211 F.3d 1280 (D.C. Cir. 2000)
Arizona Public Service Company, Petitionerv.Environmental Protection Agency, RespondentState of Michigan, et al., Intervenors
Nos. 98-1196, 98-1203, 98-1206, 98-1207, 98-1208
United States Court of AppealsFOR THE DISTRICT OF COLUMBIA CIRCUIT
Argued January 27, 2000Decided May 5, 2000

[Copyrighted Material Omitted][Copyrighted Material Omitted]
On Petitions for Review of an Order of the Environmental Protection Agency
Thomas Sayre Llewellyn argued the cause for petitioner  Arizona Public Service Company.  With him on the briefs  were Michael B. Wood and George Y. Sugiyama.
Henry V. Nickel argued the cause for petitioners National  Association of Manufacturers, et al. and Intervenors State of  Michigan and Central and South West Services, Inc.  With  him on the briefs were David S. Harlow, John B. Weldon,  Jr., Brian J. Renaud, Jennifer M. Granholm, Attorney General for the State of Michigan, and John Fordell Leone,  Assistant Attorney General for the State of Michigan.  Norman W. Fichthorn, Cynthia H. Evans, Roy S. Belden, Janice  S. Amundson, Donald D. Skypeck, Harold P. Quinn, Jr., and  Thomas L. Casey, Solicitor General for the State of Michigan,  entered appearances.
Thomas A. Lorenzen and Cynthia A. Drew, Attorneys,  United States Department of Justice, argued the cause for  respondent.  With them on the briefs were Lois Schiffer,  Assistant Attorney General, Anthony F. Guadagno and Michael W. Thrift, Attorneys, United States Environmental  Protection Agency.
Jill E. Grant argued the cause for intervenors Gila River  Indian Community, et al.  With her on the brief were William W. Quinn and Jeanette Wolfley.  Reid P. Chambers  entered appearances.
Before:  Edwards, Chief Judge, Ginsburg and Rogers, Circuit Judges.
Opinion for the Court filed by Chief Judge Edwards.
Opinion concurring in part and dissenting from Part II.A.  filed by Circuit Judge Ginsburg.
Edwards, Chief Judge:


1
In 1990, Congress passed a compendium of amendments to the Clean Air Act ("CAA" or "the  Act").  This case concerns those amendments that specifically  address the power of Native American nations (or "tribes") to  implement air quality regulations under the Act.  Petitioners  challenge the Environmental Protection Agency's ("EPA" or  "the Agency") regulations, promulgated in 1998, implementing the 1990 Amendments.  See Indian Tribes:  Air Quality  Planning and Management, 63 Fed. Reg. 7254 (1998) (to be  codified at 40 C.F.R. pts. 9, 35, 49, 50, and 81) ("Tribal  Authority Rule").  Petitioners' principal contention is that  EPA has granted too much authority to tribes.


2
Petitioners' primary challenges focus on two issues.  The  first is whether Congress expressly delegated to Native  American nations authority to regulate air quality on all land  within reservations, including fee land held by private landowners who are not tribe members.  The second is whetherEPA has properly construed "reservation" to include trust  lands and Pueblos.


3
Petitioners also raise several other challenges to the Tribal  Authority Rule.  They argue:  (1) that EPA violated the Act  in authorizing tribes to administer programs affecting nonreservation "allotted lands" and "dependent Indian communities";  (2) that EPA unlawfully declined to accept public  comments on applications to regulate by Native American  nations;  (3) that EPA improperly held that the 1990 Amendments abrogated preexisting contracts under which tribes  agreed not to regulate certain privately-held land;  and (4)  that EPA improperly interpreted the 1990 Amendments to  exempt Native American nations from certain of the Act's  judicial review requirements.


4
We find petitioners' challenges to be mostly meritless.  We  hold that the Agency did not err in finding delegated authority to Native American nations to regulate all land within  reservations, including fee land owned by nonmembers.  We  also uphold EPA's construction of "reservation" to include  trust lands and Pueblos.  Likewise, we reject the challenge to  the Agency's decision to exempt Native American nations  from some of the Act's judicial review requirements.  Petitioners' complaint regarding the adequacy of public comment  on tribal applications is moot.  And petitioners' claim that  EPA has abrogated preexisting agreements not to regulate is  unripe for review, as is one of petitioners' arguments challenging the Agency's decision on the Act's judicial review  requirements.

I. BACKGROUND
A. Statutory Background

5
The Act establishes a framework for a federal-state partnership to regulate air quality.  The provisions of the 1990  Amendments under review, fairly read, constitute an attempt  by Congress to increase the role of Native American nations  in this partnership.  There are three areas of regulation  under the Act particularly relevant to this case.


6
First, the Act grants states primary responsibility for  assuring that air quality meets national standards.  See 42  U.S.C. S 7407(a) (1994).  States meet this burden by submitting state implementation plans ("SIPs") that "provide[ ] for  implementation, maintenance, and enforcement" of these  standards.  Id. S 7410(a)(1) (1994).  SIPs must be approved  by the Agency before they may be federally enforced.  In  1990, S 7410 was amended to authorize Native American nations to submit tribal implementation plans ("TIPs") "applicable to all areas ...  located within the exterior boundaries  of the reservation."  Id. S 7410(o).


7
Second, the Act permits states and Native American nations to "redesignate" lands pursuant to the Act's Prevention  of Significant Deterioration ("PSD") program.  See id. S 7474(a), (c) (1994).  Under the PSD program, land is classified as Class I, II, or III.  The land's classification determines the maximum allowable increase over the baseline by  which concentrations of sulfur dioxide and other particulate  matter shall not be exceeded.  See id. S 7473 (1994).  Land  may, under certain circumstances, be redesignated as Class I,  II, or III.  See id. S 7474(a).  Since 1977, Native American  nations have had authority to redesignate land "within the  exterior boundaries of reservations."  Id. S 7474(c).


8
Finally, under Title V of the Act, states must develop a  comprehensive permitting program applicable to major air  pollution sources.  See id. S 7661a (1994).  The Agency must  approve the permitting program;  if none is approved, EPA  must promulgate a permitting program that will be federally  enforceable.  See id. S 7661a(d)(3).  One of the requirements for approval is that the program provide for judicial review of  permitting actions.  See id. S 7661a(b)(6), (7).  Petitioners  claim that the Agency has improperly interpreted the 1990  Amendments to giveNative American nations the possibility  of exemption from some portions of the judicial review requirements.


9
Importantly, the 1990 Amendments added language to the  Act granting EPA the "author[ity] to treat Indian tribes as  States under this chapter," id. S 7601(d)(1)(A) (1994), provided tribes meet the following requirements:


10
(A) the Indian tribe has a governing body carrying out substantial governmental duties and powers;


11
(B) the functions to be exercised by the Indian tribe pertain to the management and protection of air re-sources within the exterior boundaries of the reservation or other areas within the tribe's jurisdiction;  and


12
(C) the Indian tribe is reasonably expected to be capable, in the judgment of the Administrator, of carrying out the functions to be exercised in a manner consistent with the terms and purposes of this chapter and all applicable regulations.


13
Id. S 7601(d)(2).


14
The 1990 Amendments also directed EPA to promulgate  regulations "specifying those provisions of this chapter for  which it is appropriate to treat Indian tribes as States."  Id.  If the Agency "determines that the treatment of Indian tribes  as identical to States is inappropriate or administratively  infeasible," EPA may announce other ways for the Agency to  administer the program "so as to achieve the appropriate  purpose."  Id. S 7601(d)(4).

B. The Challenged Rule

15
On August 25, 1994, EPA proposed rules to implement the  1990 Amendments.  See Proposed Tribal Authority Rule, 59  Fed. Reg. 43,956 (1994) (proposed Aug. 25, 1994).  On February 12, 1998, after receiving and responding to public comments, EPA issued the final Tribal Authority Rule.  See Tribal Authority Rule, 63 Fed. Reg. at 7254.  The Agency  first found that the 1990 Amendments constitute a delegation  of federal authority to regulate air quality to Native American  nations within the boundaries of reservations, regardless of  whether the land is owned by the tribes.  See id.  The  Agency read the statute to support this "territorial view of  tribal jurisdiction," authorizing a "tribal role for all air resources within the exterior boundaries of Indian reservations  without distinguishing among various categories of on reservation land."  Id.  EPA believed that this "territorial  approach ... best advances rational, sound, air quality management."  Id. at 7255.  Thus, the Agency determined that  Congress delegated to tribes the authority to regulate air  quality in areas within the exterior boundaries of a reservation.


16
The Act does not define "reservation" for the purposes of  tribal regulation.  EPA interpreted "reservation" to include  "trust lands that have been validly set apart for the use of a  tribe even though the land has not been formally designated  as a reservation."  Id. at 7258.  The Agency explained that  this interpretation was consistent with the Supreme Court's  definition of "reservation" in Oklahoma Tax Commission v.  Citizen Band Potawatomi Indian Tribe of Oklahoma, 498  U.S. 505 (1991).  EPA held that it would decide on a case-bycase basis whether other types of land may be considered  "reservations" under the Act.  See Tribal Authority Rule, 63  Fed. Reg. at 7258.


17
For areas not within a "reservation," the Agency determined that a tribe would be allowed to regulate such areas if  the tribe could demonstrate inherent jurisdiction over the  particular non-reservation area under general principles of  federal Indian law.  See id. at 7259.  This means that tribes  may propose air quality regulations in "allotted land" and  "dependent Indian communities" provided they can otherwise  demonstrate inherent jurisdiction over these areas.  Allotted land is land "owned by individual Indians and either held in  trust by the United States or subject to a statutory restriction on alienation."Felix S. Cohen, Handbook of Federal  Indian Law 40 (1982).  Dependent Indian communities include "those tribal Indian communities under federal protection that did not originate in either a federal or tribal act of  'reserving,' or were not specifically designated a reservation."  Id. at 38.


