v-xEPA
           United! States
           Environmental Protection
           Agency
          Office of Air Quality
          Planning and Standards
          Research Triangle Park NC 27711
EPA-45Q/3-85-022b
July 1989
           Air
Polymeric
Coating Of
Supporting
Substrates—
Background
Information for
Promulgated
Standards
Final
EIS

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  POLYMERIC COATING OF SUPPORTING SUBSTRATES--
BACKGROUND INFORMATION FOR PROMULGATED STANDARDS
           Emission  Standards  Division
      U.  S.  Environmental  Protection  Agency
  Office of Air Quality Planning and Standards
  Research  Triangle Park,  North Carolina  27711

                    July 1989

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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, North
Carolina  27711, or  from National Technical Information Services,
5285 Port Royal Road, Springfield, Virginia  22161.
                                   ii

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                        ENVIRONMENTAL  PROTECTION AGENCY

                            Background Information
                                   and Draft
                        Environmental  Impact Statement
              for the Polymeric Coating of Supporting Substrates

                                 Prepared by:
JacXR. Farmer                                         /  (D*fte)'
Director, Emission Standards Division
U. S. Environmental Protection Agency
Research Triangle Park, N.C. 27711

1.   The promulgated standards of performance will limit emissions of volatile
     organic compounds (VOC) from new, modified, and reconstructed facilities
     that perform polymeric coating of supporting substrates.  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, Transportation,
     Agriculture, Commerce, and Interior; the National Science Foundation; the
     Council on Environmental Quality; State and Territorial Air Pollution
     Program Administrators, EPA Regional Administrators; Association of Local
     Air Pollution Control Officials; Office of Management and Budget;  and
     other interested parties.

3.   For additional information contact:

     Ms. Laura Butler or Mr. Doug Bell
     Standards Development Branch (MD-13)
     U. S. Environmental Protection Agency
     Research Triangle Park, N.C. 27711
     Telephone:  (919) 541-5267

4.   Copies of this document may be obtained from:

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

     National Technical Information Service
     5285 Port Royal Road
     Springfield, VA 22161
                                     ill

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                             TABLE OF CONTENTS

                                                                       Page

CHAPTER 1   SUMMARY	    1_1

            1.1   SUMMARY OF CHANGES SINCE PROPOSAL	    1-1
            1.2   SUMMARY OF IMPACTS OF PROMULGATED ACTION	    1-8

CHAPTER 2   SUMMARY OF PUBLIC COMMENTS	    2-1

            2.1   SELECTION OF THE SOURCE CATEGORY	    2-6
            2.2   AFFECTED FACILITY	    2-10
            2.3   SELECTION OF BDT AND EMISSION LIMITS	    2-12
            2.4   CONTROL COSTS	    2-43
            2.5   ENVIRONMENTAL IMPACTS	    2-50
            2.6   ECONOMIC IMPACTS	    2-52
            2.7   COMPLIANCE	    2-56
            2.8   TEST METHODS AND MONITORING	    2-59
            2.9   REPORTING AND RECORDKEEPING	    2-62
            2.10  WORDING OF THE REGULATION	    2-63
            2.11  MODIFICATION/RECONSTRUCTION	    2-73
            2.12  REFERENCES FOR CHAPTER 2	    2-75
TABLE 2-1
TABLE 2-2
TABLE 2-3
                  LIST OF TABLES

LIST OF COMMENTERS ON PROPOSED STANDARDS OF
  PERFORMANCE FOR NEW STATIONARY SOURCES;
  POLYMERIC COATING OF SUPPORTING SUBSTRATES,

SUMMARY OF TOTAL ENCLOSURE
  CRITERIA	
AVERAGE AND INCREMENTAL COST EFFECTIVENESS FOR MODEL
  COATING OPERATIONS	
2-2


2-15


2-24
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                                1.  SUMMARY

     On April 30, 1987, the U. S. Environmental Protection Agency  (EPA)
proposed new source performance standards  (NSPS) for the polymeric coating
of supporting substrates (52 FR 15906) under authority of Section  111 of
the Clean Air Act.  Public comments were requested on the proposal
published in the Federal Register.  A total of 24 comments were submitted
during the comment period, including 21 from industry, 2 from trade
associations, and 1 from a State agency.  The comments that were
submitted, along with responses to these comments, are summarized  in this
document.  The summary of comments and responses serves as the basis for
the 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
reevaluation, several changes have been made to the standards since
proposal.  In addition, portions of the final regulation were reworded and
reorganized to clarify the intent of the rule.  The more significant
changes, which are categorized under the section headings in the
regulation, are summarized below.
1.1.1  Applicability and Designation of Affected Facility
     1.1.1.1  Coating Mix Preparation Equipment.  A change was made to the
definition of coating mix preparation equipment to include only mixing
vessels, and not mills, holding tanks, or other equipment used in the
preparation of polymeric coatings.  Equipment other than mixers was
included in the affected facility definition in the proposed standards
because it was believed that the controls required for mixers could be
easily applied to other types of mix equipment.  However, based on a
reexamination of the information gathered during the development of the
standards and based on the information provided by a commenter, only
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 mixing vessels are Included In the affected facility in the promulgated
 standards.
      1.1.1.2  Exclusions.   The regulation has been revised to state
 explicitly  that graphic arts facilities are not covered by the
 standards.   The exclusion  of paper,  plastic film,  metallic foil, and metal
 coil  coaters has been clarified by revising the definition of "polymeric
 coating of  supporting substrates."  The exclusion  of leather finishers has
 been  clarified by removing the reference to leather in the definition of
 "web  coating."  Comments from the leather,  graphic arts,  and paper coating
 Industries  revealed  that it was unclear if  the proposed standards were
 applicable  to these  particular industries.   The EPA did not study these
 industries  and did not intend for the  standards to be applicable to these
 industries.   An exemption  also was added for waterborne coatings because
 use of these coatings may  be incompatible with the available control
 technologies.
 1.1.2   Standards  for Volatile Organic  Compounds (VOC)
      1.1.2.1  Coating Mix  Preparation  Equipment—VOC  Use  at Least
 130 mg/yr.   The standards  for mixing vessels  serving  coating operations
 that use at  least  130 cubic  meters per year  (Mg/yr)  (144  tons per year
 [tons/yr]) of  VOC  have been  revised consistent  with the application of
 best demonstrated  technology (BOT) in  actual practice.  The proposed
 standards required "venting  all VOC emissions to a 95 percent efficient
 control device," which implies  a  100 percent capture efficiency.  The
 promulgated  standards require  that mixing vessels be covered during mixing
 and vented to  a 95 percent efficient control device.  Allowances  for
 opening the  covers during periods of legitimate need are  included in the
 standards.
     In addition, a provision has been added to the standards that allows
 the use of covers alone on mix equipment at modified or reconstructed
 affected facilities unless  there is concurrent construction of a control
 device.  This change was made because 1t is not certain that the existing
 control devices at all modified/reconstructed facilities would have
 sufficient capacity in reserve to control emissions from the mix
equipment.  As stated at proposal, the installation and use of a dedicated
control device for mix equipment emissions is not cost effective.
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 Therefore,  the  standards  have  been  revised  to ensure that control  of mix
 equipment emissions  is  cost  effective.
      1.1.2.2  Coating Mix Preparation  Equipment—VOC Use  at  Least  95 Mq/yr
 But  Less Than 130  Mq/yr.   A  change  has  been made to  the standards  for
 mixing  vessels  serving  coating operations that use at least  95  Mg/yr (105
 tons/yr) but less  than  130 Mg/yr  (144 tons/yr)  of VOC.  The  proposed
 standards required each piece  of  affected coating mix preparation
 equipment to have  a  vapor-tight cover with  a conservation vent  set at
 17.2  kilopascals (2.5 pounds per  square  inch gauge).   The promulgated
 standards require  a  cover that meets specified  requirements.  This change
 was made because there  is no significant increase in  efficiency gained  by
 using a vapor-tight  cover with a  conservation vent instead of a simple
 tight-fitting cover.  The chief benefit of  conservation vents is the
 control of  "breathing losses," which result  from diurnal  temperature
 changes.  However, mix  equipment  is not normally exposed  to  such
 temperature changes.
      1.1.2.3  Coating Operation.  The standards for the coating operation
 have been revised  to require a 90 percent overall emission reduction
 rather  than 93 percent  as  proposed.  This change was made based on a
 reevaluation of the feasibility of total enclosures in this  industry  and
 of the  test data available to  support the standards.   In general,  EPA
 concluded that while facilities that can use  total  enclosures and
 95 percent efficient control devices may achieve 93 percent or greater
 overall control, the use of this technology may not be available if
 EPA-prescribed total enclosures cannot be used in existing plants.    It was
 determined that 90 percent overall control  is universally  achievable, and
 the standards have been set at this level.
     The standards also have been revised to  include  an alternative
 standard, i.e.,  the use of a total enclosure and 95 percent efficient
control device,  as an alternative to the 90  percent overall emission
reduction standard.  While this alternative  was allowed at proposal as an
alternative means of compliance with the emission reduction standard, EPA
has now decided  to Include it as  an alternative standard in order to
clarify the intent of the rule.  This change is not a revision to the
substance of the proposed rule.
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 1.1.3   Compliance  Provisions
     1.1.3.1   Total  enclosure  specifications.   In order to provide sources
 with guidelines  for  a  total enclosure of the coating  operation,  specifica-
 tions  have  been  added  that  limit  the total  area of the  natural draft
 openings  in the  enclosure,  specify  the minimum allowable distance between
 the openings  and the sources of VOC, and require the  maintenance of an
 average inward face  velocity of at  least 3,600 meters per hour (m/h)
 (200 feet per minute [ft/min]) across the openings.   These restrictions
 are necessary to ensure complete  containment of the VOC emissions from the
 coating operation.   Flexibility has  been maintained by  allowing  enclosures
 not meeting the  requirements to be considered  for approval  by the
 Administrator on a case-by-case basis.   Test procedures  and monitoring,
 recordkeeping, and reporting requirements for  the use of  total enclosures
 also have been added.
     1.1.3.2  Coating Operation Compliance Methods.   The  final standards
 have been revised to clarify that the  use of certain  equipment,  i.e.,  a
 total enclosure  and  a 95 percent efficient control device,  are available
 as an alternate  standard to the 90 percent emission reduction standard.
 In other  words,  the owner or operator may choose  to comply with  either the
 emission  reduction standard or the alternative standard.   In addition, the
 compliance  provisions for coating operations meeting the emission
 reduction standard have been revised to clarify that owners or operators
 may demonstrate compliance by any of the  applicable methods.  The option
 of performing a one-time,  short-term (3-  to 7-day) material balance
 followed by continuous  monitoring was added as  an optional compliance
method.  This option may be attractive at facilities that cannot  or do not
want to conduct the detailed continuous monthly measurements that are
 required for the other  liquid  material balance  option.
     1.1.3.3  Equation  3.   An  error in Equation 3 (§ 60.743(b)(4)), which
 is used to determine the efficiency of the vapor capture system,  has been
corrected  in the promulgated standards.  The terms Qbl- and Cb1  have been
changed to Qd1 and  Cd1, respectively.
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 1.1.4  Monitoring  Requirements
     1.1.4.1  Accuracy  Requirements  for  Temperature Monitoring.   For
 consistency with other  VOC  control regulations,  the accuracy requirements
 for temperature monitoring  have  been changed.   In  the proposed regulation,
 the monitoring device was required to be accurate  within ±2.5 Celsius
 degrees  (±4.2 Fahrenheit degrees).   In the  promulgated regulation,  the
 monitoring device  is required to be  accurate to  within ±1 percent of the
 temperature being  measured  in Celsius degrees.
     1.1.4.2  VOC  Concentration.  The monitoring requirement for  carbon
 adsorbers has been revised  to require devices that indicate  and record the
 "concentration level of organic  compounds"  instead of the "VOC
 concentration in parts per  million by volume."   Although many monitors
 give readings in terms of parts  per  million by volume,  the revision  is
 intended to reflect the fact that EPA has not developed  performance
 specifications or  other quality  assurance procedures  to  ensure the
 accuracy of such monitors.  However, units are available that  are
 sufficiently precise to allow assessment of operation  and maintenance
 practices by comparing monitor data with the baseline  value  established
 during the performance test.
     1.1.4.3  Consistency of Monitoring and Performance  Testing
 Provisions.  The monitoring and performance testing provisions for fixed
 bed carbon adsorption systems have been revised to represent more
 accurately the performance of multiple-bed systems.  Performance tests are
 the direct means of determining the compliance status of an affected
 facility and serve as the basis for legal enforcement actions against
 noncomplying sources.  In contrast, the monitoring devices required by
 these standards serve only as indicators of control device performance to
 aid enforcement agencies in targeting inspections and performance tests
 toward  potential  violators.   The revised procedures will ensure that the
 performance test runs and averaging periods for monitoring will parallel
 the complete adsorption cycles of the individual  adsorber vessels or the
 system's complete sequential rotation through  the adsorption  cycles  of all
the vessels.   Use of a testing or monitoring period that does not
correspond to an Integral  number of actual adsorber vessel cycles  or
 system  rotations  could bias  the  results  slightly in either direction.
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 Efficiencies would be biased high if the test run or monitoring period did
 not include the elevated emissions typical at the beginning and end of a
 vessel's adsorption cycle;  efficiencies would be biased low if the period
 included a disproportionate number of these emission peaks.
      the performance testing provisions for carbon adsorption systems
 included in the standards at proposal  did not specifically index the test
 period  to discrete adsorber vessel  cycles or system rotations.  Rather,
 each of the three requisite performance test runs was required to be a
 minimum of 30 minutes duration.   While this requirement would have allowed
 the performance test runs to correspond to individual  adsorber vessel
 cycles  or system rotations  that were at least 30 minutes in duration,  it
 was not mandatory.   Because adsorption cycles in different systems can
 range from several  minutes  to  several  hours,  performance tests based only
 on  30-minute runs could  be  biased  somewhat in either  direction.   The
 proposed performance testing provisions would have  resulted in adequate
 determinations of the performance of these systems, but  the final
 provisions  provide  for improved accuracy.
      The revised  carbon  adsorption  system  performance testing  provisions
 include separate  requirements  for systems  with a  single  common exhaust
 stack and  for  systems with  individual  stacks  for  each adsorber vessel.
 The  EPA believes  that a  common exhaust  stack  allows simpler performance
 testing that  is more  representative of  the entire system's performance  but
 has  included provisions  for  individual  exhaust stacks because this is
 currently the more typical configuration.
     For adsorption systems with a common exhaust stack serving all the
 adsorber vessels, the final  performance testing provisions require that
 the  system be tested as a whole.  Three test runs are required; each run
must correspond to one or more complete rotations through the sequential
 adsorption cycles of all  the adsorber vessels.
     For adsorption systems  with individual exhaust stacks, the final
performance testing provisions require that each  adsorber vessel be tested
 individually.  Three test runs are required for each vessel; each run must
correspond to one or more complete adsorption cycles.   A procedure has
been added to the compliance provisions for computing  a system efficiency
from the individual adsorber vessel  efficiencies.
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     The final performance  testing  provisions  are  likely to result in
 somewhat increased testing  costs  in the case of  a  multiple-bed system
 because each test run must  include  at  least one  cycle  for each bed.
 However, this increased cost would  be  very small relative to the control
 system cost and is reasonable considering the  increased  accuracy that will
 result.
     The final adsorber monitoring  provisions  parallel the final
 performance testing provisions.  Again, separate provisions apply to
 systems with a common exhaust stack  and those  with  individual  stacks.   No
 increase in monitoring costs is anticipated.
     For adsorption systems with a  common exhaust  stack,  a monitoring
 device must be installed on the common exhaust stack and  one also may  be
 installed on the common inlet duct.  The owner or operator must  report
 each occurrence when the average emission level or  system efficiency
 (depending on whether only the outlet or both  the  inlet and outlet gas
 streams are monitored) over three successive system rotations  varies
 outside the specified range.
     For adsorption systems with individual  vessel  exhaust  stacks, a
 monitoring device must be installed on each  individual exhaust stack,  and
 a monitoring device also may be installed on the common inlet duct or  on
 each individual  inlet duct.  Each adsorber vessel must be monitored for a
 minimum of one complete adsorption cycle per day.  A 3-day  rolling average
 emission level or efficiency for each vessel  (depending on whether only
 the outlet or both the inlet and outlet gas  streams are monitored) must be
 computed each day from the daily averages, and  these 3-day rolling
 averages must be reported when they vary outside the specified ranges.
     1.1.4.4  General  Wording.   The section  was reorganized for clarity,
 and wording has  been added to specify clearly that  monitors must be in
place and operating during all  performance tests.
 1.1.5  Test Methods and Procedures
     Because Method 25A is not  appropriate for  determining the efficiency
of a control device when the constitution of the  gas stream varies from
the inlet to the outlet (e.g.,  when an  incinerator  is  used), Method 25 has
been added  for determining VOC  concentrations,  and  is  required when an
incinerator is used unless it is  demonstrated to  be technically infeasible
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under site-specific test conditions.  The use of Method 25A  is  still
allowed when conditions are appropriate.  In addition, Method 18  has  been
included as a method to determine VOC concentration.
1.1.6  Alternative Means of Emission Limitation
     Provisions have been added that allow a source to obtain approval
from the Administrator for an alternative to simple covers for  controlling
VOC emissions from affected coating mix preparation equipment serving
coating lines using at least 95 Mg/yr (105 tons/yr) of VOC but  less than
130 Mg/yr (144 tons/yr) of VOC or from equipment that is part of  a
facility modified or reconstructed without concurrent construction of a
new control device.  Provisions also have been added to allow facilities
to submit alternate total enclosure designs for the Administrator's
approval.
1.1.7  Reporting and Recordkeeping
     1.1.7.1  Annual VOC Use.  A requirement has been added to report when
actual annual VOC use exceeds the applicable cutoff.  The proposed
standards required a report only when the estimated annual VOC use exceeds
the cutoff.
     1.1.7.2  Monitoring Variations.  A requirement has been added to
maintain records of all 3-hour (or applicable carbon adsorption system
rotations) periods during actual coating operations when the variations
specified in § 60.747(d)(l) through (6)  occur,  as well  as  to report such
periods.  The reporting requirements have been  revised  to  require
quarterly reports of exceedances.   If none of the variations specified in
§ 60.747(d)(l)-(6) occur, a semiannual  statement certifying this fact must
be submitted.  This requirement has been added  under §  60.747(d)(7).
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
Volume I background information document (BID)  for the  proposed  standards
(EPA-450/3-85-022a).  These regulatory  alternatives reflect the  different
levels of emission control  from which one was selected  that represents
BDT, considering costs, nonair quality  health,  and  environmental,  energy,
and economic impacts,  for facilities performing  polymeric  coating  of
supporting substrates.   A new regulatory alternative, IIA,  was developed
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 post-proposal  and  represents a 90 percent overall  level  of control.  This
 alternative is identical  to Regulatory Alternative II except that the
 costs  associated with  total enclosures (from Regulatory  Alternative III)
 replace the partial  enclosure costs.   This change  was made to represent
 those  facilities that  cannot install  and operate total enclosures as
 defined in the final regulation.   However, it more accurately reflects the
 costs  of the emission  capture technology that the  industry can (and
 probably will)  use.
 1.2.2   Environmental Impacts of Promulgated Action
     The environmental  impacts projected at proposal  are discussed in
 Chapter 7 and  Appendix  B  of the Volume I BIO.  Because it is  expected that
 facilities will choose  to comply  with  the coating  operation standards by
 means  of the alternative  standard, and thus achieve at least  93  percent
 overall  control, the environmental impacts have not changed since
 proposal.   Therefore, the Volume  I BID becomes the final  Environmental
 Impact Statement for the  promulgated standards.
 1.2.3   Energy  and Economic  Impacts of  the Promulgated Action
     The energy Impacts of  the proposed  standards were evaluated  in
 Chapter  7  of the Volume I BID.  It was determined that the  control
 technologies that are the basis for the  regulatory alternatives have  a
 negligible  effect on the  energy requirements for facilities performing
 polymeric  coating of supporting substrates.  Therefore, a negligible
 energy  impact was attributed to the proposed standards; this determination
 remains  unchanged for the final standards.
     The economic impacts of the proposed standards were evaluated in
 Chapter  9 of the Volume I BID.  These  impacts remain the same.
 1.2.4  Other Considerations
     1.2.4.1  Irreversible and Irretrievable Commitment of Resources.  The
 Volume I BID concluded  in Chapter 7 that the regulatory alternatives will
 result in the irreversible and irretrievable commitment of energy
 resources.  However,  this increased energy demand for  pollution control is
 insignificant compared  to the total energy demand of the  production
 line.  No changes  to  these estimated  impacts have occurred since proposal.
     1.2.4.2  Environmental  and Energy Impacts of Delayed Standards.
There is no significant benefit to be achieved from delaying the
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standards, as discussed in Chapter 7 of the Volume I BID.  No changes in
the potential effects of delaying the standards have occurred since
proposal of the standards.
     1.2.4.3  Urban and Community Impacts.  These standards will have a
positive impact on urban areas and communities because of decreased VOC
emissions.  There should be no decrease in employment in urban areas and
communities because the economic analysis indicated that the standards
would have little impact on retail price or profit.
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                       2.   SUMMARY OF  PUBLIC COMMENTS

