Document ID: EPA-HQ-OW-2019-0166-0001
Agency: epa
Document Type: Proposed Rule
Title: Interpretive Statement on Application of the Clean Water Act National Pollutant Discharge Elimination System Program to Releases of Pollutants from a Point Source to Groundwater
Posted Date: 2019-04-23T04:00Z

[Federal Register Volume 84, Number 78 (Tuesday, April 23, 2019)]
[Proposed Rules]
[Pages 16810-16826]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-08063]

[[Page 16810]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 122

[EPA-HQ-OW-2019-0166; FRL-9991-72-OW]

Interpretive Statement on Application of the Clean Water Act 
National Pollutant Discharge Elimination System Program to Releases of 
Pollutants From a Point Source to Groundwater

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of availability of interpretive statement and request 
for comment.

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SUMMARY: The Environmental Protection Agency (``EPA'') is issuing an 
Interpretative Statement addressing whether the Clean Water Act (``the 
CWA'' or ``the Act'') National Pollutant Discharge Elimination System 
(``NPDES'') permit program applies to releases of a pollutant from a 
point source to groundwater. This Interpretative Statement reflects the 
EPA's consideration of the public comments received in response to its 
February 20, 2018 Federal Register notice, as summarized immediately 
below. Informed by those comments and based on a holistic analysis of 
the statute, its text, structure, and legislative history, the Agency 
concludes that the CWA is best read as excluding all releases of 
pollutants from a point source to groundwater from NPDES program 
coverage, regardless of a hydrologic connection between the groundwater 
and jurisdictional surface water. The Interpretive Statement provides 
the EPA's full analysis and rationale supporting its interpretation and 
is available below and at https://www.epa.gov/npdes/releases-point-source-groundwater. Concurrently with issuing its interpretation of the 
CWA, the Agency is soliciting additional public input regarding what 
may be needed to provide further clarity and regulatory certainty on 
this issue.

DATES: Comments must be received or postmarked on or before June 7, 
2019.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-OW-
2019-0166, at https://www.regulations.gov. Follow the online 
instructions for submitting comments. Once submitted, comments cannot 
be edited or removed from Regulations.gov. EPA may publish any comment 
received to its public docket. Do not submit electronically any 
information you consider to be Confidential Business Information (CBI) 
or other information whose disclosure is restricted by statute. 
Multimedia submissions (audio, video, etc.) must be accompanied by a 
written comment. The written comment is considered the official comment 
and should include discussion of all points you wish to make. EPA will 
generally not consider comments or comment contents located outside of 
the primary submission (i.e., on the web, cloud, or other file sharing 
system). For additional submission methods, the full EPA public comment 
policy, information about CBI or multimedia submissions, and general 
guidance on making effective comments, please visit https://www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Scott Wilson, Office of Wastewater 
Management, Water Permits Division (MC4203M), Environmental Protection 
Agency, 1200 Pennsylvania Ave. NW, Washington, DC 20460; telephone 
number: (202) 564-6087; email address: [email protected].

SUPPLEMENTARY INFORMATION:

I. General Information

    A. Does this action apply to me? Tribes, states, local governments, 
the regulated community, and citizens interested in federal 
jurisdiction over activities that may release pollutants to groundwater 
may be impacted by this Interpretive Statement. Potentially affected 
entities include:

------------------------------------------------------------------------
                                      Examples of potentially affected
             Category                             entities
------------------------------------------------------------------------
States, Tribes, and Territories...  State, Tribal, and Territorial water
                                     quality agencies and NPDES
                                     permitting authorities that may
                                     need to determine whether sources
                                     of pollutants should be addressed
                                     by standards or permitting actions.
Federal Agencies..................  Federal agencies with projects or
                                     other activities that may have
                                     releases that affect groundwater
                                     with connections to surface waters.
Industry..........................  Industries that may have releases
                                     that affect groundwater with
                                     connections to surface waters.
------------------------------------------------------------------------

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be affected by EPA's 
interpretation of the scope of the CWA NPDES program. Other types of 
entities not listed in the table could also be affected. If you have 
questions regarding the effect of this action on a particular entity, 
please consult the person listed in the preceding FOR FURTHER 
INFORMATION CONTACT section.
    B. How can I get copies of this document and other related 
information? You may access this document electronically at https://www.epa.gov/npdes/releases-point-source-groundwater or at https://www.federalregister.gov. EPA has established an official public docket 
for receiving comments under Docket ID No. EPA-HQ- OW-2019-0166 which 
is accessible electronically at http://www.regulations.gov that will 
also contain copies of this Federal Register notice and the 
Interpretive Statement. The public docket does not include Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. The official public docket is the collection of 
materials that is available for public viewing at the Water Docket in 
the EPA Docket Center, (EPA/DC) EPA West, Room B102, 1301 Constitution 
Ave. NW, Washington, DC. The EPA Docket Center Public Reading Room is 
open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding 
legal holidays. The telephone number for the Public Reading Room is 
(202) 566-1744, and the telephone number for the Water Docket is (202) 
566-2426.

II. February 2018 Request for Public Comment

    On February 20, 2018, EPA requested public comment regarding 
whether EPA should review and potentially revise or clarify its 
previous statements concerning the applicability of the CWA NPDES 
permit program to pollutant releases from point sources that reach 
jurisdictional surface waters via groundwater that has a direct 
hydrologic connection to a jurisdictional surface water (the ``direct 
hydrologic connection theory''). 83 FR 7126, 7128 (Feb. 20, 2018). EPA 
asked for specific comment on questions related to CWA authority, other 
programs that address these releases, what issues needed further 
clarification, and what format EPA should pursue if it chose to revise 
or clarify its position. Id. EPA received over 50,000 comments in 
response to its request. Comments addressed the

[[Page 16811]]

specific questions raised by EPA as well as other pertinent topics. EPA 
received comments from a wide audience representing state governments, 
local governments, tribes, industry, environmental organizations, 
academia, and private citizens. See EPA Docket No. EPA-HQ-OW-2018-0063, 
available at https://www.regulations.gov/docket?D=EPA-HQ-OW-2018-0063.
    Some commenters opposed the direct hydrologic connection theory on 
programmatic and legal grounds. These comments raised concerns 
regarding the activities that might be impacted if a NPDES permit is 
required for a release to groundwater with a direct hydrologic 
connection to jurisdictional surface water, including aquifer recharge, 
leaks from sewage collection systems, septic system discharges, 
treatment systems such as constructed wetlands, spills and accidental 
releases, manure management and coal ash impoundment seepage. These 
commenters also raised implementation concerns, including how a direct 
hydrologic connection would be defined and where monitoring or the 
point of compliance would be determined. Commenters opposed to the 
direct hydrologic connection theory raised a range of legal arguments, 
including that the theory was not grounded in the statutory text, 
pointing in particular to the absence of the term ``groundwater'' from 
sections authorizing the NPDES program and providing excerpts from the 
Act's legislative history.
    Other commenters supported the direct hydrologic connection theory, 
raising concerns based on the prior examples of environmental impacts 
from releases to groundwater with a direct hydrologic connection to 
jurisdictional surface water, and the importance of the authority to 
regulate or prevent those releases pursuant to the CWA. These 
commenters asserted that the CWA's goal of protecting surface waters 
encompassed releases to groundwater that could reach jurisdictional 
surface waters, and that groundwater itself does not need to be 
jurisdictional under the CWA in order to regulate discharges that pass 
through groundwater and ultimately may reach surface water.
    EPA has considered these comments, as well as the text, structure 
and legislative history of the CWA, and concludes that the 
interpretation expounded in the Interpretative Statement below is the 
best, if not the only, reading of the CWA, is more consistent with 
Congress's intent than other interpretations of the Act, and best 
addresses the question of NPDES permit program applicability for 
pollutant releases to groundwater within the authority of the CWA.

III. Interpretive Statement

Interpretive Statement

    Subject: Application of the Clean Water Act National Pollutant 
Discharge Elimination System Program to Releases of Pollutants From a 
Point Source to Groundwater.
    From: Matthew Z. Leopold (signed and dated April 12, 2019), General 
Counsel.
    David P. Ross (signed and dated April 12, 2019), Assistant 
Administrator for Water.
    To: Regional Administrators, Regions I-X.
    This Interpretive Statement sets forth the Environmental Protection 
Agency's (``EPA'' or ``the Agency'') interpretation of the Clean Water 
Act (``the CWA'' or ``the Act'') National Pollutant Discharge 
Elimination System (``NPDES'') permit program's applicability to 
releases of pollutants from a point source to groundwater that 
subsequently migrate or are conveyed by groundwater to jurisdictional 
surface waters. For the reasons explained below, EPA concludes that the 
Act is best read as excluding all releases of pollutants from a point 
source to groundwater from NPDES program coverage and liability under 
Section 301 of the CWA, regardless of a hydrologic connection between 
the groundwater and a jurisdictional surface water. See 33 U.S.C. 
1311(a), 1342.
    This Interpretive Statement is the first instance in which the 
Agency has issued guidance focused exclusively on whether NPDES permits 
are required for releases of pollutants to groundwater that reach 
surface water. As described further below, there is a mixed record of 
prior Agency statements addressing this issue and a split in the 
federal circuit courts regarding the application of the NPDES permit 
program to releases of pollutants to groundwater that reach 
jurisdictional surface waters. Recent judicial decisions addressing 
this issue contribute to an evolving and increasingly confusing legal 
landscape in which permitting and enforcing agencies, potentially 
regulated parties, and the public lack clarity on when the NPDES 
permitting requirement set forth in sections 301 and 402 of the CWA may 
be triggered by releases of pollutants to groundwater. The absence of a 
dedicated EPA statement on the best reading of the CWA has generated 
confusion in the courts and uncertainty for EPA regional offices and 
states implementing the NPDES program, regulated entities, and the 
public. This Interpretive Statement is intended to advise the public on 
how EPA interprets the relevant provisions of the CWA.
    This Interpretive Statement conveys to EPA's regional offices, 
states, and the public the Agency's reading of the applicability of 
sections 301 and 402 of the CWA to releases of pollutants to 
groundwater. It contains the Agency's most comprehensive analysis of 
the CWA's text, structure, legislative history, and judicial decisions 
that has been lacking in prior Agency statements on this issue. EPA 
thus herein provides clear guidance that balances the statute, case 
law, and the need for clarity on the scope of the CWA NPDES coverage, 
which has been recently expanded by judicial decision to potentially 
reach a new set of releases to groundwater that EPA has not 
historically regulated in the NPDES program. This Interpretive 
Statement provides important clarity to inform future permitting 
decisions and other actions; it neither alters legal rights or 
obligations nor changes or creates law.
    In February 2018, the Agency sought public comment on whether the 
NPDES permit program applies to releases of pollutants to groundwater 
and whether the Agency should revise or clarify its position on this 
issue. See 83 FR 7126, 7128 (Feb. 20, 2018). Informed by those comments 
and based on a holistic analysis of the statute, its text, structure, 
and legislative history, the Agency concludes that the best, if not the 
only, reading of the CWA is that Congress intentionally chose to 
exclude all releases of pollutants to groundwater from the NPDES 
program, even where pollutants are conveyed to jurisdictional surface 
waters via groundwater. Congress purposely structured the CWA to give 
states the responsibility to regulate such releases under state 
authorities. And, as discussed further below, other federal statutes 
contain explicit provisions that regulate the release of pollutants 
into groundwater to provide significant federal authority to address 
groundwater pollution not provided by the NPDES permitting program. In 
accordance with Congress's intent, state and federal authorities are 
collectively available to provide protection for ground and surface 
water quality in those instances where direct CWA permitting authority 
is not applicable.
    During the pendency of EPA's review of the public comments 
received, two petitions for certiorari were filed with the Supreme 
Court which posed the question of whether the CWA applies to releases 
of pollutants from a point source to groundwater that migrates to 
surface water. See Petition for Writ of

[[Page 16812]]

Certiorari, Cty. of Maui v. Hawai'i Wildlife Fund, et al. (``County of 
Maui''), No. 18-260 (Aug. 27, 2018); Petition for Writ of Certiorari, 
Kinder Morgan Energy Partners, L.P. v. Upstate Forever (``Kinder 
Morgan''), No. 18-268 (Aug. 28, 2018). Consistent with the United 
States' recommendation set forth in an amicus brief filed at the 
Court's request, the Supreme Court recently granted the petition for 
writ certiorari in County of Maui, an appeal of the Ninth Circuit's 
broad reading of the CWA. Cty. of Maui, No. 18-260 (S. Ct. cert granted 
on Feb. 19, 2019). Issuing this statement provides necessary clarity on 
the Agency's interpretation of the statute given the mixed record of 
prior Agency statements and a split in the federal circuit courts 
regarding this issue.
    The interpretation contained herein differs from the direct 
hydrological connection theory, expressed in the United States amicus 
brief filed in the Ninth Circuit County of Maui proceeding, and the 
theories advanced by the parties in that case. The Agency does not 
agree with the respondents' and Ninth Circuit's view that the CWA's 
NPDES requirements can apply when a pollutant released from a point 
source migrates to navigable waters through groundwater. The 
differences between the direct hydrological connection theory and 
today's interpretation, and EPA's explanation for why the Agency is 
modifying and clarifying its interpretation, are detailed below. While 
the Agency disagrees with the reasoning of the Ninth Circuit's decision 
in County of Maui, as well as the reasoning of the Fourth Circuit in 
its Kinder Morgan decision, for reasons discussed further below, it 
will nonetheless apply the decisions of those courts in their 
respective circuits until further clarification from the Supreme Court. 
See Hawai'i Wildlife Fund v. Cty. of Maui, 886 F.3d. 737 (9th Cir. 
2018); Upstate Forever v. Kinder Morgan Energy Partners, L.P., 887 F.3d 
637, 652 (4th Cir. 2018). Thus, the Agency's interpretation set forth 
herein applies at this time only outside of the Fourth and Ninth 
Circuits.\1\
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    \1\ Neither the Ninth Circuit decision nor Fourth Circuit 
decision prohibits application of the Agency's interpretation 
expressed in this action in those circuits. See National Cable 
Telecomms Ass'n v. Brand X internet Servs., 545 U.S. 967, 982 (2005) 
(``A court's prior judicial construction of a statute trumps an 
agency construction otherwise entitled to Chevron deference only if 
the prior court decision holds that its construction follows from 
the unambiguous terms of the statute and thus leaves no room for 
agency discretion.''). As explained herein, by not applying this 
interpretation in the Ninth and Fourth Circuits, the Agency is 
simply choosing to maintain the status quo pending further 
clarification by the Supreme Court, after which time the Agency 
intends to follow with notice and comment rulemaking.
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I. Factual Background

