean Water Act jurisdiction includes not only rivers and streams, 
but also lakes and ponds that flow directly or indirectly to downstream 
traditional navigable waters, interstate waters, the territorial seas, 
or impoundments of jurisdictional waters. See ``U.S. Army Corps of 
Engineers Jurisdictional Determination Form Instructional Guidebook,'' 
at 8, 9. They may be at the headwaters of the tributary network (e.g., 
a lake with no stream inlets that has an outlet to the tributary 
network) or farther downstream from the headwaters (e.g., a lake with 
both a stream inlet and a stream outlet to the tributary network). Once 
a water is determined to be a tributary, under the proposed rule the 
tributary must meet either the relatively permanent or significant 
nexus standards to be jurisdictional. Implementation of those standards 
is addressed in section V.D of this preamble.
    Finally, the 1986 regulations do not contain a definition of 
tributary, and the agencies are not proposing a definition in this 
rule. However, the agencies have decades of experience implementing the 
1986 regulations. The agencies' longstanding interpretation of 
tributary for purposes of the definition of ``waters of the United 
States'' includes natural, man-altered, or man-made water bodies that 
flow directly or indirectly into a traditional navigable water, 
interstate water, or the territorial seas. See Rapanos Guidance at 6. 
Given the extensive human modification of watercourses and hydrologic 
systems throughout the country, it is often difficult to distinguish 
between natural watercourses and watercourses that are wholly or partly 
manmade or man-altered. Because natural, man-altered, and manmade 
tributaries provide many of the same functions, especially as conduits 
for the movement of water and pollutants to other tributaries or 
directly to traditional navigable waters, interstate waters, or the 
territorial seas, the agencies have interpreted the 1986 regulations to 
cover such tributaries. The OHWM, a term unchanged since 1977, see 41 
FR 37144 (July 19, 1977); and 33 CFR 323.3(c) (1978), defines the 
lateral limits of jurisdiction in non-tidal waters, provided the limits 
of jurisdiction are not extended by adjacent wetlands.
    The agencies are proposing a different approach to tributaries than 
the NWPR's interpretation of that term. The NWPR defined ``tributary'' 
as a river, stream, or similar naturally occurring surface water 
channel that contributes surface water flow to a territorial sea or 
traditional navigable water in a typical year either directly or 
indirectly through other tributaries, jurisdictional lakes, ponds, or 
impoundments, or adjacent wetlands. A tributary was required to be 
perennial or intermittent in a typical year. 85 FR 22251, April 21, 
2020. The agencies are proposing an alternative to the NWPR's approach 
to tributaries for the reasons discussed in this section and in section 
V.B.3 of this preamble. The definition of ``tributary'' in the NWPR 
failed to advance the objective of the Clean Water Act and was 
inconsistent with scientific information about the important effects of 
ephemeral tributaries on the integrity of downstream traditional 
navigable waters. In addition, key elements of the NWPR's definition of 
tributary were extremely difficult to implement. All of these 
deficiencies are reflected in significant losses of federal protections 
on the ground. See section V.B.3 of this preamble.
6. Territorial Seas
    The Clean Water Act, the 1986 regulations, and the NWPR all include 
``the territorial seas'' as a ``water of the United States.'' This 
proposed rule makes no changes to that provision, and would retain the 
territorial seas provision near the end of the list of jurisdictional 
waters, consistent with the 1986 regulations.
    The Clean Water Act defines ``navigable waters'' to include ``the 
territorial seas'' at section 502(7). The Clean Water Act then defines 
the ``territorial seas'' in section 502(8) as ``the belt of the seas 
measured from the line of ordinary low water along that portion of the 
coast which is in direct contact with the open sea and the line marking 
the seaward limit of inland waters, and extending seaward a distance of 
three miles.''
7. Adjacent Wetlands
    As discussed further in section V.C.9.b of this preamble, in this 
proposed rule, the agencies are retaining the definition of 
``adjacent'' unchanged from the 1986 regulations, which defined 
``adjacent'' as follows: ``The term adjacent means bordering, 
contiguous, or neighboring. Wetlands separated from other waters of the 
United States by man-made dikes or barriers, natural river berms, beach 
dunes and the like are adjacent wetlands.'' In addition to retaining 
the definition of ``adjacent'' from the 1986 regulations, the proposed 
rule adds language to the adjacent wetlands provision regarding which 
adjacent wetlands can be considered ``waters of the United States'' to 
reflect the relatively permanent and significant nexus standards. As 
such, adjacent wetlands that would be jurisdictional under the proposed 
rule include wetlands adjacent to traditional navigable waters, 
interstate waters, or the territorial seas; wetlands adjacent to 
relatively permanent, standing, or continuously flowing impoundments or 
tributaries and that have a continuous surface connection to such 
waters; and wetlands adjacent to impoundments or tributaries that meet 
the significant nexus standard when the wetlands either alone or in 
combination with similarly situated waters in the region, significantly 
affect the chemical, physical, or biological integrity of foundational 
waters.
    Under the proposed rule, the agencies would continue, as they did 
under the 1986 regulations and the Rapanos Guidance, to assert 
jurisdiction over wetlands adjacent to traditional navigable waters 
without need for further assessment. Indeed, the Rapanos decision did 
not affect the scope of jurisdiction over wetlands that are adjacent to 
traditional navigable waters because at least five justices agreed that 
such wetlands are ``waters of the United States.'' See Rapanos, 547 
U.S. at 780 (Kennedy, J., concurring) (``As applied to wetlands 
adjacent to navigable-in-fact waters, the Corps' conclusive standard 
for jurisdiction rests upon a reasonable inference of ecologic 
interconnection, and the assertion of jurisdiction for those wetlands 
is sustainable under the Act by showing adjacency alone.''), id. at 810 
(Stevens, J. dissenting) (``Given that all four Justices who have 
joined this opinion would uphold the Corps' jurisdiction in both of 
these cases--and in all other cases in which either the plurality's or 
Justice Kennedy's test is satisfied--on remand each of the judgments 
should be reinstated if either of those tests is met.''); see also 
Riverside Bayview, 474 U.S. 121, 134 (``[T]he Corps' ecological 
judgment about the relationship between waters and their adjacent 
wetlands provides an adequate basis for a legal judgment that adjacent 
wetlands may be defined as waters under the Act.''); Rapanos Guidance 
at 5. Moreover, ample scientific information makes clear that the 
health and productivity of rivers and lakes, including foundational 
waters, depends upon the functions provided by upstream tributaries, 
adjacent wetlands, and ``other waters.''
    Under the proposed rule the agencies would also define ``waters of 
the United States'' to include wetlands adjacent to the territorial 
seas as they did under the 1986 regulations without need for further 
assessment; the territorial seas are categorically protected under the

[[Page 69423]]

Clean Water Act and are a type of traditional navigable water.
    The 1986 regulations also include wetlands adjacent to interstate 
waters and since interstate waters, like traditional navigable waters 
and the territorial seas, are foundational waters protected by the 
Clean Water Act, under the proposed rule the agencies would define 
``waters of the United States'' to include wetlands adjacent to 
interstate waters without need for further assessment.
    The proposed rule also would add the relatively permanent standard 
and the significant nexus standard to the 1986 regulations' adjacent 
wetlands provisions for wetlands adjacent to impoundments and 
tributaries. The relatively permanent standard and the significant 
nexus standard are independent of each other and this provision in the 
proposed rule is structured so that jurisdiction over wetlands adjacent 
to jurisdictional waters would be determined using the same standard 
under which the impoundment or tributary would be determined to be 
jurisdictional. For example, a wetland adjacent to a relatively 
permanent tributary must have a continuous surface connection to the 
tributary to be jurisdictional under the relatively permanent standard. 
Similarly, under the significant nexus standard an adjacent wetland and 
a tributary would be assessed for whether the waters either alone or in 
combination with similarly situated waters in the region, significantly 
affect the chemical, physical, or biological integrity of foundational 
waters. Wetlands adjacent to relatively permanent tributaries but that 
lack a continuous surface connection to such waters would then be 
assessed under the significant nexus, along with the tributary.
    The agencies are proposing to delete the cross reference to ``other 
waters'' as a water to which wetlands may be adjacent to be determined 
``waters of the United States.'' This change reflects the agencies' 
consideration of the jurisdictional concerns and limitations of SWANCC 
and Rapanos. The agencies have concluded that a provision that 
authorizes consideration of jurisdiction over adjacent wetlands that 
meet the relatively permanent or significant nexus standard when 
assessed based simply on connections to ``other waters'' would have too 
tenuous a connection to traditional navigable waters, interstate 
waters, or the territorial seas. Rather, any such wetlands that are 
adjacent to jurisdictional ``other waters'' could be assessed 
themselves under the ``other waters'' category to determine if they 
meet the relatively permanent or significant nexus standard. Thus, a 
wetland adjacent to, for example, a lake that meets the significant 
nexus standard under the ``other waters'' provision could not be 
determined to be jurisdictional simply because it significantly affects 
the physical integrity of the lake; rather, the wetland would need to 
be assessed under the ``other waters'' provision for whether it 
significantly affects a traditional navigable water, interstate water, 
or the territorial seas.
    Finally, the agencies are retaining the 1986 regulations' coverage 
of wetlands adjacent to impoundments and wetlands adjacent to 
tributaries to impoundments, updated to include the requirement that 
the wetlands meet either the relatively permanent or significant nexus 
standard. As discussed above, the agencies' longstanding interpretation 
of the Clean Water Act is that a ``water of the United States'' remains 
a ``water of the United States'' even if it is impounded. Since the 
impoundment does not ``defederalize'' the ``water of the United 
States,'' see S.D. Warren 379 n.5, the agencies similarly interpret the 
Clean Water Act to continue to protect wetlands adjacent to the 
jurisdictional impoundment and adjacent to jurisdictional tributaries 
to the impoundment.
    For wetlands adjacent to impoundments of jurisdictional waters, 
such waters were not addressed in the Rapanos decision and thus were 
not addressed by the agencies in the Rapanos Guidance. Under the 
proposed rule, the agencies would assess if the impoundment (i.e., the 
water identified in paragraph (a)(4) of the proposed rule) itself is or 
is not a relatively permanent, standing, or continuously flowing body 
of water. If it is, the agencies would assess if the adjacent wetlands 
have a continuous surface connection with the impoundment. Wetlands 
adjacent to relatively permanent impoundments and that lack a 
continuous surface connection to the impoundment and wetlands adjacent 
to non-relatively permanent impoundments would be considered under the 
significant nexus standard. The agencies are soliciting comment on the 
approach in the proposed rule for wetlands adjacent to impoundments and 
if they should instead consider alternative approaches for wetlands 
adjacent to impoundments, such as determining which jurisdictional 
standard should apply based on the water that is being impounded (e.g., 
if a non-relatively permanent tributary is impounded, the agencies 
would assess the wetlands adjacent to the impoundment under the 
significant nexus standard, even if the impoundment itself contains 
standing water at least seasonally).
    Finally, the agencies retain in the proposed rule the parenthetical 
from the 1986 regulations that limited the scope of jurisdictional 
adjacent wetlands under (a)(7) to wetlands adjacent to waters ``(other 
than waters that are themselves wetlands).'' Under this provision, a 
wetland is not jurisdictional simply because it is adjacent to another 
adjacent wetland. See Universal Welding & Fabrication, Inc. v. United 
States Army Corps of Engineers, 708 Fed. Appx. 301 (9th Cir. 2017) 
(``Despite the subject wetland's adjacency to another wetland, the 
Corps determined that its regulatory authority was not precluded by the 
parenthetical language within [section] 328.3(a)(7), which it 
interpreted as prohibiting the exercise of jurisdiction over a wetland 
only if based upon that wetland's adjacency to another wetland.''). The 
provision has created confusion, as some have argued that a wetland 
that is indeed adjacent to a jurisdictional tributary should not be 
determined to be a ``water of the United States'' simply because 
another adjacent wetland was located between the adjacent wetland and 
the tributary. Some have even suggested that the parenthetical flatly 
excluded all wetlands that are adjacent to other wetlands, regardless 
of any other considerations. These interpretations are inconsistent 
with the agencies' intent and longstanding interpretation of the 
parenthetical. Id. at 303 (holding the Corps' interpretation is ``the 
most reasonable reading of the regulation's text'' and ``[t]o the 
extent that Plaintiff argues that all wetlands adjacent to other 
wetlands fall outside the Corps' regulatory authority, regardless of 
their adjacency to a non-wetland water that would otherwise render them 
jurisdictional, we conclude that this reading is unsupported by the 
regulation's plain language.''). In addition, under the 1986 
regulations and longstanding practice, wetlands adjacent to an 
interstate wetland or wetlands adjacent to tidal wetlands, which are 
traditional navigable waters, are jurisdictional. Because this 
provision has caused confusion at times for the public and the 
regulated community, the agencies are requesting comment on whether to 
remove the parenthetical ``(other than waters that are themselves 
wetlands)'' because it is confusing and unnecessary.
    The agencies are proposing a different approach to adjacent 
wetlands than the NWPR's interpretation of that term. The NWPR defined 
``adjacent wetlands'' to be those wetlands that abut

[[Page 69424]]

jurisdictional waters and those non-abutting wetlands that are (1) 
``inundated by flooding'' from a jurisdictional water in a typical 
year, (2) physically separated from a jurisdictional water only by 
certain natural features (e.g., a berm, bank, or dune), or (3) 
physically separated from a jurisdictional water by an artificial 
structure that ``allows for a direct hydrologic surface connection'' 
between the wetland and the jurisdictional water in a typical year. 85 
FR 22251, April 21, 2020. Wetlands that do not have these types of 
connections to other waters were not jurisdictional.
    The agencies are not proposing the NWPR's approach to adjacent 
wetlands for the reasons discussed in this section and in section V.B.3 
of this preamble. Specifically, the definition of ``adjacent wetlands'' 
in the NWPR failed to advance the objective of the Clean Water Act and 
was inconsistent with scientific information about the important 
effects of wetlands that do not abut jurisdictional waters and that 
lack evidence of surface water to such waters on the integrity of 
downstream foundational waters. In addition, key elements of that 
definition were extremely difficult to implement. These deficiencies 
are reflected in significant losses of federal protections on the 
ground. See section V.B.3 of this preamble.
8. Exclusions
    The agencies are also proposing to repromulgate two longstanding 
exclusions from the definition of ``waters of the United States'': the 
exclusion for prior converted cropland and the exclusion for waste 
treatment systems. These longstanding exclusions from the definition 
provide important clarity.\47\ The agencies are not proposing to codify 
the list of exclusions established by the NWPR or the 2015 Clean Water 
Rule, as they view the two proposed regulatory exclusions as most 
consistent with the goal of this proposed rule to return to the 
familiar and longstanding framework that will ensure Clean Water Act 
protections, informed by relevant Supreme Court decisions. Moreover, as 
discussed in section V.D.1.b of this preamble, the agencies would 
expect to implement the proposed rule consistent with longstanding 
practice, pursuant to which they have generally not asserted 
jurisdiction over certain other features. The agencies solicit comment 
on this approach to codifying and implementing exclusions.
---------------------------------------------------------------------------

    \47\ The agencies note that they have never interpreted 
groundwater be a ``water of the United States'' under the Clean 
Water Act. See, e.g., 80 FR 37099-37100 (explaining that the 
agencies have never interpreted ``waters of the United States'' to 
include groundwater); 85 FR 22278, April 21, 2020 (explaining that 
the agencies have never interpreted ``waters of the United States'' 
to include groundwater). The proposed rule makes no change to that 
longstanding interpretation. This interpretation was recently 
confirmed by the U.S. Supreme Court. Maui, 140 S.Ct. at 1472 (``The 
upshot is that Congress was fully aware of the need to address 
groundwater pollution, but it satisfied that need through a variety 
of state-specific controls. Congress left general groundwater 
regulatory authority to the States; its failure to include 
groundwater in the general EPA permitting provision was 
deliberate.'') While groundwater itself is not a ``water of the 
United States,'' discharges of pollutants to groundwater that reach 
a jurisdictional surface require a NPDES permit where the discharge 
through groundwater is the ``functional equivalent'' of a direct 
discharge from the point source into navigable waters. Maui, 140 
S.Ct. at 1468.
---------------------------------------------------------------------------

a. Prior Converted Cropland
    The proposed rule would repromulgate the regulatory exclusion for 
prior converted cropland first codified in 1993, which provided that 
prior converted cropland is ``not `waters of the United States,''' and 
that ``for purposes of the Clean Water Act, the final authority 
regarding Clean Water Act jurisdiction remains with EPA,'' 
notwithstanding any other Federal agency's determination of an area's 
status. 58 FR 45008, 45036. This proposal would restore longstanding 
and familiar practice under the pre-2015 regulatory regime and 
generally maintain consistency between the agencies' implementation of 
the Clean Water Act and the U.S. Department of Agriculture's (USDA) 
implementation of the Food Security Act, providing certainty to farmers 
seeking to conserve and protect land and waters pursuant to federal 
law.
    The concept of prior converted cropland originates in the wetland 
conservation provisions of the Food Security Act of 1985, 16 U.S.C. 
3801 et seq. These provisions were intended to disincentivize the 
conversion of wetlands to croplands. Under the Food Security Act 
wetland conservation provisions, farmers who convert wetlands to make 
possible the production of an agricultural commodity crop lose 
eligibility for certain USDA program benefits. If a farmer had 
converted wetlands to cropland prior to December 23, 1985, then the 
land is considered prior converted cropland and the farmer does not 
lose eligibility for benefits. USDA defines prior converted cropland 
for Food Security Act purposes in its regulations at 7 CFR part 12. See 
7 CFR 12.2(a) and 12.33(b).
    In 1993, EPA and the Corps codified an exclusion for prior 
converted croplands from the definition of ``waters of the United 
States'' regulated pursuant to the Clean Water Act. The exclusion 
stated, ``[w]aters of the United States do not include prior converted 
cropland. Notwithstanding the determination of an area's status as 
prior converted cropland by any other Federal agency, for the purposes 
of the Clean Water Act, the final authority regarding Clean Water Act 
jurisdiction remains with EPA.'' 58 FR 45008, 45036; 33 CFR 328.3(a)(8) 
(1994); 40 CFR 230.3(s) (1994). The preamble stated that EPA and the 
Corps would interpret prior converted cropland consistent with the 
definition in the National Food Security Act Manual (NFSAM) published 
by the USDA Soil Conservation Service, now known as USDA's Natural 
Resource Conservation Service (NRCS). 58 FR 45031. It cited USDA's 
definition of prior converted cropland to mean ``areas that, prior to 
December 23, 1985, were drained or otherwise manipulated for the 
purpose, or having the effect, of making production of a commodity crop 
possible. PC [prior converted] cropland is inundated for no more than 
14 consecutive days during the growing season and excludes pothole or 
playa wetlands.'' Id.
    The purpose of the exclusion, as EPA and the Corps explained in the 
1993 preamble, was to ``codify existing policy,'' as the agencies had 
not been implementing the Act to include prior converted cropland, and 
to ``help achieve consistency among various federal programs affecting 
wetlands.'' Id. The preamble further stated that excluding prior 
converted cropland from ``waters of the United States'' was consistent 
with protecting aquatic resources because ``[prior converted cropland] 
has been significantly modified so that it no longer exhibits its 
natural hydrology or vegetation. Due to this manipulation, [prior 
converted] cropland no longer performs the functions or has values that 
the area did in its natural condition. PC cropland has therefore been 
significantly degraded through human activity and, for this reason, 
such areas are not treated as wetlands under the Food Security Act. 
Similarly, in light of the degraded nature of these areas, we do not 
believe that they should be treated as wetlands for the purposes of the 
CWA.'' Id. at 45032.
    The 1993 preamble stated that, consistent with the NFSAM, an area 
would lose its status as prior converted cropland if the cropland is 
``abandoned,'' meaning that crop production ceases and the area reverts 
to a wetland state. Id. at 45033. Specifically, the preamble states 
that prior converted cropland that now

[[Page 69425]]

meets wetland criteria will be considered abandoned unless ``once in 
every five years it has been used for the production of an agricultural 
commodity, or the area has been used and will continue to be used for 
the production of an agricultural commodity in a commonly used rotation 
with aquaculture, grasses, legumes, or pasture production.'' Id. at 
45034.
    Three years later, the Federal Agriculture Improvement and Reform 
Act of 1996 amended the Food Security Act and changed this 
``abandonment'' principle, replacing it with a new approach referred to 
as ``change in use.'' See Public Law 104-127, 110 Stat. 888 (1996). 
Under the 1996 amendments, an area retains its status as prior 
converted cropland for purposes of the wetland conservation provisions 
so long as it continues to be used for agricultural purposes. H.R. 
Conf. Rep. No. 104-494, at 380 (1996). EPA and the Corps did not 
address the 1996 amendments in rulemaking. In 2005, the Corps and NRCS 
issued a joint Memorandum to the Field in an effort to again align the 
Clean Water Act section 404 program with the Food Security Act by 
adopting the principle that a wetland can lose prior converted cropland 
status following a ``change in use.'' \48\ The Memorandum stated, ``[a] 
certified PC determination made by NRCS remains valid as long as the 
area is devoted to an agricultural use. If the land changes to a non-
agricultural use, the PC determination is no longer applicable and a 
new wetland determination is required for CWA purposes.'' It defined 
``agricultural use'' as ``open land planted to an agricultural crop, 
used for the production of food or fiber, used for haying or grazing, 
left idle per USDA programs, or diverted from crop production to an 
approved cultural practice that prevents erosion or other 
degradation.''
---------------------------------------------------------------------------

    \48\ This 2005 joint Memorandum was rescinded on January 28, 
2020. See https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll11/id/4288.
---------------------------------------------------------------------------

