establish, however, the same is likely not true for determining lead
permitting responsibility when States or Tribes assume section 404
permitting authority under 33 U.S.C. 1344(g). In assumed programs, the
question for adjacent wetlands is which regulatory authority is
responsible for permitting, not whether the wetlands themselves are
waters of the United States.
    Some members of the public commented that adjacent wetlands should
include all wetlands within the 100-year floodplain. Other commenters
disagreed and stated that wetlands with a one percent annual chance of
flooding should not be considered waters of the United States. Under
the final rule, although not all wetlands in the 100-year floodplain
are jurisdictional, many adjacent wetlands will be located within the
100-year floodplain of a jurisdictional water. In addition to the other
tests for adjacency, flooding in a typical year may occur in portions
of the 100-year floodplain. For example, wetlands which are inundated
by flooding from a paragraph (a)(1) through (3) water in a typical year
may be floodplain wetlands, or wetlands which are physically separated
from a paragraph (a)(1) through (3) water only by a natural berm or
dune may be floodplain wetlands. The agencies also recognize that it
can be difficult to measure a floodplain's extent as floodplains are
not mapped everywhere in the country. In any event, the agencies
believe that including wetlands as adjacent due solely to their
presence in the 100-year floodplain goes beyond the scope of the
agencies' legal authority under the CWA and contravenes Supreme Court
guidance. See, e.g., Rapanos, 547 U.S. at 746 (Scalia, J., plurality)
(``the Corps' definition of `adjacent,' . . . has been extended beyond
reason to include, inter alia, the 100-year floodplain of covered
waters''). Consistent with the proposal, the agencies are not including
a floodplain criterion (e.g., a general floodplain requirement or a
specific floodplain interval requirement) to determine adjacency in the
final rule.
    Some commenters recommended that the agencies include wetlands with
a significant nexus to navigable waters as jurisdictional while others
supported the agencies' proposed approach to remove the case-specific
significant nexus analysis from the determination of jurisdiction. This
final rule ends the agencies' practice of conducting case-specific
significant nexus evaluations for determining whether wetlands are
jurisdictional as adjacent. Under the agencies' Rapanos Guidance, this
evaluation required individual analyses of the relationship between a
particular wetland (or group of wetlands aggregated together with its
nearest tributary) with traditional navigable waters. Importantly,
Justice Kennedy's ``significant nexus'' test for wetlands adjacent to
non-navigable tributaries was only needed ``absent more specific
regulations,'' id. at 782 (Kennedy, J., concurring in the judgment),
because ``the breadth of [the then-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'' in this final rule, the
agencies are eliminating the case-specific significant nexus analysis
through categorical treatment of all adjacent wetlands, as defined by
this rule, as ``waters of the United States.'' The agencies recognize
that this is a new position and modifies 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. For all the reasons described in Section II.E, the
agencies are finalizing a rule that is more consistent with the body of
Supreme Court guidance, including the origins of the significant nexus
standard, and their authority under the Act, than were previous
regulations. The agencies believe that this final rule achieves the
goals of the Act and provides better clarity for the regulators and the
regulated community alike, while adhering to the basic principles
articulated in Rapanos, SWANCC, and Riverside Bayview.
    Some commenters recommended including as waters of the United
States specific waters based solely on ecological importance, such as
prairie potholes. Other commenters urged the agencies to finalize a
rule consistent with Supreme Court guidance which directs that
ecological considerations do not provide an independent basis for
federal jurisdiction. As noted above, under the final rule's
definition, ecological connections alone are not a basis for including
physically isolated wetlands within the phrase ``the waters of the
United States.'' See, e.g., Rapanos, 547 U.S. at 741-42 (Scalia, J.,
plurality); see also id. at 778 (Kennedy, J., concurring in the
judgment).
    Some commenters recommended the agencies incorporate more
scientific analysis in their interpretation of the proper scope of
``adjacent wetlands''. The definition of ``adjacent wetlands'' and the
categorical treatment of jurisdiction over wetlands adjacent to other
jurisdictional waters is informed by science, though it is not dictated
by science alone. For example, the EPA's SAB noted when reviewing the
Draft Connectivity Report in 2014, that ``[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. The agencies
considered these and other scientific principles described above in
crafting this final rule; however, as discussed in Section II.E of this
notice, 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 rule's definition draws the legal limit
of federal jurisdiction in a clear and implementable way that adheres
to established legal principles, while being informed by the policy
choices and scientific expertise of the executive branch agencies
charged with administering the CWA.
    Consistent with the proposal, the agencies are retaining the
longstanding definition of ``wetlands'' in this final rule. Some
commenters expressed support for this approach. Some commenters
requested that the agencies clarify that a wetland must satisfy all
three wetland delineation factors to be considered a wetland under the
rule. Other commenters requested that the agencies clarify the term
``normal circumstances'' as used in the definition of ``wetlands,'' and
suggested that the term should not apply when higher than normal
rainfall conditions are present.

Commenters also requested clarification on whether human alteration
affects ``normal circumstances.''
    The agencies have clarified that the presence and boundaries of
wetlands are determined based upon an area satisfying all three of the
definition's factors (i.e., hydrology, hydrophytic vegetation, and
hydric soils) under normal circumstances. This is evident in the final
definition of ``upland'' in paragraph (c)(14). The agencies have also
clarified that certain elements of the ``adjacent wetlands'' definition
include a ``typical year'' requirement to ensure that the
jurisdictional status of wetlands is being assessed under conditions
that are not too wet and not too dry. In addition, the agencies
consider climatic conditions when delineating wetlands, for example,
whether there are drought conditions or conditions of unusually high
rainfall. The term ``typical year'' is not intended to modify the
agencies' current implementation of normal circumstances.
    The agencies recognize that there have been questions over time
about the jurisdictional status of ditches that are not maintained.
Under this final rule, as discussed in more detail in Section III.E,
when a ditch constructed in an adjacent wetland contributes less than
perennial or intermittent flow to a paragraph (a)(1) water in a typical
year and yet, due to lack of maintenance, gains wetland
characteristics, that ditch may be viewed as an adjacent wetland if it
meets the definition of both ``wetlands'' under paragraph (c)(16) and
``adjacent wetlands'' under paragraph (c)(1).
3. How will the agencies implement the final rule?
    If a wetland satisfies this rule's definition of ``wetlands'' and
``adjacent wetlands'' it is considered a water of the United States
without need for further 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 meet the final rule's definition of ``adjacent wetlands,''
and other issues typically addressed during a jurisdictional
determination process.
    This rule provides a definition of ``adjacent wetlands'' that
includes wetlands that abut, meaning to touch at least at one point or
side of, a water identified in paragraph (a)(1), (2), or (3). Such
abutting wetlands need not abut the paragraph (a)(1) through (3) water
along the entire length of a delineated wetland boundary to be
considered adjacent. Rather, the wetlands need only touch the paragraph
(a)(1) through (3) water at one point. In addition, and consistent with
the proposal and Riverside Bayview, the final rule does not require
surface water exchange between wetlands and the jurisdictional waters
they abut to create the jurisdictional link. 474 U.S. at 134.
    Abutting occurs when the wetland delineated boundary touches the
delineated boundary of the paragraph (a)(1) through (3) water, which
does not require a direct hydrologic surface connection because not all
wetlands have standing or flowing surface water as their wetland
hydrology factor. For example, some wetlands may have saturated soils
or a high water table, and these are also indicators of wetland
hydrology. Abutting occurs at the interface between the adjacent
wetland and the paragraph (a)(1) through (3) water. In the field, the
agencies would identify the presence of a paragraph (a)(1) through (3)
water and delineate the boundary of such water at the lateral extent
identified by the ordinary high water mark or high tide line, depending
on which is appropriate. See 33 CFR 328.4. The agencies would then
delineate the wetlands within the review area to determine whether the
wetland boundary touches the paragraph (a)(1) through (3) water
boundary at any point or side. The wetlands need not abut for a
specific duration in order to be considered abutting. For example,
wetlands that abut a tributary only during the wet or rainy season
remain adjacent under this final rule. Similarly, if a wetland abuts an
intermittent tributary it remains abutting even when water is not
present in the tributary. Wetlands abutting an ephemeral stream or
other non-jurisdictional feature are non-jurisdictional even if the
non-jurisdictional feature maintains jurisdiction between upstream and
downstream waters.
    Some commenters stated that surface connections may not be present
or identifiable year-round. Many commenters questioned whether the use
of remote tools could identify the necessary connections and stated
that field indicators and site-specific verification for wetland
connections may be needed. In addition, commenters requested
clarification on systems with modifications, such as dikes, levees, and
other man-made structures.
    The agencies modified the final rule language from the proposal in
response to many of these comments to provide additional clarity and
ease of implementation, while remaining faithful to the overall text,
structure, and legislative history of the CWA and the legal principles
outlined in Section II.E. Culverts or other structures conveying water
through an artificial barrier, such as a levee or a road, can maintain
jurisdiction in the final rule if they provide a direct hydrological
surface connection between a wetland and a jurisdictional water in a
typical year. Where a wetland is physically separated from a tributary
by a manmade levee and such artificial structure has a culvert
connection through the levee, the culvert is visibly apparent and can
be easily observed for efficiency in identifying it as potentially
providing a direct hydrologic surface connection. In other locations,
pumps may be used to control water levels. In some scenarios, the pumps
are continually operating to maintain flow conditions, and in other
scenarios, they are turned on only when flood conditions are present.
Pumps can move water through the artificial structure or over it. A
pump can create a direct hydrologic surface connection in a typical
year between paragraph (a)(1) through (3) waters and their adjacent
wetlands. Tide gates can also allow for a direct hydrologic surface
connection in a typical year between wetlands and the paragraph (a)(1)
through (3) water to which they are adjacent under the final rule. As
long as a feature present within the artificial structure allows for a
direct hydrologic surface connection between the wetland and a
paragraph (a)(1) through (3) water in a typical year, the wetland is an
adjacent wetland even if flow is not present at the time of
observation. The agencies may not assume the presence of such
artificial features; rather they may identify such artificial features
via on-site observations or remotely using construction design plans,
permitting data, state and local information, or levee or drainage
district information. As is the case with jurisdictional determinations
made under any regulatory regime, site-specific verification may be
required in certain instances where remote tools may not be readily
available or accurate or in other, often more complex site scenarios.
    A wetland flooded by a navigable water, on average, once every 100
years would not satisfy the final rule's ``adjacent wetlands''
definition. Such inundation via flooding must occur from a paragraph
(a)(1) through (3) water at least once in a typical year for purposes
of adjacency. The agencies may determine that inundation by flooding or
a direct hydrologic surface connection exists during a typical year
using, for example, USGS stream gage records, recurrence intervals of
peak flows, wetland surface water level

