                 FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

FRIENDS OF PINTO CREEK; GRAND         
CANYON CHAPTER OF THE SIERRA
CLUB, MARICOPA AUDUBON
SOCIETY AND CITIZENS FOR THE
PRESERVATION OF POWERS
GULCH AND PINTO CREEK,
                       Petitioners,
CARLOTA COPPER COMPANY,
                                      
                                           No. 05-70785
                        Intervenor,
                                            OPINION
                v.
UNITED STATES ENVIRONMENTAL
PROTECTION AGENCY,
ENVIRONMENTAL APPEALS BOARD;
STEPHEN L. JOHNSON, Acting
Administrator, United States
Environmental Protection Agency,
                      Respondents.
                                      
         On Petition for Review of an Order of the
            Environmental Protection Agency

                Argued and Submitted
      November 13, 2006—San Francisco, California

                   Filed October 4, 2007

     Before: Procter Hug, Jr., A. Wallace Tashima, and
             Ronald M. Gould, Circuit Judges.

                  Opinion by Judge Hug


                           13505
13508         FRIENDS OF PINTO CREEK v. EPA


                      COUNSEL

Roger Flynn, Western Mining Action Project, Lyons, Colo-
rado, for the petitioners.
                FRIENDS OF PINTO CREEK v. EPA              13509
D. Judith Keith, United States Department of Justice, Envi-
ronmental Defense Section, Washington, DC; John S. Most,
United States Department of Justice, Natural Resources Sec-
tion, Washington, DC, for the respondents.

Amy R. Porter, Lewis and Roca LLP, Phoenix, Arizona, for
the intervenor.


                          OPINION

HUG, Circuit Judge:

   In this case, we determine whether the Environmental Pro-
tection Agency (“EPA”) properly issued a National Pollution
Discharge Elimination System (“NPDES”) permit under the
Clean Water Act to Carlota Copper Company (“Carlota”).
The permit allows mining-related discharges of copper into
Arizona’s Pinto Creek, a waterbody already in excess of water
quality standards for copper. Based upon provisions of the
Clean Water Act, the implementing regulations, and their
applicability to the factual scenario of this case, we vacate the
permit and remand.

I.   FACTUAL BACKGROUND

   Pinto Creek is a desert river located near Miami, Arizona,
approximately 60 miles east of Phoenix. It has been listed by
the American Rivers Organization as one of the country’s
most endangered rivers due to threats from proposed mining
operations. Pinto Creek and its riparian environs are home to
a variety of fish, birds, and other wildlife, some of which are
specially protected. Due to excessive copper contamination
from historical mining activities in the region, Pinto Creek is
included on Arizona’s list of impaired waters under § 303(d)
of the Clean Water Act, 33 U.S.C. § 1313(d), as a water qual-
ity limited stream due to non-attainment of water quality stan-
dards for dissolved copper.
13510            FRIENDS OF PINTO CREEK v. EPA
   Carlota proposed to construct and operate an open-pit cop-
per mine and processing facility approximately six miles west
of Miami, Arizona, covering over 3000 acres while extracting
about 100 million tons of ore. Part of the operation plan
includes constructing diversion channels for Pinto Creek to
route the stream around the mine, as well as groundwater cut-
off walls to block the flow of groundwater into the mine.

   In compliance with the National Environmental Policy Act
(“NEPA”), 42 U.S.C. §§ 4321 et seq., the U.S. Forest Service
prepared an Environmental Impact Statement (“EIS”), after
determining the project would potentially have a significant
impact on the environment, and later finalized the document
as its Final EIS (“Forest Service FEIS”). The Army Corps of
Engineers also prepared an Environmental Assessment
(“Corps EA”) covering the physical construction of proposed
diversion channels redirecting water from Pinto Creek and the
Powers Gulch stream around the mine and into Pinto Creek.
Because the proposed action would involve the discharge of
pollutants into Pinto Creek, Carlota applied to the EPA for an
NPDES permit under § 402 of the Clean Water Act, 33
U.S.C. § 1342, in 1996. The EPA ultimately issued the per-
mit, and the Environmental Appeals Board (“Appeals
Board”), the internal appellate board of the EPA, denied
review.

II.   ISSUES

      A.   Whether the issuance of the permit to discharge
           a pollutant, dissolved copper, into Pinto Creek,
           which already exceeded the amount of dis-
           solved copper allowed under the Section 303(d)
           Water Quality Standard, is in violation of the
           Clean Water Act and the applicable regulations.

