Court Opinion

ID: 2962065
Source: CourtListenerOpinion
Date Created: 2015-09-21 20:52:09.140061+00
Date Added: 2024-06-11T11:42:25.713050
License: Public Domain

USCA1 Opinion

	

                                       UNITED STATES COURT OF APPEALS                            UNITED STATES COURT OF APPEALS                                FOR THE FIRST CIRCUIT                                FOR THE FIRST CIRCUIT                                 ____________________        No. 92-2227                                 SIERRA CLUB, ET AL.,                               Plaintiffs, Appellants,                                          v.                              THOMAS D. LARSON, ET AL.,                                Defendants, Appellees.                                 ___________________        No. 92-2323                                 SIERRA CLUB, ET AL.,                               Plaintiffs, Appellants,                                          v.                              THOMAS D. LARSON, ET AL.,                                Defendants, Appellees.                                ______________________                    APPEALS FROM THE UNITED STATES DISTRICT COURT                          FOR THE DISTRICT OF MASSACHUSETTS                   [Hon. Edward F. Harrington, U.S. District Judge]                                               ___________________                                 ____________________        No. 92-2282                                 SIERRA CLUB, ET AL.,                                     Petitioners,                                          v.                                 JULIE BELAGA, ETC.,                                     Respondent.                                 ____________________                           PETITION FOR REVIEW OF AN ORDER                        OF THE ENVIRONMENTAL PROTECTION AGENCY                                _____________________                                        Before                                Boudin, Circuit Judge,                                        _____________                           Campbell, Senior Circuit Judge,                                     ____________________                              and Stahl, Circuit Judge.                                         _____________                                 ____________________            Thomas  B. Bracken  with  whom Bracken  & Baram  was on  brief for            __________________             ________________        appellants.            George B.  Henderson, II, Assistant  United States Attorney,  with            ________________________        whom  Myles  E.  Flint,  Acting Assistant  Attorney  General,  A. John              ________________                                         _______        Pappalardo,  United States  Attorney,  Robert L.  Klarquist, Attorney,        __________                             ____________________        Department  of  Justice,  Michael   Kenyon,  Attorney,  United  States                                  ________________        Environmental Protection Agency, Judith Tracy, Attorney, United States                                         ____________        Environmental Protection Agency and Irwin Schroeder, Attorney, Federal                                            _______________        Highway  Administration,   were  on  joint  brief   of  appellees  and        respondent, for federal appellees.            William  L. Pardee,  Assistant Attorney  General, Commonwealth  of            __________________        Massachusetts,   with  whom   Scott  Harshbarger,   Attorney  General,                                      __________________        Commonwealth  of Massachusetts, was  on joint  brief of  appellees and        respondent, for state appellees.                                 ____________________                                    August 6, 1993                                 ____________________                 BOUDIN, Circuit Judge.   In this  case, the Sierra  Club                         _____________            appeals  from the judgment of the district court declining to            enjoin construction of the central artery/third harbor tunnel            project in Boston.  It also petitions to review the action of            the Environmental Protection Agency in approving an amendment            to  Massachusetts  state  regulations  that  bears  upon  the            project.   We affirm the district court and deny the petition            for review.                          I. THE FACTS AND PRIOR PROCEEDINGS                 Massachusetts, through its  Department of Public  Works,            has  begun construction  of a  mammoth project  that includes            rebuilding a  major segment of  Interstate Route 93  that now            runs on a  viaduct through  downtown Boston and  is known  as            "the central artery."  When the central artery/tunnel project            is  completed some  years  from now,  the highway  segment in            question will be widened, sunk below ground level, and mostly            covered.  It  will connect  at the  north with  a new  bridge            across the Charles River and at the south with a newly  built            third  harbor  tunnel  running  from South  Boston  to  Logan            Airport in East Boston.                 The depressed and covered portion of the new highway and            the  tunnel will  be  ventilated by  ducts  and fans  in  six            buildings located  on the highway  route and near  the tunnel            portals.   Vast amounts of air will be drawn into the covered            highway  and tunnel, and the mixture of air and motor vehicle                                         -3-                                         -3-            emissions will be  pumped up  through the  six buildings  and            exhausted  through stacks ranging  from 90 to  225 feet high.            Studies  indicate  that  the  project  will  reduce   traffic            congestion,  increase  average speeds,  and  reduce area-wide            carbon monoxide and hydrocarbon emissions.                 The  Sierra  Club,  a  non-profit  environmental  group,            believes that whatever the  area-wide effects of the project,            it will create new "hot spots" of pollution in certain of the            neighborhoods near  to the six ventilation buildings.  In its            view, pollution  control equipment,  in the nature  of after-            burners,  should be  installed in the  ventilation buildings.            The federal and  state governments, which have  filed a joint            brief in this case, deny that any dangerous hot spots will be            created,  pointing  to  studies  conducted  as  part  of  the            project's environmental review.  