Natl Lime Assn v. EPA , 233 F.3d 625 ( 2001 )


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  •                   United States Court of Appeals
    FOR THE DISTRICT OF COLUMBIA CIRCUIT
    Argued September 5, 2000   Decided December 15, 2000
    No. 99-1325
    National Lime Association,
    Petitioner
    v.
    Environmental Protection Agency,
    Respondent
    Consolidated with
    99-1326
    On Petitions for Review of An Order of the
    Environmental Protection Agency
    Hunter L. Prillaman argued the cause for petitioner Na-
    tional Lime Association.  With him on the briefs were Arline
    M. Seeger and Kenneth A. Rubin.
    James S. Pew argued the cause for petitioner Sierra Club.
    With him on the briefs was Howard I. Fox.
    Daniel M. Flores, Attorney, U.S. Department of Justice,
    argued the cause for respondent.  With him on the brief were
    Lois J. Schiffer, Assistant Attorney General, Daniel R. Dert-
    ke, Attorney, and Steven E. Silverman, Attorney, Environ-
    mental Protection Agency.  Christopher S. Vaden and H.
    Michael Semler, Attorneys, U.S. Department of Justice, en-
    tered appearances.
    William M. Bumpers was on the brief for amicus curiae
    the American Portland Cement Alliance.
    Before:  Edwards, Chief Judge, Ginsburg and Tatel,
    Circuit Judges.
    Opinion for the Court filed by Circuit Judges Ginsburg and
    Tatel.*
    Ginsburg and Tatel, Circuit Judges:  In this case we
    consider petitions by the Sierra Club and the National Lime
    Association challenging the Environmental Protection Agen-
    cy's hazardous air pollutant emission regulations for cement
    manufacturing.  With respect to the Sierra Club petition we
    (1) reject its challenge to the emission standards for hazard-
    ous metals and dioxin/furan;  (2) find the Agency's failure to
    set standards for hydrogen chloride, mercury, and total hy-
    drocarbons contrary to the Clean Air Act's plain language;
    (3) direct EPA to consider the health impacts of potentially
    stricter standards for hazardous metals;  and (4) sustain the
    regulation's monitoring requirements.  Concluding that the
    National Lime Association has associational standing, we (1)
    reject its argument that EPA's use of particulate matter as a
    surrogate for non-volatile metal hazardous air pollutants vio-
    lates the Clean Air Act and is arbitrary and capricious;  and
    (2) reject its challenge to the testing method EPA adopted for
    determining whether a manufacturer qualifies as a "major
    source" of hazardous air pollutants.
    __________
    * Judge Tatel wrote Sections I and II.  Judge Ginsburg wrote
    Sections III and IV.
    I. Background
    The Clean Air Act requires the Environmental Protection
    Agency to establish emission standards for "major sources" of
    hazardous air pollutants listed in the statute.  42 U.S.C.
    s 7412(d)(1).  The Act directs the Agency to review the list
    periodically, and, where appropriate, to revise it by rule.  
    Id. s 7412(b)(2).
     Hazardous air pollutants are known as HAPs.
    A "major source" is any stationary source that emits ten
    tons per year or more of any single HAP or twenty-five
    tons per year or more of any combination of HAPs.  
    Id. s 7412(a)(1).
     Under section 7412(d)(2) of the statute, emis-
    sion standards must require
    the maximum degree of reduction in emissions [of HAPs]
    ... that the Administrator, taking into consideration the
    cost of achieving such emission reduction, and any non-
    air quality health and environmental impacts and energy
    requirements, determines is achievable ... through ap-
    plication of measures, processes, methods, systems or
    techniques including, but not limited to, ... process
    changes, substitution of materials or other modifications.
    In addition to this general guidance, the statute includes
    minimum stringency requirements for emission standards
    that apply without regard to either costs or the other factors
    and methods listed in section 7412(d)(2).  These stringency
    requirements differ depending on whether a source is "new"
    or "existing."  New sources are defined as "stationary
    source[s], the construction or modification of which is com-
    menced after the publication of regulations (or, if earlier,
    proposed regulations) prescribing" air pollution standards
    that will be applicable to such sources.  
    Id. s 7411(a)(2).
     For
    new sources, the statute provides that "[t]he maximum de-
    gree of reduction in emissions that is deemed achievable for
    new sources ... shall not be less stringent than the emission
    control that is achieved in practice by the best controlled
    similar source, as determined by the Administrator."  
    Id. s 7412(d)(3)
    (emphasis added).  For existing sources, defined
    as all stationary sources other than new sources, 
    id. s 7411(a)(6),
    the statute provides that standards shall not be
    less stringent than "the average emission limitation achieved
    by the best performing 12 percent of the existing sources (for
    which the Administrator has emissions information)."  
    Id. s 7412(d)(3)
    (A).
    EPA implements these statutory requirements through a
    two-step process.  The Agency begins by setting the mini-
    mum stringency standards required by section 7412(d)(3) for
    new and existing sources.  Adding confusion to this already
    complex statute, EPA calls these minimum stringency re-
    quirements "floors," even though they in fact establish maxi-
    mum emission levels.  See Sierra Club v. EPA, 
    167 F.3d 658
    ,
    660 (D.C. Cir. 1999) ("Sierra").  Once the Agency sets statu-
    tory floors, it then determines, considering cost and the other
    factors listed in section 7412(d)(2), whether stricter standards
    are "achievable."  42 U.S.C. s 7412(d)(2).  The Agency calls
    such stricter requirements "beyond-the-floor" standards.
    This case concerns emission standards for portland cement
    manufacturing plants.  See National Emission Standards for
    Hazardous Air Pollutants from the Portland Cement Manu-
    facturing Industry, 40 C.F.R. ss 63.1340-.1359.  Patented in
    1824 by Joseph Aspdin and named for its resemblance to
    portland stone, limestone from the Isle of Portland, see 9 The
    New Encyclopedia Britannica 629 (15th ed. 1998), portland
    cement is a fine powder that serves as the key ingredient in
    the concrete used in most construction.  See National Emis-
    sion Standards for Hazardous Air Pollutants;  Proposed Stan-
    dards for Hazardous Air Pollutants Emissions for the Port-
    land Cement Manufacturing Industry, 63 Fed. Reg. 14,182,
    14,185 (Mar. 24, 1998).  The cement manufacturing process
    begins by grinding together materials such as limestone, clay,
    shale, sand, iron ore, and flyash and heating the mixture in a
    kiln.  See 40 C.F.R. s 63.1341;  63 Fed. Reg. at 14,194.