      B.   Whether the EPA’s failure to include and regu-
           late all discharges from the Carlota Copper
                  FRIENDS OF PINTO CREEK v. EPA            13511
            Mine in the NPDES permit violates the Clean
            Water Act and the applicable regulations.

       C.   Whether the EPA complied with the require-
            ments of the National Environmental Policy Act
            (“NEPA”).

III.    PROCEDURAL BACKGROUND

   The EPA published for public comment a draft NPDES
permit for Carlota in 1998. To fulfill its information-gathering
requirements under NEPA, 42 U.S.C. §§ 4321-4370f, the
EPA adopted the Forest Service FEIS and the Corps EA. In
response to comments received on its draft NPDES permit,
the EPA amended the draft permit by adding two new
conditions—(1) requiring additional groundwater discharges
to augment the stream flow into Pinto Creek, and (2) an offset
provision whereby Carlota would be required to remediate
sources of copper loading from an upstream inactive mine site
called the Gibson Mine.

   On June 30, 2000, the Arizona Department of Environmen-
tal Quality (“Arizona DEQ”) certified the final permit with
the two new conditions as meeting state water quality stan-
dards under § 401 of the Clean Water Act, 33 U.S.C. § 1341,
and on July 24, 2000, the EPA issued an NPDES permit to
Carlota, as well as a Record of Decision formally adopting the
Forest Service FEIS and the Corps EA for the current permit.

   On August 24, 2000, the Petitioners filed their first Petition
for Review of the NPDES permit and the NEPA documents
with the Appeals Board. The Petitioners argued that: (1)
because Pinto Creek is an impaired water under the Clean
Water Act, the EPA should establish a Total Maximum Daily
Load (“TMDL”) for copper discharges into Pinto Creek
before issuing Carlota’s permit, (2) the EPA did not provide
public notice of and a public comment period for the two new
permit conditions, (3) Carlota needed an additional NPDES
13512           FRIENDS OF PINTO CREEK v. EPA
permit for discharges from the Gibson Mine site, and (4) the
Forest Service FEIS and Corps EA documents did not con-
sider environmental impacts of the two new permit condi-
tions.

   The EPA did not respond and, instead, withdrew portions
of the challenged NPDES permit stating that the permit was
not severable from the contested conditions and that the per-
mit should be stayed pending final agency action. The EPA
then prepared a supplemental environmental assessment
(“EPA’s supplemental EA”) analyzing only the two new con-
ditions. In response to the Petitioners’ contention of the neces-
sity to establish a TMDL, the EPA completed a TMDL for
dissolved copper in Pinto Creek. The EPA then provided a
public comment period, but only for the two new permit con-
ditions and the EPA’s supplemental EA. The Arizona Depart-
ment of Environmental Quality issued a second certification
under § 401 of the Clean Water Act in February 2002. In
accordance with its new analysis, the EPA issued a Finding
of No Significant Impact on February 27, 2002, determining
it would not have to prepare a new EIS, and issued the permit.

   On April 1, 2002, the Petitioners filed a second Petition for
Review with the Appeals Board challenging the EPA’s deci-
sion to issue the Carlota permit. The principal challenges were
that: (1) the permit should have covered the diversion chan-
nels that discharged into Pinto Creek, (2) the EPA must regu-
late all project discharges, (3) the permitted discharges
violated Arizona anti-degradation requirements and water
quality standards, and (4) the EPA violated NEPA in several
ways.

   The Appeals Board entered its order denying review on
September 30, 2004. The EPA issued the final NPDES permit
to Carlota, and the Petitioners filed for review in this court.
                  FRIENDS OF PINTO CREEK v. EPA            13513
IV.    ANALYSIS

  A.    Objective of the Clean Water Act.

   It is important to consider the objectives and purpose of the
1972 revisions of the Clean Water Act, which are presently
applicable to the considerations involved here. 33 U.S.C.
§ 1251 (1987) provides:

      The objective of this chapter is to restore and main-
      tain the chemical, physical, and biological integrity
      of the nation’s waters. In order to achieve this objec-
      tive it is hereby declared that, consistent with the
      provisions of this chapter — (1) it is the national
      goal that the discharge of pollutants into the naviga-
      ble waters be eliminated by 1985. . . . (3) it is the
      national policy that the discharge of toxic pollutants
      in toxic amounts be prohibited.