18
Some commenters claimed that the Act precludes tribal  regulation in the form of TIPs in non-reservation areas. These parties argued that the section of the Act authorizing  TIPs includes a specific provision limiting such regulation  within reservations lands.  See 42 U.S.C. S 7410(o) (providing  that TIPs "shall become applicable to all areas ... located  within the exterior boundaries of the reservation").  EPA,  however, interpreted "reservation" in § 7410(o) to be "simply  a description of the type of area over which a TIP may  apply," and ruled that "the provision was [not] intended to  limit the scope of TIPs to reservations."  Tribal Authority  Rule, 63 Fed. Reg. at 7259.  EPA's ruling was informed by S 7601(d)(1) under which the Agency "decided to include  most of the provisions of [§ 7410] in the group of provisions  for which treatment of tribes in the same manner as a state is  appropriate."  Id.


19
The final aspect of the Tribal Authority Rule under review  relates to the provisions covering judicial review of permitting  programs.  Title V of the Act authorizes regulating authorities to establish permitting programs for pollution sources. Section 7661a(b)(6) requires the authority to afford "an opportunity for judicial review in State court of the final permit  action."  42 U.S.C. S 7661a(b)(6).  In its proposed rule, EPA  indicated an intention to treat tribes like states with respect  to judicial review.  See Proposed Tribal Authority Rule, 59  Fed. Reg. at 43,972.  In its final rule, EPA withdrew this  proposal, requiring instead that, for Title V programs, tribes  must meet all of the requirements of § 7661a(b)(6) and (7)  "except those provisions that specify that review of final  action under the Title V permitting program be 'judicial' and  'in State court.' "  Tribal Authority Rule, 63 Fed. Reg. at  7261.  EPA adopted this provision in response to concerns  over tribal sovereign immunity.  See id.  Thus, EPA indicated its willingness "to consider alternative options, developed  and proposed by a tribe in the context of a tribal CAA Title V program submittal, that would not require tribes to waive  their sovereign immunity to judicial review but, at the same  time, would provide for an avenue for appeal of tribal government action or inaction to an independent review body and  for injunctive-type relief to which the Tribe would agree to be  bound."  Id. at 7262.


20
Petitioner Arizona Public Service Company ("APS") filed a  petition for review on April 10, 1998.  The remaining petitions  for review were filed shortly thereafter;  the petitions were  subsequently consolidated for consideration by this court.

II. ANALYSIS

21
Petitioners raise several challenges to EPA's final rule. First, petitioners claim that the 1990 Amendments cannot be  interpreted to constitute an express delegation of authority to  Native American nations to regulate privately owned fee land  located within a reservation.  Second, petitioners argue that  EPA impermissibly interpreted the word "reservation" to  include lands held in trust and Pueblos.  Third, petitioners  contend that EPA impermissibly interpreted the Act to permit Native American nations to issue TIPs and redesignations  for land outside the boundaries of a reservation.  Fourth, petitioners assert that EPA has failed to allow public comment on tribal applications to issue regulations under the Act.  Fifth, petitioners argue that EPA's interpretation of the 1990 Amendments effectively abrogates preexisting agreements  between tribes and regulated industry.  Finally, petitioners  contend that EPA's final rule covering judicial review procedures for Title V programs was promulgated with insufficientnotice to affected parties and that it rests on an impermissible  interpretation of the Act.


22
We analyze EPA's interpretation of the Act under familiar  principles.  "Where congressional intent is ambiguous, ... an  agency's interpretation of a statute entrusted to its administration is entitled to deference, so long as it is reasonable."  Shell Oil Co. v. EPA, 950 F.2d 741, 747 (D.C. Cir. 1992) (per  curiam) (citing Chevron U.S.A. Inc. v. Natural Resources  Defense Council, Inc., 467 U.S. 837, 842-43 (1984)).  Our primary concern under Chevron is to ensure that an agency  acts within the bounds of congressional delegation.  "[A]s  long as the agency stays within [Congress'] delegation, it is  free to make policy choices in interpreting the statute, and  such interpretations are entitled to deference."  Arent v.  Shalala, 70 F.3d 610, 615 (D.C. Cir. 1995).


23
In evaluating the extent of congressional delegation, a  reviewing court first exhausts the traditional tools of statutory construction to determine whether a congressional act  admits of plain meaning.  See Bell Atlantic Tel. Cos. v. FCC, 131 F.3d 1044, 1047 (D.C. Cir. 1997).  If, in light of its text,  legislative history, structure, and purpose, a statute is found  to be plain in its meaning, "then Congress has expressed its  intention as to the question, and deference is not appropriate."  Id.  If congressional intent is ambiguous, then we move  to the second step of the Chevron analysis, and uphold an  agency's interpretation if it is reasonable.  The reasonableness prong includes an inquiry into whether the agency  reasonably filled a gap in the statute left by Congress.  See  United Techs. Corp. v. EPA, 821 F.2d 714, 723 (D.C. Cir.  1987) (upholding filling of gap that is rational and "not  inconsistent" with amendments to the Resource Conservation  and Recovery Act of 1976).


24
A. Express Delegation of Authority to Native American Nations


25
It is undisputed that Native American nations retain significant sovereign power.  Native American nations have inherent power to determine forms of tribal government, to determine tribal membership, to make substantive criminal and civil laws governing internal matters, to administer tribal  judicial systems, to exclude others from tribal lands, and, to  some extent, to exercise civil jurisdiction over nonmembers,  including non-Indians.  See Cohen, Handbook of Federal  Indian Law, at 247-53;  Montana v. United States, 450 U.S.  544, 564 (1981).  It is this last category of power that is at  issue in the instant case, because petitioners claim that the  1990 Amendments to the Act do not authorize tribes to administer the Act over fee land within a reservation that is  owned by nonmembers.  As the Supreme Court has held,


26
exercise of tribal power beyond what is necessary to protect tribal self-government or to control internal relations is inconsistent with the dependent status of the tribes, and so cannot survive without express congressional delegation.


27
Montana, 450 U.S. at 564.


28
There is no doubt that tribes hold "inherent sovereign  power to exercise some forms of civil jurisdiction over non-Indians on their reservations, even on non-Indian fee lands." Id. at 565.  For instance, if the behavior of non-Indians on fee  lands within the reservation "threatens or has some direct  effect on the political integrity, the economic security, or the  health or welfare of the tribe," the tribe may regulate that  activity.  Id. at 566.  To satisfy this standard, however, a  tribe must show, on a case-by-case basis, that the disputed  activity constitutes a "demonstrably serious" impact that "imperil[s] the political integrity, the economic security, or the  health and welfare of the tribe."  Brendale v. Confederated  Tribes and Bands of theYakima Indian Nation, 492 U.S.  408, 431 (1989) (plurality opinion).  EPA suggests, not implausibly, that "inherent sovereign power" may apply to tribal  regulation under the Act of fee lands within a reservation, see  Proposed Tribal Authority Rule, 59 Fed. Reg. at 43,598 n.5,  but the Agency does not press this argument on appeal. Rather, EPA contends that the 1990 Amendments constitute  an express congressional delegation to the tribes of the  authority to regulate air quality on fee lands located within  the exterior boundaries of a reservation.


29
"There are few examples of congressional delegation of  authority to tribes."  Cohen, Handbook of Federal Indian  Law, at 253.  However, as is the case in any situation in  which we are called upon to find congressional intent in  construing a contested statute, we start with traditional  sources of statutory interpretation, including the statute's  text, structure, purpose, and legislative history.  See, e.g.,  Block v. Community Nutrition Inst., 467 U.S. 340, 345 (1984)  ("Whether and to what extent a particular statute precludes judicial review is determined not only from its express language, but also from the structure of the statutory scheme,  its objectives, its legislative history, and the nature of the  administrative action involved.").  Our review of the CAA  indicates that EPA's interpretation comports with congressional intent.


30
Section 7601(d), in pertinent part, authorizes EPA to treat  otherwise eligible tribes as states if "the functions to be  exercised by the Indian tribe pertain to the management and  protection of air resources within the exterior boundaries of  the reservation or other areas within the tribe's jurisdiction."42 U.S.C. S 7601(d)(2)(B).  The statute's clear distinction  between areas "within the exterior boundaries of the reservation" and "other areas within the tribe's jurisdiction" carries  with it the implication that Congress considered the areas  within the exterior boundaries of a tribe's reservation to be  per se within the tribe's jurisdiction.  Thus, EPA correctly  interpreted S 7601(d) to express congressional intent to grant  tribal jurisdiction over nonmember owned fee land within a  reservation without the need to determine, on a case-specific  basis, whether a tribe possesses "inherent sovereign power"  under Montana.


31
Petitioners do not dispute that an important purpose of the  Act is to ensure effective enforcement of clean air standards. Obviously, this is best done by allowing states and tribes to  establish uniform standards within their boundaries.  As  EPA explained in its proposed rule,


32
[a]ir pollutants disperse over areas several and some-times even hundreds of miles from their source of origin, as dictated by the physical and chemical properties of the pollutants at issue and the prevailing winds and othermeteorological conditions.  The high mobility of air pollutants, resulting area wide effects and the seriousness of such impacts, underscores the undesirability of fragmented air quality management within reservations.


