450385025b
United States      Office of Air Quality        EPA-450/3-88-025&
Environmental Protection Planning and Standards      December 1991
Agency	Hesearcn Triangle Park NC 27711	
Air          ~":
Calciners and
Dryers in Mineral
industries -
Background
Information for
Promulgated
Standards
Final
EIS

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                           EPA-450/3-85-025b
    Calciners and Dryers
   in Mineral Industries -
  Background Information
for Promulgated Standards
       Emission Standards Division
      U.S. ENVIRONMENTAL PROTECTION AGENCY
           Offlc* of Mr and Radiation
       Offlea of Air Quality Planning and Standards
      Rooaarcn Triangle Park. North Carolina 27711
              Oacambar 1991

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This report has been reviewed by the Emission Standards Division of the Office
of Air Quality Planning and Standards, EPA, and approved for publication.
Mention of trade names or commercial products is not intended to constitute
endorsement or recommendation for use.  Copies of this report are available
through the Library Services Office (MD-35), U. S. Environmental Protection
Agency, Research Triangle Park, NC 27711, or from National  Technical
Information Services, 5285 Port Royal  Road, Springfield, VA 22161.

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                        ENVIRONMENTAL  PROTECTION AGENCY

                       Background Information and Final
                        Environmental  Impact Statement
                for Calciners and Dryers in Mineral Industries

                                 Prepared by:
       ".  Jordan                                     ' Date
Director,  Emission Standards Division
U. S. Environmental Protection Agency
Research  Triangle Park, NC  27711

1.    The standards of performance would limit emissions of particulate matter
      from calciners and dryers in mineral industries.  Section 111 of the
      Clean Air Act (42 U.S.C. 7411), as amended, directs the Administrator to
      establish standards of performance for any category of new stationary
      source of air pollution that "... causes or contributes significantly
      to  air pollution which may reasonably be anticipated to endanger public
      health or welfare."

2.    Copies of this document have been sent to the following Federal
      Departments:  Labor, Health and Human Services, Defense, Office of
      Management and Budget, Transportation, Agriculture, Commerce, Interior,
      and Energy; the National Science Foundation; and the Council on
      Environmental Quality.  Copies have also been sent to members of the
      State and Territorial Air Pollution Program Administrators; the
      Association of Local Air Pollution Control Officials; EPA Regional
      Administrators; and other interested parties.

3.    For additional information contact:

      Ms.  Linda Herring
      Standards Development Branch (MD-13)
      U.  S. Environmental Protection Agency
      Research Triangle Park, NC  27711
      Telephone:  (919) 541-5358

4.    Copies of this document may be obtained from:

      U.  S. EPA Library (MD-35)
      Research Triangle Park, NC  27711
      Telephone:  (919) 541-2777

      National Technical Information Service
      5285 Port Royal Road
      Springfield, VA  22161
      Telephone:  (703) 487-4650

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                            TABLE OF CONTENTS







Section                                                                 Page



1.0    SUMMARY
2.0
1.1
1.2
SUMMARY OF CHANGES SINCE PROPOSAL 	 ,
SUMMARY OF IMPACTS OF PROMULGATED ACTION 	 ,
SUMMARY OF PUBLIC COMMENTS 	 ,
2.1

2.2

2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
2.11
2.12
NEED FOR STANDARDS AND SELECTION OF SOURCE
CATEGORY 	 ,
SELECTION OF AFFECTED FACILITY AND RECONSTRUCTION
PROVISIONS 	
EMISSION CONTROL TECHNOLOGY 	 -. 	
ECONOMIC IMPACT 	
ENVIRONMENTAL IMPACT 	 ,
ENERGY IMPACT 	 	
SELECTION OF BEST DEMONSTRATED TECHNOLOGY 	
SELECTION OF FORMAT OF STANDARDS 	 ,
SELECTION OF EMISSION LIMITS 	 	 	
TEST METHODS AND MONITORING 	
REPORTING AND RECORDKEEPING 	
MISCELLANEOUS 	
.. 1-1
.. 1-2
.. 2-1

2-5

2-13
.. 2-14
2-18
.. 2-26
2-27
.. 2-29
.. 2-31
.. 2-32
.. 2-35
2-42
2-44

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                              LIST OF TABLES


IABLE                                                               PAGE

 2-1    LIST OF COMMENTERS ON PROPOSED STANDARDS OF PERFORMANCE     2-2
         FOR CALCINERS AND DRYERS IN THE MINERAL INDUSTRY

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                                  1.   SUMMARY

      On April 23,  1986, the U. S. Environmental  Protection  Agency (EPA)
proposed standards  of performance  for calciners  and  dryers  in mineral
industries (51 FR 15438) under  authority  of  Section  111  of  the Clean Air Act
(CAA).  Public comments were requested on the  proposal  in the Federal
Register.  There were 14 commenters composed mainly  of  industry
representatives, trade associations, and  a State  agency.  Twelve presentations
were made at the public hearing on June 9, 1986.   The comments that were
submitted, along with responses to these  comments, are  summarized in this
document.  The summary of comments and responses  serve  as the basis for
revisions made to the standards between proposal  and promulgation.

1.1   SUMMARY OF CHANGES SINCE PROPOSAL
      In response to the public comments  and as a  result of  EPA's
reevaluation, a change was made to the definition  of "mineral  processing
plant" in the standards.  Specifically, the  definition was revised  to  provide
that a new, modified, or reconstructed dryer or calciner which processes a
mixture of minerals is covered by the standards  if the majority $f  the
material being processed (greater than 50 percent) is any of the following
minerals or a combination of these minerals:   alumina, ball  clay, bentonite,
diatomite, feldspar, fire clay, fuller's  earth, gypsum,  industrial  sand,
kaolin, lightweight aggregate, magnesium  compounds,  perlite,  roofing granules,
talc, titanium dioxide,  and vermiculite.
      The following changes were made .to  the opacity monitoring  requirements
in response to the pub!fc comments and as a  result of EPA's  reevaluation.
Except for the following process units, owners and operators  of  affected
calciners and dryers that use a dry control  device to comply  with the  mass
emissions standard are required to install and operate a continuous  opacity
monitoring system (COMS).  Owners or operators of  bail clay  vibrating  grate
dryers, bentonite rotary dryers, diatomite flash dryers, diatomite  rotary
calciners,  feldspar r*otary dryerc,  fire':iay rotary  dryers,   industrial  :ana
fluid bed aryers, kaolin rotary caiciners, perlite rotary aryers, roofing
granules fluid bed dryers,  roofing, granules  rotary dryers,  talc  rotary
           titanium dioxide fluid bed driers,  titanium dioxide  Gorav d
                                      l-1

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vermiculite fluid bed dryers or vermiculite rotary dryers who  use  a  dry
control device may have a certified visible emission observer  measure  and
record the opacity of the visible emissions daily in lieu of using a COMS.
Owners or operators of ball clay rotary dryers, diatomite rotary dryers,
feldspar fluid bed dryers, fuller's earth rotary dryers, gypsum rotary dryers,
gypsum flash calciners, gypsum kettle calciners, industrial sand rotary
dryers, kaolin rotary dryers, kaolin multiple hearth furnaces, perlite
expansion furnaces, talc flash dryers, talc rotary dryers, titanium  dioxide
direct or indirect rotary dryers or vermiculite expansion furnaces who use a
dry control device are exempt from the monitoring requirements.
      In Section 60.734(d), a technical correction was made to the final
standards to clarify the monitoring and recordkeeping requirements for
facilities which are controlled by wet scrubbers.  For operation and
maintenance purposes, the only requirement for monitoring devices  at this time
are daily zero and span checks.  Therefore, semiannual recalibration
requirements for monitoring devices in Section 60.734 have been deleted from
the final standards.
      Section 60.735(b) was added to clarify that each owner or operator who
uses a wet scrubber to comply with the standards must record daily an
arithmetic average over a 2-hour period of both the change in pressure  of the
gas stream across the scrubber and the scrubbing liquid flowrate.

1.2   SUMMARY OF IMPACTS OF PROMULGATED ACTION
1.2.1 Alternatives to promulgated Action
      The regulatory alternatives are discussed in Chapter 6 of the Background
Information Document (BID) to the proposed standards (EPA-450/3-85-025a).
These regulatory alternatives reflect the different levels of emission  control
from which one was selected that represents the best demonstrated

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technology, considering costs, nonair quality, health, and environmental
and economic impacts for mineral  processing plants.  These alternatives
remain the same.-
1.2.2  Environmental Impacts of Promulgated Action
     The environmental  impacts of the standards are presented in Chapter 7
of the BID for the proposed standards.  A review of these impacts indicated
no changes were necessary and, therefore, the impacts remain unchanged
since proposal.
     The analyses of environmental  impacts presented in the BID for the
proposed standards constitutes the final Environmental Impact Statement.
1.2.3  Economic and Energy Impacts of Promulgated Action
     The economic impact of the standards are discussed in Chapter 9 of
the BID for the proposed standards.  These economic impacts have been
reviewed and remain unchanged for the promulgated standards.
     The energy impacts of the standards are discussed in Chapter 7 of the
BID for the proposed standards and remain unchanged for the promulgated
standards.
1.2.4  Other Considerations
     1.2.4.1  Irreversible and Irretrievable Commitment of Resources
     Chapter 7 of the BID for the proposed standards contains a discussion
of irreversible and irretrievable commitment of resources.  These impacts
remain unchanged.
                                                                            «
     1.2.4.2  Environmental and Energy Impacts of Delayed Standards
     Chapter 7 of the BID for the proposed standards contains a discussion
of the environmental and energy impacts of delayed standards.  These impacts
remain unchanged.
                                    1-3

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                    2. SUMMARY OF PUBLIC COMMENTS

     A total of 14 letters commenting on the proposed standards and the
BID for the proposed standards were received.  In addition, a public
hearing on the proposed standards was held on June 9, 1986, and 12
industry representatives gave oral comments on the proposed standards.
A list of the commenters, their affiliations, and EPA docket numbers
assigned to their comments is given in Table 2-1.
     For the purpose of orderly presentation, the comments have been
categorized under the following topics:
     (1)  Need for Standards and Selection of Source Category
     (2)  Selection of Affected Facility and Reconstruction Provisions
     (3)  Emission Control Technology
     (4)  Economic Impact
     (5)  Environmental Impact
     (6)  Energy Impact
     (7)  Selection of 3est Demonstrated Technology
     (8)  Selection of Format of Standards
     (9)  Selection of Emission Limits
     (10) Test Methods and Monitoring
     (11) Reporting and Recordkeeping
     (12) Miscellaneous
     The comments, the issues they address, and EPA's responses are
discussed in the following sections of this chapter.  Changes to the
regulation are summarized in section 1.1 of Chaoter 1.
                                  2-1

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TABLE 2-1.  LIST OF COMMENTERS ON THE PROPOSED STANDARDS OF PERFORMANCE
            FOR CALCINERS AND DRYERS IN THE MINERAL INDUSTRY
Docket Entry Number*                Commenter/Affiliation


IV-D-1                              Frank DeVooght
                                    Texas Air Control Board
                                    6330 Hwy. 290 East
                                    Austin, kTX  78723

IV-D-2                              Kim A. Nelson
                                    North American Refractories Company
                                    P. 0. Box 56
                                    Curwensville, PA  16833

IV-D-3                              Ben A. Brodovicz
                                    Commonwealth of Pennsylvania
                                    Department of Environmental Resources
                                    P.O. Box 2063
                                    Harrisburg, PA  17120

IV-D-4                              R. W. Piekarz
                                    Eagle-Picher Industries, Inc.
                                    1755 E. Plumb Lane
                                    Reno, NV  89510

IV-D-5                              Roger A. Kauffman
                                    Heel a Mining Company
                                    6500 Mineral Drive
                                    Box C-8000
                                    Coeur D'Alene,  ID  83814

IV-0-6                              Andrew G. Kopas
                                    Harshaw/Filtrol Partnership
                                    P.O. Box 39189
                                    Cleveland, OH  44139

IV-0-7                              John W. Harris
                                    International Mineral- and Chemical Corp.
                                    Mundelein, !L  50060

IV-0-3                              Richard M. Jaffee
                                    Sorptive Minerals Institute
                                    605 Fourteenth  Street,  NW
                                    Washington, DC   20005
     designations represent docket entry numbers for Docket No. A-32-39.
These documents are available for public inspection at:  U. S. Environmetal
Protection Agency,  Air Docket Section (LE-131),  Waterside Mall, Room 1500, 1st
Hoor,  iQl M Street,  S.  W., Washington,  0.  C.   20460.

