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                   Unrted States
                   Environmental Protection
                   Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EPA 450/3-92/007(b)
March 1994
                   Air
                   Guidelines for MACT
                   Determinations under
                   Section 112(g)
                PROPOSAL

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                                                   PROPOSAL
                                                   March 1994
                        Table of Contents
Introduction	iv

Chapter 1.0    An Overview of the MACT Determination  Process....!
               1.1  Overview of Statutory Requirements	1
               1.2  Overview of the Regulatory Requirements	4
               1.3  Overview of MACT Determination	6

Chapter 2. 0    The MACT Determination	 9
               2.1  Criteria for the MACT Determination	9
               2.2  Compliance Provisions...	14
               2.3  Available Control Technologies	21

Chapter 3 . 0    The MACT Analysis	23
               3.1  Overview of the MACT Analysis Process	24
               3.2  A Detailed Look at the MACT Analysis	30
               3.3  Determining the MACT-Affec'ted Source on a
                    Case-by-Case Basis	44
               3.4  Similar Emission Units	57
               3.5  Subcategorization.	62

Chapter 4.0    The MACT Floor Finding	63
               4.1  Calculation of the MACT Floor	66
               4.2  Method 1- Computing the MACT floor using
                    existing State and Local Regulations	73
               4.3  Method 2 - Computing the MACT Floor using
                    Control Efficiency Ratings	78
               4.4  Method 3 - Computing the MACT Floor using
                    Emission Reduction Ratios (ERR) . . .-	,80
               4.5  Exceptions to the Emission Reduction
                    Ratios	85
               4.6  Other Methods to Compute
                    the MACT Floor	86

Chapter 5.0    Costs, Non-Air Quality Health and Environmental
               Impacts and Energy Requirements	87
               5.1  Costs Impacts	89
               5.2  Environmental Impacts	92
               5. 3  Energy Requirements	93


Chapter 6.0    Information Sources	96


References	108

Appendix A     Examples of MACT Analyses	A-l

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                                                  PROPOSAL
      ;                                           March  1994

Appendix A     Examples of MACT Analyses	A-l

Appendix B     Forum of Anticipated Questions	B-l

Appendix C     Definitions	C-l

Appendix D     List of Major Source Categories	D-l
                                1JL

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                                                  PROPOSAL
                                                  March  1994
                         LIST OF FIGURES
Figure 1  Stages of the MACT Determination Process	7


Figure 2  Example Notice of MACT Approval	17


Figure 3  The MACT Analysis	26


Figure 4 . Emission Units Affected by a Modification	46


Figure 5  Drainage Collection System	48


Figure 6  Combining Emission Points into a
          MACT-affected Emission Unit	51
Figure 7  Using State or Local Air Pollution Regulations to.
          compute the MACT Floor	74


Figure 8  Evaluation of State Regulations
          for Emission Unit X	76
Figure 9  Using Emission Reduction Ratios
          to Compute the MACT Floor	82
                               ill

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                                                  PROPOSAL
                                                  March 1994
                           Introduction



     This guidance document is designed to clarify the statutory

and regulatory requirements for MACT determinations as required

by Section 112(g) of the Clean Air Act (the Act) as amended in

1990.  It sets forth procedures for determining emission

limitations based on maximum achievable control technology for

major sources that construct,  reconstruct or modify.

     The manual is divided into six chapters and a four section

appendix.  Chapter 1 of this manual provides an overview of the

statutory and regulatory requirements and overviews the MACT

determination process.  Chapter 2 outlines the criteria a

permitting agency should use when evaluating applications.  It

also discusses compliance provisions and the definition of

available information.  Chapter 3 describes the process for

selecting a control technology that meets the criteria discussed

in Chapter 2.  Chapter 4 provides a detailed description of MACT

floor calculation procedures.   Chapter 5 describes the analysis

that may be required to assess the costs of achieving the

emission reduction, and any non-air quality health and

environmental impacts and energy requirements associated with use

of different control options.   Chapter 6 discusses the national

databases that may assist in the collection of available

information.

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                                                  PROPOSAL
                                                  March 1994

     Part A of the Appendix illustrates examples for defining a

MACT-affected emission unit, and selecting a ^control technology

to meet MACT.  Part B is a question and answer forum.  It is

designed to deal with detailed questions on applicability and

other issues.  Part C of the Appendix contains a glossary of

terms and definitions.  In Appendix D, a complete list of source

categories of major sources is provided.  This listing is current

only to the date of this publication.  Readers are referred to

the Federal Register for any changes to this listing.

     It is hoped that this guidance document contains useful

information for implementation of Section 112(g) of the Act.  For

more information on MACT determinations, the reader is advised to

read 40 CFR Part 63, Subpart B, and Section 112 of the Act.
                                v

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                                                   PROPOSAL

                                                   March 1994
                            Chapter 1.0


                        AN OVERVIEW OP THE


                    MACT DETERMINATION PROCESS





 1.1 An  Overview of  Statutory Requirements


     The  provisions of  Sections  112(g)  of the  Clean Air Act as


 amended in  1990 (The Act)  become effective in  a  State on the date


 that interim,  partial or  full approval  is granted to the State's


 (or local's) Title  V permit program.  Under Section 112(g), a


 MACT determination  is required for major  sources that propose to


 construct or reconstruct  (as defined by 40 CFR Part 63, Subpart


 B,) before  the promulgation of a relevant Section 112(d)  or
•

 112(h)  emission standard.   MACT  determinations are also required


 for major sources that  propose to modify  (as defined by 40  CFR


 Part 63,  Subpart B)  before and after the  setting of a relevant


 Section 112(d)  or 112(h)  emission standard.  Readers are referred


 to 40 CFR Part 63 to determine if a relevant emission standard


 has been  promulgated for  a relevant source category.


     A  MACT determination is a process  by which  a permitting


 agency  determines that  the emission points that  will be affected


 by the  construction,  reconstruction or  modification achieve a


 maximum achievable  control technology (MACT) emission limitation.


 When a  relevant Section 112(d) or 112(h)  emission standard  has


 been promulgated for the  source  category,  the  MACT determination


                                 1

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                                                  PROPOSAL
                                                  March 1994

process will ensure that the affected emission points comply with

the promulgated standard.  When no relevant emission standard

exists, a case-by-case determination of the MACT'emission

limitation is required.  This emission limitation will require

the maximum degree of reduction of hazardous air pollutant

emissions (HAPs) taking into consideration the costs of achieving

such emission reductions, and any non-air quality health and

environmental impacts, and energy requirements.  For construction

and reconstruction of major sources, the MACT emission limitation

will be no less stringent than the emission control that is

achieved in practice by the best controlled similar source.  For

modified major sources the MACT emission limitation will be no

less stringent than:

     the average emission limitation achieved by the best

     performing 12 percent of the existing sources (for which the

     Administrator has emissions information), excluding those

     sources that have, within 18 months before the emission

     standard is proposed or within 30 months before such

     standard is promulgated, whichever is later,  first achieved

     a level of emission rate or emission reduction which

     complies, or would comply if the source is not subject to

     such standard, with the lowest achievable emission rate (as

     defined by Section 171  (of the Act)) applicable to the

     source category and prevailing at the time, in the category

     or subcategory for categories and subcategories with 30 or

                                2

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                                                  PROPOSAL
                                                  March  1994

     more sources;  or,

     the .average emission limitation achieved by the best

     performing 5 sources (for which the Administrator has or

     could reasonably obtain emissions information) in the

     category or subcategory for categories or subcategories with

     fewer than 30 sources.



These minimum requirements for the MACT emission limitation are

termed the "maximum achievable control technology (MACT) floor".

     Section 112(g)  also directs EPA to establish guidelines for

carrying out the requirements of Section 112(g)  of the Act.

These requirements are contained in Chapter 40,  Part 63, Subpart

B of the Code of FederaLJRecmlation.

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                                                  PROPOSAL
                                                  March 1994

1.2 Overview of the Regulatory Requirements
                    *
     The owner or operator or a major source is required to

obtain or revise a Title V permit or obtain a Notice of MACT

Approval (NOMA) before construction, reconstruction or

modification of the major source.  This document will contain the

MACT emission limitation and other requirements to ensure

federally enforceability of the emission limitation.  If a

relevant emission standard has already been established pursuant

to Section 112(d) or Section 112(h), modifying sources may only

be required to submit a notification of the proposed change.  A

notification is acceptable if the emission point will continue to

meet the emission standard without a change in, or addition of a

different control technology.  In some instances, the MACT

standard may provide specific procedures for dealing with

modifications.  In such cases, the MACT standard should be

followed in lieu of Section 112(g).   Section 112(g)  does not

affect construction and reconstruction of major sources after a

relevant standard.  Readers are referred to the provisions of

Section 112(i)(a) for more information.

     In preparing the application for a Title V permit or a

Notice of MACT Approval,  the owner must recommend a level of

control and appropriate monitoring,  reporting and recordkeeping

parameters for control of HAP emissions from each existing source

or constructed or reconstructed source within the source

category.  The recommended level of HAP emission control should
                        \

                                4

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                                                  PROPOSAL
                                                  March 1994

be based on the maximum achievable control technology (MACT),  and
            <•             .
be no less stringent than the MACT floor (when information is

available to determine the MACT floor level of control.)

     Chapter 3 of this manual discusses a process for developing

the information required in the Title V permit application or

application for a Notice of MACT Approval.  The process is termed

the "MACT analysis".  This analysis includes a MACT floor

finding, establishing a MACT emission limitation and selecting a

control technology to meet this emission limitation.

     Once the MACT analysis is complete, the owner or operator

can prepare the Title V permit application or application for a

Notice of MACT Approval.  The application for a Title V permit

should be prepared in accordance with the provisions contained in

40 CFR Part 63 and 40 CFR part 70 or CFR Part 71 whichever is

applicable to the major source.

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                                                  PROPOSAL
                                                  March 1994

1.3 An Overview of the MACT Determination

     To meet the regulatory requirements implementing Section

112(g) of the Act, EPA developed a recommended process for

obtaining a MACT determination.  Figure 1 diagrams the steps for

this recommended process.  For most major sources, the process

will begin with a MACT analysis conducted by the owner or

operator.  The objectives of the MACT analysis are to: (1)

Determine a level of control equal to the MACT floor; (2)

Identify MACT; (3) Establish the MACT emission limitation; and

(4) Select a control strategy to meet this required level of

emission control.

     The MACT analysis is broken into three tiers.  The steps and

process for each tier are detailed in Chapter 3 of this manual.

     After receiving an application, the reviewing agency will

have a specified period of time to review the application to make

a completeness determination,  and then an additional period of

time to approve or disapprove the application.  Before issuing a

final approval notice, the permitting agency will provide an

opportunity for comment from the public, EPA, and all affected

States.  When a Notice of MACT Approval is.issued, it will

contain the MACT emission limitation(s), the required control

technology and all compliance requirements.  Compliance

requirements, and the Notice of MACT Approval are discussed in

Chapter 2.

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                                                    PROPOSAL
                                                    March 1994
                              Figure 1

                           Stages of the
                 MACT Determination Process
Stage 1    Conduct a MACT Analysis.
                Make a MACT floor finding
                Identify MACT
                Establish a MACT emission limitation
                Select a control technology
Stage 2    Submit Application for MACT Determination.
Stage 3    Await Agency Review.
                Completeness
                Public,  EPA and Affected State  Review
                Approve  or Disapprove
Stage 4    Receive Notice of MACT Approval.
Stage 5    Begin Construction, Reconstruction, or Modification.
Stage 6    Obtain an Applicable Part 70 or Part 71 Permit Revision.


          (This  stage maybe done concurrently with the other stages or after
          obtaining a MACT Determination.)

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                                                  PROPOSAL
                                                  March 1994
     Finally, the provisions of the MACT determination will be

incorporated into a Part 70 or Part 71 permit,  whichever is

applicable to the major source.  This may occur concurrently with

the MACT determination, or sometime after the determination

process.
                                8

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                                                  PROPOSAL
                                                  March  1994

                           Chapter 2.0

                      The MACT Determination



2.1  Criteria for the MACT Determination

     The process of reviewing the Title V permit application or

the application for a Notice of MACT Approval to determine the

(MACT) emission limitation is called a MACT determination.  For

case-by-case MACT determinations under Section 112(g), the MACT

emission limitation should be comparable to the emission

limitation(s) and requirements that would likely be imposed if a

Section 112(d) or Section 112(h) emission standard had already

been promulgated for that source category.  The Clean Air Act

establishes specific criteria for setting a hazardous air

pollutant emission standard under Sections 112(d) and Section

112(h).  These criteria should also be used when determining the

MACT emission limitation under Section 112(g).

     In conducting the MACT determination, the permitting agency

must determine if the owner or operator has recommended an

appropriate MACT emission limitation(s) or other requirements for

the MACT-affected emission unit (discussed in Chapter 3), given

the expected performance of the maximum achievable control

technology (MACT).   To approve the application,  it should meet

the following criteria:

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                                             PROPOSAL
                                             March 1994
(•a)   When a relevant emission standard has been promulgated

     pursuant to Section 112(d)  or 112(h)  of the Act, the

     application demonstrates that the emission unit will

     comply with the MACT emission limitation and other

     requirements of the relevant standard.




(b)   When a relevant emission standard has been proposed

     pursuant to Section 112(d)  or 112(h)  of the Act, the

     application demonstrates that the emission unit will

     meet the emission reductions and other requirements of

     the proposed rule,  unless an alternative control level

     or requirement can be adequately supported.
•



(c)   When a relevant emission standard has not been

     promulgated or proposed  pursuant to Section '112(d)  or

     Section 112(h):

     (1)   The application documents a MACT floor finding

          based on all available information, and

     (2)   When a positive MACT floor finding is made,  the

          application demonstrates that the emission unit

          will meet a MACT emission limitation that is at.

          least equal to the  MACT floor and achieves the

          maximum degree of emission reductions of the

          hazardous air pollutants with consideration to the

                           10

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                                                  PROPOSAL
                                                  March 1994

               costs, non-air quality health and environmental

               impacts and energy requirements associated with

               the emission reduction; or,

          (3)  When a negative MACT floor finding is made, the

               application demonstrates that the emission unit

               will meet a MACT emission limitation that achieves

               a maximum degree of emission reductions with

               consideration to costs, non-air quality health and

               environmental impacts, and energy requirements,

               and that this emission limitation was established

               after evaluating all commercially available

               control technologies that can be identified

               through available information and that have been

               successfully demonstrate in practice for a similar

               source.

     (d)  When a MACT emission limitation can not be prescribed

          due to the nature of the process or pollutant,  the

          application designates a specific design,  equipment,

          work practice,  operational standard,  or a combination

          thereof, that achieves a maximum degree of emission

          reduction.



     The MACT floor finding is a determination of whether a level

of HAP emission control that is equal to the MACT floor can be

determined using, available information.   The MACT floor finding

                                11

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                                                  PROPOSAL
                                                  March 1994

is discussed further in Chapter 4.  The definition of available

information is discussed in Section 2.3 of this Chapter.

     The MACT emission limitation could be expressed as a

numerical emission limitation on the total quantity of HAP

emissions from the source in tons per year (tpy);  or, it could

be expressed as a ratio of tons emitted to production unit

produced.  The MACT emission limitation could also be a

performance standard based on the expected efficiency of MACT in

reducing HAP emissions.  If it is infeasible to prescribe a

specific numerical limitation or reduction efficiency, the MACT

emission limitation can also be expressed based on a design,

equipment, work practice, operational standard, or any

combination of these.

     If an individual hazardous air pollutant is of particular

concern, a MACT limitation should also be placed on that

pollutant based on the expected level of reduction with MACT in

place.  Reviewing agencies should determine whether it is

appropriate to impose.a total HAP emission limitation and/or an

individual MACT emission limitation on a specific hazardous air

pollutant.  In addition to recommending the MACT emission

limitation, the reviewing agency should specify any requirements

that are necessary in order to make the emission limitation

federally enforceable as a legal and practical matter.   This

involves establishing appropriate operational or production

limits and monitoring parameters to ensure compliance with the

                                12

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                                                  PROPOSAL
                                                  March 1994
MACT emission limitation.  The following section discusses

compliance provisions in greater detail.
                               13

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                                                  PROPOSAL
                                                  March  1994
2.2 Compliance Provisions

     Each Title V permit and Notice of MACT Approval must contain

sufficient testing, monitoring, reporting, and recordkeeping

requirements to ensure that the MACT emission limitation is

federally enforceable as a legal and practical matter.

     In order to be federally enforceable, operational limits or

production limits must be imposed on the source in addition to a

blanket emission limitation. . For example, a blanket 40 tpy MACT

emission limitation on HAPs would not be federally enforceable.

In addition to the blanket emission limitation, a source may be

required to comply with a production limitation that limits the

amount of gallons -used per hour in the operation; or the source

may be required to comply with an operational limitation on its

hours of operation and emission rate.

     Production limits are restrictions on the amount of final

product that can be manufactured or otherwise produced at the

source.  Operation limitations are other restrictions on the

manner in which a source is run.  Operation limitations include

limits on quantities of raw material consumed, fuel combusted,

hours of operation, or conditions which specify that the source

must install and maintain controls that reduce emissions to a

specified emission rate or level.

     When the permit or Notice of MACT Approval requires an add-

on control,  operating parameters and assumptions that can be used

                                14

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                                                  PROPOSAL
                                                  March 1994

to determine the efficiency or emission rate of the devise should

be specified in the document.  For example, a source may have a

MACT emission limitation that requires a control devise to be

installed and operated at a 95% efficiency rate.  An operational

limit on the range of temperatures that the devise can be

operated under could be sufficient to ensure federal

enforceability, if operating the control devise within this

temperature range ensures that the devise achieves a 95%

destruction efficiency.

     If establishing operating parameters for control equipment

is infeasible in a particular situation, a short term emission

limit (e.g. Ibs/hr) would be sufficient provided that such limits

reflect the operation of the control equipment, and additional

requirements are imposed to install, maintain,  and operate a

continuous emission monitoring system (GEM) or other periodic

monitoring that yields sufficiently reliable data to determine

the source's compliance with the MACT emission limitation.  Such

monitoring may be instrumental or noninstrumental and may consist

of recordkeeping designed to serve as monitoring.

     If parameter monitoring of a production or operational limit

is infeasible due to the wide variety of coatings or products

used or the unpredictable nature of the operation, emission

limits coupled with a requirement to calculate daily emissions

may be required.  For instance, a source could be required to

keep the records of the daily emission calculation,  including

                                15

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                                                  PROPOSAL
                                                  March 1994

daily quantities and the HAP content of each coating used.

     For either operation or production limitations to be

enforceable as a practical matter, the limitations should extend

over the shortest practicable time period, generally not to

exceed one month.  If it is not practicable to place a monthly

limit on the source, a longer time can be used with a rolling

average period.  However, the limit should not exceed an annual

limit rolled on a monthly basis.

     In addition to conveying practical enforceability of,a MACT

emission limitation, the Title V permit or Notice of MACT

Approval should require testing or instrumental or non-

instrumental monitoring that yields data this is representative

of the source's operations and can be used to certify the

source's compliance with the terms and conditions of the Title V

permit or Notice of MACT Approval.  Such testing or monitoring

requirements may be in the form of continuous emission monitoring

systems, continuous opacity monitoring systems, periodic testing,

or it.may consist of recordkeeping designed to serve as

monitoring.  If periodic testing is required, the specific EPA

approved method or equivalent method that is to be used should be

specified in the permit or notice if such methods exist.  Figure

2 contains a suggested format for the Notice of MACT Approval.
                               16.

