Court Opinion

ID: 5125319
Source: CourtListenerOpinion
Date Created: 2021-11-11 21:00:57.648117+00
Date Added: 2024-06-11T08:22:49.500467
License: Public Domain

FOR PUBLICATION

   UNITED STATES COURT OF APPEALS
        FOR THE NINTH CIRCUIT

 UPPER MISSOURI WATERKEEPER,                  No. 19-35898
                 Plaintiff-Appellee,
                                                D.C. No.
                    v.                       4:16-cv-00052-
                                                 BMM
 U.S. ENVIRONMENTAL PROTECTION
 AGENCY; MICHAEL REGAN, *
 Administrator, United States
 Environmental Protection Agency,
                          Defendants,

 TREASURE STATE RESOURCES
 ASSOCIATION OF MONTANA; STATE
 OF MONTANA DEPARTMENT OF
 ENVIRONMENTAL QUALITY,
             Intervenor-Defendants,

                   and

 NATIONAL ASSOCIATION OF CLEAN
 WATER AGENCIES; THE MONTANA
 LEAGUE OF CITIES AND TOWNS,
   Intervenor-Defendants-Appellants.

   *
     Michael Regan has been automatically substituted for former
Administrator Andrew Wheeler. Fed. R. App. P. 43(c)(2).
2     UPPER MISSOURI WATERKEEPER V. USEPA

UPPER MISSOURI WATERKEEPER,            No. 19-35899
                Plaintiff-Appellee,
                                          D.C. No.
                 v.                    4:16-cv-00052-
                                           BMM
U.S. ENVIRONMENTAL PROTECTION
AGENCY; MICHAEL REGAN,
Administrator, United States
Environmental Protection Agency,
                         Defendants,

NATIONAL ASSOCIATION OF CLEAN
WATER AGENCIES; THE MONTANA
LEAGUE OF CITIES AND TOWNS;
STATE OF MONTANA DEPARTMENT
OF ENVIRONMENTAL QUALITY,
            Intervenor-Defendants,

                and

TREASURE STATE RESOURCES
ASSOCIATION OF MONTANA,
   Intervenor-Defendant-Appellant.
      UPPER MISSOURI WATERKEEPER V. USEPA               3

UPPER MISSOURI WATERKEEPER,            No. 20-35135
                Plaintiff-Appellee,
                                          D.C. No.
                 v.                    4:16-cv-00052-
                                           BMM
U.S. ENVIRONMENTAL PROTECTION
AGENCY; MICHAEL REGAN,
Administrator, United States
Environmental Protection Agency,
                         Defendants,

NATIONAL ASSOCIATION OF CLEAN
WATER AGENCIES; THE MONTANA
LEAGUE OF CITIES AND TOWNS;
TREASURE STATE RESOURCES
ASSOCIATION OF MONTANA,
            Intervenor-Defendants,

                and

STATE OF MONTANA DEPARTMENT
OF ENVIRONMENTAL QUALITY,
    Intervenor-Defendant-Appellant.
4     UPPER MISSOURI WATERKEEPER V. USEPA

UPPER MISSOURI WATERKEEPER,           No. 20-35136
                Plaintiff-Appellee,
                                         D.C. No.
                v.                    4:16-cv-00052-
                                          BMM
U.S. ENVIRONMENTAL PROTECTION
AGENCY; MICHAEL REGAN,
Administrator, United States
Environmental Protection Agency,
             Defendants-Appellants,

               and

NATIONAL ASSOCIATION OF CLEAN
WATER AGENCIES; THE MONTANA
LEAGUE OF CITIES AND TOWNS;
TREASURE STATE RESOURCES
ASSOCIATION OF MONTANA; STATE
OF MONTANA DEPARTMENT OF
ENVIRONMENTAL QUALITY,
            Intervenor-Defendants.
      UPPER MISSOURI WATERKEEPER V. USEPA                 5

UPPER MISSOURI WATERKEEPER,              No. 20-35137
               Plaintiff-Appellant,
                                            D.C. No.
                v.                       4:16-cv-00052-
                                             BMM
U.S. ENVIRONMENTAL PROTECTION
AGENCY; MICHAEL REGAN,
Administrator, United States               OPINION
Environmental Protection Agency,
              Defendants-Appellees,

NATIONAL ASSOCIATION OF CLEAN
WATER AGENCIES; THE MONTANA
LEAGUE OF CITIES AND TOWNS;
TREASURE STATE RESOURCES
ASSOCIATION OF MONTANA; STATE
OF MONTANA DEPARTMENT OF
ENVIRONMENTAL QUALITY,
   Intervenor-Defendants-Appellees.