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TABLE 2-1.  LIST OF COMMENTERS ON THE PROPOSED STANDARDS OF PERFORMANCE
            FOR CALCINERS AND DRYERS IN THE MINERAL INDUSTRY


Docket Entry Number3                   Commenter/Affiliation


IV-D-9, IV-F-1                    Harry C. Robinson
                                  Expanded Shale Clay and Slate Institute
                                  6218 Montrose Road
                                  Rockvilie, MD  20852

IV-0-10, IV-F-1                   George S. Kosko
                                  SOLITE Corporation
                                  P. 0. Box 27211
                                  Richmond, VA  23261

IV-D-11                           J. S. Boyt
                                  Aluminum Company of America
                                  1501 Alcoa Building
                                  Pittsburgh, PA 15219

IV-D-12, IV-F-1                   W. W. Allen, Jr.
                                  Hydraulic Press Brick Company
                                  P. 0. Box 7
                                  Brooklyn, IN  46111

IV-D-13, IV-F-1                   J. Derman
                                  Norlite Corporation
                                  P. 0. Box 694
                                  Cohoes, NY  12047

IV-D-14                           R. H. Griffin
                                  North American Refractories,  Co.
                                  P. 0. Box 56
                                  Curwensville, PA  16833

IV-F-1                            William A. Hendrick
                                  Carolina Stalite

IV-F-1                            Edgar E. Martin
                                  Expanded Shale Clay and Slate Institute
                                  6218 Montrose Road •
                                  Rockville, MD  20852

IV-F-1                            H. B. Rushing
                                  3ig River Industries,  Inc.

IV-F-1                            Oave McNeel
                                  Arkansas Lightweight Aggregate

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TABLE 2-1.  LIST OF COMMENTERS ON THE PROPOSED STANDARDS OF PERFORMANCE
            FOR CALCINERS AND DRYERS IN THE MINERAL INDUSTRY
Docket Entry Number                 Commenter/Affiliation
IV-F-1                          Carston Mortenson
                                Utelite Corporation

IV-F-1                          P. W. Martin
                                Chandler Materials Company

IV-F-1                          Charles Marvin
                                The Refractories Institute

IV-F-1                          Joseph Evans
                                Fuller Company
                               2-4

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2.1  NEED FOR STANDARDS AND SELECTION OF SOURCE CATEGORY
2.1.1  Comment (IV-D-5)
     One commenter stated that EPA should select Regulatory Alternative I
which is equivalent to no additional control beyond that required by indi-
vidual  States because the cost of replacing present dust collection
systems is not justified by the very small reduction in particulate
emissions.
     Response:  The commenter has misinterpreted what dryers and calciners
are subject to this new source performance standard (NSPS).  Existing
dryers and calciners are not covered by this standard unless they are
modified or reconstructed.  As stated in the preamble to the proposal
standards, the vast majority of dryers and calciners affected by these
standards will be new facilities because very few calciners and dryers in
the 17 mineral industries would fall under the modification .or reconstruc-
tion provisions.  For those dryers and calciners that fall under these
provisions, no cost increases will be incurred for many of these sources as
existing control equipment is often achieving the NSPS emission levels.
For affected facilities presently controlled by baghouses not presently
achieving the standard, the NSPS emission limits can be achieved by
increasing the maintenance of fabric filters.  For dryers and calciners
that become affected facilities by modification or reconstruction and are
presently controlled by wet scrubbers or electrostatic precipitators (ESP's),
some may incur retrofit costs.  However, as stated in the preamble to the
proposed standards (51 FR 15438, April 23, 1986), SPA does not believe
any existing, control devices will have to be replaced as a result of the
NSPS.  These costs would not differ significantly from the annualized
costs for new facilities.  For 15 of the 17 industries covered by these
standards, the product price increases for new sourcas that would result
from imolementation of this NSPS would be typically less than 0.5 oercant.
For the other two industries, the product price increase would be less than
2 percent.  Therefore, the economic impact of this NSPS was found to be
-easonaoie.
                                   2-5

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     Concerning the reduction in participate emissions, in the fifth year
after the NSPS for calciners and dryers in mineral industries is in
effect, nationwide emissions of particulate matter would decrease by
7,900 megagrams (Mg) (8,800 tons) compared to emissions allowed under
typical state implementation plans (SIP's).  This represents a 78 percent
reduction in emissions compared to Regulatory Alternative I.  This is a
significant reduction in particulate matter emissions.  As discussed in the
response to comment 2.1.2, EPA concluded that this standard reflects the
best demonstrated technology (BOT) and is therefore promulgating it as
required by Section 111 of the Clean Air Act.
2.1.2  Comment (IV-D-8, IV-F-1)
     One commenter wrote that EPA has submitted no evidence which suggests
that plants complying with existing environmental rules or regulations
violate national  ambient air quality standards (NAAQS) for particulate matter.
The existing requirements for particulate control for the fuller's earth
industry are more than adequate and present emission levels do not endanger
public health and welfare.  The commenter stated that this industry should
be excluded from this NSPS.  He stated that fuller's earth is inert and
contains no hazardous constituents.  Also, the commenter felt that the
same logic used for exempting other industries from this NSPS because of
their unique characteristics should have been used for the fuller's earth
industry.
     Another commenter from the refractories industry stated that EPA has
presented no data which substantiates the effect calciners and dryers in
the-mineral industry may currently have on public health.  In particular,
he pointed to the absence of scientific data to show any public health
endangennent from the calcining or drying of alumina, ball clay, bentonita,
fire clay, kaolin and magnesita which ara refractory raw materials.  Consid-
ering the absence of any public health data and the fact that the. majority
of refractory plants are in rural areas, he questioned whether the public
health aspects of the proposed standards Have been dearly defined and
justified to show the .ieed for chis standard.

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     Response:  Under Section lll(b)(l) of the CAA, the EPA Administrator
is required to publish and periodically revise a list of categories of
stationary sources.  A source category is to be included on the list "...
if in his judgment it causes, or contributes significantly to, air pollution
which may reasonably be anticipated to endanger public health or welfare."
Such categories are referred to as "significant contributors", National
Asphalt Pavement Association v. Train 539 F. 2d 775 (D.C. Cir. 1976).
The Act then requires that NSPS reflecting the BOT as defined in Section
lll(a)(l) be promulgated for all listed source categories.  The language of
the Act does not require.absolute proof that health or welfare has been
harmed by emissions from a source category before the category is listed.
In fact, the legislative history stresses two points:
     (1)  The Act is preventive, and regulatory action should be taken to
          prevent harm before it occurs; and
     (2)  The Administrator should consider the contribution of each
          single class of sources to the cumulative impact of all
          particulate matter emitters.
     On August 21, 1979, the Administrator promulgated a priority list of
source categories for which NSPS are to be promulgated (44 FR 49225).
This action was required under the 1977 CAA Amendments [Section lll(f)].
Development of the priority list was initiated by compiling data on a large
number of source categories and ranking them using the three criteria
specified in Section lll(f) of the CAA.  In this ranking, first priority
was given to quantity of emissions, second to potential  impact on health
and welfare, and third priority was given to the mobility and competitive
nature of the source category.
     There are six source categories currently listed on the NSPS priority
list (August 21, 1979, 44 FR 49225, revised January 3, 1982, 47 PR 950) that
include all 17 mineral industries being covered by the NSPS.  Number 13 on
the priority list is 'lonmetall'ic Mineral Processing,  which includes sand and
gravel, clay (ball clay, bentonite, fuller's earth, kaolin), talc, feldspar,
diatomite, ^oofing granules, and vermiculita.  'lumber 14 on the orion'tv
list, Metallic Mineral i°rocsssing,  includes aluminum, -nagnesium compounds,
and titanium.  The lightweight aggregate (LWA) industry  (clay, shale,

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slate) is Number 32 on the NSPS priority list.  Numbers 34, 46, and 54
on the list are gypsum, brick and related clay products (fire clay), and
perlite, respectively.
     These industries were included on the NSPS priority list because of
their emissions of particulate matter.  Particulate matter is a criteria
pollutant which has been determined to be an air pollutant which may
endanger public health and welfare and for which NAAQS have been promul-
gated (40 CFR 50.6, 50.7).  Fuller's earth, alumina, ball  clay, bentonitei
fire clay, kaolin, magnesite, and other dusts emitted by the industries
covered by the NSPS are types of particulate matter.  The basis for the
Administrator's determination that particulate emissions may endanger
public health and welfare is presented in the rulemaking setting and
revising the NAAQS for particulate matter (52 FR 24634, July 1, 1987).
     As stated in Section 2.1.1, the main purpose of NSPS is to minimize
increases in air pollution from new sources, thereby improving air quality
as the nation's industrial base is replaced over time.  It is not the
purpose of NSPS to bring new sources in compliance with the particulate
matter NAAQS.  The EPA has considered the emission reductions and costs and
other impacts due to emission controls and has concluded that the controls
underlying the standards are BOT.  The EPA is therefore promulgating standards
that reflect 8DT.
     The estimated reduction in particulate emissions in the fifth year
from the fuller's earth industry is approximately 240 Mg/yr.  The estimated
percent price increase for this industry is 1 percent or less.  Because the
emission reduction is significant and the economic impact on the fuller's
earth industry is considered reasonable, the Agency does not believe
including the fuller's earth industry in the NSPS will create a hardship
for that industry.
2.1.3  Comment (IV-F-1)
     One commenter felt that the local rules and regulations that apply in
Southern California are sufficient to protect the environment.  He recommended
abandoning the proposed limit or changing it to an achievable level.  Another
:ommenter statad thai: State and local agencies currently have regulations :han
apply to these industries.  In addition, he stated that wherever actual
                                   2-3

