[Federal Register Volume 83, Number 134 (Thursday, July 12, 2018)]
[Proposed Rules]
[Pages 32227-32252]
[FR Doc No: 2018-14679]

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DEPARTMENT OF DEFENSE

Department of the Army, Corps of Engineers

33 CFR Part 328

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 110, 112, 116, 117, 122, 230, 232, 300, 302, and 401

[EPA-HQ-OW-2017-0203; FRL-9980-52-OW]
RIN 2040-AF74

Definition of ``Waters of the United States''--Recodification of
Preexisting Rule

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

ACTION: Supplemental notice of proposed rulemaking.

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SUMMARY: The purpose of this supplemental notice is for the
Environmental Protection Agency (EPA) and the Department of the Army
(agencies) to clarify, supplement and seek additional comment on an
earlier proposal, published on July 27, 2017, to repeal the 2015 Rule
Defining Waters of the United States (``2015 Rule''), which amended
portions of the Code of Federal Regulations (CFR). As stated in the
agencies' July 27, 2017 Notice of Proposed Rulemaking (NPRM), the
agencies propose to repeal the 2015 Rule and restore the regulatory
text that existed prior to the 2015 Rule, as informed by guidance in
effect at that time. If this proposal is finalized, the regulations
defining the scope of federal Clean Water Act (CWA) jurisdiction would
be those portions of the CFR as they existed before the amendments
promulgated in the 2015 Rule. Those preexisting regulatory definitions
are the ones that the agencies are currently implementing in light of
the agencies' final rule published on February 6, 2018, adding a
February 6, 2020 applicability date to the 2015 Rule, as well as
judicial decisions preliminarily enjoining and staying the 2015 Rule.

DATES: Comments must be received on or before August 13, 2018.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-OW-
2017-0203, at http://www.regulations.gov. Follow the online
instructions for submitting comments. Once submitted, comments cannot
be edited or removed from Regulations.gov. The agencies may publish any
comment received to the public docket. Do not submit electronically 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. The
agencies will generally not consider comments or comment content
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 http://www2.epa.gov/dockets.commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Michael McDavit, Office of Water
(4504-T), Environmental Protection Agency, 1200 Pennsylvania Avenue NW,
Washington, DC 20460; telephone number:<PHONE_NUMBER>; email address:
[email protected]; or Stacey Jensen, Regulatory Community of Practice
(CECW-CO-R), U.S. Army Corps of Engineers, 441 G Street NW, Washington,
DC 201314; telephone number:<PHONE_NUMBER>; email address:
[email protected].

SUPPLEMENTARY INFORMATION: The agencies propose to repeal the Clean
Water Rule: Definition of ``Waters of the United States,'' 80 FR 37054,
and recodify the regulatory definitions of ``waters of the United
States'' that existed prior to the August 28, 2015 effective date of
the 2015 Rule. Those preexisting regulatory definitions are the ones
that the agencies are currently implementing in light of the agencies'
final rule (83 FR 5200, February 6, 2018), which added a February 6,
2020 applicability date to the 2015 Rule. Judicial decisions currently
enjoin the 2015 Rule in 24 States as well. If this proposal is
finalized, the agencies would administer the regulations promulgated in
1986 and 1988 in portions of 33 CFR part 328 and 40 CFR parts 110, 112,
116, 117, 122, 230, 232, 300, 302, and 401, and would continue to
interpret the statutory term ``waters of the United States'' to mean
the waters covered by those regulations, as the agencies are currently
implementing those regulations consistent with Supreme Court decisions
and longstanding practice, as informed by applicable guidance
documents, training, and experience.
    State, tribal, and local governments have well-defined and
established relationships with the federal government in implementing
CWA programs. Those relationships are not affected by this proposed
rule, which would not alter the jurisdiction of the CWA compared to the
regulations and practice that the agencies are currently applying. The
proposed rule would permanently repeal the 2015 Rule, which amended the
longstanding definition of ``waters of the United States'' in portions
of 33 CFR part 328 and 40 CFR parts 110, 112, 116, 117, 122, 230, 232,
300, 302, and 401, and restore the regulations as they existed prior to
the amendments in the 2015 Rule.\1\
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    \1\ While EPA administers most provisions in the CWA, the
Department of the Army, Corps of Engineers (Corps) administers the
permitting program under section 404. During the 1980s, both
agencies adopted substantially similar definitions of ``waters of
the United States.'' See 51 FR 41206, Nov. 13, 1986, amending 33 CFR
328.3; 53 FR 20764, June 6, 1988, amending 40 CFR 232.2.
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    The agencies are issuing this supplemental notice of proposed
rulemaking (SNPRM) to clarify, supplement and give interested parties
an opportunity to comment on certain important considerations and
reasons for the agencies' proposal. The agencies clarify herein the
scope of the solicitation of comment and the actions proposed. In
response to the July 27, 2017 NPRM, (82 FR 34899), the agencies
received numerous comments on the impacts of repealing the 2015 Rule in
its entirety. Others commented in favor of retaining the 2015 Rule,
either as written or with modifications. Some commenters interpreted
the proposal as restricting their opportunity to provide such comments
either supporting or opposing repeal of the 2015 Rule. In this SNPRM,
the agencies reiterate that this regulatory action is intended to
permanently repeal the 2015 Rule in its entirety, and we invite all
interested persons to comment on whether the 2015 Rule should be
repealed.

    The agencies are also issuing this SNPRM to clarify that the rule
adding an applicability date to the 2015 Rule does not change the
agencies' decision to proceed with this proposed repeal. For the
reasons discussed in this notice, the agencies propose to conclude that
regulatory certainty would be best served by repealing the 2015 Rule
and recodifying the scope of CWA jurisdiction currently in effect. The
agencies propose to conclude that rather than achieving its stated
objectives of increasing predictability and consistency under the CWA,
see 80 FR 37055, the 2015 Rule is creating significant confusion and
uncertainty for agency staff, regulated entities, states, tribes, local
governments, and the public, particularly in view of court decisions
that have cast doubt on the legal viability of the rule. To provide for
greater regulatory certainty, the agencies propose to repeal the 2015
Rule and to recodify the pre-2015 regulations, thereby maintaining a
longstanding regulatory framework that is more familiar to and better-
understood by the agencies, states, tribes, local governments,
regulated entities, and the public.
    Further, court rulings against the 2015 Rule suggest that the
interpretation of the ``significant nexus'' standard as applied in the
2015 Rule may not comport with and accurately implement the legal
limits on CWA jurisdiction intended by Congress and reflected in
decisions of the Supreme Court. At a minimum, the agencies find that
the interpretation of the statute adopted in the 2015 Rule is not
compelled and raises significant legal questions. In light of the
substantial uncertainty associated with the 2015 Rule, including by
virtue of a potential stay, injunction, or vacatur of the 2015 Rule in
various legal challenges, as well as the substantial experience the
agencies already possess implementing the preexisting regulations that
the agencies are implementing today, the agencies propose to conclude
that administrative goals of regulatory certainty would be best served
by repealing the 2015 Rule.
    The agencies also propose to conclude that the 2015 Rule exceeded
the agencies' authority under the CWA by adopting such an
interpretation of Justice Kennedy's ``significant nexus'' standard
articulated in Rapanos v. United States and Carabell v. United States,
547 U.S. 715 (2006) (``Rapanos'') as to be inconsistent with important
aspects of that opinion and to cover waters outside the scope of the
Act, even though that concurring opinion was identified as the basis
for the significant nexus standard articulated in the 2015 Rule. The
agencies also propose to conclude that, contrary to conclusions
articulated in support of the rule, the 2015 Rule appears to have
expanded the meaning of tributaries and adjacent wetlands to include
waters well beyond those regulated by the agencies under the
preexisting regulations, as applied by the agencies following decisions
of the Supreme Court in Rapanos and Solid Waste Agency of Northern Cook
County v. U.S. Army Corps of Engineers, 531 U.S. 159 (2001)
(``SWANCC''). The agencies believe that the 2015 Rule may have altered
the balance of authorities between the federal and State governments,
contrary to the agencies' statements in promulgating the 2015 Rule and
in contravention of CWA section 101(b), 33 U.S.C. 1251(b).

I. Background

    The agencies refer the public to the Executive Summary for the
NPRM, 82 FR 34899 (July 27, 2017), and incorporate it by reference
herein.

A. The 2015 Rule

    On June 29, 2015, the agencies issued a final rule (80 FR 37054)
amending various portions of the CFR that set forth definitions of
``waters of the United States,'' a term contained in the CWA section
502(7) definition of ``navigable waters,'' 33 U.S.C. 1362(7).
    A primary purpose of the 2015 Rule was to ``increase CWA program
predictability and consistency by clarifying the scope of `waters of
the United States' protected under the Act.'' 80 FR 37054. The 2015
Rule attempted to clarify the geographic scope of the CWA by placing
waters into three categories: (A) Waters that are categorically
``jurisdictional by rule'' in all instances (i.e., without the need for
any 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. Waters that are
``jurisdictional by rule'' include (1) waters which are currently used,
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) 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. See id. at 37104.
    The 2015 Rule added new definitions of key terms such as
``tributaries'' and revised previous definitions of terms such as
``adjacent'' (by adding a new definition of ``neighboring'' that is
used in the definition of ``adjacent'') that would determine whether
waters are ``jurisdictional by rule.'' See id. at 37105. Specifically,
a tributary under the 2015 Rule is a water that contributes flow,
either directly or through another water, to a water identified in the
first three categories of ``jurisdictional by rule'' waters and that is
characterized by the presence of the ``physical indicators'' of a bed
and banks and an ordinary high water mark. ``These physical indicators
demonstrate there is volume, frequency, and duration of flow sufficient
to create a bed and banks and therefore an ordinary high water mark,
and thus to qualify as a tributary.'' Id. The 2015 Rule does not
delineate jurisdiction specifically based on categories with
established scientific meanings such as ephemeral, intermittent, and
perennial waters that are based on the source of the water and nature
of the flow. See id. at 37076 (``Under the rule, flow in the tributary
may be perennial, intermittent, or ephemeral.''). Under the 2015 Rule,
tributaries need not be demonstrated to possess any specific volume,
frequency, or duration of flow, or to contribute flow to a traditional
navigable water in any given year or specific time period. Tributaries
under the 2015 Rule can be natural, man-altered, or man-made, and they
do not lose their status as a tributary if, for any length, there are
one or more constructed breaks (such as bridges, culverts, pipes, or
dams), or one or more natural breaks (such as wetlands along the run of
a stream, debris piles, boulder fields, or a stream that flows
underground) so long as a bed and banks and an ordinary high water mark
can be identified upstream of the break. Id. at 37105-06.
    In the 2015 Rule, the agencies did not expressly amend the
longstanding definition of ``adjacent'' (defined as ``bordering,
contiguous, or neighboring''), but the agencies added a new definition
of ``neighboring'' that impacted the interpretation of ``adjacent.''
The 2015 Rule defined ``neighboring'' to encompass all waters located
within 100 feet of the ordinary high water mark of a category (1)
through (5) ``jurisdictional by rule'' water; all waters located within
the 100-year floodplain of a category (1) through (5) ``jurisdictional
by rule'' water and not more than 1,500 feet from the ordinary high
water mark of such water;