    One district court set aside the Corps' adoption of change in use 
on the grounds that it was a substantive change in Clean Water Act 
implementation that the agencies had not issued through notice and 
comment rulemaking. New Hope Power Co. v. U.S. Army Corps of Eng'rs, 
746 F. Supp. 2d 1272, 1282 (S.D. Fla. 2010). The court explained, 
``prior to issuance of the policy, prior converted cropland that was 
shifted to non-agricultural use was treated as exempt. Following [its 
issuance], the opposite was true.'' Id. Following New Hope Power, the 
agencies did not implement change in use in areas subject to the 
court's jurisdiction.
    The NWPR provided a definition of prior converted cropland for 
purposes of the Clean Water Act for the first time since 1993. 
Generally speaking, the NWPR's approach to prior converted cropland 
significantly reduced the likelihood that prior converted cropland will 
ever lose its excluded status. The NWPR provided that an area remains 
prior converted cropland for purposes of the Clean Water Act unless the 
area is abandoned and has reverted to wetlands, defining abandonment to 
occur when prior converted cropland ``is not used for, or in support 
of, agricultural purposes at least once in the immediately preceding 
five years.'' 85 FR 22339, April 21, 2020; 33 CFR 328.3(c)(9). The NWPR 
then presented a broad interpretation of ``agricultural purposes,'' 
including but not limited to crop production, haying, grazing, idling 
land for conservation uses (such as habitat; pollinator and wildlife 
management; and water storage, supply, and flood management); 
irrigation tailwater storage; crawfish farming; cranberry bogs; 
nutrient retention; and idling land for soil recovery following natural 
disasters such as hurricanes and drought. 85 FR 22321, April 21, 2020. 
Under the NWPR, prior converted cropland maintained its excluded status 
if it is used at least once in the five years preceding a 
jurisdictional determination for any of these agricultural purposes. 
Given the breadth of ``agricultural purposes'' under the NWPR, former 
cropland that reverts to wetlands otherwise meeting the definition of 
``waters of the United States'' could maintain its excluded prior 
converted cropland status simply by, for example, being grazed or idled 
for habitat conservation once in five years. These wetlands could then 
be filled without triggering any Clean Water Act regulatory protection.
    The NWPR's imprecise language in defining prior converted cropland 
for purposes of the Clean Water Act potentially extended prior 
converted cropland status far beyond those areas USDA considers prior 
converted cropland for purposes of the Food Security Act. Specifically, 
USDA's regulation defining prior converted cropland refers to 
conversion that makes possible production of an ``agricultural 
commodity,'' which provides for annual tilling of the soil, while the 
NWPR defined prior converted cropland to encompass any area used to 
produce an ``agricultural product,'' a term not used in the regulations 
that therefore introduces significant ambiguity and further 
distinguishes the Clean Water Act's prior converted cropland exclusion 
from USDA's approach. Compare 7 CFR 12.2(a) with 33 CFR 328.3(c)(9). 
The NWPR's definition provided that the agencies would recognize prior 
converted cropland designations made by USDA, 33 CFR 328.3(c)(9), but 
the list of examples that the NWPR provided for ``agricultural 
product'' suggests the term is significantly broader than the USDA's 
exclusion for land used for ``commodity crops.'' The absence of a 
definition for the term ``agricultural product'' or any explanation as 
to how it is different from a ``commodity crop'' undermined 
transparency and the original purpose of the exclusion, which was to 
help achieve consistency among various federal programs affecting 
wetlands. See 58 FR 45031.
    The proposed rule would restore the exclusion's original purpose of 
maintaining consistency among federal programs addressing wetlands, 
while furthering the objective of the Clean Water Act. Id. at 45031-32. 
As was the case between 1993 and promulgation of the NWPR, the agencies 
propose that, for purposes of the Clean Water Act exclusion, a 
landowner may demonstrate that a water retains its prior converted 
cropland status through a USDA prior converted cropland certification. 
See id. at 45033 (``recognizing [NRCS]'s expertise in making these 
[prior converted] cropland determinations, we will continue to rely 
generally on determinations made by [NRCS].''). The agencies' proposal 
would maintain the provision promulgated in 1993 that EPA retains final 
authority to determine whether an area is subject to the requirements 
of the Clean Water Act. Moreover, by limiting the implementation of the 
exclusion to areas with a USDA prior converted cropland certification, 
the exclusion would only encompass significantly degraded waters that 
no longer perform the functions of the waters in their natural 
condition. See id. at 45032. The proposal would therefore align the 
exclusion with the objective of the Clean Water Act, to restore and 
maintain the integrity of the nation's waters, consistent with the 
agencies' intent in 1993.
    The agencies request comment as to whether any other changes could 
enhance consistency between the prior converted cropland status under 
the Food Security Act and the exclusion of prior converted cropland 
under the Clean Water Act, while effectuating the goals of the Clean 
Water Act. One way of increasing consistency could be to implement the 
text of the original prior

[[Page 69426]]

converted cropland exclusion consistent with USDA's current and 
longstanding approach, outlined in USDA's final rule addressing the 
Highly Erodible Land and Wetland Conservation provisions of the Food 
Security Act of 1985. 85 FR 53137 (August 28, 2020). Pursuant to this 
approach, cropland would lose its exclusion if it ``changes use,'' as 
USDA interprets that term. See 61 FR 47036 (September 6, 1996); 7 CFR 
12.30(c)(6) (``As long as the affected person is in compliance with the 
wetland conservation provision of this part, and as long as the area is 
devoted to the use and management of the land for production of food, 
fiber, or horticultural crops, a certification made under this section 
will remain valid and in effect until such time as the person affected 
by the certification requests review of the certification by NRCS.''). 
This approach would fulfill the exclusion's purpose of ensuring 
consistency among federal programs affecting wetlands. See 58 FR 45031. 
Alternatively, the agencies request comment as to whether to implement 
the exclusion consistent with the interpretation in the 1993 preamble, 
under which an area only loses its prior converted cropland status if 
the cropland is ``abandoned,'' meaning that commodity crop production 
ceases and the area reverts to a wetland state. See id. at 45033. Under 
this approach, an area that has been designated as prior converted 
cropland and has not reverted to a wetland state (meaning the area 
would not meet the definition of wetland) would not become a ``water of 
the United States'' regardless of agricultural activity. However, an 
area which has been designated as prior converted cropland and has 
reverted to a wetland state could be reviewed for a potential loss of 
the exclusion status under the Clean Water Act. The following scenarios 
provide examples of the way in which the exclusion could cease 
following either ``abandonment'' or ``change in use.''
    First, if the agencies were to apply the abandonment principle, the 
reverted wetland area would only regain jurisdictional status if:
    (1) The area had not been used for the production of an 
agricultural commodity, or the area had not been used and would 
continue to not be used for the production of an agricultural commodity 
in a commonly used rotation with aquaculture, grasses, legumes, or 
pasture production, at least once in every five years and
    (2) the area reverts to a wetland that meets the definition of 
``waters of the United States.''
    Under the abandonment principle, if an agricultural producer with 
an area designated as prior converted cropland fails to produce an 
agricultural commodity, or the area fails to be used in rotation as 
described above, for a period of six years, and the prior converted 
cropland area reverts to wetland, the wetland would lose the benefit of 
the exclusion and discharges of a pollutant to the wetland would be 
subject to regulation under the Clean Water Act if it meets the 
definition of ``waters of the United States'' and activities taking 
place on it are not otherwise exempt. In a second example of 
abandonment, if an agricultural producer with an area designated as 
prior converted cropland produces an agricultural commodity two years 
prior to selling its property for a residential development, the area 
retains its prior converted cropland designation even if it reverts to 
wetlands that would otherwise meet the definition of ``waters of the 
United States.'' In this example, discharges of dredged or fill 
material from the construction of the residential development into the 
wetlands which occurred within the three years remaining out of the 
five-year timeframe allowed before the abandonment provision would be 
triggered would not require authorization under Clean Water Act section 
404.
    Alternatively, if the agencies were to apply the change in use 
principle in the second example scenario above, the reverted wetland 
area could regain jurisdictional status if it were subject to a change 
in use, meaning the area is no longer available for production of an 
agricultural commodity, and if the reverted wetland met the definition 
of ``waters of the United States.'' In that scenario, if an 
agricultural producer with an area certified by NRCS as prior converted 
cropland produces an agricultural commodity two years prior to selling 
their property for a residential development, the prior converted 
cropland designation would no longer apply when the area is no longer 
available for the production of an agricultural commodity crop. If the 
prior converted cropland area reverts to wetlands and meets the 
definition of ``waters of the United States'' the discharge of dredged 
or fill material from the construction of the residential development 
would require authorization under Clean Water Act section 404. The 
agencies hope this discussion and set of examples will illuminate the 
differences between interpreting the prior converted cropland 
designation to cease upon abandonment as opposed to change in use, to 
allow for input to best inform the agencies' path forward.
    The agencies solicit comment on alternative approaches to the prior 
converted cropland exclusion as well, including retaining the 
definition of prior converted cropland in the NWPR. While the agencies 
have concerns with that definition, as discussed above, the agencies 
request comment with regard to those concerns and whether they should 
nonetheless retain the NWPR's interpretation that prior converted 
cropland retains its designation so long as it has been used for 
agricultural purposes at least once in the preceding five years, and 
that agricultural purposes include crop production, haying, grazing, 
idling land for conservation uses (such as habitat; pollinator and 
wildlife management; and water storage, supply, and flood management); 
irrigation tailwater storage; crawfish farming; cranberry bogs; 
nutrient retention; and idling land for soil recovery following natural 
disasters like hurricanes and drought. Finally, the agencies request 
comment as to whether certain specific types of documentation aside 
from USDA certification should be considered sufficient to demonstrate 
that an area is prior converted cropland.
b. Waste Treatment System Exclusion
    The agencies are also proposing to retain the waste treatment 
system exclusion from the 1986 regulations and return to the 
longstanding version of the exclusion that the agencies have 
implemented for decades. Specifically, the proposed rule provides that 
``[w]aste treatment systems, including treatment ponds or lagoons, 
designed to meet the requirements of the Clean Water Act are not waters 
of the United States.'' This language is the same as the agencies' 1986 
regulation's version of the waste treatment system exclusion, with a 
ministerial change to delete the exclusion's cross-reference to a 
definition of ``cooling ponds'' that no longer exists in the Code of 
Federal Regulations, and the addition of a comma that clarifies the 
agencies' longstanding implementation of the exclusion as applying only 
to systems that are designed to meet the requirements of the Act.\49\
---------------------------------------------------------------------------

    \49\ The NWPR defined a waste treatment system as ``all 
components, including lagoons and treatment ponds (such as settling 
or cooling ponds), designed to either convey or retain, concentrate, 
settle, reduce, or remove pollutants, either actively or passively, 
from wastewater prior to discharge (or eliminating any such 
discharge).'' 85 FR 22339, April 21, 2020.
---------------------------------------------------------------------------

    EPA first promulgated the waste treatment system exclusion in a 
1979

[[Page 69427]]

notice-and-comment rulemaking revising the definition of ``waters of 
the United States'' in the agency's NPDES regulations. 44 FR 32854 
(June 7, 1979). A ``frequently encountered comment'' was that ``waste 
treatment lagoons or other waste treatment systems should not be 
considered waters of the United States.'' Id. at 32858. EPA agreed, 
except as to cooling ponds that otherwise meet the criteria for 
``waters of the United States.'' Id. The 1979 revised definition of 
``waters of the United States'' thus provided that ``waste treatment 
systems (other than cooling ponds meeting the criteria of this 
paragraph) are not waters of the United States.'' Id. at 32901 (40 CFR 
122.3(t) (1979)).
    The following year, EPA revised the exclusion, but again only in 
its NPDES regulations, to clarify its application to treatment ponds 
and lagoons and to specify the type of cooling ponds that fall outside 
the scope of the exclusion. 45 FR 33290, 33298 (May 19, 1980). EPA 
further decided to revise this version of the exclusion to clarify that 
``treatment systems created in [waters of the United States] or from 
their impoundment remain waters of the United States,'' while 
``[m]anmade waste treatment systems are not waters of the United 
States.'' Id. The revised exclusion read: ``[w]aste treatment systems, 
including treatment ponds or lagoons designed to meet the requirements 
of CWA (other than cooling ponds as defined in 40 CFR [section] 
423.11(m) which also meet the criteria of this definition) are not 
waters of the United States.'' The provision further provided that the 
exclusion ``applies only to manmade bodies of water which neither were 
originally created in waters of the United States (such as a disposal 
area in wetlands) nor resulted from the impoundment of waters of the 
United States.'' 45 FR 33424 (40 CFR 122.3).
    Two months following this revision, EPA took action to ``suspend[ ] 
a portion'' of the waste treatment system exclusion in its NPDES 
regulations in response to concerns raised in petitions for review of 
the revised definition of ``waters of the United States.'' 45 FR 48620 
(July 21, 1980). EPA explained that industry petitioners objected to 
limiting the waste treatment system exclusion to manmade features, 
arguing that the revised exclusion ``would require them to obtain 
permits for discharges into existing waste treatment systems, such as 
power plant ash ponds, which had been in existence for many years.'' 
Id. at 48620. The petitioners argued that ``[i]n many cases, . . . EPA 
had issued permits for discharges from, not into, these systems.'' Id. 
Agreeing that the regulation ``may be overly broad'' and ``should be 
carefully re-examined,'' EPA announced that it was ``suspending [the] 
effectiveness'' of the sentence limiting the exclusion to manmade 
bodies of water. Id. EPA then stated that it ``intend[ed] promptly to 
develop a revised definition and to publish it as a proposed rule for 
public comment,'' after which the agency would decide whether to 
``amend the rule, or terminate the suspension.'' Id.
    In 1983, EPA republished the waste treatment system exclusion in 
its NPDES regulations with a note explaining that the agency's July 
1980 action had ``suspended until further notice'' the sentence 
limiting the exclusion to manmade bodies of water, and that the 1983 
action ``continue[d] that suspension.'' 48 FR 14146, 14157 (April 1, 
1983) (40 CFR 122.2) (1984). EPA subsequently omitted the exclusion's 
suspended sentence altogether in revising the definition of ``waters of 
the United States'' in other parts of the Code of Federal Regulations. 
See, e.g., 53 FR 20764, 20774 (June 6, 1988) (revising EPA's section 
404 program definitions at 40 CFR 232.2).
    Separately, the Corps published an updated definition of ``waters 
of the United States'' in 1986. This definition contained the waste 
treatment system exclusion, but it likewise did not include the 
exclusion's suspended sentence: ``Waste treatment systems, including 
treatment ponds or lagoons designed to meet the requirements of CWA 
(other than cooling ponds as defined in 40 CFR 123.11(m) which also 
meet the criteria of this definition) are not waters of the United 
States.'' 51 FR 41250 (November 13, 1986); 33 CFR 328.3 (1987).
    Later revisions to the definition of cooling ponds rendered the 
exclusion's cross-reference to 40 CFR 123.11(m) outdated. See 47 FR 
52290, 52291, 52305 (November 19, 1982) (revising regulations related 
to cooling waste streams and deleting definition of cooling ponds). In 
this rulemaking, the agencies are proposing to delete this obsolete 
cross-reference, consistent with other recent rulemakings addressing 
the definition of ``waters of the United States.'' \50\
---------------------------------------------------------------------------

    \50\ 85 FR 22250, 22325 (April 21, 2020) (``One ministerial 
change [to the waste treatment system exclusion] is the deletion of 
a cross-reference to a definition of ``cooling ponds'' that no 
longer exists in the Code of Federal Regulations.''); 80 FR 37054, 
37097 (June 29, 2015) (``One ministerial change [to the waste 
treatment system exclusion] is the deletion of a cross-reference in 
the current language to an EPA regulation that no longer exists.'').
---------------------------------------------------------------------------

    The proposed rule also deletes the suspended sentence in EPA's 
NPDES regulations limiting application of the exclusion to manmade 
bodies of water. The suspended sentence, which appeared only in the 
version of the waste treatment system exclusion contained in EPA's 
NPDES regulations (40 CFR 122.2) prior to the NWPR, states: ``This 
exclusion applies only to manmade bodies of water which neither were 
originally created in waters of the United States (such as disposal 
area in wetlands) nor resulted from the impoundment of waters of the 
United States.'' As discussed above, EPA suspended this sentence 
limiting application of the exclusion in 1980. As a result, EPA has not 
limited application of the waste treatment system exclusion to manmade 
bodies of water for over four decades. The proposed rule maintains the 
NWPR's deletion of the suspended sentence in EPA's NPDES regulations 
and is thus consistent with the other versions of the exclusion found 
in EPA's and the Corps' 1986 regulations and EPA's decades-long 
practice implementing the exclusion under the 1986 regulations.
    Indeed, for decades, both agencies have not limited application of 
the exclusion to manmade bodies of water. This longstanding approach to 
excluding waste treatment systems--including those that are not manmade 
bodies of water--is a reasonable and lawful exercise of the agencies' 
authority to determine the scope of ``waters of the United States,'' 
see Ohio Valley Envtl. Coal. v. Aracoma Coal Co., 556 F.3d 177, 212 
(4th Cir. 2009) (upholding the waste treatment system exclusion as a 
lawful exercise of the agencies' ``authority to determine which waters 
are covered by the CWA''). For all of these reasons, the agencies are 
proposing to delete the suspended sentence referenced above. The 
agencies solicit comment on this approach.
    Further, consistent with the 1986 regulations, the proposed rule 
provides that a waste treatment system must be ``designed to meet the 
requirements of the Clean Water Act.'' A waste treatment system may be 
``designed to meet the requirements of the Clean Water Act'' where, for 
example, it is constructed pursuant to a Clean Water Act section 404 
permit, Ohio Valley Envtl. Coalition v. Aracoma Coal Co., 556 F.3d 177, 
214-15 (4th Cir. 2009), or where it is ``incorporated in an NPDES 
permit as part of a treatment system,'' N. Cal. River Watch v. City of 
Healdsburg, 496 F.3d 993, 1001 (9th Cir. 2007).
    To be clear, the exclusion does not free a discharger from the need 
to comply with the Clean Water Act for pollutants discharged from a 
waste treatment system to a water of the

[[Page 69428]]

United States; only discharges into the waste treatment system are 
excluded from the Act's requirements. As such, any entity would need to 
comply with the Clean Water Act by obtaining a section 404 permit for a 
new waste treatment system constructed in ``waters of the United 
States,'' and a section 402 permit for discharges of pollutants from a 
waste treatment system into ``waters of the United States.'' Further, 
consistent with the agencies' general practice implementing the 
exclusion, under the proposed rule, a waste treatment system that is 
abandoned or otherwise ceases to serve the treatment function for which 
it was designed would not continue to qualify for the exclusion and 
could be deemed jurisdictional if it otherwise meets the proposed 
rule's definition of ``waters of the United States.''
    The agencies are aware of concerns raised by some stakeholders that 
features subject to the waste treatment system exclusion could be used 
by any party to dispose waste or discharge pollutants with abandon. In 
this proposal, the agencies are clarifying that for waters that would 
otherwise meet the proposed rule's definition of ``waters of the United 
States,'' the agencies' intent, consistent with prior practice, is that 
the waste treatment system exclusion is generally available only to the 
permittee using the system for the treatment function for which such 
system was designed. Relatedly, the agencies are also clarifying that, 
consistent with the agencies' longstanding practice, a waste treatment 
system does not sever upstream waters from Clean Water Act 
jurisdiction. In other words, discharges into those upstream waters 
remain subject to Clean Water Act requirements and thus may require a 
section 402 permit.\51\ The agencies request comment on whether to add 
language to the regulatory text of the waste treatment system exclusion 
clarifying these aspects of the exclusion.
---------------------------------------------------------------------------

    \51\ See, e.g., Memorandum of Non-Concurrence with 
Jurisdictional Determinations POA-1992-574 & POA-1992-574-Z (October 
25, 2007), available at https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll5/id/1454 (``EPA and the Corps agree 
that the agencies' designation of a portion of waters of the U.S. as 
part of a waste treatment system does not itself alter CWA 
jurisdiction over any waters remaining upstream of such system.'').
---------------------------------------------------------------------------

9. Other Definitions
    The proposed rule contains a number of defined terms unchanged from 
the 1986 regulations. Some of the terms appeared only in the Corps' 
regulations, but in the 2019 Rule and the NWPR, the agencies included 
these definitions in both agencies' regulations. The agencies are not 
proposing to amend the definitions of ``wetland,'' ``high tide line,'' 
``ordinary high water mark,'' and ``tidal water'' from the 1986 
regulations, but to provide additional clarity and consistency in 
comparison to the 1986 regulations, the proposed rule would include all 
the defined terms in EPA's regulations, where such definitions are not 
already contained. Only the definition of the term ``adjacent'' was 
amended in the NWPR; the agencies are proposing to define the term 
unchanged from the 1986 regulations. This section briefly describes the 
definitions and their history and implementation. See section V.D of 
this preamble for further discussion on implementation.
a. Wetlands
    The proposed rule makes no changes to the definition of 
``wetlands'' contained in the NWPR, which made no changes to the 1986 
regulations and defined ``wetlands'' as ``those areas that are 
inundated or saturated by surface or ground water at a frequency and 
duration sufficient to support, and that under normal circumstances do 
support, a prevalence of vegetation typically adapted for life in 
saturated soil conditions. Wetlands generally include swamps, marshes, 
bogs, and similar areas.'' The agencies are not proposing to amend this 
definition.
b. Adjacent
    The proposed rule defines the term ``adjacent'' with no changes 
from the 1986 regulations as ``bordering, contiguous, or neighboring. 
Wetlands separated from other `waters of the United States' by man-made 
dikes or barriers, natural river berms, beach dunes and the like are 
`adjacent wetlands.' '' This is a longstanding and familiar definition 
that is supported by Supreme Court case law and science. See, e.g., 
Riverside Bayview, 474 U.S. 121, 134 (`` . . . the Corps' ecological 
judgment about the relationship between waters and their adjacent 
wetlands provides an adequate basis for a legal judgment that adjacent 
wetlands may be defined as waters under the Act.''). The Supreme Court 
has noted that adjacent wetlands under this definition are not limited 
to only those that exist as a result of ``flooding or permeation by 
water having its source in adjacent bodies of open water,'' and that 
wetlands may affect the water quality in adjacent waters even when 
those waters do not actually inundate the wetlands. Id. at 134-35. As 
discussed in section V.C.7 of this preamble and consistent with the 
pre-2015 regulatory regime, to be jurisdictional under the adjacent 
wetlands provision of the proposed rule, wetlands must meet this 
definition of adjacent and either be adjacent to a traditional 
navigable water, interstate water, or territorial sea or otherwise fall 
within the adjacent wetlands provision and meet either the relatively 
permanent standard or the significant nexus standard. See section V.D 
of this preamble for further discussion on implementation.
    The NWPR substantially narrowed the definition of ``adjacent'' 
based primarily on the Rapanos plurality standard. The NWPR interprets 
``adjacent wetlands'' to be those wetlands that abut jurisdictional 
waters and those non-abutting wetlands that are (1) ``inundated by 
flooding'' from a jurisdictional water in a typical year, (2) 
physically separated from a jurisdictional water only by certain 
natural features (e.g., a berm, bank, or dune), or (3) physically 
separated from a jurisdictional water by an artificial structure that 
``allows for a direct hydrologic surface connection'' between the 
wetland and the jurisdictional water in a typical year. 85 FR 22251, 
April 21, 2020. Wetlands that do not have these types of connections to 
other jurisdictional waters are not jurisdictional under the NWPR. The 
NWPR's limits on the scope of protected wetlands to those that touch or 
demonstrate evidence of a regular surface water connection to other 
jurisdictional waters are inconsistent with the scientific information 
in the record demonstrating the effects of wetlands on the integrity of 
downstream waters when they have other types of surface connections, 
such as wetlands that overflow and flood jurisdictional waters or 
wetlands with less frequent surface water connections due to long-term 
drought; wetlands with shallow subsurface connections to other 
protected waters; or other wetlands proximate to jurisdictional waters. 
As discussed in section V.B.3.d of this preamble, within the first year 
of implementation of the NWPR, 70% of streams and wetlands evaluated 
were found to be non-jurisdictional, including 15,675 wetlands that did 
not meet the NWPR's revised adjacency criteria. The agencies anticipate 
that this increase in determinations of wetlands to be non-
jurisdictional as compared to prior regulations could reduce the 
integrity of the nation's waters (see section V.B.3.d of this 
preamble), particularly in the absence of comparable state, tribal, or 
local regulations and associated efforts to avoid, minimize, or 
compensate for impacts to aquatic resources regulated under such 
programs.

