United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park, NC 27711
EPA-453/R-95-004a
March 1995
Air
iEPA
Hazardous Air Pollutant
Emissions from Process
Units in the Thermoplastics
Manufacturing Industry--
Basis and Purpose Document
for Proposed Standards
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EPA-453/R-95-Q04a
Hazardous Air Pollutant Emissions
From Process Units in the
Thermoplastics
Manufacturing Industry—
and Purpose Document
for Proposed Standards
Emission Division
U.S. Environmental Protection Agency
Office of Air And Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
March 1995
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DISCLAIMER
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.
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ENVIRONMENTAL PROTECTION AGENCY
Hazardous Air Pollutant Emissions from Process Units in the
Thermoplastics Manufacturing Industry — Basis and Purpose
Document for Proposed Standards
1. The standards regulate organic hazardous air pollutant
(HAP) emissions from the production of acrylonitrile
butadiene styrene (ABS) resin, styrene acrylonitrile
(SAN) resin, methyl methacrylate acrylonitrile
butadiene styrene (MABS) resin, methyl methacrylate
butadiene styrene (MBS) resin, polystyrene resin,
poly(ethylene terephthalate) (PET) resin, and nitrile
resin. Only those thermoplastic product process units
that are part of major sources under section 112(d) of
the Clean Air Act (Act) will be regulated.
2. For additional information contact:
Mr. Leslie Evans
Organic Chemicals Group
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Telephone: (919) 541-5410
3. Paper copies of this document may obtained from:
U.S. Environmental Protection Agency Library (MD-36)
Research Triangle Park, NC 27711
Telephone: (919) 541-2777
National Technical Information Service (NTIS)
5285 Port Royal Road
Springfield, VA 22161
Telephone: (703) 487-4650
4. Electronic copies of this document may be obtained from
the EPA Technology Transfer Network (TTN). The TTN is
an electronic bulletin board system which is free,
except for the normal long distance charges. To access
the Basis and Purpose Document:
Set software communication setting to 8 bits, no
parity, and 1 stop bit
Set a terminal emulation of either VT100, VT102,
or ANSI
Baud rates of 1200, 2400, 9600, and 14,400 are
accepted
111
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Use access number (919) 541—5742; access problems
should be directed to the system operator at
(919) 541-5384
Register online by providing a personal name,
password, and company name, address, and phone
number
Specify TTN Bulletin Board: CAAA (Clean Air Act
Amendments)
Select menu item: Title III: Hazardous Air Poll.
Select menu item: Policy Guidance Documents
To download, type filename: PR4_BSP.ZIP (3/20/95
Basis and Purpose - Polymers/Resins Group IV)
IV
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TABLE OF CONTENTS
Page
1.0 PURPOSE OF DOCUMENT 1-1
2.0 INTRODUCTION 2-1
3.0 DESCRIPTION OF THE AFFECTED INDUSTRY 3-1
3.1 DESCRIPTION OF PROCESSES AND SOURCES OF
HAP EMISSIONS 3-5
4.0 RATIONALE FOR THE SELECTION OF SOURCE CATEGORIES,
SUBCATEGORIZATION, AND EMISSIONS AVERAGING 4-1
4.1 RATIONALE FOR THE SELECTION OF SOURCE
CATEGORIES 4-1
4.2 RATIONALE FOR SUBCATEGORIZATION 4-1
4.3 EMISSIONS AVERAGING 4-9
5.0 BASELINE EMISSIONS 5-1
6.0 MACT FLOORS AND REGULATORY ALTERNATIVES 6-1
6.1 CLEAN AIR ACT REQUIREMENTS 6-1
6.2 DETERMINATION OF MACT FLOORS 6-3
6.3 RESULTS OF MACT FLOOR DETERMINATION 6-15
7.0 SUMMARY OF ENVIRONMENTAL, ENERGY, COST,
AND ECONOMIC IMPACT 7-1
7.1 FACILITIES AFFECTED BY THESE NESHAP 7-1
7.2 PRIMARY AIR IMPACTS 7-3
7.3 NON-AIR ENVIRONMENTAL 7-5
7.4 ENERGY IMPACTS 7-5
7.5 COST IMPACTS 7-7
7.6 ECONOMIC IMPACTS 7-9
8.0 SELECTION OF THE STANDARDS 8-1
8.1 SUMMARY OF THE PROPOSED STANDARDS 8-1
8.2 RATIONALE FOR THE SELECTION OF EMISSION
POINTS TO BE COVERED BY THE PROPOSED STANDARDS . 8-44
8.3 RATIONALE FOR THE SELECTION OF THE PROPOSED
STANDARDS 8-44
8.4 RATIONALE FOR THE SELECTION OF THE FORMAT OF
THE PROPOSED STANDARDS . . ..... 8-103
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TABLE OF CONTENTS (Concluded)
Page
8.5 RATIONALE FOR THE SELECTION OF COMPLIANCE AND
PERFORMANCE TEST PROVISIONS AND MONITORING
REQUIREMENTS 8-107
8.6 RATIONALE FOR THE SELECTION OF PARAMETER
MONITORING AND COMPLIANCE CERTIFICATION
PROVISIONS 8-116
8.7 RATIONALE FOR THE SELECTION OF RECORDKEEPING
AND REPORTING REQUIREMENTS 8-119
8.8 OPERATING PERMIT PROGRAM 8-126
9.0 REFERENCES 9-1
VI
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LIST OF TABLES
TABLE 3-1
TABLE 3-2
TABLE 5-1
TABLE 5-2
TABLE 5-3
TABLE 6-1
TABLE 6-2
TABLE 6-3
TABLE 7-1
TABLE 7-2
TABLE 8-1
TABLE 8-2
TABLE 8-3
TABLE 8-4
TABLE 8-5
TABLE 8-6
TABLE 8-7
TABLE 8-8
TABLE 8-9
TABLE 8-10
TABLE 8-11
TABLE 8-12
Page
THERMOPLASTIC PRODUCTION FACILITIES . . . . .3-2
THERMOPLASTIC PRODUCTION PROCESSES BY
SUBCATEGORY 3-12
BASELINE ORGANIC HAP EMISSIONS FOR EXISTING
SOURCES 5-2
BASELINE ORGANIC HAP EMISSIONS FOR NEW SOURCES 5-4
MAJOR HAZARDOUS AIR POLLUTANTS EMITTED
BY SUBCATEGORY 5-6
MACT FLOOR ANALYSIS FOR EXISTING SOURCES . . 6-17
MACT FLOOR ANALYSIS FOR NEW SOURCES .... 6-19
SUMMARY OF MACT FLOOR STRINGENCY ...... 6-22
ORGANIC HAP EMISSIONS AND EMISSION REDUCTIONS 7-4
SUMMARY OF COST IMPACTS 7-8
SUMMARY OF PROPOSED STANDARDS FOR
EXISTING SOURCES IN RELATIONSHIP TO
SUBPARTS G AND H OF 40 CFR PART 63
AND THE POLYMERS NSPS 8-8
SUMMARY OF PROPOSED STANDARDS FOR
NEW SOURCES IN RELATIONSHIP TO SUBPARTS
G AND H OF 40 CFR PART 63
AND THE POLYMERS NSPS 8-11
PROPOSED STANDARDS FOR EXISTING STORAGE
VESSELS 8-15
PROPOSED STANDARDS FOR NEW STORAGE VESSELS . 8-16
SUMMARY OF PROPOSED PROCESS VENT
APPLICABILITY CRITERIA FOR EXISTING
FACILITIES 8-22
SUMMARY OF PROPOSED PROCESS VENT
APPLICABILITY CRITERIA FOR NEW
FACILITIES 8-23
PROPOSED WASTEWATER APPLICABILITY
CRITERIA 8-31
REGULATORY ALTERNATIVE IMPACTS FOR
EXISTING POLYSTYRENE CONTINUOUS
FACILITIES . . 8-60
REGULATORY ALTERNATIVE IMPACTS FOR
EXISTING TPA CONTINUOUS FACILITIES ..... 8-66
REGULATORY ALTERNATIVE IMPACTS FOR
EXISTING TPA BATCH FACILITIES 8-70
REGULATORY ALTERNATIVE IMPACTS FOR
EXISTING DMT BATCH FACILITIES . . . . . . . 8-73
REGULATORY ALTERNATIVE IMPACTS FOR
EXISTING DMT BATCH FACILITIES 8-77
VI1
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LIST OF FIGURES
Page
FIGURE 3-1 SIMPLIFIED FLOW DIAGRAM FOR THE
THERMOPLASTICS MANUFACTURING PROCESS 3-6
FIGURE 4-1 THERMOPLASTICS SUBCATEGORIZATION 4-6
Vlll
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1.0 PURPOSE OF DOCUMENT
The Basis and Purpose Document provides background
information on, and rationale for, decisions made by the
Environmental Protection Agency (EPA) related to the
proposed standards for the reduction of hazardous air
pollutants (HAP) emitted through the production of seven
source categories of thermoplastics (Group IV Polymers and
Resins). These source categories include the production of
acrylonitrile butadiene styrene (ABS) resin, styrene
acrylonitrile (SAN) resin, methyl methacrylate acrylonitrile
butadiene styrene (MABS) resin, methyl methacrylate
butadiene styrene (MBS) resin, polystyrene resin,
poly(ethylene terephthalate) (PET) resin, and nitrile resin.
This document is intended to supplement the preamble for the
proposed standards.
This document is separated into 8 chapters providing a
combination of background information and rationale for
decisions made in the standards development process.
Chapters 2, 3, 5, and 7 provide background information;
chapter 2 is an introduction, chapter 3 describes the
affected industry, chapter 5 presents the baseline organic
HAP emissions, and chapter 7 presents the predicted impacts
associated with the selected regulatory alternatives.
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Chapters 4, 6, and 8 provide rationale for
subcategorization, determination of MACT "floors" and
development of regulatory alternatives, and rationale for
the selection of the proposed standards, respectively.
Supporting information and more detailed descriptions
of certain analyses are contained in the memoranda
referenced in this document, the Supplementary Information
Document (SID), the preamble, and the project docket.
1-2
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2.0 INTRODUCTION
Section 112 of the Clean Air Act (Act), as amended in
1990, gives the EPA the authority to establish national
standards to reduce air emissions from sources that emit one
or more HAP. Section 112(b) contains a list of HAP to be
regulated by National Emission Standards for Hazardous Air
Pollutants (NESHAP), and Section 112 (c) directs the EPA to
use this pollutant list to develop and publish a list of
source categories for which NESHAP will be developed. The
EPA must list all known source categories and subcategories
of "major sources" that emit one or more of the listed HAP.
A major source is defined in section 112(a) as any
stationary source or group of stationary sources located
within a contiguous area and under common control that
emits, or has the potential to emit, in the aggregate,
considering controls, 10 tons per year or more of any one
HAP or 25 tons per year or more of any combination of HAP.
This list of source categories was published in the Federal
Register on July 16, 1992 (57 FR 31576), and includes the
following six source categories:
• Acrylonitrile butadiene styrene resin,
• Styrene acrylonitrile resin,
2-1
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• Methyl methacrylate acrylonitrile butadiene
styrene resin,
• Methyl methacrylate butadiene styrene resin,
• Polystyrene resin, and
• Poly(ethylene terephthalate) resin.
A seventh source category, nitrile resin is being proposed
as an addition to the source category list.
The products manufactured by facilities in these seven
source categories are called thermoplastics.a A
thermoplastic is a resin that softens with heat and
rehardens to a rigid material upon cooling, without
generally showing any change in the physical-properties of
the thermoplastic, even through repeated heating and
cooling.1 Thermoplastics are composed of high-molecular-
weight polymers which are synthesized from monomers; the
thermoplastics covered in these seven source categories,
with one exception, use styrene monomer as the basic
feedstock.
The thermoplastics produced by the seven source
categories listed above are used in the manufacture of goods
such as packaging materials and containers, polyester
fibers, electrical insulation, automotive components,
a While the term "thermoplastic" is used throughout
this document and other background materials for the
proposed NESHAP to describe the products produced by the
seven source categories listed above, these products only
make up a subset of the wide range of polymers generally
referred to as thermoplastics.
2-2
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furniture, radio and television components, housewares,
appliances, wall tiles, and x-ray film.
2-3
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3.0 DESCRIPTION OF THE AFFECTED INDUSTRY
The seven source categories covered under the proposed
rule have been grouped together because of similarities in
process operations, emission characteristics, and control
device applicability and costs. These seven thermoplastic
source categories are collectively referred to as the Group
IV polymers and resins or the Group IV thermoplastics.
The EPA identified a total of 66 plant sites producing
one or more of the seven thermoplastics. All of the
facilities considered in the analysis supporting the
proposed rule are believed to either be a major source or to
be located at a plant site that is a major source.
Table 3-1 identifies the known producers of the seven
thermoplastics, along with their facility locations. The
thermoplastics manufacturing facilities covered in the scope
of this NESHAP are located in 23 States, including South
Carolina, North Carolina, Ohio, Illinois, Alabama,
Pennsylvania, Texas, Tennessee, Massachusetts, and
California.
3-1
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TABLE 3-1. THERMOPLASTIC PRODUCTION FACILITIES
Source
Category
PET
PET
PET
PET
PET
PET
PET
PET
PET
PET
PET
PET
PET
PET
PET
PET
PET
PETa
PETa
PETa
PETa
PET3
PET,
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Company
We 11 man
YKK
Tennessee Eastman
3M
BASF
Hoechst Celanese
DuPont
DuPont
Hoechst Celanese
DuPont
DuPont
DuPont
DuPont
Allied Signal
DuPont
ICI Films
Hoechst Celanese
Carolina Eastman
Shell
Eastman Kodak
Hoechst Celanese
ICI Films
3M
Scott Polymers
Huntsman Chemical
Novacor Chemicals
Novacor Chemicals
Location
Darlington, SC
Macon , GA
Kingsport , TN
Greenville, SC
Lowland, TN
Greer, SC
Kins ton, NC
Old Hickory, TN
Spartanburg, SC
Cape Fear, NC
Brevard, NC
Florence, SC
Circleville, SC
Moncure , NC
Cooper River, SC
Hopewell, VA
Shelby, NC
Columbia, SC
Apple Grove, WV
Rochester, NY
Salisbury, NC
Fayetteville, NC
Decatur, AL
Saginaw-1, TX
Chesapeake , VA
Decatur- 1, AL
Decatur- 2, AL
3-2
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TABLE 3-1. THERMOPLASTIC PRODUCTION FACILITIES (Continued)
Source
Category
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
Polystyrene
ASA/AMSAN,
Polystyrene
Polystyrene,
ABS
Company
Novacor Chemicals
Huntsman Chemical
Huntsman Chemical
Scott Polymers
Rohm and Haas
Kama
Huntsman Chemical
Scott Polymers
Arco Chemical
BASF
BASF
BASF
Arco Chemical
Amoco Chemical
American Polymers
Amoco Chemical
Amoco Chemical
Fina Oil & Chemical
BASF
Dow Chemical
Dow Chemical
Chevron Chemical
Dart Container
Dart Container
GE Plastics
Dow Chemical
Location
Indian Orchard, MA
Belpre, OH
Peru, IL
Saginaw-2, TX
Philadelphia, PA
Hazel ton, PA
Rome , GA
Fort Worth, TX
Monaca , PA
Holyoke, MA
Santa Ana, CA
Joliet, IL
Painesville, OH
Willow Springs, IL
Oxford, MA
Joliet, IL
Torrance , CA
Carville, LA
South Brunswick, NJ
Joliet, IL
Riverside, MO
Marietta, OH
Owensboro , KY
Leola, PA
Selkirk, NY
Hanging Rock, OH
3-3
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TABLE 3-1. THERMOPLASTIC PRODUCTION FACILITIES (Continued)
Source
Category
Polystyrene,
ABS
Polystyrene,
ABS
Polystyrene ,
ABS
ABS
ABS
ABS, MABS
ABS, SAN
ABS, SAN,
Polystyrene
MBS
MBS
MBS
Nitrile
SAN
Company
Dow Chemical
Dow Chemical
Dow Chemical
BF Goodrich
GE Plastics
GE Plastics
Monsanto
Monsanto
Rohm and Haas
Elf Atochem
iCaneka Texas Corp.
BP Chemicals
GE Plastics
Location
Torrance , CA
Allyn's Point, CT
Midland, MI
Akron, OH
Ottawa, IL
Washington, WV
Muscatine, IA
Addyston, OH
Louisville, KY
Axis, AL
Pasadena, TX
Lima , OH
Bay St. Louis, MS
These facilities also use a solid state process.
3-4
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3.1 DESCRIPTION OF PROCESSES AND SOURCES OF ORGANIC HAP
EMISSIONS
Polymerization processes are used to manufacture
thermoplastics. A simplified process flow diagram of the
thermoplastics manufacturing process is provided in
Figure 3-1. Subsequent paragraphs describe the
polymerization process in general and the typical emission
points.
3-5
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1) Storage and Raw Material Preparation
2) Polymerization
3) Material Recovery
4) Finishing
Figure 3-1.
Simplified Flow Diagram
for the Thermoplastics
Manufacturing Process
3-6
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3.1.1 General Process Description
In polymerization, a large number (hundreds to
thousands) of relatively simple molecular units, or
monomers, are chemically combined to form a macromolecule,
or polymer. Polymer manufacturing can be divided into
four areas: (1) raw material storage and preparation, (2)
polymer formation in a reactor (3) material recovery, and
(4) finishing. The basic raw materials for polymerization
are monomers and either solvents or water.
Four types of polymerization are generally used in the
thermoplastics manufacturing industry: emulsion, suspension,
mass, and solution. In emulsion polymerization, monomers
are dispersed in water using a soap solution or an
emulsifier. In suspension polymerization, the monomer is
suspended in a water phase. In mass polymerization,
monomers are reacted without the use of emulsifiers,
suspending agents, salts or waters, although a solvent may
be used. In solution polymerization, monomers are dissolved
in .an organic solvent. The production of PET does not fall
under any of these four types of polymerization (see the
process description memo for PET in the SID in Category II-B
of the docket).
Following polymerization, any unreacted monomer,
solvent or other material is recovered/removed by stripping,
devolatilizing, or through some other means. Finally,
finishing operations may consist of blending, aging,
3-7
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coagulation (to produce solid polymers), washing, and drying
processes, depending on the eventual use of the polymer.
3.1.2 Description of Emission Points
Five types of organic HAP emission points are commonly
found at thermoplastic production facilities: storage of
pure organic HAP used as raw materials, process-related
emissions (process vents and process fugitives), waste and
wastewater collection and treatment operations, equipment
leaks (pumps, valves, connectors, etc), and heat exchange
systems to include process contact cooling towers.
Emissions from raw material atmospheric storage vessels
typically occur as working and breathing losses. Residual
concentrations of organic HAP are usually very low in
intermediate and finished thermoplastics products and, as a
result, emissions from product storage tanks are negligible.
Process-related organic HAP emission points include
vents from raw material preparation, monomer polymerization,
material recovery, and finishing operations. In addition,
significant fugitive emissions can occur during the
finishing and drying of solid polymer products. Emissions
from the reactors in the polymerization area may occur
during initial charging of the reactants and/or during the
polymerization reaction. These emissions may be steady or
sporadic, depending on the mode of process operation (i.e.,
continuous or batch), and generally contain organic HAP
monomer(s) and/or solvent. The organic HAP concentration in
3-8
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reactor vent emissions can be relatively high, due to the
high concentrations of unreacted monomer and solvent present
in the reactor.
Process vent streams from stripping unit operations can
have high organic HAP concentrations, but they are usually
routed to a material recovery device that recovers the
valuable monomer or solvent for re-use.
Finishing emissions can be associated with coagulation
tanks, slurry or blending tanks, and dewatering screens and
filters. The organic HAP concentrations in finishing area
process vent streams are much less than the concentrations
in reactor or stripper vent streams. Dryer vents are often
the largest source of process vent emissions from
thermoplastics production. These process vents are
characterized by low concentrations of organic HAP, but very
large volumetric flowrates.
The emissions from many of the finishing and drying
operations are not completely captured or vented to
traditional vent stacks. This type of emission is referred
to as process fugitive emissions. Finishing operations are
often located in large warehouse-type buildings, and process
fugitive emissions are removed from the work space through
roof fans and other general building ventilation.
Equipment leaks occur primarily at connections between
different equipment components. The characteristics of
these emissions for the thermoplastics industry are similar
3-9
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to those associated with the synthetic organic chemical
manufacturing industry (SOCMI), which are discussed in
greater detail in the final preamble to the Hazardous
Organic NESHAP (HON) (59 PR 19402; April 22, 1994) .
Emissions from equipment leaks associated with operations
downstream from coagulation equipment will be minimal, due
to the low residual organic HAP content in the streams.
Wastewater streams containing organic compounds may be
generated during thermoplastic production. Sources of
wastewater containing organic HAP include the monomer
refining, stripping, material recovery, and finishing
processes. While the largest wastewater generation is
associated with the finishing process, the concentration of
organic HAP in finishing wastewater is usually very low,
because residual organic HAP have been removed during the
stripping of the raw product. Heat exchange systems,
including process contact cooling towers, can be used in the
production of thermoplastics. Heat exchange systems are
emission points if either (1) a non-contact heat exchange
system develops a leak, or (2) a process contact heat
exchange system, typically a process contact cooling tower,
is used. Both non-contact and process contact heat exchange
systems are known to be used by the industry.
3.1.3 Summary of Processes
Table 3-2 shows the types of processes that were
identified to be in use at active facilities in each source
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category. Although other types of processes that produce
these products were described in the literature, no plants
were identified that actively used these other processes.
3-11
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TABLE 3-2.
THERMOPLASTIC PRODUCTION PROCESSES BY
SUBCATEGORY
Aery lonit rile
Butadiene Styrene
Production
Styrene
Acrylonitrile
Production
Methyl
Methacrylate
Acrylonitrile
Butadiene
Styrene Production
Methyl
Methacrylate
Butadiene Styrene
Production
Polystyrene
Production
Nitrile Production
Poly (ethyl ene
terephthalate
Production3
Emulsion
/
/
/
/
/
/
Suspension
/
/
/
Mass
/
/
/
Solution
/
Other
/
Poly(ethylene terephthalate) production cannot be
classified under one of these four polymerization
types. For more information on the Poly(ethylene
terephthalate) process, see the memo entitled "Process
Description for Poly(ethylene terephthalate) Resins"
contained in Docket A-92-45, Category II-B and in the
SID.
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A description of each manufacturing process, and of
organic HAP emission points for each of the seven
thermoplastics, with the exception of nitrile resins, is
contained in the process description memorandum found in the
docket (Docket No. A-92-45, Category II-B) and is included
as part of the SID.
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4.0 RATIONALE FOR THE SELECTION OF SOURCE CATEGORIES,
SUBCATEGORIZATION, AND EMISSIONS AVERAGING
4 .1. RATIONALE FOR THE SELECTION OF SOURCE CATEGORIES
Six of the seven source categories selected for the
development of the proposed rule are listed in the source
category list published on July 16, 1992 (57 FR 3156) .
Information gathered during the development of the proposed
rule indicated that all of the facilities in these six
source categories are major sources. The seventh source
category, nitrile resins, is included under the proposed
rule because information obtained during the information
gathering phase of the project demonstrated that it was
similar to the other source categories included in this
group, especially the styrene-based facilities. In
addition, the one facility identified as producing nitrile
resins was also determined to be a major source.
4.2 RATIONALE FOR SUBCATEGORIZATION
4.2.1 Subcatecrorization Results
In developing standards, the EPA has the discretion to
distinguish or segregate classes, types, and sizes of
sources within a source category and, conversely, to
aggregate among similar source categories. Criteria that
may be considered in defining categories of similar sources
include similarities in process operations (including
4-1
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differences between batch and continuous operations),
emissions characteristics, control device applicability and
costs, safety considerations, and pollution prevention
opportunities.
How source categories are defined is important because
it dictates the basis upon which the "floor" is to be
determined for a maximum achievable control technology
(MACT) standard. Put another way, the definition of source
category describes the "pool" of facilities that can be used
to define the MACT floor. (Note: Facility is the term used
in the 1990 Amendments definition of the MACT floor.) This
means that the MACT floor must be determined on the same
basis upon which source category is defined. The definition
of source category is also important in that it limits the
scope of emissions averaging; collocated emission points
cannot emissions average unless they belong to the same
source category.
Within four of the seven listed thermoplastic
production source categories, significant variations in
production methods and/or raw material usage exist.
Therefore, for purposes of the proposed rule, the EPA has
split these four categories -- ABS, SAN, polystyrene, and
PET -- into subcategories.
The major distinction within most source categories is
that some facilities use a batch operation, while other
facilities use a continuous operation. This difference
4-2
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often gives rise to very different process emission stream
characteristics, which can affect the type of control device
most suitable for control. For example, process vents from
continuous operations are often characterized by fairly
consistent pollutant concentrations, while process vents
from batch operations are often characterized by widely
varying pollutant concentrations during the emission event.
Another distinction was made in the PET industry based on
whether dimethyl terephthalate (DMT) or terephthalic acid
(TPA) is used as a raw material. When DMT is used, a large
amount of methanol is generated as a by-product, mainly
during the esterification process step. This methanol is
captured and recovered on-site. The TPA process does not
generate methanol as a by-product. The generation of
methanol, therefore, results in the presence of methanol
recovery equipment and greater esterification emissions at
DMT facilities.
In determining the definition to select for source
category, the EPA considered the similarities and
dissimilarities discussed above, and, to a much lesser
degree, the amount of collocation of processes (i.e.,
subcategories) at each facility and the potential for
emissions averaging.
The EPA concluded that subcategorization was not
necessary in three of the thermoplastic source categories
(MABS, MBS, and nitrile resin). Only three facilities were
4-3
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found to produce MBS and the process used did not vary
significantly. Only one facility was found to produce MASS
and only one to produce nitrile.
In summary, four of the seven thermoplastic source
categories were subcategorized creating a total of 18
separate subcategories.b These subcategories are:
• PET resin using a continuous TPA process,
• PET resin using a batch TPA process,
• PET resin using a continuous DMT process,
• PET resin using a batch DMT process,
• polystyrene resin using a continuous process,
• polystyrene resin using a batch process,
• expandable polystyrene (EPS) resin,
• ABS resin using a continuous emulsion process,
• ABS resin using a continuous mass process,
• ABS resin using a batch emulsion process,
• ABS resin using a batch suspension process,
• ABS latex resin,
• SAN resin using a continuous process,
• SAN resin using a batch process,
b For the purposes of this document, the term
"subcategory" will be generally used to describe the group
of sources that were analyzed together. In fact, these
groups of sources can be either sources belonging to a
single source category as defined in the EPA's original
list, sources belonging to a source category that is
proposed to be added to the EPA's list, (i.e., nitrile
sources) or sources belonging to a subcategory.
4-4
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• acrylonitrile styrene acrylate/alpha methyl styrene
acrylonitrile (ASA/AMSAN) resin,
• MASS resin,
• MBS resin, and
• nitrile resin.
Figure 4-1 contains a schematic of subcategorization for the
thermoplastic source categories.