     Twenty-four letters commenting on the  proposed standards  and  the
Volume I BID for the proposed standards were received.   (One of  these
simply corrected a minor error  in  an  earlier letter.)  A  list  of com-
menters, their affiliations, and  the  EPA document number  assigned  to their
correspondence is given in Table  2-1.  No one requested to speak at a
public hearing; thus,  none was  held.
     Docket items IV-D-11 through  IV-D-24 were received after  the  close of
the public comment period.  Nine of these commenters (IV-D-15, IV-D-17,
IV-D-18, IV-D-19, IV-D-20, IV-D-21, IV-D-22, IV-D-23, and IV-D-24)
petitioned for a reopening of the  comment period so that  EPA could
consider a separate textile subcategory.  The EPA decided not  to
officially reopen the comment period but did consider these late comments
in developing the final standards.  In addition, EPA met with  several
members of the American Textile Manufacturers Institute,  Inc.  (ATMI) at
their request to allow them to present followup information on their
public comments.  This meeting  is  summarized in Docket Item IV-E-21.
     Eight commenters  (IV-D-11, IV-D-12, and IV-D-17,  IV-D-18, IV-D-19,
IV-D-21 and IV-D-22, and IV-D-23) expressed their support for the comments
in Docket Item IV-D-7 or IV-D-15 as did ATMI members when they met with
EPA (IV-E-21).  Docket Item IV-D-7 is a letter from the ATMI.  Docket
Item IV-D-15,  which addresses some of the same issues  as Docket
Item IV-D-7, is from ATMI and the United States Industrial Fabrics
Institute (USIFI).   The supporting commenters are referenced below only if
their comments expanded upon an issue discussed in IV-D-7 or IV-D-15 or
raised a new issue.
     The comments and EPA's responses are discussed  according to the
following topics:
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    TABLE 2-1.   LIST OF COMMENTERS ON PROPOSED STANDARDS OF PERFORMANCE
  FOR NEW STATIONARY SOURCES:   POLYMERIC COATING OF SUPPORTING SUBSTRATES

Docket
item No.a                  Commenter/affiliation

IV-D-1                     Mr. E. W. Karger
                           Manager, PEPP
                           The Gates Rubber Company
                           999 South Broadway
                           Post Office Box 5887
                           Denver, Colorado  80217

IV-D-2                     Mr. Frank H. Rutland
                           Technical Director
                           Leather Industries of America, Inc.
                           2501 M. Street, N.W.
                           Washington, D.C.  20037

IV-D-3                     Mr. Roger D. Meadows
                           Vice President, Operations
                           Printing and Textile Products
                           DAY International
                           Post Office Box 360
                           Waynesville, North Carolina  28786
IV-D-4                     Mr. Ray C. Woodcock, CIH
                           DAY International
                           Post Office Box 360
                           Waynesville, North Carolina  28786
                             (Correction to p. 5 of IV-D-3)
IV-D-5                     Mr. Samuel I. Gutter
                           Attorney for W. R. Grace and Company
                           Polyfibron Division
                           Sidley and Austin
                           1722 Eye Street, N.W.
                           Washington, D.C.  20006

IV-D-6                     Mr. M. F.  Tanchuk
                           Environmental Engineer
                           Corporate Environmental  Control  Department
                           Reynolds Aluminum
                           Reynolds Metals Company
                           Richmond,  Virginia  23261
IV-D-7                     Ms. Maggie Dean
                           Director,  Safety,  Health and Environment
                           American Textile Manufacturers Institute,  Inc.
                           1101 Connecticut Avenue,  N.W.
                           Suite 300
                           Washington,  D.C.   20036

                                                   ~~~~(continued)
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                          TABLE 2-1.  (continued)
Docket
Item No.a                   Commenter/affiliation
 IV-D-8                     Mr. V. A. D'Ippolito
                           Air Quality Coordinator
                           1CI Americas,  Inc.
                           Wilmington, Delaware   19897

 IV-D-9                     Mr. William Juris,  P.E.
                           Engineering Section
                           Division of Air Pollution  Control
                           State of Ohio  Environmental  Protection Agency
                           Post Office Box 1049,  1800 Water Mark  Drive
                           Columbus, Ohio  43266-0149
 IV-D-10                    Mr. Paul F. Cash
                           Manager, Environmental Control
                           Mobil Chemical Company
                           211 College Road East
                           Princeton Forrestal Center
                           Princeton, New Jersey  08540
 IV-D-11                    Mr. R. F. Cook
                           President
                           WestPoint Pepperell
                           Industrial Fabrics Division
                           Post Office Box 71
                           West Point, Georgia  31833
 IV-D-12                    Harold E. Sells
                           Managing Director
                           Coated Fabrics Division
                           American Recreation Products
                           500 Orchard Street
                           New Haven, Missouri  63068
 IV-D-13                    Jerry Stenner
                           President
                           James R.  Ferron
                           Technical Director
                           Excello Fabric Finishers  Incorporated
                           Box  711
                           810  South Second Street
                           Coshocton,  Ohio  43812
IV-D-14                    Robert Naujelis
                           Regulatory Affairs Manager
                           Paxar
                           530  Route 303
                           Orangeburg,  New York  10962

                                           "(continued)
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                          TABLE 2-1.  (continued)
Docket
item No.a                  Commenter/affiliation
IV-D-15                    Maggie Dean
                           Director, Safety, Health & Environment
                           American Textile Manufacturer's  Institute,  Inc.
                           1101 Connecticut Avenue, NW
                           Suite 300
                           Washington, D.C.  20036
                                 and
                           Marcia Thomson
                           Director of Public Affairs
                           United States Industrial Fabrics Institute
IV-D-16                    James F. Murphy, Jr.
                           Assistant Vice President
                           Polyfibron Division
                           W. R. Grace and Company
                           55 Hayden Avenue
                           Lexington, Massachusetts  02173
IV-D-17                    Fred T.  Eslick
                           General  Manager, Engineering, Transportation,
                             and Plastics
                           American Thread Company
                          .Post Office Box 880
                           Old Fort, North Carolina  28762

IV-D-18                    Marguerita C.  Hindle
                           Vice President
                           Research and Development
                           Kenyon Industries,  Inc.
                           Kenyon,  Rhode  Island  02836
IV-D-19                    Walter L. Conine
                           John Boyle and Company
                           Salisbury Road
                           Post Office Box 791
                           Statesville, North  Carolina  28677
IV-D-20                    Paul  B.  Stelzner
                           Senior Vice President  and C.0.0.
                           American  Recreation  Products
                           1224 Fern Ridge Parkway
                           St.  Louis,  Missouri  63141
IV-D-21                    Guy  A. Bivins
                           Manager,  Plant Engineering
                           The  Bibb  Company
                           Post  Office Box  4207
                           Macon, Georgia  31208

                             ~~(continued)
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                          TABLE 2-1.   (continued)
Docket
Item No»a                  Commenter/affiliation
IV-D-22                    Wayne Holden
                           Technical Director
                           WestPoint Pepperell
                           Industrial Fabrics Division
                           Post Office Box 279
                           Pulaski, Virginia  24301

IV-D-23                    Thomas Tantillo
                           Granitevilie Company
                           Graniteville, South Carolina  29829
IV-D-24                    George E. Moseley
                           Secretary and General  Counsel
                           Reeves Brothers, Inc.
                           Post Office Box 1898
                           Spartanburg, South Carolina  29304

aThe docket number for this project is A-83-42.  Dockets  are on file at
 EPA Headquarters in Washington, D.C., and at the Office  of Air Quality
 Planning and Standards in Durham,  North Carolina.
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       1.   Selection of the Source Category;
       2.   Affected Facility;
       3.   Selection of BOT and Emission Limits;
       4.   Control  Costs;
       5.   Environmental  Impacts;
       6.   Economic Impacts;
       7.   Compliance;
       8.   Test  Methods and Monitoring;
       9.   Reporting and Recordkeeping;
      10.   Wording  of the  Regulation;  and
      11.   Modification/Reconstruction.
2.1   SELECTION  OF  THE  SOURCE CATEGORY
2.1.1 Applicability to the Leather Industry
      Comment;   One commenter (IV-D-2) wrote concerning the applicability
of the proposed standards  to leather  finishing.   For certain products,  a
thin  polymeric  coating is  applied to  the unfinished leather substrate.
Some  coatings are  applied'in organic  solvent  solution, although the use of
water-based emulsions  is  increasing.  References  ta leather as a substrate
found  in the proposal  preamble and in the proposed definition of web
coating seem to suggest that leather  finishing operations would be covered
by the proposed rule.  The commenter concluded that this would be improper
for the following  reasons.
      1.  Leather finishing does not meet the applications criteria
established in  the proposed standards.  Leather is not handled as a
continuous web  or  substrate that is unrolled, finished, dried, and
rerolled.  Rather, leather finishing is done on discrete skins, hides, or
sides.  Also, most solvent-borne finishes are sprayed on the leather
rather than applied by seasoning machine or roll coater.
     2.  The leather-like materials that can be coated in continuous form
(bonded leather  fiber products  and artificial  leathers)  are not properly
or legally referred to as "leather" according to accepted trade practice
(American Society for Testing  and  Materials [ASTM] Method D1517)  and
Federal Trade Commission guidelines.   Therefore, these  man-made substrates
should not be referred  to  as  leather  in  the final  standards.
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      3.   Leather  Tanning  and  Finishing (Standard Industrial  Classification
 [SIC]  3111)  is  not  among  the  eight SIC codes  listed in the Volume I BID as
 potentially  affected  by the proposed standards.
      4.   Consultation with a  representative of  the Emission  Standards
 Division  (ESD)  of EPA's Office  of Air Quality Planning and Standards
 confirmed that  leather finishing  was not  intended  to fall  within the scope
 of  the proposed rule.
      In view of these points, the commenter requested that all  references
 to  "leather" be deleted in the  final  rule to  avoid confusion.
      Response;  The commenter correctly noted that,  as proposed, the
 standards could be  interpreted  to apply to leather finishing operations.
 The EPA concurs that  leather, when defined as a  "general term for hide  or
 skin  . .  ."  (Annual Book  of ASTM  Standards),  is  not  a continuous
 substrate, and  leather finishing  was  not intended  to be covered  under the
 standards.   Therefore, leather  finishing has  been  excluded from  the  list
 of  web coating  operations in the  final standards.   Leather-like  materials,
 such  as urethane-coated and bonded  leather fiber products  are, however,
 covered by the  standards.
      It should  be noted that the  exclusion of the  "Leather Tanning and
 Finishing" SIC  code (SIC  3111)  from the list  of affected SIC's is not
 grounds for exclusion from the  standards.  This list was intended to  be
 representative  of potentially affected operations, not to be an  inclusive
 list.
 2.1.2  Applicability to the Graphic Arts Industry
     Comment;  One commenter (IV-D-6) wrote that the proposed standards
 could be erroneously construed to apply to the graphic arts industry.  The
 commenter stated that no facility in the graphic arts industry was studied
 during the development of the proposed NSPS and  that the Volume  I BID
 clearly excludes the* graphic arts industry.   Furthermore,  the commenter
met with a representative of the Chemicals and Petroleum Branch of ESD who
confirmed that EPA did not intend for this regulation to apply to the
graphic arts industry.  The commenter recommended that the  exclusion of
the graphic arts industry also be clearly  stated in the preamble to the
final  regulations.
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      Response;  The polymeric coating NSPS is not intended to include a
 web coating category already subject to new source performance stan-
 dards.   As the commenter points out, the Volume I BID states that
 polymeric coating of supporting substrates excludes "those operations that
 print an image on the surface of the substrate."  This exclusion also was
 included in the proposal Preamble, Section IV.A.2. Exclusions.
 Section 60.740(a)(3) has been added to the final standards to make this
 exclusion clear.   This section excludes "web coating operations that print
 an image on the surface of the substrate or coating applied on the same
 printing line  that applies the image."
 2.1.3  Applicability to the Paper Coating Industry
      Comment;   Two commenters (IV-D-9, IV-D-10)  believed  that the
 exclusion of paper coating is unclear.  One commenter (IV-D-9)  stated that
 the  confusion  results  from the definition of "polymeric coating  of sup-
 porting substrates," which states "...  a supporting web  other  than
 paper," and from  the lack  of  a definition for  paper.   The  commenter
 suggested the  exclusion of "paper,  paperboard, plastic film,  metallic
 foil, and metal coil"  be stated  in  the "polymeric  coating  of  supporting
 substrates"  definition.  The  commenter stated  that if  this  suggestion were
 followed,  the  definition of "paper  coating" could  be deleted, and  that if
 the  suggestion were  not  followed,  "paper  coating"  should be changed  to
 "paper"  or "paper web."
     The  second commenter  (IV-D-10) was concerned  specifically with  the
 plastic  film coating industry.  This commenter concluded that the proposed
 standards  exclude coating on plastic film because;  (1) the process  is
 considered a segment of  the paper coating industry (which is excluded from
 the proposed standards); (2) plastic film coating, to date, has been
 regulated by the States under paper coating State implementation plan
 (SIP) regulations; (3) the SIC code for this process (2671) was not
 included in the list of potentially affected SIC codes; (4) the customers
who subsequently print or laminate the commenter's product are not
covered; and (5) the scope of the background study did not include plastic
film coating operations.  The commenter stated that the plastic film
 industry is different from the industries surveyed with respect to the
scale and type  of equipment and the process itself.
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      Also,  the commenter (IV-D-10)  stated that because the BID did not
 survey the  plastic  film industry,  several assumptions or conclusions
 presented  in  the  proposal  preamble  are invalid when applied to this
 industry.   According  to the  commenter, (1)  statements in the proposed rule
 concerning  low-solvent  coatings  are not valid  when  applied to low-solvent
 plastic film  coating  operations  using  large-scale equipment; (2)  the
 proposed NSPS implies that line  speed  and width increases are impractical;
 however, this is  untrue in the commenter's  experience;  (3)  the incremental
 cost  of further reduction  of the commenter's low-solvent coating  formula-
 tion  emissions would  be unreasonable;  and (4)  low-solvent waterborne
 coatings should be  8DT  for the plastic film industry  regardless of the
 volume of coating used.
      If, in fact, plastic  film coating operations are included under the
 proposed regulations, the  commenter requested  that  EPA:
      1.  Reopen the comment period  for more detailed  comments;
      2.  Revise the BID  to include  plastic  film coating  operations;  and
      3.  Rescind  the  proposed NSPS  until  background Information for  the
 plastic film  coating  Industry is developed  and evaluated.
      Response;  The proposed NSPS is intended to exclude paper coating
 operations, which are defined in the proposed regulation as  "the coating
 of paper, plastic film,  or metallic foil. . .   ."  These paper coating
 operations  are  part of the industrial  surface coating source category for
 paper  and were  not Investigated during development of the standards  for
 polymeric coating of supporting substrates.  The definition of polymeric
 coating  has been revised to clarify this point, and  the definition of
 paper  coating has been deleted.
      It  should  be noted that the exclusion of  an industry segment from the
 11st of  affected SIC's does not mean the industry segment is excluded from
 the standard.   Such lists are not to be inclusive, but are intended to be
 representative of potentially affected operations.   Also, the fact that
 subsequent processors of a coated product are  not subject to the standards
does not, as suggested by one commenter, have  any bearing on the applic-
ability of the standards to the initial coating process.
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2.1.4  Applicability to the  Textile  Coating  Industry
     Comment:  Several commenters  (IV-D-15,  IV-D-18,  IV-D-19,  IV-D-20,
IV-D-21, IV-D-22,  IV-D-23, and  IV-D-24) requested  that  EPA establish a
separate subcategory in the  standards  for textile  coating  operations.   The
commenters cited product and operational variability  as factors  limiting
this industry's ability to comply with the proposed standards.
     Response;  The EPA has  carefully  reviewed the technical comments
provided by ATMI and others.  The specific comments and EPA's responses to
them are detailed elsewhere  in  this  document  (primarily in
Sections 2.3.1.1 and 2.3.1.3).  As a result of this analysis, EPA  has
decided not to create a separate subcategory or standard for the textile
coating industry.  However,  EPA has  adjusted the overall level of  the
coating operation standard downward  to 90 percent  in  response to the
concerns raised by commenters.  The  EPA believes that this level of
control is universally achievable by the polymeric coating industry,
including textile coaters.
2.2  AFFECTED FACILITY
     Comment;  One commenter (IV-D-8)  indicated that EPA should clarify
how the determination of the affected  facility is to be made for coating
operations that share mix equipment.   The commenter stated that this
situation, which is typical of the commenter's plants,  is  not adequately
addressed under the modification/reconstruction provisions.  The commenter
presented a scenario that involved the installation of a new coating
operation served by an existing central mix room.   The commenter was
concerned that existing coating operations served  by the common mix equip-
ment would become affected facilities also.
     Response;  The affected facility  is defined as "each coating
operation and any onsite coating mix preparation equipment used to prepare
coating for the coating operation."  In the case presented by the com-
menter, the existing coating operations would not  become subject to the
standards because they are not part of the affected facility that includes
the new coating operation.   However,  the existing  mix  equipment that
serves the new coating operation would become subject  to the standards.
     The only way that an existing coating operation would  come under the
standards would be if  the potentially affected facility  of  which  it is a
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part  (i.e., the  coating  operation with  associated mix equipment)  were to
be modified or reconstructed.  A modification  is  defined in the General
Provisions  (40 CFR  60.14)  as  ".  . .  any physical  or operational change to
an existing facility which results  in an increase in the emission rate to
the atmosphere of any  pollutant to which a  standard applies .  . . ."
Certain exceptions  are made,  including  the  following:   routine main-
tenance, repair, and replacement; an increase  in  production rate
accomplished without a capital expenditure; an  increase in  the hours  of
operation; use of an alternative fuel or raw material  if the existing
facility was originally  designed to accommodate it;  addition or replace-
ment of emission control equipment (as  long as emissions are not
increased); and relocation or change of  ownership.   The General Provisions
(40 CFR 60.15) define  reconstruction as  the replacement of  components of
an existing facility to  the extent that  the fixed capital cost of the new
components is greater  than 50 percent of  the fixed  capital  cost of a
comparable entirely new  facility and that compliance with the  standard is
technically and economically feasible.  An  increase  in  the  emission rate
                              * *
need not occur.
     Comment;  Commenters  noted (Docket  Item IV-E-21) that  it  is  not
always possible to dedicate a limited number of pieces  of mix  equipment  to
a given affected coating line.  The commenters were concerned  that entire
mix rooms would become affected if a new  coating operation  is  added.
     Response;  The commenters have interpreted the proposed regulation
correctly.  However, EPA has revised the  regulation to  reduce  the burden
on plants subject to the mix equipment standards.   In most cases,  venting
mix equipment emissions to a control device is judged to be cost effective
whether one piece or an entire mix room becomes affected.  When a  new
coating operation is constructed,  a new control device would be necessary
to control its emissions.  This control  device could readily be designed
to accommodate emissions from the associated mix equipment that becomes
affected when the coating operation  is  constructed.   Under this scenario,
the venting of mix equipment emissions  to a control  device is cost
effective.1
     The hypothetical  scenario of  concern is that  mix equipment could
become affected by the standards  through modification or reconstruction of
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 a coating operation that uses an existing control  device.  Although it is
 considered unlikely,  it is possible that the existing control device would
 have insufficient  capacity in reserve to handle all  or part of the mix
 equipment emissions.1   This would result in a requirement to install a
 separate  control device for these emissions; such  separate control of mix
 equipment emissions is  not cost effective.   Because  it is possible that
 mix  equipment  at some modified or reconstructed facilities could not be
 controlled by  existing  control  devices,  the standards have been revised to
 require use of covers alone (requirements discussed  in response to
 Comment 2.3.2.1) if a coating operation  is  modified  or reconstructed
 without concurrent  construction of a  control  device.   Concurrent construc-
 tion is defined in  the  final  regulation  as  the  period of  time in which
 construction of an  emission control device  serving an affected  facility is
 commenced or completed,  beginning  6 months  prior to  the date that
 construction of the affected  facility commences and  ending 2 years after
 the  date  that  construction  of the  affected  facility  is completed.   This
 period is designated.because  it is consistent with the normal planning and
 purchase  cycles for equipment of this type.  The 2-year period  also
 coincides with the  period for which records required  under these  standards
 must  be retained.
      With  this change to the  standards, EPA considered whether  the
 affected  facility definition  should be changed from a combined  defini-
 tion.  However, because growth  in  this industry is still expected to occur
 in the form of new  lines, the maximum emission reduction will be achieved
 by retaining a combined affected facility definition  (see proposal
 preamble  [52 FR 15916]  for more discussion of the criteria applicable to
 affected  facility decisions).
 2.3  SELECTION OF BDT AND EMISSION LIMITS
 2.3.1  Control of Coating Operation
     2.3.1.1  BDT and the Level of the Standard.
     Comment;   Seven commenters (IV-0-1,  IV-D-7, IV-D-8,  IV-0-11, IV-D-15,
 IV-0-16,   IV-D-17,  and  IV-0-18) questioned the capture, control device,
and/or overall  efficiency required to  comply with the proposed 93 percent
VOC emission reduction  for coating operations.   One commenter (IV-D-1)
said that  the  accessibility and clearances needed for feeding and
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retrieving products  from  a  treater,  the  practicality of capturing
virtually 100 percent  of  vapors  at all times,  the reliability of
continuous monitoring  equipment,  and  the number  of different combinations
of substrates and  coating solutions make compliance extremely doubtful.
The commenter suggested that, with diligent  attention to the equipment,  a
control device efficiency of 95  percent  and  a  capture efficiency of
80 percent could be  attained, allowing an overall  efficiency of  76 percent
to be attained.
     A commenter (IV-D-8) stated  that 93 percent overall  efficiency  has
not been demonstrated  for a polymeric coating  operation.  Specifically,
the commenter stated that the capture efficiency of 98  percent that  would
be required to obtain  the overall efficiency of  93 percent has not been
demonstrated relative  to  the design factors assumed in  the economic
analysis.  Also, the commenter stated that the selection  of  a carbon
adsorber efficiency of 95 percent is based on  insufficient data  from the
polymeric coating  industry.  The 95 percent efficiency  was based on  test
data that included only one polymeric coating operation.  According  to the
commenter, these data cannot adequately  demonstrate a control technology
for an entire industry that uses a multitude of  solvents  and coating
formulations.  The commenter stated that  EPA has failed to demonstrate
that a 95 percent efficiency is consistently achievable and that EPA needs
to review carbon adsorption data for the various solvents typically used
in the polymeric coating  industry before concluding that  such an effi-
ciency is consistently attainable.  Another commenter (IV-D-11) stated
that, based on their best information, the overall  efficiencies specified
in the regulation could not be consistently attained for new lines,  except
for those that use low-solvent coatings.
     Two commenters (IV-D-7, IV-D-15) cited batch operations, the use of
multiple solvents,  and the need for frequent (to continuous)  worker  access
to the coating application/flashoff area as reasons for not being able to
comply with the proposed standards.   In the first correspondence  (IV-D-7),
only the 95 percent efficiency ascribed by EPA to carbon adsorption  was
addressed.   The commenter indicated  that  the data from a polymeric coating
plant, which are from a plant  using  a single solvent, do not  adequately
reflect coating operations that use multiple solvents, other  solvents,  or
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multiple substrates and coating  head configurations.  The  commenter said
that the solvent recovery efficiencies  are  biased  because  they  rely on
data obtained with gas analyzers only under the most favorable  short-term
operating conditions,,  The second correspondence (IV-D-15)  also addressed
the concern that a total enclosure that would meet the required capture
efficiency while maintaining worker access  could not be designed.   Case
studies from five plants were presented as  documentation of these  claims
(IV-D-15).
     Response;  The EPA has determined  that the final standards for
coating operations are attainable.  The following discussion of support
for this conclusion addresses:   (1) capture efficiency, (2) control  device
efficiency, (3) overall control efficiency,  and (4) VOC recovery.   For the
response to the comment about the reliability of continuous monitoring
equipment, see Section 2.8.3.
     1.  Capture efficiency.  In response to comments, EPA  has  reevaluated
the feasibility of total enclosures 1n  the  polymeric coating industry.
The term "total enclosure" means a structure that is constructed around  a
source of emissions and operated so that all VOC emissions are  collected
and exhausted through a stack or duct.  With a total  enclosure, there  will
be no fugitive emissions, only stack emissions.  The drying oven itself
may be part of the total enclosure.  A total enclosure must satisfy all of
the design and operational requirements as defined  in the promulgated
regulation and summarized in Table 2-2.   Alternatively,  it must be
demonstrated, to the Administrator's satisfaction,  to be equivalent to
these requirements.  To evaluate the comments, Section 114 Information
requests were sent to three facilities that had indicated that enclosures
were in use, and plant visits were made to three facilities that had
indicated that they were batch operations and needed  frequent access to
the coating equipment during operation.   An expert  in industrial
ventilation and a vendor of local ventilation systems were contacted.
Using the data gathered and standard ventilation principles and
guidelines, EPA reached the conclusions  discussed below.2
     As indicated by the commenters,  a small total  enclosure immediately
around the applicatlon/flashoff area is  not feasible  at  facilities  where
frequent, routine access to the coating  equipment is  required.   At  such
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             TABLE  2-2.   SUMMARY  OF  TOTAL  ENCLOSURE CRITERIA
Definition;  "Total enclosure" means a structure  that  Is constructed
    around a source of emissions so that all VOC  emissions are collected
    and exhausted through a stack or duct to a control device.  With  a
    total enclosure, there will be no fugitive emissions, only stack
    emissions.  The drying oven itself may be part of  the total enclosure.