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documented need exists, SIP's are in place to make the necessary improvements
because these plans consider both the magnitude of the need and the impact
of each source.  Because these plans are approved by EPA, the commenter
questioned the need for this standard.
     Response:  As stated in section 2.1.2, the legislative history of the
CAA stresses two points:
     (1) The Act is preventive and regulatory action should be taken to
         prevent harm before it occurs; and
     (2) The Administrator should consider the contribution of each single
         class of sources to the cumulative impact of all particulate
         matter emitters.
In addition, all of the industries covered by these standards have been
listed on the NSPS priority list (44 FR 49225, August 21, 1979, revised
January 8, 1982).
     Standards of performance required by Section 111 play a unique role
under the CAA.  The main purpose of standards of performance is to require
new sources, wherever located, to reduce emissions to the level achievable
by the best technological system of continuous emission reduction considering
the cost of achieving such emission reduction, any nonair quality health
and environmental  impact, and energy requirements (BDT) [Section lll(a)(l)].
Congress recognized that establishing such standards would minimize
increases in air pollution from new sources, thereby improving air quality
as the nation's industrial base is replaced over the long term.  An NSPS
thereby serves as a distinct means of achieving the Act's goals, supple-
menting the role played by the requirements including Reasonably Available
Control Technology requirements for existing and new sources within SIP's
developed for the purpose of attaining the NAAQS.
     The existence of other environmental  regulations was considered during
selection of 3DT,  but their axistanca does not lead the EPA to conclude
that standards raflacting bettar control  technology are not necessary or
cannot be applied at reasonable costs.
2.1.4  Comment (IV-F-1)
     Three commenters stated that the LWA industry is not a sourca  which
"'nay "aasonaoiy je anticipated co .endanger juoiic neaith or .veifare.'
These commenters stated that most LWA plants are located in rural  areas
                                   2-9

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making it less probable that these emissions would endanger public health.
One of the commenters stated that LWA plants are normally located on large
tracts of rural land where particulate emissions that do occur remain on
the plant sites.  Another commenter stated that the air quality review in
the BID showed that the impact of emissions from a typical  plant are not
significant for the annual period and barely significant for the maximum 24
hour period.
     Response:  As stated in section 2.1.2, the Administrator considers the
contribution of each single class of sources to the cumulative impact of
all particulate matter emitters.  The LWA industry was listed number 32 on
the NSPS priority list.  In this ranking, first priority was given to the
quantity of emissions, second to the potential  impact on health and welfare,
and third priority was given to the mobility and competitive nature of
the source category.  The commenter did not submit, nor is  EPA aware of
information that would cause EPA to revise its  1979 decision that the LWA
industry is a significant contributor.
     The estimated reduction in particulate emissions in the fifth year
from the LWA industry is 460 Mg/yr.  The estimated percent  price increase
for this industry, assuming a selling price of  $18/Mg, is 1 percent or
less.  In addition, as discussed in Section 2.4.4, EPA evaluated the poten-
tial competitive advantage that might be given  to substitutes for LWA as a
result of this NSPS and concluded that there would be no competitive dis-
advantage for the LWA industry.  Because the emission reduction is
significant and the economic impact on the LWA  industry is  considered
reasonable, the Agency does not believe that including the  LWA industry in
the NSPS will create a hardship for that industry.
2.1.5  Comment (IV-F-1)
     One commenter from the LWA industry felt it was improper to include that
industry in a standard which applies to a very  wide variety of processes and
sources, most of which are very different from  LWA industry's processes and
sources.
     Response:  As discussed in the preamble to the oroposed standards
(51 -R  :5433, April 23, 1986),. -.Me emission iourcas (caiciner and. dryer
processing units) in the  industries covered by  the NSPS process materials
                                    2-10

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that can be controlled with similar effectiveness, costs, and control
techniques.  In the proposal BID, the particular characteristics of the LWA
industry are addressed in Chapters 3, 6, 8 and 9.  In Chapter 3, there is a
discussion of the type of processing equipment employed in the LWA.  In
Chapter 6, model plants were developed for each dryer/calciner type in all
17 mineral industries so that impacts of this NSPS could be determined.  In
Chapters 8 and 9, the cost of controlling the type of calciners used by the
LWA industry to the NSPS level  is presented and the economic impact on the
industry of requiring the NSPS level of control is analyzed.  In addition,
based on the results of EPA's test program, it was concluded that the LWA
industry was amenable to the same control technology and emission limits
as the other sources and industries covered by this NSPS.  Because the
cost and economic impacts on the LWA industry as a result of this NSPS
were found to be reasonable (see sections 2.4.3 and 2.4.4), it was deter-
mined that there was no reason to exempt the LWA industry from this NSPS.
2.1.6  Comment (IV-0-6, IV-D-11)
     One.commenter stated that EPA addressed the classical production of
alumina for use in large volume applications, such as production of aluminum
metal and refractories in the analyses in the BID.  However, the commenter
pointed out that a much smaller market exists for the production of specialty
alumina.  The commenter stated that the BID characterizes a small model
facility as being 25 tons per hour while in the specialty market the facili-
ties range from 0.25 to 5 tons per hour.  The commenter believed that the
costs associated with the proposed standards are extremely high considering
the lack of emissions and the lower volume of product produced.  He recom-
mended that calciners and dryers with"capacities of less than 10 tons, per
hour be exempted from the standards.
     One commenter stated that their alumina calciner processes at a much
lower rata (1-2 tons of material per hour) than the much larger dryers and
calciners that it appears these standards were intended to regulate.  The
commenter suggested exempting smaller dryers and calciners.
     Response:  In develooing standards of oerformanca, the EPA is mandated,
under Section 111 of iha CAA, ;o develop standards :hat reflect the degras
of emission limitations achievable through application of the best

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technological  system of continuous emission reduction (taking into consid-
eration cost,  nonair quality health and environmental impacts, and energy
requirements)  (BDT).  Where appropriate, the EPA has promulgated separate
requirements for certain subcategories of industrial source categories, as
authorized by  Section lll(b)(2).  These subcategories may be defined by
various criteria including size of operation and type of material processed.
Typically, this need for special consideration arises from one of several
causes.  For example, there may be economies of scale apparent within an
industry that  would cause a standard applied across the industry to have
disproportionately adverse economic impacts on small facilities.  Also,
there may be reasons of technical feasibility that would result in certain
segments of an industry being regulated differently or exempted from
coverage.  Such decisions are made for specific reasons for specific
subcategories.
     In analyzing the technical and economic impacts of the proposed
standard for the calciners and dryers in the mineral industries, the EPA
could find no  reasons to exempt affected facilities below a certain size
limit.  Since  the commenter indicates that the process equipment would
already have a control device affixed to it, technical feasibility is not an
issue.  Likewise, the major cost of meeting the standard is the application
of a control device.  The commenter stated that air flow would probably be
less than 20,000 acfm.  There are numerous dryers/calciners model plants
with air flow rates less than 20,000 acfm.  The lowest is 2,500 acfm.  While
the commenters are correct that their facilities are smaller than the model
alumina facilities included in EPA's regulatory impact analysis, the
incremental cost of control associated with this NSPS was estimated to be
negative for all of the model alumina facilities in the analysis due to
the value of the recovered alumina product.  Based on EPA's analysis of
the cost impacts on small model facilities in other industries, EPA believes
the costs of control associated with this NSPS are reasonable even for small
alumina facilities.  The incremental cost of an initial performance test
and the minimal recordkeeping required by these standards will not have a
significant economic impact on these operations.  Thus, EPA has decided
that these standards will cover all affected facilities regardless of size.
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2.2  SELECTION OF AFFECTED FACILITY AND RECONSTRUCTION PROVISIONS
2.2.1  Comment (IV-0-6)
     One commenter questioned whether a calciner that handles a mixture of
material, including some of the minerals regulated by this NSPS, is subject
to this NSPS.
     Response:  Any dryer or calciner which processes or produces any of
the following minerals, their concentrates or any mixture of which the
majority (> 50 percent) is any of the following minerals or a combination
of these minerals is covered by the NSPS:  alumina, ball clay, bentonite,
diatomite, feldspar, fire clay, fuller's earth, gypsum, industrial sand,
kaolin, lightweight aggregate, magnesium compounds, perlite, roofing
granules, talc, titanium dioxide, and vermiculite.  The definition of
"mineral processing plant" in section 60.731 has been revised to clarify
this point.
2.2.2  Comment (IV-F-1, IV-D-14)
     One commenter stated that his primary concern with this NSPS is the
reconstruction provision because at his plant if a kiln were modified or
reconstructed the current control device (low energy wet scrubber) would
need to be replaced by a baghouse and the cost of installing a new baghouse
would be prohibitive because the scruboer does not rely on gas pressure
drop for collection efficiency and cannot be upgraded.
     Another commenter stated that an NSPS should be limited to new
facilities.  Relative to the refractories industry in particular, the
commenter stated that the application of stringent regulations to existing
plants through the modification and reconstruction provisions can only
serve to place additional economic pressures on manufacturers and could
cause facilities to be closed due to the cost of compliance.
     Response:  The EPA believes that, for this industry, a baghouse or a
venturi scrubber with a pressure drop of 23 inches can lower emissions to
the NSPS level based on emission test results.  The cost and aconomic
impacts for these control options are considered reasonable and are
discussed in Chanters 8 and 9 of the BID for the prooosed standards and
in "he -ssponse :o comment 2.4.3.
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     The EPA disagrees with the commenters'  concerns about the economic
impact on existing facilities.  As stated in the preamble to the proposed
standards (51 FR 15438, April  23, 1986), it  was estimated that 104 existing
calciners and dryers would be replaced in the first 5 years that the NSPS
is in effect.  The costs associated with upgrading of existing control
systems for these facilities were estimated  and the economic impacts
analyzed and determined to be reasonable.  In some cases, it may not be
possible or desirable to upgrade an existing control device depending on the
remaining useful life of the equipment and limitations on its performance.
In these cases, the existing control device  may have to be replaced.  The
short-term economic impact would be higher than estimated by EPA in these
situations.  However, because all existing calciners and dryers in the
mineral industries covered by this NSPS currently control their emissions
either to comply with State regulations or to recover products, there would
be no competitive disadvantage for the few plants which face this situation,
and the long-term economic impact would be as estimated by EPA.

2.3  EMISSION CONTROL TECHNOLOGY
2.3.1  Comment (IV-D-2, IV-F-1)
     Several commenters stated that the NSPS emission limits (Regulatory
Alternative III) do not allow for the use of low energy wet scrubbers,
because control devices with greater energy  consumption are required to
achieve these limits.  They felt that energy consumption is an important
consideration in the selection of a control  device and it is inappropriate
to regulate against the use of an energy-efficient device in the face of
increasing foreign competition.  Another commenter stated that the 0.04
gr/dscf standard could not be achieved for a lightweight aggregate rotary
caiciner controlled by a venturi scrubber with a pressure drop of 6
inches.  The commentar stated that their experience shows the controlled
emissions to be in the 0.1 to 0.13 grains per dry standard cubic foot
(gr/dscf) range.

                                   2-14

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     Response:  The EPA does not necessarily recommend the use of a high
pressure drop scrubber or any other emission control technology to attain
and maintain compliance with the performance requirements of this standard.
                                                      «
Compliance with the pollutant concentration limits of this standard can
generally be achieved by application of one of many alternative emission
control strategies, and, for a specific case, the EPA does not require
that a particular control device be 'used.
     In several industries, EPA has determined that low energy wet
scrubbers (pressure drops less than 6 inches of water gauge) can achieve
the standard based on emission test data presented in Chapter 4 of the
BID.  The pressure drops required for scrubbers to meet the standards
were based on the most difficult to control case for that particular
process unit in each industry.  Other process units in that industry that
are less difficult to control should be able to comply with this NSPS using
lower pressure drops.
     When a scrubber is used to control particulate emissions from a
dryer or calciner, the actual pressure drop necessary to reach the NSPS
levels will vary from plant to plant.  A rotary dryer in one of the
commenter's (IV-D-2) plants was tested by EPA (See Plant Fl on page 4-42
of BID).  Depending on the material processed, emission levels from a
wet scrubber with a pressure drop of 12 inches af water column were 0.070
and 0.088 g/dscm (0.031 and 0.038 gr/dscf).  To achieve 0.057 g/dscm
(0.025 gr/dscf), scrubber modelling showed that an increase of only 2
inches of pressure drop is required.  The predictive capability of this
model has been widely demonstrated as discussed in the document entitled
Venturi Scrubber Performance Model (EPA-600/2-77-172) (Docket No." IV-A-1).
The increase in annualized cost was analyzed and is considered-to be
reasonable by EPA.
     Using the model described above, EPA evaluated the pressure drop
necessary for different facilities to meet the NSPS limits.  In some
cases, a high pressure drop (23 inches) was estimated to be necessary.
In all cases, the cost, energy, and economic impacts, including the imoact
of foreign comoetition associated with che increased pressure drop wera
evaluated and determined to be reasonable by EPA.