records, visual observation, aerial imagery, flood records, inundation
modeling techniques and tools (e.g., Hydrologic Engineering Centers
River System Analysis System, or HEC-RAS, or tools available from USGS
through their Flood Inundation Mapping program), or engineering design
records. The agencies may also need to complete one or more site visits
to collect field indicators of inundation. For example, the presence of
water marks, sediment and drift deposits, water-stained leaves, or
algal mats may indicate that an inundation event has recently occurred.
The agencies believe that it is also important to consider weather and
climatic conditions, i.e., to review recent precipitation and climate
records, to ensure the feature is not being assessed during a period of
drought or after a major precipitation or infrequent flood event. Tools
for determining whether climatic conditions meet the definition of
``typical year'' are described in Section III.A.1 of this notice.
    In addition, under this final rule an adjacent wetland divided by
an artificial structure, such as a road or railroad line, is treated as
a single wetland and is jurisdictional in its entirety as long as the
structure allows for a direct hydrologic surface connection through or
over that structure in a typical year. The direct hydrologic surface
connection can occur through or over the artificial structure, such as
through a culvert, or as is present in some areas, over roads designed
to overtop during certain conditions. Without a direct hydrologic
surface connection in a typical year, only that wetland (i.e., that
portion of the original wetland) which meets the terms of the
definition of ``adjacent wetlands'' under paragraph (c)(1) would be an
adjacent wetland, even if there is a subsurface hydrologic connection
(e.g., shallow subsurface flow or aquifer) between the wetlands present
on either side of the road or other artificial structure. To identify
the direct hydrologic surface connection through or over a road or
other artificial structure, the agencies may use tools similar to those
that are used to identify a direct hydrologic surface connection
through an artificial structure, such as a dike.
    To implement this aspect of the rule as applied to a particular
wetland, the agencies will first need to determine whether the wetland
is adjacent to a paragraph (a)(1) through (3) water. The agencies will
then need to consider the conditions on the ground in order to
determine whether the divided parts of the wetland should be considered
one adjacent wetland, where it otherwise meets the terms of the
definition. For example, if a wetland is present on either side of a
road which has a direct hydrologic surface connection via a culvert
connecting both parts of the wetland in a typical year, the agencies
need not recreate the history of the road construction and what the
conditions on the ground were at time of road construction. Rather, the
agencies will observe the artificial structure and will note whether
the artificial structure allows for a direct hydrologic surface
connection such that the wetlands on both sides of the road can connect
via surface hydrology in a typical year. If so, then the wetlands are
considered one wetland.
    As a general matter and consistent with longstanding practice, the
agencies take a physical separation as they find it. The physical
separation will be evaluated in its current form (unless normal
circumstances are not present or where there is evidence of unlawful
activity or efforts to circumvent jurisdiction, in which case, the
separation will be evaluated using other tools to approximate normal
circumstances). If a dike is originally designed not to allow for a
direct hydrologic surface connection between a paragraph (a)(1) through
(3) water and wetlands on the other side of the dike, but later a
culvert is added to provide adequate drainage in a typical year or a
pump is added to provide flood protection in a typical year, these
features create a direct hydrologic surface connection between the
jurisdictional water and the wetlands. In this scenario, the wetlands
become adjacent wetlands. If a natural feature is modified or changes
over time (as when a berm develops over time separating a wetland from
a paragraph (a)(1) water) the agencies intend to take the feature as
they find it, determine whether it is a natural physical separation,
and then consider whether the wetland is adjacent. Pumps are considered
to be the ``normal'' circumstances of the hydrology when they are
permanently present and are serviceable. Pumps create adjacency under
the final rule when they are permanent features which allow for a
direct hydrologic surface connection in a typical year through an
artificial structure between a wetland and the paragraph (a)(1) through
(3) water.
    Temporary structures are not subject to the ``take it as they find
it'' principle. Their presence is intended to modify the relationship
between the paragraph (a)(1) through (3) water and a wetland for only a
limited duration of time. For example, a temporary culvert in place for
three months during construction would not allow for a wetland to
become adjacent under this rule. Such temporary structures are not
considered normal circumstances when considering whether a wetland may
be adjacent.
    For purposes of adjacency under the rule, the entire wetland is
considered adjacent if any portion of the wetland meets the terms of
the definition under paragraph (c)(1), 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 is
jurisdictional in its entirety. Determining the entire wetland to be
adjacent if any portion of it satisfies the ``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 administratively bifurcating wetlands. An
adjacent wetland that changes classification (e.g., as defined in
Cowardin et al. 1979) within the overall wetland delineated boundary
due to landscape position, hydrologic inundation, or other factors,
such as changing from salt marsh to brackish to freshwater wetland, is
jurisdictional as one adjacent wetland.
    Certain wetland indicators may not be present year-round in a
typical year due to normal seasonal or annual variability. Adjacent
wetlands under this final rule include wetlands with alternating
hydroperiods and seasonal wetlands with vegetation shifts. Consistent
with the agencies' longstanding practice, the delineated boundary of a
seasonal wetland remains constant, even though all three delineation
factors may not be apparent year-round. This approach acknowledges
seasonal variation in visible wetland factors as well as the variation
in hydrology and climatic conditions across the country. For example,
seasonal wetlands with vegetation shifts may display hydrophytic
vegetation abutting another water of the United States throughout the
year except during the dry season. Also, wetlands with alternating
hydroperiods that abut another water of the United States in the arid
West may have hydrology present only for three months while otherwise
similar wetlands in the Southeast may have hydrology present for nine
months. Wetland hydrology indicators that require direct observation of
surface water or saturated soils are often present only during the
normal wet portion of the growing season and may be absent during the
dry season. The wetland hydrology factor is often much more variable on
short time scales than the hydrophytic vegetation and hydric soil
factors, especially in seasonal wetlands

like some bottomland hardwood forests which can lack flooding or
saturation.
    Some commenters noted that a ditch constructed in an adjacent
wetland can drain water and create a zone of influence which may render
the entire wetland non-jurisdictional under the proposed rule. Under
this final rule, a wetland must first be considered adjacent to a
paragraph (a)(1) through (3) water before a ditch constructed in it may
be considered a tributary. Therefore, the wetland may still be
jurisdictional as an adjacent wetland to the paragraph (a)(1) through
(3) water under (c)(1) even if the ditch's zone of influence reduces
the extent of the wetland around the ditch, as the wetland's
jurisdictional status is not directly tied to the ditch. Historical and
current aerial photographs, NWI maps, NRCS soils maps, and other
similar resources may indicate whether a ditch was constructed in an
adjacent wetland. There may also be certain instances where a ditch has
lawfully drained a wetland.

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

1. What are the agencies finalizing?
    In paragraph (b) of the final rule, the agencies are codifying
twelve exclusions from the definition of ``waters of the United
States.'' Many of the exclusions reflect longstanding agency practice
and are expressly included in the final rule to ensure predictability,
as the agencies continue to implement them in the future. Two of the
exclusions (waste treatment systems and prior converted cropland) have
been expressly included in regulatory text for decades, but the
agencies are defining them for the first time to enhance implementation
clarity. The majority of paragraph (b) has been finalized as proposed,
but as discussed in the next subsection, the agencies have made some
changes to what they proposed in response to public comments and
additional analysis of the proposed regulatory text. For example, in
the final rule the agencies split ephemeral surface features and
diffuse stormwater runoff and overland sheet flow into separate
exclusions for added clarity.
    Waters and features that are excluded under paragraph (b) of the
final rule cannot be determined to be jurisdictional under any of the
categories in the rule under paragraph (a). Any water not enumerated in
paragraphs (a)(1) through (4) is not a ``water of the United States.''
In addition to this overarching exclusion, the final rule includes
additional exclusions to provide more specificity for certain common
landscape features and land uses that are more appropriately regulated,
if at all, under the sovereign authorities of States and Tribes. For
example, the final rule excludes groundwater from the definition of
``waters of the United States,'' including groundwater drained through
subsurface drainage systems, reflecting the agencies' longstanding
practice. The rule creates a new exclusion for ephemeral features,
including ephemeral streams, swales, gullies, rills, and pools, and
excludes diffuse stormwater run-off and directional sheet flow over
upland. Adhering more closely to the agencies' original interpretation
of the CWA, the rule excludes ditches from the definition of ``waters
of the United States'' except those ditches identified as
jurisdictional under paragraph (a)(1) or (2) and those ditches
constructed in adjacent wetlands that do not meet the flow conditions
of the definition of ``tributary'' but that meet the conditions of
paragraph (a)(4). The agencies are retaining an exclusion for prior
converted cropland but are defining it for the first time in regulatory
text. The agencies are also retaining an exclusion for waste treatment
systems.
    The final rule also excludes artificially irrigated areas,
including fields flooded for agricultural production, that would revert
to upland should application of irrigation water to that area cease. In
addition, the rule excludes artificial lakes and ponds, including water
storage reservoirs and farm, irrigation, stock watering, and log
cleaning ponds, constructed or excavated in upland or in non-
jurisdictional waters, so long as those artificial lakes and ponds are
not impoundments of jurisdictional waters that meet the conditions of
paragraph (c)(6). The final rule excludes water-filled depressions
constructed or excavated in upland or in non-jurisdictional waters
incidental to mining or construction activity, and pits excavated in
upland or in non-jurisdictional waters for the purpose of obtaining
fill, sand, or gravel. The agencies also have excluded stormwater
control features constructed or excavated in upland or in non-
jurisdictional waters to convey, treat, infiltrate, or store stormwater
run-off. Also excluded in the final rule are groundwater recharge,
water reuse, and wastewater recycling structures, including detention,
retention, and infiltration basins and ponds, constructed or excavated
in upland or in non-jurisdictional waters.
    As discussed in Section III.G, the agencies have defined ``upland''
in paragraph (c)(14) and specify in the regulatory text that certain
water features constructed or excavated in upland or in non-
jurisdictional waters are excluded from the definition of ``waters of
the United States.'' In the final rule, ``upland'' means any land area
that under normal circumstances does not satisfy all three wetland
characteristics identified in the definition of ``wetlands''
(hydrology, hydrophytic vegetation, hydric soils) and does not lie
below the ordinary high water mark or the high tide line of a
jurisdictional water. The term is used in six of the exclusions listed
in paragraph (b), and the definition is intended to provide additional
clarity as the agencies implement the exclusions while also informing
the application of the ``adjacent wetlands'' definition. See Section
III.G of this notice.
    The agencies received a broad range of comments on the proposed
rule's list of exclusions, some stating that the exclusions provide
necessary clarity while allowing the regulated community to plan
investments in infrastructure and other projects with increased
regulatory certainty and predictability. Others expressed support for
the new exclusion in paragraph (b)(1), stating that it clarified that
if a water is not jurisdictional under paragraph (a), it is not subject
to CWA jurisdiction. Other commenters supported the inclusion of
definitions for prior converted cropland and waste treatment systems,
acknowledging that the new definitions help clarify those longstanding
exclusions. Some commenters opposed many of the exclusions, arguing
that they restrict CWA jurisdiction over too many ecologically
important waters. Some commenters argued that prior converted cropland
and waste treatment systems should not be excluded from CWA
jurisdiction, stating that nothing in the CWA supports the agencies'
longstanding positions. The agencies have considered these diverse
comments and have generally adhered to the approach set forth in the
proposed rule, while making some adjustments to the regulatory text to
address certain questions that were raised and to improve the clarity
of the regulatory text, as discussed in the next subsection.
2. Summary of Final Rule Rationale and Public Comment
    Many of these exclusions generally reflect the agencies' current
and historic practice, and their inclusion in the final rule furthers
the agencies' goal of providing greater clarity over which waters are
and are not regulated under