Design and operational criteria;

1.  The only openings in the enclosure shall be forced makeup air and
    exhaust ducts and natural draft openings such as those through which
    raw materials enter and exit the coating operation.

2.  The total area of all natural draft openings  shall not exceed
    5 percent of the total surface area of the total enclosure's walls,
    floor, and ceiling.

3.  All access doors and windows shall  be closed during normal operation
    of the enclosed coating operation,  except for brief, occasional
    openings to accommodate process equipment adjustments.  If such
    openings are frequent, or if the access door or window remains open
    for a significant amount of time during the process operation, it must
    be considered a natural draft opening.   Access doors used routinely by
    workers to enter and exit the enclosed  area shall be equipped with
    automatic closure devices.

4.  Average inward face velocity (FV)  across all  natural  draft openings is
    a minimum of 3,600 meters per hour  (200 feet  per minute)  and
    demonstrably inward at all times.

5.  All sources of emissions within the enclosure shall be a  minimum of
    four equivalent diameters away from each natural  draft opening.
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 facilities,  it is doubtful  that the access ports necessary to reach the
 equipment will conform with the total  enclosure specification for separa-
 tion between sources of VOC and openings in the enclosure.  Nevertheless,
 even at facilities with extensive access requirements,  local  ventilation
 systems can  be constructed  that will  achieve a very high capture effi-
 ciency while affording necessary access.  The most universally applicable
 approach consists of substantially enclosing the application/flashoff area
 while providing ports that  can  be opened when access is needed.   With a
 well-designed system, capture will  be  sufficient to maintain  the VOC
 concentration below the threshold limit  value (TLV) outside the  enclosure,
 protecting the health of the workers  in  the area.   The  airflow necessary
 in  a well-designed system will  be reduced to the point  that the  total
 volume can be used as makeup air in the  drying oven,  minimizing  control
 costs.
      In most cases,  the local ventilation system described above could  be
 used in conjunction  with a  larger enclosure to meet the  specifications  for
 a total  enclosure.   The total enclosure  could  consist of the drying  oven
 itself  coupled with  a small room (large  enough for  workers) constructed
 around  the application/flashoff  area, a  small  room  constructed around the
 entire  coating operation, or even a large coating room with several
 coating  operations.   The size of  the total  enclosure is immaterial as long
 as  the  specifications  are met.
      Despite  the  range  of acceptable total  enclosure configurations, there
 remains  the possibility that some facilities may not be able to  install  an
 enclosure  that meets the specifications.   For  instance,  at an existing
 facility adding a new coating operation or modifying/reconstructing an
 existing coating operation,  space constraints might not  allow construction
 of  any enclosure  large enough for personnel to work within during
 operation.  If the same facility could not install a small  total  enclosure
 immediately around the application/flashoff area because of access
 requirements, the use of a  total enclosure would not be  feasible  for that
 facility.  One of the facilities visited  during the investigation of this
 issue would probably encounter these constraints.
     Because there may be facilities at which a total  enclosure is not
feasible, EPA investigated capture systems that fell short  of  the
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 requirements  for  a  total  enclosure.   Based  on  EPA's  analysis, a capture
 efficiency of 95  percent  can  readily  be  achieved  without a total enclosure
 through  the use of  a well-designed  local  ventilation system.   Although the
 actual percentage varies  from facility to facility,  about 90  percent of
 the  VOC  emissions from  a  coating  operation  are generated within the drying
 oven.  Assuming that all  these emissions  are captured,  as they will be in
 a well-designed oven operating under  a slight negative  pressure, only
 50 percent of the emissions generated in  the application/flashoff area
 must be  captured  to achieve a total capture efficiency  of 95  percent.
 Even if  only  80 percent of VOC emissions  from the coating operation are
 generated  in  the  drying oven,  only 75 percent of the application/flashoff
 area emissions must be captured to achieve 95 percent overall  capture.
 The  EPA  has concluded that these  capture  efficiencies can be  achieved  in  a
 cost-effective manner with a  well-designed local ventilation  system.
     2.  Control  device efficiency.   Carbon adsorption  has been  used  for
 the  last 50 years by many industries  to recover a wide  variety of
 solvents.  With the experience gained from extensive application under
 very diverse  conditions, the  technology has matured  to  the point that an
 adequately designed, operated, and maintained system can  readily attain an
 efficiency of 95 percent or higher on a continuous basis.  This  fact has
 been demonstrated across many  industries with many different solvents and
 solvent blends.  The efficiency of a carbon adsorption  system is
 determined by its design and operating parameters and the composition of
 the  solvent-laden airstream (SLA) vented to it, not by the process
 equipment that generates the exhaust stream.3  Thus,  it is reasonable to
 expect the attainment of similar efficiencies through the application of
 this technology in the polymeric coating Industry.
     The efficiency of carbon adsorption in this  and  related web coating
 industries was discussed in the Volume I  BID.   Measurements during tests
 ranging from a short-term gaseous emissions  test  to a 78-hour material
 balance Indicated adsorber efficiencies  of 97 percent or higher.   At a
pressure sensitive tapes and  labels  (PSTL) plant,  an  overall  control
efficiency of  93 percent was  achieved  over a 4-week period.  The fact that
this plant, which coated a number of products using a wide variety of
solvents, attained a control  level of  93  percent demonstrates  that a
                                   2-17

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 carbon adsorption system is capable of operating at an efficiency high
 enough to meet the standards.   As  discussed in the next comment, data
 received  from a polymeric coating  plant also support control efficiencies
 capable of meeting the standards.
      The  EPA has recently concluded an extensive study of the ability of
 carbon adsorbers to operate continuously at least 95 percent efficiency.
 Thts  report addresses  many of  the  problems  cited by commenters that could
 be  faced  by a batch operator.   In  particular,  there are two major ways
 that  batch operations  could affect carbon adsorber performance."*  One
 effect would be expected to occur  where multiple lines are ducted to a
 carbon adsorption system.   Under this  scenario,  it is possible that as
 lines  are brought off- and on-line,  the resulting variable flowrates and
 VOC concentrations of  the  SLA  ducted to the control  device could adversely
 affect recovery efficiency.  A second  effect would be evident in a
 situation where an SLA contains varying blends of solvents.   If this
 variable  stream is ducted  to a single  control  system,  the  result could be
 decreased recovery efficiency.
     The  effect of variable  flowrates  should not  be  a problem with a
 properly  designed  system.  The primary  effect of  an  increase  in volumetric
 flowrate  is  to  change  the  width of the  mass  transfer zone  within the
 carbon  bed.  As the  superficial velocity  increases as  a result  of  a  higher
 flowrate,  the width  of  the mass transfer  zone also increases  because the
 individual carbon  pellets  are exposed to  the adsorbate for a  shorter
 period  of  time.  With  a wider mass transfer  zone, the  length of  the
 adsorption cycle prior to  breakthrough will  decrease.  However,  a  bed
 should  be  designed for worst-case flowrate conditions  (the maximum
 flowrate  expected  to be ducted to the system at a given time), so  there
 should  be  no periods of operation when breakthrough occurs before  there is
 sufficient time to have regenerated a fresh  bed.1*
     Another question related to flowrate is the effect of short-term
variations in flowrate on system efficiency.  One report presents data
from a case where the flowrate varied randomly during the entire
adsorption cycle and ranged from 25,000 to 45,000 scfm.  The recovery
efficiencies during this time period varied  less than 0.5 percent with all
efficiencies being well above 99 percent.1*  Therefore, short-term
variations in flowrate do not appear to be a problem.

                                   2-18

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      The remaining  concern  with  respect to variable flowrates is whether
 they  could result in  an  increase in outlet concentration (rather than a
 decrease in cycle length as discussed  above).   However,  increases in
 outlet  concentration  are due either to the inlet  stream  physically by-
 passing a portion of  the bed (through  channeling,  for example)  or to a
 buildup of heel  in  the last few  inches of the  bed.   Neither of  these
 situations is  expected to occur  as  a result of variations  in the
 flowrate.
      The effect  of  variable VOC  concentrations in  the SLA  on carbon
 adsorber performance  is  also expected  to  be insignificant.   Increasing the
 concentration  in the  SLA increases  the working capacity  of  the  carbon, but
 not to  such an extent that  the increase in mass loading  is  offset.   The
 result  is  that breakthrough  occurs  sooner.   Over the  long term,  this could
 affect  the performance of the system if capacity is exceeded, but  in a
 well-designed  system  this should not occur.1*
      The short-term effect  of concern  is whether variations  in  inlet
 concentration  affect;  outlet  concentration.  The outlet concentration is  a
 function of the  amount of heel that  remains  in the last  few  inches  of  the
 bed after  regeneration.  Because the inlet  stream reaches equilibrium  with
 the carbon within the mass transfer  zone, the amount of  heel at the
 adsorber outlet  is independent of inlet concentration.1*  Thus, inlet
 variations  would not  be expected to affect outlet concentration.
     The carbon  adsorption report presents test data from two performance
 tests that  verify this relationship.   In the first case,  inlet concentra-
 tions ranged from 200 to 550 ppm while the outlet concentration varied
 only from  5 to 15 ppm; the corresponding removal efficiency varied from 95
 to 99 percent.   In the second case,  the inlet concentrations varied  from
 40 to 880 ppm while  the outlet concentration remained relatively constant
 (0 to 5 ppm).  During the majority of the test period the removal effi-
 ciency was well above 95  percent.  However, when the inlet concentration
 dropped below 50 ppm,  the removal efficiency was also reduced to less than
95 percent.  This was  expected because  properly designed  and operated
carbon adsorbers are essentially  constant  outlet concentration devices, so
a very low inlet concentration for an extended  period  will  reduce short-
term efficiency.1*
                                   2-19

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     The  presence  of  low inlet concentrations or minor variations in
 outlet concentrations should not pose  a major problem for a facility
 attempting  to  show compliance with  the coating operation standard.
 Performance test and  monitoring data are averaged over adsorber system
 cycles, so  short-term inlet  variations will  not greatly affect the long-
 term average.   For the facility referenced above as  having inlet
 concentrations  below  50  ppm,  the data  were reanalyzed using the averaging
 periods that would apply under the  polymeric coating regulation.  The
 results of  this analysis show that  the average efficiency is greater than
 95 percent,  and the facility  would  not generate excess emissions.   Under
 similar inlet concentration  conditions,  a carbon adsorber at a polymeric
 coating plant should  exhibit  similar efficiencies.   It is unlikely that
 more extended periods of low  inlet  concentrations would  occur at polymeric
 coating plants.  The  standard  has been  revised  to preclude periods of
 startup and shutdown  for purposes of the gas-phase test  to prevent the
 possibility that extended periods of startup  and shutdown would  bias  test
 results.  (Liquid-phase  testing  is  not  as sensitive  to this  potential bias
 because periods of  startup and  shutdown represent only a  fraction  of  the
 overall test period of 3 to 30 days.)   This change is consistent with the
 General Provisions  (40 CFR 60.8(c)).1*
     The carbon adsorption report notes that, because the  outlet
 concentration remains relatively constant throughout an adsorption cycle,
 large variations in the  inlet concentration will result in corresponding
 variations 1n removal  efficiency.  However, if the bed is  properly
 designed and regenerated, a constant outlet concentration can be attained
 such that greater than 95 percent removal is  achieved for the entire range
 of inlet concentrations.   Furthermore,  by diverting or shutting off the
 airflow from Idle equipment,  inlet concentrations can be consistently
maintained at higher levels to ensure the desired removal efficiency.1*
     Variations in  the solvent blend and VOC  1n the SLA ducted to a carbon
adsorber can affect either adsorption time or desorption steaming require-
ments.   If this is  not accounted for, particularly if timers are used to
trigger bed  changeover, recovery efficiency could decline.  The effects  of
variable solvent blends are discussed further in Section 4 below.
                                   2-20

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      It  is  true that fixed-bed  carbon  adsorbers are  not  suited to every
 VOC  control  application.   In  such  cases,  either a fluidized-bed carbon
 adsorber or a  condenser can be  used.   The analysis of  costs  carried out
 prior to proposal  and presented in the Volume  I BID  indicated that a
 condenser would be less costly  to  purchase and operate than  a carbon
 adsorption  system.  Incinerators may also be cost effective  in some
 control  situations.5
      3.  Overall control efficiency.   An  overall  control efficiency of
 93 percent  has  been  demonstrated by a  4-week liquid material  balance at a
 plant in the PSTL  industry that is equipped with  a "total building air
 evacuation  system,"  which was assumed  to  be a  total enclosure for purposes
 of proposal analyses.  The performance of this PSTL plant is  considered
 representative  of  the control efficiency  attainable in the polymeric
 coating  industry because of the many similarities  in the two  industries.
 In both, coatings  with a similar range of  solvent  contents are  applied
 with  the same types  of applicators to continuous  substrates and dried  in
 the  same types  of  drying ovens.  Capture  and control  systems  for  emissions
 of VOC are very similar.  The production  at the PSTL plant during  the test
 period was characterized by many short runs of many different products
 using a variety of solvents, as is often the case at  polymeric coating
 plants.
     Since proposal of the polymeric coating standards, EPA received
 liquid material balance data from a member of the industry (Grace) who
 coats textile printing blankets (IV-0-16).  This operation consists of two
 coating lines in a room-type enclosure (the data presented by the
 commenter [IV-D-16] are presented in detail in the section on
 Comment 2.3.1.).  The EPA concluded that  these data,  which show 93 percent
overall recovery based on a 3-day liquid  material balance,  substantiate,
 along with the  PSTL data,  that emission capture and reduction systems are
capable of achieving 93 percent control.
     The EPA, however, has  reevaluated  the proposed standards in light of
 industry comments (particularly issues  related  to batch operations and
design and use of total  enclosures  discussed elsewhere  in this response
and in Section 2.3.1.3).    Although the polymeric coating standards
require demonstration of  an overall level  of control, the BDT for  the
                                   2-21

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 standards is  discussed typically in terms of the efficiency of capture and
 control  device  efficiencies.   The product of these efficiencies yields the
 overall  level of  control.   The control  device component of BDT has been
 demonstrated  to be  a minimum  efficiency of 95 percent for this industry
 (see Section  2  on control  device efficiency for more discussion of this
 issue).   Therefore,  the important variable in evaluating the overall level
 of control that can  be achieved by BDT  is the efficiency associated with
 capture  component.
      Any change in the assumed level  of capture efficiency should be
 evaluated considering that (1)  the two  data points at 93 percent overall
 efficiency (PSTL  and  Grace) are associated with unknown capture and
 control  device  efficiencies and (2)  neither capture system demonstrated
 complete consistency  with  EPA's total enclosure criteria.   It is quite
 possible (and perhaps probable)  that  capture  efficiency at these plants
 was  less than the 98  percent minimum  previously ascribed  to a total
 enclosure.  Therefore,  to  conclude that  capture efficiency was 98 percent,
 based on an assumed control device efficiency of 95  percent (i.e.,
 0.98 capture x 0.95 control = 0.93 overall  control  efficiency)  may  be
 oversimplification.   A more conservative means  to  estimate  the capture
 efficiency of these two facilities  is to assume that the control  device
 efficiency was higher  (i.e., 98 percent) instead of the minimum
 95 percent.  If so, the 93 percent overall control could have  resulted
 with only a 95 percent efficient capture device.
     To  ensure the selection of achievable standards for the entire
 industry, the overall level of control required should be based on the
 minimum  efficiencies of the two components of BOT.  The EPA has concluded
 that control  devices are at least 95 percent efficient, even while
 acknowledging that they are capable of,  and often achieve, much higher
 efficiencies.   Although EPA believes that total enclosures achieve
 essentially 100 percent or total capture, it has not been adequately
demonstrated  that  all segments of this diverse industry can install and
operate total  enclosures that  meet EPA's specifications (see Section 1 on
capture efficiency for more information  on this topic).  It is, therefore,
reasonable to  allow  for this variability when setting the capture system
efficiency component of BDT for this industry.  Based on these
                                   2-22

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considerations, EPA  has  adjusted the  standards  downward  from  93  percent  to
90 percent overall control  (i.e., 0.95 capture  x  0.95  control  =
0.90 overall control efficiency).  The promulgated  standards  recognize
that strict adherence to EPA's total  enclosure  criteria  may be neither
universally achievable nor  required to meet the standards  but  would  still
allow use of the alternative standard for those sources  that  can meet the
total enclosure specifications.  The  EPA believes that this will be  an
attractive alternative for  that majority of plants  for which a total
enclosure is feasible.   Because the compliance  test provisions associated
with a total enclosure are  simpler and less expensive  to carry out than  a
capture efficiency test,  there is continuing incentive for sources to
install total enclosures.
     It should also  be noted that there is flexibility in the  emission
reduction standard.  Because only the overall emission reduction is
specified, sources may vary capture and control efficiencies as they wish
as long as the required  overall emission reduction  of  90 percent is
maintained.  Thus, a source may choose to operate the  control  device in
excess of 95 percent efficiency and maintain a capture efficiency below
95 percent, or vice versa.
     In conclusion, the  standards have been established at an overall
control level of 90 percent, with BDT defined as a 90  percent efficient
emission reduction system that is composed of an emission capture system
and control device.  The option of using a total enclosure as the emission
capture system is allowed where feasible and is attractive to the source
because it simplifies the performance test.   This change to the standards
takes into account concerns about variability in measurement technique,
operating parameters, worker access requirements,  etc.   As Table  2-3
shows,  the revised standards (represented by Regulatory Alternative IIA)
remain cost effective despite a lower emission reduction.  This option
potentially results in a projected  decrease  in nationwide VOC reduction
over 5 years compared to the standards as proposed (964 Mg [1,062 tons]
compared to 1,060 Mg [1,168 tons]).   However,  because of the use  of total
enclosures or control devices that  achieve more than 95 percent
efficiency, in many cases, facilities  will actually  achieve emission
reductions much greater than 90 percent.
                                   2-23

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      4.   VOC recovery.   The type of solvent used and VOC generated is a
 key design  criterion in any carbon adsorption system.  The adsorption
 characteristics  of  each compound are assessed using data on their physical
 properties,  and  the system is designed  to accommodate these properties.
 While adsorbers  can be  designed  to recover a blend of solvents and other
 VOC successfully, changes  in the characteristics of a feed stream (i.e.,
 the introduction of varying solvent blends due to a batch process and cure
 volatiles)  can affect both adsorption and desorption cycles.**  If the
 system cannot accommodate  the new SLA stream,  it is possible that the
 working capacity of the bed could decrease below design conditions or that
 costs of  increased  steam requirements or  carbon bed replacement due to
 excessive fouling could lead to  poor performance or excessive costs of
 operation.
      The operator's  responsibilities  under these conditions  are to design
 the system to accommodate  worst-case  VOC  composition conditions and to
 monitor the  adsorber outlet streams  adequately  to  assure  that the beds are
 not operated after  breakthrough.   It  is advantageous to standardize
                                                                       *
 solvent blends and minimize the  number of  "incompatible"  solvents likely
 to  be  ducted to  the control  device simultaneously.   There may be  cases
 where  these measures are impossible and carbon  adsorber performance cannot
 be  continuously maintained  at 95 percent efficiency  at  reasonable cost;  in
 these  cases, carbon adsorption is not the appropriate control  tech-
 nology.  Incineration is often selected because  it can  control  a  wide
 variety of VOC with relative ease.
     A preliminary cost analysis shows that, when compared to  baseline
 control assuming use of an  incinerator,  a 98 percent efficient  incinerator
 can cost-effectively control emissions from a coating operation equipped
with a total enclosure.   Incinerators were not considered cost effective
 at proposal  because they were considered a more stringent regulatory
 alternative, and the incremental  cost compared to a carbon adsorber at
93 percent overall  control  was considered  unreasonable.   However, if
conditions at a  new or modified line prohibit the use of carbon adsorp-
tion, these  same conditions would prohibit the use of carbon adsorption
under baseline regulations.  In fact, 67 percent of the  VOC emission
control devices  used by  the industry at  the time of proposal  were
                                   2-25