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2.3.2  Comment (IV-F-1. IV-0-13)
     A commenter from the LWA industry stated that previous experience
with bagho.uses was totally unsuccessful  as bags would only last a week at
a gas inlet temperature of 450°F.  Another commenter in this industry
stated that a baghouse used on a rotary kiln was discontinued at his plant
due to problems related to the bags, i.e., burning and tearing and resulting
bag replacement costs.
     Response:  Emission test results from another lightweight aggregate
plant whose rotary kiln is controlled by a baghouse were obtained.  The
plant has experimented with many different filter fabrics and design
modifications.  The plant is currently using a 100 percent Teflon bag in
addition to a patented modification of the bag cage.  Bag failure and bag
wear have been drastically reduced.  In an Srmonth period, there has been
only one bag failure out of a total of 2,200 bags.  Emission test results
from this plant (K-5) are shown in Chapter 4 and Appendix C of the BID for
the proposed standards.  The outlet from the baghouse was 0.074 g/dscm
(0.032 gr/dscf) and thus was able to achieve the NSPS emission limit.
     As shown in Chapter 6 of the BID for the proposed standards, two
control options were determined by EPA to be able to achieve the NSPS
emission limit for LWA rotary calciners.  These options are a baghouse
with Nomex bags and a venturi scrubber with a pressure drop of 23 inches
water gauge.  As noted on page 4-14 of the BID, both Nomex and Teflon can
treat gases with temperatures up to 420°F.  Ambient air could be added to
reduce the temperature from 450 to 420°F.'.A venturi scrubber could also be
used with no adverse impact due to the gas temperature of 450°.  Neither of
these control options would have any severe economic impact on this industry,
2.3.3  Comment (IV-0-4)
     One commenter disagreed with EPA's assessment that there would be no
capital cost increases for baghouses used in 66 percent of the cases where
these units could meet NSPS limits through better operation and increased
maintenance.  According to the commenter, the ores are naturally occurring
heterogeneous solid material of slightly differing composition, purity,
moisture and hardness.  The softer crudes will yield more fine particles

                                   2-16

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during processing which increases the baghouse inlet grain loadings and
can affect its performance.  The commenter stated that increasing the
fabric cleaning cycle can help, but this practice is detrimental to bag
longevity and will accelerate fabric failures.  According to the commenter,
the baghouse must often be upgraded with the addition of another compartment.
     Response:  EPA agrees with the commenter that an increase in uncontrolled
emissions may require an increase in the fabric cleaning cycle so that
the baghouse pressure drop does not exceed design specifications..  An
increase in the cleaning cycle may decrease the bag life.  EPA recognized
this phenomena as the bag life that was specified and costed for the
standard was 80 percent of the bag life used for the baseline.
     As shown in Chapter 4 of the BID, all baghouses that were tested by
EPA,-or where State compliance tests were obtained, met the NSPS levels.
It is reasonable to conclude that many baghouses presently operating to
achieve emission levels set by SIP's can achieve NSPS emission limits
without adding a new compartment.
2.3.4  Comment (IV-0-7)
     One commenter wrote that the Agency has not adequately assessed al1
of the adverse economic impacts that the proposed standard would have on
existing dryers using existing ESPs for emission control.  The commenter
stated that it would not be possible to achieve the standard through
improved operation and maintenance but the specific collection area would
need to be increased or the dryer's throughput would be required to be
reduced.  Both of these options would be more costly than improved
operation and maintenance.
     Response:  Existing dryers and calciners and their control  systems are
not affected by this standard unless the dryers or calciners are modified
or reconstructed.  As stated in the preamble to the proposed standards,
not many dryers and calciners in the 17 mineral industries would fall  under
the modification or reconstruction provisions.  Information on how  a dryer
or calciner falls under these provisions is presented in the preamble and
regulation for the proposed standard (51 FR 15433, Aoril 23, L986).

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     The EPA agrees with the commenter that, to achieve the NSPS emission
limit, an increase in the specific collection area (SCA) may be required
in comparison with the SCA used to comply with State regulations.  As
shown in Chapter 6 of the BID,  the SCA would increase from 174 to 350
square feet of plate area per 1000 actual cubic feet per minute of air
flow for fluid bed dryers in the bentonite industry.  These SCA's were
used in the development of control costs of the three regulatory alter-
natives considered.  For the commenter's industry, the product price
increase estimated to result from the NSPS is less than 0.3 percent.
2.3.5 Comment (IV-D-4)
     One commenter stated that  high moisture content within the flash
dryer flue gases can cause fabric blinding problems that will  affect the
performance of a baghouse.  Increased maintenance does little or nothing
to solve the problem, according to the commenter.  The commenter stated
that increased capital investment in larger baghouses along with ripple-
effect bag cleaning equipment and air heaters would be required.  Therefore,
the commenter believes the costs of control were underestimated by EPA.
     Response:  Two of the commenter's plants were visited during the
development of this NSPS.  Two  flash dryers previously controlled by 60
inch pressure drop venturi scrubbers were replaced by baghouses.  Compared
to the scrubbers, the baghouses have required much less maintenance.  If
there is a problem with fabric  blinding, a scrubber can be used.  As
shown in Chapter 6 of the BID,  a scrubber with a gas pressure drop of 25
inches water gauge can achieve  the standard.  The product price increase
is less than 0.5 percent so no  adverse economic impacts are expect-ed..

2.4  ECONOMIC IMPACT
2.4.1  Comment (IV-0-4)
     One commenter questioned whether EPA has totaled the sum of all the
incremental costs of all environmental regulations pertaining to the domestic
mining industry.  The commenter states that the total cost to comply with
environmental regulations is becoming more burdensome to an already
depressed industry,

                                   2-18

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     Response:  In estimating and analyzing the economic impact of these
standards, only the incremental  cost associated with complying with the
standards was used.  The other environmental  regulations that the commenter
refers to are already applicable to the different industries and are part
of the normal cost of operation of any new plant.  It is impossible to
identify what percent of current operating costs is associated with
complying with the various Federal, State, and local environmental regu-
lations.  The cost associated with these regulations will vary considerably
depending on the stringency of the regulations and the method of compliance
chosen by the individual plants.  However, because these costs are already
part of the normal operating costs of the industries and reflected in
their current product prices, only the incremental cost and the resultant
economic impact associated with this NSPS on top of the current operating
costs and product prices could be evaluated.  Based on the results of the
economic impact analysis, the percent-product price increase would be
2 percent or less for the industries covered by the standards.  This impact
has been determined to be reasonable considering the emission reduction
of 7,900 Mg (8,800 tons) in the fifth year.
2.4.2  Comment (IV-0-8)
     One commenter wrote that he does not agree with the background
support document that states that the fuller's earth industry is not
likely to experience significant economic effects due to this NSPS.  The
commenter stated that some industries may not be able to meet these new
standards at all locations and may choose to keep old equipment.
     Response:  The 1982 price per ton for fuller's earth ranged from a
low of $10.00 per ton for montmorillonite to a high of $69.89 per ton for
attaoulgite.  The typical price per ton used for the price increase
calculation was $54/ton.  The highest price increase for any regulatory
scenario for the fuller's earth industry was less than 1 percent.  Sased
on the typical value of the product and the small price increase anticipated,
it would indeed appear that such an impact on product price would be
insignificant.
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     With regard to the discussion of aging equipment, it is a fact that
some plants within the fuller's earth industry are approaching the end of
their useful production life.  Some of these plants are currently producing
on a marginal profit basis.  Although it is not possible to predict exact
plants and schedules, some fuller's earth plants will  close as a result of
natural attrition in the absence of any regulations.  Obsolete machinery,
newer, more efficient and competitive plants, changing market demands and
better substitute products would all  influence the decision to close an aging
plant returning only marginal profits, irrespective of the regulatory environ-
ment.  The results of the economic analysis do not indicate that the maximum
product price increase of less than 1 percent would be an important factor
in the decision to modify or reconstruct an aging fuller's earth plant.
2.4.3  Comment (IV-F-1)
     One commenter calculated the incremental capital  cost for a
lightweight aggregate calciner to be 10 to 20 times higher than the cost
for other industries based on data in EPA's BID.  Also, the commenter
calculated the annual incremental cost for this industry to be 4-9 times
that estimated by EPA for the other industries.  If EPA had used actual
costs of electricity, the commenter estimated that this difference would be
even greater.  He also calculated the percent product  price increase to
be significantly higher than that calculated by EPA.  These costs and
price increases seemed to be overly burdensome on the  LWA industry to the
commenter because only 5.8 percent of the total national particulate
matter reduction would come from this industry.
     Response:  In order to assess the incremental cost of an NSPS, it is
important to establish a common basis.  One basis used by EPA is. the
incremental cost of the NSPS divided by the megagrams  of reduction in
particulate emissions.  The range for the LWA industry depending on the
type and size of the affected facility is $240 - $l,100/Mg.  This is
within the range of incremental cost per megagram for  the other sourca
categories.
     Another measure of incremental cost is incremental cost versus the
selling price of the product.  Calculations were done  So determine what
impact the actual price paid for electricity by the commenter, which was
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over double the cost EPA used in estimating costs, would have on the
incremental annualized costs.  If baghouses are used, there is no
increase as electrical costs are the same.  FOP scrubbers, there would be
an additional  incremental  increase of $52,000 in annualized costs for a
total increase in annualized costs of $114,000 using the commenter's
electricity cost estimate.  Based on a product price of $22/Mg for this
industry, the percent product price increase including electrical costs
would be 0.4 percent for baghouses and 2.4 percent for scrubbers.  The
Administrator considered these impacts to be reasonable and not overly
burdensome.