33
Proposed Tribal Authority Rule, 59 Fed. Reg. at 43,959.


34
Accepting petitioners' interpretation of the 1990 Amendments would result in a "checkerboard" pattern of regulation within a reservation's boundaries that would be inconsistent  with the purpose and provisions of the Act.  Indeed, the Supreme Court has condemned such an approach.  See Moe  v. Confederated Salish and Kootenai Tribes of Flathead  Reservation, 425 U.S. 463, 479 (1976) (rejecting checkerboard  approach in interpreting S 6 of the General Allotment Act, 25  U.S.C. S 349);  Seymour v. Superintendent of Washington  State Penitentiary, 368 U.S. 351, 358 (1962) (terming "impractical" a pattern of checkerboard jurisdiction under 18  U.S.C. S 1151).


35
Finally, we note that the legislative history of the 1990  Amendments supports EPA's interpretation.  As originally  introduced, 42 U.S.C. S 7601(d) differed in significant respect  from the final adopted version.  The original S 7601(d)(2)(B)  provided that treatment of tribes as states was authorized if  "the functions to be exercised by the Indian tribe are within  the area of the tribal government's jurisdiction."  S. 1630,  101st Cong. S 113(a) (1990), reprinted in Senate Comm. on  Env't and Pub. Works, 103d Cong., Legislative History of the  Clean Air Act Amendments of 1990, at 4283 (1993) (emphasis  added);  see also H.R. 2323, 101st Cong. S 604 (1989), reprinted in Legislative History of the Clean Air Act Amendments  of 1990, at 4101.  The statute as finally enacted, however,  treats tribes and states as equivalent if the tribe is to exercise  functions "within the exterior boundaries of the reservation or  other areas within the tribe's jurisdiction."  42 U.S.C. S 7601(d)(2)(B).


36
Thus, Congress moved from authorizing tribal regulation  over the areas "within the tribal government's jurisdiction"  (an admittedly general category) to a bifurcated classification  of all areas within "the exterior boundaries of the reservation" and "other areas within the tribe's jurisdiction."  This  change strongly suggests that Congress viewed all areas  within "the exterior boundaries of the reservation" to be  "within the area of the tribal government's jurisdiction."  The  change also indicates that Congress knew how to draft the  1990 Amendments to support petitioners' interpretation.  The  fact that Congress specifically rejected language favorable to  petitioners' position and enacted instead language that is consistent with EPA's interpretation only strengthens our  conclusion that the Agency has correctly ascertained Congress' intent in passing the 1990 Amendments.


37
The dissent's contrary contentions regarding the meaning  of the 1990 Amendments do not cause us to question this  conclusion.  The dissent's argument that Congress would not  use a "never-before-attempted" formulation to accomplish an  express delegation when it could use the "formulaic 'notwithstanding' proviso [used in S 7410(o)]--the gold standard for  such delegations," cannot carry much weight.  Dissent Op. at  5-6.  That a provision uses a new formulation is not dispositive of the question as to whether it constitutes an express  delegation.  Indeed, it is noteworthy that, in construing 33  U.S.C. S 1337(h)(1), which uses the dissent's so-called "gold  standard," EPA has declined to find an express delegation in  such language.  We can assume that Congress was aware of  EPA's contemporaneous interpretation of the Clean Water  Act, first proposed in 1989 (while Congress contemplated the  1990 Amendments).  See Amendments to the Water Quality  Standards Regulations That Pertain to Standards on Indian  Reservations, 54 Fed. Reg. 39,098, 39,101 (1989) (proposed  Sept. 22, 1989) (to be codified at 40 C.F.R. pt. 131) ("EPA  may treat an Indian Tribe as a State ... only where the  Tribe already possesses and can adequately demonstrate  authority to manage and protect water resources within the  borders of the reservation.  The Clean Water Act ... does  not grant additional authority to Tribes.").  Thus, Congress'  failure to use the same language in § 7601(d) does not at all  imply that it meant to avoid delegation to the tribes;  rather,  it may suggest just the opposite.


38
The dissent's argument resting on Congress' omission of a  "literal delegation" to tribes is seductive, but, ultimately, also  unconvincing.  It is true that, as originally introduced, the  bills in the Senate and the House contained language providing that "the Administrator ... may delegate to [ ] tribes  [that the Administrator is authorized to treat as States]  primary responsibility for assuring air quality and enforcement of air pollution control."  H.R. 2323, 101st Cong. S 604  (1989), reprinted in Legislative History of the Clean Air Act Amendments of 1990, at 4101.  The absenceof this language  from the final bill, however, does not compel the dissent's  conclusion that Congress "specifically rejected" language favorable to EPA's position.  Neither the majority nor the  dissent can call upon determinative legislative history to  illuminate the motivations behind this unexplained change to  the provisions at issue.  We suggest, however, that there are  at least two other explanations that account for the absence of  the cited language from the final bill.  First, Congress simply  may have deemed the language to be redundant and confusing in light of S 7601(d)(2)(B).  It would have been redundant  because S 7601(d)(2)(B) already accomplishes an express delegation.  It would have been confusing because the omitted  language can be read to apply to areas both outside and  inside the boundaries of the reservation, and, as we hold,  Congress intended to expressly delegate only with respect to  areas within the boundaries of a reservation.


39
Second, the language contained in the original bills hardly  represents, as the dissent declares ipse dixit, a "literal delegation."  Providing that the "Administrator ... may delegate" authority to tribes reads less like an express delegation  from Congress to the tribes than a permissive instruction to  the Administrator.  Moreover, the omitted language did not  expressly expand tribal jurisdiction to include those areas  within the boundaries of a reservation owned by nonmembers--which is what is necessary for express delegation--as does the language in the adopted S 7601(d)(2)(B).In other words, the language used in the progenitors to  S 7601(d) that the dissent claims is a "literal delegation" is  not easily manipulated to fit the contours of the traditional  express delegation inquiry.  We also note, as an aside, that by  treating the original bills' language as an express delegation,  our colleague seemingly abandons the "gold standard" that he  claims Congress consistently has utilized expressly to delegate authority to Indian tribes.  In short, we take more from  the language used in the adopted S 7601(d)(2)(B) than from  the language omitted.


40
What little precedent there is addressing express delegations of authority to Native American nations in other contexts supports our interpretation of § 7601(d).  In United  States v. Mazurie, the Supreme Court reviewed 18 U.S.C. S 1161 and concluded that the statute was an express delegation to tribes of the authority to regulate alcohol transactions.419 U.S. 544, 556-57 (1975).  The Court reaffirmed this  holding almost a decade later.  See Rice v. Rehner, 463 U.S.  713, 728-29 (1983).  Section 1161 provides in pertinent part  that various federal liquor laws applicable to transactions  within Indian country shall not apply


41
within any area of Indian country provided such act or transaction is in conformity both with the laws of the State in which such act or transaction occurs and with an ordinance duly adopted by the tribe having jurisdiction over such area of Indian country, certified by the Secretary of the Interior, and published in the Federal Register.


42
18 U.S.C. S 1161 (1994).  The Court read this language to  make


43
clear that Congress contemplated that its absolute but not exclusive power to regulate Indian liquor transactions would be delegated to the tribes themselves, and to the States, which historically shared concurrent jurisdiction with the Federal Government in this area.


44
Rehner, 463 U.S. at 728-29.


45
The decisions in Mazurie and Rehner are significant because the Court found an express delegation despite the  absence of any "we hereby delegate" language in the statute.The Court did not find any precise language of delegation in  the disputed statute, but, rather, rested on the implication  inherent in recognizing the power of tribes to adopt an  ordinance pertinent to liquor transactions on Indian country. See Rehner, 463 U.S. at 730-31.Similarly, in this case, we  find an express congressional delegation from the implication  inherent in the distinction between areas "within the exterior  boundaries of the reservation" and "other areas within the  tribe's jurisdiction."


46
Petitioners claim that the 1990 Amendments delegate authority to EPA to approve state or tribal air quality programs  for federal enforcement, not authority to tribes to "adopt  regulatory programs that the tribes could not adopt under  tribal and federal Indian law prior to the 1990 Amendments." Br. for Petitioners National Ass'n of Mfrs. ("NAM") at 23.Petitioners' claim misses a crucial point, however, that there  are two different powers at issue here:  (1) the authority to  regulate and (2) the derivative authority to enforce specific  provisions of the Act.  Petitioners focus on the derivative  authority.  Of course the 1990 Amendments do not constitute  an express delegation to the tribes to enact regulatory provisions absent any federal oversight or approval.  Rather, the 1990 Amendments simply establish the palette with which  tribes are permitted to paint their regulatory picture.


47
Petitioners additionally argue that although states are authorized under 42 U.S.C. S 7407(a) to enact programs "within  the entire geographic area comprising such State," EPA has  never interpreted this provision as allowing states to promulgate air quality regulations applicable to Native American  reservations located within a state's geographic area.  In  other words, petitioners claim that because states may not  promulgate regulations affecting Native American reservations, tribes may not promulgate regulations covering lands  held in fee by persons other than tribal members.  This  argument is obviously flawed, because it fails to recognize  that the relationship between fee holders and tribes is quite  different from the relationship between tribes and states.  As  the Supreme Court noted in Mazurie, Indian tribes are unique aggregations possessing attributes of sovereignty over both their members and their territory;  they are "a separate people" possessing "the power of regulating their internal and social relations...."


48
419 U.S. at 557 (citations omitted).  And there is no doubt  that Congress may delegate authority to tribes "even though the lands [are] held in fee by non-Indians, and even though  the persons regulated [are] non-Indians."  Id. at 554.