     Appeals from the United States District Court
              for the District of Montana
    Brian M. Morris, Chief District Judge, Presiding

         Argued and Submitted March 4, 2021
                  Portland, Oregon

                 Filed October 6, 2021
6          UPPER MISSOURI WATERKEEPER V. USEPA

         Before: Danny J. Boggs, ** Richard A. Paez, and
                 Paul J. Watford, Circuit Judges.

                   Opinion by Judge Watford

                          SUMMARY ***

                         Clean Water Act

    The panel reversed the portion of the district court’s
summary judgment order challenged in Nos. 19-35898, 19-
35899, 20-35135, and 20-35136, and affirmed the portion of
the summary judgment order challenged in No. 20-35137, in
actions challenging the U.S. Environmental Protection
Agency’s approval of Montana’s variance request from
approved water quality standards that were adopted under
the Clean Water Act.

    The Clean Water Act requires States to adopt water
quality standards regulating pollutants in their navigable
waters. The standards consist of two components: (1) the
designated uses for the water body, such as supporting
aquatic life or recreational use; and (2) the “water quality
criteria” necessary to protect those uses. 33 U.S.C.
§ 1313(c)(2)(A); 40 C.F.R. §§ 131.3(b), 131.11(a). States
submit proposed water quality standards to the EPA for
review and approval.

    **
       The Honorable Danny J. Boggs, United States Circuit Judge for
the U.S. Court of Appeals for the Sixth Circuit, sitting by designation.
    ***
        This summary constitutes no part of the opinion of the court. It
has been prepared by court staff for the convenience of the reader.
        UPPER MISSOURI WATERKEEPER V. USEPA                  7

    The EPA approved Montana’s water quality standards in
2015. In 2017, Montana sought, and obtained, EPA’s
approval of a variance in the water quality standard, which
covered 36 municipal wastewater treatment facilities for a
term of up to 17 years. The variance allowed those facilities
to discharge more nitrogen and phosphorus into wadeable
streams than would be permitted under the base water
standards approved in 2015. Plaintiff Upper Missouri
Waterkeeper contended that the EPA approval of the
variance violated the Administrative Procedure Act. The
district court granted partial vacatur of the EPA’s approval
of the variance, and stayed its decision pending resolution of
the appeals.

     First, the panel considered Waterkeeper’s cross-appeal,
which contended that a provision of the Clean Water Act,
33 U.S.C. § 1313(c)(2)(A), precluded the EPA from taking
compliance costs into account when approving the variance
requests. Applying Chevron analysis, the panel held at step
one, that Congress had not directly spoken to the precise
question at issue. Section 1313(c)(2)(A) does not speak at
all to whether the EPA may consider compliance costs when
approving a State’s proposed water quality standards or, by
extension, when approving a State’s variance request. At
step two, the panel held that the EPA reasonably construed
§ 1313(c)(2)(A) as permitting it to consider compliance costs
when approving water quality standards and variance
requests. The panel concluded that the EPA’s regulations
reasonably interpreted the Clean Water Act as allowing
consideration of compliance costs when the agency approves
water quality standards and variance requests.

   Next, the panel turned to the EPA’s appeal, which
challenged the district court’s partial vacatur of the agency’s
decision approving Montana’s variance request. The district
8       UPPER MISSOURI WATERKEEPER V. USEPA

court held that the variance’s term of up to 17 years was
invalid because it did not require compliance with the
highest attainable condition at the outset of the term, and did
not require compliance with Montana’s base quality water
standards by the end of the term. The panel disagreed, and
held that the EPA’s variance regulation unambiguously
provided that compliance with the highest attainable
condition was not required at the outset. The district court
did not identify any provision in the EPA’s variance
regulation supporting its view that the variance must require
compliance with the base water quality standards by the end
of the variance’s term. As reflected in the variance at issue
here, the EPA’s regulations included numerous features to
ensure that dischargers and waterbodies subject to variances
continued to improve water quality. The panel concluded
that the regulatory framework was consistent with the goals
of the Clean Water Act, which as reasonably construed by
the EPA, included supporting aquatic life and recreational
uses whenever attainable.