2.4.4  Comment (IV-F-1)
     Seven commenters stated that the LWA industry is declining due to
rising energy costs, environmental control costs, and impacts of product
substitutes, in particular pumice.  Two of these commenters stated that
if the proposed standard was implemented the LWA industry would suffer
further decline.  One commenter attributed this decline to their inability
to pass through the  cost of control  to their customers.   He pointed out
that the LWA industry's prices have been staying behind the cost of
living increases for the past several years because of competition.  Two
other commenters felt that the LWA industry would be destroyed by the
proposed standard.   One of these commenters stated that  the additional
environmental  control costs would add more uncertainty to any investment
consideration and,  therefore, many companies would continue to operate
old, existing sources.  The commenter felt that the LWA industry would
then die of old age  and lack of reinvestment.
     These commenters suggested that the LWA industry either be dropped
due to economic reasons or that an alternative control level  equal  to
current State regulations  be selected.  One "of these commenters recommended
that EPA reanalyze  the economic ircoact on the LWA industry because he
felt that EPA's current estimate represents just a fraction of the impact
anticipated by the  industry.
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     Response:  As stated earlier in section 2.4.2, many factors influence
a corporate decision as to whether it is prudent to invest in new, effi-
cient equipment or to continue to operate old, existing equipment until
operation is no longer possible.  The product price increases attributable
to the NSPS are quite small--less than 2 percent for all cases.  The
corporate decision to invest or reinvest in plant operations must be made
in terms, of course, of expected profitability.  New plants will be built
when it is feasible and financially profitable to do so--this decision
being driven by the price of the product and/or market demand.  It is
possible that various market forces external to the costs of NSPS would
preclude investment in newer plants and equipment.  The actual cost,
however, resulting from the NSPS is very small, and it is unlikely that
investment plans would be made based on a cost so small.
     With regard to pumice, there is no doubt about the fact that pumice
is a substitute- for LWA, although in many cases pumice is an inferior
substitute.  The BID for the proposed standards discusses the substitu-
tion of pumice for LWA in sections 9.1 and 9.2.  The commenter's question
involves the degree of competition that exists between LWA and pumice, and
whether the proposed NSPS control costs for LWA will significantly alter
the degree of competition that currently exists between LWA and pumice.
Production data and market share data for LWA and pumice were compared.
LWA has a far larger share of the total market (LWA plus pumice) than
pumice.  Pumice's share of the market has ranged from 9 percent to
19 percent of the total market, with an average of 13 percent.  During
1977, 1978, and 1979 pumice's share of the market increased to approxi-
mately 18 percent.  For 1983, pumice's share of the total market was
13 percent.  The current levels of production of LWA are" down sharply
from past levels reached during the early 1970's.  However, the losses
experienced by LWA are not due to gains by pumice because pumice's recent
share of the total market is similar to its historical position.  Addi-
tionally pumice produced from domestic mines has declined, as well as
pumice supplied by imports.
     Therefore, E?A believes that the cost of this MSPS will not lead to
a competitive disadvantage for the LWA industry.

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2.4.5  Comment (IV-F-1)
     One commenter stated that the cost of installing and maintaining the
equipment to meet these standards is very substantial.  He estimated it
would cost $34,500 per year to use a baghouse rather than a multiclone
system which is currently in use.  The commenter stated that this would
increase the cost of doing business by over 5 percent.  He also felt that
this cost combined with other pressures on the economy and the LWA industry
could force some LWA plants to close.  For his specific plant, he informed
EPA of the following data to support his point.  By amortizing the capital
cost of the baghouse over an 3 or 10 year life, the percent product increase
would vary from 6.8 - 11.4 percent depending on the time period that is used
for amortization and lightweight aggregate prices used ($13-14/yard
or $12.30-$13.20/ton).  The calciners have a capacity of 260 tons/day and
operate at 60-70 percent of annual capacity.
     Response:  The information provided by this commenter is not of
sufficient detail to assess the particular situation of the plant described.
However, as stated in section 2.3.4, existing operations will not be affected
by the NSPS unless the existing sources are replaced, modified or recon-
structed.  Therefore, the commenter's operating costs should remain unchanged
from current levels.  It was noted in the commenter's statement that the
calciners in question were operating at 60 to 70 percent annual capacity.
This data suggests that the need for new sources is perhaps not apparent
for the short-term.
2.4.6  Comment (IV-F-1)
     One commenter believed that this NSPS would have a doubling effect
in terms of costs on. the LWA industry as the standards also apply to the
refractory industry whose products are used by the LWA industry.  This
commenter also stated that this NSPS would have a cumulative economic
impact on the fire clay industry as this industry uses both dryers and
calciners.  He also said that other regulated minerals are used in the same
refractory products so percent price increases could approach 3-4 percent.
The commenter felt that based on EPA's cost analysis figures, these costs
would create a major ourden on the refractory industry whicn currently is
struggling to stay alive.
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     Response:  Additive effects of the NSPS are indeed possible where an
industry utilizes both calciners and dryers.  In the case of fire clay,
cumulative impacts could be as high as 2 percent although it would typically
be 1.6 percent using the least costly control  device for a rotary dryer
and the 2 percent estimate is based on the smallest plant size and resultant
worst case.
     With regard to the comment that additive impacts for refractory
products could reach 3-4 percent, this comment overstates the mathematical
outcome of the price increase calculation.  The commenter simply adds the
price increase for LWA and the price increase for fire clay and presents
the result, which is about a 3 to 4 percent increase.  The 3 to 4 percent
increase is an overstatement because refractories are only a portion of
the cost components for LWA.  Expenditures for refractories for a LWA
model plant are necessary to perform the calculation accurately.  However,
for illustration, assume a LWA model plant spends 10 percent of its total
expenses on refractories.  Then, if the price of refractories increases
by 2 percent, the price of LWA would increase 0.2 percent (or 2 percent
times 10 percent).  Therefore, the EPA does not believe the NSPS has a
doubling effect in terms of cost on the LWA industry.
2.4.7 Comment (IV-F-1)
     One commenter estimated this NSPS would impose an incremental capital
increase of $100,000 per dryer and between $250,000-$!,500,000 per calciner
on those who cannot currently meet the standards.  Thus, the rate of
return on investment in many cases would be too low for plants to modify,
reconstruct, or replace dryers or calciners at existing plants.
     Response:  EPA calculations were reviewed and found to be correct.
The average-incremental, capital cost increase is $11,000 for dryers and
calciners if baghouses are used where there is a baghouse/wet scrubber
option, and $14,900 if scrubbers are used where this option exists.  The
commenter was contacted and requested to supply supporting data for his
calculations.  These calculations were not received.  The economic analysis
as discussed in Chapter 9 of the BID for the proposed standards showed 10
adverse impacts for any of the 17 mineral industries covered by the
standards.
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2.4.8 Comment (IV-F-1)
     One commenter in the LWA industry believed that EPA underestimated
the incremental  capital cost and product price increase associated with
complying with the standard.  He stated that if a modification were made
at his existing plant, a low energy wet scrubber would have to be replaced
by a baghouse because the collection efficiency of the scrubber could not
be improved by increasing the pressure drop.  This would cost much more
than EPA has estimated and result in a significantly higher product
price increase.
     Response: As discussed in the preamble to the proposed standards
(51 FR 15438, April 23, 1986), EPA believes few, if any, existing calciners
and dryers will  become covered by the NSPS due to the modification provis-
ions of the General Provisions (40 CFR 60.14).  Calcining and drying
operations usually operate below 100 percent of capacity and are capable
of handling moderate increases in production without additional equipment.
This situation is not considered a modification.  When expansions at
existing plants take place, usually a completely new calciner or dryer is
added.  Such an increase in production would not be considered a modification
but rather a new source, and the cost of control should be considered as part
of the expansion.
     If there were a modification (or a replacement) of an existing facility
at the commenter's plant, it is unclear whether the wet scrubber used by
the commenter would have to be replaced by a baghouse to achieve the NSPS
emission level.   As mentioned in section 2.2.2, there are other techniques
than increasing the pressure drop that will improve scrubber performance
(see also section 2.7.1).  Due to the lack of emission test data, it is
uncertain whether the use of these techniques can achieve the NSPS emission
level.  If these techniques are successful, then the incremental increase
In costs attributable to this NSPS is likely to be less than what is
shown in the BID for the proposed standards.  There may be cases where an
existing control device is not capable of achieving the NSPS emission
limits, and may have-to be replaced as a result of the NSPS.  The EPA
believes chat the situation described by the commenter is very unlikely to
occur.  If it did happen, the cost associated with this replacement would
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have to be considered by the owner or operator of the existing facility
as part of his investment decision prior to commencing the modification
of the facility.

2.5  ENVIRONMENTAL IMPACT
2.5.1  Comment (IV-0-8)
     One commenter stated that the particulate emission reduction of
8,800 tons per year attributable to this NSPS sounds impressive but would
equate to a reduction of 0.011 ounce per acre per month across the contiguous
United States.  Of this  total  reduction, only 326 tons per year are
attributed to controlling the fuller's earth industry.  This reduction is
extremely small and would cost the sorptive mineral  industry millions of
dollars.  According to the commenter, the actual  national  emission reduction
is more in the order of 4,000 tons per year.  Mild winds in dry areas or
farmers' plowing cause resuspension of particulates far in excess of
these quantities.
     Response:  The 7,900 Mg (8,800 tons) per year emission reduction is an
estimate made by EPA using the best data available and reasonable assumptions,
Baseline emissions (those which would occur in the absence of an NSPS) were
estimated assuming new facilities would comply with typical State regulations.
These were compared with emissions estimated to occur if new facilities were
controlled to the level  required by the NSPS.  For details on the procedure,
see Chapter 7 of the document "Calciners and Dryers in Mineral Industries--
Background Information for Proposed Standards" (EPA 450/3-85-025a).
     Related to the commenter's concern about the significance of this-
emission reduction, the six source categories regulated under this NSPS
have been found to be significant contributors to particulate emissions
which may reasonably be anticipated to endanger public health and welfare
(see section 2.1).  The industries covered were included on EPA's priority

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list of source categories for which NSPS must be promulgated.  The EPA
estimates emissions can be reduced by 7,900 Mg/yr (8,800 tons).  This is
a large and.significant number, despite the fact that it may appear small
when divided by the land mass of the contiguous United States.  Particulate
matter sources are dispersed, each contributing a small  percent of a
large total emission.  The EPA has identified BDT for calciners and dryers
in the mineral industries which can be applied for a reasonable cost, so
an NSPS is being promulgated.  The incremental annualized cost associated
with this NSPS in the fifth year for the fuller's earth  industry is
$129,000 and the fifth year emission reduction is estimated to be 241 MG/yr
(265 tons/yr).  It was estimated that as a result of this NSPS, the price
of fuller's earth would increase by 1 percent or less.  The emission
reduction is considered significant and the cost and economic impacts are
considered reasonable.
2.5.2  Comment (IV-F-1)
     One commenter stated that the BID indicated that particulate emissions
from the LWA industry would be reduced by 56 percent or 500 tons per year.
The commenter estimated that the reduction of 500 tons per year is only a
16 percent reduction.
     Response:  The commenter's calculations were reviewed by EPA.  These
calculations are based on reduction in particulate matter for all  light-
weight aggregate rotary calciners whether or not these sources are subject
to this NSPS.  As shown in Chapter 6 of the proposal BID, the baseline
and NSPS emission limits are 0.21 g/dscm (0.09 gr/dscf)  and 0.092 g/dscm
(0.040 gr/dscf), respectively.  Therefore, the reduction in particulate
emissions for only those lightweight aggregate rotary calciners subject
to the NSPS is 56 percent.
2.6  ENERGY IMPACT
2.6.1  Comment (IV-F-1)
     One commenter indicated that the additional electricity required to
achieve the NSPS levels would result in approximately a  50 percent increase
in particulate matter, nitrogen oxides, and sulfur dioxide emissions from