4-5
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AcrylonKrile
Butadiene
Styrene
(ABS)
Styrene
Acryfonitrile
(SAN)
- Continuous, emulsion
-Continuous, mass
- Batch, wnulslon
-Bat*, latex
. Batch, suspension
Methyl
Methacrylate
Acrylonitrile
Butadiene
Styrene
(MASS)
Methyl
Methacrylate
Butadiene
Styrene
(MBS)
Poly(ethylene
terephthalate
(PET)
-Continuous
•Bald)
• EPS
Nitrite
- TPA, continuous
•TPA, batch
- DMT, continuous
. DMT. batch
ASA - aoylonitrile styrene acrylate
AMSAN - alpha methyl styrene acrylonitrile
EPS - expandable polystyrene
TPA - terephthalic acid
DMT - dimethyl terephthalate
Figure 4-1. Thermoplastics Subcategorization
4-6
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4.2.2 Options for Source Categories
In determining how to aggregate or distinguish among
the seven source categories, the EPA considered four
options. The four options considered were: (1) the
subcategory (e.g., ABS production using a continuous mass
process); (2) the source category (e.g., ABS production
regardless of the process); (3) three groupings of source
categories (styrene-based resin production, nitrile resin
production, and PET production); and (4) a single "super"
source category composed of all seven thermoplastic source
categories. The EPA selected the subcategory option (Option
1) for the reasons discussed below.
The "super" source category option (Option 4) was
rejected for two reasons. First, creating a "super" source
category would have grouped too many dissimilar processes
together, which would have resulted in MACT floor
determinations inappropriate for/not representative of some
of the processes. This is especially true when combining
the styrene-based resin processes with the PET processes.
In addition, only one facility was identified as having both
a styrene-based resin process and a PET process. Thus, this
option offers minimal potential gain through emissions
averaging. Second, the "super" source category option was
not reasonable given the available data. Using this option
would have discounted a large amount of data that showed
distinctions between the subcategories. For these reasons,
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the EPA rejected this option for defining the source
categories.
Option 3, which creates three groups of source
categories (styrene-based resins, nitrile, and PET), was
rejected primarily because the grouping of all of the
styrene-based resins has the potential, due to technological
differences, to result in inappropriate/not representative
MACT floors for some styrene-based resin processes.
Further, while there is significant collocation between ABS
and SAN facilities (both styrene-based resins), the overall
amount of collocation within the styrene- based resins is
relatively small. Less than 30 percent of styrene-based
facilities produce thermoplastics using more than one of the
processes as defined by 18 subcategories. For these
reasons, the EPA rejected this option for defining source
categories.
The source category option (Option 2) would be
consistent with the source category listing, would provide
some facilities additional opportunity to emissions .average,
and would avoid some of the problems of Options 3 and 4 by
reducing the grouping of dissimilar processes. However,
even within source categories, there are different process
technologies and raw materials usage that make division of
source categories into subcategories more defensible for
determining MACT floors. In addition, most facilities would
not have benefited from emissions averaging under Option 2.
4-8
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Therefore, the EPA determined that the subcategory option
(Option 1) was the best option for defining the source
categories.
4.3 EMISSIONS AVERAGING
The proposed standards include provisions for emissions
averaging that are essentially the same as those found in
the HON. Under the proposed standards, emissions averaging
would be allowed among collocated emission points at
existing sources belonging to the same subcategory.
In considering the use of emissions averaging, the EPA
agreed that emissions averages should achieve at least a
comparable hazard and risk benefit to point-by-point
compliance. Affected sources who elect to use emissions
averaging must demonstrate, to the satisfaction of the
implementing agency, that compliance through averaging would
not result in greater hazard or risk than compliance without
averaging. Further discussion of this topic may be found on
pages 19427 and 19428 of the preamble to the final HON rule
(59 FR 19402) promulgated on April 22, 1994.
As in the HON rule, for this proposed rule emissions
averaging is not allowed as a compliance option for new
sources. The decision to limit emissions averaging to only
existing sources was based on the fact that new sources have
historically been held to a stricter standard than existing
sources. It is most cost effective to integrate state-of-
the-art controls into equipment design and to install the
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technology during construction of new sources. By allowing
emissions averaging, existing sources have the flexibility
to achieve compliance at diverse points with varying degrees
of control already in place in the most economically and
technically reasonable fashion. This concern does not apply
to new sources which can be designed and constructed with
compliance in mind. Therefore, emissions averaging is only
allowed at existing sources. Further discussion of this
topic may be found on pages 19426 and 19427 of the preamble
to the final HON rule (59 FR 19402) promulgated on April 22,
1994.
While the EPA believes that there is limited potential
for emissions averaging in this rule, the EPA did not want
to exclude emissions averaging based on the available data
and welcomes comments on whether or not to include emissions
averaging for the Group IV thermoplastics. Commenters
supporting emissions averaging are urged to submit specific
information on how emissions averaging would benefit their
facility. In addition, the EPA requests comment on ways the
implementation of emissions averaging can be made more
flexible without reducing the emission reductions. The EPA
will consider all comments.
As stated previously, the emissions averaging
provisions of this rule are essentially identical to the
provisions contained in the HON. This rule has incorporated
the emissions averaging constraints included in the HON that
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are based on concerns expressed during the HON public
comment period. The concerns are discussed in a
supplementary Federal Register notice published on October
15, 1993; 58 FR 53479. These constraints include
consideration of: (1) State discretion on emissions
averaging, (2) inclusion of risk in averaging
determinations, (3) compliance period for emissions
averaging, (4) limit on number of emission points allowed in
an average, and (5) effect of missing monitoring
data/parameter exceedances on averaging. The EPA requests
comment on whether it is appropriate to include these
constraints in the proposed rule.
The EPA is including emissions from process contact
cooling towers and vacuum system wastewater at existing PET
facilities in the emissions averaging procedures being
proposed under §63.510. As discussed in Chapter 8, the
proposed standards would: 1) prohibit existing PET
facilities from using cooling tower water in the contact
condensers associated with vacuum systems, and 2) require
the control of any wastewater stream containing organic HAP
listed on Table 9 of the HON wastewater provisions,
generated by the vacuum system containing organic HAP listed
on Table 9 of the HON wastewater provisions, to the levels
required for a Group l process wastewater stream. Control
is required regardless of the organic HAP concentration and
flowrate of the stream.
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The proposed prohibition for cooling tower water would
eliminate organic HAP emissions from the process contact
cooling towers since the cooling tower water would not come
in contact with the organic HAP generated by the process.
If an owner or operator elected to comply with the proposed
emissions averaging procedures, the owner or operator could
elect not to eliminate process contact cooling tower water
from the vacuum system. This would create a debit; that is,
organic HAP emissions would now occur from the cooling
tower, whereas under the proposed rule no organic HAP
emissions would occur. Thus, the proposed emissions
averaging procedures only include process contact cooling
towers in the equation for the calculation of debits. On
the other hand, since the proposed rule would eliminate
organic HAP emissions from the cooling tower, there is no
opportunity for an owner or operator to control cooling
tower emissions to a level more stringent than the proposed
rule. Thus, the proposed emissions averaging procedures for
calculating credits do not include process contact cooling
towers.
Under the proposed rule, the organic HAP that would
otherwise have been contained in the cooling tower water and
released from the cooling tower would now be contained in
the vacuum system wastewater stream(s). The wastewater
stream(s) would be required to be controlled regardless of
the organic HAP concentration or flowrate, provided the
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stream contains an organic HAP listed on Table 9 of the HON
wastewater provisions. A group determination (Group 1/2)
would not be made for these wastewater streams as would be
for other process wastewater streams. The level of control
being proposed for the vacuum wastewater streams is the same
level of control required for Group 1 process wastewater
streams.
As for other Group 1 process wastewater streams, the
opportunity exists for vacuum system wastewater streams to
be controlled either more stringently or less stringently
than required. Thus, the opportunity exists for generating
either credits or debits. The proposed emissions averaging
procedures explicitly incorporate vacuum system wastewater
streams into the credit and debit equations. In addition,
since the proposed rule requires their control as if a group
determination was conducted and they were found to be Group
1 process wastewater streams, vacuum system wastewater
streams are classified as Group 1 for purposes of
calculating debits and credits.
Emissions from batch process vents have been excluded
from emissions averaging because there is no acceptable and
satisfactory methodology available to quantify the emission
reduction that would be gained or lost in an emissions
averaging scheme. While there are methods presented in the
proposed rule for determining emissions from batch process
vents, the EPA does not find them adequate for the purposes
4-13
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of emissions averaging. The EPA has judged that the
accuracy and consistency needs of emission estimates for
emissions averaging are greater than the accuracy and
consistency needs for determining applicability of the batch
process vent provisions. Further, the EPA has in the past
excluded emissions associated with batch process vents from
averaging schemes. Equipment leaks have also been excluded
from emissions averaging because: (1) the proposed standard
for equipment leaks has no fixed performance level; and (2)
no method currently exists for determining the magnitude of
allowable equipment leak emissions. Without an acceptable
method to determine the magnitude of allowable emissions to
assign for batch process vents and equipment leaks, an
averaging approach that includes these two types of emission
points has been considered technically infeasible.
Similar to the HON emissions averaging provisions, the
proposed rule limits the number of emission points allowed
in an emissions average. The concept for limiting the
number of emission points is the same as the HON, but the
exact number is different. The reasons for constraining the
number of points to be included in emissions averaging are
described on pages 19428 - 19429 of the preamble to the
final HON rule (59 FR 19402) promulgated on April 22, 1994.
In summary, there is a concern about the burden and cost to
implementing agencies of overseeing and enforcing large
numbers of emission points in averages. In addition, it was
4-14
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noted that most affected sources will not find a large
number of opportunities to generate cost-effective credits;
thus, most averages were anticipated to involve a limited
number of emission points, and imposing a limit should not
affect most sources.
In selecting the number of points to allow in an
emissions average for the proposed rule, differences in the
definition of source category for the HON and the proposed
rule were considered. The difference in the breadth of this
definition is important because emissions averaging is on a
source category/subcategory basis. The definition of source
category in the HON includes the production of any chemical
included on the HON list. Typically, facilities covered by
the HON produce multiple chemicals in multiple process units
at one plant site. The HON allows an affected source to
include no more than 20 points in an emissions average; this
is increased to 25 points where pollution prevention
measures are used to control emission points to be included
in an average. The 20- to 25-point limit would apply to the
combination of all process units at a given facility. As
discussed earlier in this chapter, the definition of source
category for the proposed rule is more limited. The
proposed rule has 18 subcategories, and the emissions
averaging provisions apply to each subcategory separately.
Emissions averaging is limited to emission points from a
single subcategory within the facility. Some facilities
4-15
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contain multiple subcategories; the maximum number of such
collocated subcategories at any one facility is 6. Thus, if
the HON emission point limit were directly applied to this
rule, this plant site would be allowed to include 20 to 25
emission points per subcategory; combined, this would
potentially equal a total of 120 to 150 emission points
across six emissions averaging plans. Under a similar
scenario under the HON, the same plant site could include
only 20 to 25 emission points in one emissions averaging
plan due to the breadth of the definition of source category
for the HON. The EPA decided that the number of emission
points allowed in the emissions averaging for the proposed
rule needed to be made more in parity with the HON.
In deriving the numerical limit to include in the
proposed rule, the EPA considered that the maximum number of
collocated subcategories at one plant site is 6. In order
to make the provisions included in the proposed rule in
parity with the HON, the maximum-number of emission points
included in averaging for each subcategory (without
pollution prevention controls) would need to be
20 -5- 6 = 3 1/3. This number seemed to be too small to allow
sufficient practical consideration of averaging; thus, it
was increased to 5. In addition, the proposed rule is
similar to the HON in that it allows additional emission
points to be included in the average if pollution prevention
measures are used to control some emission points included
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in the average. The proposed rule allows three additional
emission points to be included in the average if pollution
prevention measures are used. For example, if two points to
be included in an average are controlled by the use of a
pollution prevention measure, the facility can include up to
7 emission points in their emissions average for that
subcategory.
In the preamble to the proposed rule, the EPA
specifically requested comments on the selection of the
limit (5, or 8 if pollution prevention measures are used) of
emission points to be allowed per subcategory for purposes
of emissions averaging in the proposed rule. The EPA
inquired as to whether this limit will preclude known
opportunities within actual facilities to generate cost-
effective credits within a category or subcategory. The EPA
requested that any comments on this issue address specifics
on the emission and cost quantities computed and include
detailed calculations and references to show how these
quantities were determined.
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5,0 BASELINE EMISSIONS
Baseline organic HAP emissions for the thermoplastic
subcategories are presented in Tables 5-1 and 5-2. As shown
in the table, the total nationwide estimated organic HAP
emissions are over 24,780 megagrams per year (Mg/yr) for
existing sources and 14,920 Mg/yr for new sources.
5-1
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TABLE 5-1.
BASELINE ORGANIC HAP EMISSIONS FOR EXISTING
SOURCES
Baseline Organic HAP Emissions for Existing Sources
(Mg/yr)
Summary
ABS, Be
ABS, Bl
ABS, Bs
ABS, Ce
ABS, Cm
MABS
Nitrile
SAN, B
SAN, C
ASA/
AMSAN
MBS
EPS
PS, B
PS, C
PET TPA,
C
PET TPA,
B
PET DMT,
C
PET DMT,
B
TOTALS
Process
Vents
430
1
4
630
20
80
20
8
7
0
50
15
70
260
1,090
570
535
1,290
5,060
Storage
Vessels
6
0
1
15
6
2
0
3
4
0
3
3
10
60
3
1
80
100
310
Equipment
Leaks (a)
50
2
9
80
220
3
10
10
70
90
130
430
110
1,120
2,030
90
2,150
1,190
7,790
Wastewater (b)
20
0
1
390
0
3
0
10
30
5
10
0
0
5
1,310
35
580
110
2,510
Cooling
Towers
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1,660
620
1,140
5,690
9,110
Total
500
3
15
1,110
240
90
30
40
110
100
190
450
190
1,440
6,090
1,320
4,480
8,390
24,790
a These values were determined by estimating equipment counts and applying
SOCMI factors2 adjusted according to LDAR programs.
Be
Bl
Bs
Ce
Cm
B
C
PS
batch emulsion
batch latex
batch suspension
continuous emulsion
continuous mass
batch
continuous
polystyrene
5-2
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TABLE 5-2. BASELINE ORGANIC HAP EMISSIONS FOR NEW SOURCES
BASELINE ORGANIC
HAP EMISSIONS FOR NEW SOURCES
(Mg/yr)
Subcategory3
ABS, B
ABS, Bl
ABS, Bs
ABS, Ce
ABS, Cm
MABS
Nitrile
SAN, B
SAN, C
ASA/AMSAN
MBS
EPS
PS, B
PS, C
PET TPA, C
PET TPA, B
PET DMT, C
PET DMT, B
TOTALS
Process
Vents
10
0
5
120
0
0
0
5
0
0
15
0
0
30
1,090
570
300
360
2,510
Storage
Vessels
0
0
1
1
2
0
0
3
1
0
0
0
0
15
3
1
80
40
150
Equipment
Leaksb
20
0
6
40
90
0
0
10
40
0
4
0
0
280
2,030
90
1,690
690
5,000
Wastewater
1
0
1
240
0
0
0
3
0
0
1
0
0
0
1,310
35
270
20
1,880
Cooling
Towers
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1,660
620
850
2,270
5,400
TOTAL
30
0
10
400
90
0
0
20
40
0
20
0
0
330
6,090
1,315
3,190
3,380
14,930
a See abbreviations from Table 5-1.
b These values were determined by estimating equipment counts and applying
SOCMI factors2 adjusted according to LDAR programs.
5-3
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The organic HAP emitted include styrene, butadiene,
acrylonitrile, acetaldehyde, dioxane, methanol, and ethylene
glycol. The quantity of emissions for each individual
organic HAP was not determined, but acrylonitrile and
styrene are estimated to comprise the largest quantity of
emissions. The organic HAP emitted by each subcategory are
identified in Table 5-3.
5-4
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TABLE 5-3.
MAJOR HAZARDOUS AIR POLLUTANTS EMITTED BY
SUBCATEGORY
Subcategory
ABS
SAN
MABS
MBS
Polystyrene
PET
Nitrile
Major HAP
acrylonitrile, butadiene,
Emitted
styrene
acrylonitrile, styrene
acrylonitrile, butadiene,
styrene
butadiene , styrene
styrene
ethylene glycol, methanol
dioxane
, acetaldehyde,
acrylonitrile
5-5
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As described in Chapter 3, organic HAP are emitted from
storage vessels, process vents and process fugitives,
wastewater operations, equipment leaks, and heat exchange
systems to include process contact cooling towers. Process
vents and equipment leaks are the emission points that
comprise the largest portion of these emissions.
Emission estimates were made for each facility in
active operation. Emissions for storage, process vents,
wastewater operations, and process contact cooling towers
were taken directly from information submitted by each
facility. Baseline emissions from equipment leaks were
calculated by using component counts provided by facilities
and emission factors from the EPA's Equipment Leak Protocol
document.2 The level of equipment leak control assumed for
each facility was based either on information submitted
concerning leak detection and repair (LDAR) programs or on
applicable State regulations. More detailed information on
the calculation of baseline emissions for the proposed
NESHAP is contained in the memorandum "Baseline Emissions
Estimates for the Thermoplastics Industry," contained in
Docket No. A-92-45, Category II-D and in the SID. More
detailed information on the calculation of equipment leak
emissions is contained in the memorandum "Determination of
MACT Floors for Equipment Leaks," also contained in Docket
No. A-92-45, Category II-B and in the SID.
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6.0 MACT FLOORS AND REGULATORY ALTERNATIVES
This chapter presents the approach used to determine
MACT floors and regulatory alternatives for the Group IV
thermoplastic subcategories. The Clean Air Act requirements
for the determination of MACT floors are discussed, as well
as the general approach used to determine the MACT floors
and regulatory alternatives. Then, the results of the
analyses are presented.
6.1 CLEAN AIR ACT REQUIREMENTS
The amended Clean Air Act contains requirements for the
development of regulatory alternatives for sources of HAP
emissions. The statute requires the standards to reflect
the maximum degree of reduction in emissions of HAP that is
achievable for new or existing sources. This control level
is referred to as MACT. The amended Clean Air Act also
provides guidance on determining the least stringent level
allowed for a MACT standard; this level is termed the "MACT
floor." Consideration of control levels more stringent than
the MACT floor must reflect consideration of the cost of
achieving the emission reduction, any non-air quality,
health, and environmental impacts, and energy requirements.
For new sources, the standards for a source category or
subcategory "shall not be less stringent than the emission
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control that is achieved in practice by the best controlled
similar source, as determined by the Administrator"
[section 112(d) (3)] . Existing source standards shall be no
less stringent than the average emission limitation achieved
by the best performing 12 percent of the existing sources
for source categories and subcategories with 30 or more
sources or the average emission limitation achieved by the
best performing 5 sources for source categories or
subcategories with fewer than 30 sources [section 112(d)(3)
of the Act]. These two minimum levels of control define the
MACT floor for new and existing sources.
Two interpretations have been evaluated by the EPA for
representing the MACT floor for existing sources. One
interpretation is that the MACT floor is represented by the
worst performing facility of the best 12 percent performing
sources. The second interpretation is that the MACT floor
is represented by the "average emission limitation achieved"
by the best performing sources, where the "average" is based
on a measure of central tendency, such as the arithmetic
mean, median, or mode. This latter interpretation is
referred to as the "higher floor interpretation." In a June
6, 1994 Federal Register notice (59 FR 29196), the EPA
presented its interpretation of the statutory language
concerning the MACT floor for existing sources. Based on a
review of the statute, legislative history, and public
comments, the EPA believes that the "higher floor
6-2
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interpretation" is a better reading of the statutory
language. The determination of the MACT floor for existing
sources under the proposed rule followed the "higher floor
interpretation."
6.2 DETERMINATION OF MACT FLOORS
This section describes the approach taken for
determining the MACT floor for existing and new sources
(Section 6.2.1 and 6.2.2). The final section (Section
6.2.3) discusses the special consideration taken into
account for the requirements of the Polymers NSPS.
For determining both existing and new source MACT
floors, each type of emission point (e.g., storage vessel,
process vent, etc.) within a subcategory was evaluated
separately. The MACT floor for the subcategory is the
composite of these individual types of emission point
specific determinations.
6.2.1 Existing Source MACT Floor
For existing sources, the amended Clean Air Act
requires the standards to be no less stringent then the
average emission limitation achieved by the best performing
5 sources for source categories or subcategories with fewer
than 30 sources. All of the 18 subcategories covered by the
proposed rule have less than 30 sources.
The EPA developed a general approach for evaluating the
MACT floor and determining regulatory alternatives that were
equivalent to or more stringent that the MACT floor for
6-3
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existing sources. This approach was applied to each type of
emission point within each subcategory.
The first step in the general approach for evaluating
the MACT floor and determining regulatory alternatives for
existing sources was to identify the potential types of
emission points for each subcategory and determine which
types of emission points were being controlled at each
facility within the subcategory.
The next step in the general approach was to determine
which facilities were the best performing facilities. For
those subcategories with five or fewer facilities, all of
the facilities represented the "best performing" facilities.
However, for those subcategories with more than five
facilities, the five best performing facilities had to be
identified. This was done by examining the types of control
and the level of emission reductions being achieved (e.g.,
emission factors, percent reductions). For storage vessels,
the EPA examined the level of control, vapor pressure, and
tank capacity to determine which facilities were best
controlled. For process vents, the EPA used percent
emission reduction as the primary indicator of the best
controlled facilities. The EPA evaluated the option of
using emission factors for process vents as the primary
indicator of the best controlled facilities. However, after
considering the variability in the quality of emissions data
and the difficulty of working with confidential business
6-4
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information production rate information, the EPA decided not
to use emission factors as the primary indicator. For
equipment leaks, the EPA used percent reduction based on the
facilities actual LDAR program to identify the best
controlled facilities. For wastewater, the level of control
being applied at each facility was examined. None of the
process contact cooling towers were controlled.
The next step was to determine regulatory alternatives
equivalent to or more stringent than the MACT floor as
reflected in the existing level of control for the "best
performing" facilities. Potential regulatory alternatives
were developed based on the HON, Polymers NSPS (40 CFR part
60, subpart DDD), and the Batch Processes ACT. The HON was
selected because (l) the characteristics of the emissions
from storage vessels, continuous process vents, equipment
leaks, and wastewater at Group IV thermoplastic facilities
are similar or identical to those addressed by the HON and
(2) the levels of control required under the HON were
already determined through extensive analyses to be
reasonable from a cost and impact perspective.
The Polymers NSPS, which covers certain process
emissions at polystyrene and PET facilities using a
continuous process and cooling tower emissions at PET
facilities, was selected for the same basic reasons as the
HON. Although the Polymers NSPS was developed under section
111 of the Clean Air Act and was targeted to control
6-5
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volatile organic compounds (VOC) emissions, the requirements
for setting standards under section 111 are very similar to
the requirements under section 112 of the 1990 Amendments
and all of the HAP identified from polystyrene and PET
facilities are also VOC.
Finally, the Batch Processes ACT was selected to
identify regulatory alternatives for batch process vents,
which are not addressed by either the HON or Polymers NSPS.
As with the Polymers NSPS, the Batch Processes ACT covers
VOC emissions. Again, all of the HAP emissions identified
for the Group IV thermoplastics facilities are also VOC.
Unlike the HON and Polymers NSPS, the Batch Processes ACT is
not a regulation and, therefore, does not specify a level of
control that must be met. Instead, the Batch Processes ACT
provides information on potential levels of control, their
costs, etc. Based on the review of the Batch Processes ACT,
the EPA selected a level of control equivalent to 90 percent
reduction for batch process vents. This level of control
was selected for regulatory analysis purposes because it
represents, for the purposes of the proposed rule, a
reasonable level of control considering costs and other
impacts.
For the reasons stated above, where the HON, Polymers
NSPS, and the Batch Processes ACT are more stringent than
the MACT floor, they represent "ready made" regulatory
alternatives. Furthermore, for the HON and Polymers NSPS,
6-6
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determinations were already made during the development of
those standards that going beyond their control levels was
not reasonable. With regard to batch process vents, the EPA
determined, as noted above, that control above the 90
percent level was not reasonable considering the amount of
additional emission reduction and the cost of achieving that
emission reduction. Thus, the existing regulations and the
Batch Processes ACT have "built in" stopping points as well.
In other words, it was unnecessary to develop and analyze
more stringent regulatory alternatives.
The EPA then determined whether the HON, Polymers NSPS,
or the Batch Processes ACT were more or less stringent than
or equivalent to the MACT floor for each subcategory. This
was done by comparing the MACT floor (reflected in the
existing control level for the best performing 5 facilities)
to the appropriate HON or Polymers NSPS requirements or the
90 percent control level for batch process vents for that
type of emission point for a given subcategory.
To determine the relationship of the MACT floor to the
HON/Batch Processes ACT/Polymers NSPS, several techniques
were used. In most cases, the EPA examined the control/no
control decisions (Groups 1 and 2) for a type of emission
point that resulted from applying the HON/Batch Processes
ACT/Polymers NSPS, and compared the control/no control
results with the existing control level for each of the best
five performing facilities in the subcategory.
6-7
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If the HON/Batch Processes ACT/Polymers NSPS could not
be demonstrated to be at least as stringent as the MACT
floor using this technique, emissions allowed under existing
control levels and emissions allowed under the HON/Batch
Processes ACT/Polymers NSPS were compared and/or the
percentage of uncontrolled emissions meeting the HON/Batch
Processes ACT/Polymers NSPS requirements were determined.
These more quantitative comparisons clarified the stringency
of the MACT floor in relation to the HON/Batch Processes
ACT/Polymers NSPS requirements. (For the details of these
determinations, refer to the MACT floor memoranda in Docket
No. A-92-45, Category II-B and in the SID).
If the applicable HON or Polymers NSPS requirements or
the 90 percent control level for batch process vents were
found to be equivalent to or more stringent than the MACT
floor, then they became part of the first regulatory
alternative for that type of emission point for that
subcategory. (The first regulatory alternative is the least
stringent level of control considered that is more stringent
than, or at least as stringent as, the MACT floor across all
types of emission points.) As noted above, the EPA did not
typically consider additional regulatory alternatives beyond
the HON, Polymers NSPS, or the 90 percent control level for
batch process vents. An exception to this involves process
contact cooling towers at PET facilities, and the rationale
6-8
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for this decision is discussed in Section 6.2.3 and Chapter
8.0.
If the MACT floor was found to be more stringent than
the HON/Batch Processes ACT/Polymers NSPS, it was defined
and became part of the first regulatory alternative for that
subcategory. For these cases, the EPA did not develop a
second regulatory alternative since the MACT floor was
already more stringent than regulatory alternatives already
considered to be reasonable (i.e., above the HON/Batch
Processes ACT/Polymers NSPS control levels).
