94-22344. Standards of Performance for New Stationary Sources: Municipal Waste Combustors  

  • [Federal Register Volume 59, Number 181 (Tuesday, September 20, 1994)]
    [Unknown Section]
    [Page 0]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 94-22344]
    
    
    [[Page Unknown]]
    
    [Federal Register: September 20, 1994]
    
    
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    ENVIRONMENTAL PROTECTION AGENCY
    40 CFR Part 60
    
    [AD-FRL-5068-5]
    
     
    
    Standards of Performance for New Stationary Sources: Municipal 
    Waste Combustors
    
    AGENCY: Environmental Protection Agency (EPA).
    
    ACTION: Proposed rule and notice of public hearing.
    
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    SUMMARY: The EPA is proposing a new subpart Eb to regulate emissions 
    from new municipal waste combustor (MWC) units for which construction, 
    modification, or reconstruction began after September 20, 1994.
        Today's proposal would implement sections 111 and 129 of the Clean 
    Air Act (Act). The proposed rule would apply to new MWC units at 
    facilities with aggregate capacities to combust greater than 35 
    megagrams per day (Mg/day; a megagram is a metric ton, and one megagram 
    is equal to 2,204 pounds or about 1.1 short tons) of municipal solid 
    waste (MSW) and would require sources to achieve emission limits 
    reflecting the maximum degree of reduction in emissions of air 
    pollutants that the Administrator determines is achievable, taking into 
    consideration the cost of achieving such emission reduction, and any 
    non-air-quality health and environmental impacts and energy 
    requirements. The proposed rule establishes emission limits for MWC 
    acid gases (sulfur dioxide (SO2) and hydrogen chloride (HCl)), MWC 
    metals (particulate matter (PM), opacity, cadmium (Cd), lead (Pb), and 
    mercury (Hg)), MWC organics (dioxins/furans), nitrogen oxides 
    (NOx), and MWC fugitive fly ash/bottom ash. The proposed rule 
    would also establish standards for MWC operating practices (carbon 
    monoxide (CO), load, flue gas temperature at the PM control device 
    inlet, and operator training/certification) and siting requirements for 
    new MWC units.
    
    DATES: Comments. Comments must be received on or before November 21, 
    1994.
        Public Hearing. A public hearing will be held about 15 days 
    following proposal. See SUPPLEMENTARY INFORMATION for additional 
    information regarding the public hearing.
    
    ADDRESSES: Comments. Comments on the proposal should be submitted (in 
    duplicate, if possible) to: Air and Radiation Docket and Information 
    Center (Mail Code 6102), ATTN: Docket No. A-90-45, Room M1500, U.S. 
    Environmental Protection Agency, 401 M Street, SW., Washington, DC 
    20460. See SUPPLEMENTARY INFORMATION for additional information 
    regarding submittal of comments.
        Background Information. The key background information for the 
    proposal includes: (1) A document entitled ``FACT SHEET: New Municipal 
    Waste Combustors--Proposed Subpart Eb NSPS,'' which succinctly 
    summarizes the proposal, and (2) several technical documents listed 
    under SUPPLEMENTARY INFORMATION, including all of the background 
    information documents that supported the proposal and promulgation of 
    the subpart Ca emission guidelines. See SUPPLEMENTARY INFORMATION for 
    instructions for obtaining these documents.
        Docket. Docket Nos. A-89-08 and A-90-45, containing supporting 
    information used in developing the proposed standards, are located at 
    the EPA's Air and Radiation Docket and Information Center, Waterside 
    Mall, Room M1500, Central Mall, 401 M Street, SW., Washington, DC 
    20460. The docket may also be accessed by calling (202) 260-7548. See 
    SUPPLEMENTARY INFORMATION for further information regarding the docket.
    
    FOR FURTHER INFORMATION CONTACT: Mr. Walter Stevenson at (919) 541-5264 
    or Mr. Fred Porter at (919) 541-5251, Standards Development Branch, 
    Emission Standards Division (MD-13), U.S. Environmental Protection 
    Agency, Research Triangle Park, North Carolina 27711.
    
    SUPPLEMENTARY INFORMATION:
    
     Background Information
    
        On December 20, 1989, the EPA proposed new source performance 
    standards (NSPS) for new MWC's in subpart Ea of 40 CFR part 60. The 
    subpart Ea NSPS were promulgated on February 11, 1991 and were 
    developed under authority of paragraph (b) of section 111 of the Act of 
    1977. The Act of 1990 requires the EPA to review these emission 
    standards and determine if they are fully consistent with the 
    requirements of section 129. The EPA has reviewed the subpart Ea NSPS 
    and has concluded that they are not fully consistent with the 
    requirements of section 129 of the Act of 1990. Therefore, the EPA is 
    proposing a new NSPS in subpart Eb that would fully comply with the 
    requirements of section 129. Municipal waste combustors that begin 
    construction, modification, or reconstruction after September 20, 1994, 
    and that meet all other applicability criteria, would be subject to the 
    proposed subpart Eb. Municipal waste combustors that were constructed, 
    modified, or reconstructed after December 20, 1989 and on or before 
    September 20, 1994, and that meet all other applicability criteria, 
    would remain subject to the subpart Ea NSPS and would not be subject to 
    the proposed subpart Eb NSPS. Those sources subject to subpart Ea 
    would, however, also be subject to the emission guidelines that are 
    being proposed under subpart Cb in a separate notice in today's Federal 
    Register. The proposed subpart Cb emission guidelines would be 
    applicable to sources constructed, modified, or reconstructed on or 
    before September 20, 1994.
        The Federal Register notices for the proposed NSPS and a proposed 
    EPA test method that is associated with the NSPS, and the economic 
    impacts analysis associated with the proposed NSPS are listed below and 
    are available on the EPA's Technology Transfer Network (TTN) electronic 
    bulletin board. Also listed below and available on the EPA's TTN is a 
    FACT SHEET, which succinctly summarizes the proposal and is suggested 
    reading for persons requiring a limited overview of the proposal. The 
    TTN contains 18 electronic bulletin boards, and the items listed below 
    are included in the Clean Air Act Amendments (CAAA) bulletin board and 
    the Emissions Measurement Technical Information Center (EMTIC) bulletin 
    board. The FACT SHEET can also be obtained by calling Ms. Cassie Posey 
    at (919) 541-0069.
    
    MWC Items in the CAAA Electronic Bulletin Board
    
        (1) ``FACT SHEET: New Municipal Waste Combustors--Subpart Eb 
    Proposed NSPS.''
        (2) Federal Register notice for this proposal: ``Standards of 
    Performance for New Stationary Sources: Municipal Waste Combustors'' 
    (this document).
        (3) ``Economic Impact Analysis for Proposed Emission Standards and 
    Guidelines for Municipal Waste Combustors,'' EPA-450/3-91-029, March 
    1994.
    
    MWC Items in the EMTIC Electronic Bulletin Board
    
        1. ``Emissions Test Method 29: Determination of Metals Emissions 
    from Stationary Sources (1994 Proposal),'' EPA-454/R-94-016, April 1994 
    (the document includes both the Federal Register proposal notice 
    (chapter 1) and the full text of the rationale and regulations for the 
    proposal (chapter 2)).
        The TTN is accessible 24 hours per day, 7 days per week, except 
    Monday morning from 8 a.m. to 12 p.m., when the system is updated. The 
    service is free, except for the cost of the phone call. Dial (919) 541-
    5742 to access the TTN. The TTN is compatible with up to a 14,400 bits-
    per-second (bps) modem. Further instructions for accessing the TTN can 
    be obtained by calling the help desk at (919) 541-5384.
        The background information for today's proposal includes all of the 
    documents that supported the proposal and promulgation of the subpart 
    Ea NSPS (Docket No. A-89-08), as well as information in Docket No. A-
    90-45. Key background information documents used in developing the 
    subpart Ea NSPS and today's proposed standards are as follows:
        (1) ``Municipal Waste Combustors--Background Information for 
    Proposed Standards: 111(b) Model Plant Description and Cost Report,'' 
    EPA-450/3-89-27b, August 1989;
        (2) ``Municipal Waste Combustors--Background Information for 
    Proposed Standards: Post-Combustion Technology Performance,'' EPA-450/
    3-89-27c, August 1989;
        (3) ``Municipal Waste Combustion Assessment: Combustion Control at 
    Existing Facilities,'' EPA-600/8-89-057, August 1989;
        (4) ``Municipal Waste Combustion Assessment, Technical Basis for 
    Good Combustion Practices,'' EPA-600/8-89-063, August 1989;
        (5) ``Municipal Waste Combustors--Background Information for 
    Proposed Standards: Control of NOX Emissions,'' EPA-450/3-89-27d, 
    August 1989;
        (6) ``Municipal Waste Combustors--Background Information for 
    Proposed Standards: Cost Procedures,'' EPA-450/3-89-27a, August 1989; 
    and
        (7) ``Economic Impact Analysis for Proposed Emission Standards and 
    Guidelines for Municipal Waste Combustors,'' EPA-450/3-91-029, March 
    1994.
        Docket Nos. A-89-08 and A-90-45 are available for public inspection 
    and copying between 8 a.m. and 4 p.m., Monday through Friday, at the 
    location specified in the ADDRESSES section of this preamble. A 
    reasonable fee may be charged for copying. Additionally, the docket may 
    be accessed by telephone, as specified in the ADDRESSES section.
        Comments. Today's action is a proposal and comments are requested. 
    The MWC regulations are complex, and the EPA expects to receive 
    numerous comments on this proposal. The EPA has specifically requested 
    comments on items fundamental to the proposal, including but not 
    limited to the MACT floor, MACT performance levels, and materials 
    separation plans. The EPA seeks full public participation in arriving 
    at its final decisions, and strongly encourages comments on all aspects 
    of this proposal from all interested parties. Whenever applicable, full 
    supporting data and detailed analyses should be submitted with all 
    comments to allow the EPA to respond to the comments.
        Commenters wishing to submit proprietary information for 
    consideration should clearly distinguish such information from other 
    comments, and clearly label it ``Confidential Business Information.'' 
    Submissions containing such proprietary information should be sent 
    directly to the following address, and not to the public docket, to 
    ensure that proprietary information is not inadvertently placed in the 
    docket: Attention: Mr. Walter Stevenson, c/o Ms. Melva Toomer, U.S. EPA 
    Confidential Business Manager, 411 W. Chapel Hill Street, Room 944, 
    Durham, North Carolina 27701. Information covered by such a claim of 
    confidentiality will be disclosed by the EPA only to the extent allowed 
    and by the procedures set forth in 40 CFR part 2. If no claim of 
    confidentiality accompanies a submission when it is received by the 
    EPA, it may be made available to the public without further notice to 
    the commenter.
        Public Hearing. The public hearing will be held to provide 
    interested parties an opportunity for oral presentations of data, 
    views, or arguments concerning the proposed standards (see DATES for 
    the hearing schedule). The public hearing will be held at Research 
    Triangle Park, North Carolina, and will start at about 9 a.m. Persons 
    wishing to present oral testimony at the public hearing must call Ms. 
    Julia Latta at (919) 541-5578 at least 2 days in advance of the public 
    hearing. Persons interested in attending the hearing should also call 
    Ms. Latta to verify the time, date, and location of the hearing. 
    Persons may call (919) 541-5264 to hear a recorded message that 
    provides current information on the status of the public hearing.
        Preamble Outline. The following outline is provided to aid in 
    locating information in this preamble.
    I. Introduction
        A. Summary of Regulatory Decisions
        B. New Source Performance Standards--General Goals
        C. Overview of this Preamble
    II. Summary of the Proposed Subpart Eb Standards
        A. Source Category to be Regulated
        B. Pollutants to be Regulated
        C. Format for the Proposed Standards
        D. Proposed Standards
        E. Comparison of the 1991 NSPS and Today's Proposed NSPS
        F. Performance Testing and Monitoring Requirements
        G. Reporting and Recordkeeping Requirements
    III. Impacts of the Proposed Standards
        A. Incremental Impacts of the Proposed NSPS over the 1991 NSPS
        B. Impacts of the Proposed NSPS Over a Pre-1989 Baseline
    IV. Rationale for Proposed Standards for MWC Emissions
        A. Background
        B. Selection of Source Category
        C. Modification or Reconstruction of Existing MWC's
        D. Selection of Designated Pollutants
        E. Selection of Affected Facilities
        F. Selection of Maximum Achievable Control Technology
        G. Selection of Format for the Proposed Standards
        H. Performance Test Methods and Monitoring Requirements
        I. Reporting and Recordkeeping Requirements
    V. Rationale for the Proposed Standards for Siting Requirements
        A. Overview
        B. Siting Analysis
        C. Materials Separation Plan
        D. Public Meeting and Reporting Requirements
    VI. Rationale for the Proposed Standards for Fugitive Fly Ash/Bottom 
    Ash Emissions
        A. Background
        B. Fugitive Emission Control Techniques
        C. Proposed Fugitive Emissions Standards
    VII. Proposed Standards for Air Curtain Incinerators
    VIII. Comparison of the Proposal and European Emission Limits
    IX. Miscellaneous
    X. Administrative Requirements
        A. Public Hearing
        B. Docket
        C. Clean Air Act Procedural Requirements
        D. Office of Management and Budget Reviews
        E. Regulatory Flexibility Act Compliance
    
    I. Introduction
    
        This section provides an introduction to the proposed rule by: (1) 
    Summarizing the history of the development of NSPS for new MWC's over 
    the past 7 years; (2) summarizing the general goals of the proposed 
    rule that are specified by sections 111(d) and 129 of the Act of 1990; 
    and (3) providing a brief overview of the major issues discussed in 
    this preamble.
    
    A. Summary of Regulatory Decisions
    
        During the early and mid-1980's, several studies were performed to 
    determine whether MWC emissions should be regulated and, if so, under 
    what section of the Act. As set forth in the advance notice of proposed 
    rulemaking (ANPRM) (52 FR 25399, July 7, 1987), the EPA decided to 
    regulate air emissions from MWC's under section 111 of the Act, and 
    based the regulation on best demonstrated technology (BDT), as required 
    by section 111. On December 20, 1989, the EPA proposed NSPS for new 
    MWC's and emission guidelines for existing MWC's (54 FR 52251 and 54 FR 
    52209, respectively). On November 15, 1990, the Clean Air Act 
    Amendments of 1990 were enacted and added section 129 to the Act. 
    Section 129 of the Act specifies that revised NSPS and emission 
    guidelines must be developed for MWC's in accordance with the 
    requirements of sections 111 and 129. Section 129 further specifies 
    that revised NSPS and emission guidelines be developed for both large 
    and small MWC's and that the revised NSPS and emission guidelines must 
    reflect a more restrictive standard of performance. Section 129 
    includes a schedule for revising the 1991 NSPS. When the EPA did not 
    comply with that schedule, the Sierra Club and the Natural Resources 
    Defense Council (NRDC) filed a complaint with the U.S. District Court 
    for the Eastern District of New York. The resulting consent decree 
    requires the EPA Administrator to sign a notice of proposed rulemaking 
    not later than September 1, 1994 and a notice of promulgation not later 
    than September 1, 1995 (Nos. CV-92-2093 and CV-93-0284).
        The NSPS and guidelines promulgated on February 11, 1991 (56 FR 
    5488 and 56 FR 5514, respectively) apply to MWC's with unit capacities 
    above 225 Mg/day and reflect BDT as determined by the Administrator at 
    the time those standards were issued. Today's notice therefore proposes 
    to create new NSPS to be fully consistent with sections 111 and 129 of 
    the Act and to extend coverage of the standards to new MWC units 
    located at MWC facilities with aggregate plant capacity above 35 Mg/
    day. Additionally, under a separate notice in today's Federal Register, 
    new subpart Cb emission guidelines for existing MWC plants with 
    aggregate capacities above 35 Mg/day of MSW are being proposed pursuant 
    to sections 111 and 129 of the Act.
        Today's proposed NSPS is more stringent than the NSPS promulgated 
    on February 11, 1991. Today's proposed NSPS would replace the subpart 
    Ea NSPS for those facilities for which construction, modification, or 
    reconstruction commenced after September 20, 1994. However, the 
    February 11, 1991 subpart Ea NSPS will remain in effect for affected 
    facilities constructed, modified, or reconstructed after December 20, 
    1989 and on or before September 20, 1994. Those sources subject to the 
    February 11, 1991 subpart Ea NSPS would also be subject to the emission 
    guidelines being proposed under subpart Cb in a separate notice in 
    today's Federal Register. In most cases, the proposed subpart Cb 
    emission guidelines are more stringent than the existing subpart Ea 
    standards.
    
    B. New Source Performance Standards--General Goals
    
        The Act requires the promulgation of performance standards under 
    section 111 for categories of new and existing stationary sources that 
    may contribute to air pollution that may reasonably be anticipated to 
    endanger public health or welfare. Section 129 of the Act specifies 
    that NSPS and emission guidelines must be developed for MWC's in 
    accordance with the requirements of sections 111 and 129 of the Act. 
    Section 129(a)(2) provides that the revised standards for new MWC's 
    reflect the maximum degree of reduction in emissions of designated air 
    pollutants, taking into consideration the cost of achieving such 
    emission reduction, and any non-air-quality health and environmental 
    impacts and energy requirements that the Administrator determines are 
    achievable for a particular category of sources (this standard is 
    commonly referred to as ``maximum achievable control technology, or 
    ``MACT''). Additionally section 129 provides that standards for new 
    sources may not be less stringent than the emissions control achieved 
    in practice by the best controlled similar unit. This is referred to as 
    the ``MACT floor.'' The standards themselves are set forth as emission 
    limits and do not specify what technology must be applied.
    
    C. Overview of this Preamble
    
        This preamble will:
        (1) Summarize the proposed standards by discussing the conclusions 
    reached with respect to each of the elements in the decision summary;
        (2) Describe the environmental, energy, and economic impacts of the 
    proposed standards;
        (3) Present a rationale for each of the decisions associated with 
    this proposal;
        (4) Present a regulatory flexibility analysis; and
        (5) Discuss administrative requirements relevant to this action.
    
    II. Summary of the Proposed Subpart Eb Standards
    
        This section presents a summary of the proposed NSPS, including 
    identification of the source category and pollutants that would be 
    regulated under the proposal, discussion of the format of the proposed 
    standards, and presentation of the proposed standards and their 
    associated performance testing, monitoring, recordkeeping and reporting 
    requirements. This section also provides a comparison of the emission 
    standards in this proposed subpart Eb NSPS versus the 1991 subpart Ea 
    NSPS.
    
    A. Source Category to be Regulated
    
        Today's proposed standards would apply to each MWC unit located at 
    an MWC facility that has an aggregate plant capacity to combust over 35 
    Mg/day of MSW, for which construction, modification, or reconstruction 
    commenced after September 20, 1994. Additionally, under the proposed 
    NSPS, plants with an aggregate capacity to combust between 25 and 35 
    Mg/day would be required to submit an initial report of their facility 
    capacities and location, but would not be subject to any other 
    provisions of the NSPS. Municipal waste combustors that commenced 
    construction, modification, reconstruction on or before September 20, 
    1994 are not covered under today's proposed standards, but are being 
    addressed in a separate notice in today's Federal Register.
        An MWC is defined as any setting or equipment that combusts MSW. 
    Municipal solid waste combustion includes the burning (or pyrolysis) of 
    MSW in any type of setting or equipment, including combustion equipment 
    with or without heat recovery. This definition has been slightly 
    modified from the February 11, 1991 NSPS and is discussed below.
        Municipal solid waste is defined as either a mixture or a single-
    item stream of household, commercial, and/or institutional discards. 
    This would include materials such as paper, wood, yard wastes, tree 
    trimmings, plastics, leather, rubber, glass, metals, and other 
    combustible and noncombustible materials. The MSW definition includes 
    household discards as well as discards from institutional and 
    commercial sources, but does not include industrial process or 
    manufacturing discards. The definition of MSW also includes refuse-
    derived fuel (RDF), which is solid waste that is shredded (or 
    pelletized) and classified by size before combustion. Municipal solid 
    waste does not, however, include wastes that are solely segregated 
    medical wastes. However, if segregated medical wastes are mixed with 
    MSW, the resulting mixture remains MSW, and the proposed standards 
    would apply if the aggregate MWC plant capacity exceeded 35 Mg/day 
    capacity. Minor editing changes are proposed in the definition of MSW 
    to clarify this point.
        Air curtain incinerators that combust MSW are MWC's. However, air 
    curtain incinerators that burn only yard wastes, tree trimmings, and 
    clean untreated lumber would be covered under a separate set of 
    proposed opacity emission limits, and no other part of the proposal 
    would apply. Air curtain incinerator opacity requirements are discussed 
    in section VII of this preamble.
    
    B. Pollutants to be Regulated
    
        Section 129 of the Act requires the EPA to establish numerical 
    emission limits specifically for SO2, HCl, PM, opacity, Cd, Pb, 
    Hg, dioxins/furans, CO, and NOX. Section 129 specifies that the 
    EPA may also
    
        * * * promulgate numerical emission limitations or provide for 
    the monitoring of post-combustion concentrations of surrogate 
    substances, parameters, or periods of residence times in excess of 
    stated temperatures with respect to pollutants other than those 
    listed [above]. * * *
    
    Therefore, the EPA is proposing standards for load and flue gas 
    temperature at the PM control device inlet as additional indicators of 
    MWC operating practices. The EPA is also proposing a standard for fly 
    ash/bottom ash fugitive emissions because these emissions include Cd, 
    Pb, Hg, and dioxins/furans (see section VI of this preamble for further 
    discussion of the EPA's decision to regulate fugitive emissions from 
    MWC's).
        The February 11, 1991 NSPS includes standards for all of the 
    pollutants listed above except Cd, Pb, Hg, and fly ash/bottom ash 
    fugitive emissions. The proposed NSPS would establish standards for all 
    of the pollutants listed above. The proposed standards for the same 
    pollutants regulated by the February 11, 1991 NSPS (i.e., SO2, 
    HCl, PM, opacity, dioxins/furans, NOX, CO, load, and flue gas 
    temperature at the PM control device inlet) would be revised under the 
    proposal to reflect the requirements of section 129.
    
