This case in a somewhat more expanded form has been before this court previously. See Brown v. Environmental Protection Agency, 521 F.2d 827 (9th Cir. 1975), vacated 431 U.S. 99, 97 S. Ct. 1635, 52 L. Ed. 2d 166, (Brown I ). There we held that neither section 113(a)(1) nor section 113(a)(2) of the then existing version of the Clean Air Act, 42 U.S.C.A. § 1857c-8(a)(1) and (2), 1977 Cum.Ann. Pocket Part, authorized the Administrator to impose sanctions against the State of California and its officials, including Governor Brown, for failing to comply with the directions contained in certain regulations designed to reduce air pollution by automobiles and other types of vehicles which use California's streets and highways. These regulations are listed at 521 F.2d 827, 831. Our holding rested on our interpretation of the Clean Air Act and was influenced heavily by the serious constitutional issues which we believed a contrary interpretation necessarily would encounter. Except as modified herein, we continue to regard, or once more adopt if necessary, our opinion in Brown I as the law of this Circuit.

The Solicitor General's petition for certiorari challenged our holding only with respect to the regulation requiring state inspection and maintenance programs. 40 C.F.R. § 52.242 (Revised as of July 1, 1976). His petition was granted by the Supreme Court more or less contemporaneously with its grant of petitions with respect to cases from the Fourth and the District of Columbia Circuits involving substantially similar inspection and maintenance regulations as well as certain regulations held proper and valid by the District of Columbia Circuit. See EPA v. Brown, 431 U.S. 99, 97 S. Ct. 1635, 52 L. Ed. 2d 166 (1977); District of Columbia v. Train, EPA, 172 U.S.App.D.C. 311, 521 F.2d 971 (1975), vacated 431 U.S. 99, 97 S. Ct. 1635, 52 L. Ed. 2d 166; Maryland v. EPA, 530 F.2d 215 (4th Cir. 1975), vacated 431 U.S. 99, 97 S. Ct. 1635, 52 L. Ed. 2d 166.

The relatively narrow scope of the Solicitor General's challenge was further narrowed when prior to argument before the Supreme Court he informed the Court that certain bus purchase regulations involved in the District of Columbia Circuit decision were to be repealed and thus should not be treated as before the Court. Even this remaining small target was removed when it was conceded by the Government that the inspection and maintenance regulations to be valid should be amended to delete "all requirements that the State submit legally adopted regulations," 431 U.S. at 103, 97 S.Ct. at 1637. The Supreme Court, not wishing to render an advisory opinion with respect to regulations not then in existence, vacated the judgments of the respective Courts of Appeal and remanded the cases "for consideration of mootness and such other proceedings as may be consistent with this opinion." 431 U.S. at 104, 97 S.Ct. at 1637.

The Administrator of the Environmental Protection Agency promulgated on June 8, 1977 a revised regulation pertaining to the inspection and maintenance program California was required to establish. The revised regulation is set forth in the margin in a manner in which the portions deleted by revision appear within brackets.1 On July 19, 1977, this court, pursuant to the Supreme Court's remand, set a date for a hearing to address two issues:

(1) Whether this case in whole or in part, is either now moot or presently not ripe for decision;

(2) Assuming this case, in whole or in part, is neither not moot nor unripe for decision, why such ripe and not moot issues should not be decided in accordance with the reasoning employed in our opinion in Brown v. EPA, 521 F.2d 827 (9th Cir. 1975).

A few days prior to the above order, July 13, 1977, the State of California filed in this court a petition for review of agency action, which we numbered No. 77-2558, and in which the State asked that we declare invalid the inspection and maintenance regulations as revised on June 8, 1977. This petition was consolidated with cases which the Supreme Court remanded to us.

The final event of juridical significance which occurred prior to our hearing of these cases and their submission for decision was the enactment by Congress on August 7, 1977 of the Clean Air Amendments of 1977.