[[Page 69429]]

    Proposing the longstanding definition of ``adjacent'' is consistent 
with Riverside Bayview and Justice Kennedy's opinion in Rapanos, as 
well as with scientific information indicating that wetlands meeting 
this definition provide important functions that contribute to the 
integrity of traditional navigable waters, interstate waters, and 
territorial seas. See section V.A of this preamble. The agencies are 
proposing to retain the provision of this definition from the 1986 
regulations that includes wetlands separated from other ``waters of the 
United States'' by man-made dikes or barriers, natural river berms, 
beach dunes and the like. The Supreme Court in Riverside Bayview 
deferred to the agencies' interpretation of the Clean Water Act to 
include adjacent wetlands. Riverside Bayview, 474 U.S. at 135 (``the 
Corps has concluded that wetlands adjacent to lakes, rivers, streams, 
and other bodies of water may function as integral parts of the aquatic 
environment even when the moisture creating the wetlands does not find 
its source in the adjacent bodies of water. . . . [W]e therefore 
conclude that a definition of `waters of the United States' 
encompassing all wetlands adjacent to other bodies of water over which 
the Corps has jurisdiction is a permissible interpretation of the 
Act''). Justice Kennedy stated: ``In many cases, moreover, filling in 
wetlands separated from another water by a berm can mean that 
floodwater, impurities, or runoff that would have been stored or 
contained in the wetlands will instead flow out to major waterways. 
With these concerns in mind, the Corps' definition of adjacency is a 
reasonable one, for it may be the absence of an interchange of waters 
prior to the dredge and fill activity that makes protection of the 
wetlands critical to the statutory scheme.'' Rapanos at 775.
    Wetlands separated from other ``waters of the United States'' by 
man-made dikes or barriers, natural river berms, or beach dunes 
generally continue to have a hydrologic connection to downstream 
waters. This is because constructed dikes or barriers, natural river 
berms, beach dunes, and the like typically do not block all water flow. 
This hydrologic connection can occur via seepage or over-topping, where 
water from the nearby traditional navigable water, interstate water, 
the territorial seas, impoundment, or tributary periodically overtops 
the berm or other similar feature. Water can also overtop a natural 
berm or artificial dike and flow from the wetland to the water to which 
it is adjacent.
    River berms, natural levees, and beach dunes are all examples of 
features that are formed by natural processes and do not isolate 
adjacent wetlands from the streams, lakes, or tidal waters that form 
them. River berms, natural levees, and the wetlands and waters behind 
them are part of the floodplain. Natural levees are discontinuous, 
which allows for a hydrologic connection to the stream or river via 
openings in the levees and thus the periodic mixing of river water and 
backwater. Beach dunes are formed by tidal or wave action, and the 
wetlands that establish behind them experience a fluctuating water 
table seasonally and yearly in synchrony with sea or lake level 
changes. The terms earthen dam, dike, berm, and levee are used to 
describe similar constructed structures whose primary purpose is to 
help control flood waters. Such man-made levees and similar structures 
also do not isolate adjacent wetlands.
    In addition, adjacent wetlands separated from a jurisdictional 
water by a natural or man-made berm serve many of the same functions as 
other adjacent wetlands. There are also other important considerations, 
such as chemical and biological functions provided by the wetland. For 
instance, adjacent waters behind berms can still serve important water 
quality functions, serving to filter pollutants and sediment before 
they reach downstream waters. Wetlands behind berms, where the system 
is extensive, can help reduce the impacts of storm surges caused by 
hurricanes. Such adjacent wetlands, separated from waters by berms and 
the like, maintain ecological connection with those waters. For 
example, wetlands behind natural and artificial berms can provide 
important habitat for aquatic and semi-aquatic species that utilize 
both the wetlands and the nearby water, including for basic food, 
shelter, and reproductive requirements. Though a berm may reduce 
habitat functional value and may prevent some species from moving back 
and forth from the wetland to the nearby jurisdictional water, many 
species remain able to utilize both habitats despite the presence of 
such a berm, and in some cases, the natural or artificial barrier can 
serve the purpose of providing extra refuge from predators or for 
rearing young or other life cycle needs.
    Thus, the longstanding definition of ``adjacent'' reasonably 
advances the objective of the Act. To be jurisdictional under the 
proposed rule, however, wetlands must meet this definition of adjacent 
and either be adjacent to a traditional navigable water, interstate 
water, or territorial sea or otherwise fall within the adjacent 
wetlands provision and meet either the relatively permanent standard or 
the significant nexus standard.
c. High Tide Line
    The proposed rule makes no changes to the definition of ``high tide 
line'' contained in the NWPR, which made no changes to the 1986 
regulations and defines the term ``high tide line'' as ``the line of 
intersection of the land with the water's surface at the maximum height 
reached by a rising tide. The high tide line may be determined, in the 
absence of actual data, by a line of oil or scum along shore objects, a 
more or less continuous deposit of fine shell or debris on the 
foreshore or berm, other physical markings or characteristics, 
vegetation lines, tidal gages, or other suitable means that delineate 
the general height reached by a rising tide. The line encompasses 
spring high tides and other high tides that occur with periodic 
frequency, but does not include storm surges in which there is a 
departure from the normal or predicted reach of the tide due to the 
piling up of water against a coast by strong winds such as those 
accompanying a hurricane or other intense storm.'' The agencies are not 
proposing to amend this definition. This definition has been in place 
since 1977 (see 42 FR 37144, July 19, 1977; and 33 CFR 323.3(c) 
(1978)), and like the definitions discussed above, is a well-
established definition that is familiar to regulators, environmental 
consultants, and the scientific community. This term defines the 
landward limits of jurisdiction in tidal waters when there are no 
adjacent non-tidal ``waters of the United States.'' 51 FR 41206, 41251 
(November 13, 1986).
d. Ordinary High Water Mark
    The proposed rule makes no changes to the definition of ``ordinary 
high water mark'' (``OHWM'') contained in the NWPR, which made no 
changes to the 1986 regulations and defines OHWM as ``that line on the 
shore established by the fluctuations of water and indicated by 
physical characteristics such as clear, natural line impressed on the 
bank, shelving, changes in the character of soil, destruction of 
terrestrial vegetation, the presence of litter and debris, or other 
appropriate means that consider the characteristics of the surrounding 
areas.'' This term, unchanged since 1977, see 41 FR 37144 (July 19, 
1977) and 33 CFR 323.3(c) (1978), defines the lateral limits of 
jurisdiction in non-tidal waters, provided the limits of jurisdiction 
are not extended by adjacent wetlands. When adjacent wetlands are 
present, Clean Water Act jurisdiction extends beyond the OHWM

[[Page 69430]]

to the limits of the adjacent wetlands. Id.; Regulatory Guidance Letter 
(RGL) 05-05 (December 7, 2005) at 1. The agencies are not proposing to 
amend this definition. Establishing the presence of a non-tidal 
traditional navigable water's OHWM can be informed by remote sensing 
and mapping information.
e. Tidal Water
    The proposed rule makes no changes to the definition of ``tidal 
water'' contained in the NWPR, which made no changes to the 1986 
regulations, and defines the term ``tidal water'' as ``those waters 
that rise and fall in a predictable and measurable rhythm or cycle due 
to the gravitational pulls of the moon and sun. Tidal waters end where 
the rise and fall of the water surface can no longer be practically 
measured in a predictable rhythm due to masking by hydrologic, wind, or 
other effects.'' Although the term ``tidal waters'' was referenced 
throughout the Corps' 1977 regulations, including the preamble (e.g., 
see 42 FR 37123, 37128, 37132, 37144, 37161, July 19, 1977), it was not 
defined in regulations until 1986. As explained in the preamble to the 
1986 regulations, this definition is consistent with the way the Corps 
has traditionally interpreted the term. 51 FR 41217, 41218 (November 
13,1986). The agencies are not proposing to amend this definition.
10. Significantly Affect
    The proposed rule defines the term ``significantly affect'' for 
purposes of determining whether a water meets the significant nexus 
standard to mean ``more than speculative or insubstantial effects on 
the chemical, physical, or biological integrity of'' a traditional 
navigable water, interstate water, or the territorial seas. Waters, 
including wetlands, would be evaluated either alone, or in combination 
with other similarly situated waters in the region,\52\ based on the 
functions the evaluated waters perform. The proposal also identifies 
specific ``factors'' that will be considered when assessing whether the 
``functions'' provided by the water, alone or in combination, are more 
than speculative or insubstantial. The factors include readily 
understood criteria (e.g., distance, hydrologic metrics, and 
climatological metrics) that influence the types and strength of 
chemical, physical, or biological connections and associated effects on 
those downstream foundational waters. The functions can include 
measurable indicators (e.g., nutrient recycling, runoff storage) that 
are tied to the chemical, physical, and biological integrity of 
foundational waters. The definition of ``significantly affect'' is 
derived from the objective of the Clean Water Act, and is informed by 
and consistent with Supreme Court case law. It is also informed by the 
agencies' technical and scientific judgment and supported by the best 
available science regarding what waters must be protected to achieve 
the Clean Water Act's objective. The proposed definition recognizes 
that not all waters have the requisite connection to foundational 
waters sufficient to be determined jurisdictional.
---------------------------------------------------------------------------

    \52\ For example, under the Rapanos Guidance, the agencies 
consider the flow and functions of the reach of a tributary that is 
the same stream order (i.e., from the point of confluence, where two 
lower order streams meet to form the tributary, downstream to the 
point such tributary enters a higher order stream) together with the 
functions performed by all the wetlands adjacent to that tributary 
in evaluating whether a significant nexus is present. Rapanos 
Guidance at 10. The agencies are taking comment on other approaches 
to ``similarly situated'' and ``in the region'' in section 
V.D.2.b.ii of this preamble.
---------------------------------------------------------------------------

    The significant nexus standard that would be established by the 
proposed rule is carefully constructed to fall within the bounds of the 
Clean Water Act. First, the standard is limited to consideration of 
effects on downstream traditional navigable waters, interstate waters, 
and the territorial seas. Second, the standard is limited to effects 
only on the three statutorily identified aspects of those foundational 
waters: Chemical, physical, or biological integrity. Third, the 
standard cannot be met by merely speculative or insubstantial effects 
on those aspects of those foundational waters. Thus, the agencies must 
assess a particular water and determine whether, based on the factual 
record, relevant scientific data and information, and available tools, 
the water, alone or combination, has a more than speculative or 
insubstantial effect on the chemical, physical, or biological integrity 
of a specific foundational water.
    This section explains the proposed definition and its consistency 
with the Rapanos Guidance, then explains how the proposed definition is 
consistent with the best available science and case law, and, finally, 
provides examples of functions that are not relevant to the significant 
nexus standard and waters that have not met the significant nexus 
standard under the pre-2015 regulatory regime.
    The proposed definition is consistent with the pre-2015 regulatory 
regime. Under the Rapanos Guidance, the agencies evaluate whether 
waters ``are likely to have an effect that is more than speculative or 
insubstantial on the chemical, physical, and biological integrity of a 
traditional navigable water.'' Rapanos Guidance at 11.
    In evaluating a water individually or in combination with other 
similarly situated waters for the presence of a significant nexus to a 
traditional navigable water, interstate water, or the territorial seas, 
the agencies consider factors that influence the types and strength of 
the chemical, physical, or biological connections and associated 
effects on those downstream waters. The agencies are proposing to 
include in the definition of ``significantly affect'' the factors to be 
considered in assessing the strength of the effects: (1) The distance 
from a jurisdictional water, (2) the distance from the downstream 
traditional navigable water, interstate water, or territorial sea, (3) 
hydrologic factors, including subsurface flow, (4) the size, density, 
and/or number of waters that have been determined to be similarly 
situated (and thus can be evaluated in combination), and (5) 
climatological variables such as temperature, rainfall, and snowpack. 
The agencies are seeking comment on this list of factors and whether 
there are other factors that influence the types and strength of the 
chemical, physical, or biological connections and associated effects on 
those downstream waters the agencies should consider.
    These factors influence the strength of the connections and 
associated effects that streams, wetlands, and open waters have on the 
chemical, physical, and biological integrity of traditional navigable 
waters, interstate waters, and territorial seas and are not the 
functions themselves that the agencies might consider as part of a 
significant nexus standard. These factors also cannot be considered in 
isolation, but rather must be considered together and in the context of 
the case-specific analysis. For example, the likelihood of a connection 
with associated significant effects is generally greater with 
increasing number and size of the aquatic resource or resources being 
considered and decreasing distance from the identified foundational 
water as well as with increased density of the waters that can be 
considered in combination as similarly situated waters. However, the 
agencies also recognize that in watersheds with fewer aquatic 
resources, even a small number or low density of similarly situated 
waters can have disproportionate effects on downstream foundational 
waters. Hydrologic factors include volume (or magnitude), duration, 
timing, rate, and frequency of flow, size of the watershed or 
subwatershed, and surface and shallow subsurface hydrologic 
connections. The presence of a surface

[[Page 69431]]

or shallow subsurface hydrologic connection, as well as increased 
frequency, volume, or duration of such connections, can increase the 
chemical, physical (i.e., hydrologic), or biological impact that a 
water has on downstream foundational waters. In other situations, 
streams with low duration but a high volume of flow can significantly 
affect downstream foundational waters by transporting large volumes of 
water, sediment, and woody debris that help maintain the integrity of 
those larger downstream waters. The lack of hydrologic connections can 
also contribute to the strength of effects for certain functions such 
as floodwater attenuation or the retention and transformation of 
pollutants. Climatological factors like temperature, rainfall, and 
snowpack in a given region can influence the agencies' consideration of 
the effects of subject waters on downstream foundational waters by 
providing information about expected hydrology and the expected 
seasonality of connections and associated effects. The agencies are 
seeking comment on whether these factors are sufficiently clear or if 
further explanation or examples would be useful.
    The agencies are also taking comment on whether it would be useful 
to add to the definition of ``significantly affect'' a specific list of 
functions of upstream waters to assess when making a significant nexus 
determination. The Rapanos Guidance identified some relevant functions 
upstream waters can provide including temperature regulation, sediment 
trapping and transport, nutrient recycling, pollutant trapping, 
transformation, filtering and transport, retention and attenuation of 
floodwaters and runoff, contribution of flow, provision of habitat for 
aquatic species that also live in foundational waters (e.g., for 
refuge, feeding, nesting, spawning, or rearing young), and provision 
and export of food resources for aquatic species located in 
foundational waters. Evaluation of such functions is consistent with 
the agencies' implementation of the pre-2015 regulatory regime. See 
Rapanos Guidance at 8, 9. Under the pre-2015 regulatory regime, a water 
did not need to perform all of the listed functions. See U.S. Army 
Corps of Engineers Jurisdictional Determination Form Instructional 
Guidebook. If a water, either alone or in combination with similarly 
situated waters, performs one function, and that function has a more 
than speculative or insubstantial impact on the integrity of a 
traditional navigable water, interstate water, or the territorial seas, 
that water would have a significant nexus.
    These functions identified in the Rapanos Guidance that can be 
provided by tributaries, wetlands, and open waters are keyed to the 
chemical, physical, and biological integrity of traditional navigable 
waters, interstate waters, and the territorial seas. Water temperature 
is a critical factor governing the distribution and growth of aquatic 
life in downstream waters. Sediment storage and export via streams to 
downstream waters is important for maintaining the physical river 
network, including the formation of channel features. Nutrient 
recycling results in the uptake and transformation of large quantities 
of nitrogen and other nutrients that otherwise would be transported 
directly downstream, thereby decreasing impairments of downstream 
waters. Streams, wetlands, and open waters improve water quality 
through the assimilation and sequestration of pollutants, including 
chemical contaminants such as pesticides and metals that can degrade 
downstream water integrity. Small streams and wetlands are particularly 
effective at retaining and attenuating floodwaters. This function can 
reduce flood peaks downstream and can also maintain downstream river 
baseflows. Streams, wetlands, and open waters are the dominant sources 
of water in most rivers. Streams, wetlands, and open waters supply 
downstream waters with organic matter which supports biological 
activity throughout the river network and provide life-cycle dependent 
aquatic habitat for species located in foundational waters.
    Consistent with the pre-2015 regulatory regime, the agencies are 
also proposing that a water may be determined to be a ``water of the 
United States'' when it ``significantly affects'' any one form of 
chemical, physical, or biological integrity of a downstream traditional 
navigable water, interstate water, or the territorial seas. Congress 
intended the Clean Water Act to ``restore and maintain'' all three 
forms of ``integrity,'' section 101(a), so if any one is compromised 
then that is contrary to the statute's stated objective. It would 
contravene the plain language of the statute and subvert the objective 
if the Clean Water Act only protected waters upon a showing that they 
had effects on every attribute of the integrity of a traditional 
navigable water, interstate water, or the territorial sea. As the 
agencies stated in the Rapanos Guidance: ``Consistent with Justice 
Kennedy's instruction, EPA and the Corps will apply the significant 
nexus standard in a manner that restores and maintains any of these 
three attributes of traditional navigable waters.'' Rapanos Guidance at 
10, n.35 and surrounding text.
    The proposed rule's definition of ``significantly affect'' also is 
consistent with the conclusions of the Science Report. See Technical 
Support Document section IV.E. The Science Report concluded that 
watersheds are integrated at multiple spatial and temporal scales by 
flows of surface water and ground water, transport and transformation 
of physical and chemical materials, and movements of organisms. 
Further, the Science Report stated, although all parts of a watershed 
are connected to some degree--by the hydrologic cycle or dispersal of 
organisms, for example--the degree and downstream effects of those 
connections vary spatially and temporally, and are determined by 
characteristics of the physical, chemical, and biological environments 
and by human activities. Those spatial and temporal variations are 
reflected in the agencies' proposed requirement that ``significantly 
affect'' means more than speculative or insubstantial, in the functions 
the agencies evaluate, and in the factors they use to evaluate those 
functions. The proposed rule's provision for waters to be assessed 
either alone, or in combination with other similarly situated waters in 
the region is consistent with the Science Report, which gave as an 
example that the amount of water or biomass contributed by a specific 
ephemeral stream in a given year might be small, but the aggregate 
contribution of that stream over multiple years, or by all ephemeral 
streams draining that watershed in a given year or over multiple years, 
can have substantial consequences on the integrity of the downstream 
waters. Similarly, the downstream effect of a single event, such as 
pollutant discharge into a single stream or wetland, might be 
negligible but the cumulative effect of multiple discharges could 
degrade the integrity of downstream waters. The agencies are seeking 
comment on how to implement this aspect of the proposed rule in section 
V.D.2.b of this preamble.
    The agencies' definition of the term ``significantly affect'' in 
the proposed rule is also informed by and consistent with Supreme Court 
case law. The definition reflects that not all waters have a requisite 
connection to foundational waters sufficient to be determined 
jurisdictional. Under the significant nexus standard, to be 
jurisdictional, waters, alone or in combination with other similarly 
situated waters in the region, must

[[Page 69432]]

significantly affect the chemical, physical, or biological integrity of 
a downstream traditional navigable water, interstate water, or 
territorial sea, and significantly affect means more than ``speculative 
or insubstantial.'' Rapanos, at 780. The agencies propose to define 
``significantly affect'' in precisely those terms.
    The facts in the cases before the justices further inform the scope 
of the proposed definition. Justice Kennedy was clear that ``[m]uch the 
same evidence should permit the establishment of a significant nexus 
with navigable-in-fact waters, particularly if supplemented by further 
evidence about the significance of the tributaries to which the 
wetlands are connected.'' Id. at 784. The agencies recognize that 
``more than speculative or insubstantial'' is not a bright line 
definition, but as the Supreme Court has recently recognized in Maui, 
the scope of Clean Water Act jurisdiction does not always lend itself 
to bright lines: ``In sum, we recognize that a more absolute position . 
. . may be easier to administer. But, as we have said, those positions 
have consequences that are inconsistent with major congressional 
objectives, as revealed by the statute's language, structure, and 
purposes.'' Maui, 140 S Ct. at 1477. Because of the factual nature of 
the connectivity inquiry, any standard will require some case-specific 
factual determinations. The NWPR acknowledged that ``[a]s to simplicity 
and clarity, the agencies acknowledge that field work may frequently be 
necessary to verify whether a feature is a water of the United 
States.'' 85 FR 22270, April 21, 2020. But, like the Court in Maui, the 
agencies have proposed factors to be used in assessing the strength of 
the effects on downstream foundational waters and have identified the 
functions they will consider in making significant nexus determinations 
under the proposed rule. This approach is consistent with major 
congressional objectives, as revealed by the statute's language, 
structure, and purposes.\53\
---------------------------------------------------------------------------

    \53\ Through rulemaking the agencies could make some categorical 
jurisdictional determination based on standards and factors that are 
consistent with the Act's objective. See Riverside Bayview at 135, 
n.9 (``If it is reasonable for the Corps to conclude that in the 
majority of cases, adjacent wetlands have significant effects on 
water quality and the aquatic ecosystem, its definition can 
stand.''); see also Rapanos at 780-81 (Kennedy, J.) (``Through 
regulations or adjudication, the Corps may choose to identify 
categories of tributaries that . . . are significant enough that 
wetlands adjacent to them are likely, in the majority of cases, to 
perform important functions for an aquatic system incorporating 
navigable waters.'').
---------------------------------------------------------------------------