    Known as "clinker," the heated mixture is then cooled in a
    "clinker cooler" and ground to a fine powder in a mill.  See 40
    C.F.R. s 63.1341.
    Prior to setting cement manufacturing emission standards,
    EPA estimated that portland cement plants throughout the
    country emitted a total of 290 tons of HAPs per year.  63
    Fed. Reg. at 14,183.  EPA found that most individual cement
    plants released over ten tons of hydrogen chloride ("HCl")
    annually, qualifying them as major sources of HAPs for which
    the Clean Air Act required the Agency to set emission
    standards.  See 
    id. at 14,192-93.
     In addition to HCl, EPA
    found that cement plants emitted significant levels of HAP
    metals, dioxin/furan, mercury, and organic HAPs other than
    dioxin/furan.  See 
    id. at 14,195-96.
     These HAPs were re-
    leased by kilns, clinker coolers, and mills, as well as by
    storage and transportation of materials within cement plants.
    See 
    id. at 14,183.
     According to EPA, the potential health
    effects of these pollutants include inflammation of the respira-
    tory tract, reproductive problems, cancer, nausea, blood disor-
    ders, and damage to the immune system.  See 
    id. at 14,184.
    Acting on this information, EPA began by considering
    emission "floors" for each of the five major categories of
    HAPs released by cement plants.  For dioxin/furan, the
    Agency set emission floors for both new and existing sources.
    Considering particulate matter ("PM") to be an appropriate
    surrogate for non-volatile HAP metals--components of PM
    that are difficult to measure directly--EPA established emis-
    sion floors for new and existing sources for PM as well.  EPA
    set no floors--referred to as floors of "no control"--for the
    three remaining HAPs, HCl, mercury, and organic HAPs
    other than dioxin/furan.
    The Agency took a technology-based approach to setting
    emission floors.  For cement plants qualifying as new
    sources, EPA identified the emission control technology used
    by the best performing plant for which it had information and
    called this the MACT floor technology.  MACT means "maxi-
    mum achievable control technology."  EPA then looked at
    emissions data for all plants using the MACT floor technology
    for which it had information, not just data from the best
    performing plant, and set the new source emission floor at the
    highest emission level reported by a plant using that technol-
    ogy.  To set existing source emission floors, EPA followed a
    similar procedure.  It identified the technology used by the
    median plant out of the best twelve percent of plants for
    which it had information and set the existing source emission
    floor at the emission level of the worst performing plant in its
    database using that technology.  If, as in the case of HCl,
    mercury, and organic HAPs other than dioxin/furan, EPA
    found an insufficient number of plants in its database (one for
    new sources or twelve percent for existing sources) control-
    ling a particular HAP with pollution control technology, it set
    no standard at all, i.e., it determined that the emission floor
    was "no control."
    Proceeding to the next stage of the emission standard
    setting process, EPA declined (with one exception not rele-
    vant to this case) to set beyond-the-floor standards for either
    new or existing sources for any of the five HAPs.
    In addition to requiring EPA to set emission standards, the
    Clean Air Act directs the Agency to require owners and
    operators of major sources to conduct "enhanced monitoring"
    of their emissions and to submit "compliance certifications"
    reporting compliance with the emission standards.  42 U.S.C.
    s 7414(a)(3).  Acting pursuant to this requirement, EPA di-
    rected cement plants to use a technique known as Fourier
    transform infrared spectroscopy ("FTIR") to measure their
    HCl emissions to determine whether they qualify as major
    sources.  See 40 C.F.R. s 63.1352(a);  
    id. pt. 63,
    app. A.
    Plants qualifying as major sources must conduct performance
    tests that measure PM emissions every five years.  See 
    id. s 63.1349(b)(1),
    (c).  To test for compliance with PM stan-
    dards between performance tests, cement plants must moni-
    tor opacity either with a continuous opacity monitor or
    through visual inspections.  See 
    id. s 63.1350(c).
     Cement
    plants must also develop site-specific operations and mainte-
    nance plans to be submitted to EPA for approval as part of
    the permitting process.  See 
    id. s 63.1350(a).
    Petitioners Sierra Club and National Lime Association
    ("NLA") challenge these regulations.  The Sierra Club
    mounts four specific challenges:  (1) EPA's approach to set-
    ting emission floors for PM and dioxin/furan both violates the
    Clean Air Act and is arbitrary and capricious;  (2) the Agen-
    cy's refusal to set standards for HCl, mercury, and total
    hydrocarbons violates the statute;  (3) EPA's rejection of
    beyond-the-floor standards for mercury, total hydrocarbons,
    and HAP metals (for which PM is a surrogate) is arbitrary
    and capricious;  and (4) the monitoring requirements fail to
    provide adequate assurance of compliance with the PM stan-
    dard.  NLA, a trade association representing lime manufac-
    turers, some of which also manufacture cement, argues that
    (1) EPA's decision to use PM as a surrogate for HAP metals
    violates the statute and is arbitrary and capricious;  and (2)
    the Agency's decision to require cement plants to use the
    FTIR method to determine their major source status is
    arbitrary and capricious.  The American Portland Cement
    Alliance, a trade association representing cement manufactur-
    ers and marketers, intervenes in support of EPA.  We con-
    sider the Sierra Club's challenges in Section II and NLA's in
    Section III.
    II. Sierra Club Petition
    A.    PM and Dioxin/Furan Floors
    Relying on Chevron U.S.A. Inc. v. Natural Resources
    Defense Council, Inc., 
    467 U.S. 837
    , 842-43 (1984) (establish-
    ing that when Congress's intent is clear, "that is the end of
    the matter;  for the court, as well as the agency, must give
    effect to the unambiguously expressed intent of Congress"),
    the Sierra Club argues that the Agency's technology-based
    approach conflicts with the Clean Air Act's plain language.
