Regional Haze Regulations and Guidelines for Best Available Retrofit Technology (BART) Determinations

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

[Federal Register: May 5, 2004 (Volume 69, Number 87)]
[Proposed Rules]
[Page 25183-25232]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr05my04-38]
[[Page 25184]]

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

ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 51
[FRL-7653-6]
RIN 2060-AJ31

Regional Haze Regulations and Guidelines for Best Available
Retrofit Technology (BART) Determinations

AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.

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

SUMMARY: On July 1, 1999, EPA promulgated regulations to address
regional haze, (64 FR 3714). These regulations were challenged, and on
May 24, 2002, the U.S. Court of Appeals for the District of Columbia
Circuit issued a ruling vacating the regional haze rule in part and
sustaining it in part. American Corn Growers Ass'n v. EPA, 291 F.3d 1
(D.C. Cir. 2002). Today's proposed rule addresses the court's ruling in
that case.
In addition, prior to the court's decision, EPA had proposed
guidelines for implementation of the best available retrofit technology
(BART) requirements under the regional haze rule, (66 FR 38108; July
20, 2001). The proposed guidelines were intended to clarify the
requirements of the regional haze rule's BART provisions. We proposed
to add the guidelines and also proposed to add regulatory text
requiring that these guidelines be used for addressing BART
determinations under the regional haze rule. In addition, we proposed
one revision to guidelines issued in 1980 for facilities contributing
to ``reasonably attributable'' visibility impairment.
In the American Corn Growers case, the court vacated and remanded
the BART provisions of the regional haze rule. To respond to the
court's ruling, we are proposing new BART provisions and reproposing
the BART guidelines. The American Corn Growers court also remanded to
the Agency its decision to extend the deadline for the submittal of
regional haze plans. Subsequently, Congress amended the deadlines for
regional haze plans (Consolidated Appropriations Act for Fiscal Year
2004, Public Law 108-199, January 23, 2004). We are proposing to amend
the rule to conform to the new statutory deadlines.

DATES: Comments on this proposal must be received by July 6, 2004.

ADDRESSES: Submit your comments, identified by Docket ID No. OAR-2002-
0076 by one of the following methods:
Federal eRulemaking Portal: http://www.regulations.gov
Follow the on-line instructions for submitting comments. Agency Web site:
http://www.epa.gov/edocket. EDOCKET, EPA's electronic public docket and
comment system, is EPA's preferred method for receiving comments.
Follow the on-line instructions for submitting comments.
E-mail: http://www.epa.gov/edocket.
Fax: 202-566-1741.
Mail: OAR Docket, Environmental Protection Agency, Mailcode: B102,
1200 Pennsylvania Ave., NW., Washington, DC 20460. Please include a
total of 2 copies.
Hand Delivery: EPA/DC, EPA West, Room B102, 1301 Constitution Ave.,
NW., Washington, DC. Such deliveries are only accepted during the
Docket's normal hours of operation, and special arrangements should be
made for deliveries of boxed information.
Instructions: Direct your comments to Docket ID No. OAR-2002-0076.
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.epa.gov/edocket, 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 EDOCKET, regulations.gov, or e-
mail. The EPA EDOCKET and the federal regulations.gov Web sites are
``anonymous access'' systems, 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 EDOCKET or 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. For additional information about EPA's public
docket visit EDOCKET on-line or see the Federal Register of May 31,
2002 (67 FR 38102).
For additional instructions on submitting comments, go to unit II
of the SUPPLEMENTARY INFORMATION section of this document.
Docket: All documents in the docket are listed in the EDOCKET index
at http://www.epa.gov/edocket. Although listed in the index, some
information is not publicly available, i.e., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, is not placed on the Internet and will be
publicly available only in hard copy form. Publicly available docket
materials are available either electronically in EDOCKET or in hard
copy at the OAR Docket, EPA/DC, EPA West, Room B102, 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 (202) 566-1744, and the
telephone number for the OAR Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Kathy Kaufman at 919-541-0102 or by e-
mail at Kaufman.Kathy@epa.gov or Todd Hawes at 919-541-5591 or by e-
mail Hawes.Todd@epa.gov.

SUPPLEMENTARY INFORMATION:

I. Regulated Entities

The promulgation of the proposed rule would affect the following:
State and local permitting authorities and Indian Tribes containing
major stationary sources of pollution affecting visibility in federally
protected scenic areas.
This list is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be regulated by this
action. This list gives examples of the types of entities EPA is now
aware could potentially be regulated by this action. Other types of
entities not listed could also be affected. To determine whether your
facility, company, business, organization, etc., is regulated by this
action, you should examine the applicability criteria in Part II of
this preamble. If you have any questions regarding the applicability of
this action to a particular entity, consult the person listed in the
preceding FOR FURTHER INFORMATION CONTACT section.

II. What Should I Consider as I Prepare My Comments for EPA?

1. Submitting CBI. Do not submit this information to EPA through
EDOCKET, regulations.gov or e-mail. 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

[[Page 25185]]

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.
2. Tips for Preparing Your Comments. When submitting comments,
remember to:
A. Identify the rulemaking by docket number and other identifying
information (subject heading, Federal Register date and page number).
B. Follow directions--The agency may ask you to respond to specific
questions or organize comments by referencing a Code of Federal
Regulations (CFR) part or section number.
C. Explain why you agree or disagree; suggest alternatives and
substitute language for your requested changes.
D. Describe any assumptions and provide any technical information
and/or data that you used.
E. If you estimate potential costs or burdens, explain how you
arrived at your estimate in sufficient detail to allow for it to be
reproduced.
F. Provide specific examples to illustrate your concerns, and
suggest alternatives.
G. Explain your views as clearly as possible, avoiding the use of
profanity or personal threats.
H. Make sure to submit your comments by the comment period deadline
identified.
Outline. The contents of today's preamble are listed in the
following outline.

I. Overview of Today's Proposed Actions
II. Background
A. Regional Haze Rule
B. Partial Remand of the Regional Haze Rule in American Corn Growers
C. Proposed Changes to the Visibility Regulations
D. Reproposal of the BART Guidelines
III. Detailed Discussion of Reproposed BART Guidelines
A. Introduction
B. How to Identify BART-eligible Sources
C. How to Determine Which BART-eligible Sources are Subject to BART
D. The BART Determination Process
E. Trading Program Guidance
IV. 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 Risks and Safety Risks
H. Executive Order 13211: Actions 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

I. Overview of Today's Proposed Actions

Today's rulemaking provides for the following proposed changes to
the regional haze regulations:
(1) Revised regulatory text in response to the American Corn
Growers court's remand, to require that the BART determination includes
an analysis of the degree of visibility improvement resulting from the
use of control technology at each source subject to BART,
(2) revised regulatory text in 40 CFR 51.308(b) and deletion of 40
CFR 51.308(c) Options for regional planning in response to
Congressional legislation amending the deadlines for submittal of
regional haze implementation plans. This provision had provided for an
alternative process for States to submit regional haze implementation
plans in attainment areas,
(3) BART guidelines, contained in a new appendix Y to 40 CFR part 51,
(4) new and revised regulatory text, to be added to 40 CFR
51.308(e) to require the use of appendix Y in establishing BART
emission limits, and
(5) revised regulatory language at 51.302 to clarify the
relationship between New Source Performance Standards (NSPS) and BART
for reasonably attributable visibility impairment.
How This Preamble Is Structured. Section II provides background on
the regional haze rule, the D.C. Circuit Court decision which remanded
parts of the rule, and the proposed changes to the rule and reproposal
of the BART guidelines in response to the remand. Section III discusses
in more detail the reproposed BART guidelines, including changes from
the July 2001 proposal based the court decision and certain comments
that we received on the initial proposal. Section IV provides a
discussion of how this rulemaking complies with the requirements of
Statutory and Executive Order Reviews.

II. Background

A. Regional Haze Rule

In 1999, we published a final rule to address a type of visibility
impairment known as regional haze (64 FR 35714; July 1, 1999). The
regional haze rule requires States to submit implementation plans
(SIPs) to address regional haze visibility impairment in 156 Federally-
protected parks and wilderness areas. These 156 scenic areas are called
``mandatory Class I Federal areas'' in the Clean Air Act (CAA),\1\ but
are referred to simply as ``Class I areas'' in today's rulemaking. The
1999 rule was issued to fulfill a long-standing EPA commitment to
address regional haze under the authority and requirements of sections
169A and 169B of the CAA.
---------------------------------------------------------------------------

\1\ See, e.g., CAA Section 169A(a)(1).
---------------------------------------------------------------------------

As required by the CAA, we included in the final regional haze rule
a requirement for BART for certain large stationary sources that were
put in place between 1962 and 1977. We discussed these requirements in
detail in the preamble to the final rule (64 FR 35737-35743). The
regulatory requirements for BART were codified at 40 CFR 51.308(e), and
in definitions that appear in 40 CFR 51.301.
The CAA, in sections 169A(b)(2)(A) and in 169A(g)(7), uses the term
``major stationary source'' to describe those sources that are the
focus of the BART requirement. To avoid confusion with other CAA
requirements which also use the term ``major stationary source'' to
refer to a somewhat different population of sources, the regional haze
rule uses the term ``BART-eligible source'' to describe these sources.
The BART-eligible sources are those sources which have the potential to
emit 250 tons or more of a visibility-impairing air pollutant, were put
in place between August 7, 1962 and August 7, 1977, and whose
operations fall within one or more of 26 specifically listed source
categories. Under the CAA, BART is required for any BART-eligible
source which ``emits any air pollutant which may reasonably be
anticipated to cause or contribute to any impairment of visibility in
any such area.'' Accordingly, for stationary sources meeting these
criteria, States must address the BART requirement when they develop
their regional haze SIPs.
Section 169A(g)(7) of the CAA requires that States must consider
the following factors in making BART determinations:
(1) The costs of compliance,
(2) The energy and nonair quality environmental impacts of compliance,
(3) Any existing pollution control technology in use at the source,
(4) The remaining useful life of the source, and
(5) The degree of improvement in visibility which may reasonably be

[[Page 25186]]

anticipated to result from the use of such technology.
These statutory factors for BART were codified at 40 CFR
51.308(e)(1)(ii).
In the preamble to the regional haze rule, we committed to issuing
further guidelines to clarify the requirements of the BART provision.
The purpose of this proposed rulemaking is to fulfill this commitment
by providing guidelines for States to use in identifying their BART-
eligible sources, in identifying which of those sources must undergo a
detailed BART analysis (i.e., which are ``sources subject to BART''),
and in conducting the technical analysis of possible controls in light
of the statutory factors listed above (``the BART determination'').

B. Partial Remand of the Regional Haze Rule in American Corn Growers

In response to challenges to the regional haze rule by various
petitioners, the D.C. Circuit in American Corn Growers et al. v. EPA,
291 F.3d 1 (2002) issued a ruling striking down the regional haze rule
in part, and upholding it in part. This section discusses the court's
opinion in that case, as background for the discussion of specific
changes to the regional haze rule and the BART guidelines presented in
the next two sections, respectively.
We explained in the preamble to the 1999 regional haze rule that
the BART requirements in section 169A(b)(2)(A) of the CAA demonstrate
Congress' intent to focus attention directly on the problem of
pollution from a specific set of existing sources (64 FR 35737). The
CAA requires that any of these existing sources ``which, as determined
by the State, emits any air pollutant which may reasonably be
anticipated to cause or contribute to any impairment of visibility [in
a Class I area],'' shall install the best available retrofit technology
for controlling emissions.\2\ In determining BART, the CAA requires the
State to consider several factors that are set forth in section
169(g)(2) of the CAA, including the degree of improvement in visibility
which may reasonably result from the use of such technology.
---------------------------------------------------------------------------

\2\ CAA Sections 169A(b)(2) and (g)(7).
---------------------------------------------------------------------------

The regional haze rule addresses visibility impairment resulting
from emissions from a multitude of sources located across a wide
geographic area. Because the problem of regional haze is caused in
large part by the long-range transport of emissions from multiple
sources, and for certain technical and other reasons explained in that
rulemaking, we had adopted an approach that required States to look at
the contribution of all BART sources to the problem of regional haze in
determining both applicability and the appropriate level of control.
Specifically, we had concluded that if a source potentially subject to
BART is located within an upwind area from which pollutants may be
transported downwind to a Class I area, that source ``may reasonably be
anticipated to cause or contribute'' to visibility impairment in the
Class I area. Similarly, we had also concluded that in weighing the
factors set forth in the statute for determining BART, the States
should consider the collective impact of BART sources on visibility. In
particular, in considering the degree of visibility improvement that
could reasonably be anticipated to result from the use of such
technology, we stated that the State should consider the degree of
improvement in visibility that would result from the cumulative impact
of applying controls to all sources subject to BART. We had concluded
that the States should use this analysis to determine the appropriate
BART emission limitations for specific sources.\3\
---------------------------------------------------------------------------

\3\ See 66 FR 35737-35743 for a discussion of the rationale for
the BART requirements in the 1999 regional haze rule.
---------------------------------------------------------------------------

In American Corn Growers v. EPA, industry petitioners challenged
EPA's interpretation of both these aspects of the BART determination
process and raised other challenges to the rule. While rejecting
industry's other challenges, the court in American Corn Growers
concluded that the BART provisions in the 1999 regional haze rule were
inconsistent with the provisions in the CAA ``giving the states broad
authority over BART determinations.'' 291 F.3d at 8. Specifically, with
respect to the test for determining whether a source is subject to
BART, the court held that the method that EPA had prescribed for
determining which eligible sources are subject to BART illegally
constrained the authority Congress had conferred on the States. Id.
However, the court expressly declined to hold that the general
collective contribution approach to determining BART applicability was
necessarily inconsistent with the CAA, were it not for the infringement
on State authority. Id. at 9. Rather, the court stated that the
collective contribution approach may have been acceptable if EPA had
allowed for a State exemption process based on an individualized
contribution determination. Id. at 12.
The court in American Corn Growers also found that EPA's
interpretation of the CAA requiring the States to consider the degree
of improvement in visibility that would result from the cumulative
impact of applying controls in determining BART was inconsistent with
the language of the Act. 291 F.3d at 8. Based on its review of the
statute, the court concluded that the five statutory factors in section
169A(g)(2) ``were meant to be considered together by the states.'' Id.
at 6.
Finally, the court remanded the schedule in the regional haze rule
for the submission of implementation plans for areas that commit to
regional planning, indicating that the use of such a ``committal SIP''
does not appear to satisfy statutory requirements. The court declined
to vacate the provision, however, in light of the need to change SIP
requirements in order to satisfy the ruling on the BART issue. Id. at 15.

C. Proposed Changes in the Visibility Regulations

Today's proposed rule responds to the American Corn Growers court's
decision on the BART provisions by proposing changes to the regional
haze rule at 40 CFR 51.308, and by reproposing the BART guidelines.
This section outlines the changes to the regional haze rule due to the
court's remand and to subsequent Congressional action regarding
deadlines for the submission of regional haze implementation plans. It
also explains the minor change we are proposing to the section of the
regulation governing the use of the 1980 BART guidelines when
conducting BART analyses for certain power plants for reasonably
attributable (i.e., localized) visibility impairment.
1. Determination of Which Sources Are Subject to BART
Today's proposed action addresses the American Corn Growers court's
vacature of the requirement in the regional haze rule requiring States
to assess visibility impacts on a cumulative basis in determining which
sources are subject to BART. Because this requirement was found only in
the preamble to the 1999 regional haze rule (see 291 F.3rd at 6, citing
64 FR 35741), no changes to the regulations are required. Instead, this
issue is addressed in the BART guidelines, which provide States with a
number of options for determining which BART-eligible sources ``may
reasonably be anticipated to cause or contribute to any impairment of
visibility in any mandatory Class I Federal area.'' These options have
been designed to address the holding of American Corn Growers by
eliminating the previous constraint on State discretion, as explained in

[[Page 25187]]

further detail in sections II.D. and III below.
2. Consideration of Anticipated Visibility Improvements in BART
Determinations
Pursuant to the remand in American Corn Growers, we are proposing
to amend the regional haze rule to require the States to consider the
degree of visibility improvement resulting from a source's installation
and operation of retrofit technology, along with the other statutory
factors set out in CAA section 169A(g)(2), when making a BART
determination. This would be accomplished by listing the visibility
improvement factor with the other statutory BART determination factors
in section 308(e)(1)(A), so that States will be required to consider
all five factors, including visibility impacts, on an individual source
basis when making each individual source BART determination.
In addition, Section 308(e)(1)(B), which formerly required States
to assess visibility on a cumulative basis (i.e., for all BART-eligible
sources), would be replaced with a requirement to use the BART
guidelines at appendix Y. The guidelines, as will be explained in the
next section and in greater detail in section III, provide for source-
specific analysis of anticipated improvement in visibility. These
changes, therefore, address the court's holding with respect to the
isolation of the visibility improvement factor at this stage of the
BART analysis.
3. Implementation Plan Deadlines
As noted above, the 1999 regional haze rule contained a committal
SIP mechanism (section 308(c)) which the American Corn Growers court
remanded without vacating. This mechanism was intended to allow states
to harmonize regional haze SIP submittals for all areas within the
state. At the time the rule was promulgated, the deadline for regional
haze SIPs varied depending on the PM_2.5 attainment or
nonattainment status of the area.\4\
---------------------------------------------------------------------------

\4\ Transportation Equity Act for the 21st Century, Pub. L. 105-
178, 112 Stat. 107, 463 (1998) (TEA-21).
---------------------------------------------------------------------------

In the Omnibus Appropriations Act of 2004,\5\ Congress harmonized
both designations and regional haze SIP deadlines. Under the Omnibus
Appropriations Act, we are required to promulgate PM_2.5
designations for all areas of each state no later than December 31,
2004. Designations will become effective 30 days afterward, or no later
than January 31, 2005. The Omnibus Appropriations Act further provides
that regional haze SIPs, for each entire state, are then due not later
than 3 years after promulgation of the PM_2.5 designation.\6\
Thus, regional haze SIPs are due no later than January, 31, 2008. We
are proposing to amend 40 CFR 51.308(b) and 51.308(c) to comport with
the new statutory deadlines, and to eliminate the ``comittal'' SIP
provision.
---------------------------------------------------------------------------

\5\ Consolidated Appropriations Act for Fiscal Year 2004, Pub.
L. 108-199, January 23, 2004.
\6\ CAA Section 107(d)(7)(A), as amended by the Consolidated
Appropriations Act for Fiscal Year 2004, now reads: ``In General.--
Notwithstanding any other provision of law, not later than 3 years
after the date on which the Administrator promulgates the
designations referred to in Paragraph (6)(B) for a State, the State
shall submit, for the entire State, the State implementation plan
revisions to meet the requirements promulgated by the Administrator
under section 169B(e)(1) (referred to in this paragraph as `regional
haze requirements').''
---------------------------------------------------------------------------

We are also proposing to amend certain sections of 40 CFR 51.309 to
comport with the new statutory deadlines. Under Section 309 as
currently codified, the initial SIPs for states utilizing Section 309
were due in 2003, and a second set of SIPs for those states are due no
later than December 31, 2008. This date was designed to coincide with
the latest date Section 308 SIPs could be due under the statutory
scheme prior to amendment by the Omnibus Act. The Omnibus Amendments
contain a ``no preclusion'' provision, clarifying that nothing therein
precludes the submission of section 309 SIPs by December 31, 2003.\7\
The ``no preclusion'' provision does not expressly provide that the
later (currently 2008) section 309 deadlines are not precluded. There
is therefore some ambiguity as to whether the 3-year-after-designation
deadline applies to subsequent section 309 SIPs. We believe that policy
interests of certainty, clarity, and coordination of efforts are best
served by establishing consistent deadlines for SIPs under sections 308
and 309 where appropriate, and by avoiding any ambiguity regarding
future section 309 SIP deadlines. Therefore, we are proposing to amend
sections 309(d)(4)(v), 309(g)(2), and 309(g)(3), by replacing
``December 31, 2008'' with ``January 31, 2008'', to coincide with
section 308 SIPs.\8\
---------------------------------------------------------------------------

\7\ CAA section 107(d)(7)(B) ``No Preclusion of Other
Provisions.--Nothing in this paragraph precludes the implementation
of of the agreements and recommendations stemming from the Grand
Canyon Visibility Transport Commission Report dated June 1996,
including the submission of State implementation plan revisions by
the States of Arizona, California, Colorado, Idaho, Nevada, New
Mexico, Oregon, Utah, or Wyoming by December 31, 2003, for
implementation of regional haze requirements applicable to those States.''
\8\ These are the section of 309 establishing deadlines for SIP
revisions which contain major new policy initiatives which should,
for efficiency, be coordinated with the development of section 308
SIPs; specifically long term strategies and BART requirements for
stationary source NO_X and PM, if determined to be
necessary (section 309(d)(4)(v)), and reasonable progress provisions
for additional (non-Colorado Plateau) class I areas (section
309(g)(2)-(g)(3)).
We are aware that 2008 deadlines also appear in section
309(d)(10) (progress reports) and section 309(b)(6) (mobile source
tracking and revisions if necessary). We are not proposing to amend
these sections because they are part of a scheme establishing check
points for Sec. 309 strategies in 2008, 2013, and 2018, rather than
development of new strategies, and thus do not require integration
with Sec. 308 SIPs.
---------------------------------------------------------------------------

4. Proposed Revisions to the 1980 BART Guidelines
Background. One of the primary purposes of this reproposal is to
provide BART guidelines for the regional haze program. As described in
the 2001 proposed BART guidelines (66 FR 38108, 38109), however, we are
also proposing to make limited revisions to longstanding guidelines for
BART under the 1980 visibility regulations for localized visibility
impairment that is ``reasonably attributable'' to one or a few
sources.\9\ The visibility regulations require States to use a 1980
guidelines document when conducting BART analyses for certain power
plants for reasonably attributable visibility impairment. While the
analytical process set forth in these guidelines is still generally
acceptable for conducting BART analyses for ``reasonably attributable''
visibility impairment, there are statements in the 1980 BART Guidelines
that could be read to indicate that the NSPS may be considered to
represent best control for existing sources. While this may have been
the case in 1980 (e.g., the NSPS for sulfur dioxide (SO₂)
from boilers had been recently issued in June 1979), best control
levels for recent plant retrofits have exceeded NSPS levels. Therefore,
we are proposing to amend this provision of the 1980 visibility
regulations to clarify that BART should not be interpreted under the
1980 regulations to preclude control options which are more stringent
than NSPS standards.
---------------------------------------------------------------------------

\9\ U.S. Environmental Protection Agency, Guidelines for
Determining Best Available Retrofit Technology for Coal-fired Power
Plants and Other Existing Stationary Facilities, EPA-450/3-80-009b,
Office of Air Quality Planning and Standards, Research Triangle
Park, N.C., November 1980 (1980 BART Guidelines).
---------------------------------------------------------------------------

D. Reproposal of the BART Guidelines

Prior to the American Corn Growers decision, we had proposed
guidelines for the regional haze BART process. Specifically, on July
20, 2001, the proposed BART guidelines were published in the Federal
Register (66 FR 13108-13135). We requested written

[[Page 25188]]

comments on the proposal and conducted two public hearings. The
deadline for written comments was extended from September 18, 2001 to
October 5, 2001 in a separate Federal Register notice (66 FR 50135).
Public hearings were held on August 21, 2001 in Alexandria,
Virginia and on August 27, 2001 in Chicago, Illinois. Transcripts for
these public hearings are available in the public docket for the
regulation (Docket A-2000-28, Docket numbers IV-F-01 and IV-F-02). Oral
testimony in both public hearings was predominantly from private
citizens supportive of the proposed BART guidelines.
We received written comments on the package from many citizens and
stakeholder groups.
Today, we are reproposing the BART guidelines to take into account
the changes that we are proposing to make to the regional haze rule.
Although in reproposing the BART guidelines we have taken into account
some of the comments that we received in response to the 2001 action,
much of what is set forth in the BART guidelines proposed today is
identical to the earlier proposal. Both for those proposed requirements
in the BART guidelines which are unchanged from the 2001 proposal, as
well as for those that we have changed since 2001, you do not need to
resubmit comments unless you have additional information that you would
like us to consider, because we will carefully consider all comments
previously submitted during the comment period on the 2001 proposal in
making our final decision on the BART guidelines.
The proposed BART process is set forth in the BART guidelines we
are reproposing today in response to the remand. The rest of this
section provides an overview of this proposed BART process. The
overview summarizes both (1) the process for determining which BART-
eligible sources may be reasonably anticipated to cause or contribute
to visibility impairment, and thus should be subject to BART, and (2)
the process for evaluating visibility impacts for an individual
source's BART determination. (We will discuss these issues in further
detail in section III below.)

The BART Process

The process of establishing BART emission limitations can be
logically broken down into three steps: First, States identify those
sources which meet the definition of ``BART-eligible source'' set forth
in 40 CFR 51.301.\10\ Second, States determine whether such sources
``emit[]
any air pollutant which may reasonably be anticipated to cause
or contribute to any impairment of visibility [in a Class I area.]'' A
source which fits this description is ``subject to BART.'' Third, for
each source subject to BART, States then identify the appropriate type
and the level of control for reducing emissions.
---------------------------------------------------------------------------

\10\ ``BART-eligible source'' is defined as a stationary source
of air pollutants that falls within one of 26 listed categories
which was put into operation between August 7, 1962 and August 7,
1977, with the potential to emit 250 tons per year of any air
pollutant. CAA Sec. Sec. 169(b)(2)(A) and (g)(7); 40 CFR Sec. 51.301.
---------------------------------------------------------------------------

Identifying BART-Eligible Sources

The CAA defines BART-eligible sources as those sources which fall
within one of 26 specific source categories, were built during the 15-
year window of time from 1962 to 1977, and have potential emissions
greater than 250 tons per year. The remand did not address the step of
identifying BART-eligible sources, which is conceptually the simplest
of the three steps.

Sources Reasonably Anticipated To Cause or Contribute To Visibility
Impairment (Sources Subject to BART)

As we noted in the preamble to the 1999 regional haze rule,
defining the individual contributions of specific sources of the
problem of regional haze can be time-consuming and expensive. Moreover,
Congress established a very low threshold in the CAA for determining
whether a source is subject to BART. We are accordingly proposing
several approaches for States for making the determination of whether a
source ``emits any pollutants which may reasonably be anticipated to
cause or contribute to any visibility impairment.'' The first two of
these approaches would allow States to avoid undertaking unnecessary
and costly studies of an individual source's contribution to haze by
allowing States to adopt more streamlined processes for determining
whether, or which, BART-eligible sources are subject to BART.
In 1999, we adopted an applicability test that looked to the
collective contribution of emissions from an area. In particular, we
stated that if ``a State should find that a BART-eligible source is
``reasonably anticipated to cause or contribute'' to regional haze if
it can be shown that the source emits pollutants within a geographic
area from which pollutants can be emitted and transported downwind to a
Class I area.'' \11\ Under today's proposal, a State has the discretion
to consider that all BART-eligible sources within the State are
``reasonably anticipated to cause or contribute'' to some degree of
visibility impairment in a Class I area.
---------------------------------------------------------------------------

\11\ 64 FR 335740, July 1, 1999. The regional haze rule
discusses at length why we believe that States should draw this
conclusion. 64 FR 35739-40.
---------------------------------------------------------------------------

This option is consistent with the American Corn Growers court's
decision. As previously noted, the court's concern with our original
approach governing BART applicability determinations was that it would
have ``tie[d]
the states'' hands and force[d]
them to require BART
controls at sources without any empirical evidence of the particular
source's contribution to visibility impairment.'' 291 F.3d at 8. By the
same rationale, we believe it would be an impermissible constraint of
State authority to force States to conduct individualized analysis in
order to determine that a BART-eligible source ``emits any air
pollutant which may reasonably be anticipated to cause or contribute to
any impairment of visibility in any [Class I]
area.'' \12\ In this
respect, we believe that it is important to note that the court in
American Corn Growers expressly declined to hold that consideration of
visibility impact on a cumulative basis would be invalid in all
circumstances. 291 F.3d at 9. Given the court's emphasis on the
importance of the role of the States in making BART determinations, we
believe that a State's decision to use a cumulative analysis at the
eligibility stage would be consistent with the CAA and the findings of
the D.C. Circuit.
---------------------------------------------------------------------------

\12\ CAA Sec. 169A(b)(2)(A).
---------------------------------------------------------------------------

We believe there is ample technical evidence supporting a finding
by a State that all BART-eligible sources within the State are subject
to BART, without further analysis at that stage in the process.\13\ Any
potential for inequity towards sources would be addressed at the BART
determination stage, where we are proposing to require the
individualized consideration of a source's contribution in establishing
BART emission limits.
---------------------------------------------------------------------------

\13\ See 64 FR 35714, 35721. See also July 29, 1997 memorandum
to the regional haze docket A-95-38, ``Supporting Information for
Proposed Applicability of Regional Haze Regulations,'' by Richard
Damberg, EPA, Office of Air Quality Planning and Standards.
---------------------------------------------------------------------------

The reasoning underlying this approach is discussed in more detail
in section III below.
We are also proposing to provide States with the option of
performing an analysis to show that the full group of BART-eligible
sources in a State cumulatively do not cause or contribute

[[Page 25189]]

to any visibility impairment in Class I areas. We anticipate that in
most, if not all States, the BART-eligible sources are likely to cause
or contribute to some visibility impairment in Class I areas. However,
it is possible that using a cumulative approach, a State could show
that its BART sources do not collectively pose a measurable problem.
Finally, we are also proposing that States may consider the
individualized contribution of a BART-eligible source to determine
whether a specific source is subject to BART. Specifically, States may
choose to undertake an analysis of each BART-eligible source in the
State in considering whether each such source meets the test set forth
in the CAA of ``emit[ting]
any air pollutant which may reasonably be
anticipated to cause or contribute to any impairment of visibility in
any [Class I]
area.'' Alternatively, States may choose to presume that
all BART-eligible sources within the State meet this applicability
test, but provide sources with the ability to demonstrate on a case by
case basis that this is not the case. This approach is consistent with
the D.C. Circuit's statement that a collective contribution approach
may be appropriate so long as the States are allowed to exempt sources
on the basis of an individualized contribution determination. 291 F.3d
at 8.
For assessing the impact of BART-eligible sources located greater
than 50 kilometers (km) from a Class I area, we are proposing that the
States use an air quality model able to estimate a single source's
contribution to visibility impairment. We are also requesting comment
on methods appropriate for Class I areas closer than 50 km; and on
other potential methods of assessing a source's individualized
contribution to regional haze visibility impairment. (This is explained
in greater detail in section III below).

The BART Determination

The State must determine the appropriate level of BART control for
each source subject to BART. Section 169A(g)(7) of the CAA requires
States to consider the following factors in making BART determinations:
(1) The costs of compliance, (2) the energy and nonair quality
environmental impacts of compliance, (3) any existing pollution control
technology in use at the source, (4) the remaining useful life of the
source, and (5) the degree of improvement in visibility which may
reasonably be anticipated to result from the use of such technology.
The remand did not address the first four steps of the BART
determination (the ``engineering analysis''). The remand did address
the final step, mandating that EPA must provide a way for States to
take into account the degree of improvement in visibility that would
result from imposition of BART on each individual source.
The BART engineering analysis, comprising the first four factors,
is addressed in detail in section IV below, and is substantially
similar to the engineering analysis in the original BART guidelines
proposed in July, 2001. Section IV also contains a detailed discussion
of available and cost-effective controls for reducing SO₂
and nitrogen oxicdes (NO_X) emissions from large coal-fired
electric generating units (EGUs).
For assessing the fifth factor, the degree of improvement in
visibility from various BART control levels, we are proposing that
States require individual sources to run CALPUFF, or other EPA-approved
model, using site-specific data. To estimate a source's impact on
visibility, the source would run the model using current allowable
emissions, and then again at the post-control emissions level (or
levels) being assessed. Results would then be tabulated for the average
of the 20% worst modeled days at each receptor. The difference in the
resulting level of impairment predicted is the degree of improvement in
visibility expected.
Alternatively, we request comment on the option of using the hourly
modeled impacts from CALPUFF and assessing the improvement in
visibility based on the number of hours above a visibility threshold
for the pre- and post-control emission rates.

III. Detailed Discussion of Reproposed BART Guidelines

A. Introduction

In this section of the preamble, we discuss the details of the
reproposed BART guidelines where we are proposing to make changes to,
or to clarify, the BART guidelines proposed in July, 2001. As noted in
section II, we will be reviewing the comments received during the
comment period on the 2001 proposal and responding to those comments
when we issue a final guideline. For each provision of the guidelines
that we are changing or clarifying, we provide discussion of, as
appropriate:

--Background information,
--What we proposed in the July 2001 action,
--A summary or partial summary of the comments received on the
provision, and
--The changes or clarifications that we are proposing and the reasons
for these changes or clarifications.

B. How To Identify BART-Eligible Sources

The CAA, in section 169A(g)(7), provides a specific list of the
types of ``major stationary sources'' that are covered by the BART
requirement. Our visibility regulations include this same list in 40
CFR 51.301 in the definition of the term ``existing stationary
facility'' and by reference, ``BART-eligible source.'' Because the
terms ``major stationary source'' and ``existing stationary facility''
are general in nature and used for other air quality programs, we
decided to eliminate any potential confusion by using the term ``BART-
eligible source'' in the regional haze portions of the visibility
regulations that were published in 1999. As defined in 40 CFR 51.301, a
``BART-eligible source'' means the same thing as an ``existing
stationary facility'' as defined in EPA's 1980 visibility regulations,
and means the same thing as a ``major stationary source'' as defined in
CAA section 169A(g)(7).
Section II of the reproposed BART guidelines contains a step-by-
step process for identifying stationary sources that are ``BART-
eligible'' under the definitions in the regional haze rule. Today's
action reproposing the BART guidelines includes the same four basic
steps as in the proposed rule. The four basic steps are:

Step 1: Identify the emission units in the BART categories
Step 2: Identify the start-up dates of those emission units
Step 3: Compare the potential emissions from units identified in Steps
1 and 2 to the 250 ton/yr cutoff
Step 4: Identify the emission units and pollutants that constitute the
BART-eligible source.