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power plants due to the difference in electrical  consumption between
baseline and the NSPS level  for the LWA industry.
     Response:  The commenter is correct that particulate matter (PM),
sulfur dioxide (S02 ), and nitrogen oxides (NOX ) emissions may increase
from coal-fired power plants if they are used to  supply any additional
electricity required to achieve NSPS levels.   The commenter is incorrect
that these emissions will  increase by 60 percent  as a result of applying
this NSPS on the LWA industry.  As shown in Table 7-11 in Chapter 7 of
the proposal BID, the increase in energy usage for the LWA industry would
be 60 percent only if all  new facilities were controlled with wet scrubbers.
However, if fabric filters or baghouses were  used to control the new
facilities, there would be no increase in energy  usage for.this industry as
a result of the NSPS.  The EPA cannot predict which control devices will
be installed on new facilities within the LWA and, therefore, cannot
                                                                       *
predict the exact increase in energy associated with applying the NSPS to
the LWA industry.  A worst case analysis of the increase in emissions
from power plants as a result of this NSPS is where only wet scrubbers
are used, and coal-fired power plants are used to supply the increase in
energy.  In this case, based on the NSPS for  power plants (40 CFR 60.40
and 60.40(a)), PM emissions would increase by 1.5 Mg (1.6 tons), S0£ by
59 Mg (65 tons), and NOX by 30 Mg (33 tons).   This represents the increase
in energy usage by all 17 industries covered  by this NSPS.  These increases
are considered reasonable compared with the PM reduction attributable to
this NSPS of 7,900 Mg/yr (8,800 tons/yr).
2.6.2  Comment (IV-F-1)
     One commenter stated that the 1 percent  increase in total power
required by this NSPS may be correct but this increase .is substantial and
unreasonable.  The commenter estimated an additional annual cost of
$50,000 in electricity to operate one wet scrubber on a rotary kiln.
     Response:  As- shown in Table 8-5c of the proposal BIO, there are some
dryer/calciner types where the incremental increase in energy costs from
control devices may exceed $50,000.  However, in  many cases there is no
increase as present control devicas are achieving the standard; if baghouses

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are used there is no additional power cost compared to an assumed baghouse
baseline.  As shown in Table 7-12 of the BID, the incremental energy
requirement to operate control equipment due to the NSPS would be less.
than 1 percent of the total energy used to operate dryer and calciner
process units.  The highest price increase for facilities with higher
energy costs is estimated to be 1.4 percent based on realistic prices for
the minerals.  This increase is considered reasonable by EPA considering
the significant reduction in particulate emissions.

2.7  SELECTION OF BEST DEMONSTRATED TECHNOLOGY
2.7.1  Comment (IV-F-1)
     One commenter wrote that this NSPS not only dictates the level of
0.04 gr/dscf but also dictates the control techniques to be used to achieve
this level.  He felt this reduces competition and drives up the cost of
pollution control equipment by restricting suppliers.  Another commenter
stated that the proposed rule appears to discriminate against suppliers
as well as users of scrubbers by mandating a higher pressure drop across
the scrubber to obtain a lower emission rate.  The commenter stated that
increasing the pressure drop for wet scrubbers is not the only method to
assure better particulate control.  Alternate methods mentioned by this
commenter include lowering the solids content in recycled scrubber water,
using all fresh make-up water, and increasing the atomization of scrubbing
liquid which would all increase the particulate control  efficiency.
    •Response:  The EPA does not dictate the use of any  emission control
device that is to be employed to attain and maintain compliance with the
performance requirements of these standards.  This choice is up to the
owner or operator of the affected facility.  Compliance  with the pollutant
concentration limits of these standards generally can be achieved by
application of one of several alternative control strategies.  As stated
in the preamble to the proposed standards (51 FR 15433,  April 23, 1986),
tests of 15 wet scrubber-controlled dryers in seven industries indicate
that for 10 of the 15 dryers, relatively low energy wet  scrubbers
(3-co 10-inch water column pressure drop) were able to reduce .emissions
to less than the NSPS level.  Tests of nine scrubber-controlled calciners
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indicate that for six calciners, wet scrubbers were able to reduce emissions
to less than the NSPS level.  Therefore, the use of low energy wet scrubbers
or scrubbers which use alternative methods to reduce particulate emissions
is not always precluded by the NSPS level selected.  However,, there are
extreme case-specific factors that may require that a scrubber, if selected
by the owner, be a high-energy scrubber in order to achieve the performance
standard.  Any alternative method of increasing a scrubber's efficiency
in removing particulate matter from the dryer or calciner's vent stream
that reduces the emissions to the NSPS level is also acceptable.
2.7.2  Comment (IV-D-2, IV-F-1)
     Two commenters stated that the proposed standards discriminate against
low energy scrubbers.  They stated that stack tests by EPA on a low energy
scrubber at refractory facilities indicated removal efficiencies greater
than 99 percent, an average outlet concentration of O.OS6g/dscm, and
opacities of zero to five percent.  The commenter felt that pollution
devices which achieve that level of control should be acceptable for the
control of new sources.  The commenter also stated that wet scrubbers
require less maintenance and provide more reliable service than other
control devices.  He felt that the maintenance aspect of control devices
should be considered in selecting the level of the standards.
     Response:  As mentioned in the section 2.3.1, compliance with the
emission limits of this standard can be achieved by application of different
emission control strategies.  For any dryer or calciner subject to the
NSPS, EPA does not require the use of a particular control device.  In
several industries, EPA has determined that wet scrubbers with pressure
drops less than 6 inches of water gauge can achieve the standard.  However,
as discussed in the preamble to the proposed standards (51 FR 15438,
April 23, 1986) to evaluate the performance of higher energy scrubbers on
dryers and calciners that did not meet the NSPS emission limits, an EPA
computerized scrubber model, as described in EPA report No. EPA-600/7-78-026,
was used.  This modelling indicated that the pressure drop required to
achieve the NSPS emission limit for rotary dryers is 14 inches.  The economic

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impact of this NSPS for fire clay rotary dryers is not adverse because the
percent product price increase is less than 1 percent for all sizes as
shown in Chapter 9 of the BID for the proposed standards.
     In estimating the costs and economic impacts associated with the
standards, EPA included the cost of the improved operation and the increased
maintenance of both baghouses and scrubbers that would be required to achieve
the level of the standards.  The costs and economic impacts associated with
the increased maintenance being required were considered by EPA and determined
to be reasonable.

2.8  SELECTION OF FORMAT OF STANDARDS
2.8.1  Comment (IV-D-8)
     One commenter questioned the desirability of imposing an emission limit
without regard to the quantity of material being processed by the dryer or
calciner.  According to the writer, the existing process weight rate formula,
used by many states, was designed to ensure that there was a degree of fair-
ness in allowable emissions between large and small processes.  The commenter
said that it states in the preamble to the proposed standards (51 FR 15438,
April 23, 1986) that it is difficult to establish consistent standards by
which to measure particulate emissions at mineral processing plants.  The
commenter stated that it seemed that EPA proposed an emission limitation,
based on particulate concentration, to ease enforcement rather than
desirability of results.
     Response:  The final emission limit is in a concentration format.,
rather than.in a mass emissions per unit of production format.  In general,
this format is preferred bacause it is simpler and it is therefore selected
when it provides a good reflection of the performance of BDT.  The concen-
tration format does indirectly take into account the amount of material
being processed because air flow rates for dryers and calciners generally
increase with production rates.  The EPA's test data does support the
development of concentration standards of 0.092 g/dscm (0.040 gr/dscf) for
calciners and 0.057 g/dscm (0.025 gr/dscf) for dryers.  These limits can
be met by ail new, modified, or reconstructed dryers and calciners.  No
apparent benefit would result by basing the standard on process weight.
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Moreover, accurate measurement of process weight on a short-term basis
adds difficulty and cost.  Some processing plants do not measure production
or feed rate over the short term, so they would find it difficult to
determine compliance with a mass emissions standard.  Establishment of
the concentration format standard will  not add the cost of monitoring the
process throughputs on those industries which do not currently monitor
short-term feed rates.

