occurring only in direct response to precipitation and connecting a
wetland to a jurisdictional water does not constitute a direct
hydrologic surface connection according to the proposal.
    Under current practice and in this proposal, wetlands adjacent to
traditional navigable waters would be categorically jurisdictional. The
agencies propose to adopt this position based on the rationale that an
adjacent wetland is ``inseparably bound up with'' the jurisdictional
water; if the water is jurisdictional, so is the adjacent wetland.
Riverside Bayview, 474 U.S. at 134; Rapanos, 547 U.S. at 740 (plurality
quoting Riverside Bayview) (`` `Faced with such a problem of defining
the bounds of its regulatory authority,' we held, the agency could
reasonably conclude that a wetland that `adjoin[ed]' waters of the
United States is itself a part of those waters.'') (internal citations
omitted). This position is consistent with Riverside Bayview, about
which Justice Kennedy noted in Rapanos that ``the assertion of
jurisdiction for those wetlands is sustainable under the Act by showing
adjacency alone.'' 547 U.S. at 780.
    In addition, this proposed definition would end the current
practice of conducting case-specific significant nexus evaluations for
non-abutting wetlands to relatively permanent and non-relatively
permanent waters. Under the agencies' Rapanos Guidance, this evaluation
requires individual analyses of the relationship between a particular
wetland with traditional navigable waters. Importantly, Justice
Kennedy's ``significant nexus'' test for wetlands adjacent to
nonnavigable tributaries was only needed ``absent more specific
regulations,'' id. at 782, because ``the breadth of [the existing
tributary] standard'' . . . ``seems to leave wide room for regulations
of drains, ditches, and streams remote from any navigable-in-fact water
and carrying only minor water volumes towards it'' and thus ``precludes
its adoption as a determinative measure of whether adjacent wetlands
are likely to play an important role in the integrity of an aquatic
system comprising navigable waters as traditionally understood.'' Id.
at 781. In light of the ``more specific [tributary] regulations''
proposed today, the agencies propose to eliminate the case-specific
significant nexus analysis through categorical treatment of all
adjacent wetlands, as defined by this proposal, as waters of the United
States. The agencies recognize that this is a new position and
modification of prior agency positions on Justice Kennedy's concurring
opinion in Rapanos. The agencies also recognize that several courts
have adopted the significant nexus standard as a test for jurisdiction
for both adjacent wetlands and tributaries. The agencies believe,
however, that this proposal provides better clarity for the regulators
and the regulated community alike while adhering to the basic
principles articulated in all three Supreme Court cases on point.
    The proposed categorical inclusion of adjacent wetlands beyond the
wetlands that ``actually abut[ ]'' navigable-in-fact waters addressed
in Riverside Bayview, 474 U.S. at 135, the agencies recognize, is
dependent on the relationship between the other categories of ``waters
of the United States'' and waters more traditionally understood as
navigable. The agencies believe that the proposed definition of
``tributary,'' as described in Section III.D, would appropriately limit
federal jurisdiction to those rivers and streams that due to their
relatively permanent flow regime and contribution of flow to navigable
waters are ``significant enough that wetlands adjacent to them are
likely, in the majority of cases, to perform important functions for an
aquatic system incorporating navigable waters.'' Rapanos, 547 U.S. at
781 (Kennedy, J., concurring). Because the tributary definition as
proposed today ``rests upon a reasonable inference of ecological
interconnection'' with navigable waters, and adjacent wetlands as
proposed must be ``directly abutting'' or have a direct hydrologic
surface connection to tributaries and are thus ``inseparably bound up
with'' tributaries, the assertion of jurisdiction over wetlands
adjacent to tributaries ``is sustainable under the Act by showing
adjacency alone.'' Id. at 780 (citing Riverside Bayview, 474 U.S. at
134). The proposed ``tributary'' definition--which addresses the
``breadth of [the] standard'' about which Justice Kennedy was concerned
in Rapanos--would provide support for the Court's conclusion in
Riverside Bayview ``that a definition of `waters of the United States'
encompassing all wetlands adjacent to other bodies of water over which
the Corps has jurisdiction is a permissible interpretation of the
Act.'' Id. at 135. To be clear, there is no requirement under this
proposal to prove the existence of nor the significance of ``ecological
interconnection'' between an adjacent wetland and navigable waters. If
a wetland meets the proposed ``adjacent

wetland'' definition, it would be jurisdictional.
    The proposed definition of ``adjacent wetlands,'' which includes
the term ``abut,'' also captures the common understanding of that term,
meaning ``touching.'' See Webster's II, New Riverside University
Dictionary (1994) (defining ``abut'' to mean ``to touch at one end or
side of something''). This definition is also consistent with the
common understanding of the term ``adjacent,'' which means ``next to,''
``adjoining,'' ``to lie near,'' or ``close to,'' see id., and is
consistent with the Rapanos plurality's ``physical-connection
requirement,'' 547 U.S. at 751 n.13.
    By retaining the term ``adjacent'' in the proposed definition from
the longstanding regulations, the agencies would continue to use
terminology that is familiar to the agencies and the regulated public.
But the agencies are proposing not to include the terms ``bordering,
contiguous, or neighboring'' from the 1986 regulations, as the agencies
consider the term ``abut'' and the concept of a ``direct hydrologic
surface connection'' as reducing the potential confusion associated
with using three seemingly similar terms in the same definition. See,
e.g., U.S. General Accounting Office, Waters and Wetlands, GAO-04-297,
at 10 (Feb. 2004) (``The regulations specify that adjacent means
`bordering, contiguous, or neighboring'. . . . This definition of
adjacency leaves some degree of interpretation to the Corps
districts''); see also id. at 3 (``Districts apply different approaches
to identify wetlands that are adjacent to other waters of the United
States and are subject to federal regulation.'').
    The term ``abut'' in the proposed definition, meaning ``to touch at
least at one point or side of'' a jurisdictional water, would provide
members of the regulated community with fair notice as to whether
wetlands are subject to CWA jurisdiction. The agencies consider
wetlands that abut or have a direct hydrologic surface connection to
otherwise jurisdictional waters in a typical year to better meet the
ordinary meaning of the term ``waters'' more clearly than wetlands
separated from such waters by dry land and lacking a direct hydrologic
surface connection or located a specified distance from those waters.
See, e.g., 547 U.S. at 740 quoting Riverside Bayview, 474 U.S. at 132,
135, and n. 9 (``[W]e held, the agency could reasonably conclude that a
wetland that `adjoin[ed]' waters of the United States is itself a part
of those waters.'').
    This proposed categorical treatment of adjacent wetlands would also
effectuate the clear policy direction from Congress to ``recognize,
preserve, and protect the primary responsibilities and rights of States
to prevent, reduce, and eliminate pollution [and] to plan for the
development and use (including restoration, preservation, and
enhancement) of land and water resources . . . .'' 33 U.S.C. 1251(b);
see also Rapanos, 547 U.S. at 737 (Scalia, J., plurality). The agencies
believe that this approach avoids ``impairing or in any manner
affecting any right or jurisdiction of the States with respect to the
waters (including boundary waters) of such States.'' Id. at 1370.
Wetlands that do not abut or have a direct hydrologic surface
connection to other waters of the United States in a typical year are
not inseparably bound up with the waters of the United States and are
more appropriately regulated as land and water resources of the States
and Tribes pursuant to their own authorities.
    The agencies also note that the proposed definition of ``adjacent
wetlands'' and the categorical treatment of jurisdiction over wetlands
adjacent to tributaries as proposed is informed by, though not dictated
by, science. For example, the EPA's Science Advisory Board noted when
reviewing the Draft Connectivity Report in 2014, ``[s]patial proximity
is one important determinant of the magnitude, frequency and duration
of connections between wetlands and streams that will ultimately
influence the fluxes of water, materials and biota between wetlands and
downstream waters.'' SAB Review at 60. ``Wetlands that are situated
alongside rivers and their tributaries are likely to be connected to
those waters through the exchange of water, biota and chemicals. As the
distance between a wetland and a flowing water system increases, these
connections become less obvious.'' Id. at 55 (emphasis added). The
Connectivity Report also recognizes that ``areas that are closer to
rivers and streams have a higher probability of being connected than
areas farther away.'' Connectivity Report at ES-4. As discussed above,
however, the line between Federal and State waters is a legal
distinction, not a scientific one, that reflects the overall framework
and construct of the CWA. This proposed definition would draw the legal
limit of federal jurisdiction as those wetlands that abut or have a
direct hydrologic surface connection to otherwise jurisdictional
waters, including tributaries as defined in this proposal, in a clear
and implementable way that adheres to established legal principles
while being informed by the policy choices and expertise of the
executive branch agencies charged with administering the CWA.
3. How might the agencies implement this approach?
    Under this proposal, wetlands would be considered indistinguishable
from other jurisdictional waters, and therefore adjacent, when they
abut such waters, even in the absence of a surface hydrological
connection occurring between the two. Alternatively, when wetlands are
not abutting jurisdictional waters, for example where wetlands are
separated from jurisdictional by upland or dikes, barriers, or other
similar structures, those wetlands would not be adjacent wetlands
unless they have a direct hydrologic surface connection to a
jurisdictional water during a typical year. If a wetland satisfies this
proposed definition it would be considered a ``water of the United
States'' without need for further case-specific significant nexus
analysis. This categorical inclusion, however, does not alleviate the
need for site-specific verification of jurisdiction, such as
confirmation of wetland characteristics, whether the wetlands abut
another jurisdictional water and other issues typically addressed
during a jurisdictional determination process.
    The proposed definition of ``adjacent wetlands'' would not require
surface water exchange between wetlands and the jurisdictional waters
they abut to create the jurisdictional link, consistent with case law
and for ease of implementation. See Riverside Bayview, 474 U.S. at 129
(``The plain language of the [Corps' 1977] regulation refutes the Court
of Appeals' conclusion that inundation or `frequent flooding' by the
adjacent body of water is a sine qua non of a wetland under the
regulation.''). Rather, as proposed, a wetland that directly touches an
otherwise jurisdictional water at a point or side is ``adjacent''
regardless of where ``the moisture creating the wetlands . . . find[s]
it source.'' Rapanos, 547 U.S. at 772 (Kennedy, J., concurring), citing
Riverside Bayview, 474 U.S. at 135.
    In addition to wetlands that actually abut other jurisdictional
waters, the proposed definition considers wetlands to be ``adjacent''
when they have a direct hydrologic surface connection to jurisdictional
waters during a typical year. See Rapanos, 474 U.S. at 732 (Scalia, J.,
plurality) (recognizing that the term ``the waters'' within ``the
waters of the United States'' includes ``the flowing or moving masses,
as of waves or floods, making up . . . streams or bodies'') (emphasis
added) (internal quotations omitted); id. at 770 (Kennedy, J.,
concurring) (``the term