We received a number of comments on this proposed approach to
identifying BART-eligible sources. In this section of the preamble, we
discuss some of the previously submitted comments and any changes we
are proposing in light of these comments.

Step 1: Identify the emission units in the BART cateories.

Background. The CAA uses the following 26 source category titles to
describe the types of stationary sources that are BART-eligible:
(1) Fossil-fuel fired steam electric plants of more than 250
million British thermal units (BTU) per hour heat input,
(2) Coal cleaning plants (thermal dryers),

[[Page 25190]]

(3) Kraft pulp mills,
(4) Portland cement plants,
(5) Primary zinc smelters,
(6) Iron and steel mill plants,
(7) Primary aluminum ore reduction plants,
(8) Primary copper smelters,
(9) Municipal incinerators capable of charging more than 250 tons
of refuse per day,
(10) Hydrofluoric, sulfuric, and nitric acid plants,
(11) Petroleum refineries,
(12) Lime plants,
(13) Phosphate rock processing plants,
(14) Coke oven batteries,
(15) Sulfur recovery plants,
(16) Carbon black plants (furnace process),
(17) Primary lead smelters,
(18) Fuel conversion plants,
(19) Sintering plants,
(20) Secondary metal production facilities,
(21) Chemical process plants,
(22) Fossil-fuel boilers of more than 250 million BTUs per hour
heat input,
(23) Petroleum storage and transfer facilities with a capacity
exceeding 300,000 barrels,
(24) Taconite ore processing facilities,
(25) Glass fiber processing plants, and
(26) Charcoal production facilities.

Most of the source category titles are general descriptors that are
inclusive of all the operations at a given plant. Some plant sites may
have more than one of the categories present. Examples of this would
include plants with both ``petroleum refineries'' and ``sulfur recovery
plants,'' or with both ``iron and steel mill plants'' and ``sintering
plants.'' On the other hand, some plant sites may include some
emissions units meeting one of these 26 descriptions, but other
emissions units that do not.

2001 Proposed Rule. In the 2001 proposed BART guidelines, we noted
that the category titles were generally clear and we proposed to
clarify a few issues, including interpretations where we believed there
were ambiguities in the source category titles. We requested comment on
whether any other clarifications were needed. The 2001 proposed
guidelines clarified that in identifying emissions units for inclusion
as a BART-eligible source, States should identify all emissions units
at a plant site meeting one or more of the source category
descriptions. The 2001 proposed rule provided specific interpretations
for five of the 26 source category titles:
(1) ``Steam electric plants of more than 250 million BTU/hr heat
input.'' The 2001 proposal noted that because the category title refers
to ``plants,'' boiler capacities must be aggregated to determine
whether the 250 million BTU/hr threshold is reached.
(2) ``Fossil-fuel boilers of more than 250 million BTU/hr heat
input.'' We proposed two options for interpreting this source category
title. The first option, the approach used in the regulations for
prevention of significant deterioration (PSD) program, would be to
aggregate boiler capacities to determine whether the 250 million BTU/hr
threshold is reached. Under the second option, only those boilers that
are individually greater than 250 million BTU/hr would fall within the
BART source category.
(3) ``Petroleum storage and transfer facilities with a capacity
exceeding 300,000 barrels.'' In the 2001 proposal, we noted our
interpretation that the 300,000 barrel cutoff refers to total,
facility-wide tank capacity for tanks that were put in place within the
1962-1977 time period, and includes gasoline and other petroleum-
derived liquids.
(4) ``Phosphate rock processing plants.'' In the 2001 proposal, we
noted that this category descriptor should be interpreted broadly to
include all types of phosphate rock processing facilities, including
elemental phosphorous plants as well as fertilizer production plants.
(5) ``Charcoal production facilities.'' In the 2001 proposal, we
noted information provided by the National Association of Manufacturers
(NAM) on the legislative history for this source category. In its
letter, NAM suggested that the legislative history supported a
conclusion that BART should cover only a subset of the charcoal
production industry. While we indicated that we did not agree with this
assessment, we requested comment on whether and how the information
cited by NAM is relevant to the interpretation of this or other categories.

Finally, in the 2001 proposal, we requested comment generally on
whether any additional source category titles needed clarification.

Comments on the 2001 Proposal. We received a number of comments
related to the interpretation of the source category titles. Some of
these comments related to the category-specific clarifications we
provided in the proposed guidelines. In addition, there were a few
comments in response to our request for additional category titles
needing clarification. In this section, we only discuss the previously
submitted comments that have led to the changes we are proposing in
today's action.
We received many comments related to our interpretation of the term
``fossil-fuel boilers of more than 250 million BTUs per hour heat
input.'' A number of comments from environmental groups and States were
supportive of an interpretation which would require States to compare
the aggregate capacities of boilers against the 250 million BTU/hr
cutoff. These comments agreed with our assessment that this would
promote consistency with the PSD program. Environmental group comments
also noted that the plural term ``boilers'' was used in the CAA, rather
than the singular term ``any boiler.''
Many commenters from industry groups and some State agencies
supported the alternative interpretation of the category, which would
require States to consider as BART-eligible only those boilers which
are individually greater than 250 million BTU/hr. These commenters
generally asserted that this was the plain reading of the source
category title, and also that such an approach would be consistent with
EPA programs such as NSPS and the NO_X SIP Call.\14\ These
commenters noted that, unlike the PSD program, circumvention of the
requirements is not possible because BART only applies to boilers
already in existence. Other commenters noted that aggregation of
boilers may result in inclusion of very small boilers for which BART
controls would not be cost effective.
---------------------------------------------------------------------------

\14\ The NO_X SIP call requires a number of Eastern
States to reduce the Summertime emissions of NO_X from
sources within these States. 63 FR 57356 (Oct. 27, 1998).
---------------------------------------------------------------------------

In addition to the general comments on the interpretation of the
size cutoff for boilers, we received comments on two other aspects of
the term ``fossil fuel boilers.'' Some boilers burn solid fuels that
are not fossil fuels, such as wood products. A number of industry
commenters suggested that we should interpret the term ``fossil fuel''
as it was interpreted for the NO_X SIP Call, which treats as
``fossil fuel'' only those boilers that burn more than 50 percent
fossil fuels, on an annual heat input basis. One commenter noted as an
example that a boiler that has fossil fuel capacity greater than 250
million BTU/hr, but that only burns such fuels during startup and
shutdown, should not be considered as a ``fossil fuel fired boiler''
for purposes of BART. Comments from the paper industry requested that
EPA clarify in the guidelines that a multi-fuel boiler, with a capacity
of greater than or equal to 250 million Btu/hr, would not be considered
BART-eligible if the boiler is subject to an enforceable limitation
that would prohibit combustion at greater than 250 million BTU/hr.

[[Page 25191]]

Several commenters requested that we provide a specific
interpretation for the term ``secondary metal production facilities.''
The commenters requested that we formally define the term to include
only those facilities within the Standard Industrial Classification
(SIC) code 3341, ``Secondary Smelting and Refining of Nonferrous
Metals.'' Also, the commenters recommended that a ``Secondary Metal
Production Facility'' be defined to mean one or more emission units
that derive more than fifty percent of the metal(s) it produces from
purchased scrap and dross.
Reproposal. After considering these comments, we are proposing some
changes to the source category definitions.
We agree that the interpretation of ``fossil-fuel boilers of more
than 250 million BTU/hr heat input'' is best read to include only those
boilers at a power plant individually greater than 250 million BTU/hr.
We agree with comments that this interpretation is a better reading of
the category title than the alternative under which States would
compare the cumulative boiler capacity over all boilers at a power
plant to the 250 million BTU/hr cutoff. We do not agree with comments
that any particular meaning can be taken from the use of the plural
word ``boilers'' in the category title. On the other hand, if a boiler
smaller than 250 million BTU/hr is an integral part of an industrial
process in a BART source category other than electric utilities--for
example, part of the process description at a chemical process plant--
then we believe that the boiler should be considered for controls as
part of the BART source. The logic here is that a State should consider
all emission points at an integral industrial process to be part of the
BART-eligible source, so that later, when making the actual BART
determination, the State would be certain that it has not prematurely
ruled out any sensible control options for that process as a whole.
That way the State will have retained as much discretion as possible to
require control on all or part of an industrial process, on a case-by-
case basis, considering all of the BART factors.
We do not believe that this interpretation is likely to have a
substantial impact on the amount of BART emissions reductions achieved,
because smaller boilers are generally less cost effective to control.
Also, we believe that covering only individual utility boilers greater
than 250 million BTU/hr may help address States' concerns over the
implementation burden of the program.
We also agree with the two clarifications suggested by commenters
relating to the term ``fossil fuel.'' We propose to add a statement to
the reproposed guidelines clarifying that ``fossil fuel boilers''
refers to boilers burning greater than 50 percent fossil fuels. We
believe that this is a reasonable approach to interpreting the
definition in the CAA. Also, we agree that enforceable operational
limits for a multi-fuel boiler would be relevant to determining whether
its ``fossil fuel'' capacity exceeds 250 million BTU/hr and that it
would be reasonable for States to take such limitations into account.
We are proposing to add this clarification to the BART guidelines.
We also wish to clarify that, consistent with other EPA rules, the
definition of ``steam electric plants of more than 250 million BTU/hr
heat input'' refers only to plants that generate electricity for sale.
We are proposing to add this clarfication to the BART guidelines.
The reproposed guidelines do not take a position on the
recommendations in the comments regarding ``petroleum storage and
transfer facilities with a capacity exceeding 300,000 barrels.'' We
believe that this question is largely moot given that these storage and
transfer facilities are already subject to maximum achievable control
technology (MACT) standards and in many cases stringent SIP regulations
related to ozone nonattainment. Regardless of the interpretation, we
believe that it is unlikely that BART emissions limitations will
require further controls.
We have reviewed comments suggesting that ``secondary metal
production facilities'' may be interpreted to include only those
facilities within SIC code 3341. We note that the term ``secondary
metal production'' is broader than SIC code 3341. ``Secondary metal
production'' would include secondary ferrous metals facilities such as
secondary iron and steel facilities. On the other hand, SIC code 3341
includes only nonferrous metals facilities such as secondary copper,
aluminum and lead facilities. We believe, however, that secondary iron
and steel facilities are also included within the broad category ``iron
and steel mill plants.'' Accordingly, we are proposing that in
identifying unique ``secondary metal production'' facilities that are
not in any other BART category, States may identify those unique
facilities based upon SIC code 3341.

Step 2: Identify the start-up dates of those emission units. The EPA
interpretation of the terms ``in existence'' and ``in operation.''

Background. Step 2 in the proposed process for identifying BART-
eligible sources would be to identify all emissions units within the
listed categories which met the two tests in the definitions in the
regional haze rule: (1) The unit was ``in existence on August 7, 1977
and (2) the unit began operation after August 7, 1962. Our visibility
regulations define ``in existence'' and ``in operation'' in 40 CFR
51.301. We are proposing to retain the same definitions of ``in
existence'' and ``in operation'' as we had included in the 2001
proposal. The term ``in existence'' includes sources not yet in
operation where the owner or operator has not begun operating but which
has:

--Obtained all necessary preconstruction approvals,
--Began on-site construction, or
--Entered into binding agreements or contractual obligations to begin
construction of the facility within a reasonable time period.

In contrast, the term ``in operation'' includes only sources which are
actually operating. In the reproposed BART guidelines, as in the
previous proposal, we provide examples that illustrate the definitions
in the regional haze rule.
We also wish to eliminate any confusion over power plants having
boilers built both before 1962 and boilers built within the 1962-1977
time period. The BART guidelines would not require States to find that
all boilers at a facility are BART-eligible if one or more boilers at
the facility were put in place between the 1962 and 1977 dates. Under
Step 2 of the proposed process for identifying BART-eligible sources,
States would identify only those boilers that were put in place within
the 1962-1977 time period. Only those boilers are carried over to Step
3, and only those boilers would be subject to a BART engineering
analysis. We have included clarifying language in the reproposed
guidelines on this issue.

Step 3: Compare the potential emissions from the units identified in
steps 1 and 2 to the 250 ton/yr cutoff.

Background. Under the definition of ``major stationary source'' in
CAA section 169A(g)(7) and the corresponding definition of ``BART-
eligible source'' in the regional haze rule, BART applies only to a
stationary source if it meets the category description and time window
criteria described above, and only if it has the potential to emit 250
tons or more of ``any pollutant.''

[[Page 25192]]

There are two issues needing clarification with respect to the 250
tons per year threshold--one regarding what pollutants should be
addressed, and two, the definition of stationary source.

What Pollutants Should I Address?

2001 Proposed Rule. The 2001 proposal clarified that the 250 tons
per year cutoff applies only to visibility-impairing pollutants and
included a list of pollutants to address: SO₂,
NO_X, particulate matter, volatile organic compounds (VOC),
and ammonia.
Comments. We received a number of comments related to the proposed
inclusion of ammonia. One comment cited three reasons for not including
ammonia on the list of visibility-impairing pollutants. First, the
commenters believed that we had provided no scientific basis for
suggesting that ammonia contributes to visibility impairment. Second,
the commenters believed that we should not include ammonia on the list
of pollutants without fully discussing the implications for other
programs. For example, if ammonia became a ``regulated pollutant''
under the CAA based upon its inclusion in the guidance, the commenters
believed that there would be implications for PSD and other program
requirements. Third, the commenters believed that inclusion of ammonia
would have the unintended consequence of discouraging selective
catalytic reduction (SCR) as a control measure for NO_X,
because of the unavoidable but small amount of ``ammonia slip'' that
occurs in using SCR technology.
Reproposal. Based on the comments received on ammonia, and based on
our current state of knowledge regarding the role of ammonia in
PM_2.5 formation and the effects on regional haze that would
be expected from reductions in ammonia emissions, we believe that
ammonia should not be included on the list at this time.
The following is a our rationale for proposing not to include
ammonia. Ammonia is a gas and does not impair visibility directly. It
can, however, react with acidic particles or gases in the air to form
ammonium compounds. The most common acidic substances with which
ammonia reacts are sulfuric acid and nitric acid, which in turn are
formed from the reaction of SO₂ and NO_X with
other substances in the atmosphere. Because ammonia generally forms
visibility-impairing fine particles in the presence of acidic particles
or gases, reductions in SO₂ and NO_X emissions
will tend to reduce concentrations of ammonia-based particles in the air.
In other words, to reduce ammonium fine particles, States may
either require the reduction of ammonia or of SO₂ and
NO_X emissions. In determining the proper approach to
reducing ammonium, it is worth noting that as SO₂ and
NO_X emissions are decreased, the marginal effectiveness of
hypothetical ammonia controls will also tend to decrease.
The available ammonia emissions inventory is uncertain, although
EPA and other organizations are pursuing improvements. Consequently,
compared to the case for SO₂ and NO_X, the ability
to identify opportunities for emissions control and to quantify the
effects of such actions in advance is limited.\15\
---------------------------------------------------------------------------

\15\ For a more in-depth discussion of the contribution of
ammonia emissions from stationary sources to long-range transport of
PM_2.5, see discussion in the proposed Interstaste Air
Quality Rule (IAQR): 69 FR 4566, January 30, 2004.
---------------------------------------------------------------------------

Because of the uncertainties in assessing the impact of ammonia
emissions reductions on visibility, and because PM_2.5 will
decrease due to SO₂ and NO_X controls, we are
proposing not to include ammonia on the pollutant list at this time. We
request comment on this determination.
Also included in the original pollutant list are VOCs. We propose
that VOCs remain on the list.
Our understanding of the relationship between VOC emissions and the
formation of PM_2.5 is rapidly evolving. We recognize that
VOC emissions are most likely to contribute to particle formation, and
thus to visibility impairment, in the presence of NO_X. In
rural areas, anthropogenic VOC emissions generally do not appear likely
to be a significant contributor to PM_2.5 formation,\16\
while VOC emissions in urban areas are likely to be a contributor to
PM_2.5 formation. This is because VOC emissions are most
often present with NO_X emissions in urban areas. In rural
areas, by contrast, VOC emissions are not as often present with
NO_X emissions.
---------------------------------------------------------------------------

\16\ See discussion in the NO_X SIP call at 63 Fed.
Reg. 57,356 (Oct. 27, 1998).
---------------------------------------------------------------------------

We also recognize that some specific uncertainties about VOCs
remain. For example, only certain organic gases are precursors to
PM_2.5, but available inventories cover VOC as an aggregate.
It is therefore difficult to estimate emissions of the precursor
compounds from these inventories. In addition, available models for
estimating air quality from individual source emissions have more
uncertainty in predicting ambient PM_2.5 changes from
reductions in emissions of organic gases.
Finally, we recognize that many industrial sources and most mobile
sources of organic gases have been subjected to VOC control
requirements that have the effect of reducing emissions of the
particular compounds that are PM_2.5 precursors. Given that
fact, as well as the uncertainties about VOCs outlined above, we
request comment on the level of discretion States should exercise in
making BART determinations. Specifically, we request comment on whether
States should focus greater control requirements on VOC emissions from
BART sources in urban areas. We also request comment on the
circumstances under which, in rural areas, for sources subject to BART,
States may determine that BART would be no control for VOC.

What Is a ``Stationary Source?''

The definition of ``building, structure or facility'' in the
regional haze rule is based, in part, upon grouping of pollutant-
emitting activities by 2-digit category according to the SIC Manual. As
in the NSR program, however, facilities that convey, store or otherwise
assist in the production of the principal product, are considered to
fall within the same industrial grouping as the primary facility.
Despite this general rule, however, we would like to clarify that in
practice, this so-called ``support facility'' test for BART is narrower
than for other programs. We are proposing to add language to the
guidelines noting that emission units at a plant, even if they are a
``support facility'' for purposes of other programs, would not be
considered for BART-eligibility unless they were within one of the 26
listed source categories, and unless they were put in place within the
1962 to 1977 time period. For example, a mine, even if a ``support
facility'' for a power plant, would not be considered for BART eligibility.

Step 4: Identify the emission units and pollutants that constitute the
BART-eligible source.

Background. The final step in the identification of BART-eligible
sources would be to use the results from the previous three steps to
identify the universe of equipment that is BART-eligible. If the total
allowable emissions from the stationary source exceed a potential to
emit of 250 tons per year for any individual visibility-impairing
pollutant, then that collection of emissions units is a BART-eligible
source. A BART analysis would be required for each visibility-impairing
pollutant emitted from this collection of emissions units.

[[Page 25193]]

2001 Proposed Rule. The 2001 proposed guidelines included two
examples to clarify this point. In the first example, a source has two
emissions units having cumulative emissions exceeding 250 tons for
SO₂, but not for NO_X and particulate matter (PM).
For this example, we noted that BART would be required for all three
pollutants. In the second example, the source has potential emissions
that are less than 250 tons for each individual pollutant, but more
than 250 tons from the sum over all pollutants. For this second
example, we noted that the source would not be BART-eligible.
Reproposal. We received comments on the 2001 proposal suggesting
that some BART-eligible sources emit visibility-impairing pollutants at
levels that would make a de minimis contribution to regional haze. For
example, a source may be BART-eligible because it emits 500 tons per
year of one visibility-impairing pollutant, but it may also emit only
one ton per year of another pollutant, the emission of which would have
little effect on regional emissions loadings and visibility impairment.
A 1 ton/yr amount from a given BART-eligible source would likely
represent a de minimis fraction of a total regional inventory.
As noted previously, we believe that once a source is BART-eligible
according to the definition in CAA section 169A(g)(7), CAA section
169A(b)(2)(A) requires BART for ``any'' visibility-impairing pollutant
regardless of the amount. Notwithstanding this apparent directive, we
are proposing to provide the States with the flexibility to identify de
minimis levels of pollutants at BART-eligible sources. We believe that
it would be appropriate for States to have this flexibility once they
have collected more information on the BART population. We also agree
with comments that sources emitting pollutants at values considered de
minimis under the PSD program could be de minimis for BART as well.
Accordingly, the reproposal includes a provision that any de minimis
values that States adopt should not be higher than the PSD levels: 40
tons per year for SO₂, NO_X and VOC, and 15 tons/
yr for PM₁₀. We request comment on this provision, and on
the idea of including de minimis values. Finally, if a commenter
contends that ammonia should be included as a precursor to
PM_2.5, then the commenter should also comment on an
appropriate de minimis value for ammonia.

C. How To Determine Which BART-Eligible Sources Are Subject to BART

Background. Section 169A of the Act establishes a low triggering
threshold for determining whether a BART eligible source is required to
procure and install appropriate retrofit technology. States must
determine whether BART eligible sources emit ``any air pollutant which
may reasonably be anticipated to cause or contribute to any impairment
of visibility in [a Class I]
area.'' In the Regional Haze Rule, we
interpreted these statutory provisions as requiring a State to find
that a BART-eligible source is ``reasonably anticipated to cause or
contribute'' to regional haze if it can be shown that the source emits
pollutants within a geographic area from which pollutants can be
emitted and transported downwind to a Class I area.\17\
---------------------------------------------------------------------------

\17\ 64 FR at 35740.
---------------------------------------------------------------------------

Reproposal. As explained earlier, as part of the BART process, a
State identifies and lists all ``BART-eligible'' sources. The State
must then determine which of those BART-eligible sources may ``emit any
air pollutant which may reasonably be anticipated to cause or
contribute to any impairment of visibility in any [Class I]
area.'' A
source which fits this description is ``subject to BART.'' This section
explains our proposed process for determining which BART-eligible
sources should be subject to BART. We request comment on all aspects of
this process.

Determining Which Sources Are Reasonably Anticipated To Cause or
Contribute To Visibility Impairment (Sources Subject to BART)

Three options are proposed. First, the State may choose to consider
that all BART-eligible sources in the State are subject to BART (i.e.,
that none are exempt). As explained previously, we believe this
conclusion is reasonable in light of currently available information
[reference 1999 study]. We also believe that given American Corn
Growers' emphasis on State's prerogatives in making BART
determinations, we may lack the authority to deny this option to States.
Second, the State may choose to demonstrate, using a cumulative
approach, that none of its BART-eligible sources contribute to
visibility impairment. We propose that States should have the option of
performing an analysis to show that the full group of BART-eligible
sources in a State cumulatively do not cause or contribute to any
visibility impairment in Class I areas. We request comment on the types
of analyses that could be used. For instance, one approach may be for
States to use a regional scale grid model \18\ to demonstrate that its
BART-eligible sources do not cause or contribute to regional haze. We
anticipate that in most, if not all States, the BART-eligible sources
are likely to cause or contribute to visibility impairment in Class I
areas. However, it is possible that, using regional scale modeling, a
State could show that its BART sources do not collectively cause or
contribute to visibility impairment. In such a case, a State could
complete its BART analysis relatively quickly, without the need for
investing in studies of source-specific contributions to regional haze.
At this time, we are neither requiring nor encouraging all States to
undertake a cumulative approach.
---------------------------------------------------------------------------

\18\ For regional haze applications, regional scale modeling
typically involves use of a photochemical grid model that is capable
of simulating aerosol chemistry, transport, and deposition of
airborne pollutants, including particulate matter and ozone.
Regional scale air quality models are generally applied for
geographic scales ranging from a multi-state to the continental
scale. Such modeling may not be appropriate for all States, as
regional models are most applicable to situations involving multiple
BART-eligible sources. Because of the design and intended
applications of grid models, they may not be appropriate for all
BART assessments, so States should consult with the appropriate EPA
Regional Office prior to carrying out any such modeling.
---------------------------------------------------------------------------

Finally, the State may choose to determine which sources are
subject to BART through the use of an individual exemption process,
described below.
Individualized Source Exemption Process
We are proposing to provide States with the option of determining
which sources are subject to BART through the use of an individualized
exemption process. For this option, we propose that States use an air
quality model for an individual source to demonstrate no contribution
to visibility impairment in a Class I area. We also request comment on
alternative approaches that may be used in lieu of this approach, or as
a first step in the process by which States may determine which BART-
eligible sources, if any, to exempt.
For modeling an individual BART-eligible source located more than
50 km from a Class I area, we propose that an air quality model, such
as CALPUFF, be used. The CALPUFF system consists of a diagnostic
meteorological model, a gaussian puff dispersion model with algorithms
for chemical transformation and complex terrain, and a post processor
for calculating concentration fields and visibility impacts. CALPUFF
was incorporated into the ``Guideline on Air Quality Models'' (the
Guideline) (40

[[Page 25194]]

CFR Part 51, Appendix W) in April 2003.
Traditionally, EPA has used transport and diffusion modeling to
predict the effect of directly emitted PM_2.5 emissions on
PM_2.5 ambient concentrations. To simulate the effect of
precursor pollutant emissions on PM_2.5 concentrations
requires air quality modeling that not only addresses transport and
diffusion, but also chemical transformations. While we believe that it
is technically feasible to model secondary PM formation, and there is
at least one model, described above, which incorporates algorithms for
estimating secondary transformation, we have not yet fully tested such
modeling to determine whether its application is justified as a sole
determinant of air quality impacts involving secondary transformation.
However, where the statutory criteria for determining regulatory
applicability involve relatively low thresholds, or where regulatory
decisions involve considerations of multiple factors including, but not
limited to, model results, we believe transport and diffusion models
such as CALPUFF can be appropriate regulatory tools for evaluating air
quality impacts involving secondary transformation. Consequently, we
believe its use by States to assess whether a source is reasonably
anticipated to cause or contribute to impairment of visibility in Class
I areas is reasonable.
We are proposing that a CALPUFF assessment of an individual source
be used as the preferred approach for determining whether a BART-
eligible source may be exempt from BART. The CALPUFF assessment is
specific to each source, taking into account the individual source's
emission characteristics, location, and particular meteorological,
topographical, and climatological conditions, any of which may have an
impact on the transport of PM_2.5 and its precursors. Thus,
this approach may be more determinative than a non-modeling approach in
determining which sources are not contributing to visibility impairment
in a Class I area.
Results from the CALPUFF assessment would be used to determine the
source's impact on visibility in a Class I area. If a source has an
estimated impact on visibility that is lower than the established
threshold (described in the section below), then the State may choose
to exempt the source from further BART analysis. If the source's impact
is equal to or greater than the threshold, the State would determine
that the source is subject to BART.
The State or source would apply CALPUFF for source-receptor
distances greater than 50 km, since CALPUFF is generally intended for
use on scales from 50 km from a source to hundreds of kilometers.
However as the modeling domain increases in size, the requirements for
experience in the application of CALPUFF becomes more demanding (e.g.,
in processing and quality assurance of the meteorology, in
understanding the implications of the various model processing
options). Therefore we propose that any application of CALPUFF for
distances greater than 200 km requires development of a written
modeling protocol describing the methods and procedures to be followed,
and that the protocol be approved by the appropriate reviewing
authority. For source-receptor distances less than 50 km, we are
recommending that States use their discretion for determining
visibility impacts giving consideration to both CALPUFF and other EPA-
approved methods. For example, States would have the option of
exempting these sources if air quality modeling results, using an
appropriate local-scale model such as PLUVUEII,\19\ show that their
emissions are below a level that would be reasonably anticipated to
cause or contribute to visibility impairment in any Class I area.
---------------------------------------------------------------------------

\19\ PLUVUEII is a model used for estimating visual range
reduction and atmospheric discoloration caused by plumes resulting
from the emissions of particles, nitrogen oxides, and sulfur oxides
from a single source. The model predicts the transport, dispersion,
chemicals reactions, optical effects and surface deposition of point
or area source emissions. It is available at
http://www.epa.gov/scram001/tt22.htm#pluvue.

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

Metric for Visibility Degradation

In providing an individual source exemption option, a metric is
needed to assess a source's contribution to visibility degradation. The
metric we are using in the regional haze rule is the deciview, which is
derived directly from light extinction, an index commonly used to
measure visibility degradation.
As outlined in the 1999 Regional Haze rule (64 FR 35725-35727, July
1, 1999), a one deciview change in haziness is a small but noticeable
change in haziness under most circumstances when viewing scenes in a
Class I area. The deciview can be used to express changes in visibility
impairment that correspond to a human perception in a linear, one for
one, manner. The deciview concept was introduced in 1994 in an article
appearing in a peer-reviewed journal (Pitchford and Malm, Atmospheric
Environment, 28 (5), 1994). We believe that visible changes of less
than one deciview are likely to be perceptible in some cases,
especially where the scene being viewed is highly sensitive to small
amounts of pollution. We acknowledge that for other types of scenes,
with other site-specific conditions, a change of more than one deciview
might be required in order for the change to be perceptible.

Threshold Levels

A 1991 report from the National Acid Precipitation Assessment
Program (NAPAP) states that ``changes in light extinction of 5% will
evoke a just noticeable change in most landscapes.'' \20\ Converting a
5 percent change in light extinction to a change in deciviews yields a
change of approximately 0.5 deciviews. This is a natural breakpoint at
which to set the exemption level, since visibility degradation may
begin to be recognized by human observer at this extinction level.\21\
Thus, we are proposing a 0.5 deciview change as the threshold for
determining that an individual source is causing visibility impairment
at a Class I area. This level would be calculated by measuring the air
quality screening modeling results for an individual source against
natural visibility conditions. Natural visibility conditions are those
conditions that are estimated to exist in a given Class I area in the
absence of human-caused impairment.\22\ We believe that measuring
against natural visibility conditions is appropriate because the
ultimate goal of the regional haze program is a return to natural
conditions. Additionally, regional haze strategies are developed to
make reasonable progress towards this goal, and visibility degradation
and improvement are appropriately measured against natural conditions.
---------------------------------------------------------------------------

\20\ National Acid Precipitation Assessment Program (NAPAP).
Acid Deposition: State of Science and Technology Report 24,
Visibility: Existing and Historical Conditions--Causes and Effects,
Washington, DC, 1991. See Appendix D, p. 24-D2.
\21\ Ibid.
\22\ U.S. EPA. September 2003. Guidance for Estimating Natural
Visibility Conditions Under the Regional Haze Rule.
http://www.epa.gov/ttncaaa1/t1/memoranda/rh_envcurhr_gd.pdf This
document has estimates of default conditions as well as measures to
develop refined estimates of natural conditions.
---------------------------------------------------------------------------

We also request comment on using a threshold that is more or less
than 0.5 deciviews. Given uncertainties over the deciview change that
is perceptible, and the modeling of a source's contribution to haze in
a Class I area, a different threshold may be appropriate. Furthermore,
we recognize that there may be situations where impacts from

[[Page 25195]]

more than one BART-eligible source, when taken together, would
adversely affect visibility at a particular Class I area even though
the impact of each individual source would be below the visibility
threshold. In this case, there would be a noticeable impact on
visibility from BART-eligible sources because of the contribution of
multiple sources, yet impacts from an individual source alone would not
be noticeable. Given the statutory language that a source ``which may
reasonably be anticipated to cause or contribute to visibility
impairment'' is subject to BART,\23\ a lower threshold may be
appropriate as it would effectuate Congress's intent that the BART
applicability test not establish a high hurdle. We accordingly request
comment on what threshold would be appropriate to address these issues.
---------------------------------------------------------------------------

\23\ CAA Sec. 169A(b)(2) (emphasis added).
---------------------------------------------------------------------------

Alternative Approaches to the Assessment Using CALPUFF
The CALPUFF assessment described previously can be a time-consuming
and data-intensive approach; we are concerned about the resource
burdens this might pose for States and sources. Therefore, we are also
considering alternative approaches that would be credible and require
fewer resources. These approaches could serve as a first step in the
process for determining whether a source contributes to visibility
impairment in a Class I area. We are considering several alternative
approaches for making this exemption determination. These approaches,
in no particular order, include: (1) A simpler screening assessment
using CALPUFF (2) look-up tables (i.e., tables that require emissions
and distance information for making an exemption determination), (3)
source ranking, and (4) using Emissions divided by Distance, known as
the Q/D method.
Each approach has strengths and limitations. We request comment on
all of these approaches. A more complete and detailed explanation of
the four alternative approaches, including examples, is available in a
memo to the docket.\24\
---------------------------------------------------------------------------

\24\ Memorandum to the docket: Summary of Alternative Approaches
for Individual Source BART exemptions, Todd Hawes, March 12, 2004.
Docket No. OAR-2002-0076.
---------------------------------------------------------------------------

A Screening Assessment Using CALPUFF

We are proposing that CALPUFF be run in a screening assessment to
evaluate individual sources. This approach would be less data- and
time-intensive than running CALPUFF in the assessment described
previously due to greatly simplified preparation and processing of
input data. This simpler screening assessment utilizes source and
receptor location, as well as meteorological, topographical and
climatological conditions from a regionally-specific profile. However,
like the assessment described previously, this screening assessment
also utilizes the individual source's particular emission
characteristics. The table below illustrates the differences between
the screening assessment of the kind described previously as the
preferred approach and the simpler, more generalized screening assessment.

