Waters of the United States (WOTUS): Repealing and Revising the 2015 Clean Water Rule




October 23, 2019
Waters of the United States (WOTUS):
Repealing and Revising the 2015 Clean Water Rule

Background: What Is WOTUS?
seasonally and ephemeral streams that flow only in
Congress passed the Clean Water Act (CWA) to restore and
response to precipitation.
protect the quality of the nation’s surface waters (33 U.S.C.
3. Waters and wetlands that are categorically
§1251 et seq.). The statute protects “navigable waters,”
excluded from WOTUS, including swales and certain
which it defines as “the waters of the United States,
ditches.
including the territorial seas.” The CWA does not further
The 2008 guidance elaborated on the criteria for wetlands
define the term waters of the United States (WOTUS).
to be considered adjacent to traditionally navigable waters
Thus, the Army Corps of Engineers and U.S.
and therefore fall into category one. Under the 2008
Environmental Protection Agency (EPA) have defined
guidance, adjacency is established by (1) an unbroken
WOTUS in their regulations. However, Congress’s intent as
surface or shallow subsurface connection to regulated
to the meaning of WOTUS has been debated and litigated
waters; (2) physical separation from regulated waters by
for more than four decades.
man-made dikes or barriers, natural river berms, beach
WOTUS Regulations and Rapanos
dunes, and similar features; or (3) proximity to regulated
waters that supports an inference of ecological
In the 1980s, EPA and the Corps defined WOTUS to
interconnection.
include, among other things, all waters and wetlands the
use, degradation, or destruction of which could affect
EPA and the Corps acknowledged that their written
interstate or foreign commerce. While the Supreme Court
guidance did not provide the public or agency staff with the
never struck down this regulation, it held twice that the
information needed to ensure timely, predictable, and
agencies exceeded their CWA authority in interpreting and
consistent jurisdictional determinations. The agencies
applying the regulation.
further acknowledged that case-by-case significant nexus
determinations were resource and time-intensive. Diverse
The Supreme Court has disagreed on WOTUS’s scope. In a
stakeholders—including Members of Congress, states, the
2006 decision, Rapanos v. United States, a four-Justice
regulated community, and non-governmental
plurality (written by Justice Scalia) argued that WOTUS
organizations—requested a formal rulemaking to revise the
encompasses “relatively permanent, standing or
continuously flowing bodies of water,” such as streams,
existing rules.
rivers, or lakes and wetlands that have a “continuous
The 2015 Clean Water Rule
surface connection” to waters subject to the CWA. Justice
In 2015, EPA and the Corps issued the Clean Water Rule
Kennedy, by contrast, wrote a concurring opinion arguing
(2015 Rule), which redefined WOTUS in the agencies’
that WOTUS includes wetlands that have a “significant
nexus” to traditionally navigable waters.
regulations for the first time since the 1980s. (The 2008
Justice Kennedy
changes following Rapanos came in agency guidance.) In
elaborated that a significant nexus exists when the wetland,
publishing the 2015 Rule, the agencies sought to reduce the
either alone or in connection with similarly situated
universe of waters subject to case-by-case significant nexus
properties, significantly impacts the chemical, physical, and
analysis. The 2015 Rule retained aspects of the agencies’
biological integrity of a traditionally navigable water.
2008 guidance, including a three-tiered jurisdictional
After Rapanos, EPA and the Corps issued interpretive
analysis, but it also incorporated new features. Among other
guidance in 2008 in which they organized the CWA
things, EPA and the Corps expanded waters that are
jurisdictional analysis into three categories:
categorically WOTUS by broadening the definition of
tributaries to include intermittent and ephemeral waters that
1. Waters and wetlands that are categorically
contribute flow to certain other regulated waters and show
WOTUS, including traditionally navigable waters,
physical indicators of a bed, bank, and ordinary high water
relatively permanent tributaries, wetlands adjacent to
mark. The agencies adopted numerical distance-based
traditionally navigable waters, and wetlands that abut
criteria to determine when waters and wetlands are part of
tributaries to such waters.
WOTUS because they are adjacent to certain regulated
2. Waters and wetlands that may be deemed WOTUS
waters. For example, the 2015 Rule provides that waters
on a case-by-case basis upon a finding of a
and wetlands within 100 feet of the ordinary high water
“significant nexus” with traditionally navigable
mark of certain other regulated waters are considered
waters. This category includes wetlands adjacent to
WOTUS. While the Corps and EPA contended that their
certain tributaries as well as tributaries that are not
primary intent of the 2015 Rule was to clarify (rather than
relatively permanent—defined in the guidance as
enlarge) regulatory jurisdiction, some stakeholders and
intermittent streams that lack a continuous flow at least
observers viewed it as an expansion of CWA jurisdiction.
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Waters of the United States (WOTUS):
Repealing and Revising the 2015 Clean Water Rule
Legal Challenges to the 2015 Rule
2015 Rule, the agencies are already applying the pre-2015
In 2015, a group of 31 states and other plaintiffs challenged
regulatory regime.)
the 2015 Rule in federal courts across the country,
asserting, among other things, that the rule was
The agencies gave several reasons for rescinding the 2015
unconstitutional, that it exceeded the CWA’s statutory grant
Rule: (1) The rule misapplied prior Supreme Court
of authority, and that the agencies had violated the
precedent; (2) the agencies failed to consider adequately
Administrative Procedure Act (APA) in promulgating it.
and to weigh appropriately the congressional policy cited in
Between 2015 and 2019, several federal district courts
CWA Section 101(b) to “recognize, preserve, and protect
entered preliminary injunctions preventing the 2015 Rule
the primary responsibilities and rights of States to prevent,
from going into effect in parts of the country. In 2019, two
reduce, and eliminate pollution” and “to plan the
federal district courts held that the agencies violated the
development and use … of land and water resources;” (3)
APA, and one of those courts held that the rule exceeded
the rule improperly pressed the “outer limits” of Congress’s
the agencies’ CWA authority.
constitutional power without a “clear indication” of
congressional intent to do so; and (4) the agencies did not
Other courts ruled against 2015 Rule challenges. In 2019,
comply with the APA’s notice-and-comment requirements
two different federal district courts denied motions for
in promulgating the rule.
preliminary injunctions, allowing the 2015 Rule to go into
effect in some parts of the country. As a result of the
Commentators debate the impact of repealing the 2015
litigation, the 2015 Rule is enjoined in 27 states (shown in
Rule. EPA and the Corps assert that, while the pre-2015
teal), in effect in 22 states (blue), and subject to a motion
regulations and guidance pose certain implementation
for clarification in one state (New Mexico), as Figure 1
challenges, repealing the 2015 Rule will provide greater
shows.
regulatory certainty. However, critics of the repeal—
including environmental groups and several states—assert
Figure 1. Status of the 2015 Clean Water Rule
that repealing the 2015 rule removes important
environmental protections and plan to file legal challenges.
Some observers believe these challenges could lead to
renewed uncertainty and a patchwork of different
regulations in different states.
Step Two Proposed Rule: Revising the
Definition of WOTUS
On February 14, 2019, the agencies published a proposed
Step Two Rule, which would substantively redefine
WOTUS. The agencies have not finalized the Step Two
Proposed Rule. EPA and the Corps stated that the Step Two
Proposed Rule is intended to implement the CWA’s
objectives of protecting and restoring the nation’s waters