6.2.2 New Source MACT Floor
For new sources, the 1990 Amendments require that
standards be set that are no less stringent than the level
represented by the best controlled similar source. As for
existing sources, the EPA determined regulatory alternatives
that were equivalent to, or more stringent than the MACT
floor by comparing the MACT floor for each type of emission
point with the appropriate requirements from the HON, Batch
Processes ACT, and Polymers NSPS (as appropriate). If the
HON, Batch Processes ACT, or Polymers NSPS were found to be
equivalent to or more stringent than the MACT floor for a
given type of emission point, then the HON, Batch Processes
ACT, or Polymers NSPS became part of the first regulatory
alternative (Regulatory Alternative 1). However, if the
MACT floor for a given type of emission point was found to
be more stringent than the HON, Batch Processes ACT, and
6-9
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Polymers NSPS, the EPA defined the MACT floor for new
sources for that type of emission point and it became part
of the first regulatory alternative.
The EPA constructed the first regulatory alternative
for all subcategories by including in it the best level of
control identified for each type of emission point within
the subcategory using the procedure described above. In a
single case, a more stringent regulatory alternative was
identified for one subcategory--storage tanks at facilities
producing ABS using a continuous mass process. The
rationale for developing and accepting this regulatory
alternative is presented in Chapter 8.0.
6.2.3 Special Considerations
6.2.3.1 Polymers NSPS
The Polymers NSPS affects some process emissions from
new polystyrene facilities using a continuous process and
some process emissions from new PET facilities using a
continuous process. (It also affects emissions from process
contact cooling towers at new PET facilities using a
continuous process; this is discussed in more detail later.)
These process emission provisions have the potential to be
more stringent than the HON and were considered in
developing regulatory alternatives for both existing and new
polystyrene and PET facilities using a continuous process.
The applicability criteria for modified and reconstructed
6-10
-------
sources, which includes a threshold emission rate, was
considered for the analysis of existing facilities.
Threshold emission rates were developed under the
Polymers NSPS to set a point at which it was not cost
effective to require an existing source (i.e., modified or
reconstructed) to meet the emission limits. However,
analysis showed that with one exception, sources subject to
the proposed rule were meeting the Polymers NSPS emission
limits. For those situations where affected sources are
meeting the Polymers NSPS emission limits, the emission
limits became part of the MACT floor for existing sources,
and threshold emission rates are not required as part of
implementing the emission limits from the Polymers NSPS.
For those situations where affected sources are not meeting
the Polymers NSPS emission limits (i.e., process vents
associated with material recovery at PET facilities using a
continuous DMT process), the threshold emission rate
developed under Polymers NSPS is used in implementing these
emission limits. The analysis of new facilities entailed
comparing the appropriate process vent emissions against the
emission limits. In all cases, the best performing affected
source was already meeting the polymers NSPS emission
limits.
6.2.3.2 Process Contact Cooling Towers
The Polymers NSPS limits the ethylene glycol
concentration in the cooling tower water as the means for
6-11
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controlling emissions from process contact cooling towers at
new PET facilities using a continuous process. These
provisions are not included as a regulatory alternative,
because other techniques (which are described below) were
identified for controlling emissions from process contact
cooling towers and were determined to be both more effective
and less costly. The EPA used one of these alternatives,
the use of ethylene glycol jets in place of steam jets in
the vacuum system, to estimate costs for a regulatory
alternative that eliminates the use of cooling tower water
in vacuum system contact condensers for all PET facilities.
With few exceptions, large volumes of organic HAP-
contaminated wastewater (i.e., condensate) are generated at
PET facilities through the use of contact barometric
intercondensers in the steam jet vacuum system. At most
facilities, this wastewater stream is recycled through a
process contact cooling tower, potentially making the
cooling tower a major emission source. The EPA believes
there are several technically feasible methods for
eliminating/minimizing emissions from vacuum system
generated wastewater. These methods are briefly discussed
in the following paragraphs.
First, there is the technique of using ethylene glycol
jets in place of steam jets in the vacuum system. Ethylene
glycol jets are considered a pollution prevention technique
in that they prevent the creation of the vacuum system
6-12
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wastewater stream. Instead of using steam in the vacuum jet
as the motivating gas, ethylene glycol vapor is used.
Contaminated ethylene glycol is sent to the ethylene glycol
recovery system.
Second, mechanical vacuum pumps can be used. Like the
first technique, mechanical vacuum pumps are a pollution
prevention technique since it prevents the creation of the
vacuum system wastewater stream.
Third, non-contact condensers can be used in place of
the typical contact barometric intercondensers with steam
jet vacuum systems. This technique does not prevent the
creation of the vacuum system wastewater stream, but it
serves to minimize emissions since only the steam condensate
is HAP-contaminated and the condensed stream is not sent to
the cooling tower. To achieve emission reductions
approximately equivalent to the previous two techniques, the
vacuum system wastewater stream, if it contains any organic
HAP specified in Table 9 of the HON wastewater provisions,
would be required to meet the control level required for a
Group 1 wastewater stream, regardless of the organic HAP
concentration or flowrate.
As discussed later, the EPA has based its decision to
prohibit the use of cooling tower water in contact
condensers on the level of emission reductions and costs
associated with the use of the ethylene glycol jet system.
The EPA believes the other techniques identified above can
6-13
-------
achieve equivalent control at less expense and, in some
cases, may be more technically feasible for retrofitting
existing facilities than the ethylene glycol jet system. It
is also possible that other techniques exist (or could be
developed) that could substantially eliminate the emissions
of organic HAP from the vacuum system. If such a system
could be demonstrated to be equivalent to the techniques
described above, it would not be necessary to prohibit the
use of cooling tower water in the vacuum system contact
condensers.
In the preamble to the proposed rule, the EPA solicited
comments on the emission reduction potential, costs, and
technical feasibility of all control options for process
contact cooling towers at PET facilities. The EPA requested
that .any comments on alternate control options address the
emissions from the cooling tower, the emissions from any
wastewater discharged from the equipment required by the
control option, and any "reactor process" or "distillation
column" vent emissions associated with the control option.
As a means of complying with the proposed prohibition
of cooling tower water in contact condensers at PET
facilities, the EPA has identified three alternative vacuum
systems (as discussed above) that will allow a facility to
meet its vacuum requirements without the need for a process
contact cooling tower. One of the options -- use of non-
contact condensers in place of the contact barometric
6-14
-------
intercondensers -- will not eliminate the vacuum system
generated wastewater stream, but will minimize the volume of
the wastewater created to that of the steam condensate
alone. Further, this option prohibits exposing the
wastewater stream to the atmosphere since it can no longer
be recycled through the cooling tower. (The HON prohibits
exposing Group 1 wastewater stream to the atmosphere prior
to control,
Applying the HON wastewater provisions applicability
criteria to this vacuum system generated wastewater stream
might result in some wastewater streams being uncontrolled.
For these instances, it is possible that emissions at these
facilities will be greater than the emissions that would be
emitted at facilities using ethylene glycol jets. Thus, the
use of non-contact condensers by themselves would not result
in equivalent emission reductions. Therefore, the proposed
rule requires that all vacuum system generated wastewater
streams that contain any organic HAP specified in Table 9 of
the HON wastewater provisions be considered Group 1
wastewater streams, regardless of the organic HAP
concentration and flowrate; these streams would be required
to meet the wastewater control level required for Group 1
wastewater streams.
6.3 RESULTS OF MACT FLOOR DETERMINATION
Tables 6-1 and 6-2 present the results of the MACT
floor analysis and identify the selected regulatory
6-15
-------
alternatives for storage vessels, process vents, and
wastewater. The "MACT Floor Stringency" column on Tables 6-
1 and 6-2 reflect the comparison of the MACT floor to the
selected set of rules/guidances (i.e., HON Batch Processes
ACT/Polymers NSPS). If this column indicates "<", this
means that the MACT floor, as reflected in the existing
level of control, is less stringent than the selected set of
rules/guidances. If this column indicates "=", this means
that the MACT floor is equivalent to the selected set of
rules/guidances, and a ">" means the MACT floor is more
stringent than the selected set of rules/guidances.
6-16
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TABLE 6-1. MACT FLOOR ANALYSIS FOR EXISTING SOURCES3
Subcategory
ABS, Ce
ABS, Cm
ABS, Be
ABS, Bs
ABS, Bl
MASS
MBS
SAN, C
SAN, B
ASA/AMSAN
PS, C
Storage Vessels
MACT
Floor Regulatory
Stringency13 Alternative
HON
HON
= HON
HON
HON
a HON
HON
HON
HON
> MACT Floor
> MACT Floor
Process Vents
MACT Floor Regulatory
Stringency11 Alternative
a HON/ Batch
ACT
a HON/Batch
ACT
HON/Batch
ACT
a HON/Batch
ACT
a HON/Batch
ACT
HON/Batch
ACT
> MACT Floor
a HON/Batch
ACT
HON/Batch
ACT
> MACT Floor
HON/NSPS/
Batch ACT
Wastewater Streams
MACT
Floor Regulatory
Stringency* Alternative
HON
a HON
HON
a HON
a HON
a HON
a HON
a HON
** HON
< No control0
a HON
6-17
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TABLE 6-1. MACT FLOOR ANALYSIS FOR EXISTING SOURCES* (Concluded)
Subcategory
PS, B
EPS
PET, TPA, C
PET, TPA, B
PET, DMT, C
PET, DMT, B
Nitrile
Storage Vessels
MACT
Floor Regulatory
Stringency* Alternative
a HON
« HON
a HON
a HON
a HON
a HON
> MACT Floor
Process Vents
MACT Floor Regulatory
Stringency*5 Alternative
< HON/Batch
ACT
HON/Batch
ACT
HON/NSPS/
Batch ACT
= HON/Batch
ACT
HON/NSPS/
Batch ACT
HON/Batch
ACT
< HON/Batch
ACT
Wastewater Streams
MACT
Floor Regulatory
Stringency13 Alternative
a HON
a HON
a HON
a HON
a HON
=» HON
a HON
a In all cases, the MACT floor for equipment leaks was less stringent than the HON.
b As compared to the selected set of rules/guidances.
c It is a policy decision to not accept the control level from the selected set of rules/guidances
The reasons for this decision are discussed in Chapter 8.0.
6-18
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TABLE 6-2, MACT FLOOR ANALYSIS FOR NEW SOURCES8
Subcategory
ABS, Ce
ABS, Cm
ABS, Be
ABS, Bs
ABS, Bl
MABS
MBS
SAN, C
SAN, B
ASA/AMSAN
Storage Vessels
MACT
Floor Regulatory
Stringency* Alternative
HON
> Regulatory
Alternative
HON
HON
HON
HON
HON
> MACT Floor
HON
> MACT Floor
Process Vents
MACT
Floor Regulatory
Stringency*3 Alternative
= HON/Batch
ACT
HON/Batch
ACT
HON/Batch
ACT
HON/Batch
ACT
= HON/Batch
ACT
= HON/Batch
ACT
MACT Floor
HON/Batch
Act
> MACT Floor
> MACT Floor
Wastewater Streams
MACT
Floor Regulatory
Stringency1* Alternative
sa HON
* HON
« HON
« HON
= HON
= HON
= HON
« HON
« HON
< No controlc
6-19
-------
TABLE 6-2. MACT FLOOR ANALYSIS FOR NEW SOURCES3 (Concluded)
Subcategory
PS, C
PS, B
EPS
PET, TPA, C
PET, TPA, B
PET, DMT, C
PET, DMT, B
Nitrile
Storage Vessels
MACT
Floor Regulatory
Stringency*" Alternative
> MACT Floor
« HON
HON
HON
HON
HON
HON
> MACT Floor
Process Vents
MACT
Floor Regulatory
Stringency* Alternative
HON/NSPS/
Batch ACT
< HON/Batch
ACT
* HON/Batch
ACT
HON/NSPS/
Batch ACT
« HON/Batch
ACT
HON/NSPS/
Batch ACT
= HON/Batch
ACT
< HON/Batch
ACT
Wastewater Streams
MACT
Floor Regulatory
Stringency13 Alternative
= HON
« HON
a HON
a HON
a HON
HON
a HON
a HON
a In all cases, the MACT floor for equipment leaks was less stringent than the HON.
b As compared to the selected set of rules/guidances.
b It is a policy decision to not accept the control level from the selected set of rules/guidances
or to go beyond the MACT floor. The reasons for this decision are discussed in Chapter 8.0.
6-20
-------
For existing storage vessels, the analysis found that
for 15 out of the 18 subcategories, the MACT floor was less
stringent than or equivalent to the selected set of
rules/guidances. For the remaining three cases, the MACT
floor was determined to be more stringent than the selected
set of rules/guidances. This information, along with the
same information for process vents and wastewater, is
presented in Table 6-3. In all cases, the MACT floor for
equipment leaks was less stringent than the HON.
6-21
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TABLE 6-3. SUMMARY OF MACT FLOOR STRINGENCY
Existing Subcategories
c
Storage 0 15 3
Vessels
Process 2 14 2
Vents
Wastewater 1 17 0
Streams
New Subcategories
c
0 13 5
2 14 2
1 17 0
Number of Subcategories where MACT floor is less
stringent than selected set of rules/guidances
MACT floor equivalent to selected set of
rules/guidances.
MACT floor more stringent than selected set of
rules/guidances.
6-22
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The MACT floor analysis for process contact cooling
towers associated with PET production followed the
methodology described in Section 6.2, however, quickly
deviated from it due the availability of a more stringent,
cost effective option. The MACT floor for process contact
cooling towers at existing sources, as reflected in the
existing control level, was qualitatively compared to the
cooling tower provisions of the Polymers NSPS and found to
be less stringent. (Note: None of the facilities that had
process contact cooling towers controlled emissions from
this emission point.) For new sources, the MACT floor was
based on a facility that used ethylene glycol jets, as
opposed to steam jets, and did not have a cooling tower. In
addition to eliminating the need for a cooling tower, the
use of ethylene glycol jets prevents the generation of the
vacuum system wastewater stream(s). This level of control
was compared to the Polymers NSPS cooling tower provisions
and found to be more stringent. Therefore, the MACT floor
for new sources was informally defined (i.e., not defined in
regulatory terms) as "no process contact cooling tower" and
"no vacuum system wastewater." This option was then
considered as a regulatory alternative for existing sources
and was found to be a cost effective option.
6-23
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7.0 SUMMARY OF ENVIRONMENTAL, ENERGY, COST, AND ECONOMIC
IMPACT
This section presents the air, non-air environmental
(waste and solid waste), energy, cost, and economic impacts
resulting from the control of organic HAP emissions under
the proposed rule.
7.1 FACILITIES AFFECTED BY THESE NESHAP
The proposed rule would affect ABS, SAN, MASS, MBS,
polystyrene, PET, and nitrile facilities that are major
sources in themselves, or that are located within a major
source. Based on available information, all of the
facilities at which these thermoplastics are produced were
judged to be major sources for the purpose of developing
these standards. (Final determination of major source
status occurs as part of the compliance determination
process undertaken by each individual source.)
Impacts are presented relative to a baseline reflecting
the level of control in the absence of the rule. The
current level of control was well understood since emissions
and control data were collected on each facility included in
the analysis. The estimates of impacts include applying
control to: (1) existing facilities and (2) new facilities
(i.e., those that are expected to begin operation through
1999).
7-1
-------
The expected growth rate in each of the seven listed
source categories was analyzed (see the impacts memorandum
in Docket No. A-92-45, Category II-B). Based on this
analysis, the following average annual growth rates (percent
per year) through 1999 were estimated:
• ABS - 4 percent
• SAN - 4 percent
• MABS - 3 percent
• MBS - 3 percent
• polystyrene - 3 percent
• PET - 10 percent for bottle-grade resins and 4
percent for other PET resins
• nitrile - 3 percent.
The impacts for existing sources were estimated by
bringing each facility's control level up to the proposed
standards. For new sources, impacts were based on
identifying the number of new facilities required to meet
the expected growth within the source category, identifying
the types of facilities (e.g., batch versus continuous) that
would be built, and then selecting a subset of the existing
facilities to represent the expected growth. The impacts on
these "new" facilities were determined by applying the
proposed standards for new sources to the selected subset of
facilities assuming the existing level of control. This
methodology is discussed in detail in the impacts memorandum
7-2
-------
contained in Docket No. A-92-45, Category II-B and in the
SID.
7.2 PRIMARY AIR IMPACTS
The proposed standards are estimated to reduce organic
HAP emissions from all existing sources by 11,750 Mg/yr from
a baseline level of 24,780 Mg/yr. This is a 47 percent
reduction. For new facilities, the proposed standards are
estimated to reduce organic HAP emissions by 7,395 Mg/yr
from a baseline level of 14,920 Mg/yr, for a 50 percent
reduction. Table 7-1 summarizes the organic HAP emission
reductions for each individual subcategory.
7-3
-------
TABLE 7-1. ORGANIC HAP EMISSIONS AND EMISSION REDUCTIONS
Subcategory
ABS, continuous mass
ABS, continuous emulsion'
ABS, batch emulsion
ABS, batch suspension
ABS, latex
SAN, continuous
SAN, batch
ASA/AKSAN
NABS*
MBS
Polystyrene, continuous
Polystyrene, batch
Expandable polystyrene
PET-TPA, continuous
PET-TPA, batch*
PET -DMT, continuous
PET-DMT, batch
Uitrile
Totals"
Existing Sources
Baseline,
Mg/yr
240
1,110
500
15
3
110
35
100
86
190
1,440
190
450
6,090
1,310
4,480
8,400
30
24,780
Emission
Reduction,
Mp/yr
190
>180
56
5
2
65
13
94
>38
130
1,060
130
92
2,400
>6
2,330
4,950
10
11,750
Percent
Reduction
SOX
>16%
11%
33%
67%
60%
37%
94%
>44%
68%
74%
68%
20%
40%
>1%
52%
59%
33%
47%
New Sources
Baseline,
Mg/yr
95
400
35
13
--
40
20
--
--
20
330
"
••
6,090
1,310
3,190
3,380
--
14,920
Emission
Reduction,
Ms/yr
87
>115
15
5
..
25
6
..
,.
16
240
--
,.
2,200
»6
1,810
2,870
--
7,395
Percent
Reduction
92%
>29%
43%
38%
--
63%
30%
--
--
80%
73%
--
--
36%
>1%
57%
85%
--
50%
--No new growth projected,
* A portion of the emission
* Total values are affected
therefore, no impacts expected.
reductions for this subcategory are confidential business information.
by the subcategories for which some data are confidential business information.
7-4
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7.3 NON-AIR ENVIRONMENTAL IMPACTS
The proposed standards are not expected to generate any
adverse water impacts. Depending on the methods selected to
comply with the proposed prohibition of cooling tower water
in contact condensers, the amount of wastewater generated at
PET facilities could decrease.
The proposed standards are not expected to increase the
generation of solid waste at any Group IV thermoplastic
facility.
7.4 ENERGY IMPACTS
Energy impacts include increased energy use (fuel) for
the operation of control equipment, energy credits
attributable to the prevention of organic HAP emissions from
equipment leaks, and emissions of particulates, sulfur
dioxides (SOX) , and nitrogen oxide (NOX) (secondary air
impacts) associated with increased energy use. Under the
proposed rule, energy use is expected to increase by
approximately 30,000 barrels of oil per year for existing
sources and 44,000 for new sources. The emissions of
secondary air pollutants associated with this energy
increase are 70 Mg/yr for existing sources and 80 Mg/yr for
new sources. At the same time, energy credits attributable
to the prevention of organic HAP emissions from equipment
leaks are approximately 17,000 barrels of oil per year for
existing sources and 8,000 for new sources. This results in
7-5
-------
a net increase of approximately 13,000 barrels of oil per
year for existing sources and 36,000 for new sources.
These figures are related to the control of process
vents, wastewater operations, and equipment leaks. Energy
impacts related to storage vessels were not estimated since
many storage vessels would be controlled through the use of
internal floating roofs which do not have any associated
*
energy impacts. Further, the estimates above do not include
the projected energy savings associated with control of
emissions from process contact cooling towers and vacuum
system wastewater associated with the manufacture of PET.
The majority of existing vacuum systems are operated with
steam jets, which are very energy intensive. The precise
affect of the proposed rule on the use of steam jets cannot
be predicted with accuracy. However, it is anticipated by
the EPA that compliance with the proposed rule will, in
almost all cases, decrease the energy demand of the vacuum
systems.
Given the relatively small energy impacts projected for
the control of process vents, wastewater operations, and
equipment leaks and the projected energy savings associated
with control of vacuum system air emissions, the EPA has
judged the energy impacts associated with the proposed rule
to be acceptable.
7-6
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7.5 COST IMPACTS
Cost impacts include the capital costs of new control
equipment, the cost of energy (supplemental fuel, steam, and
electricity) required to operate control equipment,
operation and maintenance costs, and the cost savings
generated by reducing the loss of valuable product in the
form of emissions. Also, cost impacts include the costs of
monitoring, recordkeeping, and reporting associated with the
proposed standards. Average cost effectiveness ($/Mg of
pollutant removed) is also presented as part of cost impacts
and is determined by dividing the annual cost by the annual
emission reduction. Table 7-2 presents the estimated
capital and annual costs and average cost effectiveness by
subcategory.
7-7
-------
TABLE 7-2. SUMMARY OF COST IMPACTS
Subcategory
ABS, continuous mass
ABS, continuous emulsion'
ABS, batch emulsion
ABS, batch suspension
ABS, latex
SAN, continuous
SAN, batch
ASA/AMSAN
MABS9
MBS
Polystyrene, continuous
Polystyrene, batch
Expandable polystyrene
PET-TPA, continuous
PET-TPA, batch"
PET -DMT, continuous
PET -DMT, batch
NitrUe
Totals"
Existing Sources
Total Capital
Cost, $1000
210
>3,540
430
28
0.5
450
SO
550
90
550
770
300
110
40,790
>30
28,250
22,080
9
98,270
Total Annual
Costs,
$1000/yr
100
»1,300
310
19
-0.5
160
33
200
>-2
360
280
160
50
2,970
>18
3,010
3,360
7
12,330
Average
Cost-
Effectiveness
CS/Mg)
550
<7, 160
5,550
3,170
-240
2,520
2,520
2,150
>-50
2,720
260
1,270
540
1,230
<3,180
1,300
680
660
1,050
New Sources
Total Capital
Cost, $1000
150
>3,490
18
28
--
180
1
--
--
440
200
--
--
2,160
>30
2,200
1,440
--
10,340
Total Annual
Costs,
$1000/yr
38
>1,73Q
14
19
,,
38
-1.3
..
--
234
90
..
..
-3,926
>18
-970
-38
..
-2,750
Average
Cost-
Effectiveness
($/Mg)
430
<14,970
960
3,760
--
1,490
-210
--
--
14,200
350
--
--
-1,770
<3,180
-540
-13
--
-370
--No new growth projected, therefore no impacts expected.
* A portion of the costs and/or emission reductions for this subcategory are confidential business information.
6 Total values are affected by the subcategories for which some data are confidential business information.
7-8
-------
Under the proposed rule, it is estimated that total
capital costs for existing sources would be $98 million
(1989 dollars), and total annual costs would by $12.3
million (1989 dollars) per year. It is expected that the
actual compliance cost impacts of the proposed rule would be
less than presented because of the potential to use common
control devices, upgrade existing control devices, use other
less expensive control technologies, implement pollution
prevention technologies, or use emissions averaging. Since
the effect of such practices is highly site-specific and
data were unavailable to estimate how often the lower cost
compliance practices could be utilized, it is not possible
to quantify the amount by which actual compliance costs
would be reduced.
7.6 ECONOMIC IMPACTS
The economic impact analysis for the selected
regulatory alternatives shows that the estimated price
increases for the affected chemicals range from 0.1 percent
for nitrile to 2.8 percent for SAN. Estimated decreases in
output range from 0.1 percent for polystyrene to 4.6 percent
for SAN. Net annual exports (exports minus imports) are
predicted to decrease by an average of 2.5 percent.
As many as five PET facilities and one ABS facility are
at risk of discontinuing PET and ABS production,
respectively, due to the burden of compliance with the
standard. This does not mean that the facilities affected
7-9
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face the risk of closure. The facilities affected will
continue to produce other chemicals whose processes are not
affected by this standard.
Three assumptions in the analysis likely lead to an
overestimate of the number of facilities at risk of
discontinuing production of affected chemicals. First, the
economic analysis model assumes that all PET and ABS
facilities compete in a national market, though in reality
some facilities may be protected from some competitors by
regional or local trade barriers.
Second, it is assumed that the facilities with the
highest control cost per unit of production also have the
highest baseline production costs per unit. This assumption
may not always be true since the baseline production costs
per unit are not known, and thus the estimated number of
facilities that would discontinue production of affected
chemicals may be too high.
Third, for the production of PET, the selected
regulatory alternative includes the control of organic HAP
emissions from the vacuum system and process contact cooling
tower. Control of these emissions is the highest cost item
in the selected regulatory alternative and is the biggest
contributor to the risk of facilities discontinuing PET
production. The economic analysis is based on the use of
ethylene glycol jets to control these emissions. There are
a number of potential control technologies for these
7-10
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emissions that are expected by the EPA to have lower costs,
but costs for these control technologies were not
calculated. Ethylene glycol jets are being used by at least
two facilities and data were available from one facility.
The EPA has and will continue to investigate other control
technologies for control of these emissions. The EPA
invites comment and data on other control technologies.
7-11
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8.0 SELECTION OF THE STANDARDS
The purpose of this chapter is to provide the rationale
for the selection of the standards for the Group IV
thermoplastic subcategories. In order to provide background
for the subsequent discussions, the first section of this
chapter is a summary of the proposed rule. This is followed
by a discussion of the rationale for the selection of the
level and format of the standards and the compliance,
reporting, and recordkeeping provisions.
The format, reporting, recordkeeping, and compliance
provisions of the proposed standards are primarily a result
of the method used to determine MACT floors and regulatory
alternatives. In other words, the decision to use the HON,
the Batch Processes Act, and the Polymers NSPS in
determining the MACT floors and regulatory alternatives
predetermined that the proposed standards would resemble
these standards. A description of the approach used to
determine MACT floors and regulatory alternatives is
provided in Chapter 6.
8.1 SUMMARY OF THE PROPOSED STANDARDS
This section provides a summary of the proposed
standards. The full regulatory text is available in Docket
No. A-92-45, directly from the EPA, or from the Technology
8-1
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Transfer Network (TTN) on the EPA's electronic bulletin
boards. More information on how to obtain a copy of the
proposed standards are provided in the preamble.
8.1.1 Source Categories to be Regulated
The proposed standards would regulate organic HAP
process emissions from facilities in one of the 18
thermoplastic subcategories listed below, provided that a
facility is determined to be a major source. For the
proposed rule, an affected source is defined as one of the
following:
• All organic HAP emission points at a facility using
a continuous emulsion process to produce ABS.
• All organic HAP emission points at a facility using
a continuous mass process to produce ABS.
• All organic HAP emission points at a facility using
a batch emulsion process to produce ABS.
• All organic HAP emission points at a facility using
a batch suspension process to produce ABS.
• All organic HAP emission points at a facility using
a batch latex process to produce ABS.