    It is also important to note that the agencies' significant nexus 
standard in the proposed rule is carefully tailored so that only 
particular types of functions provided by upstream waters can be 
considered. Wetlands, streams, and open waters are well-known to 
provide a wide variety of functions that translate into ecosystem 
services. A significant nexus analysis, however, is limited to an 
assessment of only those functions that have a nexus to the chemical, 
physical, or biological integrity of traditional navigable waters, 
interstate waters, or the territorial seas. Therefore, there are some 
very important functions provided by wetlands, tributaries, and ``other 
waters'' that will not be considered by the agencies when making 
jurisdictional decisions under the proposed rule because they do not 
have a sufficient nexus to downstream waters.
    For example, for purposes of a jurisdictional analysis under the 
significant nexus standard, the agencies will not be taking into 
account the carbon sequestration benefits that aquatic resources like 
wetlands provide. Provision of habitat for non-aquatic species, such as 
migratory birds, and endemic aquatic species would not be considered as 
part of a significant analysis under the proposed rule.\54\ 
Furthermore, the agencies would not consider soil fertility in 
terrestrial systems, which is enhanced by processes in stream and 
wetland soils and non-floodplain wetlands that accumulate sediments, 
prevent or reduce soil erosion, and retain water on the landscape, 
benefiting soil quality and productivity in uplands. There are also a 
wide variety of functions that streams, wetlands, and open waters 
provide that translate into ecosystem services that benefit society 
that would not be considered in a significant nexus analysis under the 
proposed rule. These include recreation (e.g., fishing, hunting, 
boating, and birdwatching), production of fuel, forage, and fibers, 
extraction of materials (e.g., biofuels, food, such as shellfish, 
vegetables, seeds, nuts, rice), plants for clothes and other materials, 
and medical compounds from wetland and aquatic plants or animals. While 
these ecosystem services can contribute to the economy, they are not 
relevant to a significant nexus analysis that the agencies would 
conduct under the proposed rule.
---------------------------------------------------------------------------

    \54\ As the agencies have discussed, consideration of biological 
functions such as provision of habitat is relevant for purposes of 
significant nexus determinations under the proposed rule only to the 
extent that the functions provided by tributaries, adjacent 
wetlands, and ``other waters'' significantly affect the biological 
integrity of a downstream foundational water.
---------------------------------------------------------------------------

    The agencies have more than a decade of experience implementing the 
significant nexus standard by making determinations of whether a water 
alone or in combination with similarly situated waters has a more than 
speculative or insubstantial effect. In their experience many waters 
under the proposed rule will not have a significant nexus to downstream 
foundational waters, and thus will not be jurisdictional under the Act, 
and the agencies under current practice routinely conclude that there 
is no significant nexus. The following are examples of waters that the 
agencies found to not have a significant nexus and determined to be 
non-jurisdictional under the pre-2015 regulatory regime. The agencies 
are citing these samples to provide an indication of waters that would 
likely not be jurisdictional under the proposed rule, though they 
recognize that the significant nexus determination is case-specific.
    Examples of waters that were determined not to have a significant 
nexus to downstream foundational waters and that were non-
jurisdictional under the pre-2015 regulatory regime, and which 
therefore would likely not be jurisdictional under the proposed rule, 
are a linear stream in Ohio, hundreds of feet long, which is miles from 
a traditional navigable water and does not provide any significant 
functions for that water; an ephemeral stream in Ohio in an 
agricultural field, which loses bed and bank and flows into an upland 
swale; and ditches in California that were created from uplands, drain 
only uplands, and that do not carry a relatively permanent flow of 
water.
    Examples of wetlands that have been determined not to meet the 
significant nexus standard and therefore to be non-jurisdictional under 
the pre-2015 regulatory regime and would likely not be jurisdictional 
under the proposed rule include wetlands or open waters that drain into 
upland areas, such as emergent wetlands in Idaho that drain into upland 
swales that terminate in a closed basin upland area; wetlands in 
Wisconsin surrounded by uplands that do not exchange surface water or 
have ecological connections with the nearest tributary; wetlands in 
Ohio surrounded by upland that have no connections to any apparent 
surface water channel or to a jurisdictional water; and a non-navigable 
lake in Oregon contained within a valley and that lacks surface 
hydrologic connections to the river network. Other wetlands determined 
not meet the significant nexus standard include an emergent wetland in 
Alaska

[[Page 69433]]

surrounded by development that severed any hydrologic connections 
between the wetland and a nearby wetland complex and lake; wetlands in 
Washington separated by potential jurisdictional waters by thousands of 
feet of well-drained soils as well as impervious surfaces; a large 
forested wetland in Washington separated by the nearest jurisdictional 
waters by residential and commercial developments on a topography that 
would preclude flows into these waters and with no identified 
ecological connections; a wetland in Oregon surrounded by a concrete 
and cinder block wall, preventing any flows into downstream waters; and 
a wetland in Arkansas separated from other wetlands and surrounded by 
uplands.
    While in most of these examples, the tributary, wetland, or lake 
may well have had some effect on traditional navigable waters, 
interstate waters, or the territorial seas, the agencies concluded that 
those effects were not significant and so concluded that jurisdiction 
did not lie under the Clean Water Act. See implementation section V.D 
of this preamble for more information on significant nexus 
determinations.

D. Implementation of Proposed Rule

    The agencies are proposing to return to the longstanding definition 
of ``waters of the United States'' that two other Administrations have 
codified over the years, updated to reflect consideration of the 
intervening Supreme Court decisions. This section first discusses 
features over which the agencies generally did not assert jurisdiction 
under the preambles, guidance, and practice of the pre-2015 regulatory 
regime. The agencies intend to continue generally not asserting 
jurisdiction over such features. Then the agencies explain the Rapanos 
Guidance and how they have determined jurisdiction under the two 
Rapanos standards for various categories of waters under the pre-2015 
regulatory regime and solicit comment on potential alternative 
approaches for applying the Rapanos standards. The agencies then 
discuss the implementation tools and resources available for making 
such determinations. The agencies welcome comment on all of these 
topics, including the availability and efficacy of all of the tools and 
resources discussed. The agencies intend to issue an updated ``Approved 
Jurisdictional Determination'' form and instruction manual upon 
promulgating a final rule to aid the public and field staff in 
determining which waters are ``waters of the United States'' under the 
final rule. The agencies may provide additional guidance in the final 
rule based on public input received on this proposal.
1. Generally Not Considered ``waters of the United States''
    Under the pre-2015 regulatory regime, the waters described below 
were generally not considered ``waters of the United States'' even 
though they were not explicitly excluded by regulation. The agencies 
intend to continue this longstanding approach and are soliciting 
comment on this approach for the proposed rule. The preamble to the 
1986 regulations states that the agencies ``generally do not consider 
[these] waters to be `Waters of the United States.' '' 51 FR 41217. The 
preamble further stated that ``the Corps reserves the right on a case-
by-case basis to determine that a particular waterbody within these 
categories of waters is a water of the United States. EPA also has the 
right to determine on a case-by-case basis if any of these waters are 
`waters of the United States.' '' Id. In practice, the agencies have 
not generally asserted jurisdiction over such waters and would continue 
to implement the proposed rule consistent with this practice.
    Even when not themselves considered jurisdictional waters subject 
to the Clean Water Act, the features described below (e.g., certain 
ditches, swales, gullies, erosional features) may either be relevant to 
a ``water of the United States'' jurisdictional analysis or otherwise 
be subject to the Clean Water Act. The features may still contribute to 
a surface hydrologic connection relevant for asserting jurisdiction 
(e.g., between an adjacent wetland and a jurisdictional water). Rapanos 
Guidance at 12. In addition, these waters may function as point sources 
(i.e., ``discernible, confined, and discrete conveyances''), such that 
discharges of pollutants to other waters through these features could 
require a Clean Water Act section 402 or 404 permit. Discharges to 
these waters may be subject to other Clean Water Act regulations (e.g., 
Clean Water Act section 311). Id.
a. Certain Ditches
    Under the agencies' longstanding approach to determining which 
waters are ``waters of the United States,'' certain ditches are 
generally not considered ``waters of the United States.'' The preamble 
to the 1986 regulations explains that ``[n]on-tidal drainage and 
irrigation ditches excavated on dry land'' are generally not considered 
``waters of the United States.'' 51 FR 41217. The agencies shifted this 
approach slightly in the Rapanos Guidance and explained that ``ditches 
(including roadside ditches) excavated wholly in and draining only 
uplands and that do not carry a relatively permanent flow of water are 
generally not waters of the United States.'' Rapanos Guidance at 11-12. 
The agencies explained that these features are generally not considered 
``waters of the United States'' ``because they are not tributaries or 
they do not have a significant nexus to downstream traditional 
navigable waters.'' Id.
    The agencies intend to continue implementing the approach to 
ditches described in the Rapanos Guidance. This approach is more 
consistent with the relatively permanent standard than the approach in 
the preamble to the 1986 regulations. Consistent with previous 
practice, ditches constructed wholly in uplands and draining only 
uplands with ephemeral flow would generally not be considered ``waters 
of the United States.''
    Also consistent with previous practice, the agencies would 
typically assess a ditch's jurisdictional status based on whether it 
could be considered a tributary (and, consistent with previous 
practice, would not assess whether the ditch was jurisdictional under 
the ``other waters'' provision). The implementation section below 
includes discussion on the application of relevant reach under the 
Rapanos Guidance, and the agencies solicit comment on potential 
alternative approaches (see section V.D.2.b.ii.1.b of this preamble), 
such as whether relevant reaches can be distinguished based on a change 
from relatively permanent flow to non-relatively permanent flow. The 
agencies acknowledge that for ditches in particular there may be 
scenarios that make identification of relevant reach especially 
challenging and encourage stakeholders to identify and discuss these 
situations in their comments on relevant reach. The agencies 
specifically request comment regarding whether the interpretation of 
relevant reach for ditches should consider any particular factors for 
situations where ditches are tidal, are treated as tributaries, or 
contain wetlands.
    In some situations, ditches with wetland characteristics have been 
considered jurisdictional as adjacent wetlands. In most cases, such 
ditches have been constructed in adjacent wetlands and would be 
considered part of that larger adjacent wetland. However, consistent 
with previous practice, wetlands that develop entirely within the 
confines of a ditch that was excavated in and wholly draining only 
uplands that does not carry a relatively permanent flow would be 
considered

[[Page 69434]]

part of that ditch and generally would not be considered ``waters of 
the United States.''
    Where a ditch is jurisdictional, the agencies have historically 
taken the position that the ditch can be both a ``water of the United 
States'' and a point source and are proposing to reinstate this 
position. For example, in 1975, the General Counsel of EPA issued an 
opinion interpreting the Clean Water Act: ``it should be noted that 
what is prohibited by section 301 is `any addition of any pollutant to 
navigable waters from any point source.' It is therefore my opinion 
that, even should the finder of fact determine that any given 
irrigation ditch is a navigable water, it would still be permittable as 
a point source where it discharges into another navigable water body, 
provided that the other point source criteria are also present.'' In re 
Riverside Irrigation District, 1975 WL 23864 at *4 (emphasis in 
original). The opinion stated that ``to define the waters here at issue 
as navigable waters and use that as a basis for exempting them from the 
permit requirement appears to fly directly in the face of clear 
legislative intent to the contrary.'' Id. Further, in Rapanos, Justice 
Kennedy and the dissent rejected the conclusion that because the word 
``ditch'' was in the definition of ``point source'' a ditch could never 
be a water of the United States: ``certain water bodies could 
conceivably constitute both a point source and a water.'' 547 U.S. at 
772 (Kennedy, J., concurring); see also id. at 802 (Stevens, J., 
dissenting) (``The first provision relied on by the plurality--the 
definition of ``point source'' in 33 U.S.C. [section] 1362(14)--has no 
conceivable bearing on whether permanent tributaries should be treated 
differently from intermittent ones, since `pipe[s], ditch[es], 
channel[s], tunnel[s], conduit[s], [and] well[s]' can all hold water 
permanently as well as intermittently.'').
    The agencies recognize that this position is different than the 
position in the NWPR, which stated that a ditch is either a water of 
the United States or a point source. 85 FR 22297, April 21, 2020. The 
NWPR justified this position by noting that the Clean Water Act defines 
``point sources'' to include ditches and that the plurality opinion in 
Rapanos stated that ``[t]he definitions thus conceive of `point 
sources' and `navigable waters' as separate and distinct categories. 
The definition of `discharge' would make little sense if the two 
categories were significantly overlapping.'' 547 U.S. at 735-36 
(Scalia, J., plurality), NWPR Response to Comments, section 6 at 12-13. 
The NWPR, however, did not address that even this statement in the 
plurality opinion in Rapanos acknowledges that there may be some 
overlap between point sources and ``waters of the United States'' as 
indicated by its finding that the two categories should not be 
``significantly'' overlapping. Id. Moreover, there is no indication in 
the text of the Clean Water Act that ditches that meet that plain 
language definition of a point source cannot also be a ``water of the 
United States.'' The agencies therefore believe that their 
longstanding, historic view that a ditch can be both a point source and 
a water of the United States is the better interpretation.
b. Certain Other Features
    In addition to the ditches described above, the agencies have 
generally not asserted jurisdiction over certain other features under 
the pre-2015 regulatory regime and the agencies intend to continue the 
practice for these features. The preamble to the 1986 regulations 
explains that these other waters include: Artificially irrigated areas 
which would revert to upland if the irrigation ceased; artificial lakes 
or ponds created by excavating and/or diking dry land to collect and 
retain water and which are used exclusively for such purposes as stock 
watering, irrigation, settling basins, or rice growing; artificial 
reflecting or swimming pools or other small ornamental bodies of water 
created by excavating and/or diking dry land to retain water for 
primarily aesthetic reasons; and waterfilled depressions created in dry 
land incidental to construction activity and pits excavated in dry land 
for the purpose of obtaining fill, sand, or gravel unless and until the 
construction or excavation operation is abandoned and the resulting 
body of water meets the definition of ``waters of the United States.'' 
51 FR 41217. In the Rapanos Guidance, the agencies added an additional 
category to this list, explaining that ``[s]wales or erosional features 
(e.g., gullies, small washes characterized by low volume, infrequent, 
or short duration flow) are generally not waters of the United 
States.'' Rapanos Guidance at 11-12. The agencies explained that these 
features are generally not ``waters of the United States'' ``because 
they are not tributaries or they do not have a significant nexus to 
downstream traditional navigable waters.'' Id.
    Swales and gullies are generally not jurisdictional, and these 
features differ from ephemeral streams because they lack indicators of 
an OHWM, whereas ephemeral streams typically have at least one 
indicator of an OHWM. Ephemeral streams are jurisdictional where they 
are tributaries and have a significant nexus to downstream waters. 
Colloquial terminology may differ across the country; for example, some 
streams in the arid West are known as ``gullies'' but are in fact 
ephemeral streams because they have at least one indicator of an OHWM.
2. Determining Jurisdiction Under the Relatively Permanent Standard and 
the Significant Nexus Standard
    In this section, the agencies explain how they have determined 
jurisdiction under the relatively permanent standard and significant 
nexus standard for various categories of waters under the pre-2015 
regulatory regime. The agencies describe how each standard has been 
implemented consistent with the Rapanos Guidance, SWANCC Guidance, and 
other aspects of longstanding practice where not addressed explicitly 
by the guidances. The agencies then solicit comment on implementing the 
standards consistent with the pre-2015 regulatory regime as well as 
potential alternative approaches for applying the relatively permanent 
and significant nexus standards. Additionally, the agencies solicit 
comment on whether the implementation approaches adequately account for 
expected changes in climate, and whether alternative approaches to 
implementing the relatively permanent standard and significant nexus 
standard should be considered.
a. ``Waters of the United States'' Under the Relatively Permanent 
Standard
i. Approaches Under the Pre-2015 Regulatory Regime
(1) Background
    Under the relatively permanent standard, relatively permanent 
tributaries and adjacent wetlands that have a continuous surface 
connection to such tributaries are jurisdictional under the Clean Water 
Act as ``waters of the United States.'' Under the Rapanos Guidance, the 
agencies assert jurisdiction over tributaries as ``relatively 
permanent'' waters where the waters typically (e.g., except due to 
drought) flow year-round or have a continuous flow at least seasonally 
(e.g., typically three months). Rapanos Guidance at 6-7 (citing 126 S 
Ct. at 2221 n.5 (Justice Scalia, plurality opinion) (explaining that 
``relatively permanent'' does not necessarily exclude waters ``that 
might dry up in extraordinary circumstances such as drought'' or 
``seasonal rivers, which contain continuous flow during some months of 
the year but no flow during dry

[[Page 69435]]

months'')). The agencies also assert jurisdiction over adjacent 
wetlands that have a continuous surface connection to a relatively 
permanent, non-navigable tributary. Id. at 6-7.
(2) Tributaries
    Under the Rapanos Guidance, ``relatively permanent'' tributaries 
include perennial streams that typically flow year-round and 
intermittent streams that have continuous flow at least seasonally. 
However, ``relatively permanent'' tributaries do not include ephemeral 
streams that flow only in response to precipitation and intermittent 
streams which do not have continuous flow at least seasonally. 
Importantly, under the Rapanos Guidance, some intermittent streams are 
considered ``relatively permanent'' and some are not. Scientists, 
including agency staff, have used the terms ``perennial,'' 
``intermittent,'' and ``ephemeral'' for decades to characterize 
tributary flow classifications.
    Under the Rapanos Guidance, a ``tributary'' includes ``the entire 
reach of the stream that is of the same order (i.e., from the point of 
confluence, where two lower order streams meet to form the tributary, 
downstream to the point such tributary enters a higher order stream).'' 
Id. at 6, n. 24. The flow characteristics of a particular tributary 
generally are evaluated at the farthest downstream limit of such 
tributary (i.e., the point the tributary enters a higher order stream). 
Id. However, for purposes of determining whether the tributary is 
relatively permanent, where data indicate the flow regime at the 
downstream limit is not representative of the entire tributary (e.g., 
where data indicate the tributary is relatively permanent at its 
downstream limit but not for the majority of its length, or vice 
versa), the flow regime that best characterizes the entire tributary is 
used. A primary factor in making this determination is the relative 
lengths of segments with differing flow regimes. Id. The agencies 
stated that it is reasonable to characterize the entire tributary in 
light of the Supreme Court's observation that the phrase ``navigable 
waters'' generally refers to ``rivers, streams, and other hydrographic 
features.'' Citing Rapanos at 734, quoting Riverside Bayview, 474 U.S. 
at 131. The entire reach of a stream is a reasonably identifiable 
hydrographic feature.
(3) Wetlands
    Under the pre-2015 regime, the agencies utilize the Rapanos 
Guidance to determine where adjacent wetlands have a continuous surface 
connection with a relatively permanent, non-navigable tributary. The 
Rapanos Guidance notes that these wetlands are a subset of the broader 
definition of ``adjacent'' wetlands. The plurality opinion indicates 
that ``continuous surface connection'' is a ``physical connection 
requirement.'' Rapanos Guidance at 6, citing Rapanos at 754. 
Accordingly, under the Rapanos Guidance, a continuous surface 
connection exists between a wetland and a relatively permanent, non-
navigable tributary where the wetland directly abuts the tributary 
(e.g., they are not separated by uplands, a berm, dike, or similar 
feature). Rapanos Guidance at 7, citing Rapanos at 751, n. 13 
(referring to ``our physical-connection requirement''). A continuous 
surface connection does not require surface water to be continuously 
present between the wetland and the tributary. Rapanos Guidance at 7, 
n.28, citing 33 CFR 328.3(b) and 40 CFR 232.2 (defining wetlands as 
``those areas that are inundated or saturated by surface or ground 
water at a frequency and duration sufficient to support a prevalence of 
vegetation typically adapted for life in saturated soil conditions'').
    In some circumstances, the United States has determined that a 
continuous surface connection can include a physical connection such as 
a non-jurisdictional ditch that connects the adjacent wetland to the 
relatively permanent tributary. United States v. Cundiff, 555 F.3d at 
213 (holding wetlands were jurisdictional under the plurality where 
plaintiff created a continuous surface connection by digging ditches to 
enhance the acid mine drainage into the creeks and away from his 
wetlands; ``it does not make a difference whether the channel by which 
water flows from a wetland to a navigable-in-fact waterway or its 
tributary was manmade or formed naturally''). Generally, the agencies 
completed significant nexus analyses on adjacent wetlands with such 
connections.
    The term ``adjacent'' has been defined in agency regulations since 
1986 to mean ``bordering, contiguous, or neighboring.'' Wetlands 
separated from other ``waters of the United States'' by man-made dikes 
or barriers, natural river berms, beach dunes and the like are 
``adjacent wetlands'' (see section V.C.7 of this preamble). Under the 
Rapanos Guidance, the agencies consider wetlands ``adjacent'' if one of 
following three criteria is satisfied. First, there is an unbroken 
surface or shallow subsurface connection to jurisdictional waters and 
this hydrologic connection maybe intermittent. Second, they are 
physically separated from jurisdictional waters by man-made dikes or 
barriers, or natural breaks (e.g., river berms, beach dunes). Or third, 
their proximity to a jurisdictional water is reasonably close, 
supporting the science-based inference that such wetlands have an 
ecological interconnection with jurisdictional waters and therefore, 
will not generally require a case-specific demonstration of an ecologic 
interconnection. Rapanos Guidance at 5-6.
    As stated above, under the Rapanos Guidance the agencies assert 
jurisdiction over wetlands that have a continuous surface connection 
with a relatively permanent, non-navigable tributary. These wetlands 
are a subset of adjacent wetlands previously discussed that must have a 
continuous surface connection with the tributary. This physical 
connection requires that the wetland not be separated from the 
relatively permanent, non-navigable tributary by uplands, a berm, dike, 
or other similar feature. Although a constant hydrologic connection is 
not required, there must be a continuous surface connection on the 
landscape for these wetlands to be jurisdictional under this standard.
    It is important to note that under the pre-2015 regulatory regime, 
features such as uplands, a berm, dike, or similar feature that 
separate a wetland from a relatively permanent, non-navigable tributary 
may not be continuous. For example, an upland levee that separates a 
wetland from a relatively permanent, non-navigable tributary may have 
gaps along the length of the levee that provide for a connection 
between the wetlands and the tributary. In such cases under the pre-
2015 regulatory regime, this type of connection would satisfy the 
physical connection requirement.
ii. Other Potential Approaches To Implementing the Relatively Permanent 
Standard
    The agencies are seeking comment on whether they should implement 
the relatively permanent standard in the proposed rule consistent with 
the pre-2015 regulatory regime described above and if so whether there 
are clarifications or other issues to be addressed. In addition, the 
agencies are seeking comment on other options for making jurisdictional 
determinations under the relatively permanent standard.
(1) Tributaries
    The Rapanos Guidance limits the scope of relatively permanent 
tributaries to perennial tributaries and certain