`waters' may mean `flood or inundation' events that are impermanent by
definition'') (emphasis added) (internal citations omitted). During
times of inundation occurring from a jurisdictional water to a wetland
in a typical year, ``adjacent wetlands'' are indistinguishable from and
inseparably bound up with other waters of the United States. In
addition to regular flooding, such direct hydrologic surface
connections during a typical year may be the result of perennial or
intermittent flow between a wetland and a jurisdictional water. Surface
water from a wetland that overtops a berm and connects the wetland to a
jurisdictional water or connections from a wetland to a jurisdictional
water through upland or through a barrier as mediated by a culvert,
tide gate, or similar structure would constitute direct hydrologic
surface connections so long as such connections are perennial or
intermittent as defined in this proposal and occur in a typical year.
As proposed, a direct hydrologic surface connection may occur as either
confined or unconfined perennial or intermittent flow. Wetlands with a
direct hydrologic surface connection to other jurisdictional waters are
indistinguishable from and inseparably bound up with those waters of
the United States and are adjacent wetlands under this proposal.
Ephemeral connections as well as subsurface connections between
wetlands and jurisdictional waters do not constitute a direct
hydrologic surface connection according to this proposal.
    A mere hydrologic connection between a nonnavigable, isolated,
intrastate wetland and a jurisdictional water, however, may be
insufficient to establish adjacency under the proposed rule. For
instance, the fact that a wetland may be connected to the navigable
water by flooding, on average, once every 100 years does not satisfy
the proposed ``adjacent wetlands'' definition. To be adjacent, a
wetland that is otherwise physically separated from a ``water of the
United States'' would need to have a direct hydrologic surface
connection to a jurisdictional water during a typical year; ecological
connections between physically separated wetlands and otherwise
jurisdictional waters cannot be used to determine adjacency according
to this proposal. See 547 U.S. at 741-42 (Scalia, J., plurality)
(``SWANCC found such ecological consideration irrelevant to the
question whether physically isolated waters come within the Corps'
jurisdiction.''). The agencies may determine that a direct hydrologic
surface connection exists during a typical year using, for example,
USGS stream gage records, channel-forming discharge recurrence
interval, and/or wetland surface water level records. Physically remote
isolated wetlands, however, would not be adjacent wetlands under this
proposal.
    In addition, a jurisdictional wetland divided by an artificial
feature, such as a road, would be treated as a single wetland and
remain jurisdictional unless there is no direct hydrologic surface
connection during a typical year between the wetlands present on either
side of that feature. Without such direct hydrologic surface
connection, only that wetland (i.e., that portion of the original
wetland) which abuts or has a direct hydrologic surface connection to
another ``water of the United States'' would be jurisdictional as
adjacent, even if there is a subsurface hydrologic connection between
the wetlands present on either side of the road. If there is a direct
hydrologic surface connection between the wetlands on either side of
the road during a typical year, such as where the road has a low-flow
crossing or another direct hydrologic surface connection provided by a
conduit, such as a culvert, as well as where there is a direct
hydrologic surface connection via overtopping of the road, the wetlands
on either side of the road may be treated as one wetland and would be
jurisdictional as adjacent in its entirety.
    For purposes of adjacency under the proposed rule, the entire
wetland would be considered adjacent if any portion of the wetland
abuts or has a direct hydrologic surface connection to another ``water
of the United States,'' regardless of the size and extent of the
wetland. For example, if a portion of one side of a wetland physically
touches a tributary, then the wetland would be jurisdictional in its
entirety. Similarly, if any part of a wetland has a direct hydrologic
surface connection to a jurisdictional water, the entire wetland would
be considered adjacent. Interpreting the entire wetland to be adjacent
if any portion of it satisfies the proposed ``adjacent wetlands''
definition is consistent with longstanding practice. The agencies have
found this approach to be simpler and easier to implement in the field
than establishing a means of bifurcating wetlands. An adjacent wetland
that changes classification (e.g., as defined in Cowardin et al. 1979)
due to landscape position, hydrologic inundation, or other factors,
such as changing from salt marsh to brackish to freshwater wetland,
would remain jurisdictional as one adjacent wetland.
    The term ``adjacent wetlands'' as proposed includes reference to
``upland.'' The term upland has been used in program implementation for
at least a decade following the agencies' Rapanos Guidance and thus is
familiar to the regulated community and field staff. The term
``upland'' is defined in this proposal as any land that does not meet
the three-part test (i.e., hydrology, hydrophytic vegetation, and
hydric soils) for wetland under normal circumstances, and as the
ordinary meaning of the term clearly indicates, would not include other
``waters of the United States.''
    Wetlands separated from other ``waters of the United States'' by
upland or by dikes, barriers, or similar structures would not be
adjacent and would not be jurisdictional wetlands under the proposed
rule, unless there is a direct hydrologic surface connection between
the wetland and those waters through or over such structures during a
typical year. This is because upland or dikes, barriers, or similar
structures typically block most surface water flow. However, if there
is a direct hydrologic surface connection during a typical year between
the wetland and other ``waters of the United States'' through the dike,
barrier, or similar structure, such as through a culvert or tide gate,
the wetland would remain adjacent under this proposed rule. A direct
hydrologic surface connection can also result from water in the wetland
overtopping a berm or barrier to connect the wetland via perennial or
intermittent flow to a jurisdictional water in a typical year.
    Adjacent wetlands under this proposal would include wetlands with
alternating hydroperiods and seasonal wetlands with vegetation shifts
so long as the delineated boundary of the wetland abuts a
jurisdictional water. The delineated boundary of a seasonal wetland
remains constant, even though all three delineation factors may not be
apparent year-round, as is current practice. This proposed approach
acknowledges seasonal variation in visible wetland characteristics as
well as the variation in hydrology and climatic conditions across the
country. For example, wetlands with alternating hydroperiods that abut
another ``water of the United States'' in the arid West may only have
hydrology present for three months while those wetlands in the
southeast may have hydrology present for nine months. Wetland hydrology
indicators involving direct observation of surface water or saturated
soils often are present only during the normal wet portion of the
growing season and may be absent during the dry season. Also, seasonal
wetlands

with vegetation shifts may display hydrophytic vegetation abutting
another ``water of the United States'' except during the dry season.
Certain wetland indicators may not be present year-round in a typical
year, such as indicators of hydrophytic vegetation, hydric soil, or
wetland hydrology periodically due to normal seasonal or annual
variability.
    Where wetlands in a complex of wetlands have a continuous physical
surface connection to one another such that upland boundaries or dikes,
barriers, or other structures cannot be drawn to distinguish them as
physically separated, the agencies would evaluate these wetlands as a
single wetland under the proposed rule. If any portion of these
physically interconnected wetlands is adjacent to another ``water of
the United States,'' the wetland would be considered adjacent for
purposes of this proposed rule.
    Given the focus of the proposed adjacent wetlands definition based
on the ordinary meaning of the term ``waters,'' common principles from
case law, and the limitations on federal authority embodied in section
101(b) of the Act, this proposed definition does not include subsurface
hydrologic connectivity as a basis for determining adjacency. The
agencies are concerned that the use of shallow subsurface connection
could encroach on State and tribal authority over land and water
resources and could be confusing and difficult to implement, including
in determining whether a subsurface connection exists and to what
extent. The categorical inclusion of all wetlands that abut other
``waters of the United States'' and all wetlands with a direct
hydrologic surface connection to other jurisdictional waters will
invariably include some wetlands that also connect to those waters
through shallow subsurface flow. Physically remote wetlands and
wetlands lacking a direct hydrologic surface connection would be
reserved to regulation by States and Tribes as land and water resources
of those States and Tribes.
4. What are the specific issues upon which the agencies are seeking
comment?
    While the public may comment on all aspects of the agencies'
proposed rule, the agencies have proposed a number of ways to try to
address and clarify jurisdiction over wetlands as described above and
are seeking comment. As a threshold matter, the agencies solicit
comment on their interpretations of Riverside Bayview, SWANCC, and the
Rapanos opinions, including specifically the proposal to provide
regulatory certainty through categorical treatment of adjacent wetlands
rather than on the case-by-case application of Justice Kennedy's
significant nexus test.
    While the agencies are not proposing to change the longstanding
regulatory definition of ``wetlands,'' they request comment on whether
including in the regulatory text that areas must satisfy all three
wetland delineation criteria (i.e., hydrology, hydrophytic vegetation,
and hydric soils) under normal circumstances to qualify as wetlands
would provide additional clarity. The agencies also seek comment on
whether there are terms or phrases within the existing wetlands
definition that require clarification (e.g., ``under normal
circumstances''), and if so how such terms might be defined and if
clarification should be provided, for example, via regulatory text or
future agency guidance.
    The agencies are soliciting comment on other potential
interpretations of adjacency, such as including a distance limit to
establish the boundaries between Federal and State waters, which
several pre-proposal commenters recommended. For example, some
commenters have suggested using distance from another jurisdictional
water as the basis for asserting jurisdiction over wetlands, even if
those wetlands do not abut or have a direct hydrologic surface
connection to such waters in a typical year. Others have suggested
establishing a jurisdictional cut-off in a contiguous wetland for
administrative purposes rather than extending jurisdiction to the outer
limits of the wetland where all three wetland characteristics are no
longer satisfied. The agencies solicit comment on these alternate
suggestions.
    The agencies are also soliciting comment on whether the definition
of ``adjacent wetlands'' should not include reference to dikes,
barriers, and similar structures and instead those terms should be
included in the definition of ``upland.'' The definition of ``upland''
would then mean, ``any land area, including dikes, barriers, or similar
structures, that under normal circumstances does not satisfy all three
wetland delineation criteria (i.e., hydrology, hydrophytic vegetation,
hydric soils) identified in paragraph (c)(15) of this section, and does
not lie below the ordinary high water mark or the high tide line of a
water identified in paragraphs (a)(1)-(6) of this section.'' Upland
would include both natural and artificial land areas meeting the
definition.
    The agencies are also soliciting comment on an alternate approach,
whereby wetlands that are separated from another jurisdictional water
by upland or a dike, barrier or other similar structure would not be
jurisdictional even if they have a direct hydrologic surface connection
in a typical year to an otherwise jurisdictional water. Unlike the
proposed approach, this alternative would not allow for seasonal
overtopping, for example, to provide for a direct hydrologic surface
connection during a typical year, but wetlands would be jurisdictional
if the direct hydrologic surface connection is through the upland or
structure (e.g., through a culvert). The agencies solicit comment on
whether this approach is more consistent with the considerations
articulated above than the approach in the proposed definition.
    The agencies note that identifying remotely whether wetlands abut a
jurisdictional water can be challenging, especially with 2-D aerial
imagery and the resolution of remote tools. The agencies are soliciting
comment on which indicators can be used to determine whether a wetland
abuts a jurisdictional water, and whether surface hydrology indicators
or remote tools exist that may be helpful. The agencies believe that it
is also important to consider weather and climatic conditions, i.e.,
review recent precipitation and climate records, to ensure adjacency is
not being assessed during a period of drought or after a major
precipitation or infrequent flood event. These climatic assessments
could employ the same tools used to evaluate whether it is a ``typical
year'' for purposes of determining whether a tributary is
jurisdictional.
    The agencies seek comment on whether it is appropriate to describe
a ``direct hydrologic surface connection'' as occurring due to
inundation from an (a)(1)-(5) water or via perennial or intermittent
flow between a wetland and an (a)(1)-(5) water in a typical year.
Additionally, the agencies request comment on whether other types of
hydrologic surface connections between wetlands and jurisdictional
waters could constitute a ``direct hydrologic surface connection'' or
if and under what circumstances subsurface water connections between
wetlands and jurisdictional waters could be used to determine
adjacency.
    The agencies are also soliciting comment on other tools that may be
helpful in implementation of the proposed adjacent wetlands category.
For example, the agencies seek comment as to whether tools such as NRCS
Soil Surveys (Flooding Frequency Classes), tidal gauge data, and site-
specific modeling (e.g., Hydrologic Engineering Centers River System

Analysis System or HEC-RAS), as well as historical evidence, such as
photographs, prior delineations, topographic maps, and existing site
characteristics, could be helpful in implementation.