• All organic HAP emission points at a facility
producing MABS,
• All organic HAP emission points at a facility
producing MBS.
• All organic HAP emission points at a facility using
a continuous process to produce SAN.
• All organic HAP emission points at a facility using
a batch process to produce SAN.
• All organic HAP emission points at a facility
producing ASA/AMSAN.
• All organic HAP emission points at a facility using
a continuous process to produce polystyrene.
8-2
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• All organic HAP emission points at a facility using
a batch process to produce polystyrene.
• All organic HAP emission points at a facility
producing EPS.
• All organic HAP emission points at a facility using
a continuous TPA process to produce PET and any
collocated solid state processes.
• All organic HAP emission points at a facility using
a batch TPA process to produce PET and any
collocated solid state processes.
• All organic HAP emission points at a facility using
a continuous DMT process to produce PET and any
collocated solid state processes
• All organic HAP emission points at a facility using
a batch DMT process to produce PET and any
collocated solid state processes.
• All organic HAP emission points at a facility
producing nitrile resins.
The proposed rule regulates emissions from solid state
PET processes if they are collocated with a TPA or DMT fed
PET process, but does not regulate emissions from
independently located solid state PET processes (i.e., those
that purchase low molecular weight PET from an off-site
source). As part of the rulemaking, information was
submitted by the industry for collocated solid state PET
processes, but none was submitted for independently located
solid state PET processes. (Note: the data request did not
distinguish solid state as a separate process which might
have precipitated companies not submitting data concerning
PET produced by this process.) In addition, the EPA
believes that independently located solid state PET
processes are likely to be non-major sources because there
8-3
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is not a significant source of organic HAP emissions from
the solid state process. The emissions from a solid state
process are typically the result of release of residual
monomer in the low molecular weight PET. For these reasons,
the EPA chose not to include independently located solid
state PET processes in the proposed rule.
8.1.2 Relationship to Other Rules
Sources subject to the proposed rule are also subject
to other existing rules. In some cases, the proposed rule
supersedes existing rules and affected sources are no longer
required to comply with the existing rule. In other cases,
there is no conflict between the existing rule and the
proposed rule, and in these cases, the affected source must
comply with both rules.
Sources subject to the proposed rule and subject to the
NESHAP for Certain Processes Subject to the Negotiated
Regulation for Equipment Leaks (40 CFR part 63, subpart I)
are required to continue to comply with subpart I until the
compliance date of the proposed rule. After the compliance
date of the proposed rule, compliance with the proposed rule
will constitute compliance with subpart I.
Sources subject to the proposed rule may have storage
vessels subject to the NSPS for Volatile Organic Liquid
Storage Vessels (40 CFR part 60, subpart Kb). After the
compliance date for the proposed rule, such storage vessels
8-4
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are only subject to the proposed rule and are no longer
required to comply with subpart Kb.
Some sources subject to the proposed rule that produce
PET polymers or polystyrene are also subject to the NSPS (40
CFR part 60, subpart DDD). After the compliance date for
the proposed rule, such affected sources are only subject to
the proposed rule and are no longer required to comply with
the Polymers NSPS. As part of this rulemaking, it is
proposed to modify subpart DDD to exclude reference to the
manufacture of polystyrene and PET.
Sources subject to the proposed rule may have cooling
towers subject to the NESHAP for Industrial Cooling Towers
(40 CFR part 63, subpart Q). There is no conflict between
the requirements of subpart Q and the proposed rule.
Therefore, sources subject to both rules must comply with
both rules.
8.1.3 Pollutants to be Regulated
The subcategories covered by the proposed rule emit a
variety of organic HAP. Among the most significant
emissions of organic HAP are the following: styrene,
acrylonitrile, and butadiene from styrene-based resin
production, which includes the production of ABS, SAN, MABS,
MBS, and polystyrene; acrylonitrile from nitrile resin
production; and ethylene glycol, methanol, acetaldehyde, and
dioxane from PET production. The proposed standards would
8-5
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regulate emissions of these compounds, as well as a variety
of other organic HAP that are emitted.
8.1.4 Affected Emission Points
Emissions from the following types of emission points
are being covered by the proposed rule: storage vessels,
process vents, equipment leaks, wastewater operations, and
heat exchange systems to include process contact cooling
towers.
8.1.5 Proposed Standards
With relatively few exceptions, the standards being
proposed for storage vessels, continuous process vents,
equipment leaks, wastewater operations, and heat exchange
systems are the same as those promulgated for the
corresponding type of emission point at facilities subject
to the HON (40 CFR 63, subparts F, G, H, and I). The
proposed standards also require emissions from batch process
vents to be reduced by at least 90 percent or to be
controlled in a flare that meets the requirements of
§63.1Kb) of subpart A of 40 CFR part 63. (The criteria
used to determine which batch process vents require control
was based on the approach described in the Batch Processes
ACT.) The standards being proposed today for certain
continuous process vents from polystyrene facilities and
from PET facilities using a continuous process require the
same levels of control as were promulgated for these
facilities under the Polymers NSPS. Finally, for PET
8-6
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facilities, the proposed standards would prohibit the use of
cooling tower water in contact condensers in the vacuum
systems and would require that all vacuum system wastewater
containing any of the organic HAP identified in Table 9 of
the HON wastewater provisions be controlled to the same
level of control as required under the HON, regardless of
the wastewater streams organic HAP content or flowrate.
Under the proposed standards, emissions from existing
or new batch process vents, heat exchange systems excluding
process contact cooling towers, and equipment leaks are
required to be controlled to the levels specified in the
proposed standards. Emissions from existing storage
vessels, continuous process vents, process wastewater
streams, and process contact cooling towers are required to
be controlled to the levels specified in the proposed
standards or alternatively, the emissions averaging
compliance approach specified in the rule may be used.
Emissions from new storage vessels, continuous process
vents, process wastewater streams, and process contact
cooling towers are required to be controlled to the levels
specified in the proposed standards. The emissions
averaging compliance approach may not be used for new
sources.
Tables 8-1 and 8-2 summarize the level of control being
proposed. For those types of emission points where the
level of control is the same as the HON, this is indicated
8-7
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TABLE 8-1.
SUMMARY OF PROPOSED STANDARDS FOR EXISTING SOURCES IN RELATIONSHIP TO
SUB PARTS G AND H of 40 CFR PART 63 AND THE POLYMERS NSPS
Subcategory
ABS, continuous
emulsion
ABS, continuous mass
ABS, batch emulsion
ABS, batch suspension
ABS, latex
MABS
MBS
SAN, continuous
SAN, batch
ASA/AMSAN
Type of Emission Point
Storage vessels
HON
HON
HON
HON
HON
HON
HON
HON
HON
HACT Floor
Process Vents
HON
Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
compliant flare
Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
compliant flare
Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
compliant flare
Continuous Process Vents: HON
Batch Process Vents: 90X reduction or
compliant flare
Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
compliant flare
Continuous Process Vents: MACT Floor
Batch Process Vents: 90% reduction or
compliant flare
Continuous Process Vents: NON
Batch Process Vents: 90% reduction or
compliant flare
Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
compliant flare
MACT Floor
Equipment
Leaks
HON
HON
HON
HON
HON
HON
HON
HON
HON
HON
Wastewater
HON
HON
HON
HON
HON
HON
HON
HON
HON
No control
Heat Exchange
Systems
HON for heat
exchange
systems.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
8-8
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TABLE 8-1. SUMMARY OF PROPOSED STANDARDS FOR EXISTING SOURCES IN RELATIONSHIP TO
SUBPARTS G AND H of 40 CFR PART 63 AND THE POLYMERS NSPS (Continued)
Subcategory
Polystyrene,
continuous
Polystyrene, batch
Expandable polystyrene
PET-TPA, continuous
PET - TPA, batch
- DMT, batch
Type of Emission Point
Storage vessels
MACT Floor
HON
HON
NON
HON
Process Vents
Continuous Process Vents from material
recovery: same as subpart ODD
Other Continuous Process vents: HON
Batch Process Vents: 90% reduction or
compliant flare
Continuous Process Vents: NON
Batch Process Vents: 90% reduction or
compliant flare
Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
compliant flare
Continuous Process Vents from raw
material preparation and polymerization
reaction sections: same as subpart ODD
Other Continuous Process vents: HON
Batch Process Vents: 9QX reduction or
compliant flare
Continuous Process Vents: NON
Batch Process Vents: 90S reduction or
compliant flare
Equipment
Leaks
HON
HON
HON
HON
HON
Wastewater
HON
HON
HON
HON for
wastewater
(including all
vacuum system
generated
wastewater). "
HON for
wasteuater
(including all
vacuum system
generated
wastewater ).b
Heat Exchange
Systems
HON for heat
exchange
systems .
HON for heat
exchange
systems.
HON for heat
exchange
systems.
No cooling
tower Mater
allowed in
vacuum system
contact
condensers. HON
for heat
exchange
systems.
No cooling
toner uater
allowed in
vacuum system
contact
condensers.
HON for heat
exchange
systems.
8-9
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TABLE 8-1. SUMMARY OF PROPOSED STANDARDS FOR EXISTING SOURCES IN RELATIONSHIP TO
SUBPARTS G AND H of 40 CPR PART 63 AND THE POLYMERS NSPS (Continued)
Subcategory
PET - DHT, continuous
Nitrile
Type of Emission Point
Storage vessels
HON
HACT Floor
Process Vents
Continuous Process Vents from material
recovery and polymerization reaction
sections: same as subpart ODD
Other Continuous Process vents: HON
Batch Process Vents: 90% reduction or
compliant flare
Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
compliant flare
Equipment
Leaks
HON
HON
Wastewater
HON for
wastewater
(including all
vacuum system
generated
uastewater).
HON
Heat Exchange
Systems
No cooling
tower water
allowed in
vacuum system
contact
condensers.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
Vacuum System wastewater streams containing any organic
considered Group 1 and are required to be controlled.
HAP identified in Table 9 of the HON wastewater provisions (subpart G) shall be
8-10
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TABLE 8-2.
SUMMARY OF PROPOSED STANDARDS FOR NEW SOURCES IN RELATIONSHIP TO SUBPARTS
G & H of 40 CFR PART 63 AND THE POLYMERS NSPS
Subcategory
ABS, continuous
emulsion
ABS, continuous mass
ABS. batch emulsion
ABS. batch suspension
ABS, latex
MASS
MBS
SAN, continuous
SAN, batch
ASA/AMSAN
Type of Emission Point
Storage vessels
HON
Regulatory
Alternative 2a
HON
KON
HON
HON
HON
MACT Floor
HON
MACT Floor
Process Vents
Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
a compliant flare
Continuous Process Vents; HON
Batch Process Vents: 90% reduction or
a compliant flare
Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
a compliant flare
Continuous Process Vents; HON
Batch Process Vents: 90% reduction or
a compliant flare
Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
a compliant flare
Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
a compliant flare
Continuous Process Vents: HON
Batch Process Vents: 90X reduction or
a compliant flare
Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
a compliant flare
MACT Floor
MACT Floor
Equipment
Leaks
HON
HON
HON
HON
HON
HON
HON
HON
HON
HON
Uastewater
HON
HON
HON
HON
HON
HON
KON
HON
HON
No control
Heat Exchange
Systems
HON for heat
exchange
systems.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
HOH for heat
exchange
systems .
HON for heat
exchange
systems.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
8-11
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TABLE 8-2.
SUMMARY OF PROPOSED STANDARDS FOR NEW SOURCES IN RELATIONSHIP TO SUBPARTS
G & H of 40 CFR PART 63 AND THE POLYMERS NSPS
(Continued)
Subcategory
Polystyrene,
continuous
Polystyrene, batch
Expandable
polystyrene
PET - TPA, continuous
PET - TPA, batch
- DMT, batch
Type of Emission Point
Storage vessels
MACT Floor
HON
HQN
HON
HON
Process Vents
Continuous Process Vents from material
recovery; Same as subpart ODD
Other Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
a compliant flare
Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
a compliant flare
Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
a compliant flare
Continuous Process Vents from raw
material preparation and
polymerization reaction sections: same
as subpart DOO
Other Continuous Process Vents; HON
Batch Process Vents: 90% reduction or
a compliant flare
Continuous Process Vents: HOtt
Batch Process Vents: 90% reduction or
a compliant flare
Equipment
Leaks
HON
HON
HON
HON
HON
Uastewater
HON
HON
HON
HON for
wastewater
(including all
vacuum system
generated
wastewater). b
HON for
wastewater
(including all
vacuum system
generated
wastewater). b
Heat Exchange
Systems
HON for heat
exchange
systems.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
No cooling
tower water
allowed in
vacuum system
contact
condensers.
HON for heat
exchange
systems.
No cooling
tower water
allowed in
vacuum system
contact
condensers.
HON for heat
exchange
systems.
8-12
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TABLE 8-2.
SUMMARY OF PROPOSED STANDARDS FOR NEW SOURCES IN RELATIONSHIP TO SUBPARTS
G & H of 40 CFR PART 63 AND THE POLYMERS NSPS
(Concluded)
Subcategory
PET - DMT, continuous
Nitrite
Type of Emission Point
Storage vessels
HON
MACT Floor
Process Vents
Continuous Process Vents from material
recovery and polymerization reaction
sections: same as subpart ODD
Other Continuous Process Vents: HON
Batch Process Vents: 90% reduction or
a compliant flare
Continuous Process Vents: HOM
Batch Process Vents: 90% reduction or
a compliant flare
Equipment
Leaks
HON
HON
Uastewater
KON for
wastewater
(including all
vacuum system
generated
wastewater) .*
HON
Heat Exchange
Systems
No cooling
tower water
• Honed in
vacuum system
contact
condensers.
HON for heat
exchange
systems.
HON for heat
exchange
systems.
The proposed standard is more stringent than the MACT floor, which is more stringent than the HON.
Vacuum system wastewater streams containing any organic HAP identified in Table 9 of the KON wastewater provisions (subpart o> shall be
considered Group 1 and are required to be controlled.
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in the table by the acronym "HON." Similarly, where the
proposed level of control is the same as promulgated under
the Polymers NSPS, this is indicated by the use of the words
"same as under subpart DDD." Finally, where the proposed
level of control is more stringent than the level of control
in the HON or in subpart DDD for that type of emission
point, the words "MACT floor" are used.
8.1.5.1 Storage Vessels. Tables 8-3 and 8-4 summarize the
proposed standards for existing and new storage vessels,
respectively. The proposed standards would require owners
and operators to first determine whether or not a storage
vessel was required to be controlled. This^is done through
the application of certain criteria to each storage vessel.
For those storage vessels determined to require control, the
proposed rule then specifies the level of control required.
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TABLE 8-3. PROPOSED STANDARDS FOR EXISTING STORAGE VESSELS
Subcategory
Applicabih'ty Criteria*
Level of Control"
All ABS
SAN, continuous
SAN. batch
MABS
MBS
Polystyrene
batch
All PET
Nitrite (except
as noted below)
vapor pressure 20.75 psia and
capacity 240,000 gallons0
vapor pressure 21.9 psia and
capacity £20,000 gallons0
If vapor pressure is <11.1 psia:d
1. fixed roof and internal
floating roof; or
2. external floating roof; or
3. an external floating roof
converted to an internal
floating roof; or
it. a closed vent system and
control device
If vapor pressure >11.1 psia:
a closed vent system and control
device*1
ASA/AHSAN ANST for capacities £10,200 gallons
styrene/acrylonitrile for capacities
^1,000 gallons
acrylonitrile for capacities &20,000
gallons
any other chemical:
vapor pressure 20.75 psia
and capacity 240,000
gallons0
vapor pressure 21.9 psia and
capacity =20,000 gallons0
98 percent reduction
98 percent reduction
98 percent reduction
If vapor pressure is <11.1 psia:
1. fixed roof and internal
floating roof; or
2. external floating roof; or
3. an external floating roof
converted to an internal
floating roof; or
4. a closed vent system and
control device
If vapor pressure >11.1 psia:
a closed vent system and control
device"
Nitrite
Control all acrylonitrile storage
vessels 2 3,500 gallons
(same as the NON level of control)
Polystyrene, vapor pressure 2 0.28 psia and
continuous capacity 2 20,000 gallons
vapor pressure 2 2.08 psia and
capacity 2 10,000 but less than
20,000 gallons.
(same as the HON level of control).
' Storage vessels that meet the criteria are defined as Group 1 storage vessels and control of
their emissions would be required. Storage vessels that do not meet the criteria are defined as
Group 2 storage vessels and control of their emissions is not required.
b Required for Group 1 storage vessels only.
0 The applicability criteria for these subcategories are the same as in the HON.
" The level of control is the same as the HON.
KEY: AMST = alpha methyl styrene
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TABLE 8-4. PROPOSED STANDARDS FOR NEW STORAGE VESSELS
Subcategory
Applicability Criteria'
Level of Control"
All ABS (except vapor pressure *0.1 psia and
CM)
SAN, batch
MABS
MBS
Polystyrene,
batch
All PET
Nitrile (except
as noted below)
capacity 240,000 gallons0
vapor pressure M.9 psia and
capacity 210,000 gallonsc
If vapor pressure is <11.1 psia:11
1. fixed roof and internal floating
roof; or
2. external floating roof; or
3. an external floating roof converted
to an internal floating roof; or
4. a closed vent system and control
device
If vapor pressure >11.1 psia:
a closed vent system and control device"
ABS, continuous
mass
VP a 1.9 psia and capacity
£10,000 gallons and <12,000
gallons
styrene for capacities z12,000
gallons
VP a 0.0782 psia and *12,000
gallons
(same as the HON level of control)
SAN, continuous VP 2 0.0735 to <0.1 psia and
capacity £600,000 gallons
VP a 0.1 to <1.45 psia and
^40,000 gallons
VP a 1.45 to <14.7 psia and
capacity 28,000 to <40,000
gallons
90 percent reduction
(same "as the HON level of control)
98 percent reduction
ASA/AMSAN AMST for capacities *10,200
gallons
styrene/acrylonitrile for
capacities 21,000 gallons
acrylonitrile for capacities
220,000 gallons
any other chemical:
vapor pressure *0.1 psia and
capacity ^40,000 gallons0
vapor pressure &1.9 psia and
capacity £10,000 gallons0
98 percent reduction
98 percent reduction
98 percent reduction
(same as the HON level of control)
Nitrile
Control all acrylonitrile
storage vessels a 3,500 gallons
(same as the HON level of control)
Polystyrene, vapor pressure * 0.78 psia and
continuous capacity * 29,000 gallons
vapor pressure 2 0.09 psia and
capacity a 12,000 but less than
29,000 gallons.
vapor pressure 2 1.1 psia and
capacity * 5,170 but less than
12,000 gallons.
(same as the HON level of control)
8-16
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Footnotes to TABLE 8-4.
" Storage vessels that meet the criteria are defined as Group 1 storage vessels and control of
their emissions would be required. Storage vessels that do not meet the criteria are defined as
Group 2 storage vessels and control of their emissions is not required.
b Required for Group 1 storage vessels only.
c The applicability criteria for these subcategories are the same as those in the HON.
d The level of control is the same as in the HON.
KEY: VP = vapor pressure; ANST = alpha methyl styrene
8-17
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8.1.5.1.1 Applicability Criteria. For most existing and
new storage vessels, the proposed criteria for determining
which storage vessels are to be controlled are identical to
the criteria from the HON storage vessel provisions and are
based on storage vessel capacity and vapor pressure of the
stored material. Typically, vapor pressures and storage
vessel capacity criteria that determine Group 1 or Group 2
status are different for existing and new sources. As in
the HON, if a storage vessel meets the applicability
criteria and is required to be controlled under the proposed
rule, it is referred to as a Group 1 storage vessel. If a
storage vessel is not required to apply controls, it is
referred to as a Group 2 storage vessel.
For new ABS, continuous mass facilities, the
applicability criteria also rely on vapor pressure and
storage vessel capacity, but use different levels of each
for defining a Group 1 storage vessel (see Table 8-4).
For new continuous SAN facilities, the proposed
standards for storage vessels rely on five different
combinations of vapor pressure and storage vessel capacity
to determine Group 1 storage vessels. These combinations of
vapor pressure and storage vessel capacity are shown in
Table 8-4.
For existing continuous polystyrene facilities, the
proposed standards for storage vessels rely on two
combinations of vapor pressure and storage vessel capacity
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to determine Group 1 storage vessels. These combination of
vapor pressure and storage vessel capacity are shown in
Table 8-3.
For new continuous polystyrene facilities, the proposed
standards for storage vessels rely on three combinations of
vapor pressure and storage vessel capacity to determine
Group 1 storage vessels. These combinations of vapor
pressure and storage vessel capacity are shown in Table 8-4.
For existing and new ASA/AMSAN facilities, the proposed
standards for storage vessels have two parts to the
applicability criteria. The first part identifies specific
chemical and storage vessel capacity combinations. The
second part applies vapor pressure and storage vessel
criteria for storage vessels containing chemicals not
specifically identified.
For existing and new nitrile facilities, all
acrylonitrile storage vessels with capacities greater than
or equal to 3,500 gallons are required to be controlled.
For all other chemicals, the applicability criteria are the
same as in the HON.
8.1.5.1.2 Level of Control. Except for the subcategories
discussed below, the level of control required for storage
vessels determined to be Group 1 storage vessels under the
appropriate applicability criteria in the proposed rule is
either technical modification to the tank (e.g., the
installation of an internal floating roof) or the use of a
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closed vent system and control device that is generally
required to achieve at least 95 percent emission reduction.
(This is the same level of control as required under the
HON.) For all subcategories, storage vessels determined to
be Group 2 are not required to be controlled.
For new continuous SAN facilities, different levels of
control for two of the five applicability criteria
combinations are being proposed. For the applicability
combination of vapor pressure greater than 0.0735 but less
than 0.1 pounds per square inch absolute (psia) and storage
vessel capacity greater than or equal to 600,000 gallons,
the proposed standards would require an emission reduction
of 90 percent or more. For the applicability combination of
vapor pressure greater than or equal to 1.45 but less than
14.7 psia and storage vessel capacity greater than or equal
to 8,000 gallons but less than 40,000 gallons, the proposed
standard would require an emission reduction of 98 percent
or more.
For ASA/AMSAN facilities, different levels of control
for storage vessels determined to be Group 1 based on the
specific chemical/storage vessel capacity combination
criteria are being proposed. For these storage vessels, the
proposed standard would require an emission reduction of 98
percent or more.
8.1.5.2 Process Vents. As for storage vessels, the
proposed standards for process vents require owners and
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operators to first determine whether or not a process vent
(or set of process vents) requires control and, if so, then
specifies the level of control required.
8.1.5.2.1 Applicability Criteria. Tables 8-5 and 8-6
summarize the proposed applicability criteria for continuous
and batch process vents at existing and new facilities,
respectively. As for storage vessels, process vents that
meet the applicability criteria are referred to as Group 1
process vents and those that do not are referred to as Group
2 process vents. With the exceptions discussed below, the
proposed rule would require control of only those process
vents determined to be Group 1 process vents under the
appropriate criteria.
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TABLE 8-5.
SUMMARY OF PROPOSED PROCESS VENT APPLICABILITY
CRITERIA FOR EXISTING FACILITIES
Process Vents
Subcategory
Applicability Criteria
Continuous Unit
Operations
All (except as
specified below)
MBS
ASA/AMSAN
Polystyrene,
continuous:
material recovery
PET/DMT, continuous:
material recovery
PET/DMT, continuous:
polymerization reaction
PET/TPA, continuous:
raw material
preparation and
polymerization reaction
TRE"
TRE3 s 3.7
None. All vents are required
to be controlled
None. Must meet standard
0.12 kg TOC per Mg product"
None. Must meet standard
None. Must meet standard
Batch Unit
Operations
All
Stream
Volatility
Low
Moderate
High
Flowrate
Regression
Equation0
(0.00437) AE
- 51.6d
(0.00187) AE
- 14. Od
(0.00081) AE
- 8.5d
The total resource effectiveness (TRE) value is a reflection of the
cost effectiveness of controlling an individual process vent. There
are different TRE coefficients for existing and new process vents.
If emissions from the described process vents are greater than the
applicability criteria, control is required.
If actual stream flowrate (standard cubic meters per minute) is less
than the flowrate calculated by the regression equation, the process
vent is required to be controlled.
AE = annual emissions in kilograms per year.
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TABLE 8-6. SUMMARY OF PROPOSED PROCESS VENT
APPLICABILITY CRITERIA FOR NEW FACILITIES
Process Vents
Continuous Unit
Operations
Batch Unit
Operations
Subcategory
All (except as
specified below)
SAN, batch
ASA/AMSAN
Polystyrene,
continuous : material
recovery
PET/DMT, continuous:
material recovery and
polymerization reaction
PET/TPA, continuous :
Raw material
preparation and
polymerization reaction
All (except as
specified below)
SAN, batch
Applicability Criteria
TREa s 1
None . Must
meet standard.
None. All vents are required to
be controlled.
None . Must
None. Must
None . Must
Stream
Volatility
Low
Moderate
High
None. Must
meet standard.
meet standard.
meet standard .
Flowrate Regression
Equation*"
(0.00437) AE - 51. 6C
(0.00187) AE - 14.0°
(0.00081) AE - 8.5C
meet standard.
The total resource effectiveness (TRE) value is a reflection of the
cost effectiveness of controlling an individual process vent. There
are different TRE coefficients for existing and new process vents.
If actual stream flowrate (standard cubic meters per minute) is less
than the flowrate calculated by the regression equation, the process
vent is required to be controlled.
AE = annual emissions in kilograms per year.
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Except for certain PET and polystyrene continuous
process vents, Group I continuous process vents are
determined by comparing each process vent's total resource
effectiveness (THE) value to a THE value of unity. The TRE
is a reflection of the costs and other associated impacts of
controlling an individual process vent. It is determined
based on process vent stream characteristics such as
emissions (mass per hour), heat content, and flowrate. The
procedure in the proposed rule for determining Group l
process vents is the same procedure as in the HON.
Except for continuous process vents at existing MBS
facilities, continuous process vents with a TRE value of 1
or less would be classified as a Group 1 process vent. For
continuous process vents at existing MBS facilities, a TRE
value of 3.7 or less defines a Group 1 process vent.
As seen in Tables 8-5 and 8-6, there are no
applicability criteria specified for several subcategories.
At these facilities, a Group I/Group 2 status determination
does not need to be made and all process vents are required
to be controlled.
For process vents associated with the material recovery
section from existing PET facilities using a continuous DMT
process, Group 1 process vents are determined by comparing
uncontrolled emission rates with threshold emission rates.
Process vents associated with the material recovery section
at an existing PET facility using a continuous DMT
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process would be considered Group 1 process vents if the
uncontrolled emission rate is greater than 0.12 kg TOG
per Mg of product (see Table 8-5). For other process vents
at existing and new polystyrene and PET facilities (see
Tables 8-5 and 8-6) , there are no applicability criteria.
These process vents must meet the proposed standards.
For process vents from batch unit operations, the
process vent is first characterized as to its volatility -
low, medium, or high. Next, the estimate of the stream's
annual emissions is entered in the appropriate flowrate
regression equation. If the actual flowrate is less than
the calculated flowrate, then the batch process vent is a
Group 1 vent under these standards, and control is required.