Under the 1972 revisions of the Clean Water Act, there is
direct federal regulation of the discharge of pollutants from
point sources. Pronsolino v. Nastri, 291 F.3d 1123, 1126 (9th
Cir. 2002). “[P]oint sources of pollution are those [where the
pollutant flows] from a discrete conveyance, such as a pipe or
tunnel. Nonpoint sources of pollution are non-discrete
sources” and are the responsibility of the states, with certain
federal oversight. Id. at 1125-27. An example of a non-
discrete source is runoff from a farmland or timber harvesting.

   Our Pronsolino opinion provides a detailed description of
the operation of the Clean Water Act. We here summarize the
provisions pertinent to this case.

   Under § 303 of the Clean Water Act, 33 U.S.C. § 1313, the
states are required to set water quality standards for all waters
within their boundaries, regardless of the sources of the pollu-
tion entering the waters. Pursuant to § 303(d)(1), 33 U.S.C.
§ 1313(d)(1), each state is required to identify those waters
13514           FRIENDS OF PINTO CREEK v. EPA
that do not meet the water quality standard which is fre-
quently called the “§ 303(d)(1) list.” For impaired waters
identified in the § 303(d)(1) list, the states must establish a
TMDL for pollutants identified by the EPA. A TMDL speci-
fies the maximum amount of pollutant that can be discharged
or loaded into the waters from all combined sources, so as to
comply with the water quality standards.

   Each state is required to submit its § 303(d)(1) list and its
TMDL to the EPA for its approval or disapproval. If the EPA
disapproves either of those documents, the EPA is responsible
for preparing that document. The state then incorporates its
§ 303(d)(1) list and its TMDL or the EPA’s approved docu-
ment into its continuing planning process as required by
§ 303(e), 33 U.S.C. §1313(e).

   In this case, the state had prepared the § 303(d)(1) list, but
it had not prepared a TMDL. Therefore, in response to the
Petitioners’ objection, the EPA prepared the TMDL utilized
in its awarding of the permit.

  B.    Carlota’s Discharge into an Impaired Waterway.

   [1] The Petitioners contend that as a “new discharger” Car-
lota’s discharge of dissolved copper into a waterway that is
already impaired by an excess of the copper pollutant violates
the intent and purpose of the Clean Water Act. Under the
NPDES permitting program, 40 C.F.R. § 122.4(i) addresses
the situation where a new source seeks to permit a discharge
of pollutants into a stream already exceeding its water quality
standards for that pollutant. Section 122.4 states in relevant
part:

    No permit may be issued:

    ....

    (i) To a new source or a new discharger if the dis-
    charge from its construction or operation will cause
                    FRIENDS OF PINTO CREEK v. EPA                     13515
      or contribute to the violation of water quality stan-
      dards. The owner or operator of a new source or new
      discharger proposing to discharge into a water seg-
      ment which does not meet applicable water quality
      standards or is not expected to meet those standards
      . . . and for which the State or interstate agency has
      performed a pollutants load allocation for the pollu-
      tant to be discharged, must demonstrate, before the
      close of the public comment period, that:

      (1) There are sufficient remaining pollutant load
      allocations to allow for the discharge; and

      (2) The existing dischargers into that segment are
      subject to compliance schedules designed to bring
      the segment into compliance with applicable water
      quality standards.

40 C.F.R. § 122.4 (2000).

   [2] The plain language of the first sentence of the regula-
tion is very clear that no permit may be issued to a new dis-
charger if the discharge will contribute to the violation of
water quality standards. This corresponds to the stated objec-
tives of 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) (1987). And that “it is the
national policy that the discharge of toxic pollutants in toxic
amounts be prohibited.” 33 U.S.C. § 1251(a)(3) (1987).

   The EPA contends that the partial remediation of the dis-
charge from the Gibson Mine will offset the pollution. How-
ever, there is nothing in the Clean Water Act or the regulation
that provides an exception for an offset when the waters
remain impaired and the new source is discharging pollution
into that impaired water.1
  1
   It is questionable whether there really is an offset. See discussion in the
next section.
13516           FRIENDS OF PINTO CREEK v. EPA
   The regulation does provide for an exception where a
TMDL has been performed and the owner or operator demon-
strates that before the close of the comment period two condi-
tions are met, which will assure that the impaired waters will
be brought into compliance with the applicable water quality
standards. The plain language of this exception to the prohib-
ited discharge by a new source provides that the exception
does not apply unless the new source can demonstrate that,
under the TMDL, the plan is designed to bring the waters into
compliance with applicable water quality standards.