They also assert that after-            burner  technology  is  not   feasible  because  of  the  low            concentration of pollutants in the vented air.                 In  March  1991,  the Sierra  Club  and  certain  of its            members  who  live  in the  vicinity  of  the central  artery            brought  suit in district court against a collection of state            and  federal  officials associated  with  the  project.   The            gravamen of the  suit was  the Sierra Club's  claim that  the            ventilation buildings  planned  for the  project comprised  a            "major stationary  source" of air  pollution as that  term is            used in the  Clean Air Act,  42 U.S.C.    7401, et seq.,  and                                                            _______                                         -4-                                         -4-            counterpart Massachusetts regulations,  310 C.M.R.   7.00  et                                                                       __            seq.   It is common ground that, if the ventilation buildings            ___            were so classified,  then the project would  require a permit            or permits from Massachusetts that have not been secured.  To            frame this issue entails a brief description of the statute.                 The Clean  Air Act  enacted a complex  statutory regime,            several times amended, to  control and mitigate air pollution            in  the  United States.   Broadly  speaking,  Title I  of the            statute  regulates stationary sources  of pollution and Title            II regulates mobile sources, most importantly motor vehicles.            For  specified pollutants, national air quality standards are            promulgated  by  EPA.    42  U.S.C.     7409.    Whether  new            construction of polluting facilities is permitted in an area,            and what  kind of controls  are required, depends  on whether            the area is below  or above the standard for  each pollutant.            Part C,  42 U.S.C.     7470-7492,  governs permits where  the            standard  has  been attained;  Part  D  applies to  so-called            nonattainment areas.  Id.    7501-7515.                                   __                 In  either  event, the  construction  of  a "major"  new            stationary source--normally, one emitting 100 or more tons of            pollutant  each  year,  see 42  U.S.C.     7602(j)--generally                                    ___            requires  a permit.  42 U.S.C.     7475(a), 7502(c)(5).1   In                                            ____________________                 1The definition  of "major stationary source" in section            7602(j) directly governs permits under part  D where the same            phrase is  used in  section 7502(c)(5)'s  permit requirement.            Part  C  requires  permits  for  specified  "major   emitting            facilities," in  areas already  in compliance  with pollution                                         -5-                                         -5-            the case of  Boston, some  of the pollutants  that will  flow            through  the proposed ventilation  buildings currently exceed            national standards so  that new major sources  are subject to            the more stringent class of limitations; other pollutants are            below the standards and less stringent limitations apply.  By            way of example, the Boston area exceeds the national standard            for  carbon  monoxide, and  to  secure a  permit  the highway            proponents would have to show that a  major stationary source            can achieve  the "lowest  achievable emission rate"  for that            pollutant.  42 U.S.C.   7503(a)(2).                 The  Clean Air Act  allocates different responsibilities            to the EPA  on the one hand  and to the states on  the other.            Each  state  is  directed to  adopt  and  submit  to EPA  for            approval a state implementation  plan to achieve and maintain            the  national standards  established  by EPA.    42 U.S.C.               7410(a).  See also  id.    7471, 7502.  If the state fails to                      ________  __            adopt  an  approvable  plan,   the  EPA  must  adopt  federal            regulations   for   the  area.      42   U.S.C.      7410(c).            Massachusetts  has an  approved  state  implementation  plan.            Under  the Clean Air Act,  "citizen" suits may  be brought to            enjoin  a project that requires  a permit under  Parts C or D            but has not obtained one.  42 U.S.C.   7604(a)(3).                                            ____________________            standards, 42 U.S.C.    7475, 7479,  but--with qualifications            not  here  relevant--the  statute instructs  that  the  terms            "major stationary  source" and "major  emitting facility"  be            used interchangeably.  42 U.S.C.   7602(j).                                         -6-                                         -6-                 In  this case, in April 1991 the Sierra Club and certain            of  its  members  sought  a  preliminary  injunction  against            construction of the  central artery and tunnel  project.  The            request was  denied on July 30, 1991.   After transfer of the            case to  another judge,  the district court  received further            briefing  and argument.    On September  16, 1992,  the court            granted  summary   judgment  in   favor  of   the  government            defendants, state and  federal, holding that the  ventilation            buildings did not comprise stationary sources subject to pre-            construction permit  requirements.   The Sierra Club  and its            named members appealed.                 Shortly before the lawsuit, the Massachusetts Department            of  Environmental   Protection  submitted   to  the   EPA  on            January 30, 1991, a new regulation--regulation 7.38, codified            as  310  C.M.R.     7.38--as  a  proposed  amendment  to  the            Massachusetts  state  implementation plan.    This regulation            seeks  to classify  tunnel  ventilation systems  as "indirect            sources" under the Clean  Air Act.   In the early 1970s,  the            EPA  had begun  to  require that  state implementation  plans            regulate  such  facilities  as  parking  lots,  highways  and            garages that  do not  emit pollutants themselves  but attract            numbers of polluting vehicles.  