all waters located within 1,500 feet of the high tide line of a
category (1) though (3) ``jurisdictional by rule'' water; and all
waters within 1,500 feet of the ordinary high water mark of the Great
Lakes. Id. at 37105. The entire water is considered neighboring if any
portion of it lies within one of these zones. See id. This regulatory
text did not appear in the proposed rule, and thus the agencies did not
receive public comment on these numeric measures.
    In addition to the six categories of ``jurisdictional by rule''
waters, the 2015 Rule identifies certain waters that are subject to a
case-specific analysis to determine if they have a ``significant
nexus'' to a water that is jurisdictional. Id. at 37104-05. The first
category consists of five specific types of waters in specific regions
of the country: Prairie potholes, Carolina and Delmarva bays, pocosins,
western vernal pools in California, and Texas coastal prairie wetlands.
Id. at 37105. The second category consists of all waters located within
the 100-year floodplain of any category (1) through (3)
``jurisdictional by rule'' water and all waters located within 4,000
feet of the high tide line or ordinary high water mark of any category
(1) through (5) ``jurisdictional by rule'' water. Id. These
quantitative measures did not appear in the proposed rule, and thus the
agencies did not receive public comment on these specific measures.
    The 2015 Rule defines ``significant nexus'' to mean a water,
including wetlands, that either alone or in combination with other
similarly situated waters in the region, significantly affects the
chemical, physical, or biological integrity of a category (1) through
(3) ``jurisdictional by rule'' water. 80 FR 37106. ``For an effect to
be significant, it must be more than speculative or insubstantial.''
Id. The term ``in the region'' means ``the watershed that drains to the
nearest'' primary water.\2\ Id. This definition is different than the
test articulated by the agencies in their 2008 Rapanos Guidance.\3\
That guidance interpreted ``similarly situated'' to include all
wetlands (not waters) adjacent to the same tributary, a much less
expansive treatment of similarly situated waters than in the 2015 Rule.
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    \2\ In this notice, a ``primary'' water is a category (1)
through (3) ``jurisdictional by rule'' water.
    \3\ See U.S. EPA and 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 at 1 (Dec. 2,
2008) (``Rapanos Guidance''), available at https://www.epa.gov/sites/production/files/2016-02/documents/cwa_jurisdiction_following_rapanos120208.pdf. The agencies
acknowledge that the Rapanos Guidance did not impose legally binding
requirements, see id. at 4 n.17, but believe that this guidance is
relevant to the discussion in this notice.
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    Under the 2015 Rule, to determine whether a water, alone or in
combination with similarly situated waters across a watershed, has such
an effect, one must look at nine functions such as sediment trapping,
runoff storage, provision of life cycle dependent aquatic habitat, and
other functions. It is sufficient for determining whether a water has a
significant nexus if any single function performed by the water, alone
or together with similarly situated waters in the watershed,
contributes significantly to the chemical, physical, or biological
integrity of the nearest category (1) through (3) ``jurisdictional by
rule'' water. Id. Taken together, the enumeration of the nine functions
and the more expansive consideration of ``similarly situated'' in the
2015 Rule could mean that the vast majority of water features in the
United States may come within the jurisdictional purview of the federal
government.\4\ Indeed, the agencies stated in the 2015 Rule that the
``the chemical, physical, and biological integrity of downstream waters
is directly related to the aggregate contribution of upstream waters
that flow into them, including any tributaries and connected
wetlands.'' Id. at 37066.
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    \4\ ``[T]he vast majority of the nation's water features are
located within 4,000 feet of a covered tributary, traditional
navigable water, interstate water, or territorial sea.'' U.S. EPA
and Department of the Army. Economic Analysis of the EPA-Army Clean
Water Rule at 11 (May 20, 2015) (``2015 Rule Economic Analysis'')
(Docket ID: EPAHQ-OW-2011-0880-20866), available at https://www.regulations.gov/document?D=EPA-HQ-OW-2011-0880-20866.
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    The agencies also retained exclusions from the definition of
``waters of the United States'' for prior converted cropland and waste
treatment systems. Id. at 37105. In addition, the agencies codified
several exclusions that reflected longstanding agency practice, and
added others such as ``puddles'' and ``swimming pools'' in response to
concerns raised by stakeholders during the public comment period on the
proposed 2015 Rule. Id. at 37096-98, 37105.

B. Legal Challenges to the 2015 Rule

    Following the 2015 Rule's publication, 31 States \5\ and 53 non-
state parties, including environmental groups, and groups representing
farming, recreational, forestry, and other interests, filed complaints
and petitions for review in multiple federal district \6\ and appellate
\7\ courts challenging the 2015 Rule. In those cases, the challengers
alleged procedural deficiencies in the development and promulgation of
the 2015 Rule and substantive deficiencies in the 2015 Rule itself.
Some challengers argued that the 2015 Rule was too expansive while
others argued that it excluded too many waters from federal
jurisdiction.
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    \5\ Alabama, Alaska, Arizona, Arkansas, Colorado, Florida,
Georgia, Idaho, Indiana, Kansas, Kentucky, Louisiana, Michigan,
Mississippi, Missouri, Montana, Nebraska, Nevada, New Mexico
(Environment Department and State Engineer), North Carolina
(Department of Environment and Natural Resources), North Dakota,
Ohio, Oklahoma, South Carolina, South Dakota, Tennessee, Texas,
Utah, West Virginia, Wisconsin, and Wyoming. Iowa joined the legal
challenge later in the process, bringing the total to 32 States.
    \6\ U.S. District Courts for the Northern and Southern District
of Georgia, District of Minnesota, District of North Dakota,
Southern District of Ohio, Northern District of Oklahoma, Southern
District of Texas, District of Arizona, Northern District of
Florida, District of the District of Columbia, Western District of
Washington, Northern District of California, and Northern District
of West Virginia.
    \7\ U.S. Court of Appeals for the Second, Fifth, Sixth, Eighth,
Ninth, Tenth, Eleventh, and District of Columbia Circuits.
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    The day before the 2015 Rule's August 28, 2015 effective date, the
U.S. District Court for the District of North Dakota preliminarily
enjoined the 2015 Rule in the 13 States that challenged the rule in
that court.\8\ The district court found those States were ``likely to
succeed'' on the merits of their challenge to the 2015 Rule because,
among other reasons, ``it appears likely that the EPA has violated its
Congressional grant of authority in its promulgation of the Rule.'' In
particular, the court noted concern that the 2015 Rule's definition of
tributary ``includes vast numbers of waters that are unlikely to have a
nexus to navigable waters.'' Further, the court found that ``it appears
likely that the EPA failed to comply with [Administrative Procedure Act
(APA)] requirements when promulgating the Rule,'' suggesting that
certain distance-based measures were not a logical outgrowth of the
proposal to the 2015 Rule. North Dakota v. EPA, 127 F. Supp. 3d 1047,
1051, 1056, 1058 (D.N.D. 2015). No party sought an interlocutory
appeal.
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    \8\ Alaska, Arizona, Arkansas, Colorado, Idaho, Missouri,
Montana, Nebraska, Nevada, New Mexico, North Dakota, South Dakota,
and Wyoming. Iowa's motion to intervene in the case was granted
after issuance of the preliminary injunction.
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    The petitions for review filed in the courts of appeals were
consolidated in the U.S. Court of Appeals for the Sixth Circuit. In
that litigation, state and industry petitioners raised concerns about
whether the 2015 Rule violates the Constitution and the CWA and whether
its promulgation violated

procedural requirements under the APA and other statutes. Environmental
petitioners also challenged the 2015 Rule, including exclusions
therein. On October 9, 2015, approximately six weeks after the 2015
Rule took effect in the 37 States that were not subject to the
preliminary injunction issued by the District of North Dakota, the
Sixth Circuit stayed the 2015 Rule nationwide after finding, among
other things, that State petitioners had demonstrated ``a substantial
possibility of success on the merits of their claims.'' In re EPA &
Dep't of Def. Final Rule, 803 F.3d 804 (6th Cir. 2015) (``In re EPA'').
    On January 13, 2017, the U.S. Supreme Court granted certiorari on
the question of whether the courts of appeals have original
jurisdiction to review challenges to the 2015 Rule. See Nat'l Ass'n of
Mfrs. v. Dep't of Defense, 137 S. Ct. 811 (2017). The Sixth Circuit
granted petitioners' motion to hold in abeyance the briefing schedule
in the litigation challenging the 2015 Rule pending a Supreme Court
decision on the question of the court of appeals' jurisdiction. On
January 22, 2018, the Supreme Court, in a unanimous opinion, held that
the 2015 Rule is subject to direct review in the district courts. Nat'l
Ass'n of Mfrs. v. Dep't of Def., 138 S. Ct. 617, 624 (2018). Throughout
the pendency of the Supreme Court litigation (and for a short time
thereafter), the Sixth Circuit's nationwide stay remained in effect. In
response to the Supreme Court's decision, on February 28, 2018, the
Sixth Circuit lifted the stay and dismissed the corresponding petitions
for review. See In re Dep't of Def. & EPA Final Rule, 713 Fed. App'x
489 (6th Cir. 2018).
    Since the Supreme Court's jurisdictional ruling, district court
litigation regarding the 2015 Rule has resumed. At this time, the 2015
Rule continues to be subject to a preliminary injunction issued by the
District of North Dakota as to 13 States: Alaska, Arizona, Arkansas,
Colorado, Idaho, Missouri, Montana, Nebraska, Nevada, North Dakota,
South Dakota, Wyoming, and New Mexico. The 2015 Rule also is subject to
a preliminary injunction issued by the U.S. District Court for the
Southern District of Georgia as to 11 more States: Georgia, Alabama,
Florida, Indiana, Kansas, Kentucky, North Carolina, South Carolina,
Utah, West Virginia, and Wisconsin. See Georgia v. Pruitt, No. 15-cv-79
(S.D. Ga.). In another action, the U.S. District Court for the Southern
District of Texas is considering preliminary injunction motions filed
by parties including the States of Texas, Louisiana, and Mississippi.
See Texas v. EPA, No. 3:15-cv-162 (S.D. Tex.); Am. Farm Bureau Fed'n et
al. v. EPA, No. 3:15-cv-165 (S.D. Tex.). At least three additional
States are seeking a preliminary injunction in the U.S. District Court
for the Southern District of Ohio as well. See, e.g., States'
Supplemental Memorandum in Support of Preliminary Injunction, Ohio v.
EPA, No. 2:15-cv-02467 (S.D. Ohio June 20, 2018) (brief filed by the
States of Ohio, Michigan, and Tennessee in support of the States'
motion for a preliminary injunction against the 2015 Rule).

C. Executive Order 13778, the Notice of Proposed Rulemaking, and the
Applicability Date Rule

    The agencies are engaged in a two-step process intended to review
and repeal or revise, as appropriate and consistent with law, the
definition of ``waters of the United States'' as set forth in the 2015
Rule. This process began in response to Executive Order 13778 issued on
February 28, 2017, by the President entitled ``Restoring the Rule of
Law, Federalism, and Economic Growth by Reviewing the `Waters of the
United States' Rule.'' Section 1 of the Executive Order states, ``[i]t
is in the national interest to ensure the Nation's navigable waters are
kept free from pollution, while at the same time promoting economic
growth, minimizing regulatory uncertainty, and showing due regard for
the roles of the Congress and the States under the Constitution.'' The
Order directed the EPA and the Army to review the 2015 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 (Section 2). The Executive Order
also directed the agencies to ``consider interpreting the term
`navigable waters' . . . in a manner consistent with'' Justice Scalia's
plurality opinion in Rapanos (Section 3).
    On March 6, 2017, the agencies published a notice of intent to
review the 2015 Rule and provide notice of a forthcoming proposed
rulemaking consistent with the Executive Order. 82 FR 12532. Shortly
thereafter, the agencies announced that they would implement the
Executive Order in a two-step approach. On July 27, 2017, the agencies
published a NPRM (82 FR 34899) that proposed to rescind the 2015 Rule
and restore the regulatory text that governed prior to the promulgation
of the 2015 Rule, which the agencies have been implementing since the
judicial stay of the 2015 Rule consistent with Supreme Court decisions
and informed by applicable guidance documents and longstanding agency
practice. The agencies invited comment on the NPRM over a 62-day
period.
    Shortly after the Supreme Court decided that the courts of appeals
do not have original jurisdiction to review challenges to the 2015 Rule
and directed the Sixth Circuit to dismiss the consolidated challenges
to the 2015 Rule for lack of jurisdiction, the agencies issued a final
rule (83 FR 5200, Feb. 6, 2018), after providing notice and an
opportunity for public comment, that added an applicability date to the
2015 Rule. The applicability date was established as February 6, 2020.
When adding the applicability date to the 2015 Rule, the agencies
clarified that they will continue to implement nationwide the previous
regulatory definition of ``waters of the United States,'' consistent
with the practice and procedures the agencies implemented before and
immediately following the issuance of the 2015 Rule pursuant to the
preliminary injunction issued by the District of North Dakota and the
nationwide stay issued by the Sixth Circuit. The agencies further
explained that the final applicability date rule would ensure
regulatory certainty and consistent implementation of the CWA
nationwide while the agencies reconsider the 2015 Rule and potentially
pursue further rulemaking to develop a new definition of ``waters of
the United States.'' The applicability date rule was challenged in a
number of district courts. Generally, the challenges raise concerns
that the agencies' action was arbitrary and capricious because the
agencies did not address substantive comments regarding the 2015 Rule,
as well as procedural concerns with respect to the length of the public
comment period for the proposed applicability date rule. At this time,
these challenges remain pending in the district courts where they were
filed.

D. Comments on the Original Notice of Proposed Rulemaking

    The agencies accepted comments on the NPRM from July 27, 2017,
through September 27, 2017. The agencies received more than 685,000
comments on the NPRM from a broad spectrum of interested parties. The
agencies are continuing to review those extensive comments. Some
commenters expressed support for the agencies' proposal to repeal the
2015 Rule, stating, among other things, that the 2015 Rule exceeds the
agencies' statutory authority. Other commenters opposed the proposal,
stating, among other things, that repealing the 2015 Rule will increase

regulatory uncertainty and adversely impact water quality.
    Based on the agencies' careful and ongoing review of the comments
submitted in response to the NPRM, the agencies believe that it is in
the public interest to provide further explanation and allow interested
parties additional opportunity to comment on the proposed repeal of the
2015 Rule. Because some commenters interpreted the NPRM as restricting
their ability to comment on the legal and policy reasons for or against
the repeal of the 2015 Rule while others submitted comments addressing
these topics, the agencies wish to make clear that comments on that
subject are solicited. Additionally, some commenters appeared to be
confused by whether the agencies proposed a temporary or interim, as
opposed to a permanent, repeal of the 2015 Rule. While the agencies did
refer to the July 2017 proposal as an ``interim action'' (82 FR 34902),
that was in the context of explaining that the proposal to repeal the
2015 Rule is the first step of a two-step process, as described above,
and that the agencies are planning to take the additional, second step
of conducting a separate notice and comment rulemaking to propose a new
definition of ``waters of the United States.'' In this notice, the
agencies are clarifying that, regardless of the timing or ultimate
outcome of that additional rulemaking, the agencies are proposing a
permanent repeal of the 2015 Rule at this stage. This was also our
intent in the NPRM. Finally, some commenters did not fully understand
the precise action the NPRM proposed to take, e.g., repealing, staying,
or taking some other action with respect to the 2015 Rule. The agencies
are issuing this SNPRM and are inviting all interested persons to
comment on whether the agencies should repeal the 2015 Rule and
recodify the regulations currently being implemented by the agencies.