    It is a fundamental principle of hydrology that many groundwaters 
and surface waters are linked through the hydrologic cycle. As the 
Agency has previously explained, the ``hydrologic cycle involves the 
continual movement of water between the earth and the atmosphere 
through evaporation and precipitation.'' EPA 440/6-90-004, Citizen's 
Guide to Ground-Water Protection (1990). Rain and snow fall to the 
earth, and the resulting water runs into surface waters, evaporates, is 
absorbed by plant roots, or infiltrates the ground's surface and moves 
downward to the saturated zone, ``the area in which all interconnected 
spaces in rocks and soil are filled with water,'' also known as 
groundwater. Id. at 1. In areas where the saturated zone occurs at the 
ground's surface, groundwater discharges into surface waters, 
eventually evaporating into the atmosphere to form precipitation and 
begin the hydrologic cycle again. Id.
    The nature of the connection between groundwater and surface water 
is highly dependent on local climate, topography, geology and the type 
of groundwater formation at issue. Because of the often-slow movement 
of groundwater, pollutants tend to remain concentrated in the form of a 
plume. The speed and concentration at which pollutants move through 
groundwater depend on the amount and type of pollutant, its solubility 
and density, and the speed of the surrounding groundwater. The amount 
of a pollutant that is released into groundwater that will eventually 
reach surface water also varies and is dependent on both the 
characteristics of the pollutant itself as well as site-specific 
factors. In addition, the travel time and distance between polluted 
groundwater and surface water can allow for the reduction of the 
impacts of contamination on the surface water due to natural processes. 
These processes include, for example, dilution, oxidation, biological 
degradation (which can render pollutants less toxic), and the binding 
of materials to soil particles such that pollutants are adsorbed by 
surrounding soil before reaching surface water.
    Many commenters responding to EPA's February 2018 Federal Register 
notice identified activities that have not generally been required to 
obtain an NPDES permit and might be impacted if a permit were required 
for a release to groundwater with a hydrologic connection to 
jurisdictional surface waters. Activities listed by commenters included 
aquifer recharge, leaks from sewage collection systems, septic system 
discharges, treatment systems such as constructed wetlands, spills and 
accidental releases, manure management, and coal ash impoundment 
seepage.
    Septic systems, for example, generally operate by discharging 
liquid effluent into perforated pipes buried in a leach field, 
chambers, or other special units designed to slowly release the 
effluent into soil. The soil accepts, treats, and disperses wastewater 
as it percolates through the soil, but can in certain circumstances 
ultimately enter groundwater. Over 26 million homes in the United 
States employ septic systems to treat and dispose of household waste. 
As the Agency has explained, ``[r]ecycled water from a septic system 
can help replenish groundwater supplies; however, if the system is not 
working properly, it can contaminate nearby waterbodies.'' See EPA, 
Septic Systems and Surface Water, https://www.epa.gov/septic/septic-systems-and-surface-water. But even well-functioning septic systems can 
contribute pollutants such as nutrients to groundwater. In addition to 
household waste disposal, releases to groundwater are also employed as 
part of green infrastructure projects, including the management of 
stormwater. These projects release stormwater and recycled wastewater 
to the ground to recharge depleted aquifers and prevent or reduce 
runoff to surface waters. In arid western states experiencing low 
rainfall, states and municipalities use such surface infiltration of 
recycled wastewaters not only to replenish groundwater supplies, but 
also to mitigate salt water intrusion or abate land subsidence that can 
occur where groundwater is overly depleted.
    To date, neither EPA nor states have generally required NPDES 
permits for these types of activities, and in the select instances 
where NPDES permits have been required for discharges from a point 
source that reach jurisdictional surface waters via groundwater, they 
have been based on site-specific factors.

II. The Clean Water Act

    The objective of the CWA is ``to restore and maintain the chemical, 
physical, and biological integrity of the Nation's waters.'' 33 U.S.C. 
1251(a). In order to meet that objective, Congress declared two 
national goals: (1) ``that the discharge of pollutants into the 
navigable waters be eliminated by 1985;'' and (2) ``that wherever 
attainable, an interim goal of water quality which provides for the 
protection and propagation of fish,

[[Page 16813]]

shellfish, and wildlife and provides for recreation in and on the water 
be achieved by July 1, 1983. . . .'' Id. Sec.  1251(a)(1)-(2). The CWA 
approaches restoration and protection of the Nation's waters as a 
partnership between states and the federal government, assigning 
certain functions to each in striking the balance of the statute's 
overall regulatory scheme. Congress expressly recognized the role that 
states would continue to exercise in preventing, reducing, and 
eliminating pollution: ``It is the policy of Congress to recognize, 
preserve, and protect the primary responsibilities and rights of States 
to prevent, reduce, and eliminate pollution, to plan the development 
and use (including restoration, reservation, and enhancement) of land 
and water resources[.]'' Id. Sec.  1251(b). As the Supreme Court has 
explained, the statute ``anticipates a partnership between the States 
and the Federal Government,'' toward a shared objective of restoring 
and maintaining the integrity of the Nation's waters. Arkansas v. 
Oklahoma, 503 U.S. 91, 101 (1992).
    To accomplish the Act's broad national objective, Congress 
established respective roles for the federal government and for states. 
As one means of accomplishing the Act's objective, Congress prohibited 
any ``discharge of any pollutant'' to ``navigable waters'' or to the 
``contiguous zone or the ocean'' unless it is authorized by the 
statute, generally by a NPDES permit. 33 U.S.C. 1311(a) (``Except as in 
compliance with this section and sections 1312, 1316, 1317, 1328, 1342, 
and 1344 of this title, the discharge of any pollutant by any person 
shall be unlawful.''). The Act defines navigable waters as ``the waters 
of the United States, including the territorial seas.'' Id. Sec.  
1362(7). EPA's regulations have never defined ``waters of the United 
States'' to include groundwater.
    The statute defines ``discharge of a pollutant'' as ``any addition 
of any pollutant to navigable waters from any point source'' or ``any 
addition of any pollutant to the waters of the contiguous zone or the 
ocean from any point source other than a vessel or other floating 
craft.'' 33 U.S.C. 1362(12). A point source is defined as ``any 
discernible, confined, and discrete conveyance, including but not 
limited to any pipe, ditch, channel, tunnel, conduit, well, discrete 
fissure, container, rolling stock, concentrated animal feeding 
operation, or vessel or other floating craft, from which pollutants are 
or may be discharged.'' Id. Sec.  1362(14).
    Where there is a discharge of a pollutant from a point source to a 
water of the United States, termed herein a jurisdictional surface 
water, NPDES permits generally require permittees to meet numeric or 
narrative effluent limitations. Id. Sec. Sec.  1311(a), 1342(a). 
Effluent limitations are defined as ``any restriction established by a 
State or the Administrator on quantities, rates, and concentrations of 
chemical, physical, biological, and other constituents which are 
discharged from point sources into navigable waters, the waters of the 
contiguous zone, or the ocean, including schedules of compliance.'' Id. 
Sec.  1362(11).
    Courts have observed that nonpoint source pollution--the broad 
category of other forms of water pollution that do not fall within the 
point source definition and not defined under the Act--can be 
understood as ``all water quality problems not subject to Section 
402,'' the portion of the statute requiring NPDES permits. Nat'l 
Wildlife Fed'n v. Gorsuch, 693 F.2d 156, 166 (D.C. Cir. 1982). In 
addition to the NPDES permitting program, as another means of 
accomplishing the Act's objective, Congress reserved to states their 
exclusive role in regulating nonpoint source pollution. Am. Farm Bureau 
Fed'n v. EPA, 792 F.3d 281, 289 (3rd Cir. 2015) (``States in turn 
regulate nonpoint sources. There is significant input and oversight 
from the EPA, but it does not regulate nonpoint sources directly.''); 
see also Or. Natural Desert Ass'n v. U.S. Forest Serv., 550 F.3d 778, 
780 (9th Cir. 2008) (``The CWA's disparate treatment of discharges from 
point sources and nonpoint sources is an organizational paradigm of the 
Act.'').
    While the point and nonpoint source distinction is the 
quintessential inquiry related to the discharge of pollutants to 
surface waters, as explained further below, this inquiry is not 
relevant as applied to groundwater. Rather, the text, structure, and 
legislative history of the CWA demonstrate Congress's intent to leave 
the regulation of groundwater wholly to the states under the Act. See, 
e.g., Village of Oconomowoc Lake v. Dayton Hudson Corporation, 24 F.3d 
962, 965 (7th Cir. 1994) (``[T]he Clean Water Act does not attempt to 
assert national power to the fullest . . . . Congress elected to leave 
[regulation of groundwaters] to state law[.]''); Tenn. Clean Water 
Network v. TVA, 905 F.3d 436, 439 (6th Cir. 2018) (``[T]he CWA is 
restricted to regulation of pollutants discharged into navigable waters 
. . . leaving the states to regulate pollution of non-navigable 
waters'' such as groundwater.).

III. EPA's Interpretation of the Clean Water Act National Pollutant 
Discharge Elimination System Program's Applicability to Releases of 
Pollutants to Groundwater That May Reach Jurisdictional Surface Waters

    The CWA's definition of the ``discharge of [a] pollutant,'' 33 
U.S.C. 1311(a), includes ``any addition of any pollutant to navigable 
waters from any point source,'' 33 U.S.C. 1362(12)(A). Because 
groundwater is not a ``navigable water[[hairsp]],'' see 33 U.S.C. 
1362(7), the CWA does not regulate discharges to groundwater as such. 
But the question of whether a ``discharge'' within the statute's 
meaning has occurred when a pollutant is released from a point source, 
travels through groundwater, and ultimately migrates to navigable 
waters has generated confusion and uncertainty.\2\
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    \2\ This Interpretative Statement addresses the applicability of 
the CWA NPDES permitting requirements to the release of pollutants 
from a point source to groundwater that reach jurisdictional surface 
waters through hydrologically connected groundwater. It describes 
the movement of pollutants to and through groundwater as having been 
released from a point source. When the term ``discharge'' is used 
herein to reference pollutants being added to a surface water by or 
through groundwater, this does not connote or imply that a 
``discharge of a pollutant'' or ``discharge'' has occurred under the 
CWA. See 33 U.S.C. 1362(12) (``discharge of a pollutant''), 1362(16) 
(``discharge'').
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    Commenters to EPA's February 2018 Federal Register notice rely 
primarily on one of two interpretive possibilities for addressing this 
question. One approach is reflected in the court of appeals' decisions 
in County of Maui and Kinder Morgan. In those cases, the courts 
interpreted Section 1362(12)(A) as applying to discharges from a point 
source to navigable waters where the pollutant has travelled to the 
navigable water over or through another medium. On this view, to 
qualify as a discharge ``to navigable waters,'' a discharge via 
groundwater must, in the Ninth Circuit, be ``fairly traceable'' back to 
the point source and more than de minimis, Cty. of Maui, 886 F.3d at 
746 n.2, and in the Fourth Circuit, ``must be sufficiently connected to 
navigable waters,'' Kinder Morgan, 887 F.3d at 651. Those courts and 
commentators who have endorsed these variations on a similar approach 
have differed in describing the type of connection that qualifies under 
the CWA, but they generally agree that a ``discharge of a pollutant'' 
may occur when a pollutant has been added to a navigable water via 
groundwater with some connection to the navigable water.
    A second interpretive approach is reflected in the Sixth Circuit's 
decision in Kentucky Waterways Alliance v. Kentucky Utilities Co., 905 
F.3d 925 (6th

[[Page 16814]]