the CWA. Just as the categorical assertions of jurisdiction over
tributaries, lakes, ponds, and impoundments of jurisdictional waters,
and adjacent wetlands simplify the jurisdictional determination
process, the categorical exclusions likewise simplify the process. In
certain circumstances, they also reflect the agencies' determinations
of the limits of their jurisdiction under the CWA based on the text of
the statute, Supreme Court guidance, and the agencies' longstanding
practice and technical judgment that certain waters and features are
not subject to regulation under the CWA. These waters are or could be
subject to State or tribal jurisdiction, as the CWA recognizes that
States and Tribes can regulate more broadly than the Federal
government.
    Some State comments on the proposed exclusions indicated that the
exclusions uphold State sovereignty to administer and allocate water
resources and preserve traditional State and local authority over
private property. Some commenters also stated that the proposed
exclusions are consistent with the principles of cooperative federalism
under the CWA. For example, a commenter asserted that the types of
waters proposed for exclusion are all waters that would traditionally
fall under State jurisdiction and should remain subject to State
regulation under the framework for cooperative federalism set forth in
the CWA. The agencies agree that the CWA's cooperative federalism
approach to protecting water quality is important and continue to
reflect that approach in the exclusions finalized in this rule.
    Importantly, the agencies' final rule clarifies that all waters and
features identified in paragraph (b) as non-jurisdictional would not be
waters of the United States. As stated in paragraph (b)(1) of the final
rule, waters or water features not enumerated in paragraphs (a)(1)
through (4) would not be a water of the United States. The agencies
have taken this approach to avoid suggesting that but for an applicable
exclusion, such features could be jurisdictional. This approach in the
final rule comprehensively excludes all waters and features that the
agencies have not included as waters of the United States under
paragraph (a) of the rule. Different features are called different
names in different parts of the country, so this approach is also
intended to eliminate the risk of confusion. The agencies note that the
examples of features in each exclusion are illustrative of the types of
features covered under each exclusion.
Groundwater
    In paragraph (b)(2) of the final rule, the agencies exclude
groundwater, including groundwater drained through subsurface drainage
systems. The agencies have never interpreted waters of the United
States to include groundwater, and they continue that practice through
this final rule by explicitly excluding groundwater. The agencies also
note that groundwater, as opposed to subterranean rivers or tunnels,
cannot serve as a connection between upstream and downstream
jurisdictional waters. For example, a losing stream that flows to
groundwater without resurfacing does not meet the definition of
``tributary'' because it does not contribute surface water flow to a
downstream jurisdictional water. However, a subterranean river does not
sever jurisdiction of the tributary if it contributes surface water
flow in a typical year to a downstream jurisdictional water, as
described in Section III.A.3, even though the subterranean river itself
is not jurisdictional.
    Many commenters cited legislative history in the development of the
Act, the agencies' implementing regulations, and case law as evidence
of Congressional intent in support of the groundwater exclusion.
Commenters noted that CWA legislative history demonstrates that
Congress clearly did not intend to include groundwater as ``waters of
the United States,'' because Congress did not support a proposed
amendment to include groundwater as waters of the United States. Many
commenters stated that all subsurface water should be non-
jurisdictional. Other commenters stated that groundwater is not a
``navigable water'' or a ``channel of interstate commerce'' and
therefore should be excluded. Conversely, several commenters stated
that groundwater is important to commerce, because it is essential as a
source of drinking water for much of the population. Other commenters
stated that groundwater should be jurisdictional, based on concerns
regarding pollution moving to or from shallow subsurface waters. Some
commenters stated that groundwater, including shallow subsurface water,
could serve as a conduit for discharge of pollutants to surface water.
    The agencies agree with those commenters who stated that nothing in
the language of the CWA or its legislative history, Supreme Court
interpretations, or past agency practices support the inclusion of
groundwater, including groundwater drained through subsurface drainage
systems, in the definition of ``waters of the United States.'' The
agencies disagree with other commenters' assertion that groundwater
should be included in the definition of ``waters of the United
States.'' The agencies acknowledge the importance of groundwater as a
resource and its role in the hydrologic cycle. But its regulation is
most appropriately addressed by other Federal, State, tribal, and local
authorities. Therefore, consistent with the agencies' longstanding
practice, the final rule clarifies that groundwater is non-
jurisdictional. This includes shallow subsurface water and groundwater
that is channelized in subsurface systems, like tile drains used in
agriculture. The agencies acknowledge that, in certain circumstances,
pollutants released to groundwater can reach surface water resources.
However, the statutory reach of ``waters of the United States'' must be
grounded in a legal analysis of the limits on CWA jurisdiction that
Congress intended by use of the term ``navigable waters,'' and an
understanding and application of the limits expressed in Supreme Court
opinions interpreting that term. This final rule does that, while also
supporting the agencies' goals of providing greater clarity, certainty,
and predictability for the regulated public and regulators.
    While the final rule excludes groundwater from regulation, many
States include groundwater in their definitions of ``waters of the
State'' and therefore may subject groundwater to State regulation.
Indeed, the CWA incentivizes State protection of groundwater; for
example, grants under CWA section 319 may implement management programs
which will carry out groundwater quality protection activities as part
of a comprehensive nonpoint source pollution control program. 33 U.S.C.
1329(h)(5)(D). CWA section 319(i) directs the EPA Administrator to make
grants to States for the purpose of assisting States in carrying out
groundwater quality protection activities which the Administrator
determines will advance the State toward implementation of a
comprehensive nonpoint source pollution control program. Such
activities include research, planning, groundwater assessment,
demonstration programs, enforcement, technical assistance, education,
and training to protect the quality of groundwater and to prevent
contamination of groundwater from nonpoint sources of pollution. 33
U.S.C 1329(i). In addition, groundwater quality is regulated and
protected through several other legal mechanisms, including the Safe

Drinking Water Act, the Resource Conservation and Recovery Act, and
various State and local laws.\56\
---------------------------------------------------------------------------

    \56\ For additional description of these programs, see https://www.epa.gov/npdes/interpretative-statement-releases-pollutants-point-sources-groundwater.
---------------------------------------------------------------------------

Ephemeral Features and Diffuse Stormwater Run-Off
    In paragraph (b)(3), the final rule excludes ephemeral features,
including ephemeral streams, swales, gullies, rills, and pools. In
paragraph (b)(4), the rule excludes diffuse stormwater run-off and
directional sheet flow over upland. Such features are not
jurisdictional under the terms of paragraph (a) in the final rule or
its definitions in paragraph (c). They are specifically excluded in the
final rule for additional clarity. The final rule differs from the
proposed rule, as (b)(3) and (b)(4) were combined into one category of
exclusions in the proposal. The agencies believe that separating the
exclusions into two categories, as they have done for the final rule,
provides greater clarity. The separation does not have a practical
effect on or substantively change the types of waters and features that
the final rule excludes compared to the proposed rule. As described in
detail in Section III.A.3, the agencies have revised the proposed rule
to clarify that while ephemeral features are not waters of the United
States, a tributary does not lose its jurisdictional status if it
contributes surface water flow to a downstream jurisdictional water in
a typical year through a channelized ephemeral feature, such as an
ephemeral stream or gully. However, if an upstream reach is connected
to the downstream reach only by diffuse stormwater runoff or
directional sheet flow over upland, the upstream reach is not
jurisdictional under the final rule. Providing additional clarity in
the paragraph (b) exclusions helps to highlight that only some excluded
features are capable of providing a channelized surface water
connection between upstream and downstream perennial or intermittent
waters. Under the final rule, ephemeral features are not jurisdictional
and do not become jurisdictional even if they maintain jurisdiction of
relatively permanent upstream waters by conveying surface water from
those waters to downstream jurisdictional waters in a typical year.
    Some commenters supported the ephemeral features exclusion as being
consistent with the CWA, Commerce Clause, and case law, particularly
the plurality opinion in Rapanos. For example, one commenter indicated
that the proposed exclusion aligned with CWA section 101(b) and, by
avoiding jurisdiction over primarily dry features, did not
significantly alter the Federal-State framework. Other commenters
expressed concern that if they are not jurisdictional, ephemeral
features could be subject to uncontrolled pollution or filled, and some
commenters emphasized the potential adverse impacts to downstream
jurisdictional waters into which ephemeral features flow.
    By defining perennial and intermittent tributaries of traditional
navigable waters as jurisdictional and defining ephemeral features as
non-jurisdictional, and by including (b)(3) and (b)(4) exclusions
explicitly emphasizing the non-jurisdictional status of ephemeral
features and diffuse stormwater run-off, the agencies are balancing
Congress' intent to interpret the term ``navigable waters'' more
broadly than the classical meaning of that term and the notion that
nothing in the legislative history of the Act ``signifies that Congress
intended to exert anything more than its commerce power over
navigation.'' SWANCC, 531 U.S. at 168 n.3. The exclusions in paragraphs
(b)(3) and (b)(4) and the final rule's limitation of jurisdiction to
perennial and intermittent rivers and streams most appropriately
balances the Federal government's interest in regulating the nation's
navigable waters with respecting State and Tribal land use authority
over features that are only episodically wet during and/or following
precipitation events. See, e.g., Rapanos, 547 U.S. at 734 (Scalia, J.,
plurality) (identifying ``ephemeral streams'' and ``directional sheet
flow during storm events'' as beyond the scope of CWA jurisdiction).
    Some commenters raised concerns with potential adverse impacts to
downstream jurisdictional waters from discharges to non-jurisdictional
ephemeral features. The agencies believe that a CWA section 402
permittee currently discharging to a jurisdictional water that becomes
non-jurisdictional under this final rule would likely remain subject to
the requirements of the Act. This specific concern was raised in
Rapanos, that enforcement of section 402 could be frustrated by
``polluters . . . evad[ing] permitting requirement . . . by discharging
their pollutants into noncovered intermittent watercourses that lie
upstream of covered waters.'' Id. at 742-43. In the words of Justice
Scalia, ``That is not so.'' Id. New or continuing discharges, whether
illicit or not, could be subject to sections 301 and 402 of the Act if
the discharge is conveyed from a point source to a ``water of the
United States.'' The agencies view ephemeral features, such as arroyos
or ditches, as potential conveyances of discharges of pollutants from
point sources subject to NPDES permitting requirements. So too, the
agencies believe, did Justice Scalia. He referred to ``channels''--a
term used in the definition of ``point source'' at 33 U.S.C. 1362(14)--
as ``ephemeral streams,'' ``dry arroyos in the middle of the desert,''
and ``manmade drainage ditches'' when characterizing the types of
features that he believed stretched the meaning of the ``term `waters
of the United States' beyond parody.'' Id. at 734. Additional
discussion of the final rule's treatment of ephemeral features is
provided in Section III.A.3 of this notice.
Ditches
    The final rule's ditch exclusion in paragraph (b)(5) is intended to
provide greater clarity for the regulated public and to be more
straightforward for agency staff to implement than current practice.
The agencies have incorporated a clear statement in the final rule that
all types of ditches would be excluded except where they meet the
conditions of paragraph (a)(1) or (2) of the final rule or where, in
limited instances, they meet the conditions of paragraph (c)(1).
Further, as discussed in Section III.D and Section III.E of this
notice, the final rule clarifies that ditches are tributaries under
paragraph (a)(2) where they relocate a tributary, are constructed in a
tributary, or are constructed in an adjacent wetland, so long as the
ditch satisfies the flow conditions of the ``tributary'' definition.
Many States, regional groups, and national associations that commented
during the Federalism consultation as part of development of the
proposed rule and during the agencies' general outreach efforts noted
that the definition of ``waters of the United States'' should exclude
ditches. The agencies received further comments on the proposed rule's
category of jurisdictional ditches and the exclusion for all other
ditches. Some commenters argued that all ditches should be
jurisdictional if they convey any volume of water to a covered water,
however infrequent or insubstantial, while others took the opposite
view. As discussed in Sections III.D. and III.E., the approach adopted
in this final rule reasonably balances the exclusion of features that
are fundamental to State, tribal, and local land use planning while
respecting the need to preserve jurisdiction over certain ditches.