    The panel remanded to the district court with instructions
to deny Waterkeeper’s motion for summary judgment and to
grant the EPA’s and intervenor-defendants’ motion for
summary judgment in full.

                         COUNSEL

Janette K. Brimmer (argued), Earthjustice, Seattle,
Washington, for Plaintiff-Appellee/Cross-Appellant.

John L. Smeltzer (argued), David Gunter, and Alan D.
Greenberg, Attorneys; Eric Grant, Deputy Assistant
Attorney General; Jonathan D. Brightbill, Principal Deputy
Assistant Attorney General; Environment and Natural
        UPPER MISSOURI WATERKEEPER V. USEPA              9

Resources Division, United States Department of Justice,
Washington, D.C.; David Fatouhi, Peter Z. Ford, Heidi
Nalven, and Diane McConkey, Office of General Counsel,
United States Environmental Protection Agency; Erin
Perkins and Elyana Sutin, Office of Regional Counsel,
United States Environmental Protection Agency; for
Defendants-Appellants/Cross-Appellees United States
Environment Protection Agency and Michael Regan.

Kurt R. Moser (argued), Special Assistant Attorney General,
State of Montana Department of Environmental Quality,
Helena,     Montana,        for      Intervenor-Defendant-
Appellant/Cross-Appellee State of Montana Department of
Environmental Quality.

Fredric P. Andes and Ashley E. Parr, Barnes & Thornburg
LLP, Chicago, Illinois; Paul M. Drucker, Barnes &
Thornburg LLP, Indianapolis, Indiana; Catherine A.
Laughner, Chad E. Adams, and M. Christy S. McCann,
Browning Kaleczyc Berry & Hoven P.C., Bozeman,
Montana;     for   Intervenor-Defendant-Appellant/Cross-
Appellee National Association of Clean Water Agencies and
Montana League of Cities and Towns.

Mark L. Stermitz and Jeffery J. Oven, Crowley Fleck PLLP,
Billings,    Montana,       for      Intervenor-Defendant-
Appellant/Cross-Appellee Treasure State Resources
Association of Montana.
10      UPPER MISSOURI WATERKEEPER V. USEPA

                        OPINION

WATFORD, Circuit Judge:

    Congress enacted the Clean Water Act “to restore and
maintain the chemical, physical, and biological integrity of
the Nation’s waters.” 33 U.S.C. § 1251(a). In furtherance
of that objective, the Act requires States to adopt water
quality standards regulating pollutants in their navigable
waters. Water quality standards consist of two components:
(1) the “designated uses” for the water body in question,
such as supporting aquatic life or recreational use; and
(2) the “water quality criteria” necessary to protect those
uses, usually specified as the maximum concentration of a
pollutant that may be present in the water. § 1313(c)(2)(A);
40 C.F.R. §§ 131.3(b), 131.11(a). States must submit
proposed water quality standards to the Environmental
Protection Agency (EPA) for review and approval.
33 U.S.C. § 1313(c).       Once approved, water quality
standards are used to set effluent limits in the permits that
individual dischargers must obtain in order to discharge
pollutants from a point source into waters covered by the
Act. 40 C.F.R. § 122.44(d)(1); see 33 U.S.C. § 1342.

    In 2014, the State of Montana adopted water quality
standards governing two pollutants, nitrogen and
phosphorus, in its “wadeable streams.” Montana assigned
designated uses for wadeable streams that include the
support of aquatic life and recreation, and to protect those
uses it specified the maximum permissible concentrations of
nitrogen and phosphorus. The EPA approved Montana’s
water quality standards in 2015.