H. Waters and Features That Are Not Waters of the United States

1. What are the agencies proposing?
    In paragraph (b) of the proposal, the agencies propose eleven
exclusions from the definition of ``waters of the United States.''
Specifically, under this proposal, any water not enumerated in
paragraphs (a)(1) through (6) would not be a water of the United
States. The proposed rule would exclude groundwater, including
groundwater drained through subsurface drainage systems. This proposed
rule would exclude ephemeral surface features and diffuse stormwater
run-off such as directional sheet flow over upland. This proposal would
exclude all ditches from the definition of ``waters of the United
States'' except those ditches identified in paragraph (a)(3) of the
proposed rule. Jurisdictional ditches identified in paragraph (a)(3)
include: (1) Ditches that satisfy any of the conditions identified in
paragraph (a)(1); (2) ditches constructed in a tributary as long as
those ditches also satisfy the conditions of the tributary definition;
and (3) ditches constructed in an adjacent wetland as long as those
ditches also satisfy the conditions of the tributary definition. See
the Section III.E for further discussion on the types of ditches which
would be considered ``waters of the United States'' under this proposed
rule. All other ditches are proposed to be excluded.
    Prior converted cropland has been excluded from this definition
since 1993 and would continue to be excluded. The agencies include in
the proposed rule a definition of ``prior converted cropland'' and an
explanation of when a prior converted cropland designation would no
longer be applicable for purposes of the CWA. The agencies also propose
to exclude artificially irrigated areas, including fields flooded for
rice or cranberry growing, that would revert to upland should
application of irrigation water to that area cease. In addition, the
agencies propose to exclude artificial lakes and ponds constructed in
upland, such as water storage reservoirs, farm and stock watering
ponds, settling basins, and log cleaning ponds, as long as they are not
subject to jurisdiction under either paragraph (a)(4) or (a)(5) of the
proposed rule. The proposed rule would also exclude water-filled
depressions created in upland incidental to mining or construction
activity, and pits excavated in upland for the purpose of obtaining
fill, sand, or gravel. The agencies also propose to exclude stormwater
control features excavated or constructed in upland to convey, treat,
infiltrate, or store stormwater run-off. Also proposed to be excluded
are wastewater recycling structures constructed in upland, such as
detention, retention and infiltration basins and ponds, and groundwater
recharge basins. Waste treatment systems have been excluded from this
definition since 1979, and they would continue to be excluded under
this proposal; however, waste treatment systems are being defined for
the first time in this proposed rule under paragraph (c). A waste
treatment system would include all components, including lagoons and
treatment ponds (such as settling or cooling ponds), designed to convey
or retain, concentrate, settle, reduce, or remove pollutants, either
actively or passively, from wastewater prior to discharge (or
eliminating any such discharge). A waste treatment system requires a
section 402 permit if it discharges into a water of the United States.
2. Why are the agencies proposing this approach?
    These proposed exclusions generally reflect the agencies' current
practice, and their inclusion in the proposed rule would further the
agencies' goal of providing greater clarity over which waters are and
are not regulated under the CWA. Just as the proposed categorical
assertions of jurisdiction over tributaries and adjacent wetlands would
simplify the jurisdiction issue, the categorical exclusions would
likewise simplify the process, and they reflect the agencies' proposed
determinations of the lines of jurisdiction based on the case law and
the agencies' long-standing practice and technical judgment that
certain waters and features are not subject to the CWA.
    The plurality opinion in Rapanos noted that there were certain
features that were not primarily the focus of the CWA, such as channels
that periodically provide drainage for rainfall. See 547 U.S. at 734.
During outreach for this proposed rule, many States, regional groups,
and national associations requested ``distinct,'' ``specific,'' and
``clear'' exclusions from the definition of ``waters of the United
States.'' In this proposed rule, the agencies propose to thus draw
lines and articulate that certain waters and features would not be
subject to the jurisdiction of the CWA, consistent with the agencies'
proposed interpretation of this statutory term.
    Importantly, the agencies are proposing that all waters and
features identified in paragraph (b) as excluded would not be ``waters
of the United States.'' As stated in paragraph (b)(1) of the proposed
rule, waters or water features not enumerated in paragraphs (a)(1)
through (6) would not be a water of the United States. The agencies are
proposing to take this approach to avoid suggesting that but for an
applicable exclusion, such features could be jurisdictional. This
proposed approach comprehensively excludes all waters and features the
agencies do not intend to include as ``waters of the United States.''
Different features are called different names in different parts of the
country, so this approach is intended to also eliminate the risk of
confusion.
    In proposed paragraph (b)(2), the agencies would exclude
groundwater, including groundwater drained through subsurface drainage
systems. The agencies have never interpreted ``waters of the United
States'' to include groundwater and would continue that practice
through this proposed rule by explicitly excluding groundwater.
    In proposed paragraph (b)(3), the agencies would exclude ephemeral
features and diffuse stormwater run-off, including directional sheet
flow over upland. Such features would not be jurisdictional under the
proposed terms of paragraph (a) or the proposed definitions in
paragraph (c). They would be specifically excluded in the proposed rule
to avoid confusion. This proposed exclusion would further highlight and
clarify that such features are not tributaries under the proposed rule.
    The proposed ditch exclusion in paragraph (b)(4) is intended to be
clearer for the regulated public to identify and more straightforward
for agency staff to implement than current practice. The agencies have
proposed a clear statement that all types of ditches would be excluded
except for three instances (see paragraph (a)(3) and the Section III.E
for further information on ditches). First, ditches that are (a)(1)
waters would be ``waters of the United States.'' Second, ditches
constructed in a tributary and that continue to satisfy the conditions
of the tributary definition after alteration would be ``waters of the
United States.'' And third, ditches constructed in an adjacent wetland
that satisfy the conditions of the tributary definition would be
``waters of the United States.'' Many States, regional groups and
national associations that commented during the Federalism consultation
and during the agencies' general outreach efforts noted that the
definition of ``waters of the United States'' should exclude ditches.
This

approach reasonably balances the exclusion with the need to preserve
jurisdiction over tributaries and adjacent wetlands as defined in this
proposal. With this proposed approach, the agencies seek to address the
kinds of ditches of concern to many stakeholders.
    The definition of ``waters of the United States'' would continue to
exclude prior converted cropland in this proposed rule. The agencies
are proposing to move this exclusion to paragraph (b)(5), add a
definition of ``prior converted cropland'' in paragraph (c)(8), and
clarify that the prior converted cropland exclusion would no longer be
applicable when the cropland is abandoned and the land has reverted to
wetlands, as that term is defined in paragraph (c)(15). Under this
proposed rule, prior converted cropland is considered abandoned if it
is not used for, or in support of, agricultural purposes at least once
in the immediately preceding five years. Agricultural purposes include
land use that makes the production of an agricultural product possible,
including but not limited to grazing and haying. This proposed rule
would also clarify that cropland that is left idle or fallow for
conservation or agricultural purposes for any period of time remains in
agricultural use, and therefore maintains the prior converted cropland
exclusion. The agencies believe that this clarification is necessary to
ensure that cropland enrolled in long-term and other NRCS conservation
programs administered by the United States or by State and local
agencies that prevents erosion or other natural resource degradation
does not lose its prior converted cropland designation as a result of
implementing conservation practices. The five-year timeframe for
maintaining agricultural purposes is consistent with the 1993 preamble.
58 FR 45033. It is also consistent with the five-year timeframe
regarding validity of a jurisdictional determination. See 2005 Corps
Regulatory Guidance Letter (RGL) 05-02. These proposed revisions are
intended to clarify the scope and application of the prior converted
cropland exclusion and reaffirm key principles from the 1993 preamble.
58 FR 45033.
    In 1993, the agencies categorically excluded prior converted
cropland from the definition of ``waters of the United States.'' The
1993 preamble defined prior converted cropland as ``areas that, prior
to December 23, 1985, were drained or otherwise manipulated for the
purpose, or having the effect, of making production of a commodity crop
possible [and that are] inundated for no more than 14 consecutive days
during the growing season.'' 58 FR 45031. As explained in detail in the
1993 preamble, the agencies' objective is to protect the nation's
waters, including the navigable waters, and due to the degraded and
altered nature of prior converted cropland, the agencies determined
that such lands should not be treated as jurisdictional wetlands for
purposes of the CWA. 58 FR 45032. The 1993 preamble also set out a
mechanism to ``recapture'' prior converted cropland into the section
404 program when the land has been abandoned and wetland features
return. 58 FR 45034. This approach is consistent with the principles in
the 1990 Corps RGL 90-7. Although included in the 1993 preamble and RGL
90-7, these principles have not been incorporated into the text of any
promulgated rule. This rulemaking therefore represents the first time
the agencies are proposing regulatory language to clarify the meaning
of ``prior converted cropland,'' the application of the exclusion, and
a recapture mechanism based on abandonment and reversion to wetlands.
    Historically, the agencies have attempted to create consistency
between the CWA and the Swampbuster program for prior converted
cropland. The agencies continue to believe that consistency across
these programs is important for the regulated community (see 58 FR
45033), and therefore propose to continue excluding prior converted
cropland from the definition of waters of the United States. By
incorporating the abandonment principles from the 1993 preamble, this
proposal remains consistent with the concepts underlying the
Swampbuster program but differs in implementation from certain aspects
of USDA's current program. Incorporating the abandonment principle, as
opposed to a pure ``change in use'' policy (described below), is
important for the agencies to appropriately manage wetland resources
while providing better clarity to the farming community.
    When the 1993 preamble was published, the abandonment recapture
principle was consistent with USDA's implementation of the Swampbuster
program. Three years later, the 1996 Swampbuster amendments modified
the abandonment principle and incorporated a ``change in use'' policy.
Under the new policy, prior converted cropland would continue to be
regulated as such even if wetland characteristics returned because of
lack of maintenance of the land or other circumstances beyond the
owner's control, ``as long as the prior converted cropland continues to
be used for agricultural purposes.'' Conf. Rep. No. 104-494, at 380
(1996). In 2005, the Army and USDA issued a joint Memorandum to the
Field (the 2005 Memorandum) in an effort to again align the CWA 404
program with Swampbuster. The 2005 Memorandum provided that,
``certified [prior converted] determination made by [USDA] remains
valid as long as the area is devoted to an agricultural use. If the
land changes to a non-agricultural use, the [prior converted]
determination is no longer applicable and a new wetland determination
is required for CWA purposes.''
    The 2005 Memorandum did not clearly address the abandonment
principle that the agencies had been implementing since the 1993
rulemaking. The change in use policy was also never promulgated as a
rule and was declared unlawful by one district court because it
effectively modified the 1993 preamble language without any formal
rulemaking process. New Hope Power Co. v. U.S. Army Corps of Eng'rs,
746 F. Supp. 2d 1272, 1282 (S.D. Fla. 2010). Implementing the 2005
Memorandum created other challenges for the agencies and the regulated
community. For example, because the 2005 Memorandum did not clearly
address whether or how the abandonment principles should be applied in
prior converted cropland cases, neither the agencies nor the regulated
community could be certain which approach would be applied to a
specific case. If this proposed exclusion is finalized, the Army would
take action to withdraw the 2005 Memorandum. It is the agencies' intent
that this proposed rule will clarify the prior converted cropland issue
and provide regulatory certainty.
    The following features also would not be ``waters of the United
States'' under this proposed rule:
     Artificially irrigated areas, including fields flooded for
rice or cranberry growing, that would revert to upland should
application of irrigation water to that area cease (paragraph (b)(6));
     Artificial lakes and ponds constructed in upland
(including water storage reservoirs, farm and stock watering ponds,
settling basins, and log cleaning ponds) which are not identified in
paragraph (a)(4) or (a)(5) of this section (paragraph (b)(7)); and
     Water-filled depressions created in upland incidental to
mining or construction activity, and pits excavated in upland for the
purpose of obtaining fill, sand or gravel (paragraph (b)(8)).