Prior Converted Cropland
    The agencies are finalizing the prior converted cropland exclusion
in paragraph (b)(6) and adding a definition of ``prior converted
cropland'' in paragraph (c)(9). The definition of ``prior converted
cropland'' clarifies that the exclusion is no longer applicable when
the cropland is abandoned and the land has reverted to wetlands, as
that term is defined in paragraph (c)(16). Under this final 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. Additional discussion on agricultural
purposes is provided below. This final rule also clarifies that
cropland that is left idle or fallow for conservation or agricultural
purposes for any period or duration of time remains in agricultural use
(i.e., it is used for, or in support of, agriculture purposes), and
therefore maintains the prior converted cropland exclusion. The
agencies conclude that this clarification will ensure that cropland
enrolled in long-term and other conservation programs administered by
the Federal government 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.
    In 1993, the agencies categorically excluded prior converted
cropland from the definition of ``waters of the United States.'' 58 FR
45034-36 (August 25, 1993). As further explained below, in keeping with
the Food Security Act of 1985 (FSA), 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, 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 because regulating such
lands does not further the objective of the Act. 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 Regulatory Guidance Letter 90-7.
Although included in the 1993 preamble and Regulatory Guidance Letter
90-7, these principles have not been incorporated into the text of any
promulgated rule until now. This rule therefore represents the first
time the agencies are promulgating regulatory language to clarify the
meaning of ``prior converted cropland'' for CWA purposes, 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 FSA wetlands conservation provisions 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 are continuing to exclude prior converted
cropland from the definition of ``waters of the United States.'' By
incorporating the abandonment principles from the 1993 preamble and
providing examples of ``agricultural purposes,'' this final rule
remains consistent with the concepts underlying the FSA but differs in
implementation from certain aspects of USDA's current wetlands
compliance authority. Incorporating the abandonment principle, as
opposed to a pure ``change in use'' policy (described below), is
important for the agencies to appropriately manage certain wetland
resources while providing better clarity to the agricultural community.
    When the 1993 preamble was published, the abandonment principle was
consistent with USDA's implementation of the FSA. Three years later,
the 1996 FSA amendments modified the abandonment principle and
incorporated a ``change in use'' policy. See Public Law 104-127, 110
Stat. 888 (1996). Under the new policy, prior converted cropland would
continue to be treated 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.'' H.R. 2854, Conf. Rep.
No. 104-494, at 380 (1996). In 2005, the Corps and NRCS issued a joint
``Memorandum to the Field'' (the 2005 Memorandum) in an effort to again
align the CWA section 404 program with the FSA by adopting the amended
FSA's change in use policy. The 2005 Memorandum provided that, a
``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 cropland]
determination is no longer applicable, and a new wetland determination
is required for CWA purposes.'' \57\
---------------------------------------------------------------------------

    \57\ Memorandum to the Field on Guidance on Conducting Wetland
Determinations for the Food Security Act of 1985 and section 404 of
the Clean Water Act, February 25, 2005, available at https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll11/id/2508.
---------------------------------------------------------------------------

    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 articulated in the 2005 Memorandum
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. See 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.
    The agencies received many public comments on the prior converted
cropland exclusion, with some commenters noting that the exclusion will
provide clarification needed to protect prior converted cropland that
may be subject to flooding and to other natural occurrences that result
in wet or saturated fields. The agencies also received public comments
on both the abandonment principle and the change in use analysis. Some
commenters supported the abandonment principle, stating, for example,
that prior converted cropland should lose its status only when the land
is abandoned and the area reverts back to wetland. Other commenters
requested that the agencies finalize the change in use analysis, as
articulated in the 2005 Memorandum. The agencies have considered these
comments and for the reasons provided herein are finalizing the
abandonment principle as proposed and are not adopting the change in
use approach.
    The agencies received many comments in support of the term ``for or
in support of, agricultural purposes'' and recommendations as to how
the term should be interpreted. Commenters

requested that the agencies provide additional examples of agricultural
purposes, including, but not limited to, idling land for conservation
uses (e.g., habitat; pollinator and wildlife management; and water
storage, supply, and flood management); irrigation tailwater storage;
crawfish farming; cranberry bogs; nutrient retention; and idling land
for soil recovery following natural disasters like hurricanes and
drought. The uses listed above, in addition to crop production, haying,
and grazing, fall within the term ``agricultural purposes'' and, if
documented, may maintain the prior converted cropland exclusion.
Conservation practices, including those required or supported by USDA,
State, and local programs (including recognized private sector programs
that partner with government programs or that can provide verifiable
documentation of participation) are critical to the success of
agricultural systems across the country. Conservation practices and
programs also are conducted ``for or in support of agricultural
purposes'' and are appropriate to maintain the prior converted cropland
exclusion.
    The agencies also received public comment on the type of
documentation that a landowner should maintain to demonstrate that
cropland has been used ``for or in support of, agricultural purposes.''
Commenters suggested the use of aerial photographs, topographical maps,
cultivation maps, crop expense or receipt records, field- or tract-
specific grain elevator records, and other records generated and
maintained in the normal course of doing business. The agencies agree
that these types of documents and other documentation reasonably
establishing ``agricultural purposes'' are appropriate to demonstrate
that the prior converted cropland exclusion applies to a certain field
or tract of land.
    Finally, the agencies received public comments on whether the five-
year timeframe for maintaining agricultural purposes is appropriate.
Some commenters supported the five-year timeframe. Other commenters
thought that five years was too long to avoid federal jurisdiction if
wet cropland was providing some ecological or habitat benefit that
should be maintained. Other commenters thought that the five-year
timeframe was too short to account for unforeseen circumstances that
could leave cropland idle for longer periods of time (e.g., bankruptcy,
the probate and estate administration process, natural disasters), and
recommended that the agency adopt a seven, ten, or twenty-year
timeframe. Some commenters specifically requested that the agencies
allow more than five years when drought or flood conditions prevent
cultivation, planting or harvest. The agencies have considered these
comments and conclude that a five-year timeframe for maintaining
agricultural purposes is reasonable and consistent with the 1993
preamble (58 FR 45033) and with the five-year timeframe regarding
validity of an approved jurisdictional determination (2005 Corps
Regulatory Guidance Letter (RGL) 05-02). The five-year timeframe is
longstanding in the CWA section 404 program and will be familiar to
landowners and regulators alike, increasing clarity in implementation.
The agencies are finalizing the rule with the five-year timeframe, as
proposed, but as described in the next subsection, the agencies will
work closely with USDA, and will consider documentation from USDA,
NOAA, FEMA, or other Federal or State agencies to determine if the land
was used for or in support of agricultural purposes in the immediately
preceding five years to evaluate whether cropland has in fact been
abandoned.
    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. This final rule provides much needed clarity about
the prior converted cropland exclusion and how wetlands can be
recaptured into CWA jurisdiction through the abandonment test. In
addition to finalizing the exclusion as proposed, the Corps will
withdraw the 2005 Memorandum simultaneous with the effective date of
this rule.
Artificially Irrigated Areas, Artificial Lakes and Ponds, and Water-
Filled Depressions
    Paragraph (b) also excludes from waters of the United States under
this final rule:
     Artificially irrigated areas, including fields flooded for
agricultural production, that would revert to upland should application
of irrigation water to that area cease (paragraph (b)(7));
     Artificial lakes and ponds, including water storage
reservoirs and farm, stock watering, and log cleaning ponds,
constructed or excavated in upland or in non-jurisdictional waters, so
long as those artificial lakes and ponds are not impoundments of
jurisdictional waters that meet the conditions of paragraph (c)(6)
(paragraph (b)(8)); and
     Water-filled depressions constructed or excavated in
upland or in non-jurisdictional waters incidental to mining or
construction activity, and pits excavated in upland or in non-
jurisdictional waters for the purpose of obtaining fill, sand, or
gravel (paragraph (b)(9)).
    Paragraphs (b)(7), (8), and (9) of the final rule identify features
and waters that the agencies have generally excluded from the
definition of ``waters of the United States'' in previous preambles
since 1986 (see, e.g., 51 FR 41206, 41217 (November 13, 1986) and 53 FR
20764-65 (June 6, 1988)). The agencies have codified these longstanding
exclusions to 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 included
in the final rule a definition of ``upland'' in paragraph (c)(14). It
is important to note that a water of the United States is not
considered ``upland'' just because it lacks water at a given time.
Similarly, an area may remain ``upland'' even if it is wet sporadically
or after a rainfall or flood event. In addition, the agencies recognize
that excluded water features may be constructed or excavated in non-
jurisdictional ponds, wetlands, or other non-jurisdictional features.
Therefore, the agencies added the phrase ``non-jurisdictional waters''
to some of these exclusions to provide greater clarity and to confirm
that these features can be constructed or excavated in a non-
jurisdictional water, such as an isolated pond or wetland, while
continuing to be excluded from federal jurisdiction.
    The upland requirement does not apply to all exclusions under
paragraph (b). For those waters or features in paragraph (b) of this
final rule that do contain the stipulation that they must be
constructed or excavated in upland or in non-jurisdictional waters to
be excluded, the agencies intend that these features be constructed or
excavated wholly in upland or in non-jurisdictional waters. For
example, construction activities that enlarge a water of the United
States beyond its current boundaries are not constructed wholly in
upland. Where portions of a new or modified water feature are built in
a jurisdictional water, the agencies would not view the new or modified
feature as having been constructed or excavated wholly in upland or in
non-jurisdictional waters, and therefore not subject to the exclusion.
But where a stock watering pond, for example, is developed in a spring
that is non-jurisdictional under this final rule, that pond will be
considered by the agencies to have been constructed wholly in