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

------------------------------------------------------------------------
Type........................ CALPUFF Assessment.. CALPUFF Screening
Assessment.
Model used.................. CALPUFF............. CALPUFF.
Input meteorology........... Process 5 years of Representative met
location-specific, location (data
meteorology data. already processed).
Terrain included............ Site-specific No (assumed flat).
terrain included.
Source-Receptor distances... Source to Class I Source to Class I
area receptor. area receptor.
Location of Visibility Maximum impact at Maximum impact in
impact. receptor using any direction at
appropriate source-receptor
distance and distance.
direction from
source.
------------------------------------------------------------------------

Results from this screening assessment would be used to determine
the source's impact on visibility in a Class I area. If a source has an
estimated impact on visibility that is lower than the established
threshold, the State may choose to exempt the source from further BART
analysis. If the source's impact is equal to or greater than the
threshold, the State would determine that the source is subject to
BART. The source would then have the option of performing the screening
assessment described previously as the preferred approach to
demonstrate that its visibility impacts do not exceed the threshold
level and that it qualifies for exemption.
We request comment on the use of this approach as an assessment of
individual source impacts on visibility.

Look-Up Tables Developed From Screening-Level Air Quality Modeling

For even greater ease of use, look-up tables could be developed for
application in the individual source exemption process. Under this
approach, a State or source would use a look-up table developed by EPA
to determine the source's predicted impact on a Class I area and,
consequently, its exemption status. The State or source would use the
source's emissions information and distance from a Class I area to
determine if it is exempt from BART.
The look-up tables could be developed by first using CALPUFF in
screening assessments to estimate levels of visibility impairment (in
deciviews) associated with different combinations of distance to a
Class I area and tons per year of emissions. A table would show the
distance from the representative BART-eligible source to a Class I area
and the associated allowable emissions of visibility-impairing
pollutants (e.g., SO₂, NO_X, and direct
PM_2.5) at that distance that will yield a modeled impact of
0.5 deciviews. A State or source could ``look up'' a source's distance
and emission combination and compare its allowable emissions of
visibility-impairing pollutants to the table to make the BART exemption
determination for the source.
If a BART-eligible source has emissions of visibility-impairing
pollutants that are less than the emissions shown on the table for
sources that are the same distance as the source from a Class I area,
the State could exempt the source from BART. Alternatively, if a BART-
eligible source's emissions of visibility-impairing pollutants are
greater than the emissions shown on the table, the State could
determine that the source is subject to BART. The source would have the
option of running the CALPUFF model, or other EPA-approved model, to
demonstrate that its visibility impacts do not exceed a change in light
extinction of 0.5 deciviews and that it qualifies for exemption.
An example of a look-up table for EGUs is shown in the technical memo

[[Page 25196]]

to the docket.\25\ A more in-depth discussion of the look-up table
development is given in the Summary of Technical Analysis for the
Proposed Rule.\26\ The advantages of the look-up tables are that they
are easy to use and no modeling would be required. However, they may be
too general to represent all source categories. For instance, the
source category in the example is for EGUs. Another source category
will likely have entirely different source and emissions
characteristics which may require development of a separate look-up
table. Several sets of look-up tables requiring several sets of
assumptions would be cumbersome and complex.
---------------------------------------------------------------------------

\25\ Ibid.
\26\ Summary of Technical Analyses for the Proposed Rule, Mark
Evangelista, U.S. Environmental Protection Agency, April 12, 2004,
Docket No. OAR-2002-0076.
---------------------------------------------------------------------------

Source Ranking

A source ranking approach is another possible option for
determining whether an individual source may be exempted from BART.
This approach would require a separate analysis for each Class I area.
First, a State would determine the universe of BART-eligible
sources within a prescribed distance from the Class I area. Then, using
a pre-determined common metric, such as total emissions of visibility
impairing pollutants at each source, a State would sort the sources in
descending order according to the metric and determine the cumulative
frequency (a running total or percentage) of the ranked sources
according to the chosen metric. The sources that fall below a pre-
determined frequency level could be presumed to be insignificant
contributors, and the State could exempt them from BART. A source that
falls above the pre-determined frequency level would be subject to
BART. The source would have the option of running the CALPUFF screening
model, or other EPA-approved model, to demonstrate that its visibility
impacts do not exceed the threshold level and that it qualifies for
exemption. A more complete and detailed explanation of this approach,
including an example, is available in a memo to the docket.\27\
---------------------------------------------------------------------------

\27\ Memorandum to the docket: Summary of Alternative Approaches
for Individual Source BART Exemptions, Todd Hawes, March 12, 2004.
Docket No. OAR-2002-0076.
---------------------------------------------------------------------------

We request comment on the source ranking approach and on an
appropriate frequency level for determining individual source exemption.

Emissions Divided by Distance (Q/D) Method

Another option for exemption for which we request comment is a non-
modeling based approach identified as Q/D (with ``Q'' being allowable
emissions, in tons per year, and ``D'' representing the distance, in
km, to the nearest Class I area, multiplied by a prescribed constant).
The method, originally developed by the North Carolina Department of
Environment and Natural Resources, is a tool to eliminate distant,
insignificant emission sources from ambient assessments submitted under
the Prevention of Significant Deterioration (PSD) program.\28\ The Q/D
method determines a source to be insignificant if the allowable
emissions in tons per year (Q) divided by a constant times the distance
in kilometers (D) is greater than a value of 1. For example, North
Carolina uses a constant of 20, which was determined empirically.
Therefore, a source could be considered insignificant if its emissions
divided by 20 times its distance, in km, from the nearest Class I area
is greater than 1. For this application for determining exemption from
BART, the combined emissions of SO₂, NO_X, and
PM_2.5 of a BART-eligible unit could be divided by the
distance to the nearest Class I area. If that quotient is less than 1,
the source would not be subject to BART. If a source is not found to be
exempt under this approach, the CALPUFF screening analysis could still
be used for an exemption determination.
---------------------------------------------------------------------------

\28\ A Screening Method for PSD, Memorandum from Bruce P.
Miller, U.S. Environmental Protection Agency, to Eldewins Haynes,
North Carolina Department of Natural Resources and Community
Development, September 12, 1985, Docket No. OAR-2002-0076.
---------------------------------------------------------------------------

We request comment on the Q/D method, including comment on what
value for the constant would be appropriate and why.

D. The BART Determination Process

Background. Section 169A(g)(7) of the CAA requires States to
consider the following factors in making BART determinations: (1) The
costs of compliance, (2) the energy and nonair quality environmental
impacts of compliance, (3) any existing pollution control technology in
use at the source, (4) the remaining useful life of the source, and (5)
the degree of improvement in visibility which may reasonably be
anticipated to result from the use of such technology. The D.C.
Circuit's decision did not address the first four steps of the BART
determination (the ``engineering analysis''), which are discussed in
detail in the guideline. The court's opinion did address the final
step, mandating that the degree of improvement in visibility that would
result from imposition of BART on each individual source be taken into
account in determining BART.
2001 Proposed Rule. Section IV of the 2001 proposed BART guidelines
was entitled ``Engineering Analysis of BART Options.'' The purpose of
this section was to address the requirement in 40 CFR
51.308(e)(1)(ii)(B) in the regional haze rule that States identify the
``best system of continuous emissions control technology'' taking into
account ``the technology available, the costs of compliance, the energy
and nonair quality environmental impacts of compliance, any pollution
control equipment in use at the source, and the remaining useful life
of the source.'' Thus, in the 2001 proposed guidelines, section IV
addressed four of the five statutory factors to be considered in the
BART determination. Section V, ``Consideration of Visibility Impacts,''
contained a consolidated discussion, addressing visibility
considerations in deciding both which BART-eligible sources should be
subject to BART, as well as the fifth statutory factor--assessing the
degree of visibility improvement which may reasonably be anticipated to
result from control technology.
Reproposal. In the proposed guidelines, we are adding a fifth step
to the Engineering Analysis. The five proposed steps in the engineering
analysis are as follows:
1--Identify all available retrofit control technologies,
2--Eliminate technically infeasible options,
3--Rank remaining control technologies by control effectiveness,
4--Evaluate impacts and document the results, and
5--Evaluate the visibility impacts of applying controls.
In this portion of the preamble, we discuss a number of other issues.
1. How does BART relate to maximum achievable control technology
(MACT) standards developed under CAA section 112?
In the 2001 proposed rule, we did not provide any discussion of the
relationship of BART controls to MACT requirements. A number of
commenters suggested that there are cases where additional controls
beyond MACT are not warranted. We believe that for VOC and PM sources
subject to MACT standards, States may streamline the BART analysis by
including a discussion of the MACT controls and whether any major new
technologies

[[Page 25197]]

have been developed subsequent to the MACT standards.
We believe that there are many sources, particularly sources of VOC
and PM emissions, that are well-controlled because they are regulated
by the MACT standards. Examples of MACT sources which effectively
control VOC and PM emissions include (among others) secondary lead
facilities, organic chemical plants subject to the hazardous organic
national emissions standard for hazardous air pollutants (HON),
pharmaceutical production facilities, and equipment leaks and
wastewater operations at petroleum refineries. (We believe this is also
true for emissions standards developed for municipal waste incinerators
under the CAA amendments of 1990.) In many cases, it will be unlikely
that States will identify emission controls more stringent than the
MACT standards without identifying control options that would cost many
thousands of dollars per ton. Unless there are new technologies
subsequent to the MACT standards which would lead to cost-effective
increases in the level of control, we believe that States may conclude
that a source meeting MACT standards in these cases will satisfy the
BART requirement.
The reproposed guidelines have been revised to include the
discussion of MACT standards. The reproposed guidelines would require
that a State identify any source where they are relying on MACT
standards to achieve a BART level of control. Moreover, the reproposed
guidelines would require a State to provide the public with a
discussion of its decision to rely on a MACT standard as BART for a
given source and pollutant.
2. How do I identify all available retrofit emission control
techniques?
2001 Proposed Rule. In the 2001 proposed guidelines, we discussed a
number of concepts regarding the identification of ``all available''
retrofit technologies. This discussion noted that ``all'' means a
reasonable set of technologies. For example, the guidelines noted that
it is not necessary to list all permutations of available control
levels that exist for a given technology--the list is complete if it
includes the maximum level of control each technology is capable of
achieving.
The proposed guidelines made clear that the list of ``available''
technologies should reflect a comprehensive review, including
technologies applied outside of the United States, and including
technologies that may have only been applied previously to new sources.
The proposed guidelines noted that control measures could include add-
on control devices, switching to inherently lower-emitting processes,
or a combination of the two. The proposed guidelines stated that BART
did not require a source to undertake a complete replacement of the
source with a lower-emitting design. The guidelines included a list of
references which are available for identifying possible control
measures, noting that the list was not necessarily all-inclusive.
Finally, this passage of the proposed guidelines noted that sources
with existing control devices in place must consider any available
options for improving the performance of those control devices.
Comments. We received a few comments on this part of the 2001
proposal. Some comments recommended that controls typically used at new
sources, such as those representing best available control technology
(BACT) or lowest acheiveable emission rate (LAER), would be more
stringent than BART should require. One commenter representing a
utility company noted that the requirement to consider all controls,
including those outside of the United States, could be burdensome to
States. This commenter recommended that the analysis be limited to a
``reasonable range'' of technologies.
Reproposal. We are proposing to amend the language in the BART
guidelines on the topic of identification of ``all'' retrofit
technologies. We do not believe that it is necessary that States
conduct detailed evaluations of control measures that are very unlikely
to be selected as BART. Accordingly, we believe that, in order to
reduce the administrative burden, States may consider developing
screening levels based on the ``cost effectiveness'' of emissions
control (i.e. the cost of emission control technology per each ton of
emissions reduced). We view such dollar/ton screening levels as
criteria for rejecting control options for consideration on the basis
of costs and not as the sole basis for a BART decision. The overall
BART decision must be made in consideration of all of the statutory
factors.
We also recognize that there may be cases where States may wish to
consider control measures above whatever screening levels they may
establish. For example, the effect of nitrate particles varies and
there are a few areas where nitrates are likely to be more important
than for the rest of the nation. Also, a few sources may emit levels of
NO_X higher than the presumptive control level of 0.2 lbs/
MMBtu, even after consideration of all available control technologies
(such as low NO_X burners and other combustion controls)
below any established screening levels (see discussion in section III.
6. below).
Within the above constraints, we believe that the BART analysis
should begin with a comprehensive review of those technologies that
could be used to reduce emissions from a given BART-eligible source. We
note that this analysis may be limited to a reasonable range of options
and need not consider all permutations of control levels for a given
technology.
In this proposal, we are seeking comment on two alternative
approaches for conducting a BART engineering analysis. We prefer the
first approach. Under this first alternative, the BART analysis would
be very similar to the BACT review as described in the New Source
Review Workshop Manual (Draft, October 1990). Consistent with the
Workshop Manual, the BART engineering analysis would be a process which
provides that all available control technologies be ranked in
descending order of control effectiveness. Under this option, you must
first examine the most stringent alternative. That alternative is
selected as the ``best'' unless you demonstrate and document that the
alternative cannot be justified based upon technical considerations,
costs, energy impacts, and non-air quality environmental impacts. If
you eliminate the most stringent technology in this fashion, you then
consider the next most stringent alternative, and so on.
We also request comment on an alternative decision-making approach
that would not necessarily begin with an evaluation of the most
stringent control option. Under this approach, you would have more
choices in the way you structure your BART analysis. For example, you
could choose to begin the BART determination process by evaluating the
least stringent technically feasible control option or an intermediate
control option drawn from the range of technically feasible control
alternatives. Under this approach, you would then consider the
additional emission reductions, costs, and other effects (if any) of
successively more stringent control options. Under such an approach,
you would still be required to (1) display and rank all of the options
in order of control effectiveness, including the most stringent control
option, and to identify the average and incremental costs of each
option; (2) consider the energy and non-air quality environmental
impacts of each option; and (3) provide a justification for adopting
the control technology that you select as the ``best'' level of
control, including an explanation as to why you rejected other more
stringent control

[[Page 25198]]

technologies. While both approaches require essentially the same
parameters and analyses, we prefer the first approach described above,
because we believe it may be more straightforward to implement than the
alternative and would tend to give more thorough consideration to
stringent control alternatives.
3. Consideration of Nonair Quality Environmental Impacts
2001 Proposed Rule. The 2001 proposal called for States to address
environmental impacts other than air quality, and energy impacts, due
to controlling emissions of the pollutant in question. Such
environmental impacts include solid or hazardous waste generation and
discharges of polluted water from a control device.
The proposed guidelines contained a number of examples of the types
of nonair quality impacts that should be considered. The guidelines
noted that States should take into account that there are beneficial
nonair quality environmental impacts that could result from control
measures. For example, control measures under consideration for BART
may reduce acid deposition.
The guidelines clarified that the procedure for conducting an
analysis of nonair quality environmental impacts should be based on a
consideration of site-specific circumstances. Under the proposed
guidelines, in Step 3 it would not be necessary to perform this
analysis of environmental impacts for the entire list of technologies,
if a State proposes to adopt the most stringent alternative. Instead,
the analysis need only address those control alternatives with any
significant or unusual environmental impacts that have the potential to
affect the selection or elimination of a control alternative.
Comments. One utility commenter requested that EPA better clarify
the BART determination factors other than costs of compliance. A State
commenter wanted EPA to explain the bounds of a nonair quality review
on environmental effects, citing possible requirements to assess
statewide water quality standards as an example of how broad and open-
ended the analysis could be. Several environmental groups asked us to
be more specific with respect to consideration of the beneficial nonair
quality related effects of implementing emissions controls as part of
the BART determination. The comments pointed out that acid and total
nitrogen loading affects water quality in rivers, lakes, coastal waters
and also affects soil chemistry. These comments point out that these
impacts can be magnified at higher elevations due to direct cloud
deposition. Acidic deposition and increased nitrogen loading appear to
be linked to damage to forested ecosystems, such as declines in
sensitive tree species, death of aquatic organisms and poor water
quality. Some comments pointed out that even a qualitative assessment
of these beneficial impacts can inform the BART determination and
should be part of the process. Comments from several Midwestern States
requested that the guidelines provide that incompatibility with control
for another pollutant, such as mercury, should be a criterion for
rejecting (or modifying) a BART control option.
Reproposal. The Guidelines discussion of energy impacts remains the
same as the discussion in the 2001 proposal. For nonair quality
impacts, we agree that more clarification is needed. We do not see this
factor as requiring an open-ended analysis of every affected nonair
resource. We also do agree with commenters that the nonair quality
assessment should include the beneficial effects of control options
being considered in the BART determination. Both quantitative and
qualitative information can be used in this assessment. We do not view
this factor as requiring States to conduct an analysis of every
possibly affected nonair quality effect, but rather as requiring States
to consider clearly documented nonair quality effects. Moreover, we
expect the Federal Land Managers to provide available information for
assessing the ability of emission controls to reduce impacts on
forests, soils, native species and other resources through the
consultation requirement for regional haze SIP development contained in
40 CFR 51.308(i)(2)of the regional haze rule. This information should
identify the specific nonair quality effects to consider and specific
criteria for evaluating their significance, so that States are not
faced with open-ended analyses.
States should also consider other information on beneficial effects
which include specific data on nonair quality concerns made available
to them, such as through public comments, in making the BART
determination. We also agree with the Midwestern States comments that
when controls for a visibility-impairing pollutant are shown to be
incompatible with control of another air pollutant, this may create air
quality or nonair quality related environmental concerns that should be
taken into account in comparing control alternatives. At the same time,
we note that it is important to evaluate fully and document the
magnitude and nature of the concern identified. The mere presence of an
actual or theoretical concern should not be cited as the reason for
eliminating an option. Also, once a source-specific BART determination
is made for two regulated pollutants, if the result is two different
BART technologies that do not work well together, a State could then
substitute a different technology or combination of technologies that
achieve at least the same emissions reductions for each pollutant.
4. Evaluating the Significance of the Costs of Control
2001 Proposed Rule. The 2001 proposed rule requested comment on
evaluating the significance of the costs of compliance--specifically,
on whether the guidelines should contain specific criteria, and on
whether such criteria would improve implementation of the BART requirement.
Comments. A few industry commenters, and two State commenters,
suggested that specific criteria for evaluating cost, or for comparing
cost with visibility benefits, should be included, but did not suggest
what those specific criteria should be. Several environmental groups
and environmental consulting firms suggested that specific cost
criteria would not improve BART determinations, because BART sources
and source categories vary considerably.
Reproposal. We are proposing a sequential process for conducting
the impacts analysis that includes a complete evaluation of the costs
of control. For evaluating the significance of the costs of control, we
continue to request comment on whether such criteria would improve
implementation of the BART requirement. If commenters believe such
criteria are warranted, we request comment on what criteria would be
appropriate. For example, we request comment on whether it would be
helpful to include criteria such as those in the work of the Western
Regional Air Partnership (WRAP),\29\ wherein a system is described
which views as ``low cost'' those controls with an average cost
effectiveness below $500/ton, as ``moderate'' those controls with an
average cost effectiveness between $500 to $3000 per ton, and as
``high'' those controls with an average cost effectiveness greater than
$3000 per ton.
---------------------------------------------------------------------------

\29\ Technical Support Documentation. Voluntary Emissions
Reduction Program for Major Industrial Sources of Sulfur Dioxide in
Nine Western States and a Backstop Market Trading Program. An Annex
to the Report of the Grand Canyon Visibility Transport Commission.
Section 6A.

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

[[Page 25199]]

5. Sulfur Dioxide Controls for Utility Boilers
2001 Proposed Rule. In the 2001 proposed guidelines, we cited a
report by EPA's Office of Research and Development to support a
presumption that, for utility boilers where there is no existing
control technology in place, a 90-95 percent reduction in SO2 is
generally cost effective to achieve using scrubbers. This document is
entitled Controlling SO₂ Emissions: A Review of
Technologies, EPA-600/R-00-093. We also provided, in a memorandum to
the docket for the proposal, calculations showing scrubber costs of
about $200-$1000 per ton of SO₂ removed for the 90-95
percent control levels. The proposal made clear that we would allow
States to consider case-by-case variations (for example, type of fuel
used, severe space limitations, and presence of existing control
equipment) that could affect the costs of applying retrofit controls.
We requested comments on whether the 90-95 percent presumption is
appropriate or whether another presumption should be established instead.
Comments. We received many comments on the 90-95% control
presumption for utility boilers.
Many utility industry comments were critical of the presumptive
level. These comments did not address whether the 90-95 percent level
was achievable, nor did they address EPA's cost calculations. Instead,
the comments were generally critical of the provision as a Federal
mandate that would reduce State flexibility in making BART determinations.
Comments from States in the Northeast and from environmental groups
were generally supportive of the presumptive levels of control. Some of
these comments expressed concerns that the technology may advance to
greater levels of achievable control before BART decisions are made.
Accordingly, those comments recommended that we add language to the
final guidelines to ensure that the 90-95 percent level would not be
considered to represent the maximum level of control that States could
consider.
Comments from several Midwestern States recommended that the
presumptive level be expressed as a performance level, for example as a
pounds/million BTU level, rather than as a percent control level. These
comments expressed concerns that facilities which have already reduced
emissions for purposes of the acid rain program could inappropriately
be treated in the same way as those that had not yet reduced their
emissions.
Reproposal. In today's action reproposing the BART guidelines, we
are proposing a level of SO₂ control that is generally
achievable for electric generating units (EGU)s of a certain size.
Specifically, we are proposing that in establishing BART emission
limits, States, as a general matter, must require owners and operators
of greater than 750 MW power plants to meet specific control levels of
either 95 percent control, or controls in the range of .1 to .15 lbs/
MMBtu, on each EGU greater than 250 MW. We are proposing to establish
such a default requirement based on the consideration of certain
factors discussed below. Although we believe that this level of control
is likely appropriate for all greater than 750 MW power plants subject
to BART, a State may establish a different level of control if the
State can demonstrate that an alternative determination is justified
based on a consideration of the evidence before it. In addition, for
power plants 750 MW and less in size, we are establishing a rebuttable
presumption that States should require any EGU between 250 MW and 750
MW in size to meet these same control levels.
This presumption would apply unless the State has persuasive
evidence that an alternative determination is justified. Our intent is
that it should be extrememly difficult to justify a BART determination
less than the default control level for a plant greater than 750 MW,
and just slightly less difficult for a plant 750 MW or smaller.
As stated earlier, by specifically singling out, in section 169A of
the CAA, a specific set of existing sources to be addressed by the
States (or the Administrator) in their plans, Congress clearly signaled
through the BART requirements a particular concern that the States and
EPA focus on pollution from these sources. The CAA gives the States the
authority ``to decide which sources impair visibility and what BART
controls should apply to those sources.'' American Corn Growers v. EPA,
291 F.3d at 8. However, section 169A further states that ``[i]n the
case of a fossil-fuel fired generating plant having a total generating
capacity in excess of 750 MW, the [BART]
emission limitations * * *
shall be determined pursuant to guidelines' issued by EPA. This
language, and the legislative history, indicate that although Congress
generally left the determination of BART emission limits to the States
(subject to the requirements of EPA's implementing regulations), it
intended EPA to take a more active role in the process of establishing
BART emission limits for large power plants. Furthermore, the
legislative history from 1977 makes clear that Congress understood 25
years ago that a specific type of SO₂ controls (flue gas
desulfurization (FGD) or ``scrubbers'') was readily available for these
plants. We believe it is consistent with Congress' mandate that EPA
establish guidelines for determining BART emission limitations for this
category of sources and, given the availability and low cost of
controls for these sources, for EPA to require that these power plants
meet specific control levels, unless the State has persuasive evidence
that an alternative determination is justified.
In addition to the statutory language and the legislative history,
we believe that requiring specific BART emission limitations for
greater than 750 MW power plants in most cases is supported by sound
policy considerations and a careful review of the information we have
regarding these sources' emissions, costs of control, and impacts on
visibility. First, sulfates resulting from SO₂ emissions are
an important contributor to visibility impairment nationwide, and
preliminary data that we have suggests that the estimated 28 BART-
eligible EGUs located at 750 MW power plants emit over one million tons
of SO₂ per year, or, on an individual EGU basis, an average
of over 39,000 tons of SO₂ per year.\30\ In other words,
these sources are some of the largest emitters of SO₂ in the
United States.
---------------------------------------------------------------------------

\30\ See http://www.epa.gov/airmarkets/epaipm/results2003.html.
This is the Table of Parsed Run Data for EPA Modeling Applications
Using IPM. Most of the 750 MW power plants addressed by this
provision contain one or more 250 MW boilers constructed between
1962 and 1977. Thus, on average, most (each) plant emits far more
than 39,000 tons per year of SO₂ from units covered by
the BART requirement.
---------------------------------------------------------------------------

Second, as discussed below, highly effective control technologies
(i.e., FGD) are available to control SO₂ emissions from
utility boilers; the average costs per ton of emissions removed from
such EGUs (usually between $200 and $1300 per ton) are well within the
levels considered for application under many CAA regulatory programs.
Based on the cost models in the Controlling SO2 Emissions report,\31\
for example, it appears that, where there is no existing control
technology in place, 95 percent control can generally be achieved at
EGUs using coal with relatively high

[[Page 25200]]

sulfur content at cost-effectiveness values cited above.\32\ Similarly,
for EGUs using relatively low sulfur coal, reducing SO₂
emission levels to 0.1 to 0.15 lbs/MMBtu is also cost-effective as
compared to other measures to reduce pollution, falling within the same
range of cost effectiveness as that discussed above.\33\
---------------------------------------------------------------------------

\31\ Documentation of the presumption that 90-95 percent control
is achievable is contained in a recent report entitled Controlling
SO₂ Emissions: A Review of Technologies, EPA-600/R-00-
093, available on the internet at http://cfpub.epa.gov/si/
osp_sciencedisplay.cfm?dirEntryID=18978.
This report summarizes percentage controls for FGD systems
worldwide, provides detailed methods for evaluating costs, and
explains the reasons why costs have been decreasing with time.
\32\ We have used the cost models in the Controlling
SO₂ Emissions report to calculate cost-effectiveness ($/
ton) estimates for FGD technologies for a number of example cases.
(See note to docket A-2000-28 from Tim Smith, EPA/OAPS, December 29,
2000). We also believe it is reasonable to expect States to consider
the maximum level that these scrubbers are capable of achieving.
Thus, for example, we believe that a scrubber installation which
allowed part of the flue gas stream to bypass the scrubber and
remain uncontrolled, or be controlled to a lesser degree, should not
be considered to represent BART.
\33\ Ibid.
---------------------------------------------------------------------------

Third, we believe that individual BART-eligible EGUs subject to
this provision contribute substantially to visibility impairment in
Class I areas. For example, based on modeling runs using CALPUFF for a
typical 250 MW EGU, modeling results have shown visibility effects
greater than 7 deciviews at Class I areas at distances of 200 km.\34\
At 90 percent control for a 250 MW source, the maximum modeled impact
would improve to 1.3 deciviews. A 95 percent control level would yield
further substantial improvement in visibility to just under 1 deciview.
Note however that even at a 95 percent control level, just one source
can have maximum impacts above the threshold of the visible range (0.5
deciviews) and may still impair visibility at the nearest Class I area.
---------------------------------------------------------------------------

\34\ Summary of Technical Analyses for the Proposed Rule, Mark
Evangelista, U.S. Environmental Protection Agency, April 12, 2004,
Docket No. OAR-2002-0076.
---------------------------------------------------------------------------

Therefore considering the range of the costs of compliance for
these sources and the degree of improvement in visibility that may be
anticipated from the use of the highly effective control technologies
that are available for these sources, we have determined that it is
appropriate to establish in these guidelines specific control levels
for States to use in determining BART for these sources. We are
proposing that as a general matter, States must find that for EGUs
greater than 250 MW at 750 MW power plants subject to BART, the
appropriate BART emission limitation reflects either at least 95
percent control, or a comparable performance level of 0.1 to 0.15 lbs
of SO₂ per million BTU range, unless the State has
persuasive evidence (as discussed below) that an alternative
determination is justified.
We are proposing a performance level as an alternative to a
percentage reduction to account for the difference between coal with
higher, as opposed to lower, sulfur content. As noted, we received
comments on the proposed 2001 BART guidelines that the control
technology presumption should be expressed as a performance level (lb/
million BTU) rather than as a percentage control. In response to these
comments, we are taking into account the fact that the actual level of
performance after application of scrubber technologies will be
influenced not only by the percentage control, but also by the sulfur
content of the fuel used.
As discussed above, we believe that this proposal of 95 percent
control, or a comparable performance level of 0.1 to 0.15 lbs of
SO₂ per million BTU, represents controls that are achievable
at reasonable cost-effectiveness levels. These control levels are
functionally equivalent to the 90-95% control levels contained in the
2001 proposal. However the choice between 95 percent and an emission
rate in the range of 0.1 to 0.15 lbs/MMBtu better reflects a
recognition of the differences in overall emissions that are achievable
by using different coal types. For example, coal boilers in the West
generally use lower sulfur content Western coals. The low end of the
range in the 2001 proposal recognized that dry scrubbers employed in
the West would have difficulty achieving a 95% level of control.
However, the 2001 proposal did not explicitly recognize that 90%
control in the West may actually represent a lower overall sulfur
emission rate, given the lower sulfur content in the coal used.
Conversely, wet scrubbers employed in the East could easily get 95%
control or more. But because Eastern coal boilers generally use higher
sulfur content Eastern coals, the overall sulfur emission rate might
still remain higher in the East than in the West.
While emission rates vary by both sulfur content and scrubber type,
the following table illustrates demonstrated control efficiencies for
the West and East.
Emission Rates and Scrubber Control Percentages for Bituminous Coal

Emission Rates and Scrubber Control Percentages for Bituminous Coal
------------------------------------------------------------------------
Sulfur Coal (percent) Scrubber (percent) SO2/MMBtu (lbs)
------------------------------------------------------------------------
WEST
------------------------------------------------------------------------
0.7 90 0.10
------------------------
1.0 90 0.15
------------------------
EAST
------------------------------------------------------------------------
2.5 95 0.18
2.5 96 0.15
------------------------------------------------------------------------

Assume: 13,000 lb Coal/Btu and 1 MW = 10.5 x 106 Btu/hr,
from AP-42 \35\
---------------------------------------------------------------------------

\35\ Examples of SO₂ control calculations for various
sulfur contents in bituminous coal, Note from Todd Hawes to Docket
OAR-2002-0076, April 8, 2004.
---------------------------------------------------------------------------

We request comment on whether these control levels are appropriate,
or whether different levels should be established instead. We also
request comment on which specific target number in the 0.1 to 0.15 lb/
million BTU range should be considered to represent BART, especially
for those EGUs that cannot achieve 95 percent control. For whatever
target levels commenters wish to offer, they should provide
documentation supporting the basis for their proposals.
Although we are proposing to establish a requirement that these
control levels are BART for 250 MW EGUs at greater than 750 MW power
plants that are subject to BART, States would still have the ability to
take into account any unique circumstances that support an alternative
determination. The CAA identifies five factors that the States
generally must consider in making a BART determination. CAA section
169A(g)(2). If, in any specific case, the State finds that these
factors demonstrate that the presumed control levels do not represent
BART, we propose that the State may make a reasoned determination as to
the appropriate level of control. If a State chooses to deviate from
the required level, it must provide documentation supporting and
explaining its determination.
Nevertheless, we believe that it would be extremely difficult to
argue, in any instance, that the above control levels should not be
determined to be BART for these units at these large power plants. For
the reasons outlined above, we believe that only in extremely rare and
unique circumstances could a State determine that such controls are not
cost effective, or that the visibility impact of such a plant does not
warrant

[[Page 25201]]

such controls. We also believe that only under extreme circumstances
would consideration of any of the remaining three factors (energy and
nonair quality environmental impacts, existing pollution control
technology in place, and remaining useful life of the source) suggest
that these control levels are too stringent to be determined to be
BART. For example, a source might show proof that it will be shutting
down within the next 5 years. Or a source might be located in a remote
desert area, where use of water for FGD would deplete an aquifer. As
discussed above, however, in the vast majority of cases, we believe
that these control levels should be considered to represent BART.
In addition, the control levels at issue are based on our
understanding of the current capabilities of scrubbers, as well as the
costs faced by the utility industry for installing these controls. We
recognize that it is possible that capabilities of scrubber
technologies may improve and it is likely that scrubber costs will
continue to decline as scrubber technologies improve.\36\ \37\
Accordingly, we have added a brief discussion to the reproposed
guidelines to ensure that States take into account updated information
on scrubber performance as scrubber technology improves.
---------------------------------------------------------------------------

\36\ Zipper and Gilroy, Sulfur Dioxide Emissions and Market
Effects under the Clean Air Act Acid Rain Program (Air and Waste
Management Association, 1998, vol. 48, pp. 829-37) shows that
capital costs for FGD fell by 50 percent between 1989 and 1996. See
http://www.awma.org/journal/ShowAbstract.asp?Year=1998&PaperID=748.

\37\ See also, Market-Based Advanced Coal Power Systems--Final
Report (Office of Fossil Energy, US Department of Energy, 1999),
section 1, at http://www.fossil.energy.gov/programs/powersystems/
publications/MarketBasedPowerSystems/Market-Based_Advanced_Coal_Power_Systems.html.