E. Comments on This Supplemental Notice of Proposed Rulemaking

    As discussed in the next sections, the agencies are proposing to
permanently repeal the 2015 Rule. The agencies welcome comment on all
issues that are relevant to the consideration of whether to repeal the
2015 Rule. In response to the initial NPRM, many commenters have
already provided comment on considerations and issues that weigh in
favor of or against repeal, including many of the issues articulated
below. The agencies will consider all of those previously submitted
comments, in addition to any new comments submitted in response to this
SNPRM, in taking a final action on this rulemaking. As such, commenters
need not resubmit comments already provided in response to the
agencies' July 27, 2017 NPRM (82 FR 34899).

II. Proposal To Repeal the 2015 Rule

A. Legal Authority To Repeal

    The agencies' ability to repeal an existing regulation through
notice-and-comment rulemaking is well-grounded in the law. The APA
defines rulemaking to mean ``agency process for formulating, amending,
or repealing a rule.'' 5 U.S.C. 551(5). The CWA complements this
authority by providing the Administrator with broad authority to
``prescribe such regulations as are necessary to carry out the
functions under this Act.'' 33 U.S.C. 1361(a). This broad authority
includes regulations that repeal or revise CWA implementing regulations
promulgated by a prior administration.
    The Supreme Court has made clear that ``[a]gencies are free to
change their existing policies as long as they provide a reasoned
explanation for the change,'' and ``[w]hen an agency changes its
existing position, it `need not always provide a more detailed
justification than what would suffice for a new policy created on a
blank slate.' '' Encino Motorcars, LLC v. Navarro, 136 S. Ct. 2117,
2125 (2016) (citations omitted). The NPRM discussed how the agencies
may revise or repeal the regulatory definition of ``waters of the
United States'' so long as the agencies' action is based on a reasoned
explanation. See 82 FR 34901. The agencies can do so based on changes
in circumstance, or changes in statutory interpretation or policy
judgments. See, e.g., FCC v. Fox Television Stations, Inc., 556 U.S.
502, 514-15 (2009); Ctr. for Sci. in Pub. Interest v. Dep't of
Treasury, 797 F.2d 995, 998-99 & n.1 (D.C. Cir. 1986). The agencies'
interpretation of the statutes they administer, such as the CWA, are
not ``instantly carved in stone''; quite the contrary, the agencies
``must consider varying interpretations and the wisdom of [their]
policy on a continuing basis, . . . for example, in response to . . . a
change in administrations.'' Nat'l Cable & Telecommc'ns Ass'n v. Brand
X Internet Servs., 545 U.S. 967, 981-82 (2005) (``Brand X'') (internal
quotation marks omitted) (quoting Chevron U.S.A., Inc. v. NRDC, 467
U.S. 837, 863-64 (1984)) (citing Motor Vehicle Mfrs. Ass'n v. State
Farm Mut. Auto. Ins. Co., 463 U.S. 29, 59 (1983) (Rehnquist, J.,
concurring in part and dissenting in part)). The Supreme Court and
lower courts have acknowledged an agency's ability to repeal
regulations promulgated by a prior administration based on changes in
agency policy where ``the agency adequately explains the reasons for a
reversal of policy.'' See Brand X, 545 U.S. at 981. 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,'' and
``[a] change in administration brought about by the people casting
their votes is a perfectly reasonable basis for an executive agency's
reappraisal'' of its regulations and programs. Nat'l Ass'n of Home
Builders v. EPA, 682 F.3d 1032, 1038 & 1043 (D.C. Cir. 2012)
(``NAHB'').

B. Legal Background

1. The Clean Water Act
    Congress amended the Federal Water Pollution Control Act (FWPCA),
or Clean Water Act (CWA) as it is commonly called,\9\ in 1972 to
address longstanding concerns regarding the quality of the nation's
waters and the federal government's ability to address those concerns
under existing law. Prior to 1972, the ability to control and redress
water pollution in the nation's waters largely fell to the Corps under
the Rivers and Harbors Act of 1899. Congress had also enacted the 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 (giving the statute is current formal
name), 1961, and 1965. The early versions of the CWA promoted 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.
---------------------------------------------------------------------------

    \9\ The FWPCA is commonly referred to as the CWA following the
1977 amendments to the FWPCA. Public Law 95-217, 91 Stat. 1566
(1977). For ease of reference, the agencies will generally refer to
the FWPCA in this notice as the CWA or the Act.
---------------------------------------------------------------------------

    These early statutory efforts, however, 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), so Congress performed
a ``total restructuring'' and ``complete rewriting'' of the existing
statutory framework in 1972, id. at 317 (quoting legislative history of
1972 amendments). That restructuring resulted in the enactment of a
comprehensive scheme designed to prevent, reduce, and eliminate
pollution in the nation's waters generally, and to regulate the
discharge of pollutants into navigable waters specifically. See, e.g.,

S.D. Warren Co. v. Maine Bd. of Envtl. Prot., 547 U.S. 370, 385 (2006)
(``[T]he Act does not stop at controlling the `addition of pollutants,'
but deals with `pollution' generally[.]'').
    The objective of the new statutory scheme was ``to restore and
maintain the chemical, physical, and biological integrity of the
Nation's waters.'' 33 U.S.C. 1251(a). In order to meet that objective,
Congress declared two national goals: (1) ``that the discharge of
pollutants into the navigable waters be eliminated by 1985;'' and (2)
``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 by
July 1, 1983. . . .'' Id. at 1251(a)(1)-(2).
    Congress established several key policies that direct the work of
the agencies to effectuate those goals. For example, Congress declared
as a national policy ``that the discharge of toxic pollutants in toxic
amounts be prohibited; . . . that Federal financial assistance be
provided to construct publicly owned waste treatment works; . . . that
areawide waste treatment management planning processes be developed and
implemented to assure adequate control of sources of pollutants in each
State; . . . [and] that programs for the control of nonpoint sources of
pollution be developed and implemented in an expeditious manner so as
to enable the goals of this Act to be met through the control of both
point and nonpoint sources of pollution.'' Id. at 1251(a)(3)-(7).
    Congress envisioned a major role for the states in implementing the
CWA, and the CWA also recognizes the importance of preserving the
states' independent authority and responsibility in this area. The CWA
balances the traditional power of states to regulate land and water
resources within their borders with the need for a federal water
quality regulation to protect the waters of the United States. For
example, the statute reflects ``the policy of the Congress to
recognize, preserve, and protect the primary responsibilities and
rights of States to prevent, reduce, and eliminate pollution'' and ``to
plan the development and use . . . of land and water resources. . . .''
Id. at 1251(b). Congress also declared as a national policy that states
manage the major construction grant program and implement the core
permitting programs authorized by the statute, among other
responsibilities. Id. Congress added that ``nothing in this Act shall .
. . be construed as impairing or in any manner affecting any right or
jurisdiction of the States with respect to the waters (including
boundary waters) of such States.'' Id. at 1370. Congress also pledged
to provide technical support and financial aid to the states ``in
connection with the prevention, reduction, and elimination of
pollution.'' Id. at 1251(b).
    To carry out these policies, Congress broadly defined ``pollution''
to mean ``the man-made or man-induced alteration of the chemical,
physical, biological, and radiological integrity of water,'' id. at
1362(19), to parallel the broad objective of the Act ``to restore and
maintain the chemical, physical, and biological integrity of the
Nation's waters,'' id. at 1251(a). Congress then crafted a non-
regulatory statutory framework to provide technical and financial
assistance to the states to prevent, reduce, and eliminate pollution in
the broader set of the nation's waters. For example, section 105 of the
Act, ``Grants for research and development,'' authorized EPA ``to make
grants to any State or States or interstate agency to demonstrate, in
river basins or portions thereof, advanced treatment and environmental
enhancement techniques to control pollution from all sources, . . .
including nonpoint sources, . . . [and] for research and demonstration
projects for prevention of pollution of any waters by industry
including, but not limited to, the prevention, reduction, and
elimination of the discharge of pollutants.'' 33 U.S.C. 1255(b)-(c)
(emphases added); see also id. at 1256(a) (authorizing EPA to issue
``grants to States and to interstate agencies to assist them in
administering programs for the prevention, reduction, and elimination
of pollution''). Section 108, ``Pollution control in the Great Lakes,''
authorized EPA to enter into agreements with any state to develop plans
for the ``elimination or control of pollution, within all or any part
of the watersheds of the Great Lakes.'' Id. at 1258(a) (emphasis
added); see also id. at 1268(a)(3)(C) (defining the ``Great Lakes
System'' as ``all the streams, rivers, lakes, and other bodies of water
within the drainage basin of the Great Lakes''). Similar broad
pollution control programs were created for other major watersheds,
including, for example, 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).
    For the narrower set of the nation's waters identified as
``navigable waters'' or ``the waters of the United States,'' id. at
1362(7), Congress created a federal regulatory permitting program
designed to address the discharge of pollutants into those waters.
Section 301 contains the key regulatory mechanism: ``Except as in
compliance with this section and sections 302, 306, 307, 318, 402, and
404 of this Act, the discharge of any pollutant by any person shall be
unlawful.'' Id. at 1311(a). A ``discharge of a pollutant'' is defined
to include ``any addition of any pollutant to navigable waters from any
point source,'' such as a pipe, ditch or other ``discernible, confined
and discrete conveyance.'' Id. at 1362(12), (14) (emphasis added). The
term ``pollutant,'' as compared to the broader term ``pollution,'' id.
at 1362(19), means ``dredged spoil, solid waste, incinerator residue,
sewage, garbage, sewage sludge, munitions, chemical wastes, biological
materials, radioactive materials, heat, wrecked or discarded equipment,
rock, sand, cellar dirt and industrial, municipal, and agricultural
waste discharged into water.'' Id. at 1362(6). Thus, it is unlawful to
discharge pollutants into navigable waters (defined in the Act as ``the
waters of the United States'') from a point source unless the discharge
complies with certain enumerated sections of the CWA, including
obtaining authorizations to discharge pollutants pursuant to the
section 402 National Pollutant Discharge Elimination System (NPDES)
permit program and the section 404 dredged or fill material permit
program. See id. at 1342 and 1344.
    Under this statutory scheme, the states are responsible for
developing water quality standards for waters of the United States
within their borders and reporting on the condition of those waters to
EPA every two years. Id. at 1313, 1315. States are also responsible for
developing total maximum daily loads (TMDLs) for waters that are not
meeting established water quality standards and must submit those TMDLs
to EPA for approval. Id. at 1313(d). States also have authority to
issue water quality certifications or waive certification for every
federal permit or license issued within their borders that may result
in a discharge to navigable waters. Id. at 1341. A change to the
interpretation of ``waters of the United States'' may change the scope
of waters subject to CWA jurisdiction and thus may change the scope of
waters for which states may assume these responsibilities under the
Act.
    These same regulatory authorities can be assumed by Indian tribes
under section 518 of the CWA, which authorizes EPA to treat eligible
Indian tribes in a manner similar to states for a variety of purposes,
including administering each of the principal