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 Incinerators.  Therefore, the cost of incineration under the NSPS should
 more logically be compared to the cost of incineration under baseline
 regulations.  The cost effectiveness of control is reasonable in all cases
 when analyzed using these assumptions.5
      Even if the use of multiple solvents does not affect carbon adsorber
 performance, it is possible that the cost of VOC recovery may be adversely
 affected.  The model plant analysis did include the cost of simple
 distillation (one water-soluble solvent and one blend of two solvents),
 but allowed a 100 percent credit for the recovered solvent.  It is
 possible  that, in the case of multiple solvents that are difficult and
 expensive to distill or where stringent solvent purity requirements  exist,
 a  100 percent credit may overstate  the actual  credit available  to some
 facilities.   An analysis of the regulatory alternatives developed at
 proposal  (RA's I,  II,  and III)  and  of  an alternative developed  post-
 proposal  (RA IIA)  shows that  solvent credits  less  than 100  percent (i.e.,
 60,  30, and  0)  result  in reasonable control costs  in the  majority of
 cases.  Reduced solvent recovery  credits are not cost effective  for  some
 lines, particularly  small  lines.5   However, these  lines would likely have
 the  same  problem at  baseline  conditions,  and incineration would  be the
 control device  of  choice.   Therefore,  commenters are  correct that VOC
 recovery  could  be  precluded under some conditions, but this is not the
 result of the  NSPS.
      Comment;   A commenter  (IV-D-16) presented data that, according  to  the
 commenter, indicated that only under ideal conditions could the plant
 (Grace) recover 93 percent of the VOC applied at the coating operation  and
 that, on  a day-to-day basis, recovering 93 percent is very unlikely.  (The
 data  are  claimed to be confidential business information and, therefore,
 are not presented here.)  The commenter stated that their equipment  is  the
 same  as Regulatory Alternative III.  The commenter uses a knife-over-roll
 coater with a substantially enclosed coater.  The coating operation
 (including the  substantially enclosed coater)  is enclosed in a room that
 is under negative pressure.  Exhaust from the room is sent to a  carbon
 adsorption system.  Over a 3-day continuous run, the operation achieved
93 percent recovery based on a liquid-liquid material balance.   The
average recovery efficiency over a month for this operation, also
                                   2-26

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 calculated using  a  liquid-liquid  material  balance,  was 86 percent.  The
 commenter stated  that even  though 93  percent  is  theoretically possible,
 85  percent is the maximum practical recovery  rate.
      Response;  Followup contacts were made with the  commenter to
 determine the differences between the "ideal"  conditions  during the 3-day
 run when a 93 percent overall  efficiency was  measured and the "typical"
 operation during  the remainder of the month when a  monthly average of
 86  percent was measured.  The  two major differences noted by that
 commenter were (1) more careful measurement taken during  the 3-day run  and
 (2) a shorter carbon bed adsorption time during  the 3-day run.   The com-
 menter emphasized the extensive effort and extreme  care used in obtaining
 measurements for  the 3-day material balance.   The adsorption time was
 decreased to 75 percent of the normal adsorption  time during the 3-day  run
 to  ensure that breakthrough would  not occur.   The commenter  noted that
 this  reduction in adsorption cycle time was not cost  effective  because  of
 the increased steam requirements  for desorption.  However, the  commenter
 added  that the difference in cycle time would  probably not have a
 significant effect on performance because the  original cycle length  is
 "very  conservative.1"7  The commenter stated that  the  plant would  prefer to
 use breakthrough monitors instead of timers to control
 adsorption/desorption cycles; however, a reliable monitor has not  been
 found  (IV-D-16).
     Although it is not possible to determine quantitatively the cause of
 the difference between the two data sets because separate control  and
 capture efficiency are not provided in either case,  comparison of  the
 short-term and long-term performance data indicates  that the measured
 differences  may largely be due to accounting for mix room losses, retained
 VOC in the web,  and waste VOC in the short-term calculations.  These
 losses were  not taken into account in  the monthly efficiency calcula-
 tions.  When  the  short-term  efficiency is recalculated without accounting
 for these losses,  the value  is consistent with the typical monthly
efficiencies  reported by the source.   Thus,  it is reasonable to expect
that,  if these types of  losses were taken into account during the long-
term measurements, the measured overall  efficiency would  approximate the
short-term results.   This  indicates that  short-term  data  may be reasonably
                                   2-27

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 representative of long-term performance if measured on the same basis.6
 Furthermore,  the short-term measurement techniques reflect the facility's
 efficiency as it is  to  be  determined for the purposes of conducting a
 liquid material  balance.   Thus,  EPA believes that rather than discredit
 the  level  of  the standard,  these test data support the standard.
     The  information from  the  commenter does indicate that performing a
 monthly material  balance in some cases (i.e.,  when multiple coatings are
 used) may  require more  resources than are reasonable to spend on
 compliance demonstrations.   However,  alternative  methods of demonstrating
 compliance with  the  standards  are available (see  Section 2.7.2) such as the
 alternative standard, gas-phase  test,  and short-term (3- to 7-day)  liquid
 material balance.  In any case,  the monthly liquid material  balance
 compliance provision has limited applicability and would not be an
 appropriate compliance  method  for the  situation described  by the commenter
 because multiple  emission sources are  ducted to the same control device.
     Comment;  One commenter (IV-0-17)  stated  that a major  flaw in  the
 regulation is  the  lack  of acknowledgment  of the variability  in any  coating
 process and in measuring its efficiency.   The  commenter  stated that  all
 available  data should be statistically  analyzed and  the  control limit
 based on,  at a minimum, the average  less  three sigma.  The commenter
 pointed out that the results from this  type of statistical analysis were
 used in EPA's  textile treated wastewater  effluent  regulations.
     Response;  The  EPA has considered  the  range of variable operating
 conditions  likely to be found in  this industry.  Based on both the theory
 and actual application of BDT,  EPA has determined that these variable
 operating conditions do not affect a facility's ability to meet an overall
 control level   of 90 percent, representative of BOT.  For example,  carbon
 adsorption has been shown to achieve 95 percent efficiency on a continuous
 basis despite  the use of multiple solvents and multiple runs.**  Enclosures
 capable of achieving 95 percent or greater capture efficiency while
 allowing safe worker access have been demonstrated.***6  Also, the  PSTL
plant data that are used as the basis for determining the performance of
BDT resemble these operating conditions more closely than they resemble
cases of single solvents,  long  production runs, and limited worker  access.
                                   2-28