Cir. 2018). In that case, the court read the relevant statutory 
language as applying only where pollution has been added directly to 
navigable waters ``by virtue of a point-source conveyance,'' rather 
than through some other mechanism (such as groundwater). Id. at 934. 
Under this interpretation, sometimes described as the ``terminal point 
source'' theory, any intermediary between the point source and the 
navigable water means that a pollutant has not been discharged ``to 
[the] navigable water[[hairsp]] from [the] point source.''
    EPA's interpretation differs from these two theories. The Agency's 
view is that the best, if not the only, reading of the statute is that 
all releases to groundwater are excluded from the scope of the NPDES 
program, even where pollutants are conveyed to jurisdictional surface 
waters via groundwater. This interpretation is appropriately tailored 
to releases to groundwater. On this view, because the CWA clearly 
evinces a purpose not to regulate groundwater, and because groundwater 
is extensively regulated under other statutory regimes, discussed 
further below in section VI.B, any circumstance in which a pollutant is 
released from a point source to groundwater is categorically excluded 
from the CWA's coverage. The interposition of groundwater between a 
point source and the navigable water thus may be said to break the 
causal chain between the two, or alternatively may be described as an 
intervening cause. Today's interpretation pertains to releases to 
groundwater and thus leaves in place the Agency's case-by-case approach 
to determining whether pollutant releases to jurisdictional surface 
waters that do not travel through groundwater require an NPDES permit. 
Whether a permit is required for such a release is necessarily a fact-
specific inquiry, informed by the point source definition and an 
analysis of intervening factors.
    In the Agency's view, the text, structure, and legislative history 
of the CWA, as well as the better-reasoned judicial decisions, support 
the legal conclusion that Congress intended to exclude all releases of 
pollutants to groundwater from NPDES program coverage, regardless of a 
hydrologic connection or conveyance to jurisdictional surface water. 
When attempting to interpret a statute, a court or agency cannot look 
to one single word or phrase, but instead must look to the text as a 
whole. See Star Athletica, LLC v. Varsity Brands, Inc., 137 S. Ct. 
1002, 1010 (2017); Dole v. United Steelworkers of Am., 494 U.S. 26, 35 
(1990) (``[W]e are not guided by a single sentence or member of a 
sentence, but look to the provisions of the whole law, and to its 
object and policy.''). While no single provision of the CWA expressly 
addresses whether pollutants discharged from a point source that reach 
jurisdictional surface waters through groundwater are subject to NPDES 
permitting requirements, when analyzing the statute in a holistic 
fashion, Congress's intent becomes evident: Congress did not intend for 
the NPDES program to address any pollutant discharges to groundwater, 
even where groundwater may be hydrologically connected to surface 
waters. Relevant legislative debate confirms that Congress fully 
understood the hydrologic connections that exist between groundwater 
and surface water, yet chose this jurisdictional line to strike the 
balance between state and federal responsibility for protection of the 
Nation's waters.
    Congress was explicit where it intended the Act to apply to 
groundwater. It included references to groundwater in provisions aimed 
at providing information, guidance, and funding to states, to enable 
them to regulate pollutant discharges to groundwater. Explicit 
reference to groundwater, by contrast, is absent in the operative 
regulatory sections of the Act. Further, Congress refers to 
groundwaters exclusively as one unified category of waters; the Act is 
devoid of any indication that Congress viewed releases of pollutants to 
groundwater as susceptible to different treatment under the Act based 
on the presence or absence of a connection to surface water. The 
legislative history is unambiguous that Congress was aware of the 
potential for releases to groundwater to reach surface water, and 
nonetheless rejected proposed amendments seeking to require NPDES 
permits for discharges to groundwater. As with nonpoint source 
pollution, the statute's structure and references to groundwater 
therein are reflective of Congress's intent to leave regulation of 
releases of pollutants to groundwater with the states.
    A. The operative, enforceable provisions of the Clean Water Act 
that make up the NPDES permitting program neither reference nor 
contemplate releases to groundwater.
    The foundational definitional terms and provisions that establish 
the NPDES program extend only to discharges of pollutants to navigable 
waters, waters of the contiguous zone, and the ocean, i.e., discharges 
to jurisdictional surface waters. The Act provides that a NPDES permit 
may be issued ``for the discharge of any pollutant.'' 33 U.S.C. 
1342(a). The definition of discharge of a pollutant refers to ``any 
addition of any pollutant to navigable waters from any point source,'' 
or ``any addition of any pollutant to the waters of the contiguous zone 
or the ocean from any point source.'' Id. Sec.  1362(12) (emphasis 
added). The Act thus explicitly refers to the addition of any pollutant 
to three of the four categories of waters referred to throughout the 
statute; the addition of any pollutant to groundwater--the fourth 
category--is notably absent. Congress specified which sections of the 
Act applied to which categories of waters: groundwater, navigable 
waters, contiguous zone waters, and the ocean. See, e.g., id. Sec.  
1254(a)(5) (setting forth provisions aimed at monitoring the quality of 
``the navigable waters and ground waters and the contiguous zone and 
the oceans''); Sec.  1314(a)(2) (requiring that the Administrator shall 
publish information on the ``factors necessary to restore and maintain 
the chemical, physical, and biological integrity of all navigable 
waters, ground waters, waters of the contiguous zone, and the 
oceans''). In other words, ``when Congress wanted certain provisions of 
the CWA to apply to groundwater, it stated so explicitly.'' Umatilla 
Waterquality Protective Ass'n. v. Smith Frozen Foods, 962 F. Supp. 
1312, 1318 (D. Or. 1997).
    Congress also elected to leave groundwater out of the definition of 
``effluent limitations'' and related provisions. Effluent limitations 
are defined as ``any restriction established by a State or the 
Administrator on quantities, rates, and concentrations of chemical, 
physical, biological, and other constituents which are discharged from 
point sources into navigable waters, the waters of the contiguous zone, 
or the ocean, including schedules of compliance.'' 33 U.S.C. 1362(11) 
(emphasis added). Similarly, section 304(g), establishing the 
requirement that EPA publish certain guidelines to assist states in 
implementing their NPDES program, provides that these guidelines will 
apply to control discharges to every form of water except groundwater. 
See id. Sec.  1314(g) (providing that, for the purposes of assisting 
states in carrying out NPDES programs, EPA shall publish guidelines 
``to control and prevent the discharge into the navigable waters, the 
contiguous zone, or the ocean'').
    The absence of groundwater in the sections of the statute 
foundational to the NPDES permitting program is meaningful: ``[a] 
familiar principle of statutory construction . . . is that a negative 
inference may be drawn from the exclusion of language from one

[[Page 16815]]

statutory provision that is included in other provisions of the same 
statute.'' Hamdan v. Rumsfeld, 548 U.S. 557, 578 (2006). Here, Congress 
elected not to include groundwater in the definition of ``discharge of 
a pollutant''--the critical definition in determining whether a NPDES 
permit is required--nor did Congress include groundwater in the 
definition of ``effluent limitations,'' a primary vehicle in 
implementing the NPDES permitting requirement. See Umatilla, 962 F. 
Supp. at 1318 (``[T]hroughout the CWA, Congress appeared to have four 
categories of waters in mind--`navigable waters,' the contiguous zone, 
the ocean, and `ground waters.' Only the first three of these . . . are 
included within the definition of `discharge of a pollutant,' 
indicating that Congress did not consider discharges to groundwater to 
be discharges that would trigger the NPDES requirement.'').
    Congress's intent to deliberately leave groundwater out of the 
definition of ``discharge of a pollutant'' is confirmed by the 
legislative history of the Act. In a hearing before the House Public 
Works Committee, Representative Leslie Aspin recommended that the term 
``ground water'' be added to the operative NPDES provisions so that 
discharges to groundwater also would be covered by the statute, 
explaining that ``[s]ometimes a navigable water and ground-water source 
run into each other, or come close to each other, so that seepage from 
polluted ground-water source could pollute the navigable water[;] . . . 
[t]o say that the Federal Government can regulate the ecology of one, 
but not the other, is silly and counterproductive.'' Water Pollution 
Control Legislation-1971 (Proposed Amendments to Existing Legislation): 
Hearings before the H. Comm. on Pub. Works, 92nd Cong. 793 (1971) 
(remarks of Rep. Aspin) (emphasis added).
    Representative Aspin went on to propose an amendment to regulate 
groundwater under the NPDES program by amending Title IV of the statute 
to include explicit references to groundwater and adding the term 
``ground waters'' to the definition of ``discharge of pollutant'' found 
in Section 502(12). He explained that these amendments were necessary 
given the likelihood that polluted groundwater would contaminate 
jurisdictional surface waters:

    The amendment brings ground water into the subject of the bill, 
into the enforcement of the bill. Ground water appears in this bill 
in every section, in every title except title IV. It is under the 
title which provides EPA can study ground water. It is under the 
title dealing with definitions. But when it comes to enforcement, 
title IV, the section on permits and licenses, then ground water is 
suddenly missing. That is a glaring inconsistency which has no 
point. If we do not stop pollution of ground waters through seepage 
and other means, ground water gets into navigable waters, and to 
control only the navigable water and not the ground water makes no 
sense at all.

    118 Cong. Rec. 10,666 (1972), 1 Leg. Hist. 589 (remarks of Rep. 
Aspin) (emphasis added). The amendments were rejected by a vote of 86 
to 34. Id. at 597. The failure of a proposed amendment ``strongly 
militates against a judgment that Congress intended a result that it 
expressly declined to enact.'' Gulf Oil Corp. v. Copp Paying Co., 419 
U.S. 186, 200 (1974).
    The only section in the extensive NPDES permitting provisions where 
discharges to groundwater are contemplated is section 402(b)(1)(D), 
which sets forth the requirements for EPA approval of state programs to 
assume NPDES authority. This section requires that to approve a state-
submitted NPDES program, the Administrator must determine that adequate 
authority exists within the state to ``control the disposal of 
pollutants into wells.'' 33 U.S.C. 1342(b)(1)(D). The Fifth Circuit 
found this provision significant in rejecting EPA's prior view that it 
had authority to regulate groundwater pollution resulting from deep-
well disposal, observing that ``[t]he simple requirement of Sec.  
402(b)(1)(D) that state permit programs have adequate authority to 
issue permits which control the disposal of pollutants into wells, 
which is not fleshed out elsewhere in the Act or mirrored in any of the 
sections setting forth the Administrator's powers, is entirely 
consistent'' with Congress's intention to ``stop short of establishing 
federal controls over groundwater pollution.'' Exxon Corp. v. Train, 
554 F.2d 1310, 1324 (5th Cir. 1977).
    The legislative history of 402(b)(1)(D) illuminates Congress's 
intent in the CWA to require states, but not the federal government, to 
regulate deep well disposal, which is consistent with its intent to 
leave regulation of all pollutant discharges to groundwater to states. 
The Senate Committee on Public Works report explains that, like the 
House, the Senate Committee rejected amendments to impose federal 
regulation over groundwater but included the provision in section 
402(b)(1)(D) requiring states to maintain programs to regulate deep 
well disposal to encourage states to carry out such regulation. 
Specifically, the report explained that:

    Several bills pending before the Committee provided authority to 
establish Federally approved standards for groundwaters which 
permeate rock, soil, and other subsurface formations. Because the 
jurisdiction regarding groundwaters is so complex and varied from 
State to State, the Committee did not adopt this recommendation.
    The Committee recognizes the essential link between ground and 
surface waters and the artificial nature of any distinction. Thus 
the Committee bill requires in section 402 that each State include 
in its program for approval under section 402 affirmative controls 
over the injection or placement in wells of any pollutants that may 
affect ground water. This is designed to protect ground waters and 
eliminate the use of deep well disposal as an uncontrolled 
alternative to toxic and pollution control.
    The importance of groundwater in the hydrological cycle cannot 
be underestimated. Although only about 21.5 percent of our domestic, 
industrial[,] [and] agricultural supply comes directly from wells, 
it must be remembered that rivers, streams and lakes themselves are 
largely supplied with water from the ground--not surface runoff.

    S. Rep. No. 414, 92d Cong., 1st. Sess. at 73 (1971), 2 Legislative 
History of the Water Pollution Control Act Amendments of 1972, at 1491 
(emphasis added); see also 118 Cong. Rec. 10667 (1972), 1 Leg. Hist. 
591 (remarks of Rep. Clausen) (opposing amendment to require NPDES 
permits for discharges to groundwater and stating that the House 
committee had ``recognized the need for control of disposal of 
pollutants into wells in order to protect our ground waters. Therefore, 
in section 402(b)(1)(D) we provided that the Administrator shall 
approve a State program unless he determines that authority does not 
exist to control the disposal of pollutants into wells.'').
    The legislative history makes evident that Congress declined to 
extend coverage of the NPDES program to discharges to groundwater and 
did so with the understanding that releases of pollutants to 
groundwater often reached jurisdictional surface water and could affect 
its quality. For example, at a 1971 hearing before the Senate Public 
Works Committee, then EPA Administrator William Ruckelshaus requested 
that EPA be granted authority to regulate groundwater quality, 
explaining the basis for that request as follows:

    The only reason for the request for Federal authority over 
ground waters was to assure that we have control over the water 
table in such a way as to insure that our authority over interstate 
and navigable streams cannot be circumvented, so we can obtain water 
quality by maintaining a control over all the sources of pollution, 
be they discharged directly into any stream or through the ground 
water table.

    Water Pollution Control Legislation-1971 (Proposed Amendments to

[[Page 16816]]

