[Federal Register: April 4, 2007 (Volume 72, Number 64)]
[Proposed Rules]
[Page 16635-16676]
[DOCID:fr04ap07-30]

-----------------------------------------------------------------------

Part IV

Environmental Protection Agency

-----------------------------------------------------------------------

40 CFR Part 63

 National Emission Standards for Hazardous Air Pollutants for Area
Sources: Acrylic and Modacrylic Fibers Production, Carbon Black
Production, Chemical Manufacturing: Chromium Compounds, Flexible
Polyurethane Foam Production and Fabrication, Lead Acid Battery
Manufacturing, and Wood Preserving; Proposed Rule

-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2006-0897; FRL-8293-2]
RIN 2060-AN44

National Emission Standards for Hazardous Air Pollutants for Area
Sources: Acrylic and Modacrylic Fibers Production, Carbon Black
Production, Chemical Manufacturing: Chromium Compounds, Flexible
Polyurethane Foam Production and Fabrication, Lead Acid Battery
Manufacturing, and Wood Preserving

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

-----------------------------------------------------------------------

SUMMARY: EPA is proposing six national emissions standards for
hazardous air pollutants for seven area source categories. The proposed
emissions standards and associated requirements for two area source
categories (Flexible Polyurethane Foam Production and Flexible
Polyurethane Foam Fabrication) are combined in one subpart. The
proposed emissions standards for new and existing sources are based on
EPA's proposed determination as to what constitutes the generally
available control technology or management practices for each area
source category.

DATES: Comments must be received on or before May 4, 2007, unless a
public hearing is requested by April 16, 2007. If a hearing is
requested on the proposed rules, written comments must be received by
May 21, 2007. Under the Paperwork Reduction Act, comments on the
information collection provisions must be received by OMB on or before
May 4, 2007.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2006-0897 by one of the following methods:
     http://www.regulations.gov: Follow the on-line instructions for

submitting comments.
     E-mail<EMAIL_ADDRESS>     Fax:<PHONE_NUMBER>.
     Mail: National Emission Standards for Hazardous Air
Pollutants for Area Sources: Acrylic and Modacrylic Fibers Production,
Carbon Black Production, Chemical Manufacturing: Chromium Compounds,
Flexible Polyurethane Foam Production and Fabrication, Lead Acid
Battery Manufacturing, and Wood Preserving Docket, Environmental
Protection Agency, Mailcode: 6102T, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460. Please include a total of two copies. In
addition, please mail a copy of your comments on the information
collection provisions to the Office of Information and Regulatory
Affairs, Office of Management and Budget (OMB), Attn: Desk Officer for
EPA, 725 17th St., NW., Washington, DC 20503.
     Hand Delivery: EPA Docket Center, Public Reading Room, EPA
West, Room 3334, 1301 Constitution Ave., NW., Washington, DC 20460.
Such deliveries are only accepted during the Docket's normal hours of
operation, and special arrangements should be made for deliveries of
boxed information.

    Note: The EPA Docket Center suffered damage due to flooding
during the last week of June 2006. The Docket Center is continuing
to operate. However, during the cleanup, there will be temporary
changes to Docket Center telephone numbers, addresses, and hours of
operation for people who wish to make hand deliveries or visit the
Public Reading Room to view documents. Consult EPA's Federal
Register notice at 71 FR 38147 (July 5, 2006) or the EPA Web site at
http://www.epa.gov/epahome/dockets.htm for current information on

docket operations, locations and telephone numbers.

    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2006-0897. EPA's policy is that all comments received will be included
in the public docket without change and may be made available online at
http://www.regulations.gov, including any personal information provided,

unless the comment includes information claimed to be confidential
business information (CBI) or other information whose disclosure is
restricted by statute. Do not submit information that you consider to
be CBI or otherwise protected through http://www.regulations.gov or e-mail.

The http://www.regulations.gov Web site is an ``anonymous access'' system,

which means EPA will not know your identity or contact information
unless you provide it in the body of your comment. If you send an e-
mail comment directly to EPA without going through http://www.regulations.gov,

your e-mail address will be automatically captured and included as part
of the comment that is placed in the public docket and made available
on the Internet. If you submit an electronic comment, EPA recommends
that you include your name and other contact information in the body of
your comment and with any disk or CD-ROM you submit. If EPA cannot read
your comment due to technical difficulties and cannot contact you for
clarification, EPA may not be able to consider your comment. Electronic
files should avoid the use of special characters, any form of
encryption, and be free of any defects or viruses.
    Docket: All documents in the docket are listed in the
http://www.regulations.gov index. Although listed in the index, some

information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy
form. Publicly available docket materials are available either
electronically in http://www.regulations.gov or in hard copy at the National

Emission Standards for Hazardous Air Pollutants for Area Sources:
Acrylic and Modacrylic Fibers Production, Carbon Black Production,
Chemical Manufacturing: Chromium Compounds, Flexible Polyurethane Foam
Production and Fabrication, Lead Acid Battery Manufacturing, and Wood
Preserving Docket, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave.,
NW., Washington, DC. The Public Reading Room is open from 8:30 a.m. to
4:30 p.m., Monday through Friday, excluding legal holidays. The
telephone number for the Public Reading Room is<PHONE_NUMBER>, and the
telephone number for the Air Docket is<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: Ms. Sharon Nizich, Sector Policies and
Programs Division, Office of Air Quality Planning and Standards (D243-
02), Environmental Protection Agency, Research Triangle Park, North
Carolina 27711, telephone number:<PHONE_NUMBER>; fax number: (919)
541-3207; e-mail address<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this action apply to me?

    The regulated categories and entities potentially affected by the
proposed standards include:

------------------------------------------------------------------------
                                                  Examples of regulated
            Category             NAICS code \1\          entities
------------------------------------------------------------------------
Industry:
    Acrylic and modacrylic               325222  Area source facilities
     fibers production.                           that manufacture
                                                  polymeric organic
                                                  fibers using
                                                  acrylonitrile as a
                                                  primary monomer.

    Carbon black production....          325182  Area source facilities
                                                  that manufacture
                                                  carbon black using the
                                                  furnace, thermal, or
                                                  acetylene
                                                  decomposition process.
    Chemical manufacturing:              325188  Area source facilities
     chromium compounds.                          that produce chromium
                                                  compounds, principally
                                                  sodium dichromate,
                                                  chromic acid, and
                                                  chromic oxide, from
                                                  chromite ore.
    Flexible polyurethane foam           326150  Area source facilities
     production.                                  that manufacture foam
                                                  made from a
                                                  polyurethane polymer.
    Flexible polyurethane foam           326150  Area source facilities
     fabrication operations.                      that cut or bond
                                                  flexible polyurethane
                                                  foam pieces together
                                                  or to other
                                                  substrates.
    Lead acid battery                    335911  Area source facilities
     manufacturing.                               that manufacture lead
                                                  acid storage batteries
                                                  made from lead alloy
                                                  ingots and lead oxide.
    Wood preserving............          321114  Area source facilities
                                                  that treat wood such
                                                  as lumber, ties,
                                                  poles, posts, or
                                                  pilings with a
                                                  preservative.
------------------------------------------------------------------------
\1\ North American Industry Classification System.

    This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be affected by this
action. To determine whether your facility would be regulated by this
action, you should examine the applicability criteria in 40 CFR
63.11393 of subpart LLLLLL (NESHAP for Acrylic and Modacrylic Fibers
Production Area Sources), 40 CFR 63.11400 of subpart MMMMMM (NESHAP for
Carbon Black Production Area Sources), 40 CFR 63.11407 of subpart
NNNNNN (NESHAP for Chemical Manufacturing Area Sources: Chromium
Compounds), 40 CFR 63.11414 of subpart OOOOOO (NESHAP for Flexible
Polyurethane Foam Production and Fabrication Area Sources), 40 CFR
63.11421 of subpart PPPPPP (NESHAP for Lead Acid Battery Manufacturing
Area Sources), or 40 CFR 63.11428 of subpart QQQQQQ (NESHAP for Wood
Preserving Area Sources). If you have any questions regarding the
applicability of this action to a particular entity, consult either the
air permit authority for the entity or your EPA regional representative
as listed in 40 CFR 63.13 of subpart A (General Provisions).

B. What should I consider as I prepare my comments to EPA?

    Do not submit information containing CBI to EPA through
http://www.regulations.gov or e-mail. Send or deliver information identified

as CBI only to the following address: Roberto Morales, OAQPS Document
Control Officer (C404-02), Office of Air Quality Planning and
Standards, Environmental Protection Agency, Research Triangle Park,
North Carolina 27711, Attention Docket ID EPA-HQ-OAR-2006-0897. Clearly
mark the part or all of the information that you claim to be CBI. For
CBI information in a disk or CD ROM that you mail to EPA, mark the
outside of the disk or CD ROM as CBI and then identify electronically
within the disk or CD ROM the specific information that is claimed as
CBI. In addition to one complete version of the comment that includes
information claimed as CBI, a copy of the comment that does not contain
the information claimed as CBI must be submitted for inclusion in the
public docket. Information so marked will not be disclosed except in
accordance with procedures set forth in 40 CFR part 2.

C. Where can I get a copy of this document?

    In addition to being available in the docket, an electronic copy of
this proposed action will also be available on the Worldwide Web (WWW)
through the Technology Transfer Network (TTN). Following signature, a
copy of this proposed action will be posted on the TTN's policy and
guidance page for newly proposed or promulgated rules at the following
address: http://www.epa.gov/ttn/oarpg/. The TTN provides information

and technology exchange in various areas of air pollution control.

D. When would a public hearing occur?

    If anyone contacts EPA requesting to speak at a public hearing
concerning the proposed rules by April 16, 2007, we will hold a public
hearing on April 19, 2007. If you are interested in attending the
public hearing, contact Ms. Pamela Garrett at<PHONE_NUMBER> to verify
that a hearing will be held.

E. How is this document organized?

    The supplementary information presented in this preamble is
organized as follows:

I. General Information
    A. Does this action apply to me?
    B. What should I consider as I prepare my comments to EPA?
    C. Where can I get a copy of this document?
    D. When would a public hearing occur?
    E. How is this document organized?
II. Background Information for Proposed Area Source Standards
III. Proposed Area Source NESHAP for Acrylic and Modacrylic Fibers
Production
    A. What area source category is affected by the proposed NESHAP?
    B. What are the production processes and emissions points at
facilities that manufacture acrylic and modacrylic fibers?
    C. What are the proposed requirements for area sources?
    D. What is our rationale for selecting the proposed standards
for area sources?
IV. Proposed Area Source NESHAP for Carbon Black Production
    A. What area source category is affected by the proposed NESHAP?
    B. What are the production processes and emissions points at
facilities that manufacture carbon black?
    C. What are the proposed requirements for area sources?
    D. What is our rationale for selecting the proposed standards
for area sources?
V. Proposed Area Source NESHAP for Chemical Manufacturing: Chromium
Compounds
    A. What area source category is affected by the proposed NESHAP?
    B. What are the production processes and emissions points at
facilities that manufacture chromium compounds?
    C. What are the proposed requirements for area sources?
    D. What is our rationale for selecting the proposed standards
for area sources?
VI. Proposed Area Source NESHAP for Flexible Polyurethane Foam
Production and Fabrication
    A. What area source categories are affected by the proposed
NESHAP?
    B. What are the production processes and emissions points for
flexible polyurethane foam and fabrication?
    C. What are the proposed requirements for area sources?
    D. What is our rationale for selecting the proposed standards
for area sources?
VII. Proposed Area Source NESHAP for Lead Acid Battery Manufacturing
    A. What area source category is affected by the proposed NESHAP?
    B. What are the production processes and emissions points at
facilities that manufacture lead acid batteries?
    C. What are the proposed requirements for area sources?
    D. What is our rationale for selecting the proposed standards
for area sources?