   [3] The EPA argues that under the requirements of clause
(1), there are sufficient remaining load allocations to allow for
the discharge because the TMDL provides a method by which
the allocations could be established to allow for the discharge.
There is no contention, however, that these load allocations
represent the amount of pollution that is currently discharged
from the point sources and nonpoint sources, and there is no
indication of any plan that will effectuate these load alloca-
tions so as to bring Pinto Creek within the water quality stan-
dards. The TMDL merely provides for the manner in which
Pinto Creek could meet the water quality standards if all of
the load allocations in the TMDL were met, not that there are
sufficient remaining pollutant load allocations under existing
circumstances.

   With regard to the requirements of clause (2), the EPA
argues that the requirement of “compliance schedules” per-
tains only to point sources for which there is a permit. This
does not correspond to the plain language of clause (2), which
provides “the existing discharges into that segment [of Pinto
Creek] are subject to compliance schedules designed to bring
the segment into compliance with applicable water quality
standards.” 40 C.F.R. § 122.4(i)(2) (2000).

  [4] We examine that language utilizing the definitions pro-
vided in the regulation. The term “discharge” is defined to
mean “the discharge of a pollutant.” 40 C.F.R. § 122.2 (2000).
                FRIENDS OF PINTO CREEK v. EPA             13517
The term “discharge of a pollutant,” is defined as any addition
of any “pollutant” or combination of pollutants to “waters of
the United States” from “any point source.” Id. at § 122.2(a)
(emphasis added). Thus, under the plain language of the regu-
lation, compliance schedules are not confined only to “permit-
ted” point source discharges, but are applicable to “any” point
source.

   The EPA contends that this would amount to a complete
ban of the discharge of pollution to impaired waters. This is
based on its misreading of the plain language of the regulation
to state that the remediation has to be completed before Carlo-
ta’s discharge. The plain language of clause (2) of the regula-
tion, instead, provides that existing discharges into that
segment (of the waters) are “subject to compliance schedules
designed to bring the segment into compliance with applica-
ble water quality standards.” 40 C.F.R. § 122.4(i)(2) (2000)
(emphasis added). This is not a complete ban but a require-
ment of schedules to meet the objective of the Clean Water
Act.

   [5] Here the existing discharges from point sources are not
subject to compliance schedules designed to bring Pinto
Creek into compliance with water quality standards. Thus,
Carlota has not demonstrated that clause (2) of 40 C.F.R.
§ 122.4(i) has been met. This is the regulation upon which
Carlota and the EPA rely for issuance of the permit.

   Initially, Carlota and the EPA contended that the first and
second sentences of § 222.4(i) could be construed to apply
independently, thus not requiring compliance with clauses (1)
and (2) when an offset would result in a substantial net reduc-
tion of pollution to the impaired waters. The Petitioners, on
the other hand, maintained that the two sentences must be
read together, not independently. However, the EPA subse-
quently asked the Appeals Board to assume, for purposes of
this decision, that clauses (1) and (2) do apply. See In re Car-
lota Copper Co., 11 E.A.D. 692, 766 (EAB 2004). Thus, we
13518           FRIENDS OF PINTO CREEK v. EPA
are concerned in this case with whether the EPA required Car-
lota to fulfill all of the requirements of § 122.4(i), including
clauses (1) and (2), in order to issue a permit to it as a new
discharger.

   The Respondents and Carlota rely on Arkansas v. Okla-
homa, 503 U.S. 91 (1992) in support of their contentions.
That case involved the issuance of a permit for a city in
Arkansas to discharge effluent into a stream in Arkansas that
entered a river that eventually flowed into Oklahoma. Okla-
homa challenged the permit before the EPA, alleging that the
discharge violated Oklahoma Water Quality Standards. In that
case, the EPA found that the discharge would not lead to a
“detectable change in water quality,” which the Supreme
Court held was supported by substantial evidence. Arkansas,
503 U.S. at 112. In the opinion, the Court stated that “the par-
ties have pointed to nothing that mandates a complete ban on
discharges into a waterway that is in violation of those stan-
dards. The statute does, however, contain provisions designed
to remedy existing water quality violations and to allocate the
burden of reducing undesirable discharges between existing
sources and new sources. See, e.g. § 1313(d).” Id. at 108. Sec-
tion 1313(d) of the Clean Water Act, referred to by the Court,
is the one that provides for the establishment of water quality
standards and TMDLs.