    According to the Sierra Club, section 7412(d)(3) requires EPA
    to set new source floors at the lowest recorded emission level
    for which it has data and existing source floors at the average
    of the lowest twelve percent of recorded emission levels for
    which it has data.  Nothing in the statute, the Sierra Club
    argues, permits the Agency to set floors based on the perfor-
    mance of technology as opposed to the recorded performance
    of plants.
    In resolving this issue, we do not write on a clean slate.
    EPA's technology-based approach to setting new source emis-
    sion standards has already faced and survived a Chevron one
    challenge.  In Sierra, 
    167 F.3d 658
    , we reviewed a new source
    emission standard for solid waste combustion that EPA pro-
    mulgated pursuant to section 7429, which establishes emission
    requirements virtually identical to section 7412's.  There, as
    here, the Sierra Club argued that EPA's MACT technology
    approach to setting emission standards is unambiguously
    forbidden by the Clean Air Act.  Sierra rejected that argu-
    ment, holding that EPA may estimate the performance of the
    best performing units and that it was not "impossible" that
    EPA's methodology constituted a reasonable estimation tech-
    nique.  
    See 167 F.3d at 665
    .  Concluding that EPA could
    reasonably interpret the statutory phrase "emissions control
    that is achieved in practice" to mean emissions control that is
    "achieved under the worst foreseeable circumstances," see 
    id. (citing National
    Lime Ass'n v. EPA, 
    627 F.2d 416
    , 431 n.46
    (D.C. Cir. 1980)), we hypothesized:  "perhaps considering all
    units with the same technology is justifiable because the best
    way to predict the worst reasonably foreseeable performance
    of the best unit with the available data is to look at other
    units' performance."  
    Id. at 665.
     But because EPA failed to
    explain why it adopted the MACT approach, we remanded to
    the Agency for further explanation, thus never needing to
    determine whether the MACT approach would have survived
    petitioners' Chevron two or arbitrary and capriciousness chal-
    lenges.
    EPA has now explained why it adopted the MACT ap-
    proach.  In the announcement of the regulations challenged
    in this case, the Agency, citing Sierra, explains (1) that it
    must ensure that emission "standards are achievable 'under
    [the] most adverse circumstances which can reasonably be
    expected to recur,' " 64 Fed. Reg. 31,898, 31,915 (June 14,
    1999) (quoting 
    Sierra, 167 F.3d at 665
    ), and (2) that "evaluat-
    ing how a given MACT technology performs is a permissible
    means" of estimating the actual performance of the top
    twelve percent of plants.  
    Id. EPA explains
    further that the
    emission standards it set "are based on the emission levels
    achieved through the application of MACT floor technologies
    and account for variation in the process and in the air
    pollution control device effectiveness."  
    Id. at 31,916.
    The Sierra Club does not challenge EPA's extension of
    Sierra to existing source standards.  Instead, it argues that
    Sierra's Chevron one analysis does not control this case
    because section 7412 (at issue here) differs from section 7429
    (at issue in Sierra).  Although the two sections contain identi-
    cal stringency requirements for new sources, section 7412, the
    Sierra Club emphasizes, directs the Agency to base emission
    standards for existing sources on those plants "for which the
    Administrator has emissions information," 42 U.S.C.
    s 7412(d)(3)(A), a limitation appearing nowhere in section
    7429.  See 
    id. s 7429(a)(2).
     According to the Sierra Club,
    section 7412's additional limitation implies that EPA must
    directly calculate the average of the best twelve percent from
    the data it has, thus precluding the Agency from estimating
    emissions based on the use of MACT technology.
    We do not agree that the difference between the two
    sections requires a different result in this case.  Section
    7412's additional phrase says nothing about what data the
    Agency should use to calculate emission standards.  It says
    only that standards must be based on the best performing
    "sources (for which the Administrator has emissions informa-
    tion)."  42 U.S.C. s 7412(d)(3)(A).  Following this directive,
    EPA set standards for PM and dioxin/furan at the average
    emission levels it estimated the best 12 percent (for which it
    had information) achieved.  In doing so, the Agency simply
    did not limit itself to consideration of data from the best
    twelve percent of plants;  instead it used data it had from
    other plants that use the same technology as the best twelve
    percent to estimate the performance of the best twelve per-
    cent.  Sierra found this approach not unambiguously forbid-
    den by the statute.  
    See 167 F.3d at 665
    .
    Thus bound by Sierra's Chevron one analysis, we turn to
    the Sierra Club's argument that the MACT approach is both
    unreasonable, see 
    Chevron, 467 U.S. at 843
    ("if the statute is
    silent or ambiguous with respect to the specific issue, the
    question for the court is whether the agency's answer is
    based on a permissible construction of the statute"), and
    arbitrary and capricious.  See 42 U.S.C. s 7607(d)(9)(A).  Ac-
    cording to the Sierra Club, EPA has never explained why
    emission floors set through the MACT approach accurately
    estimate the performance of the relevant best performing
    plants:  "The Agency provide[d] absolutely no reason to be-
    lieve that an emission level that is achievable by every source
    that uses a particular control technology is necessarily a
    reasonable estimate of the actual performance of the best
    performing twelve percent of sources."  Sierra Club Br. at
    23.
    We agree that to comply with the statute, EPA's method of
    setting emission floors must reasonably estimate the perfor-
    mance of the relevant best performing plants.  See 42 U.S.C.
    s 7412(d)(3);  
    Sierra, 167 F.3d at 665
    .  Yet the Sierra Club's
    brief does not explain why the emission standards EPA set
    might not accurately estimate the performance of the best
    performing twelve percent of plants.  The brief never even
    suggests that the MACT approach in fact fails to predict the
    emission levels of the best performing sources.  When we
    asked about this at oral argument, it became clear that the
    Sierra Club believes that EPA's MACT approach would not
    accurately estimate emission levels of the best performing
    twelve percent of plants if the best performing plants
    achieved their emission levels not just by using technology,
    but also by selecting cleaner manufacturing inputs.  For
    example, the best performing twelve percent of plants might
    perform well because, in comparison to other plants having
    the same technology, they use less-polluting fuels or purer
    raw materials.  Such plants would have predictably lower
    emissions than plants using MACT floor technology alone.