    C. Format for the Proposed Standards
    
        The format of the proposed standards is similar to the format of 
    the February 11, 1991 NSPS. In most cases, the format is in the form of 
    emission limits (concentrations).
        The February 11, 1991 NSPS specifies emission limits for PM and 
    opacity. Particulate matter is measured as a concentration (milligrams 
    per dry standard cubic meter (mg/dscm)) and is corrected to 7 percent 
    oxygen (O2), and opacity is measured on a percentage basis. The 
    format for the PM and opacity standards would not change in today's 
    proposal, but Cd, Pb, and Hg emission limits would be added. Emissions 
    of Cd, Pb, and Hg would be calculated as a concentration (mg/dscm) 
    corrected to 7 percent O2, dry basis. For Hg, today's proposed 
    standards would also establish an alternative percentage reduction 
    requirement. A new method (Method 29) that would measure these 
    pollutants is being proposed in a separate part of today's Federal 
    Register.
        The February 11, 1991 NSPS establishes control requirements for 
    SO2 and HCl (MWC acid gases) by specifying both numerical emission 
    limits and alternative percentage reduction requirements for both 
    SO2 and HCl. The concentration emission limits for HCl and 
    SO2 are calculated as parts per million by volume (ppmv) corrected 
    to 7 percent O2, dry basis. Today's proposed standards for 
    SO2 and HCl would also be based on the same format.
        The February 11, 1991 NSPS addresses a numerical emission limit for 
    NOX emissions. The concentration emission limit for NOX is 
    calculated as ppmv. Today's proposed standard for NOX is based on 
    the same format as the February 11, 1991 NSPS.
        The February 11, 1991 NSPS establishes MWC organics control by 
    specifying an emission limit for dioxins/furans. The format of the 
    dioxin/furan emission limit would be revised by today's proposal. In 
    the February 11, 1991 NSPS, emissions of dioxins/furans are calculated 
    as a concentration (nanograms per dry standard cubic meter (ng/dscm)) 
    corrected to 7 percent O2, dry basis, on a total mass basis (i.e., 
    the mass of all tetra- through octa- congeners were added together). In 
    today's proposal, dioxin/furan emissions could be reported either in 
    units of ng/dscm toxic equivalency (TEQ) or in units of ng/dscm total 
    mass dioxins/furans. Reporting in TEQ units is done by first measuring 
    the total mass of dioxin/furan congeners and then adjusting the results 
    for the toxicity of each dioxin/furan congener. The same test method 
    (Method 23) is used in either case. See section II.F of this preamble 
    for further discussion of the proposed method of reporting dioxin/furan 
    emissions in terms of TEQ.
        In addition to controlling stack emissions, the February 11, 1991 
    NSPS also establishes good combustion operating standards for MWC's. 
    These operating standards are part of good combustion practices (GCP) 
    and ensure that emissions of MWC organics (dioxins/furans) are 
    minimized on a continuous basis. The GCP requirements are included in 
    today's proposal, but they are being extended to apply to MWC's at 
    plants of 35 Mg/day aggregate capacity or larger. Additionally, some 
    minor revisions are being proposed. The proposed revisions would 
    include: (1) A requirement that all shift operators and chief facility 
    operators obtain full operator certification, (2) ``stand in'' 
    authority for MWC control room operators, and (3) required training of 
    MWC shift supervisors. These items are discussed below.
        The February 11, 1991 NSPS requires provisional certification of 
    the chief facility operator and shift supervisors by the American 
    Society of Mechanical Engineers (ASME) or a State certification 
    program. Development of a site-specific training manual to be used for 
    training other MWC personnel is also required. Today's proposal would 
    require that the chief facility operator and shift supervisor obtain 
    both provisional and then full operator certification.
        Today's proposal would also allow for the optional certification of 
    one or more control room operators. Under the February 11, 1991 NSPS, 
    all chief facility operators and shift supervisors shall be certified, 
    and one of these individuals must be onsite during all periods of MWC 
    operation. Under today's proposal, a provisionally certified control 
    room operator may ``stand in'' for the chief facility operator or shift 
    supervisor during periods in which the certified chief facility 
    operator or certified shift supervisor is offsite, in order to fulfill 
    the requirement that a certified individual be onsite during all 
    periods of MWC operation. This would provide additional operating 
    flexibility. Today's proposal would also require that all chief 
    facility operators, shift supervisors, and control room operators 
    complete the EPA or a State MWC operator training course. The EPA has 
    developed a model training program that has been distributed to State 
    air pollution control agencies, the EPA Regional Offices, and MWC 
    industry groups. The EPA believes that operator training is an integral 
    part of the implementation of GCP.
        Today's proposed standards would establish siting requirements for 
    all new MWC's at plants with aggregate capacities above 35 Mg/day. 
    These siting requirements would include three components. First, an 
    analysis of the impact of the facility on ambient air quality, 
    visibility, soils, and vegetation would be required. Second, the siting 
    requirements would include submittal of a materials separation plan for 
    the area served by the affected facility. Third, the MWC owner or 
    operator would be required to make both the siting analysis and the 
    materials separation plan available to the public, hold public meetings 
    to receive comments on the siting analysis and materials separation 
    plan, and respond in writing to the comments received. These siting 
    requirements were not included in the February 11, 1991 NSPS. See 
    section V.D of this preamble for a more detailed discussion of the 
    proposed siting requirements.
        Today's proposed standards also establish standards for fugitive 
    fly ash/bottom ash emissions from ash handling facilities. The proposed 
    standards would establish visible emissions limits for emissions of ash 
    from buildings where ash was transferred and from external ash transfer 
    equipment and ash handling areas at the MWC facility. This requirement 
    was not included in the February 11, 1991 NSPS.
    
    D. Proposed Standards
    
        Today's proposal would establish standards for MWC acid gases 
    (SO2 and HCl), MWC metals (PM, opacity, Cd, Pb, and Hg), MWC 
    organics (dioxins/furans), and NOX. The proposed standards also 
    include requirements for fly ash/bottom ash fugitive handling, MWC 
    operating practices (CO, load, and flue gas temperature), operator 
    training and certification, and siting for new MWC units.
        The proposed NSPS would divide the MWC population into two 
    subcategories: The first would be for MWC units located at small MWC 
    plants (i.e., those with aggregate capacities to combust greater than 
    35 Mg/day of MSW but equal to or less than 225 Mg/day), and the second 
    would be for MWC units at large plants (i.e., those with aggregate 
    capacities to combust more than 225 Mg/day of MSW). The aggregate 
    capacity of all MWC units at one site constructed after September 20, 
    1994 would be added together to define aggregate MWC plant capacity for 
    determining NSPS applicability.
        The proposed NSPS for each subcategory of MWC's are summarized in 
    table 1. The proposed NSPS are also discussed briefly below.
    
                 Table 1. Summary of Proposed NSPS for New MWC's            
                                 [Subpart Eb]a                              
    ------------------------------------------------------------------------
         Plant size (MSW combustion                                         
                 capacity)                           Requirement            
    ------------------------------------------------------------------------
    Applicability                                                           
                                                                            
    The proposed NSPS would apply to                                        
     new MWC units located at plants                                        
     with capacities to combust greater                                     
     than 25 Mg/day of residential,                                         
     commercial, and/or institutional                                       
     discards.b Industrial discards are                                     
     not covered by the proposed NSPS.                                      
                                                                            
        25 Mg/day...........  Not covered by standards.          
        >25 Mg/day but  35    Initial report of MWC design       
         Mg/day.                          capacity and startup date.        
        >35 Mg/day but  225   Subject to provisions listed below.
         Mg/day (referred to as small                                       
         MWC plants).                                                       
        >225 Mg/day (referred to as      Subject to provisions listed below.
         large MWC plants).                                                 
    ------------------------------------------------------------------------
    
    
    Good Combustion Practices:                                              
      Applies to large and small MWC plants.                        
      A site-specific operator training manual would be required to 
       be developed and made available for MWC personnel. The EPA or State  
       MWC operator training course would be required to be completed by the
       MWC chief facility operator, shift supervisors, and control room     
       operators.                                                           
      The ASME or a State MWC operator certification would be       
       required to be obtained by the MWC chief facility operator           
       (mandatory), shift supervisors (mandatory), and control room         
       operators (optional).                                                
      The MWC load level would be required to be measured and not to
       exceed the maximum load level as demonstrated during the most recent 
       dioxin/furan performance test.                                       
      The PM control device inlet flue gas temperature would be     
       required to be measured and not to exceed the level demonstrated     
       during the most recent dioxin/furan performance test.                
      The CO level would be required to be measured using CEMS, and 
       the concentration in the flue gas would be required not to exceed the
       following.                                                           
                                                                            
    
    
    ------------------------------------------------------------------------
                    MWC type                    CO Levelc     Averaging time
    ------------------------------------------------------------------------
    Modular starved-air and excessair.......  50 ppmv         4-hour.       
    Mass burn waterwall and refractory......  100 ppmv        4-hour.       
    Mass burn rotary refractory.............  100 ppmv        4-hour.       
    Fluidized-bed combustion................  100 ppmv        4-hour.       
    Coal/RDF mixed fuel-fired...............  150 ppmv        4-hour.       
    RDF stokers.............................  150 ppmv        24-hour.      
    Mass burn rotary waterwall..............  100 ppmv        24-hour.      
    ------------------------------------------------------------------------
    
    
    MWC Organic Emissions (measured as dioxin/furan)c,d                     
    Dioxins/furans (compliance test by EPA Reference Method 23)     
                                                                            
        Large and small MWC plants.....  13 ng/dscm total mass or 0.20 ng/  
                                          dscm dioxin/furan TEQe.           
        Basis for dioxin/furan   GCP and SD/FF/CI.                  
         standard.                                                          
                                                                            
    MWC Metal Emissionsc                                                    
                                                                            
     PM (compliance test by EPA Reference Method 5)                 
                                                                            
        Large and small MWC plants.....  15 mg/dscm (0.007 gr/dscf).        
                                                                            
     Opacity (compliance test by EPA Reference Method 9)            
                                                                            
        Large and small MWC plants.....  10 percent (6-minute average).     
                                                                            
    Cd (compliance test by EPA Reference Method 29)f                
                                                                            
        Large and small MWC plants.....  0.010 mg/dscm (4.4 gr/million      
                                          dscf).                            
                                                                            
    Pb (compliance test by EPA Reference Method 29)f                
                                                                            
        Large and small MWC plants.....  0.10 mg/dscm (44 gr/million dscf). 
                                                                            
    Hg (compliance test by EPA Reference Method 29)f                
                                                                            
        Large and small MWC plants.....  0.080 mg/dscm (35 gr/million dscf) 
                                          or 85-percent reduction in Hg     
                                          emissions.                        
    Basis for PM, opacity, Cd, Pb, and Hg standards                 
                                                                            
        Large and small MWC plants.....  See basis for dioxin/furan         
                                          standard.                         
                                                                            
    MWC Acid Gas Emissionsc                                                 
                                                                            
    SO2 (compliance test by CEMS)                                   
                                                                            
        Large and small MWC plants.....  30 ppmv or 80-percent reduction in 
                                          SO2 emissions (24-hour).          
                                                                            
    HCl (compliance test by EPA Reference Method 26)                
                                                                            
        Large and small MWC plants.....  25 ppmv or 95-percent reduction in 
                                          HCl emissions.                    
        Basis for SO2 and HC1    See basis for dioxin/furan         
         standards.                       standard.                         
                                                                            
    Nitrogen Oxides Emissionsc                                              
                                                                            
    NOX (compliance test by CEMS)                                   
                                                                            
        Large MWC plants...............  180 ppmv.                          
        Small MWC plants...............  No NOX control requirement.        
                                                                            
    Basis for NOx standard                                          
        Large MWC plants...............  SNCR.                              
        Small MWC plants...............  No NOX control requirement.        
                                                                            
    Fly Ash/Bottom Ash Fugitive Emissions                                   
                                                                            
    Fly Ash/Bottom Ash (compliance test by EPA Reference Method 22) 
                                                                            
        Large and small MWC plants.....  No visible emissions from          
                                          buildings, ash transfer points, or
                                          ash handling areas.               
    Basis for fugitive           Wet ash handling or enclosed ash   
     emissions standard                   handling.                         
                                                                            
    Siting Requirements                                                     
                                                                            
        Large and small MWC      (1) Siting analysis, (2) materials 
         plants.                          separation plan, and (3) public   
                                          meetings (including response to   
                                          comments)g.                       
                                                                            
    Compliance Testing and Monitoring Requirements                          
                                                                            
        Load, flue gas           Continuous monitoring, 4-hour      
         temperature.                     arithmetic average.               
        CO.....................  CEMS, 4- or 24-hour arithmetic     
                                          average, as applicable.           
                                                                            
    Dioxins/furansd, PM, Cd, Pb, Hg, and HCl                        
                                                                            
        Large MWC plants...............  Annual stack test.                 
        Small MWC plants...............  Annual or third year stack testh.  
        Opacity................  COMS (6-minute average) and annual 
                                          stack test.                       
        SO2....................  CEMS, 24-hour geometric mean.      
        NOX (large MWC plants    CEMS, 24-hour arithmetic average.  
         only).                                                             
        Fly ash/bottom ash       Annual test.                       
         fugitive emissions.                                                
    aDefinition of Abbreviations Used in Table:                             
    ASME=American Society of Mechanical Engineers                           
    Cd=cadmium                                                              
    CEMS=continuous emission monitoring system                              
    CO=carbon monoxide                                                      
    COMS=continuous opacity monitoring system                               
    GCP=good combustion practices                                           
    gr/dscf=grains per dry standard cubic foot                              
    gr/million dscf=grains per million dry standard cubic feet              
    HCl=hydrogen chloride                                                   
    Hg=mercury                                                              
    Mg/day=megagrams per day (1 Mg/day=1.1 short tons/day (2,204 pounds/    
      day))                                                                 
    mg/dscm=milligrams per dry standard cubic meter (100 mg/dscm=0.044 gr/  
      dscf)                                                                 
    MSW=municipal solid waste                                               
    MWC=municipal waste combustor                                           
    ng/dscm=nanograms per dry standard cubic meter (1,000,000 ng=1 mg)      
    NOX=nitrogen oxides                                                     
    NSPS=new source performance standards                                   
    Pb=lead                                                                 
    PM=particulate matter                                                   
    ppmv=parts per million by volume                                        
    RDF=refuse-derived fuel                                                 
    SD/FF/CI=spray dryer/fabric filter/activated carbon injection           
    SNCR=selective noncatalytic reduction                                   
    SO2=sulfur dioxide                                                      
    TEQ=toxic equivalency of 2,3,7,8- tetrachlorinated dibenzo-p-dioxin     
      (North Atlantic Treaty Organization (NATO) 1989 international         
      criteria)                                                             
    Total mass=total mass of tetra- through octa-chlorinated dibenzo-p-     
      dioxins and dibenzofurans.                                            
    bAir curtain incinerators that combust only yard wastes, tree trimmings,
      and/or clean lumber would be subject to an opacity emission limit but 
      to no other parts of the proposed NSPS. Air curtain incinerators that 
      combust other MSW are subject to all requirements under the proposed  
      NSPS.                                                                 
    cAll concentration levels in the table are corrected to 7 percent O2,   
      dry basis.                                                            
    dDioxins/furans measured as total tetra- through octa-chlorinated       
      dibenzo-p-dioxins and dibenzofurans. For plants complying with the TEQ
      format of the standard, TEQ is determined using 1989 international    
      toxicity equivalency factors.                                         
    eFor MWC's constructed after September 20, 1994, but on or before       
      September 22, 1997, the standard would be 0.50 ng/dscm TEQ or 30 ng/  
      dscm total mass for the first 3 years of operation of the MWC. After  
      the first 3 years, the standard would be 0.20 ng/dscm TEQ or 13 ng/   
      dscm total mass. For all MWC's constructed after September 22, 1997,  
      the standard at startup would be 0.20 ng/dscm TEQ or 13 ng/dscm total 
      mass.                                                                 
    fMethod 29 is being proposed in a separate notice in today's Federal    
      Register.                                                             
    gTwo public meetings would be held for review of the materials          
      separation plan. The first public meeting would focus on review of a  
      draft materials separation plan. The draft materials separation plan  
      and the summary of responses to public comments about the plan would  
      be submitted to EPA prior to application for a construction permit    
      under New Source Review (NSR). A second public meeting would be held  
      after submission of the application for a construction permit and     
      would focus on both the final materials separation plan and the siting
      analysis. The siting analysis, the materials separation plan, and the 
      summary of responses to public comments on the siting analysis and the
      materials separation plan would be submitted as part of the initial   
      notification of construction.                                         
    hThe proposed NSPS includes provisions that would allow small MWC plants
      to conduct performance tests for dioxins/furans, PM, Cd, Pb, Hg, and  
      HCl every third year if the MWC meets certain specified criteria      
      discussed in section II.F of this preamble.                           
    
        The proposed standards are summarized below.
    
    1. Municipal Waste Combustor Organics
    
        The proposed standards for MWC organics would require new MWC's at 
    MWC plants with capacities above 35 Mg/day for which construction 
    commences after September 20, 1994, but on or before September 22, 
    1997, to meet a dioxin/furan emission limit of either 0.50 ng/dscm TEQ 
    or 30 ng/dscm total mass, at 7 percent O2 for the first 3 years 
    following the date of initial startup. Thereafter, the standard would 
    be 0.20 ng/dscm TEQ or 13 ng/dscm total mass. For MWC's at plants with 
    capacities above 35 Mg/day for which construction commences after 
    September 22, 1997, the standard at startup would be 0.20 ng/dscm TEQ 
    or 13 ng/dscm total mass. Emissions reported in TEQ would be calculated 
    using the 1989 North Atlantic Treaty Organization (NATO) international 
    toxic equivalency factors (TEF's), using the methods described in 
    section II.F of this preamble and section 60.58b of the proposed 
    subpart Eb NSPS.
    
    2. Municipal Waste Combustor Metals
    
        The proposed standards for MWC metals would require all MWC's at 
    MWC plants with capacities above 35 Mg/day to meet a PM emission limit 
    of 15 mg/dscm at 7 percent O2. Municipal waste combustors at both 
    large and small MWC plants would also be required to meet an opacity 
    limit of 10 percent based on a 6-minute averaging period.
        The proposed standards would also establish specific emission 
    levels for Cd, Pb, and Hg. The proposed standards would require new 
    MWC's at MWC plants with capacities above 35 Mg/day to meet a Cd limit 
    of 0.010 mg/dscm, a Pb limit of 0.10 mg/dscm, and an Hg limit of 0.080 
    mg/dscm or an 85-percent reduction in potential Hg emissions. These 
    proposed emission limits are corrected to 7 percent O2 on a dry 
    basis.
    
    3. Municipal Waste Combustor Acid Gases
    
        The proposed standards for MWC acid gases would require MWC's at 
    plants with capacities above 35 Mg/day to meet an HCl emission limit of 
    either 25 ppmv or 95-percent reduction (at 7 percent O2, dry 
    basis). These MWC plants would also be required to achieve an SO2 
    emission limit of either 30 ppmv or 80-percent reduction (at 7 percent 
    O2, dry basis, on a 24-hour geometric mean basis, measured 
    continuously).
    
    4. Good Combustion Practices
    
        Today's proposed NSPS would require all new MWC's at MWC plants 
    with capacities above 35 Mg/day to comply with specific operating 
    practices that reflect GCP. These operating practices include CO 
    emission limits, combustor load levels, and flue gas temperatures at 
    the inlet to the PM control device.
        The GCP CO levels remain basically unchanged from the February 11, 
    1991 NSPS. For modular starved-air and modular excess-air types of 
    MWC's, the CO emission limit would be 50 ppmv (at 7 percent O2, 
    dry basis) on a 4-hour block average basis. For mass burn waterwall, 
    mass burn refractory (rotary and fixed-wall), and fluidized-bed types 
    of MWC's, the CO emission limit would be 100 ppmv (at 7 percent 
    O2, dry basis) on a 4-hour block average basis. For mass burn 
    rotary waterwall MWC's, the CO emission limit would be 100 ppmv (at 7 
    percent O2, dry basis) on a 24-hour block average basis. For RDF-
    stoker MWC's, the CO limit would be 150 ppmv (at 7 percent O2, dry 
    basis) on a 24-hour block average basis. For coal/RDF mixed fuel-fired 
    MWC's, the CO limit would be 150 ppmv (at 7 percent O2, dry basis) 
    on a 4-hour block average basis. These limits remain unchanged from the 
    February 11, 1991 NSPS except that a limit specifically for mass burn 
    rotary refractory units has been added for clarification.
        Municipal waste combustors would be allowed to operate up to 110 
    percent of the maximum capacity, as achieved during the most recent 
    dioxin/furan compliance test. Maximum capacity would be based on the 
    steam flow rate, which would be continuously monitored according to the 
    ASME Power Test Code (PTC) for Steam Generating Units (PTC4.1 and 
    PTC19.5). This requirement is unchanged from the February 11, 1991 
    NSPS. The EPA requests comments on this method of measuring load for 
    steam-generating MWC's. Specifically, the EPA has questions regarding 
    the requirement for calibration of the measuring device (e.g., orifice 
    plate) before and after each dioxin/furan compliance test. The EPA is 
    concerned that this calibration requirement may be overly burdensome 
    because the main steam line that contains the orifice plate may need to 
    be cut in order to access the orifice plate for recalibration. Also, 
    the EPA requests comments on whether the ASME PTC adequately addresses 
    the need for calibrating the signal from the flow meter.
        Additionally, the EPA requests comments on the use of boiler feed 
    water flow as an alternative method for continuously monitoring load 
    for steam-generating MWC's.
        Furthermore, the EPA is considering allowing the use of the 
    continuous flue gas volumetric flow rate to measure maximum capacity 
    for both steam-generating MWC's, as well as those MWC's that do not 
    generate steam. These types of monitors are based on ultrasonic, 
    thermal, or differential pressure methods, and are now being required 
    as part of the EPA's Acid Rain Program (40 CFR part 75). The EPA 
    requests comments on whether continuous flue gas volumetric flow rate 
    monitors are adequately demonstrated and accurate methods for 
    determining compliance with the load level requirements, and if they 
    should be allowed as an alternative to the use of the ASME PTC.
        Under the NSPS, MWC's would establish a site-specific maximum flue 
    gas temperature at the final PM control device inlet demonstrated 
    during their most recent dioxin/furan compliance test. Similar to the 
    provisions for establishing a maximum load level measurement, the 
    maximum demonstrated PM control device inlet temperature is established 
    as the maximum 4-hour block average temperature measured during the 
    most recent dioxin/furan compliance test. The MWC must then be operated 
    so that the temperature at the final PM control device inlet does not 
    exceed this level by more than 17  deg.C (30  deg.F) (4-hour block 
    average basis).
    
    5. Operator Certification and Training
    
        The proposed NSPS would require full operator certification of all 
    MWC shift supervisors and MWC chief facility operators by the ASME or a 
    State certification program. The proposed standards would also require 
    that at least one of the following persons be on duty at all times 
    during which the MWC is combusting waste: A fully certified chief 
    facility operator, a fully certified shift supervisor, or a 
    provisionally certified control room operator. A provisionally 
    certified control room operator would be allowed to ``stand in'' during 
    times a fully certified chief facility operator or shift supervisor is 
    offsite. These requirements would become effective on the date of 
    promulgation of the NSPS or 6 months after startup of a new MWC, 
    whichever is later.
        In addition, the proposed NSPS would require each owner or operator 
    of an MWC plant with an aggregate capacity greater than 35 Mg/day to 
    develop and maintain a site-specific training manual and to review it 
    with all employees associated with the operation of the MWC (including 
    MWC maintenance personnel, crane/load operators, and ash handlers). The 
    manual and training would be updated annually. This site-specific 
    training requirement would be effective on the date of promulgation of 
    the NSPS or 6 months after startup of a new MWC, whichever is later.
        Section 129 of the Act of 1990 requires the EPA to develop and 
    promote a model program for the training and certification of MWC 
    operators. Section 129 specifies that ``any person with control over 
    processes affecting emissions from a unit'' must successfully complete 
    an acceptable training program. Consistent with section 129, today's 
    proposed revisions would require all MWC chief facility operators, 
    shift supervisors, and control room operators to complete the EPA or a 
    State MWC operator training course before operating an MWC or within 6 
    months following promulgation of the standards, whichever is later. The 
    EPA has developed a model training program and has distributed it to 
    State air pollution control agencies, EPA regional offices, and MWC 
    industry groups. This model training program could be used to fulfill 
    this requirement and prepare for the ASME certification.
    
    6. Nitrogen Oxides Emissions
    
        The proposed standards include a NOX control requirement for 
    MWC's at large plants and would require these MWC's to meet a NOX 
    emission limit of 180 ppmv (corrected to 7 percent O2, dry basis, 
    on a 24-hour daily average basis). A ``no control'' NOX emission 
    limit for MWC's at small plants is also proposed and is discussed in 
    section VII of this preamble.
    
    7. Siting Requirements
    
        Siting requirements are being proposed for all new MWC's at plants 
    with capacities above 35 Mg/day. These siting requirements are not 
    included in the 1991 subpart Ea NSPS. The siting requirements would 
    include the following three components: (1) A siting analysis, (2) a 
    materials separation plan, and (3) public meetings. The siting analysis 
    would address the impact of the facility, taking into account other 
    major industrial facilities near the proposed site, on ambient air 
    quality, visibility, soils, vegetation, and other factors that may be 
    relevant in determining that the benefits of the proposed facility 
    significantly outweigh the environmental and social costs imposed as a 
    result of its location and construction. The materials separation plan 
    would summarize materials separation requirements for the facility and 
    its service area. Following public meetings on the siting analysis and 
    materials separation plan, the facility would be required to prepare 
    transcripts of the public meetings and summaries of comments and 
    responses for the public meetings.
    