VIII. Proposed Area Source NESHAP for Wood Preserving
    A. What area source category is affected by the proposed NESHAP?
    B. What are the production processes and emissions points at
wood preserving facilities?
    C. What are the proposed requirements for area sources?
    D. What is our rationale for selecting the proposed standards
for area sources?
 IX. Proposed Exemption of Certain Area Source Categories From Title
V Permitting Requirements
X. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination with
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children from
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer Advancement Act
    J. Executive Order 12898: Federal Actions to Address
Environmental Justice in Minority Populations and Low-Income
Populations

II. Background Information for Proposed Area Source Standards

    Section 112(k)(3)(B) of the Clean Air Act (CAA) requires EPA to
identify at least 30 hazardous air pollutants (HAP) that pose the
greatest potential health threat in urban areas, and section 112(c)(3)
requires EPA to regulate the area source \1\ categories that represent
90 percent of the emissions of the 30 ``listed'' HAP (``urban HAP'').
We implemented these listing requirements through the Integrated Urban
Air Toxics Strategy (64 FR 38715, July 19, 1999).\2\ Sierra Club sued
EPA, alleging a failure to complete standards for the source categories
listed pursuant to CAA section 112(c)(3) within the timeframe specified
by the statute. See Sierra Club v. Johnston, No. 01-1537, (D.D.C.). On
March 31, 2006, the court issued an order requiring EPA to promulgate
standards under CAA section 112(d) for those area source categories
listed pursuant to CAA section 112(c)(3).
---------------------------------------------------------------------------

    \1\ An area source is a stationary source of HAP emissions that
is not a major source. A major source is a stationary source that
emits or has the potential to emit 10 tons per year (tpy) or more of
any HAP or 25 tpy or more of any combination of HAP.
    \2\ Since its publication in the Integrated Urban Air Toxics
Strategy in 1999, the area source category list has undergone
several amendments.
---------------------------------------------------------------------------

    Among other things, the order requires that, by June 15, 2007, EPA
complete standards for six area source categories. We have selected
seven area source categories to meet this obligation even though
standards are required for only six area sources categories. The seven
area source categories that we have selected to meet this obligation
are: (1) Acrylic and Modacrylic Fibers Production; (2) Carbon Black
Production; (3) Chemical Manufacturing: Chromium Compounds; (4)
Flexible Polyurethane Foam Production; (5) Flexible Polyurethane Foam
Fabrication Operations; (6) Lead Acid Battery Manufacturing; and (7)
Wood Preserving.
    We listed Flexible Polyurethane Foam Fabrication Operations as an
area source category under CAA section 112(c)(3) as part of the 1999
Integrated Urban Strategy (64 FR 38721, July 19, 1999). On June 26,
2002, we amended the area source category list by adding source
categories, including Acrylic and Modacrylic Fibers Production,
Flexible Polyurethane Foam Production, Lead Acid Battery Manufacturing,
and Wood Preserving (67 FR 43112, 43113). On November 22, 2002, we
added Carbon Black Production and Chemical Manufacturing: Chromium
Compounds to the area source category list (67 FR 70427, 70428).
    The inclusion of each of these source categories on the section
112(c)(3) area source category list is based on 1990 emissions data, as
EPA used 1990 as the baseline year for that listing. The Acrylic and
Modacrylic Fibers area source category listing was based on emissions
of the HAP acrylonitrile (AN). Emissions of chromium were the basis for
the listing of the Chemical Manufacturing: Chromium Compounds source
category. The Lead Acid Battery Manufacturing area source category
listing was based on emissions of lead and cadmium. The listing of
Carbon Black Production was based on HAP emissions of polycyclic
organic matter (POM). The listings of Flexible Polyurethane Foam
Production and Flexible Polyurethane Foam Fabrication Operations were
based on HAP emissions of methylene chloride, and the listing of Wood
Preserving was based on HAP emissions of arsenic, chromium, methylene
chloride, and dioxin.
    Under CAA section 112(d)(5), the Administrator may, in lieu of
standards requiring maximum achievable control technology (MACT) under
section 112(d)(2), elect to promulgate standards or requirements for
area sources ``which provide for the use of generally available control
technologies or management practices by such sources to reduce
emissions of hazardous air pollutants.'' Under section 112(d)(5), the
Administrator has the discretion to use generally available control
technology or management practices (GACT) in lieu of MACT. Pursuant to
section 112(d)(5), we have decided not to issue MACT standards and
concluded that GACT is appropriate for these seven source categories.
    Legislative history describes GACT as standards or requirements
reflecting application of generally available control technology or
management practices, that is, ``methods, practices and techniques
which are commercially available and appropriate for application by the
sources in the category considering economic impacts and the technical
capabilities of the firms to operate and maintain the emissions control
systems'' (Senate Report Number 101-228, December 20, 1989). Consistent
with the legislative history, in addition to considering technical
capabilities of the facilities and the availability of control
measures, we may consider costs and economic impacts in determining
GACT, which is particularly important when developing regulations for
source categories that may have few establishments and many small
businesses, or when determining whether additional control is necessary
for sources with emissions that are already well controlled as a result
of other existing or applicable standards.
    Determining what constitutes GACT involves considering the control
technologies and management practices that are generally available to
the area sources in the source category. We also consider the standards
applicable to major sources in the same industrial sector to determine
if the control technologies and management practices are transferable
and generally available to area sources. In appropriate circumstances,
we may also consider technologies and practices at area and major
sources in similar categories to determine whether such technologies
and practices could be considered generally available for the area
source category at issue. Finally, as noted above, in determining GACT
for a particular area source category, we consider the costs and
economic impacts of available control technologies and management
practices on that category.
    Existing facilities in the area source categories at issue in this
proposal are currently well controlled as a result of State and
national standards and permitting requirements for criteria pollutants
that obtain co-control of HAP. There is only one area source plant in
the U.S. in the Acrylic and Modacrylic Fibers Production area

source category, and this plant is currently subject to State permit
requirements. The two area source plants that manufacture chromium
compounds and the one area source plant in the Carbon Black Production
area source category are well controlled as a result of title V permit
requirements for the control of criteria pollutants, which provide co-
control of urban HAP. We believe that all of the 58 area source plants
in the Lead Acid Battery Manufacturing area source category can achieve
the requirements of the new source performance standard (NSPS) for
lead-acid battery manufacturing plants at 40 CFR part 60, subpart KK.
Facilities constructed, reconstructed, or modified after 1982 are
already subject to the NSPS.
    There are hundreds of facilities in the Flexible Polyurethane Foam
Production and Flexible Polyurethane Foam Fabrication area source
categories, which were listed because of the use of methylene chloride.
The vast majority of these facilities no longer use methylene chloride
in the processes for several reasons, including State air emissions
standards and worker exposure limits established by the Occupational
Safety and Health Administration (OSHA).
    There are approximately 400 area source facilities in the wood
preserving area source category. All of these facilities are well
controlled in terms of metal HAP (i.e., chromium and arsenic) emissions
and dioxin emissions. These facilities have also discontinued the use
of methylene chloride.

III. Proposed Area Source NESHAP for Acrylic and Modacrylic Fibers
Production

A. What area source category is affected by the proposed NESHAP?

    The Acrylic and Modacrylic Fibers Production area source category
consists of facilities engaged in the manufacture of synthetic fibers
made from AN. Acrylic fibers are synthetic fibers in which the fiber-
forming substance is any long-chain synthetic polymer composed of at
least 85 percent by weight of AN. Modacrylic fibers are composed of 35
to 85 percent by weight of AN.
    There are currently four plants in the U.S. that are known to
produce acrylic and modacrylic fibers. Three of these plants are major
sources. The fourth plant is an area source and is located in an urban
area (Decatur, Alabama). The area source plant produces
polyacrylonitrile that is primarily used as a feed stock for the
production of carbon fibers.

B. What are the production processes and emissions points at facilities
that manufacture acrylic and modacrylic fibers?

    Acrylonitrile is the only urban HAP that was reported to be
released during the production of acrylic and modacrylic fibers at the
one known existing area source plant. The AN is fed to a polymerization
reactor where the reaction (polymerization) takes place. The area
source plant uses a suspension process in which insoluble beads of
polymer are formed in the reactor. Residual unreacted AN is removed
from the polymer in a monomer recovery column and is recycled to the
process. After removal of the residual AN, the resulting polymer is
spun into fibers. Fibers are formed by forcing the viscous polymer
solution, referred to as ``dope,'' through the small orifices of a
spinnerette and immediately solidifying or precipitating the resulting
filaments.
    At the area source plant, two 100,000 gallon storage tanks that
receive the purchased AN monomer are controlled by internal floating
roofs and are subject to the NSPS for volatile organic liquids (40 CFR
part 60, subpart Kb). A packed column scrubber controls emissions from
the polymerization process equipment, including storage tanks,
recovered monomer tanks, monomer measuring tanks, monomer preparation
tanks, monomer feed tanks, slurry receiver tanks, polymerization
reactors, and drum filters. A second packed column scrubber controls
emissions from the monomer recovery process, including polymer holding
tanks, polymer buffer tanks, the monomer vacuum pump flush drum, and
the drum filter vacuum pump flush drum.
    Many of the pumps which move AN at this facility are canned motor
pumps, which have no shaft protrusion to seal. The common leak point on
other types of pumps is the seal for the shaft protrusion;
consequently, canned motor pumps by design reduce leakage. Most of the
piping is connected by welding rather than flanges, which reduces
emissions from pipe connectors.

C. What are the proposed requirements for area sources?

1. Applicability and Compliance Dates
    These proposed NESHAP apply to any existing or new acrylic or
modacrylic fibers production plant that is an area source. We are
proposing that owners or operators of existing sources comply with all
the requirements of the area source NESHAP by 6 months after the date
of publication of the final rule in the Federal Register. A new
affected source would be required to comply by the date of publication
of the final rule in the Federal Register or upon initial startup,
whichever is later.
2. Proposed Emissions Standards
    Existing sources. The proposed standards for existing area sources
apply to process vents from the polymerization process, process vents
from monomer recovery, spinning lines at plants that do not have a
monomer recovery process, and AN storage tanks. We are proposing to
adopt the State permit requirements applicable to the one existing area
source as the NESHAP for existing acrylic and modacrylic fiber
production area sources. The State operating permit for the existing
area source establishes numerical limits for AN emissions from the
control devices for polymerization process equipment and monomer
recovery process equipment. The permit also establishes operating
limits for the scrubbers.
    The control device for polymerization process equipment would be
subject to an AN emissions limit of 0.2 pound per hour (lb/hr). A
control device operating limit would require a minimum daily average
water flow rate to the scrubber of 50 liters per minute (l/min). The
control device for emissions from the monomer recovery process
equipment would be subject to an AN emissions limit of 0.05 lb/hr, and
the daily average water flow rate must not drop below 30 l/min.
    This proposed rule does not include requirements for spinning lines
for existing sources that remove residual AN using a monomer recovery
process prior to spinning. (See section D.1 of this preamble.) However,
existing sources that do not have a monomer recovery process prior to
spinning must meet the requirements for spinning lines in 40 CFR part
63, subpart YY.
    This proposed NESHAP for existing sources would require that AN
storage tanks meeting certain capacity/vapor pressure conditions comply
with one of three control options: (1) A fixed roof in combination with
an internal floating roof, (2) an external floating roof, or (3) a
closed vent system and control device.
    New sources. The proposed standards for new area sources apply to
process vents, fiber spinning lines, AN storage tanks, process
wastewater, maintenance wastewater, and equipment leaks. The proposed
process vent requirements apply to each vent stream with an AN
concentration of 50 parts per million by volume (ppmv) or greater and a
flow rate of 0.005 cubic meters per minute or greater. The owner or
operator would be required to control AN emissions from process vents
meeting this applicability criteria by reducing uncontrolled

