EPA and the Army Corps’ Rule to Define
“Waters of the United States”
Claudia Copeland
Specialist in Resources and Environmental Policy
January 4, 2016
Congressional Research Service
7-5700
www.crs.gov
R43455
EPA and the Army Corps’ Rule to Define “Waters of the United States”
Summary
On May 27, the Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers
(Corps) jointly announced a final rule defining the scope of waters protected under the Clean
Water Act (CWA). The rule revises regulations that have been in place for more than 25 years.
Revisions are being made in light of 2001 and 2006 Supreme Court rulings that interpreted the
regulatory scope of the CWA more narrowly than the agencies and lower courts were then doing,
and created uncertainty about the appropriate scope of waters protected under the CWA.
According to the agencies, the new rule revises the existing administrative definition of “waters
of the United States” consistent with the CWA, legal rulings, the agencies’ expertise and
experience, and science concerning the interconnectedness of tributaries, wetlands, and other
waters and effects of these connections on the chemical, physical, and biological integrity of
downstream waters. Waters that are “jurisdictional” are subject to the multiple regulatory
requirements of the CWA. Non-jurisdictional waters are not subject to those requirements.
This report describes the final revised rule—which the agencies refer to as the Clean Water
Rule—and includes a table comparing the existing regulatory language that defines “waters of the
United States” with the revisions. The rule is particularly focused on clarifying the regulatory
status of surface waters located in isolated places in a landscape. It does not modify some
categories of waters that are jurisdictional under existing rules (traditional navigable waters,
interstate waters and wetlands, the territorial seas, and impoundments). The rule also lists waters
that would not be jurisdictional, such as prior converted cropland and certain ditches. It makes no
change to existing statutory exclusions, such as CWA permit exemptions for normal farming and
ranching activities. The rule will replace EPA-Corps guidance that was issued in 2003 and 2008,
which has guided agency interpretation of the Court’s rulings but also has caused considerable
confusion. Much of the controversy since the Supreme Court rulings has focused on the degree to
which isolated waters and small streams are jurisdictional. Under the EPA-Corps guidance, many
of these waters have required case-specific evaluation to determine if jurisdiction applies. Under
the final rule, some of these waters would continue to need case-specific review, but fewer than
under the existing agency guidance documents. The final rule also explicitly excludes specified
waters from the definition of “waters of the United States” (e.g., prior converted croplands,
stormwater management systems, and groundwater).
Changes in the final rule would increase the categorical assertion of CWA jurisdiction, in part as
a result of expressly declaring some types of waters jurisdictional by rule (such as all waters
adjacent to a jurisdictional water), making these waters subject to the act’s permit and other
requirements if pollutant discharges occur. Nevertheless, the agencies believe that the rule does
not exceed the CWA’s lawful coverage or protect new types of waters that have not been
protected historically (i.e., under existing rules that the new rule will replace). While it would
enlarge jurisdiction beyond that under the existing EPA-Corps guidance, they believe that it
would not enlarge jurisdiction beyond what is consistent with the Supreme Court’s current
reading of jurisdiction and would reduce jurisdiction over some waters, as a result of exclusions
and exemptions. The agencies estimate that the new rule will result in approximately 3-5% more
positive assertions of jurisdiction over U.S. waters, compared with current field practice.
Congressional interest in the rule has been strong since it was proposed in 2014 and is continuing
in the 114th Congress. The agencies contend that the final rule responds to those criticisms of the
proposed rule. Their stated intention has been to clarify the rules and make jurisdictional
determinations more predictable, less ambiguous, and more timely. Some stakeholders believe
that the agencies largely succeeded in that objective, while others do not. Challenges to the rule
were filed in multiple federal district and appellate courts by industry groups, more than half of
Congressional Research Service
EPA and the Army Corps’ Rule to Define “Waters of the United States”
the states, and several environmental groups. The rule became effective on August 28, 2015, but
on October 9, a federal court blocked the rule’s implementation nationwide.
Congressional Research Service
EPA and the Army Corps’ Rule to Define “Waters of the United States”
Contents
Introduction ..................................................................................................................................... 1
The CWA and the Revised Rule ...................................................................................................... 2
Overview of the Revised Rule .................................................................................................. 4
Waters That Are Categorically Jurisdictional ..................................................................... 4
Waters Requiring Significant Nexus Analysis .................................................................... 6
Exclusions and Definitions ................................................................................................. 8
Impacts of the Rule ........................................................................................................................ 10
Concerns of Agriculture and Local Governments ................................................................... 12
Local Government Concerns ............................................................................................ 13
Conclusion ..................................................................................................................................... 13
Recent Developments .............................................................................................................. 14
Figures
Figure 1. Jurisdictional Waters under the Final Clean Water Rule .................................................. 5
Tables
Table 1. Comparison of “Definition of Waters of the United States” Regulatory Language ........ 16
Appendixes
Appendix. EPA’s Connectivity Report and Review by the Science Advisory Board .................... 29
Contacts
Author Contact Information .......................................................................................................... 32
Congressional Research Service
link to page 20 EPA and the Army Corps’ Rule to Define “Waters of the United States”
Introduction
On May 27, the Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers
(Corps) jointly announced a final rule defining the scope of waters protected under the Clean
Water Act (CWA). The rule revises regulations that have been in place for more than 25 years.1
Revisions were proposed in March 2014 in light of Supreme Court rulings in 2001 and 2006 that
interpreted the regulatory scope of the CWA more narrowly than the agencies and lower courts
were then doing, and created uncertainty about the appropriate scope of waters protected under
the CWA.2
In April 2011, EPA and the Corps proposed guidance on policies for determining CWA
jurisdiction to replace guidance previously issued in 2003 and 2008; all were intended to lessen
confusion over the Court’s rulings for the regulated community, regulators, and the general
public. The guidance documents sought to identify, in light of the Court’s 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 2011 proposed guidance identified
similar categories as in the 2003 and 2008 documents, but it would have narrowed categories that
require case-specific analysis in favor of asserting jurisdiction categorically for some types of
waters. The new rule replaces the existing 2003 and 2008 guidance, which had remained in effect
because the 2011 proposed guidance was not finalized.3
The 2011 proposed guidance was extremely controversial, especially with groups representing
property owners, land developers, and the agriculture sector, who contended that it represented a
massive federal overreach beyond the agencies’ statutory authority. Most state and local officials
were supportive of clarifying the extent of CWA-regulated waters, but some were concerned that
expanding the CWA’s scope could impose costs on states and localities as their own actions (e.g.,
transportation projects) become subject to new requirements. Most environmental advocacy
groups welcomed the proposed guidance, which would more clearly define U.S. waters that are
subject to CWA protections, but some in these groups favored even a stronger document. Still,
both supporters and critics of the 2011 proposed guidance urged the agencies to replace guidance,
which is non-binding and not subject to full notice-and-comment rulemaking procedures, with
revised regulations that define “waters of the United States.” Three opinions in the 2006 Supreme
Court Rapanos ruling similarly urged the agencies to initiate a rulemaking, as they did
subsequently.
In the 112th and 113th Congresses, a number of legislative proposals were introduced to bar EPA
and the Corps from implementing the 2011 proposed guidance or developing regulations based on
it; none of these proposals was enacted. Similar criticism followed almost immediately after
release of the proposed rule on March 25, 2014, with some Members asserting that it would result
in job losses and damage economic growth. Supporters of the Administration, on the other hand,
defended the agencies’ efforts to protect U.S. waters and reduce frustration that has resulted from
1 Definition of “waters of the United States” is found at 33 C.F.R. §328.3 (Corps) and 40 C.F.R. §122.2 (EPA). The
term is similarly defined in other EPA regulations, as is the term “navigable waters.” It is not defined in the CWA. See
Table 1.
2 Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers (SWANCC), 531 U.S. 159 (2001),
and Rapanos v. United States, 547 U.S. 715 (2006).
3 For background on the Supreme Court rulings, subsequent guidance, and other developments, see CRS Report
RL33263, The Wetlands Coverage of the Clean Water Act (CWA): Rapanos and Beyond, by Robert Meltz and Claudia
Copeland.
Congressional Research Service
1
link to page 18 link to page 18 link to page 20 EPA and the Army Corps’ Rule to Define “Waters of the United States”
the unclear jurisdiction of the act.4 Support was expressed by environmental and conservation
organizations, among others.5
The CWA and the Revised Rule
The proposed rule was published in the Federal Register on April 21, 2014.6 The revised rule,
announced on May 27, 2015, became effective August 28, 60 days after publication in the
Federal Register.7 Judicial review of the rule began on July 13, 2015,8 but legal challenges were
filed in multiple federal courts even before that date. On October 9, a federal court issued an
order to stay implementation of the rule nationwide, pending further developments (see “Recent
Developments”). Table 1 in this report provides a comparison of the existing regulatory language
promulgated in 1986 that defines “waters of the United States” with language in the proposed rule
and the final rule.
The CWA protects “navigable waters,” a term defined in the act to mean “the waters of the United
States, including the territorial seas.”9 Waters need not be truly navigable to be subject to CWA
jurisdiction. Both the legislative history and the case law surrounding the CWA confirm that
jurisdiction is not limited to traditional navigable waters, that is, waters that are, were, or could be
used in interstate or foreign commerce.10 Waters that are jurisdictional are subject to the multiple
regulatory requirements of the CWA: standards, discharge limitations, permits, and enforcement.
Non-jurisdictional waters, in contrast, are not subject to these federal legal requirements. The
act’s single definition of “navigable waters” applies to the entire law. In particular, it applies to
federal prohibition on discharges of pollutants except in compliance with the act’s requirements
(§301), requirements for point sources to obtain a permit prior to discharge (§§402 and 404),
water quality standards and measures to attain them (§303), oil spill liability and oil spill
prevention and control measures (§311), certification that federally permitted activities comply
with state water quality standards (§401), and enforcement (§309). It impacts the Oil Pollution
Act and other environmental laws, as well.11 The CWA leaves it to the agencies to define the term
“waters of the United States” in regulations, which EPA and the Corps have done several times,
most recently in 1986.
4 Anthony Adragna and Amena Saiyid, “Republicans Contend EPA Overreached on Clean Water Act Jurisdiction
Proposal,” Daily Environment Report, vol. 58 (March 26, 2014), p. A-7.
5 U.S. Environmental Protection Agency, “Here’s What They're Saying About the Clean Water Act Proposed Rule,”
press release, March 26, 2014, http://yosemite.epa.gov/opa/admpress.nsf/3881d73f4d4aaa0b85257359003f5348/
3f954c179cf0720985257ca7004920fa.
6 Department of Defense, Department of the Army, Corps of Engineers, and Environmental Protection Agency,
“Definition of ‘Waters of the United States’ Under the Clean Water Act, Proposed Rule,” 79 Federal Register 22188-
22274, April 21, 2014. The agencies extended the original 90-day comment period twice for a total of 207 days.
7 Department of the Army, Corps of Engineers, and Environmental Protection Agency, “Clean Water Rule: Definition
of ‘Waters of the United States,’ Final Rule,” 80 Federal Register 37054-37127, June 29, 2015. Hereinafter, Final
Rule. Documents related to the rule on the EPA website include an economic analysis of the Clean Water Rule and a
technical support document; see http://www2.epa.gov/cleanwaterrule/documents-related-clean-water-rule.
8 See 40 C.F.R. §23.2.
9 CWA §502(7); 33 U.S.C. §1362(7).
10 United States v. Riverside Bayview Homes, Inc., 474 U.S. §121, 133 (1985).
11 For example, the reach of the Endangered Species Act (ESA) is affected, because that act’s requirement for
consultation by federal agencies over impacts on threatened or endangered species is triggered through the issuance of
federal permits.