    Paragraphs (b)(6), (7), and (8) of the proposed rule identify
features and waters that the agencies have identified as generally not
``waters of the United States'' in previous preambles. The agencies
intend that codifying these longstanding practices would further the
agencies' goals of providing greater clarity and predictability for the
regulated public and the regulators. Several of these exclusions use
the phrase ``upland.'' In keeping with the goal of providing greater
clarity, the agencies have proposed a definition of ``upland'' in
paragraph (c)(13). It is important to note that a ``water of the United
States'' would not be considered ``upland'' just because it lacks water
at a given time. Similarly, an area may remain ``upland'' even if it is
wet after a rainfall or flood event. Also, the upland requirement would
not apply to all exclusions under paragraph (b). Those waters/features
under proposed paragraph (b) that do contain the stipulation that they
must be created in upland to be excluded must be created wholly in
upland. Features not constructed wholly in upland could meet the
proposed definition of ``waters of the United States,'' unless
otherwise excluded under another part of paragraph (b). The agencies
note that the mere interface between the excluded feature constructed
wholly in upland and a jurisdictional water would not make that feature
jurisdictional. For example, a ditch constructed wholly in upland that
connects to a tributary would not be considered a jurisdictional ditch.
Finally, a proposed excluded feature that develops wetland
characteristics within the confines of the water/feature would remain
excluded from the definition of ``waters of the United States.''
    In proposed paragraph (b)(7) regarding artificial lakes and ponds
constructed in upland, the agencies have removed language regarding
``use'' of the ponds, including the term ``exclusively,'' which were
used in the 1986 and 1988 preambles. In most cases, the ``use'' of the
pond is captured in its name. More importantly, the agencies recognize
that artificial lakes and ponds are often used for more than one
purpose and can have a variety of beneficial purposes, including water
retention or recreation. The proposed exclusion reflects the agencies'
practice and would ensure that waters the agencies have historically
not treated as jurisdictional would not become so because of another
incidental beneficial use. In the text of the proposed exclusion, the
agencies are also clarifying that these features would not be excluded
if they are jurisdictional impoundments because altering a water by
impounding it would not change the water's jurisdictional status,
consistent with longstanding agency practice. However, when an
applicant receives a permit to impound a water of the United States in
order to construct a waste treatment system (as excluded under
(b)(11)), the agencies are affirmatively relinquishing jurisdiction
over the resulting waste treatment system as long as it is used for
this permitted purpose, consistent with longstanding practice. Also
consistent with longstanding practice, waters upstream of the waste
treatment system may still be considered jurisdictional where they meet
the proposed definition of ``waters of the United States.''
    In proposed paragraph (b)(8), the proposed rule includes several
refinements to the existing 1986 and 1988 preamble language related to
the exclusion for water-filled depressions created in upland as a
result of certain activities. In addition to construction activity, the
agencies have also proposed to exclude water-filled depressions created
in upland incidental to mining activity. This is consistent with the
exclusion in the 2015 Rule and with the agencies' 1986 and 1988
preambles, which generally excluded pits excavated for obtaining fill,
sand or gravel, and the agencies believe there is no need to
distinguish between features based on whether they are created by
construction or mining activity.
    In proposed paragraph (b)(9), the agencies would exclude stormwater
control features excavated or constructed in upland to convey, treat,
infiltrate, or store stormwater runoff. The agencies' practice is to
view stormwater control measures that are not built in ``waters of the
United States'' as non-jurisdictional. Conversely, the agencies
currently view some waters, such as channelized streams with
intermittent or perennial flow, as jurisdictional even where used as
part of a stormwater management system. Nothing in the proposed rule is
intended to change that practice. Rather, this exclusion would clarify
the appropriate limits of jurisdiction relating to these systems. A key
element of the exclusion is whether the feature or control system was
built in upland and whether it conveys, treats, or stores stormwater.
Certain features, such as curbs and gutters, may be features of
stormwater collection systems, but have never been considered waters of
the United States. Stormwater control features have evolved
considerably over the past several years, and their nomenclature is not
consistent, so in order to avoid unintentionally limiting the proposed
exclusion, the agencies have not included a list of excluded features
in the rule. The proposed rule is intended to exclude the diverse range
of stormwater control features that are currently in place and may be
developed in the future.
    Traditionally, stormwater controls were designed to direct runoff
away from people and property as quickly as possible. Cities built
systems to collect, convey, or store stormwater, using structures such
as curbs, gutters, and sewers. Retention and detention stormwater ponds
were built to store excess stormwater until it could be more safely
released. More recently, treatment of stormwater has become more
prevalent to remove pollutants before the stormwater is discharged.
Even more recently, cities have turned to green infrastructure, using
existing natural features or creating new features that mimic natural
hydrological processes that work to infiltrate or evapo-transpirate
precipitation, to manage stormwater at its source and keep it out of
the conveyance system. These engineered components of stormwater
management systems can address both flood control and water quality
concerns, as well as provide other benefits to communities. This
proposed rule is designed to avoid disincentives to this
environmentally beneficial trend in stormwater management practices.
    The agencies propose to exclude wastewater recycling structures
constructed in upland, such as detention, retention and infiltration
basins and ponds, and groundwater recharge basins in paragraph (b)(10).
This proposed exclusion clarifies the agencies' current practice that
waters and water features used for water reuse and recycling would not
be jurisdictional when constructed in upland. The agencies recognize
the importance of water reuse and recycling, particularly in areas like
California and the Southwest where water supplies can be limited and
droughts can exacerbate supply issues. This proposed exclusion responds
to numerous commenters and is intended to avoid discouraging or
creating barriers to water reuse and conservation. Many commenters
noted the growing interest in and commitment to water recycling and
reuse projects. Detention and retention basins can play an important
role in capturing and storing water prior to beneficial reuse.
Similarly, groundwater recharge basins and infiltration ponds are
becoming more prevalent tools for water reuse and recycling. These
features are used to

collect and store water, which then infiltrates into groundwater via
permeable soils. Though these features are often created in upland,
they are also often located in close proximity to tributaries or other
larger bodies of water. The proposed exclusion in paragraph (b)(10)
would codify longstanding agency practice and encourage water
management practices that the agencies recognize are important and
beneficial.
    Proposed paragraph (b)(11) would exclude waste treatment systems.
The waste treatment system exclusion has existed since 1979, and the
agencies are continuing such exclusion under this proposal. The
agencies are also for the first time proposing a definition of ``waste
treatment system'' under paragraph (c)(14) to clarify which waters and
features are considered part of a waste treatment system and therefore
excluded. Continuing current practice, any entity with a waste
treatment system would need to comply with the CWA by obtaining a
section 404 permit if constructed in waters of the United States, and a
section 402 permit for discharges from the waste treatment system into
waters of the United States. The agencies intend for this exclusion to
apply only to waste treatment systems constructed in accordance with
the requirements of the CWA and to all waste treatment systems
constructed prior to the 1972 CWA amendments. One proposed ministerial
change is the deletion of a cross-reference in the current language to
an EPA regulation that no longer exists.
    Some pre-proposal commenters suggested the agencies clarify how the
waste treatment system exclusion is currently implemented. Many
comments raised questions about stormwater systems and wastewater reuse
and whether such facilities are considered part of a complete waste
treatment system for purposes of the waste treatment system exclusion.
For clarity, the agencies propose related exclusions in paragraphs
(b)(9) and (b)(10) and propose to add settling basins and cooling ponds
to the definition of ``waste treatment system'' in paragraph (c)(14).
The agencies note that cooling ponds that are created under section 404
in jurisdictional waters and that have section 402 permits are and
would continue to be subject to the waste treatment system exclusion
under the proposed rule. Cooling ponds created to serve as part of a
cooling water system with a valid state permit constructed in waters of
the United States prior to enactment of the 1972 amendments of the CWA
and currently excluded from jurisdiction would also remain excluded
under the proposed rule.
3. How might the agencies implement this approach?
    The agencies propose to include an exclusion for groundwater under
paragraph (b)(2), including groundwater drained through subsurface
drainage systems. The agencies added the subsurface drainage
clarification to specify that even when groundwater is channelized in
subsurface systems, like tile drains used in agriculture, it still
remains subject to the exclusion. However, the exclusion would not
apply to surface expressions of groundwater, such as where groundwater
emerges on the surface and becomes baseflow in intermittent or
perennial streams.
    The proposed rule would exclude ephemeral features and diffuse
stormwater run-off including directional sheet flow over upland under
proposed paragraph (b)(3). This exclusion would include ephemeral
flows, swales, and erosional features, including gullies and rills, as
non-jurisdictional features. Tributaries can be distinguished from
these excluded features by the flow regime proposed in the definition
of ``tributary.'' Tributaries would have intermittent or perennial flow
while these proposed excluded features would have ephemeral flow. It
should be noted that some streams are colloquially called ``gullies''
or the like even when they exhibit the characteristics of a tributary;
regardless of the name they are given locally, waters that meet the
definition of ``tributary'' would not be excluded ephemeral features.
    With respect to implementing the proposed ditch exclusions
consistent with the proposed rule, that reach of a ditch that meets any
of the three categories in paragraph (a)(3) would be considered a
``water of the United States.'' The jurisdictional status of other
reaches of the same ditch would have to be assessed based on the
specific facts and under the terms of the proposed rule to determine
the jurisdictional status of the ditch. For example, a ditch that is
constructed in a tributary would not be an excluded ditch under
proposed paragraph (b)(4) so long as it satisfies the conditions of the
tributary definition, and a ditch is constructed in a tributary when at
least a portion of the tributary's original channel has been physically
moved. Further, the exclusion of a ditch does not affect the possible
status of the ditch as a point source. The agencies believe the
proposed ditch exclusion included in the proposed rule would address
the majority of irrigation and drainage ditches, including most
roadside and other transportation ditches, as well as agricultural
ditches.
    For the proposed prior converted cropland exclusion, the agencies
propose to clarify that when cropland has been abandoned and wetlands
have returned, any prior converted cropland designation for that site
would no longer be valid for purposes of the CWA. In general, the
Corps' current practice has been to defer to certifications of prior
converted cropland made by the USDA for areas in agricultural use; but
in instances when land has been proposed to change from agricultural to
non-agricultural use, the Corps has made new jurisdictional
determinations, regardless of any previous designation of prior
converted cropland or if an actual change in use has occurred. In other
instances when cropland may have been abandoned, the Corps may apply
the test from the 1993 preamble. This proposed rule would clarify that
the Corps would only apply abandonment principles consistent with the
1993 preamble and would no longer apply the change in use analysis.
Under the proposed rule, the Corps must first determine if the land has
been ``abandoned.'' Prior converted cropland will be considered
abandoned if it is not used for, or in support of, agricultural
purposes at least once in the immediately preceding five years. If the
Corps determines that the land is abandoned, then it must evaluate the
current condition of the land to determine whether wetlands conditions
have returned. If wetlands are currently present on the property, the
Corps must determine whether the wetlands are waters of the United
States, consistent with this proposed rule.
    As the term ``prior converted cropland'' suggests, and as stated in
the preamble to the 1993 Rule, land properly designated prior converted
cropland has typically been so extensively modified from its prior
condition that it no longer exhibits wetland hydrology or vegetation,
and no longer performs the functions it did in its natural and original
condition as a wetland. 58 FR 45032. It is often altered and degraded,
with long-term physical and hydrological modifications that
substantially reduce the likelihood of reestablishment of hydrophytic
vegetation. Consistent with longstanding Corps policy and wetland
delineation procedures, if a former wetland has been lawfully
manipulated to the extent that it no longer exhibits wetland
characteristics under normal circumstances, it would not be a
jurisdictional wetland under the CWA. The altered nature of prior
converted

cropland and its conditions constitute the ``normal circumstances'' of
such areas. The agencies expect the majority of prior converted
cropland in the nation to fall into this category and not be subject to
CWA regulation, even after it is abandoned.
    However, at least some abandoned prior converted cropland may,
under normal circumstances, meet the proposed definition of
``wetlands'' under paragraph (c)(15). To determine whether wetland
characteristics are present under ``normal circumstances,'' and whether
the site contains waters of the United States as defined under this
proposed rule, the agencies could, pursuant to existing regulations and
guidance, and in accordance with this proposed rule, prepare a new
jurisdictional determination for abandoned prior converted cropland.
Such a determination would also evaluate whether the wetland is
adjacent within the meaning of paragraph (c)(1) of this proposed rule.
    The agencies consider rulemaking to be appropriate here in order to
clarify the definition of ``prior converted cropland'' and to provide
regulatory certainty over when such lands are no longer eligible for
the CWA exclusion. The USDA is responsible for making the determination
as to whether land is prior converted cropland for its program
purposes, which the agencies would adopt for purposes of the prior
converted cropland exclusion under this proposed rule. The EPA and the
Corps enforce the prior converted cropland exclusion for CWA purposes
and identify whether lands that are no longer prior converted cropland
may be waters of the United States. The EPA and the Corps intend to
consult with other federal agencies as appropriate, including USDA,
when evaluating whether a parcel of land may no longer be eligible for
the CWA prior converted cropland exclusion. The agencies'
implementation of the proposed prior converted cropland exclusion for
CWA regulatory purposes does not affect USDA's administration of the
Swampbuster program or a landowner's eligibility for benefits under
that program.
    In paragraph (b)(6), the agencies propose to clarify their
longstanding view that the artificial irrigation exclusion would only
apply to the specific land being directly artificially irrigated,
including fields flooded for rice or cranberry growing, which would
revert to upland should artificial irrigation cease; it is not the case
that all waters within watersheds where irrigation occurs would be
excluded. Historically, the agencies have taken the position that ponds
for rice growing are generally not considered waters of the United
States, as reflected in the 1986 preamble and the 2015 Rule. See 51 FR
41217. In the past, the agencies have considered those under the
artificial lakes or ponds exclusion but propose today to include them
in the artificial irrigation category as any wetland crop species, such
as rice and cranberry operations, is typically supplied with artificial
flow irrigation or similar mechanisms. The agencies take comment on
whether this approach is better aligned with existing practices or if
rice and cranberry operations should remain in the artificial lakes and
ponds exclusion.
    In the proposed exclusion at (b)(7) for artificial lakes or ponds,
the agencies have also proposed to add farm ponds, log cleaning
ponds,\33\ and cooling ponds to the list of excluded ponds in the rule
for additional clarity. Artificial lakes and ponds created in upland
and not subject to jurisdiction under paragraphs (a)(4) or (a)(5) would
be excluded. As proposed, this exclusion would also apply to artificial
lakes and ponds created as a result of impounding non-jurisdictional
waters or features. Conveyances created in upland that are physically
connected to and are a part of the proposed excluded feature would also
be excluded. The agencies emphasize that ponds that are proposed to be
excluded from ``waters of the United States'' could, in some
circumstances, be point sources of pollutants subject to section 301 of
the Act.
---------------------------------------------------------------------------

    \33\ Log cleaning ponds are used to float logs for removal of
twigs, branches, and large knots.
---------------------------------------------------------------------------