    Under such circumstances, the Sierra Club argues, because
    technology would represent only one of the factors determin-
    ing emission levels of the best performing plants, EPA could
    not assume that emission levels from the worst-performing
    plant using MACT floor technology predict the performance
    of the best performing plants under the worst conditions.
    Although this argument may well have merit, the Sierra
    Club's failure to include the argument in its opening brief
    precludes us from considering it.  See Corson & Gruman Co.
    v. NLRB, 
    899 F.2d 47
    , 50 n.4 (D.C. Cir. 1990).  Claiming only
    that the Agency has "never explained" why the MACT ap-
    proach accurately predicts the performance of the relevant
    best performing sources falls far short of alerting EPA to the
    argument we now understand the Sierra Club to be making,
    thus giving the Agency no opportunity to respond.  The
    Sierra Club's failure is particularly serious because the
    MACT approach would accurately estimate the performance
    of the best performing sources of a particular HAP if pollu-
    tion control technology were the only factor determining
    emission levels of that HAP--in other words, if emissions
    were unaffected by the use of either alternative fuels or raw
    materials.  To be sure, as the Sierra Club points out in a
    letter submitted after oral argument pursuant to Rule 28(j) of
    our rules, it did raise its multiple control factors argument
    during the rulemaking in a comment regarding emission
    standards for mercury.  Record comments, however, cannot
    cure a failure to raise a key argument here.  We will there-
    fore deny the Sierra Club's petition for review with respect to
    emission floors for PM and dioxin/furan.
    B.   Failure to set floors for HCl, mercury, and total hydro-
    carbons
    EPA established emission floors of "no control" for HCl,
    mercury, and total hydrocarbons (a surrogate for organic
    HAPs other than dioxin/furan) because the Agency found no
    cement plants using control technologies for these pollutants.
    The Sierra Club argues that EPA's failure to set emission
    limits for these HAPs violates the statute's requirement that
    the Agency establish emission standards for each of "the
    hazardous air pollutants listed for regulation."  42 U.S.C.
    s 7412(d)(1).  Defending its decision, EPA points to Sierra's
    suggestion that the worst foreseeable performance of the best
    performing unit might be predictable from the performance
    of the worst performing unit using the same technology.  See
    64 Fed. Reg. at 31,915 (citing 
    Sierra, 167 F.3d at 665
    ).
    According to EPA, if no control technology exists, then the
    worst foreseeable performance "could vary day by day" and
    the standard must be no control.  See EPA Response to
    Comments (May 7, 1999), at 190.
    On this issue, we agree with the Sierra Club.  Nothing in
    the statute even suggests that EPA may set emission levels
    only for those listed HAPs controlled with technology.  To
    the contrary, the statute lists over one hundred specific
    HAPs, 42 U.S.C. s 7412(b)(1), and requires EPA to "promul-
    gate regulations establishing emission standards for each
    category or subcategory of major sources ... of hazardous
    air pollutants listed for regulation."  
    Id. s 7412(d)(1).
     The
    statute directs the Agency to promulgate these emission
    standards by November 15, 2000.  
    Id. s 7412(e)(1)(E).
     Con-
    gress added the list of pollutants to be regulated, regulation
    deadlines, and minimum stringency requirements to the
    Clean Air Act precisely because it believed EPA had failed to
    regulate enough HAPs under previous air toxics provisions.
    "The [air toxics] law has worked poorly.  In 18 years, EPA
    has regulated only some sources of only seven chemicals....
    The legislation reported by the Committee would entirely
    restructure the existing law, so that toxics might be adequate-
    ly regulated by the Federal Government."  S. Rep. No.
    101-228, at 128 (1989);  see also H.R. Rep. No. 101-490, pt. 1,
    at 322 (1990) ("Since 1970, EPA has listed only eight sub-
    stances as hazardous air pollutants ... and has promulgated
    emissions standards for seven of them.").
    Contrary to EPA's argument, nothing in Sierra relieves it
    of the clear statutory obligation to set emission standards for
    each listed HAP.  Although Sierra permits the Agency to
    look at technological controls to set emission standards, 
    see 167 F.3d at 665
    , it does not say that EPA may avoid setting
    standards for HAPs not controlled with technology.
    Although we thus believe that section 7412(d)(1)'s language
    disposes of this issue, we add that our reading of that section
    is reinforced by
    the Clean Air Act's legislative history. A report by the Senate
    Committee on Environment and Public Works states:
    The technologies, practices or strategies which are to be
    considered in setting emission standards under this sub-
    section go beyond the traditional end-of-the-stack treat-
    ment or abatement system.  The Administrator is to give
    priority to technologies or strategies which reduce the
    amount of pollution generated through process changes
    or the substitution of materials less hazardous.  Pollution
    prevention is to be the preferred strategy wherever
    possible.
    S. Rep. No. 101-228, at 168.
    For all of these reasons, the absence of technology-based
    pollution control devices for HCl, mercury, and total hydro-
    carbons did not excuse EPA from setting emission standards
    for those pollutants.  We thus will remand for EPA to do so.
    C.   Beyond-the-Floor Standards
    The Sierra Club presents a number of objections to EPA's
    refusal to set general beyond-the-floor emission standards for
    mercury, total hydrocarbons, and HAP metals (for which PM
    is a surrogate).  Because EPA will now need to initiate new
    rulemaking proceedings to establish emission floors for mer-
    cury and total hydrocarbons, we need not consider the Agen-
    cy's refusal to set beyond-the-floor standards for those two
    HAPs.  We address only the Sierra Club's challenge to the
    Agency's refusal to set beyond-the-floor standards for HAP
    metals.
    When determining whether to set beyond-the-floor stan-
    dards, the Clean Air Act requires EPA to consider "the cost
    of achieving such emission reduction, and any non-air quality
    health and environmental impacts and energy requirements."
    42 U.S.C. s 7412(d)(2).  The Sierra Club argues that EPA
    violated the statute by failing to consider the non-air quality
    health and environmental impacts of potential beyond-the-
    floor standards for HAP metals.  Again, we agree.  Although
    EPA considered costs and energy requirements, nowhere in
    the record does it appear to have taken account of any non-air
    quality health effects.