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                                                  PROPOSAL
                                                  March 1994
                             Figure 2

             Example Notice of MACT Approval
                     Notice of MACT Approval
                   CFR 40, Part 63, Subpart B
    Maximum Achievable Control Technology Emission Limitation
                               for
          Constructed, Reconstructed or Modified Source


     This notice establishes federally enforceable maximum
achievable control technology emission limitation(s)  and
requirements for Name of  manor source for the  MACT-affected
emission unit(s) located  at location all MACT-affected emission
units.  The emission limitations  and requirements set forth in
this document are federally enforceable on effective  date of
notice.

A. Major source information

     1.   Mailing address of owner or operator:
     2.   Mailing address for location  of  manor  source:

     3.   Source category for major source:

     4.   MACT-affected emission unit(s):  List  all  emission
          unit(s)  subject to this Notice of  MACT Approval  along
          with.the source identification number  if applicable.

     5.   Type of modification,  construction or  reconstruction:
          Describe the action taken by  the owner or  operator  of
          the major source that  triggered  the requirements of 40
          CFR Part 63, Subpart B,

     6.   Anticipated commencement date for  construction,
          reconstruction or modification:

     7.   Anticipated start-up date of  constructed,  reconstructed
          or modified emission unitfs):

     8.   List of the hazardous  air pollutants potentially
          emitted by MA_CT-affected emission  unitfs^ :  List all

                               17

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                                                  PROPOSAL
                                                  March 1994
          hazardous air pollutants that are or could possibly be
          emitted from the affected emission unit(s)..  Any
          pollutant not listed in this section can not be emitted
          by the emission unit without an amendment to the Notice
          of MACT Approval.


B.  MACT Emission limitation

     1.   The above stated owner or operator shall not exceed the
          following emission limitation(s)  for the above stated
          MACT-affected emission unit(s). Write in emission
          standard or MACT emission limitation for overall
          hazardous air pollutant emissions from each affected
          emission unit.  If the permitting authority determines
          that an individual pollutant emission limitation is
          appropriate, it should also be listed in this section.

     2.   The above stated owner or operator shall install and
          operate the following control technology(s),  specific
          design equipment, work practice,  operational standard,
          or combination thereof to meet the emission standard or
          MACT emission limitation listed in paragraph 1 of this
          section.  List all control technologies to be installed
          by the owner or operator and which emission units the
          control technologies will reduce HAP emissions from.

     3.   The above stated owner or operator shall adhere to the
          following production or operational parameters for the
          technologies listed in paragraph 2 of this section.
          State all production or operational parameters.  For
          example:
               The owner or operator may, subject to [name of
               agency] approval, by pass the emission control
               device for a limited period of time for purposes
               such as maintenance of the control device.

               The owner or operator shall operate and maintain
               the control equipment such that it has a 95%
               hazardous air pollutant destruction efficiency.

               The owner or operator shall not operate the MACT-
               affected emission unit for greater than 6 hours in
               any 24 hour period of time.
C. Monitoring requirements

     For each MACT emission limitation and operational
     requirement established in Section B (MACT emission
     limitation) the above stated owner or operator shall comply

                                13

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                                                  PROPOSAL
                                                  March 1994

     with the following monitoring requirements.  State all
     monitoring requirements. For example:
          After installing the control equipment required to
          comply with Section(B)(1) visually inspect the internal
          floating roof, the primary seal, and the secondary
          seal, before filling the storage vessel

          The owner or operator shall calibrate, maintain and
          operate a continuous monitoring system for the
          measurement of opacity of emissions discharged from the
          control device required in Section(B)(2) according to
          the following procedures:


D. Reporting and Recordkeeping Requirements

     List all reporting and recordkeeping requirements in this
     section.  For example:
          The owner or operator shall maintain at the source for
          a period of at least 5 years records of the visual
          inspections, maintenance and repairs performed on each
          secondary hood system as required in Section(B)(2).


E.  Other requirements

     I.   The above stated owner or operator shall comply with
          all applicable requirements specified in the general
          provisions set forth in Subpart A of 40 CFR Part. 63,
          including but -not limited to notification operation and
          maintenance, performance testing, monitoring,
          reporting, and recordkeeping requirements.  If there are
          any specific requirements that the reviewing agency
          would like to clarify, those requirements should also
          be stated in this paragraph. This paragraph could also
          include requirements for emergency provisions and
          start-up and shut-down procedures.

     2.   In addition to the requirements stated in paragraph 1
          of this section,  the owner or operator will be subject
          to these additional requirements.  Any additional
          requirements not specified in Subpart A of 40 CFR Part
          63 should be stated in this paragraph.   If the
          reviewing agency wishes to require a mandatory retest
          of a failed performance test that should be stated in
          this paragraph,  along with any other, requirements
          specified by the reviewing agency.
                               19

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                                                  PROPOSAL
       	      .                       March 1994


F.  Compliance Certifications
                               •»
     The above stated owner or operator shall certify compliance
     with the terms and conditions of this notice according to
     the following procedures:  This sections should include a
     description of the terms and condition that the owner or
     operator will use to certify compliance, as well as, the
     format and frequency of the certification.
                                20

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                                                  PROPOSAL
                                                  March 1994

2.3 Available Control Technologies

     Before issuing a permit or NOMA, the permit agency must

assure that the MACT emission limitation achieves a degree of

emission reduction equal to or greater than the MACT floor.  To,

do this the agency will need to make a MACT floor finding, or

verify the finding made by the applicant.

     For the purposes of Section 112(g) MACT determinations,

emission information is considered available or reasonably

obtainable to the permitting agency if the information can be

obtained from EPA's Office of Air Quality, Planning and Standards

or Regional offices, the EPA's National MACT database or other

publically available databases (See Chapter 6), or from within

the permitting^agency itself.  A permitting authority is not

required to search for available information if a Section 112(d)

or Section 112(h) proposed standard is used to establish the MACT

floor.

     It is not necessary for the MACT floor to be determined

based on emissions information from every existing source in the

source category if such information is not available.   Once a

permitting agency has obtained available information,  the MACT

floor can be determine using this information if it is

representative of the source category.  For example,  suppose

there are 100 sources in a source category.  Control technology X

and Y are generally considered to achieve the greatest amount

emission reductions among existing sources.  Thirty sources in

                               21

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                                                  PROPOSAL
                                                  March 1994

the category use these technologies.  The floor could be

determined based on these technologies, even if information was

not available on the other seventy sources.

     EPA realizes that the information that is reasonably

available or obtainable for the permitting agency is'not

necessarily reasonably available to the owner or operator.

Owner's or operator should submit an application for a Title V

permit or a Notice of MACT Approval based on information that the

owner or operator is able to obtain.  The permitting agency

should use the completeness of application review period to

determine if the owner or operator should consider additional

information that is reasonably available to the permitting

authority.  An amended application should be submitted if

additional information should be consider in the MACT analysis.

Information that is made available subsequent to the completeness

determination need not be consdiered before issuing the Title V

permit, or Notice of MACT Approval if the information was not

reasonably available at the time of the completeness

determination.
                                22

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                                                  PROPOSAL
                                                  March 1994
                           Chapter 3.0

                        The MACT Analysis



     For most source categories, the process of recommending a

level of control involves a number of decisions either on the

part of the owner or operator preparing an application for a

Title V permit or NOMA, or a permitting agency who is reviewing

the application.  First, it must be determined in which source

category each of the affected emission points belong.  Then,

affected emission units must be identified.  Emission units could

be an aggregration of affected emission points from within the

same source category.  Or, a single emission point could be

considered an emission unit.

     For each affected emission unit, the application submitted

by an owner or operator must recommend a MACT emission limitation

that is no less stringent than the MACT floor, but could be more

stringent if a greater degree of HAP emission reductions can be

achieved with consideration to the costs, non-air guality health

and environmental impacts and energy requirements associated with

achieving the additional emission reductions.  A MACT floor

finding, a determination of MACT, and a consideration of control

technologies to meet a MACT emission limitation must be included

in the application submittal.  The process by which these

decisions are made have been termed the MACT analysis.  The

                                23

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                                                  PROPOSAL
                                                  March 1994

following sections of this Chapter describe a MACT analysis

process that EPA has developed to meet the requirements of 40 CFR

Part 63, Subpart B as described in Section 2.1 of Chapter 2.

Other programs may also meet the regulatory requirements of that

subpart.
3.1 Overview of the MACT Analysis Process

     The MACT analysis uses available information to make a MACT

floor finding.  There are several possible situations that may

arise in the course of conducting a MACT analysis.  First, the

MACT floor could be determined based on emission reductions

currently being achieved by controlled emission units in the

source category.  This is known as a positive MACT floor finding.

Other possible outcomes are that the MACT floor can not be

determined, or that the MACT floor equals "no control".  It -may

not be possible to calculate a MACT floor due to the nature of

the pollutants emitted from the source, the lack of available

data, or because there are less than five sources in the source

category.  A MACT floor could equal "no control" if a substantial

number of sources within the category are not currently

controlling HAP emissions.  In either cases, EPA believes that a

more detailed analysis is required in order to determine the

appropriate level of control.  Therefore, a negative MACT floor

finding is made.

                                24

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                                                  PROPOSAL

                                                  March 1994


     Because of the variety of situations that could arise, the


MACT analysis-has been divided into three tiers.  Figure 3


diagrams the steps for Tier I, Tier II and Tier III of the


analysis.  A MACT floor finding is made during Tier I.  Tier II


evaluates all commerically available and demonstrated controls


that could be applied to the emission unit after a negative MACT


floor finding is made.  Tier III uses the information developed


in Tier I or Tier II to establish a MACT emission limitation.


     Ordinarily, the analysis would begin with Tier I.  However,


if an owner or operator agrees to establish the MACT emission


limitation based on the control technology that achieves the


greatest degree of emission reductions, then it would be


necessary to complete only Tier III of the analysis.  In such a
                                         •

case, a positive MACT floor finding is assumed because the


emission reductions achieved would meet or exceed the minimimum


level of control required by the floor.  If a positive MACT floor


finding is made, it is only necessary to complete Tier I and Tier


III of the MACT analysis.  This analysis allows the applicant or


permitting agency to compare the costs, non-air quality health


and environmental impacts and energy requirements associated with


using control technologies that obtain a level of HAP emission


reductions that are equal to or greater than the MACT floor.  If


the MACT floor can not be determined or is equal to "no control"
                                25

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                                                         March 1394
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                                   26

-------
                                                  PROPOSAL
                                                  March 1994

(a negative MACT floor finding), the applicant is also required

to complete Tier II of the analysis.

     During Tier I, the applicant or the permitting agency will

determine the MACT-affected emission unit, and make a MACT floor

finding for each of these emission units.  The applicant or the

permitting agency can make a MACT floor finding by using

available emissions information to determine: (1) if a specific

MACT floor level of control can be calculated; or (2) if there is

a previous case-by-case MACT determination for an emission unit

within that source category.  The procedures detailed in

Chapter 4 explain several acceptable methods for determining.a

MACT floor level of control.

     If a negative MACT floor finding is made the owner or

operator would move to Tier II of the MACT analysis.  The purpose

of Tier II is to identify all commercially available and

demonstrated control technologies using available information,

including work practices, and pollution prevention methods that

could reasonably be applied to the emission unit subject to the

MACT determination.  Available control technologies include but

are not limited to: reducing the volume of, or eliminating

emissions of pollutants through process changes,  substitution of

materials or other techniques; enclosing systems or processes to

eliminate emissions;  collecting, capturing,  or treating

pollutants when released from a process, stack,  storage or

fugitive emission point;  using designs, equipment,  work

                               27

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                                                  PROPOSAL
                                                  March 1994

practices, or operational standards (including requirements for

operator training or certification);  or, a combination of any of

these methods.  Strategies for identifying available control

technologies are discussed later in this chapter.

     Once a list of available control technologies is developed,

each control technology should be evaluated to consider the

costs, non-air quality health and environment impacts, and energy

requirements associated with using each control technology.  The

control technology(s) achieving the maximum degree of HAP

emission reductions taking into consideration the costs of

achieving such emission reductions and the non-air quality health

and environmental impacts and energy requirements should be

selected as MACT.  Once MACT has been selected through either

Tier I or Tier II of the analysis, the applicant should move to

Tier III.

     In Tier III, a MACT emission limitation (s)* should be

established based on the degree of emission reductions that can

be achieved through the application of the maximum achievable

control technology (MACT); or, a design, equipment, work practice

or operational standard, or combination there of, should be

designated if it is infeasible in the judgement of the permitting

agency to prescribe or enforce a specific MACT emission

limitation based on MACT.  The applicant or the permitting agency

should also suggest operating conditions and appropriate

monitoring parameters to make this emission limitation federally

                                28

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                                                  PROPOSAL
                                                  March 1994

enforceable.

     Once the owner or operator has made a MACT floor finding,

established a MACT emission limitation, and selected a control

technology to meet this limitation, the owner and operator should

apply for a Title V permit, or Notice of MACT Approval in

accordance with the procedures contained in 40 CFR Part 63,

Subpart B and 40 CFR Part 70.
                               29

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                                                  PROPOSAL
                                                  March 1994


3.2  A Detailed Look at the MACT Analysis
                                                     *




Tier I - Making a MACT floor finding





Step 1 — Identify the MACT-affected emission unit(s) and


relevant source categories


     In accordance with the provisions established in 40 CFR Part


63, Subpart B, the owner or operator is required to identify all


emission points increasing emissions due to a proposed


modification of the major source, and all emission points that


will emit HAPs due to construction or reconstruction of the major


source.  These "affected emission points" will be grouped into


emission units (MACT-affected emission units).  Emission points


may only be grouped into a single emission unit if they are


within the same source category.  Therefore, the affected


emission points must assigned to the appropriate source


categories.


     On July 16,  1992 the EPA published a notice of source


categories in the Federal Register (57 FR 31576.)   This list may


be periodically updated in future Federal Register notices to


reflect changes to this list due to addition or deletion of


source categories.  A background information document,


"Documentation for Developing the Initial Source Category List"


EPA-450/3-91-030, is also available to describe the types of


processes in each source category.  Both the Federal Register


                                30

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                                                  PROPOSAL
     .       	    	         March 1994

notice and the background information document can be used by the

owner or operator to determine the source category for the major

source.  A listing of major sources can be found in Appendix D.

This list should be consider current only to the date of

publication of this guidance manual.

     Each emission units that is designated will be subject to a

MACT determination.  When a relevant emission standard has been

proposed, the application should designate a MACT-affected

emission unit that is consistent with the existing source

definition, or affected emission points in the proposed emission

standard.  When no relevant emission standard has-been proposed,

the MACT-affected emission unit will be determined on a case-by-

case basis.  Section 3.3 of this chapter discusses principles for

determining the MACT-affected emission unit on a case-by-case

basis.



Step 2 — Make a MACT floor finding

     The owner or operator will need to determine if there is

enough information available about other emission units to

calculate a level of HAP emission control that is equal to the

MACT floor for each type of emission unit undergoing review.  For

emission units requiring a new source level of control, the MACT

floor  (or best controlled similar source) can be determined using

emissions information on similar emission units from within and

outside of the source category.  (Section 3.4 clarifies the term

                                31

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                                                  PROPOSAL
                                                  March 1994

similar emission unit.)  For modifying emission units, the MACT

floor should be calculated "using only emissions information on

other emission units within the source category.  In many cases,

the determination of the level of control achieved by the best

controlled similar source may be less difficult then determining

the existing source level of control.  Modifying sources may

chose to apply this level of control and move quickly to Tier III

of the analysis.

     The easiest method for determining a specific level of

control equal to the MACT floor is to rely on a MACT

determination that was previously made for a similar emission

unit within the source category.  The owner or operator is

referred to any existing Federal, State or local data bases as

well as the public record to determine if a MACT determination

for a similar emission unit has recently been made.  This MACT

determination can be used to establish the MACT floor, a MACT

emission limitation, and select a control technology as long as

there is no reason to believe that the MACT floor may have

changed since the effective date of that determination.  Reasons

to believe that the MACT floor may have changed would include,

but are not limited to, the passing of a State regulation in a

particular State that specifically regulates that type of

emission unit.  And, the close down or start up of a number" of

major sources within the source category.

     If no previous MACT determination was made, the owner or

                                32

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                                                  PROPOSAL
                                                  March 1994

operator or penniting agency will need to make its own MACT floor

finding.  Chapter 4 discusses three ways to establish a MACT

floor: using (1)  State and local regulations, (2)  control

efficiencies and (3) emission reduction ratios.   Use of any of

these methodologies to determine the floor depends on the format

of available information.  It is possible that a hybrid of these

approaches may be necessary, or none of the methods may be

appropriate given the format of the available information.  These

methods are provided in this guidance document to demonstrate the

types of methodologies that would be appropriate for establishing

a MACT floor.

     If the MACT floor can not be determined or if it is equal to

"no control", a negative MACT finding is made.  Under these

circumstances the owner or operator should discontinue Tier I of

the analysis and begin with Tier II as later outlined in this

chapter.



Step 4 — Identifying MACT

     When a positive MACT floor finding is made, the owner or

operator will need to identify control technologies that reduce

HAP emissions from the MACT-affected emission unit to the maximum

extent and to a level that is at least equal to the MACT floor.

For emission units requiring a new source level of control,

consideration can be given to transfer and innovative

technologies used to control emissions from other emission units

                                33

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                                                  PROPOSAL
                                                  March 1994

that may not have met the definition of similar but nevertheless

use technologies that can be applied to the. MACT-affected

emission unit.

     The control technology that achieves the maximum degree of

HAP emission reductions with consideration to costs, non-air

quality health and environmental impacts, and energy requirements

is MACT.  The Act does not provide direction on the signficance

of one factor to another.  EPA believes that it is inappropriate

to provide specific guidance for determining the amount of

consideration that should be given to any one factor.  Such

decisions will need to be made based on the information available

at the time of the MACT determination.  However, under no

circumstances should the MACT emission limitation be less

stringent than the MACT floor.

     In general, a control option that reduces overall HAP

emissions to the greatest extent should be identified as MACT;

however, there may be occasions when the hazard to human health

and the environment from a particular HAP warrants the selection

of a MACT specifically for the control of that HAP.

Identification of more than one control technology may be

necessary when an emission unit has multiple HAP emissions.  An

owner or operator is advised to consult with the permitting

agency to determine if this is the case.  After this step .is

completed an owner or operator should skip to Tier III of the

analysis.

                                34

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                                                  PROPOSAL
                                                  March 1994
           Tier II  - Considering  all  control  technology



Step 1 —  List available control technologies

     Using available information, the owner or operator or

permitting agency should develop a list of commercially available

control technologies that have been successfully demonstrated in

practice for similar emission units.   Similar emission units are

discussed in more detail in Section 3.4 of this chapter.  In

addition, the owner or operator may wish ta consider innovative

technologies and transfer technologies that might reasonably be

applied to the MACT-affected emission unit.



Step 2 — Eliminate technically infeasible control technologies

     All control technologies that could not be applied to the

MACT-affected emission unit because of technical infeasibility

should be eliminated from the list.  A technology is generally

considered technically infeasible if there are structural,

design, physical or operational constraints that prevent the

application of the control technology to the emission unit.  Cost

to install and maintain the control technology is not considered

a factor in determining technical feasibility.  An owner or^

operator should be prepared to justify the elimination of a

control technology in the application for avMACT determination.

                               35

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                                                  PROPOSAL
                                                  March 1994

Step 3 — Conduct an impacts analysis

     The owner or operator or the permitting agency should

conduct a detailed analysis on all of the available control

technologies.  The efficiency of each control technology in

reducing overall HAP emissions should be determined.  A reviewing

agency may require an owner or operator to select MACT based on

the degree of emission reductions achieved for one or more

specific HAPs when the risk to human health and the environment

warrants establishing MACT emission limitations specifically for

these HAPs.  Otherwise, MACT should be selected based on an

overall reduction of all HAP emissions.  It should be noted that

the application of more than one control technology may be

necessary in order to address multiple HAP emissions.

