June 3, 2015
Overview of EPA and the Army Corps’ Rule to Define “Waters
of the United States”
Overview: What Is It?
it was not finalized, but it was the substantive basis for the
2014 proposed rule.
On May 2014, the Army Corps of Engineers (the Corps)
and the Environmental Protection Agency (EPA) finalized
revised regulations that define the scope of waters protected
under the Clean Water Act (CWA). Discharges to waters
under CWA jurisdiction, such as the addition of pollutants
from factories or sewage treatment plants and the dredging
and filling of spoil material through mining or excavation,
require a CWA permit. The legal and policy questions
regarding the outer geographic limit of CWA jurisdiction
and the consequences of restricting or expanding that scope
have challenged regulators, landowners, developers, and
policy makers for over 40 years.
What Is the Current Status?
The revised rule will become effective 60 days after
publication in the Federal Register, which has not yet
occurred, to allow time for review under the Congressional
Review Act. Legal challenges to the rule can be filed on the
date two weeks after publication in the Federal Register.
What’s in the Final Rule?
The final rule retains much of the structure of the agencies’
existing definition of “waters of the United States.” It
focuses particularly on clarifying the regulatory status of
waters located in isolated places in a landscape and streams
that flow only part of the year, along with nearby wetlands,
the types of waters with ambiguous jurisdictional status
following the Supreme Court’s rulings. Like the 2003 and
2008 guidance documents and the 2014 proposal, it
identifies categories of waters that are and are not
jurisdictional, as well as categories of waters that require a
• Under the final rule, all tributaries to the nation’s
traditional navigable waters, interstate waters, the
territorial seas, or impoundments of these waters would
be jurisdictional per se. All of these waters are
jurisdictional under existing rules, but the term
“tributary” is newly defined in the rule.
Background of the Rule
• Waters—including wetlands, ponds, lakes, and similar
The CWA protects “navigable waters,” a term defined in
the act to mean “the waters of the United States, including
the territorial seas.” Waters need not be truly navigable to
be subject to CWA jurisdiction. The act’s single definition
of “navigable waters” applies to the entire law, including
the federal prohibition on pollutant discharges except in
compliance with the act (§301), permit requirements (§§402
and 404), and enforcement (§309). The CWA gave the
agencies the authority to define the term “waters of the
United States” in regulations, which EPA and the Corps
have done several times, most recently in 1986.
• Some waters—but fewer than under current practice—
Revisions to the Corps’ and EPA’s regulations were
proposed in 2014 in light of two Supreme Court rulings
(Solid Waste Agency of Northern Cook County v. U.S. Army
Corps of Engineers, 531 U.S. 159 (2001); and Rapanos v.
United States, 547 U.S. 716 (2006)) that interpreted the
regulatory scope of the CWA more narrowly than
previously, and created uncertainty about the appropriate
scope of waters that are protected by the CWA.
The agencies issued guidance in 2003 and 2008 to lessen
confusion over the Court’s rulings. The non-binding
guidance sought to identify, in light of those rulings,
categories of waters that remain jurisdictional, categories
not jurisdictional, and categories that require a case-specific
analysis to determine if CWA jurisdiction applies. The
Obama Administration proposed revised guidance in 2011;
waters—that are adjacent to traditional navigable
waters, interstate waters, the territorial seas,
jurisdictional tributaries, or impoundments of these
waters would be jurisdictional by rule (i.e., no casespecific evaluation would be required). The final rule for
the first time puts some boundaries on “adjacency.”
would remain subject to a case-specific evaluation of
whether or not they meet the legal standards for federal
jurisdiction established by the Supreme Court.
• The final rule identifies a number of types of waters to
be excluded from CWA jurisdiction. Some restate
exclusions under current rules (e.g., prior converted
cropland); some have been excluded by practice and
would be expressly excluded by rule for the first time
(e.g., groundwater and some ditches). Some are new in
the final rule (e.g., stormwater management systems).
The rule makes no change and does not affect existing
statutory exclusions: exemptions for normal farming,
ranching, and silviculture practice and for maintenance
of drainage ditches (CWA §404(f)), as well as for
agricultural stormwater discharges and irrigation return
flows (CWA §402(l)).
Issues and Controversy
The rule has been and remains highly controversial. The
agencies’ intention in proposing it was to clarify questions
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Overview of EPA and the Army Corps’ Rule to Define “Waters of the United States”
of CWA jurisdiction, in view of the Supreme Court’s
rulings while reflecting the agencies’ scientific and
technical expertise. Much of the controversy since the
Court’s rulings has centered on the many instances that
have required applicants for CWA permits to seek a timeconsuming case-specific evaluation to determine if CWA
jurisdiction applies to their activity, due to uncertainty over
the geographic scope of the act. The agencies’ stated
intention was to clarify jurisdictional questions by clearly
articulating categories of waters that are and are not
protected by the CWA and thus limiting the types of waters
that still require case-specific analysis.