upland and/or non-jurisdictional waters. Even if a feature is not
constructed or excavated wholly in upland or in non-jurisdictional
waters and meets the definition of ``waters of the United States,'' it
may be otherwise excluded under another part of paragraph (b). The
agencies note, however, that the mere interface between the excluded
feature constructed or excavated wholly in upland and a jurisdictional
water does not make that feature jurisdictional. For example, a ditch
constructed or excavated wholly in upland that connects to a tributary
would not be considered a jurisdictional ditch. The connection to a
jurisdictional water does not eliminate applicability of a paragraph
(b) exclusion conditioned by the upland or non-jurisdictional waters
language. To avoid any confusion in implementation, this is why the
agencies have not included the term ``wholly'' in the final regulatory
text. Finally, an excluded feature under the final rule that develops
wetland characteristics within the confines of the non-jurisdictional
water or feature remains excluded from the definition of ``waters of
the United States,'' with the exception in limited circumstances of
wetlands that develop in ditches constructed in adjacent wetlands, as
discussed in Section III.G.
    Many commenters were in favor of the proposed exclusion under
(b)(6) of the proposed rule, now under (b)(7), for artificially
irrigated areas. A few commenters were opposed to the exclusion
entirely, and some commenters were opposed to expanding the exclusion
for other crops and/or aquaculture. Some commenters cited the need for
clarity as to whether the listed crops were the only ones covered under
the exclusion. After considering the comments received, the agencies
have modified this exclusion in the final rule to clarify their intent
that it is not limited to rice and cranberry production and applies
more generally to ``agricultural production.'' The references to
cranberries and rice in the proposed rule were examples and were not an
exhaustive list of crops to which the exclusion would apply. When
evaluating an area to determine whether it meets the exclusion, the
focus should be on whether the area is artificially irrigated or
flooded for the purpose of agricultural production and on whether it
would revert to upland if the irrigation ceases.
    Paragraph (b)(8) of the final rule provides that artificial lakes
and ponds, including water storage reservoirs and farm, irrigation,
stock watering, and log cleaning ponds, are excluded from the
definition of ``waters of the United States'' so long as these features
are constructed or excavated in upland or in non-jurisdictional waters,
and so long as these features are not impoundments of jurisdictional
waters meeting the conditions of paragraph (c)(6). Many commenters
provided edits and additions to the list of water features included in
paragraph (b)(8). However, the agencies did not intend to provide an
exhaustive list of features that are excluded under paragraph (b)(8)
and have determined that any feature that meets the conditions of
paragraph (b)(8) will be non-jurisdictional under this rule.
    The agencies modified the proposed exclusion for artificial lakes
and ponds to clarify their intent. As drafted in the proposed rule, the
exclusion unintentionally would have been narrower than under the 1980s
regulations. For example, when a farm pond is constructed in upland and
connected via a ditch also constructed in upland to divert flow from a
tributary and the farm pond does not connect back into the tributary
system, it has been longstanding agency practice that the farm or stock
pond is non-jurisdictional, similar to irrigation ditches which do not
connect back into the tributary network. The pond's source of water is
the tributary and serves to provide water for irrigation, livestock,
and other agricultural uses. Because such ponds do not contribute
surface water flow to a downstream paragraph (a)(1) water, they have
not been jurisdictional under historic practice and are not
jurisdictional under this final rule. Another example involves a stock
watering pond developed in a non-jurisdictional spring. If that pond
has a spillway that creates a potential surface water connection to a
nearby stream, the pond has traditionally been excluded from CWA
jurisdiction. This final rule adopts that longstanding position.
    In the final rule, the agencies are clarifying that artificial
features including water storage reservoirs and farm, irrigation, stock
watering, and log cleaning ponds are not jurisdictional unless they are
impoundments of jurisdictional waters meeting the conditions of
paragraph (c)(6), as discussed in Section III.F of this notice. The
agencies acknowledge that many artificial lakes and ponds may have been
created by impounding other waters. The text of the final rule
clarifies that artificial lakes and ponds that also meet the conditions
of a jurisdictional impoundment under paragraph (c)(6) are not excluded
under paragraph (b)(8). However, consistent with longstanding practice,
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 paragraph (b)(12)), under this final rule the agencies are
affirmatively relinquishing jurisdiction over the resulting waste
treatment system as long as it is used for this permitted purpose. Also
consistent with longstanding practice, waters upstream of the waste
treatment system are still considered jurisdictional where they meet
the final rule's definition of ``waters of the United States.''
    The (b)(8) exclusion for artificial lakes and ponds uses the term
``constructed or excavated'' in the final rule, while the proposed rule
used the term ``constructed.'' The agencies do not intend for this
change to alter the meaning of the exclusion from proposal. The
agencies believe that this edit provides clarity to the public about
how excluded artificial lakes and ponds can be created--some are
constructed through dams, dikes, or barriers, while some are excavated
pits. Excavation can entail construction, and construction can entail
excavation, but the agencies have decided to use both terms in the
final rule for added clarity.
    Several commenters stated that artificial lakes and ponds should be
excluded regardless of whether they are located either wholly or
partially in upland, and that the (b)(8) exclusion should extend to
artificial lakes and ponds not constructed or excavated in upland. A
few commenters noted that farmers and ranchers often determine the
location of farm and stock ponds based on topography, which will
typically result in the construction of such features in low areas that
may have some characteristics of wetlands or a natural ephemeral
feature. One commenter noted that many artificial lakes or ponds are
isolated features, and that their connectivity to waters of the United
States rather than their relationship to upland should be the primary
factor in determining jurisdiction.
    The final rule continues to require an artificial lake or pond to
be constructed or excavated wholly in upland or in non-jurisdictional
waters to be considered excluded under (b)(8). This reflects the
agencies' longstanding policy, as discussed above with the stock
watering pond example. Artificial lakes and ponds constructed or
excavated partially in uplands or in non-jurisdictional waters and
partially in jurisdictional waters are jurisdictional if such lakes and
ponds meet the conditions of paragraph (c)(6). The agencies are
concerned that if only

part of an artificial lake or pond need be in upland, the exclusion
could be inappropriately applied to waters where just a small portion
is constructed in upland. The agencies again note that the mere
interface between the excluded lake or pond otherwise constructed or
excavated wholly in upland and a jurisdictional water does not make
that feature jurisdictional. For example, an artificial lake or pond
that meets the conditions of paragraph (b)(8) and that connects to a
tributary would not be considered jurisdictional. With respect to
artificial lakes and ponds that are constructed in isolated or
ephemeral features, the agencies modified the exclusion to make clear
that artificial lakes or ponds constructed or excavated in non-
jurisdictional features are excluded.
    Paragraph (b)(9) of the final rule excludes water-filled
depressions constructed or excavated in upland or in non-jurisdictional
waters incidental to mining or construction activity, and pits
excavated in upland or in non-jurisdictional waters for the purpose of
obtaining fill, sand, or gravel. In this final rule, the agencies have
modified this exclusion from the proposal. In the proposed rule, such
depressions would have been excluded where they are ``created in
upland,'' but in the final rule such depressions are excluded where
they are ``constructed or excavated in upland or in non-jurisdictional
waters.'' The change from ``created'' to ``constructed or excavated,''
as discussed above, is not meant to change the meaning or applicability
of the exclusion from the proposed rule, but rather is intended to add
clarity to the regulated public about how such excluded water-filled
depressions can be created.
    Aside from this clarifying change, the agencies are finalizing this
exclusion as it was proposed. In the final rule, this exclusion
clarifies longstanding practice reflected in the agencies' 1986 and
1988 preambles, 51 FR 41206, 41217 (November 13, 1986); 53 FR 20764-65
(June 6, 1988) and includes several refinements to the language in
those preambles. In addition to construction activity, the agencies
have also reflected in the final rule an exclusion for water-filled
depressions created in upland incidental to mining activity. This is
consistent with the 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.
    Several commenters supported the (b)(9) exclusion, because such
water-filled depressions are often needed for facility management but
are not part of the tributary system and are not natural waters. Some
commenters opposed the exclusion, stating that the exclusion benefited
mining companies and would allow mining activities to negatively impact
water quality. Other commenters stated that the exclusion should be
expanded to include water-filled depressions constructed or excavated
incidental to other activities such as silviculture, or incidental to
all activities, asserting that the agencies should not have singled out
specific industries in the exclusion. With respect to expanding the
exclusion to encompass additional industries or activities, the
agencies note that the (b)(9) exclusion is not the only one that
addresses artificial waters. Paragraph (b) of the final rule excludes a
number of artificial features not limited to specific industries. In
addition, CWA section 404(f) exempts a number of discharges associated
with certain activities in jurisdictional waters from the requirement
to obtain a section 404 permit, including normal farming, ranching, and
silviculture activities as part of an established operation. 33 U.S.C.
1344(f)(1)(A).
    Some commenters wanted the (b)(9) exclusion to be expanded so that
once a water-filled depression was excluded, it remained excluded for
CWA section 404 purposes. The 1986 and 1988 preambles stated that these
depressions were excluded ``unless and until the construction or
excavation operation is abandoned and the resulting body of water meets
the definition of waters of the United States.'' (51 FR 41206, 41217
(November 13, 1986); 53 FR 20764-65 (June 6, 1988)). The agencies
proposed that such water-filled depression would remain excluded, which
represented a change from the 1986 and 1988 preamble language. After
further consideration, and after considering comments received, the
agencies have concluded that once a feature subject to the (b)(9)
exclusion is no longer used for the original purpose for which it was
excluded, it no longer qualifies for the (b)(9) exclusion. This is
consistent with the approach to other exclusions, such as waste
treatment systems and artificially irrigated areas, and reaffirms the
agencies' longstanding practice regarding this exclusion. In many
cases, even if the (b)(9) exclusion may no longer apply to a feature,
the feature may still remain non-jurisdictional because it does not
meet the conditions of paragraphs (a)(1) through (4) and thus is
excluded under paragraph (b)(1).
Stormwater Control Features
    In paragraph (b)(10) of the final rule, the agencies exclude
stormwater control features constructed or excavated in upland or in
non-jurisdictional waters to convey, treat, infiltrate, or store
stormwater runoff. Although stormwater control features are not
specifically included in the list of waters that the agencies consider
to be generally non-jurisdictional per the 1986 and 1988 preamble
language, 51 FR 41206 (November 13, 1986) and 53 FR 20764 (June 6,
1988), the agencies' longstanding practice is to view stormwater
control features that are not built in waters of the United States as
non-jurisdictional. Conversely, the agencies view some relatively
permanent bodies of water, such as channelized streams with
intermittent or perennial flow, as jurisdictional even when used as
part of a stormwater management system. Nothing in this final rule
changes the agencies' longstanding practice. Rather, this exclusion
clarifies the appropriate limits of jurisdiction relating to these
systems.
    A key element of the exclusion is whether the feature or control
system was built wholly in upland or in a non-jurisdictional water. As
discussed above and as further clarified below, the agencies recognize
that upland features may be connected to jurisdictional waters and that
such a connection does not preclude application of the exclusion.
Another key element is that the feature must convey, treat, infiltrate,
or store stormwater. Stormwater control features have evolved
considerably over time, and their nomenclature is not consistent, so in
order to avoid unintentionally limiting the exclusion, the agencies
have not included a list of excluded features in the final rule. The
rule excludes the diverse range of stormwater control features that are
currently in place and may be developed in the future. However, the
agencies note that excluded stormwater control features when they have
channelized surface water may provide a connection between the upstream
reach of a relatively permanent water and a downstream jurisdictional
water such that the upstream reach is jurisdictional. Even in this
circumstance, the stormwater control feature would remain non-
jurisdictional under this final rule. See Section III.D of this notice
for further discussion. The agencies also note that while excluded from
the definition of ``waters of the United States,'' stormwater control
features may function as a conveyance of a discharge of pollutants from
a point source to a water of the United States.