     After determining the control efficiency of each available

control technology, the owner or operator should identify the

control technology(s) that allows for a maximum degree of HAP

emission reductions with consideration to the costs of achieving-

such emission reductions, and the non-air quality health and

environmental impacts and energy requirements.  This is the MACT.

See Chapter 3 of this guidance document for a more detailed

discussion on the analysis of the costs, non-air quality health

and environmental impacts, and energy requirements. •
                                36

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                                                  PROPOSAL
                                                  March  1994

       Tier III —— Establishing a MACT emission limitation

     An owner or operator of a modifying major source can avoid

completing Tier I and Tier II of the MACT analysis or minimize

the degree of analysis required if the MACT emission limitation

is based on a control technology that achieves the greatest

degree of emission reductions or meets the level of control

required for new sources.  The owner of operator is referred to

existing EPA control technology guideline documents (CTG) and

background information documents (BID).  These documents may help

identify best control strategies for the control of HAPs from a

given type of emission unit.  An owner or operator could also

develop a list of available control technologies (similar to that

which would be developed under a Tier II analysis)  and establish

a MACT emission limitation based on the control technology that

achieves a maximum reduction in hazardous air pollutant emissions

with consideration to the costs of achieving the emission

reductions, and the non-air quality health and environmental

impacts, and-energy requirements.  However, minimal consideration

should be.given to cost in such an analysis.



Step I — Establish a MACT emission limitation (MEL)

     The owner or operator should determine the degree of

emission reduction that pan be obtained from the MACT-affected

emission unit, if MACT is applied,  and properly operated and

maintained.  The MACT emission limitation should be based on an

                                37

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                                                  PROPOSAL
                                                  March 1994

.overall reduction of all HAP emissions;  however, if possible,

the efficiency of the MACT in reducing each potential HAP

emission should also be stated.  The permitting agency will also

have the discretion to establish a MACT emission limitation for

an individual HAP when the risk to human health and the

environment warrants such an emission limitation, or when such a

limitation is necessary to make the overall HAP emission

limitation federally enforceable.  If it is not feasible to

establish a specific numerical or efficiency limitation, then a

specific design, process, or control technology should be

designated.

     When control efficiencies are used to establish a MACT

floor, the MACT emission limitation (MEL) can be computed by

multiplying the efficiency of MACT by the uncontrolled emission

level (UCEL)  of the emission unit as follows:

                  MEL  =  UCEL * MACT efficiency



     The UCEL for emission units requiring a new or existing

source level of control is the maximum amount of HAP that could

be emitted from the unit under current design specifications and

at full capacity utilization.  For existing emission units, the

UCEL could be computed as the amount of HAP that could be emitted

from the unit under design specification used within the past

five years and at full capacity utilization if the source has

used a source reduction method to reduce its total capacity to

                               38

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                                                  PROPOSAL
                                                  March 1994

to emit.  EPA recognizes that' many major sources are adapting

innovative measures to reduce the source's total capacity to emit

HAPs.  By allowing a five year period of time to compute the

uncontrolled emissions, sources can take credit for good control

measures that might otherwise not be recognized in a calculation

of UCEL and controlled emissions.

     For example, in 1992, an owner and operator of a major

source used trichloroethylene in a degreasing operation.  In

1993, the owner or operator switched to a water-based solvent in

the degreasing operation.  In 1994, the owner or operator wishes

to change to use a low-VOC based solvent because the water-based

solvent performed poorly.  If a Section 112(g) MACT determination

is conducted for the emission unit, the uncontrolled emission

level would be computed using trichloroethylene in the

calculation.  (Although, the owner or operator may be required to

meet a level of emission reductions equal to use of the water-

based solvent if this technology is determined to be MACT.)

      Acceptable methbds for computing the UCEL are:

     (a)  Engineering calculation using material balance or

          emission factors;

     (b)  Actual emission data from the similar emission unit;

     (c)  Average annual hourly emission rate multiplied by hours

          of operation;

     (d)  Emission limits and test data from EPA documents,

          including background information documents;

                               39

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                                                  PROPOSAL
                                                  March 1994

     (e)  Equipment . vendor emission data and guarantees;

     (f)  State emission inventory questionnaires for comparable

          sources ;

     (g)  Federal or State enforceable permit limits; or,

     (h)  For equipment leaks use, "Protocols for Generating

          Unit-Specific Emission Estimates for Equipment Leaks of

          VOC and VHAP," EPA-453/R-93-026.



     When an emission reduction ratio (ERR) is used to determine

the MACT. floor, the MACT emission limitation can be computed by

multiplying the uncontrolled emission level by the emission

reduction ratio of MACT using the following formula:
                    MEL - UCEL * (1 -
See Section 4.4 of this manual for more information on the

emission reduction ratio.

                                          •

Step 2 — Select a control technology to meet the MACT emission

          limitation

     Once the MACT emission limitation is established, the owner

or operator should- propose a control strategy, that allows the

emission unit to to obtain the required MACT emission limitation

In many cases, this will be through the application of the MACT
                                40

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                                                  PROPOSAL
                                                  March 1994

technology.  However, in some cases, the emission unit may

already be controlled to a some extent with an existing control

devise.  The owner or operator could demonstrate that using

additional control strategies in combination with existing

controls will allow the emission unit to achieve the required

emission reductions.  For instance, an emission unit may

currently be controlled with a baghouse.  MACT for the emission

unit may be an electric static precipitator.  The emission unit

may be able to meet the MACT emission limitation by installing a

series of baghouses in lieu of the electric static precipitator.

The amount of additional control required (ARC) can be computed

by subtracting the MACT emission limitation from the controlled

emission level (GEL) as follows:



                         ARC = CEL - MEL

     The CEL is the maximum amount of HAP that could be emitted

from the unit under current design specification and at full

capacity utilization taking into consideration the application of

federally enforceable controls.   Acceptable methods for making

this calculation are:

     (a)   Engineering calculations using material balance or

          emission factors;

     (b)   Any reported or measured emission that offers a true

          representation of yearly emissions;

     (c)   Average annual hourly  emission rate  multiplied by hours

                                41

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                                                  PROPOSAL
                                                  March 1994

          of operation;

     (d)  Emission limits- and test data from EPA documents,

          including background information documents;

     (e)  Equipment vendor emission data and guarantees;

     (f)  State emission inventory questionnaires for comparable

          sources;

     (g)  Federal or State enforceable permit limits; or,

     (h)  For equipment leaks use, "Protocols for Generating

          Unit-Specific Emission Estimates for Equipment Leaks of

          VOC and VHAP," EPA-450/3-88-010.



     If ARC is equal to zero or is a negative number, no

additional control is required.  The emission unit is currently

meeting the criteria for MACT.  If ARC is a positive number, the

owner or operator must reduce hazardous emissions by this amount.

In some cases, it may only be necessary for the sourde to

establish federal enforceability of existing State requirements

to meet the MEL.

     Owners or operators are reminded that the application of a

case-by-case MACT to an emission unit does not exempt that owner

or operator from complying with any future emission standards

affecting that emission unit.  The MACT floor emission limitation

as calculated on a case-by-case basis should be considered only a

relative indicator of the future MACT emission standard.  Changes

in technology or application of controls to under-controlled

                                42

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                                                  PROPOSAL
                                                  March  1994

sources may shift the MACT floor to a higher control  level,

-additional emissions information may be- available that generates

a different level of control for the MACT floor, or a control

technology that is more effective in controlling HAP  emissions

may be selected based on the relative cost of applying that

technology on a nationwide basis.  Owners or operators may wish

to consider these factors when selecting a control technology to

meet the MACT emission limitation.




Step 3 — Establish appropriate monitoring, reporting and

          recordkeeping parameters




     The owner or operator or the permitting agency should

identify monitoring parameters to assure compliance with the MACT

emission limitation.  Section 2.2 of Chapter 2 discusses
                                               •
compliance provisions in greater detail.




Step 4 — Prepare application for a Title V permit or Notice of

          MACT Approval

     Once a control technology(s) is identified and the MACT

emission limitation(s)  is established,   the owner or  operator

should prepare an application for a Title V permit or Notice of

MACT Approval consistent with the procedures contained in 40 CFR

Part 63, Subpart B.
                                43

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                                                  PROPOSAL
                                                  March 1994

3.3 Determining the MACT-affected emission unit

     Sections 63.42 and 63.43 of 40 CFR Part 63, Subpart B define

the emission points that are affected by the proposed

construction, reconstruction, or modification of a major source.

For construction or reconstruction of a major source, all new

emission points at the major source are affected.  A modifying  .

major source may have several affected emission points.

     The first type of emission point that could be affected by a

modification is one that will increase actual emissions of a HAP

by greater than de minimis amounts, without being offset.  Also,

when a new emission point is added to an existing major source,

and that emission point will have the potential to emit or will

emit greater than de minimis amounts of a HAP, without being

offset, that emission point is also affected by the modification.

     A third type of emission point could be affected by a

modification if an owner or operator modifies a major source such

that the sum of emission increases of a HAP from multiple

emission points is greater than de minimis amounts.  In this

instance,'all emission points that contribute to the greater than

de minimis increase in emissions of that HAP are affected by that

modification.

     For example, an owner or operator modifies an operation such

that vent A will increase emissions of HAP X by 6 tpy;  Vent B

will increase emissions of HAP X by 2 tpy;  and, Vent C will

increase emissions of HAP X by 0.5 tpy.  The de minimis amount

                                44

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                                                  PROPOSAL
                                                  March 1994
for HAP X translates to 3 tpy.  Vents A, B, and C would all be
affected by the modification because the total increase of HAP X
from the major source is greater than de minimis amounts for that
HAP.  Figure 4 illustrates this example.
     In another example, an owner or operator of a major source
increases its production capacity, with an associated capital
expenditure.  The production material is currently passed through
one of two treatment units.  To accommodate the increased
production rate the owner or operator proposes to add a third
treatment unit.  At any given time, only two of the treatment
units will be used while the third is off-line for maintenance.
The emission increase from the physical or operation change
occurs from each of the emission points depending on which are in
operation.  In this situation, all three emission points
contribute to greater than de minimis increases and would all be
affected by the modification.
     A final example can be1 explained with a wastewater
conveyance system.  An owner or operator adds a spray coating
booth to an existing coating operation.  This change also
requires additional drains to be added to the wastewater
conveyance system.  The additional paint load to the wastewater
will cause an emission increase in not only the additional drain
but all existing drains.  Controlling the drains may prevent or
                               45

-------
                                                                                         March  1994
                               0
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                 a
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-------
                                                  PROPOSAL
                                                  March 1994
reduce emissions from these affected points, but in doing so it
causes the emission release to occur further downstream.  These
downstream emission points may contribute to greater than de
minimis increases.  (See Figure 5.)  The owner or operator would
be required to select a control technology for MACT that would
remove the HAP from the stream before it proceeds downstream, or
the downstream emission points that would increase in emissions
will be affected by the modification.  If the owner or operator
had not added a spray booth, but had simply added a drain to the
existing water conveyance system, the owner or operator would
only be required to control that drain, (if it contributes to an
above de minimis increase.)  There would not be an increase in
the HAP loading to the water conveyance system.  Therefore, the
downstream emission points would not be affected, because the
emission potential of the downstream emission points would not
change with the addition of the drain.
      A fifth type of emission point can be affected by a
modification at an owner or operator's discretion.  The option
may be preferred when controlling emissions from multiple
emission points obtains a greater degree of emission control than
could be achieved by applying control technologies to a single
affected emission point within the process unit.  When making
case-by-case MACT determinations, EPA would like to focus on
pollution prevention,  recycle and reuse control strategies.  By
allowing an.owner or operator to combine affected emission points
                                47

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                                                              March  1994
                                       5 <
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                                                  PROPOSAL
                                                  March 1994

with other points within a process unit, an overall greater HAP

emission reduction from the major source can be achieved.  This

is especially true when a major source constructs or

reconstructs.  Combining emission points into one affected

emission unit could be a much more cost-effective method of

control than point-by-point compliance.

     For example, a major source in the surface coating of light

duty auto trucks source category proposes to add a drying oven to

the paint coating operation to accommodate an increased

production rate.  HAP emissions from the major source will have

greater than de minimis increases for a HAP due to this

modification.  After reviewing existing databases, the owner or

operator determines that an incinerator operated at a 98%

efficiency meets the emission limitation required by the MACT

floor.  Instead of installing an incinerator, the owner or

operator could control emission points from the spray booth and

bake oven through the use of water-based paints.  In this

situation, it would be appropriate for the owner or operator to

include the emission points from the booth as affected emission

points.

     Likewise, suppose a waste treatment operation modifies by

adding an aerobic degradation tank.  If the focus of the MACT

determination were limited to the tank, some type of

covering/venting system may be required.  However, if other

emission points such as those associated with flocculation or

                               49

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                                                  PROPOSAL
                                               •   March 1994

neutralization are combined with the emission points associated

with the aerobic degradation tank, a steam stripper could be

added to reduce the overall volatile organic content of the

operation and provide for an even greater reduction in HAP

emissions from the emission unit.  Again, the owner or operator

could opt to have these emission points affected by the

modification.  Figure 6 illustrates this example.

     Once all the affected emission points are identified, they

need to be group into MACT-affected emission units.  A MACT

affected emission unit could be combrised of either a single

affected emission point, or a combination of affected emission

points.  Each MACT-affected emission unit will require a MACT

determination to establish the appropriate emission limitation.

      There are four basic principles to follow when designating

the MACT-affected emission unit.  The principles can be

summarized as. follows:  1}  When a relevant Section 112(d) or

Section 112(h)  standard has been proposed, the owner or operator

and the. permitting agency should refer to the relevant standard

to determine the MACT-affected emission unit; or,  (2) When a

source category on the source category list is designated as a

specific piece of equipment, the MACT-affected emission unit is

that piece of equipment or apparatus; or, (3)  The EPA's Office

of Air Quality Planning and Standard's should be consulted to

determine if a suggested method for grouping of affected emission
                                50

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                                            PROPOSAL

                                            March 1994
                                                         (0



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-------
                                                  PROPOSAL
                                                  March 1994
points is available; or, (4)  Emission points should be combined
into a single MACT-affected emission unit when the combination of
points leads to a much more cost-effective method of control, and
achieves a greater degree of emission reductions when compared to
point-by-point compliance.
     The best indicator of how a source category may be regulated
after the promulgation of a relevant -standard is found in a
proposed standard.  For this reason, EPA believes that owners or
operators and permitting agencies should follow the guidelines in
the proposed standard for determining the MACT-affected emission
unit for a Section 112(g) MACT determination.  Although there may
be no proposed standard for the source category, information on
the source category may have been collected which allows EPA to
recommend a specific method for determining the emission unit for
a Section 112(g) MACT determination.  Therefore, EPA should be
consulted before attempts are made to define the MACT-affected
emission unit on a case-by-case basis.  EPA can be contacted
through the Control Technology Center Hotline operated by the
Office of Air Quality Planning and Standards at (919)-541-0800.
     When an affected emission point(s) is associated with a
piece of equipment or apparatus specifically listed on the source
category list, that affected emission point(s) is the MACT-
affected emission unit.  The source category list (See Appendix
D) contains sources that are defined by a manufacturing or
process operation, or as an individual piece of equipment.  In
                                52

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                                                  PROPOSAL
                                                  March 1994
developing the source category list, EPA determined that some
individual pieces of equipment have the potential to emit major
amounts.  For example, under the fuel combustion industrial
grouping, stationary internal combustion engines are listed as a
source category of major sources.  When a source category is
designated by a single type of apparatus, the EPA believes that
the intent is for emission limitations and requirements to be
placed on that specific piece of equipment.  As such,  if a
Section 112(g) determination is conducted for any piece of
equipment from one of these source categories, the specific piece
of equipment or apparatus should be designated as the MACT-
affected emission unit.  Other examples of apparatus that are
listed as a source category of major sources are municipal waste
incinerators, process heaters, and stationary turbines.  The
owner or operator should review the list found in Appendix D to
determine other source categories that could be defined as the
MACT-affected emission unit.
     Otherwise, individual affected emission point can be
considered a MACT-affected emission unit, or a group of affected
emission points can be combined into one affected emission unit.
There are several ways in which emission points could be combined
to form an emission unit.  A few points could be combined, an
entire process unit could be included in the MACT-affected
emission unit, or the MACT-affected emission unit could be as
large as the source category.
                                53

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                                                  PROPOSAL
                                                  March 1994
     For example, a single emission point such as a storage tank
could be consider the MACT-affected emission unit.  Or, emission
points from a distillation column, a condenser and distillate
receiver could be consolidated into one emission unit.  Larger
groupings of emission points maybe appropriate when a single
control technology can be used to control the aggregation or when
a pollution prevention or waste reduction strategy is considered.
For instance, affected emission points from the entire wastewater
treatment operation could be considered one emission unit.  As
explained in an earlier example, collectively, a single steam-
stripper could be used at the beginning of the operation to
remove HAPs from the wastewater and prevent downstream emissions
from occurring, or a process modification such as' changing the
paint can reduce emissions throughout the process.
     Another reason to combine affected emission points into a
single emission unit is that many major sources are already
subject to regulation under 40 CFR Part 60 and Part 61.  In
promulgating these standards, "affected facility" definitions
were developed to designate the apparatus to which a standard
applies.  It may make sense to use these same designation for the
"MACT-affected emission unit".  It should be noted that a
particular piece of apparatus or equipment should not be excluded
from a MACT determination because of an applicability "cut-off"
established under a Part 60 or Part 61 regulation.
     Emission points could be consolidated into an. emission unit
                                54

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                                                  PROPOSAL
                                                  March 1994
that is as large as the source category boundary for several
reasons.  First, the MACT floor needs to be calculated
specifically for the MACT-affected emission unit.  The
information that is available to calculate the MACT floor may
only be available for the source category as a whole, not
individual points within the category.  Also, the operations
within some-source categories are quite variable.  Either the
nature of the process requires a large latitude of flexibility in
establishing the emission unit that should be controlled, or the
types of facilities within the category are so diverse that it
only makes sense to compare the existing sources on a source
category wide level.  In these instances, a source category wide
MACT-affected emission unit could allow some emission points to
be under controlled while others are controlled to a level that
would exceed the level of control that would be placed on that
individual point• through the application of MACT.   Permitting
agencies are cautioned that it would be generally inappropriate
to include emission points associated with equipment leak
emissions into such a MACT-affected emission unit.
     There are some situations which would not make the
combination of emission points reasonable.  First, the combined
emission unit can not generate an emission unit that is so unique
that it precludes comparing the emission unit to other sources in
the source category.  Second, the combining of emission points
should reduce emissions from all of the affected emission points
                                55

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                                                  PROPOSAL
                                                  March 1994

within the MACT-affected emission unit through use of a control

technology that affects all of those emission point, or involves

recycling or reuse, or constitutes an overall source reduction

strategy as defined in the Pollution Prevention Act, P.L. 101-

503.  The types of activities that would be considered pollution

prevention or source reduction measures include changes in

technology, process or procedures, reformulation or redesign of

products, and substitution of raw materials.  A decrease in

production rate alone would not constitute a source reduction

strategy unless the rate reduction was associated with a

pollution prevention measure such as increasing efficiency of the

operation.