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

We also believe that States should find that the control levels
described above are cost effective for all utility boilers greater than
250 MW in size, regardless of the size of the power plant at which they
are located. There appears to be no significant difference in utility
boilers at power plants that are greater than 750 MW, and those 750 MW
or less, other than the number of boilers located at the facility. For
the most part, plants greater than 750 MW generally consist of multiple
units, many of which are smaller than 750 MW each.\38\ Absent unusual
circumstances which would lead to substantially higher costs than for
typical facilities, a utility boiler greater than 250 MW in size should
be able to achieve either a 95 percent reduction in SO₂
emissions or a comparable performance level of 0.1 to 0.15 lbs/MMBtu at
a very reasonable cost. We request comment on whether this level of
control is reasonable for such sources. Such unusual circumstances
could be similar to the examples cited above with regard to greater
than 750 MW plants (that a source might show proof that it will be
shutting down within the next 5 years, or a source might be located in
a remote desert area, where use of water for FGD would deplete an
aquifer.) Although the hurdle for not achieving the default control
level for greater than 750 MW plants is intended to be higher than the
hurdle for less than 750 MW plants, we are unable to think of an
example that would apply to 250 MW units and above at one size plant
but not the other. We request comment on any such examples that might
exist.
---------------------------------------------------------------------------

\38\ See http://www.epa.gov/airmarkets/epaimp/#documentation.
This is the NEEDS (National Electric Energy System) Database for IPM
V.2.1, NEEDS (National Electric Energy System) Database for IPM
2003. The NEEDS database contains the generation unit records used
to construct the ``Model'' plants that represent existing and
planned/committed units in EPA modeling applications of IPM. NEEDS
includes basic geographic, operating, air emissions, and other data
on all the generation units that are represented by ``model'' plants
in EPA's v. 2.1 update of IPM. See Chapter 4 of the Documentation
Report (link) for a discussion of the data sources underlying NEEDS.
---------------------------------------------------------------------------

6. Nitrogen Oxide Controls for Utility Boilers
Background. In addition to being a major source of SO₂
emissions, EGUs and other combustion units are a major source of
NO_X emissions. NO_X emissions also contribute to
regional haze, both through formation of light scattering nitrate
particles in a manner similar to sulfate formation from SO₂
emissions, but also through promoting the formation of sulfate
particles. Based on an examination of the contribution to haze in Class
I areas from the IMPROVE network, SO₂ emissions comprise the
most significant contribution. However, in some areas and at some
times, the NO_X contribution can be greater than the
SO₂ contribution. Also, NO_X emissions can be an
important direct and indirect contributor to PM2.5 formation. In
addition, in areas with high EGU SO₂ and NO_X
contributions, a reduction only of SO₂ emissions would
result in nitrate `substitution' for sulfates, reducing the regional
haze benefits.\39\
---------------------------------------------------------------------------

\39\ See http://vista.cira.colostate.edu/improve/Publications/
Reports/2000/PDF/Cahpter3final100.pdf. These are summary statistics
of exctinction by species from the IMPROVE network.
---------------------------------------------------------------------------

2001 Proposed Rule. In discussing the process for identifying all
available retrofit emission control techniques in the 2001 proposed
guidelines, we identified general information sources that address
NO_X control strategies (66 FR 38123). The proposed
guidelines, however, did not contain a detailed discussion of available
NO_X control strategies for utilities.
Comments. We received several comments from environmental and
multi-state organizations requesting that we specifically address
technologies for control of NO_X at BART sources. These
commenters provided information showing that NO_X emissions
result in the formation of visibility-impairing nitrate particles. In
addition, these commenters requested that we establish a presumptive 90
percent removal of emissions of NO_X from currently
uncontrolled utility boilers. The commenters provided information
regarding the level of visibility impairment in Class I areas, as well
as in urban areas, created by secondary particles related to emissions
of NO_X. The commenters noted that, while nitrate contributes
less to visibility impairment, relative to sulfate, on the worst
impaired days in summer, it has a more significant role in visibility
impairment in winter when some of the worst days occur. In addition,
the commenters point out that major reductions in SO₂
emissions, and the ammonium sulfate particles they create in the
atmosphere, could lead to increases in nitrate particles. The reason
for this is that reductions in ammonium sulfate particles could ``free
up'' ammonia, making it available to form ammonium nitrate particles.
The commenters argued that BART should control SO₂ and
NO_X simultaneously.
In addition to direct visibility concerns in and around Class I
areas, commenters stated that NO_X emissions reductions would
contribute to improved public health. One commenter noted that
reductions of NO_X emissions from BART sources would result
in enhanced benefits to ecosystems in high elevation Class I areas.
Another commenter noted increasing trends in particulate nitrate
concentrations at several Class I areas and suggested that EPA conduct
a review of technologies, similar to the ORD report on SO₂
emissions controls, to be used as basis for a presumptive level of control.
Reproposal. We agree that emissions of NO_X from sources
subject to BART, and the resulting nitrate particles formed by
NO_X in the atmosphere, should be appropriately addressed in
a BART analysis. We also agree with commenters that greater control of
SO₂ at large coal-fired utility plants may result in greater
availability of NO_X in the atmosphere. Recent data from
EPA's IMPROVE monitoring networks confirms that the contribution of

[[Page 25202]]

nitrates to visibility impairment is significant, and may be
increasing, at a number of sites in the West.\40\
---------------------------------------------------------------------------

\40\ See http://wrapair.org/forums/ioc/meetings/030728/index.html
(especially presentation by John Vimont, National Park Service).
---------------------------------------------------------------------------

The approach to assessing the available methods for removal of
NO_X differs from the approach used to assess controls for
removal of SO₂. The engineering approach for removal of
SO₂ from existing combustion sources is generally removal
technology applied to the flue gas stream. For reducing emissions of
NO_X at existing combustion sources, there are two somewhat
distinct engineering approaches available.\41\ One is to use combustion
modifications (including careful control of combustion air and/or low-
NO_X burners) and the other is removal technology applied to
the flue gas stream (selective catalytic reduction (SCR) or selective
non-catalytic reduction (SNCR)). These overall techniques can be
applied alone or in combination.
---------------------------------------------------------------------------

\41\ An overview of NO_X control technologies is
available at the following Web site:
http://www.fetc.doe.gov/coalpower/environment/nox/index.html.

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

Unlike the methods for controlling SO₂, which overall
fall within a fairly narrow range of cost effectiveness and control
efficiencies, the removal efficiencies and costs associated with the
two overall categories of control techniques for NO_X vary
considerably, depending upon the design and operating parameters of the
particular boiler being analyzed.\42\ In general combustion controls
and low-NO_X burners are cost effective for utility boilers
burning sub-bituminous coal, and may be less cost effective for units
burning lignite.\43\
---------------------------------------------------------------------------

\42\ See http://www.epa.gov/ttn/catc/products.html#cccinfo (EPA
Air Pollution Control Cost Manual), section 4 (NO_X
controls), chapter 2.
\43\ See http://www.epa.gov/airmarkets/epa-ipm/#documentation.
This is the NEEDS Database for IPM V.2.1, the NEEDS Database for IPM
2003. The NEEDS database contains the generation unit records used
to construct the ``model'' plants that represent existing and
planned/committed units in EPA modeling applications of IPM. The
NEEDS database includes basic geographic, operating, air emissions,
and other data on all the generation units that are represented by
``model'' plants in EPA's v. 2.1 update of IPM. See Chapter 4 of the
Documentation Report for a discussion of the data sources underlying
NEEDS. Data on units, their controls and characteristics are also
part of the NEEDS database.
---------------------------------------------------------------------------

In this rulemaking, we are proposing that States, in establishing
BART emission limits for NO_X, must, as a general matter,
require sources to determine BART as discussed below. For sources
currently using controls such as SCR to reduce NO_X emissions
during part of the year, we are proposing that a State should presume
in a BART determination that using these same controls year-round would
be cost effective.\44\ As the most significant costs associated with
SCR are capital costs, the additional costs of operating this control
technology throughout the year would be relatively modest.\45\
---------------------------------------------------------------------------

\44\ In 1998, we issued a rule requiring a number of Eastern
States to reduce the summertime emissions of NO_X from
sources within these States. 63 FR 57356, October 27, 1998). As a
result of this rule, 19 States and the District of Columbia have
required power plants to reduce NO_X emissions seasonally.
\45\ See Status Report on NO_X Control Technologies
and Cost-Effectiveness for Utility Boilers, Northeast States for
Coordinated Air Use Management and Mid-Atlantic Regional Air
Management Association, June 1998, at:
http://www.nescaum.org/pdf/execsum_nox.pdf.

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

For all other power plants subject to BART, we believe that States
should require the lowest emission rate that can be achieved without
the installation of post-combustion controls. Thus, we are proposing
that the States must, as a general matter, require these sources to
achieve a control level of 0.2 lbs/MMBtu.\46\ We are proposing to
establish such a presumption because for most of the utilities subject
to this rule, a 0.2 lb/MMBtu emission rate can be generally achieved
through the use of combustion controls or low-NO_X burners.
We request comment on this emission rate. We also request comment on
whether another emission rate higher or lower than 0.2 lb/MMBtu
reflects an emission rate that can generally be achieved through the
use of combustion controls or low-NO_X burners. These
controls are applicable to most EGUs, are relatively inexpensive,\47\
and are already widely applied. We recognize that a small number of the
largest power plants may need to install an SCR unit to meet this
control level. In such relatively rare cases, a State, at its
discretion, may find SCR to be appropriate if the source causes
visibility impacts sufficiently large to warrant the additional capital
cost.
---------------------------------------------------------------------------

\46\ The EPA Clean Air Market Division's ``Cost Tool'' gives
information on control effectiveness (dollar/ton removed) and
overall NO_X control efficiencies for various control
technologies.
\47\ http://www.epa.gov/airmarkets/epa-ipm/#documentation This
is the Documentation Report (2003 Analyses), and Documentation
Report (V. 2.1 Update). Data on units, their controls and
characteristics are also part of the NEEDS database, referenced above.
---------------------------------------------------------------------------

Notwithstanding the general assessment presented above, we ask for
comment in particular on the question of what rate of NO_X
emissions can be achieved with low NO_X burners or advanced
combustion controls on certain specific types of boilers. For instance,
we recognize that some wall-fired dry bottom boilers may not be able to
meet an emissions rate of 0.2 lb/MMBtu without post-combustion
controls. Similarly, we also recognize that, without post-combustion
controls, wet bottom, cyclone, and cell burners probably cannot achieve
a rate of 0.2 lb/MMBtu due to unique design and operational
characteristics, such as relatively small furnace size or relatively
large heat release rate. We also seek comment on the impact of coal
rank on NO_X emissions rates that can be achieved without
post-combustion controls.
If you choose to comment on any of these issues, please provide
data or technical information supporting your comments and recommendations.
We believe that States should determine in almost every case that
these control levels represent a reasonable determination of BART for
large EGUs. As discussed above, achieving these emissions reductions is
generally cost effective. In addition, as commenters on the 2001
guideline noted, nitrates contribute significantly to regional haze.
Thus, a State considering the costs of meeting these control levels and
the degree of improvement in visibility should, in most instances, find
that at a minimum, these controls represent BART. We acknowledge that
there could be unique or extreme circumstances, for those few of the
largest EGUs that cannot achieve 0.2 lbs/MMBtu without SCR or SNCR,
under which a State might find SCR or SNCR to be unreasonable. We
request comment on what specific circumstances might exist, if any, to
justify a lesser degree of control. Commenters should provide
documentation for any such examples.
7. Consideration of Visibility Impacts.
2001 Proposed Rule. Under the 2001 proposed guidelines, States
would have been required to use a regional modeling analysis to assess
the cumulative impact on visibility of the controls selected in the
engineering analysis. States would use this cumulative impact
assessment to make a determination of whether the controls, in their
entirety, provide a sufficient visibility improvement to justify
installation.
Comments. We received many comments regarding the cumulative nature
of our process for considering the degree of visibility improvement.
These commenters believed that the degree of visibility analysis should
consider source-specific visibility impacts. These commenters also
asserted that our process was not consistent with the requirements for
BART in the CAA.

[[Page 25203]]

Reproposal. The fifth statutory factor addresses the degree of
improvement in visibility which may reasonably be anticipated to result
from the use of control technology. The American Corn Growers decision,
discussed in detail in section II above, vacated the approach in the
regional haze rule of requiring States to assess the degree of
visibility improvement from the imposition of controls on all sources
subject to BART in a State. We understand the court decision to require
that we allow for an analysis of impacts that focuses on each
individual source undergoing a BART determination.
Therefore, this reproposal focuses on the use of single source
emissions modeling for assessing the degree of improvement in
visibility from various BART control levels. For the purpose of the
BART determination, a State or individual source would run the CALPUFF
model, or other EPA-approved model, using source-specific and site-
specific data. We recognize that such models may be useful in analyses
where modeling results alone are not determinative of regulatory
consequences. We believe that CALPUFF is based on sufficiently sound
technical grounds to inform regulatory decisions that are based on a
cumulative weight of evidence such as the statutorily-defined factors
for consideration in assessing BART for regional haze.
For sources subject to BART that are located greater than or equal
to 50 km from all receptors in a Class I area, the State or source
would run the model at the current allowable emissions level, and then
again at the post-control emissions level (or levels) being assessed.
Results would be tabulated for the average of the 20% worst modeled
days at each receptor. The difference in the resulting level of
impairment predicted is the degree of improvement in visibility
expected. For example, if the average impact from the 20% worst days
for a source's pre-control emission rate for a particular receptor is a
change of 1.0 deciviews, and its post-control impact is 0.4 deciviews,
the net visibility improvement is 0.6 deciviews (60 percent). All
receptors in the Class I area should be analyzed.
For sources subject to BART that are located less than 50 km from a
Class I area, the State would use its discretion in determining
visibility impacts for current allowable versus post-control emissions
giving consideration to both CALPUFF and other EPA-approved methods
such as PLUVUEII.\48\ We request comment on this and other possible
approaches to calculating the degree of visibility improvement expected
for sources located less than 50 km from a Class I area.
---------------------------------------------------------------------------

\48\ PLUVUEII is a model used for estimating visual range
reduction and atmospheric discoloration caused by plumes resulting
from the emissions of particles, nitrogen oxices, and sulfur oxides
from a single source. The model predicts the transport, dispersion,
chemical reactions, optical effects and surface deposition of point
or area source emissions. It is available at
http://www.epa.gov/scram001/tt22.htm#pluvue.

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

We also note that the proposed methodology is for Regional Haze
Rule BART determination only; other metrics may be used for BART
determinations made in response to certification of impairment by a
Federal Land Manager.
Alternatively, we are requesting comment on the option of using the
hourly modeled impacts from CALPUFF and assessing the improvement in
visibility based on the number of hours above the 0.5 deciview
threshold for the pre- and post-control emission rates. We also request
comment on combinations of the proposed and alternative options above.
For example, the deciview change for each hour of the 20% worst modeled
days could be assessed. Finally, we request comment on the use of the
simpler screening version of CALPUFF to do the analysis.

E. Trading Program Guidance

Background. The regional haze rule allows States the option of
implementing an emissions trading program or other alternative measure
instead of requiring BART (40 CFR 51.308(e)(2)). This option provides
the opportunity for achieving better environmental results at a lower
cost than under a source-by-source BART requirement. A trading program
must include participation by BART sources, but may also include
sources that are not subject to BART.
2001 Proposed Rule. In the 2001 proposed guidance, we provided an
overview of the steps involved in developing a trading program
consistent with 40 CFR 51.308(e)(2). We focused this discussion on
emission cap and trade programs which we believe will be the most
common type of economic incentive program (EIP) developed as an
alternative to BART. The BART guidelines discussed three basic steps
for cap and trade programs: (1) Developing emission budgets; (2)
allocating emission allowances to individual sources; and (3)
developing a system for tracking individual source emissions and
allowances.
The proposal noted that an emissions budget generally represents a
total emissions amount for a single pollutant such as SO₂.
As noted in the preamble to the regional haze rule (64 FR 35743, July
1, 1999), we believe that unresolved technical difficulties generally
preclude interpollutant trading for addressing visibility impairment.
Once an emissions budget or ``cap'' is set, the next step in an
emission trading program alternative to BART is to issue allowances to
individual sources, consistent with the cap. Once the allowances are
established, it is also necessary to have in place a tracking system to
ensure that the allowances are met.
In the 2001 proposed guidelines, we did not include detailed
recommendations on how to allocate emissions or how to develop a
tracking system. We noted that it would not be appropriate for us to
require a particular process and criteria for individual source
allocations. The 2001 proposal noted that we did, however, agree to
provide information on allocation processes to State and local agencies.
Comments. Regarding the sources to include in a trading program,
some commenters suggested that a trading program could be expanded
beyond the set of BART-eligible sources.
With regard to the geographic area covered by a trading program for
BART, the WRAP enquired whether the backstop emissions trading program
under section 309 of the regional haze rule could be expanded to other
western States when they submit their section 308 SIPs.
Comments from the environmental officials for Indian Tribes
suggested that the guidelines should ensure that some number of
allowances are set aside for Tribes. Otherwise, the commenters believed
that a trading program may perpetuate historical barriers to economic
development in Indian country.
Reproposal. The reproposed guidelines largely reflect the same
overall approach and level of detail as the 2001 proposal. We continue
to believe that the trading program alternative provided by the
regional haze rule can serve to reduce the administrative burden of the
program while providing greater long-term environmental benefits. We
discuss specific issues below.
Consistent with the regional haze rule, we propose that the
guidelines continue to require participation by BART sources and allow
for the option of additional participation. We note that by enlarging
the universe of sources affected, it will be more likely that more
sources with relatively low-cost emission reduction potential will be
included. Therefore broader participation in the program is likely to

[[Page 25204]]

provide greater opportunities for emissions trading and cost savings.
In addition, regional trading programs can potentially lower
transaction costs and produce efficiencies by creating uniform
requirements for firms which operate sources in multiple states.
Therefore, we believe that States should consider whether it is
appropriate to design and implement a trading program in conjunction
with other States. Consistent with this overall approach, in the
proposed Interstate Air Quality rule (IAQR) (69 FR 4566, January 30,
2004), we requested comment on whether compliance with the IAQR by
affected EGUs in affected States would satisfy, for those sources, the
BART requirements of the CAA, provided that a State imposes the full
amount of SO₂ and NO_X emissions reductions on
EGUs that the IAQR deemed highly cost effective. We are in the process
of evaluating those comments. Based on our current evaluation, we
believe the IAQR, as proposed, is clearly better than BART for those
affected EGUs in the affected States which we propose to cover under
the IAQR. We thus expect that the final IAQR would satisfy the BART
requirements for affected EGUs that are covered pursuant to the final IAQR.
We continue to believe that there are no legal or regulatory
obstacles to expanding the WRAP trading program to other States in the
WRAP area, provided that technical analyses support such a plan.\49\
Consistent with the regional haze rule, such a program must demonstrate
greater reasonable progress for the Class I areas affected by sources
in those States. We continue to request comment on how greater
reasonable progress could be demonstrated, including in particular on
whether overall visibility improvements across Class I areas, on
balance, would be sufficient to determine that such a trading program
is ``better than BART.''
---------------------------------------------------------------------------

\49\ Letter from Lydia Wegman to Rick Sprott, Director, Utah
Division of Air Quality, July 31, 2002.
---------------------------------------------------------------------------

Finally, in 1980, we published regulations addressing visibility
impairment from one or more sources close to a Class I area. This type
of visibility impairment is referred to as ``reasonably attributable''
impairment under the 1980 regulations. These regulations included a
requirement for BART to address reasonably attributable impairment in
40 CFR 51.302. Given that these requirements remain in place even after
publication of the regional haze rule, one issue needing clarification
in the BART guidelines is the interface between these BART requirements
established in 1980 and the requirements for BART under the regional
haze program, and between the 1980 BART requirements and the provisions
of a trading program alternative to BART.
We believe that the proposed guidelines appropriately clarify that
the 1980 provisions for reasonably attributable impairment, including
the BART requirement, remain in effect until the BART requirement is
satisfied. We believe that it is relatively unlikely that many--if
any--sources will be found to be subject to the 1980 BART requirement,
given that Federal Land Managers (FLMs) have certified impairment on
only a few occasions since 1980. Nonetheless, if evidence were to
suggest that an individual source was causing localized visibility
impairment, we believe that it would be improper to remove FLMs' and
States' ability to craft a solution using the tools provided by our
visibility regulations. We note that the regional haze rule includes
provisions allowing ``geographic enhancements'' to trading programs
that can address local visibility concerns up front. Accordingly, we
continue to believe that States and FLMs have the ability to provide
assurances to sources that any trading program established for regional
haze will satisfy all of the BART provisions in EPA's visibility
regulations.

IV. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

Under Executive Order 12866 (58 FR 51735, October 4, 1993), EPA
must determine whether the regulatory action is ``significant'' and,
therefore, subject to Office of Management and Budget (OMB) review and
the requirements of the Executive Order. The Order defines
``significant regulatory action'' as one that is likely to result in a
rule that may:
(1) Have an annual effect on the economy of $100 million or more or
adversely affect in a material way the economy, a sector of the
economy, productivity, competition, jobs, the environment, public
health or safety, or State, local, or Tribal governments or communities;
(2) Create a serious inconsistency or otherwise interfere with an
action taken or planned by another agency;
(3) Materially alter the budgetary impacts of entitlements, grants,
user fees, or loan programs or the rights and obligations of recipients
thereof; or
(4) Raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.
Pursuant to the terms of Executive Order 12866, it has been
determined that this rule is a ``significant regulatory action,'' thus
EPA has submitted this rule to OMB for review. The drafts of the rules
submitted to OMB, the documents accompanying such drafts, written
comments thereon, written responses by EPA, and identification of the
changes made in response to OMB suggestions or recommendations are
available for public inspection at EPA's Air and Radiation Docket and
Information Center (Docket Number OAR-2002-0076). The EPA has prepared
the document entitled ``Regulatory Impact Analysis of the Proposed
Guidelines for Best Available Retrofit Technology Determinations Under
the Regional Haze Regulations' (RIA) to address the requirements of
this executive order.
The RIA presents estimates of the health and welfare benefits and
the estimated costs of the BART reproposal in 2015 and the estimated
benefits and costs of the recently signed IAQR proposal (69 FR 4566,
January 30, 2004). Reviewing these results, it is important to
recognize that the BART and IAQR proposals are likely to be overlapping
actions that address many of the same power plants. However, IAQR as
proposed will affect a 29 State and the District of Columbia region in
the eastern U.S., and the BART rule is applicable nationwide. In the
proposed IAQR, we requested comment on whether compliance with the IAQR
by affected EGUs in affected States would satisfy, for those sources,
the BART requirements of the CAA, provided that a State imposes the
full amount of SO₂ and NO_X emissions reductions
on EGUs that the IAQR deemed highly cost effective. We are in the
process of evaluating those comments. Based on our current evaluation,
we believe the IAQR, as proposed, is clearly better than BART for those
affected EGUs in the affected States which we propose to cover under
the IAQR. We thus expect that the final IAQR would satisfy the BART
requirements for affected EGUs that are covered pursuant to the final
IAQR. EPA projects that both of these rules are likely to achieve
significant health and welfare benefits. The BART analysis presented
here is limited to the electric utility sector because of limitations
in the data currently available on non-EGU sources. It is also
important to note that States will make the ultimate decisions as to
how the BART requirements are implemented.

[[Page 25205]]

Thus, the analysis results reported reflect the EPA's best estimate of
the benefits and costs of this State determined process.
Significant health and welfare benefits are likely to occur as a
result of this rule. Based upon EPA estimates, thousands of premature
deaths and other serious health effects would be prevented each year.
The EPA estimates monetized annual benefits of approximately $44
billion (assuming a 7 percent discount rate) or $47 billion (assuming a
3 percent discount rate) in 2015 (1999$). Table IV-1 presents the
primary estimates of reduced incidence of PM health effects for 2015
for the source-specific BART proposal and the IAQR proposed rule.
Specifically, the table lists the PM-related benefits associated with
the reduction of ambient PM.
In interpreting the results, it is important to keep in mind the
limited set of effects we are able to monetize. Thus, the benefits
reported for this rule are understated due to the omissions listed in
Table II-4.
Nonetheless, the benefits quantified and monetized are substantial
both in incidence and dollar value. In 2015, we estimate that reduction
in exposure to PM_2.5 from the BART rule will result in
approximately 7,400 fewer premature deaths annually associated with
PM_2.5, as well as 3,900 fewer cases of chronic bronchitis,
9,800 fewer nonfatal heart attacks (acute myocardial infarctions),
6,000 fewer hospitalizations (for respiratory and cardiovascular
disease combined), and significant reductions in days of restricted
activity due to respiratory illness (with an estimate of 4.4 million
fewer cases). We also estimate substantial health improvements for
children from reductions in upper and lower respiratory illnesses,
acute bronchitis, and asthma attacks.
Table IV-2 presents the estimated monetary value of reductions in
the incidence of health and welfare effects. PM-related health benefits
are estimated to be approximately $43 billion (assuming a 7 percent
discount rate) or $46 billion (assuming a 3 percent discount rate) in
2015. Estimated annual visibility benefits in the U.S. brought about by
the BART rule due to visibility improvements in federal Class I areas
in the Southeast, Southwest, and California are estimated to be
approximately $940 million in 2015. All monetized estimated values are
stated in 1999$. Table IV-2 shows the total annual monetized benefits
for the year 2015. This table also indicates with a ``B'' those
additional health and environmental effects that we were unable to
quantify or monetize. These effects are additive to the estimate of
total benefits, and the EPA believes there is considerable value to the
public of the benefits that could not be monetized.

Table IV-1.--Estimated Reductions in Incidence of Health Effects of the BART Rule
[In 2015]
----------------------------------------------------------------------------------------------------------------
Endpoint Constituent BART IAQR proposal
----------------------------------------------------------------------------------------------------------------
Premature Mortality--adult................... PM2.5 7,400 13,000
Mortality-infant............................. PM2.5 17 29
Chronic bronchitis........................... PM2.5 3,900 6,900
Acute myocardial infarction--total........... PM2.5 9,800 18,000
Hospital admissions--respiratory............. PM2.5 3,200 *8,100
Hospital admissions--cardiovascular.......... PM2.5 2,800 5,000
Emergency room visits, respiratory........... PM2.5 5,300 9,400*
Acute bronchitis............................. PM2.5 9,000 16,000
Lower respiratory symptoms................... PM2.5 110,000 190,000
Upper respiratory symptoms................... PM2.5 350,000 620,000
Asthma exacerbation.......................... PM2.5 150,000 240,000
Acute respiratory symptoms (MRADs)........... PM2.5 4,400,000 8,500,000\*\
Work loss days............................... PM2.5 740,000 1,300,000
School loss days............................. O\3\ \**\ 390,000
----------------------------------------------------------------------------------------------------------------
MRADs = minor restricted activity days.
*Includes estimates for ozone health effects. Although ozone health benefits occur with the BART proposal, ozone
health effects are not estimated.
** School loss days are not estimated for BART.

A listing of the benefit categories that could not be quantified or
monetized in our estimate is provided in Table IV-3. Major benefits not
quantified for this proposed rule include ozone health benefits, the
value of increases in yields of agricultural crops and commercial
forests, the value of improvements in visibility in places where people
live and work and recreational areas outside of federal Class I areas,
and the value of reductions in nitrogen and acid deposition and the
resulting changes in ecosystem functions.
In summary, EPA's primary estimate of the annual benefits of the
rule is approximately $44 + B billion (assuming a 7% discount rate) or
$47 + B billion (assuming a 3 percent discount rate) in 2015. These
estimates account for growth in the willingness to pay for reductions
in environmental health risks due to growth in real gross domestic
product (GDP) per capita between the present and 2015.

Table IV-2.--Results of Human Health and Welfare Benefits Valuation for the Proposed BART Rule
[Millions of 1999 dollars]
a b
----------------------------------------------------------------------------------------------------------------
Endpoint BART IAQR Proposalf
----------------------------------------------------------------------------------------------------------------
Premature mortality c
Long-term exposure, (adults, >30yrs)
3% discount rate.................................................. $43,000 $77,000
7% discount rate.................................................. 40,000 72,000

[[Page 25206]]

Long-term exposure (child, < 1 yr).................................... 100 180
Chronic bronchitis (adults, 26 and over).................................. 1,500 2,700
Non-fatal myocardial infarctions
3% discount rate...................................................... 810 1,500
7% discount rate...................................................... 790 1,400
Hospital Admissions from Respiratory Causes............................... 55 e130
Hospital Admissions from Cardiovascular Causes............................ 59 110
Emergency Room Visits for Asthma.......................................... 1.5 e 2.6
Acute bronchitis (children, 8-12)......................................... 3.3 5.7
Lower respiratory symptoms (children, 7-14)............................... 1.7 3.0
Upper respiratory symptoms (asthmatic children, 9-11)..................... 16 17
Asthma exacerbations...................................................... 5.8 10
Work loss days (adults, 18-65)............................................ 97 170
Minor restricted activity days (adults, age 18-65)........................ 230 e 440
School absence days (children, age 6-11).................................. (e) 28
Worker productivity (outdoor workers, age 18-65).......................... (e) 17
Recreational visibility (SE, SW, and CA Class I areas).................... 940 1,400
Monetized Total d.........................................................
Base estimate
3% discount rate.................................................. 47,000 + B e 84,000
7% discount rate.................................................. 44,000 + B e 79,000
----------------------------------------------------------------------------------------------------------------
\a\ Monetary benefits are rounded to two significant digits.
\b\ Monetary benefits are adjusted to account for growth in real GDP per capita between 1990 and the analysis
year (2015).
\c\ Valuation assumes the 5 year distributed lag structure described earlier. Results reflect the use of two
different discount rates; a 3 percent rate that is recommended by EPA's Guidelines for Preparing Economic
Analyses (U.S. EPA, 2000b) and OMB's Circular A-4 (OMB, 2003) and 7 percent which is also recommended by OMB's
Circular A-4 (OMB, 2003).
\d\ B represents the monetary value of the nonmonetized health and welfare benefits. A detailed listing of
unquantified PM, ozone, and mercury related health effects is provided in Table IV-4.
\e\ Results presented for the IAQR proposal include benefits associated with modeled ozone reductions. Ozone-
related benefits are not generated for BART.
\f\ The estimated benefits for the IAQR proposal are based upon a control scenario for EGU sources only in the
29 State + DC proposed IAQR region.

Costs of the Proposed BART Rule
EPA modeled the costs and economic impacts to the EGU sector
anticipated to result from the source-specific BART requirements.
Modeling assumptions for the SO₂ affected units included the
choice of meeting a 0.1 lbs/mmBtu emission rate or achieving 90 percent
reductions from base case emissions. Affected units were also required
to meet a 0.2 lbs/mmBtu emission rate limit for NO_X. In the
model, EPA required controls only on BART-eligible units, a subset
representing 179 GW out of about 305 GW total coal-fired U.S.
generation. BART-eligible units were defined as units greater than 250
MW that were online after August 7, 1962 and under construction prior
to August 7, 1977. No additional necessary controls were assumed for
any units within the five WRAP 309 States of UT, AZ, WY, OR or NM that
have existing agreements to achieve reduction goals. Also, because of
modeling limitations, no additional reductions were assumed from units
with existing scrubbers, even if they were performing at less than 90
percent removal. This assumption, the assumption of 90 percent removal
rather than the proposed 95 percent removal rate, and an analysis that
focuses on EGU sources only, are limitations of the analysis that would
tend to understate the estimated costs, emission reductions, and
benefits of the rule.
Based upon the foregoing modeling assumptions, the EPA estimates
the annual costs of the BART rule to be $3.9 billion in 2015 (1999
dollars). The costs are estimated using a discount rate that
approximates the cost of capital for firms in the EGU industry and
ranges from 5.34 to 6.74 percent.
Benefit-Cost Comparison
The estimated annual social benefits of the BART rule are compared
to the annual estimated cost to implement the proposed rule in Table IV-3.

Table IV-3.--Summary of Annual Benefits, Costs, and Net Benefits of the
BART Rule in 2015
[Billions of 1999 dollars]
------------------------------------------------------------------------
IAQR
Description BART proposal
e
------------------------------------------------------------------------
Social costs a...................................... $3.9 $3.7
Social benefits b c................................. 47+B 84+B
Ozone-related benefits.............................. f f 0.1
PM-related health benefits.......................... 46 82.3
Visibility benefits................................. 0.9 1.4
Net benefits (benefits-costs) a b c d............... 43+B 80+B
Net benefits (benefits-costs) a c d g............... 40+B 75+B
------------------------------------------------------------------------
\a\ Note that costs are the annual total costs of reducing pollutants
including NOX and SO2. Costs of the rules are estimated using the
Integrated Planning Model (IPM) assuming discount rates that
approximate the cost of capital for firms operating EGUs ranging from
5.34 to 6.74 percent.
\b\ As the table indicates, total benefits are driven primarily by PM-
related health benefits. Benefits in this table are associated with
NOX and SO2 reductions. Benefits presented assume a 3% discount rate
for monetization.
\c\ Not all possible benefits or disbenefits are quantified and
monetized in this analysis. B is the sum of all unquantified benefits
and disbenefits. Potential benefit categories that have not been
quantified and monetized are listed in Table IV-4.

[[Page 25207]]

\d\ Net benefits are rounded to the nearest billion. Columnar totals may
not sum due to rounding.
\e\ The estimated IAQR proposal benefits and costs relate to a control
strategy for EGU sources only in the 29 + DC State IAQR proposed region.
\f\ Ozone health benefits will result from the BART rule and IAQR
proposal, but monetary benefits are estimated for the IAQR proposal only.
\g\ Benefits presented assume a 7% discount rate for monetization.