We hold that the cases before us are not entirely moot, that each of them is at least partially ripe for decision, and that our decision should be substantially on the same, but not identical, basis as was our opinion in Brown I.

Mootness and Ripeness As To Revised Inspection and

Maintenance Regulations.

The mere recital of the rather quick moving events which affect these cases reveals that there exists a duly promulgated inspection and maintenance regulation applicable to California. This regulation requires the State (1) to "establish an inspection and maintenance program", (2) to "inspect all light duty motor vehicles" at certain intervals, (3) to "apply inspection failure criteria" of a prescribed sort, (4) to "ensure" that vehicles which fail inspection "receive the maintenance necessary" to pass inspection, (5) to begin the first inspection cycle on October 1, 1975, completing it by September 30, 1976, (6) to "designate an agency or agencies responsible" for carrying out the program, (7) to refuse to register vehicles which do not pass inspection, and (8) to submit no later than February 1, 1974 a detailed compliance schedule showing the steps it will take to establish "the inspection and maintenance program."

California at present insists, as it did previously in Brown I, with respect to the inspection and maintenance regulation which then existed, that this regulation exceeds the EPA's statutory authority and that if such authority is provided by the Clean Air Act as amended, it is void because in excess of the power of Congress acting under the Commerce Power. California takes this position although it acknowledges that under the revised regulation it is no longer required to submit to the EPA an advance text of laws and regulations implementing the required inspection and maintenance program. In brief, California contends that the Administrator's June 8, 1977 amendments achieved no more than a cosmetic change of the regulation previously before the Supreme Court, that it currently refuses to comply with the amended regulation and, as a consequence, is now in default unless we find the amended regulation invalid. Thus, as California sees it, there exists a "live" issue in which both parties have a "cognizable interest in the outcome." See Powell v. McCormack, 395 U.S. 486, 496-97, 89 S. Ct. 1944, 23 L. Ed. 2d 491 (1968). California contends that the case is neither moot nor unripe insofar as it pertains to the revised inspection and maintenance regulation.

EPA does not challenge this conclusion. It points out that its amended regulation has "removed any requirement that the State adopt regulations and any reference to state legislative activity," Memorandum For The Environmental Protection Agency, Nos. 73-3306, 73-3305, 73-3307, and that there remain other regulations invalidated by Brown I, some of which contained references to state legislative activity and the necessity for the state regulations and some of which did not, that were "rehabilitated" by the Supreme Court's vacation of our judgment in Brown I. The asserted validity of at least those regulations which avoid mentioning legislative activity and the necessity to promulgate regulations provides, according to the EPA, a ripe and not moot controversy.

Although the history of Brown I indicates that assertions by the EPA of its intention to adhere steadfastly to a specific position should be viewed with mild skepticism, we must accept its current assertions, at least for the purposes of determining mootness and ripeness of the controversy involving the revised inspection and maintenance regulations. Therefore, it is clear that the State of California and the EPA have taken directly opposing views with respect to the validity of the inspection and maintenance regulations as amended on June 8, 1977. It follows that the cases before us to the extent they concern these regulations are not moot and are ripe for decision.

Disposition of the Controversy Pertaining to the Revised

Inspection and Maintenance Regulation.

EPA's deletion of all references to state legislative activity and the necessity to adopt regulations clearly could not have been for the purpose of establishing that the revised regulations do not impose upon the State of California substantial duties. The recital of commands previously set forth unequivocally demonstrates that to comply the State would be compelled to undertake significant duties which in the nature of government would require the promulgation by the State of juridically effective orders in one form or another. While it is true that the revised regulation leaves to the State a wide range of choice in selecting the means by which it will discharge its duties, even the EPA acknowledges, as it must, that the revised inspection and maintenance regulation "imposes an affirmative duty on the State of California." Memorandum For The Environmental Protection Agency, p. 15.