2.9  SELECTION OF EMISSION LIMITS
2.9.1  Comment (IV-0-2)
     The commenter recommended the selection of Regulatory Alternative I,
which would allow States to control emissions through SIP's, or Regulatory
Alternative II, which would limit emissions from both calciners and
dryers to 0.09 g/dscm over Alternative III, which the commenter felt
precluded the use of low energy scrubbers.
     Response:  The standards are based on EPA's judgment of the technology
which represents BOT considering the cost, any nonair quality health and
environment impact and energy requirements.  In this case, BOT is a baghouse
or high energy scrubber although in some instances low energy scrubbers may
achieve comparable performance.  A standard based on low energy scrubbers for
all sources covered by this NSPS would not reflect BDT or reduce emissions to
a level achievable by BDT.
2.9.2   Comment (IV-D-2, IV-F-1)
     Two commenters questioned the fairness and rationale of having a more
stringent standard (0.025 gr/dscf) for dryers alone compared with the
standard (0.040 gr/dscf) for dryers and calciners in series.  One of the
commenters stated that it did not seem equitable because producers without'
calciners but with dryers would be bound by a more stringent standard.
     Response:  The NSPS emission level for dryers and calciners in series
(0.040 gr/dscf) is different than for dryers alone (0.025 gr/dscf) because
EPA's emission test data and analysis indicate that these levels reflect BDT.
As shown on page 4-46 of the BID, all emission test data for dryers were
less than 0.025 gr/dscf except for four dryers controlled by wet scrubbers
and one controlled by a baghouse which was not operating properly as there
was leakage through a closed bypass damper.  By using EPA's wet scrubber
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model, increases in pressure drop were calculated to ascertain what is
required to achieve 0.025.  As shown on page 4-47 of the BID, all emission
test data for calciners were less than 0.04 gr/dscf except for three  •
calciners controlled by wet scrubbers.  Again, EPA's wet scrubber model was
used to determine the pressure drop required to achieve 0.04.  Also,
emission test results for a flash dryer/rotary calciner installed in
series in the diatomite industry (Plant 01) on page 4-49 of the BID were
0.040 gr/dscf.  As defined in the regulation, "installed in series" means
a dryer and calciner installed such that the exhaust gases from one flow
through the other and then the combined exhaust gases are discharged to
the atmosphere.  No emission data were submitted to support changing the
standard for these sources.
2.9.3  Comment (IV-F-1)
     Four commenters questioned why the NSPS emission limits on particulate
matter for the proposed standard are much stricter than the limits placed
on hazardous waste incinerators (0.08 gr/dscf).  They felt this was
inappropriate because the emissions from their facilities are nonhazardous
while the emissions from a hazardous waste incinerator will almost certainly
include hazardous materials.  Some of these commenters questioned why the
emission level for lightweight aggregate is not the same as for the cement
industry (0.13 gr/dscf) since the production processes are similar.
     Response:  As stated in section 2.1, the main purpose of standards
of performance required by Section 111 of the Clean Air Act is to require
new sources, wherever located, to reduce emissions to the level achievable
by the best technological system of continuous emission reduction considering
the cost of achieving such emission' reduction,-any nonair quality health
and environmental impact and energy requirements [Section lll(a)(!)].  It
is not unusual in developing NSPS for different industries to identify
differences in control  technologies and removal efficiencies, cost and
economic impacts associated with control technologies, and other unique
characteristics associated with the industry being regulated.  The actual
emission limits selected are based on available test data and cost and
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economic impact analyses of the alternative control  levels.  The commenters
were incorrect in their understanding of the Portland cement NSPS.  The
emission limit in that standard is 0.3 Ib of participate matter emissions
per ton of material  processed.  This equates to a concentration standard
of 0.03 gr/dscf which is less than the limits for calciners or calciners
and dryers in series in this NSPS.
     As discussed in sections 2.9.1 and 2.9.2 and in the preamble for the
proposed standards (51 CFR 15438, April 23, 1986), the EPA test data
for calciners and dryers in the mineral industry clearly show that the
emission limits are achievable.  After analysis, the cost and economic
impacts associated with the NSPS level of control were determined to be
reasonable.  Related to the hazardous waste incinerators, similar tests
led to the selection of the 0.08 gr/dscf emission limit (47 FR 27520,
June 24, 1982).
2.9.4  Comment (IV-F-1)
     One commenter stated that there have been background readings taken
that show the particulate level in the ambient air is 0.02 gr/dscf.  He
concluded that, therefore, the proposed standards will  permit only
0.02 gr/dscf more than is in the ambient air.  He felt this was overly
restrictive.
     Response:  A background level of 0.02 gr/dscf is approximately 46,000
micrograms per cubic meter.  This value is unrealistically high and is
not representative of the background particulate matter levels anywhere
in the United States.  In addition, the test data and analysis as discussed
in Chapter 4 of the proposal BID clearly shows outlet particulate concen-
trations less than the NSPS emission limits are achievable.  A total of
52 source tests comprise the data base.  The 25 dryers and 27 calciners
tested were processing a variety of minerals in many different geographic
locations.  In none of these cases did the background level of particulate
matter in the ambient air cause the outlet particulate emissions to
exceed the NSPS emission limits.  Because the emission limits are achievable
and the cost and economic impacts are reasonable, EPA sees no reason to
cnange the NSPS emission limits.
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2.10  TEST METHODS AND MONITORING
2.10.1  Comment
      One commenter requested that the participate concentration  standard  be
corrected to a certain percent oxygen measured at the stack.   For example,  he
suggested using the average oxygen level from test data used to establish  the
standards.  If this is not acceptable, then the commenter recommended  the
source continuously monitor the oxygen level with a continuous emission
monitor which should be calibrated per Appendix B, Specification  3 of  40 CFR
60.  This monitor should be located near the stack sampling site  and be
certified before the performance test according to the commenter.
      Response:  As noted in the preamble to the proposed standards
(51 FR 15438, April 23, 1986), a concentration-based standard could be
circumvented by adding dilution air to the gas stream.  However,  this  is
unlikely to occur at mineral calciner and dryer facilities, because the size
and operating costs of fans and motors increase with increasing gas volume  to
be handled.  Also, Section 60.12 of the General Provisions clearly states  that
gaseous diluents cannot be used to achieve compliance with a standard which is
based on the concentration of a pollutant in the gases discharged to the
atmosphere.
2.10.2  Comment
      One commenter stated that the requirement for semiannual  recalibration
of a COMS refers to 40 CFR 60.13 which contains only daily zero and span check
procedures.  According to this comment, it would be more appropriate to
require repetition of calibration error check procedures of 40 CFR 60,
Appendix B, on a quarterly basis to check the linearity of the analyzer.
      Response:  The requirement of the repetition of calibration error check
procedures of 40 CFR 60,  Appendix B,  Specification 1,  on a quarterly basis to
check the linearity of the analyzer is intended for monitors that, by terms of
applicable NSPS, are used to determine compliance.  In this case,  the
installation of a COMS is intended to evaluate operations and maintenance of
the control equipment; the frequency of the repetition of calibration effort
check has not yet been determined.  The only requirement for COM's intended
for operation and maintenance at this time are daily zero and span checks.
The reference to semiannual  recalibration has been deleted from the final
standards.
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 2.10.3  Comment (IV-D-4)
       One commenter stated that dryers are used in their diatomite operation
 for the evaporation of uncombined water.   He pointed, out that the measured
 moisture contents  within  these flue gases vary from 7 to 22 percent by volume
 and during cold weather,  plume moisture occurs with little or no plume stack
 separation.   In addition,  he stated that condensed water has appeared on the
 stack  exterior in  the vicinity of the sample ports at his plant.  According to
 the commenter, these conditions are not conducive to in-stack opacity
.monitoring devices.  He felt it would be more reasonable to require a
 certified observer to record opacities on a periodic basis similar to EPA's
 proposed monitoring requirements for gypsum and perlite pyroprocessing units.
       Response: Condensation on the outside of the stack should have no
 effect on the opacity inside the stack.   The commenter had no data to support
 that opacity readings were erroneous when moisture was sighted on the stack
 exterior.   However, if high moisture content in the stack causes malfunction
 of the COM's,  the  owner or operator may petition the Administrator to approve
 an alternative monitoring  procedure,  requirement,  or location according to
 Section 60.13(i).
       In addition,  the promulgated standards allow owners or operators of
 diatomite flash dryers who use a dry control  device to have a certified
 visible emission observer  record daily three 6-minute opacity averages in lieu
 of installing a COMS,  and  diatomite rotary dryers  are exempt from any
 monitoring requirements.
 2.10.4  Comment (IV-D-7)
       One commenter felt that a COMS for  an ESP controlling a dryer used in
 bentonite processing would continuously yield erroneous readings due to
 dripping water, falling clay-laden films,  and clay film bridging.   He cited
 problems his company has experienced wi'th a bentonite dryer controlled by a
 "dry"  ESP.   The commenter  stated that extensive insulation of the stack has
 reduced the  film thickness but it has not eliminated it.   He recommended that
 emissions from "dry"  control  devices  be treated similarly to emissions from
 "wet"  control  devices  and  that periodic visual  opacities  plus recording of
 certain' operating  parameters  be allowed  for the assessment of compliance with
 the proposed opacity requirements.   He felt the requirements should be
 flexible and depend on the configuration  of the control  device and its
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operating requirements rather than having  a  rigid  across-the-board
requirement, even  it not attainable,  imposed on  all  "dry"  ESP installations.
      Response:  Conditions downstream  of  a  dry  ESP  should be reasonably dry.
However, if a high moisture, content of  the exhaust gas  causes erroneous
readings from the COMS, the owner or  operator may  petition the Administrator
to approve an alternative monitoring  procedure or  location according  to
Section 60.13(1).
2.10.5  Comment  (IV-D-2, IV-D-5, IV-F-1)
      Three commenters felt that the  reasons used  by EPA to justify continuous
opacity monitoring, and the associated  recordkeeping and reporting are
inadequate.  Two of the commenters stated  that broken bags in a collector are
apparent without the need for a COMS  and the increased  capital  and operating
costs associated with continuous opacity monitoring  are not commensurate with
the benefits.  They felt that this requirement should apply only to major
sources of pollution.  The other commenter stated  that  his company's
experience with these monitors has shown them to be  expensive,  difficult to
install, very difficult to maintain and inaccurate.  He recommended these
requirements be dropped.
      Response:  Section 114 of the CAA authorizes EPA  to  require  such
monitoring as is appropriate for enforcing NSPS.   Also, Section  301(1)  of the
CAA defines "standards of performance" to  include  "any  requirement relating to
the operation and maintenance of a source  to  assure  continuous  emission
reduction."  The-EPA's experience with control devices  shows  that  regular
maintenance, both remedial  and preventive, greatly enhances  control equipment
efficiency and reduces overall costs.  As  stated in  the preamble to the
proposed standards (51 FR 15438), opacity  monitoring can indicate  when  fabric
filter bags are torn loose and when ESP electrodes are  damaged  or
malfunctioning.  EPA's experience with COMS's is that the  devices  operate
accurately and with minimum downtime with  regular  and reasonable maintenance.
      The EPA agrees with the commenters that a sudden  increase  in emissions
resulting from either broken bags in a baghouse or a sudden  failure of  a
baghouse or ESP would be immediately apparent and require  attention by the
source operator.   However,  the purpose of  a COMS or other  monitoring
alternatives such as daily visible emissions observations  is  to alert industry
and enforcement personnel  to potential violations of the mass emission
:tandara and to ensure "he  proper operation  and .naintenanca  of oartICLJ 1 ate
                                      2-3:

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control equipment on a continuous basis, i.e., to alert the operator  to  more
subtle and gradual deterioration of the control device efficiency  that occurs
over time and results in increased emissions unless corrected.  The emission
reduction performance of air pollution control equipment  is dependent upon  the
proper operation of many components of the control system.  While  certain
parameters can provide information on the status of certain key components,  it
is generally not possible to determine overall control device performance by
monitoring parameters other than emissions.  Without COMS's, operators have
essentially no tools that they can use to monitor the continued performance of
ESP's or fabric filter systems or to ensure that necessary maintenance is
performed.  The broken rapper welds and bag deterioration are examples of
items that affect emissions and that cannot be evaluated or detected  except
with COMS's.  The reporting of excursions as recorded by COMS's also  helps
State and local enforcement programs with their control devices.   Since  plant
inspections and testing are infrequent, gradual deterioration will not be
detected until a major failure occurs unless opacity monitoring is required.
      The benefits of using a COMS are documented in a recent study conducted
at Portland cement plants (Docket Item II-A-130).  The study concludes that
COMS's installed on control equipment at these plants contributed
significantly to lower emissions.  The emission reduction benefits are derived
from:  (1) indicating when repairs and maintenance of control  equipment  is
needed, (2) signalling the need for a change in operating and maintenance
practices for the process and the air pollution control device, and (3)
quantifying emission reductions after the installation of a COMS.  Factors
which contributed to the lower emissions from the facilities were:  (1)  an
increased sensitivity of the plant operating personnel that changes in process
operating conditions and flue gas characteristics affect stack emissio.ns, (2)
the awareness by plant operators that increased stack opacities below the
opacity limit can be indications of excess  particulate emissions, and (3) an
enforcement presence on a continuous basis.
      Nevertheless, as the amount of emissions from an individual source
decreases, the benefits of monitoring also  decrease and at some point it is no
longer reasonable to require a COMS or other monitoring alternative.
Therefore, as a result of the comments received,  £PA evaluated four
alternative monitoring requirements:  the use of a COMS;  the reading of
visible emissions daily or weekly by a certified visible emissions observer:
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and no monitoring requirements (Docket No. A-82-39,  IV-B).
      As a result of the analysis, the Administrator has determined  that  it  is
reasonable to require the installation of the COMS's on all dryers and
calciners of a certain type within an industry where the typical  size unit of
that type has emissions after NSPS control equal to or greater than  22.7  Mg/yr
(25 tons/yr).  For typical size units with emissions less than 22.7  Mg/yr (25
tons/yr) but greater than or equal to 10 Mg/yr (11 tons/yr),  EPA  has
determined that owners or operators may perform daily visible emission
observations in lieu of installing a COMS.  The EPA has also determined that
typical units with emissions less than 10 Mg/yr (11 tons/yr) should  be exempt
from any monitoring requirements. Because of the variation  in emissions after
NSPS control for each size and type of calciner or dryer and for  each
industry, the monitoring requirements are based on the typical size  of a
particular type of calciner or dryer in each industry.  The specific
monitoring requirements for each type of dryer or calciner  in each industry
are presented in Section 60.734 of the final standards.
      The following discussion summarizes the basis for the specific
monitoring requirements for each type of dryer or calciner.  The  EPA used 22.7
Mg/yr (25 tons/yr) as the cutoff level  for particulate matter (PM) emissions
in determining which facilities would be required to install COMS's  if they
use dry control  devices.  In the prevention of significant deterioration  (PSD)
rules, EPA set de minimis levels of emissions for various pollutants.  For PM
emissions, the level was selected by evaluating the potential effect of
different emission levels on the area's air quality and how that  related  to
the national ambient air quality standard for PM.   The analysis was based on a
source's potential to emit after application of all appropriate Federal
regulations such as NSPS.   The significance level  for PM emissions was set at
22.7 Mg/yr (25 tons/yr).  Therefore,  the Administrator has determined that it
is beneficial and reasonable to require the installation of COMS's on all
calciners of a certain type within an industry where the typical   size unit of
that type has emissions after NSPS control  equal  to or greater than 22.7 Mg/yr
(25 tons/yr).
      As stated  previously,  however,  as the amount of amiss ions from an
individual source decreases,  the expected benefits of monitoring   also decrease
and at some point it is no longer reasonable to require a COMS or other
monitoring alternative.   As a result,  "or calciners and dryers with emissions
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of less than 22.7 Mg/yr (25 tons/yr) after NSPS controls, the EPA assessed
alternatives other than the installation of a COMS.  These alternatives
included daily or weekly visible emission observations and no monitoring
requirements.  In assessing the reasonableness of performing daily versus
weekly visible emission observations, it was determined that the cost of
either one would be similar but not deliver the same benefits.  In both cases,
employees of the affected plant would need to be formally certified as opacity
readers twice per year.  The costs associated with the certification would be
incurred regardless of whether a daily or weekly monitoring requirement was
imposed.  The other costs associated with these alternatives are the annual
cost of performing the observations and recording the results.  The annual
cost of weekly readings of visible emissions would be reduced somewhat, but
because of the fixed cost of certification, would cost approximately 40
percent of the cost of doing daily observations.  Moreover,  a daily
observation program would be more effective at identifying gradual
deterioration of the control device efficiency and allowing a plant operator
time to correct the problem prior to complete failure of the device.  A weekly
observation program would not identify the gradual deterioration of the
control device as quickly and, in some cases, a failure of the control device
could occur between two weekly observations.  Because requiring daily
observations would yield substantially greater benefits than weekly
observations and the cost difference was considered reasonable,  the
alternative of weekly observations was considered inferior for the sources
with less than 22.7 Mg/yr of emissions after NSPS control.  Therefore, for
typical size units with emissions less than 22.7 Mg/yr, but  greater
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than or equal to 10 Mg/yr, the regulation has been revised to allow the
owner or operator to perform daily visible emission observations in lieu
of installing a COMS.
     On the other hand, the Administrator has determined that typical
size units with emissions less than 10 Mg/yr should be exempt from any
monitoring requirements.  In making this determination, consideration was
given to the size of the source in terms of the emissions after NSPS
control is applied.  In addition, the benefits associated with monitoring,
such as identifying sources that are having control equipment problems
for the appropriate enforcement agency so corrective action can be taken,
were considered.  For very small sources with small control devices, the
benefits associated with a COMS or daily visible emission observations, in
terms of reducing excess emissions, are smaller in comparison to larger
sources.  The cost of daily visible emission observations as a percent of
the annualized cost of operating the control equipment was also considered.
For these reasons, typical size units with emissions less than 10 Mg/yr are
exempt from any monitoring requirements.  The new monitoring requirements
per type of dryer or calciner and per industry are presented in Section 1.1.
2.10.6  Comment (IV-F-1)
     One commenter noted that at an earlier EPA hearing, an EPA representative
stated that opacity monitors are 98 percent reliable.  Because his company
operates 24 hours a day, seven days a week, it would be 3.4 hours a week
of built-in possible problems.  He is concerned that when the instrument
is not working properly, its findings might stop the plant from operating
or place them out of compliance with the fina-1 standard.  He feel.s that
until the technology is perfected this burden should not be placed on the
LWA industry.
     Response:  Section 60.13 of the General Provisions addresses Che
commenter's concerns.  The EPA recognizes that there will be times when
the monitors will  break down and be in need of repair.  However, these
occurrences can be minimized with good operating and maintenance practices.
However, if there is a problem with the monitor, Section 50.13(h)  clearly
states that data recorded during periods of continuous monitoring system
breakdowns, repairs, calibration checks, and zero and span adjustment