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      The fact that statistical analysis has been used under other EPA
 programs is not relevant to the NSPS program.  Standards prepared under
 this program are established under Section 111 of the Clean Air Act and
 are required to reflect "the degree of emission limitation and the per-
 centage reduction achievable through application of" best demonstrated
 technology (BDT).  The selection of BDT is to be based on:
      .  . . application of the best system of continuous
      emission reduction which (taking into consideration the
      cost of achieving such emission reduction, and nonair
      quality health and environmental impacts and energy
      requirements)  the Administrator determines has been
      adequately documented.
 The selection of BDT from a range of alternatives is based on  engineering
 and cost evaluations of the technical feasibility and environmental  and
 cost impacts from application of the technology to the industries  in the
 source  category.   Once BOT is selected,  it is assumed,  by definition,  to
 apply uniformly to  the source category.   If  a single BDT does  not  apply to
 the entire source category,  alternate BOT's  may be designated  for  subcate-
 gories.   A statistical  basis  for the standard  such as  that  suggested by
 the commenter is  not appropriate under the NSPS process  described  above.
      2.3.1.2  Exemption  Level.
      Comment:   A  State  agency  (IV-D-9) recommended  adding a requirement
 for 90 percent  control  for facilities  using  less than  110 m3/yr
 (29,059  gal/yr)  (95  Mg/yr  [105 tons/yr]) of VOC  if  the incremental cost
 effectiveness  is  less than $l,100/Mg.  The commenter stated that
(29,059 gal/yr) (95 Mg/yr [105 tons/yr]) of VOC and suggested evaluating
this option by using model operation(s) below 95 m3/yr (25,096 gal/yr)
(82 Mg/yr [91 tons/yr]) of VOC usage.
     Response;  With the development of Regulatory Alternative IIA and the
decision to reduce the overall level of control required by the standards
from 93 to 90 percent, EPA reevaluated the VOC use cutoff level for this
industry.  This analysis focused on the same basic question as that raised
by the commenter,  e.g., would cost-effective control  be possible for
facilities that qualify for the lower cutoff level.   As can be seen from
Table 2-3, cost effective control  of such  facilities  at a 90 percent (or
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 lower) overall control  level  (Regulatory Alternative  IIA)  is theoretically
 possible.  However,  it  is  expected  that the environmental  impact of the
 change would be relatively small.   According  to  the economic impact
 analysis conducted at proposal,  it  is expected that growth in this
 industry will occur  in  lines  with annual VOC  usage greater than  110 m3/yr
 (29,059 gal/yr) (95  Mg/yr  [105 tons/yr]).  Therefore,  the  promulgation of
 a  lower VOC use cutoff  will not  affect the costs  and emission reductions
 projected as a result of the  NSPS and the cutoff  level  has been  retained
 as proposed.  Furthermore,  it is expected that most facilities will  choose
 to comply with the alternative standard, thus achieving at least 93
 percent overall control.   For these facilities, the analysis that
 determined the proposed cutoff is still applicable.  In any case, EPA  will
 reconsider the cutoff level at the 4-year review  of the NSPS if  additional
 data indicate that there is an environmental benefit to use of a lower
 cutoff.
     2.3.1.3  Consideration of Variable Operating Conditions.
     Comment;  Ten commenters (IV-0-5, IV-D-7, IV-D-8,  IV-0-12,  IV-D-13,
 IV-D-14, IV-D-15, IV-D-17,  IV-0-18, IV-D-21) believed that  EPA did  not
 properly consider the full range of practices in the industry  in develop-
 ment of the proposed standard.  One of the commenters (IV-0-5) indicated
 that the unique character of  the printing blanket coating  industry makes
 total enclosure of the coating operation infeasible (see Section 2.4.1).
 According to the commenter, EPA has failed to satisfy its statutory duty
 to consider the range of relevant variables that may affect emissions  in
 different plants and promulgate achievable standards.   Another commenter
 (IV-D-8) stated that EPA needs to review a broader cross-section of the
 fabric coating industry.  Specifically,  coating operations often have
 traces of fine resin particulate matter entrained in the dryer exhaust
 stream that would cause blinding of the carbon bed or  catalytic incin-
 erator.  The issue of carbon bed contamination was also addressed by
 another commenter (IV-D-12).  This commenter stated that the carbon beds
would become contaminated by airborne plasticizers emitted during curing
processes and powders emitted during mixing.
     Other commenters (IV-D-7, IV-D-13,  IV-D-14,  IV-D-15,  IV-D-18,
 IV-D-19, IV-D-20,  IV-D-21,  IV-D-22,  IV-D-23,  IV-D-24)  believed that  EPA's
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models do  not  adequately  reflect  the  diversity in the polymeric coating
industry because  the models  are based on  operations that use one solvent
on one substrate  utilizing equipment  dedicated to one method of coating.
However, according  to  the commenters, much  of  the coating equipment is
used with  several solvents or  solvent blends;  substrates of  several types,
thicknesses, and  widths;  and various  impregnating and coating head
configurations.   Also, because of the specialized properties of coated
fabrics, long, efficient  runs  are rare, and  batch processing is typical.
One commenter  (IV-D-13) stated that coating  runs  vary from 500 to
25,000 yards and  that  some days one coating  formulation  is run con-
tinuously, while  other days as many as six different  formulations may  be
used.  Another commenter  (IV-D-14) presented production  parameters  that
may affect emission rates and that demonstrate  the  variety of substrates,
coatings,  solvents, and manufacturing methods used.   This  commenter stated
that the coating  processes use seven  different  solvents.   A  commenter
(IV-0-7) contended that models that base control  efficiency  only on size
and solvent use fail to consider adequately major differences  in process
operations that affect both efficiencies and costs.   One commenter
(IV-D-12) stated that a review of each plant should be made  to  determine
the final standard because of the diversity of formulated  products  in  the
textile finishing market.
     A commenter  (IV-D-7) disagreed with the assumptions and models used
by EPA in developing the proposed standards.  The commenter  stated  that
the characterization of magnetic tape coating operations as  similar to the
polymeric coating industry is grossly inaccurate and jeopardizes the
validity and supportability of the proposed rule.  Another commenter
(IV-D-13) also expressed concern about data transfer from an organic
solvent-based tape coating line because all  polymeric coaters do not have
continuous production like the tape manufacturers.
     A commenter (IV-0-7)  indicated that EPA was in error in including a
model  plant controlled  by an  air-atmosphere condensation system in its
analysis, while not  considering the use of an inert-atmosphere condenser.
The commenter stated that no  air-atmosphere  condenser is in use in the
polymeric coating industry and  that EPA has  not demonstrated  that one can
be designed to fit such operations.   The commenter also stated that  EPA
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was  1n  error to assume  the  use  of a VOC  concentration of 25 percent of the
lower explosive limit (LEL)  as  the concentration  in  the oven exhaust and
the  control device  inlet  stream.   This assumption fails to account for the
lower concentrations found  in air from solvent  storage tanks,  mixers,  and
flashoff areas that would reduce  the concentration in the inlet to the
control device, thus reducing efficiency.   In addition, the commenter
stated  that an oven cannot  be safely operated at  this VOC concentration.
According to the commenter,  EPA has  accepted the  claims of vendors in  this
matter, but has no factual  data to support  this contention.
     Response;  The EPA believes  that the range of practices typical in
the  polymeric coating industry  have  been adequately  considered  in  the
development of the standards.   Based  on contacts  with and visits to a
large number of polymeric coating  plants over the course  of  standards
development, four different  types  of  "model lines" were developed  to
represent the diverse segments  of  the industry.   To  account  for the range
of sizes typically found in  each  sector of  the industry,  the impacts of
the  regulatory alternatives were  analyzed for two  or  three annual  VOC  use
rates within each type of model facility.   In all, a  total of nine
different combinations of facility type and size were analyzed.  In the
judgment of EPA, these model plants cover the range of  variables that
affect VOC emissions, and these variables have been given proper
consideration in the development of the standards.   In  fact, after
proposal EPA visited and requested detailed process information from
representative plants in order to learn more about enclosure design and
capture efficiency parameters as well as batch operations.  This
information confirmed the validity of EPA's approach.
     The commenter that  manufactures printing blankets  (IV-0-5) has not
shown that the process used  by his company cannot  be  controlled with
reasonable cost effectiveness.   The EPA believes that cost-effective
control  is feasible.  A  more detailed treatment  of this issue is presented
in Section 2.4.1.
     Difficulties  with particulate matter in the SLA  stream were not
raised as  an issue by industry  contacts  during the background study.
However, they have been  encountered in many  applications of emission
control  technology.   Filters upstream of  the VOC control device can
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 generally  alleviate  the problem at low cost.8  In cases where participate
 contamination  is  excessive or where the gas stream quickly deteriorates
 the  filters  (assuming  that there is no cost-effective,  compatible filter
 material), thermal  incineration, rather than carbon adsorption or
 catalytic  incineration, may be the best control  technique.  In any case,
 the  source would  encounter the same difficulties in the absence of the
 NSPS under baseline  control  regulations,  so the  costs incurred cannot be
 ascribed to  the NSPS.
     In response  to  the commenters who stated that EPA  needs  to review a
 broader cross-section  of the industry,  EPA  believes,  as discussed above,
 that the model line  analysis carried out  adequately considered the range
 of practices in the  industry.   The model  lines were developed based on
 extensive contact with  industry (including  textile and  other  commission
 coaters) in the form of plant  visits,  Section 114  information requests,
 and telephone contacts.   Because of the variability of  the industry,  plant
 parameters were developed  based  on annual VOC consumption  and basic
 coating line configurations  rather than product  specific parameters.   This
 approach is feasible because control device efficiency  depends  on  design
 and operating parameters of  the control device and  the  composition  of  the
 SLA stream, not on the  process or  equipment that generates the  exhaust
 stream.  Emission capture  systems  can be configured to  achieve  the
 required capture efficiency without interfering with necessary  process
 operations.2  If the variations in VOC, substrates, coating heads,  and run
 lengths are properly considered during the design phase of the  control and
 capture systems and appropriate operation and maintenance procedures are
 established and observed, process variations need not result  in reduced
 efficiency.
     The EPA has determined that most coating operations can be totally
 enclosed.   The appropriate enclosure design may vary from a small struc-
 ture fitting closely about the application/flashoff area to the entire
 room in which the coating operation is  located.  Even in cases where
 access  requirements rule out a close-fitting total  enclosure and space
constraints make a room-type enclosure  impossible,  a well-designed local
ventilation system can  achieve adequate capture to  meet  the final
standards.   Carbon adsorption, when designed for  the worst-case
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 conditions,  can  readily  handle  varied  loading.   (See Section 2.3.1.1 for
 discussion of  BDT  and  the  level  of  the standard.)   Two types of model
 lines that were  analyzed by  EPA included  distillation equipment for the
 separation of  blended  or water-miscible solvents and were found to be cost
 effective in meeting the standards.  Thus,  the  use  by some plants of
 multiple solvents, substrates,  and  coating  techniques does not render
 invalid the  analyses carried out by EPA.
     The responses to  the  other points raised by commenter IV-0-7 are as
 follows:
     1.  Although there are differences between magnetic  tape and polymeric
 coating lines, the general characterization of  the  two  as  similar is
 justified.   The  basic  configuration  of unwind station,  application/flashoff
 area, drying oven, and rewind station  is  common to  both.   The VOC content
 of the coatings  found  in the magnetic  tape  industry are within the range
 of those found in the  polymeric  coating industry, and many of the same
 solvents are used.  Some coating application techniques are  common to both
 industries,  and  the mix equipment is often  similar.  The SLA streams
 generated by the processes are similar in composition, as  are  the
 applicable control technologies.  Based on  these considerations,  EPA feels
 it has made  appropriate use of data derived from this industry.   However,
 the EPA does recognize that the magnetic tape coating process  is  largely
 automated, requires little worker access compared to some polymeric
 coating operations, and is characterized by a relatively narrow range of
 coatings and substrates.   It should be noted that the magnetic tape
 industry data do not provide the basis of support for the polymeric
 coating standard.  Rather,  data from the pressure sensitive tapes and
 labels industry, flexible vinyl  coating and printing, publication roto-
 gravure, and the polymeric coating industry itself  provide the basis for
 the standard.
     2.   At  least one air-atmosphere condenser has  been used on a polymeric
 coating operation.   A representative of the plant  indicated that no major
difficulties with the system had been encountered.9   However, it is
unlikely that this  control  technology will be  used  at polymeric plants
that are controlling  mix  equipment emissions as  well as coating operation
emissions  because the operation  of a fine-tuned, closed-loop condenser can
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 be  adversely  affected  by the moist,  intermittent airflow from mix
 equipment.    The  use of an inert-atmosphere condenser was not analyzed
 because  use of  this system is incompatible with a process where oxygen in
 the application/flashoff area is essential for worker access.  (See
 Section  2.4.2.)
      3.  The  assumption that the SLA stream at the inlet of the control
 device has a  concentration as high as 25  percent of the LEL is
 justified.  The standards contain no requirement that emissions from
 solvent  storage tanks  be ducted  to a control  device.   Moreover, a system
 using dampers could be designed  to deliver emissions  from solvent storage
 tanks to the  control device at a concentration of 25  percent of the LEL.
 Alternatively, a  more  dilute SLA stream could be used as makeup air in the
 drying oven.  Emissions from mix equipment are expected to be ducted to
 the control device at  a concentration of  25 percent of the LEL.   In
 addition, the airflow  from this  source 1s  quite small  in comparison to
 that  from the drying oven,  so a  reduced concentration would  have  little
 effect on the overall  concentration  of the Inlet SLA  stream.   The air
 containing the emissions  from the applicatlon/flashoff area  is expected to
 be  used  as makeup air  for the drying  oven,  not  ducted  directly to the
 control  device.   Drying ovens in this  and  other industries are operated
 safely at a concentration of  25  percent of  the  LEL.   In  fact,  ovens
 equipped with appropriate  safety features  are allowed  to  operate  at  up  to
 50  percent of the LEL.10
      For the  reasons presented above,  EPA believes that the varied
 production practices in this  industry were  adequately considered  in  the
 standards development process and that the  standards are  achievable  over
 the range of production practices expected to occur.
     2.3.1.4  Waterborne and Organic Solvent Coating Systems.
     Comment:   One commenter  (IV-D-15) stated that there  is no best
demonstrated technology for a coating operation that uses both aqueous and
organic solvent coating systems,  nor is there a provision for handling
this type of operation  where a common mixer is used.
     Response:  The commenter is  correct  that use of the proposed control
technologies may be incompatible  with the  use of waterborne coatings.
Therefore,  an  exemption for waterborne coatings has been added in
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 § 60.740, Applicability and Designation of Affected Facility, to specify
 that the coating operation or mix equipment may be vented directly to the
 atmosphere while waterborne coatings are used.  A definition of waterborne
 coatings sets the minimum water content (5 percent by weight of the
 volatile fraction) necessary to be considered a waterborne coating.
 Because "waterborne" coatings may actually contain organic solvent and
 generate VOC emissions, the exemption for their use provides a VOC content
 ceiling of 9 weight percent of the volatile fraction.   This ceiling was
 developed based on a "worst-case" baseline coating that is 85 percent VOC
 (15 percent solids) by volume.  The level  specified in the exemption is
 equivalent to a 90 percent VOC reduction for this coating.  The VOC in
 waterborne coatings is not to be included  in the annual  VOC usage rate
 when determining if a facility is below the VOC use cutoff.  However, the
 amount  of VOC in waterborne coatings  reported by the industry is
 negligible (zero to 2 percent by weight of coating applied) and the impact
 of  this exclusion is expected to be minor.11
 2.3.2  Control  of Coating  Mix Preparation  Equipment
      2.3.2.1   Equipment Considered  as  Coating Mix  Preparation Equipment.
      Comment;   One commenter (IV-D-3)  recommended  that coating  mix
 preparation equipment include only  mixers  and not  mills, holding tanks, or
 other equipment.   The commenter  observed that the  only coating  mix  prepar-
 ation equipment considered  in developing the  standards and  demonstrating
 the  feasibility of the  standards was the mix  tank.  The feasibility of the
 proposed  standard  for mills,  holding tanks, and other equipment, which are
 included  in the definition for coating mix preparation equipment, was not
 considered.  At the  commenter's plant, portable containers are used to
 transport coating  from  the mixing area to subsequent coating preparation
 and  application areas.  These portable containers appear to be included in
 the  definition  as  "holding tanks," but, according to the commenter, there
 is no feasible  or  practical way for these portable containers to comply
with the requirement that all VOC emissions be vented to a control device.
The  commenter also questioned the feasibility of (1) capturing and venting
all  VOC emissions from mills to a control device at a concentration range
within which the control device is efficient or (2) installing a vapor-
tight cover equipped with a conservation vent.  The commenter said that
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 only equipment that was specifically addressed in the development of the
 standard should be included in the definition of coating mix preparation
 equipment.  The commenter recommended that "coating mix preparation
 equipment" be defined as "mix tanks in which solvent and polymer are
 blended to prepare polymeric coating formulations."
      Response;  The final  rule requires that only affected mixing vessels
 be covered and vented to a 95 percent efficient control device.  The
 definition of "coating mix preparation equipment" has been changed to "all
 mixing vessels in  which solvent and other materials are blended to prepare
 polymeric coatings."
      The commenter is correct in noting that only mixing vessels were
 considered in the  analysis of the cost and cost effectiveness of mix
 equipment control.  This approach was adopted because essentially all
 mixing area emissions that were intended to be regulated are generated  at
 the mixers.   Mills  in this industry are most frequently operated using  dry
 ingredients alone  and are  often tightly sealed to contain the ingredients.
 Emissions from holding tanks  are negligible compared  to those from the
 mixers because both breathing  and working  losses  are  minimized.   Breathing
 losses are minimized  because  holding  tanks  are generally located indoors
 at  relatively constant temperatures and because the vessels  typically are
 covered  during  storage to  minimize coating  composition  changes  through
 solvent  loss  and contamination.   Working losses due to  the filling of
 vessels  are minimized because  holding  tanks  typically are cleaned  between
 uses;  a  clean, dry vessel  does  not have any  vapor  in the air  space to be
 displaced  as  the coating is introduced.  Emissions during the cleaning
 process  are not regulated  because  of the inherent difficulties of
 control.   Nevertheless, mills,  holding  tanks, and other equipment were
 included  in the proposed rule because  it had been determined that the
 controls mandated for the mixers could  be easily applied to such
 equipment.
     However, based on a reexamination of the information gathered during
 the development of the standard and on the information presented by the
 commenter, EPA has decided that the standards should be applied only to
mixers because they are the primary source of mix room emissions and the
costs of controlling emissions from mills were not demonstrated.  The EPA
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 also agrees with the commenter that it is infeasible to duct emissions
 from portable equipment to a control device.  However, during the actual
 mixing process these portable containers are stationary and ducting
 emissions to a control device is feasible.  Thus, portable tanks,
 including holding tanks, are required to be covered and vented during
 those times that they are in use as mixing vessels.
      2.3.2.2  Feasibility of 100 Percent Capture.
      Comment;  Three commenters (IV-D-3, IV-D-5, and IV-D-7)  stated that
 capture of all emissions from mix equipment has not been demonstrated.
 The  commenters questioned the technical  feasibility of capturing and
 venting all  VOC emissions from coating mix preparation equipment.
      One commenter (IV-D-3)  whose plant  was cited in the proposal preamble
 as an example of BDT for mix equipment stated  that the existing  system
 actually falls short of the  technology specified as BDT.   The  mixer covers
 are  tight fitting but are not "sealed."   The need for access to  the mixers
 makes sealed  covers  impractical.   The  plant has  a system whereby dampers
 open to increase the draft to the control  device when mixer covers  are
 opened,  but the commenter questioned the  contention that all emissions are
 prevented in  this way.   In addition, the  commenter stated  that EPA  failed
 to consider emissions during  the  transfer  of coatings when EPA proposed
 the  requirement that all  emissions from mix  equipment be captured.   Accord-
 ing  to  the commenter,  total enclosure  of all transfers  from mixers to
 transfer  containers,  strainers, coaters, and other mixers  is not  feasible;
 nor  is  it feasible to  duct emissions from  these  transfer points or mix
 equipment other than mixers (see Section 2.3.2.1)  to the control  device.
      In addition, the  commenter (IV-D-3)  pointed out that, while  the
 proposal preamble states that BDT for mix equipment is the use of covers
 vented to a control device and that the format for the standard is an
 equipment format, the proposed standard does not mention equipment.  The
 commenter stated that: the requirement that all  VOC emissions be captured
 and vented makes the proposed standard a  performance standard.   The
 commenter stated that as a performance standard the word "all"  imposes a
condition that  is impossible  to meet because no engineered  system is
 100 percent effective, nor can it be operated with 100 percent  reli-
ability.  The commenter also  stated that  EPA does not present objective
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 evidence  to  support  the  use  of  the terms "expected,"  "sufficient," and
 "all"  and does  not define  the term "sealed"  in the proposal  preamble,
 Section IV(D)(l)(c).  The  commenter recommended that  the performance
 standard  language be deleted and  that the standard (§ 60.742(a)(2)as
 proposed)  be restated as an  equipment standard as  follows:
     Control  emissions from  onsite coating mix preparation
     equipment  servicing coating  lines using at least 150 m   of
     solvent/year by installing a cover on each piece of
     affected coating mix  preparation equipment and venting  the
     equipment  to a 95 percent efficient control device; the
     cover must be closed  at all  times except when adding
     ingredients, withdrawing samples, transferring the  con-
     tents,  or  making visual inspections when such activities
     cannot  be  carried out with covers in place; when possible,
     such  activities should  be carried out through ports of  the
     minimum practical size. .  .  .
     A second commenter  (IV-D-5)  focused on  the portable containers  or
 "change cans" used specifically in  the printing blanket  industry for high-
 viscosity  coatings that cannot readily be pumped beyond  the  shortest
 distances.   According to the commenter,  the  change  cans  are  generally
 covered during  storage, movement, and  mixing .but cannot  be ducted  to a
 control device  because of their portable nature.   Some VOC emissions from
 these containers are inevitable when covers  are necessarily  removed
 between the  steps of the process.   The  commenter noted that  EPA estimates
 that coating mix preparation equipment  accounts for only  10  percent  of the
 VOC emissions from a coating plant.  The  comnenter  suggested that  the
 final rule allow the use on change  cans  of a plastic film cover at least
 2 mils thick and taped around the periphery during storage,  transport, and
 piping of coating to the coating heads, which would result in control  at a
 "somewhat" less stringent standard.  Fixed covers with conservation  vents
 are not a viable alternative based on the commenter's  experience that  such
 covers are too heavy to be handled manually in a safe  manner and that  the
 use of mechanical  equipment is  cumbersome and may damage the cover,
 reducing its effectiveness as a control device.  The commenter reiterated
 these comments in Docket Item IV-D-16 and added that the minimum measured
VOC concentration at the carbon  adsorber outlet was 25 ppm,  which would
result in no net VOC reduction  because of the low level (probably 10 to
25 ppm) of VOC in the air from  the mixing room.
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      The third commenter (IV-D-7) pointed out that companies frequently
 use different types and sizes of mix equipment.  Some are totally
 enclosed, while others are virtually impossible to enclose well enough to
 meet the proposed standard.  The size of containers varies from a 5-gallon
 pail to a 500-gallon portable tank.  The commenter maintained that
 companies would find it impossible to capture all emissions from mix
 equipment because of the nature of the process, cleanups, color changes,
 short runs,  container handling, etc.  The commenter also questioned the
 validity of  EPA's contention that coating lines that apply urethane
 coatings, which are purchased premixed, do not use mix equipment.
 According to the commenter, all such operations use mix equipment  either
 to adjust the specific properties of a batch of coating or to obtain the
 proper coating consistency.
      Response;  The format  of the standard for mix equipment was intended
 to be an equipment standard.   But,  as noted by the commenters,  the use of
 the term "all" in the  proposed standard implies  100 percent  capture,  which
 has not  been demonstrated in  the polymeric coating industry.  The
 standards for mixing vessels  that serve coating  operations that  use  at
 least 130 Mg/yr  (144 tons/yr)  of VOC (and  are  not  associated with  a
 coating  operation without concurrent construction  of a control device)
 have  been revised to be consistent with  actual workplace  conditions as
 described by  the  commenters.   These  mixing  vessels  are required  to be
 covered  during mixing  and vented  to  a 95 percent efficient control
 device.   The  covers shall be closed  at all times except when adding
 ingredients, withdrawing samples, transferring the contents, or making
 visual inspection when such activities cannot be carried out with the
 cover in  place.  The cover must extend at least 2 centimeters (cm)
 (0.8  inch  (in.J) beyond the outer rim of the equipment or be attached to
 the rim and must be of such design and construction that contact is
 maintained between cover and rim along the entire perimeter.   Any breach
 in the cover (such as a slit for insertion of the mixer shaft or port for
 addition of ingredients) must be covered as discussed above when not
 actively in use.  An opening sufficient to allow safe clearance  for a
mixer shaft is acceptable during periods when the shaft is in place.   A
polyethylene  or other nonpermanent cover may be used provided it  meets the
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 requirements above.  Such covers may not be reused after once being
 removed.   As discussed in Section 2.3.2.1, the requirements for mix
 equipment other than mixing vessels have been dropped from the final rule.
      The  EPA does not believe that the use of portable containers or
 containers of varying sizes precludes the venting of emissions to a
 control device during the actual mixing process.  In cases where portable
 tanks are used, the mixing apparatus remains stationary.  Ductwork can be
 installed from this point to the control  device.  No evidence has been
 presented that small  mixing vessels cannot be similarly equipped.  The
 intent of the proposed mix equipment standards was not to require ducting
 of  the ventilation air from the  entire mix room to the control  device but
 to  allow  installation of  ductwork at the  mixing station, which  would
 provide a higher solvent  concentration for more efficient control.   The
 change from requiring the control  of "all" mix equipment emissions  to an
 equipment format,  with allowances for opening covers  during  periods of
 legitimate need,  addresses the concerns cited by the  commenters.
      The  commenter's  (IV-D-7) contention  that sources applying  urethane
 coatings  employ mix equipment does  not change the conclusions of  the
 background study.   Should  these  sources use mix equipment, the  same cost
 factors that  apply to mix  equipment  at other plants would  apply.  In fact,
 the higher value of the solvents  saved by  the application  of control  tech-
 nology at  this  type of plant would  improve the cost effectiveness of
 control beyond  that calculated for other types of polymeric coating
 plants.   Because of the direction of  this  change,  the  impacts of the
 standards  were  not  recalculated.  When  such  sources use mixers, the
 beneficial  impacts  of  the  standards will be  obtained with reasonable cost
 effectiveness and will far outweigh the negative  impacts.
      2.3.2.3  Efficiency of Mix Equipment  Covers.
      Comment;  One  commenter (IV-D-3)  said that EPA appears to have
 incorrectly applied information on emissions from solvent storage tanks to
 emissions from mix  tanks.   The resulting estimate that vapor-tight covers
with conservation vents would reduce emissions by 40 percent significantly
understates the emission reduction that would be obtained.  The commenter
went on to say that even a simple cover not equipped with vapor-tight
seals or a conservation vent would conserve much more than 40 percent of
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 the solvent lost from an open mixer.  The commenter presented the results
 of a bench-scale experiment testing this hypothesis.  A Pensky-Martens
 flashpoint tester was used with a small amount of coating to approximate a
 mixer.   It was  reported that, relative to an uncovered mixing vessel,
 covers  over 87  percent and 100 percent (not vapor tight) of the vessel
 opening achieved emission reductions of about 74 percent and 96 percent,
 respectively.   The commenter contended that economic analysis would show
 that the small  gain in emissions control  achieved by a vapor-tight cover
 with a  conservation vent as opposed to a simple cover would not be cost
 effective.   The commenter suggested that the standard for mix equipment
 using at least  110 m;}/yr (29,059 gal/yr)  (95 Mg/yr [105 tons/yrj)  but less
 than 150 m3/yr  (39,626 gal/yr)  (130 Mg/yr [144 tons/yr])  of VOC
 (§ 60.742(a)(3)  as proposed)  be revised to  require only a cover that
 encloses at  least  95 percent  of the opening and that must be closed at all
 times except when  adding ingredients,  withdrawing samples,  transferring
 the contents, or making visual  inspection when such  activities  cannot be
 carried  out with the cover in place.
      Response;   The  EPA agrees  that the improvement  in  control  efficiency
 on mix equipment to  be  gained from  a vapor-tight  cover  with  a conservation
 vent compared to that  from a  simple tight-fitting cover is  insignificant.
 The chief benefit  to be gained  from conservation  vents  is the control  of
 "breathing losses" resulting  from diurnal temperature changes.   Because
 mix equipment is not  normally exposed  to  such  changes in this industry,
 the requirement  that  covers be  sealed  and equipped with conservation  vents
 has  been dropped.  However, EPA does not agree that the emission reduction
 ascribed to covers is significantly underestimated.  The experiment
 conducted by the commenter explored only evaporative losses during the
mixing process.   This treatment neglects the impact of the "working
 losses" that occur due to the filling and emptying of a vessel that
contains a solvent-saturated air space.  An analysis of cover efficiency
was  carried out  for mix equipment in the magnetic tape manufacturing
 industry, and the results of this analysis are considered representative
of the polymeric coating industry as well.12  The efficiency of covers was
determined by this analysis to be 40 percent.
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     The  standard  for mixing  vessels  that use at least 95 Mg/yr
 (105 tons/yr)  but  less than  130  Mg/yr (144 tons/yr) of VOC,  § 60.742(c)(3),
 has been  revised to  require the  equipment to be covered at all  times except
 when adding  ingredients,  withdrawing  samples, transferring the  contents,  or
 making visual  inspection  when such  activities cannot be carried out with
 the cover in place.   The  same requirements have been extended to mix
 equipment at facilities using at least  130 Mg/yr (144 tons/yr)  of VOC that
 are associated with  coating operations  without concurrent construction of
 a control  device.  The cover  must extend  at least 2 cm (0.8  in.)  beyond
 the outer rim of the equipment or be  attached to the rim and must be of
 such design  and construction  that contact is maintained between cover and
 rim along the entire perimeter.   Any  breach in the cover (such  as a slit
 for insertion of the mixer shaft or port  for addition of ingredients)  must
 be covered as discussed above when not  actively in use.   An  opening suffi-
 cient to  allow safe  clearance for a mixer shaft is acceptable during
 periods when the shaft is in  place.   A  polyethylene or other nonpermanent
 cover may be used  provided it meets the requirements above.  Such covers
 may not be reused  after once  being removed.   The  cost of  compliance with
 the revised  standard  will be  less than  that  associated with  the use of
 covers and conservation vents, which  were  cost  effective  under the
 proposed  standard.   This  is because the cost  of covers  is expected  to be
 included  in  the purchase price of new equipment so  that there is  no
 incremental  cost associated with  the  emission reduction.
 2.4  CONTROL COSTS
 2.4.1  Total Enclosure  of Print Blanket Coating Equipment
     Comment;  One commenter  (IV-D-5)  stated that the cost of totally
 enclosing print blanket coating equipment was seriously underestimated.
 This segment of the polymeric coating industry uses very viscous coatings
 that must be applied  in precise thickness according to strict specifica-
 tions.   The operator must constantly observe for dirt contamination or
 accumulations of dried coatings on the back of the blade and inspect for a
 smooth  appearance of the coating.  These factors necessitate constant
operator access to the coater.  Thus,  according to the commenter, a small
enclosure immediately around  the coating application/flashoff area cannot
be used.   The commenter also  stated  that a total room enclosure  is
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 infeaslble for existing plants (see Section 2.11.1), because there are
 typically multiple lines In a single large room with many openings and
 ventilation systems.   The remaining option 1s to enclose the equipment
 within a smaller room of sufficient size to allow the constant presence
 and mobility of equipment operators.  However, for worker safety, the
 concentration of solvent within this enclosure is currently limited to
 100 parts per million by volume.   According to the commenter, this limit
 cannot be achieved using a blower system to supply fresh air to the area
 where the operator is stationed because of the large size of the equipment
 (up to 80 feet long)  and the requirement that the workers be able to move
 about the equipment to monitor and adjust critical  parameters.   The
 commenter also rejected the use of airpacks,  which  are  a serious incon-