Congressional Research Service
2
link to page 33 EPA and the Army Corps’ Rule to Define “Waters of the United States”
According to the agencies, the new rule—which they now refer to as the Clean Water Rule—
revises the existing administrative definition of “waters of the United States” in regulations
consistent with legal rulings—especially the recent Supreme Court cases—and science
concerning the interconnectedness of tributaries, wetlands, and other waters to downstream
waters and effects of these connections on the chemical, physical, and biological integrity of
downstream waters. The agencies assert that the rule also reflects their expertise and experience
in administering the CWA, including making more than 120,000 case-specific jurisdictional
determinations since 2008. The rule is particularly focused on clarifying the regulatory status of
surface waters located in isolated places in a landscape (the types of waters with ambiguous
jurisdictional status following the Supreme Court’s 2001 ruling in SWANCC) and small streams,
rivers that flow for part of the year, and nearby wetlands (the types of waters affected by the
Court’s 2006 ruling in Rapanos).
In developing the rule, EPA and the Corps relied on a synthesis prepared by EPA’s Office of
Research and Development of more than 1,200 published and peer-reviewed scientific reports;
the synthesis discusses the current scientific understanding of the connections or isolation of
streams and wetlands relative to large water bodies such as rivers, lakes, estuaries, and oceans.
The purpose of the scientific synthesis report was to summarize current understanding of these
connections, the factors that influence them, and the mechanisms by which connected waters
affect the function or condition of downstream waters. The document was reviewed by EPA’s
Science Advisory Board (SAB), which provides independent engineering and scientific advice to
the agency and which completed its review in October 2014. A number of EPA’s critics suggested
that the agencies should have deferred developing or proposing a rule until a final scientific
review document was complete. Some also expressed concern that the final report would not be
available during the public comment period on the rule, which closed on November 14, 2014.
Based on completion of the SAB review, EPA issued a final scientific assessment report in
January 2015, saying that it would assist the agencies in developing the final rule. (See the
Appendix for discussion of the connectivity report.)
A key conclusion in the science report that was also emphasized by the SAB review is that
streams and wetlands fall along a gradient of connectivity that can be described in terms of
frequency; duration; magnitude; timing; and rates of change of water, material, and biotic fluxes
to downstream waters. However, science cannot in all cases provide “bright lines” to interpret and
implement policy. In the preamble to the final rule, EPA and the Corps acknowledge this point.
... the agencies’ interpretive task in this rule ... requires scientific and policy judgment, as
well as legal interpretation. The science demonstrates that waters fall along a gradient of
chemical, physical, and biological connection to traditional navigable waters, and it is the
agencies’ task to determine where along that gradient to draw lines of jurisdiction under
the CWA. In making this determination, the agencies must rely, not only on the science,
but also on their technical expertise and practical experience in implementing the CWA
during a period of over 40 years. In addition, the agencies are guided, in part, by the
compelling need for clearer, more consistent, and easily implementable standards to
govern the administration of the Act, including brighter line boundaries where feasible
and appropriate.12
12 Final Rule, p. 37057.
Congressional Research Service
3
link to page 9 EPA and the Army Corps’ Rule to Define “Waters of the United States”
Overview of the Revised Rule
The final rule announced on May 27 retains much of the structure of the agencies’ existing
definition of “waters of the United States.” Like the 2003 and 2008 guidance and the 2014
proposal, it identifies categories of waters that are and are not jurisdictional, as well as categories
of waters that require a case-specific evaluation. The final rule revises parts of the 2014 proposed
rule; the text box, below, lists the key changes in the final rule. Figure 1 illustrates waters that are
jurisdictional by rule and waters that may be determined to be jurisdictional based on case-
specific analysis.
Key Changes in the Final Rule from the Proposed Rule
In the preamble to the final rule, EPA and the Corps observe that—
many ... commenters and stakeholders urged EPA to improve upon the April 2014
proposal, by providing more bright line boundaries and simplifying definitions that
identify waters that are protected under the CWA, all for the purpose of minimizing
delays and costs, making protection of clean water more effective, and improving
predictability and consistency for landowners and regulated entities. (Final Rule, p.
37057)
To that end, the final rule revises parts of the proposal.
Adjacent waters—the final rule establishes distance limits, based on waters that are defined as “neighboring,”
which is an aspect of “adjacent.”
Tributaries—the final rule removes wetlands and other waters that typically lack a bed and bank and an ordinary
high water mark from the definition of “tributary” and moves such waters to “adjacent waters.”
The final rule identifies two sets of waters for purposes of conducting a case-specific significant nexus analysis to
determine if CWA jurisdiction applies, narrowing the scope of waters that could be assessed under a case-
specific significant nexus analysis compared with the proposed rule. First are five specific subcategories of waters
(prairie potholes, Carolina bays and Delmarva bays, pocosins, western vernal pools, and Texas coastal prairie
wetlands). Second are waters located in whole or in part within the 100-year floodplain of a traditional navigable
water, interstate water, or the territorial seas and within 4,000 feet of the high tide line or ordinary high water
mark of a jurisdictional water.
The final rule redefines excluded ditches.
The final rule refines proposed exclusions (e.g., artificial lakes and ponds, certain water-fil ed depressions).
The final rule adds exclusions for features that were not previously excluded (e.g., stormwater management
structures and systems, water distributary and wastewater recycling structures, groundwater recharge basins,
puddles).
Waters That Are Categorically Jurisdictional
Under the first section of the revised regulation, the following six categories of waters would be
jurisdictional by rule without additional or case-specific analysis:
Waters susceptible to interstate commerce, known as traditional navigable waters
(no change from existing rules or the 2014 proposal);
All interstate waters, including interstate wetlands (no change from existing rules
or the 2014 proposal);
The territorial seas (no change from existing rules or 2014 the proposal);
Congressional Research Service
4
EPA and the Army Corps’ Rule to Define “Waters of the United States”
Figure 1. Jurisdictional Waters under the Final Clean Water Rule
(Not drawn to scale)
Source: Prepared by CRS, from Department of the Army, Corps of Engineers, and Environmental Protection
Agency, “Clean Water Rule: Definition of ‘Waters of the United States,’ Final Rule,” 80 Federal Register 37054-
37127, June 29, 2015.
Notes: “Jurisdictional by Rule” waters are jurisdictional per se without case-specific analysis. Other waters in
this figure may be jurisdictional if there is a significant nexus to a jurisdictional downstream water. See text for
discussion.
Tributaries of the above waters if they meet the definition of “tributary” (these
waters are jurisdictional under existing rules, but the term “tributary” is newly
defined in the proposed and final rule);
Impoundments of the above waters or a tributary, as defined in the rule (no
change from existing rules or the 2014 proposal); and
All waters, including wetlands, ponds, lakes, oxbows, and similar waters, that are
adjacent to a water identified in the above categories (these are considered
jurisdictional under the final rule because the agencies conclude that they have a
significant nexus to a traditional navigable water, interstate water, or the
territorial seas; the final rule provides a revised definition that for the first time
sets limits on what will be considered “adjacent”).
The concept of significant nexus is critical because courts have ruled that, to establish CWA
jurisdiction of waters, there needs to be “some measure of the significance of the connection for
downstream water quality,” as Justice Kennedy stated in the 2006 Rapanos case. He said, “Mere
hydrologic connection should not suffice in all cases; the connection may be too insubstantial for
the hydrologic linkage to establish the required nexus with navigable waters as traditionally
understood.”13 However, as EPA and the Corps observed in the proposed and final rules,
13 547 U.S. at 784-785.
Congressional Research Service
5
link to page 20 link to page 20 link to page 20 EPA and the Army Corps’ Rule to Define “Waters of the United States”
significant nexus is not itself a scientific term, but rather a determination made by the agencies in
light of the law, science, and the agencies’ experience and expertise. Functions that might
demonstrate significant nexus include sediment trapping and retention of flood waters. In the rule,
the agencies note that a hydrologic connection is not necessary to demonstrate significant nexus,
because the function may be demonstrated even in the absence of a connection (e.g., pollutant
trapping is another such function).
In the final rule, the agencies responded to comments that had requested some limits on the
definition of adjacent waters. Under the rule, a water that is adjacent to a jurisdictional water is
itself jurisdictional if it meets the related definition of “neighboring” (see Table 1). The final rule
establishes maximum distances, or specific boundaries from jurisdictional waters, for purposes of
defining “neighboring:”
1. all waters located in whole or in part within 100 feet of the ordinary high water
mark (OHWM)14 of a jurisdictional water;
2. all waters located in whole or in part within the 100-year floodplain15 that are not
more than 1,500 feet from the OHWM of a jurisdictional water;
3. all waters located in whole or in part within 1,500 feet of the high tide line of a
jurisdictional water and within 1,500 feet of the OHWM of the Great Lakes.
The entire water is “neighboring” if a portion of it is located within these defined boundaries.
Also, for purposes of adjacency, an open water such as a pond includes any wetlands within or
abutting its ordinary high water mark.
Under existing regulations, tributaries have been jurisdictional without qualification and were not
defined. In the final rule, a tributary can be natural or constructed, but it must have both a bed and
bank16 and ordinary high water mark to be categorically jurisdictional. A tributary as defined by
the rule does not lose its jurisdictional status even if there is one or more natural breaks (e.g., a
debris pile) or constructed/man-made breaks (e.g., a bridge or dam).
Waters Requiring Significant Nexus Analysis
Beyond the categories of waters that would be categorically jurisdictional under the rule are
waters that will be jurisdictional based on a determination that there is a significant nexus to a
jurisdictional downstream water. Under existing rules, the regulatory term “other waters” applies
to wetlands and non-wetland waters that do not fall into the category of waters that are
susceptible to interstate commerce (traditional navigable waters), interstate waters, the territorial
seas, tributaries, or waters adjacent to waters in one of these four categories. Existing regulations
contain a non-exclusive list of “other waters,” such as intrastate lakes, mudflats, prairie potholes,
and playa lakes (see Table 1). Headwaters, which constitute most “other waters,” supply most of
the water to downstream traditional navigable waters, interstate waters, and the territorial seas.
EPA and the Corps recognize that the Supreme Court decisions in SWANCC and Rapanos put
limitations on the scope of waters that may be determined to be jurisdictional under the CWA.
Much of the controversy since the Court’s rulings has focused on uncertainty as to what degree
14 Ordinary high water mark (OHWM) generally defines the lateral limits of a water. The term is defined in the final
rule; see Table 1.
15 The 100-year floodplain is the land that is predicted to flood during a 100-year storm, that is, a storm which has a 1%
chance of occurring in any given year.
16 In many tributaries, the bed is that part of the channel below the OHWM, and the banks often extend above the
OHWM.
Congressional Research Service
6
EPA and the Army Corps’ Rule to Define “Waters of the United States”
“other waters” are jurisdictional, either by definition/rule, or as determined on a case-by-case
basis to evaluate significant nexus to a jurisdictional water. In his opinion in the Rapanos case,
Justice Kennedy concluded that wetlands have the requisite significant nexus to a jurisdictional
water if the wetlands “either alone or in combination with similarly situated [wet]lands in the
region, significantly affect the chemical, physical, and biological integrity of other covered waters
more readily understood as ‘navigable.’”17
Since SWANCC, intrastate, non-navigable waterbodies (often referred to as geographically
isolated waters) for which the sole basis for asserting jurisdiction is interstate commerce are
excluded from jurisdiction, unless Corps and EPA Headquarters jointly approve case-specific
assertion of jurisdiction. Under the 2003 and 2008 guidance, which will be replaced by the new
rule, all other “other waters” have required a case-by-case evaluation to determine if a significant
nexus exists, thus providing a finding of CWA jurisdiction. There likewise has been uncertainty as
to what degree “other waters” that are not excluded from jurisdiction are similarly situated and
thus may be aggregated or combined for a significant nexus determination, as described by
Justice Kennedy in Rapanos.