Existing Legislation): Hearings before the H. Comm. on Pub. Works, 92nd 
Cong. 230 (1971) (statement of Hon. William Ruckelshaus, Administrator, 
EPA) (emphasis added). This statement, before the same Senate Committee 
that rejected amendments to extend the scope of the NPDES program at 
the time of the passage of the Act, supports the conclusion that 
Congress was aware that contaminated groundwater could reach 
jurisdictional surface waters and nonetheless chose to leave releases 
to groundwater to state regulation in the CWA paradigm. As the Fifth 
Circuit observed in analyzing this legislative history, throughout the 
ensuing debate ``there is not the slightest hint that any Member 
thought the bill would grant the Administrator any power to regulate 
deep-well disposal or any other form of groundwater pollution. Instead, 
all the evidence points to precisely the opposite understanding.'' 
Exxon, 554 F.2d at 1329; see also Kelley on behalf of Michigan v. 
United States, 618 F. Supp. 1103, 1107 (W.D. Mich. 1985) (acknowledging 
the ``unmistakably clear legislative history . . . demonstrat[ing] that 
Congress did not intend the Clean Water Act to extend federal 
regulatory and enforcement authority over groundwater contamination'').
    B. Explicit references to groundwater are found in sections of the 
Act that serve to provide information, guidance, assistance, or funding 
to states in regulating groundwater, and in sections of the Act 
addressing state programs to control nonpoint source pollution.
    The Act's provisions explicitly addressing groundwater can be 
placed into two groups. Analysis of these two groups of statutory 
references reinforces Congress's intent to leave regulation of 
groundwater--no matter how hydrologically connected to surface water--
to the states. First, the Act contains forward-looking sections aimed 
at gathering information that could inform subsequent legislation and 
current state efforts to regulate discharges to groundwater. Indeed, 
``a clear pattern of congressional intent with respect to groundwaters 
emerges upon close examination of those sections of the Act that deal 
with the subject. That pattern is one of information gathering and 
encouragement of state efforts to control groundwater pollution--but 
not of direct federal control over groundwater pollution.'' See Exxon, 
554 F.2d at 1322. Second, the Act contains sections addressing state 
programs to manage nonpoint source pollution, evidencing Congress's 
intent to retain states' lead role with respect to both nonpoint source 
and groundwater pollution. The provisions described below are 
reflective of Congress's intent that states retain responsibility for 
addressing groundwater pollution, and that the federal government's 
role would be to provide resources, both in the form of information, 
funding or other support, for states to take on this issue. These 
resources and incentives for state programs, like the NPDES program, 
are an important component of the CWA, but one in which states retain 
regulatory decision-making and authority and elect to what extent they 
chose to utilize federal support.
    Groundwater is first mentioned in the statute in Title I, setting 
forth ``Research and Related Programs.'' This Title contains several 
provisions directing EPA to address groundwater pollution through 
information gathering and coordination with states, as opposed to 
through binding regulatory requirements found elsewhere in the Act. 
See, e.g., 33 U.S.C. 1252, 1254. During the debate on the amendment to 
regulate discharges to groundwater through the NPDES program, 
Representative Donald H. Clausen, a member of the House Committee on 
Public Works and sponsor of the House bill, noted in explaining his 
opposition to the amendment that ``it was determined by the committee 
that there was not sufficient information on ground waters to justify 
the types of controls that are required for navigable waters.'' 118 
Cong. Rec. 10667 (1972), 1 Leg. Hist. 591 (remarks of Rep. Clausen). He 
explained that the Committee recognized the need for additional 
information and research ``both in determining the effect of 
underground disposal of pollutants and the migration of such 
pollutions.'' Id. Thus, the Committee drafted ``broad research'' powers 
for EPA under Title I of the statute, and, based on that research, in 
the future, ``Congress might have a basis for determining the need and 
appropriately extending the controls of H.R. 11896 as they apply to 
navigable waters to ground waters if needed.'' Id.
    Congress also included non-regulatory provisions focused on the 
protection of groundwater in Title II of the Act, in which Congress 
authorized EPA to make grants to states for the construction of 
publicly owned treatment works (POTWs). Of relevance here, Congress 
included a provision in section 202 authorizing increased funding for 
construction of POTWs if states provide a certificate indicating that 
the quantity of available groundwater will be ``insufficient, 
inadequate, or unsuitable for public use, including the ecological 
preservation and recreational use of surface water bodies,'' unless 
effluents from POTWs, after adequate treatment, are returned to the 
groundwater. 33 U.S.C. 1282(b)(2). This is an example of ``Congress 
employ[ing] the power of the federal purse to encourage protection by 
the states of underground waters.'' Exxon, 554 F.2d at 1323. Notably, 
this provision also links the quantity of available groundwater to 
``ecological preservation and recreational use of surface water 
bodies,'' 33 U.S.C. 1282(b)(2), indicating Congress's decision to 
explicitly acknowledge and account for the connection between 
groundwater and jurisdictional surface waters when it chose to do so.
    Title III of the CWA, ``Standards and Enforcement,'' also contains 
several provisions related to groundwater, each of which set forth non-
regulatory information gathering requirements and provisions for 
guidance or funding to states. Section 304(a)(1) of the statute 
requires that the Administrator develop and publish water quality 
criteria, on, in pertinent part, the kind and extent of identifiable 
effects on health and welfare ``which may be expected from the presence 
of pollutants in any body of water, including ground water.'' 33 U.S.C. 
1314(a)(1). Section 304(a)(2) requires that the Administrator develop 
and publish information on the factors necessary to restore and 
maintain the chemical, physical, and biological integrity of all 
navigable waters and ground waters. Id. Sec.  1314(a)(2). Neither 
Section 304(a)(1) nor section 304(a)(2), however, create compliance 
obligations for individual dischargers. E. I. Du Pont de Nemours & Co. 
v. Train, 430 U.S. 112, 119 n.6 (1977) (``There is no provision for 
compliance with Sec.  304, the guideline section.''). Rather, EPA's 
role in executing Section 1314(a) is to provide guidance to states. 
City of Albuquerque v. Browner, 865 F. Supp. 733, 738 (D.N.M. 1993) 
(``Section 304(a) of the Act requires EPA to develop criteria for water 
quality that reflect the latest scientific knowledge, and to provide 
those criteria to the States as guidance.''). As the Fifth Circuit 
observed, ``the absence of other provisions in the Act . . . for 
transforming this information into enforceable limitations, strongly 
suggests that Congress meant to stop short of establishing federal 
controls over groundwater pollution, at least for the time being.'' 
Exxon, 554 F.2d at 1325.
    These provisions providing for support to states to regulate 
groundwater arise in the context of general informational support to 
states (sections 102, 104, and 304) and funding tied to protection of 
groundwater related to discharges from a specific type of

[[Page 16817]]

facility (section 202). 33 U.S.C. 1252, 1254, 1282, 1314. 
Significantly, Congress also explicitly included groundwater in 
provisions addressing states' programs for control of nonpoint source 
pollution. These provisions, including sections 208, 304(f), and 319, 
together make up the portions of the Act in which Congress addressed 
nonpoint source pollution--not through regulatory requirements, but 
through support for state programs. Id. Sec. Sec.  1288, 1314(f), 1329.
    Section 208 of the statute is an example of a provision where 
Congress was concerned about nonpoint source pollution impacting 
groundwater, which it was aware could also reach surface water. That 
section requires that states submit to EPA ``areawide waste treatment 
management plans,'' which must include a process to control the 
disposal of pollutants on land or in subsurface excavation to ``protect 
both ground and surface water quality.'' Id. Sec.  1288(a), (b)(2)(K) 
(emphasis added). The statute provides that areawide waste treatment 
management plans shall include a process to identify mine-related 
sources of pollution, such as surface and underground mine runoff, and 
the plans must also set forth procedures and methods to control those 
sources of runoff. Id. Sec.  1288(a), (b)(2)(G). Thus, Congress viewed 
underground mine runoff, i.e., seepage to groundwater that could reach 
jurisdictional surface waters, as best dealt with for CWA purposes 
through an areawide waste treatment management plan for controlling 
nonpoint source pollution, rather than through the regulatory program 
under NPDES. See also id. Sec.  1314(f) (directing the Agency to issue 
guidelines for identifying and evaluating types of nonpoint sources of 
pollutants, including ``the disposal of pollutants in wells or in 
subsurface excavations'').
    Congress's intent to treat releases to groundwater as analogous to 
nonpoint sources, subject to control by states, is further evidenced by 
analyzing section 319 of the statute, entitled ``Nonpoint source 
management programs.'' Section 319 was added to the statute in 1987 and 
includes requirements and related funding provisions directed at states 
to control pollution from nonpoint sources to navigable waters. Id. 
Sec.  1329 (codifying Water Quality Act of 1987, Pub. L. 100-4, 319, 
100 Stat. 7, 52). Section 319 authorizes the Administrator to give 
priority in making grants where States have implemented or are 
proposing to implement programs to ``carry out ground water quality 
protection activities which the Administrator determines are part of a 
comprehensive nonpoint source pollution control program.'' Id. Sec.  
1329(h)(5)(D). In addition, section 319 contains a groundwater-specific 
grant provision in 319(i), ``Grants for Protecting Groundwater 
Quality,'' for the purpose of assisting states in ``carrying out 
groundwater quality protection activities'' that will ``advance the 
State toward implementation of a comprehensive nonpoint source 
pollution control program.'' Id. Sec.  1329(i)(1). Activities that 
could be supported by the grants include activities ``to protect the 
quality of groundwater and to prevent contamination of groundwater from 
nonpoint sources of pollution.'' Id. (emphasis added). This and the 
other provisions discussed in this section, aimed at equipping states 
with information and funding needed to enact programs to protect 
groundwater quality, stand in contrast to the sections of the statute, 
discussed above, that set forth enforceable limitations as well as the 
NPDES permitting and related provisions and contain no explicit mention 
of groundwater.

IV. Comments Regarding Prior Agency Statements

    The Agency has for the first time conducted a public process, 
initiated by EPA's February 2018 Federal Register notice, regarding 
prior Agency statements addressing this issue, and, in conjunction with 
that process, has conducted a more-substantial review of its prior 
statements than previously undertaken by the Agency. As the Agency 
stated in that notice, ``most of these statements were collateral to 
the central focus of a rulemaking or adjudication.'' 83 FR at 7127. In 
fact, most of these statements do not include any explanation for the 
Agency's previous interpretation of the Act. As described above, EPA is 
now clearly stating its position on this issue in a comprehensive 
manner that is consistent with the text and legislative history of the 
CWA.
    As commenters pointed out, there have been a range of prior 
statements by the Agency that align with the legal position articulated 
in this Interpretive Statement. For example, in a number of documents 
discussed below, the Agency has stated simply that discharges to 
groundwater are not subject to the CWA, without any qualification. The 
Agency has reexamined these statements in light of what the Agency 
views as the more appropriate legal question at issue here--whether the 
CWA categorically excludes releases of pollutants to groundwater from 
coverage under the Act--without drawing a distinction between isolated 
groundwater and groundwater with a direct hydrologic connection to 
jurisdictional surface waters. Viewed through this legal lens, the 
statements discussed below in section (A) are highly relevant, and 
supportive of the interpretation of the statute explained in this 
Interpretive Statement.
    A selection of these prior statements identified by commenters are 
summarized below. Many commenters observed that lack of consistent and 
comprehensive direction from EPA on this issue has led to inconsistent 
interpretation across the country and has created uncertainty for 
regulated entities and the public. Even where the Agency stated an 
interpretation, the Agency has not issued regulations or guidance 
focused clearly on this issue. Thus, courts have attempted to fill this 
void, but have issued conflicting decisions about whether these 
releases are covered by the CWA. EPA's adoption of a precise position 
on this issue and thorough explanation of the reasons why the Agency's 
position is the best, if not the only, reading of the CWA will provide 
certainty to EPA staff, state permitting authorities, and regulated 
entities as to how EPA interprets the statute.

A. Commenters' Citation of Examples of Prior Agency Statements 
Indicating Discharges to Groundwater Are Outside the Scope of the NPDES 
Program

    In addressing EPA's request for comment on potential clarification 
of the Agency's prior statements, commenters pointed to certain 
instances in which the Agency stated that discharges to groundwater are 
not subject to the CWA, without any qualification. For example, in a 
1973 EPA Office of General Counsel memorandum, EPA considered whether 
certain discharges to wells are subject to the NPDES program and stated 
that ``[u]nder Sec.  502(12) the term `discharge of a pollutant' is 
defined so as to include only discharges into navigable waters (or the 
contiguous zone or the ocean). Discharges into ground waters are not 
included.'' Memorandum from the U.S. EPA Acting Deputy Gen. Counsel to 
the U.S. EPA Region IX Reg'l Counsel 2-3 (Dec. 13, 1973). The Agency 
did not include any language indicating that, at that time, it viewed 
groundwaters as distinguishable based on their connection to 
jurisdictional surface waters. Notably, this memorandum was issued 
close-in-time to the passage of the CWA amendments creating the NPDES 
program and reflects the Agency's initial view of the statute's text, 
which has not been amended in

[[Page 16818]]

pertinent part since that time. See also Ground Water Pollution from 
Subsurface Excavations, EPA-430/9-73-012 at 131-35 (1973) (EPA report 
explaining that subsurface excavations, e.g., lagoons, pits, basins, 
etc., used to store or dispose of pollutants can contaminate 
groundwater and that contamination can reach surface waters, without 
mentioning regulation under NPDES as one of several identified methods 
to address this contamination).
    Commenters also pointed out that, in its brief in Kelley on behalf 
of Michigan v. United States, the United States argued that discharges 
to groundwater, per se, are excluded from the CWA, and applied that 
view to discharges to groundwater with a direct hydrologic connection 
to jurisdictional surface waters. 618 F. Supp. 1103 (W.D. Mich. 1985). 
In that case, Michigan alleged that certain toxic chemicals were 
released into the ground at a U.S. Coast Guard facility, that the 
chemicals contaminated the groundwater underlying the facility, and 
that the plume of contamination migrated and was discharged to a 
jurisdictional surface water. In its brief, the United States argued 
that ``Michigan cannot make these claims under the Clean Water Act 
since the Act does not regulate pollutant discharges onto soil or into 
underlying ground water.'' U.S. Mem. In Supp. of Rule 12(b) Mot. & In 
The Alternative for Summ. J. at 5, Kelley on behalf of Michigan v. 
United States, No. G83-630, 618 F. Supp. 1103 (W.D. Mich. 1985).
    Commenters also pointed to a policy document issued during the 
Clinton administration which explicitly stated that it was unclear 
whether the CWA regulated discharges to groundwater with a direct 
hydrologic connection to jurisdictional surface water. President 
Clinton's Clean Water Initiative sought to update the CWA and stated 
that it was ``presently unclear whether a discharge to the ground or to 
ground water that rapidly moves into surface water through a `direct 
hydrologic connection' between the point of discharge and the surface 
water is subject to NPDES regulation.'' President Clinton's Clean Water 
Initiative at 104, EPA 800-R-94-001 (Feb. 1994). To address this, EPA 
suggested that the ``CWA should be amended to . . . [c]onfirm and 
clarify that a point source discharge to ground or to ground water that 
has a direct hydrological connection with surface waters is subject to 
regulation as a NPDES point source discharge . . . .'' Id. at 105; see 
also EPA 100-R-93-001 at 1-27, Final Comprehensive State Ground Water 
Protection Guidance (Dec. 1992) (stating that ``[w]hile a number of 
States have incorporated ground water discharges into their NPDES 
permits and pretreatment requirements, there is no national requirement 
to do so'').
    Commenters also cited to instances in permitting proceedings where 
EPA indicated that NPDES permits are not required for discharges to 
groundwater, without also referring to the direct hydrologic connection 
theory. In a response to comments document on an NPDES pesticide 
general permit, EPA explained that one commenter requested that the 
permit ensure that discharges do not affect groundwater. EPA, Response 
to Public Comments, EPA NPDES Pesticide General Permit at xxii (Oct. 
31, 2011). EPA responded and clarified that ``the Clean Water Act's 
NPDES program, under which EPA issued the [pesticide general permit], 
is for the control of discharges to waters of the United States. 
Generally, discharges to groundwater are not regulated under the NPDES 
program; rather, discharges to groundwater are regulated under Safe 
Drinking Water Act along with any additional protections that may be 
incorporated in FIFRA regulations.'' Id. EPA did not qualify this 
statement with any discussion of discharges to groundwater with a 
direct hydrologic connection to surface water. See also EPA, Fact 
Sheet, Draft General Permits for Stormwater Discharges Systems from 
Small Municipal Separate Sewer Systems in Massachusetts at 18 (Sept. 
30, 2014) (``NPDES permits are applicable for point source discharges 
to waters of the U.S.; discharges to groundwater are not addressed in 
the NPDES program and as such are not addressed by this permit.'').
    Finally, commenters also noted that EPA has not comprehensively 
explained its previous interpretation in a key document that permit 
writers and regulated entities frequently look to for guidance on the 
NPDES program. EPA's NPDES Permit Writers' Manual (NPDES Manual) 
describes the statutory and regulatory framework of the NPDES program 
and examines technical considerations for developing NPDES permits. 
U.S. EPA, NPDES Permit Writers' Manual vii (2010). While the NPDES 
Manual is designed as a comprehensive reference on the program for 
permit writers, it only briefly mentions EPA's prior interpretation:

    The CWA does not give EPA the authority to regulate ground water 
quality through NPDES permits. If a discharge of pollutants to 
ground water reaches waters of the United States, however, it could 
be a discharge to the surface water (albeit indirectly via a direct 
hydrological connection, i.e., the ground water) that needs an NPDES 
permit.