   The Supreme Court in Arkansas v. Oklahoma also referred
to § 1288(b)(2), which provides for the development of area-
wide programs to eliminate existing pollution in the context
of area-wide waste treatment management. Id. That section
provides details required of any plan to eliminate the pollu-
tion, including schedules, time lines, identification of agen-
cies, and identification of measures necessary to carry out the
plan.

  The Appeals Board stated that prior Agency pronounce-
ments “confirm our position that, rather than completely ban-
ning new source discharges, § 122.4(i) provides new sources
                     FRIENDS OF PINTO CREEK v. EPA                    13519
with the opportunity to obtain a permit if the requirements
specified in that section are met.” In re Carlota Copper Co.,
11 E.A.D. 692, 765 (EAB 2004). The prior Agency position
quoted states:

       A new source or new discharger may, however,
       obtain a permit for discharge into a water segment
       which does not meet applicable water quality stan-
       dards by submitting information demonstrating that
       there is sufficient loading capacity remaining in
       waste load allocations (WLAs) for the stream seg-
       ment to accommodate the new discharge and that
       existing dischargers to that segment are subject to
       compliance schedules designed to bring the segment
       into compliance with the applicable water quality
       standards.

Id. (emphasis added). The language quoted by the Appeals
Board from the prior agency action requires compliance
schedules designed to bring the water segment into compli-
ance with the applicable water quality standards.

   [6] In Carlota’s case, there are no plans or compliance
schedules to bring the Pinto Creek segment “into compliance
with applicable water quality standards,” as required by
§ 122.4(i)(2), which Carlota and the EPA both acknowledge
is the applicable section with which Carlota must comply. The
error of both the EPA and Carlota is that the objective of that
section is not simply to show a lessening of pollution, but to
show how the water quality standard will be met if Carlota is
allowed to discharge pollutants into the impaired waters.2
  2
   The only step the EPA or Carlota has taken to meet the requirements
of § 122.4(i)(2) is the partial remediation of the Gibson Mine discharge.
The following statement illustrates the Appeals Board’s erroneous view of
the objective of § 122.4(i)(2):
      The goal of the proposal is not, as Petitioners and other com-
      menters seemed to believe, the restoration of the entirety of Pinto
      Creek to water quality standards. While desirable, this is not the
      intent of the proposed action.
In re Carlota Copper Co., 11 E.A.D. 692, 784 (EAB 2004).
13520            FRIENDS OF PINTO CREEK v. EPA
   [7] The EPA has the responsibility to regulate discharges
from point sources and the states have the responsibility to
limit pollution coming into the waters from non-point sources.
If point sources, other than the permitted point source, are
necessary to be scheduled in order to achieve the water qual-
ity standard, then the EPA must locate any such point sources
and establish compliance schedules to meet the water quality
standard before issuing a permit. If there are not adequate
point sources to do so, then a permit cannot be issued unless
the state or Carlota agrees to establish a schedule to limit pol-
lution from a nonpoint source or sources sufficient to achieve
water quality standards.

   The EPA contends that it cannot be judicially compelled to
act against point sources that are illegally discharging into
Pinto Creek. The EPA notes that while it has the authority to
act against violators, its decision to do so in ordering its prior-
ities is a matter that is typically committed to its absolute dis-
cretion, citing Sierra Club v. Whitman, 268 F.3d 898, 903 (9th
Cir. 2001) and Heckler v. Chaney, 470 U.S. 821, 831-32
(1985).

   In Carlota’s case, there is nothing in § 122.4(i) that compels
the EPA to act against point sources that are violating the
Clean Water Act by their discharges into Pinto Creek or
requiring judicial review of the EPA’s ordering of priorities
in any failure to act. The requirement of § 122.4(i)(2) is sim-
ply a condition that must be met before a permit can be issued
to a new discharger into impaired waters. There is no compul-
sion on the EPA to act against point source violators, as in
Sierra Club or Heckler. The EPA remains free to establish its
priorities; it just cannot issue a permit to a new discharger
until it has complied with § 122.4(i)(2).