    Under regulations issued by the EPA, States may obtain
a variance from approved water quality standards (known as
the “base” water quality standards) if compliance with such
        UPPER MISSOURI WATERKEEPER V. USEPA                11

standards is shown to be infeasible. See 40 C.F.R. § 131.14.
A variance is a narrow, time-limited exemption from the
base water quality standards, applicable to specific
pollutants and to specific dischargers or a particular water
body. §§ 131.3(o), 131.14(a). The EPA may approve a
variance when the State demonstrates that compliance with
the base water quality standards is not feasible for one of
several specified reasons. §§ 131.14(b)(2)(i)(A), 131.10(g).
One of those reasons, and the reason relevant in this case, is
that implementing the pollution controls necessary to attain
compliance with the base water quality standards “would
result in substantial and widespread economic and social
impact.” § 131.10(g)(6).

    To be approved, a variance must set interim limits that,
although less stringent than those imposed by the base water
quality standards, nonetheless “represent the highest
attainable condition of the water body or waterbody segment
applicable throughout the term of the [water quality
standards] variance.” § 131.14(b)(1)(ii). The term of a
variance may last “only . . . as long as necessary to achieve
the highest attainable condition.” § 131.14(b)(1)(iv).

    In 2017, Montana sought EPA approval of the variance
at issue in this appeal, which covers 36 municipal
wastewater treatment facilities for a term of up to 17 years.
The variance allows those facilities to discharge more
nitrogen and phosphorus into wadeable streams than would
be permitted under the base water quality standards
approved in 2015. In support of the proposed variance,
Montana submitted evidence demonstrating that these
36 facilities could not attain compliance with the base water
quality standards unless they adopted reverse osmosis
technology, and that the high cost of adopting such
technology would result in substantial and widespread
12      UPPER MISSOURI WATERKEEPER V. USEPA

economic and       social   impact   on   the   surrounding
communities.

    After reviewing Montana’s evidence and conducting its
own analysis, the EPA approved the variance. The EPA
agreed with Montana’s assessment that (1) implementing
reverse osmosis technology would be necessary to attain
compliance with the base water quality standards, and (2) the
cost of implementing such technology would result in
substantial and widespread economic and social impact on
the communities served by the 36 municipal wastewater
treatment facilities. In reaching that conclusion, the EPA
relied on economic guidance that it had previously issued,
which provides that an average annual cost per household
exceeding 2% of median household income in the affected
community constitutes a substantial economic impact. The
EPA’s analysis confirmed that costs of that magnitude would
indeed be imposed on each of the affected communities. The
EPA also determined that the interim limits imposed by the
variance represented the highest attainable condition for all
36 facilities, and that the variance’s term of up to 17 years
would last only “as long as necessary to achieve the highest
attainable condition.” 40 C.F.R. § 131.14(b)(1)(iv), (2)(ii).

    In this action, plaintiff Upper Missouri Waterkeeper
(Waterkeeper) does not challenge any of the EPA’s factual
determinations. It instead contends that the EPA’s approval
of Montana’s variance request violates the Administrative
Procedure Act because it is “not in accordance with law.”
5 U.S.C. § 706(2)(A). Specifically, Waterkeeper argues that
the Clean Water Act prohibits the EPA from considering
compliance costs when granting variance requests.

   On cross-motions for summary judgment, the district
court rejected Waterkeeper’s argument.        The court
concluded that the EPA has reasonably construed the Clean
        UPPER MISSOURI WATERKEEPER V. USEPA                 13

Water Act as permitting it to grant variances based on the
economic impact that would be caused by requiring
compliance with the base water quality standards. The court
nevertheless held that the EPA’s approval of the variance’s
term of up to 17 years was arbitrary and capricious because
it does not require compliance with the highest attainable
condition at the beginning of the variance term and does not
require compliance with Montana’s base water quality
standards by the end of the term. The court granted partial
vacatur of the EPA’s approval of the variance and stayed its
decision pending resolution of these appeals.