    Id. at 1-7. The NPDES Manual does not elaborate on this statement 
or provide guidance on how this interpretation should be implemented.

B. Commenters' Citation of Examples of Prior Agency Statements 
Indicating Discharges to Groundwater With a Direct Hydrologic 
Connection to Surface Water are Subject to NPDES Requirements

    As described in the February 2018 Federal Register notice 
soliciting public comment on this issue, EPA has articulated its 
previous position that discharges to groundwater with a direct 
hydrologic connection to jurisdictional surface waters are subject to 
the CWA. 83 FR at 7127 (``EPA has previously stated that pollutants 
discharged from point sources that reach jurisdictional surface waters 
via groundwater or other subsurface flow that has a direct hydrologic 
connection to the jurisdictional water may be subject to CWA permitting 
requirements.''). Commenters noted that the Agency has, in several 
public documents, including rulemakings, permits, letters, and briefs 
filed on EPA's behalf by the Department of Justice, indicated that 
NPDES permits are required for discharges to groundwater that have a 
direct hydrologic connection to jurisdictional surface waters. See, 
e.g., id. (listing Agency statements in several rulemaking preambles); 
Federal Appellees' Response Brief at 48, Greater Yellowstone Coal. v. 
Lewis, No. 09-35729, 628 F.3d 1143 (9th Cir. 2010) (``Groundwater is 
not directly regulated by the Clean Water Act . . . . Nonetheless, EPA 
has consistently interpreted the Act to cover discharges into 
groundwater that have a direct hydrologic connection to surface 
water.''); Final General NPDES Permit for Concentrated Animal Feeding 
Operations (CAFO) in Idaho ID-G-01-0000, 62 FR 20,178 (1997) (``[T]he 
Clean Water Act does not give EPA the authority to regulate groundwater 
quality through NPDES permits. The only situation in which groundwater 
may be affected by the NPDES program is when a discharge of pollutants 
to surface waters can be proven to be via groundwater . . . the permit 
requirements . . . are intended to protect surface waters which are 
contaminated via a groundwater (subsurface) connection.''); EPA, 
Memorandum from Director, Office of Solid Waste to Waste Management 
Division Directors (1995) (``In addition, such groundwater discharges 
are subject

[[Page 16819]]

to CWA jurisdiction, based on EPA's interpretation that discharges from 
point sources through groundwater where there is a direct hydrologic 
connection to nearby surface waters of the United States are subject to 
the prohibition against unpermitted discharges, and thus are subject to 
the NPDES permitting requirements.''); EPA, In the Matter of Bethlehem 
Steel Corp, UIC Appeal Nos. 85-8 & 86-13 (1989) (EPA ``declines to 
exercise CWA jurisdiction over injection wells (except those that 
inject into ground water with a physically and temporally direct 
hydrologic connection to surface water).''). However, each of these 
statements is included in preambles to rules or in permits where the 
complex jurisdictional issue of releases of pollutants to groundwater 
were not the central focus. In other words, these statements were 
collateral to the central issues addressed in the documents in which 
they are included.
    Commenters highlighted one preamble--to a proposed rule that 
applied to only one category of dischargers--in which EPA discussed its 
prior interpretation in some detail. In a proposed rule revising the 
NPDES permit requirements and effluent limitation guidelines for CAFOs, 
EPA proposed national requirements for certain CAFOs to address 
potential discharges to jurisdictional surface waters via groundwater 
that has a direct hydrologic connection to jurisdictional surface 
waters. 66 FR 2960 (Jan. 12, 2001). In the preamble to this proposed 
rule, EPA explained its interpretation of the Act as applying to these 
types of discharges. Id. at 3015-20. Notably, EPA did not engage in a 
detailed analysis of the Act's text, structure, and legislative history 
in the 2001 preamble that has now led the Agency to the position 
articulated in this Interpretive Statement. Moreover, EPA did not 
finalize these proposed requirements for certain CAFOs and explained in 
the preamble to the final rule that ``the factors affecting whether 
such discharges are occurring . . . are so variable from site to site 
that a national technology-based standard is inappropriate.'' 68 FR 
7176, 7216 (Feb. 12, 2003).\3\
---------------------------------------------------------------------------

    \3\ In reviewing this regulation, the Second Circuit did note 
that NPDES authorities still had the power to impose groundwater 
related requirements on a case-by-case basis. Waterkeeper Alliance 
v. EPA, 399 F.3d 486, 514 & n. 26, 515 (2d Cir. 2005).
---------------------------------------------------------------------------

C. Rationale for the Agency's Rejection of Commenters' Alternative 
Interpretations of the CWA

    Commenters to EPA's February 2018 Federal Register notice offered 
extensive legal arguments both supporting the Agency's previous direct 
hydrologic connection theory, and as a basis for rejecting that theory. 
Some commenters recommending the Agency retain the direct hydrologic 
connection theory cited to the purpose of the statute and the 
definition of ``discharge of a pollutant'' as requiring that the Agency 
construe the statute as covering releases of pollutants to groundwater 
that reach jurisdictional surface waters through a direct hydrologic 
connection. They argued that the definition of ``discharge of a 
pollutant'' is broad, and asks only whether the pollutant travels from 
a point source to a jurisdictional surface water; if so, a NPDES permit 
is required. Commenters in favor of the Agency's rejection of the 
direct hydrologic connection theory asserted that the theory is 
atextual and inconsistent with the overall statutory scheme and 
legislative history of the Act. Some of these commenters offered an 
alternative theory of jurisdiction that limits the scope of the CWA to 
discharges of a pollutant from a point source or series of point 
sources that carry the pollutant directly into the water of the United 
States. In other words, they asserted that pollution must pass through 
an unbroken chain of point sources for a ``discharge of a pollutant'' 
to have occurred, sometimes referred to as the ``terminal point 
source'' theory. The Agency's position articulated herein differs from 
both the direct hydrologic connection theory and the terminal point 
source theory, as explained below. EPA believes its reading of the 
statute--which is based on the statute as a whole and not a single 
definition viewed in isolation--is most consistent with Congress's 
intent. It is also carefully tailored to the specific issue of releases 
of pollutants to groundwater which has generated confusion among 
courts, states, regulated entities, and the public.
    Many environmental organizations that commented on EPA's February 
2018 Federal Register notice urged the Agency to retain the direct 
hydrologic connection theory articulated in prior Agency statements. 
The Agency notes that it is maintaining several elements of that 
position--that groundwater is not a water of the United States and that 
groundwater is not a point source. The Agency's brief before the Ninth 
Circuit in the County of Maui proceeding stated that it ``[did] not 
contend that groundwater is a point source, nor [did it] contend that 
groundwater is a water of the United States regulated by the Clean 
Water Act.'' Brief for the United States as Amicus Curiae at 2, Cty. Of 
Maui, No. 15-17447, 886 F.3d. 737.
    EPA's interpretation here departs from the position the Agency took 
in the County of Maui amicus brief on the application of the definition 
of ``discharge of a pollutant'' to releases of pollutants into 
groundwater. The amicus brief, as well as the commenters urging the 
Agency to retain the direct hydrologic connection theory, failed to 
take into account Congress's unique treatment of groundwater in the CWA 
when interpreting the definition of discharge of a pollutant. The 
Agency's previous interpretation that a release of a pollutant from a 
point source to groundwater that is conveyed to jurisdictional surface 
waters could be the functional equivalent of a release to 
jurisdictional surface waters thus was premised on viewing releases of 
pollutants to groundwater through the NPDES point source paradigm 
rather than viewing such releases in light of Congress's specific 
approach to groundwater under the CWA.
    In arguing that the direct hydrologic connection theory is 
consistent with the Act, the Agency's County of Maui amicus brief, like 
some commenters, recognized that Congress drew a line between 
regulation of discharges to groundwater and regulation of discharges to 
jurisdictional surface water. EPA's amicus brief asserted that Maui 
``emphatically is not a case about the regulation of groundwater'' and 
``[i]nstead it is about the regulation of discharges of pollutants to 
waters of the United States.'' Brief for the United States as Amicus 
Curiae at 21. However, this approach takes insufficient account of the 
explicit treatment of groundwater under the CWA, as reflected in the 
statute's text, structure, and legislative history. In the Agency's 
view, releases to groundwater should not be distinguished based on the 
connection (or lack thereof) between groundwater and jurisdictional 
surface waters. The text, a holistic analysis of the statute, and the 
legislative history indicate that Congress's intent was to 
categorically exclude groundwater from coverage of the permitting 
provisions of the Act and to leave regulation of groundwater to the 
states, irrespective of the type of groundwater formation and whether 
it allows for discharge to jurisdictional surface waters or the 
directness of such a conveyance. The direct hydrologic connection 
theory upsets the careful balance that Congress struck between the 
states and the federal government by pushing a category of pollutant 
discharges from the state-regulated paradigm to the point source, 
federally controlled, program.
    The County of Maui amicus brief, and some commenters urging that 
EPA

[[Page 16820]]

retain the direct hydrologic connection theory, also erred by 
improperly equating releases of pollutants to groundwater with releases 
of pollutants from a point source to surface water that occur above 
ground. The statute and its legislative history indicate that Congress 
intended for all discharges to groundwater to be left to state 
regulation and control, ending any potential for federal permitting 
obligations once the pollutant enters groundwater, regardless of any 
future contribution of any modicum of pollutants to jurisdictional 
surface waters. Thus, the statute does not support analogizing 
pollutants discharged from a point source to groundwater that migrate 
to jurisdictional surface water to ``discharges of pollutant[s] [that] 
have moved from a point source to navigable waters over the surface of 
the ground or by some other means.'' Brief for the United States as 
Amicus Curiae at 14, Cty. Of Maui, No. 15-17447, 886 F.3d. 737.
    As the Act's legislative history in particular demonstrates, 
Congress recognized the complex and highly-localized nature of releases 
to groundwater, that additional research and understanding of the 
interactions between surface and groundwater are needed, and determined 
that states, rather than EPA, are best positioned to regulate such 
releases. Today's interpretation pertains to releases to groundwater 
and thus leaves in place the Agency's case-by-case approach to 
determining whether pollutant releases to jurisdictional surface waters 
that do not travel through groundwater require an NPDES permit. Whether 
a permit is required for such a release is necessarily a fact-specific 
inquiry, informed by the point source definition and an analysis of 
intervening factors. EPA and authorized states have exercised that 
judgment on a case-by-case basis.\4\ It is unnecessary to posit a 
categorical rule with respect to fact patterns such as those described 
in footnote 4 in this Interpretive Statement because, as explained 
above, the statute categorically excludes releases to and from 
groundwater from the permitting requirements of the Act irrespective of 
the directness of the hydrological connection.\5\
---------------------------------------------------------------------------