     Determining the MACT-affected emission unit on a case-by-

case basis is a complex undertaken.  While this document includes

this step as a separate component of the Tier I approach, in

actual practice the identification of methods to control specific

groups of emission units will be an integrated process with the

identification of control technology options.  Some aggregations

of emission points may be inappropriate because the information

available to calculate the MACT floor would dictate combining

emission points into certain emission units, or because controls

applied to the unit would not achieve a MACT level of control

when compared to point-by-point compliance or some other

combination of emission units.
                                56

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                                                  PROPOSAL
                                                  March 1994
3.4  Similar Emission Units
     There are at least two occassions in which an applicant is
required to evaluate control technologies used by emission units
in other source categories: (1)  When a MACT floor can not be
determined for existing emission units during Tier I of the MACT
analysis; and, (2) When an owner or operator is constructing or
reconstructing an emission unit.  Whether control technologies
from other sources categories should be considered in the MACT
analysis depends on whether the emission unit is "similar".  Two
questions should be answered to determine if an emission unit is
similar: 1) Do the two emission units have similar emission
types, and 2)  Can the emission units be controlled with the same
type of control technology.  If the two emission units do have
similar emission types and are controllable with the same control
technologies then the two emission units are considered similar
for the purposes of a case-by-case MACT determination under
Section 112(g).
     The EPA developed an emission classification system to be
used for determining emission types for case-by-'case MACT
determination.  The five emission classifications are as follows:

     Process vent or stack discharges - the direct or indirect
     discharge of an organic liquid, gas, fume, or particulate by
     mechanical or process-related means.  Examples would be
                                57

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                                             PROPOSAL
                                             March 1994
emission discharges from columns and receiving tanks from
distillation, fractionation, thin-film evaporation, solvent
extraction, air and steam stripping operations, absorbers,
condensers, incinerators, flares, and closed-looped
biological treatment units.

Equipment leaks -  fugitive emissions from the following
types of equipment: valves, pumps, compressors, pressure
relief devices, sampling connection systems, open-ended
valves and lines, flanges, agitators, sampling connection
systems, and valve connectors.

Evaporation and breathing losses - emissions from storage or
accumulation of product or waste material;  for example:
stationary and mobile tanks, containers, landfills, and
surface impoundments, and pilings of material or waste.  .

Transfer losses - emission of an organic liquid, gas, fume,
vapor or particulate resulting from the agitation of
material during transfer of the material from one unit to
another.  Examples of such activities are filling of mobile
tanks, dumping of coke into coke quench cars, transfer of
coal from bunker into larry car, emptying of baghouse
hoppers, and sludge transfer.
                           58

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                                                  PROPOSAL
                                                  March 1994

     Operational losses - emissions resulting from the process
                                           *              ,
     operation which would result .in fugitive emissions if

     uncontrolled by hoods or vacuum vent, or other vent systems,

     Examples of operation loses are emission resulting from

     spray coating booths, dip-coating tanks, quenching towers,

     lubricating stations, flash-off areas, or grinding and

     crushing operations.



     The classification scheme has been developed to serve as a

general guide in identifying available control options.  When

using the list of classifications, consideration should be given

to the concentration and the type of constituents of a gas

stream.  While two pieces of apparatus are classified within the

same emission type, this dpes not automatically mean that the

emission points can be controlled using the same type of control

technology.  For instances, storage tanks and landfills are both

listed in the evaporation and breathing losses classification,

but it is unlikely that a storage tank and landfill would be

controlled with the same technology.   In order for an emission

unit to be considered similar it must fit both criteria: have a

similar emission type and be controllable with the same

technology.

     For example, suppose a major source within the captan

production source category (a source listed on the source

category list in Appendix D,)  proposes to modify by adding
                                                \

                                59

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                                                   PROPOSAL
                                                   March 1994

additional product accumulation vessels  (tanks) and  additional
                                   »             .
pipes, pumps,  flanges and valves  to direct  the product  to the

tanks.  After  reviewing a database during Tier I of  the MACT

analysis, the  owner or operator determines  that there are no

regulations  controlling HAP emissions  from  pumps within the

source category.  And, there  is not enough  emission  information

available on other emission units within the  source  category to

•calculate a  MACT  floor.  During Tier II  of  the analysis, the

owner or operator discovers that  the Synthetic Organic  Chemical

Manufacturing  Industry  (SOCMI) source  category is  currently

subject to regulations controlling equipment  leaks.  Because the

pipes, pumps,  and flanges all have equipment  leak  emissions, the

emission units in the SOCMI source category would  be considered

similar emission  units.  And, the regulations for  SOCMI equipment

leaks should be considered for the control  of the  MACT-affected

emission unit  during Tier II  of the analysis. When  determining

the  existing source level of  control,  identification of a similar

emission unit  does not mean that  the controls will automatically

be applied to  the MACT-affected emission unit.   Costs, non-air

quality health and environmental  impacts, and energy requirements

should be used to assess the  technologies ability  to meet MACT

criteria.

     Now, suppose that this same  change  to  the major source  is

considered construction of a  major source rather than a

modification.   After reviewing available information, the owner
                                        i

                              •  60

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                                                  PROPOSAL
                                                  March 1994
or operator determines that the best controlled tank within a
source category does not have state-of-the-art controls. Yet,
tanks from outside the source category storing similar organic
liquids use state-of-the-art controls vented to an emission
control device.  Such tanks are clearly "similar".  The controls
these tanks would be considered in establishing the best
controlled similar source.
     It is not always appropriate to consider all transferrable
technologies when determining the best controlled similar source.
It would be inappropriate to consider a transfer technology when
the emission units have different emission types.  For example,
within source category X, spray booths tend to be uncontrolled
due to gas streams with low concentrations and relatively high
airflows.  Source category Y uses incineration to control
emissions from spray boothes with high concentrations and low
airflow volumes.  The emissions from these sources are clearly
not similar, and controls for category Y would not be used to
determine the best controlled.similar source for category X.
However, if it is technologically feasible to apply the controls,
these same controls could be considered to establish a new source
level of control beyond the best controlled similar source,  if
consideration is given to cost, non-air quality health and
environmental impacts, and energy requirements.
                                61

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                                                    PROPOSAL
                                                    March 1994
  3.5 Subcategorization
       When the source category list was developed,  sources with
'  some common features were grouped together to form a "category".
  During the standard-setting process,  EPA may find it appropriate
  to combine several categories or further divide a category to
  distinguish among classes,  types,  and sizes of sources.  EPA
  chose to establish broad source categories at the time the source
  category list was developed because there was too little
  information to anticipate specific groupings of similar sources
  that are appropriate for defining MACT floors for the purpose of
  establishing emission standards.
       The broad nature of some source category descriptions may
  pose some difficulty in establishing an appropriate MACT emission
  limitation for a MACT-affect emission unit on a case-by-case
  basis.  Subcategorization within a source category for the
  purposes of a case.-by-case MACT determination should be
  considered only when there is enough evidence to clearly
  demonstrate that there are air pollution control engineering
  differences.  Criteria to consider include process operations
  (including differences between batch and continuous operations),
  emissions characteristics,  control device applicability and
  costs, safety, and opportunities for pollution prevention.
                                .  62

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                                                  PROPOSAL
        ,  	                                      March 1994


                           Chapter 4.0
        m             t

                      The MACT Floor  Finding


     During Tier I of the MACT analysis, an owner or operator or


the permitting agency is required to make a positive or negative


MACT floor finding.  A positive finding would be made if there is


enough information to determine a emission control level that is


at least equal to the MACT floor.  A negative MACT floor finding


would be made if: (1) the MACT floor equals "no control";   (2) a
                                 \

MACT floor can not be determined due to the nature of the


pollutant or process;  or, (3) there is not enough emissions


information to compute a MACT floor.


     The EPA recognizes that computing the MACT floor for a MACT-


affected emission unit may be time consuming and burdensome for


the owner or operator or the permitting agency.  To avoid


calculating a specific emission control level that equals the


MACT floor,  the applicant can propose to meet the greatest degree


of emission control.  This control level will meet or exceed the


level of emission 'reduction required by a MACT floor finding,


therefore, a positive MACT floor finding is assumed.


     Owners or operators and the permitting agency should refer


to existing EPA control technology guidelines (CTG),  background


information documents (BID,)  existing New Source Performance


Standards (40 CFR Part 60,)  or existing National Emission


Standards for Hazardous Air Pollutants (40 CFR Part 61)  to


identify control strategies that obtain the greatest degree of


                                63

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                                                  PROPOSAL

                                                  March 1994


emission reductions for-a given MACT-affected emission unit.  The
•              ,

greatest level of contro.l can also be established by conducting a


costs, the non-air quality health and environmental impacts, and


energy requirements analysis on all commercially-available and


demonstrated control technologies.  Minimal consideration should


be given to cost impact in such an analysis.  If the new source


level of control is known for an emission unit, a modifying major


source may opt to meet this level of control in lieu of making a


specific MACT floor finding.


     An owner or operator could also avoid calculating a specific


MACT-floor by referring to existing databases to document whether


a MACT determination for another similar emission unit in the


source category has recently been made.  This MACT determination


could be used to establish the MACT floor for the MACT-affected


emission unit provided there is no reason to believe that the


control technology no longer represents MACT.  This was


previously discussed in Section 3;1.


     Because the above methods will not always clearly identify a


control technology or emission limitation that meets the MACT


floor, an owner or operator or the permitting agency may be.


required to review existing emissions information to make a


specific MACT floor finding.  Section 4.1 of this chapter


discusses the calculation procedure for, determining an "average


emission limitation".  This procedure establishes a hierarchical


system for determining the average emission limitation using the


                                64

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                                                  PROPOSAL
                                                  March 1994

arithmetic mean, median or mode.

     Using the calculation procedures discussed in Section 4.1,

the EPA has established three acceptable methods for determining

a MACT floor.  If the emissions information is available, all

three methods should be considered before the owner or operator

concludes that a MACT floor can not be found.  The three methods

include using:  (1) existing State and local air toxic control

regulations;  (2)  control efficiency ratings; or (3) emission

reduction ratios.   Each of these methods is discussed in greater

detail later in this Chapter.

     The first method compares air pollution regulations in

different States.   This method is likely to require the least

amount of data search and analysis.   The second and third methods

base the MACT floor on a level of emission reductions, allowing

the MACT-affected emission unit more flexibility in determining

control technologies to meet the MACT floor.  The second method

is applicable only when the control technologies under

consideration can be assigned an efficiency rating for HAP

emission reductions.  This is most-likely to occur with add-on

control devises.  The third method can be used for add-on control

devises, work practices, recycling,  reuse or pollution prevention

strategies.  Depending on the format of available information, a

hybrid of the three approaches may be necessary.
                               65

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                                                  PROPOSAL
                                                  March 1994


4.1  Calculation of the MACT Floor


     Section 112(d) of the Act instructs EPA to set emission


standards for new sources based on the emissions control achieved


in practice by the best controlled similar source and to set


emission standards for existing sources based on an average


emission limitation achieved by the best performing 12% of


existing sources or best performing five sources in the source


category.  For new sources the direction provided by the Act is


relatively clear.   For existing sources, further clarification is


required by EPA to determine how an average emission limitation


should be computed.


     The word average can have several different meanings,


including arithmetic mean, median and mode.  EPA has developed
               •

the following hierarchy for determining the average emission


limitation that is equal to the MACT floor.  First, if the


emissions data that is to be used to calculate the floor is in


the form of a numerical expression, (i.e. 95% reduction), the


MACT floor should be determined by taking the arithmetic mean of


the best performing 12% of existing sources or the best


performing five sources.  An arithmetic mean is calculated by


summing all of the data and dividing by the number of data


elements in the calculation.  The following example illustrates


this concept:
                                66-

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                                                  PROPOSAL
                                                  March 1994

Example 1

     The following emission limitations are representative of the

     best performing 12% of existing source:

          % reduction

               99                  Average emission limitation =
               99
               95                            656/7 = 93.7%
               93
               92
             •  89
               89
     Total     656

     # of sources = 7



     Under some circumstances the arithmetic mean results in a

number that may not correspond to the application of a specific

control technology.  For instance suppose the arithmetic mean of

emission limitations of the best performing 12% of exist sources

is equal to 92.3%.  Application of control Technology X would

provide a source 91% control, while application of Technology Z

would limit the source's emissions by 96%. . In most cases, when

the arithmetic mean can not be specifically achieved by the

application of a control technology, the MACT floor should be

elevated to the level of control associated with the control

technology that exceeds the MACT floor.  In Example 1,  the MACT

emission limitation should be no less stringent than 95% control.

This concept would not make sense if there is a large discrepancy

between the amount of emission reductions that can be achieved by


                                67

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                                                  PROPOSAL
                                                  March 1994

available control options.  This is illustrated with the

following example:



Example 2

          An arithmetic mean is computed for the best performing

     12% of storage tanks.  There are 10 sources among the best

     performing 12% of storage tanks.  Two tanks are controlled

     by 99%, the remaining 8 tanks are not controlled.  The

     emissions limitations considered in the floor calculation

     are:

          % reduction

               99
               99                  average emission limitation =
                0
                0             '          19.8% reduction
                0
                0
                0
                0
                0
                0
     Total     198

     # of sources = 10


In this example, no technology corresponds to 19.8% control, and
                                                 «•
it might be inappropriate to elevate the MACT floor to 99%

control.

     If there is a large discrepancy between the amount of

emission reductions that can be achieved by available control

options, the median should be used in lieu of the arithmetic mean


                                68

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                                                  PROPOSAL
                                                  March 1994

to determine the average emission limitation equal to the MACT

floor.  A median is the value that falls in the- middle of a set

of numbers when those numbers are arranged in an increasing order

of magnitude;  in other words, there will be an equal number of

values above and below the median.  If the middle falls between

two values, the median is equal to the arithmetic mean of those

two numbers.  This situation will occur when there is an even

number of values in the set of numbers.  When computing the

average emission limitation for the best performing 12% of

existing sources, the median will always be equal to the lowest

emission limitation achieved by the best 6% of sources in the

source category.  For example:


                                                        •
Example 3

          There are 84 sources in the source category..  The

     number of sources in the best performing 12% of source is

     equal to 10.  The median is to be computed for the following

     emissions data:

          % reduction
               24
               26             There are a total of 10 numbers
               30             the median would be the arithmetic
               30             mean of the 5th and 6th numbers
               33             in the column.
               40
               56             median = (33 + 40)/2 = 36.5
               88
               93
               99
                               69

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                                                   PROPOSAL
      ,....,     ,    .'.,.,.      .             March 1994

      Like the computation of the arithmetic mean, the  value

 obtained for the median may not always correspond to a specific

 control technology.  If there is a control technology  that

 obtains slightly greater emission reduction than the median,  the

 MACT floor should be based on that control technology.   For

 instances, in Example 3, the MACT floor would be equal to 40%

 emission reductions.  This value coincides with the lowest

 emission limitation achieved by the best performing 6% of

 sources.  However, if there is a large discrepancy between the

 control technologies used to establish a median such that no

 technology could realistic obtain a reduction close to the

 median, the mode should be used to calculate the MACT  floor.

      A mode is the most frequent occurrence among a set of data.

 In Example 1, there are two modes, 99% and 89% emission

 reductions.  In Example 2, the mode would be equal to  0% emission

 reductions; and the mode in Example 3 would be 30.  When there  is

 more than one mode in the data set, the MACT floor should be

 based on the least degree of emission control.  However,

• existence of more than one mode may be an indicator that the  MACT

 floor should be established at a level of control more stringent

 than the MACT floor.

      The mode may also be used as a method to compute  an average

 emission limitation if the emissions data for a source category

 is not based on a numerical number.  This could occur  if sources

 were regulated by several different equipment or work  practice

                                 70

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                                                  PROPOSAL
                                                  March 1994

standards.  Unless a specific level of emission reduction can be

associated with each different standard or unless the standards

can be ranked in some order of increasing level of control, an

arithmetic mean and median can not be calculated.  A mode could

be used if one of the control options was used more frequently by

one of the best performing 12% of existing sources.  For example:



Example 4

     There are 44 tanks in the source category.  Five sources are

     among the best performing 12% of existing sources.  These

     five tanks are subject to the following regulations in the

     source category:

          3 of the 5 must be covered and vented to a carbon

          canister;

          2 of the 5 must use a fixed roof



     The mode would be to cover and vent the tank to a carbon

canister.

          The following sections of this chapter detail the three

acceptable methods for computing a MACT floor.  It should be

noted that when the best controlled similar source is being

determined for constructing or reconstructing major sources/ all

references to using emissions information from within the source

category should be ignored.  Identifying the MACT floor for

constructing and reconstructing major sources requires that the

                               71

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                                                  PROPOSAL

                                                  March 1994



emission information used to determine the best controlled
                                                  w


similar source not be limited to within the source category.



Readers are referred to Section 3.4 of this chapter for a



definition of similar emission unit.
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                                                  PROPOSAL
                                                  March 1994

4.2  Method 1 - Computing the MACT Floor Using Existing State and

     Local Regulations '

     The steps for computing a MACT floor using this method are

listed in Figure 7.  The following describes these steps.



Step (A) Conduct a geographical survey

     Determine the number of existing similar emission units in

the source category, and conduct a survey to determine the

geographical location of these similar emission units.  Group the

emission units according to the state or locality in which they

are located.

Step (B)  Review State or local air pollution regulations

     Review the different State or local air pollution control
                      •

regulations that are applicable to the emission unit in each

State or locality where an emission unit is located.



Step (C)  Rank the State or local air pollution regulations

     For the State and local regulations identified in Step B,

rank the regulations in order of stringency.  The regulations

that require the greatest level of control should be listed

first.
                               73

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                                                  PROPOSAL
                                                  March 1994
                             Figure 7

                     Using State or Local
                   Air Pollution Regulations
                to Compute the MACT Floor
Step A    Conduct a Geographical Survey
Step B     Review State and Local Air Pollution Regulations
Step C     Rank the Regulations according to Stringency
Step D     Determine the Percentage of Emission Units Complying with
          each Stringency Level
Step E     Determine MACT Floor
                               74

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                                                  PROPOSAL
                                                  March 1994

Step (D)  Determine the number of emission units regulated by

each stringency level.

     For each level of stringency identified in Step  (C) , a

percentage of emission units required to comply with the

regulations should be computed.



Step (B)  Make a MACT floor finding

     For constructing or reconstructing major sources, the MACT

floor will equal the most stringent State or local regulation

applying to a similar emission unit.  For a modified major

source, the MACT floor will either be equal to the arithmetic

mean of the best 12% of existing emission units in the source

category, or the best 5 existing emission units in the source

category.  If the arithmetic mean can not be calculated, the

median or mode should be used to compute the MACT floor for

existing sources.

     Figure 8 illustrates the following example of this concept:

In Step  (A),  the owner or operator determines that there are 42

similar emission units in the MACT-affected emission unit's

source category.  Sixteen of the sources are located in State A,

five in State B, three in State C, and 18 in State D.  A specific

numerical value can not be determined for all of these

regulations,  but it is possible to list the regulations in order

of stringency.  Upon reviewing the regulations in these four

States, it is determined that States A and B have the most

                               75

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                                                  PROPOSAL
                                                  March 1994
                            Figure  8

                 Evaluation  of  State Regulations
                       for Emission Unit X
STATE
A
B
C
D
TOTAL
STRINGENCY*
1
1
2
3
	
# OF SOURCES
16
5
3
18
42
Total # of emission units

# of emission units within the top
6% of existing emission units

Stringency level top 6 emission
units must comply with

MACT floor
  42
=3  (42 * 0.06)
= 1
  regulations
  in State A or B
*  Stringency is rated 'from the most stringent State regulation
beginning at 1 and increasing in number as the regulation is
rated less stringent.
                                76.

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                                                  PROPOSAL
                                                  March 1994

stringent regulations for this source;  and, they are equally

stringent.  These State regulations are followed in stringency by

State C.  State D is the least stringent state; there are no

regulations and the sources are uncontrolled.