CWA regulatory programs. Id. at 1377(e). In addition, states and tribes
retain sovereign authority to protect and manage the use of those
waters that are not navigable waters under the CWA. See, e.g., id. at
1251(b), 1251(g), 1370, 1377(a). Forty-seven states administer the CWA
section 402 permit program for those waters of the United States within
their boundaries, and two administer the section 404 permit program. At
present, no tribes administer the section 402 or 404 programs.
    The agencies must develop regulatory programs designed to ensure
that the full statute is implemented as Congress intended. See, e.g.,
Hibbs v. Winn, 542 U.S. 88, 101 (2004) (``A statute should be construed
so that effect is given to all its provisions, so that no part will be
inoperative or superfluous, void or insignificant.''). This includes
pursuing the overall ``objective'' of the CWA to ``restore and maintain
the chemical, physical, and biological integrity of the Nation's
waters,'' 33 U.S.C. 1251(a), while implementing the specific ``policy''
directives from Congress to, among other things, ``recognize, preserve,
and protect the primary responsibilities and rights of States to
prevent, reduce, and eliminate pollution'' and ``to plan the
development and use . . . of land and water resources,'' id. at
1251(b). See Webster's II, New Riverside University Dictionary (1994)
(defining ``policy'' as a ``plan or course of action, as of a
government[,] designed to influence and determine decisions and
actions;'' an ``objective'' is ``something worked toward or aspired to:
Goal''). To maintain that balance, the agencies must determine what
Congress had in mind when it defined ``navigable waters'' in 1972 as
simply ``the waters of the United States''--and must do so in light of,
inter alia, the policy directive to preserve and protect the states'
rights and responsibilities.
    Congress' authority to regulate navigable waters derives from its
power to regulate the ``channels of interstate commerce'' under the
Commerce Clause. Gibbons v. Ogden, 22 U.S. (9 Wheat.) 1 (1824); see
also United States v. Lopez, 514 U.S. 549, 558-59 (1995) (describing
the ``channels of interstate commerce'' as one of three areas of
congressional authority under the Commerce Clause). The Supreme Court
explained in SWANCC that the term ``navigable'' indicates ``what
Congress had in mind as its authority for enacting the Clean Water Act:
its traditional jurisdiction over waters that were or had been
navigable in fact or which could reasonably be so made.'' 531 U.S. 159,
172 (2001). The Court further explained that nothing in the legislative
history of the Act provides any indication that ``Congress intended to
exert anything more than its commerce power over navigation.'' Id. at
168 n.3.
    The Supreme Court has cautioned that one must look to the
underlying purpose of the statute to determine the scope of federal
authority being exercised over navigable waters under the Commerce
Clause. See PPL Montana, LLC v. Montana, 132 S. Ct. 1215, 1228 (2012).
The Supreme Court did that in United States v. Riverside Bayview Homes,
for example, and determined that Congress had intended ``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.'' 474 U.S. 121, 133 (1985) (``[T]he evident breadth of
congressional concern for protection of water quality and aquatic
ecosystems suggests that it is reasonable for the Corps to interpret
the term `waters' to encompass wetlands adjacent to waters as more
conventionally defined.''); see also SWANCC, 531 U.S. at 167 (noting
that the Riverside Bayview ``holding was based in large measure upon
Congress' unequivocal acquiescence to, and approval of, the Corps'
regulations interpreting the CWA to cover wetlands adjacent to
navigable waters'').
    The classical understanding of the term navigable was first
articulated by the Supreme Court in The Daniel Ball:

    Those rivers must be regarded as public navigable rivers in law
which are navigable in fact. And they are navigable in fact when
they are used, or are susceptible of being used, in their ordinary
condition, as highways of commerce, over which trade and travel are
or may be conducted in the customary modes of trade and travel on
water. And they constitute navigable waters of the United States
within the meaning of the Acts of Congress, in contradistinction
from the navigable waters of the States, when they form in their
ordinary condition by themselves, or by uniting with other waters, a
continued highway over which commerce is or may be carried on with
other States or foreign countries in the customary modes in which
such commerce is conducted by water.

77 U.S. (10 Wall.) 557, 563 (1871). Over the years, this traditional
test has been expanded to include waters that had been used in the past
for interstate commerce, see Economy Light & Power Co. v. United
States, 256 U.S. 113, 123 (1921), and waters that are susceptible for
use with reasonable improvement, see United States v. Appalachian Elec.
Power Co., 311 U.S. 377, 407-10 (1940).
    By the time the 1972 CWA amendments were enacted, the Supreme Court
had also made clear 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. See Oklahoma ex rel. Phillips v. Guy F. Atkinson Co., 313
U.S. 508, 523 (1941) (``Congress may exercise its control over the non-
navigable stretches of a river in order to preserve or promote commerce
on the navigable portions.''). The Supreme Court had also clarified
that Congress could regulate waterways that formed a part of a channel
of interstate commerce, even if they are not themselves navigable or do
not cross state boundaries. See Utah v. United States, 403 U.S. 9, 11
(1971).
    These developments were discussed during the legislative process
leading up to the passage of the 1972 CWA amendments, and certain
members referred to the scope of the amendments as encompassing
waterways that serve as ``links in the chain'' of interstate commerce
as it flows through various channels of transportation, such as
railroads and highways. See, e.g., 118 Cong. Rec. 33756-57 (1972)
(statement of Rep. Dingell); 118 Cong. Rec. 33699 (Oct. 4, 1972)
(statement of Sen. Muskie).\10\ Other references suggest that
congressional committees at least contemplated applying the ``control
requirements'' of the Act ``to the navigable waters, portions thereof,
and their tributaries.'' S. Rep. No. 92-414, 92nd Cong., 1st Sess. at
77 (1971). And in 1977, when Congress authorized State assumption over
the section 404 dredged or fill material permitting program, Congress
limited the scope of assumable waters by requiring the Corps to retain
permitting authority over Rivers and Harbors Act waters (as identified
by the Daniel Ball test) plus wetlands adjacent to those waters, minus
historic use only waters. See 33 U.S.C. 1344(g)(1).\11\ This suggests
that Congress had in mind a broader scope of waters subject to CWA
jurisdiction than waters traditionally understood as navigable. See
SWANCC, 531 U.S. at 171; Riverside Bayview, 474 U.S. at 138 n.11.
---------------------------------------------------------------------------

    \10\ The agencies recognize that individual member statements
are not a substitute for full congressional intent, but they do help
provide context for issues that were discussed during the
legislative debates. For a detailed discussion of the legislative
history of the 1972 CWA amendments, see Albrecht & Nickelsburg,
Could SWANCC Be Right? A New Look at the Legislative History of the
Clean Water Act, 32 ELR 11042 (Sept. 2002).
    \11\ For a detailed discussion of the legislative history
supporting the enactment of section 404(g), see Final Report of the
Assumable Waters Subcommittee (May 2017), App. F.
---------------------------------------------------------------------------

    Thus, Congress intended to assert federal authority over more than
just waters traditionally understood as navigable, and Congress rooted
that

authority in ``its commerce power over navigation.'' SWANCC, 531 U.S.
at 168 n.3. However, there must necessarily be a limit to that
authority and to what water is subject to federal jurisdiction. How the
agencies should exercise that authority has been the subject of dispute
for decades, but the Supreme Court on three occasions has analyzed the
issue and provided some instructional guidance.

2. U.S. Supreme Court Precedent

a. Adjacent Wetlands
    In Riverside Bayview, the Supreme Court considered the Corps'
assertion of jurisdiction over ``low-lying, marshy land'' immediately
abutting a water traditionally understood as navigable on the grounds
that it was an ``adjacent wetland'' within the meaning of the Corps'
then-existing regulations. 474 U.S. at 124. The Court addressed the
question whether non-navigable wetlands may be regulated as ``waters of
the United States'' on the basis that they are ``adjacent to''
navigable-in-fact waters and ``inseparably bound up with'' them because
of their ``significant effects on water quality and the aquatic
ecosystem.'' See id. at 131-35 & n.9.
    In analyzing the meaning of adjacency, the Court captured the
difficulty in determining where the limits of federal jurisdiction end,
noting that the line is somewhere between open water and dry land:

    In 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 (emphasis added). Within this statement, the Supreme Court
identifies a basic principle for adjacent wetlands: The limits of
jurisdiction lie within the ``continuum'' or ``transition'' ``between
open waters and dry land.'' Observing that Congress intended the CWA
``to regulate at least some waters that would not be deemed
`navigable,' '' the Court therefore held that it is ``a permissible
interpretation of the Act'' to conclude that ``a wetland that actually
abuts on a navigable waterway'' falls within the ``definition of
`waters of the United States.' '' Id. at 133, 135. Thus, a wetland that
abuts a navigable water traditionally understood as navigable is
subject to CWA permitting because it is ``inseparably bound up with the
`waters' of the United States.'' Id. at 134. ``This holds true even for
wetlands that are not the result of flooding or permeation by water
having its source in adjacent bodies of open water.'' Id. The Court
also noted that the agencies can establish categories of jurisdiction
for adjacent wetlands. See id. at 135 n.9.
    The Supreme Court in Riverside Bayview declined to decide whether
wetlands that are not adjacent to navigable waters could also be
regulated by the agencies. See id. at 124 n.2 & 131 n.8. In SWANCC,
however, the Supreme Court analyzed a similar question in the context
of an abandoned sand and gravel pit located some distance from a
traditional navigable water, with excavation trenches that ponded--some
only seasonally--and served as habitat for migratory birds. 531 U.S. at
162-65. The Supreme Court rejected the government's stated rationale
for asserting jurisdiction over these ``nonnavigable, isolated,
intrastate waters.'' Id. at 171-72. In doing so, the Supreme Court
noted that Riverside Bayview upheld ``jurisdiction over wetlands that
actually abutted on a navigable waterway'' because the wetlands were
``inseparably bound up with the `waters' of the United States.'' Id. at
167.\12\ As summarized by the SWANCC majority:
---------------------------------------------------------------------------

    \12\ For additional context, at oral argument during Riverside
Bayview, the government attorney characterized the wetland at issue
as ``in fact an adjacent wetland, adjacent--by adjacent, I mean it
is immediately next to, abuts, adjoins, borders, whatever other
adjective you might want to use, navigable waters of the United
States.'' Transcript of Oral Argument at 16, United States v.
Riverside Bayview Homes, Inc., 474 U.S. 121 (1985) (No. 84-701).

    It was the significant nexus between the wetlands and
``navigable waters'' that informed our reading of the CWA in
Riverside Bayview Homes. Indeed, we did not ``express any opinion''
on the ``question of authority of the Corps to regulate discharges
of fill material into wetlands that are not adjacent to bodies of
open water. . . . In order to rule for [the Corps] here, we would
have to hold that the jurisdiction of the Corps extends to ponds
that are not adjacent to open water. But we conclude that the text
---------------------------------------------------------------------------
of the statute will not allow this.

Id. at 167-68 (internal citations omitted). That is because the text of
section 404(a)--the permitting provision at issue in the case--included
the word ``navigable'' as its operative phrase, and signaled a clear
direction to the Court that ``Congress had in mind . . . its
traditional jurisdiction over waters that were or had been navigable in
fact or which could reasonably be so made.'' Id. at 172.
    The Court dismissed the argument that the use of the abandoned
ponds by migratory birds fell within the power of Congress to regulate
activities that in the aggregate have a substantial effect on
interstate commerce, or that the targeted use of the ponds as a
municipal landfill was commercial in nature. Id. at 173. Such
arguments, the Court noted, raised ``significant constitutional
questions.'' Id. ``Where 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 172-73
(``Congress does not casually authorize administrative agencies to
interpret a statute to push the limit of congressional authority.'').
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; see also Atascadero State
Hospital v. Scanlon, 473 U.S. 234, 242-43 (1985) (finding that where
Congress intends to alter the ``usual constitutional balance between
the States and the Federal Government,'' it must make its intention to
do so ``unmistakably clear in the language of the statute''); Gregory
v. Ashcroft, 501 U.S. 452, 460-61 (1991) (``[The] plain statement rule
. . . acknowledg[es] that the States retain substantial sovereign
powers under our constitutional scheme, powers with which Congress does
not readily interfere.''). ``Rather than expressing a desire to
readjust the federal-state balance in this manner, Congress chose [in
the CWA] to `recognize, preserve, and protect the primary
responsibilities and rights of States . . . to plan the development and
use . . . of land and water resources. . . .'' SWANCC, 531 U.S. at 174
(quoting 33 U.S.C. 1251(b)). The Court therefore found no clear
statement from Congress that it had intended to permit federal
encroachment on traditional state power, and construed the CWA to avoid
the significant constitutional questions related to the scope of
federal authority authorized therein. Id.
    The Supreme Court considered the concept of adjacency again several
years later in consolidated cases arising out of the Sixth Circuit. See
Rapanos v. United States, 547 U.S. 715 (2006). In one case, the Corps
had determined that wetlands on three separate sites were subject to
CWA jurisdiction because they were adjacent to ditches or man-made
drains that eventually connected to traditional navigable waters
several miles away through other ditches, drains, creeks, and/or
rivers. Id. at 719-20, 729. In another case, the Corps had asserted