As seen in Tables 8-5 and 8-6, the batch process vent
applicability criteria are the same for existing and new
sources, except for new SAN batch facilities.
For new SAN batch facilities, there are no
applicability criteria for individual process vent streams;
all process vents are subject to control in that the
proposed standard for these facilities requires an overall
emission reduction of 84 percent from all process vents.
A batch process vent that is combined with a continuous
process vent prior to a control or recovery device is not
required to comply with the batch process vent provisions if
there are no emissions to the atmosphere up until the point
the batch vent stream is combined with the continuous vent
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stream. The combined vent would be required to comply with
the continuous process vent provisions. The presence of a
batch process vent in a continuous process vent stream would
necessitate that all applicability tests and performance
tests be conducted while the batch process vent is emitting
(i.e. at maximum operating conditions).
8.1.5.2.2 Level of Control. For continuous process vents,
most of the facilities are required to control Group 1
process vents by at least 98 percent. If a flare is used,
it must meet the design and operating requirements of
§63.1Kb) of subpart A of 40 CFR part 63. Exceptions to
this are discussed in the paragraphs below.
For continuous process emissions from the material
recovery section of polystyrene plants using a continuous
process, the proposed standards would (l) limit the
emissions of total organic compounds (TOO (minus methane
and ethane) to 0.0036 kilograms (kg) of TOC per megagram
(Mg) of product (0.0036 pounds (Ibs) TOC/1,000 Ibs of
product) from each material recovery section, or (2) limit
the outlet gas temperature from each final condenser in each
material recovery section to -25°C (-13°F) , or (3) reduce
emissions from each material recovery section by 98 weight
percent or to 20 parts per million by volume (ppmv). These
are the same requirements as in the Polymer NSPS.
For PET facilities using a continuous TPA process, the
proposed standards would limit continuous process vent
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emissions from (1) the raw material preparation section to
0.04 kg TOC/Mg of product and (2) the polymerization
reaction section to 0.02 kg TOC/Mg of product. Similarly,
for PET facilities using a continuous DMT process, the
proposed standards would limit continuous process vent
emissions from (1) the material recovery section to 0.018 kg
TOC/Mg of product or the temperature to 37°F from each final
condenser in the material recovery section and (2) the
polymerization reaction section to 0.02 kg TOC/Mg of
product. These are also the same requirements that are in
the Polymers NSPS, with the exception that cooling tower
emissions would not be considered as part of the
polymerization reaction section.
For Group 1 continuous process emissions from other
process sections at polystyrene and PET facilities, the
proposed standards would require emission reduction by at
least 98 percent or control by a flare that meets the
requirements of §63.11(b) of subpart A of 40 CFR part 63.
For batch process vents, the proposed standards would
require Group 1 process vents from batch unit operations to
be controlled by at least 90 percent.
There are three subcategories where the proposed
standards are based on the MACT floor. These subcategories
are existing MBS facilities, existing and new ASA/AMSAN
facilities, and new SAN, batch facilities.
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For existing MBS facilities, the proposed standards
require continuous process vents at facilities to either (1)
meet an emission level of 0.000590 kg of emissions per
megagram of product for all continuous process vents or (2)
control all continuous process vents with a TRE of 3.7 or
less by at least 98 percent. The TRE is to be calculated
for each process vent using the same TRE coefficients as for
other existing sources. The development of the MACT floor
and applicability criteria for MBS existing sources is
documented in Docket A-92-45, Category II-B and in the SID.
For both existing and new ASA/AMSAN facilities, the
proposed rule requires all process vents (continuous and
batch) at both existing and new facilities to control
emissions by at least 98 percent.
For new SAN, batch facilities, the proposed rule
requires an overall emission reduction of 84 percent of
process vent emissions.
8.1.5.3 Equipment Leaks. For all the subcategories, both
existing and new facilities would be required to implement a
leak detection and repair (LDAR) program. With a few
exceptions, the LDAR program being proposed is the same as
that specified in the HON (40 CFR part 63, subpart H) and
the National Emission Standards for Organic HAP for Certain
Processes Subject to the Negotiated Regulation for
Equipment Leaks (40 CFR part 63, subpart I). Under the
proposed standards, work practice requirements to reduce
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emissions from equipment that are in volatile HAP service
for 300 or more hours per year are specified. The proposed
standards define "in volatile HAP service" as being in
contact with or containing process fluid that contains a
total of 5 percent or more total HAP. Equipment subject to
the proposed standards are: valves, pumps, compressors,
connectors, pressure relief devices, open-ended valves or
lines, sampling connection systems, instrumentation systems,
agitators, surge control vessels, bottoms receivers, and
closed-vent systems and control devices.
Affected sources currently complying with the NESHAP
for Certain Processes Subject to the Negotiated Regulation
for Equipment Leaks (40 CPR part 63, subpart I) are required
to continue to comply with subpart I until the compliance
date of the proposed rule. Further, affected sources
complying with subpart I through a quality improvement
program shall be allowed to continue these programs without
interruption as part of complying with the proposed rule.
In other words, becoming subject to the proposed rule does
not restart or reset the "compliance clock" as it relates to
reduced burden earned through a quality improvement program.
8.1.5.4 Wastewater. Except for ASA/AMSAN facilities, the
proposed standards require owners and operators to determine
for each wastewater stream at its point of generation
whether it is a Group 1 or Group 2 wastewater stream. As
for process vents, Group 1 wastewater streams are required
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to be controlled, while Group 2 wastewater streams are not
required to be controlled. The wastewater stream
characteristics used to make the Group I/Group 2
applicability determination are flowrate and organic HAP
concentration. The proposed criteria for determining
Group 1 wastewater streams are presented in Table 8-7 and
are the same as used in the HON. The level of control
required for Group 1 wastewater streams is dependent upon
the organic HAP constituents in the wastewater stream. The
levels of control proposed for these standards are the same
as those for the HON. The proposed rule would not control
wastewater emissions from any existing or new ASA/AMSAN
facilities.
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TABLE 8-7. PROPOSED WASTEWATER APPLICABILITY CRITERIA3'*
Existing Source Criteria
New Source Criteria
VOHAP0 concentration 2
10,000 ppmw
or
Same as existing criteria
and
VOHAPC concentration 2 1,000 for a subset of organic
ppmw and flow rate a 10 HAP. . .VOHAP0 concentration
liters per minute alO ppmw and flowrate &0.02
liters per minute
a Wastewater streams meeting these criteria are considered
Group 1 wastewater streams and control is required.
b There are exemptions for minimal flowrates and
concentrations.
0 VOHAP = volatile organic HAP.
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The proposed standards require owners and operators to
comply with the maintenance wastewater requirements in
§63.105 of subpart F of part 63. These provisions require
owners and operators to include a description of procedures
for managing wastewaters generated during maintenance in
their start-up, shutdown and malfunction plan'. The start-
up, shutdown, and malfunction plan is required under subpart
A of part 63.
8.1.5.5 Heat Exchange Systems and Process Contact Cooling
Towers. The proposed standards would require a monitoring
program to detect leakage of organic HAP from the process
into the cooling water. The proposed monitoring program is
the same as that in the HON (subpart F) . The proposed rule
would also prohibit the use of cooling tower water in
contact condensers in the vacuum systems at PET facilities.
Further, if a wastewater stream is generated from the vacuum
system and it contains any of the organic HAP identified in
Table 9 of the HON wastewater provisions (subpart G), the
proposed rule would require it to be controlled regardless
of its organic HAP concentration or flowrate. The level of
control required is the same as that for a Group 1
wastewater stream.
These provisions for control of emissions from process
contact cooling towers are independent of the provisions of
the NESHAP for Industrial Cooling Towers (40 CFR Part 63,
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Subpart Q) which may also be applicable to these cooling
towers.
8.1.5.6 Emissions Averaging. The proposed standards would
apply essentially the same emissions averaging scheme as has
been adopted by the HON, although the emissions averaging
provisions of the proposed rule are entirely contained in
the proposed rule instead of referring to the subpart G
emissions averaging provisions. Under the proposed rule,
emissions averaging would be allowed among five collocated
existing emission points belonging to the same subcategory.
This number may be increased by three additional points if
pollution prevention measures are to be used to control
emission points to be included in the average. However,
emissions from batch process vents and equipment leaks,
would not be allowed to be averaged. The owner or operator
must demonstrate that the averaging scheme will not result
in greater hazard or risk relative to strict compliance with
the standards in the absence of averaging.
8.1.5.7 Compliance and performance test provisions and
monitoring requirements. Compliance and performance test
provisions and monitoring requirements contained in the
proposed rule are very similar to those found in the HON
(subpart G). Each type of emission point is discussed
briefly in the paragraphs below. Also, significant
differences from the parameter monitoring requirements found
in subpart G are discussed.
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8.1.5.7.1 Continuous Process Vents. The proposed
regulations for process vents from continuous unit
operations (continuous process vents) require the owner or
operator to either calculate a TRE index value to determine
whether each continuous process vent is a Group 1 or Group 2
vent, or the owner or operator can elect to comply with the
control requirements without calculating the TRE index. The
TRE index value is determined after the last recovery device
in the process or prior to venting to the atmosphere. The
TRE calculation involves an emissions test or engineering
assessment and use of the TRE equations in the proposed
rule.
Performance test provisions are included for Group 1
continuous process vents to verify that the control device
achieves the required performance. Monitoring provisions
necessary to demonstrate compliance are also included in the
proposed rule.
Compliance provisions for continuous process vents at
polystyrene and PET facilities are included in the proposed
rule. For owners or operators electing to comply with a
kg TOC/Mg of product limit, procedures to demonstrate
compliance are provided. Also, procedures are included in
the proposed rule to demonstrate compliance with the
requirement to reduce overall process vent emissions
(continuous and batch) by 84 percent for new SAN, batch
facilities.
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8.1.5.7.2 Batch Process Vents. Similar to the provisions
for continuous process vents, there is a procedure for
determining which batch process vents are Group 1 and which
are Group 2. This procedure is based on annual emissions
and annual average flowrate of the batch process vent.
Equations for estimating annual emissions and annual average
flowrates are provided in the proposed rule.
Performance test provisions are included for Group 1
batch process vents to verify that the control or recovery
device achieves the required performance. Monitoring
provisions necessary to demonstrate compliance are also
included in the proposed rule.
For Group 2 batch process vents, the proposed rule
requires owners and operators to establish a batch cycle
limitation. The batch cycle limitation limits the number of
batch cycles that can be accomplished for a given batch unit
operation per year (i.e., for the operations that feed a
single batch process vent). This enforceable limitation
ensures that a Group 2 batch process vent does not become a
Group 1 batch process vent as a result of running more
batches than anticipated when the group determination was
made. The determination of the batch cycle limitation is
not tied to any previous production amounts. An affected
source may set the batch cycle limitation at any level it
desires as long as the batch process vent remains a Group 2
batch process vent. Alternatively the proposed rule would
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allow owners and operators to declare any Group 2 batch
process vent to be a Group 1 batch process vent. In such
cases, control of the batch process vent is required.
As described in Section 8.1.5.2.1, procedures are
included in the proposed rule to demonstrate compliance with
the requirement to reduce overall process vent emissions
(continuous and batch) by 84 percent for new SAN, batch
facilities.
8.1.5.7.3 Storage Vessels. Monitoring and compliance
provisions include periodic visual inspections of vessels,
roof seals, and fittings, as well as internal inspections.
If a control device is used, the owner or operator must
identify the appropriate monitoring procedures to be
followed in order to demonstrate compliance. Monitoring
parameters and procedures for many of the control devices
likely to be used are already identified in other parts of
the proposed rule. Reports and records of inspections,
repairs, and other information necessary to determine
compliance are also required by the proposed rule.
8.1.5.7.4 Wastewater. For demonstrating compliance with
the various requirements, the proposed rule allows the
owners or operators to either conduct performance tests or
to document compliance using engineering calculations.
Appropriate compliance and monitoring provisions are
included in the regulation.
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8.1.5.7.5 Equipment Leaks. The proposed rule retains the
use of Method 21 to detect leaks. Method 21 requires a
portable organic vapor analyzer to monitor for leaks from
equipment in use. A "leak" is a concentration specified in
the regulation for the type of equipment being monitored and
is based on the instrument response to methane (the
calibration gas) in air. The observed screening value may
require adjustment for response factor relative to methane
if the weighted response factor of the stream exceeds a
specified multiplier. The proposed rule requires the use of
Method 18 to determine the organic content of a process
stream. Test procedures using either a gas or a liquid for
pressure testing the batch system are specified to test for
leaks.
8.1.5.7.6 Heat Exchange Systems. Monitoring of cooling
water is required to detect leaks in noncontact heat
exchange systems. If a leak is detected, the heat exchange
system must be repaired.
8.1.5.7.7 Process Contact Cooling Towers. Owners and
operators of sources subject to these provisions are
required to indicate in their Implementation Plan and
Notification of Compliance Status report that cooling tower
water will not be used in contact condensers associated with
vacuum systems.
8.1.5.7.8 Continuous Parameter Monitoring. When compared
to the HON, the proposed rule contains two significant
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differences related to continuous parameter monitoring.
First, the proposed rule does not allow any excused
excursions. The proposed rule, as did subpart G requires at
least 75 percent of monitoring data to constitute a valid
days worth of data for continuous and batch process vents.
Failure to have a valid day's worth of monitoring data is
considered an excursion. The criteria for determining a
valid day's or hour's worth of data are provided in the
proposed rule. Second, the procedure for determining the
parameter monitoring level for continuous and batch process
vents is both more specific and restrictive than the
procedure in the HON because it relies exclusively on
performance tests.
8.1.5.8 Recordkeeping and Reporting Requirements. The
general recordkeeping and reporting requirements of this
subpart are very similar to those found in the HON. The
proposed rule also relies on the provisions of subpart A of
part 63. A table included in the proposed rule designates
which sections of subpart A apply to the proposed rule.
Specific recordkeeping and reporting requirements for each
type of emission point are also included in the proposed
rule.
The proposed rule requires sources to keep records and
submit reports of information necessary to document
compliance. Records must be kept for 5 years. The
following six types of reports must be submitted to the
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Administrator as appropriate: (1) Initial Notification,
(2) Implementation Plan (if an operating permit application
has not been submitted or, for new sources, an application
for approval of construction or reconstruction), (3)
Emissions Averaging Plan, (4) Notification of Compliance
Status, (5) Periodic Reports, and (6) other reports. The
requirements for each of the six types of reports are
summarized below. In addition, affected sources complying
with the equipment leak requirements contained in subpart H
must follow the recordkeeping and reporting requirements of
subpart H.
8.1.5.8.1 Initial Notification. The Initial Notification
is due 120 days after the date of promulgation for existing
sources. For new sources, it is due 180 days before
commencement of construction or reconstruction, or 45 days
after promulgation, whichever is later. The notification
must list the thermoplastic processes that are subject to
the proposed rule, and which provisions may apply
(e.g., continuous process vents, batch process vents,
storage vessels, wastewater, and/or equipment leak
provisions). A detailed identification of emission points
is not necessary for the Initial Notification. The
notification, however, must include a statement of whether
the affected source expects that it can achieve compliance
by the specified compliance date.
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8.1.5.8.2 Implementation Plan. The Implementation Plan
details how the affected source plans to comply. An
Implementation Plan would be required only for affected
sources that have not yet submitted an operating permit
application or for new sources that have not yet submitted
the same information as part of their application for
approval of construction or reconstruction.
The Implementation Plan would be due 12 months prior to
the date of compliance. For new sources, Implementation
Plans would be submitted with the Notification of Compliance
Status.
The information in the Implementation Plan should be
incorporated into the affected source's operating permit
application. The terms and conditions of the plan, as
approved by the permit authority, would then be incorporated
into the operating permit.
The Implementation Plan would include a list of
emission points subject to the continuous process vents,
batch process vents, storage vessels, wastewater, heat
exchange system, process contact cooling tower, and
equipment leak provisions and, as applicable, whether each
emission point (e.g., storage vessel or process vent) is
Group 1 or Group 2. The control technology or method of
compliance planned for each Group 1 emission point must be
specified.
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The plan must also certify that appropriate testing,
monitoring, reporting, and recordkeeping will be done for
each Group 1 emission point. If an affected source requests
approval to monitor a unique parameter, a rationale must be
included.
8.1.5.8.3 Emissions Averaging Plan. The Emissions
Averaging Plan would be due 18 months prior to the date of
compliance. New sources are not allowed to comply through
the use of emissions averaging.
For points included in emissions averaging, the
Emissions Averaging Plan would include: an identification
of all points in the average and whether they are Group 1 or
Group 2 points/ the specific control technique or pollution
prevention measure that will be applied to each point; the
control efficiency for each control used in the average; the
projected credit or debit generated by each point; and the
overall expected credits and debits. The plan must include
a demonstration that the emissions averaging scheme will not
result in greater hazard or risk than if the emission points
would comply with the standards in the absence of averaging.
The plan must also certify that the same types of testing,
monitoring, reporting, and recordkeeping that are required
by the proposed rule for Group 1 points will be done for all
points (both Group 1 and Group 2) included in an emissions
average. If an affected source requests approval to monitor
a unique parameter or use a unique recordkeeping and
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reporting system, a rationale must be included in the
Emissions Averaging Plan.
8.1.5.8.4 Notification of Compliance Status. The
Notification of Compliance Status would be required
150 days after the affected source's compliance date. It
contains the information for Group l emission points and for
all emission points in emissions averages, necessary to
demonstrate that compliance has been achieved. Such
information includes, but is not limited to, the results of
any performance tests for continuous and/or batch process
vents and wastewater emission points; one complete test
report for each test method used for a particular kind of
emission point; TRE determinations for continuous process
vents; group determinations for batch process vents; design
analyses for storage vessels and wastewater emission points;
monitored parameter levels for each emission point and
supporting data for the designated level; and values of all
parameters used to calculate emission credits and debits for
emissions averaging.
8.1.5.8.5 Periodic Reports. Generally, Periodic Reports
would be submitted semiannually. However, there are two
exceptions. First, quarterly reports must be submitted for
all points included in an emissions average. Second, if
monitoring results show that the parameter values for an
emission point are above the maximum or below the minimum
established levels for more than 1 percent of the operating
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time in a reporting period, or the monitoring system is out
of service for more than 5 percent of the time, the
regulatory authority may request that the owner or operator
submit quarterly reports for that emission point. After
1 year, semiannual reporting can be resumed, unless the
regulatory authority requests continuation of quarterly
reports.
All Periodic Reports would include information required
to be reported under the recordkeeping and reporting
provisions for each emission point. For emission points
involved in emissions averages, the report would include the
results of the calculations of credits and debits for each
month and for the quarter. For continuously monitored
parameters, the data on those periods when the parameters
are above the maximum or below the minimum established
levels are included in the reports. Periodic Reports would
also include results of any performance tests conducted
during the reporting period and instances when required
inspections revealed problems. Additional information the
affected source is required to report under its operating
permit or Implementation Plan would also be described in
Periodic Reports.
8.1.5.8.6 Other reports. Other reports required under the
proposed rule include: reports of start-up, shutdown, and
malfunction; process changes that change the compliance
status of process vents; and requests for extensions of
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repair and notifications of inspections for storage vessels
and wastewater.
In addition, quarterly reporting of the number of batch
cycles accomplished for Group 2 batch process vents is
required. Every fourth quarterly report would be required
to include the total batch cycles accomplished during the
previous 12 months, and a statement whether the owner or
operator is in compliance with the batch cycle limitation.
8.2 RATIONALE FOR THE SELECTION OF EMISSION POINTS TO BE
COVERED BY THE PROPOSED STANDARDS
Emissions from the production of Group IV
thermoplastics were identified as occurring from storage
vessels, process vents, equipment leaks, wastewater
operations, and heat exchange systems to include process
contact cooling towers. The EPA is proposing standards for
all of these types of emission points in the proposed rule.
8.3 RATIONALE FOR THE SELECTION OF THE PROPOSED STANDARDS
The approach for determining the MACT floor and
developing regulatory alternatives is discussed in Chapter
6.0. Chapter 6.0 also presents in tabular form the results
of the MACT floor analysis and identifies the selected
regulatory alternative. This chapter discusses the results
of the MACT floor analysis and provides the rationale for
the selection of the proposed standards. Throughout
Sections 8.3.1 and 8.3.2, the use of the term "HON" in
reference to process vents is meant to include the Batch
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Processes ACT. When a sentence states "the HON was
equivalent to the MACT floor for process vents," it should
be understood that the HON and Batch Processes ACT were
equivalent to the MACT floor for process vents.
In some instances, the EPA has required control more
stringent than that required by the MACT floor. In these
instances, the EPA has judged the impacts to be reasonable.
The EPA specifically solicits comments on these decisions.
8.3.1 Selection of the Standards for Existing Sources
The following paragraphs discuss the selection of the
standards for existing sources for each subcategory.
ABS. Continuous Emulsion Process
Based on available information, there are two existing
facilities in the U.S. at which ABS is produced using a
continuous emulsion process. The information on controls at
both facilities was used to evaluate the MACT floor. Based
on the analysis for determining the relationship between the
MACT floor and the HON, the EPA determined that the HON was
equivalent to the MACT floor for storage vessels, process
vents, and wastewater, and that the HON was more stringent
than the MACT floor for equipment leaks.
The first regulatory alternative considered for
existing continuous emulsion ABS facilities consisted of
applying the HON to storage vessels, process vents,
equipment leaks, and wastewater. For storage vessels,
process vents, and wastewater, Regulatory Alternative 1 is
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equivalent to the MACT floor; thus, no emission reductions
or costs beyond those required to achieve the MACT floor
level of control would be incurred. For equipment leaks,
the HON requirements are more stringent than the MACT floor,
and emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions and costs
associated with implementing the HON equipment leak
requirements compared to the existing levels of control.
These impacts are based on confidential information and
cannot be presented. Considering these impacts, as well as
non-air environmental and energy impacts, the EPA judged
that this level of control was reasonable. No additional
regulatory alternatives were identified. Therefore, the
Administrator selected Regulatory Alternative 1 as the
proposed standard for existing continuous emulsion ABS
facilities.
ABS. Continuous Mass Process
Based on available information, there are five existing
facilities in the U.S. at which ABS is produced using a
continuous mass process. The information on controls at all
five facilities was used to evaluate the MACT floor. Based
on the analysis for determining the relationship between the
MACT floor and the HON, the EPA determined that the HON was
equivalent to the MACT floor for storage vessels, process
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vents, and wastewater, and that the HON was more stringent
than the MACT floor for equipment leaks.
The first regulatory alternative considered for
existing continuous mass ABS facilities consisted of
applying the HON to storage vessels, process vents,
equipment leaks, and wastewater. For storage vessels,
process vents, and wastewater, Regulatory Alternative 1 is
equivalent to the MACT floor; thus, no emission reductions
or costs beyond those required to achieve the MACT floor
level of control would be incurred. For equipment leaks,
the HON requirements are more stringent than the MACT floor,
and emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions (171 Mg/yr) and
costs ($70,000/yr) associated with implementing the HON
equipment leak requirements compared to the existing levels
of control. Considering these impacts, as well as non-air
environmental and energy impacts, the EPA judged that this
level of control was reasonable. No additional regulatory
alternatives were identified. Therefore, the Administrator
selected Regulatory Alternative 1 as the proposed standard
for existing continuous mass ABS facilities.
ABS, Batch Emulsion Process
Based on available information, there are four existing
facilities in the U.S. at which ABS is produced using a
batch emulsion process. The information on controls at all
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four facilities was used to evaluate the MACT floor. Based
on the analysis for determining the relationship between the
MACT floor and the HON, the EPA determined that the HON was
equivalent to the MACT floor for storage vessels/ process
vents, and wastewater, and that the HON was more stringent
than the MACT floor for equipment leaks.
The first regulatory alternative considered for
existing batch emulsion ABS facilities consisted of applying
the HON to storage vessels, process vents, equipment leaks,
and wastewater. For storage vessels, process vents, and
wastewater, Regulatory Alternative 1 is equivalent to the
MACT floor; thus, no emission reductions or costs beyond
those required to achieve the MACT floor level of control
would be incurred. For equipment leaks, the HON
requirements are more stringent than the MACT floor, and
emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions (37 Mg/yr) and
costs ($28,000/yr) associated with implementing the HON
equipment leak requirements compared to the existing levels
of control. Considering these impacts, as well as non-air
environmental and energy impacts, the EPA judged that this
level of control was reasonable. No additional regulatory
alternatives were identified. Therefore, the Administrator
selected Regulatory Alternative 1 as the proposed standard
for existing batch emulsion ABS facilities.
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ABS. Batch Suspension Process
Based on available information, there are two existing
facilities in the U.S. at which ABS is produced using a
batch suspension process. The information on controls at
both facilities was used to evaluate the MACT floor. Based
on the analysis for determining the relationship between the
MACT floor and the HON, the EPA determined that the HON was
equivalent to the MACT floor for storage vessels, process
vents, and wastewater, and that the HON was more stringent
than the MACT floor for equipment leaks.
The first regulatory alternative considered for
existing batch suspension ABS facilities consisted of
applying the HON to storage vessels, process vents,
equipment leaks, and wastewater. For storage vessels,
process vents, and wastewater, Regulatory Alternative 1 is
equivalent to the MACT floor; thus, no emission reductions
or costs beyond those required to achieve the MACT floor
level of control would be incurred. For equipment leaks,
the HON requirements are more stringent than the MACT floor,
and emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions of 5 Mg/yr and a
very small cost savings associated with implementing the HON
equipment leak requirements compared to the existing levels
of control. Considering these impacts, as well as non-air
environmental and energy impacts, the EPA judged that this
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level of control was reasonable. No additional regulatory
alternatives were identified. Therefore, the Administrator
selected Regulatory Alternative 1 as the proposed standard
for existing batch suspension ABS facilities.
ABS. Latex Process
Based on available information, there is one existing
facility in the U.S. at which ABS is produced using a latex
process. The information on controls at this facility was
used to evaluate the MACT floor. Based on the analysis for
determining the relationship between the MACT floor and the
HON, the EPA determined that the HON was equivalent to the
MACT floor for storage vessels, process vents, and
wastewater, and that the HON was more stringent than the
MACT floor for equipment leaks.
The first regulatory alternative considered for
existing ABS latex facilities consisted of applying the HON
to storage vessels, process vents, equipment leaks, and
wastewater. For storage vessels, process vents, and
wastewater, Regulatory Alternative 1 is equivalent to the
MACT floor; thus, no emission reductions or costs beyond
those required to achieve the MACT floor level of control
would be incurred. For equipment leaks, the HON
requirements are more stringent than the MACT floor, and
emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions of 2 Mg/yr and a
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cost savings of $500/yr associated with implementing the HON
equipment leak requirements compared to the existing levels
of control. Considering these impacts, as well as non-air
environmental and energy impacts, the EPA judged that this
level of control was reasonable. No additional regulatory
alternatives were identified. Therefore, the Administrator
selected Regulatory Alternative 1 as the proposed standard
for existing ABS latex facilities.