     State A and B regulate 50% of the sources.  Using the median

to compute the MACT floor, the MACT floor would be equal to the

least stringent regulations governing the most strictly regulated

3 sources (42 * 0.06 rounded to the next largest whole number.)

In this case, the MACT floor would be equal to either State A or

State B's regulations.
                               77

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                                                  PROPOSAL
                                                  March 1994

4.3  Method 2 ~ Computing the MACT Floor using Control

     Efficiency Ratings      .-..-.



     To use this method to calculated the MACT floor, the owner

or operator will evaluate emission units that use add-on control

devices or other methods whose HAP control efficiencies have been

clearly demonstrated.  The MACT floor and MACT emission

limitation can be computed as follows:



Step (A)  Determine HAP emission reduction efficiency for each

          control device.

          For each emission unit in the source category, the

ability of each control technology to reduce HAP emissions should

be determined as a percentage of reduction efficiency.  For

constructing and reconstructing emission units, the reduction

efficiency should be computed for all similar emission units.

Acceptable methods for determining the efficiency rating are:

     1)   Equipment vendor emission data and guarantees;

     2)   Federal and State enforceable permits limits on

          operation of the control technology;

     3)   Actual reported efficiency from the similar emission

          unit.

Step (B)  Calculate the MACT floor

     For constructing and reconstructing emission units, the MACT

floor equals the level of emission reductions that can be

                                78

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                                                  PROPOSAL
                                                  March 1994

obtained by the control technology with the highest emission

control rating.  For existing emission units, the MACT floor

equals the arithmetic mean of the best five or the best

performing 12% of control efficiency ratings.  Or, if the median

is used the MACT floor equals the lowest control efficiency

rating achieved by the best 6% of sources if there are greater

than 30 sources in the source category; or, the MACT floor equals

the lowest control efficiency rating among the best 3 sources if

there are less than 30 sources in the source category.  Under

most circumstances, it should not be necessary to use the mode to

compute an average emission limitation;  however, if it is used,

the MACT floor would be equal to the most frequent control

efficiency rating among the best performing 12% of existing

sources or the best performing five sources.
                               79

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                                                  PROPOSAL
                                                  March 1994
4.4  Method 3 - Computing the MACT floor Using Emissions

     Reduction Ratios (ERR)




     The emission reduction ratio is a fraction of uncontrolled

emissions to controlled emissions.  The MACT floor is computed

using the emission reduction ratios.  To compute the emission

reduction ratio for each emission unit, the owner or operator

must review emissions data or other information to determine

uncontrolled and controlled emissions levels for these units.

The step-by-step process is detailed below and summarized in

Figure 9.



                                          /
Step (A)  Compute an uncontrolled emission level (UCELr) for each

emission unit

     For modifying sources an UCEL should be computed for each

emission unit in the source category.  For constructing and

reconstructing sources, a UCEL should be computed for each

similar source.  The UCEL for an emission units is the amount of

HAP that could be emitted from the unit under current design

specification at full capacity utilization.

      Acceptable methods for computing the UCEL are:

     (a)  Engineering calculation using material balance or

          emission factors;

     (b)  Actual emission data from the similar emission unit;

                                30

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                                                  PROPOSAL
                                                  March 1994

     (c)  Average annual hourly emission rate multiplied by hours

          "Of operation;

     (d)  Emission limits and test data from EPA documents,

          including background information documents;

     (e)  Equipment vendor emission data and guarantees;

     (f)  State emission inventory questionnaires for comparable

          sources;

     (g)  Federal or State enforceable permit limits; or,

     (h)  For equipment leaks use, "Protocols for Generating

          Unit-Specific Emission Estimates for Equipment Leaks of

          VOC and VHAP," EPA-453/R-93-026.

See Section 3.2 for a more detailed discussion of UCEL and its

use.



Step (B)  Compute a controlled emission level (GEL)  for each

emission unit

     The CEL is the maximum amount of HAP that could be emitted

from the unit under current design specification and at at full

capacity utilization taking into consideration the application of

federally enforceable controls.  Acceptable methods for making

this calculation are:

     (a)  Engineering calculations using material balance or

          emission.factors;

     (b)  Any reported or measured emission that offers a true

          representation of yearly emissions;

                                81

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                                                 PROPOSAL
                                                 March 1994
                            Figure 9

              Using Emission Reduction Ratios
                to Compute the  MACT Floor
Step A    Compute an Uncontrolled Emission Level (UCEL) for each
          emission unit.
Step B     Compute a Controlled Emission Level (CEL) for each emission
          unit.
Step C     Compute an Emission Reduction Ratio (ERR) for each emission
          unit.

                   ERR = UCEL - CEL
                            UCEL
Step D     Determine the MACT Floor.
                               32

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                                                  PROPOSAL
                           '                       March 1994

     (c)  Average annual hourly emission_rate multiplied by hours

          of operation;

     (d)  Emission limits and test data from EPA documents,

          including background information documents;

     (e)  Equipment vendor emission data and guarantees;

     (f)  State emission inventory questionnaires for comparable

          sources;

     (g)  Federal or State enforceable permit limits; or,

     (h)  For equipment leaks use, "Protocols for Generating

          Unit-Specific Emission Estimates for Equipment Leaks of

          VOC and VHAP," EPA-450/3-88-010.



Step (C)  Compute the emission reduction ratio (ERR) for each

emission unit:

               ERR -  UCEL - CEL
                         UCEL



Step (D)  Determine the MACT floor.

     For construcing and reconstructing sources the MACT floor

would be equivalent to the highest ERR.  For existing sources,

the MACT floor equals the arithmetic mean of the best five or

best 12% of ERRs.  If the median is used, the MACT floor equals

the lowest ERR among the best 6% of ERRs or the best three ERRs

depending on the number of sources in the source category.  If

the mode is used, the MACT floor equals the most frequently
                                     *

                                33

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                                                  PROPOSAL
                                                  March 1994

occurring ERR among the best performing 12% of sources or best 5

sources depending on the number of sources in the source

category.

     For example, suppose a major source determined that there

are four emission units in the top 12% of existing emission units

for the source category.  These four emission units had emission

reduction ratios of 0.90, 0.92, 0.93, and 0.99.  The control

technologies used by these best performing 12% of similar source

are a wet scrubber, a solvent change, a condenser, and an

incinerator.  The arithmetic mean for these values equals 0.935.

If this value does not correspond to the application of a

specific control technology, the MACT floor would be equal to an

emission reduction ratio of 0.99.  If it is determined that

elevation of the MACT floor to this level is infeasible,  then the

median should be computed for these sources.  The median would be

equal to best performing 6% of sources or the lowest of the

highest two emission reduction ratios.  This is equal to 0.93.
                               84

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                                                  PROPOSAL
                                                  March 1994
4.5 Exceptions Emission Reduction Ratios
     In most circumstances the emission reduction ratio, is a
reliable method for calculating the MACT floor.  However, there
are some circumstances when a very low emission reduction ratio
could be computed for a well-controlled emission unit.  This may
occur if pollution prevention strategies are used for greater
than five years at the major source, or a process has an
inherently low potential to emit hazardous air pollutants.  The
owner or operator could be reducing emissions to the maximum
extent possible without being able to credit the pollution
prevention strategy in computing the uncontrolled emissions.  The
uncontrolled and controlled emission rate could be nearly the
same, causing the emission reduction ratio to be a very low
number.  A reviewing agency should keep such situations in mind
when making a MACT determination.  In such instances, the
pollution prevention method should not be eliminated as a
candidate to meet the MACT floor.
                                85

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                                                  PROPOSAL
                                                  March 1994

4.6  Other Methods to Compute the MACT Floor

     As future MACT standards are proposed or promulgated for

different source categories, more methods for determining the

MACT floor could be developed.  The reader is referred to the

Federal Register to locate any other methods for calculating the

MACT floor that have been approved by the EPA and used in

developing a MACT standard under Section 112(d) or 112(h) of the

Act.
                               86

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                                                  PROPOSAL
                                                  March  1994

                            Chapter 5
                                                         »
                      Costs/  Non-air Health
                    and Environmental Impacts,
                      and Energy Requirements


     Section 112(d) of the Act specifies that if control

technology alternatives are being considered to establish an

emission standard that would result in emission limitations more

stringent than the emission "floor";  or, if insufficient data

exists to specify an emission limitation based on the MACT floor,

then control technology alternatives must be evaluated by

considering costs, non-air quality health and environmental

impacts, and energy requirements associated with the expected

emission reductions.

     The costs, non-air quality health and environmental impacts,

and energy requirements discussed below, are illustrative only and

not intended as an exclusive list of considerations for MACT

determinations.  Some of these factors may not be appropriate in

all cases, while in other instances, factors that are not

included here may be relevant to the MACT determination.  The

discussion does not address the evaluation of each factor nor the

weighing of any factor relative to another.  Such determinations

should be made on a case-by-case basis by the owner/operator and

permitting agency.  For the purpose of this discussion, terms

sush as "emission control system" or "MACT system" refer to

design, equipment, or operating standards and inherently less
                                                             v

                                37

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                                                  PROPOSAL

                                                  March 1994


polluting processes, as well as add-on control equipment.
                                                »             ,

     In general, the impact analyses for MACT determinations


should address the direct impacts of alternative control systems.


Indirect energy or environmental impacts are usually difficult to


assess, but may be considered when such impacts are found to be


significant and quantifiable.  Indirect energy impacts include


such impacts as energy to produce raw materials for construction


of control equipment, increased use of imported oil, or increased


fuel use in the utility grid.  Indirect environmental impacts


include such considerations as pollution at an off-site


manufacturing facility which produces materials needed to


construct or operate a proposed control system.  Indirect impacts


generally will not be considered in the MACT analysis since the


complexity of consumption and production patterns in the economy


makes those impacts difficult to quantify.  For example, since


manufacturers purchase capital equipment and supplies from many


suppliers, who in turn purchase goods from other suppliers,


accurate assessment of indirect impacts may not be possible.  Raw


materials may be needed to operate control equipment, and


suppliers of these resources may change over time. . Similarly, it  .


is usually not possible to determine.specific power stations and


fuel sources which would be used to satisfy demand over the


lifetime of a control device.


     In most cases, duplicative analyses are not required in


preparing the MACT impact analyses.  Any studies previously


                                38

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                                                  PROPOSAL
                                                  March 1994

performed for Environmental Impact Statements, water pollution

permits, or other programs may be used when appropriate;

however, the permitting agency may consider any special economic

or physical constraints which might limit the application of

certain control techniques to an existing emission unit, such as

retro-fitting costs that would not be borne by a new unit, or the

remaining useful life of the emission unit.  The result may be

that the level of control required for an existing emissions unit

may not be as stringent as that which would be required if the

same unit were being newly constructed at an existing plant- or at

a "greenfield" facility.  However, in no event shall the level of

control yield an emission limit less stringent than the MACT

floor when information is available to compute the MACT floor.
5.1 Cost Impacts

     Cost impacts are the costs associated with installing

operating, and maintaining alternative emission contro.l systems

(add-on emission control devices or process changes.)  Normally,

the submittal of very detailed and comprehensive cost data is not

necessary.  Presentation of the quantified costs of various

emission control systems (referred to as control costs,) coupled

with quantities of HAP emission reductions associated with each

of the emissions control systems, is usually sufficient.

     Once the control technology alternatives and emission

                                89

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                                                  PROPOSAL
                                                  March 1994

performance levels have been identified, total capital investment

and total annual cost should be developed.  Total capital

investment (purchased equipment plus installation) and total

annual costs of each emission control system should be presented

separately.  Total annual coasts are comprised of operation and

maintenance costs ("direct annual costs11,) administrative changes

("indirect annual costs"), plus overhead, taxes, insurance, and

capital recovery costs minus recovery credits (credit for product

recovery and by-product sales generated from the use of control

systems and other emission reduction credits.)  These costs

should be reported in equal end-of-year payments over the time of

the equipment.  Total annual costs should be reported on an

overall basis, as well as an incremental basis.   The various

emission control systems should be presented or arrayed in terms

of increasing total annual cost.  The incremental annual cost of

a particular emission control system is the difference in its

cost and the cost of the next less stringent control.

     A method for determining the excessiveness or acceptability

of control costs is the comparison of the cost-effectiveness of

alternative control systems.  Average cost-effectiveness is the

ratio of total annual costs (calculated using the above

guidelines) to the total amount (tons or Mg) of HAP removed.

Incremental cost effectiveness is calculated using the same

procedure as outlined for calculating incremental annual cost.

Generally, cost-effectiveness falling within the range of

                                90

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                                                  PROPOSAL
     .                                             March 1994

previously acceptable MACT decisions are not considered

excessive.  Therefore, consistency with the relative 'cost, or

cost effectiveness, of a past MACT determination for a similar

source is an indication that such a cost is reasonable for the

MACT determination in question.

     For most MACT determinations, a cost analysis focusing on

incremental cost-effectiveness of various MACT alternatives is

sufficient.  The analysis should include and distinguish the

various components used to calculate the incremental cost-

effectiveness of the control alternatives (i.e., lifetime of the

equipment, total annual costs, tons of total HAP, removed, etc.).

     If there is reason to believe that the control costs place a

significant burden on the entity being controlled, then the cost

analysis should include financial or economic data that provide

an indication of the affordability of a control relative to the

source.  For example, if the per unit cost is a significant

portion of the unit price of a product or if the economic status

of the industry is declining, then the cost analysis should

present the relevant economic or financial data.  Financial or

economic data should include parameters such as after-tax income

or total liabilities.  An example of a financial criterion used

to determine affordability would be the ratio of a facility's

capital costs to the facility's parent company's total

liabilities.  This ratio would provide an assessment of the

company's capital structure.,

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                                                  PROPOSAL

                                                  March 1994


5.2  Environmental Impacts
               •             ,

     The environmental impacts concentrate on collateral


environmental impacts due to control of emissions of the
     /

pollutant in question, such as solid or hazardous waste


generation, discharges of polluted water from a control device,


visibility impacts (e.g. visible steam plume), or emissions of


other air pollutants.  The applicant should identify any


environmental impacts associated with a control alternative that


has the potential to affect the selection or rejection of that


control alternative.   Some control technologies may have


potentially significant secondary environmental impacts.


Scrubber effluent, for example, may affect water quality and land


use, and, similarly,  technologies using cooling towers may affect


visibility.  Other examples of secondary environmental impacts


could include hazardous waste discharges, such as spent catalysts


or contaminated carbon.  Generally, these types of environmental


concerns become important when sensitive site-specific receptors


exist or when the incremental emissions reduction potential of


one control option is only marginally greater than the next most


effective option..


     The procedure for conducting an analysis of environmental


impacts should be made based on a consideration of site-specific


circumstances.  In general, the analysis of environmental impacts


starts with the identification and quantification of the solid,


liquid, and gaseous,discharges from the control device or devices


                                92

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                                                  PROPOSAL
                                                  March 1994

under review.  Initially, a qualitative or semi-quantitative

screening can be performed to narrow the analysis to discharges

with potential for causing adverse environmental effects.  Next,

the mass and composition of any such discharges should be

assessed and quantified to the extent possible, based on readily

available information.  As previously mentioned, the analysis

need only address those control alternatives with any

environmental impacts that have the potential to affect the

selection or rejection of a control alternative.  Pertinent

information about the public or environmental consequences of

releasing these materials should also be assembled.  Thus, the

relative environmental impacts (both positive and negative) of

the various alternatives can be compared with each other.

     Also the generation or reduction of toxic and hazardous

emissions other than those for which the MACT determination is

being made and compounds not regulated under the Clean Air Act

are considered part of the environmental impacts analysis.  A

permitting authority should take into account the ability of a

given control alternative for regulated pollutants to affect

emissions of pollutants not subject to regulation under the Clean

Air Act in making MACT decisions.   Consequently, the ability of a

given control alternative to control toxic or hazardous 'air

contaminants other than those for which the MACT -determination is

being made,  should be considered in the MACT analysis.
                               93

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                                                  PROPOSAL
                        ........                    March 1994

5.3  Energy Impacts

     Energy impacts should address energy use in terms of

penalties or benefits associated with a control system and the

direct effects of such energy use on the facility.  A source may,

for example, benefit from the combustion of a concentrated gas

stream rich in volatile organic compounds; on the other hand,

extra fuel or electricity is frequently required to power a

control device or incinerate a dilute gas stream.  If such

benefits or penalties exist, they should be quantified to the

extent possible. -

     In quantifying energy impacts, the application could

estimate the direct energy impacts of the control alternative in

units of energy consumption at the source (e.g., Btu, Kwh,

barrels of oil, tons of coal).  The energy requirements of the

control options could be shown in terms of total and/or

incremental energy costs per ton of pollutant removed.  In many

cases, because energy penalties or benefits can usually be

quantified in terms of additional cost or income to the source,

the energy impacts analysis can be converted into dollar costs

and, where appropriate, be factored into the cost analysis.

     Indirect energy impacts (such as energy to produce raw

materials for construction of control equipment) are usually not

considered.  However, if the reviewing agency determines, either

independently or based on a showing by the applicant, that an

indirect energy impact is unusual or significant, the indirect

                                94

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                                                  PROPOSAL
                                                  March 1994

impact may be considered.  The energy impact should still,
 *  t            ,
however, relate to the application of the control alternative and

not to a concern over energy impacts associated with the project

in general.

     The energy impact analysis may also address the concern over

the use of locally scarce fuels.  The designation of a scarce

fuel may vary from region to region, but in general a scarce fuel

is one which is in short supply locally and can be better used

for alternative purposes, or one which may not be reasonably

available to the source either at the present time or in the near

future.
                               95

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                                                  PROPOSAL
                                                  March 1994
                           Chapter 6.0

                      Sources  of Information


     There are currently several programs under development to

house and disseminate toxics information.  Some of these programs

are designed for specific, narrow purposes, while others are

employed in a broader range of uses.  Many data collection

programs are designed for immediate interface with the AIRS

toxics program, which^ is currently under development.

     The purpose of this chapter is to present various sources of

toxics information available in a database format.  EPA believes

the requirements of 112(g) can be less burdensome to both

industry and States by employing a database system to calculate

the 12% floor which may involve using complex mathematical

algorithms and procedures.
BACT/LAER CLEARINGHOUSE INFORMATION SYSTEM (BLIS)

     The BACT/LAER Clearinghouse, or the BACT/LAER Information

System (BLIS)  is a database consisting of best achievable control

technology (BACT)  determination information on specific sources,

to a process level.  Database parameters include facility

information; process description; pollutant information; control

device type, installation date, efficiency; and calculation

                                96

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                                                  PROPOSAL
                                                  March 1994

method; and stack test information if it exists.

     Participation in BLIS is on a voluntary basis.  If

participation in BLIS increases, it may be able to provide

sufficient information to determine the 12% floor with increasing

accuracy.

     BLIS has undergone substantial revision.  Additional fields

for use with toxics work have been added, changes to improve

"user-friendliness" of the system, such as menus and help screens

have been added, and BLIS is now available on the TTN Bulletin

Board.
JEIOG PROGRAMS
                                                              «

     The Joint Emissions Inventory Oversight Group (JEIOG),

support for a data system for air toxics emissions inventories

focuses on the expressed requirements of the urban area source

program (UASP, Section 112(k),  of the CAAA) and the Great Waters

Program (GWP, Section 112(m)).

     Under the JEIOG programs,  there are both short term,

immediate needs and long-term needs.  Since the UASP data

collection effort is scheduled to be completed by mid-1994, JEIOG

may need to select a system for immediately use by the Urban Area

Source Program.