emissions by 98 weight percent or meeting an emissions limit (20 ppmv)
by venting vapors through a closed vent system to a recovery device,
control device, or flare. The owner or operator would be required to
determine which process vents meet the applicability criteria by using
the procedures and methods in Sec.  63.1104 of subpart YY. The closed
vent system, recovery or control device, and flare would be subject to
the applicable testing, monitoring, recordkeeping, and reporting
requirements in 40 CFR part 63, subpart SS. The owner or operator would
be required to submit a monitoring plan if another type of control
device is used.
    The proposed emissions limits for fiber spinning lines at new
sources require the owner or operator to: (1) Reduce AN emissions by 85
weight-percent (e.g., by venting emissions from a total enclosure
through a closed vent system to a control device that meets the
requirements in 40 CFR part 63, subpart SS), (2) reduce AN emissions
from the spinning line to 0.5 pounds of AN per ton (lb/ton) of acrylic
and modacrylic fiber produced, or (3) reduce the AN concentration of
the spin dope to less than 100 parts per million by weight (ppmw). The
requirements in 63.1103(b)(4) of subpart YY would apply to an enclosure
for a fiber spinning line.
    For all AN storage vessels at a new area source, the owner or
operator would be required to: (1) Reduce AN emissions by 98 weight-
percent by venting emissions through a closed vent system to any
combination of control devices as specified in Sec.  63.982(a)(1) of
subpart SS or reduce AN emissions by 95 weight-percent or greater by
venting emissions through a closed system to a recovery device as
specified in Sec.  63.993 of subpart SS; or (2) comply with the
equipment standards for internal or external floating roofs in 40 CFR
part 63, subpart WW.
    Process wastewater and maintenance wastewater at new sources would
be subject to the requirements in Sec.  63.1106(a) and (b) of subpart
YY. The owner or operator would also be required to comply with the
equipment leak requirements in subpart YY. Subpart YY applies the
requirements in either subpart TT or UU to equipment that contains or
contacts 10 percent by weight or greater of AN and that operates at
least 300 hours per year.
3. Compliance Requirements
    We are proposing to include in this proposed NESHAP the monitoring,
testing, recordkeeping, and reporting requirements in the State
operating permit for the existing area source. Continuous parameter
monitoring systems (CPMS) would be required to measure and record the
scrubber water flow rates at least every 15 minutes. The owner or
operator would determine compliance with the daily average operating
limits for the scrubber water flow rates on a monthly basis and submit
quarterly compliance reports to EPA or the delegated authority.
Compliance with the operating limits would be determined on a monthly
basis; quarterly compliance reports also would be required. The owner
or operator would be required to keep records of each monthly
compliance determination and retain the records for at least 2 years
following the date of each compliance determination. If the daily
average water flow rate falls below the operating limit, the owner or
operator must notify EPA or the delegated authority within 10 days of
the identification of the exceedance.
    The owner or operator of an existing source would be required to
conduct a performance test for each control device for polymerization
process equipment and monomer recovery process equipment. A performance
test would not be required for an existing source if a prior
performance test has been conducted using the methods required by this
rule, which are the requirements contained in Sec.  63.1104 of subpart
YY, and either no process changes have been made since the test, or the
owner or operator can demonstrate that the results of the performance
test, with or without adjustments, reliably demonstrate compliance
despite process changes.
    For AN storage tanks at existing sources, the owner or operator
would be required to comply with the applicable testing, inspection,
and notification procedures in 40 CFR 60.113b(a) and the recordkeeping
and reporting requirements in 40 CFR 60.115b and 60.116b of subpart Kb.
The testing, monitoring, recordkeeping, and reporting requirements in
40 CFR part 65, subpart C would apply if the owner or operator selected
to comply with the part 65 control option for AN storage tanks. See 40
CFR 60.110b(e).
    The owner or operator of an existing area source would be required
to comply with certain notification requirements in 40 CFR 63.9 of the
General Provisions (40 CFR part 63, subpart A). These requirements
would include a notification of applicability and a notification of
compliance status. We are also proposing that the owner or operator
comply with the requirements for startup, shutdown, and malfunction
(SSM) plans, reports, and records in 40 CFR 63.6(e)(3).
    In the notification of compliance status required in 40 CFR
63.9(h), the owner or operator of an existing source may certify
initial compliance with the emissions limits based on a previous
performance test if applicable. The owner or operator must also certify
initial compliance with the NSPS requirements in 40 CFR part 60,
subpart Kb.
    The owner or operator of a new area source would be required to
perform assessments \3\ to identify affected process vents, equipment,
and wastewater streams; conduct initial performance tests and/or
compliance demonstrations; and comply with the monitoring, inspection,
recordkeeping, and reporting requirements in each applicable subpart.
The testing, monitoring, recordkeeping, and reporting requirements in
the subparts described above, which we are adopting in this proposed
rule, vary according to the emissions point and control option (e.g.,
subpart SS for process vents). The owner or operator of a new area
source would also be required to comply with all of the NESHAP General
Provisions (40 CFR part 63, subpart A), including requirements for
notifications; performance tests and reports; SSM plans and reports;
recordkeeping, and reporting. We have identified in the proposed NESHAP
the General Provisions of 40 CFR part 63 applicable to existing and new
sources.
---------------------------------------------------------------------------

    \3\ These assessments are used to determine which process vents
and wastewater streams must be controlled.
---------------------------------------------------------------------------

D. What is our rationale for selecting the proposed standards for area
sources?

1. Selection of Proposed Standards
    Existing sources. The process vents at the existing area source
plant are controlled by packed bed scrubbers and are subject to
emissions limits established in the State operating permit. Emissions
from the polymerization process equipment are limited to 0.2 lb/hr.
This process equipment includes process storage tanks, recovered
monomer tanks, monomer measuring tanks, monomer preparation tanks,
monomer feed tanks, the polymerization reactors, and drum filter.
Emissions from the monomer recovery process equipment are limited to
0.05 lb/hr. These process units include the polymer holding tank,
polymer buffer tank, monomer vacuum pump flush drum, and the drum
filter vacuum pump flush drum. Test data for these two process vents
show that the vents are well controlled because the

facility achieves the level of control required for major sources
subject to 40 CFR part 63, subpart YY. We have determined that the
State operating permit limits are GACT for process vents at existing
area sources.
    The fiber spinning line at the existing area source plant is not a
source of AN emissions because the residual monomer is stripped from
the polymer in a monomer recovery column prior to spinning. However,
other existing facilities might become area sources in the future, and
they might not have a monomer recovery process. Consequently, we are
proposing that any existing source without a monomer recovery process
must reduce the residual AN concentration in the polymer by removing
residual monomer prior to spinning or install an enclosure for the
spinning line and vent the emissions to a control device. Existing area
sources without a monomer recovery process must meet requirements for
fiber spinning lines in 40 CFR part 63, subpart YY. We have determined
that the requirements in 40 CFR part 63, subpart YY are GACT for
existing area sources without a monomer recovery process.
    The AN storage tanks at the existing area source plant are subject
to the NSPS for volatile organic liquids (40 CFR part 60, subpart Kb).
The NSPS requires that a storage tank meeting certain capacity/vapor
pressure conditions comply with either the requirements for storage
vessels in subpart C of 40 CFR part 65 (Consolidated Federal Air Rules)
or the NSPS requirements for a fixed roof in combination with an
internal floating roof, an external floating roof, or a closed vent
system and control device. The AN storage tanks at the existing area
source are equipped with internal floating roofs to comply with the
NSPS requirements. The controls in the NSPS are currently being applied
to AN storage tanks and are the types of controls generally applied to
tanks storing volatile organic liquids. Consequently, we determined
that the controls required by the NSPS are GACT for storage tanks at
existing sources.
    The potential for emissions from equipment leaks is low at the
existing area source plant because of the use of canned motor pumps and
pipes connected in large part by welding rather than flanges. A
fugitive emissions survey using EPA's protocol for estimating emissions
from equipment leaks coupled with capture and measurement of leaks
resulted in estimated emissions of only 0.5 tpy of AN (assuming any
leak that was detected emitted for the full year). A leak detection and
repair program for this plant would cost several thousand dollars in
labor and in capital for the monitoring equipment. After considering
the low level of current emissions, the additional costs, and the small
emissions reduction that would be achieved by a leak detection and
repair program, we propose that GACT for existing area sources is no
additional control for equipment leaks.
    Wastewater at the existing plant is sent to a biological treatment
unit to degrade AN. Emissions of organic compounds from wastewater can
be reduced by steam stripping the wastewater to remove and recover the
organics. We estimate that the capital cost of steam stripping to
remove AN from the wastewater at the existing area source plant is
$700,000 with a total annualized cost of $630,000 per year. Even
assuming 90 percent removal by the steam stripper, the emissions
reduction would be 7 tons per year. We propose to conclude that
pretreatment using steam stripping is not GACT because of the high cost
effectiveness of processing a low concentration stream with a high
volumetric flow rate. This conclusion is consistent with previous cost
effectiveness analyses such as those performed for major sources where
EPA determined that it is not cost effective to apply controls to
wastewater below certain cutoffs (e.g., a concentration less than 1,000
ppmw and a flow rate less than 10 liters per minute (57 FR 62608,
December 31, 1992). The process wastewater at the existing area source
is below these cutoffs. Consequently, we are not proposing additional
controls for wastewater at the existing area source plant and conclude
that GACT is the current level of control.
    We are alternatively proposing that GACT for this existing area
source is no further emission reduction. We request comment on the
basis, consistent with section 112(d)(5), for asserting that GACT is no
further control for the existing source. We request comment on this
issue because the standard proposed above will not result in any
emission reductions beyond what is already required by the State permit
to which the existing facility is already subject.
    New Sources. Test results for the control devices applied to
process vents at the existing area source show that a standard of 98
weight-percent reduction or an outlet concentration of 20 ppmv or less
has been achieved by the controls we propose as GACT at the existing
source.\4\ Consequently, we are proposing that GACT for process vents
at a new area source is a 98 weight-percent reduction of AN emissions,
an outlet concentration of 20 ppmv or less, or venting emissions to a
flare. This format of the proposed standard is more appropriate for new
sources than a process vent limit expressed in lb/hr (as applied to the
existing area source) because we do not know what the size,
configuration, or emissions potential of a new source might be.
---------------------------------------------------------------------------

    \4\ This is also the level of control that major sources must
meet for process vents.
---------------------------------------------------------------------------

    As discussed earlier, the fiber spinning line at the existing area
source plant is not a source of AN emissions because the residual
monomer is stripped from the polymer in a monomer recovery column prior
to spinning. However, we cannot be certain what process configuration a
new source might use or that it would have a monomer recovery system.
Consequently, we are proposing that a new source must reduce the
residual AN concentration in the polymer by removing residual monomer
prior to spinning or install an enclosure for the spinning line and
vent the emissions to a control device. Data from acrylic and
modacrylic fiber production indicates that a monomer recovery system
can reduce the AN concentration in the spin dope to less than 100 ppmw,
which we are proposing as GACT for new area sources. We are proposing
alternatives to the AN residual concentration limit for new sources
that are the same as the alternatives that are available for major
sources in 40 CFR part 63, subpart YY. One alternative is to reduce AN
emissions from the spinning line by 85 weight-percent or more. The
second alternative is to reduce AN emissions from the spinning line to
less than or equal to 0.5 lb/ton of acrylic and modacrylic fiber
produced.
    For storage tanks at new area sources, we are proposing to adopt
the requirements in 40 CFR part 63, subpart YY. These requirements have
been applied to AN storage tanks at other acrylic and modacrylic fiber
plants and represent GACT for new sources because they are cost
effective and can be easily included in the design and construction of
a new source.
    We also evaluated emissions controls and management practices for
equipment leaks at new sources. We know that equipment leaks are well
controlled at the existing area source facility; however, we do not
know with assurance that a new source will have primarily leakless
equipment. In addition, our studies of synthetic organic chemical
plants indicate that leak inspection and repair requirements are cost
effective and not overly burdensome. Consequently, we are

proposing that new area sources be subject to the same equipment leak
provisions as those applied to major sources in 40 CFR part 63, subpart
YY.
    For wastewater streams at new area sources, we do not know what
flow rates, concentrations and emissions potential might occur, but our
studies of wastewater treatment controls indicate that it is cost
effective to control these emissions when the concentration of AN is
high. For example, at most acrylic and modacrylic fiber plants, all
wastewater streams with a concentration of 10,000 parts per million by
weight (ppmw) or more must be controlled, as well as streams with both
a concentration of 1,000 ppmw or more and a flow rate of 10 l/min or
more. Controls are not required for wastewater streams below these
cutoffs because they are not cost effective. Thus we are proposing that
GACT for new sources is the control of wastewater streams that exceed
the cutoffs of concentration and/or flow rate as specified in subpart
YY.
2. Selection of Proposed Compliance Requirements
    We have reviewed the compliance requirements in the State operating
permit, the NSPS for volatile organic liquid storage tanks, and other
requirements that apply to the existing area source plant, and we
propose that these requirements are sufficient to ensure compliance
with the proposed emissions standards. Therefore, we are proposing to
include the inspection, monitoring, recordkeeping, and reporting
requirements that apply to the existing area source plant in this
proposed rule for existing sources.
    We are proposing to require that an existing area source be subject
to certain notification requirements in the NESHAP General Provisions
(40 CFR part 63, subpart A). Because permit information for the
existing facility does not identify requirements for an SSM plan, we
are also proposing to require the owner or operator of an existing area
source to comply with the SSM requirements in 40 CFR 63.6(e)(3). We are
proposing to allow additional time (6 months after promulgation) to
allow for preparation of the plan.
    We have also reviewed the compliance requirements in the subparts
of part 63 that would apply to process vents, storage tanks, equipment
leaks, and wastewater at new area sources as a result of this proposed
rule. These requirements are sufficient to ensure compliance with the
proposed emissions limits and management practices. Therefore, we are
proposing to include the testing, monitoring, recordkeeping, and
reporting requirements in each applicable subpart in this proposed rule
for new sources.
    We are also proposing to apply to new sources the notification,
testing, monitoring, operation and maintenance, recordkeeping, and
reporting requirements in the part 63 General Provisions (40 CFR part
63, subpart A). The General Provisions are necessary for effective
application of the standard for new area sources and are, therefore,
incorporated into the proposed rule. We propose that these requirements
are sufficient to ensure compliance with the proposed emissions limits
and management practices for new sources.