The true purpose of the EPA's deletion, as we see it, was to draw attention to the fact that it no longer contends, as in Brown I we believed it did, that sections 113(a)(1) and (a)(2), 42 U.S.C. § 1857c-8(a)(1) and (a)(2), empower it to impose sanctions on the State, or its appropriate officials, should it or they fail to enforce a state implementation plan against polluters.2 Its present contention is that the State "because it owns roads and highways and is therefore itself a polluter, can, pursuant to Section 113, be required to comply with measures designed to reduce the pollution generated on those roads and highways, especially the inspection and maintenance of automobiles." Memorandum For The Environmental Protection Agency, p. 13. In this manner the EPA presently seeks to treat the State as a polluter and bring its regulation within the scope of the authority of the Clean Air Act which, as we put it in Brown I, "permits sanctions against a state that pollutes the air, but not against a state that chooses not to govern polluters as the Administrator directs." 521 F.2d at 832. The requirement to institute an inspection and maintenance program, asserts the EPA, in essence does not differ from a requirement that a state power plant adopt prescribed pollution control devices. Each requirement is directed against the State as a polluter not as a sovereign exercising police power.

In Brown I we refused to read the Clean Air Act as authorizing the EPA to treat the State's failure to adopt an inspection and maintenance program as pollution per se. We continue to adhere to this view. Our principal reason for doing so then was our inability to discern a clear intention on the part of Congress to adopt such an attenuated notion of pollution and our belief that the EPA was in fact insisting that a state's governance of commerce under its police power was itself commerce subject to regulation by Congress acting under the Commerce Power, a view which to us raised momentous constitutional questions. While the EPA in this proceeding eschews what we believed in Brown I was the burden of its constitutional argument, we remain convinced that Congress has not enacted EPA's view of what constitutes pollution by a state.

An early manifestation of the EPA's view that the failure of the State of California to adopt an inspection and maintenance program constitutes pollution by the State may be found in 40 C.F.R. § 52.22(b)(1)(i) where an "indirect source" of pollution was defined to include "a facility, building, structure, or installation which attracts or may attract mobile source activity that results in emissions of a pollutant for which there is a national standard." Such indirect sources included, among others, highways and roads. Inasmuch as highways and roads "attract" automobiles which pollute, a state which owns such highways and roads indirectly pollutes when it fails to obey a directive of the EPA to adopt an inspection and maintenance program.

Had Congress embraced this view we would proceed immediately to consider the constitutionality of such legislation in the light of our opinion in Brown I. Congress, however, has not enacted such legislation. Prior to the Clean Air Amendments of 1977 the Act made no mention of "indirect sources" of pollution. Moreover, in the face of Congressional hostility to that portion of 40 C.F.R. § 52.22(b) covering parking-related facilities,3 the EPA suspended that portion of its regulations, 40 F.Reg. 28064-65 (July 1975), but asserted that "different considerations govern the agency's position with respect to highways and airports." Id. at 28065. Shortly thereafter this suspension was made indefinite, 40 F.Reg. 29713-714, and, for certain purposes, has been regarded by the EPA as a revocation. See State of Arizona, et al. v. Environmental Protection Agency, 521 F.2d 825 (9th Cir. 1975), vacated 431 U.S. 99, 97 S. Ct. 1635, 52 L. Ed. 2d 166. In the face of this abortive attempt by the EPA to regulate parking facilities as "indirect sources" and the silence of the Act, at that time, we concluded in Brown I that merely building, owning, and managing roads and highways did not make the State the source of automobile emissions and thus a polluter within the meaning of the Act. Cf. 521 F.2d at 838.