EPA estimates the costs of implementing the rule at $3.9 billion in
2015. Thus, the annual quantified net benefits (social benefits minus
social costs) of the program in 2015 are approximately $40 + B billion
(assuming a 7 percent discount rate for benefits) or $43 + B billion
(assuming a 3 percent discount rate for benefits). Therefore,
implementation of the proposed rule is expected to provide society with
a net gain in social welfare based on economic efficiency criteria.
Every benefit-cost analysis examining the potential effects of a
change in environmental protection requirements is limited to some
extent by data gaps, limitations in model capabilities (such as
geographic coverage), and uncertainties in the underlying scientific
and economic studies used toconfigure the benefit and cost models.

Table IV-4.--Additional Nonmonetized Benefits of the BART Rule
------------------------------------------------------------------------
Pollutant Unquantified effects
------------------------------------------------------------------------
Ozone Health...................... Premature mortality a.
Increased airway responsiveness to
stimuli.
Inflammation in the lung.
Chronic respiratory damage.
Premature aging of the lungs.
Acute inflammation and respiratory
cell damage.
Increased susceptibility to
respiratory infection.
Non-asthma respiratory emergency
room visits.
Ozone Welfare..................... Decreased yields for commercial
forests.
Decreased yields for fruits and
vegetables.
Decreased yields for commercial and
non-commercial crops.
Damage to urban ornamental plants.
Impacts on recreational demand from
damaged forest aesthetics.
Damage to ecosystem functions.
PM Health......................... Low birth weight.
Changes in pulmonary function.
Chronic respiratory diseases other
than chronic bronchitis.
Morphological changes.
Altered host defense mechanisms.
Non-asthma respiratory emergency
room visits.
PM Welfare........................ Visibility in many Class I areas.
Residential and recreational
visibility in non-Class I areas.
Soiling and materials damage.
Damage to ecosystem functions.
Nitrogen and Sulfate Deposition Impacts of acidic sulfate and
Welfare. nitrate deposition on commercial
forests.
Impacts of acidic deposition to
commercial freshwater fishing.
Impacts of acidic deposition to
recreation in terrestrial
ecosystems.
Reduced existence values for
currently healthy ecosystems.
Impacts of nitrogen deposition on
commercial fishing, agriculture,
and forests.
Impacts of nitrogen deposition on
recreation in estuarine ecosystems.
Damage to ecosystem functions.
Mercury Health.................... Neurological disorders.
Learning disabilities.
Developmental delays.
Potential cardiovascular effects *.
Altered blood pressure regulation *.
Increased heart rate variability *.
Myocardial infarction *.
Potential reproductive effects *.
Mercury Deposition Welfare........ Impact on birds and mammals (e.g.,
reproductive effects).
Impacts to commercial, subsistence,
and recreational fishing.
Reduced existence values for
currently healthy ecosystems.
------------------------------------------------------------------------
a Premature mortality associated with ozone is not separately included
in this analysis.
* These are potential effects as the literature is either contradictory
or incomplete.

Deficiencies in the scientific literature often result in the inability
to estimate quantitative changes in health and environmental effects,
such as potential increases in fish populations due to reductions in
nitrogen loadings in sensitive estuaries. Deficiencies in the economics
literature often result in the inability to assign economic values even
to those health and environmental outcomes that can be quantified.
Although these general uncertainties in the underlying scientific and
economics literatures (that can cause the valuations to be higher or
lower) are discussed in detail in the economic analyses and its
supporting documents and references, the key uncertainties that have a
bearing on the results of the benefit-cost analysis of this proposed
rule include the following:
? The exclusion of potentially significant benefit
categories (such as health and ecological benefits of ozone),
? Errors in measurement and projection for variables such as
population growth and baseline incidence rates,

[[Page 25208]]

? Uncertainties in the estimation of future-year emissions
inventories and air quality,
? Variability in the estimated relationships of health and
welfare effects to changes in pollutant concentrations,
? Uncertainties in exposure estimation,
? Uncertainties in the size of the effect estimates linking
air pollution and health endpoints,
? Uncertainties about relative toxicity of different
components within the complex mixture,
? Uncertainties in quantifying visibility benefits, and
? Uncertainties associated with the effect of potential
future actions to limit emissions.

Despite these uncertainties, we believe the benefit-cost analysis
provides a reasonable indication of the expected economic benefits and
costs of the proposed rulemaking in future years under a set of
reasonable assumptions.
In addition, in valuing reductions in premature fatalities
associated with PM, we used a value of $5.5 million per statistical
life. This represents a central value consistent with a range of values
from $1 to $10 million suggested by recent meta-analyses of the wage-
risk value of statistical life (VSL) literature.\50\
---------------------------------------------------------------------------

\50\ Mrozek, J.R. and L.O. Taylor, What determines the value of
a life? A Meta Analysis, Journal of Policy Analysis and Management
21 (2), pp. 253-270.
---------------------------------------------------------------------------

The benefits estimates generated for the proposed BART rule are
subject to a number of assumptions and uncertainties, that are
discussed throughout the RIA document. As Table IV-2 indicates, total
benefits are driven primarily by the reduction in premature fatalities
each year, that account for a significant portion of total benefits.
For example, key assumptions underlying the primary estimate for the
premature mortality category include the following:
(1) Inhalation of fine particles is causally associated with
premature death at concentrations near those experienced by most
Americans on a daily basis. Although biological mechanisms for this
effect have not yet been definitively established, the weight of the
available epidemiological evidence supports an assumption of causality.
(2) All fine particles, regardless of their chemical composition,
are equally potent in causing premature mortality. This is an important
assumption, because PM produced via transported precursors emitted from
EGUs may differ significantly from direct PM released from automotive
engines and other industrial sources, but no clear scientific grounds
exist for supporting differential effects estimates by particle type.
(3) The C-R function for fine particles is approximately linear
within the range of ambient concentrations under consideration. Thus,
the estimates include health benefits from reducing fine particles in
areas with varied concentrations of PM, including both regions that are
in attainment with fine particle standard and those that do not meet
the standard.
Although recognizing the difficulties, assumptions, and inherent
uncertainties in the overall enterprise, these analyses are based on
peer-reviewed scientific literature and up-to-date assessment tools,
and we believe the results are highly useful in assessing this proposal.
We were unable to quantify or monetize a number of health and
environmental effects. A full appreciation of the overall economic
consequences of today's action requires consideration of all benefits
and costs expected to result from the proposed rule, not just those
benefits and costs that could be expressed here in dollar terms. A
listing of the benefit categories that could not be quantified or
monetized in our estimate is provided in Table IV-4. These effects are
denoted by ``B'' in Table IV-3 above and are additive to the estimates
of benefits.
The Regulatory Impact Analysis (RIA) supporting this proposal is
subject to OMB's new Circular A-4, Guidelines for the Conduct of
Regulatory Analysis. These guidelines set forth a number of analytical
requirements, most of which overlap with EPA's own Economic Guidelines.
Because of the consent decree deadline for proposing this rule, the
Agency has not yet completed all the analyses called for in EPA's and
OMB's guidelines. Thus, the Agency will be conducting additional
analytical work and including the results of this work in the public
docket. We will publish a notice of data availability (NODA) to advise
the public when these materials are available. In particular, the
Agency plans to conduct and make available the following analyses:
(1) Quantitative Analysis of Uncertainty. This rule will have
economic impacts (benefits plus costs) that total more than $1 billion
per year. Circular A-4 calls for a formal quantitative analysis of the
relevant uncertainties about benefits and costs for such rules.
(2) Cost-effectiveness analysis. In addition to the benefit-cost
analysis, EPA will conduct a cost-effectiveness analysis because the
primary benefits of this rule are improved public health.
(3) Analysis of all regulated entities. Because the Agency already
has extensive data about electric generating units, the current RIA
includes a detailed analysis of the power sector. The Agency intends to
gather additional data about BART-eligible sources in other sectors and
conduct a more complete analysis of the costs, benefits, and cost-
effectiveness of controls on non-EGU sources covered by the rule.
(4) Options and incremental analysis. The proposed rule identifies
the proposed IAQR as an additional regulation that will likely affect
the number of EGUs that will be covered by this rule. We currently
believe that the IAQR, as proposed, is ``better than BART'' for those
affected EGUs in the affected States that we propose to cover under the
IAQR. We thus expect that the final IAQR would satisfy this rule for
affected EGUs that are covered pursuant to the final IAQR. EPA intends
to assess the incremental costs and benefits of this rule, assuming
that the IAQR, as proposed, is in place.

B. Paperwork Reduction Act

Today's proposal clarifies but does not modify the information
collection requirements for BART. Therefore, this action does not
impose any new information collection burden. However, the OMB has
previously approved the information collection requirements contained
in the existing regulations [40 CFR Part 51]
under the provisions of
the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. and has assigned
OMB control number 2060-0421, EPA ICR number 1813.04. A copy of the OMB
approved Information Collection Request (ICR) may be obtained from
Susan Auby, Collection Strategies Division; U.S. Environmental
Protection Agency (2822T); 1200 Pennsylvania Ave., NW., Washington, DC
20460 or by calling (202) 566-1672.
Burden means the total time, effort, or financial resources
expended by persons to generate, maintain, retain, or disclose or
provide information to or for a Federal agency. This includes the time
needed to review instructions; develop, acquire, install, and utilize
technology and systems for the purposes of collecting, validating, and
verifying information, processing and maintaining information, and
disclosing and providing information; adjust the existing ways to
comply with any previously applicable instructions and requirements;
train personnel to be able to respond to a collection of information;
search data sources; complete and review the collection of

[[Page 25209]]

information; and transmit or otherwise disclose the information.
An agency may not conduct or sponsor, and a person is not required
to respond to a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for EPA's
regulations in 40 CFR are listed in 40 CFR part 9.

C. Regulatory Flexibility Act

The Regulatory Flexibility Act (RFA) generally requires an agency
to prepare a regulatory flexibility analysis of any rule subject to
notice and comment rulemaking requirements under the Administrative
Procedure Act or any other statute unless the agency certifies that the
rule will not have a significant economic impact on a substantial
number of small entities. Small entities include small businesses,
small organizations, and small governmental jurisdictions.
For purposes of assessing the impacts of today's proposed rule on
small entities, small entity is defined as: (1) A small business as
defined by the Small Business Administrations' regulations at 13 CFR
121.201; (2) a small governmental jurisdiction that is a government of
a city, county, town, school district or special district with a
population of less than 50,000; and (3) a small organization that is
any not-for-profit enterprise which is independently owned and operated
and is not dominant in its field.
In the July 1, 1999 regional haze rule (64 FR 35760) and in the
July 20, 2001 BART guidelines proposal (66 FR 38110) the EPA determined
that it was not necessary to prepare a regulatory flexibility analysis
in connection with either action. The EPA also determined that the 1999
regional haze rule and the 2001 BART guidelines proposal would not have
a significant economic impact on a substantial number of small entities
because neither would establish requirements applicable to small
entities. After considering the economic impacts of today's proposed
rule on small entities, we certify that this action, proposing new
regulations to address the BART requirements remanded by the D.C.
Circuit and reproposing the 2001 BART guidelines proposal, will not
have a significant economic impact on a substantial number of small
entities.
The Regulatory Flexibility Act (5 U.S.C. 601 et seq.), as amended
by the Small Business Regulatory Enforcement Fairness Act (Public Law
104-121) (SBREFA), provides that whenever an agency is required to
publish a general notice of proposed rulemaking, it must prepare and
make available an initial regulatory flexibility analysis, unless it
certifies that the rule, if promulgated, will not have ``a significant
economic impact on a substantial number of small entities.'' 5 U.S.C.
605(b). Courts have interpreted the RFA to require a regulatory
flexibility analysis only when small entities will be subject to the
requirements of the rule. See Motor and Equip. Mfrs. Ass'n v. Nichols,
142 F. 3d 449 (D.C. Cir., 1998); United Distribution Cos. v. FERC, 88
F. 3d 1105, 1170 (D.C. Cir., 1996); Mid-Tex Elec. Co-op, Inc. v. FERC,
773 F . 2d 327, 342 (D.C. Cir., 1985) (agency's certification need only
consider the rule's impact on entities subject to the rule).
Similar to the discussion in the proposed and final regional haze
rules, today's reproposal of the BART rules and guidelines would not
establish requirements applicable to small entities. The proposed rule
would apply to States, not to small entities. The BART requirements in
the regional haze rule require BART determinations for a select list of
major stationary sources defined by section 169A(g)(7) of the CAA.
However, as noted in the proposed and final regional haze rules, the
State's determination of BART for regional haze involves some State
discretion in considering a number of factors set forth in section
169A(g)(2), including the costs of compliance. Further, the final
regional haze rule allows States to adopt alternative measures in lieu
of requiring the installation and operation of BART at these major
stationary sources. As a result, the potential consequences of the BART
provisions of the regional haze rule (as clarified in today's
reproposal of the BART guidelines) at specific sources are speculative.
Any requirements for BART will be established by State rulemakings. The
States would accordingly exercise substantial intervening discretion in
implementing the BART requirements of the regional haze rule and
today's proposed guidelines. In addition, we note that most sources
potentially affected by the BART requirements in section 169A of the
CAA are large industrial plants. Of these, we would expect few, if any,
to be considered small entities. We request comment on issues regarding
small entities that States might encounter when implementing the BART
provisions.
Although not required, a small business impact analysis was
conducted for entities owning potentially affected BART-eligible EGUs.
We found that 66 entities (companies or governments) currently own the
EGU units subject to BART. Of these 66 entities, only two are
considered small. One of the entities is a small government and the
other an investor-owned company. The BART rule is not anticipated to
have an impact on the government entity. The small business may
experience a cost-to-sales impact of approximately 4 percent.

D. Unfunded Mandates Reform Act

Title II of the Unfunded Mandates Reform Act of 1995 (Public Law
104-4) establishes requirements for Federal agencies to assess the
effects of their regulatory actions on State, local, and Tribal
governments and the private sector. Under section 202 of UMRA, 2 U.S.C.
1532, EPA generally must prepare a written statement, including a cost-
benefit analysis, for any proposed or final rule that ``includes any
Federal mandate that may result in the expenditure by State, local, and
tribal governments, in the aggregate, or by the private sector, of
$100,000,000 or more * * * in any one year.'' A ``Federal mandate'' is
defined under section 421(6), 2 U.S.C. 658(6), to include a ``Federal
intergovernmental mandate.'' A ``Federal intergovernmental mandate,''
in turn, is defined to include a regulation that ``would impose an
enforceable duty upon State, local, or tribal governments,'' section
421(5)(A)(I), 2 U.S.C. 658(5)(A)(I). A ``Federal private sector
mandate'' includes a regulation that ``would impose an enforceable duty
upon the private sector,'' with certain exceptions, section 421(7)(A),
2 U.S.C. 658(7)(A).
Before promulgating an EPA rule for which a written statement is
needed under section 202 of UMRA, section 205, 2 U.S.C. 1535, of UMRA
generally requires EPA to identify and consider a reasonable number of
regulatory alternatives and adopt the least costly, most cost
effective, or least burdensome alternative that achieves the objectives
of the rule.
The RIA prepared by EPA and placed in the docket for this
rulemaking is consistent with the requirements of section 202 of the
UMRA. Furthermore, EPA is not directly establishing any regulatory
requirements that may significantly or uniquely affect small
governments, including tribal governments. Thus, EPA is not obligated
to develop under section 203 of the UMRA a small government agency
plan. Further, EPA carried out consultations with the governmental
entities affected by this rule in a manner consistent with the
intergovernmental consultation provisions of section 204 of the UMRA.
The EPA also believes that today's proposal meets the UMRA
requirement in section 205 to select the least costly and burdensome
alternative in light of

[[Page 25210]]

the statutory mandate for BART. As explained above, we are proposing
the BART rule and guideline following the D.C. Circuit's remand of the
BART provisions in the 1999 regional haze rule. The 1999 regional haze
rule provides substantial flexibility to the States, allowing them to
adopt alternative measures such as a trading program in lieu of
requiring the installation and operation of BART. Today's reproposal
does not restrict the ability of the States to adopt such alternatives
measures. The regional haze rule accordingly already provides an
alternative to BART that gives States the ability to chose the least
costly and least burdensome alternative.
The EPA is not reaching a final conclusion as to the applicability
of UMRA to today's rulemaking action. The reasons for this are
discussed in the 1999 regional haze rule (64 FR 35762) and in the 2001
BART guidelines proposal (66 FR 38111-38112). Notwithstanding this, the
discussion in chapter 8 of the RIA constitutes the UMRA statement that
would be required by UMRA if its statutory provisions applied.
Consequently, we continue to believe that it is not necessary to reach
a conclusion as to the applicability of the UMRA requirements.

E. Executive Order 13132: Federalism

Executive Order 13132, entitled Federalism (64 FR 43255, August 10,
1999), requires EPA to develop an accountable process to ensure
``meaningful and timely input by State and local officials in the
development of regulatory policies that have federalism implications'
are defined in the Executive Order to include regulations that have
``substantial direct effects on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government.'' Under
Section 6 of Executive Order 13132, EPA may not issue a regulation that
has federalism implications, that imposes substantial direct compliance
costs, and that is not required by statute, unless the Federal
government provides the funds necessary to pay the direct compliance
costs incurred by State and local governments, or EPA consults with
State and local officials early in the process of developing the
proposed regulation. The EPA also may not issue a regulation that has
federalism implications and that preempts State law unless EPA consults
with State and local officials early in the process of developing the
proposed regulation.
We have concluded that today's action, reproposing the BART
guidelines, will not have federalism implications, as specified in
section 6 of the Executive Order 13132 (64 FR 43255, August 10, 1999),
because it will not have substantial direct effects on the States, nor
substantially alter the relationship or the distribution of power and
responsibilities between the States and the Federal government.
Nonetheless, we consulted with a wide scope of State and local
officials, including the National Governors Association, National
League of Cities, National Conference of State Legislatures, U. S.
Conference of Mayors, National Association of Counties, Council of
State Governments, International City/County Management Association,
and National Association of Towns and Townships, during the course of
developing this rule.

F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments

Executive Order 13175, entitled ``Consultation and Coordination
with Indian Tribal Governments'' (59 FR 22951, November 9, 2000),
requires EPA to develop an accountable process to ensure ``meaningful
and timely input by Tribal officials in the development of regulatory
policies that have Tribal implications.''
This proposed rule does not have Tribal implications as defined by
Executive Order 13175. It does not have a substantial direct effect on
one or more Indian Tribes. Furthermore, this proposed rule does not
affect the relationship or distribution of power and responsibilities
between the Federal government and Indian Tribes. The CAA and the TAR
establish the relationship of the Federal government and Tribes in
developing plans to attain the NAAQS, and this proposed rule does
nothing to modify that relationship. Because this proposed rule does
not have Tribal implications, Executive Order 13175 does not apply.

G. Executive Order 13045: Protection of Children From Environmental
Health and Safety Risks

Executive Order 13045, ``Protection of Children from Environmental
Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997) applies
to any rule that (1) is determined to be ``economically significant''
as defined under Executive Order 12866, and (2) concerns an
environmental health or safety risk that EPA has reason to believe may
have a disproportionate effect on children. If the regulatory action
meets both criteria, Section 5-501 of the Order directs the Agency to
evaluate the environmental health or safety effects of the planned rule
on children, and explain why the planned regulation is preferable to
other potentially effective and reasonably feasible alternatives
considered by the Agency.
The BART proposed rule and guideline are not subject to the
Executive Order because it does not involve decisions on environmental
health or safety risks that may disproportionately affect children. The
EPA believes that the emissions reductions from the strategies proposed
in this rulemaking will further improve air quality and will further
improve children's health.

H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use

We have conducted a Regulatory Impact Analysis for this reproposed
rule, that includes an analysis of energy impacts and is contained in
the docket (Docket No. OAR-2002-0076). According to Executive Order
13211, ``Actions Concerning Regulations That Significantly Affect
Energy Supply, Distribution, or Use'', this proposed rule is
significant because it has a greater than a 1 percent impact on the
cost of energy production. We are reproposing today's rule following
the D.C. Circuit's remand of the BART provisions in the 1999 regional
haze rule. The 1999 regional haze rule provides substantial flexibility
to the States, allowing them to adopt alternative measures such as a
trading program in lieu of requiring the installation and operation of
BART. This rulemaking does not restrict the ability of the States to
adopt alternative measures. The regional haze rule accordingly already
provides an alternative to BART that reduces the overall cost of the
regulation and its impact on the energy supply. The BART proposal
itself offers flexibility by offering the choice of meeting
SO₂ requirements between an emission rate and a removal rate.
For a State that chooses to require case-by-case BART, today's rule
would establish default levels of controls for SO₂ and
NO_X for EGUs that the State finds are subject to BART. Based
on its consideration of various factors set forth in the regulations,
however, a State may conclude that a different level of control is
appropriate. The States will accordingly exercise substantial
intervening discretion in implementing the final rule. Additionally, we
have assessed that the proposed compliance dates will provide adequate
time for EGUs to install the required emission controls.

[[Page 25211]]

I. National Technology Transfer and Advancement Act

Section 12(d) of the National Technology Transfer Advancement Act
of 1995 (NTTAA), Public Law No. 104-113, Sec. 12(d)(15 U.S.C. 272
note) directs EPA to use voluntary consensus standards (VCS) in its
regulatory activities unless to do so would be inconsistent with
applicable law or otherwise impractical. Voluntary consensus standards
are technical standards (e.g., materials specifications, test methods,
sampling procedures, and business practices) that are developed or
adopted by VCS bodies. The NTTAA directs EPA to provide Congress,
through OMB, explanations when the EPA decides not to use VCS.
This action does not involve technical standards; thus, EPA did not
consider the use of any VCS.

J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations

Executive Order 12898, ``Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations,'' requires
federal agencies to consider the impact of programs, policies, and
activities on minority populations and low-income populations.
According to EPA guidance \51\, agencies are to assess whether minority
or low-income populations face risks or a rate of exposure to hazards
that are significant and that ``appreciably exceed or is likely to
appreciably exceed the risk or rate to the general population or to the
appropriate comparison group.'' (EPA, 1998)
---------------------------------------------------------------------------

\51\ U.S. Environmental Protection Agency, 1998. Guidance for
Incorporating Environmental Justice Concerns in EPA's NEPA
Compliance Analyses. Office of Federal Activities, Washington, DC,
April, 1998.
---------------------------------------------------------------------------

In accordance with E.O. 12898, the Agency has considered whether
this proposed rule may have disproportionate negative impacts on
minority or low income populations. Because the Agency expects this
proposed rule to lead to reductions in pollutant loadings and exposures
generally, negative impacts to these sub-populations that appreciably
exceed similar impacts to the general population are not expected.

List of Subjects in 40 CFR Part 51

Environmental protection, Administrative practice and procedure,
Air pollution control, Carbon monoxide, Nitrogen dioxide, Particulate
matter, Sulfur oxides, Volatile organic compounds.

Dated: April 15, 2004.
Michael O. Leavitt,
Administrator.

For the reasons set forth in the preamble, part 51 of chapter I of
title 40 of the Code of Federal Regulations is proposed to be amended
as follows:

PART 51--REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF
IMPLEMENTATION PLANS

1. The authority citation for part 51 continues to read as follows:

Authority: 23 U.S.C. 101; 42 U.S.C. 7410-7671q.

2. Section 51.302 is amended by revising paragraph (c)(4)(iii) to
read as follows:

Sec. 51.302 Implementation control strategies for reasonably
attributable visibility impairment.

* * * * *
(c) * * *
(4) * * *
(iii) BART must be determined for fossil-fuel fired generating
plants having a total generating capacity in excess of 750 megawatts
pursuant to ``Guidelines for Determining Best Available Retrofit
Technology for Coal-fired Power Plants and Other Existing Stationary
Facilities'' (1980), which is incorporated by reference, exclusive of
appendix E, which was published in the Federal Register on February 6,
1980 (45 FR 8210), except that options more stringent than NSPS must be
considered. Establishing a BART emission limitation equivalent to the
NSPS level of control is not a sufficient basis to avoid the detailed
analysis of control options required by the guidelines. It is EPA
publication No. 450/3-80-009b and is for sale from the U.S. Department
of Commerce, National Technical Information Service, 5285 Port Royal
Road, Springfield, Virginia 22161.
* * * * *
3. Section 51.308 is amended by revising paragraphs (b), (c), and
(e)(1)(ii) to read as follows:

Sec. 51.308 Regional haze program requirements.

* * * * *
(b) When are the first implementation plans due under the regional
haze program? Except as provided in Sec. 51.309(c), each State
identified in Sec. 51.300(b)(3) must submit, for the entire State, an
implementation plan for regional haze meeting the requirements of
paragraphs (d) and (e) of this section no later than 3 years after the
date on which the Administrator promulgates for the State the
designation for the PM_2.5 National Ambient Air Quality
Standard at 40 CFR Part 81.
(c) In no event may the State's regional haze implementation plan
be submitted later than January 31, 2008.
* * * * *
(e) * * *
(1) * * *
(ii) A determination of BART for each BART-eligible source in the
State that emits any air pollutant which may reasonably be anticipated
to cause or contribute to any impairment of visibility in any mandatory
Class I Federal area. All such sources are subject to BART.
(A) The determination of BART must be based on an analysis of the
best system of continuous emission control technology available and
associated emission reductions achievable for each BART-eligible source
that is subject to BART within the State. In this analysis, the State
must take into consideration the technology available, the costs of
compliance, the energy and nonair quality environmental impacts of
compliance, any pollution control equipment in use at the source, the
remaining useful life of the source, and the degree of improvement in
visibility which may reasonably be anticipated to result from the use
of such technology.
(B) Appendix Y of this part provides guidelines for conducting the
analyses under paragraphs (e)(1)(ii) and (e)(1)(ii)(A) of this section.
All BART determinations that are required in paragraph (e)(1) of this
section must be made pursuant to the guidelines in appendix Y of this part.
* * * * *
4. Section 51.309 is amended by revising paragraphs (d)(4)(v),
(g)(2), and (g)(3) to read as follows:

Sec. 51.309 Requirements Related to the Grand Canyon Visibility
Transport Commission

* * * * *
(d) * * *
(4) * * *
(v) Provisions for stationary source NO_X and PM. The
plan submission must include a report which assesses emissions control
strategies for stationary source NO_X and PM, and the degree
of visibility improvement that would result from such strategies. In
the report, the State must evaluate and discuss the need to establish
emission milestones for NO_X and PM to avoid any net increase
in these pollutants from stationary sources within the transport
region, and to support potential future development and implementation
of a multipollutant and possibly multisource market-based program. The
plan

[[Page 25212]]

submission must provide for an implementation plan revision, containing
any necessary long-term strategies and BART requirements for stationary
source PM and NO_X (including enforceable limitations,
compliance schedules, and other measures) by no later than January 31, 2008.
* * * * *
(g) * * *
(2) In a plan submitted no later than January 31, 2008, provide a
demonstration of expected visibility conditions for the most impaired
and least impaired days at the additional mandatory Class I Federal
area(s) based on emissions projections from the long-term strategies in
the implementation plan. This demonstration may be based on assessments
conducted by the States and/or a regional planning body.
(3) In a plan submitted no later than January 31, 2008, provide
revisions to the plan submitted under (c) of this section, including
provisions to establish reasonable progress goals and implement any
additional measures necessary to demonstrate reasonable progress for
the additional mandatory Federal Class I areas. These revisions must
comply with the provisions of Sec. 51.308(d)(1)-(4).
* * * * *
5. Appendix Y to Part 51 to read is added to read as follows:

Appendix Y to Part 51--Guidelines for BART Determinations Under the
Regional Haze Rule

Table of Contents

I. Introduction and Overview
A. What is the purpose of the guidelines?
B. What does the CAA require generally for improving visibility?
C. What is the BART requirement in the CAA?
D. What types of visibility problems does EPA address in its
regulations?
E. What are the BART requirements in EPA's regional haze
regulations?
F. Do States have an alternative to requiring BART controls at
specific facilities?
G. What is included in the guidelines?
H. Who is the target audience for the guidelines?
J. Do EPA regulations require the use of these guidelines?
II. How to Identify BART-eligible Sources
A. What are the steps in identifying BART-eligible sources?
1. Step 1: Identify emission units in the BART categories
2. Step 2: Identify the start-up dates of the emission units
3. Step 3: Compare the potential emissions to the 250 ton/yr cutoff
4. Final step: Identify the emission units and pollutants that
constitute the BART-eligible source.
III. How to Identify Sources ``Subject to BART''
IV. The BART Determination: Analysis of BART Options
A. What factors must I address in the Engineering Analysis?
B. How does a BART engineering analysis compare to a BACT review
under the PSD program?
C. Which pollutants must I address in the engineering review?
D. How does a BART review relate to maximum achievable control
technology (MACT) standards under CAA section 112?
E. What are the five basic steps of a case-by-case BART
engineering analysis?
1. Step 1: How do I identify all available retrofit emission
control techniques?
2. Step 2: How do I determine whether the options identified in
Step 1 are technically feasible?
3. Step 3: How do I develop a ranking of the technically
feasible alternatives?
4. Step 4: For a BART engineering analysis, what impacts must I
calculate and report? What methods does EPA recommend for the
impacts analyses?
a. Impact analysis part 1: how do I estimate the costs of control?
b. How do I take into account a project's ``remaining useful
life'' in calculating control costs?
c. What do we mean by cost effectiveness?
d. How do I calculate average cost effectiveness?
e. How do I calculate baseline emissions?
f. How do I calculate incremental cost effectiveness?
g. What other information should I provide in the cost impacts
analysis?
h. Impact analysis part 2: How should I analyze and report
energy impacts?
i. Impact analysis part 3: How do I analyze ``non-air quality
environmental impacts?''
j. What are examples of non-air quality environmental impacts?
5. Step 5: How should I consider visibility impacts in the BART
determination?
F. How do I select the ``best'' alternative, using the results
of Steps 1 through 5?
1. Summary of the impacts analysis
2. Selecting a ``best'' alternative
3. In selecting a ``best'' alternative, should I consider the
affordability of controls?
4. SO₂ limits for utility boilers
5. NO_X limits for utility boilers
V. Enforceable Limits / Compliance Date
VI. Emission Trading Program Overview
A. What are the general steps in developing an emission trading
program?
B. What are emission budgets and allowances?
C. What criteria must be met in developing an emission trading
program as an alternative to BART?
1. How do I identify sources subject to BART?
2. How do I calculate the emissions reductions that would be
achieved if BART were installed and operated on these sources?
3. For a cap and trade program, how do I demonstrate that my
emission budget results in emission levels that are equivalent to or
less than the emissions levels that would result if BART were
installed and operated?
4. How do I ensure that trading budgets achieve ``greater
reasonable progress?'
5. How do I allocate emissions to sources?
6. What provisions must I include in developing a system for
tracking individual source emissions and allowances?
7. How would a regional haze trading program interface with the
requirements for ``reasonably attributable'' BART under Sec. 51.302
of the regional haze rule?

I. Introduction and Overview

A. What Is the Purpose of the Guidelines?

The Clean Air Act (CAA), in sections 169A and 169B, contains
requirements for the protection of visibility in 156 scenic areas
across the United States. To meet the CAA's requirements, we published
regulations to protect against a particular type of visibility
impairment known as ``regional haze.'' The regional haze rule is found
in this part (40 CFR part 51), in Sec. Sec. 51.300 through 51.309.
These regulations require, in Sec. 51.308(e), that certain types of
existing stationary sources of air pollutants install best available
retrofit technology (BART). The guidelines are designed to help States
and others (1) identify those sources that must comply with the BART
requirement, and (2) determine the level of control technology that
represents BART for each source.

B. What Does the CAA Require Generally for Improving Visibility?

Section 169A of the CAA, added to the CAA by the 1977 amendments,
requires States to protect and improve visibility in certain scenic
areas of national importance. The scenic areas protected by section
169A are called ``mandatory Class I Federal Areas.'' In these
guidelines, we refer to these as ``Class I areas.'' There are 156 Class
I areas, including 47 national parks (under the jurisdiction of the
Department of Interior--National Park Service), 108 wilderness areas
(under the jurisdiction of the Department of Interior--Fish and
Wildlife Service or the Department of Agriculture--U.S. Forest
Service), and one International Park (under the jurisdiction of the
Roosevelt-Campobello International Commission). The Federal Agency with
jurisdiction over a particular Class I area is referred to in the CAA
as the Federal Land Manager. A complete list of the Class I areas is
contained in 40 CFR part 81, Sec. Sec. 81.401 through 81.437, and you
can find a map of the Class I areas at the following internet site:

[[Page 25213]]

http://www.epa.gov/ttn/oarpg/t1/fr_notices/classimp.gif .
The CAA establishes a national goal of eliminating man-made
visibility impairment from all Class I areas. As part of the plan for
achieving this goal, the visibility protection provisions in the CAA
mandate that EPA issue regulations requiring that States adopt measures
in their State Implementation Plans (SIPs), including long-term
strategies, to provide for reasonable progress towards this national
goal. The CAA also requires States to coordinate with the Federal Land
Managers as they develop their strategies for addressing visibility.