[[Page 69436]]

intermittent tributaries. The agencies could interpret relatively 
permanent waters more generally to include perennial tributaries and 
all intermittent tributaries. With such an interpretation, the agencies 
could use an approach to ``perennial,'' ``intermittent,'' and 
``ephemeral'' as the NWPR did and could specify that the agencies 
generally intend to consider perennial and intermittent tributaries as 
relatively permanent waters in light of their characteristics and flow, 
but ephemeral tributaries would not be considered relatively permanent. 
Such an approach would not limit intermittent tributaries under the 
relatively permanent standard to only those that have continuous flow 
at least seasonally (e.g., typically three months). The agencies could 
clarify that intermittent streams under the relatively permanent 
standard may flow less than three months (e.g., streams that flow 
``continuously during certain times of the year,'' similar to the 
language in the NWPR), as certain intermittent streams may flow for 
shorter periods of time but are still distinct from ``ephemeral'' 
streams.
    The Rapanos Guidance does not explicitly address whether 
intermittent flow must come from particular sources (e.g., groundwater, 
snowpack melt, effluent flow, or upstream contributions of flow) under 
the relatively permanent standard. The agencies solicit comment about 
whether the final rule should clarify the required sources of 
intermittent flow, and what those sources of flow should be. For 
instance, the NWPR clarified that intermittent flow must occur more 
than in direct response to precipitation, and the NWPR explained that 
could mean, for example, seasonally when the groundwater table is 
elevated or when snowpack melts. The NWPR differentiated between 
ephemeral flows driven by ``snowfall,'' and intermittent flows driven 
by ``snowpack melt,'' where snowpack was defined as ``layers of snow 
that accumulate over extended periods of time in certain geographic 
regions or at high elevation (e.g., in northern climes or mountainous 
regions).'' Alternatively, the final rule could allow for regionally 
specific interpretations of intermittent flow sources to allow for 
flexible implementation of the rule.
    This proposed rule does not provide specific definitions for 
tributary flow classifications, including the terms ``perennial,'' 
``intermittent,'' and ``ephemeral.'' The agencies are seeking comment 
on whether they should define these flow classifications in the final 
rule. Any specific definitions would depend in part on how the agencies 
describe intermittent tributaries under the relatively permanent 
standard in the final rule, including the scope of intermittent 
tributaries and any description of required sources of flow. For 
example, if the agencies interpret the relatively permanent standard to 
include all perennial and intermittent tributaries and decide to 
include groundwater and snowpack melt as appropriate sources of 
intermittent flow, the agencies could use the same definitions as the 
NWPR:
     The term ``perennial'' means surface water flowing 
continuously year-round.
     The term ``intermittent'' means surface water flowing 
continuously during certain times of the year and more than in direct 
response to precipitation (e.g., seasonally when the groundwater table 
is elevated or when snowpack melts).
     The term ``ephemeral'' means surface water flowing or 
pooling only in direct response to precipitation (e.g., rain or snow 
fall).
    Alternatively, the agencies could interpret the relatively 
permanent standard using modified definitions of these terms.
(2) Wetlands
    In some circumstances, the United States has concluded that a non-
jurisdictional ditch or other such feature can serve as a physical 
connection that maintains a continuous surface connection between a 
wetland and a relatively permanent water. See United States v. Cundiff. 
The agencies seek comment on whether to provide guidance on when 
specific features (e.g., ditches, culverts, pipes, or swales) can serve 
as physical connections that can maintain a continuous surface 
connection between a wetland and a relatively permanent water.
(3) Open Waters
    The agencies do not discuss in the Rapanos Guidance the assessment 
of open waters such as lakes and ponds under the relatively permanent 
waters standard. As discussed above, the agencies' longstanding 
position, reflected in the U.S. Army Corps of Engineers Jurisdictional 
Determination Instructional Guidebook, is that tributaries for purposes 
of the definition of ``waters of the United States'' include lakes and 
ponds that flow directly or indirectly to downstream traditional 
navigable waters, interstate waters, or the territorial seas. See U.S. 
Army Corps of Engineers Jurisdictional Determination Form Instructional 
Guidebook, at 8, 9. In practice, the agencies have asserted 
jurisdiction over relatively permanent tributary lakes and ponds. The 
agencies are soliciting comment on whether they should explicitly 
explain this implementation approach in the final rule.
    The agencies do not address the ``other waters'' category in the 
Rapanos Guidance with respect to either the relatively permanent 
standard or the significant nexus standard. The proposed rule adds both 
standards to the ``other waters'' category. The agencies are soliciting 
comment on whether they should take an approach to assessing 
jurisdiction over non-tributary open waters under the relatively 
permanent standard that is similar to the approach described in the 
Rapanos Guidance for assessing jurisdiction over adjacent wetlands with 
a continuous surface connection to relatively permanent waters. Under 
such an approach, the agencies would assert jurisdiction over 
relatively permanent open waters that have a continuous surface 
connection with a relatively permanent, non-navigable tributary. The 
agencies note that some such lakes and ponds are jurisdictional under 
the NWPR when they are inundated by flooding from a jurisdictional 
water in a typical year.
b. ``Waters of the United States'' Under the Significant Nexus Standard
ii. Approaches Under the Pre-2015 Regulatory Regime
(1) Background
    The significant nexus standard as clarified by Justice Kennedy's 
opinion in Rapanos is: ``wetlands possess the requisite nexus, and thus 
come within the statutory phrase `navigable waters,' if the wetlands, 
either alone or in combination with similarly situated lands in the 
region, significantly affect the chemical, physical, and biological 
integrity of other covered waters more readily understood as 
`navigable.''' Rapanos at 780. The agencies in the Rapanos Guidance use 
the significant nexus standard for determining jurisdiction over 
certain adjacent wetlands and tributaries. As discussed above, the 
proposed rule would add the significant nexus standard to the ``other 
waters,'' tributary, and adjacent wetland categories in the 1986 
regulations. In the Rapanos Guidance, the agencies explain: ``While 
Justice Kennedy's opinion discusses the significant nexus standard 
primarily in the context of wetlands adjacent to non-navigable 
tributaries, his opinion also addresses Clean Water Act jurisdiction 
over tributaries themselves. Justice Kennedy states that, based on the 
Supreme Court's decisions in Riverside Bayview

[[Page 69437]]

and SWANCC, `the connection between a non-navigable water or wetland 
may be so close, or potentially so close, that the Corps may deem the 
water or wetland a ``navigable water'' under the Act.''' Rapanos 
Guidance at 9, citing Rapanos at 767 (emphasis added in Rapanos 
Guidance).
(2) Scope of Significant Nexus Analysis
    In the Rapanos Guidance, the agencies assess tributaries and their 
adjacent wetlands together and state: ``In considering how to apply the 
significant nexus standard, the agencies have focused on the integral 
relationship between the ecological characteristics of tributaries and 
those of their adjacent wetlands, which determines in part their 
contribution to restoring and maintaining the chemical, physical and 
biological integrity of the Nation's traditional navigable waters. The 
ecological relationship between tributaries and their adjacent wetlands 
is well documented in the scientific literature and reflects their 
physical proximity as well as shared hydrological and biological 
characteristics. The flow parameters and ecological functions that 
Justice Kennedy describes as most relevant to an evaluation of 
significant nexus result from the ecological inter-relationship between 
tributaries and their adjacent wetlands.'' Rapanos Guidance at 9.
    Under the Rapanos Guidance, when performing a significant nexus 
analysis, the first step is to determine the relevant reach of the 
tributary being assessed, even when the subject water may only include 
a wetland. Under the guidance, a tributary is the entire reach of the 
stream that is of the same order (i.e., from the point of confluence, 
where two lower order streams meet to form the tributary, downstream to 
the point such tributary enters a higher order stream). The guidance 
states that for purposes of demonstrating a connection to traditional 
navigable waters, it is appropriate and reasonable to assess the flow 
characteristics of the tributary at the point at which water is in fact 
being contributed to a higher order tributary or to a traditional 
navigable water. As discussed above, the agencies' longstanding 
position is that tributaries for purposes of the definition of ``waters 
of the United States'' include lakes and ponds that flow directly or 
indirectly to downstream traditional navigable waters, interstate 
waters, or the territorial seas. See ``U.S. Army Corps of Engineers 
Jurisdictional Determination Form Instructional Guidebook,'' at 8, 9. 
In practice, the agencies have asserted jurisdiction over tributary 
lakes and ponds that meet the significant nexus standard.
    After establishing the relevant reach of the tributary, under the 
Rapanos Guidance the agencies then determine if the tributary has any 
adjacent wetlands. Where a tributary has no adjacent wetlands, the 
agencies consider the flow characteristics and functions of only the 
tributary itself in determining whether such tributary has a 
significant effect on the chemical, physical and biological integrity 
of downstream traditional navigable waters, interstate waters, or the 
territorial seas. Rapanos Guidance at 10. If the tributary has adjacent 
wetlands, the significant nexus evaluation needs to recognize the 
ecological relationship between tributaries and their adjacent 
wetlands, and their closely linked role in protecting the chemical, 
physical, and biological integrity of downstream traditional navigable 
waters. Id. at 10.
    Under the Rapanos Guidance the agencies consider the flow and 
functions of the tributary together with the functions performed by all 
the wetlands adjacent to the tributary in evaluating whether a 
significant nexus is present. This approach reflects the agencies' 
interpretation in the Rapanos Guidance of Justice Kennedy's term 
``similarly situated'' to include all wetlands adjacent to the same 
tributary. Under this approach, where it is determined that a tributary 
and its adjacent wetlands collectively have a significant nexus with 
traditional navigable waters, the tributary and all of its adjacent 
wetlands are jurisdictional. Id. at 10.
    In addition, the Rapanos Guidance states that certain ephemeral 
waters in the arid West are distinguishable from the geographic 
features like non-jurisdictional swales and erosional features, where 
such ephemeral waters are tributaries and they have a significant nexus 
to downstream traditional navigable waters. For example, in some cases 
these ephemeral tributaries may serve as a transitional area between 
the upland environment and the traditional navigable waters. The 
guidance explains that during and following precipitation events, 
ephemeral tributaries collect and transport water and sometimes 
sediment from the upper reaches of the landscape downstream to the 
traditional navigable waters. These ephemeral tributaries may provide 
habitat for wildlife and aquatic organisms in downstream traditional 
navigable waters. These biological and physical processes may further 
support nutrient cycling, sediment retention and transport, pollutant 
trapping and filtration, and improvement of water quality, functions 
that may significantly affect the chemical, physical, and biological 
integrity of downstream traditional navigable waters. Id. at 12. In 
practice, the agencies have regulated some but not all ephemeral 
tributaries evaluated under the significant nexus standard under the 
pre-2015 regulatory regime.
(3) Assessment of a Significant Nexus
    To implement the Rapanos Guidance, the agencies instruct field 
staff evaluating the significant nexus of a tributary and its adjacent 
wetlands to evaluate all available hydrologic information (e.g., gage 
data, precipitation records, flood predictions, historic records of 
water flow, statistical data, personal observations/records, etc.) and 
physical indicators of flow including the presence and characteristics 
of a reliable OHWM when assessing significant nexus. Rapanos Guidance 
at 10. The use of relevant geographic water quality data in conjunction 
with site-specific data produced from improved field sampling 
methodology and hydrologic modelling are important for understanding 
the chemical, physical, and biological functions provided by 
tributaries and their adjacent wetlands and their effects on downstream 
traditional navigable waters.
    While EPA regions and Corps districts must exercise judgment to 
identify the OHWM on a case-by-case basis, the regulations identify the 
factors to be applied. These regulations have been further explained in 
RGL 05-05, and the Corps continues to improve regulatory practices 
across the country through ongoing research and the development of 
regional and national OHWM delineation procedures. The agencies will 
apply the regulations, RGL 05-05, and applicable OHWM delineation 
manuals and take other steps as needed to ensure that the OHWM 
identification factors are applied consistently nationwide. Rapanos 
Guidance at 10-11, n. 36.
    In the Rapanos Guidance, the agencies identify numerous functions 
provided by tributaries and wetlands that are relevant to the 
significant nexus determination. The duration, frequency, and volume of 
flow in a tributary, and subsequently the flow in downstream 
traditional navigable waters, is directly affected by the presence of 
adjacent wetlands that hold floodwaters, intercept sheet flow from 
uplands, and then release waters to tributaries in a more even and 
constant manner. Wetlands may also help to maintain more consistent 
water temperature in tributaries, which is important for some

[[Page 69438]]

aquatic species; adjacent wetlands trap and hold pollutants that may 
otherwise reach tributaries (and downstream traditional navigable 
waters) including sediments, chemicals, and other pollutants. 
Tributaries and adjacent wetlands provide habitat (e.g., refuge, 
feeding, nesting, spawning, or rearing young) for many aquatic species 
that also live in traditional navigable waters. Id. at 9. Under the 
Rapanos Guidance, the agencies take into account other relevant 
considerations, including the functions performed by the tributary 
together with the functions performed by any adjacent wetlands.
    Another specific consideration from the Rapanos Guidance is the 
extent to which the tributary and adjacent wetlands have the capacity 
to carry pollutants (e.g., petroleum wastes, toxic wastes, sediment) or 
flood waters to traditional navigable waters, or to reduce the amount 
of pollutants or flood waters that would otherwise enter traditional 
navigable waters. Id. at 11; citing Rapanos at 782, citing Oklahoma ex 
rel. Phillips v. Guy F. Atkinson Co., 313 U.S. 508, 524-25 (1941) 
(``Just as control over the non-navigable parts of a river may be 
essential or desirable in the interests of the navigable portions, so 
may the key to flood control on a navigable stream be found in whole or 
in part in flood control on its tributaries.'').
    The agencies under the Rapanos Guidance also evaluate ecological 
functions performed by the tributary and any adjacent wetlands which 
affect downstream traditional navigable waters, such as the capacity to 
transfer nutrients and organic carbon vital to support downstream 
foodwebs (e.g., macroinvertebrates present in headwater streams convert 
carbon in leaf litter making it available to species downstream), 
habitat services such as providing spawning areas for recreationally or 
commercially important species in downstream waters, and the extent to 
which the tributary and adjacent wetlands perform functions related to 
maintenance of downstream water quality such as sediment trapping. 
Rapanos Guidance at 11. In the context of the Rapanos Guidance, 
ecological functions were meant to represent the suite of chemical, 
physical, and biological functions performed by the waters being 
assessed that affect downstream traditional navigable waters.
    To demonstrate effects on physical integrity of downstream waters, 
the agencies have used evidence of physical connections, such as flood 
water or sediment retention (flood prevention). Indicators of 
hydrologic connections between the water being evaluated and 
jurisdictional waters may also provide evidence of a physical 
connection. In addition, relevant considerations for physical 
connectivity could include rain intensity, duration of rain events or 
wet season, soil permeability, distance of hydrologic connection 
between the water and the traditional navigable water, and depth from 
surface to water table, all of which may indicate evidence of 
connection to stream baseflows, and any preferential flowpaths.
    Evidence of a significant effect on the chemical integrity of 
foundational waters has been found by identifying the properties of the 
water(s) under evaluation in comparison to the traditional navigable 
water; signs of retention, release, or transformation of nutrients or 
pollutants; and the effect of landscape position on the strength of the 
connection to the nearest jurisdictional water and through those waters 
to a traditional navigable water. Relevant considerations for chemical 
connectivity could include hydrologic connectivity, surrounding land 
use and land cover, the landscape setting, and deposition of chemical 
constituents (e.g., acidic deposition).
    To determine whether a water has a significant effect on the 
biological integrity of traditional navigable waters, interstate 
waters, or territorial seas, the agencies have identified biological 
factors or uses present in the relevant stream reach, and then 
evaluated the effects of these factors or uses on the downstream 
waters. Examples of biological factors and uses include: Resident 
aquatic or semi-aquatic species present in the water being evaluated, 
the tributary system, and downstream traditional navigable waters 
(e.g., fish, amphibians, aquatic and semi-aquatic reptiles, aquatic 
birds, benthic macroinvertebrates); whether those species show life-
cycle dependency on the identified aquatic resources (foraging, 
feeding, nesting, breeding, spawning, use as a nursery area, etc.); and 
whether there is reason to expect presence or dispersal around the 
water being evaluated, and if so, whether such dispersal extends to the 
tributary system or beyond or from the tributary system to the water 
being evaluated. In addition, relevant factors influencing biological 
connectivity and effects could include species' life history traits, 
species' behavioral traits, dispersal range, population sizes, timing 
of dispersal, distance between the water being evaluated and a 
traditional navigable water, the presence of habitat corridors or 
barriers, and the number, area, and spatial distribution of habitats. 
Under such an approach, non-aquatic species or species such as non-
resident migratory birds do not demonstrate a life cycle dependency on 
the identified aquatic resources and are not evidence of a significant 
nexus.
    As discussed in section V.C.10 of this preamble, the agencies' 
proposed definition of ``significantly affect'' at paragraph (g) 
includes a list of factors that the agencies will consider when 
assessing the significance of the effect of a function. These factors 
are consistent with the approach the agencies used in assessing 
significant nexus under the Rapanos Guidance, and the agencies are 
soliciting comment on whether to include these or other factors, as 
well as whether to include functions identified in the Rapanos Guidance 
or other functions in the proposed rule or in approaches for 
implementing the rule.
ii. Other Potential Approaches To Implementing the Significant Nexus 
Standard
    The agencies solicit comment on how to apply the significant nexus 
standard in the field, including whether they should implement the 
significant nexus standard in the proposed rule consistent with the 
Rapanos Guidance for all waters under the proposed rule that require a 
significant nexus evaluation--i.e., certain ``other waters,'' non-
relatively permanent tributaries, and certain adjacent wetlands (i.e., 
waters identified in paragraphs (a)(3)(ii), (a)(5)(ii), (a)(7)(iii) of 
the proposed rule). Should the agencies implement the significant nexus 
standard consistent with the Rapanos Guidance, the agencies are seeking 
comment on whether there are clarifications or other issues to be 
addressed to improve that implementation approach. The agencies are 
also seeking comment on other approaches to implementing the 
significant nexus standard, such as a broader, science-based approach 
to some aspects of a significant nexus analysis or an approach that 
tailors the scope of a significant analysis based on facts like the 
geographic region or type of water being assessed, as discussed below.
(1) Scope of Significant Nexus Analysis for Adjacent Wetlands and 
Tributaries
    Under the significant nexus standard, waters possess the requisite 
significant nexus if they ``either alone or in combination with 
similarly situated [wet]lands in the region, significantly affect the 
chemical, physical, and biological integrity of other covered waters 
more readily understood as `navigable.''' Rapanos at 780. These 
significant nexus analyses underpin

[[Page 69439]]

determinations of jurisdiction for certain categories of waters under 
the proposed rule. However, several terms in this standard were not 
defined in Rapanos. The agencies are soliciting comment on approaches 
for implementing the proposed rule, including regarding (1) which 
waters are ``similarly situated,'' and thus should be analyzed in 
combination, in (2) the ``region,'' for purposes of a significant nexus 
analysis, and (3) the types of functions that should be analyzed to 
determine if waters significantly affect the chemical, physical, or 
biological integrity of traditional navigable waters, interstate 
waters, or the territorial seas. Discussion of the alternative 
approaches regarding relevant functions is in section V.D.2.b.ii.2 of 
this preamble.
a. Similarly Situated Waters
    As discussed above, the Rapanos Guidance interpreted ``similarly 
situated'' to mean a tributary and its adjacent wetlands. The agencies 
could implement the final rule consistent with this approach or take an 
approach that interprets which waters are ``similarly situated'' 
differently than the Rapanos Guidance. One such approach would be to 
interpret ``similarly situated'' in terms of particular waters that are 
providing common, or similar, functions for downstream waters such that 
it is reasonable to consider their effect together. Such an approach 
could consider tributaries to be similarly situated with other 
tributaries, adjacent wetlands to be similarly situated with adjacent 
wetlands, and ``other waters'' to be similarly situated with ``other 
waters'' (e.g., lakes and ponds with similar functions and geographic 
position on the landscape). Another approach would be to consider 
similarly situated waters to be tributaries of the same flow regime 
(for example, assessing an ephemeral stream in combination with other 
ephemeral streams in the region). The agencies could also consider 
tributaries of the same stream order to be similarly situated (for 
example, assessing all first order streams in combination with other 
first order streams in the region).
    The agencies note that the best available science supports 
evaluating the connectivity and effects of streams, wetlands, and open 
waters to downstream waters in a cumulative manner in context with 
other streams, wetlands, and open waters. See Technical Support 
Document.
b. In the Region
    The agencies could implement the scope of the significant nexus 
analysis (what is considered ``in the region'') consistent with the 
Rapanos Guidance, which relied on a concept of a relevant ``reach'' of 
a tributary--defined as the entire reach of the stream that is of the 
same order (i.e., from the point of confluence, where two lower order 
streams meet to form the tributary, downstream to the point such 
tributary enters a higher order stream). Rapanos Guidance at 10.
    Alternatively, the agencies could implement what is considered ``in 
the region'' for significant nexus evaluations with an approach 
different from that in the Rapanos Guidance. For example, the relevant 
reach for purposes of considering what is ``in the region'' for a 
significant nexus evaluation could be implemented the way the term 
``reach'' was interpreted in the NWPR, meaning a section of a stream or 
river along which similar hydrologic conditions exist, such as 
discharge, depth, area, and slope. 85 FR 22290, April 21, 2020. Under 
the NWPR's approach, a reach can be any length of a stream or river, 
but for implementation purposes that length is bounded by similar flow 
characteristics. Similarly, the agencies could implement the ``relevant 
reach'' to incorporate the entire length of the stream that is of the 
same flow regime (i.e., relatively permanent and non-relatively 
permanent flow, or perennial, intermittent, and ephemeral flow). For 
example, if a perennial tributary becomes intermittent and then 
ephemeral and then perennial again, it may be viewed as four separate 
relevant reaches (e.g., perennial reach, intermittent reach, ephemeral 
reach, perennial reach). Alternatively, the agencies could use an 
approach that is substantially similar to the Rapanos Guidance but that 
identifies the relevant reach based on certain hydrologic or geomorphic 
characteristics. For instance, the relevant reach of a tributary could 
rely on factors identified in stream field assessments and monitoring 
protocols such as the similarity of the channel's substrate or 
geomorphic classification. Additional factors identified through field 
observations or remote-sensing could also be used to determine the 
extent of a tributary's relevant reach such as the presence of natural 
features like bedrock outcrops or valley confinements, and non-natural 
features like culverts or road crossings, which can modify or influence 
hydrologic characteristics and geomorphic processes. Aerial and 
satellite imaging, National Hydrography Dataset (NHD) Plus High 
Resolution data, and high resolution digital elevation models could be 
used to evaluate whether hydrologic and geomorphic conditions within a 
channel are similar enough to be defined as the relevant reach of a 
tributary. Another option is for the agencies to interpret a tributary 
for purposes of the significant nexus analysis to be the entire length 
of a stream based on maps or best professional judgment.
    There are also a range of approaches for determining the ``region'' 
in which waters to be assessed lie and which could allow for a more 
regionalized approach to significant nexus assessments. For example, 
the region could be sub-watersheds or the watershed defined by where a 
tributary and its upstream tributaries drain into a traditional 
navigable water, interstate water, or the territorial seas. If the 
watershed draining to the traditional navigable water, interstate 
water, or territorial sea is too large, the watershed could be 
evaluated at a subwatershed scale (e.g., at the hydrologic unit code 
(HUC) 8, 10, or 12 watershed scale). Alternatively, the watershed could 
be considered just the watershed of the relevant reach (i.e., 
catchment), and the relevant reach could be determined using the 
options described above. Another option is for the watershed to be 
delineated from the downstream-most point of the relevant reach--that 
is, the region would be the watershed that drains to and includes the 
relevant reach in question. Many existing spatial analysis tools based 
on watershed frameworks and elevation models can be used to delineate 
watersheds quickly and reliably in most parts of the country.
    Other options for determining a ``region'' in which similarly 
situated waters would be considered cumulatively could include a 
narrower interpretation such as waters within a contiguous area of land 
with relatively homogeneous soils, vegetation, and landform (e.g., 
plain, mountain, valley, etc.) providing similar functions such as 
habitat, water storage, sediment retention, and pollution 
sequestration. This approach would be highly case specific and rely on 
the use of resources such as soil surveys and possibly watershed 
assessment reports to determine those waters that are similarly 
situated within a region.
    More broadly, ``region'' could be interpreted to mean an ecoregion 
which serves as a spatial framework for the research, assessment, 
management, and monitoring of ecosystems and ecosystem components. 
Ecoregions are areas where ecosystems (and the type, quality, and 
quantity of environmental resources) are generally similar (see https://www.epa.gov/eco-research/ecoregions). Ecoregions are identified by