jurisdiction over a wetland separated from a man-made drainage ditch by
a four-foot-wide man-made berm. Id. at 730. The ditch emptied into
another ditch, which then connected to a creek, and eventually
connected to Lake St. Clair, a traditional navigable water,
approximately a mile from the parcel at issue. The berm was largely or
entirely impermeable, but may have permitted occasional overflow from
the wetland to the ditch. Id. The Court, in a fractured opinion,
vacated and remanded the Sixth Circuit's decision upholding the Corps'
asserted jurisdiction over the four wetlands at issue, with Justice
Scalia writing for the plurality and Justice Kennedy concurring in the
judgment. Id. at 757 (plurality), 787 (Kennedy, J.).
    The plurality determined that CWA jurisdiction only extended to
adjacent ``wetlands with a continuous surface connection to bodies that
are `waters of the United States' in their own right, so that there is
no clear demarcation between `waters' and wetlands.'' Id. at 742. The
plurality then concluded that ``establishing that wetlands . . . are
covered by the Act requires two findings: first, that the adjacent
channel contains a `wate[r] of the United States,' (i.e., a relatively
permanent body of water connected to traditional interstate navigable
waters); and second, that the wetland has a continuous surface
connection with that water, making it difficult to determine where the
`water' ends and the `wetland' begins.'' Id. (alteration in original).
    In order to reach the adjacency conclusion of this two-part test,
the plurality interpreted the Riverside Bayview decision, and
subsequent SWANCC decision characterizing Riverside Bayview, as
authorizing jurisdiction over wetlands that physically abutted
traditional navigable waters. Id. at 740-42. The plurality focused on
the ``inherent ambiguity'' described in Riverside Bayview in
determining where on the continuum between open waters and dry land the
scope of federal jurisdiction should end. Id. at 740. It was ``the
inherent difficulties of defining precise bounds to regulable waters,''
id. at 741 n.10, according to the plurality, that prompted the Court in
Riverside Bayview to defer to the Corps' inclusion of adjacent wetlands
as ``waters'' subject to CWA jurisdiction based on ecological
considerations. Id. at 740-41 (``When we characterized the holding of
Riverside Bayview in SWANCC, we referred to the close connection
between waters and the wetlands they gradually blend into: `It was the
significant nexus between the wetlands and `navigable waters' that
informed our reading of the CWA in Riverside Bayview Homes.' ''). The
plurality also noted that ``SWANCC rejected the notion that the
ecological considerations upon which the Corps relied in Riverside
Bayview . . . provided an independent basis for including entities like
`wetlands' (or `ephemeral streams') within the phrase `the waters of
the United States.' SWANCC found such ecological considerations
irrelevant to the question whether physically isolated waters come
within the Corps' jurisdiction.'' Id. at 741-42 (emphasis in original).
    Justice Kennedy disagreed with the plurality's determination that
adjacency requires a ``continuous surface connection'' to covered
waters. Id. at 772. In reading the phrase ``continuous surface
connection'' to mean a continuous ``surface-water connection,'' id. at
776, and interpreting the plurality's standard to include a ``surface-
water-connection requirement,'' id. at 774, Justice Kennedy stated that
``when a surface-water connection is lacking, the plurality forecloses
jurisdiction over wetlands that abut navigable-in-fact waters--even
though such navigable waters were traditionally subject to federal
authority,'' id. at 776, even after the Riverside Bayview Court
``deemed it irrelevant whether `the moisture creating the wetlands . .
. find[s] its source in the adjacent bodies of water,'' id. at 772
(internal citations omitted). This is one reason why Justice Kennedy
stated that ``Riverside Bayview's observations about the difficulty of
defining the water's edge cannot be taken to establish that when a
clear boundary is evident, wetlands beyond that boundary fall outside
the Corps' jurisdiction.'' Id. at 773.
    The plurality did not directly address the precise distinction
raised by Justice Kennedy, but did note in response that the
``Riverside Bayview opinion required'' a ``continuous physical
connection,'' id. at 751 n.13 (emphasis added), and focused on
evaluating adjacency between a ``water'' and a wetland ``in the sense
of possessing a continuous surface connection that creates the
boundary-drawing problem we addressed in Riverside Bayview.'' Id. at
757. The plurality also noted that its standard includes a ``physical-
connection requirement'' between wetlands and covered waters. Id. at
751 n.13. In other words, the plurality appeared to be more focused on
the abutting nature rather than the source of water creating the
wetlands at issue in Riverside Bayview to describe the legal constructs
applicable to adjacent wetlands, see id. at 747; see also Webster's II,
New Riverside University Dictionary (1994) (defining ``abut'' to mean
``to border on'' or ``to touch at one end or side of something''), and
indeed agreed with Justice Kennedy and the Riverside Bayview Court that
``[a]s long as the wetland is `adjacent' to covered waters . . . its
creation vel non by inundation is irrelevant.'' Id. at 751 n.13.\13\
---------------------------------------------------------------------------

    \13\ The agencies' Rapanos Guidance recognizes the plurality's
``continuous surface connection'' does not refer to a continuous
surface water connection. See, e.g., Rapanos Guidance at 7 n.28 (``A
continuous surface connection does not require surface water to be
continuously present between the wetland and the tributary.'').
---------------------------------------------------------------------------

    Because physically disconnected wetlands do not raise the same
boundary-drawing concerns presented by actually abutting wetlands, the
plurality determined that the rationale in Riverside Bayview does not
apply to such features. The plurality stated that ``[w]etlands with
only an intermittent, physically remote hydrologic connection to
`waters of the United States' do not implicate the boundary-drawing
problem of Riverside Bayview, and thus lack the necessary connection to
covered waters that we described as a `significant nexus' in
SWANCC[.]'' Id. at 742. The plurality supported this position by
referring to the Court's treatment of isolated waters in SWANCC as non-
jurisdictional. Id. at 726, 741-42 (``[W]e held that `nonnavigable,
isolated, intrastate waters'--which, unlike the wetlands at issue in
Riverside Bayview, did not `actually abu[t] on a navigable waterway,'--
were not included as `waters of the United States.' ''). The plurality
found ``no support for the inclusion of physically unconnected wetlands
as covered `waters' '' based on Riverside Bayview's treatment of the
Corps' definition of adjacent. Id. at 746-47; see also id. at 746
(``[T]he Corps' definition of `adjacent' . . . has been extended beyond
reason.'').
    Concurring in the judgment, Justice Kennedy focused on the
``significant nexus'' between the adjacent wetlands and traditional
navigable waters as the basis for determining whether a wetland is a
water subject to CWA jurisdiction: ``It was the significant nexus
between wetlands and navigable waters . . . that informed our reading
of the [Act] in Riverside Bayview Homes. Because such a nexus was
lacking with respect to isolated ponds, [in SWANCC] the Court held that
the plain text of the statute did not permit the Corps' action.'' Id.
at 767 (internal quotations and citations omitted). Justice Kennedy
noted that the wetlands at issue in Riverside Bayview were ``adjacent
to [a] navigable-in-fact waterway[ ],'' while the ``ponds and

mudflats'' considered in SWANCC ``were isolated in the sense of being
unconnected to other waters covered by the Act.'' Id. at 765-66.
``Taken together, these cases establish that in some instances, as
exemplified by Riverside Bayview, 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. In other instances, as exemplified by SWANCC,
there may be little or no connection. Absent a significant nexus,
jurisdiction under the Act is lacking.'' Id. at 767.
    According to Justice Kennedy, whereas the isolated ponds and
mudflats in SWANCC lack the ``significant nexus'' to navigable waters,
it is the ``conclusive standard for jurisdiction'' based on ``a
reasonable inference of ecological interconnection'' between adjacent
wetlands and navigable-in-fact waters that allows for their categorical
inclusion as waters of the United States. Id. at 780 (``[T]he assertion
of jurisdiction for those wetlands [adjacent to navigable-in-fact
waters] is sustainable under the act by showing adjacency alone.'').
Justice Kennedy surmised that it may be that the same rationale
``without any inquiry beyond adjacency . . . could apply equally to
wetlands adjacent to certain major tributaries,'' noting that the Corps
could establish by regulation categories of tributaries based on volume
of flow, proximity to navigable waters, or other factors 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.'' Id. at 780-81. However, ``[t]he
Corps' existing standard for tributaries'' provided Justice Kennedy
``no such assurance'' to infer the categorical existence of a requisite
nexus between waters traditionally understood as navigable and wetlands
adjacent to nonnavigable tributaries. Id. at 781. That is because:

the breadth of [the tributary] standard--which seems to leave wide
room for regulation of drains, ditches, and streams remote from any
navigable-in-fact water and carrying only minor water volumes
towards it--precludes its adoption as the determinative measure of
whether adjacent wetlands are likely to play an important role in
the integrity of an aquatic system comprising navigable waters as
traditionally understood. Indeed, in many cases wetlands adjacent to
tributaries covered by this standard might appear little more
related to navigable-in-fact waters than were the isolated ponds
held to fall beyond the Act's scope in SWANCC.

Id. at 781-82.
    Justice Kennedy stated that, absent development of a more specific
regulation, the Corps ``must establish a significant nexus on a case-
by-case basis when it seeks to regulate wetlands based on adjacency to
nonnavigable tributaries. Given the potential overbreadth of the Corps'
regulations, this showing is necessary to avoid unreasonable
applications of the statute.'' Id. at 782. Justice Kennedy explained
that ``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.' '' Id.
at 780. ``Where an adequate nexus is established for a particular
wetland, it may be permissible, as a matter of administrative
convenience or necessity, to presume covered status for other
comparable wetlands in the region.'' Id. at 782.
    In describing this significant nexus test, Justice Kennedy relied,
in part, on the overall objective of the CWA to ``restore and maintain
the chemical, physical, and biological integrity of the Nation's
waters.'' Id. at 779 (quoting 33 U.S.C. 1251(a)). Justice Kennedy also
agreed with the plurality that ``environmental concerns provide no
reason to disregard limits in the statutory text.'' Id. at 778. With
respect to wetlands adjacent to nonnavigable tributaries, Justice
Kennedy therefore determined that ``mere adjacency . . . is
insufficient. A more specific inquiry, based on the significant-nexus
standard, is . . . necessary.'' Id. at 786. Not requiring adjacent
wetlands to possess a significant nexus with navigable waters, Justice
Kennedy noted, would allow a finding of jurisdiction ``whenever
wetlands lie alongside a ditch or drain, however remote and
insubstantial, that eventually may flow into traditional navigable
waters. The deference owed the Corps' interpretation of the statute
does not extend so far.'' Id. at 778-79.
    Based on the agencies' review of this Supreme Court precedent,
although the plurality and Justice Kennedy established different
standards to determine the jurisdictional status of wetlands adjacent
to nonnavigable tributaries, they both appear to agree in principle
that the determination must be made using a two-part test that
considers: (1) The proximity of the wetland to the tributary; and (2)
the status of the tributary with respect to downstream traditional
navigable waters. The plurality and Justice Kennedy also agree that the
proximity between the wetland and the tributary must be close. The
plurality refers to that proximity as a ``continuous surface
connection'' or ``continuous physical connection,'' as demonstrated in
Riverside Bayview. Id. at 742, 751 n.13. Justice Kennedy recognized
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.'' Id. at 767. The second part of the two-part tests established by
the plurality and Justice Kennedy is addressed in the next section.
b. Tributaries
    The definition of tributaries was not addressed in either Riverside
Bayview or SWANCC. And while the focus of Rapanos was on whether the
Corps could regulate wetlands adjacent to nonnavigable waters, the
plurality and concurring opinions provide some guidance on the
regulatory status of tributaries to navigable-in-fact waters.
    The plurality and Justice Kennedy both recognized that the
jurisdictional scope of the CWA is not restricted to traditional
navigable waters. See id. at 731 (plurality) (``[T]he Act's term
`navigable waters' includes something more than traditional navigable
waters.''); id. at 767 (Justice Kennedy) (``Congress intended to
regulate at least some waters that are not navigable in the traditional
sense.''). Both also agree that federal authority under the Act is not
without limit. See id. at 731-32 (plurality) (``[T]he waters of the
United States . . . cannot bear the expansive meaning that the Corps
would give it.''); id. at 778-79 (Justice Kennedy) (``The deference
owed to the Corps' interpretation of the statute does not extend'' to
``wetlands'' which ``lie alongside a ditch or drain, however remote or
insubstantial, that eventually may flow into traditional navigable
waters.'').
    With respect to tributaries specifically, both the plurality and
Justice Kennedy focus in large part on a tributary's contribution of
flow to, and connection with, traditional navigable waters. The
plurality would include as waters of the United States ``only
relatively permanent, standing or flowing bodies of water'' and would
define such ``waters'' as including streams, rivers, oceans, lakes and
other bodies of waters that form geographical features, noting that all
such ``terms connote continuously present, fixed bodies of water . . .
.'' Id. at 732-33, 739. On the other hand, the plurality would likely
exclude ephemeral streams