MASS Process
Based on available information, there is one existing
facility in the U.S. at which ABS is produced. The
information on controls at this facility was used to
evaluate the MACT floor. Based on the analysis for
determining the relationship between the MACT floor and the
HON, the EPA determined that the HON was equivalent to the
MACT floor for storage vessels, process vents, and
wastewater, and that the HON was more stringent than the
MACT floor for equipment leaks.
The first regulatory alternative considered for
existing MABS facilities consisted of applying the HON to
storage vessels, process vents, equipment leaks, and
wastewater. For storage vessels, process vents, and
wastewater, Regulatory Alternative 1 is equivalent to the
MACT floor; thus, no emission reductions or costs beyond
those required to achieve the MACT floor level of control
would be incurred. For equipment leaks, the HON
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requirements are more stringent than the MACT floor, and
emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions and costs
associated with implementing the HON equipment leak
requirements compared to the existing levels of control.
These impacts are based on confidential information and
cannot be presented. Considering these impacts, as well as
non-air environmental and energy impacts, the EPA judged
that this level of control was reasonable. No additional
regulatory alternatives were identified. Therefore, the
Administrator selected Regulatory Alternative 1 as the
proposed standard for existing MABS facilities.
MBS Process
Based on available information, there are three
existing facilities in the U.S. at which MBS is produced.
The information on controls at all three facilities was used
to evaluate the MACT floor. Based on the analysis for
determining the relationship between the MACT floor and the
HON, the EPA determined that the HON was equivalent to the
MACT floor for storage vessels and wastewater, that the HON
was less stringent than the MACT floor for process vents,
and that the HON was more stringent than the MACT floor for
equipment leaks.
Since the HON was determined to be less stringent than
the MACT floor for process vents, the EPA defined the MACT
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floor and included it as part of the first regulatory
alternative (Regulatory Alternative 1). The EPA analyzed
several options for defining the MACT floor. These options
were a TRE, an emission factor, a percent reduction, and
various combinations of these. Based on this analysis (see
Docket A-92-45, Category II-B), the EPA determined that the
option of either complying with a TRE or an emission factor
was the best representation of the MACT floor.
The first regulatory alternative considered for
existing MBS facilities consisted of applying the MACT floor
to process vents and the HON to storage vessels, equipment
leaks, and wastewater. For storage vessels, process vents,
and wastewater, Regulatory Alternative 1 is equivalent to
the MACT floor; thus, no emission reductions or costs beyond
those required to achieve the MACT floor level of control
would be incurred. For equipment leaks, the HON
requirements are more stringent than the MACT floor, and
emission reductions and costs Jseyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions (109 Mg/yr) and
costs ($44,000/yr) associated with implementing the HON
equipment leak requirements compared to the existing levels
of control. Considering these impacts, as well as non-air
environmental and energy impacts, the EPA judged that this
level of control was reasonable. No additional regulatory
alternatives were identified. Therefore, the Administrator
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selected Regulatory Alternative 1 as the proposed standard
for existing MBS facilities.
SAN. Continuous Process
Based on available information, there are three
existing facilities in the U.S. at which SAN is produced
using a continuous process. The information on controls at
all three facilities was used to evaluate the MACT floor.
Based on the analysis for determining the relationship
between the MACT floor and the HON, the EPA determined that
the HON was equivalent to the MACT floor for storage
vessels, wastewater, and process vents, and the HON was more
stringent than the MACT floor for equipment leaks.
The first regulatory alternative (Regulatory
Alternative 1) considered for existing SAN facilities using
a continuous process consisted of applying the HON to each
of the four types of emission points. For storage vessels,
process vents, and wastewater, Regulatory Alternative 1 is
equivalent to the MACT floor; thus, no emission reductions
or costs beyond those required to achieve the MACT floor
level of control would be incurred. For equipment leaks,
the HON requirements are more stringent than the MACT floor,
and emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions (46 Mg/yr) and
costs ($55,000/yr) associated with implementing the HON
equipment leak requirements compared to the existing level
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of controls. Considering these impacts, as well as non-air
environmental and energy impacts, the EPA judged that this
level of control was reasonable. No additional regulatory
alternatives were identified. Therefore, the EPA selected
Regulatory Alternative 1 as the proposed standard for
existing SAN facilities using a continuous process.
SAN. Batch Processes
Based on available information, there are two existing
facilities in the U.S. at which SAN is produced using a
batch process. The information on controls at both
facilities was used to evaluate the MACT floor. Based on
the analysis for determining the relationship between the
MACT floor and the HON, the EPA determined that the HON was
equivalent to the MACT floor for storage vessels,
wastewater, and process vents, and that the HON was more
stringent than the MACT floor for equipment leaks.
The first regulatory alternative (Regulatory
Alternative 1) considered for existing SAN facilities using
a batch process consisted of applying the HON to each of the
four types of emission points. For storage vessels, process
vents, and wastewater, Regulatory Alternative 1 is
equivalent to the MACT floor; thus, no emission reductions
or costs beyond those required to achieve the MACT floor
level of control would be incurred. For equipment leaks,
the HON requirements are more stringent than the MACT floor,
and emission reductions and costs beyond those required to
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achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions (7 Mg/yr) and cost
savings ($l,200/yr) associated with implementing the HON
equipment leak requirements compared to the existing level
of controls. Considering these impacts, as well as non-air
environmental and energy impacts, the EPA judged that this
level of control was reasonable. No additional regulatory
alternatives were identified. Therefore, the Administrator
selected Regulatory Alternative 1 as the proposed standard
for existing SAN facilities using a batch process.
ASA/AMSAN Process
Based on available information, only one facility in
the U.S. produces ASA/AMSAN. The information on the
controls used at this one facility was used to evaluate the
MACT floor. Based on the analysis for determining the
relationship between the MACT floor and the HON, the EPA
determined that the HON was less stringent than the MACT
floor for storage vessels and process vents, and the HON was
more stringent than the MACT floor for equipment leaks and
wastewater emissions.
Since the HON was determined to be less stringent than
the MACT floor for storage vessels and process vents, the
EPA defined the MACT floor and included it as part of the
first regulatory alternative (Regulatory Alternative 1).
Since there is only one facility in this subcategory, the
MACT floor is equivalent to the existing level of control.
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For storage vessels, the EPA evaluated three options for
defining the MACT floor. These options were: (1) define
vapor pressure and storage vessel capacity combinations; (2)
define chemical type and storage vessel capacity
combinations; and (3) Option 2 supplemented by Option 1 for
chemicals not specified under Option 2. Based on this
analysis (see Docket A-92-45, Category II-B), the EPA
determined that the best option for defining the MACT floor
was to use vapor pressure and storage vessel size
combinations. For process vents, the one facility controls
all process vents. Therefore, the best representation of
the MACT floor is the same - control of all process vents.
The first regulatory alternative considered for the
existing ASA/AMSAN facility consisted of applying the MACT
floor to storage vessels and process vents and the HON to
equipment leaks and wastewater. For storage vessels and
process vents, Regulatory Alternative 1 is equivalent to the
MACT floor; thus no emission reductions or costs beyond
those required to achieve the MACT floor level of control
would be incurred. For equipment leaks and wastewater, the
HON requirements are more stringent than the MACT floor, and
emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions (89 Mg/yr) and
costs ($74,000/yr) associated with implementing the HON
equipment leaks requirements compared to the existing level
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of control. Considering these impacts, as well as non-air
environmental and energy impacts, the EPA judged that this
level of control was reasonable. The EPA also estimated the
emission reductions (5 Mg/yr) and costs ($127,000/yr)
associated with implementing the HON wastewater
requirements. The EPA found these impacts were not
reasonable. No additional regulatory alternatives were
identified. Based on these considerations, the
Administrator selected Regulatory Alternative I for storage
vessels, process vents, and equipment leaks as the proposed
standard for existing ASA/AMSAN facilities. No standards
are being proposed for wastewater emissions.
Polystyrene. Continuous Processes
Based on available information, there are 22 facilities
in the U.S. at which polystyrene is being produced using a
continuous process. The information on controls for the
best performing five facilities was used to evaluate the
MACT floor. Based on the analysis for determining the
relationship between the MACT floor, the HON, and the
Polymers NSPS, the EPA determined that the HON and Polymers
NSPS were equivalent to the MACT floor for process vents,
the HON was equivalent to the MACT floor for wastewater, the
HON was more stringent than the MACT floor for equipment
leaks, and the HON was less stringent than the MACT floor
for storage vessels.
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The first regulatory alternative (Regulatory
Alternative 1) considered for existing polystyrene
facilities using a continuous process consisted of applying
1) the MACT floor to storage vessels, 2) the HON and
Polymers NSPS to process vents, and 3) the HON to
wastewater, and equipment leaks. For storage vessels,
process vents, and wastewater, Regulatory Alternative 1 is
equivalent to the MACT floor; thus, no emission reductions
or costs beyond those required to achieve the MACT floor
level of control would be incurred. For equipment leaks,
the HON requirements are more stringent than the MACT floor,
and emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions and costs
associated with implementing those requirements in
Regulatory Alternative 1 that are more stringent than the
MACT floor (see Table 8-8). Considering these impacts, as
well as non-air environmental and energy impacts, the EPA
judged that those portions of Regulatory Alternative 1 more
stringent than the MACT floor were reasonable. Therefore,
the Administrator selected Regulatory Alternative 1 as the
proposed standard for existing polystyrene facilities using
a continuous process.
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TABLE 8-8. REGULATORY ALTERNATIVE IMPACTS FOR
EXISTING POLYSTYRENE CONTINUOUS FACILITIES
Regulatory
Alternative
Existing
Control
1
Emission
Reduction
Mg/yr
--
897
Total Annual
Costs,
$l,000/yr
--
414
Cost-
Ef f ectiveness ,
$/Mg
Average
--
460
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Polystyrene. Batch Processes
Based on available information, there are 11 existing
facilities in the U.S. at which polystyrene is produced
using a batch process. The information on controls for the
best performing five facilities was used to evaluate the
MACT floor. Based on the analysis for determining the
relationship between the MACT floor and the HON, the EPA
determined that the HON was equivalent to the MACT floor for
storage vessels and wastewater, and that the HON was more
stringent than the MACT floor for equipment leaks and
process vents.
The first regulatory alternative (Regulatory
Alternative 1) considered for existing polystyrene
facilities using a batch process consisted of applying the
HON to each of the four types of emission points. For
storage vessels and wastewater, Regulatory Alternative 1 is
equivalent to the MACT floor; thus, no emission reductions
or costs beyond those required to achieve the MACT floor
level of control would be incurred. For process vents and
equipment leaks, the HON requirements are more stringent
than the MACT floor, and emission reductions and costs
beyond those required to achieve the MACT floor level of
control would be incurred. The EPA estimated the emission
reductions (139 Mg/yr) and cost savings ($119,000/yr)
associated with implementing the HON to process vents and
equipment leaks compared to the existing level of controls.
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Considering these impacts, as well as non-air environmental
and energy impacts, the EPA judged that this level of
control was reasonable. No additional regulatory
alternatives were identified. Therefore, the Administrator
selected Regulatory Alternative 1 as the proposed standard
for existing polystyrene facilities using a batch process.
Expandable Polystyrene Processes
Based on available information, there are 7 existing
facilities in the U.S. at which expandable polystyrene is
produced. The information on controls for the best
performing five facilities was used to evaluate the MACT
floor. Based on the analysis for determining the
relationship between the MACT floor and the HON, the EPA
determined that the HON was equivalent to the MACT floor for
storage vessels, wastewater, and process vents, and that the
HON was more stringent than the MACT floor for equipment
leaks.
The first regulatory alternative (Regulatory
Alternative 1) considered for existing expandable
polystyrene facilities consisted of applying the HON to each
of the four types of emission points. For storage vessels,
process vents, and wastewater, Regulatory Alternative 1 is
equivalent to the MACT floor; thus, no emission reductions
or costs beyond those required to achieve the MACT floor
level of control would be incurred. For equipment leaks,
the HON requirements are more stringent than the MACT floor,
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and emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions (92 Mg/yr) and
cost savings ($49,000/yr) associated with implementing the
HON equipment leak requirements compared to the existing
level of controls. Considering these impacts, as well as
non-air environmental and energy impacts, the EPA judged
that this level of control was reasonable. No additional
regulatory alternatives were identified. Therefore, the
Administrator selected Regulatory Alternative 1 as the
proposed standard for existing expandable polystyrene
facilities.
PET - TPA. Continuous Processes
Based on available information, there are 12 facilities
in the U.S. at which PET is being produced using the TPA
continuous process. The information on controls for the
best performing five facilities was used to evaluate the
MACT floor. Based on the analysis for determining the
relationship between the MACT floor, the HON, and the
Polymers NSPS, the EPA determined that the HON was
equivalent to the MACT floor for storage vessels and
wastewater, that the HON and Polymers NSPS were equivalent
to the MACT floor for process vents, and that the HON was
more stringent than the MACT floor for equipment leaks.
As has been discussed earlier, process contact cooling
towers are addressed by the Polymers NSPS. Of those
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facilities with process contact cooling towers as a type of
emission point, none control the emissions from the cooling
towers. Based on this information, the EPA determined that
the MACT floor for process contact cooling towers at
existing facilities using a TPA continuous process was no
control. Thus, the Polymers NSPS is more stringent than the
MACT floor. However, as discussed earlier, ethylene glycol
jets were determined to be more cost effective in reducing
emissions than the requirements of the Polymers NSPS.
The first regulatory alternative (Regulatory
Alternative 1) considered for existing PET sources using a
continuous TPA process consisted of applying the HON to
storage vessels, equipment leaks, and wastewater and
applying the HON and Polymers NSPS to process vents. In
addition, the HON wastewater applicability criteria were
applied to the vacuum system generated wastewater as part of
the first regulatory alternative. For storage vessels,
process vents, and (non-vacuum system generated) wastewater,
Regulatory Alternative 1 is equivalent to the MACT floor;
thus, no emission reductions or costs beyond those required
to achieve the MACT floor level of control would be
incurred. For equipment leaks and vacuum system generated
wastewater, Regulatory Alternative 1 is more stringent than
the MACT floor, and emission reductions and costs beyond
those required to achieve the MACT floor level of control
would be incurred.
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A second regulatory alternative was developed for
existing PET facilities using a continuous TPA process. In
the second regulatory alternative, control of emissions from
the process contact cooling tower, which result from the
vacuum system generated wastewater, was considered by
prohibiting the use of cooling tower water in the contact
condensers in the vacuum system. For the purposes of this
analysis, this prohibition was assumed to be implemented by
replacing the existing steam jet vacuum systems with
ethylene glycol jet vacuum systems. (Other methods for
achieving this prohibition were judged by the EPA to obtain
equivalent results at less cost.) The requirements for
storage vessels, process vents, equipment leaks, and
wastewater remained the same. No additional regulatory
alternatives were identified.
The EPA estimated the emission reductions and costs
associated with implementing those requirements in
Regulatory Alternatives 1 and 2 that are more stringent than
the MACT floor (see Table 8-9) . Considering these impacts,
as well as non-air environmental and energy impacts, the EPA
judged that those portions of Regulatory Alternative 2 more
stringent than the MACT floor were reasonable. Therefore,
the Administrator selected Regulatory Alternative 2 as the
proposed standard for existing PET facilities using a
continuous TPA process. The EPA solicits comment on this
decision to go beyond the MACT floor.
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TABLE 8-9. REGULATORY ALTERNATIVE IMPACTS FOR
EXISTING TPA CONTINUOUS FACILITIES
Regulatory
Alternative
Existing
Control
1
2
Emission
Reduction
Mg/yr
--
1,380
2,472
Total
Annual
Costs,
$l,000/yr
--
1,441
3,436
Cost -Effectiveness,
$/Mg
Average
--
1,040
1,390
Incremental
--
--
1,830
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Based on the available data, the Polymers NSPS
requirements did not gain any additional control over and
above that which the HON would obtain. Since there does not
appear to be any impact from the Polymers NSPS on existing
continuous TPA facilities, the EPA is specifically
requesting comments on whether to adopt a combination of the
Polymers NSPS and HON or only the HON for this subcategory.
In support of their position, commenters are specifically
requested to provide documentation on (1) which emission
streams would be required to be controlled or not controlled
and (2) for each stream that would be required to be
controlled, which rule (HON or Polymers NSPS or both) would
require control, the emission reduction as the result of
control, and the costs of control. The regulatory
alternative selected for the final standard could range from
the Polymers NSPS to the HON or a combination of both,
depending on the data submitted.
PET - TPA. Batch Processes
Only one facility in the U.S. has been identified as
producing PET using a batch TPA process. The information on
the controls used at this facility was used to evaluate the
MACT floor. Based on the analysis for determining the
relationship between the HON and the MACT floor, the HON was
determined to be equivalent to the MACT floor for storage
vessels, wastewater, and process vents, and the HON was
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determined to be more stringent than the MACT floor for
equipment leaks.
The one facility using the batch TPA process does not
control emissions from the process contact cooling tower.
Therefore, the MACT floor for process contact cooling towers
is no control. One potential regulatory alternative is to
apply the requirements for cooling towers from the Polymers
NSPS. However, as discussed earlier, several methods,
including ethylene glycol jets, were determined to be more
cost effective in reducing emissions from process contact
cooling towers.
The first regulatory alternative (Regulatory
Alternative 1) considered for the existing PET facility
using a batch TPA process consisted of applying the HON to
storage vessels, process vents, equipment leaks, and
wastewater (including vacuum system generated wastewater).
For storage vessels, process vents, and wastewater,
Regulatory Alternative 1 is equivalent to the MACT floor;
thus, no emission reductions or costs beyond those required
to achieve the MACT floor level of control would be
incurred. For equipment leaks and vacuum system generated
wastewater, Regulatory Alternative 1 is more stringent than
the MACT floor, and emission reductions and costs beyond
those required to achieve the MACT floor control level would
be incurred.
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A second regulatory alternative was developed for batch
TPA processes. As for continuous TPA processes, in the
second regulatory alternative, control of emissions from the
cooling tower was considered through the replacement of
existing steam jet vacuum systems with ethylene glycol jet
vacuum systems. Requirements for the other types of
emission points remained the same. No additional regulatory
alternatives were identified.
The EPA estimated the emission reductions and costs
associated with implementing those requirements in
Regulatory Alternatives l and 2 that are more stringent than
the MACT floor (see Table 8-10}. Considering these impacts,
as well as non-air environmental and energy impacts, the EPA
judged that those portions of Regulatory Alternative 2 more
stringent than the MACT floor were reasonable. Therefore,
the Administrator selected Regulatory Alternative 2 as the
proposed standard for existing PET facilities using a batch
TPA process.
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TABLE 8-10. REGULATORY ALTERNATIVE IMPACTS FOR
EXISTING TPA BATCH FACILITIES
Regulatory
Alternative
Existing
Control
1
2a
Emission
Reduction
Mg/yr
--
5.6
CBI
Total
Annual
Costs,
$l,000/yr
--
18
CBI
Cost-
Ef f ectiveness ,
$/Mg
Average
--
3,180
CBI
a Impacts for the control included in this regulatory
alternative are based on confidential information and cannot
be presented.
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PET - DMT. Continuous Processes
Based on available information, there are 10 facilities
in the U.S. at which PET is produced using a DMT continuous
process. The information on controls for the best
performing five facilities was used to evaluate the MACT
floor. Based on the analysis for determining the
relationship between the MACT floor, the HON, and the
Polymers NSPS, the EPA determined that the HON was
equivalent to the MACT floor for storage vessels, process
vents, and wastewater, and that the HON was more stringent
than the MACT floor for equipment leaks.
As has been discussed earlier, process contact cooling
towers are addressed by the Polymers NSPS. Of those
facilities with process contact cooling towers as a type of
emission point, none control the emissions from the cooling
towers. Based on this information, the EPA determined that
the MACT floor for process contact cooling towers at
existing facilities using a continuous DMT process was no
control, and the Polymers NSPS is more stringent than the
MACT floor. However, also as noted earlier, ethylene glycol
jets were determined to be more cost effective in reducing
emissions.
The first regulatory alternative (Regulatory
Alternative 1) considered for existing PET sources using a
continuous DMT process consisted of applying the HON to
storage vessels, process vents, equipment leaks, and
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wastewater (including the vacuum system generated
wastewater). For storage vessels, process vents, and
wastewater, Regulatory Alternative 1 is equivalent to the
MACT floor; thus, no emission reductions or costs beyond
those required to achieve the MACT floor level of control
would be incurred. For equipment leaks, the HON
requirements are more stringent than the MACT floor, and
emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
A second regulatory alternative was developed for
continuous DMT processes. The second regulatory alternative
also considered the application of the Polymers NSPS to
process emissions from the material recovery section and the
polymerization reaction section, in addition to the HON for
other process vents. As for continuous TPA processes, in
the second regulatory alternative, control of emissions from
the cooling tower was considered through the replacement of
existing steam jet vacuum systems with ethylene glycol jet
vacuum systems. The requirements for storage vessels,
equipment leaks, and wastewater remained the same. No
additional regulatory alternatives were identified.
The EPA estimated the emission reductions and costs
associated with implementing those requirements in
Regulatory Alternatives 1 and 2 that are more stringent than
the MACT floor (see Table 8-11). Considering these impacts,
as well as non-air environmental and energy impacts, the EPA
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TABLE 8-11. REGULATORY ALTERNATIVE IMPACTS FOR
EXISTING DMT BATCH FACILITIES
Regulatory
Alternative
Existing
Control
1
2
Emission
Reduction
Mg/yr
--
1,190
1,881
Total
Annual
Costs,
$l,000/yr
--
1,489
2,909
Cost-
Ef f ectiveness ,
$/Mg
Average
--
1,250
1,546
Incremental
--
—
2,050
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judged that those portions of Regulatory Alternative 2 more
stringent than the MACT floor were reasonable. Therefore,
the EPA selected Regulatory Alternative 2 as the proposed
standard for existing PET facilities using a continuous DMT
process. The EPA solicits comment on this decision to go
beyond the MACT floor.
Based on the available data, the Polymers NSPS applied
to continuous DMT process sources was estimated to obtain
additional control from process vents in the material
recovery section over and above what the HON would obtain,
but not for the polymerization reaction section. Since the
impact of the Polymers NSPS on existing facilities is
unclear, the EPA is specifically requesting comments on
whether to adopt a combination of the Polymers NSPS and HON
or only the HON for this subcategory. In support of their
position, commenters are specifically requested to provide
documentation on which emission streams would be required to
be controlled or not controlled and, for each stream that
would be required to be controlled, which rule (HON or
Polymers NSPS or both) would require control, the emission
reduction as the result of control, and the costs of
control. The regulatory alternative selected for the final
standard could range from the Polymers NSPS to the HON or a
combination of both, depending on the data submitted.
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PET - DMT. Batch Processes
Based on available information, there are 10 facilities
in the U.S. at which PET is produced using a batch DMT
process. The information on controls for the best
performing five facilities was used to evaluate the MACT
floor. Based on the analysis for determining the
relationship between the MACT floor and the HON, the EPA
determined that HON was equivalent to the MACT floor for
storage vessels, wastewater, and process vents, and that the
HON was more stringent than the MACT floor for equipment
leaks.
Of those facilities with process contact cooling towers
as a type of emission point, none control the cooling tower
emissions. Based on this information, the EPA determined
that the MACT floor for process contact cooling towers at
existing facilities using a batch DMT process was no
control. One potential regulatory alternative is to apply
the requirements for cooling towers from the Polymers NSPS.
However, as noted earlier, ethylene glycol jets were
determined to be more cost effective in reducing emissions
from process contact cooling towers than the requirements of
subpart DDD.
The first regulatory alternative (Regulatory
Alternative l) considered for existing PET sources using a
batch DMT process consisted of applying the HON to storage
vessels, process vents, equipment leaks, and wastewater.
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For storage vessels, process vents, and wastewater,
Regulatory Alternative 1 is equivalent to the MACT floor;
thus, no emission reductions or costs beyond those required
to achieve the MACT floor level of control would be
incurred. For equipment leaks and vacuum system generated
wastewater, the HON is more stringent than the MACT floor,
and emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
A second regulatory alternative was developed for batch
DMT processes. As for continuous TPA processes, in the
second regulatory alternative, control of emissions from the
process contact cooling tower was considered through the
replacement of existing steam jet vacuum systems with
ethylene glycol jet vacuum systems. The requirements for
the remaining types of emission points remained the same.
No additional regulatory alternatives were identified.
The EPA estimated the emission reductions and costs
associated with implementing the requirements in Regulatory
Alternatives 1 and 2 that are more stringent than the MACT
floor (see Table 8-12). Considering these impacts, as well
as non-air environmental and energy impacts, the EPA judged
that those portions of Regulatory Alternative 2 more
stringent than the MACT floor were reasonable. Therefore,
the EPA selected Regulatory Alternative 2 as the proposed
standard for existing PET facilities using a batch DMT
process.
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TABLE 8-12. REGULATORY ALTERNATIVE IMPACTS FOR
EXISTING DMT BATCH FACILITIES
Regulatory
Alternative
Existing
Control
1
2
Emission
Reduction
Mg/yr
--
2,567
4,551
Total
Annual
Costs,
$l,000/yr
--
12,023
2,741
Cost-Effectiveness ,
$/Mg
Average
--
4,680
602
Incremental
--
-4,680
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Nitrile Resin Process
Based on available information, only one facility in
the U.S. produces nitrile resin. The information on the
controls used at this one facility was used to evaluate the
MACT floor. Based on the analysis for determining the
relationship between the MACT floor and the HON, the EPA
determined that the HON was less stringent than the MACT
floor for storage vessels, more stringent than the MACT
floor for process vents and equipment leaks, and equivalent
to the MACT floor for wastewater emissions.
Since the HON was determined to be less stringent than
the MACT floor for storage vessels, the EPA defined the MACT
floor and included it as part of the first regulatory
alternative (Regulatory Alternative 1). Since there is only
one facility in this subcategory, the MACT floor is
equivalent to the existing level of control. The EPA
determined that the best representation of the current level
of control for storage vessels is the control of all
acrylonitrile tanks of at least 3,500 gallons capacity and
the application of the HON applicability criteria for all
other chemical storage vessels (see Docket A-92-45,
Category II-B).
The first regulatory alternative considered for the
existing nitrile resin facility consisted of applying the
MACT floor to storage vessels and the HON to process vents,
equipment leaks, and wastewater. For storage vessels and
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wastewater, Regulatory Alternative 1 is equivalent to the
MACT floor/ thus no emission reductions or costs beyond
those required to achieve the MACT floor level of control
would be incurred. For process vents and equipment leaks,
the HON requirements are more stringent than the MACT floor,
and emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA-estimated the emission reductions (10 Mg/yr) and
costs ($6,600/yr) associated with implementing the HON
process vents and equipment leaks requirements compared to
the existing level of control. Considering these impacts,
as well as non-air environmental and energy impacts, the EPA
judged that this level of control was reasonable. No
additional regulatory alternatives were identified. Based
on these considerations, the Administrator selected
Regulatory Alternative 1 as the proposed standard for
existing nitrile resin facilities.