   In this case, the Petitioners do not argue for an absolute ban
on discharges into a waterway that is in violation of the water
quality standards. Rather, the Petitioners point to the
§ 122.4(i) exception by which a new discharger can comply
                FRIENDS OF PINTO CREEK v. EPA            13521
with the Clean Water Act requirements. Those requirements
simply were not met. Thus, no conflict exists with the
Supreme Court’s opinion in Arkansas v. Oklahoma.

  C.   Pollution From the Diversion Channels.

   Carlota proposed to construct two diversion channels that
would divert surface and groundwater around the mine facili-
ties. The Pinto Creek diversion channel would extend approx-
imately 5250 feet and then into Pinto Creek. The Powers
Gulch stream diversion channel would extend approximately
7900 feet into the Powers Gulch stream, which eventually
connects to Pinto Creek. Both channels will eventually add
pollutants, including copper, into Pinto Creek especially from
the groundwater that Carlota will be directing into the chan-
nels for discharge into Pinto Creek.

   In order to block groundwater from entering the main Car-
lota Mine pit, Carlota will construct a cutoff wall down to
bedrock that will divert the groundwater to the surface and
into the Pinto Creek diversion channel. The Forest Service
FEIS stated: “The cutoff wall would be an impermeable bar-
rier extending from the surface down through the alluvium
and into the bedrock. The cutoff wall would be designed to
prevent water from moving toward the pit and would encour-
age the alluvial flow to surface into the diversion channel to
be routed around the pit.” Fed. Envtl. Impact Statement for
Carlota Copper Project, Vol. 1, Ch. 2, p. 16 (1997). The For-
est Service FEIS also noted that the alluvial groundwater that
will enter the diversion channel contains dozens of pollutants,
including copper, that will be added to Pinto Creek. Accord-
ing to the Forest Service FEIS, the amount of dissolved cop-
per in this groundwater would be significant. In addition to
the groundwater directed into Pinto Creek via the Pinto Creek
diversion channel, a similar cutoff wall is proposed to direct
groundwater into the Powers Gulch stream diversion channel
and ultimately into Pinto Creek. Like the groundwater added
to the Pinto Creek via the Pinto Creek diversion channel, the
13522           FRIENDS OF PINTO CREEK v. EPA
groundwater added to the Powers Gulch stream contains ele-
vated levels of copper and other pollutants. The EPA did not
consider the copper contributions from the use of the pro-
posed diversion channels and groundwater cutoffs. The
Appeals Board refused to consider these additional sources of
copper pollution because it was not raised in the first com-
ment period for the permit.

   In the Petitioners’ first Petition for Review of the NPDES
permit and the NEPA documents before the Appeals Board,
the Petitioners contended, among other things, that the EPA
had not allowed a comment period on the two new conditions
added to the permit and that the EPA should establish a
TMDL for copper discharges into Pinto Creek before issuing
Carlota’s permit. The EPA did not respond and, instead, with-
drew portions of the challenged NPDES permit stating that
the permit was not severable from the contested conditions
and that the permit should be stayed until pending final
agency action.

   [9] After establishing a TMDL for copper in Pinto Creek,
Carlota then pursued a renewal of the permit based upon 40
C.F.R. § 122.4(i). Carlota has conceded that for the purpose
of this decision § 122.4(i), including clauses (1) and (2), is
applicable. Carlota was thus proceeding on the basis that a
TMDL had been issued and that it was required to comply
with clauses (1) and (2). Section 122.4(i) requires that a new
discharger into impaired waters for which a pollutant’s load
allocation for the pollutant to be discharged “must demon-
strate, before the close of the comment period,” the compli-
ance with clauses (1) and (2). 40 C.F.R. § 122.4(i) (2000)
(emphasis added). The comment period referred to could not
have been the initial comment period before a TMDL was
sought or established. The comment period had to relate to the
new basis for Carlota’s permit under § 122.4(i).