    EPA's analysis of potential beyond-the-floor standards for
    HAP metals suffers from a second defect.  As the Sierra
    Club points out, EPA, responding to a comment in the
    rulemaking suggesting that stricter emission standards for
    HAP metals could be achieved if cement kilns switched to
    natural gas, asserted that "[t]here are no data available to
    EPA that indicate that [fuel switching] can or has achieved
    metals emission reductions."  64 Fed. Reg 31,917.  Yet a
    study in the record contains just such information, demon-
    strating that switching to natural gas would in fact reduce
    metal emissions.  See Office of Air Quality Planning and
    Standards, U.S. EPA, Study of Hazardous Air Pollutants
    Emissions from Electric Utility Steam Generating Units
    13-2 (1998).  EPA now tells us that fuel switching is not a
    viable alternative because of inadequate supplies of natural
    gas.  In support of this proposition, the Agency points to a
    handwritten notation on a report in the administrative record.
    But that note, supposedly written by an EPA employee, is
    virtually illegible--even the Agency's counsel was unable to
    decipher it at oral argument.  Therefore, the note cannot
    supply a basis for EPA's decision.  Although the Agency's
    brief cites one other study in support of its assertion that the
    supply of natural gas is inadequate, nothing in the rulemaking
    indicates that EPA relied on it.  "[A]n agency's action must
    be upheld, if at all, on the basis articulated by the agency."
    Motor Vehicle Mfrs. Ass'n v. State Farm Mut. Auto. Ins. Co.,
    
    463 U.S. 29
    , 50 (1983).
    Thus, because EPA failed to consider non-air quality health
    and environmental impacts of potential beyond-the-floor stan-
    dards for HAP metals, and because it relied on a factually
    incorrect assertion in rejecting such standards, we will re-
    mand the beyond-the-floor determination for HAP metals for
    further consideration consistent with this opinion.  In view of
    the Sierra Club's request that we not vacate the EPA's
    regulations, because "to do so would at least temporarily
    defeat [Sierra Club's] purpose, the enhanced protection" of
    the environment, Environmental Defense Fund, Inc. v.
    Adm'r of the EPA, 
    898 F.2d 183
    , 190 (D.C. Cir. 1990), we will
    leave the current PM regulations in place during remand.
    D.   Monitoring
    In its final challenge, the Sierra Club argues that the
    regulation's monitoring requirements fail to provide reason-
    able assurance of compliance with the emission standards.
    Specifically, it argues that the opacity monitoring required by
    the regulation will not guarantee compliance with the PM
    standard.  EPA responds that opacity monitoring promotes
    good operation and maintenance, which in turn reasonably
    ensure compliance with the PM standard.  Because the Sier-
    ra Club has given us no basis for doubting this assertion, and
    because analysis of this issue "requires a high level of techni-
    cal expertise, we must defer to the informed discretion" of the
    Agency.  Marsh v. Oregon Natural Resources Council, 
    490 U.S. 360
    , 377 (1989) (internal quotation marks omitted).
    III. Petition of the National Lime Association
    Petitioner National Lime Association (NLA) claims that
    two additional aspects of the portland cement rule are con-
    trary to law and arbitrary and capricious:  the EPA's use of
    PM as a surrogate for HAP metals, and its requirement that
    cement kilns use a specified technique to measure their HCl
    emissions under certain circumstances.  We consider these
    arguments only after concluding that the NLA has standing
    to raise them.
    A.   Standing of the NLA
    The EPA argues that the NLA lacks standing to object to
    the portland cement rule because it is a trade association of
    lime and not of cement manufacturers.  Although the EPA
    recognizes that some NLA members manufacture both ce-
    ment and lime, the agency asserts that the NLA made no
    mention of its cement members during proceedings before
    the agency, "suggesting only that [the portland cement rule]
    could establish adverse precedents ... for the commercial
    lime industry."  The EPA also emphasizes that NLA mem-
    bers that manufacture both lime and cement are also mem-
    bers of the American Portland Cement Association (APCA),
    which--in the view of the agency--adequately represents
    their cement interests.  The APCA, as mentioned above, has
    intervened in this case in defense of the portland cement rule.
    The EPA cites no authority--and we know of none--
    suggesting that the position taken by one association affects
    the right of another to seek judicial review;  and although the
    possibility of an adverse precedent is clearly insufficient to
    establish the injury necessary for standing under Article III,
    an association anxious to avoid an adverse precedent may still
    bring a petition if it otherwise meets the requirements for
    standing.  Those requirements are straightforward:
    [A]n association has standing to bring suit on behalf of its
    members when:  (a) its members would otherwise have
    standing to sue in their own right;  (b) the interests it
    seeks to protect are germane to the organization's pur-
    pose;  and (c) neither the claim asserted nor the relief
    requested requires the participation of individual mem-
    bers in the lawsuit.
    Hunt v. Washington State Apple Advertising Comm'n, 
    432 U.S. 333
    , 343 (1977).  That the NLA meets requirement (c) is
    unquestioned.  In order to prevail on the standing question,
    then, the EPA must show that the NLA fails to meet
    requirement (a) or (b).
    Requirement (a) is met if "any one" of the association's
    members can "make out a justiciable case."  Warth v. Seldin,
    
    422 U.S. 490
    , 511 (1975).  The member must show (i) that it
    was injured in fact, (ii) that its injury was caused by the
    challenged rule, and (iii) that its injury would likely be
    redressed by a favorable decision of the court.  Lujan v.
    Defenders of Wildlife, 
    504 U.S. 555
    , 560-61 (1992).  The NLA
    submits an affidavit from the "Environmental Director" of
    Blue Circle, Inc. affirming that Blue Circle is an NLA mem-
    ber, stating that it operates both cement and lime manufac-
    turing plants, and asserting facts indicating that it meets all
    three elements of requirement (a).  Blue Circle asserts both
    that the use of PM as a surrogate and the HCl measurement
    requirement impose "significant" monitoring and compliance
    costs upon its cement operations, which would be avoided by
    this court's favorable decision.  Blue Circle's specific asser-
    tions as to harm, causation, and redressability are neither
    "general" nor "conclusory," as the EPA suggests.  We con-
    clude, therefore, that the NLA has at least one member that
    could assert a justiciable claim in its own right.