    Under proposed paragraph (b)(8), the proposed rule would exclude
water-filled depressions created in upland incidental to mining or
construction activity, and pits excavated in upland for the purpose of
obtaining fill, sand, or gravel. In addition to construction activity,
the agencies have proposed to exclude water-filled depressions created
in upland incidental to mining activity. Since pits excavated in upland
for the purpose of obtaining fill, sand, or gravel, which are forms of
mining, were not considered to be ``waters of the United States'' as
described in the 1986 and 1988 preambles, the agencies believe mining
activities should also be explicitly excluded. This is consistent with
the 2015 Rule. In addition, through this proposed exclusion the
agencies intend to make clear that such water-filled depressions and
pits would typically not become ``waters of the United States.''
    The agencies also propose to exclude in paragraph (b)(9) stormwater
control features excavated or constructed in upland to convey, treat,
infiltrate or store stormwater run-off. As stated previously, the
proposed rule is intended to exclude the diverse range of stormwater
control features that are currently in place and may be developed in
the future. This proposed exclusion does not cover ditches, as ditches
would be addressed under paragraph (b)(4) of the proposed rule.
    Paragraph (b)(10) of the proposed rule clarifies that wastewater
recycling structures constructed in upland would be excluded. The
agencies propose to include in this exclusion detention and retention
basins as well as groundwater recharge basins and infiltration ponds
built for wastewater recycling. The proposed exclusion would also cover
water distributary structures that are built in upland for water
recycling. These features often connect or carry flow to other water
recycling structures, for example a channel or canal that carries water
to an infiltration pond. The agencies have not considered these water
distributary systems jurisdictional.
    The existing exclusion for waste treatment systems moves to
paragraph (b)(11). As discussed above, the agencies propose to not
change the longstanding approach to implementing the waste treatment
exclusion. As a result, the agencies would continue to apply the
exclusion to systems that are treating water so as to meet the
requirements of the CWA. Discharges from these systems to waters of the
United States would continue to be subject to regulation by the section
402 permitting program. Similarly, if a waste treatment system is
abandoned or otherwise ceases to serve the treatment function for which
it was designed, it would not continue to qualify for the exclusion.
    The agencies also considered other exclusions recommended by
stakeholders that were not added to the proposed rule. The agencies did
not propose these additional exclusions because they were either so
broadly characterized as to introduce significant confusion and
potentially exclude waters that the agencies have consistently
determined should be covered as ``waters of the United States,'' they
were so site-specific or activity-based that they did not warrant
inclusion in the nationally-applicable definition, or they were covered
by another exclusion in the proposed rule.
    It is important to note that while the waters and features listed
in the proposed exclusions would not be ``waters of the United
States,'' some of

them may convey perennial or intermittent flow to a downstream
jurisdictional water, so that portions of a tributary upstream and
downstream of the excluded water may meet the definition of
``tributary'' at (c)(11). For example, when water from a tributary is
moved into another jurisdictional water through an excluded ditch, the
ditch itself would be excluded from jurisdiction under the proposed
rule but the tributary upstream and downstream of such break would
remain ``waters of the United States.'' Excluded geographic features,
such as ditches, may function as ``point sources'' under CWA section
502(14), so that discharges of pollutants to navigable waters through
these features would be subject to other parts of the CWA (e.g., CWA
section 402).
4. What are specific issues upon which the agencies are seeking
comment?
    The agencies seek comment on all aspects of the proposed
exclusions. In addition, the agencies solicit comment on whether they
should enumerate additional specific exclusions for the purposes of
clarity, or whether proposed paragraphs (a) and (b) are sufficiently
clear as to account for all of the agencies' intended jurisdictional
and non-jurisdictional waters. For example, features that move water
(particularly in the arid West) that do not eventually reconnect into a
tributary or other jurisdictional water would not be jurisdictional and
therefore do not need their own specific exclusion. These features
would not meet the definition of ``tributary'' or may meet the
currently proposed ditch exclusion as an artificial conveyance of
water. However, the agencies seek comment on the jurisdictional status
of features (other than the ditches the agencies currently propose to
exclude) whose purpose is to move water and which do eventually
reconnect to the tributary system.
    Further, the agencies seek comment on the clarity of the
groundwater exclusion in proposed paragraph (b)(2) and ask commenters
to consider whether the exclusion could instead read, ``groundwater,
including diffuse or shallow subsurface flow and groundwater drained
through subsurface drainage systems.'' The agencies recognize that
unique groundwater situations such as shallow aquifers and tile
drainage systems exist around the country and welcome comments on the
parameters of the groundwater exclusion and any implementation issues
that may arise.
    With respect to the proposed exclusion for ditches, the agencies
solicit comment on whether certain ditches excavated in upland but with
perennial or intermittent flow to an (a)(1) through (5) water should be
treated as a jurisdictional tributary and why, and if so, what flow
regime would apply (e.g., perennial only or both perennial and
intermittent). Recognizing that excluded ditches must be used to convey
water, the agencies also seek comment on whether the exclusion for
ditches should instead focus on particular ditch use, such as roadside,
railway, agriculture, irrigation, water supply, or other similar uses,
and if so, why. As discussed in Section III.E, the agencies are
soliciting comment on available tools to help identify whether a
``ditch'' is artificial or whether it was constructed in a tributary or
adjacent wetland.
    The agencies solicit comment on the proposed exclusion of prior
converted cropland that uses the abandonment principle to determine
whether prior converted cropland would be subject to CWA jurisdiction
or if the agencies should apply the change in use analysis. The
agencies also solicit comment on procedures that may be useful in
implementing the proposed exclusion for prior converted cropland. In
particular, the agencies solicit comment as to what constitutes ``for,
or in support of, agricultural purposes'' as the term applies to the
proposed prior converted cropland definition in this proposal. The
agencies also seek comment on the kind of documentation a landowner
must maintain to demonstrate that cropland has not been abandoned, or
in the alternative, that the land has been used for, or in support of,
agricultural purposes at least once in the immediately preceding five
years. The agencies also solicit comment on what evidence, other than a
USDA determination, the agencies should evaluate and rely upon to
determine if cropland is eligible for the prior converted cropland
exclusion. Finally, the agencies solicit comment on whether the five-
year timeframe for maintaining agricultural purposes is appropriate.
    The agencies also request comment on whether the proposed exclusion
for artificially irrigated areas should include fields flooded to
support the production of other wetland crop species in addition to
rice and cranberries. Additionally, the agencies seek comment on
whether the proposed artificially irrigated areas exclusion should be
expanded to include areas flooded to support aquaculture, such as
crayfish production.
    The agencies also seek comment on whether the waters and features
proposed to be excluded in paragraphs (b)(7), (b)(8), (b)(9), and
(b)(10) must be constructed wholly in upland, not just in upland as
provided in the proposed regulatory text, in order for the exclusion to
apply and how such a requirement would affect the utility of these
proposed exclusions. The agencies also request comment on whether the
proposed exclusion in paragraph (b)(9) for stormwater control features
should be expanded or clarified to include permitted municipal separate
storm sewer systems (MS4s). If so, the agencies request comment on
whether the exclusion would apply to the entire MS4 or limited portions
thereof. The agencies also request comment on how they might implement
such an exclusion.
    The agencies intend for the exclusion in paragraph (b)(11) to apply
only to lawfully constructed waste treatment systems. The agencies
solicit comment on whether greater clarity is needed by including in
the rule text that the exclusion only applies to ``lawfully constructed
waste treatment systems.''

I. Summary of Proposed Rule as Compared to the 1986 and 2015
Regulations

    The agencies are proposing a definition of ``waters of the United
States'' that they consider to be superior to both the 1986 and 2015
Rules. The agencies are proposing to revise previous regulatory
definitions of this term to distinguish between water that is a ``water
of the United States'' subject to Federal regulation under the CWA and
water or land that is subject to exclusive State or tribal
jurisdiction, consistent with the scope of jurisdiction authorized
under the CWA and the direction in that Act to ``recognize, preserve,
and protect the primary responsibilities and rights of States to . . .
plan the development and use (including restoration, preservation, and
enhancement) of land and water resources . . . .'' 33 U.S.C. 1251(b).
The Supreme Court has recognized that new administrations may
reconsider the policies of their predecessors so long as they provide a
reasonable basis for the change in approach. Nat'l Ass'n of Home
Builders v. EPA, 682 F.3d 1032, 1038 & 1043 (D.C. Cir. 2012), citing
FCC v. Fox Television Stations, Inc., 556 U.S. 502, 514-15 (2009)
(Rehnquist, J., concurring in part and dissenting in part). The
agencies intend that the proposed revised interpretation of the Federal
regulatory scope of the CWA would resolve longstanding confusion over
broad and unclear definitions of ``waters of the United States.''
    The agencies propose to replace the 2015 Rule for the reasons
discussed in the Step 1 proposal and supplemental

notice of proposed rulemaking (SNPRM). See 83 FR 32227 (July 12, 2018).
In addition, the agencies consider this proposal to adhere more closely
than the 2015 Rule to the text of the CWA and its legislative history,
to the scope of Congress' authority in promulgating the CWA, to the
guiding principles that the Supreme Court has articulated in Riverside
Bayview, SWANCC, and Rapanos for interpreting the reach of the CWA, and
because it provides a straightforward definition that would be easier
to implement than the 2015 Rule. As discussed in Section II of the
preamble, this proposed definition of ``waters of the United States''
reflects the ordinary meaning of the term ``waters,'' such as oceans,
rivers, and lakes, as opposed to, as discussed in the Step 1 SNPRM, for
example, ephemeral geographic features that are dry almost all of the
year, as well as nonnavigable, isolated waters as the 2015 Rule would
regulate.
    The agencies consider the proposed definitions of ``tributary'' and
``adjacent wetlands'' to be more consistent with the Supreme Court's
interpretation of the agencies' authority than the scope of ``waters of
the United States'' under the 2015 Rule. Congress' traditional commerce
power over navigation extends beyond waters traditionally considered
navigable, but it is not unlimited. This proposed interpretation of the
scope of ``waters of the United States'' would adhere more closely to
the limits of Congress' authority over navigable waters than the 2015
Rule, which allows for jurisdiction over a range of ephemeral waters
that meet that regulation's definition of ``tributary'' (as well as
physically remote isolated wetlands and other waters) that may be
located at great distances from traditional navigable waters, so long
as they have indicators of a bed, banks, and ordinary high-water mark
and eventually contribute flow to a navigable water.
    In addition, this proposal would also adhere more closely than the
2015 Rule to the statute and legislative history of the Act, including
the policy articulated in CWA section 101(b) that States should
maintain primary responsibility over land and water resources. 33
U.S.C. 1251(b). As noted in the Step 1 SNPRM, many commenters on the
2015 Rule indicated that the potential breadth of the 2015 Rule could
interfere with State and local land use planning. They expressed
particular concern that the 2015 Rule's use of the 100-year floodplain
as a factor to establish jurisdiction and the extension of jurisdiction
potentially to water features as far as 4,000 feet from a covered
tributary, traditional navigable water, interstate water, or
territorial sea extended into the regulatory domain of States, Tribes,
and local governments. This proposed definition of ``waters of the
United States,'' which would limit CWA jurisdiction over rivers and
streams to those that contribute perennial or intermittent flow to
traditional navigable waters or territorial seas in a typical year,
certain lakes and ponds, and wetlands abutting or having a direct
hydrologic surface connection to other jurisdictional waters in a
typical year, would restore the authority of States, Tribes, and local
governments over large swaths of lands and waters that they have
traditionally managed based on the preferences of their citizens. See
SWANCC, 531 U.S. at 174.
    The agencies believe that this proposal is also more consistent
with Rapanos than the 2015 Rule. It reflects the key concepts in the
plurality opinion that limited jurisdiction to relatively permanent
waters and wetlands with a continuous surface connection to those
waters, 547 U.S. at 742, 751 n.13, as well as addressing Justice
Kennedy's concern with respect to regulation of wetlands adjacent to
``drains, ditches, and streams remote from any navigable-in-fact water
and carrying only minor water volumes towards it,'' id. at 781. The
plurality and Justice Kennedy both agreed in principle that the
definition of ``waters of the United States'' must consider: (1) The
connection of the wetland to the tributary; and (2) the status of the
tributary with respect to downstream traditional navigable waters. The
plurality refers to the necessary connection of a wetland to a
tributary as a ``continuous surface connection'' or ``continuous
physical connection,'' as demonstrated in Riverside Bayview. Id. at
742, 751 n.13. Justice Kennedy states that the Act requires a water or
wetland have a connection in the form of a ```significant nexus' to
waters that are or were navigable in fact or that could reasonably be
so made.'' Id. at 759. Justice Kennedy recognized that ``the connection
between a nonnavigable water or wetland and a navigable water may be so
close, or potentially so close, that the Corps may deem the water or
wetland a `navigable water' under the Act. In other instances, as
exemplified by SWANCC, there may be little or no connection.'' Id. at
767. The agencies are particularly concerned that the 2015 Rule's
reading of Justice Kennedy's significant nexus test exceeds the
agencies' authority under the Act, for the reasons discussed in the
Step 1 SNPRM.
    For example, as the Step 1 SNPRM explains, Justice Kennedy wrote
that adjacent ``wetlands possess the requisite nexus, and thus come
within the statutory phrase `navigable waters,' if the wetlands, either
alone or in combination with similarly situated lands in the region,
significantly affect the chemical, physical, and biological integrity
of other covered waters more readily understood as `navigable.' '' Id.
at 780. The opinion does not define the terms ``in the region'' or
``similarly situated,'' but it is reasonable to presume that that
Justice Kennedy did not intend ``similarly situated'' to be synonymous
with ``all'' waters in a region. The 2015 Rule, however, effectively
applied the significant nexus test to lakes, ponds, and other waters,
not just wetlands, either alone or in combination with other waters in
an entire watershed. See, e.g., 80 FR 37106. The agencies are concerned
that this broad reading of the significant nexus test relies too
heavily on considerations that Justice Kennedy expresses regarding the
interconnected nature of waters but fails to balance those
``environmental concerns'' with the ``limits in the statutory text''
the agencies cannot disregard. See 547 U.S. at 778. The agencies also
do not think that the opinion of a single justice in a complex case
should be the primary determinant of federal jurisdiction over
potentially large swaths of aquatic resources, particularly an approach
that relies on potentially subjective case-by-case application that
reduces regulatory certainty for the regulated community and hinders
straightforward implementation by regulatory agencies.
    The agencies also believe the definitions of ``tributary'' and
``adjacent wetlands'' in this proposed rule better reflect the
importance of the term ``navigable'' in ``navigable waters,'' id. at
778-79, than did the analogous definitions in the 2015 Rule. This
proposal would give effect to the term ``navigable'' by limiting
jurisdiction to tributaries and wetlands that have a continuous
physical connection, during some part of a typical year, to traditional
navigable waters or the territorial seas. In contrast, under the 2015
Rule, all features meeting the ``tributary'' definition, including
ordinarily dry channels, are categorically jurisdictional no matter how
small, remote, or frequently flowing, and all ``adjacent'' waters and
wetlands, such as those located within 1,500 feet of the high tide line
of an (a)(1) or (a)(3) water, are categorically jurisdictional.
Additionally, the 2015 Rule provides that waters and wetlands as far as
4,000