In the proposed rule, “other waters,” including wetlands, that are adjacent to a jurisdictional water
were categorically jurisdictional. Non-adjacent “other waters” and wetlands would continue to
require a case-by-case determination of significant nexus. Also, the proposed rule allowed
broader aggregation of “other waters” that are similarly situated than under the existing
guidance,18 which could result in more “other waters” being found to be jurisdictional following a
significant nexus evaluation.
Some in the regulated community urged EPA and the Corps to provide metrics, such as
quantifiable flow rates or minimum number of functions for “other waters,” to establish a
significant nexus to jurisdictional waters. The agencies declined to do so in the proposed rule,
saying that absolute standards would not allow sufficient flexibility to account for variability of
conditions and the varied functions that different waters provide.
The agencies acknowledged that there may be more than one way to determine which “other
waters” are jurisdictional, and they requested comment on alternate approaches, combinations of
approaches, scientific and technical data, case law, and other information that would clarify which
“other waters” should be considered categorically jurisdictional or following a case-specific
significant nexus determination. In addition, they asked for public comment on whether to
conclude by rule that certain types of “other waters”—prairie potholes, pocosins, and perhaps
other categories of waters—have a significant nexus and are per se jurisdictional. These waters
would not require a case-by-case analysis.
The final rule no longer refers to “other waters,” but it establishes two defined sets of additional
waters that will be a “water of the United States” if they are determined to have a significant
nexus to a jurisdictional water. Under the rule, only these waters will require case-specific
evaluation, as others are either categorically jurisdictional or categorically excluded from
jurisdiction.
First are five subcategories of waters previously considered “other waters”: prairie potholes,
Carolina bays and Delmarva bays, pocosins, western vernal pools, and Texas coastal prairie
17 547 U.S. at 780.
18 Under the proposed rule, “other waters” could be aggregated for a significant nexus determination if they perform
similar functions and are located sufficiently close together to be evaluated as a single landscape unit in the same
watershed with regard to their effect on a jurisdictional downstream water.
Congressional Research Service
7
EPA and the Army Corps’ Rule to Define “Waters of the United States”
wetlands. Historically under existing rules (which the new rule will replace), these were “other
waters” and were jurisdictional if their use, degradation, or destruction could affect interstate or
foreign commerce. Since 2008, some waters in these categories (e.g., vernal pools, pocosins) that
are adjacent to a tributary system have been subject to case-specific significant nexus evaluation
to determine if jurisdiction applies. According to the Corps, broadly speaking, when a significant
nexus evaluation has been completed under the 2008 guidance on any type of aquatic resource, a
high percentage of those evaluations resulted in a finding of jurisdiction.19
In the final rule, based on reviewing the science concerning these types of waters, the agencies
concluded that waters within the five subcategories are “similarly situated” in areas of the country
where they are located (following Justice Kennedy’s opinion). Under the rule, they will be
jurisdictional if a significant nexus to downstream waters is found, based on case-specific
evaluation in combination with waters from the same subcategory in the same watershed. While
these subcategories of waters are not jurisdictional as a class under the final rule—as some
environmental advocates would prefer—the rule allows for case-specific analysis that may find
them to be a “water of the United States”20 and is likely to find them jurisdictional in most cases,
according to EPA.21
The second set of additional waters that require a significant nexus evaluation under the final rule
are waters located in whole or in part within the 100-year floodplain of a traditional navigable
water, interstate water, or the territorial seas and within 4,000 feet of the high tide line or OHWM
of a jurisdictional water. However, because waters located in the 100-year floodplain and within
1,500 feet of the OHWM of a jurisdictional water are “adjacent” under the new rule, they are
categorically jurisdictional. Thus, this second set of waters requiring a significant nexus analysis
really applies to waters located within the 100-year floodplain of a traditional navigable water,
interstate water, or the territorial seas that are between 1,500 feet and 4,000 feet of the OHWM of
a jurisdictional water.
As noted previously, one of the agencies’ goals in developing the new rule was to clarify its
requirements and lessen the number of instances requiring a time-consuming analysis to
determine if CWA jurisdiction applies. The final rule provides two specific categories or
subcategories of waters that will need a significant nexus evaluation, which is more limited than
under current field practice and the existing EPA-Corps guidance documents. Under the final rule,
waters other than these two types are either categorically jurisdictional or categorically excluded
from jurisdiction.
Exclusions and Definitions
The second section of the final rule excludes specified waters from the definition of “waters of
the United States.” The listed waters and features are not jurisdictional even if they would
otherwise be included within categories that are jurisdictional. The exclusions are:
Waste treatment systems, including treatment ponds or lagoons that are designed
to meet CWA requirements (no substantive change from existing rules or the
2014 proposal);
Prior converted cropland (no change from existing rules or the 2014 proposal);
19 U.S. Army Corps of Engineers, personal communication, June 5, 2015.
20 Also under the final rule, if a water in any of these subcategories meets the rule’s definition of “adjacent,” it is
jurisdictional without requiring a significant nexus determination.
21 Annie Snider, “In Major Shift, new Rule Excludes Some Wetlands, Ponds,” E&E News, May 28, 2015.
Congressional Research Service
8
link to page 20 link to page 16 link to page 16 link to page 20 EPA and the Army Corps’ Rule to Define “Waters of the United States”
A list of features that have been excluded by long-standing practice and guidance
and would now be excluded by rule, such as artificially irrigated areas that would
revert to dry land should application of irrigation water to the area cease;
artificial reflecting pools or swimming pools created in dry land; and puddles
(see Table 1 for the full list);
Groundwater (traditionally not regulated under the CWA and expressly excluded
under the rule);
Stormwater control features constructed to convey, treat, or store stormwater that
are created in dry land (new provision in the final rule responding to concerns
that the rule would adversely affect the ability of municipalities to operate and
maintain stormwater systems, including rain gardens and green infrastructure);
Constructed detention and retention basins created in dry land used for
wastewater recycling, as well as groundwater recharge basins and percolation
ponds built for wastewater recycling (new in the final rule, in response to public
comments); and
Three types of ditches: ditches with ephemeral flow that are not a relocated
tributary or excavated in a tributary; ditches with intermittent flow that are not a
relocated tributary, or excavated in a tributary, or that do not drain wetlands,
regardless of whether or not the wetland is a jurisdictional water; and ditches that
do not flow, either directly or through another water, to a traditional navigable
water, interstate water, impoundment, or the territorial seas, regardless of whether
the flow is ephemeral, intermittent, or perennial. The treatment of ditches was
one of the largest controversies of the proposed rule (see “Concerns of
Agriculture and Local Governments”). Under existing rules and long-standing
practice, many but not all ditches have been jurisdictional. The proposed rule for
the first time attempted to define which ditches are and are not protected under
the CWA, but the proposal was confusing and widely criticized. Under the final
rule, a ditch may be a “water of the United States” only if it meets the definition
of “tributary” and is not otherwise excluded under this provision.
The final rule makes no change to and does not affect existing statutory and regulatory
exclusions: exemptions for normal farming, ranching, and silviculture activities such as plowing,
seeding, and cultivation (CWA §404(f)); exemptions for permitting of agricultural stormwater
discharges and return flows from irrigated agriculture; or exemptions for water transfers that do
not introduce pollutants into a waterbody. Nor would it directly change permitting processes.
Definitions of key terms are included in the third section of the rule. Because definitions often are
critical to interpreting statutory law and regulations, some stakeholder groups criticized the
proposed rule, suggesting that the definitions would enable broader assertion of CWA jurisdiction
than is consistent with law and science. Many argued that several of the defined terms in the
proposal were confusing, and further that the proposed rule failed to define terms such as
“upland,” “gullies,” and “rills,” which they believed needed to be clarified.
The agencies responded in several ways (See Table 1):
In some cases, a particular term that was controversial with public commenters is
not used in the final rule, therefore no definition is needed (e.g., “upland”).
In some cases, the term is clarified in the preamble to the rule (e.g., “ephemeral,
intermittent, and perennial,” “bed and banks,” “dry land,” and “puddle”).
Congressional Research Service
9
EPA and the Army Corps’ Rule to Define “Waters of the United States”
In some cases, the rule was modified to clarify the term (e.g., “significant
nexus”).
In some cases, the agencies declined to add a definition if they concluded that
doing so might lead to more confusion (e.g., “ditch”).
Two terms defined in other Corps regulations are carried forward into the final
rule, without change, at the request of commenters (“ordinary high water mark”
and “high tide line”).
Finally, the agencies declined to define some terms that might have a narrow or
geographic-specific application that would not be appropriate for a national rule.
Definitions of two terms in the proposed rule (“riparian area” and “floodplain”) are omitted from
the final rule, although they are defined in the preamble to the new rule. Both terms had been
criticized by commenters for vagueness or ambiguity. Many requested that a specific floodplain
interval or other clear limitation be established. In the final rule, the agencies reference the “100-
year floodplain,” in part because the Federal Emergency Management Agency (FEMA) and
Natural Resources Conservation Service (NRCS) have mapped large portions of these areas in the
United States, producing maps that are publicly available, well known, and well understood. Also,
the agencies concluded that the use of “riparian area” was unnecessarily complicated and that, as
a general matter, waters in a riparian area will also be in the 100-year floodplain.22
Impacts of the Rule
Overall, EPA and the Corps say that their intent in the Clean Water rule was to clarify their
jurisdiction, in light of the Supreme Court’s ruling, not to expand it. Nevertheless, the agencies
acknowledge that the rule would increase the categorical assertion of CWA jurisdiction, when
compared to a baseline of current practices under the 2003 and 2008 EPA-Corps guidance. This
results in part from the agencies’ expressly declaring some types of waters categorically
jurisdictional and not requiring case-specific evaluation of them (such as all waters adjacent to a
jurisdictional water).
In changing the regulatory definition of “waters of the United States,” there may be instances in
which the CWA applies categorically for the first time, and there also may be instances in which
the CWA no longer applies (i.e., as a result of exemptions and exclusions). The agencies intend
that the rule will result in less ambiguity about whether the CWA applies than under existing
regulations, legal rulings, and guidance.
The agencies believe that the rule does not protect any new types of waters that have not been
protected historically (that is, beyond the existing regulations, which the new rule will replace)
and that it does not exceed the CWA’s coverage. That is, while it would enlarge categorical
jurisdiction beyond that under the 2003 and 2008 EPA-Corps guidance, which the agencies
believe was narrower than is justified by science and the law, they believe that it would not
enlarge jurisdiction beyond what is consistent with the Supreme Court’s current reading of
jurisdiction.
The agencies’ categorical assertion of waters that are jurisdictional, compared to current practice,
does not identify specific waters that will be found to be jurisdictional—i.e., a particular stream or
pond—but the rule attempts to draw more of a bright line of CWA jurisdiction than in the past.
22 Final Rule, p. 37082. The rule does not address changes that might result from future revisions to or updating of
FEMA and NRCS maps.
Congressional Research Service
10
EPA and the Army Corps’ Rule to Define “Waters of the United States”
Moreover, the agencies made a number of changes in the final rule to provide more certainty and
clarity, including “bright lines” of jurisdictional demarcation in several parts of the rule.
In an Economic Analysis document accompanying the final rule, the agencies estimate that the
new rule will result in 2.84%-4.65% more positive assertions of jurisdiction over U.S. waters,
compared with current field practice.23 However, compared with the agencies’ existing
regulations, the final rule reflects a reduction in waters protected by the CWA, according to EPA
and the Corps.