    On appeal, Waterkeeper urges us to reverse the district
court’s rejection of its Administrative Procedure Act
challenge to the EPA’s approval decision, while the EPA and
the intervenor-defendants (the Montana Department of
Environmental Quality, Treasure State Resources
Association of Montana, Montana League of Cities and
Towns, and National Association of Clean Water Agencies)
urge us to reverse the district court’s partial vacatur of that
decision. We affirm in part, reverse in part, and remand with
instructions to enter judgment in favor of the EPA and the
intervenor-defendants.

                               I

    We take up Waterkeeper’s cross-appeal first. It contends
that the following provision of the Clean Water Act
precludes the EPA from taking compliance costs into
account when approving variance requests:

       Whenever the State revises or adopts a new
       standard, such revised or new standard shall
       be submitted to the Administrator. Such
       revised or new water quality standard shall
       consist of the designated uses of the
14      UPPER MISSOURI WATERKEEPER V. USEPA

       navigable waters involved and the water
       quality criteria for such waters based upon
       such uses. Such standards shall be such as to
       protect the public health or welfare, enhance
       the quality of water and serve the purposes of
       this chapter.     Such standards shall be
       established taking into consideration their use
       and value for public water supplies,
       propagation of fish and wildlife, recreational
       purposes, and agricultural, industrial, and
       other purposes, and also taking into
       consideration their use and value for
       navigation.

33 U.S.C. § 1313(c)(2)(A). This provision addresses the
establishment of water quality standards, not the granting of
variances, and thus appears at first blush to be of limited
relevance to Waterkeeper’s argument. Water quality
standards and variances, however, are closely linked in the
regulatory framework created by the EPA after the Clean
Water Act’s passage. A bit more background on that
framework is necessary before proceeding.

    The EPA has interpreted § 1313(c)(2)(A) as authorizing
States to consider compliance costs when they first adopt
water quality standards. In enforcing that provision’s
directive that water quality standards “serve the purposes of
this chapter,” the EPA has looked to the opening provision
of the Clean Water Act, § 101, codified at 33 U.S.C. § 1251,
to identify those purposes. Section 1251(a)(2) of the Act
declares that “it is the national goal that wherever attainable,
an interim goal of water quality which provides for the
protection and propagation of fish, shellfish, and wildlife and
provides for recreation in and on the water be achieved by
July 1, 1983.” 33 U.S.C. § 1251(a)(2) (emphasis added).
          UPPER MISSOURI WATERKEEPER V. USEPA                        15

Although the deadline set by this provision has passed, the
EPA has reasonably construed § 1251(a)(2) as an ongoing
expression of Congress’s intent that the stated goal be
achieved (albeit much later than hoped for) whenever the
specified uses are “attainable.” See 40 C.F.R. § 131.2.

    The EPA’s regulations require States to adopt water
quality standards that protect the uses described in
§ 1251(a)(2) unless the State can show through a “use
attainability analysis” that attaining the water quality
necessary to support those uses is not feasible for any one of
the several reasons referenced earlier. See 40 C.F.R.
§ 131.10(g), (j); Water Quality Standards Regulatory
Clarifications, 78 Fed. Reg. 54,518, 54,522–23 (Sept. 4,
2013). Thus, a State may adopt a water quality standard that
does not designate the uses described in § 1251(a)(2) if it can
show that implementing the pollution controls necessary to
protect those uses “would result in substantial and
widespread economic and social impact.” 40 C.F.R.
§ 131.10(g)(6). Economic impact, of course, involves
consideration of the costs that would be imposed on the
affected stakeholders. 1

    The EPA adopted its variance regulation by building on
this same framework. The agency recognized that States
could decline to designate a use in the first instance (or

     1
       The EPA’s regulations make clear that compliance costs may be
considered only when designating the uses to be protected by water
quality standards. Once those uses have been designated, States must
adopt water quality criteria adequate to protect those uses, “based on
sound scientific rationale.” 40 C.F.R. § 131.11(a)(1); see Mississippi
Commission on Natural Resources v. Costle, 625 F.2d 1269, 1277 (5th
Cir. 1980). A variance does not modify the water quality criteria alone.
A variance is instead a time-limited modification of both the “designated
use and criterion.” 40 C.F.R. § 131.3(o).
16      UPPER MISSOURI WATERKEEPER V. USEPA

remove a previously designated use) by conducting a use
attainability analysis and making the required showing that
attainment of such a use is not feasible. If approved, that
action would remove the designated use and associated
water quality criteria from the water quality standard as
applied to all dischargers and all pollutants.