    8. Fly Ash/Bottom Ash Fugitive Emissions
    
        Standards are proposed for fly ash/bottom ash fugitive dust 
    emissions from ash handling and storage facilities at all MWC's at 
    plants above 35 Mg/day capacity. The proposed standards would establish 
    a no visible emissions limit for fly ash/bottom ash handling and would 
    apply to ash handling, conditioning, loading and storage buildings, any 
    external ash conveyors, ash transfer points, or ash handling activities 
    (e.g., truck loading), and any other area at the facility that is a 
    potential source of fly ash or bottom ash fugitive emissions.
    
    E. Comparison of the 1991 NSPS and Today's Proposed NSPS
    
        The subpart Ea NSPS promulgated on February 11, 1991 and today's 
    proposed subpart Eb standards both include emission limits for dioxins/
    furans, PM, SO2, HCl, and NOX; however, today's proposed 
    standards for most of these pollutants are more stringent than the NSPS 
    promulgated on February 11, 1991. The February 11, 1991 NSPS did not 
    address Cd, Pb, Hg, or fly ash/bottom ash fugitive emissions, but these 
    pollutants are included in today's proposal. Also, today's proposal 
    would apply to all MWC units at plants with aggregate capacities above 
    35 Mg/day, whereas the February 11, 1991 NSPS only included MWC's with 
    unit capacities above 225 Mg/day. A comparison of the 1991 NSPS and the 
    proposed NSPS emission limits for these pollutants is shown in table 2.
    
                  Table 2.--Comparison of the Proposed NSPS (Subpart Eb) and the 1991 NSPS (Subpart Ea)             
    ----------------------------------------------------------------------------------------------------------------
                                                                    NSPS emission limita                            
                                      ------------------------------------------------------------------------------
         Pollutant or parameter                Proposed NSPS (subpart Eb)                1991 NSPS (subpart Ea)     
                                      ------------------------------------------------------------------------------
                                                 MWC plants >35 Mg/dayb                    MWC's >225 Mg/dayc       
    ----------------------------------------------------------------------------------------------------------------
    Dioxins/furans...................  0.20 ng/dscm toxic equivalence or 13 ng/    30 ng/dscm, total mass           
                                        dscm total mass.                            (equivalent to about 0.50 ng/   
                                                                                    dscm toxic equivalence).        
    SO2..............................  30 ppmv or 80-percent reductiond..........  30 ppmv or 80-percent reductiond.
    HCl..............................  25 ppmv or 95-percent reductiond..........  25 ppmv or 95-percent reduction.d
    PM...............................  15 mg/dscm................................  34 mg/dscm.                      
    Opacity..........................  10 percent................................  10 percent.                      
    Cd...............................  0.010 mg/dscm.............................  None.                            
    Pb...............................  0.10 mg/dscm..............................  None.                            
    Hg...............................  0.080 mg/dscm (or 85-percent reduction)d..  None.                            
    Nox..............................  180 ppmve.................................  180 ppmv.                        
    Fly ash/bottom ash fugitive        No visible emissions from buildings, ash    None.                            
     emissions.                         transfer points, or ash handling areas.                                     
    Siting requirements..............  Siting analysis, materials separation       None.                            
                                        plan, and public meeting requirements.                                      
    ----------------------------------------------------------------------------------------------------------------
    aAll emission limits are corrected to 7 percent O2, dry basis.                                                  
    bRefers to aggregate MWC plant capacity.                                                                        
    cRefers to MWC unit capacity.                                                                                   
    dWhichever is less stringent.                                                                                   
    ePlants >225 Mg/day only.                                                                                       
    
        The MWC operating standards (GCP) contained in today's proposal are 
    the same as those in the February 11, 1991 NSPS. The training and 
    certification requirements have changed somewhat. The February 11, 1991 
    standards require only provisional certification of MWC chief facility 
    operators and shift supervisors, but today's proposed standards would 
    require both provisional and then full certification. This change is 
    being proposed because the full operator certification program is now 
    widely available. In 1991, the program was not widely available.
        Today's proposal also adds a provision to allow provisionally 
    certified control room operators to stand in for the MWC chief facility 
    operators or shift supervisors in their temporary absence from the MWC. 
    Additionally, today's proposal would require all MWC chief facility 
    operators, shift supervisors, and control room operators to complete 
    the EPA or a State MWC training course. This training course 
    requirement was not included in the February 11, 1991 NSPS.
    
    F. Performance Testing and Monitoring Requirements
    
        Information related to the performance testing and monitoring 
    requirements for MWC acid gases (SO2 and HCl), MWC organics 
    (dioxin/furan), PM, opacity, MWC operating practices, and NOX has 
    been published in a previous Federal Register notice (56 FR 5488, 
    February 11, 1991). These same requirements would be adopted by today's 
    proposed NSPS and would be extended to apply to all MWC's at plants 
    with aggregate capacities above 35 Mg/day. Because the proposed NSPS 
    allows compliance with a dioxin/furan limit either on a TEQ basis or on 
    a total mass basis, procedures are being proposed for determining 
    dioxin/furan emissions on a TEQ basis. The mass of each tetra- through 
    octa- chlorinated dibenzo-p-dioxin and dibenzofuran congener would be 
    measured by EPA Reference Method 23. Each congener mass would then be 
    adjusted by the corresponding toxic equivalency factor (TEF; the 1989 
    NATO international TEF's). Finally, the adjusted congener masses would 
    be added together to determine dioxins/furans in ng/dscm TEQ. 
    Furthermore, today's proposal would require both large and small MWC 
    facilities to conduct annual opacity tests using EPA Reference Method 
    9. This testing would be in addition to the continuous monitoring of 
    opacity levels. Also, today's proposal allows small MWC facilities to 
    conduct less frequent testing for dioxin/furan, HCl, and PM emissions 
    if the small facility consistently demonstrates compliance. More 
    specifically, if three consecutive annual compliance tests for an MWC 
    at a small MWC plant indicate compliance with the emission limit for a 
    pollutant (i.e., dioxins/furans, PM, or HCl), the MWC would be allowed 
    to wait 3 years before retesting for the pollutant. If the next test 
    conducted in the third year shows compliance with the emission limit 
    for that pollutant, then the facility could again wait 3 years to test 
    for the pollutant. If noncompliance with the emission limit for the 
    pollutant occurs, corrective actions would be required to be undertaken 
    and annual testing would be required to be conducted until 3 
    consecutive years of compliance with the emission limit is established. 
    At a minimum, performance tests for dioxins/furans, PM, and HCl would 
    be required to be performed for each MWC unit at small MWC plants every 
    3 years. All large MWC plants would continue to be required to conduct 
    annual compliance tests.
        Annual performance tests to determine compliance with the Cd, Pb, 
    and Hg emission limits would be based on EPA Reference Method 29. The 
    average emission rates of three or more test runs using this 
    methodology would be used to determine compliance. The EPA considered 
    the use of EPA Reference Method 101A for Hg testing; however, based on 
    available data, the EPA has concluded that Method 29 is a better 
    measure of Cd, Pb, and Hg emissions than Method 101A and has therefore 
    proposed Method 29 for testing MWC's.
        Also, as discussed above for dioxins/furans, PM, and HCl, if small 
    plants demonstrate compliance with the Cd, Pb, and Hg emission limits 
    for 3 consecutive years, they would be allowed to begin testing for 
    these three pollutants every third year.
        The EPA Reference Method 29 is proposed in a separate part of 
    today's Federal Register. Method 29 is very similar to the method that 
    has been used by the EPA's Office of Solid Waste to measure metals 
    emissions from boilers cofiring hazardous waste, commonly referred to 
    as the EPA multimetals method. The proposed Method 29 is discussed in 
    section IV.H of this preamble.
        Testing and monitoring requirements for NOX at large MWC's are 
    the same as those contained in the February 11, 1991 Federal Register 
    notice (56 FR 5488), and are based on use of a CEMS.
        Annual performance tests to determine compliance with the proposed 
    fly ash/bottom ash visible emissions limits would be based on EPA 
    Reference Method 22 (3-hour continuous visual observation). The limits 
    would apply at all times and the tests would be conducted during 
    periods of time when fly ash/bottom ash is transferred from the 
    combustor or from the air pollution control device to the ash loading 
    area, and when ash is loaded for transportation or is being transported 
    onsite.
        The data availability requirement for CEMS (SO2, NOX, CO, 
    and O2 (or CO2)) has been increased from the 1991 NSPS. 
    Today's proposal would require that valid paired CEMS hourly averages 
    (i.e., SO2 and O2 (or CO2), NOX and O2 (or 
    CO2), and CO and O2 (or CO2)) be obtained for 75 percent 
    of the hours per day for 90 percent of the days per calendar quarter 
    that the affected facility is operated and combusting MSW.
    
    G. Reporting and Recordkeeping Requirements
    
        The MWC NSPS promulgated on February 11, 1991 established reporting 
    and recordkeeping requirements for MWC organics (dioxins/furans), MWC 
    metals (PM and opacity), MWC acid gases (SO2 and HCl), operating 
    practices (CO, load, flue gas temperature, and operator training/
    certification) and NoX. These reporting and recordkeeping 
    requirements are discussed in the February 11, 1991 Federal Register 
    notice (56 FR 5488). These same reporting and recordkeeping 
    requirements would be adopted under the proposed NSPS, with two 
    exceptions. First, dioxins/furans would be recorded and reported on 
    either a total mass basis or a TEQ basis. Second, if small MWC's meet 
    the criteria allowing them to conduct performance tests for dioxins/
    furans, PM, and HCl every third year, they would submit a simplified 
    annual report for those years in which testing was not conducted.
        Today's proposal also would add reporting and recordkeeping 
    requirements for Cd, Pb, and Hg. The proposed standards would require 
    that initial and annual compliance reports be submitted for Cd, Pb, and 
    Hg for MWC's at plants with aggregate capacities above 35 Mg/day. If 
    small MWC's meet the criteria allowing them to conduct performance 
    tests for Cd, Pb, or Hg every third year, they would be allowed to 
    submit a simplified annual report for those years when a full 
    compliance test was not required. The proposed NSPS would also require 
    that the amount of activated carbon injected for Hg control at small 
    and large plants be recorded during MWC operation.
        Initial and annual compliance reports for fly ash/bottom ash 
    visible emissions testing would be required under today's proposal for 
    both small and large plants.
        Additionally, today's proposal would require that the siting 
    analysis, materials separation plan, and summary of responses to public 
    comments be submitted to the State. Refer to section V.D of this 
    preamble for a discussion of these proposed requirements.
        Records of all data, including results of emission tests and 
    compliance reports, would be maintained for 5 years following the date 
    of submission of the data.
    
    III. Impacts of the Proposed Standards
    
        The EPA projects that about 72 new MWC plants with a total MSW 
    combustion capacity of about 17.6 million Mg/yr will begin construction 
    by the year 2000. Of those 72 plants, 48 are projected to be large 
    plants and 24 are projected to be small plants. The proposed subpart Eb 
    NSPS would cover both the small and large plants, while the 1991 
    subpart Ea NSPS covers only large plants. This section describes the 
    impacts (i.e., air, water, solid waste, energy, control cost, and 
    economic impacts) of the proposed NSPS. The impacts of the proposed 
    rule are provided in two forms. First, the incremental impacts of the 
    proposed NSPS over the 1991 subpart Ea NSPS are presented. Second, the 
    impacts of the proposed NSPS over a pre-1989 baseline (i.e., a baseline 
    prior to the effective date of the subpart Ea NSPS) are presented. A 
    summary of these impacts is provided in table 3.
    
    Table 3.--Impacts of the Current Subpart Ea and Proposed Subpart Eb NSPS
    ------------------------------------------------------------------------
                               Increment of                                 
                               proposed NSPS                                
            Parameter          over the 1991    1991 NSPSa        Totalb    
                                   NSPS                                     
    ------------------------------------------------------------------------
    New MWC's subject to                                                    
     NSPS in the Fifth Year                                                 
     after Promulgation:                                                    
        Combustion capacity                                                 
         (10\6\ Mg/yr)......            0.8            16.8            17.6 
        Number of MWC plants           24              48              72   
    Cost (1990 Dollars):                                                    
        Capital cost                                                        
         ($10\6\)...........          156             613             769   
        Annualized cost                                                     
         ($10\6\/yr)........           43             157             200   
        Average cost                                                        
         increase ($/Mg MSW                                                 
         combusted).........            1.95           11.55           13.50
    Annual Emissions                                                        
     Reduction (Mg/yr):                                                     
        SO2.................        3,000          35,000          38,000   
        HCl.................        4,000          46,000          50,000   
        PM..................          800           5,700           6,500   
        Cd..................            1               9              10   
        Pb..................           17             140             157   
        Hg..................           18               9              27   
        NOX.................          200          10,300          10,500   
        Total dioxins/furans                                                
         (kg/yr)c...........            1              28              29   
        Dioxin/furan TEQ (g/                                                
         yr)d...............           17             467             484   
    ------------------------------------------------------------------------
    aThe impacts are based on a pre-1989 baseline (i.e., a baseline prior to
      the effective date of the subpart Ea NSPS.                            
    bThe total impacts are calculated by adding the incremental impacts of  
      the proposed NSPS (subpart Eb) to the impacts of the 1991 NSPS        
      (subpart Ea). These impacts would be equivalent to the total impacts  
      of the proposed NSPS over a pre-1989 baseline.                        
    ckg/yr=kilograms per year.                                              
    dg/yr=grams per year.                                                   
    
        In addition, a summary of economic impacts (e.g., household, 
    community, and business impacts) is presented that provides projected 
    economic burdens resulting from the combination of the 1991 subpart Ea 
    NSPS and the proposed subpart Eb NSPS.
        The cost estimates provided in this section are in 1990 dollars, 
    and include costs for emission control and compliance testing. The 
    estimates do not include costs for such things as permitting and 
    enforcement. For further information on the impacts of the proposed 
    NSPS, refer to the document entitled ``Economic Impact Analysis for 
    Proposed Emission Standards and Guidelines for Municipal Waste 
    Combustors'' that is included in the list of items under SUPPLEMENTARY 
    INFORMATION at the beginning of this preamble.
    
    A. Incremental Impacts of the Proposed NSPS over the 1991 NSPS
    
        The following is a discussion of the incremental air, water and 
    solid waste, energy, and cost impacts of the proposed NSPS over the 
    impacts of the 1991 subpart Ea NSPS.
    1. Air Impacts
        The air emission reductions discussed below, as well as other 
    impacts discussed in today's proposal, are nationwide impacts that 
    would result from full implementation of the NSPS in the fifth year 
    after adoption. These are incremental impacts of the proposal over the 
    1991 subpart Ea NSPS.
        Under today's proposed standards, nationwide emissions of total 
    dioxins/furans would be reduced by about 1 kilogram per year (kg/yr), 
    total mass, over the reductions associated with the 1991 subpart Ea 
    NSPS. Emissions of dioxins/furans on a TEQ basis would reduced by about 
    10 grams per year (g/yr). On a nationwide basis, dioxin/furan emissions 
    would be reduced by about 33 percent over levels under the 1991 subpart 
    Ea NSPS.
        Under the proposed NSPS, nationwide emissions of PM would be 
    reduced by about 800 megagrams per year (Mg/yr) over the levels 
    associated with the 1991 subpart Ea NSPS. This represents a nationwide 
    reduction of about 34 percent over the subpart Ea levels.
        Nationwide emissions of Cd and Pb would be reduced by about 1 and 
    17 Mg/yr, respectively, over the levels associated with the 1991 
    subpart Ea NSPS. This represents an incremental reduction of about 53 
    percent for Cd and 81 percent for Pb over subpart Ea NSPS levels.
        Nationwide emissions of Hg would be reduced by about 18 Mg/yr over 
    levels associated with the 1991 subpart Ea NSPS. This represents an 
    incremental reduction of about 72 percent over subpart Ea NSPS levels.
        Nationwide emissions of SO2 and HCl would be reduced by about 
    3,000 and 4,000 Mg/yr, respectively, over reductions associated with 
    the 1991 subpart Ea NSPS. Total acid gas emissions would be reduced by 
    about 58 percent over subpart Ea NSPS levels.
        Nationwide emissions of NOX would be reduced by about 200 Mg/
    yr, or about 1 percent nationwide, over levels associated with the 1991 
    subpart Ea NSPS.
    
    2. Water and Solid Waste Impacts
    
        The acid gas/PM and NOX control technologies used as the basis 
    for today's proposed NSPS are the same technologies used as a basis for 
    the subpart Ea NSPS. Those technologies were determined to have 
    negligible water or solid waste impacts, as discussed in the previous 
    Federal Register notice (56 FR 5488).
        In the proposed NSPS, activated carbon injection is the 
    technological basis for controlling Hg emissions. Activated carbon 
    injection does not produce a wastewater stream, and it would have a 
    negligible solid waste impact.
        As with the 1991 NSPS, the EPA concludes that MWC ash disposal is 
    adequately addressed by waste management standards so that 
    considerations of ash quality do not play a role in this rulemaking.
    
    3. Energy Impacts
    
        The energy impact of applying acid gas/PM controls to small plants 
    and applying Hg controls to both small and large MWC plants will result 
    in a total national energy increase of about 27 gigawatt hours per year 
    (GW-hr/yr) of electricity. No increase in the use of natural gas is 
    anticipated.
        Many of the small plants covered under today's proposal produce 
    steam that is used to generate electricity for sale. For example, a 
    typical 100 Mg/day MWC plant would generate about 12 GW-hr/yr of 
    electricity. Such an MWC would require additional energy to operate 
    pollution control equipment. The required energy would be about 0.7 GW-
    hr/yr of electricity, which has a relatively small impact on energy 
    generated at the plant (about 6 percent of energy generated).
    
    4. Control Cost Impacts
    
        The EPA estimates the incremental annual social cost of control of 
    the proposed NSPS over the 1991 subpart Ea NSPS to be about $43 million 
    per year and the incremental national average cost per unit of waste 
    combusted to be about $1.95/Mg. The incremental capital cost of control 
    in the first 5 years of application is estimated to be $156 million 
    over the cost of the 1991 subpart Ea NSPS.
    
    B. Impacts of the Proposed NSPS Over a Pre-1989 Baseline
    
        The following provides a discussion of the impacts of the proposed 
    subpart Eb NSPS over a pre-1989 baseline. Since the 1991 subpart Ea 
    NSPS has been effective for 3 years, the impacts presented below 
    provide a useful account of the total impact of the NSPS, based on both 
    the 1991 subpart Ea and proposed subpart Eb standards.
    
    1. Air Impacts
    
        The air emission reductions discussed below are nationwide impacts 
    that would result from full implementation of the NSPS in the fifth 
    year after adoption. These are not incremental impacts relative to the 
    February 11, 1991 NSPS (see section III.A for a description of 
    incremental impacts).
        In combination, today's proposed standards and the 1991 NSPS would 
    reduce nationwide emissions of dioxins/furans by about 29 kg/yr, total 
    mass. Emissions of dioxin/furans on a TEQ basis would be reduced by 
    about 480 g/yr. This represents an overall reduction of about 97 
    percent compared to baseline dioxins/furans emission levels in the 
    absence of the 1991 and proposed NSPS.
        Under the proposed standards and the 1991 NSPS, nationwide 
    emissions of PM would be reduced by about 6,500 Mg/yr. This represents 
    an overall control level of over 80 percent for PM emissions compared 
    to baseline levels in the absence of the 1991 and proposed NSPS.
        Nationwide emissions of Cd and Pb would be reduced by 10 and 157 
    Mg/yr, respectively. This represents an overall reduction of about 94 
    percent for Cd emissions and about 98 percent for Pb emissions, 
    compared to emission levels in the absence of the 1991 and proposed 
    NSPS.
        As a result of the 1991 and proposed NSPS, nationwide Hg emissions 
    would be reduced by about 27 Mg/yr over baseline levels. This 
    represents an overall reduction of about 80 percent for Hg emissions 
    compared to baseline levels in the absence of the 1991 and proposed 
    NSPS.
        Nationwide emissions of SO2 would be reduced by about 38,000 
    Mg/yr, and nationwide emissions of HCl would be reduced by about 50,000 
    Mg/yr. The 1991 and proposed NSPS would reduce MWC acid gas emissions 
    by about 94 percent compared to baseline emission levels.
        Nitrogen oxides emissions would be reduced by about 10,500 Mg/yr. 
    This represents an overall nationwide reduction in NOX emissions 
    of about 35 percent as compared to levels in the absence of the 1991 
    and proposed NSPS.
    
    2. Water and Solid Waste Impacts
    
        As discussed in section III.A.2, the technologies used to comply 
    with both the 1991 subpart Ea and proposed subpart Eb NSPS do not 
    produce a wastewater stream; therefore, no significant water pollution 
    impacts are projected to occur. Additionally, the application of these 
    technologies would result in a negligible solid waste impact.
    
    3. Energy Impacts
    
        As a result of the proposed and 1991 standards, total national 
    usage of energy is estimated to increase by about 290 GW-hr/yr of 
    electricity above baseline. No increase in the usage of natural gas is 
    anticipated.
        The majority of the MWC's covered under the proposal produce steam 
    that is used to generate electricity for sale. Those MWC's would 
    require energy to operate pollution control equipment, but such energy 
    requirements have a relatively small impact on energy generated at the 
    plant (about 4 to 6 percent of total energy generated).
    
    4. Control Cost Impacts
    
        a. National Overview. The EPA estimates the total combined annual 
    social cost of control of the 1991 NSPS and today's proposed standards 
    to be about $200 million per year, and the overall national average 
    cost per unit of waste combusted would be about $13.50/Mg. For 
    perspective, typical costs incurred in 1990 by the general public for 
    the collection, transportation, and combustion of MSW and ash disposal 
    ranged from $22/Mg to over $145/Mg of MSW, averaging about $90/Mg. 
    Additionally, the EPA estimates the capital cost of control in the 
    first 5 years of application of the 1991 NSPS and today's proposal to 
    be $769 million.
        b. Control Costs for Typical MWC Plants. The previous section 
    presented costs of the proposal on a national basis. This section 
    presents examples of typical costs that would be experienced at both a 
    large MWC plant and a small MWC plant. These are typical costs.
        The costing data presented in this section are provided in the 
    following formats: capital cost, annualized cost, and cost per Mg of 
    municipal waste combusted. The costing information is subcategorized by 
    air pollution control components (i.e., acid gas scrubber, activated 
    carbon injection application, and NOX control). For perspective, 
    the estimated cost of combustion units (which includes the cost of GCP) 
    is also displayed. This costing information has been derived from 1989 
    background information documents that were used in developing the 1991 
    NSPS (see SUPPLEMENTARY INFORMATION for more information about these 
    documents), and is presented in 1987 dollars (the escalation factor for 
    converting to mid-1990 dollars is 1.111).
        From table 3A, it can be noted that the capital cost for control at 
    a new large MWC plant (730 Mg/day capacity) would be about $14.2 
    million of which $12.0 million would be for the acid gas control, 2.0 
    million for NOX control, and less than one million for activated 
    carbon injection. On an annualized basis, the cost would be about $4.2 
    million/yr or about $17.50/Mg of waste combusted. This would increase 
    baseline combustor cost from about $60/Mg combusted to about $77/Mg 
    combusted. Large MWC plants represent about 95 percent of MWC 
    combustion capacity.
        For a new small MWC plant (90 Mg/day capacity), table 3A shows a 
    capital cost for control of about $3.14 million of which $3.1 million 
    would be for the acid gas control system and the remaining for 
    activated carbon injection. On an annualized basis, the cost would be 
    about $920,000/yr or about $31/Mg of waste combusted. This would 
    increase baseline combustor cost from about $60/Mg combusted to about 
    $91/Mg combusted. Small MWC plants represent about 5 percent of MWC 
    combustion capacity.
    