    \4\ For example, in the 2012 criminal case against Robert 
Armstrong and RCA Oil and Gas LLC, the indictment states that the 
defendant ``using a backhoe, breached the wall of the reservoir 
causing the wastewater to flow into Rockcamp Run.'' United States v. 
Armstrong, No. 2:12-cr-243, ECF-1, at *4 (S.D. Ohio 2013). In the 
2012 criminal case against Chamness Technology Inc., Attachment A to 
the Plea Agreement states that a hose from a lagoon to a rotating 
water irrigator became unhooked and was observed ``discharging dark, 
foamy, and odiferous liquid into a wooded draw which flowed downward 
into the Palestine Creek.'' United States v. Chamness Tech., Inc., 
No. 4:14-cr-149, ECF-8-1, at *2 (S.D. Iowa 2013). In the 2014 
criminal case against Freedom Industries, the Stipulation of Facts 
in the Plea Agreement states that the chemical at issue leaked from 
a tank, ``breached containment, including a dike wall, ran down the 
riverbank and discharged into the Elk River at two discernible, 
confined and discrete channels or fissures.'' United States v. 
Freedom Industries, Inc., No. 2:14-cr-275, ECF-9, at *23-*24 (S.D. 
W.Va. 2016). EPA's regulations for concentrated animal feeding 
operations (CAFOs) prohibit discharges from manure storage lagoons 
unless the lagoon is properly designed and the discharge is the 
result of a 24-hour, 25-year storm. See 40 CFR part 412. EPA has 
taken action against CAFOs with discharges that do not satisfy these 
requirements. See United States v. Meadowvale Dairy, No. 5:16-cv-
4016, ECF-2, at *10 (N.D. Iowa 2017) (Complaint alleging that an 
``inspection at Meadowvale North . . . observed manure laden process 
wastewater flowing from the northern portion of [the basin] into 
Unnamed Tributary East'').
    \5\ The Agency recognizes that the Sixth Circuit recently 
adopted and applied a rationale similar to the terminal point source 
theory. In Kentucky Waterways Alliance, the Sixth Circuit rejected 
environmental groups' argument that coal ash ponds that released 
pollutants into groundwater which flowed through a karst network to 
a jurisdictional surface water constituted a discharge of a 
pollutant under the statute. 905 F.3d 925 (6th Cir. 2018). The 
environmental groups argued that the releases required a NPDES 
permit, relying on both the direct hydrologic connection theory, 
which the court rejected as contrary to the text and structure of 
the statute, and, in the alternative, asserting that the discharge 
of coal ash pollutants from the karst formation was itself a point 
source discharge. On the latter claim, the court determined that 
neither groundwater itself, nor groundwater flowing through a karst 
network, is a point source. Id. at 932-33. The court recognized that 
groundwater ``may indeed be a `conveyance,' '' but concluded that 
``karst . . . is neither discernible, discrete, nor confined.'' Id. 
at 933. Application of the Agency's interpretation of the Act 
described herein--that all releases from a point source to 
groundwater that reach a jurisdictional surface water are, as a 
legal matter, categorically outside of the NPDES program--leads to 
the same result as the Sixth Circuit, but based on a different 
rationale. Nothing in the Kentucky Waterwaters Alliance decision 
would preclude application of the Agency's interpretation within the 
Sixth Circuit.
---------------------------------------------------------------------------

    Finally, the County of Maui amicus brief and some commenters 
improperly rely on the broad goal of the Act to justify applying the 
definition of ``discharge of a pollutant''--which exclusively addresses 
point source discharges to navigable, ocean, and contiguous zone 
waters--to releases of pollutants to groundwater. The brief argues that 
reading the statute as excluding discharges from a point source to 
groundwater ``would allow dischargers to avoid responsibility simply by 
discharging pollutants from a point source into jurisdictional surface 
waters through any means that was not direct.'' Brief for the United 
States as Amicus Curiae at 20. This position fails to give sufficient 
weight to the structure and legislative history of the statute 
indicating that Congress intended in the CWA to leave regulation of all 
releases of pollutants to groundwater to states, in pursuit of the 
overall objective of the statute. In addition, views about the general 
purpose of the Act should not override Congress's evident intent not to 
regulate discharges to groundwater of any kind. As the Supreme Court 
has explained, ``the textual limitations upon a law's scope are no less 
a part of its `purpose' than its substantive authorizations.'' Rapanos 
v. United States, 547 U.S. 715, 752 (2006) (plurality op.). Further, 
excluding these releases from the scope of the NPDES program does not 
equate to no protection for ground and surface waters; rather, as 
described further below, states will continue to exercise their 
authority over these waters as will other federal programs.
    Some commenters placed significance on a statement in the 
government's County of Maui amicus brief that the direct hydrologic 
connection theory was the Agency's ``longstanding position.'' Brief for 
the United States as Amicus Curiae at 5. However, as the full suite of 
public comments reveal, there have in fact been a range of prior 
statements by the Agency, some of which align with this Interpretive 
Statement, that the Agency has now considered in its analysis for the 
first time. Lack of consistent and comprehensive direction from EPA on 
this issue has led to inconsistent interpretation across the country 
and has created uncertainty for regulated entities. Even where the 
Agency has stated an interpretation, the Agency has not issued 
regulations nor formal guidance focused on and explaining the basis for 
the position. As noted above, this Interpretive Statement contains the 
Agency's most comprehensive analysis of the CWA's text, structure, 
legislative history and judicial decisions that has been lacking in 
prior Agency statements on this issue. In so doing, today's statement 
establishes a firm legal foundation for regulatory decisions by EPA and 
states administering CWA programs and clear guidance for the courts.
    Some commenters to EPA's February 2018 Federal Register notice 
highlighted certain factual scenarios, such as movement of groundwater 
through a sub-surface lava tube or karst network that may resemble 
formations which courts have found to be point sources. See Nat'l 
Groundwater Assoc. Comments at 2 (describing certain groundwater 
formations, such as ``lava tube openings, cave or conduit openings 
(including karst conduit networks), or other geologic features'' that 
``function as natural pipelines capable of transporting water, 
effluents, and

[[Page 16821]]

contaminants from one point to another point and behave similarly to 
manmade pipes conveying fluids''). In accordance with EPA's 
interpretation of the statute, because releases of pollutants from a 
point source to groundwater are categorically excluded from the scope 
of the NPDES program, even if those pollutants reach jurisdictional 
surface waters, it is immaterial whether pollutants subsequently travel 
through groundwater in a manner resembling point source discharges. 
EPA's position is that, in accordance with the best, if not the only, 
interpretation of the statute, releases to groundwater are not subject 
to the point source analysis, i.e., the CWA Section 301(a) prohibition, 
because the statute does not cover such releases. Accordingly, 
groundwater cannot be deemed a point source.
    Given the indications in both the text of the statute as well as 
the legislative history that Congress intended to categorically leave 
regulation of groundwater to the states, these factual distinctions are 
of no legal significance. Applying the commenters' theory that releases 
to groundwater are excluded because the physical characteristics of 
groundwater are dissimilar to what some courts have found to be point 
sources is unnecessary. The numerous provisions in the Act linking 
groundwater to nonpoint source pollution, and the absence of discussion 
of groundwater in any of the regulatory sections of the CWA, provide 
ample support that in establishing the NPDES program Congress intended 
to leave regulation of all releases of pollutants to groundwater, akin 
to nonpoint source pollution, to the states.\6\
---------------------------------------------------------------------------

    \6\ While not the conclusion reached herein, some courts have 
resolved these issues by deeming releases of pollutants that have 
seeped into groundwater and subsequently reached surface waters to 
be nonpoint source pollution. See Sierra Club v. El Paso Gold Mines, 
Inc., 421 F.3d 1133, 1141 n. 4 (10th Cir. 2005) (``Groundwater 
seepage that travels through fractured rock would be nonpoint source 
pollution which is not subject to NPDES permitting.''); Penn 
Environment v. PPG Indus., Inc., 964 F. Supp. 2d 429, 455-56 (W.D. 
Pa. 2013) (``[A] discharge occurring through the migration of 
groundwater and soil runoff . . . represents `nonpoint source' 
pollution.'').
---------------------------------------------------------------------------

V. Case Law

    Over the 46-year history of the CWA, numerous courts have grappled 
with the question that EPA addresses with this interpretation. Many 
courts, including the Fifth, Sixth, and Seventh Circuit Courts of 
Appeals, have looked to both the language of the Act and the 
legislative history and determined that the Act excludes from its 
regulatory requirements all pollutant discharges to groundwater, 
regardless of whether that groundwater is hydrologically connected to 
jurisdictional surface waters. Other courts, including the Fourth and 
Ninth Circuit Courts of Appeals, have cited the broad, protective goals 
of the Act, and applied in isolation the definition of ``discharge of a 
pollutant'' to releases of pollutants from point sources to groundwater 
that migrate to jurisdictional surface waters. Upon this premise, these 
courts have then found that, upon meeting the courts' respective tests 
for assessing the connectedness between the groundwater and 
jurisdictional surface waters, such releases are subject to NPDES 
requirements. The Agency believes that these interpretations departed 
from the text and history of the CWA, and finds the decisions of the 
Fifth and Seventh Circuit more persuasive and true to Congress's intent 
in enacting the statute.
    The decisions of other circuits which have taken a different 
approach than the Fourth and Ninth Circuit--taking a holistic view of 
the statute and accounting for the legislative history--are 
informative. In the 1977 Exxon v. Train decision, the Fifth Circuit 
conducted an extensive analysis of the text, structure, and legislative 
history of the statute, and held that the Act did not give EPA 
authority to regulate certain releases of pollutants into groundwater. 
There, EPA had asserted authority to require NPDES permits for 
subsurface disposal into deep wells where an entity already had a 
permit for surface discharge. 554 F.2d at 1319. The Agency did not 
argue that a permit was required because disposal was an addition of a 
pollutant to ``navigable waters,'' id. at 1318 n.17, but instead that 
its authority was premised on the presence of an existing 
jurisdictional surface water discharge, id. at 1320. In analyzing the 
question of EPA's authority over deep well disposal, the court noted 
that ``EPA has not argued that the wastes disposed of into wells here 
do, or might, `migrate' from groundwaters back into surface waters that 
concededly are within its regulatory jurisdiction,'' and thus, the 
court ``express[ed] no opinion on what the result would be if that were 
the state of facts.'' Id. at 1312 n.1.
    However, in holding that EPA's assertion of authority was 
unsupported by the text and legislative history of the statute, the 
court made two observations that are relevant to the broader question 
of regulation of any discharges to groundwater. First, that the court's 
construction was true ``to Congress' intention not to interfere with 
existing state controls over groundwater'' generally, given the 
complex, state-specific nature of groundwater regulation. And second, 
that the legislative history of the Act gives not ``the slightest hint 
that any Member thought the bill would grant the Administrator any 
power to regulate deep-well disposal or any other form of groundwater 
pollution.'' Id. at 1329 (emphasis added).
    In Rice v. Harken Exploration Co., the Fifth Circuit addressed a 
factual scenario where the plaintiff's Oil Pollution Act (OPA) claim 
was premised on pollutant discharges to groundwater migrating to and 
polluting jurisdictional surface waters. In analyzing the merits of 
that claim, the court relied on Exxon to determine whether the OPA's 
requirements governing discharges to ``navigable waters of the United 
States'' apply to discharges to groundwater that reach such surface 
waters. There, the plaintiffs alleged that groundwater under their land 
was contaminated by pollutants discharged by Harken Exploration's oil 
and gas operations, and that those pollutants seeped from the 
groundwater into several bodies of surface water, in violation of the 
OPA. Rice v. Harken Exploration Co., 250 F.3d 264, 265-66, 270 (5th 
Cir. 2001).
    Due to the lack of case law construing the term ``navigable waters 
of the United States'' in the OPA context, the court's analysis focused 
on cases construing the scope of the CWA, given the court's view that 
the use of the term ``navigable waters'' in both statute was analogous. 
Id. at 267-68 (``The legislative history of the OPA and the textually 
identical definitions of `navigable waters' in the OPA and the CWA 
strongly indicate that Congress generally intended the term `navigable 
waters' to have the same meaning in both the OPA and the CWA.''). The 
court recognized that ``[i]n Exxon, we held that the legislative 
history of the CWA belied any intent to impose direct federal control 
over any phase of pollution of subsurface waters.'' Id. at 269. 
However, acknowledging that Exxon addressed the specific question of 
CWA regulation of deep-well disposal, the court explained that ``[t]his 
Court has not yet decided whether discharges into groundwater that 
migrate into protected surface waters are covered'' under the CWA or 
the OPA. Id. at 271. Relying on its CWA analysis in Exxon, and the 
analogous absence of any indication that Congress intended to regulate 
any type of groundwater under the OPA, the Fifth Circuit held that ``a 
generalized assertion that covered surface waters will eventually be 
affected by remote, gradual, natural seepage from the contaminated 
groundwater'' was outside the scope of the OPA in order ``to respect 
Congress's decision to leave the

[[Page 16822]]

regulation of groundwater to the States.'' Id. at 272.
    In Village of Oconomowoc Lake v. Dayton Hudson Corporation, the 
Seventh Circuit squarely addressed the issue of point source discharges 
that reach jurisdictional surface waters through groundwater, and 
concluded that ``[n]either the Clean Water Act nor the EPA's definition 
[of waters of the United States] asserts authority over ground waters, 
just because these may be hydrologically connected with surface 
waters.'' 24 F.3d at 965. In that case, a municipality in Wisconsin 
filed a CWA citizen suit claiming that a NPDES permit was required for 
a waste retention pond at a Target Stores distribution center, due to 
potential seepage of waste into groundwater, which could reach 
jurisdictional surface waters. Id. at 963, 965.
    In analyzing the facts before it, the Seventh Circuit explicitly 
recognized the possibility that ``water from the pond will enter the 
local ground waters, and thence underground aquifers that feed lakes 
and streams that are part of the `waters of the United States.' '' Id. 
at 965. The court also recognized, however, that ``the Clean Water Act 
does not attempt to assert national power to the fullest,'' and 
intentionally does not apply to all waters. Id. Based on the text of 
the statute and the same compelling legislative history analyzed by the 
Fifth Circuit and discussed above, the court concluded that ``[t]he 
omission of ground waters from regulations is not an oversight,'' as 
``Congress elected to leave the subject [of groundwater regulation] to 
state law[.]'' Id. Thus, there was no cognizable CWA claim based on 
discharges to ground water that may reach jurisdictional surface 
waters. Id.
    Most recently, the Sixth Circuit concluded, in two related cases 
addressing pollutants from coal ash ponds that seeped into groundwater 
that subsequently reached jurisdictional surface waters, that the NPDES 
permitting requirements do not apply to releases to groundwater. In 
Kentucky Waterways Alliance v. Kentucky Utilities Co., the Sixth 
Circuit held that the ``text and statutory context of the CWA'' make 
clear that the statute ``does not extend to reach this form of 
pollution.'' 905 F.3d at 933. In Tennessee Clean Water Network v. TVA, 
the court reversed a district court decision adopting the direct 
hydrologic theory, finding that ``any alleged leakages into the 
groundwater are not a violation of the CWA.'' 905 F.3d at 444. The 
Sixth Circuit recognized the statute's broad goal of protecting the 
Nation's waters, but held that this goal cannot be pursued at all costs 
``because the CWA precludes federal regulation over non-navigable-water 
pollution and over nonpoint-source-pollution.'' Ky. Waterways Alliance, 
905 F.3d at 937. The court explained:

    It is true that Congress sought to protect navigable waters with 
the CWA . . . But it also imposed several textual limitations on the 
means used to reach that goal. Had it wished to do so, Congress 
could have prohibited all unpermitted discharges of all pollutants 
to all waters. But it did not go so far. Instead, Congress chose to 
prohibit only the discharge of pollutants to ``navigable waters from 
any point source.''