Congress responded in 1977 by            barring the EPA from regulation of what were called "indirect                                         -7-                                         -7-            sources."  42 U.S.C.   7410(a)(5)(B).2   However, Congress at            the same time gave  the states permission, if they  so chose,            to regulate such indirect sources themselves as part of their            state implementation plans.  Id.    7410(a)(5)(A), (C).                                           __                 Massachusetts, exercising this option through regulation            7.38,    proposed   to  regulate  roadway/tunnel  ventilation            systems   as  indirect   sources.      The  regime   involves            certification   by  the  builder   that  specified  pollution            standards will  be met,  and the Department  of Environmental            Protection may  accept, conditionally approve,  or reject the            certification after  notice and  hearing.   Monitoring  after            construction and  periodical renewal  of the certificate  are            required.  The  new regulation also  states that the  systems            are not  subject to the pre-construction  permitting required            for  various  stationary sources  under regulation  7.02, 310            C.M.R.   7.02.                 The Sierra Club opposed  the approval of regulation 7.38            when Massachusetts submitted it to the EPA as an amendment to            the state implementation plan.   The Sierra Club  argued that            the  effect would  be indirectly  to  relieve the  project at            issue  in this  case of  the more  stringent pre-construction                                            ____________________                 2To the  extent that a  highway or other  major indirect            source  is federally  assisted, the  EPA retains  some direct            regulatory authority,  see 42 U.S.C.    7410(a)(5)(B); but no                                   ___            claim has  been made  that  the project  in this  case is  in            violation of any requirements laid down by the EPA under this            reservation.                                         -8-                                         -8-            approval required of major stationary sources under the Clean            Air  Act  and the  Massachusetts  regulations  that apply  to            stationary  sources.   After  notice  and  receipt of  public            comments, the EPA on October 8, 1992, published notice of its            approval,  57 Fed. Reg. 46310  (1992).  The  Sierra Club then            petitioned  for review  of  the EPA's  action  in this  court            pursuant to 42 U.S.C.   7607(b)(1).                 Because of the  overlapping issues  and common  subject,            this  court  consolidated  the  two appeals  taken  from  the            district court judgment with the proceeding for direct review            of  the EPA  action.   In this  opinion, we  address first  a            jurisdictional  objection raised  by the  federal defendants,            then statutory issues posed by the appeals from the  district            court,  and  finally  the  additional  issues  posed  by  the            Massachusetts regulations  and by the petition  to review the            EPA's action approving regulation 7.38.                                   II. JURISDICTION                 The   federal  defendants  renew  in  this  court  their            argument,  not passed  upon  below, that  the district  court            "lacked jurisdiction" over the  complaint against the federal            defendants.  The  "citizen suits" provision of  the Clean Air            Act permits private suits in three defined classes of  cases.            As  already  noted,  it  explicitly permits  a  private  suit            against  anyone   who  "proposes  to   construct"  any  major            stationary  source without a permit required by parts C or D.                                         -9-                                         -9-            42 U.S.C.    7604(a)(3).   The federal  defendants deny  that            they  are proposing to construct  the project or  any part of            it; in other  words, they argue that if anyone  is subject to            suitunder subsection(a)(3), itis onlyMassachusetts officials.                 The  statute  also  permits  such  citizen  suits  where            emission standards or limitations  are exceeded, or where the            EPA  Administrator has failed to perform an act or duty under            the Clean  Air Act "which  is not  discretionary . .  ."   42            U.S.C.     7604(a)(1),  (2).   As  to  these categories,  the            federal  defendants argue  that  any violations  of  emission            standards or  limitations would  be those of  the state,  and            that the  EPA Administrator  cannot be  sued for  violating a            non-discretionary duty since enforcement by the Administrator            is inherently a discretionary matter.                 The  Sierra  Club,  responds, unpersuasively,  that  any            jurisdictional objection  has been  waived by the  failure of            the federal defendants to cross appeal.3   More usefully, the            Sierra Club urges that  the Administrator did violate a  non-            discretionary duty by  failing to take  action to enjoin  the            project,  and   that  in   any  event  the   Federal  Highway            Administration  is so  closely  involved in  the funding  and            planning of this project as to  be effectively a party to its                                            ____________________                 3The  jurisdictional  objection  could be  viewed  as an            alternative  ground   for   sustaining  the   denial  of   an            injunction,  dispensing with any need for a cross appeal.  In            any  event, courts  are  expected to  "notice" jurisdictional            objections even if no one has raised them.                                         -10-                                         -10-            construction.  However, like the government brief, the Sierra            Club's  brief is  silent  as to  what practical  implications            these questions have in  this case where no one  has disputed            that   Massachusetts  defendants   can   be   enjoined   from            construction if a permit is required.                 Absent some  showing that  the jurisdictional  issue has            practical importance in  this case, we decline to address it.            Since  the Massachusetts  officials are  subject to  suit for            constructing the project without a permit, the merits must be            reached in  any event.   