     Urban Area Source Program

                                97

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                                                  PROPOSAL
                                                  March 1994

     The Urban Area Source Program (UASP) is collecting emission

inventory data for use by mid -1994 to meet the CAA November 1995

date for development of a national strategy for control of HAP

emissions in urban areas.  The inventory focuses on an adequate

number of urban areas to "understand the urban area source

problem."  Baltimore, Chicago and Houston are the leading

candidate cities.  Other cities could be added (such as

Milwaukee, Detroit or Seattle) as the resources become available.

The primary data need is for a single year "snapshot" of

emissions data for use in developing the national control

strategy plan.  As of the date of this writing, JEIOG has not

committed to any single system for storing the UASP data.  AIRS
                                           i
is under consideration with other database systems.



     Great Waters Program

     The Great Waters program requires HAP emissions data for

most of the U.S. and portions of Canada.  The Great Lakes region

probably requires the most attention.  Biennial assessments as

reports to Congress are required under the Great Waters program.

The first report is expected in November 1993.   Emissions

inventory data are used primarily for input to models for the

assessment of the relative atmospheric loading of toxic

pollutants into the Great Lakes and other waterways.  Updates of

the emission inventory are anticipated to support the periodic

assessments and for input to refined models as they become

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                                                  PROPOSAL

                                                  March 1994
available.
GENERIC ICR DATA (SECTION 114)



     Under the Authority of Section 114, EPA developed a survey



to obtain the information needed to calculate regulatory floors



for both new and existing stationary sources (See Appendix     ).



This survey is commonly referred to as a "generic ICR", or



information collection request.  It is customized within narrow



parameters for each source category, and comes in both a "long



form" and a "short form".  EPA sends the survey to facilities at



the time it initiates regulatory development for the affected



source category.  In other words, the survey is not sent to



facilities in all source categories at the same time.
                                                 •


     In the generic ICR, EPA requests information regarding each



compound identified as a HAP that is used in or emitted by any



operations, including fugitive emissions sources, occurring from



the source category at the facility.



     Recipients of the form are required to fill out the



information request as completely as possible from existing



information. .At a minimum, the facility must provide  (1)



information of the presence of HAP emissions and (2) HAP emission



estimates based on previously obtained test data or on



engineering calculations provided there is a basis for such



calculations.



     Since the Generic ICR data is collected by EPA from



                                99

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                                                  PROPOSAL
                                                  March 1994

industries, it is called "Agency data".  As such, it can not be

used to update (or replace) existing data which was obtained from

States, or "State data".  The ICR data is currently stored and

analyzed on a commercial database software files.  The Agency is

evaluating options to make the ICR data "safe" (without

confidential information) and accessible to States on a workfile

within AIRS/AFS.
XATEF: TOXIC EMISSION FACTORS
                        /
     The requirements of the CAAA dictate immediate sampling and


analysis to obtain data for determination of emission factors.


These emission factors will be used to determine control


measures.  EPA developed screening methods for the development of


air toxics emission factors, and applies the screening to test


results as they become available for use.  The EPA is enhancing


the XATEF system for housing and manipulating the data.  The

XATEF system is being redesigned to export toxic emission

factors, in a form similar to the AFSEF package for criteria


pollutants.  The new system should be available by the fall of


1992.


     The toxic emission factors available through the XATEF


system will be rated A (most reliable, based on several tests


meeting high confidence criteria) through E (least reliable,


having limited available information), similar to the way


                               100

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                                                  PROPOSAL
                                                  March 1994

criteria emission factors are presented JLn the AP-42.

     Toxic emission factors are being developed for 400 toxic

compounds, of which about 170 are on the list of 189 HAPs in

Section 112(b).   About 40 of these have been targeted as

"critical" pollutants because they are found in a wide variety of

industries, and/or are. especially toxic.   This group of about 40

toxic compounds  have a rating of A or B,  enabling users to arrive

at the most accurate emissions estimates presently possible.

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                                                  PROPOSAL
                                                  March 1994
AIRS/APS NATIONAL OPERATING PERMIT SYSTEM

     The EPA promulgated a new part 70 of Chapter I of title 40

of the Code of Federal Regulations (CFR) on July 21, 1992,

establishing provisions for the Operating Permit Program, and the

minimum data elements of State operating permit programs,  states

must develop and submit programs for issuing operating permits to

major stationary sources of HAPs.

     The requirements of Section 112(g)(2) (A&B) are triggered by

the effective date of a permit program under Title V in any

State.  Section 112(g)(3) states that "the Administrator  (or the

State) shall establish reasonable procedures for assuring that

the requirements applying to modifications under this section are

reflected in the permit".

     The most far-reaching program established under the CAAA is

that'of a national operating permit program under Title V.  The

National Air Data Branch (NADB) is developing a database as a

subsystem under AIRS/AFS to handle the new data coming in from

States Title V permit programs.  This database is generally

referred to as the permit system.  The permit system is under

design to provide much of the information needed for determining

the MACT floor both for case-by-case MACT determinations and for

MACT standards.  It is expected that this system will become

available for use by the fall of 1993.
                               102

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                                                  PROPOSAL
                                                  March 1994
AEROMETRIC INFORMATION RETRIEVAL SYSTEM (AIRS) TOXICS PROGRAM

     The Aerometric Information Retrieval System (AIRS) was

designed and executed to accommodate the expansion of emissions

data.  AIRS Facility Subsystem (AFS) is the stationary source

component of this system and replaced the old NEDS as the data

repository for point source data (e.g./ electric utilities,

industrial plants and commercial enterprises).  Enhancement of

AIRS continues to support the new programs designated by the

CAAA.  The National Air Data Branch (NADB) is currently

considering data support of the requirements under Section 112

for HAP. '
NATICH
                       •.
     The National Air Toxics Information Clearinghouse  (NATICH)

has been established by EPA to support State and local agencies

in the control of non-criteria air pollutants.  The NATICH

program has both a database and a reporting capability.


     The database component of the clearinghouse contains


information on various air toxics regulatory programs  •


administered through State and local agencies.  Elements such as

permitting, source testing, ambient monitoring, agency contacts,

acceptable ambient, limits and guidelines, and program overviews


are all contained within the database.  Information is collected

                               103

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                                                  PROPOSAL

                                                  March 1994



on an annual basis by voluntary submittal from participating



agencies.








     Since its introduction in 1984, NATICH has undergone



periodic modifications in an attempt to expand and meet the 'needs



of the user community.  In the fall of 1989, a link was



established between NATICH and the Toxic Release Inventory System



(TRIS).  A modification is in the planning stages to move the



database from the NCC's IBM mainframe onto the OAQPS TTN Bulletin



Board System for easier and wider accessibility.
STATE AIR OFFICE DATABASES
   •



     Emissions Standards Division (BSD) staff have been working




with STAPPA/ALAPCO to better characterize the toxics information




available in database form and hard copy within the State air




offices.




     Most States have compiled pollutant information in some form




in response to State Implementation Plan (SIP) requirements.




Many States also have toxics information collection systems, as




well as State requirements for toxics programs in the air




offices.  Most States find that although internally their system




is widely used (intra-State system),  to down load or upload data




on an inter-State basis is nearly impossible (with the primary




exception to this being States within a transport region, and




                               104

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                                                  PROPOSAL
                       ,            .               March 1994

then usually under limited circumstances).  Many States have

expressed a keen interest in a National database that each State

could down load State-specific data into, and upload multi-State

retrievals from.  This capability is met by three main systems in

EPA:  BLIS, AIRS, and NATICH.



     Many States use the Aerometric Information Retrieval System

(AIRS) to input their information and perform calculations and

retrievals.  When a converter (an interface between AIRS and the

State system) is used, the data can be input directly into the

State system" and the converter then enters it into the

appropriate fields in AIRS.  Data can also be retrieved from AIRS

into the State format with a converter.

     Since many data sources are fed into AIRS/AFS, the system

becomes a repository of a vast amount of data.  A great deal of

this will be useful for case-by-case MACT determinations and MACT

standards.  This advantage is expected to" become more visible as

the search for the 12% floor for a source category becomes a

common occurrence.

     Some State data is not generally found in the State systems

because it is not needed for their current reporting

requirements.  However, much of the information missing from the

database system can be found in the files documenting source

categories and processes of industry reports.  States may wish to

enhance their current systems to hold such additional data fields

                               105

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                                                  PROPOSAL
                                                  March 1994

and data elements from their participating industries.



                   OTHER SOURCES OF INFORMATION



TRADE JOURNALS

     Caution should be taken when employing these sources,

especially in noting the method of emissions estimation, number

of tests which were used in developing estimates, and the

conditions'under which tests were conducted.  Other factors which

may affect the emissions estimates should also be identified, and

the effects of their differences quantified as accurately as

possible.  Because results applicable to only one facility can

not be completely accurate for other facilities, this source of

information is not regarded as highly accurate.

     This source of information may be somewhat biased as trade

journals are commonly published and•funded by the industry

members of a trade association.  However, these journals are

completely acceptable as long as the results used, can be

substantiated.



TOXIC RELEASE INVENTORY SYSTEM (TRIS)

     This is a source of data that was used to identify HAP

emitters.  The TRIS database contains emissions data reported by

individual industrial facilities as required under Section 313 of

the Emergency Planning and Community Right-to-Know Act of 1988.

                               106

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                                                  PROPOSAL
                                                  March 1994

Emissions data in TRIS are reported on a plant wide basis.

Standard Industrial Classification (SIC) Codes are reported in

TRIS but the entries are usually not specific enough to identify

categories of sources.   The TRIS database is reportedly capable

of identifying plants emitting pollutants listed in Section

112(b).
                               107

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                                                  PROPOSAL
                                                  March 1994
                        List of References
Air Pollution Training Institute (APTI).  December 1983.
     Overview of PSD Regulations.  EPA 450/2-82-008.


Air Pollution Treaining Institute (APTI).  June 1983.  Air
     Pollution Control Systems for Selected Industries.
     EPA 450/2-82-006.


Environmental Protection Agency (EPA).  May 1992.  Facility
     Pollution Prevention Guide.  EPA, 600/R-92/088.


Environmental Protection Agency (EPA).  February 1992.
     Documentation for Developing the Initial Source Category
     List.  EPA, 450/3-91-030


Environmental Protection Agency (EPA).  June 1991.  Hazardous
     Waste TSDF - Background Information for Proposed RCRA Air
     Emission Standards.  EPA, 450/3-89-023 (a)  and (c).


Environmental Protection Agency (EPA). October,  1990.  New Source
     Review Workshop Manual. EPA,  Research Triangle Park, NC
     (Draft Document).


Environmental Protection Agency (EPA), January 1990.  OAQPS
     Control Cost Manual.  EPA, 450/3-90-006.


Environmental Protection Agency (EPA).  September 1986.  Control
     Technologies for Hazardous Air Pollutants.
     EPA, 625/6-86-014.
                               108

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                                             PROPOSAL

                                             March 1994





                           Appendix A ,



          The following detailed examples presented in this
           (


manual are for illustrative purposes only.  Numbers and values



presented in this Appendix do not necessarily reflect any known



cases and are not meant to establish any US EPA position



regarding MACT determinations for a particular emission unit.



These examples are fictitious and are designed to highlight many



of the subtle aspects of the .MACT determination process.  In many



cases, the scenarios and available control technologies have been



grossly oversimplified to streamline the presentation of the



examples.



     The proceeding examples assume that an owner or operator has



already determined that the major source will be constructed,



reconstructed or modified.
                           A -  1

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                                             PROPOSAL
                                             March 1994

                            Example 1

     Using Control Efficiency Ratings to Determine the MACT floor




Descrj.pt ion of Mai or Source:

     A by-product coke plant proposes to construct a new

quenching tower to accommodate an increased production rate.

Hazardous emissions can be released when the hot coke in the

quench car is sprayed with water to decrease the coke's

temperature.  Phenol and naphthalene emissions can occur in the

gaseous state.  Other pollutants can sorb to particulate matter

and be collectively released.  In this example, there will be an

increase in hazardous emissions by greater than a de minimis

amount from this major source that will not be offset.  The owner

or operator will need to conduct a MACT analysis to recommend a

MACT and an MACT emission limitation to comply with the MACT

floor for existing major sources.  No relevant standard exists

for the source, so a case-by-case MACT determination would apply.

The owner or operator will begin with the Tier I analysis.



Steps 1) Identify the MACT-affected emission unit(s)

     MACT-affected source:    quenching tower and coke car

     # of existing sources:    36

     The equipment used in.this production process include the

quenching tower, the coke car, water delivery system, and water
                           A  -  2

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                                             PROPOSAL
                                             March 1994

storage system.  Emission will increase at all these emission

points.  Therefore, they are all affected by the modification.

The owner or operator decides to consider the quenching tower and

coke car as one affected emission unit, the water delivery system

and water storage system as another affected emission unit.  The

example will be continued for only the quench tower/coke car

emission unit.



Step 2) Identify the source category for the major source and the

MACT-affected emission unit



     source category:         coke ovens:  pushing, quenching,

                              and battery stacks

     Rationale:     The major source is a facility engaged in

metallurgical coke production by the destructive distillation of

coal.  Given this information and description of major sources

listed in EPA-450/3-91-030 "Documentation for Developing the

Initial Source Category List", the major source fits the

description of the source category "coke ovens: pushing,

quenching and battery stacks."
                           A  -  3

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                                             PROPOSAL
                                             March 1994
Step 3)  Make a MACT floor Finding
     Techno locry

1)   Use clean water

     to quench coke

     with baffles at the top

     of the quench tower
of plants using   %efficiencv

    10             not

                   quantifiable
2)    Use covered quenched car.

     Cool outside of car.

     Water does not impact

     coke.  Place car on cooling

     rack after quenching for

     additional heat

     dissipation.
                  almost 100%
3)   Wet scrubber, connected

     to fixed duct system

4)   Wet scrubber, mobile unit

     attached to coke quench car

5)   Dry quenching with inert

     gases. Heat transported to

     waste-heat boiler
   10
   14
80-90%
80-90%
                  99-100%
                           A  -  4

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                                             PROPOSAL
                                             March 1994
     The owner or operator has decided to use the control

efficiency ratings to determine the MACT floor.  There are a

total of 36 existing sources.  Because an exact efficiency is not

know for each emission unit in the source category and accurate

MACT floor can not be computed using an arithmetic mean.  The

median will be computed instead.  The MACT floor is equivalent to

the emission reductions achieved by the emission limitation that

can be achieved by the three best performing emission units in

the source category.  This equates to between an 80-90% emission

reductions.  Technologies which meet this criteria are numbers 2,

3, 4, and 5.  A specific numerical emission level can not be

established in this instance because the emission rate will vary

with the purity of the coke.   The MACT floor will be established

based an operational efficiency associated with use of control

technologies 2, 3, 4 or 5.                        •



Step 4 Select a control technology as the MACT

     Technologies 2, 3, 4, or 5 could be chosen as MACT.  Number

I could also be consider because its control efficiency is not

quantifiable.  If the owner wished to consider technology 1,  a

more detailed analysis would be required to prove that the

technology could obtain an equal or greater amount of emission

reductions.  In this case, the efficiency of technology 1 will

vary by the concentration of hazardous constituents.  Using clean

                            A  -  5

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                                             PROPOSAL
                                             March 1994

water could result in a less toxic release when the concentration

of toxins in the hot coke are less, but increased emissions could

result with increased concentrations.  The other proposed

technologies would operate at a relatively constant efficiency

rate, regardless of the pollutant concentration.  Therefore,

technology number 1 would be considered inferior and should be

eliminated as a potential candidate.

     ,The owner or operator should consult with the reviewing

agency to determine whether a costs, non air quality health and

environmental impacts and energy requirements analysis is

required for the available control technologies.  If not, the

owner or operator could select any of these control technologies.

If an analysis is required, the control technology achieving a

maximum degree of reduction in emissions of the HAPs should be

selected based on the costs, non-air quality environmental and

health impacts and energy requirements analysis.  After selecting

the technology the owner or operator would proceed to Tier III of

the analysis.  In Tier III, the appropriate operation conditions

and design specification would be prescribed in addition to the

MACT emission limitation.  .
                            A -  6

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                                             PROPOSAL
                                             March 1994
                            Example 2
                When the MACT floor is Determined
                  using Emission Reduction Ratios
Description of Maior Source

     A surface coating operation proposes to treat a new product

with its existing equipment consisting of a dip-tank priming

stage followed by a two-step spray application and bake-on enamel

finish coat.  Minor changes to the existing equipment that

requires a capital expenditure will be made.  The product is a

specialized electronics component (resistor) with strict

resistance property specifications that restrict the types of

coatings that may be employed.  Because of the type of coating

required, the source will increase HAP emissions above a de

minimis level in all stages of the surface coating operation.

This increase in emissions will not'be offset.  There is no

standard currently in effect for this source category; therefore,

a case-by-case MACT determination is required.  The owner or

operator will begin with Tier I of the analysis.
                           A -  7

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                                             PROPOSAL
                                             March 1994
Step 1) Identify the MACT-affected emission unit(s)

MACT-affected emission units -     1. dip-tank

                                   2. feed and waste lines in

                                   prime coating operation

                                   3. spray coat booth, spray

                                   coat application equipment

                                   4. drying oven

                                   5. storage tank in prime

                                   coating operation

                                   6. storage tank in finish

               s                    coating line

     There are two process units influenced by the modification,

the prime coating line and the finish coating line.  Equipment

within the prime coating line that have affected emission points

are a dip-tank, storage containers, feed line to supply new

coating into the dip-tank, a waste line to drain the dip-tank.

Because the feed line and waste lines have equipment leak

emissions, these emission ppints must be combined to form a MACT-

affected emission unit.  The owner or operator will consider the

dip-tank and each storage container a separate affected emission

unit.  The three MACT-affected emission units in this process

unit are the dip-tank, the storage container, and the feed and

waste lines.

     The finish coating line consists of two spray booths, spray

                            A - 8

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                                             PROPOSAL
                                             March 1994

application equipment, paint supply system, a storage container,

and a drying oven.  The owner or operator combines affected

emission points to form the following MACT-affected emission

units:  the spray application equipment and spray booths; the

paint supply system, the storage container, and the drying oven.

     For simplicity of this example, the MACT analysis will be.

continued for only the spray application equipment and spray

booths.



Step 2 - Determine the Source Category

     Source category -   Miscellaneous metal parts and products

                         (surface coating)


                                                •
Rationale:  The major source is a facility engaged in the surface

coating of an electronic resistor for calculators.  Given this

information and the descriptions of source categories in EPA

450/3-91-030 "Documentation for Developing the Initial Source

Category List", the major source would be included in the

miscellaneous metal parts and products (surface coating).'
                           A -  9

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                                             PROPOSAL
                                           y  March 1994

step 3) Hake a MACT floor finding

     Steps A and B:  Computing the Uncontrolled Emissions and

Controlled Emissions

Overview Analysis of emissions information for similar emission

units within the source category:
     Technolocry               # of sources using

1)   water-based coat              2
2)   low-VOC solvent/high
     solids coat
3)   electrostatic spray
     application to enhance
     transfer efficiency
4)   low voc solvent/high solids   8
     coating with electrostatic
     spray application
5)   powder coat paint with
     electrostatic spray
     application
6)   high-voc solvent coating      8
                            A -  10

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                                             PROPOSAL
                                             March 1994
Detailed analysis
Source
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
Technology
t
6 ' '
3
2
3
3
6
6
3
2
2
6
6
6
3
2
3
4
5
4
3
4
4
Uncontrolled
emissions
(tons/yr)
10
26
48
86
98
26
35
78
69
' 15
11
12
23
85
141
25
159
126
35
25
68
46
Controlled
emissions
(tons/yr)
10
14
22
56
55
22
34
55
25
11
11
12
22
52
89
20
100 '
11'
14
16
22
10
Emission
reduction
ratio
0
.46
.54
.35
.44
.15
.03
.29
.64
.27
0
0
.04
.39
.39
;20
.37
.91
.6
.36
.70
.78
                           A - 11

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                  PROPOSAL
                  March 1994
Source
23
24
25
26
27
28
29
29
Technology
#
1
6
4
4
4
4
6
1
Uncontrolled
emissions •
(tons/yr)
95
96
64
98
168
196
186
255
Controlled
emissions
(tons/yr)
10
16
25
31
45
63
186
26
Emission
Reduction
Ratio
.89
.83
.61
.68
.73
.68
0
.90
A - 12

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                                             PROPOSAL
                                             March 1994
     Step C    Computing the Emission Reduction Ration for the
              -MACT- Affected Emission Unit

     Because there are 30 sources, the MACT floor should be based

on the arithmetic mean of the emission reduction ratios achieved

by the best 12% of existing emission units.  Twelve percent of 30

emission units is equal to 3.5 sources.  The owner or operator

should round up all fractions to the next largest number.  The

MACT floor is equal to the arithmetic mean of the emission

reductions obtained by the best 4 sources in the source category.