    Id.; see also, e.g., Prairie Rivers Network v. Dynegy Midwest 
Generation, LLC, No. 18-CV 2148, slip op. at 14 (C.D. Ill. Nov. 14, 
2018) (Applying the Seventh Circuit's decision in Village of Oconomowoc 
to hold that ``[i]f the discharge is made into groundwater, and the 
pollutants somehow later find their way to navigable surface waters via 
a discrete hydrological connection, the CWA is still not implicated, 
because the offending discharge was made into groundwater, which is not 
subject to the CWA''); Cape Fear River Watch v. Duke Energy Progress, 
25 F. Supp. 3d 798, 810 (E.D.N.C. 2014) (``Congress did not intend for 
the CWA to extend federal regulatory authority over groundwater, 
regardless of whether that groundwater is eventually or somehow 
`hydrologically connected' to navigable surface waters.''); Umatilla, 
962 F. Supp. at 1318 (observing that ``the CWA's NPDES program should 
apply to groundwater to adequately protect surface water,'' but 
concluding that ``the law as written, as intended by Congress, and as 
applied in Oregon for over two decades does not regulate even 
hydrologically-connected groundwater''); 26 Crown Assocs., LLC v. 
Greater New Haven Reg'l Water Pollution Control Auth., No. 3:15-cv-
1439, 2017 U.S. Dist. LEXIS 106989, *24 (D. Conn. 2017) (noting that 
``if the Clean Water Act were to apply as a routine matter to the 
discharge of pollution onto the ground that ends up seeping into the 
ground water, then Congress's purpose to limit the scope of the Clean 
Water Act [to point source discharges] would be easily thwarted.'').
    In contrast, the circuit and district court decisions concluding 
that certain releases to groundwater are subject to NPDES requirement 
have often left unaddressed the text, structure, and legislative 
history of the Act pointing to Congress's intent to exclude all 
discharges to groundwater from the NPDES program. The Fourth Circuit 
recently held that point source releases to groundwater that reach 
jurisdictional surface waters require a NPDES program in certain 
instances, adopting EPA's historical direct hydrological connection 
approach. Kinder Morgan, 887 F.3d at 652. In that decision, the court 
did not address any of the legislative history discussed herein, nor 
did the court acknowledge or address the decisions of the Fifth or 
Seventh Circuit.
    Rather, in analyzing whether gasoline from a ruptured underground 
pipeline that undisputedly leached from groundwater into navigable 
waters required a NPDES permit, the Fourth Circuit framed its inquiry 
as only whether, first, the discharge was from a point source, id. at 
649-50, and second, whether there was a direct hydrological connection 
between the groundwater and jurisdictional surface water, a fact-
specific determination. Id. at 651. The court cited to the broad 
purpose of the Act to restore and maintain the chemical, physical, and 
biological integrity of the Nation's waters, asserting that ``the 
statute established a regime of zero tolerance for unpermitted 
discharges of pollutants.'' Id. at 652. The court reasoned that ``if 
the presence of a short distance of soil and ground water were enough 
to defeat a claim, polluters easily could avoid liability under the CWA 
by ensuring that all discharges pass through soil and ground water 
before reaching navigable waters.'' Id. The court ultimately concluded 
that ``an alleged discharge of pollutants, reaching navigable waters 
located 1000 feet or less from the point source by means of ground 
water with a direct hydrological connection to such navigable waters, 
falls within the scope of the CWA.'' Id. at 652. In reaching this 
holding,\7\ however, the court failed to consider Congress's intent, 
evident from the text, structure, and legislative history of the Act, 
to treat groundwater and nonpoint source discharges differently under 
the Act, by leaving their regulation to states.\8\
---------------------------------------------------------------------------

    \7\ One judge dissented from the panel's holding, finding that 
there was no Clean Water Act violation because the discharge of 
pollutants from the pipe had been repaired, and that the continued 
migration through groundwater was not a ``discharge of a pollutant'' 
under the Act. Kinder Morgan, 887 F.3d at 662-63 (Floyd, J. 
dissenting). The dissent recognized that ``[t]his kind of migration 
of pollutants through the natural movements of groundwater amounts 
to nonpoint source pollution,'' and that, ``[w]hile there is no 
doubt this kind of nonpoint source pollution affects the quality 
[of] navigable waters, Congress deliberately chose not to place 
nonpoint source pollution within the CWA's reach.'' Id.
    \8\ On September 12, 2018, in Sierra Club v. Virginia Electric 
Power Co., the Fourth Circuit applied its decision in Kinder Morgan 
to another fact pattern involving the addition of pollutants to 
jurisdictional surface waters through groundwater. In that case, the 
court recognized the precedent in Kinder Morgan that the addition of 
a pollutant into navigable waters via groundwater can violate 
Section 301(a) if the plaintiff can show a direct hydrological 
connection between the ground water and navigable waters. 903 F.3d 
403, 409 (4th Cir. 2018). The court went on to hold that a coal-
fired power plant that stored coal ash on site in a landfill and in 
settling ponds was not liable under CWA Section 301(a) for 
discharges of arsenic that leached from the coal ash into 
groundwater and ultimately into a nearby river because the settling 
ponds did not constitute ``point sources'' under the CWA. Id. at 
411.

---------------------------------------------------------------------------

[[Page 16823]]

    Applying a similar analysis, in its decision in County of Maui, the 
---------------------------------------------------------------------------
Ninth Circuit explained:

    We assume without deciding that groundwater here is neither a 
point source nor a navigable water under the CWA. Hence, it does not 
affect our analysis that some of our sister circuits have concluded 
that groundwater is not a navigable water. We are not suggesting 
that the CWA regulates all groundwater. Rather, in fidelity to the 
statute, we are reinforcing that the Act regulates point source 
discharges to a navigable water, and that liability may attach where 
a point source discharge is conveyed to a navigable water through 
groundwater.

    Cty. of Maui, 886 F.3d at 746 n.2 (citations omitted). The court 
also rejected the direct hydrological connection theory espoused by the 
United States as amicus, as ``it reads two words into the CWA (`direct' 
and `hydrological') that are not there.'' Id. at n.3. Then, despite the 
court's claim of ``fidelity to the statute,'' it ultimately determined, 
without any grounding in the statute's text, that point source 
discharges to groundwater that reach jurisdictional surface water are 
subject to NPDES permitting requirements where they are fairly 
traceable back to the point source and more than de minimis. Id. at 
749. The court also left ``for another day the task of determining 
when, if ever, the connection between a point source and a navigable 
water is too tenuous to support liability under the CWA,'' thus 
expanding the scope of the Act to cover any release of pollutants to 
groundwater that reaches a jurisdictional surface water. Id.
    The Ninth Circuit stated that its decision was consistent with Rice 
and Village of Oconomowoc, despite reaching the opposite conclusion 
about the proper scope of the Act. The court's basis for claiming 
consistency with Rice was that the Fifth Circuit, in its analysis of 
the facts in that case, ``required some evidence of a link between 
discharges and contamination of navigable waters.'' Id. With respect to 
the Village of Oconomowoc decision, the Ninth Circuit asserted that the 
Seventh Circuit ``only considered allegations of a `potential [rather 
than an actual] connection between ground waters and surface waters,' 
'' while the connection in its own case was undisputed. Id. However, 
these are factual distinctions that should not affect the ultimate 
outcome. While it is accurate that in both Rice and Village of 
Oconomowoc, the courts looked to whether a connection to jurisdictional 
surface waters existed, this factual inquiry and observation does not 
alter the courts' ultimate interpretations of the CWA and OPA, and 
their recognition of the line Congress drew with respect to pollutant 
discharges to groundwater.
    In Rice, the court observed that ``[i]n light of Congress's 
decision not to regulate ground waters under the CWA/OPA,'' it was 
``reluctant to construe the OPA in such a way as to apply to discharges 
onto land, with seepage into groundwater, that have only an indirect, 
remote, and attenuated connection with an identifiable body of 
`navigable waters.' '' Rice, 250 F.3d at 272. However, while the 
court's reluctance was stated in relation to the facts in that case, 
its ultimate interpretation was based on Congress's intent: ``[w]e must 
construe the OPA in such a way as to respect Congress's decision to 
leave the regulation of groundwater to the States.'' Id. (emphasis 
added). Similarly, though the facts before the Seventh Circuit 
addressed only a potential hydrologic connection between groundwater 
and jurisdictional surface water, the court's determination was 
unequivocal: ``Neither the Clean Water Act nor the EPA's definition [of 
navigable waters] asserts authority over ground waters, just because 
these may be hydrologically connected with surface waters.'' 24 F.3d at 
965.
    The tests adopted by the Ninth and Fourth Circuits and certain 
district courts create a confusing patchwork of judicial 
interpretations, which the Agency has concluded lack support in the 
text, structure, and legislative history of the Act. As the Supreme 
Court has explained, ``an administrative agency's power to regulate in 
the public interest must always be grounded in a valid grant of 
authority from Congress,'' and ``in [its] anxiety to effectuate the 
congressional purpose,'' an agency ``must take care not to extend the 
scope of the statute beyond the point where Congress indicated it would 
stop.'' See FDA v. Brown & Williamson Tobacco Corp., 529 U.S. 120, 161 
(2000) (internal citations omitted). While the Ninth Circuit adopted a 
``fairly traceable'' standard, rejecting EPA's prior ``direct 
hydrologic connection'' test, and the Fourth Circuit imposed a 1,000 
foot distance limitation, other courts have adopted other variations on 
when groundwater is sufficiently connected to jurisdictional surface 
water to require a NPDES permit. See, e.g., Tenn. Clean Water Network 
v. TVA, 273 F. Supp. 3d 775, 827 (M.D. Tenn. 2017) (holding that ``[a]s 
long as a connection [between groundwater and surface water] is shown 
to be real, direct, and immediate, there is no statutory, 
constitutional, or policy reason to require that every twist and turn 
of its path be precisely traced''), rev'd 905 F.3d 436 (6th Cir. 2018); 
McClellan Ecological Seepage Situation v. Weinberger, 707 F. Supp. 
1182, 1196 (E.D. Cal. 1998) (discharges to groundwater are subject to 
CWA regulation if ``the groundwater is naturally connected to surface 
waters'' (emphasis added)); vacated on other grounds, McClellan 
Ecological Seepage Situation v. Perry, 47 F.3d 325 (9th Cir. 1995).
    These decisions expand the Act's coverage beyond what Congress 
envisioned, potentially sweeping into the scope of the statute 
commonplace and ubiquitous activities such as releases from homeowners' 
backyard septic systems that find their way to jurisdictional surface 
waters through groundwater. The interpretations adopted by the Ninth 
Circuit and Fourth Circuits both contravene Congress's intent to leave 
regulation of all releases of pollutants to groundwater to states under 
the CWA, and, as a practical matter, stretch the Act's carefully 
constructed program of regulation of point sources beyond a point that 
Congress would recognize. A holistic reading of the CWA leads to the 
conclusion that releases of pollutants to groundwater are categorially 
excluded from the NPDES program, and thus, Congress did not intend for 
discharges from point sources that reach jurisdictional surface waters 
through hydrologically connected groundwater to require a NPDES permit. 
It follows that neither EPA nor the courts need engage with specific 
factual questions of traceability via subsurface hydrogeology that are 
currently required by certain court decisions such as County of Maui 
and Kinder Morgan.

VI. Policy Considerations Supporting EPA's Interpretation

    There is sufficient legal authority to address releases of 
pollutants to groundwater that subsequently reach jurisdictional 
surface waters at both the state and federal level without expanding 
the CWA's regulatory reach beyond what Congress envisioned. Consistent 
with Congress's intent in structuring the CWA, states may regulate 
groundwater quality in the manner best suited to their particular 
circumstances. This interpretation will

[[Page 16824]]

continue to give states primacy for regulating ubiquitous groundwater 
discharges from sources such as septic tanks which are known to affect 
jurisdictional surface water quality in some instances. Beyond state 
programs, three other federal statutes, the Safe Drinking Water Act 
(``SDWA''), the Resource Conservation and Recovery Act (``RCRA''), and 
the Comprehensive Environmental Response, Compensation, and Liability 
Act (``CERCLA'') will continue to provide important protections for 
groundwater quality, and for surface waters impacted by releases to 
groundwater.