According to the analysis, costs to regulated entities and governments (federal, state, and local)
are likely to increase as a result of the rule, but the rule itself does not impose direct costs.
Indirect costs would result from additional permit application expenses (for CWA Section 404
permitting; stormwater permitting for construction and development activities; and permitting of
pesticide discharges and confined animal feeding operations [CAFOs] for discharges to waters
that would now be determined jurisdictional) and additional requirements for oil storage and
production facilities needing to develop and implement spill prevention, control and
countermeasure (SPCC) plans. Federal and state governments would likely experience about $1
million annually in additional costs to administer and process permits. Other costs would likely
include compensatory mitigation requirements for permit impacts (if applicable), affecting land
developers and state and local governments. The economic analysis considered two scenarios for
analyzing impacts of the rule. The agencies estimate that indirect costs associated with the final
rule range from $158 million to $307 million per year under a “low end” estimate and $237
million to $465 million per year under a “high end” estimate.24
The Section 404 program would see the greatest potential impact as a result of revised assertion
of CWA jurisdiction. Most of the projected costs are likely to affect landowners and development
companies, state and local governments investing in infrastructure, and industries involved in
resource extraction.
The agencies believe that indirect benefits accruing from the proposed rule include the value of
ecosystem services provided by the waters and wetlands protected as a result of CWA
requirements, such as habitat for aquatic and other species, support for recreational fishing and
hunting, and flood protection. Other benefits would include government savings on enforcement
expenses, because the rule is intended to provide greater regulatory certainty, thus reducing the
need for government enforcement. Business and government may also achieve savings from
reduced uncertainty concerning where CWA jurisdiction applies, they believe. In all, the agencies
estimate that benefits of the final rule range from $339 million to $350 million per year under a
“low end” estimate and $555 million to $572 million under a “high end” estimate. However, they
note that there is uncertainty and there are limitations associated with the results, due to data and
information gaps, as well as analytic challenges. The analysis does not quantify all possible costs
and benefits, and values are meant to be illustrative, not definitive.25 Overall, they conclude that
benefits would exceed costs.
23 U.S. Environmental Protection Agency and U.S. Department of the Army, Economic Analysis of the EPA-Army
Corps Clean Water Rule, May 2015, http://www2.epa.gov/cleanwaterrule/final-clean-water-rule-economic-analysis, p.
53. Hereinafter, Economic Analysis.
24 See the Economic Analysis for explanation and details.
25 Ibid., p. v.
Congressional Research Service
11
EPA and the Army Corps’ Rule to Define “Waters of the United States”
Concerns of Agriculture and Local Governments
The agriculture sector has been vigorous in criticizing and challenging EPA regulatory actions
that may affect the sector’s operations, making potential impacts of the proposed rule on
agriculture a likely focus of controversy. Even before release of the proposed rule, one of the
sector’s concerns about a new “waters of the United States” rule has been whether it would
modify existing statutory provisions that exempt “normal farming and ranching” practices from
dredge and fill permitting or others that exclude certain agricultural discharges, such as irrigation
return flow and stormwater runoff, from all CWA permitting. As described above, the final rule
makes no change and does not affect these exemptions, which are self-implementing. An EPA fact
sheet discusses the continued exclusions and exemptions.26 Another of agriculture’s concerns was
the proposed rule’s exclusion of some ditches; many said that the proposal was confusing and
could be interpreted as extending CWA jurisdiction to agricultural drainage ditches.
Simultaneous with announcing the Clean Water Rule in March 2014, EPA and the Corps issued
an interpretive rule that identified 56 conservation practices approved by the U.S. Department of
Agriculture’s Natural Resources Conservation Service (NRCS) that qualify for exemption under
the CWA Section 404(f)(1)(A) exclusion of “normal farming and ranching” activities from
Section 404 permit requirements and do not require determination whether the discharge involves
a “water of the United States.” Essentially, the interpretive rule was intended to provide guidance
to determine activities that qualify for 404(f)(1)(A) exemptions. The 56 practices, which are a
subset of all NRCS conservation practices, are practices such as stream crossings and wetland
restoration that take place in aquatic, riparian, or wetland environments. Through this interpretive
rule, the agencies intended to resolve uncertainties about “normal farming” activities that are
exempt from permitting when these conservation practices are used. In other words, effective
immediately, producers who utilize any of the 56 identified practices according to NRCS
technical standards would not need to seek a determination of CWA jurisdiction nor seek a CWA
permit. The three agencies also signed a Memorandum of Understanding detailing
implementation of the interpretive rule and identifying a process for reviewing and updating the
list of qualifying NRCS conservation practices. Although the interpretive rule became effective
immediately, EPA and the Corps accepted public comment until July 7, 2014.27
The interpretive rule was intended to clarify agricultural practices that are exempt from CWA
Section 404 permitting. Nevertheless, there was confusion about many issues, including NRCS’s
role in providing technical assistance to farmers with respect to 404 permitting, and the apparent
requirement that these practices had to meet NRCS technical standards to qualify for the
exemption. Public comments submitted on the interpretive rule were uniformly critical—
including comments submitted by agriculture stakeholder groups, environmental groups, and
some state environmental agencies. Agriculture groups argued that it was procedurally flawed,
because it would have substantive impact on farmers, and thus should have been subject to
notice-and-comment rulemaking procedures under the Administrative Procedure Act. Many also
26 See http://www2.epa.gov/sites/production/files/2014-03/documents/cwa_ag_exclusions_exemptions.pdf. Comments
submitted to the docket for the interpretive rule (Docket ID No. EPA-HQ-OW-2013-0820) are available at
http://www.regulations.gov.
27 Department of Defense, Department of the Army, Corps of Engineers, and Environmental Protection Agency,
“Notice of Availability Regarding the Exemption From Permitting Under Section 404(f)(1)(A) of the Clean Water Act
to Certain Agricultural Conservation Practices,” 79 Federal Register 22276, April 21, 2014.The list of practices, the
Memorandum of Understanding, and the interpretive rule are available at http://water.epa.gov/lawsregs/guidance/
wetlands/agriculture.cfm. USDA had no formal role in developing the Corps-EPA proposed rule, but it was among the
federal agencies commenting on it during interagency review.
Congressional Research Service
12
link to page 17 EPA and the Army Corps’ Rule to Define “Waters of the United States”
argued that the interpretive rule narrowed the CWA 404(f)(1)(A) statutory exemptions, because
the practices listed in the rule already were excluded from Section 404. Under the interpretive
rule, farmers would have to comply with NRCS standards in order to qualify for exemption,
resulting in a disincentive to conservation, they said. On the other hand, environmental groups
and some state environmental agencies were critical of the interpretive rule for different reasons.
They contended that it would exempt activities from permitting that are not truly associated with
ongoing farming and that the rule was thus too broad. Some of the listed practices, such as stream
crossings, can have significant harmful impacts on water quality and result in violations of state
water quality standards, they said.
EPA and Corps officials acknowledged that the 2014 interpretive rule did not appear to have had
the intended benefits of clarifying agricultural exemptions and exempting, not contracting, the
number of exempted activities, and they said that the agencies and U.S. Department of
Agriculture (USDA) were weighing alternatives to the rule. However, before the agencies
proposed or took action on the interpretive rule, in the FY2015 omnibus appropriations act,
passed in December 2014 (H.R. 83/P.L. 113-235), Congress included a provision directing EPA
and the Corps to withdraw it (see “Conclusion” below). On January 29, 2015, the agencies signed
a memorandum withdrawing the interpretive rule, effective immediately.28 Following Congress’s
action in December, the EPA Administrator indicated that the agency would work with USDA to
provide certainty to the regulated community, in a way that provides value both to the
government and the agriculture community. No further actions have been announced.
Local Government Concerns
Some local governments also criticized the proposed “waters of the United States” rule. In
particular, the National Association of Counties (NACo) argued that counties and other local
governments would be affected by the proposed rule in the arena of ditches. NACo pointed out
that local governments own and maintain public infrastructure including roadside ditches, flood
control channels, and stormwater management structures. Because the proposed rule would have
defined some ditches as “waters of the United States” if they meet certain conditions, NACo
contended that the proposal potentially increases the number of county-owned ditches under
federal jurisdiction. Permit requirements are not an issue, NACo says, but permitting can be time-
consuming and expensive.
EPA and Corps officials believed that exclusion of most ditches in the proposed rule actually
would decrease federal jurisdiction over ditches. But the issue remained controversial and was
addressed with modifications in the final rule. The agencies believe that the exclusions included
in the final rule will address the vast majority of roadside and other transportation ditches, as well
as ditches on agricultural lands.29
Conclusion
The EPA Administrator stated at a congressional hearing in 2014 that it generally takes about one
year to finalize a rule. Complex and controversial rules often take much longer from proposal to
promulgation. This rule to define “waters of the United States” was finalized 14 months after the
proposed rule was announced.
28 Environmental Protection Agency and Department of Defense, “Notice of Withdrawal,” 80 Federal Register 6705,
February 6, 2015.
29 Final Rule, p. 37097.
Congressional Research Service
13
EPA and the Army Corps’ Rule to Define “Waters of the United States”
Legal challenges are likely to delay implementation of any rule for years. New regulations may
clarify many current questions, but they are unlikely to please all of the competing interests, as
one environmental advocate observed.
However, a rulemaking would only benefit wetlands if it did not reduce the jurisdiction
offered by current regulations and if the Administration remained faithful to sound
science. If politics were to trump science in the rulemaking process, the likelihood of
such a protective rule would not be promising. Also, rules are subject to legal challenge
and can be tied up in court for years before they are implemented.30
Another consideration is possible action by Congress, even though a final rule has been
promulgated. Congressional interest in the rule has been strong since the proposed rule was
announced in March 2014. Hearings were held during the 113th Congress and have continued in
the 114th Congress; bills to bar the agencies from finalizing the proposed rule or otherwise alter
the agencies’ course regarding the rule have been introduced. (For information, see CRS Report
R43943, EPA and the Army Corps’ “Waters of the United States” Rule: Congressional Response
and Options, by Claudia Copeland.)
Many critics in Congress and elsewhere urged that the proposed Clean Water Rule be withdrawn,
or that the agencies propose a supplemental rule, subject to another round of public comments.
EPA and Corps officials pointed out that doing so would leave in place the status quo—with
determinations of CWA jurisdiction being made by 38 Corps districts pursuant to existing
regulations, coupled with non-binding agency guidance, and many of these determinations
involving time-consuming case-specific evaluation.
Some industry and agriculture groups that had criticized the status quo in the past said more
recently that they preferred it to the 2014 proposed rule, which they believed was ambiguous and
overly broad. EPA and Corps officials believe that the final rule responds to those criticisms. The
agencies’ intention has been to clarify the rules and make jurisdictional determinations more
predictable, less ambiguous, and more timely. Based on press reports of stakeholders’ early
reactions to the final rule, some believe that the agencies largely succeeded in that objective,
while others believe that they did not.31
Recent Developments
Legal challenges to the Clean Water Rule were filed in multiple federal courts soon after it was
announced. These lawsuits, filed by industry groups, more than half of the states, and several
environmental groups (nearly 90 plaintiffs so far), will test whether the agencies’ interpretation of
CWA jurisdiction is consistent with the Supreme Court’s rulings and whether the rule complies
with substantive and procedural requirements of the CWA and other laws.
Because of uncertainty about the correct judicial venue for challenging the rule,32 petitions for
review have been filed both in federal district courts and courts of appeal. As of December 1,
30 James Murphy, “Rapanos v. United States: Wading Through Murky Waters,” National Wetlands Newsletter, vol. 28,
no. 5, September-October 2006, p. 19.