    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, use of stormwater controls to remove
pollutants before the stormwater is discharged has become more
prevalent. 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, evaporate, or transpire 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 final rule is designed to avoid
disincentives to this environmentally beneficial trend in stormwater
management practices.
    Many commenters supported the proposed rule's exclusion for
stormwater control features constructed or excavated in upland,
asserting that environmentally beneficial solutions to manage
stormwater could be discouraged if such features were designated as
``waters of the United States.'' Several commenters noted concerns that
an exclusion dependent on an upland location could potentially deter
stormwater system operators from installing beneficial green
infrastructure and suggested that jurisdictional waters incorporated
into the stormwater system should be excluded. Many commenters
suggested that the final rule should define ``stormwater control
features'' that would be excluded.
    The agencies' longstanding practice is to view stormwater control
features as non-jurisdictional when built outside of waters of the
United States. The agencies do not agree with commenters who stated
that jurisdictional waters that are incorporated into a drainage or
stormwater conveyance system should be excluded by virtue of the fact
that they are part of the larger stormwater control system. A water
does not lose its jurisdictional status if it is modified for use as a
stormwater control measure. The agencies recognize that highly
engineered municipal separate storm sewer systems (MS4s) that may have
replaced natural drainage features may therefore have jurisdictional
waters within their systems, but this does not represent a change from
longstanding practice. For example, the Los Angeles River is a
traditional navigable water highly engineered for stormwater control,
and it still meets the requirements of a paragraph (a)(1) water.
Regarding comments related to defining the term ``stormwater control
features,'' the agencies do not name specific stormwater control
features that would fall under the stormwater control feature
exclusion, as they do not want the final rule to be perceived as
limiting the exclusion, particularly given differences among regional
naming conventions and the likelihood that technologies and
nomenclature will evolve in the future.
Groundwater Recharge, Water Reuse, and Wastewater Recycling Structures
    In this final rule under paragraph (b)(11), the agencies exclude
from the definition of ``waters of the United States'' groundwater
recharge, water reuse, and wastewater recycling structures constructed
or excavated in upland or in non-jurisdictional waters. While such
features are not explicitly listed in the categories of waters that the
agencies generally consider to be non-jurisdictional in the 1986 and
1988 preamble language, 51 FR 41206 (November 13, 1986) and 53 FR 20764
(June 6, 1988), this exclusion clarifies the agencies' longstanding
practice that waters and water features used for water reuse and
recycling are not jurisdictional when constructed in upland or in non-
jurisdictional waters. The agencies recognize the importance of water
reuse and recycling, particularly in the arid West where water supplies
can be limited and droughts can exacerbate supply issues. This
exclusion is intended to avoid discouraging or creating barriers to
water reuse and conservation practices and 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 exclusion in paragraph (b)(11) of the final rule codifies
the agencies' longstanding practice and encourages water management
practices that the agencies recognize are important and beneficial.
    Many commenters expressed support for the proposed rule's exclusion
for wastewater recycling structures. Some commenters stated that the
exclusion would encourage water reuse and other innovative approaches
to water management. A few commenters supported the exclusion because
they said wastewater recycling structures should be regulated at the
State level. Some commenters stated that considering a wastewater
recycling structure a water of the United States could create
unnecessary regulatory and economic burdens, while providing no
additional water quality protection. Several commenters stated that the
exclusion of groundwater recharge basins and similar structures was
consistent with Justice Scalia's plurality opinion in Rapanos, as
groundwater recharge basins do not discharge to any navigable waters,
are filled only during part of the year, and do not otherwise
constitute a traditional navigable water within the meaning of the
plurality's jurisdictional test. A number of commenters suggested that
the qualifying language in the proposed rule's wastewater recycling
structures exclusion, which would have limited the exclusion to
wastewater recycling structures ``constructed in upland,'' could create
barriers to water reuse and conservation.
    For the reasons described above, the agencies believe that the
(b)(11) exclusion reflects an appropriate balance among CWA policies
and encouraging water reuse and effective water management. As a
result, this final rule includes the (b)(11) exclusion largely
unchanged from the proposal. The agencies did modify the exclusion in
response to comments to add the term ``water reuse'' to the exclusion
as it is commonly used in water and wastewater management. The agencies
also added ``or non-jurisdictional waters'' to the exclusion to ensure
that it is not narrowly restricted to construction in upland only. As
discussed above, the agencies will apply the qualifier ``constructed or
excavated in upland or in non-jurisdictional waters'' consistently
across four exclusions that use the term.
Waste Treatment Systems
    Paragraph (b)(12) of the final rule excludes waste treatment
systems. The waste treatment system exclusion has existed since 1979
(44 FR 32854), and the agencies are continuing the exclusion under this
final rule. The agencies are also for the first time providing in the
final rule a definition of ``waste treatment system'' under paragraph
(c)(15), so as to clarify which waters and features are considered part
of a waste treatment system and therefore excluded. Continuing the
agencies' longstanding practice, any

entity with a waste treatment system would need to comply with the CWA
by obtaining a section 404 permit for new construction in a water of
the United States, and a section 402 permit for discharges from the
waste treatment system into waters of the United States. Consistent
with the proposal, 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 ministerial change in the final
rule from the 2019 Rule is the deletion of a cross-reference to a
regulatory definition of ``cooling ponds'' that no longer exists in the
Code of Federal Regulations.\58\
---------------------------------------------------------------------------

    \58\ See 47 FR 52290, 52291, 52305 (Nov. 19, 1982) (deleting
definition of cooling ponds at 40 CFR 423.11(m)).
---------------------------------------------------------------------------

    Many commenters supported the waste treatment system exclusion and
definition as proposed and agreed that the proposed exclusion would
codify the agencies' longstanding practice. Some commenters requested
that the exclusion be expanded to include all ancillary systems,
channels, appurtenances, conveyances, and diversion ditches associated
with the waste treatment system. Other commenters stated that the
proposed exclusion was unlawful and that it should be eliminated
entirely. Some commenters suggested that there may be confusion
concerning the agencies' intent to apply the exclusion to waste
treatment systems constructed prior to the 1972 CWA amendments and
requested that this concept be explicitly included in the final
regulatory text.
    The agencies have considered these public comments and have
finalized the waste treatment exclusion as it was proposed. As noted
above, the agencies agree with commenters that this final rule codifies
the longstanding exclusion that was first included in regulation in
1979. The agencies disagree with suggestions to expand or eliminate the
exclusion and have finalized the definition as proposed. The agencies
also disagree with the suggestion that the exclusion is unlawful and
that there is confusion over the agencies' intent to apply this
exclusion to all waste treatment systems constructed prior to the 1972
CWA amendments. The agencies clearly stated their intent to do so in
the notice of proposed rulemaking and in this final rule, and do not
believe it is necessary to repeat this intent in the regulatory text.
The regulatory text applies to all waste treatment systems that meet
the definition set forth therein, including systems constructed prior
to the 1972 CWA amendments, and there is no basis for construing the
exclusion not to apply to such systems.
    The agencies also considered other exclusions recommended by
stakeholders prior to the proposed rule and suggested in comments on
the proposed rule. The agencies did not include these additional
proposed exclusions in the final rule. Some of the suggested exclusions
were so broadly characterized that they would have introduced confusion
and potentially excluded waters that the agencies have consistently
determined should be covered as waters of the United States. Other
suggested exclusions were so site-specific or activity-based that they
did not warrant inclusion in the nationally-applicable definition.
Still other suggested exclusions were covered by another exclusion in
the rule, and thus would have been superfluous, in whole or in part.
3. How will the agencies implement the final rule?
    To determine whether a water meets the final rule's exclusions in
paragraphs (b)(1) through (b)(12), the agencies will first evaluate
whether the water meets the definition of ``waters of the United
States'' under paragraphs (a)(1) through (4). If the water does not
satisfy any of the paragraph (a)(1) through (4) conditions, it is non-
jurisdictional under paragraph (b)(1). If the water does satisfy one or
more of the conditions to be a paragraph (a)(1) through (4) water, the
agencies will evaluate if the water is identified in any of the
categories of excluded waters and features under paragraphs (b)(2)
through (12) of this final rule. If the water meets any of these
exclusions, the water is excluded even if the water satisfies one or
more of the conditions to be a paragraph (a)(1) through (4) water.
    As discussed above, the agencies' final rule includes an exclusion
for groundwater under paragraph (b)(2), including groundwater drained
through subsurface drainage systems. The final rule clarifies that even
when groundwater is channelized in subsurface systems, like tile drains
used in agriculture, it remains subject to the exclusion. However, the
exclusion does not apply to surface expressions of groundwater, such as
where groundwater discharges to the channel bed and becomes baseflow in
intermittent or perennial streams. The agencies' exclusion for
groundwater in the final rule is consistent with longstanding agency
practice.
    Some commenters requested that the agencies provide guidance as to
how to implement the exclusion for ephemeral features. For example, a
commenter stated that a blanket exclusion of ephemeral streams without
regard to flow quantity could increase the difficulty in delineating
such features and could limit activities to certain time periods. Some
commenters suggested the agencies consider certain ephemeral features
to be jurisdictional on a situational or regional basis, while other
commenters supported a case-by-case determination of ephemeral features
that would fall under the exclusion, rather than excluding ephemeral
features categorically. One commenter requested implementation tools,
including visual aids or benchmarks to identify excluded features,
observing that distinguishing between ephemeral and intermittent waters
may be challenging.
    This final rule is intended to establish categorical bright lines
that provide clarity and predictability for regulators and the
regulated community. Consistent with that goal, the final rule
eliminates the case-specific application of Justice Kennedy's
significant nexus test, and instead establishes clear categories of
jurisdictional waters and non-jurisdictional waters and features that
adhere to the basic principles articulated in the Riverside Bayview,
SWANCC, and Rapanos decisions, including key principles expressed in
Justice Scalia's plurality opinion and Justice Kennedy's concurring
opinion in that case, as discussed at length in this preamble, while
respecting the overall structure and function of the CWA. The agencies
have existing field and remote tools and additional implementation
tools and methods under development that will help distinguish flow
classifications of streams and other waterbodies. The agencies can use
many tools and remote and field-based methods described in Section
III.D.3 to distinguish between paragraph (b)(3) ephemeral streams,
swales, gullies, rills, and pools and paragraph (b)(4) areas with
diffuse stormwater run-off and directional sheet flow over upland,
while comparing both against waters subject to jurisdiction under
paragraph (a). Under past and existing practice, the agencies have
substantial experience using remote tools and field observations to
distinguish between channelized and non-channelized features, and the
agencies expect that many landowners can distinguish between these
features using visual observations. Under this final rule, landscapes
with non-channelized, diffuse stormwater and overland sheet flow are
excluded regardless of the flow regime characteristics, because under

these circumstances, flow is occurring only in direct response to
precipitation over areas that meet the definition of ``upland.'' As
explained by the Rapanos plurality, regulating these features as waters
of the United States extends beyond the rational meaning of the term.
547 U.S. at 734.
    With respect to implementing the final rule's paragraph (b)(5)
exclusion for certain ditches, the reach of a ditch that meets
paragraph (a)(1) or (2) of the final rule is considered a water of the
United States, with ``reach'' interpreted similarly to how it is used
for tributaries in Section III.D of this notice (i.e., a section of a
ditch along which similar hydrologic conditions exist, such as
discharge, depth, area, and slope). The jurisdictional status of other
reaches of the same ditch must be assessed based on the specific facts
and under the terms of the final rule to determine the jurisdictional
status of those reaches. For example, a ditch that is constructed in a
tributary is not an excluded ditch under paragraph (b)(5) so long as it
satisfies the flow conditions of the ``tributary'' definition or the
conditions of the ``adjacent wetlands'' definition as further described
in Section III.D and Section III.E. Further, the ditch exclusion does
not affect the possible status of a ditch as a point source. Also, a
ditch constructed in an adjacent wetland that satisfies the conditions
of paragraph (a)(4) is not excluded. The agencies believe that the
final rule's ditch exclusion encompasses most irrigation and drainage
ditches, including most roadside and other transportation ditches, as
well as most agricultural ditches.
    In paragraph (b)(6) of this final rule, the agencies are
reconfirming the longstanding prior converted cropland exclusion. This
final rule also codifies the abandonment principle as applied to the
prior converted cropland exclusion, as first articulated in the 1993
preamble (58 FR 45033), and provides additional clarification regarding
what constitutes ``agricultural purposes.'' As a result of this final
rule, the change in use analysis will no longer be used to evaluate
whether the prior converted cropland exclusion applies. Under the final
rule, when cropland has been abandoned (i.e., the cropland has not been
used for or in support of agricultural purposes for a period of greater
than five years), and wetlands have returned, any prior converted
cropland designation for that site will no longer be valid for purposes
of the CWA.
    The USDA is responsible for making determinations as to whether
land is prior converted cropland for its FSA purposes, whereas the
agencies are responsible for determining applicability of the exclusion
for CWA purposes, consistent with the government's longstanding
interpretation of the agencies' authority under the CWA. See 33 CFR
328.3(a)(8) (``Notwithstanding the determination of an area's status as
prior converted cropland by any other Federal agency, for the purposes
of the Clean Water Act, the final authority regarding Clean Water Act
jurisdiction remains with EPA.''); CWA Regulatory Programs, 58 FR
45,008, 45,036 (Aug. 25, 1993); Administrative Authority to Construe
Sec.  404 of the Federal Water Pollution Control Act (``Civiletti
Memorandum''), 43 Op. Att'y Gen. 197 (1979). The agencies will defer to
USDA for purposes of establishing whether a parcel or tract of land has
received a prior converted cropland determination and is therefore
eligible for the prior converted cropland exclusion under this rule. A
landowner without an existing prior converted cropland determination
may seek a new determination from the USDA.\59\ The USDA is subject to
specific statutes designed to protect landowner privacy and, as such,
is prohibited from making certain parcel-specific information available
without the landowner's consent. To ensure that the agencies can rely
on a USDA prior converted cropland determination, the landowner will
need to either provide a copy of the determination or provide the
agencies with a signed consent form to allow the agencies access to the
relevant information for the limited purpose of verifying USDA's prior
converted cropland determination. The agencies recognize that privacy
and confidentiality issues concerning certain producer information is
addressed at section 1619 of the Food, Conservation, and Energy Act of
2008 (7 U.S.C. 8791(b)) and section 1244(b) of the Food Security Act of
1985, as amended (16 U.S.C. 3844(b)). If a parcel is found to be prior
converted cropland, as defined in this rule, it is not a water of the
United States.
---------------------------------------------------------------------------