8.3.2 Selection of the Standards for New Sources
The following paragraphs discuss the selection of the
standards for new sources for each subcategory.
ABS. Continuous Emulsion Process
As noted earlier, the EPA identified two facilities in
the U.S. at which ABS is produced using a continuous
emulsion process. The information on controls at both
facilities was used to identify the best level of control
(i.e., MACT floor) for each type of emission point. Based
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on the analysis for determining the relationship between the
MACT floor and the HON, the EPA determined that the HON was
equivalent to the MACT floor for storage vessels, process
vents, and wastewater, and the HON was more stringent than
the MACT floor for equipment leaks.
The first regulatory alternative (Regulatory
Alternative 1) considered for new ABS facilities using a
continuous emulsion process was the HON for storage vessels,
process vents, equipment leaks, and wastewater. For storage
vessels, process vents, and wastewater, Regulatory
Alternative 1 is equivalent to the MACT floor; thus no
emission reductions or costs beyond those required to
achieve the MACT floor level of control would be incurred.
For equipment leaks, the HON requirements are more stringent
than the MACT floor, and emission reductions and costs
beyond those required to achieve the MACT floor level of
control would be incurred. The EPA estimated the emission
reductions and costs associated with implementing the HON
equipment leak requirements. These impacts are based on
confidential information and cannot be presented.
Considering these impacts, as well as non-air environmental
and energy impacts, the EPA judged that this level of
control was reasonable. Therefore, the EPA selected
Regulatory Alternative 1 as the proposed standard for new
ABS facilities using a continuous emulsion process.
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ABS, Continuous Mass Process
As noted earlier, the EPA identified five facilities in
the U.S. at which ABS is produced using a continuous mass
process. The information on controls at all five facilities
was used to identify the best level of control (i.e., MACT
floor) for each type of emission point. Based on the
analysis for determining the relationship between the MACT
floor and the HON, the EPA determined that the HON was less
stringent than the MACT floor for storage vessels, the HON
was equivalent to the MACT floor for process vents and
wastewater, and the HON was more stringent than the MACT
floor for equipment leaks.
Since the HON was less stringent than the MACT floor
for storage vessels, the EPA defined the MACT floor. Three
options were considered for defining the MACT floor:
(l) define vapor pressure and storage vessel capacity
combinations; (2) define chemical type and storage vessel
capacity combinations/ and (3) Option 2 supplemented by
Option 1 for chemicals not specified under Option 2. Based
on this analysis (see Docket A-92-45, Category II-B), the
EPA determined that the best option for defining the MACT
floor was to use vapor pressure and storage vessel size
combinations.
The first regulatory alternative (Regulatory
Alternative 1) considered for new ABS facilities using a
continuous mass process was the MACT floor for storage
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vessels and the HON for process vents, equipment leaks, and
wastewater. For storage vessels, process vents, and
wastewater, Regulatory Alternative 1 is equivalent to the
MACT floor; thus no emission reductions or costs beyond
those required to achieve the MACT floor level of control
would be incurred. For equipment leaks, the HON
requirements are more stringent than the MACT floor, and
emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA developed a second regulatory alternative, which
considered more stringent controls on storage tanks.
The EPA estimated the emission reductions and costs
associated with implementing those requirements of
Regulatory Alternatives 1 and 2 that are more stringent than
the MACT floor. For Regulatory Alternative 2, the EPA
estimated 86 Mg/yr of emission reduction at a cost of
$38,000. These estimates, however, do not reflect the cost
of the more stringent storage vessel requirements in
Regulatory Alternative 2, because the facility selected to
represent new growth would not be affected by the more
stringent requirements. The EPA estimated the emission
reduction and costs of the more stringent storage vessel
requirement for the facility on which the storage vessel
MACT floor was based. For this facility, the more stringent
storage vessels requirements would reduce emissions by 0.75
Mg/yr and a cost of $4,650/yr. Considering these impacts,
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as well as non-air environmental and energy impacts, the EPA
judged that the level of control under Regulatory
Alternative 2 was reasonable. Therefore, the Administrator
selected Regulatory Alternative 2 as the proposed standard
for new ABS facilities using a continuous mass process.
ABS, Batch Emulsion Process
As noted earlier, the EPA identified four facilities in
the U.S. at which ABS is produced using a batch emulsion
process. The information on controls at all four facilities
was used to identify the best level of control (i.e., MACT
floor) for each type of emission point. Based on the
analysis for determining the relationship between the MACT
floor and the HON, the EPA determined that the HON was
equivalent to the MACT floor for storage vessels, wastewater
and process vents, and the HON was more stringent than the
MACT floor for equipment leaks.
The first regulatory alternative (Regulatory
Alternative 1) considered for new ABS facilities using a
batch emulsion process was the HON for storage vessels,
equipment leaks, process vents and wastewater. For storage
vessels, process vents, and wastewater, Regulatory
Alternative 1 is equivalent to the MACT floor; thus no
emission reductions or costs beyond those required to
achieve the MACT floor level of control would be incurred.
For equipment leaks, the HON requirements are more stringent
than the MACT floor, and emission reductions and costs
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beyond those required to achieve the MACT floor level of
control would be incurred. The EPA estimated the emission
reductions (15 Mg/yr) and costs ($14,000/yr) associated with
implementing the HON equipment leak requirements.
Considering these impacts, as well as non-air environmental
and energy impacts, the EPA judged that this level of
control was reasonable. Therefore, the EPA selected
Regulatory Alternative 1 as the proposed standard for new
ABS facilities using a batch emulsion process.
ABS. Batch Suspension Process
As noted earlier, the EPA identified two facilities in
the U.S. at which ABS is produced using a batch suspension
process. The information on controls at both facilities was
used to identify the best level of control (i.e., MACT
floor) for each type of emission point. Based on the
analysis for determining the relationship between the MACT
floor and the HON, the EPA determined that the HON was
equivalent to the MACT floor for storage vessels,
wastewater, and process vents, and the HON was more
stringent than the MACT floor for equipment leaks.
The first regulatory alternative (Regulatory
Alternative 1) considered for new ABS facilities using a
batch suspension process was the HON for storage vessels,
equipment leaks, process vents, and wastewater. For storage
vessels, process vents, and wastewater, Regulatory
Alternative 1 is equivalent to the MACT floor; thus no
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emission reductions or costs beyond those required to
achieve the MACT floor level of control would be incurred.
For equipment leaks, the HON requirements are more stringent
than the MACT floor, and emission reductions and costs
beyond those required to achieve the MACT floor level of
control would be incurred. The EPA estimated the emission
reductions of 5 Mg/yr and a cost savings of $500/yr
associated with implementing the HON equipment leak
requirements. Considering these impacts, as well as non-air
environmental and energy impacts, the EPA judged that this
level of control was reasonable. Therefore, the EPA
selected Regulatory Alternative 1 as the proposed standard
for new ABS facilities using a batch suspension process.
ABS, Latex Process
As noted earlier, the EPA identified one facility in
the U.S. at which ABS is produced using a latex process.
The information on controls at this facility was used to
identify the best level of control (i.e., MACT floor) for
each type of emission point. Based on the analysis for
determining the relationship between the MACT floor and the
HON, the EPA determined that the HON was equivalent to the
MACT floor for storage vessels, process vents, and
wastewater, and the HON was more stringent than the MACT
floor for equipment leaks.
The first regulatory alternative (Regulatory
Alternative 1) considered for new ABS latex facilities was
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the HON for storage vessels, process vents, equipment leaks,
and wastewater. For storage vessels, process vents, and
wastewater, Regulatory Alternative 1 is equivalent to the
MACT floor; thus no emission reductions or costs beyond
those required to achieve the MACT floor level of control
would be incurred. For equipment leaks, the HON
requirements are more stringent than the MACT floor, and
emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions and costs
associated with implementing the HON equipment leak
requirements for any new facilities based on existing
facilities. Considering these impacts, as well as non-air
environmental and energy impacts, the EPA judged that this
level of control was reasonable. Therefore, the EPA
selected Regulatory Alternative 1 as the proposed standard
for new ABS latex facilities.
MABS Process
The EPA identified one facility in the U.S. at which
MABS is produced. The information on controls at this
facility was used to identify the best levels of control
(i.e., MACT floor) for each type of emission point. Based
on the analysis for determining the relationship between the
MACT floor and the HON, the EPA determined that the HON was
equivalent to the MACT floor for storage vessels, process
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vents, and wastewater, and more stringent than the MACT
floor for equipment leaks.
The first regulatory alternative (Regulatory
Alternative 1) considered for new MABS facilities consisted
of applying the HON to all types of emission points. For
storage vessels, process vents, and wastewater, Regulatory
Alternative 1 is equivalent to the MACT floor; thus, no
emission reductions or costs beyond those required to
achieve the MACT floor level of control would be incurred.
For equipment leaks, the HON requirements are more stringent
than the MACT floor, and emission reductions and costs
beyond those required to achieve the MACT floor level of
control would be incurred. The EPA estimated the emission
reductions and costs associated with implementing the HON
equipment leak requirements for any new facilities based on
existing facilities. These impacts are based on
confidential information and cannot be presented.
Considering these impacts, as well as non-air environmental
and energy impacts, the EPA judged that this level of
control was reasonable. Therefore, the EPA selected
Regulatory Alternative 1 as the proposed standard for new
MABS facilities.
MBS Process
The EPA identified three facilities in the U.S. at
which MBS is produced. The information on controls at all
three facilities was used to identify the best levels of
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control (i.e., MACT floor) for each type of emission point.
Based on the analysis for determining the relationship
between the MACT floor and the HON, the EPA determined that
the HON was equivalent to the MACT floor for storage
vessels, process vents, equipment leaks, and wastewater.
The first regulatory alternative (Regulatory
Alternative 1) considered for new MBS facilities consisted
of applying the HON to all types of emission points. For
all types of emission points, Regulatory Alternative 1 is
equivalent to the MACT floor; thus, no emission reductions
or costs beyond those required to achieve the MACT floor
level of control would be incurred. Therefore, the EPA
selected Regulatory Alternative 1 as the proposed standard
for new MBS facilities.
SAN. Continuous Process
As noted earlier, the EPA identified three facilities
in the U.S. at which SAN is produced using a continuous
process. The information on controls at all three
facilities was used to identify the best level of control
(i.e., MACT floor) for each type of emission point. Based
on the analysis for determining the relationship between the
MACT floor and the HON, the EPA determined that the HON was
less stringent than the MACT floor for storage vessels, the
HON was equivalent to the MACT floor for process vents and
wastewater, and the HON was more stringent than the MACT
floor for equipment leaks.
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Since the HON was less stringent than the MACT floor
for storage vessels, the EPA defined the MACT floor. Three
options were considered for defining the MACT floor:
(1) define vapor pressure and storage vessel capacity
combinations; (2) define chemical type and storage vessel
capacity combinations; and (3) Option 2 supplemented by
Option 1 for chemicals not specified under Option 2. Based
on this analysis (see Docket A-92-45, Category II-B), the
EPA determined that the best option for defining the MACT
floor was to use vapor pressure and storage vessel size
combinations.
The first regulatory alternative (Regulatory
Alternative 1) considered for new SAN facilities using a
continuous process was the MACT floor for storage vessels
and the HON for process vents, equipment leaks, and
wastewater. For storage vessels, process vents, and
wastewater, Regulatory Alternative 1 is equivalent to the
MACT floor; thus no emission reductions or costs beyond
those required to achieve the MACT floor level of control
would be incurred. For equipment leaks, the HON
requirements are more stringent than the MACT floor, and
emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions (25 Mg/yr) and
costs ($38,000/yr) associated with implementing the HON
equipment leak requirements. Considering these impacts, as
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well as non-air environmental and energy impacts, the EPA
judged that this level of control was reasonable.
Therefore, the EPA selected Regulatory Alternative 1 as the
proposed standard for new SAN facilities using a continuous
process.
SAN. Batch Processes
The EPA identified two existing facilities in the U.S.
at which SAN is produced using a batch process. The
information on controls at both facilities was used to
identify the best level of control (i.e., MACT floor) for
each type of emission point. Based on the analysis for
determining the relationship between the MACT floor and the
HON, the EPA determined that the HON was equivalent to the
MACT floor for storage vessels and wastewater, that the HON
was less stringent than the MACT floor for process vents,
and that the HON was more stringent than the MACT floor for
equipment leaks.
Since the HON and Batch Processes ACT were less
stringent than the MACT floor for process vents, the EPA
defined the MACT floor. The EPA considered an emission
factor and a percent reduction for defining the MACT floor.
Based on its analysis (see Docket A-92-45, Category II-B),
the EPA determined that percent reduction was the best
option for defining the MACT floor.
The first regulatory alternative (Regulatory
Alternative 1) considered for new SAN facilities using a
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batch process consisted of applying the HON to storage
vessels, equipment leaks, and wastewater, and the MACT floor
to process vents. For storage vessels, process vents, and
wastewater, Regulatory Alternative 1 is equivalent to the
MACT floor; thus, no emission reductions or costs beyond
those required to achieve the MACT floor level of control
would be incurred. For equipment leaks, the HON
requirements are more stringent than the MACT floor, and
emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions (6.4 Mg/yr) and
costs ($l,300/yr) associated with implementing the HON
equipment leak requirements. Considering these impacts, as
well as non-air environmental and energy impacts, the EPA
judged that this level of control was reasonable.
Therefore, the Administrator selected Regulatory Alternative
1 as the proposed standard for new SAN facilities using a
batch process.
ASA/AMSAN Facilities
As noted earlier, only one facility in the U.S. was
identified as producing ASA/AMSAN resins. Since there is
only one facility, the MACT floor for new facilities is the
same as for existing facilities, and the relationship of the
current level of control to the HON was found to be the same
as that for ASA/AMSAN existing facilities. For these
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reasons, the EPA is proposing the same standards for new
ASA/AMSAN facilities as for existing ASA/AMSAN facilities.
Polystyrene. Continuous Processes
As noted earlier, the EPA identified 22 facilities in
the U.S. at which polystyrene is produced using a continuous
process. The information on controls at all 22 facilities
was used to identify the best level of control (i.e., MACT
floor) for each type of emission point. Based on the
analysis for determining the relationship between the MACT
floor, the HON, and the Polymers NSPS, the EPA determined
that the HON was equivalent to the MACT floor for
wastewater, that the HON and Polymers NSPS were equivalent
to the MACT floor for process vents, that the HON was more
stringent than the MACT floor for equipment leaks and that
the HON was less stringent than the MACT floor for storage
vessels.
The first regulatory alternative (Regulatory
Alternative 1) considered for new polystyrene facilities
using a continuous process consisted of applying the MACT
floor to storage vessels, applying the HON to process vents
from process sections other than the material recovery
section, equipment leaks, and wastewater, and applying the .
Polymers NSPS to process vents from the material recovery
section. For storage vessels, wastewater, and process
vents, Regulatory Alternative 1 is equivalent to the MACT
floor; thus no emission reductions or costs beyond those
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required to achieve the MACT floor level of control would be
incurred. For equipment leaks, the HON requirements are
more stringent than the MACT floor, and emission reductions
and costs beyond those required to achieve the MACT floor
level of control would be incurred. The EPA estimated the
emission reductions (212 Mg/yr) and costs ($85,600/yr)
associated with implementing the HON requirements for
equipment leaks. Considering these impacts, as well as non-
air environmental and energy impacts, the EPA judged that
this level of control was reasonable. Therefore, the EPA
selected Regulatory Alternative 1 as the proposed standard
for new polystyrene facilities using a continuous process.
Polystyrene, Batch Processes
The EPA identified 11 existing facilities in the U.S.
at which polystyrene is produced using a batch process. The
information on controls at these 11 facilities was used to
identify the best level of control (i.e., MACT floor) for
each type of emission point. Based on the analysis for
determining the relationship between the MACT floor and the
HON, the EPA determined that the HON was equivalent to the
MACT floor for storage vessels and wastewater, and that the
HON was more stringent than the MACT floor for process vents
and equipment leaks.
The first regulatory alternative (Regulatory
Alternative 1) considered for new polystyrene facilities
using a batch process consisted of applying the HON to
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storage vessels, equipment leaks, process vents, and
wastewater. For storage vessels and wastewater, Regulatory
Alternative 1 is equivalent to the MACT floor; thus, no
emission reductions or costs beyond those required to
achieve the MACT floor level of control would be incurred.
For process vents and equipment leaks, the HON requirements,
are more stringent than the MACT floor, and emission
reductions and costs beyond those required to achieve the
MACT floor level of control would be incurred. The EPA
estimated the emission reductions and costs associated with
implementing the HON equipment leak and process vent
requirements for any new facilities based on existing
facilities. Considering these impacts, as well as non-air
environmental and energy impacts, the EPA judged that this
level of control was reasonable. Therefore, the
Administrator selected Regulatory Alternative I as the
proposed standard for new polystyrene facilities using a
batch process.
Expandable Polystyrene Processes
The EPA identified 7 existing facilities in the U.S. at
which expandable polystyrene is produced. The information
on controls at these 7 facilities was used to identify the
best level of control (i.e., MACT floor) for each type of
emission point. Based on the analysis for determining the
relationship between the MACT floor and the HON, the EPA
determined that the HON was equivalent to the MACT floor for
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storage vessels, process vents, and wastewater, and that the
HON was more stringent than the MACT floor for equipment
leaks.
The first regulatory alternative (Regulatory
Alternative 1) considered for new expandable polystyrene
facilities consisted of applying the HON to storage vessels,
equipment leaks, process vents, and wastewater. For storage
vessels, process vents, and wastewater, Regulatory
Alternative 1 is equivalent to the MACT floor; thus, no
emission reductions or costs beyond those required to
achieve the MACT floor level of control would be incurred.
For equipment leaks, the HON requirements are more stringent
than the MACT floor, and emission reductions and costs
beyond those required to achieve the MACT floor level of
control would be incurred. The EPA estimated the emission
reductions and costs associated with implementing the HON
equipment leak requirements for any new facility based on
existing facilities. Considering these impacts, as well as
non-air environmental and energy impacts, the EPA judged
that this level of control was reasonable. Therefore, the
Administrator selected Regulatory Alternative 1 as the
proposed standard for new expandable polystyrene facilities.
PET - TPA. Continuous Processes
As noted earlier, 12 facilities in the U.S. were
identified at which PET is being produced using a continuous
TPA process. The information on controls at all 12
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facilities was used to determine the best levels of controls
(i.e., MACT floor) for each type of emission point. Based
on the analysis for determining the relationship between the
MACT floor, the HON, and Polymers NSPS the EPA determined
that the HON was equivalent to the MACT floor for storage
vessels, and wastewater, that the HON and Polymers NSPS were
equivalent to the MACT floor for process vents, and that the
HON was more stringent than the MACT floor for equipment
leaks. In addition, it was determined that the best
controlled facility did not have a process contact cooling
tower and used ethylene glycol jets in its vacuum system.
Therefore, these emission reduction design aspects of a
continuous TPA facility were determined to be part of the
MACT floor for this subcategory.
The first regulatory alternative (Regulatory
Alternative 1) considered for new PET facilities using a
continuous TPA process consisted of applying 1) the HON to
storage vessels, equipment leaks, and wastewater, 2) the HON
and Polymers NSPS to process vents, and 3) prohibiting the
use of cooling tower water in the contact condensers in the
vacuum system. For all emission points other than equipment
leaks, Regulatory Alternative 1 is equivalent to the MACT
floor; thus, no emission reductions or costs beyond those
required to achieve the MACT floor level of control would be
incurred under Regulatory Alternative 1. For equipment
leaks, the HON requirements are more stringent than the MACT
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floor, and emission reductions and costs beyond those
required to achieve the MACT floor level of control would be
incurred.
The EPA estimated the emission reductions (473 Mg/yr)
and costs ($744,000/yr) associated with implementing the HON
equipment leaks requirements. Considering these impacts, as
well as non-air environmental and energy impacts, the EPA
judged that this level of control was reasonable.
Therefore, the EPA selected Regulatory Alternative 1 as the
proposed standard for new PET facilities using the
continuous TPA process.
PET - TPA. Batch Processes
Only one facility in the U.S. has been identified as
producing PET using a batch TPA process. The information on
the controls used at this facility was used to determine the
best levels of control (i.e., MACT floor) for storage
vessels, process vents, equipment leaks, and wastewater.
However, for process contact cooling towers, the EPA
determined that it was appropriate to look to similar
sources outside the subcategory for determining the best
level of control. As presented previously for continuous
TPA processes, the best level of control is represented by
no process contact cooling tower and the use of ethylene
glycol jets in the vacuum system. The EPA believes that
this level of control represents the MACT floor for
facilities using a batch TPA process.
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Based on the analysis for determining the relationship
between the MACT floor and the HON, the EPA determined that
the HON was equivalent to the MACT floor for storage
vessels, process vents, and wastewater, and the HON is more
stringent than the MACT floor for equipment leaks. Further,
the EPA judged that prohibiting the use of cooling tower
water in the contact condensers in the vacuum system is
equivalent to the MACT floor.
The first regulatory alternative (Regulatory
Alternative 1) considered for the new PET facilities using a
batch TPA process consisted of applying the HON to storage
vessels, equipment leaks, process vents, and wastewater, and
prohibiting the use of cooling tower water in the contact
condensers in the vacuum system. For all emission points
other than equipment leaks, Regulatory Alternative 1 is
equivalent to the MACT floor; thus no emission reductions or
costs beyond those required to achieve the MACT floor
control level would be incurred. For equipment leaks, the
HON requirements are more stringent than the MACT floor, and
emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions (5.6 Mg/yr)
and costs ($17,700/yr) associated with implementing the HON
equipment leak requirements. Considering these impacts, as
well as non-air environmental and energy impacts, the EPA
judged that this level of control was reasonable.
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Therefore, the EPA selected Regulatory Alternative 1 as the
proposed standard for new PET facilities using a batch TPA
process.
PET - DMT. Continuous Processes
The EPA identified 10 facilities in the U.S. at which
PET is produced using a DMT continuous process. The
information on controls at all 10 facilities was used to
determine the best level of control (i.e., MACT floor) for
each emission source type. Based on the analysis for
determining the relationship between the MACT floor, the
HON, and Polymers NSPS, the EPA determined that the HON was
equivalent to the MACT floor for storage vessels and
wastewater, the HON and Polymers NSPS were equivalent to the
MACT floor for process vents, and the HON was more stringent
than the MACT floor for equipment leaks. In addition, it
was determined that the best controlled facility did not
have a process contact cooling tower and used ethylene
glycol jets in its vacuum system. Therefore, these emission
reduction design aspects of a continuous DMT facility were
determined to be part of the MACT floor for this
subcategory.
The first regulatory alternative (Regulatory
Alternative 1) considered for new PET facilities using a
continuous DMT process consisted of applying 1) the HON to
storage vessels, equipment leaks, and wastewater, 2) the HON
and Polymers NSPS to process vents, and 3) prohibiting the
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use of cooling tower water in the contact condensers in the
vacuum system. For all emission points other than equipment
leaks, Regulatory Alternative 1 is equivalent to the MACT
floor; thus no emission reductions or costs beyond those
required to achieve the MACT floor control level would be
incurred. For equipment leaks, the HON requirements are
more stringent than the MACT floor, and emission reductions
and costs beyond those required to achieve the MACT floor
level of control would be incurred.
The EPA estimated the emission reductions (903 Mg/yr)
and costs ($988,000/yr) associated with implementing the HON
equipment leak requirements. Considering these impacts, as
well as non-air environmental and energy impacts, the EPA
judged that this level of control was reasonable.
Therefore, the EPA selected Regulatory Alternative 1 as the
proposed standard for new PET facilities using a continuous
DMT process.
PET - DMT. Batch Processes
As noted earlier, the EPA identified 10 facilities in
the U.S. at which PET is produced using a DMT batch process.
The information on controls at all 10 facilities was used to
determine the best levels of controls (i.e., MACT floor) for
each type of emission point. Based on the analysis for
determining the relationship between the MACT floor and the
HON, the EPA determined that the HON was equivalent to the
MACT floor for storage vessels, process vents, and
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wastewater, and the HON was more stringent than the MACT
floor for equipment leaks. In addition, it was determined
that the best controlled facility did not have a process
contact cooling tower. Therefore, the EPA has defined the
MACT floor for new batch DMT facilities as "no process
contact cooling towers".
As for batch TPA facilities, the EPA determined that it
was appropriate to look to similar sources outside the
subcategory for determining the best level of control for
the control of emissions from the vacuum system generated
wastewater. As presented previously for continuous TPA
processes, the best level of control is represented by no
process contact cooling tower and the use of ethylene glycol
jets in the vacuum system. As discussed above, "no process
contact cooling towers" was determined to be part of the
MACT floor for new facilities using a batch DMT process.
The EPA believes that the use of ethylene glycol jets also
represents the MACT floor for new facilities using a batch
DMT process.
The first regulatory alternative (Regulatory
Alternative 1) considered for new PET facilities using a
batch DMT process consisted of applying the HON to storage
vessels, equipment leaks, process vents and wastewater, and
prohibiting the use of cooling tower water in the contact
condensers in the vacuum system. For all emission points
other than equipment leaks, Regulatory Alternative 1 is
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equivalent to the MACT floor; thus, no emission reductions
or costs beyond those required to achieve the MACT floor
level of control would be incurred. For equipment leaks,
the HON requirements are more stringent than the MACT floor,
and emission reductions and costs beyond those required to
achieve the MACT floor level of control would be incurred.
The EPA estimated the emission reductions (408 Mg/yr)
and costs ($569,000/yr) associated with implementing the HON
equipment leak requirements. Considering these impacts, as
well as non-air environmental and energy impacts, the EPA
judged that this level of control was reasonable.
Therefore, the EPA selected Regulatory Alternative 1 as the
proposed standard for new PET facilities using a batch DMT
process.
Nitrile Resin Process
As noted earlier, only one facility in the U.S. was
identified as producing nitrile resins. Since there is only
one facility, the MACT floor for new facilities is the same
as for existing facilities, and the relationship of the
current level of control to the HON was found to be the same
as that for ASA/AMSAN existing nitrile resin facilities.
For these reasons, the EPA is proposing the same standards
for new nitrile resin facilities as for existing nitrile
resin facilities.
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8.4 RATIONALE FOR THE SELECTION OF THE FORMAT OF THE
PROPOSED STANDARDS
The proposed standards adopt the formats found in the
HON, the Batch Processes ACT, and Polymers NSPS. The
Federal Register notice for the HON (57 FR 62608;
December 31, 1992) provides the rationale for the selection
of the specific formats used in the final rule for the HON.
The Batch Processes ACT document discusses the selection of
formats presented by the ACT. The Federal Register notice
for the Polymers NSPS (57 FR 36678, September 30, 1987)
provides the rationale for the selection of the formats
associated with the process vent limits. The EPA finds no
reason for changing those formats and, therefore, has
adopted the same formats for this rule as have been
promulgated for the HON and Polymers NSPS and as were
presented in the Batch Processes ACT.