49
Finally, petitioners note that the Agency declined to find an  express delegation of power to regulate fee lands under SS 518(e) and (h) of the Clean Water Act;  this is noteworthy  to petitioners, because they can glean no difference between  the cited provisions under the Clean Water Act and the  disputed provisions in this case under the Clean Air Act.  We  find no merit in this argument.  The Clean Water Act states  that "[t]he Administrator is authorized to treat an Indian  tribe as a State ... if ... the functions to be exercised by the  Indian tribe pertain to the management and protection of  water resources which are held by an Indian tribe ... within  the borders of an Indian reservation."  33 U.S.C. S 1377(e)(2)  (1994).  "Reservation" is defined as "all land within the limits  of any Indian reservation under the jurisdiction of the United  States Government, notwithstanding the issuance of any patent, and including rights-of-way running through the reservation."  Id. S 1377(h)(1).  In construing these provisions, EPA  concluded that because the legislative history was "ambiguous  and inconclusive," it would not find that the Clean Water Act  expanded or limited the scope of tribal authority beyond that  inherent in the tribe.  Amendments to the Water Quality  Standards Regulation That Pertain to Standards on Indian  Reservations, 56 Fed. Reg. 64,876, 64,880 (1991) (codified at  40 C.F.R. pt. 131).


50
The situation here is quite different from what EPA found  with respect to the lean Water Act.  Although the disputed  language in the Clean Air Act and theClean Water Act is  somewhat similar, it is far from identical.  As noted above, EPA correctly relied on the CAA's clear distinction between  areas "within the exterior boundaries of the reservation" and  "other areas within the tribe's jurisdiction" to find a congressional intention to define the areas within the exterior boundaries of a tribe's reservation to be per se within the tribe's  jurisdiction.  Furthermore, as we have already indicated, the  legislative history of the 1990 Amendments plainly supports  EPA's interpretation.  Thus, the legislative history underlying the Clean Air Act is not "ambiguous and inconclusive," as  was found to be the case with respect to the Clean Water Act.


51
It is also of some significance that EPA's interpretation of  the Clean Water Act never has been subject to judicial review  on the question of the presence or absence of an express  delegation to tribes to regulate fee lands within the bounds of  reservations.  One federal court has observed, in dicta, that  "the statutory language [in the Clean Water Act] seems to  indicate plainly that Congress did intend to delegate ...  authority to tribes."  State of Montana v. EPA, 941 F. Supp.  945, 951 (D. Mont. 1996).  The court noted, however, that in  construing the provisions of the Clean Water Act, "EPA  determined that it would take the more cautious view, that  Congress did not expressly delegate jurisdiction to tribes  over non-Indians and that tribes would have to prove on a  case-by-case basis that they possess such jurisdiction."  Id. at  952.  There was no reason for EPA to take a similarly  "cautious view" with respect to the Clean Air Act, because the  language and legislative history of the 1990 Amendments  differ from that of the Clean Water Act.


52
B. EPA's Interpretation of "Reservation"


53
Given that EPA correctly interpreted S 7601(d) to expressly delegate jurisdiction to otherwise eligible tribes over all  land within the exterior boundaries of reservations, including  fee land, the next question is what areas are covered by a  "reservation."  EPA interprets "reservation" as used in three different statutory provisions (42 U.S.C. SS 7410(o), 7474(c),  7601(d)(2)(B)) to mean formally designated reservations as  well as "trust lands that have been validly set apart for the  use of a tribe even though the land has not been formally  designated as a reservation."  Tribal Authority Rule, 63 Fed.  Reg. at 7258.  This includes what EPA terms "Pueblos" and  tribal trust land.  Pueblos are villages, primarily located in  New Mexico, held by tribes in communal fee-simple ownership, originally acquired under grants from Spain and Mexico,  and confirmed by Congress in the late 1800s.  See United  States v. Sandoval, 231 U.S. 28, 38-39 (1913).  Petitioners  ignore the status of Pueblos and concentrate their attack on EPA's interpretation of "reservation" to include tribal trust land.


54
The Secretary of the Interior is authorized to acquire land  in trust for a tribe under 25 U.S.C. S 465 (1994), and such  land can only formally be designated a reservation via the  process provided by 25 U.S.C. S 467 (1994).  Petitioners  claim that EPA's interpretation contravenes the Act's plain  language and renders 25 U.S.C. S 467 superfluous by ignoring the distinction between "trust lands" and "reservations."  EPA counters that the statute is ambiguous, and that its  reasonable interpretation is entitled to Chevron deference.


55
We start with Chevron step one and rely on traditional  principles of statutory construction to determine whether  EPA's interpretation contravenes congressional intent as  manifested by the 1990 Amendments.  Significantly, the Act  nowhere defines "reservation."  Therefore, we look to the  term's ordinary and natural meaning, and the context in  which the term is used.  See Smith v. United States, 508 U.S.  223, 228-30 (1993).  And we must remain cognizant of the  rule that courts construe federal statutes liberally to benefit  NativeAmerican nations.  See Montana v. Blackfeet Tribe of  Indians, 471 U.S. 759, 766 (1985).


56
The dictionary defines "reservation" to be a "tract of public  land set aside for a particular purpose (as schools, forest, or  the use of Indians)."  Webster's Third New Int'l Dictionary  1930 (1993).  This definition surely encompasses both trust  lands and formally designated reservations.  Nothing in the  United States Code is clearly to the contrary, for the term  "reservation" has no rigid meaning as suggested by petitioners.  See 7 U.S.C. S 1985(e)(1)(A)(ii) (Supp. IV 1998) (defining  "reservation" to include land "within the limits of any Indian  reservation under the jurisdiction of the United States, ...  trust or restricted land located within the boundaries of a  former reservation of a federally recognized Indian tribe in  the State of Oklahoma[,] ... [and] all Indian allotments the  Indian titles to which have not been extinguished if such  allotments are subject to the jurisdiction of a federally recognized Indian tribe");  id. S 2012(j) (1994) (defining "reservation" as "the geographically defined area or areas over which  a tribal organization ... exercises governmental jurisdiction");  25 U.S.C. S 1452(d) (1994) (defining "reservation" to  include Indian reservations, public domain Indian allotments,  former Indian reservations in Oklahoma, and land held by  incorporated Native groups, regional corporations, and village  corporations under the provisions of the Alaska Native  Claims Settlement Act);  id. § 1903(10) (1994) (defining "reservation" to be "Indian country as defined in section 1151 of  Title 18" and any trust land not encompassed by S 1151);  id.  S 3103(12) (1994) (" '[R]eservation' includes Indian reservations established pursuant to treaties, Acts of Congress or  Executive orders, public domain Indian allotments, and former Indian reservations in Oklahoma");  33 U.S.C. S 1377(h)(1) (defining "Federal Indian reservation" to mean  "all land within the limits of any Indian reservation under the  jurisdiction of the United States Government, notwithstanding the issuance of any patent, and including rights-of-way  running through the reservation").


57
These varying definitions of "reservation" lay to waste  petitioners' argument.  Petitioners appear to assert that, in  the absence of any specific definition, "reservation" as used in  the 1990 Amendments to the Act can only mean the formal  reservation contemplated by 25 U.S.C. S 467.  This is a  specious contention.  First, S 467 does not purport to offer an  exclusive definition of "reservation";  it simply defines the  terms under which federal land is formally designated a  reservation.  Second, if Congress had wanted to limit the term "reservation" as petitioners suggest, Congress could  have done so.  Indeed, Congress on many occasions has  defined "reservation" in terms of other statutes.  See 12  U.S.C. S 4702(11) (1994) (defining "reservation" according to  25 U.S.C. S 1903(10));  22 U.S.C. S 2124c(m)(1) (1994) (defining "Indian reservation" with reference to 25 U.S.C. S 1452(d));  25 U.S.C. S 1903(10) (defining "reservation" with  reference to 18 U.S.C. S 1151, as well as trust land);  26  U.S.C. S 168(j)(6) (1994 & Supp. III 1997) (defining "Indian  reservation" with reference to 25 U.S.C. S 1452(d) and 25  U.S.C. S 1903(10));  42 U.S.C. S 10101(19) (1994) (defining "reservation" to include communities referred to in 18 U.S.C. S 1151(a), (b));  id. S 11332(a) (1994) (defining "reservation"  according to 25 U.S.C. S 1452(d)).  Moreover, given the varying definitions of the term used throughout the Code, it would  be a curious result indeed for this court to insist that the  absence of a definition requires EPA to advance the most  restrictive definition as put forth by petitioners.


58
Aside from the statute's plain meaning and its context, other sources of statutory interpretation offer no insight into  congressional intent with respect to the meaning of "reservation."  The Report of the Senate Committee on Environment  and Public Works refers to the authority ofIndian tribes to  "administer and enforce the Clean Air Act in Indian lands,"  as well as enforcement of the Act in "Indian country."  S. Rep. No. 101-228, at 79, 80 (1989), reprinted in Legislative  History of the Clean Air Act Amendments of 1990, at 841920.  These terms are arguably broader than the definition of  "reservation" urged by petitioners, and simply confirm the  term's ambiguity as used by Congress.