 venience to the worker.  The commenter concluded  that the only  remaining
 option would be to flush high volumes  of air  through the enclosure to
 maintain the low solvent concentration required for employee safety.
      The commenter presented an analysis of the costs and cost
 effectiveness of this approach  at  one  of his  company's  print blanket
 coaters.   The analysis was  based on  the capture of  an additional
 110 pounds of toluene per hour.  To  dilute  this quantity of  solvent to  the
 safe concentration, the air handling system would have  to be designed for
 approximately 77,000  cubic  feet of air per  minute.   The commenter  stated
 that an  additional  carbon adsorption system sized to  handle  this airflow
 would  cost approximately  $2.5 million.   The cost-effectiveness calcula-
 tions  were based on the  actual  solvent  use  for the  subject coating line.
 (Many  of  the  details  of  this analysis were  claimed  to be  confidential
 business  information  and  are not presented  here.)   The  commenter1s
 analysis,  taking Into  account capital depreciation, steam costs, power
 costs, and  solvent recovery credits, resulted in a cost effectiveness of
 $21,005 per ton of solvent recovered relative to the emission level
 currently  allowed by State regulations, which is represented by Regulatory
Alternative I.
     Response;  The commenter's analysis of costs and cost effectiveness
was based on the faulty assumption that the only way to  protect workers
within a total enclosure is to assume that the emissions are released into
the enclosure and to dilute the emissions in the enclosure to the level
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 considered  safe for personnel.  This assumption resulted in an airflow
 rate  so  high  that an entirely new carbon adsorption system would be
 required to control  the emissions.   The capital cost of this system,
 coupled  with  the high operating costs associated with maintaining a high
 removal  efficiency from such a dilute SLA stream, resulted in an
 unreasonable  cost-effectiveness value.
      The commenter's assumption is  unrealistic and erroneous.  In
 practice, localized  pickup points (hoods or other partial  enclosures)
 should be placed within the total enclosure to both protect any workers
 that  must be  inside  and reduce the  ventilation rate to a level  such that
 the air  from  the enclosure can be used as makeup air in the drying oven.
 Thus, a  new carbon adsorption system would not be required, and the
 composition of  the SLA stream ducted to the control  device would be
 similar  to  that assumed in EPA's  analyses.
      The EPA  reworked  the  commenter's analysis using more  realistic
 assumptions.  Based  on the use of local  ventilation  devices within a total
 enclosure,  a  reasonable concentration for the  captured fugitive VOC is
 5 percent of  the  LEL.   The ventilation rate of the enclosure under these
 conditions  would  be  about  12,000  actual  cubic  feet per minute.   Given the
 drying requirements  in the oven under the commenter's  scenario,  this
 quantity of ventilation air could be  readily accommodated  as makeup air
 for the  drying  oven, and a new carbon adsorber would not be  necessary.
 Using the commenter's  values  for annual  VOC  use,  electricity and steam
 costs, and  the  value of reclaimed solvent and  the  factors from  EPA's
 original analysis  for  adsorber steam  and  electricity demand, the cost
 effectiveness of moving from  the source's current  control level to  the
 level  required  by the  NSPS  is  less than  $200 per ton of additional  solvent
 recovered.    The EPA  considers this to  be a reasonable value.  Thus, EPA
 believes that the costs associated with  totally enclosing equipment such
 as that operated by the commenter were not underestimated.
 2.4.2   Accuracy of Cost Analysis
     Comment;   Three commenters (IV-D-7, IV-D-8,. IV-D-14) questioned the
assumptions  and models used in performing the cost analyses.  The
commenters noted the following specifics:
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      1.   Leak-proof ovens.   One commenter (IV-D-7)  stated that the
 efficiencies  used  1n the  cost  analysis  were based on leak-proof ovens,
 which  are virtually impossible to construct.  The commenter suggested that
 the efficiencies be based on demonstrated efficiencies  such as monthly
 averages  rather than the  maximum efficiency achieved over a short
 period.   Also,  operating  efficiencies for process lines are lower than
 vendors'  claims.
     2.   Recovered  solvent credit.   Each  of the commenters (IV-D-7,
 IV-D-8, IV-0-14) stated that the cost credit from recovered solvent  is
 lower  than the  estimates  in  the proposed  regulation.  One commenter
 (IV-D-7)  stated that the  costs were  based on recovery of  a single solvent
 rather than mixed solvents,  which are typically used  in the industry.
 Mixed  solvents  may  have to be  disposed  of as hazardous  wastes.   The  other
 commenters (IV-D-8,  IV-D-14) noted that the cost analysis did  not address
 processes for which  the solvent cannot  be reused.  One  commenter (IV-D-8)
 said that recovered  solvent  would probably not  meet the stringent quality
 standards required  for solvents used 1n aerospace and defense  applica-
 tions.  The second  commenter (IV-D-14)  stated that solvent  recovery  is not
 a viable  alternative for  fabric coating of labeling material for the
 garment Industry because  of  the high purity solvents required.   This
 commenter said  that  recovered  solvents would  likely have  to be disposed of
 as hazardous waste.   The  commenter also stated  that incineration  would be
 prohibitive because  of the large  volume of  air  and low VOC concentration.
     3.  Air-atmosphere condensation.  One  commenter (IV-D-7) stated that
 the cost data were based  on  an  air-atmosphere condensation system that has
 not been demonstrated as  a feasible technology  for the polymeric coating
 industry.  The  cost  of modifications required to apply this technology to
 the polymeric coating Industry was not considered in the analysis.
     4-  Costs  of air pollution and wastewater controls.  One commenter
 (IV-D-7) stated that  the cost of air and wastewater  pollution control
 equipment was not addressed.   Specifically, the commenter cited that the
 cost of distillation  systems, which are  needed to purify solvents and
 clean up wastewaters, was not included in some models, and that the
 capital costs for air pollution control  equipment, which refer to a 1978
manual, seem low.   A  second  commenter (IV-D-8) stated that the economic
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 Impact of wastewater discharges should be reassessed because of the
 recently passed Clean Water Act amendments.   The preamble to the proposed
 standards states that carbon adsorber wastewater discharges to municipal
 sewer systems are permissible,  but the commenter suggested that pretreat-
 ment may be required by the recent Clean Water Act amendments.
      Response;   The  EPA continues to believe that the assumptions used in
 the cost analysis are valid and that the model  plants are representative
 of  typical  facilities expected  to be constructed, modified, or recon-
 structed in the near future.  The following  responds to  the specific
 comments summarized  above:
      1.   First, EPA  believes  an essentially  leak-proof oven is possible
 with proper design and  operation at a slightly  negative  pressure relative
 to  its surroundings.   Second, the standards  were  based on demonstrated
 effldences.  An overall efficiency of 93 percent has  been demonstrated
 using a  30-day  material  balance at a PSTL facility using  BDT (See
 Section  2.3.1.1).  This  performance is considered representative of  the
 performance of  a well-designed  and well-operated  control  system  in the
 polymeric coating Industry.  Thus,  demonstrated performance over a 30-day
 period was  considered  1n the development of  the standards.
      2.  The  EPA's survey of existing  plants indicates that typical
 practice for  the  polymeric coating  industry  1s to  use  a single solvent or
 a reusable  mixture, rather than mixed  solvents that may have to  be
 disposed as  stated by the commenter (IV-D-7).  However, the model lines
 analyzed by  EPA  also accounted for  the use of two types of  solvents that
 required distillation, a two-solvent blend (dimethyl formamide and
 toluene) and a water-soluble solvent (acetone).   In both cases,  it was
 determined  that control at the level of the standard is cost effective.
     Onsite distillation is expected to become more attractive as
 regulations on the disposal of liquid hazardous wastes become more
 restrictive.  As the cost of such disposal rises, the relative benefit of
 distillation increases.  Thus, while the cost of reclaiming solvents may
 not be justified by the value of the solvents themselves, it may be
 justified when the cost of disposal is considered.  If onsite distillation
remains infeasible, and the solvent is sold  to a reclaimer or disposed as
a hazardous waste, the operator  will not accrue full  value of the
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 solvent.   However,  the same will  hold true under any of the regulatory
 alternatives;  therefore,  the incremental  cost to go from one regulatory
 alternative to the  next most stringent regulatory alternative would in
 most cases be  small,  and  the regulatory decisions would not change.
      As one commenter pointed out,  the inability to reuse solvents is most
 likely to  occur in  aerospace and  defense  applications because of stringent
 quality specifications for solvents.   However, EPA is working with the
 Department of  Defense to  encourage  development of end-product specifica-
 tions.     This may  enable the defense industry to reuse solvents.   If
 solvents are not recovered and reused,  the economic impact to the  aero-
 space and  defense industries is expected  to be small.   Incineration is
 currently  used,  without adverse economic  impacts, as a VOC emission
 control measure  for these industries  (including the commenter's  [IV-D-8]
 plant that was visited during the background study).
      As discussed in  the  response to  Comment 2.3.1.1,  even solvent
 recovery credits less than 100 percent  (i.e.,  60, 30,  and  0)  result in
 reasonable control  costs  in the majority  of cases.   However,  where carbon
 adsorption control  is not cost effective,  incineration is  a viable
 alternative that has  been successfully  used by the  polymeric  coating
 industry.1*
      3.  At least one polymeric coating plant  has operated an
 air-atmosphere condensation  system.  At the time  the cost  analyses  for the
 standard were  performed,  this  condensation  system had  not  been in  opera-
 tion  long  enough  for  meaningful efficiency  data to  be  collected.   However,
 preliminary  data  indicated that the air-atmosphere  condensation system
 would be a  viable option.   A recent discussion with  a  representative at
 the polymeric coating plant that uses an air-atmosphere condensation
 system supported  this  conclusion.9  The air-atmosphere condenser at this
 plant achieves a  control efficiency of 90 to 95 percent.  There have been
 no problems with  this  system during approximately 3 years of operation.
 However,  as a result of EPA's analysis of the cost and performance of
 various technologies applicable to the polymeric coating industry,  carbon
 adsorption, not air-atmosphere condensation, was chosen as the BDT on
which the  standard 1s based.  In addition, it is anticipated that most
affected  lines, which will also have to duct and control mix equipment
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 emissions, would be unable to use condensers because the moist,
 intermittent airflow from mix equipment interferes with condenser perfor-
 mance.  The cost of an inert-gas atmosphere condenser was not developed
 because of its limitations for application in this industry (i.e., the
 need to purge the unit of inert atmosphere every time workers must access
 the oven or application/flashoff area).
      The costs to fit a coating operation with an air-atmosphere condenser
 were included in EPA's analyses.  These costs consist of the costs of the
 total enclosure and ductwork.
      4.  The cost of distillation systems was included for all  models
 requiring distillation,  that  is, those.model  coating  operations using a
 solvent blend or a water-soluble solvent.   Capital  costs for a  condenser
 were developed from estimates  provided by a vendor.   Capital  costs for an
 incinerator and carbon adsorber were developed using  the 1978 Economic
 Analysis Branch Control  Cost manual.  However,  these  costs were adjusted
 to  1984 dollars using the  Plant Cost Index in Chemical  Engineering.   (All
 costs are reported in first quarter  1984 dollars.)
      The commenter (IV-D-8) correctly points  out  that wastewater generated
 because of compliance with the  polymeric coating  NSPS may  be  subject  to
 either effluent limitations if  the wastewater is  discharged to  a receiving
 stream or pretreatment standards  if  the  wastewater is discharged to a
 municipal  sewer.   Both the wastewater generated because of compliance with
 the  polymeric  coating  NSPS and  the wastewater generated currently because
 of compliance  with existing State pollution regulations for VOC  emissions
 have  to  meet the applicable treatment  requirements.  Because the treatment
 requirements have to  be met under baseline conditions for wastewater
 discharged currently and because the  increase in the volume of wastewater
 generated  after compliance with the polymeric coating NSPS is small,  the
 cost  to  treat  the wastewater was not  included in the costs used   in the
 economic evaluation of the technology alternatives for the NSPS.  The
 small  Increase  in treatment costs because of the additional volume of
wastewater generated after compliance with the NSPS would affect neither
the results of the economic analysis of the technology alternatives nor
the selection of the technology used as the basis for  the polymeric
coating NSPS.
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 2.5   ENVIRONMENTAL  IMPACTS
 2.5.1 Total  Enclosure  Requirement
      Comment;  One  commenter  (IV-D-5)  believed  that EPA failed to account
 for the environmental advantages  of  high-solids coatings.   The commenter
 stated that the need for  constant operator  access  and  attention while
 applying the  current high-solids  coating formulations  used  in printing
 blanket coating operations  render the  proposed  standards economically
 infeasible (see Section 2.4.1).   To  avoid this  problem,  a printing blanket
 manufacturer  contemplating  a  new  coating line might attempt to develop a
 new process that utilizes a low-solids coating  formulation  so that port-
 able  mix equipment  and  constant operator access  to  the coater are not
 required.  Such a process might comply with the  proposed mix  equipment and
 coating operation standards while  actually  increasing  emissions  relative
 to existing practice using  high-solids coatings.   (The commenter presented
 an example of such  a situation, but many of the  details  were  claimed  to  be
 confidential business information  and, thus, are not presented here.)  The
 commenter suggested that Regulatory Alternative  I,  the prevailing  SIP
 limit in nonattainment  areas, be adopted in the final  rule.
      Response;  The EPA does not believe that any manufacturer would  need
 to develop a new process using a low-solids coating formulation  in order
 to comply with the standards.  The commenter's assertion that a total
 enclosure would be Infeasible for his company's high-solids coating
 operation was based on faulty assumptions (see Section 2.4.1).  Also, a
 revision to the definition of coating mix preparation equipment excludes
 the portable mix equipment described by the commenter except during those
 periods when the portable vessels are in use as mixing vessels (see
 Section 3.2.1).   Thus,  the hypothetical scenario presented  by the
commenter is  not expected to occur.  The EPA has demonstrated that the
final  standards  (with a solvent use cutoff  to exempt small  sources)
provides a greater emission reduction than  would be achieved under base-
 line conditions  for a reasonable cost.   The  commenter has not provided
 information that would  change  this determination.
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 2.5.2   Accuracy of Environmental  Impact Analysis
     Comment;   One commenter (IV-D-9)  questioned the accuracy of the
 environmental  and  economic  impact analyses because of discrepancies in the
 data base  for  existing  plants.  The  commenter stated that only 6 of the
 13 Ohio plants listed in  Table  9-7 of  the  Volume I BID (Plants Applying
 Polymeric  Coatings to Supporting  Substrates .  .  .) actually  apply a
 polymeric  coating; the  others apply  a  printing ink to vinyl  or vinyl
 fabric.  The commenter  provided a list of  the  13 plants  and  the process
 used at each plant.  The  commenter stated  that this discrepancy "casts a
 shadow"  over the analyses of environmental  and economic  impacts.
     Response:   The  environmental  and  economic impact analyses were based
 on a projection of sources  expected  to become  subject to  the  NSPS in  the
 next 5 years.   These sources are  expected  to be  new coating  lines rather
 than modified  or reconstructed  lines.   The  analyses were  performed  using
 model lines developed from  information about existing polymeric coating
 plants  that are considered  to be  representative  of new polymeric  plants,
 and not  using  the  list of existing sources  presented  in Table  9-7 of  the
 Volume  I BID.   Thus,, any  Inaccuracies  1n the Information presented  in
 Table 9-7 would  not  affect  the  environmental or  economic impact analyses.
 2.5.3  Baseline  Control  Level
     Comment;   Two commenters (IV-D-5,  IV-D-9) questioned the determination
 of the baseline  emission  level  for coating operations.  One commenter
 (IV-D-5) stated  that; the designated baseline, Regulatory Alternative  I,
 actually represents a control level that would require significant reduc-
 tions in emissions from many coating operations.  Many State regulations
 allow a  level of control that is considerably more lax than Regulatory
Alternative I, and various States  that do require this level  allow excep-
tions under some circumstances.   On the basis of this and the analysis in
Section 2.5.1, this commenter suggested that Regulatory Alternative I be
adopted in the final standards.   The  second commenter (IV-D-9) noted that
some fabric coating plants in Ohio had  variances from the SIP control
level  requirement.
     Response;   The baseline control  level  is defined as  the  existing
level  of control that is typical for  the Industry.  The baseline emission
level  used in the analyses for coating  operations is 0.35  kilogram of VOC
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 per liter of  coating  (kg  VOC/i)  (2.9 pounds  of VOC per gallon of coating
 [15 VOC/gal]).  This  level  is  the most prevalent  and among the most
 stringent of  the State  standards.  Because it  is  uncertain where faci-
 lities  subject to the NSPS  will  be located and it is uncertain whether
 these facilities will be  exempt  from a particular State's  standards,
 0.35 kg VOCA (2.9  Ib VOC/gal) was judged to be the best choice for
 baseline.   If actual  SIP  requirements affecting a significant portion of
 the industry  are, in  fact,  less  stringent than this baseline  level, the
 emission reductions for the regulatory alternatives have been under-
 estimated,  and average cost-effectiveness values  have  been overstated.
 Because the choice of a baseline level  of 0.35 kg VOCA (2.9  Ib VOC/gal)
 results in  a  conservative analysis,  raising  the baseline emission  level
 would not alter but would actually reinforce the  selection of the  level  of
 the final standards.
 2.6 ECONOMIC IMPACTS
 2.6.1   Accuracy of Economic Impact Analysis
     Comment;  One commenter (IV-D-7)  believed that the economic impact
 was underestimated because the analysis was based on faulty data (see
 Section  2.3.1.3).  The Volume I  BID  states that for all regulatory
 alternatives other than Regulatory Alternative IV, the use of  incinera-
 tion, price and cost increases would be relatively small.   However, the
 commenter contended that incineration  is the  only control  method that
 could achieve compliance with the proposed standard.
     A  second commenter (IV-0-12) stated that because the  enclosures
 recommended by EPA would create  LEL concentrations that are unacceptable
 for current insurance coverage,  insurance rates would increase and it  may
 become difficult  to get coverage.  The commenter stated that this
 increased cost would be passed on to the customers, decreasing their
competitiveness.
     Response; As  discussed in Sections 2.3.1.1 and 2.3.1.3,  available
data support the  selection of carbon adsorption system as BOT, even under
the variable operating conditions discussed by  the commenter.   However,
EPA does acknowledge that  incineration may be cost effective in some
situations.   In  any case, EPA  maintains that the  economic  impact of the
standards was  correctly  determined and supports the selection  of
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 90 percent overall control, for which price and cost increases are
 relatively small, as the basis for the coating operation standard.
      The LEL insurance requirements for enclosures are the same as for
 ovens, i.e., enclosures would typically have to be maintained at less than
 25 percent of the LEL.  Analysis has indicated that a local ventilation
 system in the application/flashoff area can be constructed so that the
 bulk of the drying oven makeup air is drawn through the system, carrying
 nearly all the emissions from this area with it.2  The very low level of
 emissions escaping from such a local capture system would be far below the
 level  necessary to approach 25 percent of the LEL in the surrounding
 area.   In fact, a well-designed system would achieve sufficient capture to
 maintain a safe level  of worker exposure (i.e.,  a concentration below the
 TLV)  in the coating room.  The concentration within the capture system
 also would be well  below 25 percent of the LEL.   Emissions  in the
 application/flashoff area typically are on the order of 10  percent  of
 total  emissions from the coating operation.   Using most of  the oven makeup
 air  (which is sufficient to dilute  the 90 percent  of the solvent
 volatilized in the  drying oven to below 25 percent of the LEL)  to capture
 this fraction of the total  emissions will  result  in an  SLA  far below
 25 percent of the LEL.   Therefore,  fire  hazard and worker exposure  will
 not increase  as a result of the NSPS,  and  insurance rates would not be
 adversely  affected.  For these reasons,  no changes have  been made to  the
 economic analysis.
 2.6.2  Trend  Toward  Reduced  Solvent Usage
     Comment;   One commenter (IV-0-7) stated that  a continued trend toward
 reduced solvent  usage as  projected  in the economic  analysis may not be
 accurate.  The  commenter  noted that certain high-specification and
 defense-related  products must be made with solvents and must continue to
 be manufactured  in the United States.
     Response;  The number of new facilities likely to become subject to
 the standards from 1986 to 1990 was derived from the estimated percentage
of industry production using organic solvent-based coatings  and the
estimated change in industry capacity required to meet market demand
during this 5-year period.    The percentage of production using organic
solvent-based coatings for each year was based on a linear extrapolation
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 of  values  from 1976  and  1981.15   The calculated VOC use factors and new
 VOC-based  production capacity  requirements for the 5-year period are
 presented  in  Table 9-18  (page  9-44)  of the Volume  I BID.   The estimated
 number  of  new facilities  and potential total  fifth year net annualized
 costs that would  result from adoption of the  most  costly regulatory
 alternatives  are  presented  in  Table  9-19 (page 9-48)  of the Volume  I BID.
     If, as suggested by  the commenter,  the reduction in VOC use were less
 than that  projected  over  the 5-year  period, there  would be a larger number
 of  facilities subject to  the standards,  and the total  fifth year net
 annualized cost would be  greater  than that presented  in the Volume  I
 BID.  However, this  would have no affect on the economic  impacts of the
 standards.  Production cost and price impacts  were calculated based on
 individual  facilities and products and would  not be affected by the
 increase in the total number of affected facilities.
     If the VOC use  factor were to remain constant  at  its  1981  level
 instead of continuing the downward trend noted  between  1976 and 1981,  the
 estimated  new VOC-based production capacity necessary to meet projected
 market demand would  approximately double.   As  a result, the total number
 of  new facilities and the total net annualized costs shown  in Table 9-19
 (page 9-48) of the Volume I BID would  also  nearly double.   As a
 consequence of this change, the potential worst-case fifth year net
 annual1zed  cost of the standards would increase from $1.86 million  to
 about $3.7 million.  Thus, even if the VOC  use factor is assumed to  remain
 constant,  the total estimated fifth year cost 1s considerably less  than
 the $100 million listed in Executive Order  12291 as indicative  of a  "major
 rule."
     If the number of facilities subject to the standards were  nearly to
 double,  the environmental  and energy impacts would  be similarly Increased.
 Thus, the reduction 1n nationwide VOC emissions in  the fifth year would be
 about 2,400 Mg beyond the emission level stated in  the typical SIP.   All
 impacts  would be Increased proportionally, so  the judgment based on  the
original analysis  that the beneficial impacts  outweigh the negative
 impacts  would not  be  altered.
     The original  analyses performed  by EPA have not been revised as a
result of this comment.   In  EPA's  judgment, the estimation techniques used
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 previously remain valid.   The commenter only speculated that the
 "projection may not be accurate"  and offered no data to support this
 contention.  As mentioned in Section 2.4.2,  EPA is working with the
 Defense  Department toward end-product specifications that have the
 potential  of allowing increased use of low-solvent coatings in defense
 applications.     Because  a change in the trend toward reduced VOC use in
 this  industry would have  no effect on the production cost and price
 impacts  of the standards  and the  other impacts would be affected
 proportionally, EPA sees  no need  for new impact analyses.
 2.6.3 Industry Growth
      Comment;   One commenter (IV-D-15)  questioned  EPA's estimate that
 18 new solvent-borne lines would  be constructed by 1990.   The commenter
 predicted  that, if the proposed regulations  go into effect,  no new lines
 would be built in the U.S.  because EPA has failed  to demonstrate that
 available  technology can  achieve  the required  emission  reductions.   The
 commenter  continued to say that no company can afford to  invest  in  new
 equipment  without data to  demonstrate that it  will  meet environmental
 requirements.   The commenter also  stated  that  without relief,  textile
 coaters  could  not expand  nor could  they  successfully compete  with foreign
 imports.   Another commenter  (IV-D-11)  stated that  no new lines other  than
 low-solvent lines will  be  built in  the U.S. and expansion of  solvent-borne
 lines will  move overseas.  A  third  commenter (IV-D-18) stated  that their
 industry,  which is  one  of  the largest specialty fabric commission coaters
 in the U.S., could  not  grow  or may  not even survive  if they do not get
 some  relief from  the  proposed standards.  A second commenter  (IV-D-16)
 stated that the  standards, as proposed, would prevent the addition of new
 equipment  and the modification of existing equipment at their older
 plants.
     Response;  Because the standards for coating lines are achievable and
 cost effective  for  all segments of the polymeric coating industry (see
 Section 2.3.1.1 and Chapter 8 of the Volume I BID), EPA continues to
 support its estimate that 18 new lines will be constructed in the U.S. by
 1990.   The EPA believes that most  affected facilities will  choose to
demonstrate compliance for coating operations by the alternative standard
 (§ 60.743(b)), which requires a total enclosure vented to a 95 percent
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 efficient  control  device.  These  provisions  have been  clarified by adding
 design  and operating  specifications  for  a  total  enclosure.   This should
 simplify the  process  of obtaining approval for a total  enclosure and
 reassure Industry  that compliance can  be demonstrated  for new equipment
 that  1s properly designed and operated.  The EPA also  continues to support
 its position  that  the standards are  achievable for most coating lines  that
 would be modified  or  reconstructed.
 2.7   COMPLIANCE
 2.7.1  Control Device Downtime
      Comment;  One comnenter (IV-0-3)  stated that the  standard  should
 allow for  the fact that solvent recovery systems are not 100  percent
 reliable and  that  some downtime is inevitable.   The commenter cited  design
 deficiencies, steam and electric  interruptions,  mechanical breakdowns,  and
 major maintenance  such as replacing  the  carbon or overhauling components
 as causes  for downtime.  Since it  1s not always  feasible to shut down
 production during  these Interruptions, the commenter recommended that
 enforcement be based  on failure to correct a solvent recovery system
 deficiency 1n a reasonable time, rather than  on  the occurrence of  such  a
 deficiency.
      Response;  The EPA recognizes the Inevitability of air pollution
 control equipment  downtime and accounts for  this  1n the General Provi-
 sions.  Section 60.8(c) (Performance tests)  states that emissions  in
 excess of  the applicable emission limit during periods  of malfunction are
 not considered a violation unless otherwise specified in the applicable
 standard.  The polymeric coating standard does not specify that excess
 emissions due to malfunctioning air pollution control equipment trigger a
 violation.   "Malfunction"  is  defined in § 60.2 (Definitions)  as "any
 sudden and  unavoidable failure of air pollution control equipment or
 process equipment or of a  process to operate  1n a normal or  usual manner.
 Failures that are caused entirely or in part  by poor  maintenance careless
operation,  or any other preventable equipment breakdown shall  not be
considered  malfunctions."
     Section 60.7(b)  (Notification and  Recordkeeping) requires that
records of  the occurrence  and  duration  of any malfunction of  air pollution
control  equipment be  maintained.   Also, § 60.11(d) (Compliance with
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 standards and maintenance requirements) requires that at all times,
 including periods of malfunction, owners and operators shall, to the
 extent practical, maintain and operate any affected facility including
 associated air pollution control  equipment in a manner consistent with
.good  air pollution control  practice for minimizing emissions.  Information
 used  to determine whether operating and maintenance procedures are
 acceptable includes monitoring results, opacity observations, review of
 operating and maintenance procedures,  and inspection of the source.  Thus,
 the reporting of an exceedance is only an indication that the facility may
 not be in compliance.
 2.7.2  Comp1iance Provisions
      Comment;  One commenter  (IV-D-16)  sought confirmation that under the
 proposed  regulations compliance could  be demonstrated with an "approved"
 room  enclosure around  the  coating equipment  and data that indicate proper
 operation of  collecting  equipment.   The commenter's interpretation is that
 the design of the room enclosure  will  be approved  by EPA  on a case-by-case
 basis  and that the major requirement for approval  is that the room be
 under  negative pressure  and the exhaust which produces  this negative
 pressure  be vented to  a  95 percent  efficient  control  device.   Data to prove
 proper  operation  of the  control device  would  be taken from continuous
 recordings  of the pollutant concentration  in  the gas  vented from the
 carbon  beds.
     Response;  The final standards  have been revised to  clarify that the
use of  certain  equipment, i.e., a total  enclosure  and a 95  percent
efficient  control  device, is available  as  an  alternative  standard  to  the
90 percent  emission reduction standard.  In other words,  the owner or
operator may  choose to comply with either  the  emission reduction standard
or the  alternative  standard.  The EPA also has  revised the  compliance
provisions  to  include specifications for a total enclosure.  Case-by-case
approval by the Administrator is not required  if these specifications are
met.   After the initial determination of compliance,  an approved parameter
(such as fan amperage or duct flow rates) shall be monitored to demon-
strate proper operation of the vapor capture system.  Also, the control
device must be monitored in accordance with the same provisions that apply
when  the two-part gaseous emissions test is used to demonstrate
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 compliance.   If  the  control  device is a carbon  adsorber, monitoring of the
 pollutant  concentration  in either the control device outlet stream or both
 inlet  and  outlet streams is  required.
     In addition,  the  compliance  provisions  for coating operations meeting
 the emission  reduction standard have  been  clarified  and revised  since
 proposal.   In the  final  standards, one method of demonstrating compliance
 is to  perform a  two-part gaseous  emissions test to measure both  capture
 efficiency and control device  efficiency.  Compliance is demonstrated if
 the product of these two efficiencies is equal  to or greater than  0.90.
 This compliance  method is available to all affected  facilities.  Another
 alternative to performing the  gaseous emissions tests is performing  a
 liquid-liquid material balance.   However,  this  compliance provision  has
 limited applicability.   A liquid-liquid material  balance can only  be  used
 when a single coating operation is vented  to a  dedicated control device
 (i.e., the control device may  not  be  used  to control  emissions from  any
 other emission source, including mix  equipment).  This  compliance
 provision  is most  likely to be applicable  for facilities with mix
 equipment  that is  not; required to  be  vented to  the control device.  The
 liquid-liquid material balance compliance  provisions  include  two
 options.  The first option requires that a liquid-liquid  material balance
 be performed for each nominal  1-month period.  When using this option, no
 monitoring is required beyond that necessary to perform  the material
 balance.  The second option, which has been added since  proposal, requires
 performing a one-time material balance over 3 to 7 days followed by con-
 tinuous monitoring.  The  number of days for the performance test is
 selected by the operator  and shall provide data that represent the plant's
 typical coating practices.  The monitoring requirements are the same as
 those specified for the two-part gaseous emissions test and alternative
 standard.   This second option may be attractive  for facilities that cannot
or do not  want to conduct the detailed continuous monthly liquid  material
 balance measurements that are required for an accurate balance (e.g., VOC
 applied at the coater,  retained VOC [optional],  VOC waste losses).
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 2.8  TEST METHODS AND  MONITORING
 2.8.1  Proposed Compliance Provisions
      Comment;   One commenter (IV-D-1) stated that the 93 percent reduction
 required of coating operations  will  be unattainable because of the inher-
 ent vagaries of the parameters  that  must be measured to perform the liquid
 material balance compliance test.  The commenter  stated that the method
 requires measurement techniques that are not currently used.  Factors
 anticipated to  affect  the  accuracy of the measurements are residual
 materials left  in dip  tanks,  the change in solvent concentration during a
 normal  process  run,  and water entrained in the recovered VOC following
 carbon  adsorption.
      The commenter stated  that  the measurement techniques and formula for
 the control  device efficiency in the gas balance  compliance test are
 realistic but that the formula  for capture efficiency  appears to assume
 that all  uncontrolled  solvent vapors will  be discharged  through  a
 measurable point and! that  there  will  be no "stray"  fugitive emissions.
      Response;   The  EPA acknowledges that  short-term variations  in  process
 conditions could affect a  facility's ability to perform  the measurements
 required  to  demonstrate compliance in  the  short term by  means  of a  liquid
 material  balance.  For this reason,  a  relatively  long  averaging  time  (in
 this  case,  1 month)  is available to  allow  for a representative variety  of
 coatings  and products, as well as to reduce the impact of  short-term
 variations due to process upsets, solvent  spills, and variable amounts  of
 solvent  in use in the process (Vol.  I  BID, p. D-16).  Facilities  should
 already  keep at  least some of the required records as part of normal
 business  practices and should be able  to negotiate any specific  problems
 faced by  an  individual  facility with the enforcing agency.  As stated in
 the previous section, facilities that find the recordkeeping and measure-
 ments burdensome may opt to conduct the short-term liquid balance or gas-
 phase test to demonstrate compliance.   In any case, the alternative
 standard, use of a total  enclosure  and a 95 percent efficient control
 device, is available to facilities  that do not wish to perform the testing
 and measurements associated with the  capture portion of emission reduction
 standard.  Because EPA  has  determined that facilities can conduct the
measurements required for a liquid  material balance and because several
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 alternatives  are  available,  the  month-long  liquid material balance has
 been retained in  the  final  standards.