Industries that are the primary applicants for CWA permits
and agriculture groups (although farms are exempt from
most permitting) raised numerous objections over how
broadly they fear that the proposed rule would be
interpreted. Many urged that it be withdrawn. Because
definitions often are key to interpreting statutory law and
regulations, critics contended that the proposed new
definitions were ambiguous and would enable broader
assertion of CWA jurisdiction than is consistent with law
and science. The final rule adds new definitions of key
terms, such as “tributary” and “significant nexus,” and
modifies parts of the proposal in an effort to provide more
clarity. Agriculture has been concerned that the rule would
modify existing CWA exemptions for agricultural practices.
The rule does not affect or alter these exclusions.
Some local governments also criticized the rule. They point
out that localities own and maintain public infrastructure
including roadside ditches, flood control channels, and
stormwater management structures. Because the rule would
define some ditches as “waters of the United States” if they
meet certain conditions, while excluding other ditches,
these local governments contend that the proposal
potentially increased the number of locally-owned ditches
under federal jurisdiction. EPA and Corps officials believed
that the proposed exclusion of most ditches actually
decreases federal jurisdiction, but the issue remained
controversial. The final rule expressly excludes stormwater
management systems and structures from jurisdiction.
Many states and state environmental agencies have
expressed support for a rule to clarify the scope of CWA
jurisdiction, but there was no state consensus on the CorpsEPA proposal or on whether it should be withdrawn. Some
were generally supportive, but others believed that the
agencies did insufficient consultation with the states prior to
proposing the rule. States, they point out, are co-regulators
of the CWA with EPA, making determinations of federal
jurisdiction equally important to states as to industry.
Environmental groups defend the agencies’ efforts to
protect U.S. waters and reduce frustration resulting from
unclear jurisdiction of the CWA. Still, some of them argued
that the proposed rule should be strengthened, for example
by designating additional categories of waters and wetlands
such as prairie potholes as categorically jurisdictional. The
final rule did not do so; instead, such waters will require
case-specific analysis to determine if jurisdiction applies.
Officials of the Corps and EPA have vigorously defended
the proposed rule. But they acknowledged that it raised
questions that required clarification in the final rule. They
believe that the rule announced on May 27 does not protect
any new types of waters that have not been protected
historically, that it does not exceed the CWA’s coverage
and that it would not enlarge jurisdiction beyond what is
consistent with the Supreme Court’s current reading of
jurisdiction and consistent with scientific understanding of
connections between small streams and downstream waters.
If the proposed rule were withdrawn or adoption of a new
rule were delayed, they note, the confusing status quo
would remain in place, although some critics of the
proposed rule said that they preferred the status quo. EPA
and the Corps assert that the final rule addresses criticisms
of the proposal, such as: defining tributaries more clearly,
better defining how protected waters are significant, and
preserving CWA exclusions and exemptions for agriculture.
Based on press reports of stakeholders’ early reactions to
the final rule, some believe that the agencies largely
succeeded in their objective to clarify the rule, while others
believe that they did not.
Congressional interest in the rule has been strong. On
February 4, 2015, the Senate Environment and Public
Works Committee and the House Transportation and
Infrastructure Committee held a joint hearing on impacts of
the proposed rule on state and local governments, hearing
from agency and public witnesses, and other Senate and
House committee hearings also have been held.
On May 12, the House passed legislation to require EPA
and the Corps to start a new rulemaking (H.R. 1732). A
related bill in the 114th Congresss is S. 1140; it would
provide principles to be included in a new rule. Other bills
also have been introduced. The 113th Congress took one
legislative action, enacting a provision in the Consolidated
and Further Continuing Appropriations Act, 2015 (P.L.
113-235) directing EPA and the Corps to withdraw an
interpretive rule on agriculture exemptions from CWA
permitting that is related to but separate from the proposed
“waters of the United States” rule, which had confused and
been controversial with the agriculture sector. The agencies
did withdraw the interpretive rule on January 29, 2015.
P.L. 113-235 did not include any policy provision on the
“waters of the United States” proposal itself.
For additional information, see CRS Report R43455, EPA
and the Army Corps’ Rule to Define “Waters of the United
States”; CRS Report R43943, EPA and the Army Corps’
Proposed “Waters of the United States” Rule:
Congressional Response and Options; and CRS Report
IN10212, Withdrawal of the EPA-Army Corps Interpretive
Rule for Agriculture.
Claudia Copeland, firstname.lastname@example.org, 7-7227
www.crs.gov | 7-5700