    In light of this reality, the EPA concluded that variances
“are an environmentally preferable tool over a designated
use change because variances retain designated use
protection for all pollutants as they apply to all sources with
the exception of those specified in the variance.” 78 Fed.
Reg. at 54,531. The variance procedure thus affords States
a more targeted option when compliance with a water quality
standard is unattainable only for certain dischargers or only
with respect to certain pollutants. The variance regulation
requires States to make the same showing required by a use
attainability analysis, just one that is limited in scope to the
specific dischargers and pollutants covered by the variance.

    Waterkeeper recognizes this link between water quality
standards and variances.         Its contention under the
Administrative Procedure Act is that the provision quoted at
the outset, 33 U.S.C. § 1313(c)(2)(A), precludes the EPA
from taking compliance costs into account when approving
either water quality standards or variances. In assessing this
contention, we employ the two-step framework established
in Chevron U.S.A. Inc. v. Natural Resources Defense
Council, Inc., 467 U.S. 837 (1984).

     At step one, we ask whether “Congress has directly
spoken to the precise question at issue.” Id. at 842. The
answer here is no. Section 1313(c)(2)(A) does not speak at
all to whether the EPA may consider compliance costs when
approving a State’s proposed water quality standards or, by
extension, when approving a State’s variance request. The
        UPPER MISSOURI WATERKEEPER V. USEPA                  17

provision is silent on the precise question at issue, but if
anything, its reference to protecting the “public health or
welfare” favors the EPA’s interpretation. 33 U.S.C.
§ 1313(c)(2)(A) (emphasis added). The concept of the
public welfare is broad enough to encompass a regulatory
program’s impact on the economic welfare of a community,
and an assessment of that impact requires consideration of
costs.

    It is true, as Waterkeeper argues, that § 1313(c)(2)(A)
includes a list of uses and values that States must “tak[e] into
consideration” when establishing water quality standards,
without expressly mentioning the costs of compliance. But
the inference that Waterkeeper asks us to draw—that
Congress’s silence as to costs reflects an intention to forbid
their consideration—is not supported by the text of the
provision or the broader statutory context. Requiring States
to formulate water quality standards by “taking into
consideration” various uses and values does not tell us
anything about whether Congress intended to mandate
compliance with water quality standards regardless of how
exorbitant the cost might prove to be. And nothing in the
other provisions of the Clean Water Act suggests that
Congress’s silence as to costs in § 1313(c)(2)(A) should be
accorded special weight, as was true of the statutory
provision at issue in Whitman v. American Trucking
Associations, Inc., 531 U.S. 457 (2001), the principal case
on which Waterkeeper relies.

    In American Trucking, certain provisions of the Clean
Air Act “explicitly permitted or required economic costs to
be taken into account in implementing the air quality
standards,” whereas the provision under review in that case
did not, leading to the conclusion that Congress’s silence
was intended to foreclose consideration of costs. Id. at 467.
18      UPPER MISSOURI WATERKEEPER V. USEPA

The same cannot be said of the portion of the Clean Water
Act we are reviewing, which precludes us from drawing the
inference Waterkeeper urges about the supposed import of
Congress’s silence as to costs in § 1313(c)(2)(A). Rather, as
in Entergy Corp. v. Riverkeeper, Inc., 556 U.S. 208 (2009),
we think Congress’s silence as to costs in § 1313(c)(2)(A)
can be understood “to convey nothing more than a refusal to
tie the agency’s hands as to whether cost-benefit analysis
should be used, and if so to what degree.” Id. at 222
(interpreting § 316(b) of the Clean Water Act, codified at
33 U.S.C. § 1326(b)).

    Having concluded that the statute is silent or ambiguous
as to the precise question raised, we ask at step two of the
Chevron analysis whether “the agency’s answer is based on
a permissible construction of the statute.” Chevron,
467 U.S. at 843. For two reasons, both alluded to above, we
think the EPA has reasonably construed § 1313(c)(2)(A) as
permitting it to consider compliance costs when approving
water quality standards and variance requests.