31 See, for example, Amena H. Saiyid, “Obama Says Water Jurisdiction Rule Provides Clarity, Certainty; Critics Claim
Overreach,” Daily Environment Report, May 28, 2015, p. A-1. Also see releases from organizations such as the
American Farm Bureau Federation, “Final ‘Waters of the U.S.’ Rule: No, No, No! No Clarity, No Certainty, No Limits
on Agency Power,” June 11, 2015 (http://www.fb.org/index.php?action=newsroom.news_article&id=311); and the
National Association of Counties, “NACo Voices Concern on Final ‘Waters of the U.S.’ Rule,” June 8, 2015
(http://www.naco.org/legislation/WW/Lists/Posts/Post.aspx?ID=1037).
32 The judicial review section of the CWA, Section 509, vests exclusive, original review jurisdiction over enumerated
(continued...)
Congressional Research Service
14
EPA and the Army Corps’ Rule to Define “Waters of the United States”
2015, petitions for review of the rule have been filed in eight appellate courts; most have been
consolidated in the Sixth Circuit. Sixteen separate challenges also were filed in 12 federal district
courts. On October 9, a three-judge panel of the U.S. Court of Appeals for the Sixth Circuit
placed a nationwide stay on the 2015 rule, pending further developments, including the need to
determine the court’s own jurisdictional authority.33 On the substance of the complaints, the court
said there was a good chance that the plaintiffs would prevail on the merits. A two-judge majority
said that the significance of the new rule warranted leaving the prior regulatory regime in place,
while the third judge said that until the question of subject-matter jurisdiction is answered, the
new rule should not be stayed.34 The Sixth Circuit court heard arguments on December 8 on
whether it has exclusive jurisdiction to review the rule, but the court has not yet issued its ruling.
As a result of the court’s order, the Corps and EPA will continue to make CWA jurisdictional
determinations based on the 2008 guidance, as they did before promulgation of the 2015 rule.
(...continued)
EPA actions under the act in the federal courts of appeals. The initial issue with Section 509 is that none of the listed
EPA actions clearly cover the Clean Water Rule. Indeed, in the preamble to the final rule, EPA and the Corps
acknowledge that “[t]he Supreme Court and lower courts have reached different conclusions on the types of actions
that fall within section 509,” and offers no opinion of its own as to review of the Clean Water Rule. If a court finds that
the rule is not covered by Section 509, review jurisdiction presumably will lie in the district courts pursuant to the
federal question statute. That statute, applicable where no more specific statute provides otherwise, gives the district
courts original jurisdiction over “all civil actions arising under the ... laws ... of the United States.” (28 U.S.C. §1331)
See CRS Legal Sidebar WSLG1369, The EPA/Corps Clean Water Rule: What Court or Courts Get to Rule on the
Legal Challenges?
33 On August 27, a district court in North Dakota issued a preliminary injunction that blocked implementation of the
rule in 13 states, but not in the remaining 37 states.
34 In re Environmental Protection Agency and Department of Defense, Nos. 15-3799 et al. (6th Cir., Oct. 9, 2015),
http://www.ca6.uscourts.gov/opions.pdf/15a0246p-06.pdf.
Congressional Research Service
15
link to page 32 link to page 32
Table 1. Comparison of “Definition of Waters of the United States” Regulatory Language
Existing Regulatory Language, 2014 Proposed Rule, and Revised Language in Final Rule Announced May 27, 2015
Existing Regulatory Languagea
Proposed Regulatory Language
Revised Regulatory Language
Commentsb
(a) The term waters of the United States
(a) For purposes of all sections of the
(a) For purposes of all sections of the
means
Clean Water Act, 33 U.S.C. 1251 et seq.
Clean Water Act, 33 U.S.C. 1251 et seq.
and its implementing regulations, subject
and its implementing regulations, subject
to the exclusions in subsection (b) of this to the exclusions in subsection (b) of this
section, the term “waters of the United
section, the term “waters of the United
States” means:
States” means:
(1) All waters which are currently used,
(1) All waters which are currently used,
(1) All waters which are currently used,
These waters are often referred to as
or were used in the past, or may be
were used in the past, or may be
were used in the past, or may be
“traditional navigable waters” (TNWs),
susceptible to use in interstate or foreign susceptible to use in interstate or foreign susceptible to use in interstate or foreign which include but are not limited to the
commerce, including all waters which are commerce, including all waters which are commerce, including all waters which are “navigable waters of the United States”
subject to the ebb and flow of the tide;
subject to the ebb and flow of the tide;
subject to the ebb and flow of the tide;
within the meaning of Section 10 of the
Rivers and Harbors Act of 1899. No
change from the existing rule or 2014
proposal.
(2) All interstate waters including
(2) All interstate waters, including
(2) All interstate waters, including
These waters include tributaries to
interstate wetlands;
interstate wetlands;
interstate wetlands;
interstate waters, waters adjacent to
interstate waters, waters adjacent to
tributaries of interstate waters, and
others that have a significant nexus to
interstate waters. No change from the
existing rule or 2014 proposal. Interstate
waters would continue to be “waters of
the United States” even if they are not
navigable in fact and do not connect to
such waters.
(3) All other waters such as intrastate
(7) On a case-specific basis, other
(7) All waters in paragraphs (i) through
In the existing rule, there is a non-
lakes, rivers, streams (including
waters, including wetlands, provided that
(v) of this paragraph where they are
exclusive list of the types of “other
intermittent streams), mudflats, sandflats, those waters alone, or in combination
determined, on a case-specific basis, to
waters” which may be found to be
wetlands, sloughs, prairie potholes, wet
with other similarly situated waters,
have a significant nexus to a water
“waters of the U.S.”
meadows, playa lakes, or natural ponds,
including wetlands, located in the same
identified in paragraphs (a)(1) through
The existing description is omitted under
the use, degradation or destruction of
region, have a significant nexus to a
(3) of this section. The waters identified
the final rule as unnecessary and
which could affect interstate or foreign
water identified in paragraphs (a)(1)
in paragraphs (i) through (v) of this
confusing because it has been incorrectly
commerce including any such waters:
through (3) of this section.
paragraph are similarly situated and shall
read as an exclusive list.
(i) Which are or could be used by
be combined, for purposes of a
CRS-16
link to page 32 link to page 32
Existing Regulatory Languagea
Proposed Regulatory Language
Revised Regulatory Language
Commentsb
interstate or foreign travelers for
significant nexus analysis, in the
Under the final rule, the five
recreational or other purposes; or
watershed that drains to the nearest
subcategories of waters listed in this
(ii) From which fish or shellfish are or
water identified in paragraphs (a)(1)
paragraph are not jurisdictional as a
could be taken and sold in interstate or
through (3) of this section. Waters
single category or class, but the agencies
foreign commerce; or
identified in this paragraph shall not be
have determined that they are similarly
combined with waters identified in
situated because they perform similar
(ii ) Which are or could be used for
paragraph (a)(6) of this section when
functions and are located sufficiently
industrial purpose by industries in
performing a significant nexus analysis. If
close to each other to function together
interstate commerce;
waters identified in this paragraph are
in affecting downstream waters.
also an adjacent water under paragraph
Therefore, EPA and the Corps believe
(a)(6), they are an adjacent water and no
that it is reasonable that these waters be
case-specific significant nexus analysis is
evaluated in combination (i.e., prairie
required.
potholes with prairie potholes) for
(i) Prairie potholes. Prairie potholes are a
purposes of a case-specific significant
complex of glacially formed wetlands,
nexus. They may be evaluated either
usually occurring in depressions that lack
individually or as a group of waters in a
permanent natural outlets, located in the
region, meaning the watershed that
upper Midwest.
drains to the nearest traditional
navigable water, interstate water, or the
(ii) Carolina bays and Delmarva bays.
territorial seas through a single point of
Carolina bays and Delmarva bays are
entry.
ponded, depressional wetlands that
occur along the Atlantic coastal plain.
(ii ) Pocosins. Pocosins are evergreen
shrub- and tree-dominated wetlands
found predominantly along the Central
Atlantic coastal plain.
(iv) Western vernal pools. Western vernal
pools are seasonal wetlands located in
parts of California and associated with
topographic depression, soils with poor
drainage, mild, wet winters and hot, dry
summers.
(v) Texas coastal prairie wetlands. Texas
coastal prairie wetlands are freshwater
wetlands that occur as a mosaic of
depressions, ridges, intermound flats,
and mima mound wetlands located along
CRS-17
link to page 32 link to page 32
Existing Regulatory Languagea
Proposed Regulatory Language
Revised Regulatory Language
Commentsb
the Texas Gulf Coast.
(8) All waters located within the 100-
For these waters, the agencies have not
year floodplain of a water identified in
made a determination that the waters
(a)(1) through (3) of this section and all
are “similarly situated” (unlike the
waters located within 4,000 feet of the
waters described in paragraph (a)(7)). As
high tide line or ordinary high water
a result, a significant nexus analysis for
mark of a water identified in paragraphs
these waters wil include a case-specific
(a)(1) through (5) of this section where
assessment of whether there are any
they are determined on a case-specific
similarly situated waters, as well as
basis to have a significant nexus to a
whether the water, alone or in
water identified in paragraphs (a)(1)
combination with any waters determined
through (3) of this section. For waters
to be similarly situated, has a significant
determined to have a significant nexus,
nexus to a traditional navigable water,
the entire water is a water of the United
interstate water, or territorial seas.
States if a portion is located within the
In a change from the proposed rule, the
100-year floodplain of a water identified
final rule sets a distance threshold for
in (a)(1) through (3) of this section or
case-specific evaluation of these waters
within 4,000 feet of the high tide line or
for significant nexus. In addition to
ordinary high water mark. Waters
distance, aquatic functions wil play a
identified in this paragraph shall not be
prominent role in determining whether
combined with waters identified in
specific waters covered by this paragraph
paragraph (a)(6) of this section when
have a significant nexus.
performing a significant nexus analysis. If
waters identified in this paragraph are
also an adjacent water under paragraph
(a)(6), they are an adjacent water, and no
case-specific significant nexus is required.
(4) All impoundments of waters
(4) All impoundments of waters
(4) All impoundments of waters
Impoundments of a traditional navigable
otherwise defined as waters of the
identified in paragraphs (a)(1) through
otherwise identified as waters of the
water, interstate water, the territorial
United States under the definition;
(3) and (5) of this section;
United States under this section;
seas, or a tributary are jurisdictional by
rule.
As a matter of policy and law,
impoundments do not de-federalize a
water, even where there is no longer
flow below the impoundment. That is,
damming or impounding a water of the
United States does not make the water
CRS-18
link to page 32 link to page 32
Existing Regulatory Languagea
Proposed Regulatory Language
Revised Regulatory Language
Commentsb
non-jurisdictional.
(5) Tributaries of waters identified in
(5) All tributaries of waters identified in
(5) All tributaries, as defined in
Tributaries, as defined in the final rule, of
paragraphs (a)(1) through (4) of this
paragraphs (a)(1) through (4) of this
paragraph (c)(3) of this section, of
a traditional navigable water, interstate
section;
section;
waters identified in paragraphs (a)(1)
water, the territorial seas, or an
through (3) of this section;
impoundment would be jurisdictional by
rule and do not require a case-specific
significant nexus analysis.
Unless excluded under subsection (b) of
the rule, any water that meets the rule’s
definition of tributary is a water of the
United States. Waters that meet the
rule’s definition of tributary remain
tributaries even if there is a manmade or
natural break at some point along the
connection to the traditional navigable
water, interstate water, or the territorial
sea, so long as bed and banks and an
ordinary high water mark are present
upstream of the break.