And since we  resolve the merits  in            their  favor,  the jurisdictional  issue  as  to the  federal            defendants is pretty  close to moot, affecting  only the form            of the  dismissal as to them.   There is  ample precedent for            by-passing jurisdictional objections when  the court can more            easily dismiss on the  merits.  E.g., Norton v.  Mathews, 427                                            ____  ______     _______            U.S. 524, 532 (1976).                               III. THE STATUTORY ISSUES                 The  merits  of  the  appeals from  the  district  court            judgment  turn principally  on  a narrow  point of  statutory            construction, namely, whether the ventilation  buildings that            will vent the underground  highway and harbor tunnel comprise            a "stationary source or sources" within the meaning the Clean            Air Act.  If so labeled, a permit is required; apparently the            amount  of pollutant needed to qualify as a "major" source is            not  at issue.    Easily stated,  the  issue is  less  easily                                         -11-                                         -11-            resolved: there is little by way  of statutory definition, no            useful  judicial precedent or  legislative history offered to            us, and a reasonable possibility that Congress never gave any            thought  to  the  idiosyncracy  posed  by  these  ventilation            buildings.                   Starting as one normally does with language, parts C and            D, which contain the pre-construction permit requirements for            major stationary sources, originally contained  no definition            of  stationary  source.   Instead  part  D  defines  a "major            stationary  source" as  "any  stationary facility  or source"            emitting the  specified quantity  of pollutant.   Part C,  by            cross-reference  (see  note  1,   above),  adopts  the   same            language.    Part  A, concerned  with  so-called  performance            standards, other than air quality standards, did use the term            "stationary  source" in 42 U.S.C.   7411, defining it as "any            building, structure, facility, or installation which emits or            may  emit any air pollutant."  42 U.S.C.    7411(a)(3).  That            definition,  however,  was  adopted  "for  purposes  of  this            section," i.e., section 7411.4                        ____                                            ____________________                 4The obscurity  of the  relationship between the  part A            definition just  quoted and the "major  stationary source" in            parts C and D was the subject of comment by the Supreme Court            in Chevron U.S.A., Inc. v. Natural Resources Defense Council,               ____________________    __________________________________            Inc., 467 U.S. 837,  859-860 (1984).  Yet  another definition            ____            of stationary  source appears  in, and is  apparently limited            to, a provision  of part A concerned with  accidental release            of hazardous substances.  See 42 U.S.C.   7412(r)(2)(C).                                      ___                                         -12-                                         -12-                 Thus far the breadth of the  language appears helpful to            the Sierra Club position, since linguistically  a ventilation            system  with a stack could be called a "facility," a "source"            or even a "building."  The table tilted back the other way in            1977  when Congress  amended  the Clean  Air  Act to  exclude            "indirect   sources"  from   mandatory   coverage  in   state            implementation  plans.    42  U.S.C.     7410(a)(5)(A).    An            indirect source is defined in the statute as                 a facility, building, structure, installation, real                 property, road,  or highway which attracts,  or may                 attract, mobile  sources of pollution.   Such  term                 includes parking  lots, parking garages,  and other                 facilities subject to any measure for management of                 parking supply  . . . .            42 U.S.C.   7410(a)(5)(C).  Asserting that auto makers should            bear  the  brunt  of  reducing  tailpipe  emissions, Congress            imposed the limitations already  described on the EPA efforts            to regulate the magnets for vehicles rather than the vehicles            themselves.  See  H.R. Rep.  No. 294, 95th  Cong., 1st  Sess.                         ___            219-227 (1977).                 Although indirect sources are not in terms excluded from            the definition of stationary sources--the former provision is            cast instead as  a limitation on EPA authority--the effect of            the amendment  is  to treat  indirect sources  as a  separate            category of sources subject to a different legal regime.  The            states  may  still  "choose[]"  to  regulate  them  in  state            implementation  plans, 42  U.S.C.     7410(a)(5)(i), but  the            decision whether and how  to regulate is left largely  to the                                         -13-                                         -13-            states.   Our best reading  of the statute is  that, at least            after 1977,  an indirect  source is  not to be  treated as  a            stationary  source under Parts C  and D.   Cf. South Terminal                                                       __  ______________            Corp. v. EPA,  504 F.2d  646, 669 (1st  Cir. 1974)  ("parking            _____    ___            structures, which themselves emit  no pollutants but  instead            only  attract   vehicles  which   emit  pollution,   are  not            stationary sources").                 Assuming that a stationary source and an indirect source            are  exclusive  categories,  the difficult  question  remains            whether ventilation  buildings should be  assimilated to  the            former or to the latter.   It is a question that dictionaries            cannot answer.   The terms  are technical rather  than common            ones,  and they  were developed against  the background  of a            complex statute  with  interlocking provisions  and  specific            goals.  Nor does  legislative history furnish any clue  as to            Congress' intent  for  ventilation buildings.   Perhaps  this            small corner  among possible applications of  the statute was            simply overlooked.                 