    \59\ The agencies note that the USDA's regulatory definition of
``prior converted cropland'' in the FSA and the definition being
established in this final rule have different purposes and they are
substantively different. Based on the FSA's statutory requirements,
the USDA definition of ``prior converted cropland'' requires that
agricultural commodity crop production be made possible prior to
1985. See 7 CFR 12.2(a)(8); 16 U.S.C. 3801 (defining converted
wetland) and 16 U.S.C. 3822(b)(1)(A) (establishing the pre-1985
exemption). If commodity crop production was made possible on a
particular parcel or tract of land prior to 1985, that land is
eligible for the prior converted cropland exclusion in this final
rule. Once eligibility is determined, the agencies will evaluate the
land to determine if the exclusion currently applies, or if the land
has been abandoned, as described in this final rule.
---------------------------------------------------------------------------

    Once a threshold determination has been made that certain lands are
prior converted cropland, the EPA and the Corps are responsible for
implementing the prior converted cropland exclusion for CWA purposes
and identifying (as further explained below) whether the lands have
been abandoned and whether wetlands conditions have returned such that
they are no longer eligible for the prior converted cropland exclusion
in this rule and thus may be waters of the United States. In addition
to working closely with the USDA, the agencies will consider
documentation from NOAA and FEMA when evaluating whether a parcel of
land may no longer be eligible for the CWA prior converted cropland
exclusion. In all cases, the burden to prove that such parcel is a
water of the United States remains on the agencies. The agencies'
implementation of the prior converted cropland exclusion for CWA
regulatory purposes does not affect the USDA's administration of the
FSA or a landowner's eligibility for benefits under FSA programs.\60\
---------------------------------------------------------------------------

    \60\ See the Notice of Proposed Rulemaking at 84 FR 4193 for a
summary of how the agencies historically implemented and enforced
this exclusion.
---------------------------------------------------------------------------

    Under the final rule, to determine the continuing applicability of
the prior converted cropland exclusion, the Corps must first determine
whether the land has been ``abandoned.'' As described previously, 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. In making an abandonment
determination, the Corps will work with the landowner and USDA, as
appropriate, to determine whether the land is currently or has been
used for or in support of agricultural purposes at least once in the
immediately preceding five years. As noted above, there are many uses
that may fall within this category, including but not limited to,
grazing; haying; idling land for conservation purposes (e.g., habitat;
pollinator and wildlife management; and water storage, water supply,
and flood management); irrigation tailwater storage; crawfish farming;
cranberry bogs; nutrient retention; and idling land for soil recovery
following natural disasters like hurricanes and drought. Some of those
land uses may not be obvious to Corps field staff, so the agencies may
rely on public or private documentation to demonstrate that the land is
enrolled in a conservation program or is otherwise

being used for or in support of agricultural purposes. Such information
may include aerial photographs, topographical maps, cultivation maps,
crop expense or receipt records, field- or tract-specific grain
elevator records, and other records generated and maintained in the
normal course of doing business, including government agency records
documenting participation in a conservation program, and other
documentation reasonably establishing one or more ``agricultural
purposes.''
    The final rule requires that the land be used for or in support of
agricultural purposes within the immediately preceding five years. In
implementing this requirement, the agencies will consider documentation
from USDA, NOAA, FEMA, and other Federal and State agencies to
determine whether the land was used for or in support of agricultural
purposes in the immediately preceding five years. For example, USDA
administers multiple programs that track whether fields have been
planted or harvested in the normal course, or enrolled in long-term
conservation rotations, and the agency provides crop insurance for
years where those activities were halted for reasons covered under
their insurance policies; NOAA tracks long- and short-term weather
patterns and can provide information and data concerning flood or
drought conditions that may cause or contribute to idling land in
support of agricultural purposes; and FEMA administers emergency
response programs for natural disasters, including hurricanes,
wildfires, and other events that could also require idling land for
soil recovery and other agricultural purposes. The agencies will take
into account this information, and additional documentation reasonably
establishing ``agricultural purposes'' when evaluating whether cropland
has been used for or in support of agricultural purposes 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 wetland
conditions have returned. If wetlands are currently present on the
property, the agencies will determine whether the wetlands are
``adjacent wetlands'' and therefore ``waters of the United States,''
consistent with this final rule. As the term ``prior converted
cropland'' suggests, and as stated in the preamble to the 1993 Rule,
land properly designated as 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
agency 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
jurisdictional 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 to be subject
to CWA regulation, even after it is abandoned. However, at least some
abandoned prior converted cropland may, under normal circumstances,
meet the definition of ``wetlands'' under paragraph (c)(16).
    In paragraph (b)(7), the agencies clarify their longstanding view
that the artificial irrigation exclusion applies only to the specific
land being artificially irrigated, including fields flooded for
agricultural production, including but not limited to rice or cranberry
growing, which would revert to upland should artificial irrigation
cease. 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 and 1988 preambles. See 51 FR 41206,
41217 (November 13, 1986) and 53 FR 20764-65 (June 6, 1988). In the
past, the agencies have considered those under the artificial lakes or
ponds category of waters that are generally non-jurisdictional, but
this final rule includes them in the artificial irrigation exclusion
category as any wetland crop species, such as rice and cranberry
operations, that is typically supplied with artificial flow irrigation
or similar mechanisms.
    A number of commenters addressed the difficulty in proving that
land would revert to upland when irrigation ceased and suggested
clarification as to whether documentation was needed as proof. The
agencies agree that proving that land would revert to upland may be
challenging in some circumstances. The agencies have developed
strategies and guidance to assist with determining if wetland
conditions will persist when irrigation ceases. This includes, but is
not limited to, utilizing aerial photography, soil maps, LiDAR, remote
sensing, and field assessments to determine if wetland conditions are
the result of irrigation or are naturally occurring.
    Commenters also raised concern about whether the exclusion is only
available for rice and cranberry growing areas. The inclusion of rice
and cranberries in the proposed rule were simply examples and not
intended to be exhaustive. In this final rule, the agencies conclude
that it is not necessary to list all crops potentially eligible for the
exclusion, and therefore simply reference ``agricultural production.''
The relevant factor in determining the application of the exclusion is
not what type of crop may be planted or cultivated, but whether the
area is artificially irrigated and would revert to upland should
irrigation cease.
    Under the final rule, the exclusion for waters meeting the
conditions of paragraph (b)(8) applies to artificial lakes and ponds
created through construction or excavation in upland or in non-
jurisdictional features. Such artificial lakes and ponds would not be
jurisdictional under the final rule even if they maintain a hydrologic
surface connection to waters of the United States or are inundated by
waters of the United States. Conveyances created in upland that are
physically connected to and are a part of the excluded feature also are
excluded.
    A commenter inquired as to whether the artificial waterbody created
by impounding a jurisdictional tributary would be jurisdictional. The
agencies note that under the final rule, impoundments are considered
jurisdictional if they impound a paragraph (a)(1) through (4) water,
which includes jurisdictional tributaries, and contribute surface water
flow in a typical year to a paragraph (a)(1) water or are inundated by
flooding from a paragraph (a)(1) through (3) water in a typical year.
Impounding a jurisdictional tributary does not create a non-
jurisdictional lake or pond that would be excluded under paragraph
(b)(8), but rather creates a jurisdictional impoundment so long as it
meets the conditions of paragraph (a)(3) as defined in paragraph
(c)(6). The agencies note that artificial lakes and ponds that are
excluded from the definition of ``waters of the United States'' could,
in some circumstances, be point sources of pollutants subject to
sections 301 and 402 of the Act.
    Under paragraph (b)(9), water-filled depressions constructed or
excavated in upland or in non-jurisdictional waters that are incidental
to mining or construction activity, and pits excavated in upland or in
non-jurisdictional waters for the purpose of obtaining fill,

sand, or gravel are excluded from the definition of ``waters of the
United States.'' To determine whether a water or feature meets this
exclusion, the agencies will evaluate whether the water feature is
constructed or excavated in upland or in non-jurisdictional waters as
part of these industrial activities. In addition, such water-filled
depressions and pits could become waters of the United States once
construction or mining activities have permanently ceased and the
depressions or pits meet the conditions of a paragraph (a)(1) through
(4) water.
    The final rule excludes in paragraph (b)(10) stormwater control
features constructed or excavated in upland or in non-jurisdictional
waters to convey, treat, infiltrate, or store stormwater run-off. As
stated previously, the rule excludes a diverse range of stormwater
control features that are currently in place and that may be developed
in the future. To determine if such a water or feature meets the
exclusion, the agencies will evaluate whether the stormwater feature is
constructed or excavated in upland or in non-jurisdictional waters.
    Paragraph (b)(11) of the final rule clarifies that groundwater
recharge, water reuse, and wastewater recycling structures constructed
or excavated in upland or in non-jurisdictional waters are excluded. To
determine whether a such a structure meets this exclusion, the agencies
will evaluate whether the water or feature is constructed or excavated
in upland or in non-jurisdictional waters. This exclusion includes
detention and retention basins as well as groundwater recharge basins
and infiltration ponds excavated in upland or in non-jurisdictional
waters for wastewater recycling. The exclusion also covers water
distributary structures that are built in upland or in non-
jurisdictional waters for water recycling. These features often connect
or carry surface water flow to other water recycling structures, for
example, a channel or ditch that carries water to an infiltration pond.
Consistent with longstanding practice, the agencies do not consider
these water distributary systems jurisdictional.
    As discussed previously, the agencies are not changing the
longstanding approach to implementing the waste treatment system
exclusion. As a result, the agencies will continue to apply the
exclusion to systems that are treating water 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 CWA 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 does not continue to qualify for the exclusion.
    Some commenters suggested the agencies clarify the way in which the
waste treatment system exclusion is currently implemented. Many
comments inquired as to whether stormwater systems and wastewater reuse
facilities are considered part of a complete waste treatment system for
purposes of the waste treatment system exclusion. To enhance clarity,
the agencies have provided in the final rule two related exclusions in
paragraphs (b)(10) and (b)(11) and have added settling basins and
cooling ponds to the definition of ``waste treatment system'' in
paragraph (c)(15). The agencies note that cooling ponds that are
created under CWA section 404 in jurisdictional waters and that have
CWA section 402 permits are subject to the waste treatment system
exclusion under the 2019 Rule and will also be excluded under the final
rule. Cooling ponds created to serve as part of a cooling water system
with a valid State or Federal permit constructed in waters of the
United States prior to enactment of the 1972 amendments of the CWA and
excluded from jurisdiction under the 2019 Rule also remain excluded
under the final rule. Some commenters on the proposed rule's waste
treatment system exclusion expressed confusion regarding whether
stormwater treatment features would be excluded under the exclusion for
stormwater control features or under the waste treatment exclusion.
Such determinations will depend on the specific attributes of the
control and the water feature and thus need to be made on a case-by-
case basis. It is possible that a stormwater feature could qualify for
both the stormwater control features exclusion and the waste treatment
systems exclusion. This same principle applies to other exclusions that
may have similar cross-over features, like certain ditches used in
stormwater management systems.
    It is important to reiterate that while the waters and features
listed in the final rule's exclusions are not waters of the United
States, some of them may convey surface water flow to a downstream
jurisdictional water, so that reaches of a water upstream and
downstream of the excluded water or feature may meet the definition of
``tributary'' in paragraph (c)(12). For example, when some water from a
tributary is moved into a downstream jurisdictional water through an
excluded ditch, the ditch itself is excluded from jurisdiction under
the final rule but the tributary upstream of the ditch is
jurisdictional if the non-jurisdictional ditch conveys surface water
flow in a typical year to the downstream jurisdictional reach.