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shall not be included in the data averages computed.  Therefore, the
findings of a.COMS that is not working properly will not cause a plant to
stop operating or cause a plant to be cited for being out of compliance
with the standards.
2.10.7  Comment (IV-D-3)
     One commenter stated that it was inconsistent to allow 18 minutes of
visible emission observations per week to be substituted for COM's on certain
sources.  Also, at a minimum, the commenter felt that these observations
should be required on at least a daily instead of a weekly basis.  To
avoid a source selecting periods of low opacity to conduct the observations,
a predetermined schedule for these observations should be specified
according to this commenter.
     Response:  As discussed in section 2.10.5, EPA re-evaluated the
opacity monitoring requirements for dry control devices.   The EPA determined
that for those cases where daily visible emission observations were not
reasonable no monitoring requirements were appropriate.  (See Docket
No. A-82-39, IV-B).  The final monitoring requirements for dry control
devices are presented in Section 1.1.
     Related to the commenter's concern that sources will select periods
of low opacity to conduct the observations, EPA has determined that it is
not practical to require these sources to make their observations on
a specified schedule.  Because differences in operating schedules and
times exist from plant to plant and industry to industry, it is not
possible to specify a schedule for visible emission readings that would
be practical.                      .       ,

2.11  REPORTING AND RECOROKEEPING
2.11.1  Comment (IV-D-3)
     One commenter requested that the semiannual reporting of exceedances
as described in Section 60.735 should be increased to quarterly, in order
to be consistent with the reporting frequency of other sources and to
help identify potential problems in a more timely manner.
     Response:  The EPA uses the following procedure to determine reporting
frequencies for NSPS.
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     For NSPS, the Information collected is of three different types that
are of different uses to the enforcing agency.  These types of information
are:
     1.  Monitored Parameter Data - information on control  device or
     process parameters (e.g., pressure drop).  This information is used
     as an indicator of how well  the control  device is being operated- and
     maintained and is useful for targeting inspections.
     2.  Excess Emission Data - generally continuous emission monitor
     reports.  This information is used as an indicator of the compliance
     status of the source and may be used to target inspections or
     performance tests.  In most  cases, neither this nor monitored parameter
     data may be used as the sole evidence of a violation of the standard.
     3.  Direct Compliance Information - data which may be used by the
   •  enforcement agency as the sole evidence of a violation, of the standard.
     Direct compliance information is most useful to an enforcement agency
because the compliance status of  the source is evident from the information
itself and no further testing is  necessary to document a violation.  Because
these data can be used so quickly, and because it is beneficial to an
enforcement action to have the freshest data available, sources are required
to report this information to EPA on a quarterly basis.  However, if no
exceedances of the standard have  occurred during a particular quarter,
only a statement to that effect (negative declaration.) is needed.  Further,
these negative declarations may be made on a semiannual basis.  Thus, the
quarterly reporting period is activated only when a source has had an      .
exceedance of the standard during that particular quarter.   This helps
focus the resources both of the industry and of EPA on sources where
remedial action is warranted.  For NSPS, semiannual  reporting is required
in the absence of evidence as to  why this is not sufficient.  Factors
that are considered include size, number and location of sources, likelihood
of excess emissions, potential for severe adverse air quality impacts.
For this particular NSPS, after weighing the factors described above, it
was determined that semiannual reporting of the monitored data was appropriate,

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2.12  MISCELLANEOUS
2.12.1  Comment (IV-D-7)
     One commenter stated that in the preamble to the proposed standards
the Agency appeared to assume that particle size distribution and emissions
loading from all  bentonite dryers are identical.  According to the commenter,
the particle size distribution in dryer emissions is influenced by the
processing history of the bentonitic material  prior to the drying and/or
prior to final emission control and would also tend to vary markedly
between rotary dryers and fluid bed dryers.
     Response;  The commenter was contacted to determine if he had any
emission test data which indicated what was the worst case of uncontrolled
emissions for bentonite dryers.  He had no specific data but felt that
uncontrolled emissions from dryers that process Wyoming bentonite would
be a little higher than from dryers in Mississippi.  He also felt that
coal burning would increase the emission problem and could not estimate
whether emissions from rotary dryers are harder to control than fluid bed
dryers.
     As shown in Chapter 4 of the BID, emission test data on two bentonite
rotary dryers were obtained.  Both plants are  located in Wyoming and burn
coal.  Controlled emissions were 0.014 g/dscm  (0.006 gr/dscf) and
0.047 g/dscm (0.020 gr/dscf).  In addition, test data from dryers in the
titanium dioxide industry where the particles  were much smaller and,
therefore harder to control than emissions at  the bentonite facilities,
show that the standard can be met.
2.12.2  Comment (IV-F-1)
     One commenter requested a better definition of the mineral industry.
He questioned whether users as well as producers were covered.  He stated
that refractory producers are under SIC 3255,  clay refractories, and
3297, non-clay refractories.  He questioned whether they were covered or
if the coverage was limited to major SIC group 14.  He also questioned
whether magnesium compounds applied only to magnesium minerals or are
recycled magnesia brick and shapes included.
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     Response:  This regulation covers calciners and dryers at mineral
processing plants.  A mineral  processing plant is any facility that
processes or produces any of the following minerals, their concentrates,
or any mixture of which the majority is any of the following minerals:
alumina, ball clay, bentonite, diatomite, feldspar, fire clay, fuller's
earth, gypsum, industrial sand, kaolin, lightweight aggregate, magnesium
compounds, perlite, roofing granules, talc, titanium dioxide, and vermicu-
lite.  To determine whether a particular mineral  is or is not covered,
the EPA bases its determination on the United States. Bureau of Mines
definitions for these minerals in their annual yearbook.  Standard
industrial codes are not used in this determination.  However, as stated
in the preamble at proposal (51 FR 15438, April 23, 1986) for the brick
and related clay products source category, only calcining and drying of
raw materials prior to firing of the brick are covered under this NSPS.
Section 60.730 and the definition of "mineral  processing plant" in Section
60.731 of the regulation have been revised to clarify this point.  Magnesium
compounds covered by the NSPS are caustic-calcined and specified magnesias,
magnesium hydroxide, magnesium sulfate, precipitated magnesium carbonate,
and refractory magnesia.
                                   2-45

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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing/
1. REPORT NO. 2.
EPA 450/3-85-025b
4. TITLE AND SUBTITLE
Calciners and Dryers in Mineral Industries
3. RECIPIENT'S ACCESSION NO.
5. REPORT DATE
December 1991
Background Information for Promulgated Standards 6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Office of Air Quality Planning & Standards
U. S. Environmental Protection Agency
Research Triangle Park, NC 27711
12. SPONSORING AGENCY NAME AND ADDRESS
Director of Air Quality Planning & Standard
Office of Air and Radiation
U. S. Environmental Protection Agency
Research Triangle Park, NC 27711
8. PERFORMING ORGANIZATION REPORT NO.
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
13. TYPE OF REPORT AND PERIOD COVERED
s Final
14. SPONSORING AGENCY COOE
EPA/ 2 00/04
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Standards of performance for the control of emissions from calciners and dryers in
mineral industries are being promulgated under the authority of Section 111 of the
Clean Air Act. These standards would apply to new, modified, or reconstructed
calciners and dryers in 17 mineral industries. This document contains a summary
of the contents on the proposed standards, the Agency's response to the comments,
and a summary of the changes to the standards since proposal.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
• Air Pollution
Pollution Control
Standards of Performance
Particualte Emissions
Mineral Processing Plants
18. DISTRIBUTION STATEMENT
Unlimited
b.lOENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Air Pollution Control 13B
19. SECURITY CLASS iTIlis Report 1 21. .NO. OF PAGES
Unclassified 53
20. SECURITY CLASS (This oazei I 22. PRICE
I
Unclassified
EPA Form 2220-1 (Re».-4-77)    PREVIOUS EDITION is OBSOLETE

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                                                        INSTRUCTIONS

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       Include ZIP code.

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ePA Form 2220-i (Rev. 4-771 (Revsriei

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