“Tributary” is defined below. It includes
natural, undisturbed waters and those
that have been man-altered or
constructed, but which science shows
function as a tributary.
(6) The territorial seas;
(3) The territorial seas;
(3) The territorial seas;
This term establishes the seaward limit
of “waters of the United States.”
Jurisdictional by rule; no change from the
existing rule. The term generally refers
to the part of the ocean immediately
adjacent to shoreline and extending
seaward up to 12 miles.
CRS-19
link to page 32 link to page 32 link to page 32 link to page 32
Existing Regulatory Languagea
Proposed Regulatory Language
Revised Regulatory Language
Commentsb
(7) Wetlands adjacent to waters (other
(6) All waters, including wetlands,
(6) All waters adjacent to a water
All waters adjacent to a traditional
than waters that are themselves
adjacent to a water identified in
identified in paragraphs (a)(1) through
navigable water, interstate water, the
wetlands) identified in paragraphs (a)(1)
paragraphs (a)(1) through (5) of this
(5) of this section, including wetlands,
territorial seas, impoundment, or
through (6) of this section.
section; and
ponds, lakes, oxbows, impoundments,
tributary would be jurisdictional by rule.
and similar waters;
Under the rule, an adjacent water
includes wetlands within or abutting its
ordinary high water mark. Waters
separated by a berm or other similar
feature remain “adjacent.”
(b) The following are not “waters
(b) The following are not “waters
of the United States”
of the United States”
(8) Waters of the United States do not
(2) Prior converted cropland.
(2) Prior converted cropland.
No change proposed.
include prior converted cropland.c
Notwithstanding the determination of an
Notwithstanding the determination of an
Notwithstanding the determination of an
area’s status as prior converted cropland
area’s status as prior converted cropland
area’s status as prior converted cropland
by any other federal agency, for the
by any other federal agency, for the
by any other Federal agency, for the
purposes of the Clean Water Act, the
purposes of the Clean Water Act, the
purposes of the Clean Water Act, the
final authority regarding Clean Water
final authority regarding Clean Water
final authority regarding Clean Water
Act jurisdiction remains with EPA.
Act jurisdiction remains with EPA.
Act jurisdiction remains with EPA.
Waste treatment systems, including
(1) Waste treatment systems, including
(1) Waste treatment systems, including
The agencies do not believe that
treatment ponds or lagoons designed to
treatment ponds or lagoons, designed to
treatment ponds or lagoons designed to
omitting the parenthetical reference to
meet the requirements of CWA (other
meet the requirements of the Clean
meet the requirements of the Clean
40 C.F.R. 423.11(m) is a change in
than cooling ponds as defined in 40
Water Act.
Water Act.
substance to the waste treatment
C.F.R. 423.11(m) which also meet the
exclusion or how it is applied.
criteria of this definition) are not waters
of the United States.d
(3) Ditches that are excavated whol y in
(3) The fol owing ditches:
Under the final rule, a ditch may be a
uplands, drain only uplands or non-
(i) Ditches with ephemeral flow that are
“water of the United States” only if it
jurisdictional waters, and have less than
not a relocated tributary or excavated in
meets the definition of “tributary” and is
perennial flow.
a tributary.
not excluded under this subparagraph.
(ii) Ditches with intermittent flow that
The final rule codifies and clarifies long-
(4) Ditches that do not contribute flow,
are not a relocated tributary, excavated
standing practice and guidance (including
either directly or through another water, in a tributary, or drain wetlands.
1986 and 1988 preamble language),
to a water identified in paragraphs (a)(1)
which has been to exclude these waters
(ii ) Ditches that do not flow, either
through (4) of this section.
from jurisdiction.
directly or through another water, into a
CRS-20
link to page 32 link to page 32
Existing Regulatory Languagea
Proposed Regulatory Language
Revised Regulatory Language
Commentsb
water identified in paragraphs (a)(1)
A ditch that relocates a stream is not an
through (3) of this section.
excluded ditch, and a stream is relocated
either when at least a portion of its
original channel has been physically
moved, or when the majority of its flow
has been redirected.
If a ditch has been cut to carry
intermittent or perennial flow from a
wetland, the ditch is serving as a conduit
for transferring flow from a wetland to a
downstream water. Thus, the ditch has
changed the wetland’s hydrologic regime,
and the segment of the ditch that
physically intersects the wetland would
be considered jurisdictional.
The final rule confirms long-standing
policy that ditches may function as point
sources that discharge pol utants, thus
subject to CWA Section 402.
(5) The fol owing features:
(4) The fol owing features:
The final rule codifies long-standing
(i) Artificial y irrigated areas that would
(i) Artificial y irrigated areas that would
practice and guidance (including 1986
revert to upland should application of
revert to dry land should application of
and 1988 preamble language), which has
irrigation water to that area cease;
water to that area cease;
been to exclude these waters from
jurisdiction. These waters would not be
(ii) artificial lakes or ponds created by
(ii) Artificial, constructed lakes and
jurisdictional by rule. The final rule is
excavating and/or diking dry land and
ponds created in dry land such as farm
revised to omit terms that were
used exclusively for such purposes as
and stock watering ponds, irrigation
confusing in the proposal (e.g., “upland”)
stock watering, irrigation, settling basins,
ponds, settling basins, fields flooded for
and clarify others (e.g., “water-fil ed
or rice growing;
rice growing, log cleaning ponds, or
depressions”).
(ii ) artificial reflecting pools or swimming cooling ponds;
The list of excluded features is
pools created by excavating and/or
(ii ) Artificial reflecting pools or
il ustrative, not exhaustive.
diking dry land;
swimming pools created in dry land;
(iv) small ornamental waters created by
(iv) Small ornamental waters created in
excavating and/or diking dry land for
dry land;
primarily aesthetic reasons;
(v) Water-fil ed depressions created in
(v) water-fil ed depressions created
dry land incidental to mining or
incidental to construction activity;
construction activity, including pits
CRS-21
link to page 32 link to page 32
Existing Regulatory Languagea
Proposed Regulatory Language
Revised Regulatory Language
Commentsb
(vi) groundwater, including groundwater
excavated for obtaining fil , sand, or
drained through subsurface drainage
gravel that fil with water;
systems; and
(vi) Erosional features, including gul ies,
(vii) gul ies and ril s and non-wetland
ril s, and other ephemeral features that
swales.
do not meet the definition of tributary,
non-wetland swales, and lawful y
constructed grassed waterways; and
(vii) Puddles.
(5) Groundwater, including groundwater
The exclusion does not apply to surface
drained through subsurface drainage
expressions of groundwater, such as
systems.
where groundwater emerges on the
surface and becomes baseflow in streams
or spring fed ponds.
(6) Stormwater control features
The exclusion is intended to address
constructed to convey, treat, or store
engineered stormwater control
stormwater that are created in dry land.
structures in municipal or urban
environments.
It is intended to exclude the diverse
range of stormwater control features
that are currently in place, such as rain
gardens, low impact development and
flood control systems, and may be
developed in the future.
(7) Wastewater recycling structures
This exclusion codifies long-standing
constructed in dry land; detention and
agency practice and encourages water
retention basins build for wastewater
management practices that the agencies
recycling; groundwater recharge basins;
agree are important and beneficial.
percolation ponds built for wastewater
recycling; and water distributary
structures built for wastewater recycling.
(c) Definitions—
(c) Definitions—In this section, the
fol owing definitions apply:
(b) The term wetlands means those areas
(6) Wetlands: The term wetlands means (4) Wetlands. The term wetlands means
No change.
that are inundated or saturated by
those areas that are inundated or
those areas that are inundated or
Wetlands are ecosystems that often
surface or ground water at a frequency
saturated by surface or ground water at
saturated by surface or groundwater at a occur at the edge of aquatic (water,
CRS-22
link to page 32 link to page 32
Existing Regulatory Languagea
Proposed Regulatory Language
Revised Regulatory Language
Commentsb
and duration sufficient to support, and
a frequency and duration sufficient to
frequency and duration sufficient to
fresh or salty) or terrestrial (upland)
that under normal circumstances do
support, and that under normal
support, and that, under normal
systems. Wetlands typically represent
support, a prevalence of vegetation
circumstances do support, a prevalence
circumstances, do support, a prevalence
transitional zones between aquatic and
typically adapted for life in saturated soil
of vegetation typically adapted for life in
of vegetation typically adapted for life in
upland systems.
conditions. Wetlands generally include
saturated soil conditions. Wetlands
saturated soil conditions. Wetlands
swamps, marshes, bogs, and similar
generally include swamps, marshes, bogs,
generally include swamps, marshes, bogs,
areas.
and similar areas.
and similar areas.
(c) The term adjacent means bordering,
(1) Adjacent: The term adjacent means
(1) Adjacent. The term adjacent means
The rule includes wetlands and other
contiguous, or neighboring. Wetlands
bordering, contiguous or neighboring.
bordering, contiguous, or neighboring a
waters that meet the definition of
separated from other waters of the
Waters, including wetlands, separated
water identified in paragraphs (a)(1)
adjacent, including “neighboring,” which
United States by man-made dikes or
from other waters of the United States
through (5) of this section, including
is defined separately.
barriers, natural river berms, beach
by man-made dikes or barriers, natural
waters separated by constructed dikes
Only waters, not land, are adjacent.
dunes and the like are ‘ adjacent
river berms, beach dunes and the like
or barriers, natural river berms, beach
wetlands.’
are “adjacent waters.”
dunes, and the like. For purposes of
Within the definition of “adjacent,” the
adjacency, an open water such as a pond
terms bordering and contiguous are well
or lake includes any wetlands within or
understood, and the agencies wil
abutting its ordinary high water mark.
continue to interpret and implement
Adjacency is not limited to waters
those terms consistent with current
located laterally to a water identified in
policy and practice.
paragraphs (a)(1) through (5) of this
section. Adjacent waters also include all
waters that connect segments of a water
identified in paragraphs (a)(1) through
(5) or are located at the head of a water
identified in paragraphs (a)(1) through
(5) of this section and are bordering,
contiguous, or neighboring such waters.
Waters being used for established
normal farming, ranching, and silviculture
activities (33 U.S.C. 1344(f)) are not
adjacent.
(d) The term high tide line means the line
No change proposed
(7) High tide line. The term high tide line
of intersection of the land with the
means the line of intersection of the land
water’s surface at the maximum height
with the water’s surface at the maximum
reached by a rising tide. The high tide
height reached by a rising tide. The high
line may be determined, in the absence
tide line may be determined, in the
of actual data, by a line of oil or scum
absence of actual data, by a line of oil or
along shore objects, a more or less
scum along shore objects, a more or less
CRS-23
link to page 32 link to page 32
Existing Regulatory Languagea
Proposed Regulatory Language
Revised Regulatory Language
Commentsb
continuous deposit of fine shell or debris
continuous deposit of fine shell or debris
on the foreshore or berm, other physical
on the foreshore or berm, other physical
markings or characteristics, vegetation
markings or characteristics, vegetation
lines, tidal gages, or other suitable means
lines, tidal gages, or other suitable means
that delineate the general height reached
that delineate the general height reached
by a rising tide. The line encompasses
by a rising tide. The line encompasses
spring high tides and other high tides
spring high tides and other high tides
that occur with periodic frequency but
that occur with periodic frequency but
does not include storm surges in which
does not include storm surges in which
there is a departure from the normal or
there is a departure from the normal or
predicted reach of the tide due to the
predicted reach of the tide due to the
piling up of water against a coast by
piling up of water against a coast by
strong winds, such as those
strong winds such as those
accompanying a hurricane or other
accompanying a hurricane or other
intense storm.
intense storm.