and related features. Id. at 733-34, 739, 741. Justice Kennedy would
likely exclude some streams considered jurisdictional under the
plurality's test. Id. at 769 (noting that under the plurality's test,
``[t]he merest trickle, if continuous, would count as a `water' subject
to federal regulation, while torrents thundering at irregular intervals
through otherwise dry channels would not'').
    In addition, both the plurality and Justice Kennedy would likely
include some intermittent streams as waters of the United States. See
id. at 732-33 & n.5 (plurality); id. at 769-70 (Justice Kennedy). The
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). However, neither the plurality nor Justice Kennedy defined
with precision where to draw the line. Nevertheless, the plurality
provided that ``navigable waters'' must have ``at bare minimum, the
ordinary presence of water,'' id. at 734, and Justice Kennedy noted
that the Corps can identify by regulation categories of tributaries
based on volume of flow, proximity to navigable waters, or other
factors 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.'' Id. at 780-81.
And both the plurality and Justice Kennedy agreed that the Corps'
assertion of jurisdiction over the wetlands adjacent to the ``drains,
ditches, and streams remote from any navigable-in-fact water,'' id. at
781 (Kennedy), at issue in Rapanos raised significant jurisdictional
questions. Id. at 737-38 (plurality); id. at 781-82 (Kennedy).
3. Principles and Considerations
    From this legal foundation, a few important principles emerge from
which the agencies can evaluate their authorities. First, the power
conferred on the agencies to regulate the waters of the United States
is grounded in Congress' commerce power over navigation. The agencies
can choose to regulate beyond waters more traditionally understood as
navigable given the broad purposes of the CWA, including some
tributaries to those traditional navigable waters, but must provide a
reasonable basis grounded in the language and structure of the Act for
determining the extent of jurisdiction. The agencies also can choose to
regulate wetlands adjacent to the traditional navigable waters and some
tributaries, if the wetlands are in close proximity to the tributaries,
such as in the transitional zone between open waters and dry land. In
the agencies' view, it would not be consistent with Justice Kennedy's
Rapanos opinion or the Rapanos plurality opinion to regulate wetlands
adjacent to all tributaries, no matter how small or remote from
navigable water. The Court's opinion in SWANCC also calls into serious
question the agencies' authority to regulate nonnavigable, isolated,
intrastate waters that lack a sufficient connection to traditional
navigable waters, and suggests that the agencies should avoid
regulatory interpretations of the CWA that raise constitutional
questions regarding the scope of their statutory authority. The
agencies can, however, regulate certain waters by category, which could
improve regulatory predictability and certainty and ease administrative
burden while still effectuating the purposes of the Act.
    In developing a clear and predictable regulatory framework, the
agencies also must respect the primary responsibilities and rights of
States and Tribes to regulate their land and water resources. See 33
U.S.C. 1251(b), 1370. The oft-quoted objective of the CWA to ``restore
and maintain the chemical, physical, and biological integrity of the
Nation's waters,'' id. at 1251(a), must be implemented in a manner
consistent with Congress' policy directives to the agencies. The
Supreme Court long ago recognized the distinction between federal
waters traditionally understood as navigable and waters ``subject to
the control of the States.'' The Daniel Ball, 77 U.S. (10 Wall.) 557,
564-65 (1871). Over a century later, the Supreme Court in SWANCC
reaffirmed the State's ``traditional and primary power over land and
water use.'' 531 U.S. at 174; accord Rapanos, 547 U.S. at 738 (Scalia,
J., plurality opinion). Ensuring that States and Tribes retain
authority over their land and water resources pursuant to CWA section
101(b) and section 510 helps carry out the overall objective of the
CWA, and ensures that the agencies are giving full effect and
consideration to the entire structure and function of the Act,
including Congress' intent as reflected in dozens of non-regulatory
grant, research, nonpoint source, groundwater, and watershed planning
programs to assist the states in controlling pollution in the nation's
waters, not just its navigable waters.
    Further, the agencies are cognizant that the ``Clean Water Act
imposes substantial criminal and civil penalties for discharging any
pollutant into waters covered by the Act without a permit. . . .'' U.S.
Army Corps of Eng'rs v. Hawkes Co., 136 S. Ct. 1807, 1812 (2016); see
also Sackett v. EPA, 566 U.S. 120, 132-33 (2012) (Alito, J.,
concurring) (``[T]he combination of the uncertain reach of the Clean
Water Act and the draconian penalties imposed for the sort of
violations alleged in this case still leaves most property owners with
little practical alternative but to dance to the EPA's tune.''). As the
Chief Justice observed in Hawkes, ``[i]t is often difficult to
determine whether a particular piece of property contains waters of the
United States, but there are important consequences if it does.'' 136
S. Ct. at 1812; see also id. at 1816-17 (Kennedy, J., concurring)
(``[T]he reach and systemic consequences of the Clean Water Act remain
a cause for concern,'' and the Act ``continues to raise troubling
questions regarding the Government's power to cast doubt on the full
use and enjoyment of private property throughout the Nation.''). Given
the significant civil and criminal penalties associated with the CWA,
it is important for the agencies to promote regulatory certainty while
striving to provide fair and predictable notice of the limits of
federal jurisdiction. See, e.g., Sessions v. Dimaya, 138 S. Ct. 1204,
1223-25 (2018) (Gorsuch, J., concurring in part and concurring in the
judgment) (characterizing fair notice as possibly the most fundamental
of the protections provided by the Constitution's guarantee of due
process, and stating that vague laws are an exercise of ``arbitrary
power . . . leaving the people in the dark about what the law demands
and allowing prosecutors and courts to make it up'').

C. Proposed Reasons for Repeal

    The agencies' proposal is based on our view that regulatory
certainty may be best served by repealing the 2015 Rule and recodifying
the preexisting scope of CWA jurisdiction. Specifically, the agencies
are concerned that rather than achieving their stated objectives of
increasing regulatory predictability and consistency under the CWA,
retaining the 2015 Rule creates significant uncertainty for agency
staff, regulated entities, and the public, which is compounded by court
decisions that have increased litigation risk and cast doubt on the
legal viability of the rule. To provide for greater regulatory
certainty, the agencies propose to revert to the pre-2015 regulations,
a regulatory regime that is more familiar to and better-understood by
the agencies, States, Tribes, local governments, regulated entities,
and the public.

    Further, as a result of the agencies' review and reconsideration of
their statutory authority and in light of the court rulings against the
2015 Rule that have suggested that the agencies' interpretation of the
``significant nexus'' standard as applied in the 2015 Rule was
expansive and does not comport with and accurately implement the limits
on jurisdiction reflected in the CWA and decisions of the Supreme
Court, the agencies are also concerned that the 2015 Rule lacks
sufficient statutory basis. The agencies are proposing to conclude in
the alternative that, at a minimum, the interpretation of the statute
adopted in the 2015 Rule is not compelled, and a different policy
balance can be appropriate.
    Considering the substantial uncertainty associated with the 2015
Rule resulting from its legal challenges, and the substantial
experience the agencies and others possess with the longstanding
regulatory framework currently being administered by the agencies, the
agencies conclude that clarity, predictability, and consistency may be
best served by repealing the 2015 Rule and thus are proposing to do so.
The agencies may still propose changes to the definition of ``waters of
the United States'' in a future rulemaking.
    Further, the agencies are concerned that certain findings and
assumptions supporting adoption of the 2015 Rule were not correct, and
that these conclusions, if erroneous, may separately justify repeal of
the 2015 Rule. The agencies are concerned and seek comment on whether
the 2015 Rule significantly expanded jurisdiction over the preexisting
regulatory program, as implemented by the agencies, and whether that
expansion altered State, tribal, and local government relationships in
implementing CWA programs. The agencies therefore propose to repeal the
2015 Rule in order to restore those preexisting relationships and
better serve the balance of authorities envisioned in CWA section
101(b).
1. The 2015 Rule Fails To Achieve Regulatory Certainty
    The agencies are proposing to repeal the 2015 Rule because it does
not appear to achieve one of its primary goals of providing regulatory
certainty and consistency. When promulgating the 2015 Rule, the
agencies concluded the rule would ``increase CWA program predictability
and consistency by clarifying the scope of `waters of the United
States' protected under the Act.'' 80 FR 37054. The agencies stated
that the 2015 ``rule reflect[ed] the judgment of the agencies in
balancing the science, the agencies' expertise, and the regulatory
goals of providing clarity to the public while protecting the
environment and public health, consistent with the law.'' Id. at 37065.
Since then, developments in the litigation against the 2015 Rule and
concerns raised since the rule's promulgation indicate that maintaining
the 2015 Rule would produce substantial uncertainty and confusion among
state and federal regulators and enforcement officials, the regulated
public, and other interested stakeholders. To provide for greater
regulatory certainty, the agencies propose to repeal the 2015 Rule and
restore a longstanding regulatory framework that is more familiar to
and better-understood by the agencies, our co-regulators, and regulated
entities, until the agencies propose and finalize a replacement
definition.
a. Litigation to Date
    As noted above, the 2015 Rule has been challenged in legal actions
across multiple district courts, in which plaintiffs have raised a
number of substantive and procedural claims against the rule. Petitions
for review were also filed in multiple courts of appeals and were
consolidated in the U.S. Court of Appeals for the Sixth Circuit. To
date, all three of the courts that substantively have considered the
2015 Rule--the Sixth Circuit, the District of North Dakota, and the
Southern District of Georgia--have found that petitioners seeking to
overturn the rule are likely to succeed on the merits of at least some
of their claims against the rule.
    In the Sixth Circuit, the court granted a nationwide stay of the
2015 Rule after finding, among other factors, that the petitioners
showed a ``substantial possibility of success on the merits'' of their
claims against the 2015 Rule, including claims that the rule was
inconsistent with Justice Kennedy's opinion in Rapanos and that the
rule's distance limitations were not substantiated by specific
scientific support. In re EPA, 803 F.3d 804, 807 (6th Cir. 2015).
    The District of North Dakota made similar findings in issuing a
preliminary injunction against the 2015 Rule. There, the court found
that the plaintiff-States are ``likely to succeed on the merits of
their claim'' that the rule violated the congressional grant of
authority to the agencies under the CWA because the rule ``likely
fails'' to meet Justice Kennedy's significant nexus test. North Dakota
v. EPA, 127 F. Supp. 3d 1047, 1055-56 (D.N.D. 2015). The court also
found that the plaintiff-States have a fair chance of success on the
merits of their procedural claims that the agencies failed to comply
with APA requirements in promulgating the rule. Id. at 1056-57.
    The Southern District of Georgia also preliminarily enjoined the
2015 Rule, holding that the State plaintiffs had demonstrated ``a
likelihood of success on their claims that the [2015] WOTUS Rule was
promulgated in violation of the CWA and the APA.'' Georgia v. Pruitt,
No. 15-cv-79, 2018 U.S. Dist. LEXIS 97223, at *14 (S.D. Ga. June 8,
2018) (``Georgia'') (granting preliminary injunction). The court
determined that the 2015 Rule likely failed to meet the standard
expounded in SWANCC and Rapanos, and that the rule was likely fatally
defective because it ``allows the Agencies to regulate waters that do
not bear any effect on the `chemical, physical, and biological
integrity' of any navigable-in-fact water.'' Id. at *17-18. The court
also held that the plaintiffs ``have demonstrated a likelihood of
success on both of their claims under the APA'' that the 2015 Rule ``is
arbitrary and capricious'' and ``that the final rule is not a logical
outgrowth of the proposed rule.'' Id. at *18.
    These rulings indicate that substantive or procedural challenges to
the 2015 Rule are likely to be successful, particularly claims that the
rule is not authorized under the CWA and was promulgated in violation
of the APA. A successful challenge to the 2015 Rule could result in a
court order vacating the rule in all or part, in all or part of the
country, and potentially resulting in different regulatory regimes
being in effect in different parts of the country, which would likely
lead to substantial regulatory confusion, uncertainty, and
inconsistency.
    Notably, the agencies face an increasing risk of a court order
vacating the 2015 Rule. The District of North Dakota is proceeding to
hear the merits of the plaintiff-States' claims against the 2015 Rule
in that case, and the plaintiff-States in the Southern District of
Georgia have requested a similar merits-briefing schedule. See
Scheduling Order, North Dakota v. EPA, No. 15-cv-59 (D.N.D. May 2,
2018); Response to Defendants' Updated Response to Plaintiff States'
Motion for Preliminary Injunction at 11-12, Georgia, No. 15-cv-79 (S.D.
Ga. May 29, 2018). Although the applicability date rule ensures that
the 2015 Rule will not go into effect until February 6, 2020, the
prospect of a court order vacating the 2015 Rule creates additional
regulatory uncertainty.

b. Stakeholder Confusion Regarding the Scope of the 2015 Rule and
Extent of Federal CWA Jurisdiction
    Statements made in the litigation against the 2015 Rule and in
comments regarding the 2015 Rule indicate that there has been
substantial disagreement and confusion as to the scope of the 2015 Rule
and the extent of federal CWA jurisdiction more broadly. In the Sixth
Circuit, for example, State petitioners asserted that the 2015 Rule
covers waters outside the scope of the CWA pursuant to SWANCC and
Rapanos and ``extends jurisdiction to virtually every potentially wet
area of the country.'' \14\ Industry petitioners contended that the
rule's ``uncertain standards are impossible for the public to
understand or the agencies to apply consistently.'' \15\ In contrast,
environmental petitioners found that SWANCC and Rapanos led to
widespread confusion over the scope of the CWA and that the pre-2015
regulatory regime could theoretically apply to ``almost all waters and
wetlands across the country.'' \16\ These petitioners asserted that the
2015 Rule violated the CWA by failing to cover certain waters,
including waters that may possess a ``significant nexus'' to
traditional navigable waters.\17\ Whether such comments are accurate or
not, they indicate continued widespread disagreement and confusion over
the meaning of the 2015 Rule and extent of jurisdiction it entails.
---------------------------------------------------------------------------

    \14\ Opening Brief of State Petitioners at 15, 61, In re EPA,
No. 15-3751 (6th Cir. Nov. 1, 2016).
    \15\ Opening Brief for the Business & Municipal Petitioners, In
re EPA, No. 15-3751 (6th Cir. Nov. 1, 2016).
    \16\ Brief of Conservation Groups at 11, In re EPA, No. 15-3751
(6th Cir. Nov. 1, 2016).
    \17\ See, e.g., id. at 22, 43.
---------------------------------------------------------------------------