    Beyond injury in fact, causation, and redressability, re-
    quirement (b) of Hunt demands that the interest an associa-
    tion seeks to protect be "germane to the organization's pur-
    
    pose." 432 U.S. at 343
    .  This requirement of germaneness is
    "undemanding";  "mere pertinence between litigation subject
    and organizational purpose" is sufficient.  Humane Soc'y v.
    Hodel, 
    840 F.2d 45
    , 58 (D.C. Cir. 1988).  The subject of this
    litigation is the regulation of portland cement manufacturing;
    that is certainly "pertinent" to the NLA as a trade association
    of manufacturers of lime.  Not only do some companies
    manufacture both cement and lime, but both industries share
    a critical raw material--limestone--and lime itself is some-
    times used as an ingredient in portland cement.  See 63 Fed.
    Reg. at 14,194/2;  J.A.H. Oates, Lime and Limestone 81, 124
    (1998).  The processes underlying the two types of manufac-
    ture are also similar, as is made abundantly clear by the
    NLA's efforts to introduce into the record in this case data
    from the EPA's administrative record regarding the manufac-
    ture of lime.  Ct. Op. at 24-25 below.  The two manufactur-
    ing processes also emit some of the same pollutants.  The
    regulation of portland cement thus falls well within the "spe-
    cialized expertise and research resources" of the NLA.  Hu-
    mane 
    Soc'y, 840 F.2d at 56
    .
    Our analysis of germaneness is unaffected by the EPA's
    argument that the NLA, in advancing its lime interests, has
    taken a position on the cement rule adverse to the interests of
    cement manufacturers.  The NLA is entitled to be an advo-
    cate for a subgroup of cement manufacturers whose interests
    diverge from those of the run of cement producers--for
    example, companies such as Blue Circle that manufacture
    both cement and lime.  Cf. National Maritime Union v.
    Commander, Military Sealift Command, 
    824 F.2d 1228
    , 1234
    (D.C. Cir. 1987) (quoted in Humane 
    Soc'y, 840 F.2d at 59
    n.25) ("mere fact of conflicting interests among members of
    an association does not of itself defeat the association's stand-
    ing to urge the interests of some members in litigation, even
    though success may harm the legal interests of some mem-
    bers").
    Because the NLA has at least one member that could have
    pressed the same claims in its own right, and because those
    claims are germane to the organizational purpose of the NLA,
    we conclude that the association has standing to petition for
    review of the portland cement rule.
    B.   The Use of PM as a Surrogate
    The NLA's primary objection to the portland cement rule
    is that it limits PM emissions from cement kilns instead of
    regulating emissions of HAP metals individually.  The EPA
    justifies its decision to regulate PM as "a surrogate for non-
    volatile HAP metals" by noting first that PM generated by
    cement kilns invariably contains HAP metals, so that prevent-
    ing the emission of a unit of PM necessarily prevents the
    emission of some quantum of HAP metals.  Using PM as a
    surrogate thus "achieves exactly the same level of HAP metal
    emissions limitation" as would be reached were the metals to
    be regulated directly.  The agency also states that "the
    MACT floor equipment and level of control for HAP metals
    ... is identical to that for PM."  Finally, the agency notes
    that the use of a surrogate "eliminates the cost of perfor-
    mance testing to comply with numerous standards for individ-
    ual metals."  64 Fed. Reg. at 31,916/3.
    The EPA may use a surrogate to regulate hazardous
    pollutants if it is "reasonable" to do so.  See Dithiocarbamate
    Task Force v. EPA, 
    98 F.3d 1394
    , 1399 (D.C. Cir. 1996) (EPA
    may attribute characteristics of a subclass of substances to an
    entire class of substances if doing so is scientifically reason-
    able);  NRDC v. EPA, 
    822 F.2d 104
    , 125 (D.C. Cir. 1987)
    (EPA may regulate pollutant indirectly when its emissions
    are controllable by regulation of other pollutants).  Even a
    reasonable surrogate, of course, may not be used where doing
    so would be otherwise contrary to law.  The NLA does not
    challenge the legality of surrogacy in general, but does main-
    tain that in this case the use of PM as a surrogate is both
    contrary to law and unreasonable.
    1.   Legality of using a criteria pollutant as a surrogate
    The NLA argues first that the EPA may not use PM as a
    surrogate for HAP metals because PM is a criteria pollu-
    tant--one of several ubiquitous pollutants that the EPA
    regulates by establishing national ambient air quality stan-
    dards (NAAQS) under ss 108-09 of the Clean Air Act.  42
    U.S.C. ss 7408-09.  The provision authorizing the EPA to
    regulate HAPs in the Clean Air Act is limited by the qualifi-
    cation that "no [criteria] air pollutant ... may be added to
    the list [of regulable HAPs]."  
    Id. s 7412(b)(2).
     The NLA
    argues that although surrogates for HAPs are permissible in
    general, using a criteria pollutant as such a surrogate has the
    effect of regulating that pollutant as a HAP "through the
    back door" and thus illicitly supplementing (or even supplant-
    ing) the NAAQS applicable to that pollutant.
    The EPA suggests first that the NLA's interpretation is
    inconsistent with the stated expectation of the Congress that
    HAP metals might be regulated under the Clean Air Act by
    way of a PM surrogate, but the agency's point is not well-
    taken.  The EPA relies principally upon a report accompany-
    ing Senate Bill 1630, a version of which would ultimately
    become the Clean Air Act Amendments of 1990.  The report,
    in a discussion of the EPA's discretionary authority to lower
    the level of emissions that qualifies a facility as a "major
    source" of HAPs, see 42 U.S.C. s 7412(a)(1), notes that the
    agency may find this power "especially useful in the control of
    particulate emissions including metals for some source cate-
    gories."  S. Rep. No. 101-228, at 151.  The authors of the
    report thus appear to have contemplated that the regulation
    of "metals" could be subsumed by controls placed upon
    "particulate emissions."