Similarly,  it  is difficult  to  derive  any clear  cut            answer  from analogy or policy.5  A covered highway or tunnel                                            ____________________                 5The Sierra Club urges that the definition of stationary            source is analogous to the  definition of "point source",  33            U.S.C.    1362(14), in the Clean Water Act and that we should            regard  the  related  caselaw  as precedent.    See  National                                                            ___  ________            Wildlife v. Gorsuch, 693 F.2d  156, 173-174 (D.C. Cir. 1982).            ________    _______            We find little help from a different term used in a different            statutory scheme.  Nor  do we think that it  matters whether,            as the  Sierra Club  asserts, pollution tests  or projections            done by  engineers for  the ventilation  systems are akin  to                                         -14-                                         -14-            with  a ventilation system is akin to an uncovered highway or            open  sided  garage--clearly,  indirect sources--in  multiple            senses: in each instance the  facility or space attracts more            cars, pollution in the vicinity may be greatly increased, and            the initial source  of the pollution is  the cars themselves.            On the other hand, the possibility exists (no information has            been  provided to  us  on the  point)  that the  large  scale            ventilation systems  may  be more  potent than  a highway  or            garage  in  concentrating  and  expelling  pollutants   in  a            specific area; and  on this  ground, if no  other, one  might            distinguish between  them and  a facility that  is ordinarily            ventilated without  mechanical aid.  Thus  the analogy hardly            dispels all doubt.                 Two other  arguments pressed by  the parties seem  to us            inconclusive.   The Sierra Club points us to a new provision,            added  to  Title  I in  1990  without  limitation  as to  its            application,  which for  the  first time  defines  stationary            source as meaning "generally  any source of an air  pollutant            except those  emissions resulting  directly from an  internal            combustion  engine  for  transportation purposes  or  from  a            nonroad engine or nonroad vehicle  as defined in section 7550            .  . . ."  42 U.S.C.   7602(z).  The Sierra Club stresses the            word   "directly,"  arguing  that   the  emissions  from  the                                            ____________________            those  done for  stationary sources;  presumably, they  would            also be similar if the system vented a large garage, which is            unquestionably an indirect source.                                         -15-                                         -15-            ventilation shaft do not fit the  "except" clause because the            auto emissions  are emitted first ("directly,"  in the Sierra            Club's  view) into the air  of the covered  highway or tunnel            andonly thengatheredbyfansand spewedoutthroughtheventilators.                 The government brief offers its  own parsing of this new            language, but  both sides'  arguments about what  is "direct"            and  what  is an  "indirect" emission  have  the flavor  of a            Medieval dispute in theology.   The reality is that  Congress            framed  this new  subsection  (z) to  deal  with an  entirely            different problem,  namely, to include  within the stationary            source definition mobile sources  of pollution, like ships in            port and  portable asphalt  concrete plants,  so far  as they            emit pollutants as part of their stationary activities, e.g.,                                                                    _____            by leaking fuel at dockside  (in contrast to engine emissions            that   occur  when  the  ship  or  plant  travels  to  a  new            destination).   S. Rep. No.  228, 101st Cong.,  1st Sess. 376            (1990).  In other words,  Congress was not addressing  tunnel            ventilation when it drew up this new provision.                 Conversely,  we  are  doubtful  about  the  government's            argument   based  upon   the   structure   of  the   statute.            Admittedly,  Congress did  establish  two different  regimes:            that  in Title  I,  with  which  we are  concerned,  governed            stationary  sources;  that  in   Title  II  created  a  quite            different regime, part of which is familiar to anyone who has            a  car  inspected, to  regulate  vehicle emissions  directly.                                         -16-                                         -16-            This  symmetry could  suggest  that  tailpipe  pollution--the            source of the pollutants at issue here--was not meant to fall            within Title I at all.  The difficulty is that Congress might            not have minded two layers of control, and contrivances  like            the "indirect  source" provision in  Title I blur  the notion            that auto pollution is exclusively a Title II problem.                 In the end,  we think the balance is  tipped here by the            explicit administrative interpretation  of the Clean Air  Act            adopted  by the EPA.  In approving the addition of regulation            7.38  to Massachusetts'  state  implementation plan,  the EPA            stated:                 Tunnel ventilation  systems, which do  not generate                 their  own  emissions  but  rather   simply  funnel                 emissions from mobile  sources, are not  stationary                 sources  within the meaning of the Clean Air Act.              57 Fed. Reg. 46310, 46311 (1992).  The Supreme Court has told            us that in  construing a statute the courts should ordinarily            show  a  measure  of  deference to  the  agency  charged with            administering the  statute.6  The  case most often  cited for            that  precept   is  Chevron,   which  involved  a   different                                _______            application of  the very  same "stationary  source" provision            that is now before us.                                            ____________________                 6See Environmental Protection Agency v. National Crushed                  ___ _______________________________    ________________            Stone Ass'n, 449 U.S. 64, 83 (1980); Chevron, U.S.A., Inc. v.            ___________                          _____________________            Natural Resources Defense Council, Inc., 467 U.S. 837 (1984);            _______________________________________            United  States v. City of  Fulton, 475 U.S.  657, 666 (1986);            ______________    _______________            National Labor Relations Board v. Food and Commercial Workers            ______________________________    ___________________________            Union, 484 U.S. 112, 123 (1987).            _____                                         -17-                                         -17-                 The Chevron doctrine has been the subject of much debate                     _______            and,  in subsequent  decisions,  the Supreme  Court may  have            softened its  impact somewhat and  in some situations.   See,                                                                     ____            e.g., INS v. Cardoza-Fonseca,  480 U.S. 421, 448 (1987).   To            ____  ___    _______________            be  sure,  the  courts  have   the  last  word  on  statutory            interpretation--the  question  is one  of  the  weight to  be                                                            ______            accorded to agency views--and often the statute's language or            history  leaves no latitude for  the agency.   In other cases            the  issue  of  interpretation  may  be  so  central  to  the            operation  of  the statute  that,  whether  or not  Congress'            meaning  is clear, it  is improbable that  Congress meant for            the courts to  defer to the agency.  We do not think these or            other qualifications on Chevron deflect its impact here.                                    _______                 On the contrary, this statute  is ambiguous on the issue                                                __            before us,  at least when  the words "stationary  source" are            read  together with  the  "indirect source"  proviso and  the            structural  juxtaposition  of  Titles  I   and  II.       The            application of the stationary and indirect source language to            tunnel  ventilation is  not the  heart of  the statute  but a            fringe  issue on which  Congress did not  clearly express its            intent.   The  Clean  Air Act  is  an immensely  complex  and            technical statute  more familiar to EPA than  to anyone else,            and  the   task  of   making  its  parts   function  together            harmoniously is entrusted to many actors but above all to the            EPA.                                           -18-                                         -18-                 In sum this is a case in which Chevron  and deference to                                                _______            the agency  are  not make-weights  or  subsidiary  arguments.            Rather,  in  this  fairly  debatable  case,  where  statutory            language  is  ambiguous, legislative  history  is silent  and            policies  and analogies can be and have been mustered on both            sides,  we  think  that  the EPA's  unqualified  and  precise            reading  is  decisive.     It  is  unnecessary  to  calibrate            perfectly  the weight to be accorded to  the agency view in a            case of this species:  once "considerable" weight is accorded            to EPA's reading  of the  statute, see Chevron,  467 U.S.  at                                               ___ _______            844, it is enough to tip a set of scales otherwise so closely            balanced.                  IV. THE MASSACHUSETTS REGULATIONS AND EPA APPROVAL                 Our concern  with the district  court case is  not quite            over.   Even if Congress  did not  designate the  ventilation            facilities  in   this   case  as   stationary  sources,   the            possibility  remains that  Massachusetts  has adopted  in its            state implementation plan--and then  sought to ignore for its            own construction project--pertinent  legal restrictions  that            can be implemented through a  suit under the Clean Air Act.              Of  course, not every state-law restriction on a project is a            matter of federal  concern, but a  state restriction that  is            part of a federally  approved state implementation plan under            the  Clean  Air Act  may at  least  in some  circumstances be                                         -19-                                         -19-            within the purview of a citizens suit under 42 U.S.C.   7604.                 At  one point  in its  brief, the  Sierra Club  seems to            argue  that whatever  Congress may  have meant  by stationary            source,  Massachusetts  in  its  general  permit  requirement            regulation  7.02,  310  C.M.R.     7.02,  has  required  pre-            construction approval of a  class of facilities that includes            the ventilation  buildings  in this  case.   One  version  of            regulation  7.02   has  been  approved  by  EPA  as  part  of            Massachusetts'   state   implementation   plan.      Although            Massachusetts has  adopted a later version  not yet approved,                                                        ___            we will  assume arguendo that the  original, approved version                            ________            of the regulation still exists as a matter of federal law and            that a violation of this version  might well be remedied by a            citizen suit under the federal statute.7                 The difficulty  with the Sierra Club's  argument, as the            government brief points out, is  that this regulation on  its            face applies  to a short  list of specific  facilities (e.g.,                                                                    ____            chemical products manufacturing plants)  that do not  include            highways,  tunnels or  associated ventilation  systems.   The                                            ____________________                 7The  Sierra  Club  also  argues that  the  more  recent            version of regulation 7.02 applies to the project (or  would,            if not invalidly qualified  by regulation 7.38); but we  need            not  decide whether  the  more general  language  of the  new            version could embrace highway and tunnel ventilation systems.            The  new  version  does  not  reflect  a  federally  approved            requirement, nor do we think that it casts any light upon, or            represents an exercise of authority under, the older version.                                         -20-                                         -20-            regulation  also applies  to  "such other  facilities as  the            [state]   Department   [of   Environmental  Protection]   may            require,"  but  that  state  agency  has  not  required  pre-            construction review of  the ventilation buildings  under this            version of the regulation.  The most that the Sierra Club can            extract  from the  affidavit  submitted by  the  head of  the            agency is that his  agency wobbled over  the issue of how  to            regulate the ventilators at issue  in this case, and  finally            decided to propose the  "indirect source" regime now embodied            in regulation 7.38.                   Regulation 7.38  which  now governs  tunnel  ventilation            systems says  that they are  not subject to  regulation 7.02.            We think that this exclusion seeks to remove ambiguity and is            very weak  evidence that the  new version of  regulation 7.02            would otherwise cover such systems, and no evidence at all of            the meaning of  the old version.   Nor do  we agree with  the            Sierra  Club that its reading of old regulation 7.02 is borne            out by Town of Brookline v. Commissioner of the Department of                   _________________    _________________________________            Environmental Quality  Engineering, 387 Mass. 372, 439 N.E.2d            __________________________________            372 (1982).  That case involved the application of regulation            7.02  to   a  diesel  fuel-powered  facility   (in  fact,  an            electrical generating station), which is listed as a facility            automatically covered by old regulation 7.02.                 To  construe   the  old  version   of  regulation   7.02            definitively is  a daunting  task, for  it was complex,  ill-                                         -21-                                         -21-            structured, and apparently confusing even to the state agency            that administered it.  But the Sierra Club's argument depends            upon a showing by it that  the old regulation 7.02 did govern            highway and tunnel ventilation systems.  Such systems do  not            fall within the list of  specifically named facilities in the            regulation.   Similarly, the Sierra  Club has not  shown that            the state agency ever extended that version of the regulation            to such systems under the "may require" clause.                 This  brings us to the attack on regulation 7.38 that is            the subject of  Sierra Club's  direct review  petition.   One            might  at first wonder why  the Sierra Club  is interested in            overthrowing a  regulation which, if less  stringent than the            pre-construction  permit  requirement  for  major  stationary            sources,  is  at least  a sizable  step  in the  direction of            regulating ventilation  systems, a  step that the  state need            not  take at all if--as  the EPA has  ruled--such systems are            not  stationary  sources  but  merely  adjuncts  to  indirect            sources.    Indeed,  the   EPA's  notice  approving  the  new            regulation  notes  that   the  Conservation  Law   Foundation            endorsed it.  57 Fed. Reg. 46310, 46311 (1992).                 The answer  is that  the Sierra Club,  with considerable            imagination, has constructed the following argument: the 1990            amendments to  the Clean Air  Act contained a  savings clause            that  sought to  forbid  states from  softening pre-amendment            "control requirement[s]"  in areas that had  not attained the                                         -22-                                         -22-            national air quality  standard for a  pollutant, 42 U.S.C.               7515;  the Boston area has admittedly not met these standards            for certain pollutants; and  therefore (says the Sierra Club)            regulation 7.38 is in violation of the savings clause because            it substitutes  as to  tunnel ventilation systems  the softer            regime of  the new regulation  7.38 for  the more  stringent,            previously applicable regime of regulation 7.02.                 We will assume without  deciding that the savings clause            would prevent  the weakening of a  state implementation plan.            But even so  we do not  read the savings  clause to refer  to            anything  other than  an effective, federally  approved state            implementation plan.8  It is  the older version of regulation            7.02  which alone was federally  approved at the  time of the            1990 Clean  Air Act Amendments.   And, as  already explained,            the Sierra  Club has failed  to establish that  the pertinent            older version of regulation 7.02 did apply to covered highway            or tunnel ventilation systems.  Accordingly, regulation  7.38                                            ____________________                 8As Senator Chafee explained in the floor debate on this            provision:                      "The  savings  provision was  intended to                      ensure  that there  is no  backsliding on                      the   implementation   of   adopted   and                      currently feasible measures that  EPA has                      approved    as    part    of   a    State                      implementation plan in  the past, or that                      EPA has  added to State plans  on its own                      initiative or pursuant  to a court  order                      or settlement."            136 Cong. Rec. S17,237 (daily ed., October 26, 1990).                                         -23-                                         -23-            does  not  weaken a  federally approved  state implementation            plan but rather strengthens  it by extending a new  regime to            such  ventilation  systems   where  previously  no  federally            approved regime applied at all.                   We are  left with two  further arguments in  relation to            regulation  7.38.  First, it is  claimed that regulation 7.38            is  invalid because, according to  the Sierra Club, the state            was  required  by  M.G.L. ch.  111,     142A,  to obtain  the            approval of  the Governor of Massachusetts  and the Executive            Council  but did  not  do so.    This argument  was  made, it            appears,  on the premise  that regulation 7.38  was needed by            the government defendants in order  to remove a bar otherwise            presented by regulation 7.02.   