59
Accordingly, we turn to step two of the Chevron inquiry. That is, did the Agency reasonably interpret the term "reservation" to include formal reservations, Pueblos, and trust  lands?  EPA supported its interpretation of "reservation" by looking to relevant case law, in particular Supreme Court  precedent holding that there is no relevant distinction between tribal trust land and reservations for the purpose of  tribal sovereign immunity.  See Oklahoma Tax Comm'n, 498 U.S. at 511.  This view is consonant with other federal court  holdings that an Indian reservation includes trust lands.  See  United States v. John, 437 U.S. 634, 649 (1978) (finding "no  apparent reason" why lands held in trust should not be  considered a "reservation" under S 1151(a));  HRI, Inc. v.  EPA, 198 F.3d 1224, 1249-54 (10th Cir. 2000) (same);  United  States v. Azure, 801 F.2d 336, 339 (8th Cir. 1986) (considering  tribal trust land to be Indian country under either S 1151(a)  as a "de facto" reservation or S 1151(b) as a dependent Indian  community);  United States v. Sohappy, 770 F.2d 816, 822-23  (9th Cir. 1985) (holding that trust land is a "reservation"  under S 1151(a)).


60
Petitioners note that, for several years, EPA has defined  reservation, for the purposes of the PSD program, to be "any  federally recognized reservation established by Treaty,  Agreement, executive order, or act of Congress."  40 C.F.R.  52.21(b)(27) (1999).  Given the Agency's reasoned justification  for a broader definition of "reservation" in the Tribal Authority Rule, and its proposal to amend the PSD definition to  ensure consistency with the Tribal Authority Rule, EPA's  departure from the PSD definition does not preclude this  court from upholding EPA's new definition.  In light of the  ample precedent treating trust land as reservation land in  other contexts, and the canon of statutory interpretation  calling for statutes to be interpreted favorably towards Native American nations, we cannot condemn as unreasonable  EPA's interpretation of "reservations" to include Pueblos and  tribal trust land.


61
C.  Areas over which Tribes May Exercise Jurisdiction to Propose TIPs and Redesignations


62
The next issue that arises in this case is whether EPA  defensibly interprets the extent of Native American authority  to redesignate geographic areas and propose TIPs under the  Act.  Native American nations are authorized to redesignate  "[l]ands within the exterior boundaries of reservations of  federally recognized Indian tribes."  42 U.S.C. S 7474(c).Similarly, Indian tribes may submit TIPs "applicable to all  areas ... located within the exterior boundaries of the reservation, notwithstanding the issuance of any patent and including rights-of-way running through the reservation."  42  U.S.C. S 7410(o).


63
EPA interpreted both of these provisions to authorize  tribal redesignation and implementation of TIPs not just  within the limits of reservations (including trust lands and  Pueblos), but also within allotted lands and dependent Indian  communities.  No one argues that allotted lands and dependent Indian communities are within the compass of a "reservation."  Instead, EPA contends that so long as a tribe  demonstrates inherent jurisdiction over non-reservation areas, it may issue redesignations and TIPs for those lands.  In other words, although tribes do not have express delegated  authority to issue redesignations and TIPs for nonreservation areas, neither does the Act bar tribes from acting  on acase-by-case basis pursuant to demonstrated inherent  sovereign power.


64
Petitioners contend that both S 7474(c) and 7410(o) operate  as geographical limitations on the power of tribes to redesignate areas and issue TIPs.  Petitioners' argument with  respect to S 7474(c) falls flat.  This provision says that  "[l]ands within the exterior boundaries of reservations of  federally recognized Indian tribes may be redesignated only  by the appropriate Indian governing body."  42 U.S.C. S 7474(c).  Petitioners seek to twist this language into the  following:  "Indian tribes may only redesignate lands within  the exterior boundaries of reservations."  All S 7474(c) establishes, however, is the exclusive power of Indian tribes to  redesignate land within a reservation;  it does not address the  inherent power of tribes to redesignate land in nonreservation areas.


65
Nor do petitioners fare better with respect to S 7410(o),  which states that EPA-approved TIPs "shall become applicable to all areas (except as expressly provided otherwise in the  plan) located within the exterior boundaries of the reservation, notwithstanding the issuance of any patent and including  rights-of-way running through the reservation."  42 U.S.C. S 7410(o).  Petitioners read this to mean that EPA may only  approve a TIP if it applies within reservation areas.  As EPA  points out, petitioners' interpretation cannot stand for several  reasons.  First, S 7410(o) cross-references S 7601(d), which  allows for tribes to exercise jurisdiction over reservation  areas or "other areas within the tribe's jurisdiction."  42  U.S.C. S 7601(d)(2)(B).  Most importantly, S 7410(o) provides  that TIPs apply to all areas within the borders of a reservation once the plan "becomes effective in accordance with the  regulations promulgated under section 7601(d) of this title."42 U.S.C. S 7410(o).  Therefore, it is permissible for EPA to  give § 7410(o) the reading it proffers:  a reinforcement of  tribes' jurisdiction to implement TIPs in reservation land. Petitioners would instead read the statute as an express limitation of tribal jurisdiction.  Under step one of Chevron,  we cannot say that congressional intent is free of ambiguity  on this question.


66
Accordingly, we turn to whether EPA's interpretation is  reasonable.  We believe that it is undoubtedly so.  To read  the statute otherwise would result in several anomalies. First, EPA notes without dispute that petitioners' interpretation would allow a state's implementation plan to apply to non-reservation areas, even where a tribe has demonstrated  inherent jurisdiction over those areas.  Second, petitioners'  reading would disable a tribe from comprehensively administering the Act.  A tribe could implement, in non-reservation  areas, new source performance standards under the Act, but  not administer a TIP, even though the regulated activity  "threatens or has some direct effect on the ... health or  welfare of the tribe." Montana, 450 U.S. at 566.  EPA's  reading of the statute to allow such regulation is a reasonable  interpretation of SS 7410(o) and 7601(d).


67
D. The Right of The Public To Comment on Tribal Applications to Regulate


68
EPA's final rule limited the opportunity of the public to  comment directly to the Agency on "competing claims over  tribes' reservation boundary assertions and assertions of jurisdiction over non-reservation areas," allowing only "appropriate governmental entities" to submit comments.  Tribal Authority Rule, 63 Fed. Reg. at 7267.  Petitioners challenge this  limitation of the public's opportunity to comment directly to  EPA.  Before this court, however, EPA indicated its intent to  clarify that the Agency will accept comments directly from all  commenters on the determination of a tribe's eligibility to be  treated as a state.  See Br. for Respondent at 43.  Subsequently, EPA issued a clarification to this effect.  See Indian  Tribes:  Air Quality Planning and Management, 65 Fed. Reg.  1322, 1323 (2000).


69
Therefore, this issue is moot.  See Motor & Equip. Mfrs.  Ass'n v. Nichols, 142 F.3d 449, 458 (D.C. Cir. 1998) (finding  challenge to EPA's waiver for state's program was moot  where actions complained of were revised after lawsuit was filed).  A dispute may be rendered moot where the complained of conduct has been voluntarily discontinued if "(1)  there is no reasonable expectation that the conduct will recur  and (2) 'interim relief or events have completely and irrevocably eradicated the effects of the alleged violation.' "  Id. at  459 (quoting County of Los Angeles v. Davis, 440 U.S. 625,  631 (1979)).  In this case, there is no indication that EPA will  revert to its past proposal only to receive direct comments  from "appropriate governmental units," and all of the adverse  effects of the Agency's alleged illegal action have been remedied by EPA's clarification.


70
E. Abrogation of Existing Agreements By Tribes Not to Regulate Certain Land


71
Petitioners argue that EPA's final rule abrogates preexisting agreements by Native American nations not to regulate  certain individual parties.  Specifically, petitioner APS points  to its 1960 lease with the Navajo Nation that APS claims  prohibits the Nation from regulating the operation of the  Four Corners Power Plant.  See Br. of Petitioner APS at 2.APS further claims that the Secretary of the Interior covenanted to protect APS from tribal regulation.  See id. at 3.


72
Petitioners point to footnote 5 in the final rule which states,  in response to industry comments that preexisting agreements may limit the extent of a tribe's regulatory jurisdiction,  that "EPA believes that the CAA generally would supersede  pre-existing treaties or binding agreements that may limit the  scope of tribal authority over reservations."  Tribal Authority  Rule, 63 Fed. Reg. at 7256 n.5.  Petitioners ignore the  sentence following footnote 5, however, in which EPA states  that it "will consider on a case-by-case basis whether special  circumstances exist that would prevent a tribe from implementing a CAA program over its reservation."  Id. at 7256  (emphasis added).  EPA maintains in its brief that it has  made no judgment on the scope and effect of the specific  agreements to which petitioners refer, and that it will consider such questions as they arise.  As counsel for APS acknowledged at oral argument, it is quite possible that the abrogation issue never will arise.  For instance, if the Navajo Nation agrees that it will not regulate the Four Corners Plant, there  will be no controversy in need of resolution.


73
There is still a concern, however.  In EPA's preamble to a  proposed federal implementation plan, promulgated after the  Tribal Authority Rule, the Agency stated that,


74
[u]pon review of the circumstances surrounding the location and operation of [the Four Corners Power Plant] on the Navajo Indian Reservation, EPA concluded that jurisdiction under the Act over this facility lies with EPAand the Navajo Nation.


75
64 Fed. Reg. 48,731, 48,732 (1999);  see also 64 Fed. Reg.  48,725, 48,726 (1999) (taking same position with respect to the  Navajo Generating Station).  EPA now acknowledges that, to  the extent these preambles imply that the Agency has determined that the indicated plants are subject to regulation by  the Navajo Nation, these statements were incorrect.  See  Supp. Br. of Respondent at 4.  In fact, EPA has confirmed  this position by publishing an official notice in the Federal  Register clearly indicating that it has not yet determined  whether the Navajo Nation may regulate the indicated power  plants under the Act.  See id. at 4-5.