    Some comments received on the July 27, 2017 NPRM also demonstrate
continued confusion over the scope and various provisions of the 2015
Rule. For example, one commenter found that the rule's definitions of
``adjacent,'' ``significant nexus'' and other key terms lack clarity
and thus lead to regulatory uncertainty.\18\ This same commenter
contended that the rule could raise constitutional concerns related to
the appropriate scope of federal authority and encouraged the agencies
to undertake a new rulemaking to more clearly articulate the extent of
federal CWA authority. Another commenter echoed these concerns,
alleging that the 2015 Rule resulted in a ``vague and indecipherable
explanation'' of the definition of ``waters of the United States'' that
has caused confusion and uncertainty as to the extent of jurisdiction
that can be asserted by federal, state and local authorities.\19\
---------------------------------------------------------------------------

    \18\ See comments submitted by Oregon Cattlemen's Association
(July 27, 2017) (Docket ID: EPA-HQ-OW-2017-0203-0039), available at
https://www.regulations.gov/document?D=EPA-HQ-OW-2017-0203-0039.
    \19\ See comments submitted by Skagit County Dike, Drainage and
Irrigation District No. 12 and Skagit County Dike District No. 1
(Sept. 27, 2017) (Docket ID: EPA-HQ-OW-2017-0203-11709), available
at https://www.regulations.gov/document?D=EPA-HQ-OW-2017-0203-11709.
---------------------------------------------------------------------------

    The agencies have received comments from numerous other individuals
and entities expressing confusion and concern about the extent of
federal CWA jurisdiction asserted under the 2015 Rule, and the agencies
are continuing to review and consider these comments.
c. Impact on State Programs
    Like other commenters on the proposal to the 2015 Rule, some States
expressed confusion regarding the scope of the proposal and, uniquely,
the potential impacts of that uncertainty on States' ability to
implement CWA programs. Though some States have stated that the 2015
Rule ``more clearly identifies what types of waters would be considered
jurisdictional,'' \20\ others assert that the extent of CWA
jurisdiction under the rule remained ``fuzzy'' and unclear.\21\ Certain
States noted that this uncertainty could ``create time delays in
obtaining permits which previously were not required'' \22\ and
``result in increased costs to the State and other private and public
interests, along with decreased regulatory efficiency.'' \23\ One State
suggested that even if the 2015 Rule established greater regulatory
clarity, the rule's case-by-case determinations could result in
permitting delays when a jurisdictional determination is required.\24\
---------------------------------------------------------------------------

    \20\ See, e.g., comments submitted by State of Washington,
Department of Ecology (Nov. 13, 2014) (Docket ID: EPA-HQ-OW-2011-
0880-13957), available at https://www.regulations.gov/document?D=EPA-HQ-OW-2011-0880-13957.
    \21\ See, e.g., comments submitted by State of Oklahoma (Nov.
14, 2014) (Docket ID: EPA-HQ-OW-2011-0880-14625), available at
https://www.regulations.gov/document?D=EPA-HQ-OW-2011-0880-14625;
see also comments submitted by National Association of Counties
(Nov. 14, 2014) (Docket ID: EPA-HQ-OW-2011-0880-15081), available at
https://www.regulations.gov/document?D=EPA-HQ-OW-2011-0880-15081.
    \22\ See comments submitted by State of Utah, Governor's Office
(Nov. 14, 2014) (Docket ID: EPA-HQ-OW-2011-0880-16534), available at
https://www.regulations.gov/document?D=EPA-HQ-OW-2011-0880-16534.
    \23\ See comments submitted by Wyoming Department of
Environmental Quality (Nov. 14, 2014) (Docket ID: EPA-HQ-OW-2011-
0880-16393), available at https://www.regulations.gov/document?D=EPA-HQ-OW-2011-0880-16393.
    \24\ See comments submitted by State of Washington, Department
of Ecology, supra note 20.
---------------------------------------------------------------------------

    Similar concerns have been raised in the litigation challenging the
2015 Rule. For example, in the Southern District of Georgia, the State
of Indiana has asserted that the 2015 Rule's definition of ``waters of
the United States'' is ``vague'' and that the rule ``imposes . . .
unclear regulatory requirements that will result in an inefficient use
of limited regulatory resources.'' \25\ In particular, the State
asserts concerns that implementing the 2015 Rule will divert resources
by ``[d]emanding the time and attention of regulators to make the now-
difficult determination of when and whether a feature is a WOTUS'' and
``[g]enerating unnecessary administrative appeals and lawsuits to
resolve jurisdictional disputes.'' \26\
---------------------------------------------------------------------------

    \25\ Statement of Bruno L. Pigott, Georgia, No. 15-cv-79 (S.D.
Ga. July 21, 2015).
    \26\ Id.
---------------------------------------------------------------------------

d. Agency Experience With the 1986 Regulations
    The agencies have been implementing the pre-2015 regulations
(hereinafter referred to as the ``1986 regulations'') almost
uninterruptedly since 1986. Corps staff are trained on making
jurisdictional determinations in the field and through national
webinars and classroom or field-based trainings. From June 2007 through
June 2018, the Corps issued 241,857 \27\ approved jurisdictional
determinations (AJDs) under their 1986 regulations, as informed by
applicable Supreme Court precedent and the agencies' guidance.
---------------------------------------------------------------------------

    \27\ U.S. Army Corps of Engineers, OMBIL Regulatory Module (June
5, 2018).
---------------------------------------------------------------------------

    Through over 30 years of experience, the agencies have developed
significant technical expertise with the 1986 regulations and have had
the opportunity to refine the application of the rules through guidance
and the agencies' experience and federal court decisions. Indeed, the
1986 regulations have been the subject of a wide body of case law,
including three significant U.S. Supreme Court decisions \28\ and
dozens of cases in federal district courts and courts of appeals that
have addressed the scope of analysis required. Since 1986, the agencies
have issued numerous memoranda, guidance, and question-and-answer
documents explaining and clarifying these regulations.\29\
---------------------------------------------------------------------------

    \28\ Riverside Bayview, 474 U.S. 121 (1985); SWANCC, 531 U.S.
159 (2001); Rapanos, 547 U.S. 715 (2006).
    \29\ The Corps maintains many of these documents on its public
website, available at https://www.usace.army.mil/Missions/Civil-Works/Regulatory-Program-and-Permits/Related-Resources/CWA-Guidance/
. The EPA maintains many of these documents as well; see also
https://www.epa.gov/wotus-rule/about-waters-united-states.
---------------------------------------------------------------------------

    Given the longstanding nature and history of the 1986 regulations,
this

regulatory regime is more familiar to the agencies, co-regulators, and
regulated entities. For this reason, as between the 2015 Rule and the
1986 regulations, the 1986 regulations (as informed by applicable
Supreme Court precedent and the agencies' guidance) would appear to
provide for greater regulatory predictability, consistency, and
certainty, and the agencies seek public comment on this issue. Though
the agencies acknowledge that the 1986 regulations have posed certain
implementation difficulties and were the subject of court decisions
that had the effect of narrowing their scope, the longstanding nature
of the regulatory regime--coupled with the agencies' and others'
extensive experience with the regulatory scheme--make it preferable to
the regulatory uncertainty posed by the 2015 Rule.
2. The 2015 Rule May Exceed the Agencies' Authority Under the CWA
    The agencies are concerned that the 2015 Rule exceeded EPA's
authority under the CWA by adopting an expansive interpretation of the
``significant nexus'' standard that covers waters outside the scope of
the Act and stretches the significant nexus standard so far as to be
inconsistent with important aspects of Justice Kennedy's opinion in
Rapanos, even though this opinion was identified as the basis for the
significant nexus standard articulated in the 2015 Rule. In particular,
the agencies are concerned that the 2015 Rule took an expansive reading
of Justice Kennedy's significant nexus test and exceeds the agencies'
authority under the Act.
    As expounded in Rapanos, Justice Kennedy's significant nexus
standard is a test intended to limit federal jurisdiction due to the
breadth of the Corps' then-existing standard for tributaries and in
order to ``prevent[ ] problematic applications of the statute.'' 547
U.S. at 783. ``Given the potential overbreadth of the Corps' [1986]
regulations,'' Justice Kennedy found that the showing of a significant
nexus ``is necessary to avoid unreasonable applications of the
statute.'' Id. at 782. The agencies are concerned, upon further
consideration of the 2015 Rule, that the significant nexus standard
articulated in that rule could lead to similar unreasonable
applications of the CWA.
    Justice Kennedy wrote that adjacent ``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.' '' 547 U.S. at 780. The opinion did not
expressly define the relevant ``region'' or what was meant by
``similarly situated,'' but it is reasonable to presume that that the
Justice did not mean ``similarly situated'' to be synonymous with
``all'' waters in a region. The agencies' Rapanos Guidance, for
example, had interpreted the term ``similarly situated'' more narrowly
to ``include all wetlands adjacent to the same tributary.'' \30\ ``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).'' \31\ Thus, under the
agencies' 2008 guidance, ``where evaluating significant nexus for an
adjacent wetland, the agencies will consider the flow characteristics
and functions performed by the tributary to which the wetland is
adjacent along with the functions performed by the wetland and all
other wetlands adjacent to that tributary. This approach reflects the
agencies' interpretation of Justice Kennedy's term `similarly situated'
to include all wetlands adjacent to the same tributary. . . .
Interpreting the phrase `similarly situated' to include all wetlands
adjacent to the same tributary is reasonable because such wetlands are
physically located in a like manner (i.e., lying adjacent to the same
tributary).'' \32\
---------------------------------------------------------------------------

    \30\ Rapanos Guidance at 8.
    \31\ Id. at 10.
    \32\ Id.
---------------------------------------------------------------------------

    The 2015 Rule departed from this interpretation of ``similarly
situated'' wetlands in a ``region,'' including applying it to other
waters, not only wetlands, that were not already categorically
jurisdictional as tributaries or adjacent waters. The proposed rule,
for example, stated that ``[o]ther waters, including wetlands, are
similarly situated when they perform similar functions and are located
sufficiently close together or sufficiently close to a `water of the
United States' so that they can be evaluated as a single landscape unit
with regard to their effect on the chemical, physical, or biological
integrity of a [primary] water.'' 79 FR 22263 (April 21, 2014). The
2015 Rule took it a step further and stated that ``the downstream
health of larger downstream waters is directly related to the aggregate
health of waters located upstream, including waters such as wetlands
that may not be hydrologically connected but function together to
ameliorate the potential impacts of flooding and pollutant
contamination from affecting downstream waters.'' 80 FR 37063. The 2015
Rule thus concluded that ``[a] water has a significant nexus when any
single function or combination of functions performed by the water,
alone or together with similarly situated waters in the region,
contributes significantly to the chemical, physical, or biological
integrity of the nearest [primary] water.'' Id. at 37106. The ``term
`in the region' means the watershed that drains to the nearest
[primary] water.'' Id.
    An examination of all of the waters in ``the watershed'' of ``the
nearest [primary] water'' under the 2015 Rule therefore may have
materially broadened the scope of aggregation that determines
jurisdiction in a ``significant nexus'' inquiry for waters not
categorically jurisdictional from the focus in the proposed rule on
waters ``located sufficiently close together or sufficiently close to a
`water of the United States' so that they can be evaluated as a single
landscape unit.'' 79 FR 22263. The agencies in finalizing the rule
viewed the scientific literature through a broader lens as ``the effect
of landscape position on the strength of the connection to the nearest
`water of the United States,' '' and that ``relevant factors
influencing chemical connectivity include hydrologic connectivity . . .
, surrounding land use and land cover, the landscape setting, and
deposition of chemical constituents (e.g., acidic deposition).'' 80 FR
37094. The agencies are concerned that this important change in the
interpretation of ``similarly situated waters'' from the proposed 2015
Rule and the 2008 Rapanos Guidance may not be explainable by the
scientific literature, including the Connectivity Report \33\ cited
throughout the preamble to the 2015 Rule, in light of the agencies'
view at the time that ``[t]he scientific literature does not use the
term `significant' as it is defined in a legal context.'' 80 FR 37062.
The agencies solicit comment on whether the agencies' justification for
the 2015 Rule's interpretation of ``similarly situated'' with reference
to an entire watershed for purposes of waters not categorically
jurisdictional relied on the scientific literature without due regard
for the restraints imposed by the statute and case law, and whether
this interpretation of Justice Kennedy's significant nexus standard is
a reason, at a minimum because of the legal risk it

creates, to repeal the 2015 Rule. As discussed, the 2015 Rule included
distance-based limitations that were not specified in the proposal. In
light of this, the agencies also solicit comment on whether these
distance-based limitations mitigated or affected the agencies' change
in interpretation of similarly situated waters in the 2015 Rule.
---------------------------------------------------------------------------

    \33\ U.S. EPA. Connectivity of Streams and Wetlands to
Downstream Waters: A Review and Synthesis of the Scientific Evidence
(Jan. 2015) (EPA/600/R-14/475F).
---------------------------------------------------------------------------