  [10] All of the claims that the Petitioners now rely upon
were raised during the comment period after the TMDL was
                FRIENDS OF PINTO CREEK v. EPA              13523
performed. They could not have been raised in the first com-
ment period. These claims were made known to the EPA not
only in the second comment period but also at the time of the
preparation of the TMDL by a letter that raised the point, a
copy of which was furnished directly to the EPA. Thus, the
claim with regard to the copper discharge from the diversion
channels and the cutoff walls was timely raised and should
not have been deemed forfeited, but it should have been con-
sidered by the Appeals Board. This would be important in
determining whether the requirement for compliance sched-
ules set out in § 122.4(i)(2) had been met and also it would
be important in determining the extent of the pollutants con-
tributed by Carlota that would be offset by the Gibson Mine
remediation.

  D.   The State of Arizona’s Requirements.

   In addition to violating 40 C.F.R. § 122.4(i), the Petitioners
contend that the permit also violates the provisions of 40
C.F.R. § 122.4(d), which provides that no permit may be
issued “[w]hen the imposition of conditions cannot ensure
compliance with the applicable water quality requirements of
all affected States.” 40 C.F.R. § 122.4(d) (2000). This must be
considered in connection with § 122.4(a), which states that no
permit may be issued “when the conditions of the permit do
not provide for compliance with the applicable requirements
of the Clean Water Act or regulations promulgated under the
Clean Water Act.” Id. at § 122.4(a). Thus, the requirements of
§ 122.4(d) are in addition to complying with all of the require-
ments of the Clean Water Act and the regulations promul-
gated under the Clean Water Act.

   [11] Since we here hold that the permit does not comply
with § 122.4(i), the additional requirement of § 122.4(d) need
not be considered at this time. It would be appropriate to con-
sider the requirements of § 122.4(d) if a permit is properly
issued under § 122.4(i).
13524           FRIENDS OF PINTO CREEK v. EPA
  E.    Compliance With the Requirements of NEPA.

   NEPA requires agencies to examine potential environmen-
tal effects of any proposed action, and to inform the public of
its studies and resulting concerns. If any agency determines
that its action may have a significant impact on the environ-
ment, the agency is required to prepare an EIS describing the
impacts of the action and possible alternatives. 42 U.S.C.
§ 4332(2)(C) (1975). To determine if the action will require
an EIS, the agency may first prepare an environmental assess-
ment (“EA”). 40 C.F.R. § 1508.9 (1998). If the EA indicates
that there will not be a significant impact on the environment,
the agency may issue a Finding of No Significant Impact, in
which case an EIS is not required. 40 C.F.R. § 1508.13
(1998).

   [12] In the first appellate review before the Appeals Board,
the Petitioners challenged the EPA’s failure to allow com-
ments on the two new permit conditions and also the failure
to conduct a TMDL prior to issuing the permit. The supple-
mental EA issued by the EPA addressed only the environmen-
tal effect of the two new conditions, not the effect of a permit
issued to a new discharger under § 122.4(i), including clauses
(1) and (2). There is nothing wrong with incorporating and
relying upon the Forest Service FEIS because it had discussed
the effect on waters by the proposed Carlota Mine. However,
the EA produced by the EPA should have discussed the
revised permit issued under § 122.4(i), including clauses (1)
and (2).

   [13] The Petitioners argued that the EPA failed to take a
“hard look” at its failure to consider the discharges from the
two diversion channels, including the walls to be established
to prevent groundwater from reaching the mine facilities,
which would contribute alluvial water, including copper pol-
lution, to Pinto Creek. The Appeals Board refused to consider
this argument because it contended that it had not been raised
during the first comment period. As we have previously
                FRIENDS OF PINTO CREEK v. EPA            13525
explained, it was not possible to comment upon the request
for a permit based upon the TMDL and the requirements of
§ 122.4(i) until after the TMDL had been issued. Thus, for the
reasons we expressed in the prior section, it was error for the
Appeals Board not to consider additional discharges from the
diversion channels.

   [14] The Petitioners also raised other questions concerning
the compliance with NEPA, such as reasonable alternatives to
the proposed action. Because we have held that the permit
was improperly issued under the provisions of § 122.4(i),
including clauses (1) and (2), these NEPA issues need not be
considered at this time.

V.    CONCLUSION

   Because the issuance of the NPDES Permit to Carlota Cop-
per Mine was based on errors of law under the Clean Water
Act, 40 C.F.R. § 122.4(i), and the NEPA, we vacate and
remand the permit to the EPA for further proceedings consis-
tent with this opinion.

     VACATED and REMANDED.