[[Page 69440]]

analyzing the patterns and composition of biotic and abiotic phenomena 
that affect or reflect differences in ecosystem quality and 
integrity.\55\ \56\ These phenomena include geology, landforms, soils, 
vegetation, climate, land use, wildlife, and hydrology. Under the 
ecoregion approach, similarly situated waters would be considered 
cumulatively within an ecoregion (see, e.g., https://www.epa.gov/eco-research/ecoregions-north-america). The scale of ecoregion (e.g., Level 
I, Level II, Level III, or Level IV ecoregions identified by EPA in 
North America) used for determining the ``region'' could be quite 
broad, such as the 12 different Level I ecological regions in the 
continental United States or narrower like the 105 different Level III 
ecological regions in the continental United States or the 967 Level IV 
ecoregions in the conterminous United States. Because Level I 
ecoregions are quite large, considerations of similarly situated waters 
at the Level I ecoregion scale could potentially obscure the measurable 
effects of a single aquatic resource on a downstream traditional 
navigable water, interstate water, or territorial sea. However, the 
scale of the similarly situated analysis within an ecoregion could be 
refined using the smaller Level III or Level IV ecoregions which allow 
local characteristics to be identified and are more specifically 
oriented towards environmental management strategies. Under this 
approach in a jurisdictional analysis, scientific literature describing 
or studying characteristics of the Level III or Level IV ecoregions 
could be used to inform the evaluation of specific ecological functions 
performed by similarly situated waters. A benefit of using this 
approach is that ecoregions are spatial datasets which have been, or 
could be, incorporated into many existing spatial analysis tools and 
mapping platforms. In addition, stakeholders have called for 
acknowledging regional differences in the definition of ``waters of the 
United States,'' and an ecoregion approach could allow for such 
consideration in implementation.
---------------------------------------------------------------------------

    \55\ Omernik, J.M. 1987. Ecoregions of the conterminous United 
States. Map (scale 1:7,500,000). Annals of the Association of 
American Geographers 77(1):118-125.
    \56\ Omernik, J.M. 1995. Ecoregions: A spatial framework for 
environmental management. In: Biological Assessment and Criteria: 
Tools for Water Resource Planning and Decision Making. Davis, W.S. 
and T.P. Simon (eds.), Lewis Publishers, Boca Raton, FL. p. 49-62.
---------------------------------------------------------------------------

    In addition to ecoregions, other methods of mapping boundaries 
where similarly situated waters could be considered cumulatively for a 
significant nexus analysis would be to rely on hydrologic landscape 
regions or physiographic groupings. Hydrologic landscape regions are 
groups of watersheds that are clustered together on the basis of 
similarities in land-surface form, geologic texture, and climate 
characteristics.\57\ Hydrologic landscape regions are based on a 
concept that reflects fundamental hydrologic processes that are 
expected to affect water quality and other environmental 
characteristics. Based on a commonly used method to delineate 
hydrologic landscape regions that was developed by the USGS, there are 
20 regions that cover the entire United States.\58\ This method could 
present similar challenges as the Level I ecoregion approach described 
above, whereby the hydrologic landscape region scale obscures the 
measurable effects of single aquatic resources. Alternatively, the 
agencies could rely on well-established physiographic divisions based 
on topography, geology, and geomorphology, including the eight 
physiographic regions across the contiguous United States, the 25 
physiographic provinces within those regions, or the 85 physiographic 
sections within those regions (available at https://water.usgs.gov/GIS/metadata/usgswrd/XML/physio.xml).
---------------------------------------------------------------------------

    \57\ Winter, T.C., 2001. The concept of hydrologic landscapes: 
Journal of the American Water Resources Association, v. 37, p. 335-
349.
    \58\ Wolock, D.M. 2003. Hydrologic landscape regions of the 
United States (No. 2003-145). US Geological Service.
---------------------------------------------------------------------------

(2) Other Waters
    The agencies seek comment on potential approaches to address a 
significant nexus analysis for waters under the ``other waters'' 
provision of the proposed rule. As discussed in section V.C.3 of this 
preamble, ``other waters'' were not addressed by the Rapanos Guidance. 
The agencies could adopt the approach used in the SWANCC Guidance, 
whereby field staff were directed to seek approval from agency 
headquarters before asserting jurisdiction over isolated waters that 
are intrastate and non-navigable. See 68 FR at 1996, January 15, 2003. 
As a matter of practice since the issuance of the SWANCC Guidance, the 
Corps has not asserted jurisdiction over such ``other waters.'' The 
agencies would not be precluded as a legal matter from asserting 
jurisdiction over ``other waters'' under this proposed rule, which 
would retain the ``other waters'' provision from the 1986 regulations 
and add the relatively permanent and significant nexus standards, but 
following the SWANCC Guidance approach would require an additional 
approval process before the agencies asserted jurisdiction. The 
agencies could also modify the prior approach by identifying a 
subsection of ``other waters'' that could be determined jurisdictional 
without headquarters' authorization, such as lakes and ponds which meet 
the definition of ``adjacent,'' but do not fall within the adjacent 
wetlands provision because they are open waters, not wetlands (e.g., 
oxbow lakes and ponds).
    ``Other waters'' that meet the definition of ``adjacent'' could be 
treated like adjacent wetlands under the Rapanos Guidance. Under such 
an approach, the agencies could adopt the same interpretation of 
``similarly situated'' that is used to complete a significant nexus 
determination for adjacent wetlands (see section V.D.2.b.ii.1 of this 
preamble), or the agencies could adopt a different interpretation of 
``similarly situated'' that is specifically applicable to ``other 
waters.''
    The various options for implementing significant nexus are not 
mutually exclusive and the agencies are interested in any other 
approaches for assessing significant nexus under the proposed rule, 
particularly approaches that utilize existing science-based tools and 
resources to assist in predictability and ease of implementation for 
the public and the agencies.
3. Resources for Making Jurisdictional Determinations
    Many field-based and remote tools and sources of data are available 
to determine Clean Water Act jurisdiction under the proposed rule. In 
some cases, a property owner may be able to determine whether a 
property includes a ``water of the United States'' based on observation 
or experience. In other cases, a property owner may seek assistance 
from a consultant to assess the jurisdictional status of features on 
their property. Property owners may also seek a jurisdictional 
determination from the Corps, which provides jurisdictional 
determinations as a public service. When conducting a jurisdictional 
determination, the Corps will review any documentation that a property 
owner, or consultant, provides to assist in making a jurisdictional 
determination. EPA staff also regularly assess the jurisdictional 
status of waters in implementing Clean Water Act programs. The agencies 
expect that EPA and Corps staff, as well as private consultants, would 
be the primary users of the tools and sources of remote data described 
below, and they have ample

[[Page 69441]]

experience in using them from prior regulatory regimes.
    The resources covered in this section include tools for identifying 
relatively permanent tributaries (section V.D.3.a of this preamble); 
tools for identifying wetlands adjacent to traditional navigable 
waters, interstate waters, the territorial seas, impoundments of 
jurisdictional waters, or tributaries (section V.D.3.b of this 
preamble); and tools for applying a significant nexus standard (section 
V.D.3.c of this preamble). This section presents a non-exclusive list 
of tools that the agencies have used in the past and will continue to 
use to assist in making jurisdictional decisions, but other tools could 
also be used to determine jurisdiction. The agencies have also 
identified a number of recent advancements in the data, tools, and 
methods that can be used to make jurisdictional decisions (section 
V.D.3.d of this preamble).
a. Identifying Relatively Permanent Tributaries
    Relatively permanent tributaries include rivers, streams, and other 
hydrographic features with standing or flowing bodies of water, and may 
also include certain lakes and ponds. These features can be identified 
on the landscape using various remote sensing resources such as USGS 
stream gage data (available at https://waterdata.usgs.gov/nwis/rt), 
USGS topographic maps (available at https://www.usgs.gov/core-science-systems/ngp/tnm-delivery/topographic-maps), high-resolution elevation 
data and associated derivatives (e.g., slope or curvature metrics), 
Federal Emergency Management Agency (FEMA) flood zone maps (available 
at https://msc.fema.gov/portal/home), NRCS soil maps (available at 
https://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx), NHD 
data, National Wetland Inventory (NWI) data, maps and geospatial 
datasets from state, tribal, or local governments, and/or aerial or 
satellite imagery. For example, tributaries are observable in aerial 
imagery and high-resolution satellite imagery by their topographic 
expression, characteristic linear and curvilinear patterns, dark 
photographic tones, or the presence of riparian vegetation. USGS 
topographic maps often include different symbols to indicate mapped 
hydrographic features such as perennial and intermittent tributaries 
(see ``Topographic Map Symbols,'' available at https://pubs.usgs.gov/gip/TopographicMapSymbols/topomapsymbols.pdf). Due to limitations 
associated with some remote tools, field verification for accuracy may 
be necessary, and some examples of field indicators will be discussed 
in more detail below.
    Under the Rapanos Guidance, tributaries may be considered 
relatively permanent if they typically flow year-round or have 
continuous flow at least seasonally (e.g., typically three months). A 
key factor that the agencies typically consider when assessing the 
length and timing of expected ``seasonal'' flows is the geographic 
region. The time period, including length, constituting ``seasonal'' 
varies across the country due to many relevant factors including 
climate, hydrology, topography, soils, and other conditions. For 
example, in parts of the southeastern United States (Southeast), 
precipitation is distributed somewhat uniformly throughout the year, 
but increased evapotranspiration during the growing season can reduce 
surficial ground water levels and lead to reduced or absent surface 
flows late in the growing season (e.g., late summer or early autumn). 
Consequently, ``seasonal'' flows in the Southeast may typically occur 
in the winter or early spring. In other areas, snowmelt drives 
streamflow more than rainfall, with seasonal flow coinciding with 
warming temperatures typically in the spring or early summer. In 
addition, the agencies have found that two months of continuous flow, 
for example, is considered ``seasonal'' flow in certain regions of the 
country and can be sufficient to support a relatively permanent 
designation.\59\ Sources of information that can facilitate the 
evaluation of seasonal flow from snowmelt are NOAA national snow 
analyses maps (available at https://www.nohrsc.noaa.gov/nsa/), NRCS 
sources (available at https://www.wcc.nrcs.usda.gov/snow/), or use of 
hydrographs to indicate a large increase in stream discharge due to the 
late spring/early summer thaws of melting snow. The agencies have 
experience evaluating seasonal flow and will continue to use multiple 
tools, including remote and field-based indicators to inform decisions.
---------------------------------------------------------------------------

    \59\ See, e.g., Memorandum to Assert Jurisdiction for NWP-2007-
945 (January 23, 2008), available at https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll5/id/1437.
---------------------------------------------------------------------------

    While not providing explicit flow classifications (e.g., perennial, 
intermittent, or ephemeral), various remote or desktop tools can help 
the agencies and the public better understand streamflow and inform 
determinations of flow classifications. These tools include local maps, 
StreamStats by the USGS (available at https://streamstats.usgs.gov/ss/
), Probability of Streamflow Permanence (PROSPER) by the USGS, which 
provides streamflow permanence probabilities during the summer for 
stream reaches in the Pacific Northwest (available at https://www.usgs.gov/centers/wy-mt-water/science/probability-streamflowpermanence-prosper), and NRCS hydrologic tools and soil maps. 
Other tools include regional desktop tools that provide for the 
hydrologic estimation of a discharge sufficient to generate 
intermittent or perennial flow (e.g., a regional regression analysis or 
hydrologic modeling), or modeling tools using drainage area, 
precipitation data, climate, topography, land use, vegetation cover, 
geology, and/or other publicly available information. Some models that 
are developed for use at the reach scale may be localized in their 
geographic scope.
    Remote or desktop tools can also illustrate the relative permanence 
of flow. Aerial photographs showing visible water on multiple dates can 
provide evidence of the sufficient frequency and duration of surface 
flow to facilitate a potential flow classification. Aerial photographs 
may also show other indicators commonly used to identify the presence 
of an OHWM (see definition of OHWM in section V.C.9.d of this preamble 
and https://www.erdc.usace.army.mil/Media/Fact-Sheets/Fact-Sheet-Article-View/Article/486085/ordinary-high-water-mark-ohwm-research-development-and-training/). These may include the destruction of 
terrestrial vegetation, the absence of vegetation in a channel, and 
stream channel morphology with evidence of scour, material sorting, and 
deposition. These indicators from aerial photographs can be correlated 
to the presence of USGS stream data to support a potential flow 
classification for a tributary. In addition to aerial photographs, 
desktop tools, such as a regional regression analysis and the 
Hydrologic Modeling System (HEC-HMS), provide for the hydrologic 
estimation of stream discharge in tributaries under regional 
conditions. The increasing availability of light detection and ranging 
(LIDAR) derived data can also be used to help implement this proposed 
rule. Where LIDAR data have been processed to create elevation data 
such as a bare earth model, detailed depictions of the land surface are 
available and subtle elevation changes can indicate a tributary's bed 
and banks and channel morphology. Visible linear and curvilinear 
incisions on a bare earth model can help inform the potential

[[Page 69442]]

flow regime of a water in greater detail than aerial photography 
interpretation alone. Several tools (e.g., TauDEM, Whitebox, GeoNet) 
can assist in developing potential stream networks based on 
contributing areas, curvature, and flowpaths using GIS. Potential 
LIDAR-indicated tributaries can be correlated with aerial photography 
or high-resolution satellite imagery interpretation and USGS stream 
gage data, to reasonably conclude the presence of an OHWM and shed 
light on the potential flow regime.
    Field indicators for the region can be used to verify desktop 
assessments of the relative permanence of a tributary, when necessary. 
Geomorphic indicators could include active/relict floodplain, substrate 
sorting, clearly defined and continuous bed and banks, depositional 
bars and benches, and recent alluvial deposits. Hydrologic indicators 
might include wrack/drift deposits, hydric soils, or water-stained 
leaves. Biologic indicators could include aquatic mollusks, crayfish, 
benthic macroinvertebrates, algae, and wetland or submerged aquatic 
plants. Regionalized streamflow duration assessment methods (SDAMs) 
that use physical and biological field indicators, such as the presence 
of hydrophytic vegetation and benthic macroinvertebrates, can also be 
used to determine the flow duration class of a tributary as perennial, 
intermittent, or ephemeral (e.g., the Streamflow Methodology for 
Identification of Intermittent and Perennial Streams and Their Origins, 
developed by the North Carolina Division of Water Quality, available at 
http://portal.ncdenr.org/c/document_library/get_file?uuid=0ddc6ea1-d736-4b55-8e50-169a4476de96&groupId=38364). EPA, the Corps, and the 
State of Oregon developed a regionalized SDAM that has been validated 
for use throughout the Pacific Northwest (available at http://www.epa.gov/measurements/streamflow-duration-assessment-method-pacific-northwest). EPA and the Corps have also developed a beta SDAM for the 
arid West (available at https://www.epa.gov/streamflow-duration-assessment/beta-streamflow-duration-assessment-method-arid-west) and 
are working to develop additional regionalized SDAMs in other parts of 
the country. Flow duration classifications can then be used to assist 
in determining the relative permanence of the tributary. Ultimately, 
multiple indicators, data points, and sources of information may be 
used to determine flow classification.
b. Identifying Wetlands Adjacent to Traditional Navigable Waters, 
Interstate Waters, Territorial Seas, Impoundments, or Tributaries
    Before determining if a wetland is jurisdictional, the agencies 
first determine if the wetland in question meets the definition of 
``wetlands'' (see section V.C.9.a of this preamble). As under prior 
regimes, wetlands are identified in the field in accordance with Corps' 
1987 Wetland Delineation Manual and applicable regional delineation 
manuals. Field work is often necessary to confirm the presence of a 
wetland and to accurately delineate its boundaries. However, in 
addition to field observations on hydrology, vegetation, and soils, 
remote tools and resources can be used to support the identification of 
a wetland, including USGS topographic maps (available at https://www.usgs.gov/core-science-systems/ngp/tnm-delivery/topographic-maps), 
NRCS soil maps and properties of soils including flood frequency and 
duration, ponding frequency and duration, hydric soils, and drainage 
class (available at https://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx or via the NRCS Soil Survey Geographic Database 
(SSURGO) available at https://catalog.data.gov/dataset/soil-survey-geographic-database-ssurgo), aerial or high-resolution satellite 
imagery, high-resolution elevation data (e.g., https://apps.nationalmap.gov/downloader/#/), and NWI maps (available at https://www.fws.gov/wetlands/data/mapper.html).
    Once a feature is identified as a wetland, if the wetland itself is 
not a traditional navigable water (i.e., it is not a tidal wetland) or 
an interstate water, the agencies assess whether it is adjacent to a 
traditional navigable water, interstate water, territorial sea, 
jurisdictional impoundment, or jurisdictional tributary. A variety of 
remote tools can help to assess adjacency, including maps, high-
resolution elevation data, aerial photographs, and high-resolution 
satellite imagery. For example, USGS topographic maps, elevation data, 
and NHD data may identify a physical barrier or illustrate the location 
of the traditional navigable water, interstate water, territorial sea, 
jurisdictional impoundment, or jurisdictional tributary; the wetland's 
proximity to the jurisdictional water; and the nature of topographic 
relief between the two aquatic resources. Aerial photographs or high-
resolution satellite imagery may illustrate hydrophytic vegetation from 
the boundary (e.g., ordinary high water mark for non-tidal waters or 
high tide line for tidal waters) of the traditional navigable water, 
interstate water, territorial sea, jurisdictional impoundment, or 
jurisdictional tributary to the wetland boundary, or the presence of 
water or soil saturation. NRCS soil maps may identify the presence of 
hydric soil types, soil saturation, or potential surface or subsurface 
hydrologic connections. Additionally, methods that overlay depressions 
on the landscape with hydric soils and hydrophytic vegetation can be 
used to identify likely wetlands and hydrologic connections. NWI maps 
may identify that the wetlands are near the traditional navigable 
water, interstate water, territorial sea, jurisdictional impoundment, 
or jurisdictional tributary. Field work can help confirm the presence 
and location of the OHWM or high tide line of the traditional navigable 
water, interstate water, territorial sea, jurisdictional impoundment, 
or jurisdictional tributary and can provide additional information 
about the wetland's potential adjacency to that water (e.g., by 
traversing the landscape from the traditional navigable water, 
interstate water, territorial sea, jurisdictional impoundment, or 
jurisdictional tributary to the wetland and examining topographic and 
geomorphic features, as well as hydrologic and biologic indicators). 
Wetlands adjacent to traditional navigable waters, interstate waters, 
or the territorial seas do not need further analysis to determine if 
they are ``waters of the United States.''
    For a wetland adjacent to relatively permanent, non-navigable 
tributaries and relatively permanent impoundments of jurisdictional 
waters, similar remote tools and resources as those described above may 
be used to identify if the wetland has a continuous surface connection 
to such waters. The tools and resources most useful for addressing this 
standard are those that reveal breaks in the surface connection between 
the wetland and the relatively permanent water, such as separations by 
uplands, or a berm, dike, or similar feature. For example, USGS 
topographic maps may show topographic highs between the two features, 
or simple indices can be calculated based on topography to indicate 
where these connectivity breaks occur. FEMA flood zone or other 
floodplain maps may indicate constricted floodplains along the length 
of the tributary channel with physical separation of flood waters that 
could indicate a break. High-resolution elevation data can illustrate 
topographic highs between the two features that