The reluctance of the EPA to surrender its "indirect source" rationale as it relates to highways and airports and its continuing dissatisfaction with the analysis of Brown I suggest that it would turn to Congress for an amendment which would clarify the Act in a manner that would put all relevant statutory issues at rest. This it did and in H.R. 6161, passed by the House on May 26, 1977, there appeared a section 208 which required a state either "to adopt and implement a vehicle inspection and maintenance program" or to "devise and implement some other measure which would be adequate to attain and maintain the national primary ambient air quality standards by the statutory attainment dates." H.Rep.No.294, 95th Cong., 1st Sess., 288 (1977). U.S.Code Cong. & Admin.News 1977, p. 1367. Section 208 did not require a state to adopt a particular form of vehicle inspection and maintenance and, although it envisioned that a state would operate and enforce the inspection and maintenance program, it recognized explicitly that Federal implementation and enforcement was appropriate when a state refused to cooperate. Moreover, cooperation by the states was to be obtained by offering or withholding grants under other sections of H.R. 6161 and by delegating authority to operate such programs to general purpose local governments. Finally, and of prime importance to this proceeding, section 208 envisioned injunctive relief under section 113 of the Act to obtain compliance by a state as a possible tool available to the EPA.4 This section would have forced us to confront the constitutional issues which we avoided in Brown I.

The section, however, never existed in S. 252, the Senate-passed version of the 1977 Amendments, and was not enacted in P.L. 95-95, the Clean Air Act Amendments of 1977. We construe this as an unwillingness on the part of Congress to overturn our refusal in Brown I to adopt EPA's "indirect source" theory in construing the relevant provisions of the Clean Air Act. The EPA attempts to refute this construction by pointing out that Congress in the 1977 Amendments made no attempt "to circumscribe the Administrator's understanding of his authority under section 110(c)." Memorandum For The Environmental Protection Agency, p. 6, and by referring to remarks by Senator Muskie, the Senate Floor manager for the 1977 Amendments and principal author of the original 1970 Act, in which the Administrator's understanding of his authority was endorsed. 123 Cong.Rec. § 9168 (daily ed., June 8, 1977). We are unpersuaded. What Congress in this instance did not do in 1977 is more compelling than what the Administrator and Senator Muskie believe was done in 1970. Moreover, as in Brown I, we remain reluctant to interpret the Act in a manner that compels the consideration of constitutional issues.

Our reading of the 1977 Amendments, as they relate to "indirect source review programs," also strengthens our interpretation. Section 108(a) of the Amendments grants to the Administrator limited authority to promulgate regulations respecting "indirect source review programs." Such programs are applicable only "to federally assisted highways, airports, and other major federally assisted indirect sources and federally owned or operated sources." An "indirect source review program" embraces only a facility-by-facility preconstruction or premodification review of "indirect sources" of air pollution. "Indirect sources" means a facility, including a road or highway, which attracts mobile sources of pollution. This limited recognition of the "indirect source" concept, a concept not previously appearing in the language of the Clean Air Act, provides no basis for interpreting the general language of sections 110(a)(2)(B) and 110(c), 42 U.S.C. §§ 1857c-5(a)(2)(B) and (c), to embrace the expansive indirect source concept urged upon us in this proceeding. The maxim, expressio unius est exclusio alterius, is not without force. It is also worth observing that section 108(e) of the Amendments provides that "transportation control" measures, within the meaning of section 110(a)(2)(B), do not include a measure which is an "indirect source review program."5

Thus, we remain convinced that the Clean Air Act, as amended in 1977, does not authorize the EPA to treat the State of California as a polluter subject to section 113 sanctions because of its refusal to adopt the inspection and maintenance promulgated by the Administrator on June 8, 1977.

Constitutional Concerns.

While we do not pass on the constitutional issues which would have arisen had section 208 of the House version of the 1977 Amendments, or its equivalent, been adopted, we do wish to acknowledge that the indirect source concept by which the EPA seeks to characterize the State as a polluter is a more restrained constitutional position than we believed the EPA to be advancing in Brown I. Pollution, the EPA insists, is not an act of governance but one which affects commerce and thus within reach of federal regulation under the Commerce Power. Its regulation, the EPA continues, does not operate "to directly displace the States' freedom to structure integral operations in areas of traditional governmental functions . . ." National League of Cities v. Usery, 426 U.S. 833, 852, 96 S. Ct. 2465, 2474, 49 L. Ed. 2d 245 (1976).