    First, the provision states that water quality standards
shall protect the “public . . . welfare,” and that term can
reasonably be understood to encompass consideration of
whether compliance costs would cause substantial and
widespread economic and social impact. And second, the
EPA has reasonably construed § 1313(c)(2)(A)’s
requirement that water quality standards “serve the purposes
of this chapter” as incorporating the purposes referred to in
33 U.S.C. § 1251(a)(2). Congress declared in § 1251(a)(2)
that water quality necessary to protect aquatic life and
recreational use is to be achieved “wherever attainable.” The
statute does not define what factors may be taken into
account when deciding whether a particular use is
“attainable,” so it fell to the EPA to flesh out the meaning of
        UPPER MISSOURI WATERKEEPER V. USEPA                 19

that term. The agency could perhaps have interpreted the
term to focus solely on whether achieving water quality of a
particular level is technologically feasible, even if the costs
involved would prove financially ruinous to the
communities benefitting from the improvements. But it
seems far more plausible that Congress used the term in the
sense reflected in the EPA’s regulations—as including an
assessment of whether achieving the necessary water quality
is economically feasible, given the costs that would be
imposed on the affected communities.

    We thus conclude that the EPA’s regulations reasonably
interpret the Clean Water Act as allowing consideration of
compliance costs when the agency approves water quality
standards and variance requests.

                              II

    We turn now to the EPA’s appeal, which challenges the
district court’s partial vacatur of the agency’s decision
approving Montana’s variance request. The court held that
the variance’s term of up to 17 years is invalid because it
(1) does not require compliance with the highest attainable
condition at the outset of the term, and (2) does not require
compliance with Montana’s base water quality standards by
the end of the term. The district court believed these
requirements were imposed by the EPA’s own variance
regulation, but the plain language of the regulation
unambiguously provides otherwise. We therefore have no
need to decide whether the EPA’s interpretation of its
regulation is entitled to deference under Kisor v. Wilkie,
139 S. Ct. 2400 (2019).
20      UPPER MISSOURI WATERKEEPER V. USEPA

                               A

    In ruling that compliance with the highest attainable
condition must be achieved at the outset of a variance’s term,
the district court relied on the EPA’s definition of a variance.
The regulation defines the term “water quality standards
variance” as a “time-limited designated use and criterion for
a specific pollutant(s) or water quality parameter(s) that
reflect the highest attainable condition during the term of the
[water quality standards] variance.” 40 C.F.R. § 131.3(o)
(emphasis added). The court concluded that the phrase
“during the term” requires compliance with the highest
attainable condition at the beginning of the variance’s term.
On appeal, in defending the district court’s ruling,
Waterkeeper points to another provision of the regulation,
which states that the interim limits imposed by the variance
must represent “the highest attainable condition of the water
body or waterbody segment applicable throughout the term
of the [water quality standards] variance.” § 131.14(b)(1)(ii)
(emphasis added). Waterkeeper contends that the phrase
“throughout the term” has the same meaning as the phrase
“during the term” in § 131.3(o), and that both require
compliance with the highest attainable condition at the very
outset of the term.

    We do not think either phrase can fairly be read in the
manner that the district court and Waterkeeper suggest. To
be sure, both of the cited provisions provide that the highest
attainable condition specified in the variance shall apply
throughout (or during) the variance’s term, from the
beginning of the term to the end. But those provisions do
not state that an individual discharger must be in compliance
with the highest attainable condition on day one.

   Instead, the EPA’s variance regulation unambiguously
provides that compliance with the highest attainable
        UPPER MISSOURI WATERKEEPER V. USEPA                  21

condition is not required at the outset. A variance request
may be approved only when a State can show that
compliance with the base water quality standards cannot
feasibly be attained. § 131.14(b)(2)(i)(A). If approved, the
variance replaces the base water quality standard with the
most rigorous standard that can feasibly be attained—the
“highest attainable condition.” § 131.14(b)(1)(ii). The
regulation then provides that a variance may remain in effect
only “as long as necessary to achieve the highest attainable
condition.” § 131.14(b)(1)(iv) (emphasis added). That
provision makes clear that the purpose of a variance is to
provide the time needed to achieve this attainable interim
standard, which means, of course, that compliance with the
highest attainable condition is required by the end of the
variance’s term, not at the beginning.