    C. Economic Impacts
    
        The following provides a discussion of the total economic impacts 
    (e.g., household, community, and business impacts) of the proposed and 
    1991 NSPS over a pre-1989 baseline. As discussed in sections III.A.4 
    and III.B.4 of this preamble, the proposed subpart Eb standards would 
    have a small incremental national average cost per unit of waste 
    combusted ($1.95/Mg) as compared to the combined impact of the 1991 
    subpart Ea NSPS and the proposed subpart Eb NSPS ($13.50/Mg). Since the 
    proposed NSPS is based on the same technologies as the 1991 NSPS, and 
    since the 1991 NSPS has been effective for 3 years, the impacts 
    presented below provide a useful account of the total economic impacts 
    of the NSPS, based on both the 1991 and proposed NSPS. In estimating 
    the economic impacts, the EPA assumed that all new MWC's would have 
    been built with no more emission control than that mandated by 
    regulations promulgated before 1991, specifically, 40 CFR part 60, 
    subparts E and Db. This pre-1991 situation represents the baseline for 
    estimating regulatory costs; therefore, all cost estimates provided are 
    the full costs above this baseline.
    
      Table 3A.--Capital and Annualized Costs of Air Pollution Control for Typical New Large and Small MWC Plantsa  
    ----------------------------------------------------------------------------------------------------------------
                                                                      Air pollution control device costa            
                                                        ------------------------------------------------------------
                                             Baseline                                                       Total   
                  Parameter                 combustorb   Acid gas/PM                        Total APCD    combustor 
                                                                         CIc        NOX        costd      and APCD  
                                                                                                            cost    
    ----------------------------------------------------------------------------------------------------------------
    New large MWC plant (730 Mg/day MB/WW                                                                           
     with SD/FF, CI, and SNCR)e, f, g:                                                                              
        Capital cost ($106)..............         50          12          0.150      2.0         14.2          64.2 
        Percent of total capital cost                                                                               
         (%)h............................         78          19          0.2        3           22           100   
        Annualized cost ($106/yr)........         14.4         3.56       0.091      0.582        4.23         18.6 
        Average cost increase ($/Mg MSW                                                                             
         combusted)......................         59.5        14.8        0.37       2.39        17.5          77.05
    New small MWC plant (90 Mg/day MOD/SA                                                                           
     with SD/FF and CI)i:                                                                                           
        Capital cost ($106)..............          5.5         3.1        0.043      0            3.14          8.64
        Percent of total capital cost                                                                               
         (%)h............................         64          36          0.5        0           36           100   
        Annualized cost ($106/yr)........          1.83        0.91       0.014      0            0.92          2.76
        Average cost increase ($/Mg MSW                                                                             
         combusted)......................         60.5        30.2        0.46       0           30.7          91.2 
    ----------------------------------------------------------------------------------------------------------------
    aThe costs presented are in 1987 dollars. To calculate mid-1990 dollars, multiply 1987 dollars by a factor of   
      1.111. Total cost values may not add due to rounding.                                                         
    bCosts for good combustion practices are included in combustor design (no cost).                                
    cCI = activated carbon injection.                                                                               
    dAPCD = air pollution control device.                                                                           
    eMB/WW = mass burn waterwall combustor.                                                                         
    fSD/FF = spray dryer and fabric filter.                                                                         
    gSNCR = selective noncatalytic reduction.                                                                       
    hDoes not add to 100 percent due to rounding.                                                                   
    iMOD/SA = modular starved-air combustor.                                                                        
    
        The overall incremental national average cost per unit of waste 
    combusted of $13.50/Mg (presented in section III.B.4 of this preamble) 
    breaks down as follows: $11 for acid gas/PM and metals control; $0.40 
    for Hg control; $1.80 for NOX control; and $0.35 for testing, 
    reporting, and recordkeeping. The $1.80 cost for NOX control is 
    for large MWC plants only, because no small plants will incur NOX 
    control costs.
        The standard will have a wide range of impacts on the price of 
    combustion services. To study these potential impacts, the EPA first 
    applied a cost accounting procedure that approximates the one that 
    would be used by an individual publicly owned MWC. Then, using a 1993 
    average tipping fee of $57/Mg of MSW combusted (1990 dollars) and 
    assuming the full cost of meeting acid gas, PM, Hg, and NOX 
    requirements is passed directly to MWC customers, the EPA found that 
    the lowest and highest tipping fee increases for the model plants used 
    in the EPA's economic analysis would be about $11/Mg and $85/Mg, 
    respectively. The majority of tipping fee increases would be in the 
    $13/Mg to $18/Mg range. This increase would be equivalent to about 
    $1.00/month to $1.50/month for a typical household.
        The EPA projects that, regardless of how the regulatory costs are 
    financed, most of the burden will find its way directly or indirectly 
    to households served by MWC's. Costs that are directly assessed to 
    households are likely to be in the form of increased collection fees 
    and/or increased taxes. Indirect household costs are price increases 
    charged by businesses that similarly are faced with increases in 
    collection fees and/or taxes. For the 1991 NSPS and the standards being 
    proposed today, the EPA projects an increase in the average annual 
    household cost of waste disposal of about $21 for communities that 
    construct new MWC's. The actual cost per household will depend on local 
    conditions, including the extent to which recycling and landfilling are 
    also used within the affected community. Approximately 54 percent of 
    the total average household cost is a direct cost, thus the annual 
    direct household cost would be a little over $11. The EPA estimates 
    that the average annual household cost breaks down to $17 per year for 
    communities over 250,000 in population, $23 for communities with 
    populations between 100,000 and 250,000, $29 for communities with 
    populations between 50,000 and 100,000, and $27 for communities with 
    populations under 50,000. This range represents 0.04 to 0.09 percent of 
    household income. The EPA expects that comparatively few communities 
    under 100,000 will be affected by the standards, because such 
    communities tend to rely on landfilling.
        The adoption of new regulations increases costs for a community and 
    at some point has the potential to affect abilities to issue bonds. To 
    address this issue, the EPA used demographic and financial data to 
    project potential difficulty that might confront communities planning 
    to construct new MWC's with bond financing. Applying generally accepted 
    criteria for issuance of revenue and general obligation bonds, the EPA 
    found that no community, large or small, should experience difficulty 
    with bond financing as a result of the proposed standards.
        To address the issue of cost increases, the EPA identified five 
    private firms that plan to construct one or more MWC's that will be 
    subject to the standards. Of the five, four are small (i.e., have less 
    than $6 million in annual sales). (Firms for which annual sales data 
    are not available are assumed to be small.) Financial data are 
    available for only one firm, which is a large firm. Total annual costs 
    of the 1991 and proposed NSPS as a percentage of sales is less than 1 
    percent for that firm. Potential tipping fee increases, based on the 
    full pass-through of emission control costs (i.e., passing all control 
    costs to consumers via the tipping fee) and an average tipping fee of 
    $57/Mg (1990 dollars), will average about 28 percent for MWC's owned by 
    small firms, and about 17 percent for MWC's owned by large firms.
        In its analysis of cost, economic, and environmental impacts, the 
    EPA assumed that the 1991 NSPS and the standards being proposed today 
    will not cause communities to alter their plans to construct new (or to 
    use already constructed) MWC plants. Specifically, the EPA is assuming 
    that its projections of how much MSW will be combusted in the year 
    2000, and the types and sizes of new combustors that will be used, will 
    not be effected by the standards being proposed today. However, some 
    communities, if faced with large compliance costs, may choose to delay 
    or cancel construction, or to downsize MWC's, or to change combustion 
    technology. These communities probably would expand landfilling, 
    recycling, or source-reduction activities. If the standards do cause 
    some communities to shift away from combustion, the result will be a 
    general reduction of the cost impacts reported here. However, any such 
    shifts caused by the standards, and the net economic and environmental 
    effects of those shifts, are extremely difficult to project. This is in 
    part due to the fact that environmental regulations for landfills, as 
    well as landfill site location problems, will be exerting an opposite 
    influence on communities--causing them to look with more favor on 
    combustion alternatives.
        The EPA has been able to quantify some of the benefits of the 
    standards. The absence of sufficient exposure-response and valuation 
    information precludes a comprehensive benefits analysis for many of the 
    MWC pollutants. The EPA expects partial benefits for reduction of PM 
    and SO2--primarily benefits from reductions in morbidity and 
    mortality--to total about $160 million annually. However, recent 
    evidence suggests the mortality reduction benefits of particulate 
    matter controls may be higher than is assumed in this analysis.
        In conclusion, based on the combined economic impacts analysis of 
    both the 1991 and proposed NSPS, the EPA expects that no community will 
    be significantly impacted by the proposed and 1991 NSPS. Since the 
    incremental impact of the proposal over the 1991 NSPS is only one-
    seventh the total combined impact (based on incremental national 
    average cost per unit of waste combusted), the proposal is expected to 
    have a very small impact on communities.
    
    IV. Rationale for Proposed Standards for MWC Emissions
    
        This section addresses the legal, technical, and economic basis for 
    the proposed NSPS. The basis for regulating MWC's, for regulating the 
    specified pollutants, and for regulating MWC's according to the 
    specified size categories are discussed. The section also presents the 
    EPA's approach in establishing the MACT floor and selecting MACT. 
    Additionally, the section discusses the selected format for the 
    proposed standards, the proposed performance testing and monitoring 
    requirements, and the proposed reporting and recordkeeping 
    requirements.
    
    A. Background
    
        On November 15, 1990, the Act was amended. The amendments added a 
    new section 129 to the Act, which applies to a range of solid waste 
    incinerators including MWC's, medical waste incinerators (MWI's), 
    infectious waste incinerators, and industrial waste incinerators.
        Under authority of sections 111 and 129 of the Act of 1990, the EPA 
    was directed to develop and promulgate MACT-based NSPS for MWC's 
    according to a specified schedule. At the time of enactment of the Act 
    as amended in 1990, the EPA had already proposed, under section 111 of 
    the Act, NSPS based on BDT for all sizes of new MWC's. Section 129 of 
    the Act of 1990 directed the EPA to promulgate standards based on BDT 
    under the deadlines imposed in the consent decree in State of New York 
    et al. versus Reilly (No. 89-1729 D.D.C.), but limited applicability of 
    the standards to combustors with unit capacities greater than 225 Mg/
    day. As a result, the standards, which were proposed in 1989, under 
    development for promulgation in late 1990 were revised to be applicable 
    only to these MWC units. The final standards were signed by the 
    Administrator on January 11, 1991 published in the Federal Register on 
    February 11, 1991 (56 FR 5488).
        Section 129 of the Act also directs the EPA to develop another NSPS 
    for MWC's that would be based on a more stringent control scenario, 
    apply to smaller facilities, and cover more pollutants. Specifically, 
    section 129 directs the EPA to promulgate MACT-based NSPS for MWC units 
    at MWC plants with capacities to combust less than 225 Mg/day. Section 
    129 also directs the EPA to develop numerical emission limits for Cd, 
    Pb, and Hg, to incorporate siting requirements for new units, and to 
    develop operator training requirements. Additionally, section 129 
    directs the EPA to develop an opacity limit for air curtain 
    incinerators firing certain ``clean'' fuels.
        Today's proposal complies with all requirements of section 129 
    described above. This has been done by: (1) Proposing MACT-based NSPS 
    that cover MWC units at plants with capacities above 35 Mg/day; (2) 
    proposing numerical emission limits for Cd, Pb, and Hg; (3) proposing 
    siting requirements for new MWC units; (4) proposing operator training 
    requirements; and (5) proposing opacity limits for air curtain 
    incinerators firing specific ``clean'' fuels.
        The proposed NSPS are, in effect, replacing the February 11, 1991 
    subpart Ea NSPS for MWC facilities for which construction, 
    modification, or reconstruction begins after September 20, 1994, 
    because the February 11, 1991 subpart Ea NSPS are based on BDT rather 
    than MACT. The February 11, 1991 subpart Ea NSPS will remain in effect 
    for facilities for which construction, modification or reconstruction 
    began after December 20, 1989 but on or before September 20, 1994. 
    Those existing facilities constructed after December 20, 1989 but 
    before this proposal would be subject to both the 1991 subpart Ea NSPS 
    and the subpart Cb guidelines proposed in a separate notice in today's 
    Federal Register. This dual coverage under both the proposed subpart Cb 
    and the 1991 subpart Ea is further discussed in the preamble to the 
    proposed subpart Cb in today's Federal Register notice.
    
    B. Selection of Source Category
    
        The previous MWC NSPS adopted on February 11, 1991 provided the 
    rationale for the selection of MWC's as a source category to be 
    regulated (56 FR 5488). Moreover, section 129 of the Act directs the 
    EPA to issue NSPS for this source category, and thereby confirms the 
    EPA's earlier decision.
        Today's proposed NSPS (subpart Eb) would apply to new MWC's, 
    defined as those MWC's for which construction, modification, or 
    reconstruction commenced after September 20, 1994. Municipal waste 
    combustors for which construction, modification, or reconstruction 
    commenced on or before September 20, 1994, would be covered by the 
    subpart Cb emission guidelines proposed in a separate notice in today's 
    Federal Register.
        Also, as required by section 129 of the Act, today's proposed NSPS 
    would establish opacity limits for certain new air curtain 
    incinerators, for which construction, modification, or reconstruction 
    commenced after September 20, 1994. Under the proposed NSPS, air 
    curtain incinerators that burn only yard wastes, tree trimmings, and 
    clean untreated lumber would be required to meet an opacity limit and 
    no other requirements would apply. The proposed standards for these air 
    curtain incinerators are presented in section VII of this preamble.
    
    C. Modification or Reconstruction of Existing MWC's
    
        The subpart Ea NSPS proposal published in the Federal Register on 
    December 20, 1989 (54 FR 52251) provided a discussion of the terms and 
    conditions associated with construction, modification, and 
    reconstruction for MWC's. One change is being proposed. Previously, the 
    terms ``modification'' and ``reconstruction'' were defined under 
    sections 60.14 and 60.15 of subpart A of part 60. Section 129 of the 
    Act has specified a new definition of ``modified solid waste 
    incineration unit'' that combines and revises the previous definitions 
    of ``modification'' and ``reconstruction.'' Specifically, ``modified 
    solid waste incineration unit'' refers to:
        (1) Modifications for which the
    
        * * * cumulative costs of the modifications, over the life of 
    the unit, exceed 50 per centum of the original cost of the 
    construction and installation of the unit (not including the cost of 
    any land purchased in connection with such construction or 
    installation) updated to current costs * * *.
    
    or (2) modifications involving
    
        * * * a physical change in or change in the method of operation 
    of the unit which increases the amount of any air pollutant emitted 
    by the unit for which standards have been established under [section 
    129] or section 111 * * *.
    
    D. Selection of Designated Pollutants
    
        The previous MWC NSPS proposal published in the Federal Register on 
    December 20, 1989 (54 FR 52251) provided the rationale for the 
    selection of ``MWC emissions'' and NOX as designated pollutants 
    under section 111(b) of the Act. Additionally, section 129 of the Act 
    specifies that emission limits shall be developed for PM, opacity, 
    SO2, HCl, NOX, CO, Cd, Pb, Hg, and dioxins/furans. Emission 
    limits for all but three of these pollutants (Cd, Pb, and Hg) were 
    established in the February 11, 1991 standards. Section 129 also 
    requires that siting requirements be established for new MWC's that 
    will minimize, on a site-specific basis, potential risks to public 
    health or the environment. Today's proposal responds to these new 1990 
    Act requirements.
        Standards for fugitive MWC fly ash/bottom ash emissions are 
    proposed today because these emissions contain PM, Cd, Pb, Hg, and 
    dioxins/furans, which are components of the designated pollutant ``MWC 
    emissions.''
    
    E. Selection of Affected Facilities
    
        For the proposed NSPS, the affected facility, an MWC facility, is 
    defined as any setting or equipment chamber or pit used to burn MSW 
    (including RDF) and extends to MWC fly ash/bottom ash emission points, 
    including ash storage areas, conveyor transfer points, and ash loading 
    areas for hauling trucks at the MWC site. This does not extend to ash 
    handling outside of the MWC property boundary or at ash fill sites.
        Municipal waste combustion includes the burning (or pyrolysis) of 
    MSW in any type of equipment, chamber, or pit, including equipment with 
    and without heat recovery. Municipal solid waste is defined as either a 
    mixture or a single-item stream of household, commercial, and/or 
    institutional discards. This would include discards such as paper, 
    wood, yard wastes, tree trimmings, plastics, leather, rubber, glass, 
    metals, and other combustible and noncombustible materials. The MSW 
    definition includes household discards as well as discards from 
    institutional and commercial sources, but does not include segregated 
    industrial process/manufacturing discards or medical waste. The MSW 
    definition also includes RDF, which is a type of MSW that is shredded 
    (or pelletized) and classified by size before combustion. However, any 
    mixtures of medical waste with nonmedical hospital waste or with 
    household, commercial, or institutional waste is considered to be MSW. 
    Any mixtures or industrial process/manufacturing discards with 
    nonprocess industrial waste or with household, commercial, or 
    institutional waste is considered to be MSW. Minor editing has been 
    made in the definition of MSW to clarify this point.
        Cofired combustors are those that fire MSW with non-MSW fuel such 
    as coal. Cofired combustors that combust a fuel feed stream comprised, 
    in aggregate, of equal to or less than 30 percent MSW or RDF (by 
    weight, based on a 24-hour average) would not be subject to the NSPS 
    and would be required only to submit an initial notification of 
    construction and subsequent reports of the amount of MSW and other 
    fuels combusted. The exclusion of cofired combustors from the NSPS is 
    consistent with section 129 of the 1990 Act. This exclusion is 
    unchanged from the February 11, 1991 NSPS.
        Air curtain incinerators with unit capacities to combust greater 
    than 35 Mg/day of MSW are subject to the proposal; however, air curtain 
    incinerators that combust only tree trimmings, yard wastes, and clean 
    untreated lumber (these are a subset of MSW) would be subject to an 
    opacity standard and its associated testing, recordkeeping, and 
    reporting, which are included in today's proposal, but would not be 
    subject to any other parts of today's proposal. This exclusion does not 
    apply to air curtain incinerators that combust other MSW materials.
        Additionally, waste-fuel power generation facilities that combust a 
    single-item waste stream of tires, fuel derived solely from tires, or 
    used oil would be subject only to an initial notification of 
    construction and would not be subject to any other provisions in 
    today's proposal. This exclusion is unchanged from the NSPS promulgated 
    on February 11, 1991.
        The NSPS for MWC's proposed today would apply to MWC units at 
    plants with capacities above 35 Mg/day. The lower size threshold of 35 
    Mg/day aggregate plant capacity for controlling MWC emissions under the 
    proposed NSPS was selected after reviewing the population distributions 
    of MWI's and MWC's. Most incinerators at medical waste facilities are 
    smaller incinerators that fire segregated medical waste with general 
    hospital discards (MSW), and these incinerators would have the 
    potential to be covered by today's proposal. The population 
    distribution of MWI's is distinctly different from the population 
    distribution of traditional MWC plants that are the target of today's 
    proposal. The existing distribution of MWC's is composed of about 179 
    plants, with an average plant size of about 600 Mg/day combustion 
    capacity, with two or three MWC units per plant. Assuming continuous 
    operation, the potential nationwide combustion capacity of existing 
    MWC's is about 107,000 Mg/day. The MWI distribution is quite different 
    and includes about 7,000 combustors with a single combustion unit per 
    facility and an average unit size of less than 3 Mg/day combustion 
    capacity. The total U.S. capacity of MWI's is about 20,000 Mg/day. This 
    population is being addressed under a separate rulemaking. These 
    population distributions of existing MWC's and MWI's are for existing 
    units but are considered representative of new unit applications. 
    Clearly, the MWC population represents a smaller number of 
    comparatively larger combustors, and MWI's represent a much larger 
    number of smaller combustors. The lower size cutoff of 35 Mg/day 
    aggregate plant capacity that is included in today's proposal would 
    exclude less than 1 percent of the total nationwide combustion capacity 
    of MWC's and would result in over 99 percent of total MWC capacity 
    being covered by the standards. The same lower size cutoff of 35 Mg/day 
    would prevent significant dual coverage under the proposal by excluding 
    more than 99 percent of MWI units and about 97 percent of nationwide 
    MWI capacity from today's proposed revisions.
        The proposed standards would therefore cover the great majority of 
    MWC's, but cover only a few of the largest regional MWI's (nine units 
    at three sites are known to cofire medical waste with MSW and are above 
    the 35 Mg/day total plant capacity cutoff). The Act of 1990 requires 
    that regulations for MWI's be developed separately. For these reasons, 
    it is appropriate that today's proposed standards focus on MWC's and 
    that a separate regulation focus on MWI's. The NSPS and emission 
    guidelines for MWI's are scheduled to be proposed in 1995.
        Those MWC's at plants with aggregate capacities below 35 Mg/day 
    would not be subject to the emission limits or any other emission 
    control requirements under today's proposal. However, MWC plants with 
    aggregate capacities greater than 25 Mg/day and less than or equal to 
    35 Mg/day would be required to provide a one-time notification of 
    construction, which would include their location, planned startup date, 
    the types of fuels that will be combusted, and aggregate plant capacity 
    and supporting information including calculations used to determine 
    plant capacity. This one-time report would allow the EPA or State 
    agency to enforce the lower size cutoff for applicability to the 
    proposed standards. Plants with aggregate capacities of 25 Mg/day or 
    below would not be subject to any provisions under this proposal.
        The proposed standards for MWC's are subdivided into two 
    subcategories of air emissions requirements: The first for MWC's 
    located at MWC plants with aggregate capacities to combust more than 35 
    Mg/day but less than or equal to 225 Mg/day of MSW (referred to as 
    small MWC plants), and the second for MWC's located at MWC plants with 
    aggregate capacities to combust greater than 225 Mg/day of MSW 
    (referred to as large MWC plants). The 225 Mg/day dividing point was 
    established because the population of plants with aggregate capacities 
    equal to or below 225 Mg/day contains many modular MWC's, and there are 
    concerns about how applicable technologies such as selective 
    noncatalytic reduction (SNCR) are to modular MWC's.
        The EPA projects that the population of new MWC's at plants with 
    aggregate capacities above 225 Mg/day will account for about 93 percent 
    of new combustion capacity, whereas the population of MWC's at plants 
    with aggregate capacities greater than 35 Mg/day but equal to or less 
    than 225 Mg/day will account for about 7 percent of new combustion 
    capacity.
    
    F. Selection of Maximum Achievable Control Technology
    
        The following discussion addresses the EPA's selection of MACT. The 
    existing technologies for controlling emissions of the designated 
    pollutants from MWC's are first reviewed, followed by a summary of the 
    EPA's approach for establishing the MACT floor. Finally, the discussion 
    presents the EPA's selection of MACT for MWC's.
    