    The report, however, was issued in conjunction with Senate
    Bill 1630 as it went to the floor of the Senate on December 20,
    1989.  In that version of the bill, the passage that would have
    become s 7412(b)(2) authorized the Administrator to add to
    the list of hazardous air pollutants any additional pollutants
    which present, or may present, ... a threat of adverse
    human health effects (including, but not limited to, sub-
    stances which are known to be, ... carcinogenic [etc.,]
    but not including effects for which a pollutant has been
    listed pursuant to section 108 of [the Clean Air] Act).
    S. 1630, 101st Cong. s 301, at 324 (1989) (emphasis added).
    The italicized clause in the reported version of Senate Bill
    1630 does not appear in the statute as enacted.  The sentence
    that appears in the legislation that the Congress ultimately
    passed, and upon which the NLA bases its statutory claim,
    provides:  "No air pollutant which is listed under section
    7408(a) of this title [i.e., s 108 of the Clean Air Act,] may be
    added to the list [of HAPs] under this section."  42 U.S.C.
    s 7412(b)(2).
    The italicized clause in the unenacted bill is materially
    different from the statutory provision upon which the NLA
    bases its claim.  The earlier version would have prohibited
    the regulation of a criteria pollutant as a HAP only if such
    regulation was based upon the same reason for which the
    pollutant was listed as a criteria pollutant under s 108.  The
    final statute, by contrast, unqualifiedly prohibits listing a
    criteria pollutant as a HAP, that is, regardless of the reason.
    Because the comment in the Senate Report regarding PM
    and metals was made before the blanket prohibition upon
    regulating PM as a HAP was added to the statute, the report
    is irrelevant to our construction of s 7412(b)(2) as enacted.
    The enacted statute, to which we now turn, prohibits the
    addition of any criteria pollutant to "the list" of HAPs, with a
    single exception for certain precursor pollutants not relevant
    to this case.  See 
    id. This prohibition
    extends of necessity
    not only to rules that literally list a criteria pollutant as a
    HAP but also to any rule that in effect treats a criteria
    pollutant as a HAP.  As the EPA shows, however, the
    portland cement rule does not treat PM as a HAP generally;
    it regulates only PM that is emitted from cement kilns.  The
    rule does not treat PM, unlike a HAP metal, as a pollutant
    the emissions of which determine whether a cement plant is a
    "major source" of emissions.  See 
    id. s 7412(a)(1).
     Nor does
    the EPA suggest in any way that it contemplates broad
    regulation of PM pursuant to s 7412.  To the contrary, all of
    the evidence upon which the agency relies to justify its use of
    PM as a surrogate is particular to the cement industry.  See
    Memorandum from Elizabeth Heath, Research Triangle In-
    stitute, to Joseph Wood, EPA 2-8 (Feb. 21, 1996);  Memoran-
    dum from Michael Benson, Research Triangle Institute, to
    Mary Johnson, EPA 1 (June 21, 1993);  Portland Cement
    Ass'n, An Analysis of Selected Trace Metals in Cement and
    Kiln Dust at 3-4 (1992).  We therefore conclude that the use
    of PM as a surrogate for HAP metals is not contrary to law.
    2.   Reasonableness of the PM surrogate
    The NLA also contends that PM is an unreasonable surro-
    gate for HAP metals because HAP metals make up a "very
    small and variable" portion of cement kiln PM emissions.
    The NLA faults the EPA both because it did not demonstrate
    and quantify a consistent correlation between PM stack emis-
    sions and their HAP metal content, and because it selected a
    surrogate of which HAP metals make up only "about one
    tenth of one percent."
    The EPA acknowledges both points.  The closest the agen-
    cy comes to making a numerical estimate of the correlation
    between PM and the HAP metals it contains is the statement
    that "the total average HAP metal content of kiln exhaust
    PM is approximately one weight percent."  63 Fed. Reg. at
    14,195/2.  The EPA thus admits that the ratio of HAP metals
    to total particulates is small;  and the agency nowhere dis-
    cusses the variance associated with its estimated average.
    The EPA contends, however, that it justified the surrogacy
    adequately by demonstrating that "where there is cement kiln
    PM, HAP metals are always in it, and when cement kiln PM
    is removed from emissions, HAP metals are always removed
    with it."  According to the EPA, as long as it demonstrates
    that there is a correlation between HAP metals and PM, it
    need not quantify that correlation or assess its variability
    because PM control technology is such that each unit of PM
    emissions avoided "carries" within it some quantum of HAP
    metals.
    The agency's analysis is not unreasonable.  If HAP metals
    are invariably present in cement kiln PM, then even if the
    ratio of metals to PM is small and variable, or simply
    unknown, PM is a reasonable surrogate for the metals--
    assuming, as both the EPA and the NLA appear to do, that
    PM control technology indiscriminately captures HAP metals
    along with other particulates, an assumption about which we
    say more in the next paragraph.  The EPA is under no
    obligation to achieve a particular numerical reduction in HAP
    metal emissions;  it must reduce their emission only to the
    level "achieved" by the best performing facility or, for exist-
    ing sources, to the level achieved by the median of the best-
    performing 12 percent of facilities.  42 U.S.C. s 7412(d)(3).
    If PM control is the only means by which facilities "achieve"
    reductions in HAP metal emissions, then the EPA may
    require PM control without quantifying the reduction in HAP
    metals thus achieved.
    We should add, however, that the EPA may need to
    reconsider whether PM is an appropriate surrogate for HAP
    metals when, upon remand, it considers whether to establish
    beyond-the-floor standards for HAP metals (for which PM is
    a proxy).  We held above, see Ct. Op. at 14, that the EPA
    must consider the potential impact upon emissions of changes
    in inputs to the cement manufacturing process, especially the
    possibility of fuel switching.  The EPA decided to use PM as
    a surrogate for HAP metals because PM control technology
    traps HAP metal particles and other particulates indiscrimi-
    nately.  In considering the role of inputs, the EPA must also
    assure itself that fuels and other inputs affect HAP metal
    emissions in the same fashion that they affect the other
    components of PM.  For example, PM might not be an
    appropriate surrogate for HAP metals if switching fuels
    would decrease HAP metal emissions without causing a corre-
    sponding reduction in total PM emissions.