feet from an (a)(1) through (5) water are jurisdictional if they,
either alone or in combination with other similarly situated waters in
the region, significantly affect the chemical, physical, or biological
integrity of an (a)(1) through (3) water. Such interpretations create
considerable tension with Justice Kennedy's understanding of the term
``significant nexus.'' See id. at 781-82 (``[I]n many cases wetlands
adjacent to tributaries covered by [the Corps' 1986 tributary] standard
might appear little more related to navigable-in-fact waters than were
the isolated ponds held to fall beyond the Act's scope in SWANCC.'').
The agencies are concerned that these expansive interpretations of key
elements of the definition of ``waters of the United States'' in the
2015 Rule may not comport with the CWA. See id. at 778. As the agencies
described in the Step 1 SNPRM, the 2015 Rule may have failed to
appropriately recognize that the science in the Connectivity Report,
while informative and important to consider, is not dispositive in
interpreting the statutory reach of ``waters of the United States,''
which is ultimately a legal determination based on the language and
structure of the Act and applicable judicial precedent. Id.\34\
---------------------------------------------------------------------------

    \34\ In the 2015 Rule, the agencies acknowledged that science
cannot dictate where to draw the line of federal jurisdiction. See,
e.g., 80 FR 37060. Notwithstanding that qualifier, the agencies
relied on the Connectivity Report extensively in establishing the
2015 Rule's definition of ``waters of the United States.''
---------------------------------------------------------------------------

    The agencies are mindful that courts that have considered the
merits of challenges to the 2015 Rule have similarly observed that the
rule may conflict with Justice Kennedy's opinion in Rapanos,
particularly the rule's definition of ``tributary.'' See North Dakota,
127 F. Supp. 3d at 1056; Georgia, 2018 U.S. Dist. LEXIS 97223, at *17.
Likewise, the Sixth Circuit stated in response to petitioners' ``claim
that the Rule's treatment of tributaries, `adjacent waters,' and waters
having a `significant nexus' to navigable waters is at odds with the
Supreme Court's ruling in Rapanos'' that ``[e]ven assuming, for present
purposes, as the parties do, that Justice Kennedy's opinion in Rapanos
represents the best instruction on the permissible parameters of
`waters of the United States' as used in the Clean Water Act, it is far
from clear that the new Rule's distance limitations are harmonious with
the instruction.'' In re EPA, 803 F.3d at 807 & n.3 (noting that
``[t]here are real questions regarding the collective meaning of the
[Supreme] Court's fragmented opinions in Rapanos''). This proposed
tributary definition as a river or stream that contributes perennial or
intermittent flow to a traditional navigable water or territorial sea
in a typical year, better reflects the limits to the agencies'
authority that the plurality, as well as Justice Kennedy, recognized in
Rapanos.
    The proposed definition of ``adjacent wetlands'' in this
rulemaking, which encompasses wetlands abutting or having a direct
hydrologic surface connection to other jurisdictional non-wetland
waters in a typical year also specifically reflects the Supreme Court's
longstanding views on the scope of jurisdictional wetlands, as opposed
to the far broader interpretation in the 2015 Rule. Since Riverside
Bayview, the Court has held that the Corps could define ``waters of the
United States'' to include wetlands ``actually abut[ting]'' navigable
waters, but it has not extended its deference to an agency
interpretation to encompass more physically remote wetlands. Rapanos,
547 U.S. at 740, 741 n.10 (Scalia, J., plurality), citing Riverside
Bayview, 474 U.S. at 135, and SWANCC, 531 U.S. 159. The 2015 Rule
expanded the scope of jurisdictional wetlands well beyond those
wetlands ``that form the border of or are in reasonable proximity to
other waters of the United States,'' Riverside Bayview, 474 U.S. at
134, quoting 42 FR 37128 (July 19, 1977), that the Supreme Court has
long held to be a permissible exercise of authority of the CWA. For
instance, the 2015 Rule defined ``adjacent'' and, in turn,
``neighboring'' to include as categorically jurisdictional all waters
located within the 100-year floodplain of an (a)(1) through (5) water
and not more than 1,500 feet from the ordinary high water mark of such
water. The agencies propose to correct this broad interpretation,
thereby maintaining consistency with the Supreme Court's opinions and
ensuring the agencies operate within the bounds of our Constitutional
authority, see SWANCC, 531 U.S. at 172, as well as protecting the
States' traditional authority over their waters and land use, and the
right of the public to clear limits to agency authority.
    The proposed rule's specific tributary and adjacent wetlands
definitions would eliminate the need for the case-specific significant
nexus test that was required for many features after Justice Kennedy's
concurring opinion in Rapanos and according to the agencies' Rapanos
Guidance. The categorical treatment of all tributaries and adjacent
wetlands, as defined by this proposal, will provide clarity to the
regulated public regarding the jurisdictional status of such features
and ease the administrative burden the agencies face in conducting a
case-specific significant nexus analysis to complete many
jurisdictional determinations under previous regulations and guidance.
    This proposal would also establish greater clarity with respect to
the scope of CWA jurisdiction than the 2015 Rule. The Step 1 SNPRM
described the widespread confusion regarding the reach of the 2015
Rule. Filings in the Sixth Circuit demonstrate that petitioners
representing the States in that case view the 2015 Rule as extending
``jurisdiction to virtually every potentially wet area of the
country.'' Opening Brief of State Petitioners at 15, 61, In re EPA, No.
15-3751 (6th Cir. Nov. 1, 2016). In contrast, petitioners representing
environmental organizations viewed the 2015 Rule as violating the CWA
by failing to cover certain waters. Brief of Conservation Groups at 11,
In re EPA, No. 15-3751 (6th Cir. Nov. 1, 2016). In addition to the
differing interpretations of stakeholders, the litigation itself could
lead to further uncertainty. A successful challenge to the 2015 Rule
could result in a court order vacating the rule in all or part of the
country, potentially contributing to the existing patchwork of legal
regimes in effect in different parts of the country. This proposed
definition of ``waters of the United States'' would establish bright
line jurisdictional boundaries that are intended to be easily
comprehensible and implementable by the regulated community, and would
avoid the potentially extremely complex jurisdictional landscape that
could result from litigation over the 2015 Rule.
    The agencies believe that the proposed rule would also be clearer
than both the substantive content of the 1986 Rule and the way it has
been implemented as a result of litigation. For the reasons discussed
in the Step 1 proposal and SNPRM, the 1986 Rule, as interpreted by the
Supreme Court and implemented through agency guidance, is preferable to
the 2015 Rule. However, a clear, comprehensive regulation that
encompasses the Supreme Court's interpretations and agency guidance is
preferable to the 1986 Rule. The language of the original 1986 Rule
leaves substantially more room for discretion and case-by-case
variation than this proposal, particularly paragraph (a)(3) in the 1986
regulation, which claims jurisdiction over waters that are used by
interstate or foreign travelers for recreational or other purposes,
with no reference to navigable waters. Following the Supreme Court's
opinions on the definition of ``waters of the United States,''
particularly

SWANCC and Rapanos, the 1986 Rule cannot be implemented as promulgated,
but rather it must be implemented taking into account the Court's
holdings and agency guidance interpreting those cases. In the decade
since the Rapanos decision, the agencies and the public have become
familiar with this multi-layered interpretive approach, which is the
reason that the agencies have proposed maintaining this regime during
the process of developing and considering public comments on this
proposal. Yet a codified definition of ``waters of the United States''
that incorporates Supreme Court caselaw and guidance, and is clear as
to the scope of jurisdictional waters, certainly provides greater
regulatory predictability than the 1986 regulations, as interpreted by
the Supreme Court and implemented through agency guidance.
    This proposal more appropriately reflects the scope of the
agencies' authority under the statute, the Constitution, the vital role
of the States and Tribes in managing their land and water resources,
and the need of the public for predictable, easily implementable
regulations.

J. Placement of the Definition of Waters of the United States in the
Code of Federal Regulations

    Consistent with existing placement of the definition of ``waters of
the United States'' in the Code of Federal Regulations, the agencies
propose to locate the proposed definition of ``waters of the United
States'' at 33 CFR 328.3, 40 CFR 110.1, 112.2, 116.3, 117.1, 122.2,
230.3, 232.2, 300.5, 401.11, and Appendix E to 40 CFR part 300.
Alternatively, the agencies seek comment on whether the definition
should be codified in just two places in the Code of Federal
Regulations for the sake of simplicity, rather than in the eleven
locations in which it currently appears. Following this alternate
approach, the agencies would retain one definition in Title 33 of the
Code of Federal Regulations, which implements the Corps' statutory
authority, and one in Title 40, which generally implements EPA's
statutory authority. The agencies are not aware of any implications
that this alternate approach might have on program implementation aside
from making references to the definition less confusing. The agencies
solicit comment on any potential impacts this alternate placement
approach could have on program implementation.