    1. Summary of MWC Control Technologies
    
        The following discussion reviews the existing technologies for 
    controlling emissions of acid gases, dioxins/furans, PM, Cd, Pb, Hg, 
    and NOX from MWC's.
        a. Acid Gas/PM Control Technologies. Municipal waste combustor acid 
    gas/PM control is a general term that refers to a group of MWC air 
    pollution control technology combinations. These combinations control a 
    wide range of pollutants, such as MWC acid gases (including SO2 
    and HCl), MWC organics (including dioxins/furans), and PM and metals 
    (including Cd, Pb, and a number of other metals except Hg). The two 
    acid gas/PM controls most commonly used in the United States for new 
    MWC's are: (1) GCP plus dry sorbent injection (DSI) followed by a 
    fabric filter (FF); and (2) GCP plus a spray dryer (SD) followed by an 
    FF. Discussions of these two acid gas/PM control systems were presented 
    in the December 20, 1989 proposal preamble for the 1991 acid gas and PM 
    NSPS in subpart Ea (54 FR 52251). Control of Cd, Pb, and Hg were not 
    discussed in detail in the 1989 preamble.
        Since 1991, the performance of the acid gas/PM control systems for 
    removal of Cd, Pb, and Hg has been investigated in more depth. Cadmium 
    and Pb are volatile at temperatures present in combustion systems, but 
    condense onto PM at temperatures associated with the operation of most 
    PM control systems. As a result, the control of Cd and Pb is generally 
    related to the control of PM emissions. However, because of the 
    potential for adsorption of these metals onto fine PM that is less 
    readily collected than larger PM, the control efficiency for these 
    metals may be lower than that for total PM.
        Fabric filter-equipped systems (e.g., DSI/FF's and SD/FF's) 
    generally have better Cd and Pb control because these devices are 
    better able to collect fine PM than electrostatic precipitator (ESP)-
    equipped systems. For DSI/FF and SD/FF systems, data for controlled Cd 
    emissions range from 0.001 to 0.010 mg/dscm. Emissions of Pb from MWC's 
    with these systems range up to 0.10 mg/dscm, but the majority are 
    generally less than 0.050 mg/dscm.
        Although the above technologies are effective at removing Cd, Pb, 
    and other metals, they do not consistently remove Hg without 
    integrating some other form of Hg control. A discussion of Hg control 
    is presented below.
        b. Mercury Control Technologies. The EPA estimates that typical 
    uncontrolled Hg emission levels from MWC's in the United States range 
    from 0.20 to 1.4 mg/dscm at 7 percent O2. Unlike other metals, Hg 
    has a high vapor pressure at typical operating temperatures of air 
    pollution control devices; therefore, collection of Hg by the PM 
    control device is highly variable. The EPA collected test data from 
    more than 30 MWC's with various air pollution control device systems 
    that indicate a wide range of Hg control. High-efficiency PM control, 
    lower flue gas temperatures in the air pollution control system, and a 
    sufficient level of carbon in the fly ash facilitate Hg control. Higher 
    levels of carbon in the fly ash and reduced flue gas temperatures 
    enhance Hg adsorption onto the carbon, which can then be removed by the 
    PM control device. To promote Hg adsorption, it is important to operate 
    the control systems at temperatures less than about 150 to 200  deg.C. 
    Low flue gas temperature is inherent to acid gas control.
        Municipal waste combustors with high combustion efficiency will 
    have effective carbon burnout and, therefore, will have low fly ash 
    carbon content. These units may achieve little or no Hg control even 
    when equipped with acid gas/PM control systems, and the control may be 
    highly variable even at the same site.
        Three techniques of Hg control are currently being used: Activated 
    carbon injection, sodium sulfide (Na2S) injection, and wet 
    scrubbing. Activated carbon injection and Na2S injection are used 
    in conjunction with an acid gas control device. Brief discussions of 
    these three Hg control technologies and their capabilities are 
    presented below.
        Injection of powdered activated carbon into the flue gas prior to 
    the acid gas/PM control device has been tested at U.S. MWC's. The 
    removal mechanism is not fully understood, but it is believed that 
    activated carbon is a catalyst for the oxidation of elemental Hg to 
    mercuric oxide and mercuric chloride, which can more readily be 
    captured in the air pollution control device. This technology has been 
    applied commercially to MWC's in Europe equipped with SD/ESP's and 
    during test programs in Europe and Canada to MWC's with SD/FF's and 
    DSI/FF's. The EPA also recently tested activated carbon injection at 
    the Stanislaus County MWC in California and the Camden County MWC in 
    New Jersey. The Stanislaus County MWC is equipped with an SD/FF, and 
    the Camden County MWC is equipped with an SD/ESP. Test results show Hg 
    reductions greater than 85 percent when injecting activated carbon.
        Another Hg control technology that has been applied to MWC's is 
    Na2S injection. Sodium sulfide is a crystalline solid that 
    dissolves in water. The resulting Na2S solution is sprayed into 
    the flue gas prior to the acid gas/PM control device. The reaction of 
    Na2S and Hg precipitates solid mercuric sulfide (HgS) that is 
    collected in the PM control device.
        Three MWC's in Sweden, two in Germany, and one in Canada have used 
    Na2S injection to control Hg emissions. All of these facilities 
    use DSI/FF systems for acid gas/PM control, and injection of Na2S 
    occurs prior to the DSI/FF system at flue gas temperatures of 130 to 
    250  deg.C. In addition, Hg emission tests were conducted at the 
    Stanislaus County MWC in California while using Na2S injection. 
    Results from tests at European, Canadian, and U.S. MWC's have shown Hg 
    removal efficiencies of 40 to 90 percent when using Na2S 
    injection.
        Wet scrubbing is a form of acid gas control that also controls Hg 
    without use of an add-on Hg control system. This technology has 
    primarily been used on MWC's in Europe and Japan. Typically, the flue 
    gas is first directed through an ESP to reduce PM, followed by wet 
    scrubbing, which involves passing the flue gas through a one- or two-
    stage absorber system where the gas stream is saturated with an 
    alkaline solution. During this process, flue gas temperatures are 
    reduced to as low as 55  deg.C. The low absorber operating temperature 
    promotes Hg condensation, resulting in an Hg reduction of greater than 
    80 percent. The alkaline solution used in the wet scrubbing process, 
    typically containing calcium hydroxide (Ca(OH)2), reacts with the 
    acid gas to form salts, which are generally insoluble and may be 
    removed by sequential clarifying, thickening, and vacuum filtering. The 
    dewatered salts or sludges are then sent to a landfill. The 
    disadvantages of wet scrubbing include the quantity of water required, 
    potential difficulties with waste handling, and undefined performance 
    at U.S. MWC units firing U.S. MSW streams.
        c. Nitrogen Oxides Control Technologies. During combustion, 
    NOX are formed through oxidation of fuel-bound nitrogen (N2) 
    contained in MSW, and fixation and oxidation of atmospheric N2. 
    Emissions of NOX can be controlled using SNCR add-on control 
    technology that reduces NOX to N2 without the use of 
    catalysts. Techniques include Thermal DeNOXTM, which injects 
    ammonia into the combustor as a reducing agent; the NOXOUTTM 
    process, which injects urea with chemical additives; and a two-stage 
    urea/methanol injection process. A discussion of SNCR NOX control 
    was presented in the December 20, 1989 proposal preamble for the 1991 
    NSPS for new MWC's (54 FR 52251). The use of SNCR at MWC's results in 
    NOX emission reductions of about 45 percent.
        There are some concerns about the applicability of SNCR to modular 
    MWC's. The SNCR technology has never been applied to modular MWC's, and 
    several factors may complicate the use of SNCR and may reduce its 
    performance level. First, many modular units are batch fed in cycles of 
    about 6 to 12 minutes per charge (due to small combustor size), which 
    may cause frequent temperature fluctuations. When the temperature 
    fluctuates above the required injection temperature window, the 
    reducing reagent is oxidized to NOX, and NOX emissions can 
    increase. When the temperature drops below the required range, 
    unreacted ammonia (NH3) emissions can occur. In addition, the 
    varying moisture and nonhomogeneous nature of the waste burned can also 
    result in temperature fluctuations in a small unit. With certain 
    modifications, it may be possible to accommodate SNCR at new modular 
    units; however, the NOX reduction performance of an SNCR system on 
    a modular unit will probably be lower than that for a combustor with 
    more stable operating temperatures, as occurs at large MWC's.
        The EPA requests comment on the applicability of SNCR and other 
    NOX control techniques to MWC's at small plants. The EPA requests 
    that comments address the cost, technical performance, and reliability 
    of application of SNCR or other NOX control techniques 
    specifically to modular starved-air MWC's and modular excess-air MWC's. 
    Based on the comments and information received, the EPA will reconsider 
    requiring NOX control on MWC's at small plants.
        The amount of NOX formed varies by combustor type. Three types 
    of MWC's, mass burn/rotary combustors, fluidized-bed combustors, and 
    modular/excess-air combustors, are considered ``low NOX'' 
    combustors. Available data show that these types of MWC's consistently 
    show NOX levels below 150 ppmv without the use of SNCR.
    
    2. MACT Floor and MACT Requirements of the Act
    
        The NSPS promulgated under subpart Ea on February 11, 1991 is based 
    on BDT. Section 129 requires that the NSPS promulgated under subpart Ea 
    be reviewed and revised based on MACT. Congress established a minimum 
    floor for the standards. For new sources, the standard may be no less 
    stringent than ``the emission control that is achieved in practice by 
    the best controlled similar unit.'' This is often referred to as the 
    ``MACT floor'' for new sources.
        To establish the emission control level achieved by the best 
    controlled similar unit, the EPA reviewed available MWC emissions test 
    data associated with all types of combustors and all types of emission 
    control technologies that are currently being used to control emissions 
    of SO2, HCl, PM, Pb, Cd, Hg, dioxins/furans, and NOX. The EPA 
    identified the best controlled unit and reviewed the performance of its 
    associated control technology. The EPA has concluded that the control 
    technology used by the best controlled unit is applicable to all types 
    of combustors (with one exception, as noted below) and achieves the 
    same level of performance on all combustor types. Thus, there is no 
    need to subcategorize performance to different classes of similar MWC 
    units. The EPA determined that the best controlled MWC (i.e., the basis 
    for the MACT floor) would be an MWC equipped with an SD/FF and SNCR 
    (large MWC plants only). Based on test data from MWC's equipped with 
    SD/FF and SNCR (large plants only) control systems, the EPA established 
    the MACT floor as the emission control level for each pollutant 
    achieved in practice by the best controlled MWC unit.
        The MACT floor defines the minimum level of emission control that 
    may be considered to be MACT, regardless of cost or other 
    considerations. However, in requiring control beyond the MACT floor 
    when determining MACT, the EPA must determine the maximum emission 
    reduction achievable for new MWC units taking into consideration the 
    cost of achieving such emission reduction and any non-air-quality 
    health and environmental impacts and energy requirements. Therefore, 
    the level of control that represents MACT may be more stringent than 
    the MACT floor. The following section presents the EPA's rationale for 
    establishing the MACT floor and MACT for MWC's.
    
    3. MACT Floor and MACT
    
        This section summarizes the MACT floor and presents the EPA's 
    rationale for establishing MACT for each pollutant for MWC's at both 
    small and large MWC plants.
        In establishing the MACT floor and MACT for each pollutant for 
    small and large plants, the EPA used principally the data base created 
    for establishing the NSPS for MWC's proposed in 1989 and promulgated in 
    1991 under subpart Ea. For a few pollutants in this proposal, the EPA 
    utilized more recent test data to supplement the 1989 data base. 
    Because most of the test data used for this proposal are more than 4 
    years old, and in consideration of the fact that most MWC's retest at 
    least once per year, the EPA requests submittal of the most recent MWC 
    emissions test data.
        Additionally, the EPA requests comment on which MWC emissions test 
    data would be the most appropriate basis for judging the performance of 
    SD/FF's in establishing the MACT floor and MACT for new MWC's. For 
    example, should the EPA consider test data for only the most recently-
    built MWC's (e.g., units that have begun operation since 1990), or 
    should consideration be made of all operational MWC's, independent of 
    unit age? Also, if the EPA has multiple emission tests for a given MWC 
    over its operating history (which is common), should the EPA utilize 
    the data from all of the emission tests performed for the unit or from 
    only the most recent emission test, in determining the performance of 
    the unit? The EPA also requests comment on suggestions of analytical 
    methods to use for analysis of the data (e.g., analytical methods that 
    could be used to address emissions variability, including methods for 
    analyzing variable data collected over multiple years for one MWC and 
    methods of adjusting the emissions data to account for variability). 
    The appropriate treatment of variability will be related to the format 
    chosen for the standards (see discussion of alternative formats below).
        Based on the new data submitted and on the final choice of which 
    test data and what analytical methods to use, the EPA may promulgate 
    final emission limits that are more or less stringent than those 
    proposed today.
        a. Summary of the MACT floor. This proposal determines the MACT 
    floor for new units based on performance of the best control 
    technology. Under the proposal, emission control level achieved in 
    practice by an MWC equipped with the best emission control technology 
    (i.e., an SD/FF and SNCR (large MWC plants only)) represents the MACT 
    floor for each pollutant (see table 4).
    
               Table 4.--MACT Floor Emission Levels for New MWC's           
    ------------------------------------------------------------------------
       Pollutant                   MACT floor emission levela,b             
    ------------------------------------------------------------------------
    SO2.............  30 ppmv or 80-percent reduction.                      
    HCl.............  25 ppmv or 95-percent reduction.                      
    Pb..............  0.10 mg/dscm.                                         
    Cd..............  0.010 mg/dscm.                                        
    PM..............  15 mg/dscm.                                           
    Hg..............  0.65 mg/dscm.                                         
    Dioxins/furans..  20 ng/dscm total mass or about 0.40 ng/dscm TEQ.      
    NOX.............  180 ppmv (large MWC plants) Uncontrolled (small MWC   
                       plants).                                             
    ------------------------------------------------------------------------
    aAll emission levels are corrected to 7 percent O2, dry basis.          
    bMost of the MACT floor requirements for large MWC plants are more      
      stringent than the 1991 subpart Ea NSPS (see table 2).                
    
        The MACT floor for new sources (best control) could be constructed 
    in a number of different ways including a technology basis (this 
    proposal), a permit basis, or an emission data basis. For example, 
    under the permit basis the most stringent MWC operating permit 
    limitation might determine the floor. Other approaches are also 
    possible. The different approaches would result in noticeably different 
    MACT floor performance levels. The EPA specifically requests comment on 
    what approach is most appropriate and the rationale for that approach. 
    Based on the EPA's review of comments received on this issue, as well 
    as reanalysis of the data submitted, the MACT floor for the promulgated 
    NSPS may be noticeably higher or lower than the floor included in the 
    proposal.
        b. MACT for Sulfur Dioxide. Uncontrolled SO2 emission levels 
    at both small and large MWC plants are, on average, 160 ppmv. The best 
    emission control system for controlling SO2 emissions is an SD/FF. 
    The EPA's analysis of test data from existing MWC's with SD/FF systems 
    indicates that an SO2 emission level of either 30 ppmv or an 80-
    percent reduction of SO2 emissions can be continuously achieved 
    over a 24-hour block averaging period. Therefore, the MACT floor for 
    SO2 emissions is either 30 ppmv or 80-percent reduction, whichever 
    is less stringent. The proposed MACT standard for SO2 for MWC's at 
    both small and large MWC plants is the MACT floor level of 30 ppmv or 
    80-percent reduction, whichever is less stringent.
        c. MACT for Hydrogen Chloride. Uncontrolled HCl emission levels at 
    both small and large MWC plants are, on average, 500 ppmv. The best 
    emission control system for controlling HCl emissions is an SD/FF. The 
    EPA's analysis of test data from existing MWC's with SD/FF systems 
    indicates that an HCl emission level of either 25 ppmv or a 95-percent 
    reduction in HCl emissions can be achieved. Compliance with the HCl 
    limit is determined by an annual stack test rather than CEMS, so there 
    is no CEMS data averaging period associated with this level of 
    performance. Based on the EPA's analysis, the MACT floor for HCl 
    emissions is either 25 ppmv or 95-percent reduction, whichever is less 
    stringent. The proposed MACT standard for HCl for MWC's at both small 
    and large MWC plants is the MACT floor level of either 25 ppmv or 95-
    percent reduction, whichever is less stringent.
        d. MACT for Particulate Matter. Uncontrolled PM emission levels at 
    small and large MWC plants are, on average, 1,500 and 3,700 mg/dscm, 
    respectively. The best emission control system for controlling PM 
    emissions is an SD/FF. The EPA's analysis of recent test data has shown 
    that SD/FF systems can continuously achieve a PM emission level of 15 
    mg/dscm, which represents greater than 99-percent reduction. Therefore, 
    the MACT floor for PM emissions is 15 mg/dscm. The proposed MACT 
    standard for PM for MWC's at both small and large MWC plants is the 
    MACT floor level of 15 mg/dscm.
        e. MACT for Cadmium. Uncontrolled Cd emission levels at both small 
    and large MWC plants are, on average, 1.2 mg/dscm. The best emission 
    control system for controlling Cd emissions is an SD/FF. The EPA's 
    analysis of test data from existing MWC's with SD/FF systems indicates 
    that these systems can continuously achieve a Cd emission level of 
    0.010 mg/dscm, which represents greater than 99-percent reduction. 
    Therefore, the MACT floor for Cd emissions is 0.010 mg/dscm. The 
    proposed MACT standard for Cd for MWC's at both small and large MWC 
    plants is the MACT floor level of 0.010 mg/dscm.
        f. MACT for Lead. Uncontrolled Pb emission levels at both small and 
    large MWC plants are, on average, 25 mg/dscm. The best emission control 
    system for controlling Pb emissions is an SD/FF. The EPA's analysis of 
    test data from existing MWC's with modern SD/FF systems indicates that 
    these systems can continuously achieve a Pb emission level of 0.10 mg/
    dscm, which represents greater than 99-percent reduction. Therefore, 
    the MACT floor for Pb emissions is 0.10 mg/dscm. The proposed MACT 
    standard for Pb for MWC's at both small and large MWC plants is the 
    MACT floor level of 0.10 mg/dscm.
        g. MACT for Mercury. Uncontrolled Hg emission levels at both small 
    and large MWC plants are, on average, 0.65 mg/dscm. The MACT floor is 
    based on using an SD/FF. Control of Hg is highly variable, and the 
    EPA's analysis of recent test data has indicated that the control 
    efficiency of SD/FF systems for Hg ranges from no control to 50-percent 
    Hg reduction (i.e., achieving Hg emission levels of 0.33 to 0.65 mg/
    dscm). Therefore, the MACT floor for Hg is 0.65 mg/dscm.
        As discussed in section IV.F.1.b of this preamble, the EPA has 
    determined that Hg control is based on three variables: Lower flue gas 
    temperatures in the air pollution control system, high-efficiency PM 
    control (e.g., based on use of an FF or ESP), and a sufficient level of 
    carbon in the fly ash (i.e., based on use of activated carbon 
    injection). Recent testing programs at the MWC plants in Stanislaus 
    County, California, and Camden County, New Jersey, have demonstrated 
    that the combination of an SD/FF or SD/ESP system, activated carbon 
    injection, and low flue gas temperature at the PM control device inlet 
    can achieve high Hg control efficiency. The EPA's analysis of this test 
    data has indicated that MWC's equipped with this combination of control 
    technologies could continuously achieve an Hg emission level of either 
    less than 0.080 mg/dscm, corrected to 7 percent O2, or an 85-
    percent reduction in Hg emissions. Data from individual test runs show 
    occasional spikes of high inlet Hg emissions due to the variability in 
    the waste feed composition. In cases where Hg levels are temporarily 
    elevated, a 0.080 mg/dscm level may not be consistently achievable; 
    however, activated carbon injection could achieve an 85-percent 
    reduction during such episodes. Based on the data from MWC's using 
    activated carbon injection, Hg control to these levels is achievable by 
    properly operated systems on all types of MWC's. Since activated carbon 
    injection is a relatively new technology and has not yet been applied 
    commercially, the 0.080 mg/dscm or 85-percent reduction Hg emission 
    level is not part of the MACT floor. The EPA estimates the cost to add 
    carbon injection to be reasonable, at a cost effectiveness of $1.00/Mg 
    of MSW combusted. Therefore, the EPA is proposing MACT for Hg for MWC's 
    at both small and large MWC plants to be more stringent than the MACT 
    floor, at a level of 0.080 mg/dscm or an 85-percent reduction in Hg 
    emissions, whichever is least stringent.
        The EPA has selected activated carbon injection as the basis for 
    achieving MACT for Hg, although facilities may use any technology 
    capable of meeting the proposed standard. Of the three Hg control 
    technologies discussed in section IV.F.1.b of this preamble, the EPA 
    has determined that the performance of activated carbon injection is 
    the best demonstrated of the three Hg control technologies in the 
    United States.
        h. MACT for Dioxins/Furans. Uncontrolled dioxin/furan emission 
    levels at both small and large MWC plants are, on average, 1,000 ng/
    dscm, total mass. The best emission control system for controlling 
    dioxin/furan emissions is an SD/FF system and GCP. The EPA's analysis 
    of available test data for dioxin/furan emissions from new MWC's with 
    SD/FF systems and GCP indicates that dioxin/furan emission levels of 
    less than 20 ng/dscm total mass are continuously achievable. Therefore, 
    the MACT floor for dioxins/furans is 20 ng/dscm, which represents a 98-
    percent reduction.
        The EPA has determined that additional dioxin/furan control is 
    achievable with activated carbon injection, which is the basis for MACT 
    for Hg, as discussed above. The EPA's analysis of test data from a 
    recent testing program at an MWC at the Camden County, New Jersey, 
    facility and other facilities indicates that the injection of activated 
    carbon into the flue gas of an SD-based scrubbing system provides 
    additional removal of dioxins/furans (greater than 50 percent 
    additional control over levels achieved with SD/ESP systems alone). As 
    such, the EPA believes a dioxin/furan level of approximately 10 ng/dscm 
    total mass (which represents a 99-percent reduction) is achievable for 
    MWC's using GCP and equipped with SD/FF's and activated carbon 
    injection. Because carbon injection is being proposed as part of the 
    basis for MACT for Hg, the EPA is proposing MACT for dioxins/furans for 
    MWC's at both small and large MWC plants based on carbon injection. The 
    EPA is proposing MACT for dioxins/furans on both a TEQ basis and a 
    total mass basis. Based on the EPA's analysis of an average TEQ ratio, 
    the 10 ng/dscm total mass emission level translates to 0.16 TEQ. 
    However, because there is uncertainty about the ratio, the proposed 
    MACT floor for dioxins/furans on a TEQ basis is 0.20 ng/dscm. Using the 
    average TEQ ratio, 0.20 ng/dscm TEQ is equivalent to about 13 ng/dscm 
    total mass dioxins/furans. Therefore, the EPA is proposing MACT for 
    dioxins/furans for MWC's at both small and large MWC plants at a level 
    of 0.20 ng/dscm TEQ or 13 ng/dscm total mass. Sources may comply with 
    either format of the limit.
        However, since the activated carbon injection technology does not 
    have a long-term record of commercial application in the United States 
    and since the 0.20 ng/dscm TEQ or 13 ng/dscm total mass standard is 
    restrictive, the EPA is proposing a 3-year optimization schedule for 
    activated carbon injection applied at initial subpart Eb applications. 
    All affected facilities commencing construction after September 20, 
    1994, but on or before September 22, 1997 would be required to meet a 
    standard of 0.50 ng/dscm TEQ or 30 ng/dscm total mass for the first 3 
    years following the date of initial startup. Thereafter, the standard 
    would be 0.20 ng/dscm TEQ or 13 ng/dscm total mass. For all affected 
    facilities commencing construction after September 22, 1997, the 
    standard at startup would be 0.20 ng/dscm TEQ or 13 ng/dscm total mass. 
    Starting in 1994, MWC units with activated carbon injection technology 
    will be initiating commercial operation. As dioxin/furan data become 
    available from MWC's operating with carbon injection technology, the 
    EPA will reconsider the appropriateness of the 3-year optimization 
    schedule.
        i. MACT for Nitrogen Oxides. The average NOX emission level 
    for MWC's without postcombustion NOX control (at both small and 
    large MWC plants) is 225 ppmv. The best emission control system for 
    controlling NOX emissions from MWC's at large MWC plants is SNCR. 
    The EPA's analysis of test data for existing MWC's (excluding modular 
    MWC's) equipped with SNCR indicates that an emission level of 180 ppmv 
    can be continuously achieved. Therefore, the MACT floor for NOX 
    for MWC's at large MWC plants is 180 ppmv (24-hour averaging period).
        As discussed in section IV.F.1.c of this preamble, the addition of 
    SNCR postcombustion NOX control has not been demonstrated on any 
    modular MWC, and the performance of such a system on a modular MWC is 
    in question. Since the performance of an SNCR system on a modular MWC 
    is in question, postcombustion NOX control is not being considered 
    for MWC's at small MWC plants; therefore, the MACT floor for NOX 
    for MWC's at small MWC plants is no control.
        The proposed MACT standard for NOX for MWC's at large MWC 
    plants is the MACT floor level of 180 ppmv. The proposed MACT standard 
    for NOX for MWC's at small MWC plants is based on no control. 
    Section IX of this preamble discusses the proposed ``no control'' 
    NOX standard for MWC's at small MWC plants.
    