    3.   The NLA's other arguments against PM as a surrogate
    The NLA offers several other reasons for thinking the
    EPA's use of PM as a surrogate for HAP metals might be
    unreasonable or contrary to law, but each of them is without
    merit.  First, the NLA claims that the use of PM as a
    surrogate is incompatible with the agency's own methodology
    for setting MACT floors.  According to the NLA, this meth-
    odology requires the agency to set a floor of "no control" for
    HAP metals because no cement plant intentionally controls
    HAP metals;  metal emissions are controlled only incidentally
    by controls placed upon PM.  The EPA's response is the
    correct one:  "cement plants actually are controlling HAP
    metals[,] [i]ntentionally or not."  The Clean Air Act requires
    the EPA to set MACT floors based upon the "average
    emission limitation[s] achieved," 42 U.S.C. s 7412(d)(3);  it
    nowhere suggests that this achievement must be the product
    of a specific intent.  Moreover, as we have seen, the EPA's
    floor-setting methodology does not permit the agency to set a
    MACT floor of "no control" simply because no controls are in
    place, see Ct. Op. at 12 above;  a fortiori, the EPA may not
    set such a floor when the controls are in place but the cement
    kilns have not intentionally deployed them for that purpose.
    Second, the NLA claims that the EPA, in limiting PM
    emissions, failed to meet the statutory requirement to "tak[e]
    into consideration the cost of achieving ... emissions reduc-
    tion[s]" for the underlying HAP metals.  42 U.S.C.
    s 7412(d)(2).  According to the NLA, the per unit cost of
    preventing HAP metal emissions is prohibitively high.  Cost,
    however, may be taken into account only in considering
    beyond-the-floor emissions limitations, which in the case of
    PM we have remanded to the agency;  cost may not influence
    the determination of a MACT floor, which depends exclusive-
    ly upon the emissions reductions achieved by the best-
    performing sources.  See 
    id. s 7412(d)(3).
     Relatedly, the
    NLA also claims that in light of both the high costs and the
    low quantities of HAP metals to be controlled, the EPA
    should read a de minimis exception into the requirement that
    it regulate all hazardous air pollutants emitted by major
    sources.  The EPA reasonably rejected this argument on the
    ground that the statute "does not provide for exceptions from
    emissions standards based on de minimis principles where a
    MACT floor exists."  Response to Comments at 211.
    C.   Measurement of HCl Emissions
    HCl is emitted in sufficient quantity from most cement
    kilns to qualify each kiln as a "major source," that is, a source
    that "emits or has the potential to emit considering controls,
    in the aggregate, 10 tons per year or more of any [HAP]," 42
    U.S.C. s 7412 (a)(1).  See 63 Fed. Reg. at 14,192-93.  The
    challenged rule allows a single technique for measuring HCl
    emissions from a cement kiln--Fourier Transform Infrared
    Spectroscopy (FTIR)-if the kiln "wishes to claim it is not a
    major source."  64 Fed. Reg. at 31,907/2.  The EPA refused
    to allow kilns to use two other methods--so-called Method 26
    and its variant, Method 26A--to support such a claim be-
    cause, in the agency's view, these methods "may underesti-
    mate HCl emissions by a factor of 2 to 25."  63 Fed. Reg. at
    14,193/1.  The NLA claims that this determination was un-
    lawful and arbitrary and capricious.  It also asserts that the
    EPA acted unlawfully when it refused to consider NLA's
    comments suggesting potential improvements in Method
    26/26A.
    The NLA bases its claim upon data regarding Method
    26/26A that it submitted to the EPA but the agency did not
    consider.  The EPA was under no obligation to do so, howev-
    er, because the materials the NLA cites were not part of the
    administrative record.  All but one of the letters from the
    NLA transmitting the disputed information to the EPA are
    dated after June 26, 1998, the close of the comment period.
    64 Fed. Reg. at 31,900/1.  Information submitted to the
    agency out of time is incorporated into the administrative
    record only if the Administrator of the EPA determines that
    it is "of central relevance to the rulemaking."  42 U.S.C.
    s 7607(d)(4)(B)(i).  Because she did not so determine, the
    NLA may not present arguments based upon that informa-
    tion.
    The one document the NLA proffers that was submitted
    within the comment period is a letter dated June 22, 1998,
    transmitting a summary of a conference call that day between
    officials of the NLA and of the EPA.  See Letter from Arlene
    Seeger, Executive Director, NLA, to Joseph P. Wood, EPA 1.
    The June 22 letter nowhere suggests, however, that it is
    being submitted in connection with the proposed portland
    cement rule.  Instead, as is also implied in later correspon-
    dence between the EPA and the NLA, the conference call
    appears to have been part of an ongoing dialogue between the
    agency and the NLA regarding a proposed rule affecting the
    lime industry.  The EPA is not required to consider in its
    deliberations here information apparently submitted in con-
    nection with a different rulemaking proceeding when no one
    timely asked it to do so.
    The NLA also suggests that the EPA unlawfully failed to
    consider several pages of handwritten calculations that pur-
    port to test whether another approach to measuring HCl
    emissions--gas filter correlation infrared spectroscopy
    (GFCIR)--generates biased results relative to FTIR.  The
    EPA concedes that this test should have been, but was not,
    included in the administrative record.  As the EPA points
    out, however, the omission is immaterial because the agency
    used the calculations only to determine that GFCIR was too
    biased to be a usable testing method--and the NLA does not
    challenge that determination.  We therefore conclude that the
    EPA was not required to consider the data the NLA cites in
    deciding that Method 26/26A could not be used to challenge
    "major source" determinations.
    Separately, the EPA concedes that it failed to consider the
    NLA's properly submitted comments regarding possible im-
    provements to Method 26/26A.  We therefore remand this
    matter to the agency so that it may respond to those com-
    ments.
    IV. Conclusion
    In summary, we remand the rule to the EPA to allow the
    agency to (1) set "MACT floor" standards for HCl, mercury,
    and total hydrocarbons;  (2) consider setting "beyond-the-
    floor" standards for HAP metals;  and (3) respond to com-
    ments suggesting improvements to Method 26/26A for meas-
    uring HCl emissions.  With respect to all other issues dis-
    cussed herein, the petitions are denied.
    So ordered.