IV. Proposed Area Source NESHAP for Carbon Black Production

A. What area source category is affected by the proposed NESHAP?

    The Carbon Black Production area source category includes any
facility that produces carbon black by the furnace black process,
thermal black process, or the acetylene decomposition process. Carbon
black is used primarily as a reinforcing agent for rubber and is used
largely in the manufacturing of automotive tires. It is also used as a
colorant in inks, paints, plastics, and paper.
    Currently, there are 20 carbon black production facilities
operating in the U.S. Nineteen of these facilities are major sources of
HAP emissions and are subject to NESHAP requirements for carbon black
production in 40 CFR part 63, subpart YY. According to the National
Emissions Inventory (NEI) and the Toxics Release Inventory (TRI), one
carbon black production facility is an area source of HAP emissions. We
are requesting comments on whether there are any other area sources in
this source category.

B. What are the production processes and emissions points at facilities
that manufacture carbon black?

    A carbon black unit (CBU) consists of the equipment used to produce
carbon black by either the furnace, thermal or acetylene decomposition
processes. The major components of the CBU include: (1) Feedstock and
raw material storage tanks; (2) production unit reactors; (3)
separation filters; (4) wet or dry pelletization equipment and
densification equipment; (5) final product silos and packaging for
pellets and powders; and (6) shipping storage areas.
    Carbon black is produced by the furnace black process via thermal-
oxidative decomposition in a closed system. The feedstock is primarily
aromatic oils based on crude oil. Feedstock is injected into the
reactor and is converted to carbon black. The reactor is heated by a
fuel, usually natural gas.
    The thermal black process produces carbon black via thermal
decomposition in a cyclic process. The primary feedstock is natural
gas. The process generally includes two vertical reactors in parallel.
While one reactor is heating, the other reactor is in the decomposition
cycle.
    The acetylene black process uses an acetylene feedstock to produce
carbon black via thermal decomposition in a continuous process. The
acetylene black reactor is similar to the reactor for the thermal black
process; however, since it is a continuous process, usually only one
reactor is used.
    The remaining processes for the furnace black, thermal black and
acetylene black production processes are similar. The carbon black and
tailgas stream from the reactor is cooled in a heat exchanger. Energy
from the carbon black and tailgas stream is used to preheat combustion
air for the reactor. Following the heat exchanger, a secondary quench
chamber is used to further cool the carbon black and tailgas stream.
    Carbon black is separated from the tailgas in the main separation
filter. Tailgas may be collected and used as fuel in the dryer (if
present), burned to preheat the feedstock (if a preheater is present),
vented to the atmosphere, or vented to a combustion device for
destruction.
    Carbon black is separated from the conveying air in the process
filter. Solid contaminants (e.g., coke particles, abraded particles
from the refractory lining of the furnace, or rust particles) are
removed from the carbon black in the grit separator.
    Initial densification of the carbon black takes place in the surge
tank, which also acts as a buffer to maintain constant production
levels. Carbon black is processed into pellets in either a wet
pelletizer or a dry pelletizer. In the wet pelletization process,
water, and sometimes additives, is injected into the pelletizer and the
carbon black leaves as wet pellets and are dried in the dryer. Tailgas
may be used as fuel in the dryer for external heating. Carbon black and
steam from the dryer exhaust are separated in the purge filter and the
carbon black is recycled to the process filter.
    In the dry pelletization process, the pelletizer is a rotating
drum. A portion of the pelletized carbon black is recycled to the inlet
of the drum to act as seeds for the new pellets. Pelletized

carbon black is housed in the storage silo until it is discharged to
trucks or rail cars, intermediate bulk storage, or packaging.
    The Carbon Black Production area source category was listed for
regulation due to emissions of the urban HAP POM. Benzene is another
urban HAP emitted from the CBU. The HAP are released into the
atmosphere from the tailgases from the reactors. The carbon black and
tailgas stream is sent to a baghouse where the carbon black is
separated from the tailgas. After separation of the carbon black
product, the tailgas is either emitted to the atmosphere or sent to a
combustion control device.

C. What are the proposed requirements for area sources?

1. Applicability and Compliance Dates
    The proposed NESHAP applies to each new or existing carbon black
production facility that is an area source of HAP. Because the one
existing area source is already meeting requirements that are the same
as those in this proposed NESHAP, we are proposing that an existing
affected source comply by the date of publication of the final rule in
the Federal Register. A new affected source would be required to comply
by the date of publication of the final rule in the Federal Register or
upon initial startup, whichever is later.
2. Proposed Emissions Standards
    We are proposing that the owner or operator of an existing or new
source be required to control HAP emissions from each carbon black
production main unit filter process vent that has a HAP concentration
equal to or greater than 260 ppmv. The specific control requirements
are: (1) Reduce emissions of HAP by using a flare meeting all the
requirements of 40 CFR part 63, subpart SS; or (2) reduce total HAP
emissions by 98 weight-percent or to a concentration of 20 ppmv,
whichever is less, by venting emissions through a closed vent system to
any combination of control devices meeting the requirements 40 CFR
63.982(a)(2).
3. Compliance Requirements
    For existing and new area sources, we are proposing to adopt the
testing, monitoring, recordkeeping, and reporting requirements in
subpart YY. Compliance with the proposed emissions limit for existing
and new area sources would be demonstrated by monitoring the operating
parameters of the control device or devices selected to comply with the
requirements of the NESHAP. The proposed NESHAP specifies requirements
for the initial notification, the notification of compliance status,
periodic reporting, and SSM requirements.
    The owner or operator of an existing or new area source would be
required to comply with the subpart YY notification requirements in 40
CFR 63.1110. In the notification of compliance status required in 40
CFR 63.1110(d), the owner or operator of an existing source may
demonstrate initial compliance with the proposed HAP emissions
standards based on the results of a performance test that has been
previously conducted provided certain conditions are met (e.g., using
the same methods as the test methods in the proposed rule).

D. What is our rationale for selecting the proposed standards for area
sources?

1. Selection of Proposed Standards
    Based on information in the NEI and TRI, we identified only one
existing carbon black production facility that is an area source. We
are requesting comments on whether there are any other area sources in
this source category. This carbon black production facility operates
emissions control systems that capture and control tailgases from their
four CBUs. The tailgases from each CBU are routed to control devices
(two are routed to a flare and two are routed to a thermal incinerator)
that achieve high-efficiency removal of volatile organic compounds
(VOC), including polycyclic organic matter (POM) and benzene.
    The existing area source is currently operating under a title V
permit, which requires a 98 weight-percent VOC emissions reduction. The
facility's ability to demonstrate compliance with their title V permit
emissions limits on a long-term basis indicates that the facility owner
has the technical and economic capabilities to continue to reduce VOC
emissions (including POM and benzene) sufficiently to achieve these
limits. Further, although the existing area source facility utilizes
the furnace black production process, a 98 weight-percent emissions
reduction would apply equally to all types of production processes.
Consequently, we do not distinguish between the different carbon black
production processes.
    After reviewing the existing facility's title V permit
requirements, we concluded that the permit requirements are equivalent
to the provisions of 40 CFR 63, subpart YY, which is the rule to which
major source carbon black facilities are subject. Further, the facility
has applied for renewal of their title V permit to specifically include
the requirements of subpart YY for their CBU. Because control
technologies to reduce VOC emissions also reduce POM and benzene
emissions, the 98 weight-percent VOC emission reduction in their title
V permit is equivalent to the 98 weight-percent HAP level of control
specified in subpart YY. We have no reason to believe that this
emissions reduction is infeasible or inappropriate for all area sources
in this category. Therefore, we have determined that a 98 weight-
percent HAP emissions reduction is GACT for existing and new carbon
black production area source facilities, which may be achieved using
one or more control devices or a flare subject to Sec.  63.11 of the
NESHAP General Provisions (40 CFR part 63, subpart A).
    In addition to the 98 weight-percent level of control, we have
established that for low concentration streams (e.g., streams with
concentrations less than about 1,000 ppmv), a 98 weight-percent
reduction may not be achievable for all process vents from the main
unit filter (65 FR 76423). Therefore, we have determined that a HAP
concentration limit of 20 ppmv (corrected to 3 percent oxygen if a
combustion device is the control device and supplemental combustion air
is used to combust the emissions) is appropriate as GACT for low-
concentration streams.
    The subpart YY NESHAP also include a 260-ppmv control applicability
cutoff. This cutoff represents the lowest control device inlet
concentration reported at one of the best-controlled facilities. We do
not have available information to indicate that the single existing
area source controls process vent emissions streams with concentrations
below this level. Therefore, we have included the 260-ppmv control
applicability cutoff in this proposed area source NESHAP.
    We are alternatively proposing that GACT for this existing area
source is no further emission reduction. We request comment on the
basis, consistent with section 112(d)(5), for asserting that GACT is no
further control for the existing source. We request comment on this
issue because the standard proposed above will not result in any
emission reductions beyond what is already required by the Federal
permit to which the existing facility is already subject.
2. Selection of Proposed Compliance Requirements
    The existing carbon black area source facility's title V permit
requires operating parameter monitoring, recordkeeping, and periodic
reporting. We reviewed these compliance requirements and concluded that
they

are sufficient to ensure compliance with the proposed emissions
standards for existing and new sources. Because these requirements are
equivalent to those in 40 CFR part 63, subpart YY, we have adopted the
subpart YY compliance requirements in this proposed rule. These
requirements include operating parameter monitoring, initial
performance testing, notifications, and periodic reports.
    Because permit information for the existing facility does not
identify requirements for an SSM plan, we are proposing that the owner
or operator of an existing area source comply with the SSM requirements
in 40 CFR 63.1111. Section 63.1111(a)(1) of subpart YY requires that
the title V permit for a source include provisions for an SSM plan.

V. Proposed Area Source NESHAP for Chemical Manufacturing: Chromium
Compounds

A. What area source category is affected by the proposed NESHAP?

    The area source category, ``Chemical Manufacturing: Chromium
Compounds,'' includes facilities that use chromite ore as the basic
feedstock to manufacture chromium compounds, primarily sodium
dichromate, chromic acid, and chromic oxide. There are only two plants
in this area source category, and both are located in urban areas. One
plant is located in Castle Hayne, North Carolina (near Wilmington) and
the other is in Corpus Christi, Texas.
    Most of the sodium dichromate produced by the two plants is used to
make chromic acid. Sodium dichromate is also used in leather tanning,
chromic oxide production, pigments manufacture, textile dyeing, and in
the manufacture of numerous other products. Chromic acid is used in the
metal finishing industry to produce resistant coatings for a variety of
base metals. Other uses include decorative plating, conversion
coatings, and metal coloring compounds. The two main uses of chromic
oxide are in pigments and refractories.