76
This issue, therefore, is not ripe for review before this  court.  The ripeness doctrine seeks to balance institutional  interests in delaying review against litigants' interests in  promptly reviewing allegedly unlawful government actions.  See FloridaPower & Light Co. v. EPA, 145 F.3d 1414, 142021 (D.C. Cir. 1998).  First a court must ask if the disputed  issues are fit for judicial review.  See Abbot Labs. v. Gardner,  387 U.S. 136, 149 (1967).  If the institutional interests of the agency or reviewing court favor postponing review, then a  party must demonstrate "hardship" in order to show that the  issue should nonetheless be made subject to judicial review.  See City of Houston v. HUD, 24 F.3d 1421, 1431 (D.C. Cir. 1994).


77
The fitness inquiry asks if a case " 'presents a concrete  legal dispute [and] no further factual development is essential  to clarify the issues ... [and] there is no doubt whatever that the challenged [agency] practice has "crystallized" sufficiently  for purposes of judicial review.' "  Rio Grande Pipeline Co. v.  FERC, 178 F.3d 533, 540 (D.C. Cir. 1999) (quoting Payne Enters., Inc. v. United States, 837 F.2d 486, 492-93 (D.C. Cir.  1988)) (alterations in original).  Here, petitioners cannot satisfy this prong because EPA has not issued any order relating to the preexisting covenants prohibiting regulation by  Native American nations.  See Florida Power & Light, 145  F.3d at 1421 (finding lack of fitness for review where it was  unclear "whether, or on what grounds, EPA would even  apply" the challenged rule to petitioners).


78
Additionally, petitioners cannot point to any hardship they  would suffer from deferred judicial review.  It is axiomatic  that mere delay, absent other extenuating circumstances, in  adjudication of a dispute cannot satisfy the hardship prong. See Clean Air Implementation Project v. EPA, 150 F.3d  1200, 1205-06 (D.C. Cir. 1998);  Florida Power & Light, 145  F.3d at 1421 (burden of participating in further proceedings  does not constitute a hardship).


79
Contrary to petitioners' argument, this case is not on all  fours with Better Government Association v. Department of  State, 780 F.2d 86 (D.C. Cir. 1986).  In Better Government,  petitioners challenged Department of Justice regulations applied by the Department of State and the Department of the  Interior to evaluate fee waiver applications for Freedom of  Information Act requests.  The court found that the claim  was ripe for review because the departments relied on the  Department of Justice guidelines, and the government agreed  that the regulations "govern[ ] and will continue to govern  its decisions."  Id. at 93.  Here, EPA has made no decision  that will govern its analysis of whether the preexisting agreements are abrogated by its interpretation of the Act.  Until  the Agency takes a position on the enforceability of the  covenants not to regulate, there is no concrete issue for this  court to consider.


80
F. Judicial Review of Tribal Permitting Programs


81
Under Title V of the Act, states must develop a comprehensive permitting program applicable to major air pollution sources.  See 42 U.S.C. S 7661a.  Section 7661a enunciates  the requirements for administering permitting programs, including elements of judicial review.  Pursuant to § 7661a,


82
[t]hese elements shall include ...


83
(6) Adequate, streamlined, and reasonable procedures for ... expeditious review of permit actions, ... including an opportunity for judicial review in State court of the final permit action....


84
(7) To ensure against unreasonable delay by the permit-ting authority, adequate authority and procedures to provide that a failure of such permitting authority to acton a permit application or permit renewal application ...shall be treated as a final permit action solely for purposes of obtaining judicial review in State court of an action brought by any person referred to in paragraph(6) to require that action be taken by thepermitting authority on such application without additional delay. Id. § 7661a(b)(6), (7).


85
EPA initially proposed that tribes "will have to meet the  same requirements" as states in providing an opportunity for  judicial review of a final permit action.  Proposed Tribal  Authority Rule, 59 Fed. Reg. at 43,972.  EPA withdrew this  proposal in its final rule.  Instead, EPA required tribes to  meet all the requirements of S 7661a(b)(6) and (7) except that  review of a tribe's Title V permitting program need not be  "judicial" or "in State court."  See Tribal Authority Rule, 63  Fed. Reg. at 7261.  Petitioners present two challenges to the  final rule on judicial review:  (1) that EPA had no authority to  exempt tribes from the Act's judicial review requirements; and (2) that interested parties received insufficient notice of  the final rule's content.


86
EPA promulgated its final rule in response to comments  that expressed concern over "waivers of tribal sovereign  immunity to judicial review."  Id.  Some Native American  representatives observed that requiring a waiver of sovereign  immunity for a tribe to administer a Title V permit program  would operate as a disincentive to a tribe's establishing such programs.  Industry commenters also sought assurances that  nonmembers of tribes would have access to tribal courts for  judicial review.


87
EPA identified two alternatives for ensuring that "some  form of citizen recourse be available for applicants and other  persons affected by permits issued under tribal Title V programs."  Id.  One option was for tribes to voluntarily waive  their sovereign immunity in tribal courts.  A second possibility was for the Agency to consider "alternative options ...that would not require tribes to waive their sovereign immunity to judicial review but, at the same time, would provide  for an avenue for appeal of tribal government action or  inaction to an independent review body and for injunctive type relief to which the Tribe would agree to be bound."  Id.  at 7262.  EPA interpreted 42 U.S.C. § 7601(d) to "provide[ ]  EPA with the discretion to balance the goals of ensuring  meaningful opportunities for public participation under the  CAA and avoiding undue interference with tribal sovereignty  when determining those provisions for which it is appropriate  to treat tribes in the same manner as states."  Id.


88
Section 7601(d) authorizes EPA to treat Native American  nations as states for the purposes of the Act.  However, if  EPA determines "that the treatment of Indian tribes as  identical to states is inappropriate or administratively infeasible, the Administrator may provide, by regulation, other  means by which the Administrator will directly administer  such provisions so as to achieve the appropriate purpose."  42  U.S.C. S 7601(d)(4).  EPA relies on this statutory provision  to justify the approach taken on judicial review.


89
Petitioners argue that EPA lacks authority to exempt  tribes from the judicial review requirements, because S 7601(d) does not affect the operation of CAA provisions  "that define rights that must be afforded to those affected by  a program in order [for either a tribe or a state] to receive  EPA approval to administer a federally enforceable program."  Br. for Petitioners NAM at 42.  We see no merit in  this claim.  EPA's interpretation is not clearly contradicted  by the statute.  In fact, S 7601(d)(4) allows the Agency the discretion to determine whether it is "inappropriate or administratively infeasible" to treat Indian tribes exactly the same  as states in administering the Act.  Petitioners offer no  support for their assertions that the judicial review requirements do not come within the EPA's discretion under this  section.  It is obvious, then, that the Agency had a choice as  to whether to treat Indian tribes identical to states with  regard to the judicial review elements of S 7661a(b).  The  clear meaning of the statutedoes not foreclose the Agency's  interpretation.


90
Nor is the Agency's interpretation unreasonable.  EPA  understandably was concerned that the effect of requiring  tribes to submit their permitting disputes to state courts  would conflict with policies supporting tribal sovereignty and  also discourage the institution of tribal permitting programs.  The Agency's decision to allow tribes to submit alternatives to  waiving sovereign immunity accomplishes a reasonable balancing of these interests.  This is bolstered by EPA's expressed intention to ensure that any alternative to a waiver of  sovereign immunity nonetheless provides an impartial forum  allowing for "injunctive-type relief."  Tribal Authority Rule,  63 Fed. Reg. at 7262.


91
Petitioners also argue that, assuming that EPA could exempt tribes from judicial review requirements, S 7601(d)(4)  requires that EPA provide an alternative means of ensuring  effective judicial review.  Petitioners suggest that EPA must at least "provide for review by the Regional Administrator of  all tribal permit decisions, and resolve all federal or tribal  challenges to the tribe's actions."  Br. for Petitioners NAM at  44.  To the extent that this argument merely reiterates the  contention that EPA has no authority to alter tribes' judicial  review responsibilities, nothing more need be said.  To the  extent that this argument challenges the alternative tribal  review procedures to be approved by EPA in lieu of judicial  review in state court, this issue is not ripe for review.  EPA  has not yet approved any alternative tribal judicial review  procedures.  See Tribal Authority Rule, 63 Fed. Reg. at 7262  ("EPA will develop guidance in the future on acceptable  alternatives to judicial review.").  As such, there is no decision "fit" for judicial review, nor have petitioners demonstrated any hardship from deferred review.


92
Petitioners advance a separate contention in support of  vacating the rule:  that interested parties did not receive  sufficient notice of the substance of the final rule.  The  Administrative Procedure Act requires that an agency publish  notice of its proposed rulemaking that includes "either the  terms or substance of the proposed rule or a description of  the subjects and issues involved."  5 U.S.C. S 553(b)(3)  (1994).  An agency satisfies this notice requirement if the  final rule is a "logical outgrowth" of the proposed rule.  See  Aeronautical Radio, Inc. v. FCC, 928 F.2d 428, 445-46 (D.C.  Cir. 1991).  In other words, we consider " 'whether ... [the  party], ex ante, should have anticipated that such a requirement might be imposed' " in determining whether adequate  notice was given in a notice of proposed rulemaking.  Id. at  446 (quoting Small Refiner Lead Phase-Down Task Force v.  EPA, 705 F.2d 506, 549 (D.C. Cir. 1983)) (alterations in  original).