Reviewing the data above, the MACT floor equals an emission

reduction ratio of 0.88 ([0.91 + 0.90 + 0.89 + 0.83]/4)  or the

emission-reductions that can be achieved when control

technologies 1 or 5 are used.  In this example, the nature of the
              •
product requires a specific type of coating.  Technology l and 5

are inappropriate for application to this MACT-affected emission

unit.  The owner or operator continues with the analysis to

identify other technologies that can meet a 0.88 emission

reduction ratio.



     Step D    Determine a MACT emission limitation (MEL)

     The owner or operator of the MACT-affected emission unit

needs to calculate an uncontrolled emission rate for the MACT-

affected emission unit.  Because current design specifications

for the existing emission unit cause a larger uncontrolled

emission rate than any other designs used in the past 5 years, •

                           A -  13

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                                             PROPOSAL
                                             March 1994

the current operational designs will be used to determine the

uncontrolled emissions.  With the existing coating material, the

MACT-affected emission unit has an uncontrolled emission level'of

125 tons/yr total HAPs.  The MEL for this emission unit would be


                                                              •

          MEL = 125 tons/yr * (1 - 0.88)

              = 15 tons/yr




Step 4    Select a control technology to meet the MACT Emission

          Limitation.

     In this case, the owner or operator must select a control

technology that allows the source to meet the MACT emission

limitation.  Because the owner and operator can not use any of
      •                                               *
the identified control technologies to meet the MACT floor,

control technologies to control similar emission points will be

considered.  In this example, the similar emission points have

operational losses.  Review of control technologies to control

operational losses identifies add-on control devises such as a

carbon absorber, a thermal or catalytic incinerator, or a

condenser.  The owner or operator should conduct a costs, non-air

quality health and environmental impacts and energy requirements

analysis on the available control technologies.

     The major source already has a catalytic incinerator on

site.  The emissions from the spray application equipment and

spray booth could be channeled to the incinerator.  Thi$ would

                            A -  14

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                                             PROPOSAL
                                             March 1994

require the installation of a venting system including a pump

mechanism.  It would also require an increased volumetric flow

rate to the incinerator and increase auxiliary fuel requirements.

The incinerator had been operating at a 90% efficiency.  With an

increased volumetric flow rate, the efficiency is projected to

drop to 87% efficiency.  The owner and operator must obtain an

additional 1% emission reductions.  Possible control technologies

include increasing the operating temperature of the incinerator,

or adding electrostatic application to the spray process to

enhance transfer efficiency.  Limiting the hours of operation at

the MACT-affected emission unit could be considered if the

reduced production were part of an overall source reduction

program.

     Use of the specialized coating in this operation will

increase the concentration of hazardous pollutants in the water

used for the water curtain.  The proposed control technology does

not affect the concentration of pollutants in the wastewater.

This could be considered a negative environmental impact and may

be reason to consider another control technology to meet the MACT

emission limitation.   In this instance,  the owner or operator

will not violate the NPDES permit, so the MACT candidate will not

be eliminated from consideration.

     The owner or operator uses this step to demonstrate that

despite the increase in volumetric flow rate and the auxiliary

fuel requirement, a significant increase in criteria pollutant

                            A -  15

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                                             PROPOSAL
                                             March 1994

emissions does not occur.  The owner or operator concludes that

the impacts associated with use of this technology are

reasonable.

     After reviewing the technologies the owner or operator

selects the incinerator with a limit on the hours of operation.

The owner or operator proposes to start a training program for
                                     *
spray booth operators to decrease the error and product rejection

rate.  By doing this, the owner or operator can reduce the hours

of operation and still meet customer demands for the product.

This option was chosen over the other two because increasing the

incinerator's operating temperature would require additional

auxiliary fuel input, and enhancing the transfer efficiency with

electrostatic application would be cost prohibitive.  The owner

or operator would document that use of the selected control

technologies can reduce emissions to the required level.

     The owner or operator would move to Tier III of the analysis

and document the MACT emission limitation, and suggest

appropriate conditions to assure that this MACT emission

limitation is federally enforceable.
                            A  -  16

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                                             PROPOSAL
                                             March 1994

                            Example 3

           When the MACT floor is Equal to "No Control"

Description of Maior Source;

     A pesticide manufacture historically sent its waste to an

off-site commercial treatment, storage and disposal facility

(TSDF).   The TSDF is no longer accepting wastes.   The

manufacturer has decided to treat its own waste on-site.  The

solvent/aqueous/pesticide mixed waste will be passed through a

distillation column where the organic solvents will be vaporized

and then condensed into a distillate receiver.   The solvent will

be transferred using tank cars to a tank farm that will be

located at another portion of the plant.  It will be stored there

for later use.  The pesticide-laden wastewater will be sent from

the distillation column to a carbon adsorber where the pesticide

will be removed from the wastewater.  The wastewater will be

recycled to the manufacturing process.   The adsorber will be

periodically steam stripped to regenerated the carbon.  The major

source will increase emission by greater than a de minimis amount

for a HAP.  The modification will require a MACT determination.
                           A - 17

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                                             PROPOSAL

                                             March 1994
                              Tier I


Step 1) Identify the MACT-affected emission unit(s)


MACT-affected emission units:      1) each storage tank


                                   2) the distillation column,


                                   condenser, and distillate

           ^
                                   receiver


                                   3) the three carbon absorbers


                                   4) pumps, feed lines and


                                   transfer lines


                                   5) loading racks





     The two process units that contain emission points affected


by this modification are the recycling process, and the tank


farm.  The equipment and apparatus associated with the affected


emission points are pumps, feed lines, a distillation column, a


condenser, a distillate receiving tank, three carbon absorbers


and transfer lines, a loading rack, and storage tanks.  The owner


or operator will consider the three carbon absorbers and the


associated emission points as one emission unit because a single


control technology could be practically designed to cover all


three affected emission points.  The owner or operator will also


group the distillation column, distillate receiver and condenser


into one MACT-affected emission unit.  The feed lines, pumps, and


transfer lines would have equipment leak emission losses and
                          *

                           A - 18

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                                             PROPOSAL
                                             March 1994

would be another affected emission unit.  The owner and operator

has decided to consider the emission points and equipment for the

loading rack and tanks as separate MACT-affected emission units.

If all the tanks were structurally similar in design, one

determination could be made that would be applicable to all the

tanks.
   %


Step 2) Identify the source category for the major source and the

MACT-affected emission unit



     Source category:    2,4-D salt and esters production



     The pesticide manufacture produces the pesticide 2,4,-D.  .

There is a specific source category for 2,4,-D salt and esters

production.  The pesticide manufacture fits the description of

this source category.



Step 3)  Hake a MACT floor finding

     For simplicity, this example MACT analysis will only be

continued for a tank emission unit.  All the storage tanks will

be structurally similar, so only one MACT determination will be

required.  The manufacturer has reviewed existing data bases and

determined that less than 12% of tanks in the source category are

controlled.  Therefore the MACT floor is equal to "no control".

This is not automatically an acceptable "control" measure, so the

                            A -  19

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                                             PROPOSAL
                                             March 1994

owner or operator will move to Tier II of the MACT analysis.  In

Tier II of the analysis control technologies for similar emission

points from outside the source category will also be considered.
                           A - 20

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                                             PROPOSAL
                                             March 1994

owner or operator will move to Tier II of the MACT analysis.  In

Tier II of the analysis control technologies for similar emission

points from outside the source category will also be considered.
                           A - 20

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                                             PROPOSAL
                                             March 1994

                             Tier II

Step 1)   List All Available Control Technologies

     The following technologies have been identified as possible

control technologies that can be applied to a storage tank to

control working and breathing emission losses:

                                                Emission control
                                                  efficiency
                                                   *

     1.  fixed-roof                                    86-99
     2.  fixed-roof plus internal floating roof        97-99
     3.  fixed roof vented to a carbon canister        95-100
     4.  fixed-roof vented to a combustion devise      99-100
     5.  fixed-roof vented to carbon absorber          99-100
     6.  pressure tank                                 95-100


Step 2)  Eliminate Technically Infeasible Control Technologies


     All of the available control technologies are technically

feasible.



Step 3)  Conduct a Non-air Quality Health, Environmental,

Economic and Energy Impacts Analysis

The following series.of tables illustrate a non-air quality

health, environmental, cost and energy impacts analysis for each

control option.

     Table 1 presents information describing the various control

technologies that are technically feasible.  Secondary air

impacts as well as energy impacts and other resource demands.
                           A - "21

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                                             PROPOSAL
                                             March 1994
Table l
 Control Option
Secondary Air

Impacts
Resource Demands
 1 fixed roof
none
none
 2 fixed roof +

   internal roof
none
none
 3 pressure tank
none
none
 4 cover and

   vented to

   carbon canister
emission if

carbon regenerated
disposal of

container, solvents

for regeneration
 5 cover and vent

   to combustion

   devise
increased CO, NOx,

SOx, and

particulate

emissions
fuel source,

disposal of ash
 6 cover and vent to

  carbon absorber
emissions when

carbon regenerated
disposal of spent

carbon, solvents

for regeneration
                           A - 22

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                                             PROPOSAL
      -                                     March 1994

     Table 2 presents the control options along with- their costs

and emission reductions.  The average cost effectiveness of each-

control option is also presented.  The average cost effectiveness

is the ratio of the total annual cost to the total amount of HAP

removed.  Note that the control options are presented in terms of

increasing annual cost (i.e., control option 1 has the smallest

annual cost, control option 2 has the second smallest annual

cost, etc.)

     Using Table 2, several control options can be eliminated

from further consideration.  Control option 3 should be

eliminated because control option 2 achieves the same amount of

HAP reductions but at a lower cost.  Control option 2 should be

eliminated because control option 4 achieves a greater degree of

emission reduction for lower cost.  The elimination of control

options 2 and 3 reduces the number of technically feasible and

economically efficient options to four control technologies.

     Table 3 presents the incremental cost effectiveness of the

remaining options.  The incremental cost effectiveness of control

option 1 is the same as its average cost effectiveness since

control option 1 is the first incremental option from the

baseline.  The incremental cost effectiveness of control option 4

is the ratio of the difference in cost between options I and 4 to

the difference in HAP emission reductions between the two ratios.
                           A - 23

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Table 2
                                             PROPOSAL
                                             March 1994
CONTROL
OPTION
1
2
3
4
5
6
CONTROL
EFFICIENCY
93
96
96
98
99
100
ANNUAL COST
($)
85,000
113,000
232,000
110,000
136,000
189,000
EMISSION
REDUCTION
(Mg/Yr)
72
88
88
92
103
117
AVERAGE
COST-
EFFECTIVENESS
<$/Mg)
1,161
1,264
2,636
1,156
1,320
1,615
Table 3
CONTROL
OPTION
1
4
5
6
ANNUAL COST
($)
85,000
110,000
136,000
189,000
EMISSION
REDUCTION
(Mg/Yr)
72"'
92
103
117
AVERAGE
COST-
EFFECTIVENESS
($/Mg)
1,161
1,156
1,320
1,615
INCREMENTAL
COST
EFFECTIVE-
NESS ($/Mg)

1,250
2,364
3,766
                           A - 24

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                                             PROPOSAL
                                             March 1994

Step 4)  Identify MACT

     Examination of the cost effectiveness of the' various control

options can lead to the elimination of some control options.

Control option 6 is eliminated because the incremental cost is

deemed too high.  The incremental cost of control option 5 is

deemed acceptable but upon closer examination, the secondary air

and energy impacts make this option undesirable.  The incremental

cost of both options 1 and 4 are deemed acceptable; however,

control option 1 is eliminated because other considerations

(secondary air impacts, etc) do not preclude the selection of

control option 4 which achieves a greater degree of emission

reductions.

     The owner or operator should progress to Tier III.
                           A - 25

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                                             PROPOSAL
                                             March 1994
                            Appendix B
                  Forum of  Anticipated Questions



1.   When computing the number of sources in^the "best 12% of

similar sources in the source category" should the number of

sources be rounded to the nearest or next largest whole number?

For example if there are forty-five similar sources in the source

category would the "best 12%" include 5 or 6 sources.



     The number should be rounded to the next largest number.  In

     the example the "best 12%" would include 6 sources.



2.   How many decimal points should be in the emission reduction

ratio, and the manufacturer's efficiency rating?



     The emission reduction ratio should be carried to two

     decimal places.  The efficiency rating should be rounded to

     the nearest whole number.



3.   Should the emission limitation(s) be based on overall HAP

emissions or emissions of an individual HAP?

     The emission limitation may be based on overall HAP

     emissions or a specific emission limitation may be specified

     for an individual HAP.   A specific emission limitation may

                           B  -   l

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                                             PROPOSAL
                                             March 1994

     be established if health risks warrant placing an individual

     emission limitation, or if an individual emission limitation

     is needed to make the overall HAP emission limitation

     federally enforceable.

                                    •

4.   If a major source increase emissions above a de minimis

amount due to a modification what emission points are subject to

the MACT determination:  all emission points contributing to an

above de minimis increase, emission points whose increases can be

summed above de minimis, or the "straw that backs the de minimis

level".

Example:   Assume de minimis is 9 tpy.

               Increase in emissions tpy



Emission point 1         3

Emission point 24                        .

Emission point 3         6

Do all the sources require a MACT determination, because all

increase in emissions.  Or, do Emission points 2 and 3 require a

MACT determination because the sum of the emissions from these

points exceed de minimis, or just Emission point 3 because it

causes de minimis to be exceed?



     All thrtfe emission points would require a MACT determination

     because the sum total of emission increases exceeds a de

                           B  -   2

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                                             PROPOSAL
                                             March 1994
     minimis amount.
5.   If a non-major source undergoes a construction,

reconstruction or modification and increases emissions above  a

de minimis amount, and reclassifies the source as a major source

based on its potential to emit is a case-by-case MACT

determination required?  If so, is existing source or new source

MACT required?

     The source would be reclassified as a major source and will

     be required to file for a Part 70 or Part 71 permit, but it

     would not be subject to any determination under Section

     112(g) until it reconstructs, constructs, or modifies again.
6.   Is there an official form to apply for a MACT determination?



     No.  The application for a MACT determination is required to

     contain certain information, but there is no official form

     required by the Federal government.  However, reviewing

     agencies may develop there own official form.



7.   Is the MACT emission limitation always based on add-on

control devises?



     No.  The MACT emission limitation should be based on the

                          B  -   3

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                                             PROPOSAL
                                             March 1994

     best control technologies which can include add-on controls,

     work practices, pollution prevention methods, etc.

                                                  ^

8.  A major source modification results in an above de minimis

increase in emissions of a HAP.  The owner or operator can offset

emission from some of the emission points that contribute to the

above de minimis increase, but not all of the emission points.

Is a MACT determination required for those emission points that

could be offset?

     An above de minimis increase in HAP emissions must be

     completely offset, or all emission points contributing to

     the increase require a MACT determination.  In this

     instance, a MACT determination would be required.



9.  A major source has agreed to participate in the early

reductions program.  Through this program, an owner or operator

of a major source can obtain a compliance extension for a future

MACT standard, if a 90% reduction in emissions is achieved before

promulgation of that relevant emission standard.  If the major

source proposes to modify is a MACT determination required.

     A MACT determination is not required for major source

     participating in the early reductions program,  if the source

     continues to meet the early reductions committment.  If the

     source is no longer able to meet the 90% reductions, a MACT

     determination would be required.
        *

                           B  -  4

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                      ,                       PROPOSAL
                                             March 1994

10.  In the course of conducting a MACT analysis, the owner or

operator discovers that the MACT floor is equal to 97% control.

Could the owner or operator enter the early reductions program

and only obtain 90% control?

          •

     If a relevant emission standard has not yet been proposed,

     the owner or operator could join the early reductions

     program and avoid a MACT determination.  The owner or

     operator would be required to participate in this program

     before beginning any construction,  reconstruction,  or

     modification.
                          B -

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                                             PROPOSAL
                                             March 1994

                            Appendix C

                           DEFINITIONS

Act - the Clean Air Act as amended in 1990  (42 U.S.C. 7401 et
seg., as amended by Pub. L. 101-104 Stat. 2399).

Administrator - the United States Environmental Protection Agency
or his or her authorized representative  (e.g a State that has
been delegated the authority to implement the provisions of this
part.)

Affected emission point - an emission point identified as being
part of a modification, construction or reconstruction and
requiring a MACT determination.

Alternative test method - any method of sampling and analyzing
for an air pollutant that is not a test method in 40 CFR Part 63
and that has been demonstrated to the Administrator's
satisfaction, using Method 301 in Appendix A of Part 63, to
produce results adequate for the Administrator's determination
that it may be used in place of a test method specified in that
part.

Approved permit program - a State permit program approved by the
Administrator as meeting the requirements of 40 CFR Part 70, or a
federal permit program established under 40 CFR Part 71.


Controlled emissions - the sum of all hazardous air emissions
from all emission points given the maximum design capacity
currently in use by the emission unit taking 'into consideration
the application of all existing control technologies and
federally enforceable limits.

Control technology - measures, processes method," systems, and
techniques to limit the emission of hazardous air pollutants
including, but not limited to, measures which

     (1) reduce the volume of, or eliminate emissions of, such
     pollutants through process changes, substitution or
     materials or other modifications,

     (2) enclose systems or processes to eliminate emissions,

     (3) collect, capture or treat such pollutants when released
     from a process, stack, storage or fugitive emissions point,

     (4) are design, equipment work practice, operational

                           B -  1

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                                             PROPOSAL
                                            „ March 1994

                            Appendix C

                           DEFINITIONS

Act - the Clean Air Act as amended in 1990  (42 U.S.C. 7401 et
seq., as amended by Pub. L. 101-104 Stat. 2399).

Administrator - the United States Environmental Protection Agency
or his or her authorized representative  (e.g a State that has
been delegated the authority to implement the provisions of this
part.)

Affected emission point - an emission point identified as being
part of a modification, construction or reconstruction and
requiring a MACT determination.

Alternative test method - any method of sampling and analyzing
for an air pollutant that is not a test method in 40 CFR Part 63
and that has been demonstrated to the Administrator's
satisfaction, using Method 301 in Appendix A of Part 63, to
produce results adequate for the Administrator's determination
that it may be used in place of a test method specified in that
part.

Approved permit program - a State permit program approved by the
Administrator as meeting the requirements of 40 CFR Part 70, or a
federal permit program established under 40 CFR Part 71.


Controlled emissions - the sum of all hazardous air emissions
from all emission points given the maximum design capacity
currently in use by the emission unit taking into consideration
the application of all existing control technologies and
federally enforceable limits.