B. What are the production processes and emissions points at facilities
that manufacture chromium compounds?

    Although the basic processes at the two plants are similar, there
are some subtle differences in the processing steps, and the two plants
have somewhat different emissions points and control configurations.
Consequently, separate profiles of the processes and emissions controls
are provided in sections V.B.1 through V.B.4 of this preamble.
1. Sodium Chromate Production
    The main feedstock for the manufacturing process is chromite ore
imported from South Africa and Finland, typically containing about 45
percent or more chromium oxide. At the Texas plant, the chromite ore is
dried and ground in a ball mill. The ground ore is mixed with alkaline
material (soda ash, sodium bicarbonate, and sodium hydroxide) and fed
to a rotary kiln where it is heated to about 2,000 degrees Fahrenheit
([deg]F). This process (known as ``roasting'') oxidizes the chromite
ore, converting the majority of the chromium in the ore from trivalent
to hexavalent chromium. Baghouses on the ore drying and grinding unit
control emissions. Baghouses also control emissions from the rotary
kiln during roasting. After roasting, the material typically contains
20 to 40 percent hexavalent chromium as sodium chromate and 10 to 20
percent trivalent chromium. The material exiting the rotary kiln is
quenched with water in quench tanks. The quenching process is
controlled by a wet scrubber and wet electrostatic precipitator.
    The resulting ore slurry goes through a belt filter to filter and
purify the sodium chromate. The filters remove solid aluminum,
vanadium, and calcium residues. Sodium dichromate is added to the ore
slurry to aid in the removal of aluminum. Calcium hydroxide (lime) is
added to remove vanadium. Soda ash solution is added to remove calcium.
A baghouse on the impurity treatment and filtration units controls
emissions.
    Some of the impurities from the impurity treatment and filtration
unit are placed in a secondary roasting kiln with sodium hydroxide and
additional chromite ore for another round of chromium recovery. Roasted
and quenched material from the secondary kiln travels to impurity
treatment and filtration units for the same purification process
described above for materials from the primary roasting unit. A
baghouse on the secondary kiln and wet scrubber on the quench system
control emissions.
    At the North Carolina plant, the chromite ore is dried in rotary
dryers and then pulverized in ball mills. The pulverized ore is
prepared for roasting by mixing the ore with lime, soda ash, and
recycled residue from the roasting kilns. Emissions from the ore drying
and grinding units are controlled by cyclones and dry electrostatic
precipitators. The kiln feed is fed to one of three rotary kilns in
which the chromite ore is roasted. The hot gases generated in the kilns
are sent to waste heat boilers for energy recovery. Emissions from the
waste heat boilers travel to dry electrostatic precipitators and are
vented through the main stack. The dry electrostatic precipitators
process several gas streams, including emissions from the ore drying
and grinding units, the roasting kiln waste heat boilers, the ore
mixing unit and roasting kiln, and the post-leach ore residue drying
unit.
    After exiting the kiln, the hot kiln roast is quenched and leached
with hot water in tanks to dissolve the water-soluble sodium chromate
and form a sodium chromate slurry. The sodium chromate slurry is sent
to a recycle unit where hydroclones separate unconverted ore residue
from the sodium chromate solution. The ore residue is washed and
filtered on a filter belt, dried, and recycled to the kiln. A system of
cyclonic scrubbers and wet electrostatic precipitators on the quench
tanks and filter unit are used to control emissions. Emissions from the
ore residue dryer are controlled by a cyclone and the dry electrostatic
precipitators described earlier.
2. Sodium Dichromate Production
    At the Texas plant, the purified sodium chromate solution travels
from the impurity treatment and filtration system to the electrolytic
cell system for electrolytic acidification. Water is added to the
electrolytic cells as well. This process converts the sodium chromate
solution to sodium dichromate solution. Fiber bed filters on the
electrolytic cell system control emissions. The sodium dichromate can
be sold or used on-site in the production of chromic oxide or chromic
acid.
    Some sodium chromate solution is sent to a sodium chromate
crystallization, evaporation, and drying unit to produce sodium
chromate crystals. These crystals are then packaged for sale. Some
sodium dichromate solution is also sent to a sodium dichromate
crystallization, evaporation, and drying unit for production of sodium
dichromate crystals. The crystals are sent to a packaging unit for
packaging before sale. The emissions from the crystallization,
evaporation, and drying units for the sodium chromate and sodium
dichromate solutions are controlled by an entrainment separator and wet
scrubber.
    At the North Carolina plant, the sodium chromate product stream
proceeds through a series of pH adjustment and filtration steps using
sodium carbonate and sulfuric acid to remove impurities such as iron,
aluminum, and other oxides from the

sodium chromate solution. The sodium chromate solution is neutralized
to a pH of 8.5 to precipitate and allow filtration of the remaining ore
residues. The sodium chromate liquor is mixed with a soda ash solution
in the calcium precipitator unit to precipitate the calcium as calcium
carbonate. The sodium chromate liquor is then filtered to remove the
calcium carbonate. In the acidification unit, the filtered raw sodium
chromate liquor is acidified to a pH of 4.0 with sulfuric acid to
produce sodium dichromate. This solution is partially evaporated to 85
percent concentration and then centrifuged to separate sodium sulfate
(salt cake) from the sodium dichromate solution. After separation from
the salt cake, the sodium dichromate product solution is either stored
in tanks from which, after dilution to the appropriate concentration,
it is either sold as sodium dichromate product liquor or used as
feedstock in the chromic acid plant. Some of the sodium dichromate
solution is crystallized, centrifuged, and dried to form sodium
dichromate crystalline product. Emissions from the crystallization area
are controlled by an impingement plate scrubber and demister.
3. Chromic Acid Production
    At the Texas plant, the production of chromic acid is performed by
electrolytic reaction of sodium dichromate solution through a series of
cells. Sodium dichromate solution is introduced into the anode side of
an electrolytic cell, and water is introduced to the cathode side.
Direct current causes a reaction on the anode side of the cell,
producing chromic acid, sodium ions, and oxygen gas. Sodium ions
migrate to the cathode side (water) of the cell through a membrane,
which produces sodium hydroxide and hydrogen gas. The sodium
dichromate/chromic acid solution (anode side) is withdrawn to be used
as influent for the next cell line. The effluent from the anode side of
the last stage is crystallized, centrifuged, dried, and packaged.
    Three scrubbers are used to control emissions from chromic acid
production. Emissions from the electrolytic cells are controlled by two
scrubbers; one scrubber controls oxygen gas and hexavalent chromium
emitted from the anode side of the cells and one controls hydrogen gas
and hexavalent chromium from the cathode side of the cell. Drying,
storage, and packaging operations are vented to the same wet scrubber.
    At the North Carolina plant, the sodium dichromate liquor is
further acidified with sulfuric acid to produce chromic acid crystals.
The acidified slurry is filtered to recover the chromic acid and the
filtrate is recycled to the sodium dichromate process. The chromic acid
crystals are fed to a reactor where they are melted. The melted chromic
acid produced in the reactor is cooled and then sent to a flaking
process to produce the chromic acid flakes which are packaged and sold
as final products. Emissions from the chromic acid area are controlled
by a packed bed scrubber and demister.
4. Chromic Oxide and Chromium Hydrate Production
    The Texas plant is the only facility producing chromic oxide and
chromium hydrate. In the production of chromic oxide, ammonium sulfate
and sodium dichromate solution that has been concentrated by
evaporation are mixed and fed to a rotary roasting kiln to produce
chromic oxide, sodium sulfate and nitrogen gas. The roast is quenched
with water in which the chromic oxide is insoluble and the sodium
sulfate is soluble. The mixture is washed in countercurrent thickeners,
filtered, dried, milled, and packaged. To produce metallurgic grade
chromic oxide and certain other grades, the chromic oxide is re-roasted
in a secondary rotary kiln, quenched, filtered, dried, milled, and
packaged.
    The chromic oxide plant uses baghouses and scrubbers for emissions
control; this production area has 10 bag houses and 11 scrubbers. Four
baghouses control emissions from the ammonium sulfate storage and
grinding area. Emissions from mixing of the sodium dichromate and
ammonium sulfate are vented to a wet cyclone. Wet scrubbers control
emissions from the quench tanks of both the primary and secondary
roasting kilns. A baghouse, wet scrubber, and a mist eliminator control
emissions from the primary roasting kiln. A wet scrubber controls
emissions from the secondary roasting kiln. Filtration steps after both
primary and secondary roasting are each vented to separate wet
scrubbers. The dryer vents to a bag filter. Chromic oxide storage,
grinding, and packaging steps are vented to six baghouses.
    In the production of chromium hydrate, boric acid and concentrated
sodium dichromate are mixed and fed to a furnace to produce a chromium
hydrate ``clinker'' and sodium borate. The clinker is quenched with
water. The mixture is then leached in tanks and filter presses to form
chromium hydrate, then filtered, dried, milled, and packaged. Emissions
controls include baghouses for boric acid grinding, chromium hydrate
roasting, and chromium hydrate grinding and packaging.

C. What are the proposed requirements for area sources?

1. Applicability and Compliance Dates
    The proposed NESHAP apply to the owner or operator of a new or
existing area source that manufactures chromium compounds. We are
proposing that owners or operators of existing sources comply with all
the requirements of the area source NESHAP by 6 months after the date
of publication of the final rule in the Federal Register. A new
affected source would be required to comply by the date of publication
of the final rule in the Federal Register or upon initial startup,
whichever is later.
2. Proposed Emissions Standards
    The proposed NESHAP requires new and existing facilities to operate
a capture system that collects gases and fumes from each emissions
source and conveys the gases to a PM control device. Emissions limits
for PM, in lb/hr format, would be established based on the process rate
of the emissions unit. These PM emissions limits would apply to more
than 20 emissions units in the production of chromium compounds,
including sodium chromate, sodium dichromate, chromic acid, chromic
oxide, and chromium dehydrate at new and existing sources.
3. Compliance Requirements for Existing Area Sources
    The control devices used at these facilities include baghouses, dry
electrostatic precipitators, wet electrostatic precipitators, and wet
scrubbers. The proposed monitoring requirements for existing area
sources consist of inspection and maintenance requirements specific to
the type of control device.
    For a baghouse, this proposed NESHAP requires monthly visual
inspections of the system ductwork and baghouse units for leaks. The
plant owner or operator would also be required to conduct an annual
inspection of the interior of each baghouse for structural integrity
and condition of the filter fabric. For electrostatic precipitators,
plants would be required to conduct: (1) A daily check to verify that
the electronic controls for corona power and rapper operation are
functioning, that the corona wires are energized, and that adequate air
pressure is present on the rapper manifold; (2) a monthly visual
inspection of the system ductwork,

cyclones (if applicable), housing unit, and hopper for leaks; and (3) a
biennial internal inspection to determine the condition and integrity
of corona wires, collection plates, plate rappers, hopper, and air
diffuser plates. For wet electrostatic precipitators, plants would also
be required to conduct a daily check to verify water flow and a
biennial internal inspection to determine the condition and integrity
of plate wash spray heads. For wet scrubbers, plants would be required
to conduct: (1) A daily check to verify water flow to the scrubber; (2)
a monthly visual inspection of the system ductwork and scrubber unit
for leaks; and (3) an annual internal inspection for structural
integrity and condition of the demister and spray nozzle.
    The owner or operator of an existing plant would be required to
record the results of each inspection, the results of any maintenance
performed on the control device, and the date and time of each recorded
action. The results of inspections and maintenance of control equipment
would be recorded in a logbook (written or electronic). The logbook
would be kept onsite and made available to the permitting authority
upon request. The owner or operator of an existing plant would be
required to report any deviations from the emissions limits or
monitoring requirements in a semiannual report submitted to the
permitting authority.
    The owner or operator of an existing area source would be required
to submit an initial notification of applicability and a notification
of compliance status according to the requirements in 40 CFR 63.9 of
the General Provisions (40 CFR part 63, subpart A). A performance test
would not be required if a performance test has been conducted within
the past 5 years using the specified test methods and either no process
changes have been made since the test, or the owner or operator can
demonstrate that the results of the performance test, with or without
adjustments, reliably demonstrate compliance despite process changes.
We are also proposing that the owner or operator comply with either the
requirements for SSM plans and reports in 40 CFR 63.6(e)(3) or with the
malfunction requirements in this proposed rule that are based on the
title V permit requirements. The permit requires a report if an event
occurs that results in emissions in excess of a PM limit and lasts for
more than 4 hours.
4. Compliance Requirements for New Area Sources
    The owner or operator of a new source would be required to install
and operate a bag leak detection system for each baghouse used to
comply with a PM emissions limit. The requirements for the bag leak
detection system are set forth in proposed section 63.11410(g). For
additional information on bag leak detection systems that operate on
the triboelectric effect, see ``Fabric Filter Bag Leak Detection
Guidance'', U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, September 1997, EPA-454/R-98-015, NTIS
publication number PB98164676. This document is available from the
National Technical Information Service (NTIS), 5385 Port Royal Road,
Springfield, VA 22161.
    The owner or operator of a new source that uses a control device
other than a baghouse must submit a monitoring plan to the permitting
authority for approval. The plan must describe the control device, the
parameters to be monitored, and the operating limits for the parameters
established during a performance test.
    The owner or operator of a new source would be required to
demonstrate initial compliance with each applicable PM emissions limit
by conducting a performance test according to the requirements in 40
CFR 63.7. EPA Method 5 or 5D (40 CFR part 60, appendix A), as
applicable, would be used to determine the PM emissions. All of the
testing, monitoring, operation and maintenance, recordkeeping, and
reporting requirements of the part 63 General Provisions would apply to
a new area source. We have identified in the proposed NESHAP the
General Provisions of 40 CFR part 63 applicable to existing and new
sources.