(e) The term ordinary high water mark
No change proposed
(6) Ordinary high water mark. The term
“Ordinary high water mark” sets the
means that line on the shore established
ordinary high water mark means that line
boundary of adjacent non-wetland
by the fluctuations of water and
on the shore established by the
waters (e.g., open waters such as lakes
indicated by physical characteristics such
fluctuations of water and indicated by
and ponds).
as clear, natural line impressed on the
physical characteristics such as a clear,
Physical indicators of ordinary high water
bank, shelving, changes in the character
natural line impressed on the bank,
mark can be created by perennial,
of soil, destruction of terrestrial
shelving, changes in the character of soil,
intermittent, and ephemeral flows.
vegetation, the presence of litter and
destruction of terrestrial vegetation, the
debris, or other appropriate means that
presence of litter and debris, or other
consider the characteristics of the
appropriate means that consider the
surrounding area.
characteristics of the surrounding area.
(2) Neighboring: The term neighboring,
(2) Neighboring. The term neighboring
“Neighboring” is the key determinant of
for purposes of the term “adjacent” in
means:
whether a water is “adjacent,” and thus
this section, includes waters located
(i) All waters located within 100 feet of
jurisdictional by rule.
within the riparian area or floodplain of a the ordinary high water mark of a water Where the 100-year floodplain is greater
water identified in paragraphs (a)(1)
identified in paragraphs (a)(1) through
than 1,500 feet, all wetlands within 1,500
through (a)(5) of this section, or waters
(5) of this section. The entire water is
feet of the tributary’s ordinary high
with a surface or shallow subsurface
neighboring if a portion is located within
water mark are jurisdictional because
hydrologic connection to such a
100 feet of the ordinary high water
they are “neighboring” to the tributary,
jurisdictional water.
mark;
regardless of the wetland’s position
(ii) Al waters located within the 100-
relative to each other.
year floodplain of a water identified in
Waters within the 100-year floodplain
CRS-24
link to page 32 link to page 32
Existing Regulatory Languagea
Proposed Regulatory Language
Revised Regulatory Language
Commentsb
paragraphs (a)(1) through (5) of this
that are located more than 1,500 feet
section and not more than 1,500 feet
and up to 4,000 feet from the ordinary
from the ordinary high water mark of
high water mark, or high tide line, are
such water. The entire water is
subject to case-specific significant nexus
neighboring if a portion is located within
analysis under paragraph (a)(8).
1,500 feet of the ordinary high water
mark and within the 100-year floodplain;
(ii ) All waters located within 1,500 feet
of the high tide line of a water identified
in paragraphs (a)(1) or (a)(3) of this
section, and all waters within 1,500 feet
of the ordinary high water mark of the
Great Lakes. The entire water is
neighboring if a portion is located within
1,500 feet of the high tide line or within
1,500 feet of the ordinary high water
mark of the Great Lakes.
(3) Riparian area: The term riparian
Omitted in the final rule because the
area means an area bordering a water
agencies determined that the use of the
where surface or subsurface hydrology
riparian area was unnecessarily
influence the ecological processes and
complicated and that as a general matter,
plant and animal community structure in
waters within the riparian area wil be
that area. Riparian areas are transitional
within the 100-year floodplain.
areas between aquatic and terrestrial
ecosystems that influence the exchange
of energy and materials between those
ecosystems.
(4) Floodplain: The term floodplain
Omitted in the final rule, which uses
means an area bordering inland or
reference to 100-year floodplain in order
coastal waters that was formed by
to more clearly identify the outer limit of
sediment deposition from such water
“neighborning.”
under present climatic conditions and is
inundated during periods of moderate to
high water flows.
(5) Tributary: The term tributary means
(3) Tributary and tributaries. The terms
This term has not previously been
a waterbody physically characterized by
tributary and tributaries each mean a
defined in any regulation or preamble.
the presence of a bed and banks and
water that contributes flow, either
Bed and banks and ordinary high water
CRS-25
link to page 32 link to page 32
Existing Regulatory Languagea
Proposed Regulatory Language
Revised Regulatory Language
Commentsb
ordinary high water mark, as defined at
directly or through another water
mark (OHWM) are features that
33 C.F.R. §328.3(e), which contributes
(including an impoundment identified in
generally are physical indicators of flow.
flow, either directly or through another
paragraph (a)(4) of this section), to a
OHWM generally defines the lateral
water, to a water identified in paragraphs water identified in paragraphs (a)(1)
limits of a water. In many tributaries, the
(a)(1) through (4) of this section. In
through (3) of this section that is
bed is that part of the channel below the
addition, wetlands, lakes, and ponds are
characterized by the presence of the
OHWM, and the banks often extend
tributaries (even if they lack a bed and
physical indicators of a bed and banks
above the OHWM.
banks or ordinary high water mark) if
and an ordinary high water mark. These
Man-altered and man-made tributaries
they contribute flow, either directly or
physical indicators demonstrate there is
perform many of the same functions as
through another water to a water
volume, frequency, and duration of flow
natural tributaries and provide
identified in paragraphs (a)(1) through
sufficient to create a bed and banks and
connectivity between streams and
(3) of this section. A water that
an ordinary high water mark, and thus to downstream rivers.
otherwise qualifies as a tributary under
qualify as a tributary. A tributary can be a
this definition does not lose its status as
natural, man-altered, or man-made water
a tributary if, for any length, there are
and includes waters such as rivers,
one or more man-made breaks (such as
streams, canals, and ditches not excluded
bridges, culverts, pipes, or dams) or one
under paragraph (b) of this section. A
or more natural breaks (such as
water that otherwise qualifies as a
wetlands at the head of or along the run
tributary under this definition does not
of a stream, debris piles, boulder fields,
lose its status as a tributary if, for any
or a stream that flows underground) so
length, there are one or more
long as a bed and banks and an ordinary
constructed breaks (such as bridges,
high water mark can be identified
culverts, pipes, or dams), or one or
upstream of the break. A tributary,
more natural breaks (such as wetlands
including wetlands, can be a natural,
along the run of a stream, debris piles,
man-altered, or man-made waterbody
boulder fields, or a stream that flows
and includes waters such as rivers,
underground) so long as a bed and banks
streams, lakes, ponds, impoundments,
and an ordinary high water mark can be
canals, and ditches not excluded in
identified upstream of the break. A
paragraph (b)(3) or (4) of this section.
water that otherwise qualifies as a
tributary under this definition does not
lose its status as a tributary if it
contributes flow through a water of the
United States that does not meet the
definition of tributary or through a non-
jurisdictional water to a water identified
in paragraphs (a)(1) through (3) of this
section.
CRS-26
link to page 32 link to page 32 link to page 32
Existing Regulatory Languagea
Proposed Regulatory Language
Revised Regulatory Language
Commentsb
(7) Significant nexus: The term
(8) Significant nexus. The term significant
In the final rule, the agencies list specific
significant nexus means that a water,
nexus means that a water, including
functions relevant to significant nexus
including wetlands, either alone or in
wetlands, either alone or in combination
evaluation to add clarity and
combination with other similarly situated
with other similarly situated waters in
transparency. A water does not need to
waters in the region (i.e., the watershed
the region, significantly affects the
perform all functions. If a water performs
that drains to a water identified in
chemical, physical, or biological integrity
a single function that has significant
paragraphs (a)(1) through (3) of this
of a water identified in paragraphs (a)(1)
impact on a downstream water, that is a
section), significantly affects the chemical, through (3) of this section. The term “in
significant nexus.
physical or biological integrity of a water
the region” means the watershed that
Under the final rule, only waters covered
identified in paragraphs (a)(1) through
drains to the nearest water identified in
by subparagraph (a)(7) or (a)(8) require
(3) of this section. For an effect to be
paragraphs (a)(1) through (3) of this
case-specific analysis.
significant, it must be more than
section. For an effect to be significant, it
speculative or insubstantial. Other
must be more than speculative or
waters, including wetlands, are similarly
insubstantial. Waters are similarly
situated when they perform similar
situated when they function alike and are
functions and are located sufficiently
sufficiently close to function together in
close together or close to a “water of
affecting downstream waters. For
the U.S.” so that they can be evaluated
purposes of determining whether or not
as a single landscape unit with regard to
a water has a significant nexus, the
their effect on the chemical, physical, or
water’s effect on downstream (a)(1)
biological integrity of a water identified
through (3) waters shall be assessed by
in paragraphs (a)(1) through (3) of this
evaluating the aquatic functions identified
section.
in paragraphs (A) through (I) of this
paragraph.e 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 water identified in paragraphs
(a)(1) through (3) of this section.
Functions relevant to the significant
nexus evaluation are the fol owing:
(i) Sediment trapping,
(ii) Nutrient recycling,
(ii ) Pol utant trapping, transformation,
CRS-27
link to page 32 link to page 32
Existing Regulatory Languagea
Proposed Regulatory Language
Revised Regulatory Language
Commentsb
filtering, and transport,
(iv) Retention and attenuation of flood
waters,
(v) Runoff storage,
(vi) Contribution of flow,
(vii) Export of organic matter,
(vii ) Export of food resources, and
(ix) Provision of life cycle-dependent
aquatic habitat (such as foraging, feeding,
nesting, breeding, spawning, or use as a
nursery area) for species located in a
water identified in paragraphs (a)(1)
through (3) of this section.
Source: Prepared by CRS.
Notes: The proposed rule that was announced on March 25, 2014, was published in the Federal Register on April 21, 2014 (79 Federal Register 22188-22274). The final
revised rule was announced jointly by EPA and the Army Corps on May 27, 2015, and was published in the Federal Register on June 29: Department of the Army, Corps
of Engineers, and Environmental Protection Agency, “Clean Water Rule: Definition of ‘Waters of the United States,’ Final Rule,” 80 Federal Register 37054-37127, June 29,
2015.
a. 33 C.F.R. 328.3, 40 C.F.R. 122.2, 40 C.F.R. 230.3, and 40 C.F.R. 232.2 (definition of “waters of the United States”). The term “navigable waters” is defined at 40
C.F.R. 110.1 (Discharge of Oil); 40 C.F.R. 112.2 (Oil Pol ution Prevention); 40 C.F.R. 116.3 (Designation of Hazardous Substance); 40 C.F.R. 117.1(i) (Determination
of Reportable Quantities for Hazardous Substances); 40 C.F.R. 300.5 and Appendix E 1.5 to Part 300 (National Oil and Hazardous Substances Pol ution Contingency
Plan); and 40 C.F.R. 302.3 (Designation, Reportable Quantities, and Notification).
b. Comments in this table are drawn from the preamble and text of the final rule.
c. The term “prior converted cropland” is included in the U.S. Department of Agriculture’s administrative definition of the term “wetland” (see 7 C.F.R. 12.2).
d. A definition of “waste treatment system” is found in EPA regulations (35 C.F.R. 35.905): “Complete waste treatment system. A complete waste treatment system
consists of all of the treatment works necessary to meet the requirements of title III of the Act, involved in (a) The transport of waste waters from individual homes
or buildings to a plant or facility where treatment of the waste water is accomplished; (b) the treatment of the waste waters to remove pol utants; and (c) the
ultimate disposal, including recycling or reuse, of the treated waste waters and residues which result from the treatment process. One complete waste treatment
system would, normally, include one treatment plant or facility, but also includes two or more connected or integrated treatment plants or facilities.”
e. Probably should be “(i) through (ix) of this paragraph.”