    The agencies are also concerned that the 2015 Rule does not give
sufficient effect to the term ``navigable'' in the CWA. See South
Carolina v. Catawba Indian Tribe, 476 U.S. 498, 510 n.22 (1986) (``It
is our duty to give effect, if possible, to every clause and word of a
statute[.]'' (quoting United States v. Menasche, 348 U.S. 528, 538-39
(1955)) (internal quotation marks omitted)). Justice Kennedy's
concurring opinion in Rapanos, on which the 2015 Rule relied heavily
for its basis, recognized the term ``navigable'' must have ``some
importance'' and, if that word has any meaning, the CWA cannot be
interpreted to ``permit federal regulation whenever wetlands lie along
a ditch or drain, however remote and insubstantial, that eventually may
flow into traditional navigable waters.'' Rapanos, 547 U.S. at 778-79
(Kennedy, J., concurring in judgment). When interpreting the Rapanos
decision and its application for determining the scope of CWA
jurisdiction in 2008, the agencies wrote ``[p]rincipal considerations
when evaluating significant nexus include the volume, duration, and
frequency of the flow of water in the tributary and the proximity of
the tributary to a traditional navigable water.'' \34\ The agencies are
considering whether the 2015 Rule's definitions of ``tributary'' and
``adjacent'' were so broad as to eliminate consideration of these
factors in a manner consistent with Justice Kennedy's opinion and the
CWA.
---------------------------------------------------------------------------

    \34\ Rapanos Guidance at 10.
---------------------------------------------------------------------------

    The 2015 Rule stated that the agencies assessed ``the significance
of the nexus'' to navigable water ``in terms of the CWA's objective to
`restore and maintain the chemical, physical, and biological integrity
of the Nation's waters.' '' 80 FR 37056 (quoting 33 U.S.C. 1251(a)).
Under the 2015 Rule, a significant nexus may be established by an
individual water or by collectively considering ``similarly situated''
waters across a ``region,'' defined as ``the watershed that drains to
the nearest [primary] water identified.'' Id. at 37106. The agencies
are now concerned that this broad reliance on biological functions,
such as the provision of life cycle dependent aquatic habitat, may not
comport with the CWA and Justice Kennedy's statement in Rapanos that
``environmental concerns provide no reason to disregard limits in the
statutory text.'' See 547 U.S. at 778. In particular, the agencies are
mindful that the Southern District of Georgia's preliminary injunction
of the 2015 Rule was based in part on the court's holding that the 2015
Rule likely is flawed for the same reason as the Migratory Bird Rule:
``the WOTUS Rule asserts that, standing alone, a significant
`biological effect'--including an effect on `life cycle dependent
aquatic habitat[s]'--would place a water within the CWA's jurisdiction.
Thus, this WOTUS Rule will likely fail for the same reason that the
rule in SWANCC failed.'' Georgia, 2018 U.S. Dist. LEXIS 97223, at *18
(quoting 33 CFR 328.3(c)(5)). The agencies solicit comment on whether
the 2015 Rule is flawed in the same manner as the Migratory Bird Rule,
including whether the 2015 Rule raises significant constitutional
questions similar to the questions raised by the Migratory Bird Rule as
discussed by the Supreme Court in SWANCC.
    Moreover, the 2015 Rule relied on a scientific literature review--
the Connectivity Report--to support exerting federal jurisdiction over
certain waters based on nine enumerated functions. See 80 FR 37065
(``the agencies interpret the scope of `waters of the United States'
protected under the CWA based on the information and conclusions in the
[Connectivity] Report''). The report notes that connectivity ``occur[s]
on a continuum or gradient from highly connected to highly isolated,''
and ``[t]hese variations in the degree of connectivity are a critical
consideration to the ecological integrity and sustainability of
downstream waters.'' Id. at 37057. In its review of a draft version of
the Connectivity Report, EPA's Science Advisory Board (``SAB'') noted,
``[s]patial proximity is one important determinant of the magnitude,
frequency and duration of connections between wetlands and streams that
will ultimately influence the fluxes of water, materials and biota
between wetlands and downstream waters.'' \35\ ``Wetlands that are
situated alongside rivers and their tributaries are likely to be
connected to those waters through the exchange of water, biota and
chemicals. As the distance between a wetland and a flowing water system
increases, these connections become less obvious.'' \36\ The
Connectivity Report also recognizes that ``areas that are closer to
rivers and streams have a higher probability of being connected than
areas farther away.'' Connectivity Report at ES-4.
---------------------------------------------------------------------------

    \35\ Science Advisory Board, U.S. EPA. Review of the EPA Water
Body Connectivity Report at 60 (Oct. 17, 2014).
    \36\ Id. at 55.
---------------------------------------------------------------------------

    Yet, the SAB observed that ``[t]he Report is a science, not policy,
document that was written to summarize the current understanding of
connectivity or isolation of streams and wetlands relative to large
water bodies such as rivers, lakes, estuaries, and oceans.'' \37\ ``The
SAB also recommended that the agencies clarify in the preamble to the
final rule that `significant nexus' is a legal term, not a scientific
one.'' 80 FR 37065. And in issuing the 2015 Rule, the agencies stated,
``the science does not provide a precise point along the continuum at
which waters provide only speculative or insubstantial functions to
downstream waters.'' Id. at 37090.
---------------------------------------------------------------------------

    \37\ Id. at 2.
---------------------------------------------------------------------------

    The agencies now believe that they previously placed too much
emphasis on the information and conclusions of the Connectivity Report
when setting jurisdictional lines in the 2015 Rule, relying on its
environmental conclusions in place of interpreting the statutory text
and other indicia of Congressional intent to ensure that the agencies'
regulations comport with their statutory authority to regulate. This is
of particular concern to the agencies today with respect to the
agencies' broad application of Justice Kennedy's phrase ``similarly
situated lands. '' As discussed previously, the agencies took an
expansive reading of this phrase, in part based on ``one of the main
conclusions of the [Connectivity Report] . . . that the incremental
contributions of individual streams and wetlands are cumulative across
entire watersheds, and their effects on downstream waters should be
evaluated within the context of other streams and wetlands in that
watershed,'' see 80 FR 37066. Yet, Justice Kennedy observed in Rapanos
that what constitutes a ``significant nexus'' to the waters of the
United States is not a solely scientific question and that it cannot be
determined by environmental effects alone. See, e.g., 547 U.S. at 777-
78 (noting that although ``[s]cientific evidence indicates that
wetlands play a critical role in controlling and filtering runoff . . .
environmental concerns provide no reason to disregard limits in the
statutory text'' (citations omitted)). This includes how Congress' use
of the term ``navigable'' in the CWA and how the policies embodied in
section 101(b) should inform this analysis. Justice Kennedy wrote that
``the Corps deems a

water a tributary if it feeds into a traditional navigable water (or a
tributary thereof) and possesses an ordinary high-water mark,'' defined
as a ``line on the shore established by the fluctuations of water and
indicated by [certain] physical characteristics.'' Id. at 781. This
``may well provide a reasonable measure of whether specific minor
tributaries bear a sufficient nexus with other regulated waters to
constitute `navigable waters' under the Act. Yet the breadth of this
standard--which seems to leave wide room for regulation of drains,
ditches, and streams remote from any navigable-in-fact water and
carrying only minor volumes toward it--precludes its adoption as the
determinative measure of whether adjacent wetlands are likely to play
an important role in the integrity of an aquatic system comprising
navigable waters as traditionally understood.'' Id. (emphasis added).
    The 2015 Rule, by contrast, asserts jurisdiction categorically over
any tributary, including all ephemeral and intermittent streams that
meet the rule's tributary definition, as well as all wetlands and other
waters that are within certain specified distances from a broadly
defined category of tributaries (e.g., all waters located within the
100-year floodplain of a category (1) through (5) ``jurisdictional by
rule'' water and not more than 1,500 feet from the ordinary high water
mark of such water). According to the rule, tributaries are
characterized by the presence of the physical indicators of a bed and
banks and an ordinary high water mark and eventually contribute flow
(directly or indirectly) to a traditional navigable water, interstate
water, or territorial sea that may be a considerable distance away. See
80 FR 37105. The 2015 Rule defined ``ordinary high water mark'' as
``that line on the shore established by the fluctuations of water and
indicated by physical characteristics such as a 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.'' Id. at 37106. The 2015 Rule did not require
any assessment of flow, including volume, duration, or frequency, when
defining the ``waters of the United States.'' Instead, the 2015 Rule
concluded that it was reasonable to presume that ``[t]hese physical
indicators demonstrate there is volume, frequency, and duration of flow
sufficient to create a bed and banks and an ordinary high water mark,
and thus to qualify as a tributary.'' Id. at 37105. The 2015 Rule thus
covers ephemeral washes that flow only in response to infrequent
precipitation events if they meet the definition of tributary. These
results, particularly that adjacent waters, broadly defined, are
categorically jurisdictional no matter how small or frequently flowing
the tributary to which they are adjacent, is, at a minimum, in
significant tension with Justice Kennedy's understanding of the term
significant nexus as explained in Rapanos. See id. at 781-82 (``[I]n
many cases wetlands adjacent to tributaries covered by [the Corps' 1986
tributary] standard might appear little more related to navigable-in-
fact waters than were the isolated ponds held to fall beyond the Act's
scope in SWANCC.'').
    The agencies are mindful that courts that have considered the
merits of challenges to the 2015 Rule have similarly observed that the
rule may conflict with Justice Kennedy's opinion in Rapanos,
particularly the rule's definition of ``tributary.'' The District of
North Dakota found that the definitions in the 2015 Rule raise
``precisely the concern Justice Kennedy had in Rapanos, and indeed the
general definition of tributary [in the 2015 Rule] is strikingly
similar'' to the standard for tributaries that concerned Justice
Kennedy in Rapanos. North Dakota, 127 F. Supp. 3d at 1056. The Southern
District of Georgia also found that the 2015 Rule's definition of
``tributary'' ``is similar to the one'' at issue in Rapanos, and that
``it carries with it the same concern that Justice Kennedy had there.''
Georgia, 2018 U.S. Dist. LEXIS 97223, at *17. Likewise, the Sixth
Circuit stated in response to petitioners' ``claim that the Rule's
treatment of tributaries, `adjacent waters,' and waters having a
`significant nexus' to navigable waters is at odds with the Supreme
Court's ruling in Rapanos'' that ``[e]ven assuming, for present
purposes, as the parties do, that Justice Kennedy's opinion in Rapanos
represents the best instruction on the permissible parameters of
`waters of the United States' as used in the Clean Water Act, it is far
from clear that the new Rule's distance limitations are harmonious with
the instruction.'' In re EPA, 803 F.3d at 807 & n.3 (noting that
``[t]here are real questions regarding the collective meaning of the
[Supreme] Court's fragmented opinions in Rapanos'').
    One example that illustrates this point is the ``seasonally ponded,
abandoned gravel mining depressions'' specifically at issue in SWANCC,
531 U.S. at 164, which the Supreme Court determined were
``nonnavigable, isolated, intrastate waters,'' id. at 166-72, and not
jurisdictional. These depressions are located within 4,000 feet of
Poplar Creek, a tributary to the Fox River, and may have the ability to
store runoff or contribute other ecological functions in the watershed.
Thus, they would be subject to, and might satisfy, a significant nexus
determination under the 2015 Rule's case-specific analysis. However,
Justice Kennedy himself stated in Rapanos, which informed the
significant nexus standard articulated in the rule, that, ``[b]ecause
such a [significant] nexus was lacking with respect to isolated ponds,
the [SWANCC] Court held the plain text of the statute did not permit''
the Corps to assert jurisdiction over them. 547 U.S. at 767. Other
potential examples of the breadth of the significant nexus standard
articulated in the 2015 Rule are provided below in the next section.
3. Concerns Regarding the 2015 Rule's Effect on the Scope of CWA
Jurisdiction
    The agencies asserted in the preamble to the 2015 Rule that
``State, tribal, and local governments have well-defined and
longstanding relationships with the Federal government in implementing
CWA programs and these relationships are not altered by the final
rule.'' 80 FR 37054. The agencies further noted that ``[c]ompared to
the current regulations and historic practice of making jurisdictional
determinations, the scope of jurisdictional waters will decrease''
under the 2015 Rule. Id. at 37101. When compared to more recent
practice, however, the agencies determined that the 2015 Rule would
result ``in an estimated increase between 2.84 and 4.65 percent in
positive jurisdictional determinations annually.'' Id. The agencies
thus concluded that the 2015 Rule would ``result in a small overall
increase in positive jurisdiction determinations compared to those made
under the Rapanos Guidance'' and that the ``net effect'' of the
regulatory changes would ``be marginal at most.'' Brief for Respondents
at 32-33 & n.6, In re EPA, No. 15-3571 (6th Cir. Jan. 13, 2017). Since
publication of the final rule, the agencies have received information
about the impact of these changes, including through filings in
litigation against the 2015 Rule and comments received in response to
the July 27, 2017 NPRM. After further analysis and reconsideration of
how the 2015 Rule is likely to impact jurisdictional determinations,
including how the data on those impacts relate to the specific
regulatory changes made in the 2015 Rule, the agencies are now
considering whether the definitional changes in the 2015 Rule would