The State of California takes the opposite view. It is not a polluter because it builds and maintains highways and roads any more than it is a polluter merely because it issues a building permit to a private party for a smelter which pollutes after its construction. It is not the "indirect source" of all that it does not proscribe. To treat it as such a source is to efface the distinction between governance and commerce and to exceed the limits of the Commerce Power as established by National League of Cities v. Usery, supra.

Despite the restraint with which the EPA has fashioned its constitutional position, its contentions continue to raise serious questions which justify our prudent reading of the Clean Air Act as amended. National League of Cities did nothing to suggest that these concerns are insignificant. We are not prepared to dismiss lightly the contention that the EPA's indirect source argument as applied here collides with the constitutional restraints recognized by National League of Cities.

It is also perhaps worth observing that an adoption of the view that the Commerce Power is plenary and limited only by the political process, in which the states must look to their representatives in Congress for protection, when needed, from federal encroachment, National League of Cities v. Usery, 426 U.S. at 856-880, 96 S. Ct. 2465 (Mr. Justice Brennan's dissent), also would seem to require fairly strict interpretation of legislation in which federal and state interests are in conflict. Put differently, under the view of the dissenters in National League of Cities the judiciary should be reluctant to declare the federal government a winner in these contests between state and federal authorities in which the record reflects, at best, a draw.6

Only one additional comment regarding the constitutional issues which we have avoided is necessary. The Supreme Court in its opinion in which the judgment in Brown I was vacated pointed out that the Court of Appeals for the District of Columbia Circuit had held that it was constitutionally proper for Congress to require a state to deny "registration to a vehicle whose owner is unable to produce a federal certificate of compliance, should a federal inspection program be instituted." (Italics added). 431 U.S. at 103, 97 S. Ct. at 1637. We read the revised inspection and maintenance regulation before us as requiring the imposition of a state inspection system and the denial of registration of a vehicle whose owner cannot produce a state certificate of compliance. We recognize that the requirement validated by the District of Columbia Circuit may well fall within a long recognized power of Congress. In Brown I we said:

"We merely hold that under the Act a state may decline, without becoming liable for sanctions, to undertake a program of control suggested by the Administrator; a state, however, may not interfere with such regulation of the sources of pollution as the Administrator pursuant to the Act undertakes."

521 F.2d at 840.

To require the denial of registration by the state of a vehicle which has failed to pass federal inspection quite plausibly resembles legitimate steps by the federal government to prevent state interference with its regulation of pollution. It merely requires the state to proceed in a certain manner if it is to regulate this aspect of commerce at all. It does not appear to preclude the state's complete withdrawal from vehicle registration.

However, we need not address these issues. We only wish to make plain our recognition of the possible distinction between the constitutional concerns we have expressed, both in Brown I and here, and those which a program such as the District of Columbia Circuit envisioned would present.

Mootness and Ripeness As To Other Regulations Invalidated by Brown I.

As already mentioned, Brown I invalidated a number of regulations, which are set forth at 521 F.2d at 831, and our judgment was vacated in its entirety by the Supreme Court. This proceeding has focused exclusively on the revised inspection and maintenance regulations. For this reason we believe it inappropriate to consider as ripe for decision all other regulations which we previously invalidated. This determination is strengthened by the fact that the EPA's efforts to enforce these regulations have been limited and inconsistent. We are certain that a vigorous effort on the part of EPA to enforce all or part of them will engender a dispute which then will be ripe for decision.

The only exception to our limiting this decision to the revised inspection and maintenance regulations is that our disposition necessarily conflicts with the general language of 40 C.F.R. § 52.23 (violations and enforcement) to the extent that regulation authorizes the imposition of sanctions against the State of California for failure to abide by the revised inspection and maintenance regulation. To that extent we here find 40 C.F.R. § 52.23 not authorized by the Clean Air Act.

Petitions For Review granted in part.