In addition to adopting various portions of existing
standards, the proposed rule also contains standards for
controlling process contact cooling tower emissions at PET
facilities by prohibiting the use of cooling tower water in
contact condensers in the vacuum system and requiring any
vacuum system generated wastewater to be controlled,
regardless of its organic HAP content or flowrate, provided
the organic HAP present in the stream are specified on
Table 9 of the HON wastewater provisions. In some cases/
the standards are a more stringent version of the HON, yet
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the format of the standard remains the same as the HON
format. In other cases, a format found in the HON (i.e.,
percent reduction) is used with a slight variation. All of
these situations are discussed in the following paragraphs.
As has been discussed, the best controlled PET
facilities for process contact cooling towers are those that
an ethylene glycol jet vacuum system, which eliminates the
process contact cooling tower and other vacuum system
generated wastewater emissions. Since there are no known
demonstrated techniques for eliminating organic HAP
emissions from process contact cooling towers, the only
format possible was a work practice/design standard. Rather
than dictating the use of a specific type of vacuum system
(i.e., the use of ethylene glycol jets), the EPA is
proposing to (1) prohibit the use of cooling tower water in
contact condensers in the vacuum system and (2) since some
vacuum systems still may generate some wastewater, require
all vacuum system generated wastewater be controlled,
regardless of its organic HAP content or flowrate provided
the organic HAP present in the stream are specified on
Table 9 of the HON wastewater provisions.
For the following types of emission points for the
indicated subcategories, a more stringent version of the HON
is being proposed as the standard: (1) storage vessels at
existing and new ASA/AMSAN facilities, new SAN facilities
using a continuous process, new ABS facilities using a
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continuous mass process, existing and new nitrile resin
facilities, and existing and new polystyrene facilities and
(2) process vents at existing MBS facilities, existing and
new ASA/AMSAN facilities, and new SAN facilities using a
batch process. For most of these situations, the EPA finds
no reason for changing the HON formats and, therefore, have
adopted the HON formats for this rule. The following
paragraphs discuss those situations where alternative
formats have been adopted for storage tanks and process
vents.
For storage vessels at existing and new ASA/AMSAN
facilities and some storage vessels at new SAN continuous
facilities, the format of the standard is a percent
reduction. In both cases, the choice of format was greatly
influenced by the uniqueness of the facilities in the
subcategory. There is only one identified facility
producing ASA/AMSAN and the basis of the standard for new
SAN continuous facilities is the one "best controlled"
facility. In each case, the available data for the facility
considered led the EPA to select a percent reduction format.
Other format options (e.g., design and equipment standards)
would not have accurately represented the level of control
being achieved at these facilities.
For process vents at existing and new ASA/AMSAN
facilities, the uniqueness of the subcategory greatly
influences the format of the proposed standard. Only one
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facility in the U.S. that produces ASA/AMSAN was identified
and, based on the available data, every process vent is
controlled through combustion. The most appropriate formats
for representing the performance capabilities of combustion
units is percent reduction or concentration (parts per
million). These formats were therefore selected for the
proposed standards, which require these process vents to be
reduced by at least 98 percent or to 20 ppmv, whichever is
less stringent.
For process vents at new SAN batch facilities, a
percent reduction format was selected. Three other options
that were considered were identifying specific process vents
to be controlled, a "TRE-like" approach, or an emission
factor. Because of the possibility of different process
vent configurations between facilities and different
emission characteristics for process vents with the same
name (e.g., dryer vent), a format that identified specific
process vents for control was not accepted. Because stream
characteristics of batch process vents are difficult to
describe and stream characteristic data were not available,
a "TRE-like" approach could not be used. Finally, because
the MACT floor for new sources is based on a single facility
(i.e., the best controlled facility), use of an emission
factor would reveal confidential production data. After
these considerations, the EPA found a percent reduction
format to be the most widely applicable.
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8.5 RATIONALE FOR THE SELECTION OF COMPLIANCE AND
PERFORMANCE TEST PROVISIONS AND MONITORING REQUIREMENTS
For the most part, the level of control required by the
proposed rule are the same as those in the HON or Polymers
NSPS. Further, the control devices likely to be used in
complying with the proposed requirements for batch process
vents were already considered as part of the HON. As a
result, the EPA has determined that there is no need to
change performance testing provisions or the parameters
selected for monitoring. Since the rationale for the
selected provisions has been presented in detail in the
proposal and promulgation preambles to the HON, it is not
repeated here in the same depth. The paragraphs below
briefly discuss the rationale for the selected provisions
for each type of emission point. Later in this section, the
rationales for the use of parameter monitoring and the
overall compliance certification provisions are presented.
8.5.1 Continuous Process Vents
The proposed rule specifies the group determination
procedures, performance tests, monitoring requirements, and
test methods necessary to determine whether a process vent
from a continuous unit operation is required to be
controlled and to demonstrate that the allowed emission
levels are achieved when controls are applied. The
following paragraphs discuss each of these.
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8.5.1.1 Group determination procedures
Except as discussed in the next paragraph, the proposed
rule requires each owner or operator to determine for each
continuous process vent whether the vent is a Group 1 or
Group 2 process vent. There are three group determination
procedures: (1) process vent flowrate measurement,
(2) process vent organic HAP concentration measurement, and
(3) TRE index value determination. A detailed discussion of
the rationale for these three procedures is found on pages
62636-62637 of Federal Register Vol. 57, No. 252,
December 31, 1992.
An owner or operator may chose to comply directly with
the requirement to reduce organic HAP emissions by
98 weight-percent or to an outlet concentration of 20 ppmv
through use of a control device.
Finally, for continuous process vents at some
subcategories (e.g., ASA/AMSAN), a Group I/Group 2
determination is not required.
8.5.1.2 Performance test
Initial performance tests are required for all control
devices other than flares and certain boilers and process
heaters. Specifically, testing would be required for:
(1) incinerators, (2) scrubbers used with combustion devices
to control halogenated vent streams, and (3) some boilers
and process heaters smaller than 44 megawatts (MW)
[150 million British thermal units (Btu/hr)]. Performance
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tests are being required because they (1) ensure that a
control device achieves the required control level and (2)
serve as the basis for establishing operating parameter
levels required for monitoring.
Because their percent reduction and outlet
concentration cannot feasibly be measured, flares are not
required to be tested and instead must meet the requirements
in Section 63.11 for operating conditions.
8.5.1.3 Test methods
The proposed process vent provisions would require the
use of approved test methods to ensure consistent and
verifiable results for group determination procedures,
initial performance tests, and compliance demonstrations.
8.5.1.4 Monitoring
Control devices used to comply with the proposed rule
need to be maintained and operated properly if the required
level of control is to be achieved on a continuing basis.
Monitoring of the control device operating parameters can be
used to ensure that such proper operation and maintenance
are occurring.
The proposed standard lists the parameters that can be
monitored for the common types of combustion devices:
firebox temperature for thermal incinerators; temperature
upstream and downstream of the catalyst bed for catalytic
incinerators; firebox temperature for boilers and process
heaters/ and presence of a flame at the pilot light for
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flares. These parameters were selected because they are
good indicators of combustion device performance, and
instruments are readily available at a reasonable cost to
continuously monitor these parameters. The proposed rule
also allows the owner or operator to request to monitor
other parameters on a site-specific basis. The proposed
rule also specifies monitoring requirements for scrubbers
installed to remove halogens and hydrogen halides from the
combustor outlet.
The proposed standard would require the owner or
operator to establish site-specific parameter levels through
the Notification of Compliance Status report and operating
permit. Site-specific parameter levels accommodate site-
specific differences in control design and process vent
stream characteristics.
For Group 2 continuous process vents that have TRE
index values greater than 1.0 but less than or equal to 4.0
(greater than 3.7 but less than 6.7 for continuous process
vents at existing MBS facilities), monitoring of the final
recovery device would be required to ensure that it
continues to be operated as it was during the group
determination test when the initial TRE index value was
calculated. Improper recovery device operation and
maintenance could lead to increased organic HAP
concentration, potentially reducing the TRE index value
below l.O, and causing the vent to become a Group 1 process
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vent. Continuous monitoring will ensure continued good
performance of recovery devices. The TRE index value
monitoring level of 4.0 is being proposed because the
variability of the process parameters established during
normal operating conditions are unlikely to vary to the
extent that a TRE value above 4.0 would be reduced to a TRE
level less than 1.0 and thus require control.
The proposed rule specifies the parameters that can be
monitored for the three common types of recovery devices:
1) exit temperature of the absorbing liquid and exit
specific gravity for absorbers; 2) exit temperature for
condensers; and 3) total regeneration stream mass flow
during carbon bed regeneration cycle and temperature of the
carbon bed after regeneration for carbon adsorbers. These
parameters were selected because they are good indicators of
recovery device performance, and instruments are readily
available at a reasonable cost to continuously monitor these
process parameters. The proposed rule also allows the owner
or operator to request to monitor parameters on a site-
specific basis. The owner or operator would establish a
site-specific level for the parameters through the
Notification of Compliance Status report and operating
permit.
8.5.2 Batch Process Vents
As for continuous process vents, some batch process
vents are more cost effective to control than others.
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Therefore, cost effectiveness is related to the procedures
that are being proposed for the group determination for
batch process vents. These procedures are taken from the
Batch Processes Alternative Control Technologies (ACT)
document. The Batch Processes ACT describes applicability
criteria (i.e., annual emissions and annual average
flowrate) for distinguishing between batch process vents
that are cost effective to control and those that are not.
The rationale for these applicability criteria and
procedures is presented in depth in the Batch Processes ACT
document.
For the same reasons the proposed rule requires a
performance test and continuous monitoring of a control
device for a continuous process vent, performance tests and
continuous monitoring are required for the control or
recovery device used by an affected source to comply with
the batch process vents control requirement. Also, the
monitoring parameters selected for recovery devices were
presented and discussed as part of the continuous process
vent provisions and in the preamble to the proposed
subpart G.
Because compliance with the batch process vent
standards is determined on an annual basis, the EPA
established the batch cycle limitation for Group 2 batch
process vents in an attempt to minimize the number of Group
2 batch process vents that would become non-compliant. The
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purpose of the batch cycle limitation, and quarterly
reporting of the number of batch cycles accomplished, is to
ensure that a Group 2 batch process vent does not become a
Group 1 batch process vent simply due to accomplishing more
batch cycles in a year than were anticipated at the time the
initial group determination was made. As mentioned earlier,
an affected source may set the batch cycle limitation at any
level it desires as long as the batch process vent remains a
Group 2 batch process vent. Since this may prove too
"restrictive" for an owner or operator, the proposed rule
allows an owner or operator to declare any batch process
vent Group 1 and control as required by the proposed rule.
Like continuous process vents, owners or operators are
not required to make a Group 1/Group 2 determination for all
batch process vents. The proposed standards for process
vents, continuous and batch, at new SAN batch facilities
require an 84 percent emission reduction in overall process
vent emissions. The proposed standards do not require a
Group I/Group 2 determination.
8.5.3 Storage Vessels
The proposed storage vessel provisions require control
by tank improvements or a closed vent system and control
device; however, the choice of control technologies is
limited depending on the material stored. For vessels
storing liquids with vapor pressures less than
76.6 kilopascals (kPa), either control option may be
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selected. However, for vessels storing liquids with vapor
pressures greater than or equal to 76.6 kPa, tank
improvements do not achieve the expected level of emission
reductions. As a result, Group 1 storage vessels containing
liquids with a maximum true vapor pressure of organic HAP
greater than or equal to 76.6 kPa must be controlled with a
closed vent system and control device.
8.5.4 Wastewater
Two important parameters must be quantified initially,
and whenever process changes are made, to determine whether
a process wastewater stream is a Group 1 or Group 2 stream.
These parameters are the annual wastewater quantity for a
stream and the volatile organic HAP (VOHAP) concentration in
the stream. The VOHAP concentration can be quantified as a
flow-weighted annual average for total VOHAP or for
individually-speciated organic HAP. Several methods are
allowed by the proposed rule for determining both of these
parameters.
Initial performance tests for control of Group 1
wastewater streams are not required by the proposed rule.
For treatment processes and control devices, facilities have
the choice of using either performance tests or engineering
calculations to demonstrate the compliance of those units
with the standards. Engineering calculations, supported by
the appropriate documentation, have been allowed to provide
a less costly alternative to that of actual testing.
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A performance test is not specified for the design
steam stripper. Installation of the specified equipment,
along with monitoring to show attainment of the specified
operating parameter levels, demonstrates compliance with the
equipment design and operation provisions. Thus, a
performance test is not necessary.
The proposed process wastewater provisions include
requirements for periodic monitoring and inspections to
ensure proper operation and maintenance of the control
system and continued compliance.
8.5.5 Equipment Leaks
The proposed rule retains the use of Method 21 to
detect leaks of organic compounds from equipment; however,
several modifications were made to the existing procedures.
These modifications consist of changes to the calibration
gases required, addition of procedures for response factor
correction, and addition of procedures for pressure testing
of batch processes. The bases for the changes to the
provisions are presented in the preamble to the proposed
subpart H.
8.5.6 Heat Exchange Systems
Periodic monitoring for leaks is required to
demonstrate compliance for this type of emission point. The
frequency of periodic monitoring becomes less frequent as
data show that leaks are not present. This monitoring
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system is proposed to minimize the burden on the affected
source.
8.5.7 Process Contact Cooling Towers
Since the proposed rule prohibits the use of cooling
tower water in contact condensers associated with vacuum
systems, there are no continual monitoring or compliance
activities. Instead, owners or operators must initially
state that they will comply with the rule in their
Implementation Plan and Notification of Compliance Status.
8.6 RATIONALE FOR THE SELECTION OF PARAMETER MONITORING AND
COMPLIANCE CERTIFICATION PROVISIONS
The proposed rule requires monitoring of control and
recovery device operating parameters and reporting of
periods when parameter values are above maximum or below
minimum established levels. Under the NSPS and NESHAP
programs, parameter monitoring has traditionally been used
as a. tool in determining whether control devices are being
maintained and operated properly. However,
Section 114(a)(3) of the Act and Section 70.6(c) of the
operating permit rule (57 FR 32251) require the submission
of "compliance certifications" from sources subject to the
operating permit program. Section 114(a)(3) of the amended
Act requires enhanced monitoring and compliance
certifications of all major stationary sources. The annual
compliance certifications certify whether compliance has
been continuous or intermittent. Enhanced monitoring shall
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be capable of detecting deviations from each applicable
emission limitation or standard with sufficient
representativeness, accuracy, precision, reliability,
frequency, and timeliness to determine if compliance is
continuous during a reporting period. The monitoring in
this regulation satisfies the requirements of enhanced
monitoring.
In light of these requirements, the EPA has considered
how sources subject to this rule would demonstrate
compliance. The EPA has concluded that operating parameter
monitoring can be used for this purpose.
For the proposed rule, the EPA is requiring affected
sources to establish site-specific parameter levels.
Although in previous NSPS and NESHAP, the EPA has specified
a pre-determined range of operating parameter values, such
values could be considered inadequate given the increased
importance of parameter monitoring in determining and
certifying compliance due to the new requirements in
Section 114 of the Act. Allowing site-specific levels for
monitored parameters accommodates site-specific variation in
emission point characteristics and control device designs.
The proposed procedure for establishing operating parameter
levels for continuous and batch process vents is based on
performance tests.
The proposed rule requires the affected source to
record daily average values for continuously monitored
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parameters. The daily average is the average of all of the
15-minute values generated by the continuous recorder during
the operating day. If the daily average value is outside
the established range, it must be reported. The daily
averaging period was selected because the purpose of
monitoring data is to ensure proper operation and
maintenance of the control device. Because it often takes
from 12 to 24 hours to correct a problem, this averaging
period was considered to best reflect operation and
maintenance practices. This averaging period therefore
gives the owner or operator a reasonable period of time to
take action. If a shorter averaging period (for example
3 hours) was selected, affected sources would be likely to
have multiple excursions caused by the same operational
problem because it would not be possible to correct problems
in one 3-hour reporting period.
In the proposed rule, as in subpart G, at least 75
percent of monitoring data is required to constitute a valid
day's worth of data. For example, for continuous process
vents an affected source needs to have valid monitoring data
for at least 75 percent of the operating hours in a given
operating day to have a valid day's worth of monitoring
data.
Whereas the HON allows excused excursions to reflect
the uncertainty of parameter monitoring, the proposed rule
does not allow excused excursions. Excused excursions are
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not included in the proposed rule because most continuous
monitoring system problems can be dealt with in the context
of the start-up, shutdown, and malfunction plan required
under subpart A.
8.7 RATIONALE FOR THE SELECTION OF RECORDKEEPING AND
REPORTING REQUIREMENTS
The general recordkeeping and reporting requirements of
this subpart are very similar to those found in subpart G of
part 63. The proposed rule also relies on the provisions of
subpart A of part 63. A table included in the proposed rule
designates which sections of subpart A apply to the proposed
rule.
The proposed rule would require affected sources to
submit the following six types of reports:
1. Initial Notification,
2. Implementation Plan (if an operating permit
application has not been submitted or, for new
sources, an application for approval of
construction or reconstruction),
3 . Emissions Averaging Plan,
4. Notification of Compliance Status,
5. Periodic Reports, and
6 . Other reports.
The purpose and contents of each of these reports are
described in this section. The wording of the proposed rule
requires all draft reports to be submitted to the
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"Administrator". The term Administrator means either the
Administrator of the EPA, an EPA regional office, a State
agency, or other authority that has been delegated the
authority to implement this rule. In most cases, reports
will be sent to State agencies. Addresses are provided in
subpart A of part 63.
Records of reported information and other information
necessary to document compliance with the regulation are
generally required to be kept for 5 years. A few records
pertaining to equipment design would be kept for the life of
the equipment.
8.7.1 Initial Notification
The proposed rule would require owners or operators who
are subject to the proposed rule to submit an Initial
Notification. This report will establish an early dialog
between the affected source and the regulatory agency,
allowing both to plan for compliance activities. The
notification is due 120 days after the date of promulgation
for existing sources. For new sources, it is due 180 days
before commencement of construction or reconstruction, or
45 days after promulgation, whichever is later.
The notification must list the thermoplastic processes
at the source that are subject to the proposed rule, and
which provisions may apply (e.g., continuous process vents,
batch process vents, etc.). A detailed identification of
emission points is not required. The Initial Notification
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must include a statement of whether the affected source can
achieve compliance by the specified compliance date.
8.7.2 Implementation Plan
The Implementation Plan details how the affected source
plans to comply. Implementation Plans are only required for
affected sources that have not submitted an operating permit
application or application for approval of construction or
reconstruction. An operating permit application would
contain all the types of information required in the
Implementation Plan, so it would be redundant to require
affected sources to submit both.
Existing sources must submit the Implementation Plan
12 months prior to the compliance date. For new sources,
Implementation Plans would be submitted with the
Notification of Compliance Status. It is critical that
regulatory authorities have the Implementation Plans well
before the compliance date so they can plan their
implementation and enforcement activities. The early
submission of these plans may also benefit regulated sources
by allowing them to receive any feedback on their control
plans prior to the actual compliance dates.
8.7.3 Emissions Averaging Plan
The Emissions Averaging Plan is required 18 months
prior to the compliance date to allow time for review and
approval of the average. Because of the complexities and
site-specific nature of emissions averaging, an approval
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process is necessary to assure that compliance through
averaging would not result in greater hazard or risk than
compliance without averaging and that the specific averaging
plan will result in emissions credits outweighing debits.
The Emissions Averaging Plans must be more detailed and
thorough than an Implementation Plan. The additional
information is necessary for the reviewing authority to make
an informed decision about approving the average. The
projected credits and debits included in the Emissions
Averaging Plan may be based on calculations, design
analyses, or engineering assessments instead of measured
values. This flexibility is provided because, in many
cases, control measures will not have been implemented at
the time the plan is due and actual measurements would not
be possible.
8.7.4 Notification of Compliance Status
The Notification of Compliance Status would be
submitted 150 days after the affected source's compliance
date. It contains the information necessary to demonstrate
that compliance has been achieved, such as the results of
performance tests, TRE determinations, and design analyses.
Affected sources with a large number of emission points
are likely to be submitting results of multiple performance
tests for each kind of emission point. For each test method
used for a particular kind of emission point (e.g., a
process vent), one complete test report would be submitted.
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For additional tests performed for the same kind of emission
point using the same method, the results would be submitted,
but a complete test report is not required. Results would
include values needed to determine compliance (e.g., inlet
and outlet concentrations, flowrates, percent reduction) as
well as the values of monitored parameters averaged over the
period of the test. The submission of one test report will
allow the regulatory authority to verify that the affected
source has followed the correct sampling and analytical
procedures and has done calculations correctly. Complete
test reports for other emission points may be kept at the
plant rather than submitted. This reporting system was
established to ensure that reviewing authorities have
sufficient information to evaluate the monitoring and
testing used to demonstrate compliance while minimizing the
reporting burden.
Another type of information to be included in the
Notification of Compliance Status is the specific level for
each monitored parameter for each emission point, and the
rationale for why this level indicates proper operation of
the control device. (If this level has already been
established in the operating permit, it does not need to be
repeated in the Notification of Compliance Status). As an
example, for a process vent controlled by an incinerator,
the notification would include the site-specific minimum
firebox temperature that will ensure proper operation of the
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incinerator, and the data and rationale to support this
minimum temperature.
For emission points included in an emissions average,
the notification would also include the measured or
calculated values of all parameters needed to calculate
emission credits and debits, and the result of the
calculation for the first quarter. This information is
needed to ensure that the points in the average are being
controlled as described in the Emissions Averaging Plan and
that the average itself is balancing as planned.
8.7.5 Periodic Reports
Periodic Reports are required to ensure that the
standards continue to be met and that control devices are
operated and maintained properly. Generally, Periodic
Reports would be submitted semiannually, however, quarterly
reports must be submitted in some instances.
Periodic Reports specify periods when the values of
monitored parameters are above the maximum or below the
minimum established level specified in the Notification of
Compliance Status or operating permit. For continuously
monitored parameters, records must be kept of the parameter
value recorded once every 15 minutes. If a parameter is
monitored more frequently than once every 15 minutes, the
15-minute averages may be kept instead of the individual
values. This requirement ensures that there will be enough
monitoring values recorded to be representative of the
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monitoring period without requiring the affected source to
retain additional data on file and readily accessible.
For some types of emission points and controls,
periodic (e.g., monthly, quarterly, or annual) inspections
or measurements are required instead of continuous
monitoring. Records that such inspections or measurements
were done must be kept; but results are included in Periodic
Reports only if a problem is found. This requirement is
designed to minimize the recordkeeping and reporting burden
of the proposed rule.
For emission points included in an emissions average,
the results of the quarterly credit and debit calculation
are also included in the Periodic Reports, so the reviewing
authority can ensure that the quarterly requirements for the
average have been met.
8.7.6 Other Reports
There are a very limited number of other reports.
Where possible, the proposed rule is structured to allow
information to be reported in the semiannual (or quarterly)
Periodic Reports. However, in a few cases, it is necessary
for the affected source to provide information to the
regulatory authority shortly before or after a specific
event. For example, if a process change is made that causes
a continuous or batch process vent to change from Group 2 to
Group 1, the affected source must report the change within
90 days. For storage vessels, notification prior to
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internal tank inspections is required to allow the
regulatory authority to have an observer present. For
storage and wastewater, if an owner or operator requests an
extension of the repair period or a delay of repair, the
request needs to be submitted separately from the Periodic
Reports because the requests require a quick response from
the reviewing authority. Certain notifications and reports
required by subpart A of part 63 must also be submitted.
8.7.7 Possible Alternative Recordkeepina Requirements
The proposed rule requires affected sources to keep
readily accessible records of monitored parameters. For
those control devices that must be monitored continuously,
records which include at least one monitored value for every
15 minutes of operation are considered sufficient. These
monitoring records must be maintained for 5 years. However,
there are some existing monitoring systems that might not
satisfy these requirements. To comply with the proposed
rule, affected sources have the flexibility to request
approval for the use of alternative recordkeeping systems
under the proposed rule or under provisions of subpart A of
part 63 .
8.8 OPERATING PERMIT PROGRAM
Under Title V of the 1990 Amendments, facilities
subject to this rule will be required to obtain an operating
permit.
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Oftentimes, emission limits, monitoring, and reporting
and recordkeeping requirements are scattered among numerous
provisions of State implementation plans (SIP's) or Federal
regulations. As discussed in the proposed rule for the
operating permit program published on May 10, 1991 (58 FR
21712), this new permit program would include in a single
document all of the requirements that pertain to a single
source. Once a State's permit program has been approved,
each facility containing a source within that State must
apply for and obtain an operating permit. If the State
wherein the source is located does not have an approved
operating permit program, the owner or operator of a source
must submit the application under the General Provisions of
40 CFR part 63.
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9.0 REFERENCES
1. Harper, Charles A. Handbook of Plastics. Elastomers.
and Composites. McGraw-Hill, Inc., New York, 1992,
p.10.5.
2. Protocol for Equipment Leak Emission Estimates. EPA-
453-/R-93-026. Environmental Protection Agency,
Research Triangle Park, NC. June 1993.
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TECHNICAL REPORT DATA
ff lease read Instrucnom on tfie rtvtrte btforr completingl
1. REPORT NO.
EPA-453/l-95-004a
2.
3. RECIPIENT'S ACCESSION NO.
*. TITLE AND SUBTITLE
Hazardous Air Pollutant Emissions from Process Units in
the Thermoplastics Manufacturing Industry—
Basis and Purpose Document for Proposed Standards
S, REPORT DATE
March 1995
8. PERFORMING ORGANIZATION CODE
?. AUTHORISE
I. PERFORMING ORGANIZATION R6PQRT NO
9. PERFORMING ORGANIZATION NAME ANO ADDRESS
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Research Triaagle Park, ISC 27711
ia. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68D10116
12. SPONSORING AGENCY NAME ANO ADDRESS
Director
Office of Air Quality Planning and Standards
Office of Air and Radiation
U.S. Environmental Protection Agency
Research Triangle Park. NC 27711
13. TYPE OP REPORT ANO PERIOD COVERED
14. SPONSORING AGENCY CODE
EPA/200/04
IS. SUPPLEMENTARY NOTES
16. ABSTRACT
This document provides the background information and rationale for the decisions
made in the (proposed) standards setting process for the thermoplastics
manufacturing industry. The affected industry is described, the baseline organic
HAP emissions are presented as are the predicted impacts associated with the
selected regulatory alternatives. The rational for the alternatives and the
selected proposed standard is given.
7.
KEY WORDS ANO DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIiflS/OPEN ENOED TERMS
c, COSATi Field. Croup
Air Pollution
Pollution Control
Hazardous Air Pollutants
Air Pollution Control
Thermoplastic polymer
manufacturing industry
18. DISTRIBUTION STATEMENT
Release Unlimited
19. SECURITY CLASS i Tlits Repam
Unclassified
21. NO. Of 'AGES
211
20. SECURITY CLASS tThtspuget
Unclassified
22. PRICE
EPA f«t«> 2220-1 (R»». 4-?
EO«T»ON it o«soi-CTe
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