As we have seen,  the premise            is mistaken, and invalidating  regulation 7.38 would probably            free the ventilation  systems from any federally  enforceable            regulation.                 Nevertheless,   the    issue   of   governor-and-council            approval,  although irrelevant  to the injunction  action, is            raised by the Sierra Club's petition to review EPA's approval            of the new regulation.  Since the direct review statute has a            time limit  on petitions, 42  U.S.C.   7607(b)(1),  we cannot            properly defer decision on the validity of regulation 7.38 to            some future point.  Indeed,  EPA in approving the regulation,            noted  that Massachusetts'  Secretary  of State  had attested            that  the regulation  was  properly adopted,  and EPA  itself                                         -24-                                         -24-            ruled  that the  Massachusetts  Department  of  Environmental            Protection  had authority "to  adopt such regulations without            approval  by  the Governor  and Council."    57 Fed.  Reg. at            46312.                 It is difficult for anyone  but a Massachusetts court to            pronounce  with  certainty  on  this  issue.    But when  the            regulation  is attested  by  the state  secretary as  validly            adopted and its procedural validity  is supported in a  brief            signed  by the  state's  attorney general,  it  would take  a            rather  strong  showing  to  persuade  us to  hold  that  the            regulation is  invalid on  procedural grounds.   Assuming (as            seems likely) that its procedural  validity is open to review            in this  court and that the state  secretary's attestation is            necessary but  not conclusive,9  we think that  EPA correctly            concluded that the  regulation was  properly adopted  without            the approval of governor and council.                 The state in submitting regulation 7.38 to  the EPA said            that it was  adopted pursuant to M.G.L. ch.  111,    142B and            142D, not section  142A.  Section  142B establishes a  Boston            area pollution  control district and gives  the Department of            Environmental  Protection   authority  to  issue   rules  and            regulations to prevent pollution in the district.  Regulation                                            ____________________                 9The  Clean   Air  Act  requires  a   state  to  provide            "necessary assurances" that it  has authority under state law            to  carry  out   the  implementation  plan.    42   U.S.C.               7410(a)(2)(E)(i).                                         -25-                                         -25-            7.38, which  is directed exclusively to  the Boston district,            appears  to fit comfortably within the ambit of section 142B.            The  rulemaking provision  of  section 142B,  unlike  section            142A, contains no  requirement for approval  of rules by  the            state's governor or council.                 The  Sierra   Club's  contrary  argument  is   based  on            confusing  language  in M.G.L.  ch.  111,    142A,  a broader            provision governing air pollution in general.  In its opening            sentence,  this   section   says  that   the  Department   of            Environmental Protection,  "in this section  and in  sections            one hundred and forty-two  B to one hundred and  forty-two E,            inclusive, hereinafter  called the department" may subject to            the approval of the governor and council adopt regulations to            control pollution.   Id.   The  Sierra Club  apparently reads                                 ___            this sentence as  extending the governor-and-council approval            requirement of section 142A to rules made under section 142B.                 We think the more natural reading of the quoted language            in  section 142A  is to  specify that the  term "department,"            when  used without  further  explanation in  the cited  later            sections,  means the Department  of Environmental Protection.            Section  142B,   for  example,   does  refer  only   to  "the            department."    Nor   is  there  anything  remarkable   about            requiring    governor-and-council   approval    for   general            regulations while not doing so for those directed to a single            district;  indeed, the  Sierra  Club reading  would make  the                                         -26-                                         -26-            grant  of  rulemaking   power  in  section  142B   redundant.            Accordingly, we  reject this challenge to  the EPA's approval            and dismiss the petition to review.                 The  government  brief   construes  the  Sierra   Club's            argument to embrace, in addition  to the claim just rejected,            a  further  claim  that  regulation 7.38  cannot  be  applied            "retroactively" to the  central artery and tunnel at issue in            this case.  The  regulation by its terms is intended to apply            to the project.   See 310 C.M.R.   7.38(1).   In response the                              ___            government  argues at  length  that under  Massachusetts  law            whatever retroactivity  may be  involved in applying  the new            regime  to a  previously  planned but  unbuilt  portion of  a            project is permissible.                 It  is not entirely clear that the Sierra Club is making            the argument  attributed to it  by the  government.   However            this may be, the EPA did not suggest that its approval of the            regulation  depended on how or whether it would be applied to            existing  projects; the  EPA's  notice of  approval does  not            discuss  retroactivity at all.  There is no reason to suppose            that  EPA's approval is at all dependent on the retroactivity            issue.   We have no  need, in fact  no warrant, to  decide an            issue  that  is not  material  either to  the  district court            judgment nor  to the validity  of the EPA action  that is the            subject of the petition to review.                                           -27-                                         -27-                 The judgment of  the district  court is  affirmed.   The                                                          ________            petition for review is denied.                                   ______                                         -28-                                         -28-