A. State Programs for Regulating Discharges to Groundwater

    The CWA establishes a regulatory floor that protects the integrity 
of the Nation's navigable waters and provides states with broad 
authority to adopt laws and regulations that are more protective than 
the federal standards. As explained above, the Act identifies the 
preservation of state authority to regulate land and water resources 
within their borders as a primary aim of the Act and states that ``[i]t 
is the policy of the Congress to recognize, preserve, and protect the 
primary responsibilities and rights of States to prevent, reduce, and 
eliminate pollution, to plan the development and use (including 
restoration, preservation, and enhancement) of land and water resources 
. . . .'' 33 U.S.C. 1251(b). Congress also declared as a national 
policy that states manage the major construction grant program and 
implement the core permitting programs authorized by the Act, among 
other responsibilities. Id.
    The Act envisions that states will take an active role in 
regulating discharges to waters within the state and expressly provides 
states with authority to regulate beyond the Act's regulatory floor. 
The CWA states that, except as expressly provided in the Act, nothing 
in the Act shall ``preclude or deny the right of any State . . . to 
adopt or enforce . . . any standard or limitation respecting discharges 
of pollutants, or . . . any requirement respecting control or abatement 
of pollution; except that . . . such State or political subdivision or 
interstate agency may not adopt or enforce any effluent limitation, or 
other limitation, effluent standard, prohibition, pretreatment 
standard, or standard of performance which is less stringent than the 
effluent limitation, or other limitation, effluent standard, 
prohibition, pretreatment standard, or standard of performance under 
this chapter . . . .'' Id. Sec.  1370. Congress further provided that 
nothing in the Act shall be ``construed as impairing or in any manner 
affecting any right or jurisdiction of the States with respect to the 
waters (including boundary waters) of such States.'' Id.
    Several commenters on the Agency's February 2018 Federal Register 
notice described state laws and regulations that prohibit or limit 
discharges of pollutants to groundwater. For example, the Minnesota 
Pollution Control Agency stated in its comments that it ``believes 
Minnesota has adequate authority under state law to address discharges 
outside the scope of the NPDES or UIC programs.'' Comments submitted by 
Minnesota Pollution Control Agency (May 16, 2018) (Docket ID: EPA-HQ-
OW-2018-0063-0664), available at https://www.regulations.gov/document?D=EPA-HQ-OW-2018-0063-0664. MPCA further stated that ``state 
permits are developed to protect groundwater as a drinking water source 
[and] [t]hey also ensure that surface water quality standards will be 
met.'' Id. The attorneys general of West Virginia, Alabama, Arkansas, 
Colorado, Georgia, Kansas, Louisiana, Missouri, Nebraska, Nevada, 
Oklahoma, South Carolina, South Dakota, Texas, and Wyoming submitted 
comments describing state laws that protect intrastate water, including 
groundwater, independent from the CWA. Comments submitted by West 
Virginia Attorney General, et al. (May 21, 2018) (Docket ID: EPA-HQ-OW-
2018-0063-0497), available at https://www.regulations.gov/document?D=EPA-HQ-OW-2018-0063-0497.
    States that have not enacted state law-based programs that 
comprehensively regulate discharges to groundwater continue to have 
wide latitude to do so under state law and the CWA. See 33 U.S.C. 
1251(b), 1370. EPA's position that the CWA does not regulate releases 
of pollutants to groundwater, regardless of a connection to 
jurisdictional surface waters, does not preclude states from regulating 
these releases under state law. To the extent that there may be state 
laws that limit a state's ability to regulate beyond the federal floor, 
states remain free to modify these laws as they deem appropriate to 
regulate discharges in the state.

B. In Other Federal Statutes, Such as SDWA, RCRA, and CERCLA, Congress 
Explicitly Envisioned a Federal Role in Regulating Groundwater Quality

    In addition to state programs for regulating discharges into 
groundwater, several federal statutes explicitly address regulation of 
groundwater quality. Unlike in the CWA paradigm, where the federal role 
is one of providing support to states to advance state regulatory 
programs, in the statutes below, Congress provided for a clear federal 
role. Review of the explicit provisions addressing discharges to 
groundwater in these statutes makes clear that Congress can and does 
directly address the issue of groundwater quality in specific federal 
programs. It is also equally clear that Congress tailored those 
programs to the concerns over specific practices posing an endangerment 
to groundwater, while also deferring to state regulation even in those 
programs. Together these statutes, along with the state programs 
described above, form a mosaic of laws and regulations that provide 
mechanisms and tools for EPA, states, and the public to ensure the 
protection of groundwater quality, and to minimize related impacts to 
surface waters.
1. SDWA
    SDWA, enacted in 1974, two years after the CWA, contains provisions 
specifically aimed at preventing certain types of groundwater 
contamination. This statute is one of the vehicles through which 
Congress deliberately addressed the discharge of pollutants into 
groundwater, while also recognizing the important role for states to 
play in regulating groundwater pollution.
    Pursuant to Section 1421 of SDWA, EPA has established requirements 
for state programs to regulate underground injection of fluids. See 42 
U.S.C. 300h. Specifically, under that section Congress required EPA to 
establish minimum requirements for effective state programs to prevent 
underground injection which endangers drinking water sources, defined 
under SDWA to mean underground water which supplies or can reasonably 
be expected to supply any public water system. The underground 
injection control (``UIC'') program under SDWA contains regulatory 
requirements for four classes of wells; bans Class IV (shallow 
hazardous waste) wells; and by rule authorizes most Class V wells. The 
rule authorizing Class V wells requires certain reporting, and requires 
that the wells are operated in ways that do not cause movement of fluid 
that could endanger underground sources of drinking water, and that the 
wells are properly closed when they are no longer being used. See 40 
CFR 144.24, 82.
    The SDWA UIC program is one clearly designed and tailored by 
Congress to address and protect groundwater quality. While SDWA is 
targeted to a specific type of possible contamination, i.e., discharges 
through certain types of well injection that may impact nearby drinking 
water sources,

[[Page 16825]]

consistent with Congressional deference to states in the area of 
groundwater regulation generally, it also is established primarily as a 
state program. The statute expressly requires EPA to permit or provide 
for ``consideration of varying geologic, hydrological, or historical 
conditions in different States and different areas within a State,'' 
and to avoid, to the extent feasible, requirements that would 
unnecessarily disrupt state injection programs. 42 U.S.C. 300h(b)(3).
2. RCRA
    Like SDWA, in RCRA Congress chose to include provisions for federal 
regulation of discharges into groundwater, to protect groundwater 
quality from the discharge of solid and hazardous wastes. RCRA was 
enacted to ``reduce the generation of hazardous waste and to insure the 
proper treatment, storage, and disposal of that waste which is 
nonetheless generated, so as to minimize the present and future threat 
to human health and the environment.'' Meghrig v. KFC W, Inc., 516 U.S. 
479, 483 (1996). RCRA defines ``disposal'' as the ``discharge, deposit, 
injection, dumping, spilling, leaking, or placing of any solid waste or 
hazardous waste into or on any land or water so that such solid waste 
or hazardous waste or any constituent thereof may enter the environment 
or be emitted into the air or discharged into any waters, including 
groundwater.'' 42 U.S.C. 6903(3) (emphasis added).
    RCRA has several provisions that expressly address groundwater 
monitoring and remediation at hazardous waste treatment, storage, and 
disposal (``TSD'') facilities. RCRA and EPA's implementing regulations 
explicitly require groundwater monitoring for specified categories of 
hazardous waste units. See id. Sec.  6924(o), (p); see also 40 CFR 
264.90-264.99. In addition, the owner and/or operator of a RCRA 
permitted hazardous waste facility is required to perform corrective 
action for all releases of hazardous waste or constituents from any 
solid waste management unit, including releases to groundwater. 42 
U.S.C. 6924(u), (v); 40 CFR 264.100-264.101. Facilities that have or 
should have had RCRA ``interim status'' (i.e., authorization to operate 
a TSD without a permit), and some facilities that had interim status, 
are subject to corrective action orders under RCRA section 3008(h). 42 
U.S.C. 6928(h). Both RCRA permits and 3008(h) orders can thus address 
releases resulting in contaminated groundwater.
    While these requirements may not apply to hazardous waste 
``generators'' or to regulated units covered by specific exclusions or 
exemptions from groundwater monitoring, see, e.g., 40 CFR 264.90, 
264.101(d), RCRA also provides EPA with authority to address waste 
management activities of generators, transporters, owners or operators 
of treatment, storage, or disposal facilities, past or present, that 
``may present an imminent and substantial endangerment to health or the 
environment,'' 42 U.S.C. 6973(a). The Agency has used this authority to 
address releases of contaminants into groundwater.
    RCRA non-hazardous waste facilities are generally subject to EPA 
RCRA standards in 40 CFR 257 or section 258. These rules vary by unit 
type, and several categories (with exceptions) are subject to specific 
groundwater monitoring and corrective action requirements. These 
categories include facilities that manage coal combustion residuals in 
surface impoundments and landfills, as well as municipal solid waste 
landfill units. See 42 U.S.C. 6949a(c); 40 CFR 257.90-257.100 (coal 
combustion residuals surface impoundments and landfills); id. 
Sec. Sec.  258.50-258.58 (municipal solid waste landfill units).
    EPA's RCRA regulations addressing coal combustion residuals 
(``CCR'') were promulgated in 2015, with the impact of these facilities 
to groundwater as a critical consideration underlying the regulations. 
See 80 FR 21302, 21326 (Apr. 17, 2015) (Recognizing that 
``approximately 63 percent of currently operating surface impoundments 
and landfills are unlined, and thus more prone to leach contaminants 
into groundwater.''). This rule specifically addresses ``groundwater 
contamination from the improper management of CCR in landfills and 
surface impoundments,'' and ``reflect[s] Congressional intent that 
protection of groundwater be a prime objective of any new solid waste 
regulations.'' Id. at 21396. To accomplish these objectives, the rule 
establishes specific requirements for groundwater monitoring and 
remediation. 40 CFR 257.90-257.98. If monitoring detects a 
statistically significant concentration of certain constituents in 
groundwater above background levels, the facility is required to 
undertake further, ``targeted'' monitoring to determine whether 
concentrations of specific contaminants exceed the rule's groundwater 
protection standards (which, for most contaminants, are based on EPA-
established standards for drinking water). Id. Sec. Sec.  257.98, 
257.95. If contamination exceeding these levels is detected, corrective 
action is required. Id. Sec. Sec.  257.96-257.97. The remedy selected 
as a result of the corrective action must be protective of human health 
and the environment, control the sources of the releases to reduce or 
eliminate further releases, remove from the environment as much of the 
contamination as is feasible, and otherwise comply with all applicable 
RCRA requirements. Id. Sec.  257.97(b).
    RCRA also contains corrective action requirements for releases of 
regulated substances from underground storage tanks (``USTs''). 
Releases from USTs can occur due to corrosion of tank material, faulty 
installation, or inadequate operating and maintenance procedures. 
Owners and/or operators of USTs must report releases and take 
corrective action in response, including releases to groundwater. See 
42 U.S.C. 6991b(c); 40 CFR part 280, subparts E & F. The term 
``release'' in relation to USTs is defined in RCRA to mean ``any 
spilling, leaking, emitting, discharging, escaping, leaching, or 
disposing from an underground storage tank into ground water, surface 
water or subsurface soils.'' 42 U.S.C. 6991(8). Unlike the CWA NPDES 
provisions, this provision in RCRA explicitly defines a release as 
being to groundwater as well as to surface water; where Congress 
intended for a provision to relate to both, it said so clearly.
3. CERCLA
    CERCLA, also known as ``Superfund,'' is yet another example of 
Congress choosing to specifically address releases of hazardous 
substances to groundwater, which could reach and impact surface waters. 
CERCLA provides EPA with a number of tools to address releases of 
hazardous substances, pollutants and contaminants, specifically where a 
``hazardous substance is released or there is a substantial threat of 
such a release into the environment'' or where there is a release or 
substantial threat of release of any pollutant or contaminant which may 
present an imminent and substantial danger to the public health or 
welfare. 42 U.S.C. 9604(a)(1). CERCLA defines ``environment'' broadly, 
to include ``ground water,'' ``subsurface strata,'' as well as 
``surface water.'' Id. Sec.  9601(8). Thus, under CERCLA, EPA has clear 
authority to address releases into both groundwater and surface waters.
    EPA's CERCLA authorities provide a variety of mechanisms for EPA to 
address hazardous substances in groundwater, through the ability to 
address releases or threatened releases of hazardous substances to the 
environment, issue orders, and recover costs of clean-up. See 42 U.S.C. 
9604,

[[Page 16826]]

9606, 9607, 9621. In CERCLA, Congress explicitly provided that in 
remedial actions, the clean-up level for groundwater must be that 
``which at least attains Maximum Contaminant Level Goals established 
under [SDWA] and water quality criteria established under . . . the 
Clean Water Act'' where such goals or criteria are relevant and 
appropriate under the circumstances of the release or potential 
release.'' Id. Sec.  9621(d)(2)(A). EPA's National Contingency Plan 
regulations implementing CERCLA also provide that ``EPA expects to 
return usable ground waters to their beneficial uses wherever 
practicable, within a timeframe that is reasonable given the particular 
circumstances of the site.'' 40 CFR 300.430(a)(1)(iii)(F). The 
determination of a ``beneficial use'' of groundwater is tied to state 
and local classifications (unless the state classification is less 
stringent than the EPA classification scheme), evidencing EPA's 
recognition of the state-specific nature of groundwater regulation. See 
Preamble to the National Contingency Plan, 55 FR 8733 (Mar. 8, 1990).
    Finally, as the Agency has recognized, ``CERCLA cleanup levels are 
designed to address all reasonably anticipated routes of exposure that 
may pose an actual or potential risk to human health or the 
environment.'' EPA Office of Solid Waste and Emergency Response 
Directive 9283.1-33 at 9. These routes of exposure include 
``groundwaters as a source of contamination to other media'' including 
intrusion into surface waters. Id. In determining clean-up standards, 
CERCLA and the National Contingency Plan require the identification of 
``applicable or relevant and appropriate requirements,'' 42 U.S.C. 
9621(d); 40 CFR 300.400(g), which, for remedying discharges to 
groundwater that reaching surface water, could include CWA requirements 
that are specifically addressed at the receiving surface water. See 
Directive 9283.1-33 at 8 (``Where groundwaters may impact surface water 
quality, water quality criteria under sections 304 or 303 of the Clean 
Water Act, may be relevant and appropriate standards[.]''). Thus, both 
CERCLA and EPA's regulations and guidance clearly address and provide 
for remediation of not only discharges to groundwater, but specifically 
impacts to surface water from polluted groundwater.

    Dated: April 12, 2019.
David P. Ross,
Assistant Administrator, Office of Water.
[FR Doc. 2019-08063 Filed 4-22-19; 8:45 am]
BILLING CODE 6560-50-P