     In response  to the  commenter's other concern, it appears that the
 commenter  has misinterpreted the requirements  of  the gaseous emissions
 compliance test.  The standard requires  (not assumes) that all  uncon-
 trolled solvent vapors will  be passed through  stacks suitable for
 measurement.   To  carry out the compliance test, the  source must ensure
 that all VOC  emissions will  either be directed to the control device or be
 measured at the exit  stack of a  temporary enclosure  or at  all room exhaust
 points.  In other words, there should be no "stray"  fugitive emissions
 that are not  accounted for in the compliance test.
 2.8.2  Plant-Wide Material Balance
     Comment;  One commenter (IV-D-3) recommended  that the standard
 include a  plant-wide  solvent recovery of 85 percent  as an  alternative
 method of  demonstrating compliance.  The commenter stated  that  using a
 plant-wide material balance  to demonstrate compliance  is justified because
 1t is a simple, inexpensive,  and effective method.   The proposed  standards
 regulate some processes within a polymeric coating plant at  different
 levels and leave other emissions, such as those from storage, cleaning,
 and transfers, unregulated.   In the commenter's experience,  enforcement
 officers prefer methods such  as a plant-wide material  balance and
 invariably ask for this information along with the data required by  a
 particular standard.
     According to the commenter,  a plant-wide material balance can be
 easily obtained.   The solvent disbursed  to the plant can be readily
measured by metering  solvent withdrawals from solvent tanks.  Solvent
 purchases,  which  are  always measured  accurately,  are a direct measure of
emissions  from the plant  because  recovered  solvent is replaced into
 inventory.   Thus,  the plant's VOC recovery  efficiency can be calculated as
the difference between VOC  used and VOC  (including solvent) purchased,
divided by  the VOC used.
     Based  on  the  fact that some  emissions  in the  plant would be
unregulated, the commenter  concluded that the proposed standards assume
and accept  a plant-wide recovery  of less  than 93 percent.   It was
suggested that EPA analyze  plant-wide  solvent recovery data from
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 representative plants  in this and related industries to determine an
 appropriate  recovery level  under the final  standard.  Using several years
 of data  from a modern  facility that nearly  conforms with the proposed
 standard,  the commeriter  concluded that  a plant-wide recovery of 85 percent
 would  be a reasonable  level  for a new plant designed to comply with the
 proposed standard.
     Response;   The  option  of demonstrating compliance using a plant-wide
 material balance has not been incorporated  into the final  standards.
 Section  111  of the CAA requires that the standards  be based on BDT.
 Compliance methods must  demonstrate that the affected facility meets
 standards  that reflect BOT.   If a plant-wide material  balance were used to
 demonstrate  compliance for  polymeric coating operations, a plant-wide
 control  efficiency that  ensures 90 (formerly 93) percent control  of VOC
 emissions  from the affected  coating operation(s) would  be  required.
 Without  extensive testing to apportion emissions from all  VOC sources in
 the plant, a pi ant-wide  material  balance  demonstrating  less  than
 90 percent control would not  ensure that  the affected facility initially
 achieves 90  percent  control  or  maintains  90  percent  control  over  each
 month of operation.
     It  is not  feasible  to select  a  plant-wide VOC recovery  value  because
 of the wide  range of potential  emission points that  differ from plant to
 plant.  These  include existing  coating operations and mix equipment,
 solvent storage  tanks, and cleanup operations.  With the variation  in
 emissions from  such  sources,  it  is not possible to select a  single plant-
 wide recovery efficiency value that would reflect BDT, yet be  achievable
 in all cases.   Even  if such a level were established, it would be
 impossible to tell whether the affected  facilities within the  plant were
 in compliance with the standards applicable to them  individually.  For
 these reasons, a pi ant-wide material balance has not been added to the
 standards as an alternative method of demonstrating compliance.
 2.8.3  Carbon Adsorber Monitors
     Comment;  One commenter (IV-D-4) noted  the unreliability and the
expense of maintaining a continuous monitoring device for a carbon
adsorber.  The commenter stated that these monitors work well for short-
term measurements but are not reliable for continuous measurements because
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 the high water content of the  carbon  adsorber exhaust immediately after
 desorption damages  the monitors.   Thus,  the  industry  may have difficulty
 maintaining continuous monitoring  over the long  term  as  required in the
 proposed regulation.
      Response;  The EPA must have  available  the  means to determine whether
 proper carbon adsorber operation and  maintenance practices  are being
 carried out.  The monitoring of organic  compounds is  the only parameter
 that has been identified that  adequately relates to adsorber
 performance.  Without these monitors, sources  are unable to detect when
 they may be operating out of compliance.  Tests  on existing systems show
 that the lack of proper monitoring is a  major  cause of poor performance of
 carbon adsorbers systems.  Discussions with  carbon adsorber experts
 indicated that continuous monitors are available that are reliable when
 the proper calibrations and maintenance  procedures are used.16'17
 2.9  REPORTING AND  RECORDKEEPING
      Comment;  One  commenter (IV-D-1) recommended  deleting  §  60.747(d),
 which requires monitoring and reporting of all 3-hour periods  when a
 control device discharge exceeds allowable limits.  The  commenter  stated
 that reporting of monthly compliance or noncompllance based on a liquid
 material balance 1s sufficient and that the 3-hour requirement places an
 unwarranted burden on the facility.  The commenter also  stated that the
 recordkeeplng needed for the monthly calculation of the VOC balance using
 the formula in § 60.743(a)  (as proposed)  would be overwhelming.
      A second commenter (IV-D-9) noted similarly that the requirement for
 reporting 3-hour periods during which the average VOC concentration is
 more  than 20 percent greater than the average test value appears improper
 when  the compliance test goes beyond 3 hours  (e.g., a 1-month  recovery
 test).  The commenter suggested that a frequency requirement would be more
 appropriate.   The same comment applies to any other 3-hour limit that does
 not adequately relate to a  test exceeding 3  hours.
      Response;  Commenter IV-D-1 implies  that an owner or operator must
 comply with the requirements of § 60.747(d) as well as those of
 § 60.747(e).   The observations  of Commenter  IV-D-9 also reflect a
misunderstanding  of the  requirements  of the proposed  standards.  The
proposed standards required  that either § 60.747(d) or §  60.747(e),
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 depending  upon  the method used to demonstrate compliance, would be used to
 determine  reporting and  recordkeeping requirements.  The reportable
 monitoring exceedance  periods were consistent with the compliance test
 periods  in those  cases when monitoring is required.
     The final  standards have been revised to attempt to avoid
 misconceptions  of this nature.  Cross-reference tables have been added to
 the standards that summarize the final standards as well as compliance,
 reporting,  and  recordkeeping provisions.
     Although the final  standards allow the option of a short-term liquid
 material balance,  EPA  believes the recordkeeping needed for the month-long
 liquid material balance  calculation is reasonable and not excessive.   Most
 companies  routinely maintain records of at least some of the information
 needed for  the  calculation,  such as the amount of VOC used in the coating
 operation,  the  amount  of VOC recovered, and formulation data.  Also,  the
 liquid material balance  is  used  to determine compliance only when the VOC
 recovery device is  dedicated to  a single  affected coating operation.   It
 is anticipated  that  only a  small  number of facilities will  meet the
 criteria for the  use of  this compliance method and  that most of these will
 choose to demonstrate  compliance by means  of the  alternative standard.
 2.10  WORDING OF THE REGULATION
 2.10.1  General Wording
     Comment:  One commenter (IV-0-1)  recommended converting all
 references to m3 to pounds.   This would be  consistent with  the  units
 normally used by the industry  for recordkeeping,  solvent  purchases, and
 pollution control  system  and  equipment specifications.
     Response:  Consistent with  U.S. government policy, EPA  has chosen the
 International System of Units  as the format  for regulations.  However, EPA
 has revised all  references in  the final standards of m3 to Mg to be
consistent with the mass reporting basis typically used by  industry and
enforcing agencies.  Reporting emissions and VOC usage rates on a mass
basis  rather than  a volume basis also avoids the need to select average or
typical  densities  of materials when reporting general values.
     Comment:  One commenter (IV-D-1) recommended eliminating the
references  to §  60.742(a)(3) (as proposed) found in § 60.744(a) (as
proposed)  and §§ 60.747(b) and (c).  The commenter believes that the
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 wording in the latter sections, which establishes the reporting and
 recordkeeping requirements for affected facilities using less than
 110 m3/yr (29,059 gal/yr) (95 Mg/yr [105 tons/yr]) of VOC and for affected
 facilities using at least 110 m3/yr (29,059 gal/yr) (95 Mg/yr
 [105 tons/yr]) but less than 150 m3/yr (39,626 gal/yr) (130 Mg/yr
 [144 tons/yr]) of VOC,  is misleading.   The commenter stated that, because
 of the reference to § 60.742(a)(3)  (as proposed), strict interpretation of
 these provisions seems  to require vapor-tight covers for coating mix
 equipment servicing coating lines using less than 110 m3/yr
 (29,059 gal/yr)  (95 Mg/yr [105 tons/yr])  of VOC.
      Response;  References to § 60.742(a)(3) (now § 60.742(c)(3))  are made
 in order to avoid repetition of affected  facility classifications  and
 requirements.  This section clearly refers to equipment  serving  coating
 lines that use "at least  95 Mg of VOC  per year but less  than  130 Mg  of VOC
 per year."
      Section 60.744(a)  (now § 60.744(b))  sets forth  monitoring requirements
 for coating operations  that utilize less  than 95  Mg/yr (105 tons/yr)  of VOC
 and coating operations  described  in §  60.742(a)(3)  (now  § 60.742(c)(3)).
 Section 60.744(a)  (now  §  60.744(b))  does  not  state that  coating  operations
 that use less  than  95 Mg/yr (105  tons/yr)  of  VOC  are subject to  the
 requirements specified  in  §  60.742(a)(3)  (now § 60.742(c)(3)).
      Section 60.747(b)  presents reporting  and  recordkeeping requirements
 for coating operations  described  in  §  60.742(a)(3) (now § 60.742(c)(3))
 and coating operations  that use less than 95 Mg (105 tons) of VOC in  the
 first year of  operations.  Section 60.747(c)  specifies requirements for
 operations described in § 60.742(a)(3) (now § 60.742(c)(3))  that initially
 use less than  130 Mg/yr (144 tons/yr) of VOC and operations  that initially
 use less than 95 Mg/yr  (105 tons/yr) of VOC.  Neither section states that
 coating operations that use less than 95 Mg/yr (105 tons/yr) of VOC are
 subject to § 60.742(a)(3) (now § 60.742(c)(3)).
     Elimination of the references to § 60.742(a)(3) (now §  60.742(c)(3))
would exclude from the monitoring, reporting, and  recordkeeping require-
ments of the standards those coating operations using at  least 95 Mg/yr
 (105 tons/yr) but less; than 130 Mg/yr (144 tons/yr) of VOC,  leaving no
means of monitoring the  continued applicability of the standards  for  mix
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 equipment in this VOC use range.  Thus, the requested change has not  been
 made.
      Comment;  One commenter (IV-D-1) recommended revising the words  "by
 other means" to "by alternate readily available, economically feasible
 means" in § 60.743(a)(l)(iv) (as proposed).  Section 60.743(a)(l) sets
 provisions for demonstrating that the VOC retained (RS1 in Equation 1 for
 demonstrating compliance with § 60.742[a][lJ) is greater than zero.
 Specifically, § 60.743(a)(l)(iv) states that the owner or operator must
 submit "documentation that the inherent properties of the product require
 higher levels and that such properties cannot be achieved by other
 means."   The commenter believes that the words "by other means" are too
 comprehensive and do  not take into account economic and technical
 feasibility.
      Response;   The intent of § 60.743(a)(l)(iv)  (now § 60.742(c)(3))  as
 proposed  was  to ensure that all  facilities take  steps to minimize
 uncontrolled  emissions from retained VOC whenever possible.   The  exemption
 for retained  VOC was  written to permit the facility as  much  flexibility as
 possible  in demonstrating  to the Administrator the level  of,  and  need  for,
 retained  VOC.   However,  EPA has  revised  this  requirement  to minimize the
 burden on both  enforcement and  plant personnel.   The  revised  requirement
 eliminates the  need for  the  plant  to justify  the  need for retained VOC if
 the measured  value of  RS^  is  less  than or  equal to  6  percent  by weight of
 the liquid VOC  applied.  A limited survey  of the  Industry indicated that
 6 percent  is  a  common  breakpoint in  retained VOC  values and would
 encompass the majority of  plants reporting retained VOC.18  Plants
 reporting RS1 values above 6 percent by weight of the liquid VOC applied
 would still be  required to demonstrate to the satisfaction of the
 Administrator that the retained VOC  1s required for product quality or to
 meet product specifications.  In all cases, plants would be required to
 submit for approval data on the specific measurement techniques used to
 determine RS^.
     Comment;  One commenter (IV-D-9) recommended that a continuous
monitoring device (CMD) be required for a carbon  adsorber that controls
 just one emission source.  The wording in the proposal preamble indicated
that a CMD is required when two emission sources  are controlled,  but not
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      Response;   When a source chooses to make a monthly compliance
 demonstration using a liquid material balance, no monitoring of the sol-
 vent  recovery device is required.   This compliance method is applicable
 only  when  emissions from a single  affected coating operation are recovered
 by  a  dedicated  control  device.   The wording in the proposal  preamble was
 based on the  use of this compliance method.  However,  should such a source
 choose to  demonstrate compliance with the alternative  standard, the
 monitor appropriate for the control  device in use would be required.
      Comment;   One  commenter (IV-D-3)  recommended that § 60.742(a)(l)  (as
 proposed)  read  "Reduce  VOC emissions to the atmosphere by at least
 93  percent, compared to an uncontrolled coating operation, from each
 coating operation;  and.  ..."   Adding the words "compared to an
 uncontrolled  coating operation"  would  eliminate any confusion that the
 93  percent reduction may be compared to a controlled source  before
 modification  or reconstruction.
      Response;   The intent of the emission reduction standard for  coating
 operations is to require that at least 90 percent (93  percent at proposal)
 of  the  VOC content  of the  coating applied at  the coating  applicator(s)  be
 prevented from  entering  the  atmosphere.   The  EPA believes  this  intent to
 be  clear in § 60.742(a)(l)  (now  § 60.742(b)(l))  as  written.   The
 compliance provisions also make  the  intent  of  the standard clear.  Deter-
 mination of 90  percent control is based on  all  VOC  1n  the  coating  applied
 at  the  coating  applicator(s) and not just  the  incremental  increase in VOC
 resulting from  modification or reconstruction.   Therefore, no changes to
 the wording of  the  standard have been made.
     Comment;   One  commenter (IV-D-7)  noted that  the allowance for
 2 percent fugitive  losses from nix equipment is  not clearly stated in the
 proposal.
     Response;  The standards do not make an allowance for 2 percent
 fugitive losses from mix equipment.  Section 60.742(a)(2) (now
 § 60.742(c)), as proposed, clearly stated that alj VOC emissions shall be
captured.   However,  in response to other comments, the language of the
 section has been modified.  A detailed explanation of  the change can be
found in the response to Comment 2.4.2.
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     Comment;  One commenter  (IV-D-9)  suggested  that  the  volumetric flow
rate be stated on a wet basis rather than  a dry  basis since,  according to
a contact at EPA, Method 25A results in parts per million by  volume on a
wet basis.
     Response;  The commenter is correct.  Measurements made  using
Method 25A are in terms of parts per million by  volume on a wet  basis;
therefore, the volumetric flow rate also should  be stated on  a wet  basis
when this method is used.  The final standard has been corrected to
specify that volumetric flow rates used in conjunction with Method  25A
concentration measurements are to be expressed in standard cubic meters
per hour (wet basis).  However, volumetric flow  rates used in conjunction
with Method 25 concentration measurements are to be expressed in dry
standard cubic meters per hour.
2.10.2  Definitions
     2.10.2.1  "Coating Line".
     Comment;  One commenter (IV-D-9) stated that, for consistency  with
other NSPS and State regulations, coating mix preparation equipment should
not be included in the definition for a coating  line.  The commenter
believed that the term "coating line" was unnecessary since "coating
operations" and "coating mix preparation equipment" are described.  The
commenter suggested changing all references to "coating operations" to
"coating lines" since these two terms,  by his definition, are synonymous.
     Response;  In the proposed NSPS, coating line was defined as "the
coating operation(s) and coating mix preparation equipment that  service
the coating operation(s)."   According to the commenter, the term coating
line is commonly used interchangeably with coating operation.   To avoid
confusion,  the term "coating line"  is not used in the final standard.  The
term "coating operation" has been retained in order to maintain consistency
with the Volume I BID and proposal  preamble.
     2.10.2.2  "Common Emission Control Device".
     Comment;  One commenter (IV-D-9)  requested  clarification  of the
definition  of "common emission control  device."   He stated that  it was
unclear whether the proposed definition referred  to a device controlling
both a coating operation and mix equipment or a  device that controls two
or more coating operations.
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      Response:  In response to the commenter and for clarification, the
 definition has been amended to read:  "'Common emission control device1
 means a control device controlling emissions from an affected coating
 operation as well  as from any other emission source."  The "other emission
 source" may be a coating operation(s), mix equipment, or any other point
 of emissions.
      2.10.2.3  "Drying Oven".
      Comment;  One commenter (IV-D-3)  recommended eliminating references
 to baking, curing, and polymerizing from the definition for drying oven.
 In the commenter1s process,  drying and curing are done in separate ovens.
 Although the preamble makes  clear  that the curing oven is not covered by
 the standard, the  proposed definition  for "drying oven" suggests that the
 curing oven is included.
      Response:   The definition  of  drying oven has been changed to "a
 chamber within which heat is  used  to dry a surface coating;  drying may be
 the only process or one of multiple processes performed in  the chamber."
 By eliminating  references to  baking, curing,  and  polymerizing,  this
 revised definition makes it clear  that  the standard does  not  apply to
 chambers in which  drying is not performed.  The definition  also  makes  it
 clear  that  the  standard does  apply  to any  chamber within  which drying  is
 performed,  regardless of the  other  processes  performed  in the  chamber.
 This change is  consistent with the  fact  that  cure volatiles resulting  from
 separate curing  ovens are expected  to be minimal  1n this  industry  and  to
 occur  off-site,  and  thus, are not available for control.
     2.10.2.4   "Knife Coater".
     Comment;  One commenter  (IV-D-9) believed that a definition of  "knife
 coater" would be useful.  The commenter pointed out that the term  "blade"
 is used  in  the  "web coating" definition.
     Response:  A definition of "knife coater" has not been added because
 EPA believes that the term is self-explanatory.  Knife coating and blade
 coating were used interchangeably in the proposed regulation.  To avoid
 confusion, the reference to  blade coating in the definition of "web
 coating" has been changed to knife  coating.  The new definition of "web
 coating" is "the coating of  products, such as fabric,  paper, plastic film,
metallic foil, metal coil, cord, and yarn, that are flexible enough to be
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 unrolled from a large roll; coated as a continuous substrate by methods
 including, but not limited to, knife coating, roll coating, dip coating,
 impregnation, rotogravure, and extrusion; and, after drying, rerolled."
      2.10.2.5  "Solvent".
      Comment;  One commenter (IV-D-2) suggested adding a definition of
 "solvent"  to clarify  that  the regulation addresses only volatile organic
 liquids.   The commenter  stated that an increased amount of polymeric
 coating  is done with  waterborne emulsions.   Without a specific definition
 for solvent, one could erroneously conclude that polymeric coating sol-
 vents other than volatile  organic  liquids (e.g., water)  are included in
 the "solvent used"  for purposes of determining the applicability of the
 emission limits.
      Response:   The commenter correctly  pointed out that for the purposes
 of  this regulation  as proposed,  solvent  refers only to  volatile organic
 liquids and  does  not  Include  water.   Part of  the confusion resulted from
 the use of the  term's "VOC" and  "solvent" interchangeably in the proposed
 rule and supporting documents.   The final rule has  corrected this  problem
 by  specifying that  VOC 1s  the  pollutant  of  concern.  Organic solvent is a
 major component of  VOC, not water.  (See  Section  2.10.2.6  for this
 definition.)
      2.10.2.6   "Solvent (VOC)  Used".
      Comment:  One commenter  (IV-D-8) recommended changing the definition
 for  solvent  used from "the amount of solvent delivered to the coating mix
 preparation  equipment of the affected facility" to "the net quantity con-
 sumed  1n the coating operation line."  With this change, the amount of
 solvent (VOC) used would represent the amount actually applied to the
 substrate.   According to the commenter, coating mixes are typically
 prepared in greater quantities than required for a specific production
 run.  The excess coating may be recycled, which would result in double
 counting, or disposed  as a  waste material.
     Response;  "Solvent used" was  defined at proposal  as the amount of
 solvent delivered to the coating mix preparation equipment because
 (1)  this  is the simplest  and most direct  measurement point, and (2) it
reflects  the quantity  used  in determining the cutoff.   The commenter's
suggested definition of  "solvent use"  would  make accurate measurement
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 considerably more difficult because sampling and analysis of the applied
 coating would be required.  Also, the commenter's suggested definition
 does not take into account VOC emitted during mixing, which were included
 1n the computation of the solvent-(VOC-)use cutoff.  The cutoff was
 computed by  determining the minimum quantity of applied VOC that could be
 cost-effectively controlled and then adjusting this volume to account for
 VOC emitted  before the coating reaches the applicator of the affected
 coating operation.
      The proposed definition was not intended to result in double
 counting.  However,  it may require the owner or operator to keep careful
 records of VOC use in cases where prepared coatings are not used
 immediately.
      To clarify  the  meaning of this  term,  the definition has been changed
 to MVOC used."   The  amount of "VOC used" should be  computed as  the sum of
 (1)  the VOC  to the mix equipment from  storage,  (2)  any VOC added after
 initial  formulation  1s complete  (e.g.,  dilution solvent added at the
 coating operation),  and  (3)  the  VOC  content  of  any  Ingredients  prepared
 off  the plant site that  are used in  the preparation  of coatings.   When
 excess  coating 1s  recycled  for use in  a later coating  run,  the  VOC  it
 contains should  not  be counted a second time.   Should  a source  reclaim the
 VOC  from excess  coatings,  the VOC  will enter the VOC recovery system just
 as if it were applied  to a  substrate.  When this reclaimed VOC  1s reused,
 it will be properly counted  toward the volume of VOC used.   It  is true
 that coatings disposed as waste materials were  not considered when the
 annual VOC use cutoff was calculated.  However, EPA believes that such
wastes should be minimized.  Thus, to provide an incentive to minimize
 these wastes, no change has been made to this aspect of the definition.
     A change has been made to the proposed definition to account for
facilities that purchase premixed coatings  or other ingredients that
contain VOC.   The new definition reads "the amount of VOC delivered to the
coating mix preparation equipment of the affected facility (including any
contained 1n  premixed coatings or other ingredients  prepared off the plant
site).  If premixed coatings that require no mixing  at the plant site are
used, "VOC used"  means the amount of  VOC delivered to the coating
applicator(s) of  the affected facility.
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      2.10.2.7   "Web  Coating".
      Comment:   One commenter  (IV-D-9)  questioned  whether the definition of
 "web  coating,"  which states "...  flexible  enough  to be unrolled from a
 large roll;  .  .  .; and,  after  drying,  rerolled,"  should  include the
 requirement  that the web be rerolled.   The commenter pointed out that at
 some  facilities  products are cut  into  strips or sheets after drying.   In
 addition, the commenter  suggested  including  extrusion (i.e., the use  of a
 slotted die) as  an application method.
      Response;   Taken literally, the proposed definition of  "web coating"
 requires only that the substrate be flexible enough  to be unrolled,
 coated, and  rerolled,  not that these operations actually be  carried out.
 However, to  avoid confusion concerning  the EPA's  intent,  the definition of
 "coating operation"  has  been modified to clarify  the point that  no poly-
 meric coating facility is to be exempt  simply because it  lacks  a rewind
 station.  The definition has been changed to "any coating applicator(s),
 flashoff area(s), and  drying oven(s) located between a substrate unwind
 station and  a rewind  station that coat  a continuous  web to produce a
 substrate with a polymeric coating.  Should  the coating process  not employ
 a rewind station, the  end of the coating operation is  at the  end  of the
 last  drying oven in the  process."  In addition, the  definition of web
 coating has been refined to eliminate reference to rerolling.
      The commenter's suggestion that extrusion be added to the list of  web
 coating techniques contained 1n the definition of "web coating"  has been
 adopted.  Also, wording  has been added to make 1t clear that the  list of
 coating techniques is not intended to be inclusive.   As discussed in
 Section 1.1, leather has been  removed from the list  of substrates.  The
 definition of "web coating" has been revised  to "the coating of products,
 such  as fabric, paper, plastic film, metallic foil,  metal coil, cord,  and
yarn, that are flexible enough to be unrolled from a large roll; coated as
 a continuous substrate by methods including,  but  not limited to, knife
 coating, roll coating, dip coating, impregnation,  rotogravure, and extru-
 sion."
     2.10.2.8  "Mr^.
     Comment;  One commenter (IV-D-8)  suggested redefining the symbol  Mr
used in Equation 1 as the total VOC recovered before purification.  The
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 proposed definition does not allow for VOC losses during separation/
 purification.
      Response;   As proposed, the definition of "Mr" does not specify
 whether the recovered  VOC is to be measured before or after separation/
 purification.   The 93  percent recovery efficiency required to demonstrate
 compliance using Equation 1  was determined considering the VOC recovered
 after carbon adsorption  and  not after separation/purification.  Therefore,
 EPA cannot require measuring "Mr"  after separation/purification.  There
 may be cases, however, where it is more convenient to measure "Mr" after
 separation/purification.   Thus, a  measurement  point for "Mr"  has not been
 specified, but  it  is to  be established when the  compliance procedures are
 approved.   This  is explained in §  60.743(a)(3)(vi),  which  has been added
 to  the compliance  provisions.
      2.10.2.9   "RS^.
      Comment;  One commenter (IV-D-8)  suggested  redefining the term RS1  in
 Equation  1 to include all  VOC,  not just  the  solvent,  retained on the
 substrate.  A portion of  the VOC 1n some coating formulations is monomer
 that  1s retained in the substrate  as either  free monomer or polymer.  The
 suggested  definition change would  make  it clear that  any monomer retained
 1n  the  substrate would be  included  in the term RS^.
      Response;   In response to  the commenter's suggestion, the definition
 of  RSj has  been changed to "the total mass (kg) of VOC retained  in  the
 substrate  after oven drying for a given combination of coating and
 substrate."  Without this change, coatings that release reaction by-
 products when tested by Method 24 would  Indicate the presence of some VOC
 which may not be available for recovery by the VOC recovery system unless
 the coating is exposed  to a similar temperature within the oven.  If the
 amount of monomer retained on the substrate is significant, this may
 affect a source's ability to  demonstrate compliance.  Changing "solvent"
 to VOC in the definition  of RS1 enables the source to account for the
 amount of VOC retained  on the substrate.  The source is responsible for
demonstrating the quantity retained on the substrate.
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 2.11  MODIFICATION/RECONSTRUCTION
 2.11.1  Retrofitting Total Enclosures in Printing Blanket Manufacturing
      Comment;  One commenter (IV-D-5) stated that EPA failed to consider
 the feasibility of the proposed regulation for modified facilities.  The
 commenter stated that, while it may be possible to develop new coating
 techniques that would allow new coating equipment to be totally enclosed,
 it is virtually impossible to retrofit total enclosures to existing
 coating equipment in the printing blanket manufacturing industry.  Citing
 practical  limitations, the commenter ruled out a small enclosure around
 the coater, as well  as the possibility of enclosing the entire coating
 room.  The commenter stated that the only feasible method of capturing VOC
 emissions  from existing printing blanket coaters is to construct a small
 room enclosing the affected coating equipment.   The commenter determined
 that the only practical means of ensuring worker safety while implementing
 this method would be to exhaust high volumes of air from the enclosure.
 However, in the commenter's analysis,  this would drive up the cost of
 control  equipment significantly and result in an unacceptably high cost
 effectiveness (see Section 2.4.1).
      Response;   The  EPA has considered the feasibility of the standards
 for modified  facilities.   This  subject was  discussed  both in  the  preamble
 to  the proposed  standards  and  in  the Volume I BID.   It was concluded  that
 changes to  coating operations that  would  be considered modifications  under
 the General  Provisions  of  40 CFR  Part 60  are  unlikely.   In those cases
 where modifications  do  occur, the same capture  and control techniques that
 can be used at new facilities can be applied  at modified  facilities at a
 reasonable  cost.   However,  since proposal EPA has reexamined  the
 feasibility of total enclosures and reached the following conclusions.2
      1.  Because frequent  access to the application/flashoff  area  is
 required in some segments  of this industry, a small total enclosure
 immediately around the application/flashoff area could not be used in all
 cases.
     2.  A  local ventilation system could be constructed in all cases that
would capture emissions from the application/flashoff area very effi-
ciently and be protective of worker health and safety at a reasonable
cost.  In conjunction with an appropriately designed larger,  room-type
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 enclosure,  the  capture system would meet the total enclosure specifica-
 tions added since  proposal.
      3.   A  room-type total  enclosure may not be universally feasible.
 Space constraints  at existing plants may not allow construction of a room
 to  enclose  a new or modified/reconstructed coating operation.
      As  a result of this  analysis,  the standards for new and modified/
 reconstructed coating operations  have been revised to require either a
 90  percent  overall  emission  reduction or a total enclosure and 95 percent
 efficient control  device  (alternative standard).
      The EPA does  not accept the  commenter's conclusion  that workers
 inside a room-type  total  enclosure  cannot be protected in a cost-effective
 manner.   The commenter's  analysis was based on  the assumption that the
 only  way to ensure  the safety of  workers within the total  enclosure is to
 ventilate the enclosure with enough air  to dilute emissions to a safe
 level.   However, as  discussed above,  localized  pickups can be designed to
 direct emissions away from the workers while reducing  the  airflow to a
 level  allowing cost-effective control.   This issue is  more fully examined
 in  Section  2.4.1.
 2.11.2   NSPS  Applicability Date
      Comment;  One commenter (IV-D-7) stated that  compliance  with  the  NSPS
 will  be  required of  facilities where  modifications or  reconstruction  began
 after the issuance of  the proposed  rule  rather  than upon adoption  of  the
 final rule.   In the  commenter's view, this policy  is onerous.  The com-
 menter stated that EPA  has not demonstrated  that control  technology exists
 for this  industry that would  comply with the proposed regulations  (see
 Sections 2.3.1.1, 2.3.1.3, and 2.3.2.2).  Thus, companies must delay the
 installation of new equipment or modification of existing equipment,
 including pollution control  devices,  because they may not meet the final
 standards.  Companies that have incurred major capital expenditures to
meet State requirements would be at an even greater disadvantage if their
 new control  equipment fails  to meet EPA's standards but is considered
 subject to them.
     Response;  Section lll(a)(2)  of the CAA requires that the
applicability date  for NSPS  be the date of proposal.  For the polymeric
coating NSPS, the standard is applicable to affected facilities that are
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constructed, modified, or  reconstructed on or  after  April  30,  1987.   This
date could be adjusted if  it were determined that  BOT was  not  available
for use on that date.  In  this case, EPA believes  that BDT is  available
and is not aware of a technical problem that has prevented sources from
proceeding with modifications.
     As discussed in the proposal preamble and Volume I  BID, changes  to
polymeric coating operations with associated mix equipment that would be
considered modifications under the General Provisions (40  CFR  60.14)  are
expected to occur rarely,  if at all.  In any case, sources that installed
control equipment prior to April 30, 1987, to meet existing State require-
ments and that subsequently modify their facilities  are  expected only to
have to modify the capture systems at those facilities in  order to comply
with the NSPS.  The existing control devices will, with  some operational
changes, be capable of achieving the efficiency necessary  to meet the
standards.  The cost to retrofit capture systems may  be  slightly more  than
the cost of capture systems installed at the time of  original construc-
tion, but this increase is not expected to be so large as  to make the
costs unreasonable.   The cost effectiveness for such facilities is no
different than for other existing sources  at the same level of control
efficiency.
2.12  REFERENCES FOR CHAPTER 2
 1.  Memo from Lang,, C.  and Friedman, B.,  Midwest Research  Institute,  to
     Polymeric Coating project file.   December  22,  1988.  Affected
     Facility Options  for Polymeric  Coating NSPS:   Mix Equipment.
 2.  Memo from Edgerton,  S.,  Midwest  Research  Institute, to Polymeric
     Coating  project; file.   January  6,  1989.  Permanent Total  Enclosures
     in the Polymeric  Coating Industry.
 3.  Radian Corporation.   Carbon Adsorption for the Control of  VOC
     Emissions:   Theory  and Full-Scale  Performance.   Prepared for  U.S.
     Environmental Protection Agency.   Research Triangle Park,  N.C.
     Publication No. 88-239-003-20-09.  June 6,  1988.  p. 3-67.
 4. Memo  from Friedman,  B.,  Midwest  Research Institute,  to Polymeric
    Coating  project file.  January 6,  1989.  The Effects of Batch
    Operations  on Control  Device Performance and Costs.
 5. Memo  from Shine,  B., and  Srebro, S., Midwest Research  Institute,  to
    Polymeric Coating project file.  August 25, 1988.   Cost Effectiveness
    of  Incinerators to Control VOC Emissions from  Polymeric Coating
    Operations.
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  6.   Memo from Friedman,  B.,  Midwest Research Institute, to Polymeric
      Coating Coating project  file.   December 21, 1988.   Basis of the
      Polymeric Coating NSPS.