C. What Is the BART Requirement in the CAA?

1. Under section 169A(b)(2)(A) of the CAA, States must require
certain existing stationary sources to install BART. The BART
requirement applies to ``major stationary sources'' from 26 identified
source categories which have the potential to emit 250 tons per year or
more of any air pollutant. The CAA requires only sources which were put
in place during a specific 15-year time interval to install BART. The
BART requirement applies to sources that existed as of the date of the
1977 CAA amendments (that is, August 7, 1977) but which had not been in
operation for more than 15 years (that is, not in operation as of
August 7, 1962).
2. The CAA requires BART when any source meeting the above
description ``emits any air pollutant which may reasonably be
anticipated to cause or contribute to any impairment of visibility'' in
any Class I area. In identifying a level of control as BART, States are
required by section 169A(g) of the CAA to consider:
(a) The costs of compliance,
(b) The energy and non-air quality environmental impacts of compliance,
(c) Any existing pollution control technology in use at the source,
(d) The remaining useful life of the source, and
(e) The degree of visibility improvement which may reasonably be
anticipated from the use of BART.
3. The CAA further requires States to make BART emission
limitations part of their SIPs. As with any SIP revision, States must
provide an opportunity for public comment on the BART determinations,
and EPA's action on any SIP revision will be subject to judicial review.

D. What Types of Visibility Problems Does EPA Address in Its Regulations?

1. We addressed the problem of visibility in two phases. In 1980,
we published regulations addressing what we termed ``reasonably
attributable'' visibility impairment. Reasonably attributable
visibility impairment is the result of emissions from one or a few
sources that are generally located in close proximity to a specific
Class I area. The regulations addressing reasonably attributable
visibility impairment are published in Sec. Sec. 51.300 through 51.307.
2. On July 1, 1999, we amended these regulations to address the
second, more common, type of visibility impairment known as ``regional
haze.'' Regional haze is the result of the collective contribution of
many sources over a broad region. The regional haze rule slightly
modified 40 CFR 51.300 through 51.307, including the addition of a few
definitions in Sec. 51.301, and added new Sec. Sec. 51.308 and 51.309.

E. What Are the BART Requirements in EPA's Regional Haze Regulations?

1. In the July 1, 1999 rulemaking, we added a BART requirement for
regional haze. You will find the BART requirements in 40 CFR 51.308(e).
Definitions of terms used in 40 CFR 51.308(e)(1) are found in Sec. 51.301.
2. As we discuss in detail in these guidelines, the regional haze
rule codifies and clarifies the BART provisions in the CAA. The rule
requires that States identify and list ``BART-eligible sources,'' that
is, that States identify and list those sources that fall within the 26
source categories, that were put in place during the 15-year window of
time from 1962 to 1977, and that have potential emissions greater than
250 tons per year. Once the State has identified the BART-eligible
sources, the next step is to identify those BART-eligible sources that
may ``emit any air pollutant which may reasonably be anticipated to
cause or contribute to any impairment of visibility.'' Under the rule,
a source which fits this description is ``subject to BART.'' For each
source subject to BART, States must identify the level of control
representing BART based upon the following factors:

--paragraph 308(e)(1)(ii)(A) provides that States must identify the
best system of continuous emission control technology for each source
subject to BART taking into account the technology available, the costs
of compliance, the energy and non-air quality environmental impacts of
compliance, any pollution control equipment in use at the source, the
remaining useful life of the source, and the degree of visibility
improvement that may be expected from available control technology.

3. After a State has identified the level of control representing
BART (if any), it must establish an emission limit representing BART
and must ensure compliance with that requirement no later than 5 years
after EPA approves the SIP. States may establish design, equipment,
work practice or other operational standards when limitations on
measurement technologies make emission standards infeasible.

F. Do States Have an Alternative To Requiring BART Controls at Specific
Facilities?

1. States are given the option under 40 CFR 51.308(e)(2) of
adopting an alternative approach to requiring controls on a case-by-
case basis for each source subject to BART. If a State chooses to adopt
alternative measures, such as an emissions trading program, under 40
CFR 51.308(e)(2)(i) the State must demonstrate that any such
alternative will achieve greater ``reasonable progress'' than would
have resulted from installation of BART from all sources subject to
BART. Such a demonstration must include:
(a) A list of all BART-eligible sources;
(b) An analysis of the best system of continuous emission control
technology available for all sources subject to BART, taking into
account the technology available, the costs of compliance, the energy
and non-air quality environmental impacts of compliance, any pollution
control equipment in use at the source, and the remaining useful life
of the source. Unlike the analysis for BART under 40 CFR 51.308(e)(1),
which requires that these factors be considered on a case-by-case
basis, States may consider these factors on a category-wide basis, as
appropriate, in evaluating alternatives to BART;
(c) An analysis of the degree of visibility improvement that would
result from the alternative program in each affected Class I area.
States must ensure that a trading program or other such measure
includes all BART-eligible sources, unless a source has installed BART,
or plans to install BART consistent with 51.308(e)(1).\1\ A trading
program also

[[Page 25214]]

may include sources not subject to BART. A State may also work together
with other States to develop a common trading program. Under 40 CFR
51.308(e)(2) States must also include in their SIPs details on how they
would implement the emission trading program or other alternative
measure. States must provide a detailed description of the program,
including schedules for compliance, the emissions reductions that it
will require, the administrative and technical procedures for
implementing the program, rules for accounting and monitoring
emissions, and procedures for enforcement.
---------------------------------------------------------------------------

\1\ As noted in the preamble to the regional haze rule, States
need not include a BART-eligible source in the trading program if
the source already has installed BART-level pollution control
technology and the emission limit is a federally enforceable
requirement (64 FR 35742). We clarify in these guidelines that
States may also elect to allow a source the option of installing
BART-level controls within the 5-year period for compliance with the
BART requirement [see section VI of these guidelines]
rather than
participating in a trading program.
---------------------------------------------------------------------------

G. What Is Included in the Guidelines?

1. In the guidelines, we provide procedures States must use in
implementing the regional haze BART requirements on a source-by-source
basis, as provided in 40 CFR 51.308(e)(1). We address general topics
related to development of a trading program or other alternative
allowed by 40 CFR 51.308(e)(2).
2. The BART analysis process, and the contents of these guidelines,
are as follows:
(a) Identification of all BART-eligible sources. Section II of
these guidelines outlines a step-by-step process for identifying BART-
eligible sources.
(b) Identification of sources subject to BART. As noted above,
sources ``subject to BART'' are those BART-eligible sources which
``emit a pollutant which may reasonably be anticipated to cause or
contribute to any impairment of visibility in any Class I area.'' We
discuss considerations for identifying sources subject to BART in
section III of the guidance.
(c) The BART determination process. For each source subject to
BART, the next step is to conduct an analysis of emissions control
alternatives. This step requires the identification of available,
technically feasible, retrofit technologies, and for each technology
identified, analysis of the cost of compliance, and the energy and non-
air quality environmental impacts, taking into account the remaining
useful life and existing control technology present at the source. This
step also requires taking into account the degree of visibility
improvement that would be achieved in each affected Class I area as a
result of the emissions reductions achievable from sources subject to
BART. The visibility impacts analysis must take into account the degree
of improvement in visibility from the emissions reductions from the
``best technologies'' identified. For each source, a ``best system of
continuous emission reduction'' will be selected based upon these
analyses. Procedures for the BART determination step are described in
section IV of these guidelines.
(d) Emissions limits. States must establish enforceable limits,
including a deadline for compliance, for each source subject to BART.
Considerations related to these limits are discussed in section VI of
these guidelines.
(e) Considerations in establishing a trading program alternative.
General guidance on how to develop an emissions trading program
alternative is contained in section VII of these guidelines.

H. Who Is the Target Audience for the Guidelines?

1. The guidelines are written primarily for the benefit of State,
local and Tribal agencies, and describe the requirements for including
the BART determinations and emission limitations in their SIPs or
Tribal implementation plans (TIPs). Throughout the guidelines, which
are written in a question and answer format, we ask questions ``How do
I * * *?'' and answer with phrases ``you should * * *, you must * *
*.'' The ``you'' means a State, local or Tribal agency conducting the
analysis.\2\ We recognize, however, that agencies may prefer to require
source owners to assume part of the analytical burden, and that there
will be differences in how the supporting information is collected and
documented. We also recognize that much of the data collection,
analysis, and rule development may be performed by Regional Planning
Organizations, for adoption within each SIP or TIP.
---------------------------------------------------------------------------

\2\ In order to account for the possibility that BART-eligible
sources could go unrecognized, we recommend that you adopt
requirements placing a responsibility on source owners to self-
identify if they meet the criteria for BART-eligible sources.
---------------------------------------------------------------------------

2. The preamble to the 1999 regional haze rule discussed at length
the issue of Tribal implementation. As explained there, requirements
related to visibility are among the programs for which Tribes may be
determined eligible and receive authorization to implement under the
``Tribal Authority Rule'' (``TAR'') (40 CFR 49.1 through 49.11). Tribes
are not subject to implementation plan deadlines and may use a modular
approach to CAA implementation. We believe there are very few BART-
eligible sources located on Tribal lands. Where such sources exist, the
affected Tribe may apply for delegation of implementation authority for
this rule, following the process set forth in the TAR.

I. Do EPA Regulations Require the Use of These Guidelines?

Section 169A(b) requires us to issue these guidelines for States to
follow in establishing BART emission limitations for fossil-fuel fired
generating power plants having a capacity in excess of 750 megawatts.
This document is intended to fulfill that requirement. These guidelines
also establish procedures that States must follow in establishing BART
emission limitations for all other BART sources. Under 40 CFR
308(e)(1)(ii)(B), we are requiring States to follow these guidelines in
all BART determinations. We believe this approach will promote
equitable application of the BART requirement to source owners with
similar sources in different States.

II. How To Identify BART-Eligible Sources

This section provides guidelines on how to identify BART-eligible
sources. A BART-eligible source is an existing stationary source in any
of 26 listed categories which meets criteria for startup dates and
potential emissions.

A. What Are the Steps in Identifying BART-Eligible Sources?

Figure 1 shows the steps for identifying whether the source is a
``BART-eligible source'':

Step 1: Identify the emission units in the BART categories,
Step 2: Identify the start-up dates of those emission units, and
Step 3: Compare the potential emissions to the 250 ton/yr cutoff.
Figure 1. How to determine whether a source is BART-eligible:
Step 1: Identify emission units in the BART categories.
Does the plant contain emissions units in one or more of the 26
source categories?

[rtarr2]
No [rtarr2]
Stop
[rtarr2]
Yes [rtarr2]
Proceed to Step
2

Step 2: Identify the start-up dates of these emission units.
Do any of these emissions units meet the following two tests?
In existence on August 7, 1977 and, began operation after August 7,
1962.

[rtarr2]
No [rtarr2]
Stop
[rtarr2]
Yes [rtarr2]
Proceed to Step
3

Step 3: Compare the potential emissions from these emission units
to the 250 ton/yr cutoff.
Identify the ``stationary source'' that includes the emission units
you identified in Step 2.
Add the current potential emissions from all the emission units
identified in Steps 1 and 2 that are included within the ``stationary
source'' boundary.

[[Page 25215]]

Are the potential emissions from these units 250 tons per year or
more for any visibility-impairing pollutant?

[rtarr2]
No [rtarr2]
Stop
[rtarr2]
Yes [rtarr2]
These emissions
units comprise
the ``BART-
eligible
source.''.

1. Step 1: Identify Emission Units in the BART Categories
1. The BART requirement only applies to sources in specific
categories listed in the CAA. The BART requirement does not apply to
sources in other source categories, regardless of their emissions. The
listed categories are:
(1) Fossil-fuel fired steam electric plants of more than 250 million
British thermal units (BTU) per hour heat input,
(2) Coal cleaning plants (thermal dryers),
(3) Kraft pulp mills,
(4) Portland cement plants,
(5) Primary zinc smelters,
(6) Iron and steel mill plants,
(7) Primary aluminum ore reduction plants,
(8) Primary copper smelters,
(9) Municipal incinerators capable of charging more than 250 tons of
refuse per day,
(10) Hydrofluoric, sulfuric, and nitric acid plants,
(11) Petroleum refineries,
(12) Lime plants,
(13) Phosphate rock processing plants,
(14) Coke oven batteries,
(15) Sulfur recovery plants,
(16) Carbon black plants (furnace process),
(17) Primary lead smelters,
(18) Fuel conversion plants,
(19) Sintering plants,
(20) Secondary metal production facilities,
(21) Chemical process plants,
(22) Fossil-fuel boilers of more than 250 million BTUs per hour heat input,
(23) Petroleum storage and transfer facilities with a capacity
exceeding 300,000 barrels,
(24) Taconite ore processing facilities,
(25) Glass fiber processing plants, and
(26) Charcoal production facilities.
2. Some plants may have emission units from more than one category,
and some emitting equipment may fit into more than one category.
Examples of this situation are sulfur recovery plants at petroleum
refineries, coke oven batteries and sintering plants at steel mills,
and chemical process plants at refineries. For Step 1, you identify all
of the emissions units at the plant that fit into one or more of the
listed categories. You do not identify emission units in other categories.

Example: A mine is collocated with an electric steam generating
plant and a coal cleaning plant. You would identify emission units
associated with the electric steam generating plant and the coal
cleaning plant, because they are listed categories, but not the
mine, because coal mining is not a listed category.

3. The category titles are generally clear in describing the types
of equipment to be listed. Most of the category titles are very broad
descriptions that encompass all emission units associated with a plant
site (for example, ``petroleum refining'' and ``kraft pulp mills''). In
addition, this same list of categories appears in the PSD regulations,
for example in 40 CFR 52.21. States and source owners need not revisit
any interpretations of the list made previously for purposes of the PSD
program. We provide the following clarifications for a few of the
category titles:
(1) ``Steam electric plants of more than 250 million BTU/hr heat
input.'' Because the category refers to ``plants,'' boiler capacities
must be aggregated to determine whether the 250 million BTU/hr
threshold is reached. This definition also includes those plants that
cogenerate steam and electricity. Also, consistent with other EPA
rules, the definition only includes those plants that generate
electricity for sale.

Example: A stationary source includes a steam electric plant
with three 100 million BTU/hr boilers. Because the aggregate
capacity exceeds 250 million BTU/hr for the ``plant,'' these boilers
would be identified in Step 2.

``Steam electric plants'' includes combined cycle turbines because of
their incorporation of heat recovery steam generators. Simple cycle
turbines are not ``steam electric plants'' because they typically do
not make steam.
(2) ``Fossil-fuel boilers of more than 250 million BTU/hr heat
input.'' We interpret this category title to cover only those boilers
that are individually greater than 250 million BTU/hr. However, an
individual boiler smaller than 250 million BTU/hr should be subject to
BART if it is part of a process description at a plant that is in a
different BART category--for example, a boiler at a chemical process plant.
Also, you should consider a multi-fuel boiler to be a fossil-fuel
boiler if it burns at least 50 percent fossil fuels. You may take
federally enforceable operational limits into account in determining
whether a multi-fuel boiler's fossil fuel capacity exceeds 250 million
Btu/hr.
(3) ``Petroleum storage and transfer facilities with a capacity
exceeding 300,000 barrels.'' The 300,000 barrel cutoff refers to total
facility-wide tank capacity for tanks that were put in place within the
1962-1977 time period, and includes gasoline and other petroleum-
derived liquids.
(4) ``Phosphate rock processing plants.'' This category descriptor
is broad, and includes all types of phosphate rock processing
facilities, including elemental phosphorous plants as well as
fertilizer production plants.
(5) Charcoal production facilities.'' We interpret this category to
include charcoal briquet manufacturing and activated carbon production.
(6) ``Chemical process plants'' and pharmaceutical manufacturing.
Consistent with past policy, we interpret the category ``chemical
process plants'' to include those facilities within 2-digit SIC 28.
Accordingly, we interpret the term ``chemical process plants'' to
include pharmaceutical manufacturing facilities.
(7) ``Secondary metal production.'' We interpret this category to
include nonferrous metal facilities included within SIC code 3341, and
secondary ferrous metal facilities that we also consider to be included
within the category ``iron and steel mill plants.''
2. Step 2: Identify the Start-up Dates of the Emission Units
1. Emissions units listed under Step 1 are BART-eligible only if
they were ``in existence'' on August 7, 1977 but were not ``in
operation'' before August 7, 1962.

What Does ``in Existence on August 7, 1977'' Mean?

2. The regional haze rule defines ``in existence'' to mean that:
``the owner or operator has obtained all necessary preconstruction
approvals or permits required by Federal, State, or local air pollution
emissions and air quality laws or regulations and either has (1) begun,
or caused to begin, a continuous program of physical on-site
construction of the facility or (2) entered into binding agreements or
contractual obligations, which cannot be canceled or modified without
substantial loss to the owner or operator, to undertake a program of
construction of the facility to be completed in a reasonable time.''
See 40 CFR 51.301.

Thus, the term ``in existence'' means the same thing as the term
``commence construction'' as that term is used in the PSD regulations.
See 40 CFR 51.165(a)(1)(xvi) and 40 CFR 52.21(b)(9). Thus, an emissions
unit could be ``in existence'' according to this test even if it did
not begin operating until several years later.

[[Page 25216]]

Example: The owner or operator obtained necessary permits in
early 1977 and entered into binding construction agreements in June
1977. Actual on-site construction began in late 1978, and
construction was completed in mid-1979. The source began operating
in September 1979. The emissions unit was ``in existence'' as of
August 7, 1977.

Emissions units of this size for which construction commenced AFTER
August 7, 1977 (i.e., were not ``in existence'' on August 7, 1977) were
subject to major new source review (NSR) under the PSD program. Thus,
the August 7, 1977 ``in existence'' test is essentially the same thing
as the identification of emissions units that were grandfathered from
the NSR review requirements of the 1977 CAA amendments.
3. Sources are not BART-eligible if the only change at the plant
during the relevant time period was the addition of pollution controls.
For example, if the only change at a copper smelter during the 1962
through 1977 time period was the addition of acid plants for the
reduction of SO₂ emissions, these emission controls would
not by themselves trigger a BART review.

What Does ``in Operation Before August 7, 1962'' Mean?

1. An emissions unit that meets the August 7, 1977 ``in existence''
test is not BART-eligible if it was in operation before August 7, 1962.
``In operation'' is defined as ``engaged in activity related to the
primary design function of the source.'' This means that a source must
have begun actual operations by August 7, 1962 to satisfy this test.

Example: The owner or operator entered into binding agreements
in 1960. Actual on-site construction began in 1961, and construction
was complete in mid-1962. The source began operating in September
1962. The emissions unit was not ``in operation'' before August 7,
1962 and is therefore subject to BART.

What Is a ``Reconstructed Source?'

2. Under a number of CAA programs, an existing source which is
completely or substantially rebuilt is treated as a new source. Such
``reconstructed'' sources are treated as new sources as of the time of
the reconstruction. Consistent with this overall approach to
reconstructions, the definition of BART-eligible facility (reflected in
detail in the definition of ``existing stationary facility'') includes
consideration of sources that were in operation before August 7, 1962,
but were reconstructed during the August 7, 1962 to August 7, 1977 time
period.
3. Under the regulation, a reconstruction has taken place if ``the
fixed capital cost of the new component exceeds 50 percent of the fixed
capital cost of a comparable entirely new source.'' The rule also
states that ``Any final decision as to whether reconstruction has
occurred must be made in accordance with the provisions of Sec. Sec.
60.15 (f)(1) through (3) of this title.'' [40 CFR 51.301]. ``Sec. Sec.
60.15(f)(1) through (3)'' refers to the general provisions for New
Source Performance Standards (NSPS). Thus, the same policies and
procedures for identifying reconstructed ``affected facilities'' under
the NSPS program must also be used to identify reconstructed
``stationary sources'' for purposes of the BART requirement.
4. You should identify reconstructions on an emissions unit basis,
rather than on a plantwide basis. That is, you need to identify only
the reconstructed emission units meeting the 50 percent cost criterion.
You should include reconstructed emission units in the list of emission
units you identified in Step 1. You need consider as possible
reconstructions only those emissions units with the potential to emit
more than 250 tons per year of any visibility-impairing pollutant.
5. The ``in operation'' and ``in existence'' tests apply to
reconstructed sources. If an emissions unit was reconstructed and began
actual operation before August 7, 1962, it is not BART-eligible.
Similarly, any emissions unit for which a reconstruction ``commenced''
after August 7, 1977, is not BART-eligible.

How Are Modifications Treated Under the BART Provision?

1. The NSPS program and the major source NSR program both contain
the concept of modifications. In general, the term ``modification''
refers to any physical change or change in the method of operation of
an emissions unit that leads to an increase in emissions.
2. The BART provision in the regional haze rule contains no
explicit treatment of modifications. Accordingly, guidelines are needed
on how modified emissions units, previously subject to best available
control technology (BACT), lowest achievable emission rate (LAER) and/
or NSPS, are treated under the rule. The BART requirements in the CAA
do not appear to provide any exemption for sources which were modified
since 1977. Therefore we believe that the best interpretation of the
CAA visibility provisions is that a subsequent modification does not
change a unit's construction date for the purpose of BART
applicability. Accordingly, an emissions unit which began operation
within the 1962-1977 time window, but was modified after August 7,
1977, is BART-eligible. However, if an emissions unit began operation
before 1962, it is not BART-eligible if it is modified at a later date,
so long as the modification is not also a ``reconstruction.'' We note,
however, that if such a modification was a major modification subject
to the BACT, LAER, or NSPS levels of control, the review process will
take into account the level of control that is already in place and may
find that the level of controls are already consistent with BART.
3. Step 3: Compare the Potential Emissions to the 250 Ton/Yr Cutoff
The result of Steps 1 and 2 will be a list of emissions units at a
given plant site, including reconstructed emissions units, that are
within one or more of the BART categories and that were placed into
operation within the 1962-1977 time window. The third step is to
determine whether the total emissions represent a current potential to
emit that is greater than 250 tons per year of any single visibility
impairing pollutant. In most cases, you will add the potential
emissions from all emission units on the list resulting from Steps 1
and 2. In a few cases, you may need to determine whether the plant
contains more than one ``stationary source'' as the regional haze rule
defines that term, and as we explain further below.

What Pollutants Should I Address?

Visibility-impairing pollutants include the following:
(1) Sulfur dioxide (SO2),
(2) Nitrogen oxides (NO\2\),
(3) Particulate matter. (You may use PM₁₀ as the
indicator for particulate matter. We do not recommend use of total
suspended particulates (TSP). Emissions of PM₁₀ include the
components of PM_2.5 as a subset. There is no need to have
separate 250 ton thresholds for PM₁₀ and PM_2.5,
because 250 tons of PM₁₀ represents at most 250 tons of
PM_2.5, and at most 250 tons of any individual particulate
species such as elemental carbon, crustal material, etc.), and
(4) Volatile organic compounds (VOC).

Can States Establish De Minimis Levels of Emissions for Pollutants at
BART-Eligible Sources?

In order to simplify BART determinations, States may choose to
identify de minimis levels of pollutants at BART-eligible sources. De
minimis values should be identified with the purpose of excluding only
those

[[Page 25217]]

emissions so minimial that they are unlikely to contribute to regional
haze. Any de minimis values that States consider must not be higher
than the PSD applicability levels: 40 tons/yr for SO₂,
NO_X and VOC, and 15 tons/yr for PM₁₀.

What Does the Term ``Potential'' Emissions Mean?

The regional haze rule defines potential to emit as follows:

``Potential to emit'' means the maximum capacity of a stationary
source to emit a pollutant under its physical and operational
design. Any physical or operational limitation on the capacity of
the source to emit a pollutant including air pollution control
equipment and restrictions on hours of operation or on the type or
amount of material combusted, stored, or processed, shall be treated
as part of its design if the limitation or the effect it would have
on emissions is federally enforceable. Secondary emissions do not
count in determining the potential to emit of a stationary source.

This definition is identical to that in the PSD program [40 CFR 51.166
and 51.18]. This means that a source which actually emits less than 250
tons per year of a visibility-impairing pollutant is BART-eligible if
its emissions would exceed 250 tons per year when operating at its
maximum physical and operational design (and considering all federally
enforceable permit limits).

Example: A source, while operating at one-fourth of its
capacity, emits 75 tons per year of SO₂. If it were
operating at 100 percent of its maximum capacity, the source would
emit 300 tons per year. Because under the above definition such a
source would have ``potential'' emissions that exceed 250 tons per
year, the source (if in a listed category and built during the 1962-
1977 time window) would be BART-eligible.

How Do I Identify Whether a Plant Has More Than One ``Stationary Source?''

1. The regional haze rule, in 40 CFR 51.301, defines a stationary
source as a ``building, structure, facility or installation which emits
or may emit any air pollutant.'' \3\ The rule further defines
``building, structure or facility'' as:
---------------------------------------------------------------------------

\3\ Note: Most of these terms and definitions are the same for
regional haze and the 1980 visibility regulations. For the regional
haze rule we use the term ``BART-eligible source'' rather than
``existing stationary facility'' to clarify that only a limited
subset of existing stationary sources are subject to BART.
---------------------------------------------------------------------------

All of the pollutant-emitting activities which belong to the same
industrial grouping, are located on one or more contiguous or adjacent
properties, and are under the control of the same person (or persons
under common control). Pollutant-emitting activities must be considered
as part of the same industrial grouping if they belong to the same
Major Group (i.e., which have the same two-digit code) as described in
the Standard Industrial Classification Manual, 1972 as amended by the
1977 Supplement (U.S. Government Printing Office stock numbers 4101-
0066 and 003-005-00176-0, respectively).
2. In applying this definition, it is necessary to determine which
facilities are located on ``contiguous or adjacent properties.'' Within
this contiguous and adjacent area, it is also necessary to group those
emission units that are under ``common control.'' We note that these
plant boundary issues and ``common control'' issues are very similar to
those already addressed in implementation of the title V operating
permits program and in NSR.
3. For emission units within the ``contiguous or adjacent''
boundary and under common control, you must group emission units that
are within the same industrial grouping (that is, associated with the
same 2-digit Standard Industrial Classification (SIC) code).\4\ For
most plants on the BART source category list, there will only be one 2-
digit SIC that applies to the entire plant. For example, all emission
units associated with kraft pulp mills are within SIC code 26, and
chemical process plants will generally include emission units that are
all within SIC code 28. The ``2-digit SIC test'' applies in the same
way as the test is applied in the major source NSR programs.\5\
---------------------------------------------------------------------------

\4\ We recognize that we are in a transition period from the use
of the SIC system to a new system called the North American Industry
Classification System (NAICS). For purposes of identifying BART-
eligible sources, you may use either 2-digit SICS or the equivalent
in the NAICS system.
\5\ Note: The concept of support facility used for the NSR
program applies here as well. Support facilities, that is facilities
that convey, store or otherwise assist in the production of the
principal product, must be grouped with primary facilities even when
the facilities fall within separate SIC codes. For purposes of BART
reviews, however, such support facilities (a) must be within one of
the 26 listed source categories and (b) must have been in existence
as of August 7, 1977, and (c) must not have been in operation as of
August 7, 1962.
---------------------------------------------------------------------------

4. For purposes of the regional haze rule, you must group emissions
from all emission units put in place within the 1962-1977 time period
that are within the 2-digit SIC code, even if those emission units are
in different categories on the BART category list.

Examples: A chemical plant which started operations within the
1962 to 1977 time period manufactures hydrochloric acid (within the
category title ``Hydrochloric, sulfuric, and nitric acid plants'')
and various organic chemicals (within the category title ``chemical
process plants''), and has onsite an industrial boiler greater than
250 million BTU/hour. All of the emission units are within SIC 28
and, therefore, all the emission units are considered in determining
BART eligibility of the plant. You sum the emissions over all of
these emission units to see whether there are more than 250 tons per
year of potential emissions.
A steel mill which started operations within the 1962 to 1977
time period includes a sintering plant, a coke oven battery, and
various other emission units. All of the emission units are within
SIC 33. You sum the emissions over all of these emission units to
see whether there are more than 250 tons per year of potential emissions.
4. Final Step: Identify the Emissions Units and Pollutants That
Constitute the BART-Eligible Source
If the emissions from the list of emissions units at a stationary
source exceed a potential to emit of 250 tons per year for any
visibility-impairing pollutant, then that collection of emissions units
is a BART-eligible source. A BART analysis is required for each
visibility-impairing pollutant emitted at each BART-eligible source.

Example: A stationary source comprises the following two
emissions units, with the following potential emissions:
Emissions unit A--200 tons/yr SO₂; 150 tons/yr
NO_X; 25 tons/yr PM.
Emissions unit B--100 tons/yr SO₂; 75 tons/yr
NO_X; 10 tons/yr PM.

For this example, potential emissions of SO₂ are 300 tons/
yr, which exceeds the 250 tons/yr threshold. Accordingly, the entire
``stationary source'', that is, emissions units A and B, are subject to
a BART review for SO₂, NO_X, and PM, even though
the potential emissions of PM and NO_X at each emissions unit
are less than 250 tons/yr each.

Example: The total potential emissions, obtained by adding the
potential emissions of all emission units in a listed category at a
plant site, are as follows: 200 tons/yr SO₂, 150 tons/yr
NO_X, 25 tons/yr PM.
Even though total emissions exceed 250 tons/yr, no individual
regulated pollutant exceeds 250 tons/yr and this source is not BART-
eligible.

III. How To Identify Sources ``Subject to BART''

Once you have identified and compiled your list of BART-eligible
sources, you need to determine which of those sources may cause or
contribute to any visibility impairment in a Class I area (i.e., which
of those sources should be subject to BART). First, you may choose to
consider that all of the BART-eligible sources in your State are
subject to BART (i.e., none are exempt). Alternatively, you may submit
to EPA a demonstration, based on overall visibility impacts, that the
sum of all emissions from BART-eligible sources

[[Page 25218]]

in your State do not cause or contribute to any visibility impairment
in a Class I area (i.e., none of your BART-eligible sources are subject
to BART; all are exempt).
However, if you cannot or choose not to demonstrate to EPA that the
sum total of emissions from BART-eligible sources in your State do not
cause or contribute to any visibility impairment in Class I areas, and
if you also choose not to consider that all BART-eligible sources
should automatically be subject to BART, you may use the third
exemption option, individual source modeling. The individual source
exemption process is presented below.
1. Individual Source Exemption Process (CALPUFF Modeling)
You may elect to do the modeling or to require the source to do the
modeling. If the source is making the visibility impact determination,
you should review and approve or disapprove of the source's analysis
before making the exemption determination. For each BART-eligible source:
a. Submit a Modeling protocol to EPA. If you are having your
sources do the modeling, they should prepare a modeling protocol that
is acceptable to you and the EPA. If modeling is to be conducted for
receptors greater than 200 km from the emission unit, a modeling
protocol is required. Some critical items to include are meteorological
and terrain data, as well as source-specific information (stack height,
temperature, exit velocity, elevation, and allowable emission rate of
applicable pollutants), and receptor data from appropriate Class I
areas. Distances from the actual BART-eligible emission unit that is
modeled to each Class I area should be measured from the nearest point
in the Class I area. All receptors in the Class I area should be
analyzed. The State should bear in mind that, for sources 50 km from a
Class I area, some receptors within that Class I area may be less than
50 km from the source while other receptors within that same Class I
area may be greater than 50 km from the same source; this situation may
result in two different modeling approaches for the same Class I area
and source, depending upon the State's chosen method for modeling
sources less than 50 km.
b. Once the modeling methodology is approved, for each Class I area:
i. Run CALPUFF for receptors in the Class I area that are greater
than or equal to 50 km from the source. For CALPUFF setup
(meteorological data and parameter settings), we recommend following
EPA's Interagency Workgroup on Air Quality Modeling (IWAQM) Phase 2
Summary Report and Recommendations for Modeling Long Range Transport
Impacts.
(a) Tabulate Results --Calculate 24-hr values for each receptor as
the change in deciviews compared against natural visibility conditions.
(b) Make the exemption determination--If the change in the maximum
24-hour value at any receptor is greater than 0.5 deciviews, the source
is subject to BART.
ii. For sources not subject to BART under i. above and where the
distance from the BART-eligible unit modeled to the nearest receptor at
any Class I area is less than 50 km:
(1) You will need to determine whether or not to exempt the source.
Use your discretion for determining visibility impacts giving
consideration to CALPUFF and to other EPA-approved methods.
Note that each of the modeling options may be supplemented with
source apportionment data or source apportionment modeling that is
acceptable to the State and the EPA regional office.

IV. The BART Determination: Analysis of BART Options

This section describes the process for the engineering analysis of
control options for sources subject to BART.

A. What Factors Must I Address in the Engineering Analysis?

The visibility regulations define BART as follows:
Best Available Retrofit Technology (BART) means an emission
limitation based on the degree of reduction achievable through the
application of the best system of continuous emission reduction for
each pollutant which is emitted by * * * [a BART -eligible source]. The
emission limitation must be established, on a case-by-case basis,
taking into consideration the technology available, the costs of
compliance, the energy and non-air quality environmental impacts of
compliance, any pollution control equipment in use or in existence at
the source, the remaining useful life of the source, and the degree of
improvement in visibility which may reasonably be anticipated to result
from the use of such technology.
The BART analysis requirement in 40 CFR 51.308(e)(1)(ii)(A) has two
parts: an engineering analysis and a visibility impacts analysis. This
section of the guidelines addresses the requirements for the
engineering analysis. Your engineering analysis identifies the best
system of continuous emission reduction taking into account:

(1) The available retrofit control options,
(2) Any pollution control equipment in use at the source (which affects
the availability of options and their impacts),
(3) The costs of compliance with control options,
(4) The remaining useful life of the facility (which as we will discuss
below, is an integral part of the cost analysis), and
(5) The energy and non-air quality environmental impacts of control
options.