Sources: North Dakota v. EPA, 127 F. Supp. 3d 1047 (D.N.D. 2015);
while respecting state and tribal authority.
Order, North Dakota v. EPA, No. 3:14-cv-59 (D.N.D. Sep. 9, 2018);
In the Step Two Proposed Rule, the agencies departed from
Motion for Clarification, North Dakota v. EPA, No. 3:15-cv-00059
(D.N.D. May 24, 2019); Georgia v. Wheeler, No. 2:15-cv-079 (S.D.
earlier WOTUS approaches. Among other changes, the
Ga. Aug. 21, 2019); Texas v. EPA, No. 3:15-cv-00162 (S.D. Tex. May
Step Two Proposed Rule would eliminate the category two,
28, 2019).
case-by-case “significant nexus” standard, define WOTUS
Executive Order 13778
to include six categories of waterbodies, and modify the
tributary and adjacent wetlands definitions. Overall, fewer
Describing the 2015 Rule as an example of federal
waters and wetlands would be subject to the CWA under
overreach, President Trump issued Executive Order 13778
the Step Two Proposed Rule. For more information on the
on February 28, 2017, directing the agencies to review and
Step Two Proposed Rule, see CRS Report R44585,
rescind or revise the rule and consider interpreting the term
Evolution of the Meaning of “Waters of the United States”
navigable waters in a manner consistent with Justice
in the Clean Water Act, by Stephen P. Mulligan.
Scalia’s opinion in Rapanos (which described a
“continuous surface connection” test). The agencies are
Legislation in the 116th Congress
complying with the executive order by (1) repealing the
Debate over the CWA has largely stemmed from confusion
2015 Rule and (2) redefining WOTUS in a separate
over the meaning Congress intended WOTUS to have.
rulemaking. The proposed rules garnered significant public
Some Members have introduced legislation (H.R. 667, H.R.
comment, with each receiving over 600,000 comments.
2287, S. 376, and S. 2356) to repeal or nullify the 2015
Step One Rule: Repealing the 2015 Rule
Rule and amend the CWA to change the definition of
navigable waters. The language, as proposed in these bills,
On October 22, 2019, the agencies published a final Step
would narrow the scope of waters protected by the CWA.
One Rule to rescind the 2015 Rule. The effective date of the
rule is 60 days from its publication in the Federal Register.
Laura Gatz, Analyst in Environmental Policy
Once the final Step One Rule is effective, the agencies will
Stephen P. Mulligan, Legislative Attorney
implement the pre-2015 regulations consistent with prior
agency guidance. (In states where courts have enjoined the
IF11339
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Waters of the United States (WOTUS):
Repealing and Revising the 2015 Clean Water Rule


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