D. What is our rationale for selecting the proposed standards for area
sources?

1. Selection of PM as a Surrogate for Chromium
    The PM emissions from the various processes used for manufacturing
chromium compounds contain the urban HAP chromium, and emissions
control equipment that is designed and operated to control PM emissions
also control chromium emissions. Both plants have title V operating
permits that require PM emissions controls and establish emissions
limits for PM. For these reasons, we decided to establish standards
using PM as a surrogate for chromium emissions, which is the urban HAP
that was the basis for the listing. Controlling PM emissions will
control chromium emissions since they are contained within the PM--they
are in the particulate form as opposed to the gaseous form. PM controls
used at existing chromium plants are the same controls available to
control particulate HAP metals such as chromium. These controls capture
particulate HAP metals non-preferentially along with other PM, thus
making PM a reasonable surrogate for chromium. We have used this
approach in several other NESHAP in which PM was determined to be a
surrogate for the HAP metals in the PM.
2. Selection of Proposed Standards
    The two existing chromium compound production facilities currently
hold title V operating permits issued by their respective State
permitting agencies. Both permits contain PM emissions limits for all
processes used to produce chromium compounds. We determined that the PM
emissions limits applicable to these emissions sources are consistent
with the expected performance of similar operations controlled by well-
operated and maintained emission control devices. These control devices
(baghouses, wet scrubbers, and wet and dry electrostatic precipitators)
are widely used to control the emissions from both primary and
secondary production of many different metals, they have been
demonstrated to be effective at controlling emissions of metal HAP,
they are cost effective, and they represent GACT for new and existing
area sources in the chromium compounds manufacturing industry.
    We reviewed the PM limits in the title V operating permits for both
plants. The North Carolina plant has PM limits that are expressed in an
equation as a function of process throughput. For example, as the
process throughput decreases, the PM emissions limit in lb/hr also
decreases. This equation is applied to each of the production processes
for chromium compounds, and the allowable emissions limit based on
throughput accounts for changes in production levels, which affects the
level of emissions control that can be achieved. The Texas plant has
emissions limits that are fixed in terms of allowable lb/hr and are
independent of process throughput. A format that is fixed in lb/hr is
not an appropriate approach for other existing plants or for new plants
because it does not account for differences in size or capacity.
    We determined that the format used in the title V permit for the
North Carolina plant was appropriate for a national standard for new
and existing area sources. This mechanism for determining the emissions
limit accounts for differences in process rates at different plants and
it accounts for changes in the process rate at a given plant over time.
We have also determined that the Texas plant can achieve the proposed
emissions limits

based on process throughput using their existing emissions control
equipment. Consequently, we are proposing to apply this equation to
determine emissions limits for each of the production processes at all
new and existing area source plants for this national standard.
    We are alternatively proposing that GACT for these existing area
sources is no further emission reduction. We request comment on the
basis, consistent with section 112(d)(5), for asserting that GACT is no
further control for these existing sources. We request comment on this
issue because the standard proposed above will not result in any
emission reductions beyond what is already required by the Federal
permits to which the existing facilities are already subject.
3. Selection of Proposed Compliance Requirements
    We are proposing to base the compliance requirements for existing
area sources on the operation and maintenance, recordkeeping, and
reporting requirements in the title V permit of the area source located
in North Carolina. The title V permit includes requirements for
inspections and maintenance of each type of control device, semiannual
reports of any deviation, and records of control device inspections and
maintenance. In contrast, the compliance requirements for the Texas
plant include very little with respect to monitoring or maintaining
emissions control equipment. The requirements we are proposing are
necessary to ensure emissions controls are maintained and operated
properly on a continuing basis. The requirements do not pose a
significant additional burden for the Texas plant that must implement
them. We are allowing 6 additional months for existing area sources to
prepare a startup, shutdown, and malfunction plan and implement the
inspection and maintenance requirements for control devices.
    We would require that the existing plants comply with limited
initial notification requirements in 40 CFR 63.9 of the NESHAP General
Provisions (40 CFR part 63, subpart A). In the notification of
compliance status required by 40 CFR 63.9(h), the owner or operator
would certify that equipment has been installed and is operating for
each regulated emissions point and that the plant will comply with the
inspection and maintenance requirements. The plant would be required to
conduct a performance test to demonstrate initial compliance if a
performance test has not been conducted in the past five years.
    We are proposing to require bag leak detection systems for
baghouses used at new area sources; a monitoring plan would be required
if another type of control device is used. Bag leak detection systems
are typical requirements for new sources of the size and complexity of
chromium compound manufacturing facilities. In addition, these systems
can be incorporated into the design and operation for new sources and
would not require retrofitting or duplicative monitoring as would be
the case if they were applied to existing sources.
    For new area sources, we are also proposing to apply the
notification, testing, monitoring, operation and maintenance,
recordkeeping, and reporting requirements in the part 63 General
Provisions (40 CFR part 63, subpart A). The General Provisions are
necessary for effective application of the standard for new area
sources. We propose that these requirements are sufficient to ensure
compliance with the proposed emissions limits for equipment at new area
sources.

VI. Proposed Area Source NESHAP for Flexible Polyurethane Foam
Production and Fabrication

A. What area source categories are affected by the proposed NESHAP?

    This proposed NESHAP applies to two area source categories:
Flexible Polyurethane Foam Production and Flexible Polyurethane Foam
Fabrication Operations. We are addressing these two area source
categories in a single NESHAP due to similarity of their operations and
because they are often co-located.
    The Flexible Polyurethane Foam Production area source category
includes any facility which manufactures foam made from a polymer
containing a plurality of carbamate linkages in the chain backbone
(polyurethane). Polyurethane is commonly made by reacting a
polyisocyanate with an organic polyhydroxyl material in the presence of
water. Application of blowing agents, catalysts, surfactants, and
fillers transform the polyurethane into a foam with specialized
properties.
    There are three types of polyurethane foam production facilities:
slabstock flexible polyurethane foam (slabstock foam), molded flexible
polyurethane foam (molded foam), and rebond foam. Slabstock foam is
produced in large continuous ``buns'' that are then cut into the
desired size and shape. Slabstock foam is used in a wide variety of
applications, including furniture and mattresses. Molded foam is
produced by ``shooting'' the foam mixture into a mold of the desired
shape and size. Molded foam is used in office furniture, automobile
seats, novelties, and many other applications. Rebond foam is made from
scrap foam that is converted into a material primarily used for carpet
underlay.
    Prior to the promulgation of the NESHAP for major sources of foam
production (40 CFR part 63, subpart III) in 1998, we estimated that
there were 78 slabstock foam facilities in the U.S. and 228 molded foam
production facilities. A recent estimate is that there are 36 rebond
foam facilities.
    The Flexible Polyurethane Foam Fabrication Operations area source
category includes processes engaged in cutting, bonding, and/or
laminating pieces of flexible polyurethane foam together or to other
substrates. Typical bonding techniques include gluing, taping, and
flame lamination.
    Foam fabrication adhesive use operations may use methylene
chloride-based adhesives to adhere pieces of foam together. Most foam
fabrication adhesives are applied by workers using spray guns. It is
typically performed in large open rooms, with work stations spaced
along a conveyor which moves the pieces of foam to be glued together.
    Loop slitter adhesive use is a specialized type of foam fabrication
adhesive use. Loop slitters are equipment at slabstock foam production
and fabrication facilities that are used to slice large foam buns into
thin sheets. Adhesive is used to attach the ends of the foam buns to
one another before they are mounted on the loop slitter. The amount of
adhesive used for loop slitters is relatively low because the adhesive
is not applied continuously, just once or twice per shift when the foam
buns are loaded onto the loop slitter.
    Flame lamination refers to the bonding of foam to other substrates
(i.e., cloth, foam, plastic, and other materials) where the bonding
agent is scorched or melted foam. Thin sheets of foam are passed under
a flame which scorches the foam surface and makes it sticky. The tacky
foam sheet is then applied to a foam or fabric substrate.
    All slabstock foam production plants perform foam fabrication, but
there are also independently operated foam fabrication facilities.
There is no foam fabrication trade association, so we do not have a
good estimate of the number of foam fabrication facilities in the U.S.
Prior to the promulgation of subpart III, EPA estimated that there were
loop slitters at 40 slabstock foam production

facilities in the U.S. and 21 flame lamination facilities.

B. What are the production processes and emissions points for flexible
polyurethane foam production and fabrication?

    Both the Flexible Polyurethane Foam Production and Flexible
Polyurethane Fabrication Operations area source categories were listed
for regulation due to emissions of the urban HAP methylene chloride.
Historically, methylene chloride was the only urban HAP used at foam
production and foam fabrication facilities. Slabstock foam production
facilities used methylene chloride as an auxiliary blowing agent (ABA)
to control the density and other properties of the foam as it expanded
during the pouring process. Methylene chloride was also used as an
equipment cleaner, in particular for mix heads. Currently, almost all
slabstock foam producers have discontinued any use of methylene
chloride. A small number of molded and rebond foam facilities
previously used methylene chloride in mold release agents and some
molded foam facilities used it as a mix-head cleaner.
    Foam fabricators used methylene chloride-based adhesives to adhere
pieces of foam to one another. Flame laminators have never used
methylene chloride.

C. What are the proposed requirements for area sources?

1. Applicability and Compliance Dates
    This proposed NESHAP applies to both new and existing flexible foam
production and flexible foam fabrication plants that are area sources.
The owner or operator of an existing source would be required to comply
with the area source NESHAP by the date of publication of the final
rule in the Federal Register. The owner or operator of a new source
would be required to comply with the area source NESHAP by the date of
publication of the final rule in the Federal Register or at startup,
whichever is later.
2. Proposed Emission Standards
    Table 1 of this preamble summarizes the various foam production and
fabrication area sources covered by this proposed rule and the
corresponding proposed regulatory strategies. As shown in Table 1 of
this preamble, slabstock foam producers may still use limited amounts
of methylene chloride as an auxiliary blowing agent. The technologies
determined to be GACT for this industry significantly reduce, but do
not always eliminate the use of methylene chloride as an auxiliary
blowing agent. Methylene chloride use is prohibited for other uses at
foam production and foam fabrication facilities.

  Table 1.--Foam Production and Fabrication Processes and Corresponding
                          Proposed Regulations
------------------------------------------------------------------------
         Area source types                   Proposed regulation
------------------------------------------------------------------------
1. Slabstock polyurethane foam      a. Emission limits for methylene
 production.                         chloride used as an auxiliary
                                     blowing agent (ABA);
                                    b. Controls on storage vessels;
                                    c. Management practices for
                                     equipment leaks; and
                                    d. Prohibition on use of methylene
                                     chloride as an equipment cleaner.
                                    OR
                                    Eliminate use of methylene chloride
                                     in slabstock foam production
                                     processes.
2. Molded polyurethane foam         Prohibit use of methylene chloride
 production.                         as mold release agent or equipment
                                     cleaner.
3. Rebond foam production.........  Prohibit use of methylene chloride
                                     as mold release agent.
4. Foam fabrication adhesive use..  Prohibit use of methylene chloride
                                     adhesives.
------------------------------------------------------------------------

    For slabstock foam production area sources, we are proposing
emissions limits and management practices to reduce methylene chloride
emissions from the production line, storage tanks, leaking equipment,
and equipment cleaning. Emissions limits for methylene chloride used as
an ABA are based on a formula which varies depending on the grades of
foam being produced. Vapor balance systems or carbon beds would be
required for methylene chloride storage vessels. The proposed
management practices require plants to identify and correct leaking
pumps and other equipment in methylene chloride service. Specifically,
owners or operators would check periodically for equipment leaks (from
quarterly for pumps and valves to annual for connectors) using EPA
Method 21 (40 CFR part 60, appendix A). Leaks, which are defined as a
reading of 10,000 parts per million (ppm) or greater, must be corrected
within 15 days of when they are detected. The use of methylene chloride
to clean mix heads and other equipment would be prohibited.
    Slabstock foam facilities that do not use any methylene chloride at
the facility would not be subject to these emission limitations and
management practices. Such facilities would only need to submit a one-
time report.
    This proposed rule prohibits the use of methylene chloride-based
mold release agents at molded and rebond foam facilities, methylene
chloride-based equipment cleaners at molded foam facilities, and
methylene chloride-based adhesives for foam fabrication.
3. Compliance Requirements
    Slabstock foam area sources continuing to use methylene chloride
would be required to monitor the HAP added at slabstock production
mixheads and the HAP contained in and added to HAP ABA storage tanks.
Plants using carbon adsorber systems to control emissions from HAP ABA
storage tanks would be required to monitor the HAP content of exhaust
streams from outlet vents. Plants using a recovery device to reduce
methylene chloride emissions would be required to comply with a
recovered HAP ABA monitoring and recordkeeping program.
    The owner or operator would be required to submit semiannual
reports containing information on allowable and actual HAP ABA
emissions, carbon adsorbers on storage tanks, and equipment leaks.
Owners and operators would also be required to submit annual compliance
certifications. Records would be required to demonstrate compliance,
including a daily operating log of foam runs containing the grades of
foam produced and related data, and records related to storage tanks
and equipment leaks. This proposed NESHAP also includes a simpler
facility-wide compliance option that only requires that the facility
measure the total amount of methylene chloride used at the facility.
Slabstock foam plants that do not use any methylene chloride would be
required to submit a one-time certification as part of their
notification of compliance status.