We discuss the requirement for a visibility impacts analysis below
in section V.
(4) How Does a BART Engineering Analysis Compare to a BACT Review Under
the PSD Program?
The process for a BART analysis is very similar to the BACT review
as described in the New Source Review Workshop Manual (Draft, October
1990). Consistent with the Workshop Manual, the BART engineering
analysis requires that all available control technologies be ranked in
descending order of control effectiveness (i.e. percent control). You
must examine the most stringent alternative first. That alternative is
selected as the ``best'' unless you demonstrate and document that the
alternative cannot be justified based upon the consideration of the
five statutory factors discussed below. If you eliminate the most
stringent technology in this fashion, you then consider the next most
stringent alternative, and so on.
Although very similar in process, BART reviews differ in several
respects from the BACT review described in the NSR Draft Manual. First,
because all BART reviews apply to existing sources, the available
controls and the impacts of those controls may differ from source to
source. Second, the CAA requires you to take slightly different factors
into account in determining BART and BACT. In a BACT analysis, the
permitting authority must consider the ``energy, environmental and
economic impacts and other costs'' associated with a control technology
in making its determination. In a BART analysis, on the other hand, the
State must take into account the ``cost of compliance, the remaining
useful life of the source, the energy and nonair quality environmental
impacts of compliance, any existing pollution control technology in use
at the source, and the degree of improvement in visibility from the use
of such technology'' in making its BART determination. Because of the
differences in terminology, the BACT review process tends to encompass
a broader range of factors. For example,

[[Page 25219]]

the term ``environmental impacts'' in the BACT definition is more broad
than the term ``nonair quality environmental impacts'' used in the BART
definition. Accordingly, there is no requirement in the BART
engineering analysis to evaluate adverse air quality impacts of control
alternatives such as the relative impacts on hazardous air pollutants,
although you may wish to do so. Finally, for the BART analysis, there
is no minimum level of control required, while any BACT emission
limitation must be at least as stringent as any NSPS that applies to
the source.
(5) Which Pollutants Must I Address in the Engineering Review?
Once you determine that a source is subject to BART, then a BART
review is required for each visibility-impairing pollutant emitted. In
a BART review, for each affected emission unit, you must establish BART
for each pollutant that can impair visibility. Consequently, the BART
determination must address air pollution control measures for each
emissions unit or pollutant emitting activity subject to review.

Example: Plantwide emissions from emission units within the
listed categories that began operation within the ``time window''
for BART \6\ are 300 tons/yr of NO_X, 200 tons/yr of
SO₂, and 150 tons/yr of primary particulate. Emissions
unit A emits 200 tons/yr of NO_X, 100 tons/yr of
SO₂, and 100 tons/yr of primary particulate. Other
emission units, units B through H, which began operating in 1966,
contribute lesser amounts of each pollutant. For this example, a
BART review is required for NO_X, SO₂, and
primary particulate, and control options must be analyzed for units
B through H as well as unit A.
---------------------------------------------------------------------------

\6\ That is, emission units that were in existence on August 7,
1977 and which began actual operation on or after August 7, 1962.
---------------------------------------------------------------------------

D. How Does a BACT Review Relate to Maximum Achievable Control
Technology (MACT) Standards Under CAA Section 112?

For VOC and PM sources subject to MACT standards, States may
streamline the analysis by including a discussion of the MACT controls
and whether any major new technologies have been developed subsequent
to the MACT standards. We believe that there are many VOC and PM
sources that are well controlled because they are regulated by the MACT
standards, which EPA developed under CAA section 112. For a few MACT
standards, this may also be true for SO₂. Any source subject
to MACT standards must meet a level that is as stringent as the best-
controlled 12 percent of sources in the industry. Examples of these
hazardous air pollutant sources which effectively control VOC and PM
emissions include (among others) secondary lead facilities, organic
chemical plants subject to the hazardous organic NESHAP (HON),
pharmaceutical production facilities, and equipment leaks and
wastewater operations at petroleum refineries. We believe that, in many
cases, it will be unlikely that States will identify emission controls
more stringent than the MACT standards without identifying control
options that would cost many thousands of dollars per ton. Unless there
are new technologies subsequent to the MACT standards which would lead
to cost-effective increases in the level of control, you may rely on
the MACT standards for purposes of BART. We believe that the same
rationale also holds true for emissions standards developed for
municipal waste incinerators under CAA section 111(d).
Where you are relying on MACT standards to achieve a BART level of
control, you must provide the public with a discussion of how you have
reached the conclusion that it is appropriate to rely on MACT
standards, and a discussion of whether any new technologies are
available subsequent to the date the MACT standards were published.

E. What Are the Five Basic Steps of a Case-by-Case BART Engineering
Analysis?

The five steps are:
STEP 1--Identify All \7\ Available Retrofit Control Technologies,
---------------------------------------------------------------------------

\7\ In identifying ``all'' options, you must identify the most
stringent option and a reasonable set of options for analysis that
reflects a comprehensive list of available technologies. It is not
necessary to list all permutations of available control levels that
exist for a given technology--the list is complete if it includes
the maximum level of control each technology is capable of achieving.
---------------------------------------------------------------------------

STEP 2-- Eliminate Technically Infeasible Options,
STEP 3-- Rank Remaining Control Technologies By Control Effectiveness,
STEP 4-- Evaluate Impacts and Document the Results, and
STEP 5--Evaluate Visibility Impacts.
1. STEP 1: How do I Identify all Available Retrofit Emission Control
Techniques?
1. Available retrofit control options are those air pollution
control technologies with a practical potential for application to the
emissions unit and the regulated pollutant under evaluation. Air
pollution control technologies can include a wide variety of available
methods, systems, and techniques for control of the affected pollutant.
Available air pollution control technologies can include technologies
employed outside of the United States that have been successfully
demonstrated in practice on full scale operations, particularly those
that have been demonstrated as retrofits to existing sources.
Technologies required as BACT or LAER are available for BART purposes
and must be included as control alternatives. The control alternatives
should include not only existing controls for the source category in
question, but also take into account technology transfer of controls
that have been applied to similar source categories and gas streams.
Technologies which have not yet been applied to (or permitted for) full
scale operations need not be considered as available; we do not expect
the source owner to purchase or construct a process or control device
that has not already been demonstrated in practice.
2. Where an NSPS exists for a source category (which is the case
for most of the categories affected by BART), you should include a
level of control equivalent to the NSPS as one of the control
options.\8\ The NSPS standards are codified in 40 CFR part 60. We note
that there are situations where NSPS standards do not require the most
stringent level of available control for all sources within a category.
For example, post-combustion NO_X controls (the most
stringent controls for stationary gas turbines) are not required under
subpart GG of the NSPS for Stationary Gas Turbines. However, such
controls must still be considered available technologies for the BART
selection process.
---------------------------------------------------------------------------

\8\ In EPA's 1980 BART guidelines for reasonably attributable
visibility impairment, we concluded that NSPS standards generally,
at that time, represented the best level sources could install as
BART, and we required no further demonstration if an NSPS level was
selected. In the 20 year period since this guidance was developed,
there have been advances in SO₂ control technologies as
well as technologies for the control of other pollutants, confirmed
by a number of recent retrofits at Western power plants.
Accordingly, EPA no longer concludes that the NSPS level of controls
automatically represents ``the best these sources can install.''
While it is possible that a detailed analysis of the BART factors
could result in the selection of an NSPS level of control, we
believe that you should only reach this conclusion based upon an
analysis of the full range of control options.
---------------------------------------------------------------------------

3. Potentially applicable retrofit control alternatives can be
categorized in three ways.
? Pollution prevention: use of inherently lower-emitting
processes/practices, including the use of materials and production
processes and work practices that prevent emissions and

[[Page 25220]]

result in lower ``production-specific'' emissions,
? Use of, (and where already in place, improvement in the
performance of) add-on controls, such as scrubbers, fabric filters,
thermal oxidizers and other devices that control and reduce emissions
after they are produced, and
? Combinations of inherently lower-emitting processes and
add-on controls. Example: for a gas-fired turbine, a combination of
combustion controls (an inherently lower-emitting process) and post-
combustion controls such as selective catalytic reduction (add-on) may
be available to reduce NO_X emissions.
4. For the engineering analysis, you should consider potentially
applicable control techniques from all three categories. You should
consider lower-polluting processes based on demonstrations from
facilities manufacturing identical or similar products using identical
or similar raw materials or fuels. Add-on controls, on the other hand,
should be considered based on the physical and chemical characteristics
of the pollutant-bearing emission stream. Thus, candidate add-on
controls may have been applied to a broad range of emission unit types
that are similar, insofar as emissions characteristics, to the
emissions unit undergoing BART review.
5. In the course of the BART engineering analysis, one or more of
the available control options may be eliminated from consideration
because they are demonstrated to be technically infeasible or to have
unacceptable energy, cost, or non-air quality environmental impacts on
a case-by-case (or site-specific) basis. However, at the outset, you
should initially identify all control options with potential
application to the emissions unit under review.
6. We do not consider BART as a requirement to redesign the source
when considering available control alternatives. For example, where the
source subject to BART is a coal-fired electric generator, we do not
require the BART analysis to consider building a natural gas-fired
electric turbine although the turbine may be inherently less polluting
on a per unit basis.
7. In some cases, retrofit design changes may be available for
making a given production process or emissions unit inherently less
polluting.\9\ (Example: use of low NO_X burners). In such
cases, the ability of design considerations to make the process
inherently less polluting must be considered as a control alternative
for the source.
---------------------------------------------------------------------------

\9\ Because BART applies to existing sources, we recognize that
there will probably be far fewer opportunities to consider
inherently lower-emitting processes than may be available for NSR.
---------------------------------------------------------------------------

8. Combinations of inherently lower-polluting processes/practices
(or a process made to be inherently less polluting) and add-on controls
could possibly yield more effective means of emissions control than
either approach alone. Therefore, the option to use an inherently
lower-polluting process does not, in and of itself, mean that no
additional add-on controls need to be included in the BART analysis.
These combinations should be identified in Step 1 for evaluation in
subsequent steps. (Example: use of low NO_X burner and add-on
SCR for NO_X control).
9. For emission units subject to a BART engineering review, there
will often be control measures or devices already in place. For such
emission units, it is important to include control options that involve
improvements to existing controls, and not to limit the control options
only to those measures that involve a complete replacement of control
devices.

Example: For a power plant with an existing wet scrubber, the
current control efficiency is 66 percent. Part of the reason for the
relatively low control efficiency is that 22 percent of the gas
stream bypasses the scrubber. An engineering review identifies
options for improving the performance of the wet scrubber by
redesigning the internal components of the scrubber and by
eliminating or reducing the percentage of the gas stream that
bypasses the scrubber. Four control options are identified: (1) 78
percent control based upon improved scrubber performance while
maintaining the 22 percent bypass, (2) 83 percent control based upon
improved scrubber performance while reducing the bypass to 15
percent, (3) 93 percent control based upon improving the scrubber
performance while eliminating the bypass entirely, (this option
results in a ``wet stack'' operation in which the gas leaving the
stack is saturated with water) and (4) 93 percent as in option 3,
with the addition of an indirect reheat system to reheat the stack
gas above the saturation temperature. You must consider each of
these four options in a BART analysis for this source.

10. You are expected to identify all demonstrated and potentially
applicable retrofit control technology alternatives. Examples of
general information sources to consider include:
? The EPA's Clean Air Technology Center, which includes the
RACT/BACT/LAER Clearinghouse (RBLC);
? State and Local Best Available Control Technology
Guidelines--many agencies have online information--for example South
Coast Air Quality Management District, Bay Area Air Quality Management
District, and Texas Natural Resources Conservation Commission;
? Control technology vendors;
? Federal/State/Local NSR permits and associated inspection/
performance test reports;
? Environmental consultants;
? Technical journals, reports and newsletters, air pollution
control seminars; and
? The EPA's NSR bulletin board-- http://www.epa.gov/ttn/nsr;
? Department of Energy's Clean Coal Program--technical reports;
? The NO_X Control Technology ``Cost Tool''--Clean
Air Markets Division Web page-- http://www.epa.gov/airmarkets/arp/nox/controltech.html;
? Performance of selective catalytic reduction on coal-fired
steam generating units--final report. OAR/ARD, June 1997 (also
available at http://www.epa.gov/airmarkets/arp/nox/controltech.html);
? Cost estimates for selected applications of NO_X
control technologies on stationary combustion boilers. OAR/ARD June
1997. (Docket for NO_X SIP Call, A-96-56, item II-A-03);
? Investigation of performance and cost of NO_X
controls as applied to group 2 boilers. OAR/ARD, August 1996. (Docket
for Phase II NO_X rule, A-95-28, item IV-A-4);
? Controlling SO₂ Emissions: A Review of
Technologies. EPA-600/R-00-093, USEPA/ORD/NRMRL, October 2000; and
? The OAQPS Control Cost Manual.
You should compile appropriate information from all available
information sources, and you should ensure that the resulting list of
control alternatives is complete and comprehensive.
2. STEP 2: How Do I Determine Whether the Options Identified in Step 1
Are Technically Feasible?
In Step 2, you evaluate the technical feasibility of the control
options you identified in Step 1. You should clearly document a
demonstration of technical infeasibility and should show, based on
physical, chemical, and engineering principles, that technical
difficulties would preclude the successful use of the control option on
the emissions unit under review. You may then eliminate such
technically infeasible control options from further consideration in
the BART analysis.

In General, What Do We Mean by Technical Feasibility?

Control technologies are technically feasible if either (1) they
have been installed and operated successfully for

[[Page 25221]]

the type of source under review, or (2) the technology could be applied
to the source under review. Two key concepts are important in
determining whether a technology could be applied: ``availability'' and
``applicability.'' As explained in more detail below, a technology is
considered ``available'' if the source owner may obtain it through
commercial channels, or it is otherwise available within the common
sense meaning of the term. An available technology is ``applicable'' if
it can reasonably be installed and operated on the source type under
consideration. A technology that is available and applicable is
technically feasible.

What Do We Mean by ``Available'' Technology?

1. The typical stages for bringing a control technology concept to
reality as a commercial product are:

? Concept stage;
? research and patenting;
? bench scale or laboratory testing;
? pilot scale testing;
? licensing and commercial demonstration; and
? commercial sales.

2. A control technique is considered available, within the context
presented above, if it has reached the licensing and commercial sales
stage of development. Similarly, we do not expect a source owner to
conduct extended trials to learn how to apply a technology on a totally
new and dissimilar source type. Consequently, you would not consider
technologies in the pilot scale testing stages of development as
``available'' for purposes of BART review.
3. Commercial availability by itself, however, is not necessarily a
sufficient basis for concluding a technology to be applicable and
therefore technically feasible. Technical feasibility, as determined in
Step 2, also means a control option may reasonably be deployed on or
``applicable'' to the source type under consideration.
Because a new technology may become available at various points in
time during the BART analysis process, we believe that guidelines are
needed on when a technology must be considered. For example, a
technology may become available during the public comment period on the
State's rule development process. Likewise, it is possible that new
technologies may become available after the close of the State's public
comment period and before submittal of the SIP to EPA, or during EPA's
review process on the SIP submittal. In order to provide certainty in
the process, we propose that all technologies be considered if
available before the close of the State's public comment period. You
need not consider technologies that become available after this date.
As part of your analysis, you should consider any technologies brought
to your attention in public comments. If you disagree with public
comments asserting that the technology is available, you should provide
an explanation for the public record as to the basis for your conclusion.

What Do We Mean by ``Applicable'' Technology?

You need to exercise technical judgment in determining whether a
control alternative is applicable to the source type under
consideration. In general, a commercially available control option will
be presumed applicable if it has been or is soon to be deployed (e.g.,
is specified in a permit) on the same or a similar source type. Absent
a showing of this type, you evaluate technical feasibility by examining
the physical and chemical characteristics of the pollutant-bearing gas
stream, and comparing them to the gas stream characteristics of the
source types to which the technology had been applied previously.
Deployment of the control technology on a new or existing source with
similar gas stream characteristics is generally a sufficient basis for
concluding the technology is technically feasible barring a
demonstration to the contrary as described below. What type of
demonstration is required if I conclude that an option is not
technically feasible?
1. Where you assert that a control option identified in Step 1 is
technically infeasible, you should make a factual demonstration that
the option is commercially unavailable, or that unusual circumstances
preclude its application to a particular emission unit. Generally, such
a demonstration involves an evaluation of the characteristics of the
pollutant-bearing gas stream and the capabilities of the technology.
Alternatively, a demonstration of technical infeasibility may involve a
showing that there are unresolvable technical difficulties with
applying the control to the source (e.g., size of the unit, location of
the proposed site, or operating problems related to specific
circumstances of the source). Where the resolution of technical
difficulties is a matter of cost, you should consider the technology to
be technically feasible. The cost of a control alternative is
considered later in the process.
2. The determination of technical feasibility is sometimes
influenced by recent air quality permits. In some cases, an air quality
permit may require a certain level of control, but the level of control
in a permit is not expected to be achieved in practice (e.g., a source
has received a permit but the project was canceled, or every operating
source at that permitted level has been physically unable to achieve
compliance with the limit). Where this is the case, you should provide
supporting documentation showing why such limits are not technically
feasible, and, therefore, why the level of control (but not necessarily
the technology) may be eliminated from further consideration. However,
if there is a permit requiring the application of a certain technology
or emission limit to be achieved for such technology (especially as a
retrofit for an existing emission unit), this usually is sufficient
justification for you to assume the technical feasibility of that
technology or emission limit.
3. Physical modifications needed to resolve technical obstacles do
not, in and of themselves, provide a justification for eliminating the
control technique on the basis of technical infeasibility. However, you
may consider the cost of such modifications in estimating costs. This,
in turn, may form the basis for eliminating a control technology (see
later discussion).
4. Vendor guarantees may provide an indication of commercial
availability and the technical feasibility of a control technique and
could contribute to a determination of technical feasibility or
technical infeasibility, depending on circumstances. However, we do not
consider a vendor guarantee alone to be sufficient justification that a
control option will work. Conversely, lack of a vendor guarantee by
itself does not present sufficient justification that a control option
or an emissions limit is technically infeasible. Generally, you should
make decisions about technical feasibility based on chemical, and
engineering analyses (as discussed above), in conjunction with
information about vendor guarantees.
5. A possible outcome of the BART procedures discussed in these
guidelines is the evaluation of multiple control technology
alternatives which result in essentially equivalent emissions. It is
not our intent to encourage evaluation of unnecessarily large numbers
of control alternatives for every emissions unit. Consequently, you
should use judgment in deciding on those alternatives for which you
will conduct the detailed impacts analysis (Step 4 below). For example,
if two or more control techniques result in control levels that are
essentially

[[Page 25222]]

identical, considering the uncertainties of emissions factors and other
parameters pertinent to estimating performance, you may evaluate only
the less costly of these options. You should narrow the scope of the
BART analysis in this way, only if there is a negligible difference in
emissions and energy and non-air quality environmental impacts between
control alternatives.
3. STEP 3: How Do I Develop a Ranking of the Technically Feasible
Alternatives?
Step 3 involves ranking all the technically feasible control
alternatives identified in Step 2. For the pollutant and emissions unit
under review, you rank the control alternatives from the most to the
least effective in terms of emission reduction potential.
Two key issues that must be addressed in this process include:
(1) Making sure that you express the degree of control using a
metric that ensures an ``apples to apples'' comparison of emissions
performance levels among options, and
(2) Giving appropriate treatment and consideration of control
techniques that can operate over a wide range of emission performance
levels.

What Are the Appropriate Metrics for Comparison?

This issue is especially important when you compare inherently
lower-polluting processes to one another or to add-on controls. In such
cases, it is generally most effective to express emissions performance
as an average steady state emissions level per unit of product produced
or processed.
Examples of common metrics:
? Pounds of SO₂ emissions per million Btu heat
input, and
? pounds of NO_X emissions per ton of cement produced.
How Do I Evaluate Control Techniques With a Wide Range of Emission
Performance Levels?
1. Many control techniques, including both add-on controls and
inherently lower polluting processes, can perform at a wide range of
levels. Scrubbers and high and low efficiency electrostatic
precipitators (ESPs) are two of the many examples of such control
techniques that can perform at a wide range of levels. It is not our
intent to require analysis of each possible level of efficiency for a
control technique, as such an analysis would result in a large number
of options. It is important, however, that in analyzing the technology
you take into account the most stringent emission control level that
the technology is capable of achieving. You should use the most recent
regulatory decisions and performance data (e.g., manufacturer's data,
engineering estimates and the experience of other sources) to identify
an emissions performance level or levels to evaluate.
2. In assessing the capability of the control alternative, latitude
exists to consider any special circumstances pertinent to the specific
source under review, or regarding the prior application of the control
alternative. However, you must document the basis for choosing the
alternate level (or range) of control in the BART analysis. Without a
showing of differences between the source and other sources that have
achieved more stringent emissions limits, you should conclude that the
level being achieved by those other sources is representative of the
achievable level for the source being analyzed.
3. You may encounter cases where you may wish to evaluate other
levels of control in addition to the most stringent level for a given
device. While you must consider the most stringent level as one of the
control options, you may consider less stringent levels of control as
additional options. This would be useful, particularly in cases where
the selection of additional options would have widely varying costs and
other impacts.
4. Finally, we note that for retrofitting existing sources in
addressing BART, you should consider ways to improve the performance of
existing control devices, particularly when a control device is not
achieving the level of control that other similar sources are achieving
in practice with the same device.
How Do I Rank the Control Options?
After determining the emissions performance levels (using
appropriate metrics of comparison) for each control technology option
identified in Step 2, you establish a list that identifies the most
stringent control technology option. Each other control option is then
placed after this alternative in a ranking according to its respective
emissions performance level, ranked from lowest emissions to highest
emissions (most effective to least stringent effective emissions
control alternative). You should do this for each pollutant and for
each emissions unit (or grouping of similar units) subject to a BART
analysis.
4. STEP 4: For a BART Engineering Analysis, What Impacts Must I
Calculate and Report? What Methods Does EPA Recommend for the Impacts
Analysis?
After you identify and rank the available and technically feasible
control technology options, you must then conduct three types of
impacts analyses when you make a BART determination:

Impact analysis part 1: costs of compliance, (taking into account the
remaining useful life of the facility)
Impact analysis part 2: energy impacts, and
Impact analysis part 3: non-air quality environmental impacts.

In this section, we describe how to conduct each of these three
analyses. You are responsible for presenting an evaluation of each
impact along with appropriate supporting information. You should
discuss and, where possible, quantify both beneficial and adverse
impacts. In general, the analysis should focus on the direct impact of
the control alternative.
a. Impact Analysis Part 1: How Do I Estimate the Costs of Control?
1. To conduct a cost analysis, you: (1) Identify the emissions
units being controlled, (2) identify design parameters for emission
controls, and (3) develop cost estimates based upon those design
parameters.
2. It is important to identify clearly the emission units being
controlled, that is, to specify a well-defined area or process segment
within the plant. In some cases, multiple emission units can be
controlled jointly. However, in other cases, it may be appropriate in
the cost analysis to consider whether multiple units will be required
to install separate and/or different control devices. The engineering
analysis should provide a clear summary list of equipment and the
associated control costs. Inadequate documentation of the equipment
whose emissions are being controlled is a potential cause for confusion
in comparison of costs of the same controls applied to similar sources.
3. You then specify the control system design parameters. Potential
sources of these design parameters include equipment vendors,
background information documents used to support NSPS development,
control technique guidelines documents, cost manuals developed by EPA,
control data in trade publications, and engineering and performance
test data. The following are a few examples of design parameters for
two example control measures:

[[Page 25223]]

------------------------------------------------------------------------
Control device Examples of design parameters
------------------------------------------------------------------------
Wet Scrubbers.......................... Type of sorbent used (lime,
limestone, etc.)
Gas pressure drop Liquid/gas
ratio
Selective Catalytic Reduction.......... Ammonia to NOX molar ratio
Pressure drop Catalyst life
------------------------------------------------------------------------

4. The value selected for the design parameter should ensure that
the control option will achieve the level of emission control being
evaluated. You should include in your analysis, documentation of your
assumptions regarding design parameters. Examples of supporting
references would include the Office of Air Quality Planning and
Standards (OAQPS) Control Cost Manual (see below) and background
information documents used for NSPS and hazardous pollutant emission
standards. If the design parameters you specified differ from typical
designs, you should document the difference by supplying performance
test data for the control technology in question applied to the same
source or a similar source.
5. Once the control technology alternatives and achievable
emissions performance levels have been identified, you then develop
estimates of capital and annual costs. The basis for equipment cost
estimates also should be documented, either with data supplied by an
equipment vendor (i.e., budget estimates or bids) or by a referenced
source (such as the OAQPS Control Cost Manual, Fifth Edition, February
1996, EPA 453/B-96-001).\10\ In order to maintain and improve
consistency, cost estimates should be based on the EPA/OAQPS Control
Cost Manual, where possible.\11\ The Control Cost Manual addresses most
control technologies in sufficient detail for a BART analysis. While
the types of site-specific analyses contained in the Control Cost
Manual are less precise than those based upon a detailed engineering
design, normally the estimates provide results that are plus or minus
30 percent, which is generally sufficient for the BART review. The cost
analysis should take into account site-specific conditions that are out
of the ordinary (e.g., use of a more expensive fuel or additional waste
disposal costs) that may affect the cost of a particular BART
technology option.
---------------------------------------------------------------------------

\10\ The Control Cost Manual is updated periodically. While this
citation refers to the latest version at the time this guidance was
written, you should use the version that is current as of when you
conduct your impact analysis. This document is available at the
following Web site: http://www.epa.gov/ttn/catc/dir1/chpt2acr.pdf
\11\ You should include documentation for any additional
information you used for the cost calculations, including any
information supplied by vendors that affects your assumptions
regarding purchased equipment costs, equipment life, replacement of
major components, and any other element of the calculation that
differs from the Control Cost Manual.
---------------------------------------------------------------------------

b. How Do I Take Into Account a Project's ``Remaining Useful Life'' In
Calculating Control Costs?
1. You treat the requirement to consider the source's ``remaining
useful life'' of the source for BART determinations as one element of
the overall cost analysis. The ``remaining useful life'' of a source,
if it represents a relatively short time period, may affect the
annualized costs of retrofit controls. For example, the methods for
calculating annualized costs in EPA's Control Cost Manual require the
use of a specified time period for amortization that varies based upon
the type of control. If the remaining useful life will clearly exceed
this time period, the remaining useful life has essentially no effect
on control costs and on the BART determination process. Where the
remaining useful life is less than the time period for amortizing
costs, you should use this shorter time period in your cost
calculations.
2. For purposes of these guidelines, the remaining useful life is
the difference between:
(1) January 1 of the year you are conducting the BART analysis (but
not later than January 1, 2007)\12\; and
---------------------------------------------------------------------------

\12\ The reason for the year 2007 is that the year 2007 is the
latest year for which a BART analysis will be conducted in order to
be included in a regional haze SIP.
---------------------------------------------------------------------------

(2) the date the facility permanently stops operations. Where this
affects the BART determination, this date must be assured by a
federally-enforceable restriction preventing further operation. A
projected closure date, without such a federally-enforceable
restriction, is not sufficient.
3. We recognize that there may be situations where a source
operator intends to shut down a source by a given date, but wishes to
retain the flexibility to continue operating beyond that date in the
event, for example, that market conditions change. Where this is the
case, your BART analysis may account for this, but it must maintain
consistency with the statutory requirement to install BART within 5
years. Where the source chooses not to accept a federally enforceable
condition requiring the source to shut down by a given date, it is
necessary to determine whether a reduced time period for the remaining
useful life changes the level of controls that would have been required
as BART. If the reduced time period does change the level of BART
controls, you may identify, and include as part of the BART emission
limitation, the more stringent level of control that would be required
as BART if there were no assumption that reduced the remaining useful
life. You may incorporate into the BART emission limit this more
stringent level, which would serve as a contingency should the source
continue operating more than 5 years after the date EPA approves the
relevant SIP. The source would not be allowed to operate after the 5-
year mark without such controls. If a source does operate after the 5-
year mark without BART in place, the source is considered to be in
violation of the BART emissions limit for each day of operation.
c. What Do We Mean by Cost Effectiveness?
Cost effectiveness, in general, is a criterion used to assess the
potential for achieving an objective in the most economical way. For
purposes of air pollutant analysis, ``effectiveness'' is measured in
terms of tons of pollutant emissions removed, and ``cost'' is measured
in terms of annualized control costs. We recommend two types of cost-
effectiveness calculations--average cost effectiveness, and incremental
cost effectiveness.
In the cost analysis, you should take care to not focus on
incomplete results or partial calculations. For example, large capital
costs for a control option alone would not preclude selection of a
control measure if large emissions reductions are projected. In such a
case, low or reasonable cost effectiveness numbers may validate the
option as an appropriate BART alternative irrespective of the large
capital costs. Similarly, projects with relatively low capital costs
may not be cost effective if there are few emissions reduced.
d. How Do I Calculate Average Cost Effectiveness?
Average cost effectiveness means the total annualized costs of
control divided by annual emissions reductions (the difference between
baseline annual emissions and the estimate of emissions after
controls), using the following formula:

Average cost effectiveness (dollars per ton removed) = Control option
annualized cost \13\ Baseline annual

[[Page 25224]]

emissions--Annual emissions with Control option
---------------------------------------------------------------------------

\13\ Whenever you calculate or report annual costs, you should
indicate the year for which the costs are estimated. For example, if
you use the year 2000 as the basis for cost comparisons, you would
report that an annualized cost of $20 million would be: $20 million
(year 2000 dollars).
---------------------------------------------------------------------------

Because you calculate costs in (annualized) dollars per year ($/yr)
and because you calculate emissions rates in tons per year (tons/yr),
the result is an average cost-effectiveness number in (annualized)
dollars per ton ($/ton) of pollutant removed.
e. How Do I Calculate Baseline Emissions?
1. The baseline emissions rate should represent a realistic
depiction of anticipated annual emissions for the source. In general,
for the existing sources subject to BART, you will estimate the
anticipated annual emissions based upon actual emissions from a
baseline period.
2. When you project that future operating parameters (e.g., limited
hours of operation or capacity utilization, type of fuel, raw materials
or product mix or type) will differ from past practice, and if this
projection has a deciding effect in the BART determination, then you
must make these parameters or assumptions into enforceable limitations.
In the absence of enforceable limitations, you calculate baseline
emissions based upon continuation of past practice.
3. For example, the baseline emissions calculation for an emergency
standby generator may consider the fact that the source owner would not
operate more than past practice of 2 weeks a year. On the other hand,
baseline emissions associated with a base-loaded turbine should be
based on its past practice which would indicate a large number of hours
of operation. This produces a significantly higher level of baseline
emissions than in the case of the emergency/standby unit and results in
more cost-effective controls. As a consequence of the dissimilar
baseline emissions, BART for the two cases could be very different.
f. How Do I Calculate Incremental Cost Effectiveness?
1. In addition to the average cost effectiveness of a control
option, you should also calculate incremental cost effectiveness. You
should consider the incremental cost effectiveness in combination with
the total cost effectiveness in order to justify elimination of a
control option. The incremental cost effectiveness calculation compares
the costs and emissions performance level of a control option to those
of the next most stringent option, as shown in the following formula:

Incremental Cost Effectiveness (dollars per incremental ton removed) =
(Total annualized costs of control option)--(Total annualized costs of
next control option) / (Next control option annual emissions)--(Control
option annual emissions)

Example 1: Assume that Option F on Figure 2 has total annualized
costs of $1 million to reduce 2000 tons of a pollutant, and that
Option D on Figure 2 has total annualized costs of $500,000 to
reduce 1000 tons of the same pollutant. The incremental cost
effectiveness of Option F relative to Option D is ($1 million--
$500,000) divided by (2000 tons--1000 tons), or $500,000 divided by
1000 tons, which is $500/ton.
Example 2: Assume that two control options exist: Option 1 and
Option 2. Option 1 achieves a 1,000 ton/yr reduction at an annual
cost of $1,900,000. This represents an average cost of ($1,900,000/
1,000 tons) = $1,900/ton. Option 2 achieves a 980 tons/yr reduction
at an annual cost of $1,500,000. This represents an average cost of
($1,500,000/980 tons) = $1,531/ton. The incremental cost
effectiveness of Option 1 relative to Option 2 is ($1,900,000--
$1,500,000) divided by (1,000 tons--980 tons). The adoption of
Option 1 instead of Option 2 results in an incremental emission
reduction of 20 tons per year at an additional cost of $400,000 per
year. The incremental cost of Option 1, then, is $20,000 per ton--11
times the average cost of $1,900 per ton. While $1,900 per ton may
still be deemed reasonable, it is useful to consider both the
average and incremental cost in making an overall cost-effectiveness
finding. Of course, there may be other differences between these
options, such as, energy or water use, or non-air environmental
effects, which also should be considered in selecting a BART technology.

2. You should exercise care in deriving incremental costs of
candidate control options. Incremental cost-effectiveness comparisons
should focus on annualized cost and emission reduction differences
between ``dominant'' alternatives. To identify dominant alternatives,
you generate a graphical plot of total annualized costs for total
emissions reductions for all control alternatives identified in the
BART analysis, and by identifying a ``least-cost envelope'' as shown in
Figure 2. (A ``least-cost envelope'' represents the set of options that
should be dominant in the choice of a specific option.)
BILLING CODE 6560-50-P

[[Page 25225]]
[GRAPHIC]
[TIFF OMITTED]
TP05MY04.000
BILLING CODE 6560-50-C
Figure 2. Least-Cost Envelope
Example: Eight technically feasible control options for analysis
are listed in the BART ranking. These are represented as A through H
in Figure 2. The dominant set of control options, B, D, F, G, and H,
represent the least-cost envelope, as we depict by the cost curve
connecting them. Points A, C and E are inferior options, and you
should not use them in calculating incremental cost effectiveness.
Points A, C and E represent inferior controls because B will buy
more emissions reductions for less money than A; and similarly, D
and F will buy more reductions for less money than C and E, respectively.