IV. State, Tribal and Federal Agency Datasets of ``Waters of the United
States''

    During the extensive pre-proposal outreach to the general public
and focused engagement with States and Tribes, the agencies heard from
a number of States about their familiarity with waters within their
borders and their expertise in aquatic resource mapping. As co-
implementers of CWA programs, they also emphasized the potential
benefit of greater State and tribal involvement in jurisdictional
determinations. Several States suggested the agencies consider their
knowledge and increase the role of States and Tribes in identifying
those waters that are ``waters of the United States.'' Stakeholders
also indicated that maps could increase certainty and transparency
regarding the data and methods used to determine which waters are
jurisdictional and which waters are not.
    In response, the agencies are interested in advancing the
development of state-of-the-art geospatial data tools through Federal,
State and tribal partnerships to provide an enhanced, publicly-
accessible platform for critical CWA information, such as the location
of federally jurisdictional waters, the applicability of State and
tribal water quality standards, permitted facility locations, impaired
waters, and other important features.
    Such mapped features would make it easier for agency field staff,
the general public, property owners, permit-holders and others to
understand the relationship between familiar geographical features and
the overlay of CWA jurisdictional waters. For Federal, State and tribal
agencies, such geospatial data sets could improve the administration of
CWA programs and attainment of water quality goals. Geospatial datasets
and resulting future maps that indicate which waters are likely subject
to federal jurisdiction could allow members of the regulated community
to more easily and quickly ascertain whether they may want to contact a
government agency regarding the potential need for a CWA permit. These
datasets, when fully developed, would promote greater regulatory
certainty and relieve some of the regulatory burden associated with
determining the need for a permit and play an important part in helping
to attain the goals of the CWA. They could also eventually be used to
identify in one layered geospatial map water quality standards, total
maximum daily loads, water quality monitoring data, and other
beneficial information.
    The agencies are seeking public input on possible approaches to
developing or utilizing existing aquatic resource mapping, remote
sensing technology, or satellite data in order to facilitate the
implementation of this proposed definition of ``waters of the United
States.'' Specifically, the agencies are interested in suggestions for
how to create a regulatory framework that would authorize interested
States, Tribes, and Federal agencies to develop for the agencies'
approval geospatial datasets representing ``waters of the United
States,'' as well as waters excluded from the definition and ``waters
of the State'' or ``waters of the Tribe'' within their respective
borders.
    The agencies anticipate that such geospatial dataset development
would be optional and not a requirement. The agencies are not proposing
such a framework today because they would like to engage more fully in
discussions with States, Tribes, other Federal agencies, and other
technical experts before developing a proposal. The agencies anticipate
a possible future rulemaking that could propose a specific approach
that would be informed by public comments and suggestions on this
notice.
    State and tribal geospatial datasets would be unrelated to the
ability of States or Tribes to establish their own jurisdiction over
waters based on State or tribal law that may be broader than the CWA.
They would also be unrelated to the subset of waters for which a State
or Tribe could assume permitting responsibility for under the CWA, such
as section 402 and section 404 permitting. In a separate rulemaking,
the EPA intends to clarify the waters for which a State or Tribe could
assume responsibility under section 404(g).
    Developing geospatial datasets of ``waters of the United States''
may raise a number of technical and process challenges and questions.
This is why the agencies are soliciting public input on the feasibility
of creating a geospatial dataset of jurisdictional waters to help
inform the agencies' considerations rather than proposing a specific
approach today. Below is a discussion of some of the technical and
process considerations the agencies have anticipated. The public is
encouraged to comment on these and other challenges and questions that
might arise from geospatial datasets of CWA jurisdiction.
    Dataset development would likely be a longer-term activity
involving collaboration among technical geospatial experts from
Federal, State, tribal governments, and involving other

key stakeholders, such as consensus standards organizations, the
private sector, and academia. The agencies are aware that other
entities, including, but not limited to, the Advisory Committee on
Water Information, which reports to the Department of the Interior; the
National Hydrography Dataset program of the U.S. Geological Survey; the
National Wetlands Inventory program of the U.S. Fish and Wildlife
Service; the Risk Mapping, Assessment, and Planning program of the
Federal Emergency Management Agency; the National Wetland Team of the
Natural Resources Conservation Service; and others, possess geospatial
data and expertise in matters of geospatial identification of water
features. In addition, the agencies would anticipate drawing on the
expertise and infrastructure of the standing Federal Geographic Data
Committee (FGDC) for convening experts, resolving technical issues and
vetting developments and innovative ideas.
    In the realm of geospatial data, the Federal government has sought
to establish ``standards'' for geospatial data through the FGDC. The
agencies expect that a final rule defining the scope of ``waters of the
United States'' would be the policy with which any mapping effort would
need to be consistent. The primary question the methods and data
specifications would address is how to remotely identify the measurable
hydrologic features that comprise the ``waters of the United States''
in order to create these geospatial datasets. The agencies recognize
the need to provide specifications for the data in order to ensure that
``waters of the United States'' datasets are consistent nationwide.
These specifications would include the specific structure and content
details for the dataset itself, such as the acceptable geographic or
projected coordinate system(s), identification of all mandatory (and
any optional) data fields to be populated, minimum FGDC-compliant
metadata attributes, and acceptable file format(s).
    One approach the agencies could take is a future rulemaking
following collaboration with technical experts as described above and
prior to the States, Tribes, or Federal agencies creating such
datasets. States, Tribes, and Federal agencies could then submit
method(s) for creating a dataset which would be consistent with the
revised definition of ``waters of the United States.'' The EPA and
Corps would then review each proposed method in order to determine
whether the method results in a complete and accurate representation of
``waters of the United States'' within a dataset extent. Under this
approach, any methods determined to result in complete and accurate
datasets would be published in the Federal Register or through a public
website, along with a statement of the geographic area(s) where use of
each method is appropriate and approved for use. This approach would
likely account for the variation in landscapes and data availability
across the nation, would leverage the knowledge the Federal land
management agencies, States and Tribes possess regarding their own
geography, and could be completed sooner than if the agencies were to
develop applicable methods first.
    The agencies solicit comment on this proposed approach and
suggestions for alternative approaches that the agencies might consider
as part of a future rulemaking. For example, how would the methods and
datasets, once approved by the agencies, be most effectively
communicated to the public? One option might be that, as part of the
approval process, States, Tribes and Federal agencies undertake a
public notice and comment process for proposed datasets prior to
submitting the jurisdictional geospatial dataset to the EPA and the
Corps for approval. With respect to review by EPA and the Corps, should
there should be a requirement that the agencies approve or disapprove
the dataset within a set number of days? As datasets would need to be
updated periodically, the agencies also request comment on the
appropriate process for updating datasets and a reasonable frequency
for doing so such that the datasets effectively represent current
conditions.
    The goal would be to develop datasets that graphically represent
``waters of the United States'' or portions thereof, to which agencies'
staff, the potentially regulated community, and others could refer to
see waters that are presumptively jurisdictional under the CWA. No such
dataset currently exists. The agencies anticipate that, for such a
presumption, a geospatial dataset would need to be developed using a
method approved by the EPA and the Corps, be within the specifications
for the dataset, and be approved by the agencies to be of sufficient
quality. Such a dataset would be subject to potential site-specific
refinement in individual jurisdictional determinations to address, for
example, the lateral extent of jurisdiction. This approval or
disapproval could be subject to judicial review. Following approval,
the agencies anticipate that individual waters could be added to or
removed from a dataset based on site-specific jurisdictional
determinations. Presently, jurisdictional determinations by the Corps
are valid for five years, and the agencies anticipate these approved
geospatial datasets would need to be updated at a reasonable frequency
to ensure they reflect current conditions.
    As part of such an effort, the agencies would make public approved
methods, specifications and the geospatial datasets at a centralized
location. The agencies therefore solicit comment on appropriate
features and attributes of the website that would publish this
information, as well as any privacy considerations the agencies should
understand. In order to provide a useful tool to the public, the
agencies anticipate that each approved geospatial dataset would need to
be viewable online via a web-based map, on a federally-maintained
website. The EPA currently maintains a website at https://watersgeo.epa.gov/cwa/CWA-JDs/ that presents information on approved
jurisdictional determinations made by the Corps and the EPA under the
CWA since August 28, 2015. The agencies envision that in the future,
this site or another site could provide access to a web-based map.
    Because the EPA and the Corps would review the methods used to
generate the datasets for consistency with the definition of ``waters
of the United States'' and an acceptable level of completeness and
accuracy, the resulting State, tribal, and Federal agency datasets
would not inappropriately delegate the authority to determine federal
jurisdiction under the CWA. Under this proposal, the agencies would
retain their current final authority regarding the scope of ``waters of
the United States.''
    The agencies are interested in learning about experiences States,
Tribes, and other Federal agencies have had with mapping aquatic
resources and using this information for program implementation. What
technical and financial resources were required by their past mapping
efforts, and what challenges were faced in mapping various types of
aquatic resources? Does past experience recommend an incremental
approach, such that States, Tribes, and other Federal agencies start
the process with more manageable first steps such as focusing on
tributaries rather than all types of waters of the United States, or by
focusing on a portion rather than or all of the watersheds or other
defined areas within their borders? Under such an incremental approach,
the States, Tribes, and other Federal agencies could establish datasets
for additional waters over time. However, an incremental approach would
require recognition that any approved dataset would not capture

all waterbody types and therefore the agencies would identify any
limitations on the web map viewer to provide clarity. As the agencies
engage with States, Tribes, other Federal agencies, and the public in a
discussion of possible aquatic resource datasets, the agencies would
like to better understand the level of interest in developing
geospatial datasets of jurisdictional waters should such an option be
available.

V. Overview of Supporting Analyses

    The agencies conducted a series of analyses to better understand
the potential effects across CWA programs associated with a revised
definition of ``waters of the United States.'' The analyses are
contained and described more fully in the Resource and Programmatic
Assessment for the Proposed Revised Definition of ``Waters of the
United States'' and in the Economic Analysis for the Proposed Revised
Definition of ``Waters of the United States.'' Copies of these
documents are available in the docket for this action.
    As a preliminary matter, the agencies note that they are not aware
of any map or dataset that accurately or with any precision portrays
the scope of CWA jurisdiction at any point in the history of this
complex regulatory program. Establishing a mapped baseline from which
to assess regulatory changes is likewise impracticable at this time. As
summarized in Section II, for example, what was understood about the
potential scope of CWA jurisdiction changed in the 1970s, in the mid-
80s with Riverside Bayview and regulatory updates, in 2001 with the
landmark SWANCC decision, in 2006 with the fractured Rapanos decision,
in 2007 and 2008 with the agencies' attempts to discern the meaning of
the Rapanos decision through guidance and throughout the ensuing decade
of litigation that tested those interpretations, in 2015 with a major
rulemaking to redefine the operative phrase ``waters of the United
States,'' and throughout the complex litigation following that
rulemaking. As the Chief Justice of the Supreme Court succinctly
observed in 2016, ``[i]t is often difficult to determine whether a
particular piece of property contains waters of the United States . . .
.'' Army Corps of Eng'rs v. Hawkes Co., 136 S. Ct. at 1812. Given this
history, the agencies are not aware of any means to quantify changes in
CWA jurisdiction with any precision that may or may not occur as a
result of this proposed rule. The agencies acknowledge that they faced
criticism from many commenters regarding the accuracy and assumptions
they made when attempting to estimate changes in jurisdiction for the
economic analysis associated with the 2015 Rule.
    Within this complex framework, the agencies have attempted to look
at available data to analyze the potential effects of this proposed
definition across CWA programs, recognizing that there will be
limitations with any approach. In their analyses, the agencies describe
how the proposed regulation compares to the baseline of the 2015 Rule
and an alternate baseline of pre-2015 practice (i.e., the pre-2015
regulations as interpreted by the Supreme Court and implemented through
agency guidance), both of which represent current practice in some
areas of the country. The documents outline the agencies' assessment of
the potential effects of the proposed definition on aquatic resources
across the country and on CWA programs, and the Resource and
Programmatic Assessment provides further information on programs
addressing aquatic resource quality under other federal statutes. The
agencies also researched current State laws and programs to better
understand how States already regulate waters within their borders.
This information was utilized throughout the agencies' analyses; the
State descriptions may be found in Appendix B of the Resource and
Programmatic Assessment.
    The agencies also identified relevant datasets and technical
limitations for analyses of potential changes in jurisdiction for
different types of aquatic resources. For the analyses, the agencies
examined data records in the Corps' Operation and Maintenance Business
Information Link, Regulatory Module (ORM2) database that documents
Corps decisions regarding the jurisdictional status of various aquatic
resource types (i.e., jurisdictional determinations). The aquatic
resource types used in ORM2 generally track the Rapanos Guidance (e.g.,
relatively permanent waters) but do not directly correlate with the
terms used in the proposed rule, with limited exceptions. The agencies
attempted to use publicly-available data from national datasets (e.g.,
the National Hydrography Dataset (NHD) at High Resolution and the
National Wetlands Inventory (NWI)) to assess the potential extent of
types of waters whose jurisdictional status might change as a result of
the proposed rule. While the NHD and NWI datasets are widely used and
recognized as the most comprehensive national datasets that generally
map waters and wetlands, they are neither designed nor able to portray
jurisdictional waters under the CWA. Therefore, they have technical
limitations that would affect the agencies' analyses, as more fully
described in the Resource and Programmatic Assessment and Economic
Analysis for this proposal. Because of these limitations and the
uncertainties in the way in which States or Tribes might respond
following a change in the definition of ``waters of the United
States,'' many of the potential effects of the proposed rule are
discussed qualitatively, and some are discussed quantitatively where
possible.
    For the Economic Analysis, the agencies applied a two-stage
analysis to make the best use of limited local and national level water
resources information in their effort to assess the potential
implications of this proposed rule. The agencies believe that the
outputs of this two-stage analysis are the best way to illustrate the
potential overall impact of the proposed rule against the baseline of
the 2015 Rule being in effect nationwide (i.e., the sum effect of both
stages) and of the 2015 Rule not being in effect (i.e., second stage
only). The agencies acknowledge that determining what may happen
following the issuance of a new regulation requires making various
assumptions, which are discussed throughout the analyses.
    The first stage of the Economic Analysis (hereinafter Stage 1)
assesses the potential impacts of moving from the 2015 Rule to the pre-
2015 practice baseline (i.e., repealing the 2015 Rule and recodifying
the prior regulations). For the Stage 1 analysis, the agencies used the
original 2015 Rule economic analysis as a starting point and developed
a quantitative assessment limited to Stage 1. However, several
significant changes to the 2015 Rule analysis have been made in the
Stage 1 analysis to account for existing State laws and programs that
regulate water and potential State governance responses, as well as to
account for better information used to assess the potential benefits
and costs of the Stage 1 effects. The agencies developed several
scenarios using different assumptions about potential State regulation
of waters to provide a range of costs and benefits. Under the scenario
that assumes the fewest number of States regulating newly non-
jurisdictional waters, the agencies estimate the proposed rule would
produce annual avoided costs ranging between $98 and $164 million and
annual forgone benefits ranging between $33 to $38 million. When
assuming the greatest number of States are already regulating newly
non-jurisdictional waters, the agencies estimate there would be avoided
annual costs ranging