[[Page 69443]]

extend along the tributary channel. Aerial photographs or high-
resolution satellite imagery may illustrate upland vegetation along the 
tributary channel between the two features, or bright soil signatures 
indicative of higher ground. NRCS soil maps may identify mapped linear, 
upland soil types along the tributary channel. Field work may help to 
confirm the presence and location of the relatively permanent, non-
navigable tributary's OHWM. In addition, field work may confirm whether 
there is a continuous physical connection between the wetland and the 
relatively permanent, non-navigable tributary, or identify breaks that 
may sever the continuous surface connection (e.g., by traversing the 
landscape from the tributary to the wetland and examining topographic 
and geomorphic features, as well as hydrologic and biologic 
indicators).
    For adjacent wetlands that lack a continuous surface connection to 
jurisdictional relatively permanent tributaries or jurisdictional 
relatively permanent impoundments or that are adjacent to non-
relatively permanent tributaries, the agencies will conduct a 
significant nexus analysis to assess if the wetlands are 
jurisdictional. Tools to assess if the adjacent wetlands significantly 
affect foundational waters are discussed in section V.D.3.c of this 
preamble.
c. Applying the Significant Nexus Standard
    The agencies have used many tools and sources of information to 
assess significant effects on the chemical, physical, and biological 
integrity of downstream traditional navigable waters, interstate 
waters, or the territorial seas. Some tools and resources that the 
agencies have used to provide and evaluate evidence of a significant 
effect on the physical integrity of foundational waters include USGS 
stream gage data, floodplain maps, statistical analyses, hydrologic 
models and modeling tools such as USGS's StreamStats (available at 
https://streamstats.usgs.gov/ss/) or the Corps' Hydrologic Engineering 
Centers River System Analysis System (HEC-RAS), physical indicators of 
flow such as the presence and characteristics of a reliable OHWM with a 
channel defined by bed and banks, or other physical indicators of flow 
including such characteristics as shelving, wracking, water staining, 
sediment sorting, and scour, information from NRCS soil surveys, 
precipitation and rainfall data, and NRCS snow telemetry (SNOTEL) data 
or NOAA national snow analyses maps.
    To evaluate the evidence of a significant effect on the biological 
integrity of foundational waters, the agencies and practitioners have 
used tools and resources such as: population survey data and reports 
from federal, state, and tribal resource agencies, natural history 
museum collections databases, bioassessment program databases, fish 
passage inventories, U.S. Fish and Wildlife Service (FWS) Critical 
Habitat layers, species distribution models, and scientific literature 
and references from studies pertinent to the distribution and natural 
history of the species under consideration.
    Tools and resources that provide and evaluate evidence of a 
significant effect on the chemical integrity of foundational waters 
include data from USGS water quality monitoring stations, state, 
tribal, and local water quality reports, water quality monitoring and 
assessment databases, EPA's How's My Waterway (available at https://www.epa.gov/waterdata/hows-my-waterway), which identifies Clean Water 
Act section 303(d) listed waters, water quality impairments, and total 
maximum daily loads, watershed studies, stormwater runoff data or 
models, EPA's NEPAssist (available at https://www.epa.gov/nepa/nepassist), which provides locations and information on wastewater 
discharge facilities and hazardous-waste sites, the National Land Cover 
Database (NLCD), and scientific literature and references from studies 
pertinent to the parameters being reviewed. EPA has developed a web-
based interactive water quality and quantity modeling system 
(Hydrologic and Water Quality System, HAWQS; available at https://www.epa.gov/waterdata/hawqs-hydrologic-and-water-quality-system) that 
is being used to assess cumulative effects of wetlands on other waters 
they may drain into. Additional approaches to quantifying the 
hydrologic storage capacity of wetlands include statistical models, 
such as pairing LIDAR-based topography with precipitation totals. Both 
statistical and process-based models have been used to quantify the 
nutrient filtering capabilities of non-floodplain wetlands, and in some 
cases to assess the effects of non-floodplain wetland nutrient removal, 
retention, or transformation on downstream water quality. Evaluations 
of a significant effect on the chemical integrity of a traditional 
navigable water, interstate water, or territorial sea may include 
qualitative reviews of available information or incorporate 
quantitative analysis components including predictive transport 
modeling.
    A variety of modeling approaches can be used to quantify the 
connectivity and cumulative effects of wetlands, including non-
floodplain wetlands, on other waters. Some examples include the Soil 
and Water Assessment Tool (SWAT, available at https://swat.tamu.edu/), 
the Hydrologic Simulation Program in Fortran (see https://www.epa.gov/ceam/hydrological-simulation-program-fortran-hspf), and DRAINMOD for 
Watersheds (DRAINWAT, available at https://www.bae.ncsu.edu/agricultural-water-management/drainmod/). Other examples of models 
applicable to identifying effects of wetlands on downstream waters 
include the USGS hydrologic model MODFLOW (available at https://www.usgs.gov/mission-areas/water-resources/science/modflow-and-related-programs?qt-science_center_objects=0#qt-science_center_objects) and the 
USGS flow simulation model VS2DI (available at https://www.usgs.gov/software/vs2di-version-13).
d. Advancements in Implementation Data, Tools, and Methods
    Since the Rapanos decision, there have been dramatic advancements 
in the data, tools, and methods used to make jurisdictional 
determinations, including in the digital availability of information 
and data. In 2006, when the agencies began to implement the Rapanos and 
Carabell decisions, there were fewer implementation tools and support 
resources to guide staff in defensible jurisdictional decision-making 
under the relatively permanent and significant nexus standards. Agency 
staff were forced to heavily rely on information provided in applicant 
submittals and available aerial imagery to make jurisdictional 
decisions or to schedule an in-person site visit to review the property 
themselves. The U.S. Army Corps of Engineers Jurisdictional 
Determination Form Instructional Guidebook encouraged practitioners to 
utilize maps, aerial photography, soil surveys, watershed studies, 
scientific literature, previous jurisdictional determinations for the 
review area, and local development plans to complete accurate 
jurisdictional decisions or analysis. For more complicated situations 
or decisions involving significant nexus evaluations, the Guidebook 
encouraged practitioners to identify and evaluate the functions 
relevant to the significant nexus by incorporating literature citations 
and/or references from studies pertinent to the parameters being 
reviewed. For significant nexus decisions specifically, the Guidebook

[[Page 69444]]

instructed Corps field staff to consider all available hydrologic 
information (e.g., gage data, precipitation records, flood predictions, 
historic records of water flow, statistical data, personal 
observations/records, etc.) and physical indicators of flow including 
the presence and characteristics of a reliable OHWM.
    The Corps also issued Regulatory Guidance Letter (RGL) No. 07-01 
\60\ in 2007 that laid out principal considerations for evaluating the 
significant nexus of a tributary and its adjacent wetlands which 
included the volume, duration, and frequency of flow of water in the 
tributary, proximity of the tributary to a traditional navigable water, 
and functions performed by the tributary and its adjacent wetlands. 
This RGL highlighted wetland delineation data sheets, delineation maps, 
and aerial photographs as important for adequate information to support 
all jurisdictional decision-making. Gathering the data necessary to 
support preliminary or approved jurisdictional decisions was often time 
consuming for staff and the regulated public, and there were not many 
nationally available repositories for much of the information that the 
agency staff utilized in decision-making, particularly during the first 
years of implementing of the guidance. Despite these challenges, the 
agencies and others in the practitioner community gained significant 
collective experience implementing the relatively permanent and 
significant nexus standards from 2006 to 2015.
---------------------------------------------------------------------------

    \60\ It should be noted that RGL No. 07-01 was later superseded 
by RGL 08-02 and RGL 16-01, neither of which addressed significant 
nexus evaluations.
---------------------------------------------------------------------------

    Since 2015, there have been dramatic improvements to the quantity 
and quality of water resource information available on the internet. 
The agencies can use online mapping tools to determine whether waters 
are connected or sufficiently close to a water of the United States, 
and new user interfaces have been developed that make it easier and 
quicker to access information from a wide variety of sources. 
Furthermore, some information used to only be available in hard-copy 
paper files, including water resource inventories and habitat 
assessments, and many of these resources have been made available 
online or updated with new information. An overview of several tools 
and data that have been developed or improved since 2015 can help 
demonstrate how the agencies are now able to make case-specific 
evaluations more quickly and consistently than ever before.
    Advancements in geographic information systems (GIS) technology and 
cloud-hosting services have led to an evolution in user interfaces for 
publicly available datasets frequently used in jurisdictional decision-
making such as the NWI, USGS NHD, soil surveys, aerial imagery and 
other geospatial analysis tools like USGS StreamStats. Not only are the 
individual datasets more easily accessible to users, but it has also 
become much easier for users to quickly integrate these various 
datasets using desktop or online tools like map viewers to consolidate 
and evaluate the relevant data in one visual platform. The EPA 
Watershed Assessment, Tracking, and Environmental Results System 
(WATERS) GeoViewer is an example of a web mapping application that 
provides accessibility to many spatial dataset layers like NHDPlus and 
watershed reports for analysis and interpretation. Other websites like 
the Corps' Jurisdictional Determinations and Permits Decision site and 
webservices like EPA's Enforcement and Compliance History Online (ECHO) 
Map Services allow users to find geospatial and technical information 
about Clean Water Act section 404 and NPDES permitted discharges. 
Information on approved jurisdictional determinations finalized by the 
Corps is also available on the Corps' Jurisdictional Determinations and 
Permit Decisions site and EPA's Clean Water Act Approved Jurisdictional 
Determinations website.
    The data that are available online have increased in quality as 
well as quantity. The NHD has undergone extensive improvements in data 
availability, reliability, and resolution since 2015, including the 
release of NHDPlus High Resolution datasets for the conterminous U.S. 
and Hawaii, with Alaska under development. One notable improvement in 
NHD data quality is that the flow-direction network data is much more 
accurate than in the past. Improvements have also been made to the NWI 
website and geospatial database, which has served as the primary source 
of wetland information in the United States for many years. In 2016, 
NWI developed a more comprehensive dataset (NWI Version 2) that is 
inclusive of all surface water features in addition to wetlands. The 
agencies can use this dataset to help assess potential hydrologic 
connectivity between waterways and wetlands in support of 
jurisdictional decisions. For example, the NWI Version 2 dataset can be 
used in part to help the agencies identify wetlands that do not meet 
the definition of adjacent (``other waters''). This NWI Version 2 
dataset provides more complete geospatial data on surface waters and 
wetlands than has been available in the past and provides a more 
efficient means to make determinations of flow and water movement in 
surface water basins and channels, as well as in wetlands.
    The availability of aerial and satellite imagery has improved 
dramatically since 2015, which is used to observe the presence or 
absence of flow and identify relatively permanent flow in tributary 
streams and hydrologic connections to waters. The agencies often use a 
series of aerial and satellite images, spanning multiple years and 
taken under normal climatic conditions, to determine the flow 
classification for a tributary, as a first step to determine if 
additional field-based information is needed to determine the flow 
classification. The growth of the satellite imagery industry through 
services such as DigitalGlobe (available at https://discover.digitalglobe.com/) in addition to resources for aerial 
photography and imagery, such as USGS EarthExplorer (available at 
https://earthexplorer.usgs.gov/) and National Aeronautics and Space 
Administration (NASA) Earth Data (available at https://earthdata.nasa.gov/) have reduced the need to perform as many field 
investigations to verify Clean Water Act jurisdiction, though some of 
these services charge a fee for use. The USGS Landsat Level-3 Dynamic 
Surface Water Extent (DSWE) product (available at https://www.usgs.gov/core-science-systems/nli/landsat/landsat-dynamic-surface-water-extent?qt-science_support_page_related_con=0#qt-science_support_page_related_con) is a specific example of a tool that 
may be useful for identifying surface water inundation on the landscape 
in certain geographic areas.
    Similarly, the availability of LIDAR data has increased in 
availability and utility for determining Clean Water Act jurisdiction. 
Where LIDAR data have been processed to create a bare earth model, 
detailed depictions of the land surface reveal subtle elevation changes 
and characteristics of the land surface, including the identification 
of tributaries. LIDAR-indicated tributaries can be correlated with 
aerial photography interpretation to reasonably conclude the presence 
of a channel with relatively permanent flow in the absence of a field 
visit. The agencies have been using such remote sensing and desktop 
tools to assist with identifying jurisdictional tributaries for many 
years, and such tools are particularly critical where data from the

[[Page 69445]]

field are unavailable or a field visit is not possible. High-resolution 
LIDAR data are becoming more widespread for engineering and land use 
planning purposes.
    Since 2015, tools have been developed that automate some of the 
standard practices the agencies rely on to assist in determinations. 
One example of this automation is the Antecedent Precipitation Tool 
(APT), which was released to the public in 2020 and had been used 
internally by the agencies prior to its public release. The APT is a 
desktop tool developed by the Corps and is commonly used by the 
agencies to help determine whether field data collection and other 
site-specific observations occurred under normal climatic conditions. 
In addition to providing a standardized methodology to evaluate normal 
precipitation conditions (``precipitation normalcy''), the APT can also 
be used to assess the presence of drought conditions, as well as the 
approximate dates of the wet and dry seasons for a given location. As 
discussed in section V.B.3 of this preamble, above, precipitation data 
are often not useful in providing evidence as to whether a surface 
water connection exists in a typical year, as required by the NWPR. 
However, the agencies have long used the methods employed in the APT to 
provide evidence that wetland delineations are made under normal 
circumstances or to account for abnormalities during interpretation of 
data. The development and public release of the APT has accelerated the 
speed at which these analyses are completed, standardized methods, 
which reduces errors, and enabled more people to perform these analyses 
themselves, including members of the public. The APT will continue to 
be an important tool to support jurisdictional decision-making.
    Site visits are still sometimes needed to perform on-site 
observations of surface hydrology or collect field-based indicators of 
relatively permanent flow (e.g., the presence of riparian vegetation, 
or certain aquatic macroinvertebrates). The methods and instruments 
used to collect field data have also improved since 2015, such as the 
development of rapid, field-based SDAMs that use physical and 
biological indicators to determine the flow duration class of a stream 
reach. The agencies have previously used existing SDAMs developed by 
federal and state agencies to identify perennial, intermittent, or 
ephemeral streams, and will continue to use these tools whenever they 
are determined to be a reliable source of information for the specific 
water feature of interest. The agencies are currently working to 
develop region-specific SDAMs for nationwide coverage, which will 
promote consistent implementation across the United States in a manner 
that accounts for differences between each ecoregion. Additional 
information on the agencies' efforts to develop SDAMs is available at 
https://www.epa.gov/streamflow-duration-assessment.

E. Publicly Available Jurisdictional Information and Permit Data

    The agencies intend to work to enhance information that is already 
available to the public on jurisdictional determinations. The Corps 
maintains a website at https://permits.ops.usace.army.mil/orm-public 
that presents information on the Corps' approved jurisdictional 
determinations and Clean Water Act section 404 permit decisions. 
Similarly, EPA maintains a website at https://watersgeo.epa.gov/cwa/CWA-JDs/ that presents information on approved jurisdictional 
determinations made by the Corps under the Clean Water Act since August 
28, 2015. These websites will incorporate approved jurisdictional 
determinations made under the revised definition of ``waters of the 
United States.'' EPA also maintains on its website information on 
certain dischargers permitted under Clean Water Act section 402, 
including the Permit Compliance System and Integrated Compliance 
Information System database (https://www.epa.gov/enviro/pcs-icis-overview), as well as the EnviroMapper (https://enviro.epa.gov/enviro/em4ef.home), and How's My Waterway (https://www.epa.gov/waterdata/hows-my-waterway). The agencies also intend to provide links to the public 
to any guidance, forms, or memoranda of agreement relevant to the 
definition of ``waters of the United States.''
    EPA and the Army have also been working with other federal agencies 
on improving aquatic resource mapping and modeling, including working 
with the Department of Interior (DOI) to better align their regulatory 
needs with DOI's existing processes and national mapping capabilities. 
EPA, USGS, and FWS have a long history of working together to map the 
nation's aquatic resources. The agencies will continue to collaborate 
with DOI to enhance the NHD, NWI, and other products to better map the 
nation's water resources while enhancing the utility of such geospatial 
products to the Clean Water Act programs that EPA and the Corps 
implement.

F. Placement of the Definition of ``Waters of the United States'' in 
the Code of Federal Regulations

    The definition of ``waters of the United States'' had historically 
been placed in eleven locations in the Code of Federal Regulations 
(CFR). For the sake of simplicity, in the NWPR, the agencies codified 
the definition of ``waters of the United States'' in only two places in 
the CFR--in Title 33 of the CFR, which implements the Corps' statutory 
authority, at 33 CFR 328.3, and in Title 40, which generally implements 
EPA's statutory authority, at 40 CFR 120.2. In the sections of the CFR 
where EPA's definition previously existed, 40 CFR 110.1, 112.2, 116.3, 
117.1, 122.2, 230.3, 232.2, 300.5, 302.3, 401.11, and Appendix E to 40 
CFR part 300, the NWPR cross-references the newly created section of 
the regulations containing the definition of ``waters of the United 
States.'' The agencies placed EPA's definition of ``waters of the 
United States'' in a previously unassigned part of 40 CFR and stated 
that the change in placement had no implications on Clean Water Act 
program implementation; rather, the placement made it clearer to 
members of the public that there is a single definition of ``waters of 
the United States'' applicable to the Clean Water Act and its 
implementing regulations. 85 FR 22328-29, April 21, 2020. The agencies 
agree with this approach and propose no change to the placement of the 
definition of ``waters of the United States.'' As the agencies 
indicated in the NWPR, the placement of the definition in two 
locations, at 33 CFR 328.3 and 40 CFR 120.2, increases convenience for 
the reader but has no substantive implications for the scope of Clean 
Water Act jurisdiction. 85 FR 22328, April 21, 2020.
    The agencies are proposing to delete the definition of ``navigable 
waters'' at 120.2 and to add it to the ``purpose and scope'' of part 
120 at 40 CFR 120.1. The agencies are also proposing to add additional 
clarifying text to the ``purpose and scope'' at 40 CFR 120.1. The 
agencies intend this to be an editorial and clarifying change and not a 
substantive change from EPA's regulations at 40 CFR 120. The agencies 
believe that this minor revision adds consistency between EPA's 
regulations at 40 CFR 120 and the Corps' regulations defining ``waters 
of the United States'' at 33 CFR 328.3. As a result of this non-
substantive revision, the agencies' definitions would have parallel 
numerical and alphabetical subsections, providing clarity for the 
public. The Corps similarly includes the

[[Page 69446]]

definition of ``navigable waters'' within 33 CFR 328.1, which contains 
the purpose of the Corps' regulations at part 328. The agencies propose 
to retain the same definition of ``navigable waters'' within 40 CFR 
120.1 as the term is defined at section 502(7) of the Clean Water Act 
and as it was defined in the NWPR at 40 CFR 120.2, which is ``the 
waters of the United States, including the territorial seas.''
    The agencies solicit comment on their deletion of the definition of 
``navigable waters'' at 40 CFR 120.2 and adding it instead with the 
``purpose and scope'' at 40 CFR 120.1.

VI. Summary of Supporting Analyses

    This section provides an overview of the supporting analyses for 
the proposed rule. Additional detail on these analyses is contained in 
and described more fully in the Economic Analysis for the Proposed Rule 
and the Technical Support Document for the Proposed Rule. Copies of 
these documents are available in the docket for this proposed action.
    This proposed rule establishing the definition of ``waters of the 
United States'' by itself imposes no costs or benefits. Potential costs 
and benefits would only be incurred as a result of actions taken under 
existing Clean Water Act programs (i.e., sections 303, 311, 401, 402, 
and 404) that would not otherwise be modified by this proposed rule. 
Entities currently are, and would continue to be, regulated under these 
programs that protect ``waters of the United States'' from pollution 
and destruction. Each of these programs may subsequently impose costs 
as a result of implementation of their specific regulations.
    While the rule imposes no costs and generates no benefits under the 
primary baseline, the agencies nonetheless analyzed its benefits and 
costs relative to a secondary baseline and have prepared an 
illustrative economic analysis to provide the public with information 
on the potential benefits and costs associated with various Clean Water 
Act programs that could result under a state of the world without the 
proposed rule that would have the NWPR still in effect. The agencies 
prepared this economic analysis pursuant to the requirements of 
Executive Orders 12866 and 13563 to provide information to the public.
    Two courts have vacated the NWPR and since then, the agencies have 
been implementing the pre-2015 regulatory regime, which is very similar 
to the proposed rule. While the NWPR has been vacated, the agencies 
have chosen to provide additional information to the public and have 
considered two baselines in the Economic Analysis for the Proposed 
Rule: A primary baseline of the pre-2015 regulatory regime, and a 
secondary baseline of the NWPR. Because the agencies are not currently 
implementing the NWPR, the proposed rule would not depart in material 
respects from current practice; as such, the agencies find that the 
proposed rule generally maintains the legal status quo such that there 
would be no appreciable costs or benefits in comparison to the primary 
baseline of the pre-2015 regulatory regime.
    The agencies use the NWPR as a secondary baseline to provide 
information to the public on the estimated differential effects of the 
proposed rule in comparison to the NWPR. The agencies estimated that 
the NWPR would result in an increase in non-jurisdictional findings in 
jurisdictional determinations compared to prior regulations and 
practice, and that compared to the NWPR, the proposed rule would define 
more waters as within the scope of the Clean Water Act.
    Under the primary baseline, there are no costs or benefits as the 
regulatory scope between the presently implemented pre-2015 regulatory 
regime is approximately the same as the proposed rule. Comparatively, 
under the secondary NWPR baseline, quantified benefits for the 404 
program are estimated to be between $376 and $590 million annually, 
while costs are estimated to be between $109 and $276 million annually. 
The analysis of estimated costs and benefits of the proposed rule is 
contained in the Economic Analysis for the Proposed Rule and is 
available in the docket for this action.
    The agencies recognize that the burdens of environmental pollution 
and climate change often fall disproportionately on population groups 
of concern (e.g., minority, low-income, and indigenous populations as 
specified in Executive Order 12898) and are quantifying impacts to 
these groups in the Economic Analysis for the Proposed Rule. Compared 
to the average population, these groups are more likely to experience 
water-related environmental and social stressors like contaminated 
drinking water, limited access to clean water, and inadequate water 
infrastructure--all of which increase their likelihood of being exposed 
to pollutants. In addition to external stressors, behavioral and 
cultural characteristics of these groups, like engaging in subsistence 
fishing and consuming higher rates of fish from polluted waters, 
increases their vulnerability to pollution. Taken together, these 
environmental, social, and behavioral factors often increase these 
groups' risk of experiencing negative health outcomes because of their 
exposure to environmental contaminants.
    Climate change will exacerbate the existing risks faced by 
population groups of concern as identified by Executive Order 12898, in 
addition to giving rise to new risks and challenges, and such impacts 
are generally greater for disadvantaged communities. In particular, 
risks like sea level rise, flooding, and drought can all have 
disproportionate effects on these communities. Because of existing 
environmental and social stressors and their reliance on natural 
resources that may be negatively impacted by climate change (e.g., fish 
and other aquatic life that provide income or food), these communities 
may be less able to mitigate and adapt to the effects of climate 
change.
    The NWPR decreased the scope of Clean Water Act jurisdiction across 
the country, including in geographic regions where regulation of waters 
beyond those covered by the Act is not authorized under current state 
or tribal law (see section V.B.3 of this preamble). Absent regulations 
governing discharges of pollutants into previously jurisdictional 
waters, communities composed of groups of concern where these waters 
are located may experience increased water pollution and impacts from 
associated increases in health risk. Further, the NWPR categorically 
excluded ephemeral streams from jurisdiction, which disproportionately 
impacts tribes and communities of concern in the arid West. Tribes may 
lack the authority and often the resources to regulate waters within 
their boundaries, and may also be affected by pollution from adjacent 
jurisdictions. Therefore, the change in jurisdiction under the NWPR may 
have disproportionately exposed tribes to increased pollution and 
health risks. In this proposed rule the agencies affirm their 
commitment to assessing the impacts of a revised definition of ``waters 
of the United States'' on population groups of concern.
    For the proposed rule, consistent with Executive Order 12898 and 
Executive Order 14008 on ``Tackling the Climate Crisis at Home and 
Abroad'' (86 FR 7619; January 27, 2021), the agencies examined whether 
the change in benefits from the reinstatement of the pre-2015 practice 
may be differentially distributed among population groups of concern in 
the affected areas when compared to the secondary baseline of

[[Page 69447]]

the NWPR. In determining the potential for concerns in affected areas, 
the agencies considered the following factors in this analysis: 
Population characteristics, proximity to effects of the proposed rule, 
and selected indicators of vulnerability to environmental risk. The 
results of the agencies' analysis are presented in the Economic 
Analysis for the Proposed Rule. The change between the pre-2015 
regulatory regime and NWPR in the number of impacted waters was 
approximated using Corps AJD and permit data. The analysis showed that 
for most of the HUC 12 wetlands and affected waters impacted by the 
proposed rule, there was no evidence of potential environmental justice 
concerns warranting further analysis; for a select set of HUC 12 
wetlands and impacted waters, potential environmental justice concerns 
may exist, and additional analyses may be warranted. Additionally, 
analyses assessing the potential for impacts on tribes found an overlap 
in several states between tribal land and HUC 12 watersheds with 
relatively large wetland and affected waters changes, warranting 
further analysis. In the final rule, the agencies plan to expand upon 
the environmental justice analysis by including additional indicators 
of vulnerability to environmental risk in screening for potential 
environmental justice concerns and by adding illustrative case studies 
to evaluate localized impacts for areas where the need for additional 
analyses was identified.
    The Technical Support Document provides additional legal, 
scientific, and technical discussion for issues raised in this proposed 
rule. Appendix A of the Technical Support Document contains a glossary 
of terms used in the document. Appendix B of the Technical Support 
Document contains the references cited in the document. Appendix C of 
the Technical Support Document is a list of citations that have been 
published since the 2015 Science Report and that contain findings 
relevant to the report's conclusions. Appendix D is the legal 
definition of ``traditional navigable waters'' (Appendix D from the 
U.S. Army Corps of Engineers Jurisdictional Determination Form 
Instructional Guidebook).