CRS-28
EPA and the Army Corps’ Rule to Define “Waters of the United States”
Appendix. EPA’s Connectivity Report and Review
by the Science Advisory Board
In September 2013, EPA released a draft report that reviews and synthesizes the peer-reviewed
scientific literature on the connectivity or isolation of streams and wetlands relative to large water
bodies such as rivers, lakes, estuaries, and oceans. As described below, after review and revision,
this report was finalized in January 2015. The purpose of the review, according to EPA, was to
summarize current understanding about these connections, the factors that influence them, and
mechanisms by which connected waters affect the function or condition of downstream waters.
The focus of the draft report, which was prepared by EPA’s Office of Research and Development,
was on small or temporary non-tidal streams, wetlands, and open waters. Based on the reviewed
literature, it made certain findings.
All tributary streams, including perennial, intermittent, and ephemeral streams,
are physically, chemically, and biologically connected to downstream rivers.
Wetlands and open waters in riparian areas and floodplains also are physically,
chemically, and biologically connected with rivers and serve an important role in
the integrity of downstream waters. In these types of wetlands, water-borne
materials can be transported from the wetland to the river network and vice versa
(e.g., water from a stream flows into and affects the wetland).
Wetlands and open waters where water only flows from the wetland or water to a
river network, (i.e., non-floodplain waters and wetlands that lack surface water
inlets) such as many prairie potholes, vernal pools, and playa lakes, provide
numerous functions that can benefit downstream water quality and integrity.
However, because such wetlands occur on a gradient of connectivity, it is
difficult to generalize, from the literature alone, about their effects on
downstream waters or to generalize about the degree of connectivity (absolute or
relative).
EPA asked its Science Advisory Board (SAB) to review the draft report and to comment on
whether its conclusions and findings are supported by the available science.35 The EPA draft
report is not intended as a policy document—it does not reference either the Scalia plurality or
Kennedy tests in Rapanos, nor does it address legal standards for CWA jurisdiction. Nevertheless,
the report is important to EPA and the Corps because, when finalized, it will provide a scientific
basis needed to clarify CWA jurisdiction and, thus, to inform the “waters of the United States”
rulemaking.36 The SAB convened a special panel of scientists to review the draft synthesis
document. This ad hoc panel held meetings and teleconferences from late 2013 through mid-2014
and prepared a report with recommendations.
In its report,37 the SAB ad hoc panel found strong support for the first two of EPA’s major
conclusions in the synthesis document and concluded that it is a thorough and technically
35 The SAB was established pursuant to the Environmental Research, Development, and Demonstration Authorization
Act (42 U.S.C. 4365) to provide independent scientific and technical advice to the EPA Administrator on the technical
basis for agency positions and regulations.
36 See U.S. Environmental Protection Agency, “Clean Water Act Definition of ‘Waters of the United States,’”
http://water.epa.gov/lawsregs/guidance/wetlands/CWAwaters.cfm.
37 Science Advisory Board, “SAB Review of the Draft EPA Report Connectivity of Streams and Wetlands to
Downstream Waters: A Review and Synthesis of the Scientific Evidence, Draft Report,” August 11, 2014, 105 pp.,
(continued...)
Congressional Research Service
29
EPA and the Army Corps’ Rule to Define “Waters of the United States”
accurate review of the literature on the connectivity of streams and wetlands to downstream
waters. In particular, the panel agreed with EPA’s conclusions that ephemeral, intermittent, and
perennial streams exert a strong influence on the character and functioning of downstream waters
and that tributary streams are connected to downstream waters. Further, the panel agreed with
EPA that streams and wetlands in floodplain settings are physically, chemically, and/or
biologically connected to downstream navigable waters.
The ad hoc panel found that the peer-reviewed literature supports EPA’s conclusions in the
synthesis report that connectivity occurs along a gradient or continuum between fully connected
and completely isolated, with a transition in between that varies case-by-case. However, the panel
concluded that the EPA report often refers to connectivity as though it is a binary property
(connected versus not connected). Instead, the panel found that there are four dimensions to
connectivity (longitudinal, lateral, vertical, and temporal). It is technically more accurate to state
that the consequences to downstream waters are determined by variation in the frequency,
duration, predictability, and magnitude of connections and that relatively low levels of
connectivity can be meaningful in terms of impacts.
The ad hoc panel disagreed with EPA’s third major conclusion, that it is difficult to generalize
from currently available literature the degree of connectivity or the downstream effects of non-
floodplain waters and wetlands that are not connected to a river network through surface or
shallow subsurface water. The SAB panel found that “the scientific literature supports a more
definitive statement that reflects how numerous functions of non-floodplain wetlands sustain the
physical, chemical, and/or biological integrity of downstream waters, although the degree of
connectivity can vary widely.”38 The report would be strengthened, the ad hoc panel said, if it
framed the discussion of connectivity gradients and their consequences as a function of the
magnitude, duration, and frequency of connectivity pathways among wetlands and downstream
waters and if it quantified each connection, to the degree possible, while identifying research and
data gaps. The panel found that at sufficiently large spatial and temporal scales, all waters and
wetlands are connected. More important are the degree of connection (e.g., frequency, duration)
and the extent to which those connections affect the chemical, physical, and biological integrity
of downstream waters. Within non-floodplain wetlands, the degree of connectivity and
implications for integrity of downstream waters vary considerably.
The EPA Report suggests that determining the connectedness of each non-floodplain
wetland must be done on a case-by-case basis. The SAB suggests that the vast majority of
non-floodplain wetlands can be classified with respect to some degree of hydrologic,
chemical or biological connections to downstream waters; however, some hydrologically
and spatially disconnected wetlands may need to be considered on a case-by-case basis.
The challenge for the EPA is to describe the hierarchy of decisions and the tools
necessary to assess the degree of connection necessary to warrant case-by-case analysis.39
The full, chartered SAB reviewed the ad hoc panel’s report in September 2014. SAB members
said that the panel’s review of the draft EPA study was technically accurate and clear and that it
accurately established linkages between streams, wetlands, and downstream waters. The SAB
members asked for several minor revisions to the ad hoc panel’s report, which were reflected in
(...continued)
http://yosemite.epa.gov/sab/SABPRODUCT.NSF/81e39f4c09954fcb85256ead006be86e/
212BB1480331835285257D350041A1C0/$File/
SAB+Connectivity+Panel+Draft+Report_8_11_14_%28quality+review+draft%29.pdf.
38 Ibid., pp. 1, 6.
39 Ibid., p. 56.
Congressional Research Service
30
EPA and the Army Corps’ Rule to Define “Waters of the United States”
an October 17, 2014, letter to the EPA Administrator with its findings and recommendations
regarding the synthesis document.40
Based on the SAB review, EPA’s scientists revised the draft scientific assessment report and
released a final report in January 2015.41 As revised, the report endorses the SAB
recommendation in full by interpreting the literature on connectivity of streams to downstream
waters as reflecting a gradient approach that recognizes variation in the frequency, duration,
magnitude, predictability, and consequences of those connections. In the final report, EPA says
that connectivity of streams and wetlands to downstream waters occurs along a continuum, and
that variation in the degree of connectivity influences the range of functions provided by streams
and wetlands. The final report no longer concludes that there is insufficient science to find that
there are connections between non-floodplain wetlands and downstream waters, suggesting that
case-specific analysis may not be needed for all such waters to determine that CWA jurisdiction
applies.
SAB Review of the Proposed “Waters of the U.S.” Rule
In addition to advising the EPA Administrator on the “connectivity” report, the chartered SAB
agreed to review the adequacy of the scientific and technical basis of the proposed “waters of the
United States” rule. As input to the SAB, members of the ad hoc panel that reviewed the
“connectivity” report subsequently reviewed the proposed rule. (Unlike their formal review of the
“connectivity” report, the panel did not seek consensus on their views of the scientific basis of the
proposed CWA rule.) The ad hoc panel sought to bring their scientific expertise to questions of
law and policy in the proposed rule, but at the same time, members’ comments highlighted some
difficulties in doing so.
Members of the ad hoc panel found general agreement that, based on available science, tributaries
and adjacent waters and wetlands are appropriately jurisdictional under the proposed rule. They
generally agreed that from a scientist’s perspective, key terms in the proposed rule need
clarification and better definition, including “significant,” “similarly situated,” “floodplain,” and
“adjacent.” The definition of “adjacent” is important, for example, because where “adjacent” is
determined then determines the beginning of “other waters” that require case-by-case evaluation
of jurisdiction. Several said that the proposed definition of “tributary” should be broader, that is,
that it should specify a bed and bank (as proposed) and in some cases an ordinary high water
mark (but not in all cases, as proposed in the rule). Several referred to the panel’s review of the
“connectivity” report and said that the rule should equally reflect the importance of chemical and
biological connections between waters, as well as hydrological connections, in determining
significant nexus, as the panel’s report did. Similarly, several noted the emphasis in the panel’s
report on connections resulting from groundwater pathways—shallow subsurface, shallow or
deep groundwater—in questioning the categorical exclusion of federal jurisdiction over
groundwater in the proposed rule.42 Likewise, some on the panel said that the distinction between
40 The October 17, 2014, letter and SAB final peer review of the draft “connectivity” report is available at
http://yosemite.epa.gov/sab/sabproduct.nsf/WebReportsLastFiveBOARD/AF1A28537854F8AB85257D74005003D2/
$File/EPA-SAB-15-001+unsigned.pdf.
41 Environmental Protection Agency, Office of Research and Development, Connectivity of Streams & Wetlands to
Downstream Waters: A Review & Synthesis of the Scientific Evidence, EPA/600/R-14-475F, January 2015,
http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=296414.
42 In addition to uncertainty over the scope of CWA jurisdiction in general, courts are split on the question of whether
EPA and the Corps may assert jurisdiction over groundwater connected to navigable waters. The statutory language is
ambiguous when discussing groundwater. See Anna Makowski, “Beneath the Surface of the Clean Water Act:
(continued...)
Congressional Research Service
31
EPA and the Army Corps’ Rule to Define “Waters of the United States”
ditches that would and would not be jurisdictional under the proposed rule is unclear and may not
be adequately supported by the science, although they recognized that the agencies may have
policy reasons for including some ditches as jurisdictional and excluding others.
The full chartered SAB also considered the ad hoc panel’s review of the proposed “waters of the
United States” rule in September, and it approved an advisory letter to be sent to the EPA
Administrator.43 The letter also supports case-by-case consideration of most “other waters” as
“waters of the United States,” but it finds that there is adequate scientific evident to support a
determination that certain types of waters in particular U.S. regions (e.g., prairie potholes, Texas
coastal prairie wetlands) could be categorically considered waters of the United States, thus not
requiring case-specific analysis. In the letter, the SAB urged EPA to reconsider the definition of
tributaries, which the proposed rule defines as having a bed, a bank, and an ordinary high water
mark, because in the SAB’s judgment, not all tributaries have ordinary high water marks. Finally,
the letter disagrees with certain categorical exclusions in the proposed rule, saying that science
does not justify excluding waters such as groundwater, ditches with only intermittent or
ephemeral flow, gullies, rills, and non-wetland swales, because in many cases they can be
connected to jurisdictional waters or can be conduits for moving water between jurisdictional
waters.
Author Contact Information
Claudia Copeland
Specialist in Resources and Environmental Policy
ccopeland@crs.loc.gov, 7-7227
(...continued)
Exploring the Depth of the Act’s Jurisdictional Scope of Groundwater Pollution,” Oregon Law Review, vol. 91 (2012),
pp. 495-526.
43 The text of the SAB letter concerning the proposed rule is available at http://yosemite.epa.gov/sab/sabproduct.nsf/
518D4909D94CB6E585257D6300767DD6/$File/EPA-SAB-14-007+unsigned.pdf.
Congressional Research Service
32