  7.   Letter from Murphy,  J.,  W.  R.  Grace & Co., to Soltls,  V., Midwest
      Research Institute.   April  21, 1988.  Comments on  telephone contact
      reports regarding coating operation liquid material balance test
      results.

  8.   Telecon.  Shine., B., Midwest  Research Institute,  with Woodcock, R.,
      Day  International.   Effect  of  filters on carbon bed blinding.

  9.   Telecon.  Soltls, V., Midwest  Research Institute,  with Troup,  T., Dow
      Corning Corp.   September 11, 1987.   Discussion about the performance
      of an  air-atmosphere condensation system.

 10.   VOC  RACT Clearinghouse Newsletter.   Vol.  2,  No.  1,  March 1985.
      pp.  1-3.

 11.   Memo from Friedman,  B.,  Midwest Research  Institute,  to Polymeric
      Coating  project file.  January 6, 1989.   Calculation of Allowable VOC
      Content  of "Waterborne"  Coatings.

 12.   Memo to  the Magnetic Tapes file.  Docket A-82-45,  Item IV-B-4.
      December 17, 1986.

 13.   Memo from Edgerton, S., Midwest Research  Institute,  to  Polymeric
      Coating  project file.  January 6, 1989.  Cost  Effectiveness of Total
      Enclosure  at W. R. Grace plant.

 14.   Memorandum from Wade, J., Department of Defense, to Secretaries of
      the Military Departments.  July 18,   1986.  Policy Guidance for VOC
      Compliance Planning.

 15.   Frost and Sullivan, Inc., Flexible Coated and Laminated Materials and
      Products Market in the United States.  New York.  Spring 1982.
     p. 22.

 16.  Telecon.  Hecht, D.,  Midwest Research Institute, with Reber, R.,
     Allied Baron Blackeslee.   October 15, 1987.  Performance of carbon
     adsorber monitors.

17.  Telecon.  Hecht, D.,  Midwest Research Institute, with Hartman,  M.,
     Radian Corporation.  October 9, 1987.  Performance  of carbon adsorber
     monitors.

18.  Memo  from Friedman, B., Midwest Research Institute,  to  Polymeric
     Coating project file.  December 8, 1988.  Retained  Solvent Provision.
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                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
1. REPORT NO.
 EPA-450/3-85-022b
                              2.
                                                            3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
  Polymeric Coating and Supporting Substrates-Background
  Information for Promulgated  Standards
             5. REPORT DATE
               July  1989
             6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
                                                            8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
 Office  of Air Quality Planning  and Standards
 U. S. Environmental Protection  Agency
 Research  Triangle Park, North Carolina  27711
                                                            10. PROGRAM ELEMENT NO.
             11. CONTRACT/GRANT NO.
                                                               68-02-3817
12. SPONSORING AGENCY NAME AND ADDRESS
 DAA for Air Quality Planning and Standards
 Office of Air and Radiation
 U. S. Environmental Protection Agency
 Research Triangle Park, North Carolina  27711
             13. TYPE OF REPORT AND PERIOD COVERED
                Final
             14. SPONSORING AGENCY CODE
                EPA/200/04
15. SUPPLEMENTARY NOTES
16. ABSTRACT
      Standards of performance  for the control of  VOC emissions from  the polymeric
 coating of  supporting substrates  are being promulgated under the authority of
 Section 111 of the Clean Air Act.   These standards  apply to all new,  modified, or
 reconstructed polymeric coating lines using at least 95 mg/yr of VOC  per year in the
 production  of polymeric-coated supporting substrates.   This document  contains a
 detailed  summary of the public comments on the proposed standards  (52 FR 15906),
 responses to these comments, and  a summary of the changes to the proposed standards.
17.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                               b.lDENTIFIERS/OPEN ENDED TERMS
                           c.  COS AT I Field/Group
 Air Pollution
 Pollution Control
 Standards of Performance
 Volatile Organic  Compounds
 Web Coating
 Polymeric Coating  of Supporting Substrates
 Air  Pollution Control
13B
18. DISTRIBUTION STATEMENT

 Unlimited
19. SECURITY CLASS (TIlis Report)
 Unclassified
                                                                          21. NO. OF PAGES
  76
                                               20. SECURITY CLASS (This page)
                                                Unclassifed
                                                                          22. PRICE
EPA Form 2220-1 (R«v. 4-77)    PREVIOUS EDITION is OBSOLETE

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