    G. Selection of Format for the Proposed Standards
    
        The February 11, 1991 NSPS described a format for MWC acid gases 
    (SO2 and HCl), MWC metals (PM and opacity), MWC organics (dioxins/
    furans), MWC operating practices (CO, load, and flue gas temperature at 
    the PM control device inlet) and NOX, and that same format is 
    being adopted by today's proposed NSPS except for dioxins/furans. The 
    selection of the format for the standards for the above pollutants, is 
    described in previous Federal Register notices (54 FR 52251, December 
    20, 1989 and 56 FR 5488, February 11, 1991). The specific formats of 
    the proposed standards for Cd, Pb, and Hg are discussed below. For 
    dioxins/furans, the revised format is in units of either TEQ or total 
    mass dioxin/furans.
        As required by section 129(a)(4) of the Act, the proposed standards 
    would establish numerical limitations for Cd, Pb, and Hg. For the 
    purpose of regulating Cd and Pb, the format selected in the proposed 
    NSPS for the numerical emission limitations would be numerical 
    concentration limits (mg/dscm) at 7 percent O2. For the purpose of 
    regulating Hg, the format selected would be both a numerical 
    concentration limit (mg/dscm) and an alternative percentage reduction 
    requirement. The numerical Hg emission limit reflects the emission 
    level that can be achieved based on activated carbon injection in 
    combination with SD/FF controls. An alternative Hg percentage reduction 
    requirement may be met instead of the numerical emission limit because 
    emissions of Hg can be highly variable and dependent on the Hg input 
    level. Even at the same MWC, test data show occasional spikes of high 
    Hg emissions due to variability in the waste feed. In cases where Hg 
    levels are temporarily elevated, the 0.080 mg/dscm level may not be 
    consistently achievable; however, the control devices could achieve the 
    85-percent reduction during such episodes. Therefore, a combination of 
    a concentration limit and an optional percentage reduction format best 
    assures the maximum achievable Hg control while accommodating potential 
    spikes in Hg emission levels.
        As discussed above, the proposed standards for SO2, HCl, and 
    Hg include two formats: (1) a percent reduction format, and (2) an 
    emission limit (concentration) format. The EPA requests comment on and 
    test data supporting the appropriateness of promulgating final 
    standards for SO2, HCl, and Hg which include only the emission 
    limit format. For each pollutant, the commenter should specify an 
    appropriate emission limit (without an associated alternative percent 
    reduction format) and provide rationale for the limit. Based on the 
    comments received, the EPA may promulgate final standards for SO2, 
    HCl, and Hg in the form of emission limits that are higher or lower 
    than the proposed emission limits.
        The EPA has proposed emission limits that reflect the performance 
    levels achieved by MWC's equipped with properly designed, constructed, 
    and operated air pollution control systems. The proposed standards 
    would apply during all periods of MWC operation. To comply with the 
    proposed standards, the air pollution control system would be designed 
    and operated such that actual emissions are less than the proposed 
    emission limits. Where continuous monitoring systems are available, 
    such as for SO2 and NOX, the proposal would require their use 
    to determine compliance on a continuous basis. For other pollutants, an 
    annual stack test would be required. The EPA requests comment on 
    whether continuous monitoring methods exist for any additional 
    pollutants.
        The EPA also seeks comments on alternate formats of the standard 
    that would encourage optimal control system operation and optimal 
    performance, thus minimizing emissions. For example, the standard could 
    provide incentives, such as reduced testing and reporting, for MWC's 
    that operate well below the emission limit. One approach would be to 
    structure the standard such that, for an MWC with multiple units, if 
    all units demonstrated emissions at least 30 percent less than the 
    limit, then only one of the units would be tested each year. The unit 
    selected for testing would be rotated such that each unit would be 
    tested during its rotational cycle (e.g., once every three years, for 
    an MWC plant with three units).
        Another potential regulatory approach to assure optimal performance 
    would be to supplement the current emission limits (which must be 
    demonstrated by annual stack tests) with more stringent emission limits 
    calculated for each pollutant based on long-term average emission 
    levels. Compliance with this supplemental limit would be determined by 
    continuous monitoring, where applicable, or by the average of the 
    annual emissions tests from the current year and one or more preceding 
    years. The current limits account for variability from one emissions 
    test to another, whereas the composite average emission limits would 
    reflect the mean performance level over the life of the plant. This may 
    be a preferable measure of environmental performance for some of the 
    pollutants because it is their long term or cumulative emissions that 
    are of most concern. Other formats of the standard that encourage 
    optimal performance would also be possible. Comments and suggestions 
    are requested. Based on the information and comments received, the EPA 
    may change the form of the rule to include a long term emissions 
    average, an alternative compliance testing schedule, or other 
    alternative format to encourage optimal performance of the air 
    pollution control system.
        Additionally, the EPA requests comment and suggestions on specific 
    work practice requirements or equipment requirements that would assure 
    optimal operation of the air pollution control system and minimize 
    emissions. Such operating practices or equipment practices would be 
    most beneficial for minimizing emissions of those pollutants for which 
    annual stack testing is the proposed compliance test method. Comments 
    are specifically requested on work practice standards or equipment 
    requirements that would minimize dioxin/furan, Hg, Cd, and PM 
    emissions. Based on the information received, the EPA may require 
    specific work practices or equipment to supplement the emission limits 
    included in the final standards.
    
    H. Performance Test Methods and Monitoring Requirements
    
        The NSPS promulgated on February 11, 1991 for MWC's with unit 
    capacities above 225 Mg/day established performance testing and 
    monitoring requirements for MWC acid gases (SO2 and HCl), MWC 
    metals (PM and opacity), MWC organics (dioxins/furans), MWC operating 
    practices (CO, load, and flue gas temperature), and NOX. These 
    testing and monitoring requirements are described in the NSPS 
    promulgated on February 11, 1991 (56 FR 5488). These same testing and 
    monitoring requirements will apply to MWC's at all size plants under 
    today's proposed NSPS, except that: (1) Procedures are being proposed 
    for determining dioxin/furan emissions on a TEQ basis; (2) continuous 
    monitoring of NOX is not required at small plants; (3) provisions 
    have been incorporated to allow compliance testing every third year for 
    dioxins/furans, PM, and HCl at small plants that pass their compliance 
    test for 3 years in a row; and (4) annual opacity tests using EPA 
    Reference Method 9 (in combination with continuous monitoring of 
    opacity level) would be required for both large and small MWC plants. 
    Furthermore, today's proposal includes new data availability 
    requirements for CEMs. Today's proposal requires that valid paired CEMs 
    hourly averages (i.e., SO2 and O2 (or CO2), NOX and 
    O2 (or CO2), and CO and O2 (or CO2)) be obtained 
    for 75 percent of the hours per day for 90 percent of the days per 
    calendar quarter that the MWC is operating and combusting MSW.
        Because the proposed NSPS allows compliance with a dioxin/furan 
    limit either on a TEQ basis or on a total mass basis, procedures are 
    being proposed for determining dioxin/furan emissions on a TEQ basis. 
    For measuring dioxins/furans, on a TEQ basis, the mass of each dioxin/
    furan tetra- through octa- congener would be measured by EPA Reference 
    Method 23. Then, each congener mass would be adjusted by the 
    corresponding TEF's, which are listed in the proposed NSPS. Finally, 
    the adjusted congener masses would be added together to determine 
    dioxins/furans in terms of nanograms per dry standard cubic meter TEQ.
        Under the proposed standards, if three consecutive annual 
    compliance tests for an MWC at a small MWC plant indicate compliance 
    with the emission limit for a pollutant (i.e., dioxins/furans, PM, or 
    HCl), the MWC would be allowed to wait 3 years before retesting for the 
    pollutant. If the next test conducted in the third year shows 
    compliance with the emission limit for the pollutant, then the facility 
    could again wait 3 years to wait for the pollutant. If noncompliance 
    with the emission limit for the pollutant occurs, corrective actions 
    would be required to be undertaken and annual testing would be required 
    to be conducted until 3 consecutive years of compliance with the 
    emission limit established. At a minimum, performance tests for 
    dioxins/furans, PM, and HCl must be performed for each MWC at a small 
    MWC plant every 3 years. This provision is included to minimize costs 
    for small plants, while still retaining periodic testing to ensure 
    compliance.
        Testing and monitoring requirements are being proposed today to 
    ensure control of Cd, Pb, and Hg emissions. For Cd, Pb, and Hg, an 
    initial performance test would be required for MWC's at small and large 
    plants to determine compliance with the proposed emission limits. The 
    performance test for Cd, Pb, and Hg would be conducted in accordance 
    with EPA Reference Method 29. The number and location of sampling 
    points would be determined using EPA Reference Method 1, and flue gas 
    analysis would be performed using EPA Reference Method 3. All 
    performance tests would consist of a minimum of three test runs 
    conducted under representative full load operating conditions. The 
    average Cd, Pb, and Hg emission rates of three test runs or more would 
    be used to determine compliance.
        Also, as discussed above for dioxins/furans, PM, and HCl, if small 
    plants demonstrate compliance with the Cd, Pb, and Hg emission limits 
    for 3 consecutive years, they would be allowed to begin testing for 
    these three pollutants every third year. At a minimum, performance 
    tests for Cd, Pb, and Hg would be required to be conducted by small MWC 
    plants every 3 years. Large plants would be required to test for Cd, 
    Pb, and Hg annually. These annual testing requirements are consistent 
    with those for other pollutants, and MWC plants can reduce testing 
    expenses by testing for multiple pollutants during the same test 
    period.
        Studies conducted by the EPA have shown EPA Reference Method 29 to 
    be a more reliable method for measuring Hg from MWC's than EPA 
    Reference Method 101A. Recent refinements have been made to Method 
    101A, but the EPA has concluded that Method 29 remains a superior 
    method.
        In a separate notice in today's Federal Register, EPA Reference 
    Method 29 is being proposed for determining emissions of Hg and other 
    metals from MWC's, MWI's, and power plants. Method 29 consists of a 
    particulate filter followed in series by two nitric acid/hydrogen 
    peroxide (HNO3/H2O2) impingers and two acidified 
    potassium permangenate (KMnO4/H2SO4) impingers. The 
    method is identical to the EPA's Office of Solid Waste multimetals 
    method, except that Method 29 requires filtration and analysis of the 
    impinger solution collected in the KMnO4/H2SO4 
    impingers. These filtration and analysis requirements are being added 
    to the method for quality assurance purposes to protect against the 
    loss of Hg in the manganese oxide (MnO2) precipitate that can form 
    in this solution. This additional step will result in similar sample 
    preparation and analysis requirements for EPA Reference Methods 29 and 
    101A.
        The EPA does not believe that addition of the filtration and 
    analysis step will change the achievable Hg emission rates for MWC's 
    and MWI's. Because of the significant amount of chlorine in MWC and MWI 
    flue gas, most of the Hg in these flue gases occurs as water-soluble 
    ionic Hg. As a result, use of Method 29 collects most of the Hg in 
    these flue gases on the filter and in the HNO3/H2O2 
    impingers, with the remainder collected in the KMnO4/
    H2SO4 impingers. Flue gases emitted from processes having 
    lower chlorine levels and/or higher sulfur levels (e.g., coal-fired 
    power plants) have a higher fraction of their Hg emissions present as 
    water-insoluble elemental Hg that is collected in the KMnO4/
    H2SO4 impingers.
        In testing conducted by the EPA at an MWC during which Method 101A 
    KMnO4/H2SO4 impinger solutions were filtered and the 
    filters analyzed (with Method 101A, all of the Hg in the flue gas is 
    collected by the KMnO4/H2SO4 impingers), results showed 
    that less than 3 percent of the total Hg collected by the sampling 
    train was associated with precipitated MnO2. Based on review of 
    analytical procedures used with multimetal trail samples collected 
    during several other EPA-sponsored test programs, the EPA believes the 
    potential loss of Hg in precipitated MnO2 during these tests was 
    less than 3 percent (during these tests, the KMnO4/H2SO4 
    impingers were shaken prior to removal of a representative analytical 
    sample and, thus, a portion of any precipitated MnO2 was likely to 
    have been included in the analytical sample).
        Because the analytical filter makes only a negligible difference in 
    the Hg test results for MWC's and because it is desirable to use a 
    uniform Hg test method for all source categories, the EPA is proposing 
    that the full Method 29 test procedures (including the analytical 
    filter analysis) be used for measuring Hg emissions from MWC's.
        Overall, the proposed guidelines would require that CEMS be used as 
    the compliance test method for those pollutants for which CEMS are 
    available (i.e., SO2, NOX, CO, CO2 (or O2), 
    opacity, MWC load level, and air pollution control device temperature). 
    For those pollutants for which CEMS are not available (i.e., HCl, Hg, 
    Cd, Pb, PM, and dioxins/furans), the proposed guidelines would require 
    that stack test methods be used on an annual basis to determine 
    compliance. Progress continues to be made on the development of new and 
    improved CEMS. The EPA requests comment on the availability of CEMS to 
    replace stack testing for any of the pollutants listed above. The EPA 
    specifically requests comment on the availability, precision, accuracy, 
    and cost of CEMS for HCl and Hg. Based on the information received, the 
    EPA will reconsider CEMS requirements and may increase the number of 
    pollutants monitored by CEMS.
    
    I. Reporting and Recordkeeping Requirements
    
        The proposed standards would require owners and operators of all 
    affected facilities to submit notifications of construction or 
    reconstruction, date of anticipated startup, and anticipated date of 
    demonstration of the continuous emission monitoring system (CEMS) (if 
    applicable), as required under Sec. 60.7 of subpart A of part 60.
        The NSPS promulgated on February 11, 1991 include reporting and 
    recordkeeping requirements for MWC acid gases, MWC metals (PM and 
    opacity), MWC organics (dioxins/furan), MWC operating practices, and 
    NOX. These reporting and recordkeeping requirements are summarized 
    in the previous Federal Register notice (56 FR 5488, February 11, 
    1991). Under today's proposed standards, these same reporting and 
    recordkeeping requirements would apply to MWC's at both small and large 
    plants with the following four exceptions: (1) Dioxin/furan emissions 
    would be recorded and reported either in terms of dioxin/furan TEQ or 
    as total mass of dioxins/furans; (2) monitoring and reporting of 
    NOX emissions would not be required for small plants because 
    NOX control is not applicable; (3) if MWC's at small plants have 
    met the criteria allowing them to conduct compliance tests for dioxin/
    furans, PM, or HCl every third year, they would submit a simplified 
    report for years when a full compliance test was not required; and (4) 
    both small and large MWC plants would be required to report the results 
    of annual method 9 opacity tests.
        The reporting and recordkeeping requirements in the proposed NSPS 
    are necessary to inform enforcement personnel of the compliance status 
    of new MWC's that begin operation.
        In addition, the records would provide the data and information 
    necessary to ensure continued compliance of these MWC's with the 
    proposed regulation. At the same time, these requirements would not 
    impose an unreasonable burden on MWC owners or operators. All required 
    records and all quarterly and annual reports must be maintained for 5 
    years following the date of such records or submittal of such reports. 
    All information contained in the records must be open to the public.
        Recordkeeping and reporting requirements are being proposed in 
    today's NSPS for Cd, Pb, and Hg. After the initial performance test has 
    been completed, the proposed standard would require the submission of 
    annual compliance reports for Cd, Pb, and Hg for MWC's at both small 
    and large plants. However, if MWC's at small plants have met the 
    criteria allowing them to conduct compliance tests for Cd, Pb, or Hg 
    every third year, they would submit a simplified annual report for 
    years in which a full compliance test was not required.
        The proposed NSPS would require that certain types of records be 
    maintained. If an activated carbon injection system is used for Hg 
    control, MWC plants would be required to keep records of the quantity 
    of activated carbon used for each 8-hour period of MWC operation. These 
    records would provide documentation that these systems continue to be 
    operated properly between compliance tests. The proposed NSPS would 
    also require the submittal of initial and annual compliance reports for 
    fly ash/bottom ash fugitive emissions testing for MWC's at both small 
    and large MWC plants.
        Additionally, today's proposal would require that the siting 
    analysis, materials separation plan, and summary of response to public 
    comment be submitted to the State. Refer to section V.D of this 
    preamble for a discussion of the proposed reporting requirements.
    
    V. Rationale for the Proposed Standards for Siting Requirements
    
        This section presents the EPA's rationale for establishing the 
    proposed siting requirements, including a siting analysis, a materials 
    separation plan, and public meetings.
    
    A. Overview
    
        Under authority of section 129 of the Act, the EPA is proposing 
    siting requirements for new MWC's. As proposed, the siting requirements 
    include three major components: (1) A siting analysis, (2) a materials 
    separation plan, and (3) public meetings with responses to public 
    comments. These siting requirements would apply only to MWC units at 
    MWC facilities with aggregate capacities to combust greater than 35 Mg/
    day of MSW, for which the initial application for a construction permit 
    under 40 CFR part 51, subpart I, or part 52 is submitted after the date 
    of promulgation of the final rule. These siting requirements would not 
    apply to existing MWC's.
    
    B. Siting Analysis
    
        The following discussion presents the EPA's rationale for proposing 
    the requirement for sources to prepare a siting analysis, including the 
    various siting approaches considered and the proposed siting analysis.
    1. Siting Analysis Approaches Considered
        The EPA considered four approaches in the development of proposed 
    siting analysis requirements. These approaches are summarized below.
        The first approach would require that an environmental assessment 
    be conducted, patterned on requirements under the National 
    Environmental Policy Act. This would require an examination of impacts 
    in all media (i.e., air, water, solid waste, energy, and land use). It 
    would also require a description of alternatives to the proposed 
    project including alternative sites, technologies, or design. The 
    elements of this approach would cover a range of health and 
    environmental impacts that can be considered in siting an MWC. However, 
    many of these elements are addressed in current Federal, State, or 
    local permitting processes or review procedures.
        The second approach is patterned after the Resource Conservation 
    and Recovery Act (RCRA). Requirements for siting hazardous waste 
    treatment, storage, and disposal facilities. It consists of an 
    exclusion list with the provision that an MWC cannot be sited in 
    certain locations (e.g., in a 100-year floodplain or over a high-
    quality groundwater resource) unless ``it can be shown to the 
    satisfaction of EPA'' that no adverse impact will occur.
        The third approach would be a regulatory review approach. Under 
    this approach, the MWC owner or operator would prepare a document 
    listing all current Federal, State, and local regulatory requirements 
    and permit conditions that apply to the proposed MWC, along with a 
    discussion of the equipment, construction practices, operating 
    practices, and other conditions used to comply with each requirement. 
    This approach addresses relevant siting issues, and would not require 
    duplicate analyses of health or environmental impacts that are already 
    required under other authorities (e.g., New Source Review (NSR) air 
    permits, National Pollution Discharge Elimination System (NPDES) water 
    discharge permits, stormwater permits, wetland permits, State solid 
    waste permits, or local zoning permits).
        The fourth approach would establish general siting requirements 
    patterned after requirements currently in use under the NSR program. 
    This approach would require an analysis of the impact of the facility, 
    taking into account other major industrial facilities near the proposal 
    site, on ambient air quality, visibility, soils, and vegetation. This 
    approach has already been successfully implemented under the NSR 
    program. Under this approach, facilities may be able to use analyses 
    conducted under the NSR program to comply with the NSPS siting 
    requirements. This approach would also involve public meetings, and the 
    facility owner or operator would be required to prepare summaries and 
    comments to the public comments received at the public meetings.
    2. Proposed Siting Analysis
        The EPA is proposing the fourth approach, as discussed above, as 
    the basis for the proposed siting analysis. The first three approaches 
    were considered to either overlap with current requirements or be 
    overly complex. Under the proposal, MWC owners or operators would be 
    required to conduct an analysis of the impact of the proposed facility 
    on ambient air quality, visibility, soils, and vegetation. Furthermore, 
    this analysis would be required to consider the air quality, 
    visibility, soils, and vegetation impacts of other major industrial 
    facilities located near the planned MWC. Consideration of the impacts 
    of other local facilities would involve an analysis of both background 
    air quality levels and emissions from other sources in the area prior 
    to operation of the planned MWC and total air emissions in the area 
    after addition of the planned MWC due to the incremental impact of the 
    planned MWC.
        The EPA believes that requiring this type of siting analysis would 
    allow facilities to use the same type of siting analysis for complying 
    with both NSR and NSPS requirements. The Agency invites comments 
    regarding the proposed siting analysis, including suggestions of 
    alternative approaches.
    
    C. Materials Separation/Materials Management Planning
    
        The following discussion presents the EPA's rationale for proposing 
    the requirement for sources to prepare a materials separation plan.
    1. Background
        As State and local governments plan for solid waste management, the 
    EPA has encouraged them to employ the Integrated Solid Waste Management 
    (ISWM) approach. Through ISWM, communities achieve flexibility by 
    looking beyond a single solution. In tailoring systems to meet their 
    unique needs, communities consider all four elements of ISWM: 
    Reduction, recycling, combustion, and landfilling, as described in 
    EPA's document entitled ``An Agenda for Action''. In this integrated 
    approach, systems are designed so that some or all of the four waste 
    management options are used as a complement to one another to safely 
    and efficiently manage municipal solid waste. The system is ``custom 
    designed'' to meet local environmental, economic, and institutional 
    needs. A key element of integrated waste management is the hierarchy, 
    which favors source reduction (including reuse) to decrease the volume 
    and toxicity and increase the useful life of products in order to 
    reduce the volume and toxicity of waste. Recycling (including 
    composting) is the preferred waste management option to further reduce 
    potential risks to human health and the environment, divert waste from 
    landfills and combustors, conserve energy, and slow the depletion of 
    nonrenewable natural resources. In implementing source reduction and 
    recycling, shifting risks from one medium to another (e.g., groundwater 
    to air) or from one population to another must be avoided. Landfills 
    and combustors will be necessary for the foreseeable future to handle a 
    significant portion of wastes, but are lower on the hierarchy because 
    of the potential risks to human health and the environment and long-
    term management costs. This risk potential can be largely minimized 
    through proper design and management. Integrated waste management can 
    and should be implemented at a local level to the extent practical, and 
    is a useful conceptual tool for making management decisions; however, 
    it must be considered in the context of each community's unique waste 
    and demographic characteristics. Diversion of solid waste by reducing 
    the quantity generated and by recycling materials from the waste stream 
    can effectively reduce the burden on MWC's and landfills.
        Waste diversion has become increasingly popular at the local level, 
    as well as nationally and internationally, as the tool to reduce waste 
    going to MWC's or landfills. In 1989, the EPA challenged the nation to 
    reduce and recycle 25 percent of MSW by 1992. The EPA called on all 
    sectors of our society to voluntarily assume responsibility for helping 
    to attain this goal. Today, many states have source reduction programs, 
    including, for example, yard waste composting, fee-for-service 
    programs, and industrial/commercial waste minimization programs. In 
    fact, all but eight States have established waste diversion goals. 
    These goals vary, but generally call for diversion of 20 to 60 percent 
    of the solid waste stream and are to be attained over the next 5 years.
        With EPA encouragement, communities are increasingly using the 
    ``variable rate fee'' approach to charge for waste management services. 
    This approach fosters waste reduction and recycling because the waste 
    generators are charged only for the amount of waste they produce that 
    must be combusted or landfilled. Waste generators can reduce the amount 
    they pay for services by reducing the amount of waste they produce or 
    by recycling more materials, thereby diverting materials from MWC's and 
    landfills.
        Across the nation, residents, businesses, and communities are using 
    a variety of approaches to collect, separate, and otherwise prepare 
    recovery materials for recycling. These materials may be sorted into 
    different categories at the point of generation (e.g., residences or 
    businesses) for separate collection, or they may be collected together 
    and taken to a regional or community facility for sorting and 
    processing for recycling.
        The collection of recovered materials has grown dramatically and 
    continues to increase. According to EPA studies, the national recycling 
    rate was only 9 percent in 1980 and grew to 17 percent by 1992. The EPA 
    estimates the current national recycling rate at about 22 percent. 
    Certain States and communities report even higher rates. Across the 
    nation, materials that formerly were relegated to combustion or 
    landfilling are being recovered for recycling. Waste reduction and 
    recycling are increasingly becoming key factors in the sizing, design, 
    and siting of MWC's and landfills.
        Markets for recycled materials are critical to the success of 
    recycling, and this has been recognized both here and abroad. In the 
    United States, States have been creative in developing a variety of 
    nonregulatory approaches to spur markets. These include several 
    measures to help start new businesses using recovered materials and to 
    help existing businesses convert to the use of recovered materials, 
    such as: (1) Information and technical assistance, (2) financing 
    assistance, (3) direct financial assistance, (4) tax breaks (i.e., 
    credits and exemptions), and (5) ``buy recycled'' programs to encourage 
    the purchase of goods made from recovered materials.
        The EPA continues to be instrumental in enhancing markets for goods 
    from recycled materials. In an effort to position the Federal community 
    in a leadership role, the EPA is providing guidelines to assist Federal 
    procurement agencies in buying increasing quantities of goods made from 
    recovered materials. In October 1993, an Executive Order was signed by 
    the President of the United States directing Federal agencies to 
    procure goods made from recovered materials, harnessing the purchasing 
    power of the Federal community to strengthen markets for these 
    materials.
        There are substantial public and private sector efforts underway 
    across the nation to foster markets for recycled goods. For example, 
    the Chicago Board of Trade has recently announced that by late 1994 
    they will add recyclable plastics and glass to their listing of 
    commodities. From these efforts, the demand for recovered materials 
    will grow to complement the increasing supply of materials diverted 
    from the solid waste stream as more communities implement the ISWM 
    approach. This diversion will impact the characteristics of the 
    remaining portion of the waste stream.
    2. Proposed Materials Separation Plan
        The design of any element of an ISWM system, whether a landfill or 
    an MWC, must necessarily reflect the impact of the other elements. To 
    provide for proper sizing and other elements of the landfill or MWC 
    design, it is important to consider current and projected waste 
    generation rates and the impact of source reduction and diversion on 
    the character of the remaining waste stream that serves as the MWC 
    feedstock. Today's proposal is consistent with and complements the ISWM 
    approach by providing for an assessment of the impact of materials 
    separation on municipal waste combustion.
        Under today's proposal, prior to applying for a permit to construct 
    a new MWC, the owner or operator of the MWC would be required to submit 
    a materials separation plan for public review and comment. Today's 
    proposal would require the materials separation plan to be applicable 
    to the area served by the MWC. No rigid performance levels, 
    specification of separation system design, or designation of materials 
    to be separated are specified in the proposal.
        The proposal allows the materials separation plan to be tailored to 
    the service area, considered in the design of the new MWC, and reviewed 
    by the public prior to construction of the MWC. The materials 
    separation plan may be optimized for the entire service area, so that 
    certain subareas may have materials separation requirements while other 
    subareas may not have materials separation requirements. This approach 
    is fully consistent with EPA's ISWM goals for both MWC's and landfills.
        The Agency invites comments regarding the proposed materials 
    separation plan requirements, including suggestions of alternative 
    approaches. A definition of ``materials separation plan'' has been 
    included in the definitions section (Sec. 60.51b) of the proposed NSPS.
        The above requirements for a materials separation plan are being 
    proposed only for new MWC's and are not being proposed for existing 
    MWC's. The MWC industry has made impressive progress in implementing 
    materials separation programs at existing MWC's, and this should be 
    encouraged.
    