93
"In most cases, if the agency ... alters its course in  response to the comments it receives, little purpose would be  served by a second round of comment."  American Water  Works Ass'n v. EPA, 40 F.3d 1266, 1274 (D.C. Cir. 1994).Thus, the "logical outgrowth" test normally is applied to  consider "whether a new round of notice and comment would  provide the first opportunity for interested parties to offer  comments that could persuade the agency to modify its rule."Id. (emphasis added).  In this case, there was more than  enough notice for interested parties to offer comments on  EPA's treatment of the judicial review provisions of the Act  vis a vis Indian tribes.  The parties were not asked to "divine  the EPA's unspoken thoughts."  Shell Oil Co., 950 F.2d at 751.  And the final rule was not wholly unrelated or surprisingly distant from what EPA initially suggested.  In first  proposing that tribes would have to meet the "same requirements" as states, EPA effectively raised the question as to  whether this made sense.  EPA's proposal was not a "bureaucratic game of hide and seek," MCI Telecomm. Corp. v. FCC,  57 F.3d 1136, 1142 (D.C. Cir. 1995);  the proposal raised a highlyvisible and controversial issue and elicited responses  from both tribal and industry commenters.  Furthermore, any reasonable party should have understood that EPA might  reach the opposite conclusion after considering public comments.  In short, it is fair to say that the purpose of notice  and comment rulemaking has been served, and that the  Agency's change of heart on this issue only demonstrates the  value of the comments it received.

III. CONCLUSION

94
Consistent with the foregoing opinion, we deny the petitions for review in part, and dismiss in part for want of  jurisdiction and for lack of ripeness.  Petitioners' motions for  vacatur and remand are dismissed as moot.

GINSBURG, Circuit Judge, dissenting in part:

95
With certain  exceptions, of which more later, an Indian tribe lacks inherent  authority to regulate the conduct of a nonmember on land he  owns within the boundaries of the tribe's reservation.  Lacking inherent authority, a tribe may exercise regulatory authority over such non-Indian lands only by express congressional delegation.  The court today determines that S 301(d)(2)(B) of the Clean Air Act, 42 U.S.C. S 7601(d)(2)(B),  expressly delegates to tribes--contingent upon approval by  the EPA Administrator--authority to enforce the Clean Air  Act on nonmembers' lands within a reservation.  Finding no  such express delegation in S 301(d)(2)(B), I dissent from Part  II.A of the opinion for the court.

I. Background

96
In State of Montana v. United States, 450 U.S. 544 (1981),  the Crow tribe had sought to regulate nonmembers' hunting  and fishing upon lands owned in fee by the State of Montana  but lying within the boundaries of the Crow reservation.  The  Supreme Court, unanimous upon this point, held that a tribe  generally lacks authority to regulate the conduct of nonmembers upon lands owned in fee by nonmembers ("fee lands");of the two exceptions the Court noted, the only one arguably  relevant here is that "[a] tribe may ... retain inherent power  to exercise civil authority over the conduct of non-Indians on  fee lands within its reservation when that conduct threatens  or has some direct effect on the political integrity, the economic security, or the health or welfare of the tribe."  Id. at  566.  Absent such a threat or effect, tribal regulation of fee lands within a reservation requires an "express congressional  delegation."  Id. at 564.


97
The two provisions of the Clean Air Act relevant to the  question of tribal authority to enforce the Act on fee lands  were added by S 107 of the 1990 Amendments, Pub. L. No.  101-549, 104 Stat. 2399, 2464.  Section 301(d) of the Act, 42  U.S.C. S 7601(d), provides in relevant part:


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(1) Subject to the provisions of paragraph (2), the Administrator ... is authorized to treat Indian tribes as States under this chapter ...


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(2) The Administrator shall promulgate regulations ...specifying those provisions of this chapter for which it is appropriate to treat Indian tribes as States.  Such treatment shall be authorized only if


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(A) the Indian tribe has a governing body carrying out substantial governmental duties and powers;


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(B) the functions to be exercised by the Indian tribe pertain to the management and protection of air re-sources within the exterior boundaries of the reservation or other areas within the tribe's jurisdiction;  and


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(C) the Indian tribe is reasonably expected to be capable, in the judgment of the Administrator, of carrying out the functions to be exercised in a manner consistent with the terms and purposesof this chapter and all applicable regulations


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Section 110(o) of the Act, 42 U.S.C. S 7410(o), provides in its  entirety:


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If an Indian tribe submits an implementation plan to the Administrator pursuant to section [301(d), above], the plan shall be reviewed in accordance with the provisions for review set forth in this section for State plans, except as otherwise provided by regulation promulgated pursuant to section [301(d)(2)].  When such plan becomes effective in accordance with the regulations promulgated under section [301(d)], the plan shall become applicable to all areas (except as expressly provided otherwise in the plan) located within the exterior boundaries of the reservation, notwithstanding the issuance of any patent and including rights-of-way running through the reservation.


105
The EPA's Tribal Authority Rule (TAR) allows a tribe  (subject to approval by the Administrator of the EPA) to  enforce the Clean Air Act on all land within the boundaries of  a reservation without having to demonstrate its inherent  authority over all such land.  Under the clear rule of Montana, however, a tribe lacks inherent sovereign authority to  regulate fee lands (and rights of way, see Strate v. A-1  Contractors, 520 U.S. 438, 456 (1997)) within a reservation except under the aforementioned exception announced in that  case.  Therefore, the TAR must be set aside as contrary to  law unless the 1990 Amendments expressly delegate to tribes  authority over fee lands and rights of way within a reservation.  Upon that starting point for analysis the parties, the  court, and I agree.


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The EPA claims to find a delegation of authority in S 301(d)(2)(B) of the Clean Air Act.  In evaluating this claim, the court is to accord no deference to the EPA's interpretation of that section because Montana requires an "express congressional delegation" in order to expand tribal authority.  In other words, the EPA cannot prevail merely by demonstrating that its interpretation of § 301(d)(2)(B) is reasonable; the agency's interpretation must be correct if the TAR is to  stand.  Therefore, although we are reviewing an EPA rulemaking, on this issue the focal point for our inquiry is not the  EPA's interpretation but the statute itself.  Upon this methodological point, too, all agree.

II. Analysis

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With these agreed upon principles in mind, it seems to me  clear that the 1990 Amendments do contain an express delegation of authority over fee lands and rights of way--but not  in S 301(d), which governs tribal enforcement of all Clean Air  Act programs specified by the Administrator.  Rather, the  delegation is in S 110(o), which governs only tribal implementation plans (TIPs).  Because the specific delegatory text in S 110(o) is significant to my conclusion that S 301(d) is not a  delegation, I consider S 110(o) first.


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A.  Section 110(o) and the "Notwithstanding" Proviso


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The petitioners' convoluted argument to the contrary notwithstanding, S 110(o) is self-evidently an express congressional delegation of authority to enforce TIPs on fee lands  and rights of way within a reservation:  "the [TIP] shall  become applicable to all areas ... located within the exterior  boundaries of the reservation, notwithstanding the issuance of  any patent and including rights-of-way running through the  reservation."  The same "notwithstanding" proviso has been a feature in the only two cases in which the Supreme Court has found an express delegation of authority to tribes.  In United  States v. Mazurie, 419 U.S. 544 (1975), and in Rice v. Rehner,  463 U.S. 713 (1983), the Court found an express delegation of  authority over fee lands within a reservation based upon two  statutory provisions:  18 U.S.C. § 1161, which authorizesthe  tribes to enact ordinances regulating liquor in "Indian country";  and 18 U.S.C. S 1151, which defines "Indian country" to  include "all land within the limits of any Indian reservation  under the jurisdiction of the United States Government,  notwithstanding the issuance of any patent, and, including  rights-of-way running through the reservation."  See Rice,  463 U.S. at 715 & n.1 ("Congress has delegated authority ...  in Indian country [as defined in] 18 U.S.C. S 1151");  see also  Brendale v. Confederated Tribes & Bands of the Yakima  Indian Nation, 492 U.S. 408, 428 (1989) (citing 18 U.S.C. SS 1151 and 1161 together as an express congressional delegation of authority over fee lands).*

B. Section 301(d)

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The express congressional delegation just identified in S 110(o) cannot by itself support the TAR, however:  Because  the TAR allows a tribe to enforce all applicable Clean Air Act  programs--rather than just the TIP--on nonmember lands  within its reservation, the EPA must demonstrate that S 301(d) likewise contains an express congressional delegation of authority.


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The EPA argues the following text distilled from S 301(d)  contains an express delegation to tribes of authority to regulate fee lands within a reservation:


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[T]he Administrator ... is authorized to treat Indian tribes as States....  Such treatment shall be authorized only if ... the functions to be exercised by the Indian tribe pertain to the management and protection of air resources within the exterior boundaries of the reservation or other areas within the tribe's jurisdiction.


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42 U.S.C. S 7601(d)(1)-(d)(2)(B) (emphasis added).  The gist of the agency's argument, which the court accepts, is that the  Congress expressly delegated authority over all lands within  a reservation by linking "within the exterior boundaries of the  reservation" disjunctively to "other areas within the tribe's  jurisdiction."  For the following reasons, I do not agree.


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As the petitioners emphasize, when one reads the relevant  sentence as a whole--rather than focusing solely upon the  last phrase--one sees that, rather than expressing a delegation of authority over fee lands and rights-of-way within a  reservation, the sentence by its terms merely lays down a  precondition to the Administrator's treating a tribe as a state. Even more certainly, there is no way to read the phrase  deemed crucial by the court ("within the exterior boundaries  of the reservation or other areas within the tribe's jurisdiction") as an express delegation of authority.