    Molded foam, rebond foam, and foam fabrication facilities which
operate loop slitters would be required to prepare, and keep on file,
compliance certifications which certify that the facility is not using
the prohibited methylene-chloride based products and will not use them
in the future. The plants would also maintain records documenting that
the products they are using for the specific purposes do not contain
any methylene chloride. These can be records that would be kept in the
absence of this proposed rule such as adhesive usage information and
Material Safety Data Sheets. Foam fabrication plants which do not
operate loop slitters would have no compliance certification or
recordkeeping requirements.
    The owner or operator of each slabstock foam affected source that
continues to use methylene chloride and, therefore, would be subject to
the methylene chloride emissions limits, would be required to comply
with several requirements of the General Provisions in 40 CFR part 63,
subpart A. However, because of the intermittent nature of the slabstock
foam process, we are not proposing to require that affected sources
comply with the requirements for SSM plans and reports in 40 CFR
63.6(e)(3).

D. What is our rationale for selecting the proposed standards for area
sources?

1. Selection of Proposed Standards
    When the NESHAP for major sources of polyurethane foam production
in 40 CFR part 63, subpart III was promulgated in 1998, we estimated
that there were 78 slabstock foam facilities, and that all of these
facilities were major sources. The NESHAP requirements, along with the
revisions to the Occupational Safety and Health Administration (OSHA)
permissible exposure and short-term exposure limits for methylene
chloride (63 FR 50711, September 22, 1998), caused slabstock foam
facilities to investigate, evaluate, and install technologies to reduce
or eliminate the use of methylene chloride as an ABA at their
facilities. These technologies include alternative formulations to
reduce the amount of methylene chloride ABA needed, alternative non-HAP
ABAs (acetone, liquid carbon dioxide), controlled or variable pressure
foaming, and forced cooling. Based on recent contacts with the
industry, we have verified that every known slabstock facility has
converted their process to utilize one of these technologies. In many
cases, these changes were instituted prior to the compliance date for
subpart III, making the facilities area sources. As these technologies
have been universally applied to major and area source slabstock foam
production facilities, we have no reason to believe that these
emissions reduction technologies are infeasible or inappropriate for
area sources. Consequently, we propose to conclude that emissions
limitations based on the application of these technologies are
generally available control technology (GACT) for new and existing area
sources.
    Because the installation and operation of several of these
pollution prevention technologies have resulted in the near total
elimination of the use of and emissions of methylene chloride at
slabstock foam production facilities, we have included a provision in
this proposed rule that allows slabstock facilities that do not use any
methylene chloride to submit a one-time report certifying that they do
not use, and will not use in the future, any methylene chloride. We
included this provision to reduce the recordkeeping and reporting
burden for these facilities.
    We are also aware that methylene chloride usage has been eliminated
at many molded foam and rebond foam production facilities. Therefore,
we have no reason to believe that the use of non-methylene chloride
mold release agents and cleaners at molded and rebond foam production
facilities is infeasible or inappropriate for area sources. Therefore,
we determined that a prohibition of methylene chloride mold release
agents and cleaners at molded and rebond foam production facilities is
GACT for new and existing sources. While we are not aware of any area
source molded foam or rebond foam facility that is currently using
methylene chloride-based mold release agents or cleaners, we believe
that it is appropriate to propose a prohibition on the use of these
products to ensure that no methylene chloride is emitted from these
facilities in the future.\5\
---------------------------------------------------------------------------

    \5\ Flame lamination foam fabrication facilities have never
used, and thus never emitted, any methylene chloride and were not
included in the listed category. Therefore, this proposed rule does
not contain any emissions limitations for flame lamination
facilities.
---------------------------------------------------------------------------

    The changes to the OSHA permissible exposure and short-term worker
exposure limits for methylene chloride had an even more significant
impact on the flexible polyurethane foam fabrication source category,
as it made it infeasible to continue to use methylene chloride-based
adhesives for most foam fabrication operations. Current information
indicates that owners and operators of foam fabrication sources have
eliminated the use of methylene chloride-based adhesives. (Additional
details are provided in the background information for this industry in
Docket ID No. EPA-HQ-OAR-2006-0897.) The most common alternatives being
used are acetone-based and water-based adhesives. Therefore, we have no
reason to believe that the use of non-methylene chloride-based
adhesives for foam fabrication applications is infeasible or
inappropriate for area sources as a generally available management
practice. In addition, because of the nature of the adhesives
application process described above, we are not aware of control
technologies or management practices that could be employed to limit
methylene chloride emissions in foam fabrication operations.
Consequently, we are proposing that a prohibition of the use of
adhesives containing methylene chloride is GACT for foam fabrication
operations. We are requesting comments on this proposed prohibition.
    Among other things, we are asking for comment on the availability
of cost effective alternatives to methylene chloride adhesives. We are
also requesting comments on whether and under what circumstances
methylene chloride-based adhesives (e.g., in small specialty
applications) are being used or might be used by the foam fabrication
industry, and what quantities are or might be involved in such
applications. We also request information on any control technologies
or management practices used to limit emissions of methylene chloride
in the application of the methylene chloride-based adhesives and any
cost information associated with such control approaches.
2. Selection of Proposed Compliance Requirements
    For slabstock foam production facilities that continue to use
methylene chloride, we concluded that requirements for monitoring and
recording the amount of methylene chloride used are sufficient to
ensure compliance with the proposed emissions limitations.
    For slabstock foam production facilities that have eliminated the
use of methylene chloride and are exempt from the emissions limitations
in this proposed rule, we are proposing to require that owners or
operators submit a one-time notification certifying that they do not
use any methylene chloride and will not use it in the future as their
notification of compliance status report.
    In order to demonstrate compliance with the prohibition of the use
of methylene chloride based mold release agents and cleaners for molded
and rebond processes, we are proposing to

require preparation of a compliance certification, signed by a
responsible official and kept on file, indicating that the facility has
ceased the use of these prohibited products. The plant owner or
operator would be required to maintain adhesive usage records and
Material Safety Data Sheets or other documentation to show that no
methylene chloride-based products are being used.
    Currently available information from the foam fabrication industry
and adhesive manufacturers suggests that it is not possible for typical
foam fabrication operations to use methylene chloride-based adhesives
and comply with OSHA permissible exposure and short-term worker
exposure limits for methylene chloride. Because we assume that
compliance with these OSHA standards is being achieved through the
elimination of the use of methylene chloride-based adhesives, we do not
believe that additional reporting or recordkeeping is necessary to
demonstrate compliance with the proposed prohibition of the use of
methylene-chloride based adhesives. Therefore, this proposed rule
contains no compliance requirements for most foam fabrication affected
sources.
    However, unlike typical foam fabrication applications, we believe
it may be possible for loop slitters to use methylenechloride-- based
adhesives and still comply with the OSHA worker exposure limits. This
is because loop slitter adhesive application is brief and intermittent,
typically not occurring more than once during a single shift. As a
result, worker exposure is also brief and intermittent. Thus, it is
possible that some loop slitter facilities could meet the OSHA time-
weighted average exposure limitation without changing any of their
normal procedures. Additionally, we believe that if compliance with the
OSHA requirements could not be achieved without changing normal
operating procedures, there are feasible measures that could be
implemented to achieve compliance. For instance, the loop slitter
adhesive could be applied by workers wearing respiration equipment, or
a hood or other ventilation equipment could be added to the adhesive
application station. Because of these possibilities, loop slitter
operations using methylene chloride adhesives have the potential to
meet the worker exposure limits set by OSHA, but still use and emit
methylene chloride.
    Due to this possibility, we are proposing to require that flexible
polyurethane foam fabrication affected sources operating loop slitters
prepare and keep on file a compliance certification, signed by a
responsible official, indicating that the facility does not use any
methylene chloride and will not use it in the future.
    We are not proposing to apply the SSM requirements in 40 CFR
63.6(e)(3) to flexible polyurethane foam production and fabrication
area sources. For slabstock facilities that elect not to use any
methylene chloride, and for molded facilities, rebond facilities, and
loop slitters that are prohibited from using methylene chloride-based
products, SSM periods will have no impact on methylene chloride
emissions.
    There are also fundamental problems in applying the General
Provision requirements for SSM to slabstock foam production facilities
that continue to use methylene chloride. The rationale for not
subjecting area source slabstock foam plants to the SSM requirements
was laid out at promulgation of subpart III, which exempted major
sources from these provisions.
    The fundamental problem in applying the General Provisions SSM
provisions to flexible polyurethane foam production facilities is
defining a startup and a shutdown. The foam production process is
intermittent in nature and, based on the EPA's knowledge of the
industry, every foam production process will undergo at least one
routine ``startup'' and one routine ``shutdown'' per day. The EPA never
intended that these routine activities be addressed by the SSM
requirements.
    The intent of the SSM plan is to identify methods to reduce excess
emissions that occur during these events when air pollution is emitted
in quantities greater than the standard allows. Given the comprehensive
approach of the adopted sections of subpart III to regulate emissions
by restricting the amount of HAP used, EPA does not believe that, for
foam production facilities, periods of SSM provide the opportunity for
emissions not already anticipated.

VII. Proposed Area Source NESHAP for Lead Acid Battery Manufacturing

A. What area source category is affected by the proposed NESHAP?

    The Lead Acid Battery Manufacturing area source category includes
plants that manufacture batteries from lead, lead oxide paste, and
sulfuric acid. These may be either of two types of batteries: (1)
Starting, lighting, and ignition (SLI) batteries primarily used in
automobiles, or (2) industrial and traction batteries. Industrial
batteries include those used for uninterruptible power supplies and
traction batteries are used to power electric vehicles such as
forklifts.
    We estimate that there are approximately 58 lead acid battery
manufacturing area sources operating in the U.S. Many of these area
sources are subject to the NSPS for lead acid battery manufacturing
plants in 40 CFR part 60, subpart KK. Subpart KK applies to all lead
acid battery manufacturing plants constructed or modified since 1982 if
they produce or have the design capacity to produce in one day
batteries containing an amount of lead equal to or greater than 5.9
megagrams (6.5 tons).

B. What are the production processes and emissions points at facilities
that manufacture lead acid batteries?

    The lead acid battery manufacturing process includes preparing
battery grids through stamping or casting lead. Lead oxide paste is
added to the grids in the grid pasting operation creating plates that
are cured and assembled into a battery. Batteries are then charged
using sulfuric acid in the forming operations. Lead oxide may be
prepared by the battery manufacturer, as is the case for many larger
battery manufacturing plants, or may be purchased from a supplier.
    The lead acid battery manufacturing area source category was listed
for regulation due to emissions of the urban HAP lead, which is used as
a primary component of a battery. Cadmium, another urban HAP emitted in
trace amounts, was also identified in the listing of the lead acid
battery manufacturing area source category. Cadmium and other trace
urban HAP metals that are emitted by lead acid battery manufacturing
plants (arsenic, beryllium, chromium, manganese, and nickel) are
controlled by the same devices that control lead emissions.