    D. Public Meeting and Reporting Requirements
    
        The proposed NSPS requires that the MWC owner or operator make the 
    materials separation plan available to the public in the service area 
    where the affected facility is to be constructed. As part of making 
    this information available to the public, the MWC owner or operator 
    would be required to distribute a preliminary draft materials 
    separation plan to all public libraries in the affected service area 
    and to publish a notification of the public meeting in the principal 
    newspaper(s) serving the area where the MWC will be sited and where the 
    waste will be collected. The MWC owner or operator would then be 
    required to hold a public meeting and accept comments on the 
    preliminary draft materials separation plan. The public meeting would 
    be required to be held in the county where the MWC is to be constructed 
    and would be required to be scheduled 30 days or more after making the 
    materials separation plan available to the public and publishing the 
    notification of the public meeting.
        At the public meeting, information should be provided that 
    summarizes what materials are planned for separation, how they will be 
    separated, what service areas will be included in the plan, and what 
    level of separation is expected. The information presented at the 
    meeting should also identify the amount of MSW that is expected to 
    remain after the separation plan is implemented and identify 
    alternative disposal methods available for the waste (e.g., local MWC, 
    local landfill, long-distance transport to an MWC, or long-distance 
    transport to a landfill). The following hypothetical plan and 
    discussion serve as an example of the types of information that would 
    be provided at the meeting. At the public meeting, a plan is proposed 
    that: (1) Yard waste be collected from specific residential areas using 
    a curbside collection program, and (2) corrugated paper be collected 
    from commercial facilities in specific commercial area using dumpster 
    pickup. The plan is expected to reduce the overall MSW stream by 20 
    percent, resulting in a residual MSW stream of approximately 400 Mg/day 
    to be disposed of by either a local MWC or a local landfill.
        Although not included as a component of today's proposal, the EPA 
    encourages the development and public presentation of a supplementary 
    regional waste management plan. Such plans have already been developed 
    for many areas. Presentation of a materials management plan at the 
    initial materials separation public meeting would inform the public 
    about current regional waste management plans if such plans existed. If 
    a regional management plan does not exist, the meeting would provide 
    the opportunity for local public input into the development of a 
    regional solid waste management plan. A waste management plan would 
    focus on the full range of options available to manage municipal solid 
    waste, as exemplified in ISWM. Such a plan could include an analysis of 
    the current waste generation situation and the range of strategies that 
    are currently used to deal with municipal solid waste, including the 
    following examples: current waste generation rates; existing waste 
    disposal options (e.g., landfills versus MWC's); current source 
    reduction (e.g., composting and waste disposal fees); and materials 
    separation and recycling programs. The materials management plan could 
    consider the adequacy of current strategies to handle projected waste 
    generation.
        Finally, as in the integrated management approach called for under 
    ISWM, the whole range of strategies available to meet projected waste 
    disposal needs could be fully examined and considered. This could 
    include consideration of the role of landfilling, the role of MWC 
    application, the role of source reduction, and the role of materials 
    separation and recycling. The materials separation management plan 
    could outline the expected cost of these alternative strategies to the 
    public, including the cost per Mg of municipal waste disposed (or the 
    cost of waste disposal avoided), and their impact in terms of waste 
    disposal capacity or waste generation avoided.
        As mentioned above, a materials management plan is not part of the 
    proposed siting requirements. The proposed siting requirements include 
    the development of only a materials separation plan. However, the 
    materials separation plan and regional materials management plan are 
    closely related, and public input in their development is encouraged.
        The MWC owner or operator would be required to prepare responses to 
    the comments received at the public meeting. The MWC owner or operator 
    would be required to make the document summarizing responses to the 
    public comments available to the public in the service area where the 
    MWC is to be located, including distribution to all public libraries in 
    the service area. The MWC owner or operator would then be required to 
    submit the final draft materials separation plan and the document 
    summarizing responses to public comments to the State or the EPA, as 
    applicable, prior to the facility's application for a construction 
    permit under NSR (40 CFR part 51, subpart I, or part 52, as 
    applicable). The EPA concluded that the draft materials separation plan 
    should be submitted during the initial planning process with the 
    application for a construction permit to be fully consistent with the 
    EPA's ISWM approach and to ensure that the facility is designed to meet 
    the materials separation goals of the region or community. Following 
    application for a NSR construction permit, the public would again have 
    the opportunity to review and comment on the final draft materials 
    separation plan at the public meeting that would be held for public 
    review of the siting analysis, as discussed below. The final materials 
    separation plan would be submitted with the initial notification of 
    construction.
        The proposed NSPS also requires that, during the period of review 
    of the materials separation plan and NSR application for a construction 
    permit, the MWC owner or operator make the MWC siting analysis 
    available to the public in the service area where the affected facility 
    is to be constructed. As part of making this information available to 
    the public, the MWC owner or operator would be required to distribute 
    the siting analysis to all public libraries in the affected service 
    area and to publish a notification of the public meeting in the 
    principal newspaper(s) serving the area where the MWC will be sited and 
    where the waste will be collected. The MWC owner or operator would then 
    be required to hold a public meeting and accept comments on the siting 
    analysis. The public meeting would be required to be held in the county 
    where the MWC is to be constructed and would be required to be 
    scheduled 30 days or more after making the siting analysis available to 
    the public and publishing the notification of the public meeting. 
    Because the proposed siting analysis is based on the NSR requirements, 
    the EPA anticipates that if a public meeting is scheduled to address 
    the environmental impacts analysis required by the NSR program, the 
    same public meeting could also be used to discuss the proposed siting 
    analysis. Also, as discussed above, the same public meeting would 
    address the final draft materials separation plan.
        The MWC owner or operator would be required to prepare responses to 
    the comments received at the public meeting and to make the document 
    summarizing responses to public comments available to the public in the 
    service area where the MWC is to be located, including distribution to 
    all public libraries in the service area. The MWC owner or operator 
    would be required to submit the siting analysis, the final materials 
    separation plan, and the document summarizing responses to public 
    comments on the siting analysis and any additional public comment on 
    the materials separation plan as part of the facility's initial 
    notification of construction.
        As discussed above, the final materials separation plan is 
    submitted with the initial notification of construction of the MWC. 
    Under this proposal, after the final plan is submitted, no subsequent 
    reporting would be required. However, the EPA is considering requiring 
    an annual materials separation report. The EPA requests comment on the 
    usefulness of using a materials separation report to document the 
    effectiveness of the plan and any changes made to it, and to help 
    determine if any changes are warranted. Comment is also requested on 
    appropriate means to ensure that the adopted materials separation plan 
    is implemented. Based on the comments received, the final regulation 
    may require submission of annual reports for assessing the performance 
    of the materials separation plan.
    
    VI. Rationale for the Proposed Standards for Fugitive Fly Ash/Bottom 
    Ash Emissions
    
        The following discussion addresses the basis for EPA's decision to 
    regulate fugitive fly ash/bottom ash emissions from MWC facilities. The 
    available technologies for controlling these fugitive emissions and the 
    EPA's selection of MACT for these emissions are presented.
    
    A. Background
    
        Fugitive fly ash/bottom ash emissions are emissions of dust from 
    fly ash and bottom ash handling that are not confined (i.e., emissions 
    that are not contained within a fully enclosed ash handling system). 
    The fly ash/bottom ash dust consists of PM and various associated 
    pollutants adsorbed to the PM such as Cd, Pb, Hg, and organic compounds 
    (e.g., dioxins/furans). A study of MWC ash handling and storage 
    facilities at best controlled MWC facilities has shown that such 
    facilities, when improperly controlled, can be sources of these 
    pollutants through fugitive fly ash/bottom ash emissions. Therefore, 
    visible emissions standards for fugitive fly ash/bottom ash emissions 
    are being proposed to ensure control equipment and operating practices 
    are implemented to eliminate such emissions.
    
    B. Fugitive Emission Control Techniques
    
        Sources of MWC fugitive fly ash/bottom ash emissions include fly 
    ash and bottom ash conveyors and conveyor transfer points, storage 
    facilities (including ash storage bins or piles), and ash loading 
    facilities for trucks or containers.
        Fugitive fly ash/bottom ash emissions from conveyors that are not 
    already inside enclosed structures can be controlled by totally 
    enclosing the conveyors. Emissions from conveyor transfer points can be 
    controlled by totally enclosing the transfer point and ventilating it 
    to a control device if the transfer point is not inside an enclosed 
    structure. Alternatively, adequate moisture in the fly ash and bottom 
    ash can be maintained to control fugitive emissions from conveyors or 
    transfer points.
        Fugitive fly ash/bottom ash emissions from the ash storage 
    facilities at an MWC plant can be controlled by totally enclosing the 
    ash storage operations and by ensuring that the fly ash and bottom ash 
    have an adequate moisture content to prevent dust generation. Chemical 
    stabilizers and binders may also be used in addition to or in place of 
    moisture to prevent dust emissions from MWC ash for nearly all the 
    activities described in this section.
        Fugitive fly ash/bottom ash emissions from loading ash into trucks 
    or containers can be controlled by ensuring an adequate moisture 
    content of the ash, either by adding extra moisture (water) or by 
    combining and mixing fly ash with bottom ash that has passed through a 
    water-filled quench tank. Fugitive fly ash/bottom ash emissions from 
    the ash loading facility may also be controlled by enclosing the ash 
    loading facility, fitting the truck bays with doors that can be closed, 
    and discharging the vent air to a control device.
        Fugitive fly ash/bottom ash emissions from moving trucks used for 
    hauling ash can be controlled by ensuring that the ash is moist and 
    that the truck or container is properly sealed and covered during 
    transit. Truck tires can be washed prior to leaving the ash handling 
    facility to prevent ash from being tracked onto roadways where it can 
    later become airborne as fugitive fly ash/bottom ash emissions. 
    Additional emissions control can be achieved by reducing ash spills 
    during loading and by recovering any spilled ash through sweeping, 
    vacuuming, or washing before the spilled ash can be tracked out of the 
    facility.
        Data collected at several MWC's indicate that when the control 
    methods described above are applied in a consistent and conscientious 
    manner, fugitive fly ash/bottom ash emissions can be controlled so that 
    no visible emissions are observed from the ash storage facilities, ash 
    transfer points, ash loading to trucks or containers, and trucks 
    hauling MWC ash.
    
    C. Proposed Fugitive Emissions Standards
    
        A standard of no visible fugitive fly ash/bottom ash emissions from 
    ash handling and storage facilities and transfer points is being 
    proposed and is consistent with the determination that the controls 
    described above represent MACT. Section 129 of the Act requires that 
    standards for new sources cannot be less stringent than the control 
    achieved in practice by the best controlled similar source. The 
    controls described above are in place at the ash handling and storage 
    facilities at many MWC's and are the most stringent available controls 
    for new MWC's.
        Therefore, fugitive emission standards are consistent with MACT and 
    are being proposed. Fugitive fly ash/bottom ash emissions from any MWC 
    ash storage facility or any ash transfer point at an MWC plant with 
    aggregate capacity to combust greater than 35 Mg/day of MSW would have 
    to be controlled so that no visible emissions shall be detected.
        The fly ash/bottom ash visible emission standard will be determined 
    using EPA Reference Method 22 (3-hour continuous visual observation). 
    Compliance with the visible emissions standards would be determined by 
    an annual performance test. Reports of initial and annual performance 
    tests would be required.
        Any technology may be used to meet these standards. The fly ash/
    bottom ash fugitive emissions standards would apply to ash handling 
    facilities within the property boundary of the MWC, but would not apply 
    to offsite transport of ash.
    
    VII. Proposed Standards for Air Curtain Incinerators
    
        Air curtain incinerators operate by forcefully projecting a curtain 
    of air across the top of an open chamber or pit. The air curtain 
    reduces emissions during operation by promoting better combustion. 
    Incinerators of this type are built either above or below ground and 
    typically have refractory walls and a floor. Section 129 of the Act 
    exempts air curtain incinerators firing MSW from the definition of 
    ``municipal waste combustion unit'' provided that the air curtain 
    incinerator burns only tree trimmings, yard wastes, and clean untreated 
    lumber, and that it complies with an opacity limit that would be 
    established by the EPA. As clarified under the proposed NSPS, 
    ``untreated lumber'' means that the lumber has not been painted, 
    pigment-stained, or ``pressure treated.''
        Today's proposed NSPS includes opacity limits specifically for air 
    curtain incinerators that would combust greater than 35 Mg/day of yard 
    wastes, tree trimmings, or clean untreated lumber. The proposed opacity 
    limits are 10-percent opacity (6-minute average), except that a level 
    of up to 35 percent (6-minute average) would be allowed during the 
    first 30 minutes of operation of the unit. The proposed opacity limits 
    are based on levels achieved by well-designed and operated air curtain 
    incinerators. Compliance with the proposed air curtain incinerator 
    opacity limits would be demonstrated by conducting an annual compliance 
    test in accordance with EPA Reference Method 9.
        Air curtain incinerators with unit capacities above 35 Mg/day that 
    burn MSW other than yard wastes, tree trimmings, or clean untreated 
    lumber are covered by the NSPS for MWC's. Air curtain incinerators with 
    unit capacities above 35 Mg/day that burn only yard wastes, tree 
    trimmings, or clean untreated lumber would be subject to the proposed 
    opacity standard and its associated testing, reporting, and 
    recordkeeping requirements, but would not be subject to any other parts 
    of the proposed NSPS.
    
    VIII. Comparison of the Proposal and European Emission Limits for MWC's
    
        Europe is more densely populated than the United States and the 
    combustion of MSW became increasing common after World War II. Because 
    European countries have more experience combusting MSW, it is 
    interesting to compare the emission control requirements for MWC's 
    located in the Member States of the European Union (EU) to those for 
    MWC's in the United States. In addition to comparing emission 
    requirements, the EPA also compared the prevalence of waste combustion 
    in the United States and the EU.
        In general, MSW combustion is more common in the EU than in the 
    United States. There are 12 members of the EU: Belgium, Denmark, 
    France, Germany, Great Britain, Greece, Ireland, Italy, Luxembourg, The 
    Netherlands, Spain, and Portugal. The percentage of waste combusted in 
    many of the EU countries is over 30 percent, with Denmark, Luxembourg, 
    and the Netherlands, combusting 60, 60, and 40 percent of their waste, 
    respectively. As a national average for the United States, 16 percent 
    of the waste generated is combusted. In the Eastern United States, 
    where the majority of MWC's are located, the rate of waste combustion 
    is higher, averaging 25 to 30 percent. In the New England region, the 
    rate of waste combustion approaches 60 percent. Therefore, although the 
    United States as a whole has a much lower rate of waste combustion than 
    does the EU, certain regions of the United States have combustion rates 
    similar to those in the EU.
        Factors such as population density, percentage of urbanization, 
    land availability, and topography/geology influence the method of waste 
    disposal for a country or a region. In the EU, the majority of the 
    countries have population densities that range from 200 to 600 people 
    per square mile and urban population percentages of 60 to 90 percent. 
    The United States, in comparison, has a much lower average population 
    density of approximately 70 people per square mile, and the percentage 
    of the population living in urban areas is approximately 75 percent. In 
    the Eastern United States, the population density and percentage of 
    urban population are higher than national levels, at around 200 people 
    per square mile with over 80 percent of the population living in urban 
    areas, which is comparable to most of Europe. As noted above, other 
    factors contribute to the use of MWC technology. For example, in 
    Florida, the geology is such that in some cases landfilling waste is 
    not a desirable option. Similarly, the mountainous regions in parts of 
    Europe restrict the use of landfilling, and the increased use of MWC's 
    is common.
        Regarding regulatory development in the EU, the EU sets uniform 
    environmental guidelines, and individual EU countries may adopt those 
    guidelines or more stringent requirements. This is similar to the role 
    the EPA plays with the individual States. Table 5 presents: (1) The 
    proposed EPA NSPS for new MWC plants with capacities above 35 and 225 
    Mg/day and (2) the EU guidelines that apply to new MWC plants with 
    capacities greater than 72 Mg/day.
    
                 Table 5.--Comparison of the EPA's Proposed NSPS and the EU Requirements for New MWC's              
    ----------------------------------------------------------------------------------------------------------------
                                                                                Proposed EPA NSPSb                  
                                                                           ----------------------------      EU     
                 Pollutant                       Unitsa (@ 7% O2)               Small         Large      guidelinesd
                                                                               plantsb       plantsc                
    ----------------------------------------------------------------------------------------------------------------
    PM................................  mg/dscm...........................       15            15            39     
    Cd................................  mg/dscm...........................        0.010         0.0101      (e)     
    Pb................................  mg/dscm...........................        0.10          0.10        (e)     
    Hg................................  mg/dscm...........................       f0.080        f0.080       (e)     
    Hg and Cd.........................  mg/dscm...........................       g0.09         g0.09         h0.2   
    Pb+Cr+Cu+Mni......................  mg/dscm...........................      (j)           (j)            h6.5   
    HCl...............................  ppmv..............................      k25           k25          kl43     
    SO2...............................  ppmv..............................      m30           m30          h147     
    NOX...............................  ppmv..............................      500           180           (n)     
    CO................................  ppmv..............................     o100          o100          p112     
    Dioxins/furans....................  ng/dscm...........................                                          
                                        TEQ...............................        0.20          0.20        (n)     
                                        Total mass........................       13            13           (n)     
    ----------------------------------------------------------------------------------------------------------------
    aAll limits are presented on a dry basis, at standard conditions (20 oC, 101 kilopascals) corrected to 7 percent
      O2.                                                                                                           
    aApplies to plants that commence construction, modification, or reconstruction after September 20, 1994 and have
      capacities greater than 35 Mg/day and less than or equal to 225 Mg/day.                                       
    cApplies to plants that commence construction, modification, or reconstruction after September 20, 1994 and have
      capacities larger than 225 Mg/day.                                                                            
    dApplies to all new plants with capacities greater than 72 Mg/day.                                              
    eNo individual limit specified. See combined limit.                                                             
    fOr 85 percent reduction.                                                                                       
    gThe proposed NSPS does not include a combined limit for Hg and Cd; however, based on the individual limits, a  
      combined limit is shown for comparison.                                                                       
    hBased on periodic determination.                                                                               
    iCr, Cu, and Mn are abbreviations for chromium, copper, and manganese, respectively.                            
    jNo combined limit specified. See individual Pb limit.                                                          
    kOr 95-percent reduction. Emissions measured by an annual stack test.                                           
    lBased on a 7-day rolling average, measured continuously.                                                       
    mOr 80-percent reduction. Limit based on a 24-hour average, measured continuously.                              
    nNo limit specified.                                                                                            
    oFor mass burn/waterwall combustors. Based on a 4-hour average, measured continuously.                          
    pBased on an hourly average, measured continuously.                                                             
    
        As shown in table 5, the EU guidelines cover many of the same 
    pollutants as the EPA NSPS proposed in today's notice. There are 
    differences between the EPA standards and the EU guidelines with regard 
    to regulatory flexibility for demonstrating compliance, as well as the 
    test methods used to measure emissions. Factors like these should be 
    considered when comparing emission requirements. The EPA and EU both 
    have set levels for PM, HC1, SO2, and CO. For these pollutants, 
    the allowable emission levels proposed by the EPA are more restrictive 
    than the EU guidelines. No EU guidelines exist for NOX or dioxins/
    furans, and the EU metals emission guidelines are for combined metals 
    (e.g., Hg+Cd). As shown in table 5, the EPA NSPS for both large and 
    small plants for Hg and Cd, if combined, are lower than the EU Hg+Cd 
    guideline.
        Some of the EU countries have adopted limits that are more 
    stringent than the general EU guidelines. For example, The Netherlands 
    has recently adopted standards for new and existing MWC's that are 
    considered to be some of the most stringent in the world. For example, 
    the Dutch Hg limit of 0.065 mg/dscm for new MWC's (corrected to 7 
    percent O2) is lower than both the EU guideline and the EPA's 
    proposed Hg standards. The Dutch dioxin/furan limit for new MWC's is 
    0.13 ng/dscm TEQ. This limit is lower than the EPA's proposed standard 
    of 0.20 ng/dscm TEQ or 13 ng/dscm total dioxins/furans. The EU has no 
    dioxin/furan limit.
        It is difficult to directly compare the Dutch standards to the EPA 
    standards or to the performance of U.S. MWC's because the test methods 
    used in The Netherlands to measure emissions are different from those 
    used in the United States. Several new MWC plants are currently being 
    constructed in The Netherlands and are expected to demonstrate 
    compliance in 1995.
        As with some of the EU countries, some of the individual States are 
    establishing more stringent emissions standards than those in today's 
    proposed standards. Brief descriptions of the regulations under 
    consideration in Florida, Minnesota, and New Jersey are presented 
    below.
        The State of Florida has promulgated a regulation that would set an 
    Hg emission limit of 0.070 mg/dscm (corrected to 7 percent O2), or 
    an 80-percent Hg reduction, for facilities that install Hg control 
    equipment (e.g., activated carbon injection) and that are equipped with 
    acid gas control equipment. This limit must be met by July 1, 1995, and 
    compliance must be demonstrated annually using EPA Reference Method 
    101A. For facilities equipped with acid gas control equipment that 
    choose to control Hg exclusively through the use of an Hg waste 
    separation program, Hg emissions would be limited to 0.14 mg/dscm after 
    July 1, 1995 and to 0.070 mg/dscm after July 1, 1997. Compliance must 
    be demonstrated semiannually using Reference Method 101A. Facilities 
    not currently equipped with acid gas controls will be required to meet 
    the proposed Hg emission limits when the facility is required to 
    demonstrate compliance with the acid gas limits included in the EPA's 
    proposal. Florida's rulemaking procedures to develop SO2 and HC1 
    emission limits will be initiated by December 1, 1994, unless the 
    Federal regulations (today's action) have been proposed by that date.
        The State of Minnesota has also promulgated Hg requirements for 
    MWC's. For mass burn MWC's with acid gas control, the quarterly Hg 
    emission limit (one three-test run average) is 0.10 mg/dscm (corrected 
    to 7 percent O2). However, the annual average Hg emissions limit 
    (average of the four most recent quarterly tests) is 0.060 mg/dscm. 
    Measurements must be made using EPA Reference Method 29. The Minnesota 
    requirement also allows MWC's to demonstrate compliance with the 
    quarterly and annual limits by achieving an alternative 85-percent 
    reduction in Hg emissions.
        Similar to the Florida regulations, the Minnesota regulations 
    provide less stringent standards for MWC's without acid gas control 
    until the time that acid gas control is required.
        The State of New Jersey will be proposing an Hg standard for MWC's 
    of 0.028 mg/dscm (corrected to 7 percent O2), which would be 
    effective as of January 1, 2000, and an interim standard of 0.065 mg/
    dscm or an 80-percent reduction, which would be effective as of 
    December 31, 1995. The 0.028 mg/dscm limit is based on reducing the 
    uncontrolled Hg emission level (assumed to be 0.70 mg/dscm) by 80 
    percent through reduction of Hg in the waste burned, and another 80-
    percent reduction from Hg in the flue gas. These limits are annual 
    averages based on quarterly 3-run testing (i.e., a total of 12 runs), 
    using EPA Reference Method 29.
    