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One important indication that the Congress did not intend  this phrase as an express delegation is that it used the Courttested "notwithstanding" proviso in S 110(o) but not in S 301(d)(2)(B).  Sections 110(o) and 301(d)(2)(B) were enacted  at the same time, in the same section of the same bill, so the  different phrasing should not be thought just an artifact of  legislative haphazar dry.  I do not believe that the Congress,  obviously aware that it could enlarge tribal authority over  nonmember lands only through an express delegation, would  include the formulaic"notwithstanding" proviso--the gold


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standard for such delegations--in the narrower of the two  sections, and then use an obscure and never-before-attempted  formulation to accomplish the same result in the broader of  the two sections.  Further, the court's interpretation of S 301(d)(2)(B) renders the "notwithstanding" proviso in  S 110(o) surplusage--a point the court euphemistically acknowledges, Slip Op. at 1295 ("a reinforcement of tribes' ...  [S 301(d)(2)(B) authority] to implement TIPs in reservation  land").  If S 301(d)(2)(B) is so clear as to constitute an  express congressional delegation, it is difficult to believe that  the Congress would "reinforce" this point in a narrower  provision enacted at the same time as and expressly cross referencing S 301(d).1


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Finding an express congressional delegation in S 301(d) is  made even more difficult, as the petitioners contend, by the  Congress's having deleted a literal delegation to tribes that  was included in the corresponding section of the bills by  which the 1990 Amendments were first introduced in the  House and the Senate:  "the Administrator ... may delegate  to [ ] tribes primary responsibility for assuring air quality and  enforcement of air pollution control."  H.R. 2323, 101st Cong. S 604, reprinted in 2 Legislative History of the Clean Air Act  Amendments of 1990, at 4053, 4101 (1993) [hereinafter 1990  Leg. Hist.];  S. 1630, 101st Cong. § 111, reprinted in 5 1990  Leg. Hist. 9050, 9145.  The Senate passed S. 1630 with this  express delegation intact;  the House, however, did not act  upon H.R. 2323 but instead passed H.R. 3030, in which the  delegation provision did not appear.  See 2 1990 Leg. Hist.  1809, 1972-73 (House passage of S. 1630, amended in the  nature of a substitution of H.R. 3030).  The House version  prevailed in conference, see id. at 478-79, so the 1990 Amendments as finally enacted into law do not contain this literal  delegation provision.  The court is of course correct that the  Congress need not use the word "delegate" in order to effect  an express delegation, Slip Op. at 1290; S 110(o) illustrates the  point.  That the Congress "specifically rejected language  favorable to [EPA's] position," Slip Op. at 1289, however, is  further evidence that the legislature did not mean to enact a  delegation of authority.  Indeed, to believe that the Congress  meant S 301(d)(2)(B) to serve as a delegation, after it had  included the "notwithstanding" proviso in the narrower S 110(o) and removed from S 301(d) a provision that expressly provided a delegation to tribes, would require one to  believe the Congress was more interested in testing our  interpretive acumen than in clearly expressing its will upon  the important issue of tribal authority over nonmembers.


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The court claims support for its contrary conclusion in the Congress having "moved from authorizing tribal regulation  over the areas 'within the tribal government's jurisdiction' ...  to a bifurcated classification of all areas within 'the exterior  boundaries of the reservation' and 'other areas within the  tribe's jurisdiction.' "  Slip Op. at 12.  Putting aside the  question-begging interpolation of "all" into the quoted passage, Ithink the court misapprehends the significance of the  phrase "within the exterior boundaries of the reservation or  other areas within the tribe's jurisdiction."  As originally  introduced, H.R. 3030 referred only to air resources "within  the exterior boundaries of the reservation."  2 1990 Leg. Hist. 3737, 3853.  The House Committee on Energy and  Commerce without comment added the phrase "or other  areas within the tribe's jurisdiction," id. at 3021, 3069, and as  mentioned, the House version later prevailed in conference. The legislative record is silent about why the Committee  added that phrase.  The most straightforward interpretation  of the addition is that the Committee wanted to ensure that  the treatment of tribes as states extended beyond the reservation to non-contiguous areas of tribal authority, such as  dependent Indian communities.  This seems far more likely  than that a House committee, with no discussion, inserted the  phrase "or other areas within the tribe's jurisdiction" in order  to turn a simple reference to reservations into a delegation of  authority over non-Indian lands within reservations.


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Finally, I cannot agree with the court that we should find  an express congressional delegation of authority in  S 301(d)(2)(B) in any part because the contrary reading  "would result in a 'checkerboard' pattern of regulation within  a reservation's boundaries that would be inconsistent with the  purpose and provisions of the [Clean Air] Act."  Slip Op. at  11-12.  First, it is not at all clear that a "checkerboard"  pattern--really a matter of certain fee lands remaining subject to State (or federal) rather than tribal authority, while  surrounding areas go tribal--would result:  a tribe remains  free to demonstrate its inherent authority over any activity on  fee lands that "threatens or has some direct effect on ... the  health or welfare of the tribe," Montana, 450 U.S. at 566.Therefore, if a tribe does find itself without authority over  certain fee lands for want of an express delegation, that is  only because no activities on those fee lands threaten or  directly affect the health or welfare of the tribe.


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Second, tribal authority over less than all lands within the  boundaries of a reservation is the logical result of the tribes'  "diminished status as sovereigns," Montana, 450 U.S. at 565.The Montana rule on its face contemplates less than uniform  authority within a reservation;  unless an exception applies, the tribe cannot regulate a parcel owned by a nonmember  even though it retains authority over the surrounding lands  owned by the tribe.  See, e.g., Brendale, 492 U.S. at 428  (White, J., for the Court in part and dissenting in part), 443, 445 (Stevens, J., for the Court in part and concurring in the  judgment in part) (each affirming non-uniform zoning authority).  While the Congress could have chosen to sweep away  such non-uniformity in S 301(d), as it did in S 110(o), the  court's evident sense that the Congress should have done so  is no basis for reading an express delegation into the statute  where the Congress has not written one2.

III. Conclusion

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In my view, S 301(d)(2)(B) is not an express delegation of  authority for Indian tribes to regulate the conduct of nonmembers on fee lands within the boundaries of a reservation.  A tribe may be able, of course, to demonstrate its authority  over such fee lands under the exception recognized in Montana.  Without making such a showing, however, I do not  believe the tribe may regulate the conduct of nonmembers on  fee lands and rights-of-way except as provided by S 110(o).  I


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therefore respectfully dissent from Part II.A. of the opinion  for the court.



Notes:


*
 In a dictum, the Brendale Court noted as a second example of  an express congressional delegation of authority SS 518(e), (h)(1) of  the Clean Water Act, 33 U.S.C. SS 1377(e), (h)(1), the latter of  which, significantly, contains the notwithstanding clause so glaringly  absent from § 301(d).  492 U.S. at 428.  In terms that otherwise track S 301(d) of the Clean Air Act, S 518(e) provides for conditionally treating a tribe as a state with regard to water resources  "within the borders of an Indian reservation," defined in S 518(h)(1)  as "all land within the limits of any Indian reservation under the  jurisdiction of the United States Government, notwithstanding the  issuance of any patent, and including rights-of-way running through  the reservation."  In spite of the Brendale dictum, the EPA has concluded S 518 is not an express congressional delegation of  authority, see 56 Fed. Reg. 64,876, 64,880 (1991), but no court has  yet resolved the issue.


1
 The court suggests the Congress may well have intentionally  avoided using the "notwithstanding" proviso in § 301(d) in response  to the EPA's having interpreted § 518 of the Clean Water Act as  not being a delegation.  Slip Op. at 13.  The EPA's interpretation  of the CWA was not adopted, however, until December 1991, more  than a year after enactment of the 1990 Amendments.  See 56 Fed.  Reg. 64,876, 64,880.  I am not willing blithely to "assume that  Congress was aware of," much less responded to, the EPA's mere  proposal to adopt that interpretation.  When the 1990 Amendments  were enacted, the EPA's unexplained proposal was still subject to  change in the light of public comments, and even if finally adopted  would not receive deference from a reviewing court charged with  determining whether the Congress had made an express delegation  to tribes.  In contrast, we know for a certainty that the Congress  was aware of Brendale, in which the Supreme Court instanced  CWA S 518(h)(1) as an express congressional delegation:  That case  had been decided in June 1989, and is cited in the Senate Report on  an earlier version of the 1990 Amendments, see S. Rep. No.  101-228, at 79.


2
 Seymour v. Superintendent of Washington State Penitentiary,  368 U.S. 351 (1962) and Moe v. Confederated Salish and Kootenai  Tribes of Flathead Reservation, 425 U.S. 463 (1976), cited by the  court today, certainly do not counsel reading an express delegation  into a statute in order to avoid non-uniform tribal authority within a  reservation.  In Seymour, the Court held that "an impractical  pattern of checkerboard jurisdiction was avoided by the plain  language of [18 U.S.C.] S 1151," namely, the "notwithstanding"  proviso.  368 U.S. at 358.  And in Moe, the Court determined that  because the Congress had "repudiated" but never formally repealed  S 6 of the General Allotment Act, 25 U.S. S 349, the court would  read S 6 narrowly in order to avoid creating an inconsistency with  later-enacted statutes.  425 U.S. at 477-79.  Thus, the Court was  merely "follow[ing] Congress' lead in this area."  Id. at 479.  So, too, where the Congress has expressly delegated authority, as in S 110(o), we should certainly give its command full rein;  but where  it has not, we should not undertake to do so for it.