Control technology - measures, processes method, systems, and
techniques to limit the emission of hazardous air pollutants
including, but not limited to, measures which

     (1) reduce the volume of, or eliminate emissions of, such
     pollutants through process changes, substitution or
     materials or other modifications,

     (2) enclose systems or processes to eliminate emissions,

     (3) collect, capture or treat such-pollutants when released
     from a'process," stack, storage or fugitive emissions point,

     (4) are design, equipment work practice,  operational

                           C. -  1

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                                             PROPOSAL
                                             March 1994

     standards (including requirements for operator training or
     certification) as provided in subsection (h), or

     (5) are a combination of above.


Commenced - with respect to construction, reconstruction or
modification of a stationary source, that an owner or operator
has undertaken a continuous program of construction,
reconstruction or modification or that an owner or operator has
entered into a contractual obligation to undertake and complete,
within a reasonable time, a continuous program of construction,
reconstruction, or modification.

Compliance date - the date a MACT-affected emission unit is
required to be operating and meeting all the. requirements of the
Notice of MACT Approval.  For new sources this date is upon
start-up.  For existing sources this date should be as soon as
practicable, but no later than 3 years from the effective date,
or as otherwise specified by a relevant emission standard.

Compliance Plan - the action and schedule necessary to bring a
MACT-affected emission unit into compliance with the Notice of
MACT Approval.

Construct - to fabricate (on site), erect, or install a
stationary source which is or may be subject to a standard,
limitation, prohibition, or other federally enforceable
requirement established by the Administrator (or a State within
approved permit program) pursuant to Section 112 of the Act.

Construction of a major source - fabrication,  erection, or
installation of a major source that emits 10 tpy of a single HAP
or 25 tpy of any combination of HAPs.

Continuous emission monitoring system (GEMS) - the total
equipment, meeting the data acquisition and availability •
requirements of this part, used to sample, condition (if
applicable), analyze, and provide a permanent record of
emissions.

Continuous monitoring system (CMS) - a continuous emission
monitoring system or a continuous parameter monitoring system.

Controlled emission level (GEL) - the maximum amount of HAP that
could be emitted from the unit-under current design specification
and at full capacity utilization taking into consideration the
application of federally enforceable controls.
                           C -

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                                             PROPOSAL
                                             March 1994

De minimis - An amount of increased HAP emissions, below which an
owner or operator of a modified major source does not have to
obtain offsets or undergo a MACT determination before increasing
emissions.

Effective date - the date a Notice of MACT Approval is signed and
issued by a permitting agency, or the date specified in a
promulgated emission standard.

Emission Unit - one emission point or the collection of emission
points within a major source requiring a MACT determination.
An emission unit can be defined (by the permitting authority) as
any of the following:
          (1)  An emitting point that can be individually
controlled, e.g. a boiler, a spray booth, etc.
          (2)  The smallest grouping of emission points, that,
when collected together, can be commonly controlled by a single
control device or work practice.
          (3)  A grouping of emission points, that, when
collected together, can be commonly controlled by a single
control device or work practice.
          (4)  A grouping of emission points that are
functionally related. Equipment is functionally related if the
operation or action for which the equipment was specifically
designed could not occur without being connected with or relying
on the operation of another piece of equipment.
          (5)  A grouping of emission points that, when collected
together, comprise a building, structure, facility, or
installation.

Existing Source - a source that is not constructed or
reconstructed.

Federally enforceable -  all limitations and conditions which are
enforceable by the Administrator,  including those requirements
established by State or Local agencies who have received
delegation to impose such limitations through an approved Part 70
permit program or through Section 112(1) of the Act.
Requirements developed pursuant to Part 60 and Part 61 of this
chapter and requirements within any applicable State
Implementation Plan are also considered federally enforceable.
To be federally enforceable, the limits and conditions must
undergo public review and be reported to the EPA.  Emission
limits that are considered federally enforceable include limits
on the allowable capacity of the equipment; requirements for the
installation, operation and maintenance of pollution control
technologies; limits on hours of operation; and restrictions on
amounts of materials combusted, stored or produced.  To be
federally enforceable, restrictions on operation, production or

                          C -   3

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                                             PROPOSAL
                                             March 1994

emissions must reflect the shortest practicable time period  (in
no event for a period in excess of 30 days.)  General limitations
such as yearly limits (e.g. tons per year) are not considered
federally enforceable.  The use of hourly, daily, weekly, or
monthly rolling averages are acceptable.  Any federally
enforceable limitations or conditions must be practically
enforceable and ensure adequate testing, monitoring, and
recordkeeping to demonstrate compliance with the limitations and
conditions.
Fugitive emissions - emissions from a stationary source that
could not reasonably pass through a stack, chimney , vent or
other functionally equivalent opening:

Hazardous Air Pollutant (HAP) - any air pollutant listed in
Subpart C of 40 CFR Part 63 pursuant to Section 112(b) of the
Act.  When there is a discrepancy between the hazardous air
pollutant list in Section 112(b) and the list in Subpart C, the
list in Subpart C shall supersede the list in Section 112(b).

Installation schedule - an enforceable schedule of actions or
operations leading to compliance with a MACT emission limitation.

Maximum achievable control technology (MACT) - a control
technology that achieves a maximum degree of reduction in
emissions of the hazardous air pollutants with consideration to
the costs of achieving such emission reductions, and the non air
quality health and environmental impacts and energy requirements.

MACT-affee-ted emission unit - an emission unit or source
requiring a MACT determination.

MACT analysis - the process an owner/operator conducts to define
the MACT floor, recommend a MACT emission limitation, and select
the MACT.

MACT determination - a process conducted by the Administrator to
evaluate a major source's ability to comply with the requirements
of 40 CFR Part 63, Subpart B.


MACT emission limitation (MEL)  - the maximum achievable control
technology emission limitation for the hazardous air pollutants
listed under Section 112(b) of the Act that the Administrator
(or a State with an approved permit program) determines through a
promulgated emission standard or on a case-by-case basis to be
the maximum degree of reduction in emissions of the HAPs with

                           C -   4

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                                             PROPOSAL
                                             March 1994

consideration to the costs of achieving such emission reductions
and the non air quality health and environmental impacts and
energy requirements.
     If the Administrator or reviewing agency determines that it
is inappropriate to prescribe a numerical or efficiency based
MACT emission limitation a specific design, equipment/ work
practice, operational standard, or combination thereof, may be
prescribed instead.  Such standard shall, to the degree possible,
set forth the emissions reduction achievable by implementation of
such design, equipment, work practice, or operation, and shall
provide for compliance by means which achieve equivalent results.


MACT floor - for new sources or constructed or reconstructed
major sources: a level of hazardous air pollutant emission
control that is achieved in practice by the best controlled
similar source as determined by the Administrator.

     For a existing sources or a modification to a major source
the MACT floor is:
     (a)  the average emission limitation achieved by the best
          performing 12 percent of existing sources (for which
          the Administrator has emission information), excluding
          those sources that have, within 18 months before the
          emission standard is proposed or within 30 months
          before such standard is promulgated, whichever is
          later, first achieved a level of emission rate or
          emission reductions which compiles, or would comply if
          the source is not subject to such standard,  with the
          lowest achievable emission rate (as defined by Section
          171 of the Act) applicable to the source category and
          prevailing at the time, in the category or. subcategory
          for categories and subcategories with 30 or more
          sources; or,
     (b)  The average emission limitation achieved by the best
          performing 5 existing sources for sources with less
          than 30 sources in the category or subcategory.
Major source - any stationary source or group of stationary
sources located within a contiguous area and under common control
that emits or has the potential to emit considering controls, in.
the aggregate, 10 tons per year o~r more of any hazardous air
pollutant or 25 tons per year or more of any combination of
hazardous air pollutants^ unless the Administrator establishes a
lesser quantity as codified in Subpart C of 40 CFR Part 63, or in
the case of radionuclides, different criteria from those
specified in this sentence.
                                          A

                           C  -   5

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                                             PROPOSAL
                                             March 1994
Notice of MACT Approval (NOMA) - a document issued by a reviewing
agency containing all federally enforceable conditions necessary
to enforce the application of, and operation of MACT such that
the MACT emission limitation is met.

Owner or operator - any person who owns, leases, operates,
controls, or supervises a stationary source.


Part 70 permit - any permit issued, renewed, or revised pursuant
to 40 CFR Part 70.

Part 71 permit  - any permit issued ,  renewed, or revised
pursuant to Part 71 of this chapter.

Permit program - a comprehensive State or Federal operating
permit system established pursuant to regulations codified in 40
CFR Part 70 or Part 71.

Permit revision - any permit modification or administrative
permit amendment to a Part 70 or Part 71 permit as defined in
those parts.

Permitting agency -

     (1) The State air pollution control agency, including local
agencies or Indian tribes, authorized by the Administrator to
carry out a permit program under 40 CFR Part 70.

     (2) The Administrator, in the case of EPA-implemented permit
programs under 40 CFR Part 71.


Potential to emit - the maximum capacity of a stationary source
to emit a pollutant under its physical and operational design.
Any physical or operational limitation of the capacity of the
stationary source to emit a pollutant, including air pollution
control equipment and restrictions on hour of operation or on the
type or amount of material combusted,  stored, or processed, shall
be treated as part of its design if the limitation or the effect
it would have on emissions is federally enforceable.

Project - all activities associated with construction,
reconstruction, or modification of a source including design,
fabrication, erection, installation and start-up.

Reconstruction - the replacement of components of an existing

                           C  -   6

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                                             PROPOSAL
                   .                          March 1994

major source to such an extent that (1) the fixed capital cost of
the new components exceeds 50 percent of the fixed capital cost
that would be required to construct a comparable entirely new
source, and (2) it is technologically and economically feasible
for the reconstructed source to meet the Section 112(d) emission
standard(s), alternative emission limitation(s), or equivalent
emission limitation(s) established by the Administrator ( or a
State with an approved permit program) pursuant to Section 112 of
Act.  Upon reconstruction, an affected source is subject to
Section 112(d) standards for new sources, including compliance
dates, irrespective of any change in emissions of hazardous air
pollutants from that source.

Relevant standard - (1) an emission standard, (2) an alternative
emission standard, (3) an alternative emission limitation, (4) an
equivalent emission limitation that applies to a stationary
source regulated by such standard or limitation.  A relevant
standard may include or consist of.a design, equipment work
practice, or operational requirements or other measures, process,
method, system or technique (including prohibition of emissions)
that the Administrator (or a State with an approved permit
program) determines is achievable for a constructed or
reconstructed major source, new or existing source to which such
standard or limitation applies.  Every relevant standard
established pursuant to Section 112 of the Act includes Subpart A
of this part and all applicable appendices of Parts 51, 60, 61,
and 63 of Chapter 40 of the code of federal regulations that are
reference in that standard.

Similar emission unit - two or more sources or emission units
that have similar emission types and can be controlled using the
same type of control technology.

Similar emission type - See Section 2.4 of Chapter 2.

Source - an emission unit, or as otherwise specified in an
applicable 40 CFR Part 63 emission standard.

Start-up - beginning operation of a source or emission unit.

State - all non-federal permitting authorities, including local
agencies, interstate associations, and State-wide programs, that
have delegated authority to implement  (1) the provisions of 40
CFR Part 63; and/or (2) the permit program established under Part
70 of this chapter.  State shall have its conventional meaning
where clear from the context.

Stationary source - any building, structure, facility or
installation that emits or may^emit any air pollutant.  For the

                           C -   7

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                                             PROPOSAL
                                             March 1994

purposes of 40 CFR Part 63, stationary sources are listed in
categories pursuant to Section 112(c) of the ACT and published in
the Federal Register. (See Appendix D)
                                          f*

Uncontrolled emissions (UCEL) - the maximum amount of HAP that
could be emitted from the unit under current design
specifications and at full capacity utilization.  For existing
sources, design specifications used within the past five years
may be used, if a pollution prevention method was enacted at the
source within the period of time (See Section 3.2).
                          C -

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                            Appendix D
           Initial List of Categories of Major and Area
               Sources of Hazardous Air Pollutants
Fuel Combustion

Category Name
     Engine Test Facilities .
     Industrial Boilersb
     Institutional/Commercial Boilers6
     Process Heaters
     Stationary Internal Combustion Engines6
     Stationary Turbines6

Non-Ferrous Metals Processing

Category Name
     Primary Aluminum Production
     Secondary Aluminum Production
     Primary Cooper Smelting
     Primary Lead Smelting
     Secondary Lead Smelting
     Lead Acid Battery Manufacturing
     Primary Magnesium Refining

Ferrous Metals Processing

Category Name
     Coke By-Product Plants
     Coke Ovens:  Charging, Top Side, and Door Leaks
     Coke Ovens:  Pushing, Quencing, and Battery Stacks
     Ferroalloys Production
     Integrated Iron and Steel Manufacturing
     Non-Stainless Steel Manufacturing - Electric Arc
       Furnace  (EAF) Operation
     Stainless Steel Manufacturing-Electric Arc
       Furnace  (EAF) Operation
     Iron Foundries
     Steel Foundries
     Steel Pickling-HCI Process

Mineral Products Processing

Category Name
     Alumina Processing
     Asphalt/Coal Tar Application-Metal Pipes
     Asphalt Concrete Manufacturing
     Asphalt Processing
                               D-l

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                           Appendix  D

     Asphalt Roofing Manufacturing
     Chromium Refractories Production
     Clay Products Manufacturing
     Lime Manufacturing
     Mineral Wood Production
     Portland Cement Manufacturing
     Taconite Iron Ore Processing
     Wool Fiberglass Manufacturing

Petroleum and Natural Gas Production and Refining

Category Name
     Oil and Natural Gas Production
     Petroleum Refineries-Catalytic Cracking
       (Fluid and other) Units, Catalytic
       Reforming Units, and Sulfur Plant Units
     Petroleum Refineries-Other Sources
       Not Distinctly Listed
 •
Liquids Distribution

Category Name
     Gasoline Distribution (Stage 1)
     Organic Liquids Distribution (Non-Gasoline)

Surface Coating Processes
                                 «
Category Name
     Aerospace Industries
     Auto and Light Duty TrucJ: (Surface Coating)
     Flat Woods Paneling (Surface Coating)
     Large Appliances  (Surface Coating)
     Magnetic Tapes (Surface Coating)
     Manufacture of Paints Coatings,  and Adhesives
     Metal Can (Surface Coating)
     Metal Coil (Surface Coating)
     Metal Furniture (Surface Coating)
     Miscellaneous Metal Parts and Products
       (Surface Coating)
     Paper and Other Webs (Surface Coating)
     Plastic Parts and Products  (Surface Coating)
     Printing Coating,  and Dyeing of Fabrics
     Printing/Publishing (Surface Coating)
     Shipbuilding and Ship Repair (Surface Coating)
     Wood Furniture (Surface Coating)
                               D-2

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                            Appendix D

Waste Treatment and Disposal

Category Name
     Hazardous Waste Incineration
     Municipal Landfills
    . Sewage Sludge Incineration
     Site Remediation
     Solid Waste Treatment, Storage and
       Disposal Facilities  (TSDF)
     Publicly Owned Treatment Works  (POTW) Emissions

Agricultural Chemicals Production

Category Name
     2.4-D Salts and Esters Production
     4-Chloro-2-Methylphenoxyacetic Acid Production
     4.6-Dinitro-o-Cresol Production
     Captafol Production
     Captan Production
     Chloroneb Production
     Chlorothalonil Production
     Dacthal (tm) Production
     Sodium Pentachlorophenate Production
     Tordon (tm) Acid Production

Fibers Production Processes

Category Name
     Acrylic Fibers/Modacrylic Fibers Production
     Rayon Production
     Spandex Production

Food and Agricultural Processes

Category Name
     Baker's Yeast Manufacturing
     Cellulose Food Casing Manufacturing
     Vegetable Oil Production

Pharmaceutical Production Processes

Category Name
     Pharmaceutical Production

Polymers and Resins Production

Category Name
     Acetal Resins Production
     Acrylonitrile-Butadiene-Styrene Production
     Alkyd Resins Production

                               D-3

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                           Appendix D

     Aminb Resins Production
     Boat Manufacturing
     Butadiene-Furfural Cotrimer (R-ll)
     Butyl Rubber Production
     Carboxymethylcellulose Production
     Cellophane Production
     Cellulose Ethers Production
     Epichlorohydrin Elastomers Production
     Epoxy Resins Production
     Ethylene-Propylene Elastomers Production
     Flexible Polyurethane Foam Production
     Hypalon (tm) Production
     Maleic Anhydride Copolymers Production
     Methylcellulose Production
     Methylcellulose Production
     Methyl Methacrylate-Aerylonitrile-Butadiene-
       Styrene Production
     Methyl Methacrylate-Butadiene-Styrene Terpolymers
       Production
     Neoprene Production
     Nitrile Butadiene Rubber Production
     Non-Nylon Polyamides Production
     Nylon 6 Production
     Phenolic Resins Production
     Polybutadiene Rubber Production
     Polycarbonates Production
     Polyester Resins Production
     Polyethylene Teraphthalate Production
     Polymerized Vinylidene Chloride Production
     Polymethyl Methacrylate Resins Production
     Polystyrene Production
     Polysulfide Rubber Production
     Polyvinyl Acetate Emulsions Production
     Polyvinyl Alcohol Production
     Polyvinyl Butyral Production
     Polyvinyl Chloride and Copolymers Production
     Reinforced Plastic Composites Production
     Styrene-Acrylonitrile Production
     Styrene-Butadiene Rubber and Latex Production

Production of Inorganic Chemicals

Category Name
     Ammonium Sulfate Production-Captrolactam
       By-Product Plants
     .Antimony Oxides Manufacturing
     Chlorine Production
     Chromium Chemicals Manufacturing
     Cyanuric Chloride Production
     Fume Silica Production

                               D-4

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                            Appendix D

     Hydrochloric Acid Production
     Hydrogen Cyanide Production
     Hydrogen Fluoride Production
     Phosphate Fertilizers Production
     Phosphoric Acid Manufacturing
     Quaternary 'Ammonium Compounds Production
     Sodium Cyanide Production
     Uranium Hexafluoride Production

Production of Organic Chemicals

Category Name
     Synthetic Organic Chemical Manufacturing

Miscellaneous Processes

Category Name
     Aerosol Can-Filling Facilities
     Benzyltrimethylammonium Chloride Production
     Butadiene Dimers Production
     Carbonyl Sulfide Production
     Chelating Agents Production
     Chlorinated Paraffins Production
     Chromic Acid Anodizing
     Commercial Dry Cleaning (Perchloroethylene)
       Transfer Machines
     Commercial Sterilization Facilities
     Decorative Chromium Electroplating
     Dodencanedioic Acid Production
     Dry Cleaning (Petroleum Solvent)
     Ethylidene Norbornene Production-
     Explosives Production
     Halogenated Solvent Cleaners
     Hard Chromium Electroplating
     Hydrazine Production
     Industrial Dry Cleaning (Perchloroethylene)
       Transfer Machines
     Industrial Dry Cleaning (Perchloroethylene)
       Dry-to-Dry Machines
     Industrial Process Cooling Towers
     OBPA/1,3-Diisocyanate Production
     Paint Stripper Users
     Photographic Chemicals Production
     Phthalate Plasticizers Production
     Plywood/Particle Board Manufacturing
                               D-5

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                      Appendix  0

Polyether Polyols Production
Pulp and Paper Production
Rocket Engine Test Firing
Rubber Chemicals Manufacturing
Semiconductor Manufacturing
Symmetrical Tetrachloropyridine Production
Tire Production
Wood Treatment
                          D-6

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