    IX. Miscellaneous
    
        This section addresses the two following issues: (1) The selection 
    of a ``no control'' limit for NOX for MWC's at small MWC plants, 
    and (2) the July 14, 1992 remand of the issue of lead-acid vehicle 
    battery combustion, and (3) a general request for comment on the 
    proposal.
        Regarding the first issue, section 129 of the Act specifies that 
    standards for MWC's must include emission limits for PM, opacity, 
    SO2, HC1, NOX, CO, Pb, Cd, Hg, and dioxins/furans. This means 
    that emission limits for these pollutants must be specified even if the 
    MACT selected for a subcategory of facilities does not control that 
    particular pollutant. In particular, under today's proposal, the MACT 
    floor and MACT for NOX control at small MWC plants is based on no 
    control (see section IV.F.1.c for additional discussion). Therefore, a 
    ``no control'' emission limit is proposed for NOX emissions from 
    small MWC plants. The proposed ``no control'' limit for NOX for 
    small MWC plants is 500 ppmv. This proposed limit is not intended to 
    result in emissions control, and the proposal does not include any 
    testing, reporting, or recordkeeping requirements. The EPA expects that 
    the ``no control'' limit will not be exceeded.
        The 500 ppmv limit represents an emission level higher than any of 
    the test data and allows an adequate margin to accommodate the 
    variability in NOX emission levels. The EPA requests public 
    comments on whether it is appropriate to include such a ``no control'' 
    emission limit in the final NSPS or whether such a limit is not 
    necessary.
        Regarding the second issue, on December 20, 1989, the EPA proposed 
    NSPS and emission guidelines for new and existing MWC's under section 
    111 of the Act. The proposed NSPS and emission guidelines included a 
    prohibition on the combustion of lead-acid vehicle batteries in MWC's. 
    On February 11, 1991, the EPA promulgated standards and guidelines for 
    new and existing MWC's that did not prohibit the combustion of lead-
    acid vehicle batteries. The decision not to prohibit the combustion of 
    lead-acid vehicle batteries was challenged in the U.S. Court of Appeals 
    by the NRDC, the State of New York, and the State of Florida. In 1992, 
    the U.S. Court of Appeals for the District of Columbia Circuit 
    concluded that the EPA had not adequately explained its decision not to 
    require a lead acid battery separation as part of the 1991 NSPS and 
    emission guidelines, when it had included such a requirement in its 
    proposed rule (State of New York v. Reilly, 969 F.2d 1147, 1153 (D.C. 
    Cir. 1992)). The EPA is not addressing the lead acid battery issue in 
    this notice, but will publish a separate notice in the Federal Register 
    in the near future.
        Regarding the third issue, the MWC regulations are complex, and the 
    EPA expects to receive numerous comments on this proposal. The EPA has 
    specifically requested comments on items fundamental to the proposal, 
    including but not limited to the MACT floor, MACT performance levels, 
    and materials separation plans.
    
    X. Administrative Requirements
    
        This section addresses the following administrative requirements: 
    public hearing, docket, procedural requirements of the Act, Office of 
    Management and Budget review, and Regulatory Flexibility Act 
    compliance.
    
    A. Public Hearing
    
        A public hearing will be held 15 days following proposal. The 
    public hearing will discuss the proposed standards in accordance with 
    section 307(d)(5) of the Act. Persons wishing to make oral 
    presentations at the public hearing should contact the EPA at the 
    address given in the ADDRESSES section of this preamble. Oral 
    presentations will be limited to 15 minutes each. Any member of the 
    public may file a written statement before, during, or within 30 days 
    after the hearing. Written statements should be mailed to the Air and 
    Radiation Docket and Information Center at the address given in the 
    ADDRESSES section of this preamble.
        A verbatim transcript of the hearing and written statements will be 
    available for public inspection and copying during normal working hours 
    at the EPA's Air and Radiation Docket and Information Center in 
    Washington, DC (see ADDRESSES section of this preamble).
    
    B. Docket
    
        The docket is an organized and complete file of all the information 
    submitted to or otherwise considered in the development of this 
    proposed rulemaking. The principal purposes of the docket are: (1) To 
    allow interested parties to identify and locate documents so that they 
    can effectively participate in the rulemaking process; and (2) to serve 
    as the record in case of judicial review, except for interagency review 
    material (section 307(d)(7)(A)) of the Act. The docket number for this 
    rulemaking is A-90-45. Docket No. A-89-08 also includes background 
    information for this rulemaking that supported the proposal and 
    promulgation of the subpart Ea NSPS.
    
    C. Clean Air Act Procedural Requirements
    
        The following procedural requirements of the Act are addressed: 
    administrative listing, periodic review, external participation, and 
    economic impact assessment.
    1. Administrator Listing--Sections 111 and 129 of the Act
        As prescribed by section 111 of the Act, establishment of standards 
    of performance for MWC's is based on the Administrator's determination 
    (52 FR 25399, July 7, 1987) that these sources contribute significantly 
    to air pollution that may reasonably be anticipated to endanger public 
    health or welfare. Additionally, section 129 of the Act of 1990 directs 
    the Administrator to promulgate revised NSPS for new MWC's.
    2. Periodic Review--Sections 111 and 129 of the Act
        Sections 111 and 129 of the Act require that the regulation be 
    reviewed not later than 5 years following the initial promulgation. At 
    that time and at 5-year intervals thereafter, the Administrator shall 
    review the regulation and revise it if necessary. This review will 
    include an assessment of such factors as the need for integration with 
    other programs, the existence of alternative methods, enforceability, 
    improvements in emission control technology, and reporting 
    requirements.
    3. External Participation
        In accordance with section 117 of the Act, publication of this 
    proposal was preceded by consultation with appropriate advisory 
    committees, independent experts, and Federal departments and agencies. 
    The Administrator welcomes comments on all aspects of the proposal, 
    including economic and technological issues.
    4. Economic Impact Assessment
        Section 317A of the Act requires the EPA to prepare an economic 
    impact assessment for any NSPS promulgated under section 111(b) of the 
    Act. An economic impact assessment was prepared for the proposed 
    standards. In the manner described in sections III, IV, V, and VI of 
    this preamble regarding the impacts of and rationale for the proposed 
    standards, the EPA considered all aspects of the economic impact 
    assessment in proposing the standards. The economic impact assessment 
    is included in the list of key technical documents at the beginning of 
    today's notice under SUPPLEMENTARY INFORMATION.
    
    D. Office of Management and Budget Reviews
    
    1. Paperwork Reduction Act
        The information collection requirements in this proposed rule have 
    been submitted for approval to the Office of Management and Budget 
    (OMB) under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. An 
    Information Collection Request (ICR) document has been prepared by the 
    EPA (ICR No. 1506.03) and a copy may be obtained from Sandy Farmer, 
    Information Policy Branch (2136), U.S. Environmental Protection Agency, 
    401 M Street, SW, Washington, DC 20460 or by calling (202) 260-2740.
        This collection of information is estimated to have an average 
    annual reporting burden of about 0.81 person years per recordkeeper 
    (MWC facility). Very small MWC plants with capacities between 25 and 35 
    Mg/day will have a smaller burden. These plants would only be required 
    to submit reports of notification of construction, anticipated startup 
    date, and actual startup date. Small MWC plants with capacities between 
    35 and 225 Mg/day would incur the greatest burden as a result of 
    today's proposed standards. The reporting and recordkeeping burden for 
    these plants would include initial and annual testing and reporting of 
    emissions of PM, Pb, Cd, Hg, dioxins/furans, and HC1; SO2 and CO 
    CEMS demonstration and reporting; preparation of a site selection 
    analysis report, and other requirements.
        Send comments regarding the burden estimate or any other aspect of 
    this collection of information, including suggestions for reducing this 
    burden, to Chief, Information Policy Branch (2136), U.S. Environmental 
    Protection Agency, 401 M Street, SW, Washington, DC 20460, and to the 
    Office of Information and Regulatory Affairs, Office of Management and 
    Budget, Washington, DC 20503, marked ``Attention: Desk Officer for the 
    EPA.'' The final rule will address any comments on the information 
    collection requirements contained in this proposal.
    2. Executive Order 12866 Review
        Under Executive Order 12866 (58 FR 51735, October 4, 1993), the EPA 
    must determine whether the regulatory action is ``significant'', and 
    therefore, subject to the OMB review and the requirements of the 
    Executive Order. The Order defines ``significant'' regulatory action as 
    one that is likely to lead to a rule that may:
        (1) Have an annual effect on the economy of $100 million or more, 
    or adversely affect in a material way the economy, a sector of the 
    economy, productivity, competition, jobs, the environment, public 
    health or safety, or State, local or tribal governments or communities;
        (2) create a serious inconsistency or otherwise interfere with an 
    action taken or planned by another agency;
        (3) materially alter the budgetary impact of entitlements, grants, 
    users fees, or loan programs or the rights and obligations of 
    recipients thereof; or
        (4) raise novel legal or policy issues arising out of legal 
    mandates, the President's priorities, or the principles set forth in 
    the Executive Order.
        Pursuant to the terms of Executive Order 12866, the EPA considers 
    the proposed NSPS not to be a ``significant'' rule because the annual 
    effect on the economy is expected not to exceed $43 million over the 
    cost of the existing subpart Ea NSPS. However, the EPA considers this 
    proposed NSPS to be ``significant'' because of its relationship to the 
    emission guidelines for MWC's that are being proposed under a separate 
    notice in today's Federal Register. The proposed emission guidelines 
    would cost about $450 million/year. As such, this action was submitted 
    to OMB for review. Changes made in response to OMB suggestions or 
    recommendations are documented in the public docket for this 
    rulemaking.
    3. Executive Order 12875
        Under Executive Order 12875, the EPA is required to consult with 
    representatives of affected State, local, and tribal governments, and 
    keep these affected parties informed about the content and effect of 
    the proposed standards. The following discussion provides a brief 
    summary of the content, need for, and cost of the proposal, as well as 
    the actions that the EPA has taken to communicate and consult with the 
    affected parties.
        a. Summary of the Proposed Standards. The proposed NSPS would 
    establish emission limitations for new MWC units located at MWC plants 
    with plant capacities to combust greater than 35 Mg/day of MSW. The 
    proposed standards do not specify which type of air pollution control 
    equipment must be used at MWC's to meet the proposed emission 
    limitations. The EPA expects, however, that, as a result of the 
    proposal, most large MWC plants (plants with greater than 225 Mg/day 
    capacity) would use scrubbing systems (SD/FF) for dioxins/furans, 
    metals, and acid gas control and SNCR for NOX control. Small MWC 
    plants (plants with 35 to 225 Mg/day capacity) would be expected to 
    install scrubbing systems (SD/FF), but SNCR technology would not be 
    necessary. Refer to section II of this preamble for a more detailed 
    discussion of the proposed standards.
        b. Need for the Proposed Standards. Under the Act Amendments of 
    1990, section 129 includes a schedule that requires the EPA to adopt 
    the standards for large and small MWC plants by the end of 1991 and 
    1992, respectively. The EPA did not comply with that schedule and is 
    now under court order to propose the standards by September 1, 1994 and 
    promulgate the standards by September 1, 1995. As required by section 
    129, the proposed standards would establish emission limits for MWC 
    organics (dioxins/furans), MWC metals (Cd, Pb, Hg, PM, and opacity), 
    MWC acid gases (HCl and SO2), and NOX. See section I of this 
    preamble for further discussion of the regulatory history and general 
    goals of the proposed standards.
        c. Cost of the Proposal. The national cost of the proposed NSPS 
    would be about $43 million per year. The subpart Ea NSPS promulgated in 
    1991 already requires the installation of acid gas/PM control systems; 
    therefore, the cost of installing acid gas/PM control systems is not 
    included in the $43 million per year national cost of the proposal (see 
    section III.B of this preamble for a discussion of national costs based 
    on a pre-1989 baseline.) However, for perspective, the cost of the 
    entire air pollution control system (including acid gas/PM control 
    systems) is provided here. For an individual combustor subject to the 
    proposed standards, the cost of the air pollution control system will 
    vary depending on the plant size. The average annualized cost of 
    control required by the proposed standards for a typical large MWC 
    plant would be about $3.8 million per year. The average annualized cost 
    of control of the proposed standards for a typical small MWC plant 
    would be about $0.84 million per year. Tipping fees at combustors 
    currently average about $57/Mg of MSW combusted. As a result of the air 
    pollution control required by the proposal, the tipping fees for new 
    MWC plants would typically increase by $13 to $18/Mg, with the lower 
    cost being for large MWC plants and the higher cost being for small MWC 
    plants. Regarding the impact of the proposed standards directly or 
    indirectly on households, the EPA projects an increase in the household 
    cost of waste disposal of about $17 to $29 per year or about $2 per 
    month for communities that have MWC's. Refer to section III of this 
    preamble for a more complete summary of the cost and economic impacts 
    of the proposed NSPS, on both national and plant-specific bases.
        d. Communication with Affected Parties. As previously mentioned, 
    Executive Order 12875 requires the EPA to consult with representatives 
    of affected State, local, and tribal governments, and prior to 
    promulgation of final standards, summarize concerns of the governmental 
    entities and respond to their comments. The EPA has already initiated 
    consultations with numerous governmental entities including, but not 
    limited to, the U.S. Conference of Mayors, the National League of 
    Cities, the National Association of Counties, the Municipal Waste 
    Management Association, and the Solid Waste Association of North 
    America. These groups have been informed of the content of the proposal 
    and the estimated impacts. In drafting the proposal, the EPA has 
    considered the concerns expressed by these groups, and discussions with 
    these groups will continue following proposal. Following proposal, the 
    EPA will mail a copy of this proposal to all owners/operators of MWC's 
    and their associated local governmental official. The EPA awaits their 
    comments on the proposal and will respond to their comments.
    
    E. Regulatory Flexibility Act Compliance
    
        Section 605 of the Regulatory Flexibility Act (RFA) of 1980 (5 
    U.S.C. 601 et seq.) requires Federal agencies to give special 
    consideration to the impacts of regulations on small entities, which 
    are small businesses, small organizations, and small governments. The 
    major purpose of the RFA is to keep paperwork and regulatory 
    requirements from getting out of proportion to the scale of the 
    entities being regulated, without compromising the objectives of, in 
    this case, the Act.
        If a regulation is likely to have a significant economic impact on 
    a substantial number of small entities, the EPA may give special 
    consideration to those small entities when analyzing regulatory 
    alternatives and drafting the regulation. In the case at hand, the EPA 
    considers that a regulation that is likely to affect 20 percent or more 
    of small entities with MWC's is a regulation that will affect a 
    substantial number of small entities.
        Definitions of small entities are flexible. For analysis of the 
    regulations being proposed today, the EPA considers a small business in 
    this industry to be one with gross annual revenue less than $6 million, 
    and a small government to be one that serves a population less than 
    50,000. (A typical city of 50,000 generates about 90 Mg/day of MSW.) 
    Most small governments dispose of their MSW by landfilling and, 
    therefore, will not be affected by regulation of MWC emissions. In 
    regard to small organizations such as independent not-for-profit 
    enterprises, the EPA finds that they have no more than a very minor 
    involvement with MWC's, and for that reason the EPA has not found it 
    necessary to study potential direct impacts on small organizations.
        Many MWC's exist that range in size up to 35 Mg/day. The EPA 
    estimates that MWC's under 35 Mg/day in capacity except for MWI's, 
    which are being regulated in a separate action, contribute a negligible 
    fraction of total MWC emissions. Many MWC's under 35 Mg/day in 
    capacity, and a few larger ones, are owned or operated by small 
    entities. The EPA estimates that considerably fewer than 20 percent of 
    small-entity MWC's would be affected by the standards being proposed 
    today were those MWC's to be constructed in the future. The EPA 
    projects that the relative proportion of MWC's that are small-entity 
    MWC's combusting less than 35 Mg/day will remain the same in the future 
    as it is today.
        Thus, the number of affected small entities is not expected to be 
    substantial, and a regulatory flexibility analysis is not required. 
    Nevertheless, the EPA has conducted an extensive analysis of potential 
    regulatory impacts on households, small governments, and small 
    businesses. The analysis is summarized above in the discussion of 
    regulatory cost and economic impacts. The full analysis is included in 
    the economic impact assessment in the docket and is listed at the 
    beginning of today's notice under SUPPLEMENTARY INFORMATION.
        On December 20, 1989, the EPA proposed standards for MWC's that 
    applied to all sizes of MWC's. The proposal had no lower size cutoff. 
    Small businesses, small governments, and groups representing small-
    entity interests commented extensively on the need to lighten the 
    potential regulatory burden on small entities. Most commenters 
    suggested a small size cutoff considerably smaller than the one now 
    being proposed. The most frequently suggested levels were 5 to 11 Mg/
    day, 18 Mg/day, 23 Mg/day, and 45 Mg/day. The EPA has used these 
    suggestions and the information submitted by these commenters, as well 
    as information from other sources, to fulfill the intent of the RFA. 
    The EPA has incorporated into the regulation being proposed today 
    several features that will mitigate, and in most cases eliminate, any 
    potential, adverse economic impacts on small entities. These features 
    are as follows:
        (1) The regulation will apply only to MWC's with a plant capacity 
    of greater than 35 Mg/day. This cutoff eliminates from the purview of 
    the regulation the overwhelming majority of projected new, very small 
    MWC's (There will be a one-time requirement for MWC plants in the 25 to 
    35 Mg/day range to report for verification the capacities and locations 
    of the plants, but this paperwork will impose no economic burden);
        (2) The regulation is ``tiered'' so that the stringency (and 
    therefore potential economic burden) of the emission standards 
    increases as the size of the MWC plant increases. Plants with 
    capacities less than or equal to 25 Mg/day are not covered under the 
    proposed NSPS. Plants with capacities of 25 to 35 Mg/day would have 
    only the one-time reporting requirement of capacity and location. 
    Plants with capacities of 35 to 225 Mg/day are not required to control 
    NOx. Only plants with capacities larger than 225 Mg/day--plants 
    not often associated with small entities--are subject to a full 
    complement of rigorous standards; and
        (3) The regulation consists predominantly of emission standards, as 
    opposed to design, equipment, work practice, or operational standards. 
    Emission standards give MWC owners and operators the freedom to select 
    the most economical means of compliance with the standards.
        Pursuant to the provisions of 5 U.S.C. 605(b), the EPA certifies 
    that this proposed regulation, if promulgated, will not have a 
    significant economic impact on a substantial number of small entities, 
    because the number of small entities affected is not substantial.
    
    List of Subjects in 40 CFR Part 60
    
        Air pollution control, Incorporation by reference, 
    Intergovernmental relations, Reporting and recordkeeping.
    
        Dated: September 1, 1994.
    Jonathan Z. Cannon,
    Acting Administrator.
    [FR Doc. 94-22344 Filed 9-19-94; 8:45 am]
    BILLING CODE 6560-50-P
    
    
    

Document Information

Published:
09/20/1994
Department:
Environmental Protection Agency
Entry Type:
Uncategorized Document
Action:
Proposed rule and notice of public hearing.
Document Number:
94-22344
Dates:
Comments. Comments must be received on or before November 21, 1994.
Pages:
0-0 (1 pages)
Docket Numbers:
Federal Register: September 20, 1994, AD-FRL-5068-5
Supporting Documents:
» J. D. Kilgroe, EPA:CRB, to W. Stevenson, EPA:SDB. March 22, 1994. Control of CO emissions from rotary refractory MWC's. [A-90-45-II-B-24]
» R. Harrison and C. Blackley, Radian Corporation, to W. Stevenson, EPA:SDB. February 16, 1994. Comparison of municipal waste combustor total dioxin/furan emissions and toxic equivalents for MWC's with SD/FF and SD/ESP control. [A-90-45-II-B-23]
» D. Fenn and K. Nebel, Radian Corporation, to W. Stevenson, EPA: SDB. March 9, 1992. MWC database. [A-90-45-II-B-8]
» K. Nebel, Radian Corporation, to W. Stevenson, OAQPS: SDB, and M. Johnston, OAQPS: ISB, June 16, 1991, Mercury Revolatilization. [A-90-45-II-B-6]
» B. Nelson and C. Kuterdem, Alpha- Gamma Technologies, to W. Stevenson, EPA: CG. Memorandum: Performance/Test Data for Large Municipal Waste Combustors (MWCs) at MACT Compliance (Year 2000 data). [A-90-45-VIII-B-4]
» Dioxin Removal in a Wet Scrubber and Dry Particulate Remover. H. Ruegg and A. Sigg, Von Roll, Inc. Presented at the Eleventh. International Symposium on Chlorinated Dioxins and Related Compounds. [A-90-45-IV-J-33]
» B. Jordan, EPA: ESD, to T. A. Threet, Dow Chemical Company. November 10, 1994. Response to letter requesting a 30-day extension of the public comment period. [A-90-45-IV-C-2]
» D. Bevington, Radian Corporation, to W. Stevenson, EPA: ESD. October 19, 1995. Investigation of MWC Ownership by Native American Indian Tribes in the United States. [A-90-45-IV-B-16]
» C. Kane, Radian Corporation, to Docket No. A-9045. August 24, 1995. Operating Permits for Municipal Waste Combustors: Adirondack, Babylon, and Islip, New York; Wallingford, Connecticut; Mid-Maine (Auburn), Maine; [A-90-45-IV-B-7]
» C. Kane, Radian Corporation, to Docket No. A- 90- 45. August 24, 1995. Dioxin/Furan data and carbon injection feed rates from October 17-18, 1994 test at the Ogden Martin Systems Inc. Lee County Resource Recovery Facility, Ft. Meyers, Florida. [A-90-45-IV-B-6]
CFR: (1)
40 CFR 60