from $9 to $15 million and annual forgone benefits are estimated to be
approximately $3 million. Under the scenario that assumes no States
will regulate newly non-jurisdictional waters, an outcome the agencies
believe would be unlikely, the agencies estimate the proposed rule
would produce annual avoided costs ranging from $165 and $343 million
and annual forgone benefits ranging from $93 to $104 million.
    The second stage of the economic analysis (hereinafter Stage 2)
consists of a series of qualitative analyses and three detailed case
studies of moving from the pre-2015 practice to the proposal. The
qualitative analysis is intended to provide information on the likely
direction of the potential effects on CWA regulatory programs. In
addition, the agencies conducted case studies in three major watersheds
(Ohio River basin, Lower Missouri River basin, and Rio Grande River
basin) to provide information for a quantitative assessment of the
potential effects of the proposal. The case studies considered
potential ecological effects, and their accompanying potential economic
effects for programs implemented pursuant to sections 311, 402, and 404
of the CWA. Because of data limitations, the agencies were only able to
provide Stage 2 national-level estimates of the potential avoided
permit and mitigation costs and forgone benefits for the CWA 404
program. Using the same methodologies employed in the case studies and
using a meta function benefits transfer to value forgone wetland
benefits, the national annual avoided costs of the CWA 404 program are
estimated to range from $28 million to $266 million and national annual
forgone benefits from the CWA 404 program are estimated to range from
$7 million to $47 million. When considering the full range of scenarios
regarding potential State regulation of waters no longer considered
jurisdictional under the proposal, the estimated national annual
avoided costs of the CWA 404 program range from $28 million to $497
million and national annual forgone benefits range from $7 million to
$136 million.
    The agencies solicit comment on all aspects of the analyses
performed, including the assumptions made and information used, and
request that commenters provide any data that may assist the agencies
in evaluating and characterizing potential effects of the proposed
change of the definition of ``waters of the United States.'' For
example, the agencies request comment on the suitability of the NHD and
NWI datasets as tools for performing comparative analyses of revisions
to the definition of ``waters of the United States,'' the datasets used
(including how they were used) for purposes of the case studies and the
national estimates of costs and benefits for CWA 404 program, and the
appropriateness of the stated preference studies used to value
household willingness to pay for changes in wetland acreage. The
agencies also solicit comment on the utility of using focused case
studies to help inform the agencies' analysis of a nationwide rule
given the lack of comprehensive national datasets representing
jurisdictional waters.

VI. Statutory and Executive Order Reviews

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

A. Executive Order 13771: Reducing Regulation and Controlling
Regulatory Costs

    Pursuant to Executive Order 13771 (82 FR 9339, February 3, 2017),
this proposed rule is expected to be a deregulatory action.

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

    This action is an ``economically significant regulatory action''
that was submitted to the Office of Management and Budget (OMB) for
review. Any changes made in response to OMB recommendations have been
documented in the docket for this action. In addition, the agencies
prepared an analysis of the potential costs and benefits associated
with this action. This analysis is contained in Economic Analysis for
the Proposed Revised Definition of ``Waters of the United States,''
which is available in the docket and briefly summarized in Section V.
Additional analysis can be found in the Resource and Programmatic
Assessment for the Proposed Revised Definition of ``Waters of the
United States'' which is also available in the docket.

C. Paperwork Reduction Act

    This action does not impose any new information collection burden
under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. OMB has
previously approved the information collection activities contained in
the existing regulations and has assigned OMB control numbers 2050-0021
and 2050-0135 for the CWA section 311 program and 2040-0004 for the CWA
section 402 program. For the CWA section 404 program, the current OMB
approval number for information requirements is maintained by the Corps
(OMB approval number 0710-0003). However, there are no new approval or
application processes required as a result of this rulemaking that
necessitate a new Information Collection Request (ICR).

D. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency
to prepare a regulatory flexibility analysis of any rule subject to
notice and comment rulemaking requirements under the Administrative
Procedure Act or any other statute unless the agency certifies that the
rule will not have a significant economic impact on a substantial
number of small entities. Small entities include small businesses,
small organizations, and small governmental jurisdictions.
    For purposes of assessing the impacts of this proposed rule on
small entities, ``small entity'' is defined as: (1) A small business
that is a small industrial entity as defined in the U.S. Small Business
Administration's size standards (see 13 CFR 121.201); (2) a small
governmental jurisdiction that is a government of a city, county, town,
school district, or special district with a population of less than
50,000; or (3) a small organization that is any not-for-profit
enterprise that is independently owned and operated and is not dominant
in its field.
    The purpose of the RFA is ``to fit regulatory and informational
requirements to the scale of the businesses, organizations and
governmental jurisdictions subject to the regulation.'' 5 U.S.C. 601.
Small entities subject to this proposed rule are largely those entities
whose activities are directly covered by the CWA sections 402, 404, and
311 programs. The proposed rule is expected to result in fewer entities
subject to these programs, and a reduced regulatory burden for many of
the entities that will still be subject to these programs. As a result,
small entities subject to these regulatory programs are unlikely to
suffer adverse impacts as a result of regulatory compliance.
    As addressed in the Economic Analysis for the proposed rule,
narrowing the scope of CWA regulatory jurisdiction over waters may
result in a reduction in the ecosystem services provided by some
waters, and as a result, some entities may be adversely impacted. Some
business sectors that depend on habitat, such as those catering to
hunters or anglers, or that require water treatment to meet production
needs, could experience a

greater impact relative to other sectors. These changes in ecosystem
services are likely to be small, infrequent, and dispersed over wide
geographic areas, thereby limiting the significance of these impacts on
these business sectors. In addition, States and Tribes may already
address waters potentially affected by a revised definition, thereby
reducing forgone benefits.
    The sector likely to be most impacted by the proposed rule are
mitigation banks, and companies that provide restoration services.
Because fewer waters would be subject to the CWA under the proposed
rule than are subject to regulation under the 2015 Rule or pre-2015
practice, there may be a reduction in demand for mitigation and
restoration services under the section 404 permitting program.
Assessing impacts to this sector is problematic, because this sector
lacks a SBA small business definition, and many of the businesses that
fall within this sector are also classified under various other NAICs
categories. Furthermore, impacts to this sector would not be the direct
result of these businesses complying with the proposed rule, rather
they would be the indirect result of other entities no longer being
required to mitigate for discharges of dredged or fill material into
waters that would no longer be jurisdictional under the proposed rule.
In addition, potential impacts would be lessened when accounting for
State and tribal dredged and fill programs that would necessitate the
purchase of mitigation credits. For a more detailed discussion see the
RFA section of the Economic Analysis for the proposed rule.
    The agencies certify that this action will not have a significant
economic impact on a substantial number of small entities under the
RFA. In making this determination, the impact of concern is any
significant adverse economic impact on small entities. An agency may
certify that a rule will not have a significant economic impact on a
substantial number of small entities if the rule relieves regulatory
burden, has no net burden or otherwise has a positive economic effect
on the small entities subject to the rule. This is a deregulatory
action, and the burden on all entities affected by this proposed rule,
including small entities, is reduced compared to the 2015 Rule and pre-
2015 practice. The agencies have therefore concluded that this action
will relieve regulatory burden to small entities.

E. Unfunded Mandates Reform Act

    This proposed rule does not contain any unfunded mandate as
described in the Unfunded Mandates Reform Act of 1995 (UMRA), 2 U.S.C.
1531-1538, and does not significantly or uniquely affect small
governments. The proposed definition of ``waters of the United States''
applies broadly to CWA programs. The proposed action imposes no
enforceable duty on any state, local or tribal governments or the
private sector, and does not contain regulatory requirements that
significantly or uniquely affect small governments.

F. Executive Order 13132: Federalism

    Consulting with state and local government officials, or their
representative national organizations, is an important step in the
process prior to proposing regulations that may have implications for
State and local governments under the terms of Executive Order 13132
(64 FR 43255, August 10, 1999). The agencies undertook a 60-day
Federalism consultation early in the process and then conducted
additional outreach to States for this proposed rulemaking to ensure
that the agencies could hear the perspectives on how the agencies might
revise the definition of ``waters of the United States'' from our State
co-regulators. All letters received by the agencies during Federalism
consultation may be found on EPA's website at https://www.epa.gov/wotus-rule/federalism-consultation.
    State and local governments were consulted at the outset of rule
development starting on April 19, 2017. The agencies held nineteen
Federalism meetings between April 19 and June 16, 2017. Seventeen
intergovernmental associations, including nine of the ten organizations
identified in EPA's 2008 E.O. 13132 Guidance, attended the initial
Federalism consultation meeting, as well as several associations
representing State and local governments. Organizations in attendance
included: The National Governors Association, the National League of
Cities, the National Association of Counties, the U.S. Conference of
Mayors, the Council of State Governments, the National Conference of
State Legislatures, the County Executives of America, the National
Association of Towns and Townships, the Environmental Council of the
States, the Western Governors Association, the National Association of
Clean Water Agencies, the Association of Clean Water Administrators,
the National Association of State Departments of Agriculture, the
Association of State Wetlands Managers, the Association of State
Floodplain Managers, the National Water Resources Association, the
State/Local Legal Center, and several members of EPA's Local Government
Advisory Committee (LGAC).
    The LGAC met 10 times during this period to address the charge
given to its members by the EPA Administrator on a revised rule and
completed a report addressing the questions outlined in their charge.
The July 14, 2017, final report can be obtained here: https://www.epa.gov/sites/production/files/2017-07/documents/lgac-final-wotusreport-july2017.pdf.
    The agencies held two additional webinars, the first for Tribes,
States, and local governments on December 12, 2017; and, one for States
on February 20, 2018. In addition, one in-person meeting to seek
technical input on the proposed rule was held with a small group of
nine states (Arizona, Arkansas, Florida, Iowa, Maryland, Minnesota,
Oregon, Pennsylvania, and Wyoming) on March 8 and 9, 2018.
    These meetings and the letters provided by representatives provide
a wide and diverse range of interests, positions, comments, and
recommendations to the agencies. The agencies have prepared a report
summarizing their consultation and additional outreach to state and
local governments and the results of this outreach. A copy of the draft
report is available in the docket (Docket Id. No. EPA-HQ-OW-2018-0149)
for this proposed rule.
    Under the technical requirements of Executive Order 13132, the
agencies have determined that this proposed rule may not have
federalism implications but believe that the requirements of the
Executive Order have been satisfied in any event.

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

    The EPA consulted with tribal officials under the EPA Policy on
Consultation and Coordination with Indian Tribes early in the process
of developing this action to permit them to have meaningful and timely
input into its development. In the course of this consultation, the
Department of the Army participated in aspects of the process.
    EPA initiated a tribal consultation and coordination process before
proposing this rule by sending a ``Notification of Consultation and
Coordination'' letter on April 20, 2017, to all of the 567 Tribes
federally recognized at that time. The letter invited tribal leaders
and designated consultation representatives to participate in the
tribal consultation and coordination process. The agencies held two
identical webinars concerning this matter for tribal representatives on