                               B

    The district court did not identify any provision in the
EPA’s variance regulation supporting its view that a
variance must require compliance with the base water
quality standards by the end of the variance’s term. We have
found nothing in the regulation to support that view either.
As just noted, the regulation explicitly states that the term of
the variance may last only as long as necessary to achieve
compliance with the highest attainable condition—not with
the base water quality standards.                  40 C.F.R.
§ 131.14(b)(1)(iv). As this provision reflects, the purpose of
a variance is to make incremental progress toward
compliance with the base water quality standards, but the
ultimate goal by the end of the variance’s term is to achieve
compliance with the highest attainable condition. Indeed, if
compliance with the base water quality standards were
feasible within a reasonably foreseeable timeframe—say, by
the end of the variance’s term—there would be no basis for
22      UPPER MISSOURI WATERKEEPER V. USEPA

granting a variance in the first place. When attainment of
the base water quality standards is feasible within a
reasonably foreseeable timeframe, a State may instead use a
permit compliance schedule to set a specific deadline by
which compliance with the base water quality standards will
be achieved. § 122.47; see Water Quality Standards
Regulatory Revisions, 80 Fed. Reg. 51,020, 51,039–40
(Aug. 21, 2015).

     In defense of the district court’s ruling, Waterkeeper
contends that unless a variance requires compliance with the
base water quality standards by the end of the term, States
would be free to postpone compliance with the base
standards indefinitely simply by securing one variance after
another, in conflict with the goals of the Clean Water Act.
That contention reflects a misunderstanding of the nature
and purpose of a variance. A variance may be granted only
when compliance with the base water quality standards is not
feasible for one of the reasons specified in the EPA’s
regulations. To be approved, the variance must require
compliance with the highest attainable condition that is
feasible, and the variance may last only as long as necessary
to achieve compliance with the highest attainable condition.
If at the end of the variance’s term compliance with the base
water quality standards has become feasible, another
variance may not be granted. And, to obtain another
variance, the State must submit an application subject to the
same degree of EPA scrutiny and public participation as was
the application for the initial variance. In the interim, while
compliance with the base water quality standards remains
unattainable, the variance’s requirements ensure that
incremental progress toward attainment of the base
standards is being made.
        UPPER MISSOURI WATERKEEPER V. USEPA                  23

    The variance at issue here reflects these safeguards. In
accordance with the regulation, the variance states:
“Through the permitting process and the specific details of
each facility, the time required must be as short as possible
to meet the highest attainable condition.” This period may
be “up to 17 years,” but the period permitted for an
individual facility carefully tracks the steps the facility must
take to achieve compliance with the highest attainable
condition. If a facility reaches the highest attainable
condition but still cannot attain compliance with the base
water quality standards, the facility must implement a
“pollutant minimization program”—that is, “a structured set
of activities to improve processes and pollutant controls”—
as detailed in the variance. The variance is also subject to
close review every three years. Thus, as reflected in the
variance at issue here, the EPA’s regulations include
numerous features to ensure that dischargers and
waterbodies subject to variances continue to improve water
quality.

    The regulatory framework discussed above is fully
consistent with the goals of the Clean Water Act, which, as
reasonably construed by the EPA, include supporting
aquatic life and recreational uses “wherever attainable.”
33 U.S.C. § 1251(a)(2).

                       *       *       *

    We reverse the portion of the district court’s summary
judgment order challenged in Nos. 19-35898, 19-35899, 20-
35135, and 20-35136, and affirm the portion of the summary
judgment order challenged in No. 20-35137. We remand to
the district court with instructions to deny Waterkeeper’s
motion for summary judgment and to grant the EPA’s and
24       UPPER MISSOURI WATERKEEPER V. USEPA

intervenor-defendants’ motions for summary judgment in
full.

  AFFIRMED in part, REVERSED in part, and
REMANDED with instructions.

     The parties shall bear their own costs on appeal.