I. Placement of the Definition of ``Waters of the United States'' in
the Code of Federal Regulations

1. What are the agencies finalizing?
    The definition of ``waters of the United States'' has historically
been placed in eleven locations in the Code of Federal Regulations
(CFR). For the sake of simplicity, in this final rule, the agencies are
codifying the definition of ``waters of the United States'' in only two
places in the CFR--once in Title 33 (which implements the Corps'
statutory authority) and once in Title 40 (which generally implements
the EPA's statutory authority).
2. Summary of Final Rule Rationale and Public Comment
    The agencies proposed to maintain the definition of ``waters of the
United States'' at 33 CFR 328 and in ten locations in Title 40. The
agencies solicited comment on an alternative approach under which the
definition would be codified in just two locations within the CFR,
rather than in the eleven locations in which it has previously
appeared. Most commenters recommended that the definition of ``waters
of the United States'' be codified twice, once in Title 33 of the CFR
and once in Title 40 of the CFR. These commenters recommended limiting
codification to two locations in order to clarify that there is a
single definition of ``waters of the United States'' applicable to the
entire CWA, to reduce confusion and conflicting interpretations under
different programs, and to promote ease of use for the regulated
community and for laypersons. Many of these commenters suggested
including a cross-reference in the original ten locations of Title 40
of the CFR. Some commenters recommended continuing the agencies'
practice of codifying the definition of ``waters of the United States''
in eleven locations within the CFR.
    The agencies agree with commenters that stated that codifying the
definition of ``waters of the United States'' in two locations within
the CFR will reduce confusion and promote ease of use for States,
Tribes, local government, the regulated community, and the general
public. With this final rule, the agencies are codifying the definition
of ``waters of the United States'' in Title 33 of the CFR, which
implements the Corps' statutory authority, at 33 CFR 328.3, and in
Title 40, which generally implements

the EPA's statutory authority, at 40 CFR 120.2. In the sections of the
CFR where the EPA's regulatory definition previously existed, 40 CFR
110.1, 112.2, 116.3, 117.1, 122.2, 230.3, 232.2, 300.5, 302.3, 401.11,
and Appendix E to 40 CFR part 300, this final rule cross-references the
newly created section of the regulations containing the definition of
``waters of the United States.'' The agencies have placed the EPA's
definition of ``waters of the United States'' in a previously
unassigned part of 40 CFR. The change in placement has no implications
on CWA program implementation; it is made for the sole purpose of
enhancing the clarity of the federal regulations. Placing the
definition of ``waters of the United States'' in a single section in
the part of the regulations that implements the EPA's authority and
once again in the part of the regulations that implements the Corps'
authority makes clearer to members of the public that there is a single
definition of ``waters of the United States'' applicable to the CWA and
its implementing regulations.

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. For these reasons, several States suggested that 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 the Notice of Proposed Rulemaking for this rule, the agencies
solicited comment as to how to create a regulatory framework that would
authorize interested States, Tribes, and other Federal agencies to
develop for the agencies' approval geospatial datasets representing
waters of the United States, as well as waters excluded from the
definition, ``waters of the State'' or ``waters of the Tribe'' within
their respective borders. 84 FR 4154, 4198-4200 (February 14, 2019).
This concept was not part of the proposed regulatory text; the agencies
utilized the notice to solicit input and suggestions from the regulated
public, States, Tribes, and other stakeholders.
    Some commenters raised concerns regarding the limitations of data
currently available for creating geospatial datasets of jurisdictional
waters, particularly commenting on the limitations of national datasets
such as the National Hydrography Dataset (NHD) and the National
Wetlands Inventory (NWI). Some commenters expressed concerns about the
resolution, completeness, accuracy, and usefulness of publicly-
available data, with some stating that geospatial datasets cannot
accurately assess the details needed to remotely determine or delineate
jurisdictional waters. Other commenters noted that, despite the
limitations in the available data, the agencies should attempt to
quantify changes in the jurisdictional status of specific waterbody
categories as a result of the final rule.
    The agencies agree that there are significant limitations to the
extent to which currently available data can be used to identify the
scope of all or even a subset of jurisdictional waters. There are
currently no comprehensive datasets through which the agencies can
depict the universe of federally-regulated waters under the CWA. For
example, the agencies attempted to use the NHD at high resolution and
NWI to assess the potential change in CWA jurisdiction as a result of
the proposed rule to revise the definition of ``waters of the United
States,'' but ultimately concluded that the limitations of these
datasets precluded their use for quantifying the extent of waters whose
jurisdictional status could change under the proposed rule, as
discussed in Section V and in the Resource and Programmatic Assessment
for the final rule. Due to these limitations, which were confirmed
during the public comment period for the proposed rule and an
evaluation by the agencies, the agencies also did not use the NHD or
NWI to assess potential changes in jurisdiction as a result of the
final rule.
    While the NHD and NWI are the most comprehensive hydrogeographic
datasets mapping waters and wetlands in the United States and are
useful resources for a variety of Federal programs, including CWA
programs, they currently have technical limitations that present
significant challenges for use as standalone tools to determine the
full scope of CWA jurisdiction and for creating geospatial datasets of
jurisdictional waters, regardless of the regulatory definition of
``waters of the United States.'' Importantly, the NHD and NWI were not
created for regulatory purposes, so their limitations as comparative
tools for CWA jurisdiction are not surprising.
    Due in part to the resolution of the data, limitations of the NHD
for purposes of accurately mapping the scope of jurisdictional waters
under the CWA include errors of omission (e.g., failure to map streams
that exist on the ground); errors of commission (e.g., mapping streams
that do not exist on the ground); horizontal positional inaccuracies;
misclassification of stream flow condition, particularly in headwaters;
and inconsistent mapping in different parts of the country. The NWI
presents similar challenges for identifying federally-regulated waters,
including the foundational obstacle of having a ``wetlands'' definition
that differs from the federal regulatory ``wetlands'' definition. The
NWI also contains errors of omission (e.g., failure to map wetlands
that exist on the ground), errors of commission (e.g., mapping wetlands
that do not exist on the ground), and potentially inaccurate wetland
boundary identification. The limitations identified herein are examples
and do not represent an exhaustive list of challenges faced by the
agencies in potentially using them to identify the scope of CWA
jurisdiction. For a more detailed discussion of the NHD and NWI
datasets and their limitations for use as standalone tools to determine
the full scope of waters that are and are not waters of the United
States, see Chapter II of the Resource and Programmatic Assessment
supporting this final rule.
    It has been the consistent position of the agencies that the NHD
and the NWI do not represent the scope of waters subject to CWA
jurisdiction.\61\ Indeed,

as part of the 2015 rulemaking, the agencies stated that they ``do not
have maps depicting waters of the United States under either present
regulatory standards or those in the final [2015] rule.'' \62\ This
remains true today; the agencies do not have maps of waters of the
United States under the 2015 Rule, under the 2019 Rule, or under this
final rule. For this reason, and to provide the public and the agencies
with more information on which waters are or are not waters of the
United States, the agencies sought public comment on a possible
framework for developing geospatial datasets.
---------------------------------------------------------------------------

    \61\ See, e.g., Letter from Nancy Stoner, Acting Assistant
Adm'r, EPA Office of Water, to Lamar Smith, Chairman, Comm. on
Science, Space, and Tech., U.S. House of Representatives (July 28,
2014) (emphasis added), available at https://web.archive.org/web/20180919173837/https://science.house.gov/sites/republicans.science.house.gov/files/documents/epa_releases_maps_letter.pdf. (``[N]o national or statewide maps
have been prepared by any agency, including EPA, showing the scope
of waters subject to the Clean Water Act. . . . To develop maps of
jurisdictional waters requires site-specific knowledge of the
physical features of water bodies, and these data are not
available[.]'') (emphasis added); see also Letter from Nancy Stoner,
Deputy Assistant Adm'r, EPA Office of Water, to Lamar Smith,
Chairman, Comm. on Science, Space, and Tech., U.S. House of
Representatives (August 6, 2014), available at https://web.archive.org/web/20180919173837/https://science.house.gov/sites/republicans.science.house.gov/files/documents/epa_releases_maps_letter.pdf); U.S. EPA, Mapping the Truth, The EPA
Blog (Aug. 28, 2014), available at https://blog.epa.gov/2014/08/28/mapping-the-truth/ (``While these [U.S. Geological Survey and Fish &
Wildlife Service] maps are useful tools for water resource managers,
they cannot be used to determine Clean Water Act jurisdiction--now
or ever.''); Letter from Kenneth J. Kopocis, Deputy Assistant Adm'r,
EPA Office of Water, to Lamar Smith, Chairman, Comm. on Science,
Space, and Tech., U.S. House of Representatives (Jan. 8, 2015)
(``These [USGS] maps were not prepared for the purpose of, nor do
they represent, a depiction of the scope of waters protected under
the Clean Water Act.''); Impact of the Proposed ``Waters of the
United States''' Rule on State and Local Governments Before the H.
Comm. on Transp. & Infrastructure and the S. Comm. on Env't & Pub.
Works, 114th Cong. (2015)(testimony of Gina McCarthy, Adm'r,
EPA)(stating that the NHD and NWI maps were ``not used to determine
jurisdiction and not intended to be used for jurisdiction,'' ``are
not relevant to the jurisdiction of the `waters of the U.S.',''
``are not consistent with how we look at the jurisdiction of the
Clean Water Act,'' and have ``nothing to do, as far as I know, with
any decision concerning jurisdiction of the Clean Water Act'').
    \62\ See Response to Comments for the Clean Water Rule, Clean
Water Rule Comment Compendium Topic 8: Tributaries, Docket ID. No.
EPA-HQ-OW-2011-0880-20872, p. 442, https://www.regulations.gov/document?D=EPA-HQ-OW-2011-0880-20872.
---------------------------------------------------------------------------

    The agencies acknowledge that they have previously taken the
position that ``maps of all the jurisdictional or non-jurisdictional
waters are not feasible,'' \63\ and that maps ``cannot be used to
determine Clean Water Act jurisdiction--now or ever,'' see U.S. EPA,
Mapping the Truth, The EPA Blog (August 28, 2014). Rather than
declaring the task too difficult, the agencies have decided to initiate
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 significant 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
datasets could improve the administration of CWA programs and
attainment of water quality goals. Geospatial datasets and resulting
future maps that indicate waters likely subject to federal jurisdiction
could allow members of the regulated community to more easily and