C. What are the proposed requirements for area sources?

1. Applicability and Compliance Dates
    The proposed NESHAP apply to both new and existing lead acid
battery manufacturing plants that are area sources. We are not aware of
any major source lead acid battery manufacturing plants. We are
proposing that owners or operators of existing sources comply with all
the requirements of the area source NESHAP no later than 1 year after
the date of publication of the final rule in the Federal Register. The
owner or operator of a new source would be required to comply with the
area source NESHAP on the date of publication of the final rule in the
Federal Register or at startup, whichever is later.

2. Proposed Emissions Standards
    We are proposing to adopt as the NESHAP for the lead acid battery
manufacturing area source category the numerical emissions limits for
grid casting, paste mixing, three-process operation, lead oxide
manufacturing, lead reclamation, and other lead emitting processes in
40 CFR 60.372 of the NSPS for lead acid batteries. These lead discharge
limits are:
     0.40 milligram of lead per dry standard cubic meter of
exhaust (mg/m3) from grid casting facilities,
     1.00 mg/m3 from paste mixing facilities,
     1.00 mg/m3 from three-process operations,
     5.0 mg per kilogram of lead feed from lead oxide
manufacturing facilities,
     4.50 mg/m3 from lead reclamation facilities,
and
     1.0 mg/m3 from any other lead-emitting
operations.
    We are also proposing to adopt as the NESHAP for the lead acid
battery manufacturing area source category the opacity limits from the
lead acid battery NSPS. The opacity must be no greater than 5 percent
from lead reclamation facilities and no greater than 0 percent from any
affected facility except lead reclamation facilities.
3. Compliance Requirements
    We are proposing to include in this proposed NESHAP the monitoring,
testing, recordkeeping, and reporting requirements in the NSPS for lead
acid batteries. This proposed NESHAP requires controls for lead
emissions from the paste mixing, three-process operation, lead oxide
manufacturing, grid casting, lead reclamation processes, and other
lead-emitting processes. The owner or operator would be required to
submit quarterly reports containing information on emissions that
exceed the applicable limits. Records would be required to demonstrate
compliance. We are also proposing to adopt the testing, monitoring,
recordkeeping, and reporting requirements in the part 60 General
Provisions (40 CFR part 60, subpart A) and the initial notification and
notification of compliance requirements in the part 63 General
Provisions (40 CFR part 63, subpart A). We have explicitly identified
in the proposed NESHAP the applicable General Provisions of both 40 CFR
parts 60 and 63.
    The proposed NESHAP allows existing plants to utilize previously
conducted performance tests, when they are representative of current
conditions, to demonstrate compliance. Plants without representative
prior performance tests are required to conduct performance tests by
180 days after the compliance date.

D. What is our rationale for selecting the proposed standards for area
sources?

1. Selection of Proposed Standards
    The NSPS applies to all lead acid battery manufacturing plants
constructed or modified since 1982 if they produce or have the design
capacity to produce in one day batteries containing an amount of lead
equal to or greater than 5.9 megagrams (6.5 tons). Many existing lead
acid battery facilities are subject to the NSPS and use fabric filters
and impingement scrubbers to meet the lead emissions limits in the
NSPS. In addition, through discussions with the industry trade
organization, we have concluded that the existing facilities, whether
they are subject to the NSPS or not, have installed fabric filters or
other control devices that will allow them to meet the standard.
    Therefore, we have no reason to believe that the conventional
control techniques employed to meet the emissions limits in the NSPS
are infeasible or inappropriate for new or existing area sources. We
have determined that the emissions control requirements in the NSPS for
lead acid battery manufacturing are GACT for new and existing sources
in the lead acid battery manufacturing area source category.
2. Selection of Proposed Compliance Requirements
    We have reviewed the compliance requirements in the NSPS for lead
acid batteries and the NSPS General Provisions (40 CFR part 60, subpart
A) applicable to this proposed NESHAP and concluded that these
requirements are sufficient to ensure compliance with the proposed
emissions limit standards. Therefore, we are proposing to adopt the
NSPS testing, monitoring, and recordkeeping requirements in this
proposed rule.
    The part 60 General Provisions are necessary for effective
application of the lead acid battery NSPS and are therefore
incorporated into this proposed rule as well. We are also incorporating
certain provisions in the NESHAP General Provisions (40 CFR part 63,
subpart A) to address aspects of this proposed rule not covered by the
part 60 General Provisions.

VIII. Proposed Area Source NESHAP for Wood Preserving

A. What area source category is affected by the proposed NESHAP?

    The Wood Preserving area source category includes facilities that
use pressure or thermal processes to impregnate chemicals into wood to
a depth that will provide effective long-term resistance to attack by
fungi, bacteria, insects, and marine borers. As most sources in this
source category are minor sources, few are subject to State air
emissions regulations or permit requirements.
    Existing facilities in the wood preserving source category are
currently well controlled in terms of emissions of the urban HAP metals
chromium and arsenic as a result of a voluntary decision by the
industry to discontinue certain specified uses of chromated copper
arsenate (CCA). The discontinued uses include dimensional lumber and
wood used in play structures, decks, picnic tables, landscaping
timbers, residential fencing, patios, walkways, and boardwalks. The
voluntary agreement has reduced the usage and emissions of arsenic and
chromium compounds from CCA treatment facilities by more than 80
percent. On March 17, 2003, pursuant to section 6(f)(1) of the Federal
Insecticide, Fungicide, and Rodenticide Act (FIFRA), a cancellation
order was signed in response to the use terminations and cancellations
voluntarily requested by the registrants of wood preservative pesticide
products containing CCA). Under the cancellation order, as of December
31, 2003, newly produced CCA may only be used for preservative
treatment of a limited number of use categories of forest products
(e.g., lumber and timber for marine construction for salt water use;
wood for highway construction; piles; poles; agricultural posts; and
treated wood used as structural members on farms). The use of CCA has
been effectively eliminated from household commodities such as decking
as a result of the FIFRA cancellation order. Household commodities such
as decking are now generally treated with waterborne copper-based wood
preservative systems known as ammoniacal copper quat (ACQ) or copper
azole (CA). These preservatives do not contain arsenic or chromium, or
any other urban HAP as active ingredients. (See Docket Item 0001
``Background on the Wood Preserving Industry'' in Docket ID No. EPA-HQ-
OAR-2006-0897.)
    With regard to dioxin emissions, pursuant to FIFRA, EPA issued a
notice

on the wood preservative uses of pentachlorophenol to establish
reliable and enforceable methods for implementing certified limits for
hexachlorodibenzo-p-dioxin (HxCDD) and 2,3,7,8-tetrachlorodibenzo-p-
dioxin (2,3,7,8-TCDD or dioxin) (52 FR 140, January 2, 1987). Per the
EPA notice, levels of 2,3,7,8-TCDD are not allowed to exceed 1 part per
billion (ppb) in any product, and any manufacturing-use
pentachlorophenol has to have HxCDD levels below an average of 2 ppm
over a monthly release or a batch level limit of 4 ppm. The
pentachlorophenol registrant has to submit monthly analyses to EPA to
demonstrate compliance with these requirements.
    Industry representatives have reported there is no current use of
methylene chloride by the wood preserving industry. In 1992, its use as
a solvent system was removed from the standards of the American Wood
Preservers' Association, which govern the treatment of wood products.
    All wood preserving plants currently in operation are area sources.
We estimate that there are approximately 393 wood preserving area
sources operating in the U.S. and expect that new facilities will be
built in the coming years. In this rule, we are proposing standards for
both new and existing area sources.

B. What are the production processes and emissions points at wood
preserving facilities?

    Wood preserving or treatment is accomplished by either pressure or
thermal processes. To initiate either process, wood products are
debarked, sawed, and conditioned. More than 95 percent of all treated
wood is preserved through pressurized processes. These processes are
performed inside an enclosed vessel and involve the application of
pneumatic or hydrostatic pressure to expedite the movement of
preservative liquid into the wood.
    In a thermal treatment process, the wood is exposed to the
preservative in an open vessel. The thermal process involves exposing
wood to a heated preservative for 6 to 12 hours followed by exposure to
the preservative at ambient temperature for 2 to 4 hours. According to
industry representatives, there are currently only three facilities
using the thermal process to treat the bottom portion (i.e., the 6 to 8
feet that will be below ground) on certain types of utility poles.
    There are two general classes of wood preservatives: oils, such as
creosote and petroleum solutions of pentachlorophenol (also called
``penta'' or ``PCP'') and copper naphthanate, and waterborne salts that
are applied as water solutions. Treated wood is used throughout the
U.S. in a variety of capacities, including utility poles, lumber and
timber, railroad ties, fence posts, marine pilings, plywood, and other
miscellaneous products. By extending the service life of available wood
through treatment with chemicals, wood treatment reduces the demands on
forestry resources, reduces operating costs in industries such as
utilities and railroads, and helps ensure safe working conditions where
timbers are used as support structures.
    The urban HAP emitted from wood preserving operations that were the
basis for the source category listing are arsenic, chromium, methylene
chloride, and dioxins. These HAP may be released from the treatment
process or an opening or leak in the process equipment. Significant
effort is made by the industry to minimize any excess preservative that
might contribute to emissions because the preservative can be as much
as one-third of the total product cost. As a result, almost all wood
preservation employing a pressure process takes place in a closed
retort. A retort is an airtight pressure vessel, typically a long
horizontal cylinder, used for the pressure impregnation of wood
products with a liquid wood preservative. Proper use of a retort or
similar vessel minimizes the loss of excess preservative and thereby
limits HAP emissions.
    All of the thermal treatment processes that have been identified by
industry utilize air scavenging systems to capture and control
emissions coming from the process treatment vessel during the treatment
process.
    After the preservative has been impregnated in the wood, the
treated wood is set out to dry over a drip pad to collect preservative
not absorbed during the treatment process. Regulations promulgated
pursuant to the Resource Conservation and Recovery Act prohibit the
presence of any free preservative drippage from products after they
leave the process drip pad.

C. What are the proposed requirements for area sources?

1. Applicability and Compliance Dates
    The proposed NESHAP apply to both new and existing wood preserving
plants that are area sources. Because existing area sources are already
complying with the proposed standards, we are proposing that owners or
operators of existing sources comply with all the requirements of the
area source NESHAP by the date of publication of the final rule in the
Federal Register. The owner or operator of a new source would be
required to comply with the area source NESHAP by the date of
publication of the final rule in the Federal Register or at startup,
whichever is later.
2. Proposed Standards
    We are proposing to adopt as the NESHAP for the Wood Preserving
area source category the control technologies and management practices
currently used by most facilities within the wood preserving industry.
Facilities using a pressure treatment process would be required to use
a retort or similarly enclosed vessel for the preservative treatment of
wood involving any wood preservatives containing chromium, arsenic,
dioxins, or methylene chloride. Facilities using a thermal treatment
process involving any wood preservatives containing chromium, arsenic,
dioxins, or methylene chloride would be required to use process
treatment tanks equipped with air scavenging systems to capture and
control air emissions.
    These proposed standards would also require facility operators to
minimize emissions from process tanks and equipment (e.g., retorts,
other enclosed vessels, and thermal treatment tanks), as well as
storage, handling, and transfer operations. These standards would have
to be documented in a management practices plan that must include, but
not be limited to, the following activities:
     Minimizing preservative usage;
     Maintaining records on the type of treatment process and
types and amounts of wood preservatives used at the facility;
     For the pressure treatment process, maintaining charge
records identifying pressure reading(s) inside the retorts (or
similarly enclosed vessels, if applicable);
     For the thermal treatment process, maintaining records
that an air scavenging system is installed and operated properly during
the treatment process;
     For the pressure treatment process, fully draining the
retort prior to opening the retort door;
     Storing treated wood product on drip pads or in a primary
containment area to convey preservative drippage to a collection system
until drippage has ceased;
     Promptly collecting any spills; and
     Performing relevant corrective actions or preventative
measures in the event of a malfunction before resuming operations.
    Existing written standard operating procedures may be used as the

management practices plan if those procedures include the minimum
activities required for a management practices plan.
3. Compliance Requirements
    Plants would be required to comply with limited notification
requirements in the part 63 General Provisions (40 CFR part 63, subpart
A). This proposed rule establishes the content and deadlines for
submission of the notifications. We have explicitly identified in the
proposed NESHAP the applicable General Provisions of 40 CFR part 63.

D. What is our rationale for selecting the proposed standards for area
sources?