VII. Statutory and Executive Order Reviews

    Additional information about these statutes and Executive Orders 
can be found at http://www2.epa.gov/laws-regulations/laws-and-executive-orders.

A. Executive Order 12866: Regulatory Planning and Review; Executive 
Order 13563: Improving Regulation and Regulatory Review

    This action is a significant regulatory action that was submitted 
to the Office of Management and Budget (OMB) for review. Any changes 
made in response to OMB recommendations have been documented in the 
docket for this action. The agencies prepared an economic analysis of 
the potential costs and benefits associated with this action. This 
analysis, the Economic Analysis for the Proposed ``Revised Definition 
of `Waters of the United States' '' Rule, is available in the docket 
for this action and briefly summarized in section VI of this preamble.

B. Paperwork Reduction Act (PRA)

    This action does not impose an information collection burden under 
the PRA because it does not contain any information collection 
activities. However, this action may change terms and concepts used by 
EPA and Army to implement certain programs. The agencies thus may need 
to revise some of their collections of information to be consistent 
with this action.

C. Regulatory Flexibility Act (RFA)

    The agencies certify that this proposed rule will not have a 
significant economic impact on a substantial number of small entities 
under the RFA. This rule would codify a regulatory regime generally 
comparable to the one currently being implemented nationwide due to the 
vacatur of the 2020 definition of ``waters of the United States.'' On 
this basis alone, the proposed rule would not impose any requirements 
on small entities. Additionally, the agencies note that the proposed 
rule does not ``subject'' any entities of any size to any specific 
regulatory burden. It is designed to clarify the statutory term 
``navigable waters,'' defined as ``waters of the United States,'' which 
defines the scope of Clean Water Act jurisdiction 33 U.S.C. 1362(7). 
The scope of Clean Water Act jurisdiction is informed by the text, 
structure and history of the Clean Water Act and Supreme Court case 
law, including the geographical and hydrological factors identified in 
Rapanos v. United States, 547 U.S. 715 (2006). None of these factors 
are readily informed by the RFA. See, e.g., Cement Kiln Recycling Coal. 
v. EPA, 255 F.3d 869 (D.C. Cir. 2001) (``[T]o require an agency to 
assess the impact on all of the nation's small businesses possibly 
affected by a rule would be to convert every rulemaking process into a 
massive exercise in economic modeling, an approach we have already 
rejected.''); Michigan v. EPA, 213 F.3d 663, 688-89 (D.C. Cir. 2000) 
(holding that the RFA imposes ``no obligation to conduct a small entity 
impact analysis of effects'' on entities which it regulates only 
``indirectly''); Am. Trucking Ass'n v. EPA, 175 F.3d 1027, 1045 (D.C. 
Cir. 1999) (``[A]n agency may justify its certification under the RFA 
upon the ``factual basis'' that the rule does not directly regulate any 
small entities.''); Mid-Tex Elec. Co-op, Inc. v. FERC, 773 F.2d 327, 
343 (D.C. Cir. 1985) (``Congress did not intend to require that every 
agency consider every indirect effect that any regulation might have on 
small businesses in any stratum of the national economy.'').
    Nevertheless, the agencies recognize that the scope of the term 
``waters of the United States'' is of great national interest, 
including within the small business community. In light of this 
interest, the agencies sought early input from representatives of small 
entities while formulating a proposed definition of this term, 
including holding a public meeting dedicated to hearing feedback from 
small entities on August 25, 2021 (see https://www.epa.gov/wotus/2021-waters-united-states-public-meeting-materials). A variety of small 
entities such as farmers and ranchers, environmental and conservation 
non-profits, as well as building, consulting, and brewing businesses 
provided their input on both the policies under discussion in the 
proposed rulemaking and their interest in additional outreach and 
engagement with small entities, including their desire for a SBREFA 
panel. The agencies have addressed this feedback in the preamble 
relating to these topics and in the discussion above.

D. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate as described in 
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect 
small governments. The proposed definition of ``waters of the United 
States'' applies broadly to Clean Water Act programs. The action 
imposes no enforceable duty on any state, local, or tribal governments, 
or the private sector.

E. Executive Order 13132: Federalism

    Under the technical requirements of Executive Order 13132 (64 FR 
43255, August 10, 1999), the agencies have determined that this 
proposed rule may have federalism implications but believe that the 
requirements of the Executive Order will be satisfied, in any event.

[[Page 69448]]

    The agencies believe that a revised definition of ``waters of the 
United States'' may be of significant interest to state and local 
governments. Consistent with the agencies' policies to promote 
communications between the Federal government and state and local 
governments, EPA and the Army consulted with representatives of state 
and local governments early in the process of developing the proposed 
rule to permit them to have meaningful and timely input into its 
development.
    Consulting with state and local government officials, or their 
representative national organizations, is an important step in the 
process prior to proposing regulations that may have federalism 
implications under the terms of Executive Order 13132. The agencies 
engaged state and local governments over a 60-day federalism 
consultation period during development of this proposed rule, beginning 
with the initial federalism consultation meeting on August 5, 2021, and 
concluding on October 4, 2021. Twenty intergovernmental organizations, 
including eight of the ten organizations identified in EPA's 2008 
Executive Order 13132 Guidance, attended the initial Federalism 
consultation meeting, as well as 12 associations representing state and 
local governments. Organizations in attendance included the following: 
National Governors Association, National Conference of State 
Legislatures, United States Conference of Mayors, National League of 
Cities, National Association of Counties, National Association of Towns 
and Townships, County Executives of America, Environmental Council of 
the States, Association of State Wetland Managers, Association of State 
Drinking Water Administrators, National Association of State 
Departments of Agriculture, Western States Water Council, National 
Association of Clean Water Agencies, National Rural Water Association, 
National Association of Attorneys General, National Water Resources 
Association, National Municipal Stormwater Alliance, Western Governors' 
Association, American Water Works Association, and Association of 
Metropolitan Water Agencies. All letters received by the agencies 
during this consultation may be found in the docket (Docket ID No. EPA-
HQ-OW-2021-0602) for this proposed rule.
    These meetings and the letters provided by representatives provide 
a wide and diverse range of interests, positions, comments, and 
recommendations to the agencies. The agencies have prepared a report 
summarizing their consultation and additional outreach to state and 
local governments and the results of this outreach. A copy of the draft 
report is available in the docket (Docket ID. No. EPA-HQ-OW-2021-0602) 
for this proposed rule.

F. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    This action may have tribal implications. However, it will neither 
impose substantial direct compliance costs on federally recognized 
tribal governments, nor preempt tribal law.
    EPA and the Army consulted with tribal officials under the EPA 
Policy on Consultation and Coordination with Indian Tribes and the 
Department of the Army American Indian and Alaska Native Policy early 
in the process of developing this regulation to permit them to have 
meaningful and timely input into its development.
    The agencies initiated a tribal consultation and coordination 
process before proposing this rule by sending a ``Notification of 
Consultation and Coordination'' letter on July 30, 2021, to all 574 
tribes federally recognized at that time. The letter invited tribal 
leaders and designated consultation representatives to participate in 
the tribal consultation and coordination process. The agencies engaged 
tribes over a 66-day tribal consultation period during development of 
this proposed rule, including via two webinars on August 19, 2021, and 
August 24, 2021, in which the agencies answered questions directly from 
tribal representatives and heard their initial feedback on the 
agencies' rulemaking effort. The agencies met with two tribes at a 
staff-level and with two tribes at a leader-to-leader level. Additional 
consultations may be requested and scheduled after the rule is 
proposed. All letters received by the agencies during this consultation 
may be found in the docket (Docket ID. No. EPA-HQ-OW-2021-0602) for 
this proposed rule. The agencies have prepared a report summarizing the 
consultation and further engagement with tribal nations. This report 
(Docket ID. No. EPA-HQ-OW-2021-0602) is available in the docket for 
this proposed rule.

G. Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks

    EPA interprets Executive Order 13045 as applying only to those 
regulatory actions that concern environmental health or safety risks 
that EPA has reason to believe may disproportionately affect children, 
per the definition of ``covered regulatory action'' in section 2-202 of 
the Executive Order. This action is not subject to Executive Order 
13045 because it does not concern an environmental health risk or 
safety risk.

H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use

    This action is not a ``significant energy action'' because it is 
not likely to have a significant adverse effect on the supply, 
distribution, or use of energy.

I. National Technology Transfer and Advancement Act

    This rulemaking does not involve technical standards.

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    EPA and Army believe that this action does not have 
disproportionately high and adverse human health or environmental 
effects on minority populations, low-income populations, and/or 
indigenous peoples, as specified in Executive Order 12898 (59 FR 7629, 
February 16, 1994).
    The documentation for this decision is contained in in the Economic 
Analysis for the Proposed Rule, which can be found in the docket for 
this action.

List of Subjects

33 CFR Part 328

    Administrative practice and procedure, Environmental protection, 
Navigation (water), Water pollution control, Waterways.

40 CFR Part 120

    Environmental protection, Water pollution control, Waterways.

Jaime A. Pinkham,
Acting Assistant Secretary of the Army (Civil Works), Department of the 
Army.
Michael S. Regan,
Administrator, Environmental Protection Agency.

Title 33--Navigation and Navigable Waters

    For the reasons set out in the preamble, title 33, chapter II of 
the Code of Federal Regulations is proposed to be amended as follows:

PART 328--DEFINITION OF WATERS OF THE UNITED STATES

0
1. The authority citation for part 328 continues to read as follows:

    Authority: 33 U.S.C. 1251 et seq.

[[Page 69449]]

0
2. Revise Sec.  328.3 to read as follows:

Sec.  328.3  Definitions.

    For the purpose of this regulation these terms are defined as 
follows:
    (a) Waters of the United States means:
    (1) All waters which are currently used, or were used in the past, 
or may be susceptible to use in interstate or foreign commerce, 
including all waters which are subject to the ebb and flow of the tide;
    (2) All interstate waters including interstate wetlands;
    (3) All other waters such as intrastate lakes, rivers, streams 
(including intermittent streams), mudflats, sandflats, wetlands, 
sloughs, prairie potholes, wet meadows, playa lakes, or natural ponds:
    (i) That are relatively permanent, standing or continuously flowing 
bodies of water with a continuous surface connection to the waters 
identified in paragraph (a)(1), (a)(2), (a)(5)(i), or (a)(6) of this 
section; or
    (ii) That either alone or in combination with similarly situated 
waters in the region, significantly affect the chemical, physical, or 
biological integrity of waters identified in paragraph (a)(1), (2), or 
(6) of this section;
    (4) All impoundments of waters otherwise defined as waters of the 
United States under the definition, other than impoundments of waters 
identified under paragraph (a)(3) of this section;
    (5) Tributaries of waters identified in paragraph (a)(1), (2), (4), 
or (6) of this section:
    (i) That are relatively permanent, standing or continuously flowing 
bodies of water; or
    (ii) That either alone or in combination with similarly situated 
waters in the region, significantly affect the chemical, physical, or 
biological integrity of waters identified in paragraph (a)(1), (2), or 
(6) of this section;
    (6) The territorial seas;
    (7) Wetlands adjacent to the following waters (other than waters 
that are themselves wetlands):
    (i) Waters identified in paragraph (a)(1), (2), or (6) of this 
section; or
    (ii) Relatively permanent, standing or continuously flowing bodies 
of water identified in paragraph (a)(4) or (a)(5)(i) of this section 
and with a continuous surface connection to such waters; or
    (iii) Waters identified in paragraph (a)(4) or (a)(5)(ii) of this 
section when the wetlands either alone or in combination with similarly 
situated waters in the region, significantly affect the chemical, 
physical, or biological integrity of waters identified in paragraph 
(a)(1), (2), or (6) of this section;
    (8) Waste treatment systems, including treatment ponds or lagoons, 
designed to meet the requirements of the Clean Water Act are not waters 
of the United States; and
    (9) Waters of the United States do not include prior converted 
cropland. Notwithstanding the determination of an area's status as 
prior converted cropland by any other Federal agency, for the purposes 
of the Clean Water Act, the final authority regarding Clean Water Act 
jurisdiction remains with EPA.
    (b) Wetlands means those areas that are inundated or saturated by 
surface or ground water at a frequency and duration sufficient to 
support, and that under normal circumstances do support, a prevalence 
of vegetation typically adapted for life in saturated soil conditions. 
Wetlands generally include swamps, marshes, bogs, and similar areas.
    (c) Adjacent means bordering, contiguous, or neighboring. Wetlands 
separated from other waters of the United States by man-made dikes or 
barriers, natural river berms, beach dunes and the like are ``adjacent 
wetlands.''
    (d) High tide line means the line of intersection of the land with 
the water's surface at the maximum height reached by a rising tide. The 
high tide line may be determined, in the absence of actual data, by a 
line of oil or scum along shore objects, a more or less continuous 
deposit of fine shell or debris on the foreshore or berm, other 
physical markings or characteristics, vegetation lines, tidal gages, or 
other suitable means that delineate the general height reached by a 
rising tide. The line encompasses spring high tides and other high 
tides that occur with periodic frequency but does not include storm 
surges in which there is a departure from the normal or predicted reach 
of the tide due to the piling up of water against a coast by strong 
winds such as those accompanying a hurricane or other intense storm.
    (e) Ordinary high water mark means that line on the shore 
established by the fluctuations of water and indicated by physical 
characteristics such as clear, natural line impressed on the bank, 
shelving, changes in the character of soil, destruction of terrestrial 
vegetation, the presence of litter and debris, or other appropriate 
means that consider the characteristics of the surrounding areas.
    (f) Tidal waters means those waters that rise and fall in a 
predictable and measurable rhythm or cycle due to the gravitational 
pulls of the moon and sun. Tidal waters end where the rise and fall of 
the water surface can no longer be practically measured in a 
predictable rhythm due to masking by hydrologic, wind, or other 
effects.
    (g) Significantly affect means more than speculative or 
insubstantial effects on the chemical, physical, or biological 
integrity of waters identified in paragraph (a)(1), (2), or (6) of this 
section. When assessing whether the effect that the functions waters 
have on waters identified in paragraph (a)(1), (2), or (6) of this 
section is more than speculative or insubstantial, the agencies will 
consider:
    (1) The distance from a water of the United States;
    (2) The distance from a water identified in paragraph (a)(1), (2), 
or (6) of this section;
    (3) Hydrologic factors, including shallow subsurface flow;
    (4) The size, density, and/or number of waters that have been 
determined to be similarly situated; and
    (5) Climatological variables such as temperature, rainfall, and 
snowpack.

Title 40--Protection of Environment

    For reasons set out in the preamble, title 40, chapter I of the 
Code of Federal Regulations is proposed to be amended as follows:

PART 120--DEFINITION OF WATERS OF THE UNITED STATES

0
3. The authority citation for part 120 continues to read as follows:

    Authority: 33 U.S.C. 1251 et seq.

0
4. Revise Sec.  120.1 to read as follows:

Sec.  120.1  Purpose and scope.

    This part contains the definition of ``waters of the United 
States'' for purposes of the Clean Water Act, 33 U.S.C. 1251 et seq. 
and its implementing regulations. EPA regulations implementing the 
Clean Water Act use the term ``navigable waters,'' which is defined at 
section 502(7) of the Clean Water Act as ``the waters of the United 
States, including the territorial seas,'' or the term ``waters of the 
United States.'' In light of the statutory definition, the definition 
in this section establishes the scope of the terms ``waters of the 
United States'' and ``navigable waters'' in EPA's regulations.
0
5. Revise Sec.  120.2 to read as follows:

Sec.  120.2  Definitions.

    For the purposes of this part, the following terms shall have the 
meanings indicated:
    (a) Waters of the United States means:
    (1) All waters which are currently used, or were used in the past, 
or may

[[Page 69450]]

be susceptible to use in interstate or foreign commerce, including all 
waters which are subject to the ebb and flow of the tide;
    (2) All interstate waters including interstate wetlands;
    (3) All other waters such as intrastate lakes, rivers, streams 
(including intermittent streams), mudflats, sandflats, wetlands, 
sloughs, prairie potholes, wet meadows, playa lakes, or natural ponds:
    (i) That are relatively permanent, standing or continuously flowing 
bodies of water with a continuous surface connection to the waters 
identified in paragraph (a)(1), (a)(2), (a)(5)(i), or (a)(6) of this 
section; or
    (ii) That either alone or in combination with similarly situated 
waters in the region, significantly affect the chemical, physical, or 
biological integrity of waters identified in paragraph (a)(1), (2), or 
(6) of this section;
    (4) All impoundments of waters otherwise defined as waters of the 
United States under the definition, other than impoundments of waters 
identified under paragraph (a)(3) of this section;
    (5) Tributaries of waters identified in paragraph (a)(1), (2), (4), 
or (6) of this section:
    (i) That are relatively permanent, standing or continuously flowing 
bodies of water; or
    (ii) That either alone or in combination with similarly situated 
waters in the region, significantly affect the chemical, physical, or 
biological integrity of waters identified in paragraph (a)(1), (2), or 
(6) of this section;
    (6) The territorial seas;
    (7) Wetlands adjacent to the following waters (other than waters 
that are themselves wetlands):
    (i) Waters identified in paragraph (a)(1), (2), or (6) of this 
section; or
    (ii) Relatively permanent, standing, or continuously flowing bodies 
of water identified in paragraph (a)(4) or (a)(5)(i) of this section 
and with a continuous surface connection to such waters; or
    (iii) Waters identified in paragraph (a)(4) or (a)(5)(ii) of this 
section when the wetlands either alone or in combination with similarly 
situated waters in the region, significantly affect the chemical, 
physical, or biological integrity of waters identified in paragraph 
(a)(1), (2), or (6) of this section;
    (8) Waste treatment systems, including treatment ponds or lagoons, 
designed to meet the requirements of the Clean Water Act are not waters 
of the United States; and
    (9) Waters of the United States do not include prior converted 
cropland. Notwithstanding the determination of an area's status as 
prior converted cropland by any other Federal agency, for the purposes 
of the Clean Water Act, the final authority regarding Clean Water Act 
jurisdiction remains with EPA.
    (b) Wetlands means those areas that are inundated or saturated by 
surface or ground water at a frequency and duration sufficient to 
support, and that under normal circumstances do support, a prevalence 
of vegetation typically adapted for life in saturated soil conditions. 
Wetlands generally include swamps, marshes, bogs, and similar areas.
    (c) Adjacent means bordering, contiguous, or neighboring. Wetlands 
separated from other waters of the United States by man-made dikes or 
barriers, natural river berms, beach dunes and the like are ``adjacent 
wetlands.''
    (d) High tide line means the line of intersection of the land with 
the water's surface at the maximum height reached by a rising tide. The 
high tide line may be determined, in the absence of actual data, by a 
line of oil or scum along shore objects, a more or less continuous 
deposit of fine shell or debris on the foreshore or berm, other 
physical markings or characteristics, vegetation lines, tidal gages, or 
other suitable means that delineate the general height reached by a 
rising tide. The line encompasses spring high tides and other high 
tides that occur with periodic frequency but does not include storm 
surges in which there is a departure from the normal or predicted reach 
of the tide due to the piling up of water against a coast by strong 
winds such as those accompanying a hurricane or other intense storm.
    (e) Ordinary high water mark means that line on the shore 
established by the fluctuations of water and indicated by physical 
characteristics such as clear, natural line impressed on the bank, 
shelving, changes in the character of soil, destruction of terrestrial 
vegetation, the presence of litter and debris, or other appropriate 
means that consider the characteristics of the surrounding areas.
    (f) Tidal waters means those waters that rise and fall in a 
predictable and measurable rhythm or cycle due to the gravitational 
pulls of the moon and sun. Tidal waters end where the rise and fall of 
the water surface can no longer be practically measured in a 
predictable rhythm due to masking by hydrologic, wind, or other 
effects.
    (g) Significantly affect means more than speculative or 
insubstantial effects on the chemical, physical, or biological 
integrity of waters identified in paragraph (a)(1), (2), or (6) of this 
section. When assessing whether the effect that the functions waters 
have on waters identified in paragraph (a)(1), (2), or (6) of this 
section is more than speculative or insubstantial, the agencies will 
consider:
    (1) The distance from a water of the United States;
    (2) The distance from a water identified in paragraph (a)(1), (2), 
or (6) of this section;
    (3) Hydrologic factors, including shallow subsurface flow;
    (4) The size, density, and/or number of waters that have been 
determined to be similarly situated; and
    (5) Climatological variables such as temperature, rainfall, and 
snowpack.

[FR Doc. 2021-25601 Filed 12-6-21; 8:45 am]
BILLING CODE 6560-50-P