3. In calculating incremental costs, you:
(1) Rank the control options in ascending order of annualized total
costs,
(2) Develop a graph of the most reasonable smooth curve of the
control options, as shown in Figure 2. This is to show the ``least-cost
envelope'' discussed above; and
(3) Calculate the incremental cost effectiveness for each dominant
option, which is the difference in total annual costs between that
option and the next most stringent option, divided by the difference in
emissions reductions between those two options. For example, using
Figure 2, you would calculate incremental cost effectiveness

[[Page 25226]]

for the difference between options B and D, options D and F, options F
and G, and options G and H.
4. A comparison of incremental costs can also be useful in
evaluating the viability of a specific control option over a range of
efficiencies. For example, depending on the capital and operational
cost of a control device, total and incremental cost may vary
significantly (either increasing or decreasing) over the operational
range of a control device. Also, the greater the number of possible
control options that exist, the more weight should be given to the
incremental costs vs. average costs.
5. In addition, when you evaluate the average or incremental cost
effectiveness of a control alternative, you should make reasonable and
supportable assumptions regarding control efficiencies. An
unrealistically low assessment of the emission reduction potential of a
certain technology could result in inflated cost-effectiveness figures.
g. What Other Information Should I Provide in the Cost Impacts Analysis?
You should provide documentation of any unusual circumstances that
exist for the source that would lead to cost-effectiveness estimates
that would exceed that for recent retrofits. This is especially
important in cases where recent retrofits have cost-effectiveness
values that are within what has been considered a reasonable range, but
your analysis concludes that costs for the source being analyzed are
not considered reasonable. (A reasonable range would be a range that is
consistent with the range of cost effectiveness values used in other
similar permit decisions over a period of time.)

Example: In an arid region, large amounts of water are needed
for a scrubbing system. Acquiring water from a distant location
could greatly increase the cost effectiveness of wet scrubbing as a
control option.
h. Impact Analysis Part 2: How Should I Analyze and Report Energy Impacts?
1. You should examine the energy requirements of the control
technology and determine whether the use of that technology results in
any significant or unusual energy penalties or benefits. A source owner
may, for example, benefit from the combustion of a concentrated gas
stream rich in volatile organic compounds; on the other hand, more
often extra fuel or electricity is required to power a control device
or incinerate a dilute gas stream. If such benefits or penalties exist,
they should be quantified and included in the cost analysis. Because
energy penalties or benefits can usually be quantified in terms of
additional cost or income to the source, the energy impacts analysis
can, in most cases, simply be factored into the cost impacts analysis.
However, certain types of control technologies have inherent energy
penalties associated with their use. While you should quantify these
penalties, so long as they are within the normal range for the
technology in question, you should not consider such penalties to be an
adequate justification for eliminating that technology from consideration.
2. Your energy impact analysis should consider only direct energy
consumption and not indirect energy impacts. For example, you could
estimate the direct energy impacts of the control alternative in units
of energy consumption at the source (e.g., BTU, kWh, barrels of oil,
tons of coal). The energy requirements of the control options should be
shown in terms of total (and in certain cases, also incremental) energy
costs per ton of pollutant removed. You can then convert these units
into dollar costs and, where appropriate, factor these costs into the
control cost analysis.
3. You generally do not consider indirect energy impacts (such as
energy to produce raw materials for construction of control equipment).
However, if you determine, either independently or based on a showing
by the source owner, that the indirect energy impact is unusual or
significant and that the impact can be well quantified, you may
consider the indirect impact.
4. The energy impact analysis may also address concerns over the
use of locally scarce fuels. The designation of a scarce fuel may vary
from region to region. However, in general, a scarce fuel is one which
is in short supply locally and can be better used for alternative
purposes, or one which may not be reasonably available to the source
either at the present time or in the near future.
5. Finally, the energy impacts analysis may consider whether there
are relative differences between alternatives regarding the use of
locally or regionally available coal, and whether a given alternative
would result in significant economic disruption or unemployment. For
example, where two options are equally cost effective and achieve
equivalent or similar emissions reductions, one option may be preferred
if the other alternative results in significant disruption or unemployment.
i. Impact Analysis Part 3: How Do I Analyze ``Non-Air Quality
Environmental Impacts?'
1. In the non-air quality related environmental impacts portion of
the BART analysis, you address environmental impacts other than air
quality due to emissions of the pollutant in question. Such
environmental impacts include solid or hazardous waste generation and
discharges of polluted water from a control device.
2. You should identify any significant or unusual environmental
impacts associated with a control alternative that have the potential
to affect the selection or elimination of a control alternative. Some
control technologies may have potentially significant secondary
environmental impacts. Scrubber effluent, for example, may affect water
quality and land use. Alternatively, water availability may affect the
feasibility and costs of wet scrubbers. Other examples of secondary
environmental impacts could include hazardous waste discharges, such as
spent catalysts or contaminated carbon. Generally, these types of
environmental concerns become important when sensitive site-specific
receptors exist or when the incremental emissions reductions potential
of the more stringent control is only marginally greater than the next
most-effective option. However, the fact that a control device creates
liquid and solid waste that must be disposed of does not necessarily
argue against selection of that technology as BART, particularly if the
control device has been applied to similar facilities elsewhere and the
solid or liquid waste is similar to those other applications. On the
other hand, where you or the source owner can show that unusual
circumstances at the proposed facility create greater problems than
experienced elsewhere, this may provide a basis for the elimination of
that control alternative as BART.
3. The procedure for conducting an analysis of non-air quality
environmental impacts should be made based on a consideration of site-
specific circumstances. It is not necessary to perform this analysis of
environmental impacts for the entire list of technologies you ranked in
Step 3, if you propose to adopt the most stringent alternative. In
general, the analysis need only address those control alternatives with
any significant or unusual environmental impacts that have the
potential to affect the selection of a control alternative, or
elimination of a more stringent control alternative. Thus, any
important relative environmental impacts (both positive and negative) of

[[Page 25227]]

alternatives can be compared with each other.
4. In general, the analysis of impacts starts with the
identification and quantification of the solid, liquid, and gaseous
discharges from the control device or devices under review. Initially,
you should perform a qualitative or semi-quantitative screening to
narrow the analysis to discharges with potential for causing adverse
environmental effects. Next, you should assess the mass and composition
of any such discharges and quantify them to the extent possible, based
on readily-available information. You should also assemble pertinent
information about the public or environmental consequences of releasing
these materials.
j. What Are Examples of Non-Air Quality Environmental Impacts?
The following are examples of how to conduct non-air quality
environmental impacts:
(1) Water Impact
You should identify the relative quantities of water used and water
pollutants produced and discharged as a result of the use of each
alternative emission control system relative to the most stringent
alternative. Where possible, you should assess the effect on ground
water and such local surface water quality parameters as ph, turbidity,
dissolved oxygen, salinity, toxic chemical levels, temperature, and any
other important considerations. The analysis should consider whether
applicable water quality standards will be met and the availability and
effectiveness of various techniques to reduce potential adverse effects.
(2) Solid Waste Disposal Impact
You should compare the quality and quantity of solid waste (e.g.,
sludges, solids) that must be stored and disposed of or recycled as a
result of the application of each alternative emission control system
with the quality and quantity of wastes created with the most stringent
emission control system. You should consider the composition and
various other characteristics of the solid waste (such as permeability,
water retention, rewatering of dried material, compression strength,
leachability of dissolved ions, bulk density, ability to support
vegetation growth and hazardous characteristics) which are significant
with regard to potential surface water pollution or transport into and
contamination of subsurface waters or aquifers.
(3) Irreversible or Irretrievable Commitment of Resources
You may consider the extent to which the alternative emission
control systems may involve a trade-off between short-term
environmental gains at the expense of long-term environmental losses
and the extent to which the alternative systems may result in
irreversible or irretrievable commitment of resources (for example, use
of scarce water resources).
(4) Other Adverse Environmental Impacts
You may consider significant differences in noise levels, radiant
heat, or dissipated static electrical energy. Other examples of non-air
quality environmental impacts would include hazardous waste discharges
such as spent catalysts or contaminated carbon. Generally, these types
of environmental concerns become important when the plant is located in
an area that is particularly sensitive to environmental degradation and
when the incremental emissions reductions potential of the most
stringent control option is only marginally greater than the next most-
effective option, but the environmental impact is of greater concern.
(5) Benefits to the Environment
It is important to consider relative differences between options
regarding their beneficial impacts to non-air quality-related
environmental media. For example, you may consider whether a given
control option results in less deposition of pollutants, in particular
nitrogen compounds, to nearby sensitive water bodies (lakes, rivers,
coastal waters). You may also consider effects which may be unique to
high elevation ecosystems. In some eastern Class I areas with
elevations above 1000 meters, there may be direct deposition of acid
and nitrogen compounds on vegetation and soil from cloud impacts.
Growth rates and competition between alien and native species might be
affected by pollution loadings as well. As part of the consultation
requirement between States and the Federal Land Managers in 40 CFR
51.308(i)(2), we expect the Federal Land Managers to provide
information on non-air quality indicators to be considered in
determining BART and other implementation strategies. The States should
also consider such information available from other sources, such as
public comments.
5. Step 5: How Should I Determine Visibility Impacts in the BART
Determination?
The following is the approach to determine visibility impacts (the
degree of visibility improvement for each source subject to BART) in
the BART determination. You may elect to conduct the modeling or
require the source to conduct the modeling. If modeling is to be
conducted for receptors greater than 200 km from the emission unit, a
modeling protocol is required. If the source is conducting the
modeling, you should review and approve or disapprove of the source's
analysis. Note that distances from the actual BART-eligible emission
unit that is modeled to each Class I area should be measured from the
nearest point in the Class I area. All receptors in the Class I area
should be analyzed. The State should bear in mind that, for sources 50
km from a Class I area, some receptors within that Class I area may be
less than 50 km from the source while other receptors within that same
Class I area may be greater than 50 km from the same source; this
situation may result in two different modeling approaches for the same
Class I area and source, depending upon the State's chosen method for
modeling sources less than 50 km.
1. For receptors in the Class I area that are greater than or equal
to 50 km from the emission unit:
(1) Run CALPUFF, at pre-control allowable emission rates and post-
control allowable emission rates.
For CALPUFF setup (meteorological data and parameter settings), we
recommend following EPA's Interagency Workgroup on Air Quality Modeling
(IWAQM) Phase 2 Summary Report and Recommendations for Modeling Long
Range Transport Impacts. Choose an emission control level representing
the most stringent control option available for the post-control scenario.
(2) Tabulate Results;
(i) Calculate 24-hr values for each receptor as the change in
deciviews compared against natural visibility conditions (conditions
that are estimated to exist in a given Class I area in the absence of
human-caused impairment). Tabulate pre-control and post-control results.
(b) Make the net visibility improvement determination:
(i) Assess the visibility improvement based on the change in
visibility impact of the average 20% worst modeled days between the
pre-control and post-control emission rates. For example, if average
impact from the 20% worst days

[[Page 25228]]

for a source's pre-control emission rates for a particular receptor is
a change of 1.0 deciviews, and its post-control impact is 0.4
deciviews, the net visibility improvement is 0.6 deciviews (60%). All
receptors in the Class I area should be analyzed.
2. For sources that have not determined their degree of visibility
improvement under 1. above and where all receptors at a Class I area
are less than 50 km from the BART-eligible unit:
(1) Estimate visibility impacts for pre-control and post-control
emissions. Give consideration to CALPUFF or other EPA-approved methods
or local scale models for determining visibility impacts for pre-
controlled and post-controlled emissions.
(2) Estimate the degree of visibility improvement expected.
Note that each of the modeling options may be supplemented with
source apportionment data or source apportionment modeling that is
acceptable to the State and the EPA regional office.

F. How Do I Select the ``Best'' Alternative, Using the Results of Steps
1 Through 5?

1. Summary of the Impacts Analysis
From the alternatives you ranked in Step 3, you should develop a
chart (or charts) displaying for each of the ranked alternatives:
(1) Expected emission rate (tons per year, pounds per hour);
(2) Emissions performance level (e.g., percent pollutant removed,
emissions per unit product, lb/MMbtu, ppm);
(3) Expected emissions reductions (tons per year);
(4) Costs of compliance--total annualized costs ($), cost
effectiveness ($/ton), and incremental cost effectiveness ($/ton);
(5) Energy impacts (indicate any significant energy benefits or
disadvantages);
(6) Non-air quality environmental impacts (includes any significant
or unusual other media impacts, e.g., water or solid waste), both
positive and negative; and
(7) Modeled visibility impacts.
2. Selecting a ``Best'' Alternative
1. As discussed above, we are seeking comment on two alternative
approaches for evaluating control options for BART. The first involves
a sequential process for conducting the impacts analysis that begins
with a complete evaluation of the most stringent control option. Under
this approach, you determine that the most stringent alternative in the
ranking does not impose unreasonable costs of compliance, taking into
account both average and incremental costs, then the analysis begins
with a presumption that this level is selected. You then proceed to
considering whether energy and non-air quality environmental impacts
would justify selection of an alternative control option. If there are
no outstanding issues regarding energy and non-air quality
environmental impacts, the analysis is ended and the most stringent
alternative is identified as the ``best system of continuous emission
reduction.''
2. If you determine that the most stringent alternative is
unacceptable due to such impacts, you need to document the rationale
for this finding for the public record. Then, the next most-effective
alternative in the listing becomes the new control candidate and is
similarly evaluated. This process continues until you identify a
technology which does not pose unacceptable costs of compliance, energy
and/or non-air quality environmental impacts.
3. We also request comment on an alternative decision-making
approach that would not begin with an evaluation of the most stringent
control option. For example, you could choose to begin the BART
determination process by evaluating the least stringent, technically
feasible control option or by evaluating an intermediate control option
drawn from the range of technically feasible control alternatives.
Under this approach, you would then consider the additional emissions
reductions, costs, and other effects (if any) of successively more
stringent control options. Under such an approach, you would still be
required to (1) display and rank all of the options in order of control
effectiveness and to identify the average and incremental costs of each
option; (2) consider the energy and non-air quality environmental
impacts of each option; and (3) provide a justification for adopting
the technology that you select as the ``best'' level of control,
including an explanation as to why you rejected other more stringent
control technologies.
4. In the case where you are conducting a BART determination for
two regulated pollutants on the same source, if the result is two
different BART technologies that do not work well together, you could
then substitute a different technology or combination of technologies,
provided that they achieve at least the same emissions reductions for
each pollutant.
3. In Selecting a ``Best'' Alternative, Should I Consider the
Affordability of Controls?
1. Even if the control technology is cost effective, there may be
cases where the installation of controls would affect the viability of
continued plant operations.
2. As a general matter, for plants that are essentially
uncontrolled at present, and emit at much greater levels per unit of
production than other plants in the category, we are unlikely to accept
as BART any analysis that preserves a source's uncontrolled status.
While this result may predict the shutdown of some facilities, we
believe that the flexibility provided in the regional haze rule for an
alternative reduction approach, such as an emissions trading program,
will minimize the likelihood of forced shutdowns.
3. Nonetheless, we recognize there may be unusual circumstances
that justify taking into consideration the conditions of the plant and
the economic effects of requiring the use of a given control
technology. These effects would include effects on product prices, the
market share, and profitability of the source. We do not intend, for
example, that the most stringent alternative must always be selected,
if that level would cause a plant to shut down, while a slightly lesser
degree of control would not have this effect. Where there are such
unusual circumstances that are judged to have a severe effect on plant
operations, you may take into consideration the conditions of the plant
and the economic effects of requiring the use of a control technology.
Where these effects are judged to have a severe impact on plant
operations you may consider them in the selection process, so long as
you provide an economic analysis that demonstrates, in sufficient
detail for a meaningful public review, the specific economic effects,
parameters, and reasoning. (We recognize that this review process must
preserve the confidentiality of sensitive business information). Any
analysis should consider whether other competing plants in the same
industry may also be required to install BART controls.
4. Sulfur Dioxide Limits for Utility Boilers
You must require 750 MW power plants to meet specific control
levels of either 95% control, or controls in the range of .1 to .15
lbs/MMBtu, for each EGU greater than 250 MW, unless you determine that
an alternative control level is clearly justified based on a careful
consideration of the statutory

[[Page 25229]]

factors. Thus, for example, if the source convincingly demonstrates
unique circumstances affecting its ability to cost-effectively reduce
its emissions, you should take that into account in determining whether
the presumptive levels of control are appropriate for that facility.
For an EGU greater than 250 MW in size, but located at a power plant
smaller than 750 MW in size, you should similarly find that such
controls are cost-effective as a general matter when taking into
consideration the costs of compliance in your BART analysis. You should
consider these control levels as the minimum that may be required.
While these levels may represent current control capabilities, we
expect that scrubber technology will continue to improve and control
costs continue to decline. You should be sure to consider the level of
control that is currently best achievable at the time that you are
conducting your BART analysis.
5. Nitrogen Oxide Limits for Utility Boilers
You should establish specific numerical limits for NO_X
control for each BART determination. For sources currently using
selective catalytic reduction (SCR) or selective non-catalytic
reduction (SNCR) for part of the year, you should presume that use of
those same controls year-round is highly cost-effective.
For all other utility boilers, you should also presume that a
NO_X emission limit of 0.2 lbs/MMBtu is cost-effective. Most
utility boilers can achieve a degree of removal of 0.2 lbs/MMBtu with
relatively inexpensive controls such as low NO_X burners and
combustion control. For those sources who cannot achieve this control
level without SCR, you may find SCR to be appropriate if you finds
visibility impacts that are of high enough concern to warrant the
additional capital cost.

V. Enforceable Limits/Compliance Date

To complete the BART process, you must establish enforceable
emission limits and require compliance within a given period of time.
In particular, you must establish an enforceable emission limit for
each subject emission unit at the source and for each pollutant subject
to review that is emitted from the source. In addition, you must
require compliance with the BART emission limitations no later than 5
years after EPA approves your regional haze SIP. If technological or
economic limitations in the application of a measurement methodology to
a particular emission unit would make an emissions limit infeasible,
you may prescribe a design, equipment, work practice, operation
standard, or combination of these types of standards. You should ensure
that any BART requirements are written in a way that clearly specifies
the individual emission unit(s) subject to BART review. Because the
BART requirements are ``applicable'' requirements of the CAA, they must
be included as title V permit conditions according to the procedures
established in 40 CFR part 70 or 40 CFR part 71.
Section 302(k) of the CAA requires emissions limits such as BART to
be met on a continuous basis. Although this provision does not
necessarily require the use of continuous emissions monitoring (CEMs),
it is important that sources employ techniques that ensure compliance
on a continuous basis. Monitoring requirements generally applicable to
sources, including those that are subject to BART, are governed by
other regulations. See, e.g., 40 CFR part 64 (compliance assurance
monitoring); 40 CFR 70.6(a)(3) (periodic monitoring); 40 CFR 70.6(c)(1)
(sufficiency monitoring). Note also that while we do not believe that
CEMs would necessarily be required for all BART sources, the vast
majority of electric generating units already employ CEM technology for
other programs, such as the acid rain program. In addition, emissions
limits must be enforceable as a practical matter (contain appropriate
averaging times, compliance verification procedures and recordkeeping
requirements). In light of the above, the permit must:
? Be sufficient to show compliance or noncompliance (i.e.,
through monitoring times of operation, fuel input, or other indices of
operating conditions and practices); and
? Specify a reasonable averaging time consistent with
established reference methods, contain reference methods for
determining compliance, and provide for adequate reporting and
recordkeeping so that air quality agency personnel can determine the
compliance status of the source.

VI. Emission Trading Program Overview

40 CFR 51.308(e)(2) allows States the option of implementing an
emissions trading program or other alternative measure instead of
requiring BART. This option provides the opportunity for achieving
better environmental results at a lower cost than under a source-by-
source BART requirement. A trading program must include participation
by BART sources, but may also include sources that are not subject to
BART. The program would allow for implementation during the first
implementation period of the regional haze rule (that is, by the year
2018) instead of the 5-year compliance period noted above. In this
section of the guidance, we provide an overview of the steps in
developing a trading program \14\ consistent with 40 CFR 51.308(e)(2).
---------------------------------------------------------------------------

\14\ We focus in this section on emission cap and trade programs
which we believe will be the most common type of economic incentive
program developed as an alternative to BART.
---------------------------------------------------------------------------

A. What Are the General Steps in Developing an Emission Trading Program?

1. The basic steps are to:
(1) Develop emission budgets;
(2) Allocate emission allowances to individual sources; and
(3) Develop a system for tracking individual source emissions and
allowances. (For example, procedures for transactions, monitoring,
compliance and other means of ensuring program accountability).
2. A good example of an emissions trading program is the acid rain
program under title IV of the CAA. The acid rain program is a national
program--it establishes a national emissions cap, allocates allowances
to individual sources, and allows trading of allowances between all
covered sources in the United States. The Ozone Transport Commission's
NO_X Memorandum of Understanding, and the NO_X SIP
call both provide for regional trading programs. The recently proposed
Interstate Air Quality Rule (69 FR 4566, January 30, 2004) would
establish statewide emissions budgets and allows for trading programs
to achieve the budgets. Other trading programs generally have applied
only to sources within a single State. In the proposed Interstate Air
Quality rule (IAQR) (69 FR 4566, January 30, 2004), we requested
comment on whether compliance with the IAQR by affected EGUs in
affected States would satisfy, for those sources, the BART requirements
of the CAA, provided that a State imposes the full amount of SO2 and
NO_X emissions reductions on EGUs that the IAQR deemed highly
cost effective. We are in the process of evaluating those comments.
Based on our current evaluation, we believe the IAQR, as proposed, is
clearly better than BART for those affected EGUs in the affected States
which we propose to cover under the IAQR. We thus expect that the final
IAQR would satisfy the BART requirements for affected EGUs that are
covered pursuant to the final IAQR.
3. In creating a trading program as an alternative to source-
specific BART, a

[[Page 25230]]

State may wish to work with other States through a regional planning
organization to develop a regional, multi-state program. Such a program
would provide greater opportunities for emission trading. Coordination
through the Regional Planning Organization (RPO) would ensure
compatibility of the core elements of the trading program--budgets,
allocations, tracking, etc.--between the SIPs and TIPs of participating
States and Tribes. The WRAP has adopted such a regional market trading
program as a backstop to its overall emission reduction program for
SO₂. Although regional trading programs require more
interstate coordination, we have expertise that we can offer to States
wishing to pursue such a program.

B. What Are Emission Budgets and Allowances?

An emissions budget is a limit, for a given source population, on
the total emissions amount \15\ that may be emitted by those sources
over a State or region. An emission budget is also referred to as an
``emission cap.''
---------------------------------------------------------------------------

\15\ An emission budget generally represents a total emission
amount for a single pollutant such as SO₂. As noted in
the preamble to the regional haze rule (64 FR 35743, July 1, 1999)
we believe that unresolved technical difficulties preclude inter-
pollutant trading at this time.
---------------------------------------------------------------------------

In general, the emission budget is subdivided into source-specific
amounts that we refer to as ``allowances.'' Generally, each allowance
equals one ton of emissions. Sources must hold allowances for all
emissions of the pollutant covered by the program that they emit. Once
you allocate the allowances, source owners have flexibility in
determining how they will meet their emissions limit. Source owners
have the options of:
(1) Emitting at the level of allowances they are allocated (for
example, by controlling emissions or curtailing operations),
(2) Emitting at amounts less than the allowance level, thus freeing
up allowances that may be used by other sources owned by the same
owner, or sold to another source owner, or
(3) Emitting at amounts greater than the allowance level, and
purchasing allowances from other sources or using excess allowances
from another plant under the same ownership.

C. What Criteria Must Be Met in Developing an Emission Trading Program
as an Alternative to BART?

Under the regional haze rule, an emission trading program must
achieve ``greater reasonable progress'' (that is, greater visibility
improvement) than would be achieved through the installation and
operation of source-specific BART. The ``greater reasonable progress''
demonstration involves the following steps, which are discussed in more
detail below:
(1) Identify the sources that are subject to BART,
(2) Calculate the emissions reductions that would be achieved if
BART were installed and operated on sources subject to BART,
(3) Demonstrate whether your emission budget achieves emission
levels that are equivalent to or less than the emissions levels that
would result if BART were installed and operated,
(4) Analyze whether implementing a trading program in lieu of BART
would likely lead to differences in the geographic distribution of
emissions within a region, and
(5) Demonstrate that the emission levels will achieve greater
progress in visibility than would be achieved if BART were installed
and operated on sources subject to BART.
1. How Do I Identify Sources Subject to BART?
For a trading program, you would identify sources subject to BART
in the same way as we described in sections II and III of these
guidelines.
2. How Do I Calculate the Emissions Reductions That Would Be Achieved
if BART Were Installed and Operated on These Sources?
1. For a trading program under 51.308(e)(2), you may identify these
emissions reductions by:
(1) Conducting a case-by-case analysis for each of the sources,
using the procedures described above in these guidelines in sections II
through V;
(2) Conducting an analysis for each source category that takes into
account the available technologies, the costs of compliance, the energy
impacts, the non-air quality environmental impacts, the pollution
control equipment in use, and the remaining useful life, on a category-
wide basis; or
(3) Conducting an analysis that combines considerations on both
source-specific and category-wide information.
2. For a category-wide analysis of available control options, you
develop cost estimates and estimates of energy and non-air quality
environmental impacts that you judge representative of the sources
subject to BART for a source category as a whole, rather than analyze
each source that is subject to BART. The basic steps of a category-wide
analysis are the same as for a source-specific analysis. You identify
technically feasible control options and rank them according to control
stringency. Next, you calculate the costs and cost effectiveness for
each control option, beginning with the most stringent option. Likely,
the category-wide estimate will represent a range of cost and cost-
effectiveness values rather than a single number. Next, you evaluate
the expected energy and non-air quality impacts (both positive and
negative impacts) to determine whether these impacts preclude selection
of a given alternative.
3. We note that States and RPOs have the flexibility to adopt an
approach to the category-wide analysis of BART that would involve the
evaluation of different levels of BART control options (e.g., all
measures less than $1000/ton vs. all measures less than $2000/ton vs.
all measures less than $3000/ton) through an iterative process of
assessing relative changes in cumulative visibility impairment. For
example, States or regional planning organizations could use $1000 or
$2000/ton as an initial cutoff for selecting reasonable control
options. The States or regional planning organizations could then
compare the across-the-board regional emissions and visibility changes
resulting from the implementation of the initial control option and
that resulting from the implementation of control options with a $3000/
ton cutoff (or $1500/ton, etc). This approach would allow States and
other stakeholders to understand the visibility differences among BART
control options achieving less cost-effective or more cost-effective
levels of overall control.
3. For a Cap and Trade Program, How Do I Demonstrate That My Emission
Budget Results in Emission Levels That Are Equivalent To or Less Than
the Emissions Levels That Would Result if BART Were Installed and Operated?
Emissions budgets must address two criteria. First, you must
develop an emissions budget for a future year \16\ which ensures
reductions in actual emissions that achieve greater reasonable
visibility progress than BART. This will generally necessitate
development of a ``baseline forecast'' of emissions for the population
of sources included within the budget. A baseline forecast is a
prediction of the future emissions for that source population in
absence of either BART or the alternative trading program. Second, you
must take into consideration the

[[Page 25231]]

timing of the emission budget relative to the timetable for BART. If
the implementation timetable for the emission trading program is a
significantly longer period than the 5-year time period for BART
implementation, you should establish budgets for interim years that
ensure steady and continuing progress in emissions reductions.
---------------------------------------------------------------------------

\16\ As required by 40 CFR 51.308(e)(2)(iii), emissions
reductions must take place during the period of the first long-term
strategy for regional haze. This means the reductions must take
place no later than the year 2018.
---------------------------------------------------------------------------

In evaluating whether the program milestone for the year 2018
provides for a BART-equivalent or better emission inventory total, you
conduct the following steps:
(1) Identify the source population included within the budget,
which must include all BART sources and may include other sources,
(2) For sources included within the budget, develop a base year
\17\ emissions inventory for stationary sources included within the
budget, using the most current available emission inventory,
---------------------------------------------------------------------------

\17\ See 2002 Base Year Emission Inventory SIP Planning: 8-hr
Ozone, PM2.5 and Regional Haze Programs. memorandum of November 18,
2002, from Lydia Wegman and Peter Tsirigotis. This document is
available at the following Web site: http://www.epa.gov/ttn/oarpg/t1/memoranda/2002bye_gm.pdf.

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

(3) Develop a future emissions inventory for the milestone year (in
most cases, the year 2018), that is, an inventory of projected
emissions for the milestone year in the absence of BART or a trading
program,
(4) Calculate the reductions from the forecasted emissions if BART
were installed on all sources subject to BART,
(5) Subtract this amount from the forecasted total, and
(6) Compare the budget you have selected and confirm that it does
not exceed this level of emissions.

Example: For a given region for which a budget is being
developed for SO₂, the most recent inventory is for the
year 2002. The budget you propose for the trading program is 1.2
million tons. The projected emissions inventory total for the year
2018, using the year 2002 inventory and growth projections, is 4
million tons per year. Application of BART controls on the
population of sources subject to BART would achieve 2.5 million tons
per year of reductions. Subtracting this amount from the project
inventory yields a value of 1.5 million tons. Because your selected
budget of 1.2 million tons is less than this value, it achieves a
better than a BART-equivalent emission total.
4. How Do I Ensure That Trading Budgets Achieve ``Greater Reasonable
Progress?''
In some cases, you may be able to demonstrate that a trading
program that achieves greater emissions progress may also achieve
greater visibility progress without necessarily conducting a detailed
dispersion modeling analysis. This could be done, for example, if you
can demonstrate, using economic models, that the likely distribution of
emissions when the trading program is implemented would not be
significantly different than the distribution of emissions if BART was
in place. If distribution of emissions is not substantially different
than under BART, and greater emissions reductions are achieved, then
the trading program would presumptively achieve ``greater reasonable
progress.''
If the distribution of emissions is different under the two
approaches, then the possibility exists that the trading program, even
though it achieves greater emissions reductions, may not achieve better
visibility improvement. Where this is the case, then you must conduct
dispersion modeling to determine the visibility impact of the trading
alternative. The dispersion modeling should determine differences in
visibility between BART and the trading program for each impacted Class
I area, for the worst and best 20 percent of days. The modeling should
identify:

--The estimated difference in visibility conditions under the two
approaches for each Class I area,
--The average difference in visibility over all Class I areas impacted
by the region's emissions. [For example, if six Class I areas are in
the region impacted, you would take the average of the improvement in
deciviews over those six areas].
The modeling study would demonstrate ``greater reasonable
progress'' if both of the following two criteria are met:

--Visibility does not decline in any Class I area, and
--Overall improvement in visibility, determined by comparing the
average differences over all affected Class I areas.

Example: Assume that ten Class I areas are affected. You would
take the average deciview improvement from BART for each of the ten
Class I areas--one value for each Class I area--and average them
together. If the ten values are 2.5, 3.9, 4.1, 1.7, 3.3, 4.5, 3.1,
3.6, 3.8 and 4.5, then the average deciview improvement from BART
for the ten Class I areas is 3.5 deciviews. Therefore, the average
of the ten deciview values for the trading program must be 3.5
deciviews or more.
5. How Do I Allocate Emissions to Sources?
Emission allocations must be consistent with the overall budget
that you provide to us. We believe it is not appropriate for us to
require a particular process and criteria for individual source
allocations, and thus we will not dictate how to allocate allowances.
When developing an allocation methodology, the State or regional
planning organization should consult with any Indian Tribes located
within the trading area, regardless of whether BART-eligible sources
are currently on Tribal lands. We will provide information on
allocation processes to State, Tribal, and local agencies, and to RPOs.
6. What Provisions Must I Include in Developing a System for Tracking
Individual Source Emissions and Allowances?
1. In general, we expect regional haze trading programs to contain
the same degree of rigor as trading programs for criteria pollutants.
In terms of ensuring the overall integrity and enforceability of a
trading program, we expect that you will generally follow the guidance
already being developed for other economic incentive programs (EIPs) in
establishing a trading program for regional haze. In addition, we
expect that any future trading programs developed by States and/or
regional planning organizations will be developed in consultation with
a broad range of stakeholders.
2. There are two EPA-administered emission trading programs that we
believe provide good examples of the features of a well-run trading
program. These two programs provide considerable information that would
be useful to the development of regional haze trading programs as an
alternative to BART.
3. The first example is our acid rain program under title IV of the
CAA. Phase I of the acid rain reduction program began in 1995. Under
phase I, reductions in the overall SO₂ emissions were
required from large coal-burning boilers in 110 power plants in 21
midwest, Appalachian, southeastern and northeastern States. Phase II of
the acid rain program began in 2000, and required further reductions in
the SO₂ emissions from coal-burning power plants. Phase II
also extended the program to cover other lesser-emitting sources.
Allowance trading is the centerpiece of EPA's acid rain program for
SO₂. You will find information on this program in:
(1) Title IV of the CAA Amendments (1990),
(2) 40 CFR part 73 at 58 FR 3687 (January 1993),
(3) EPA's acid rain Web site, at
http://www.epa.gov/acidrain/trading.html.

[[Page 25232]]

4. The second example is the rule for reducing regional transport
of ground-level ozone (NO_X SIP Call). The NO_X SIP
Call requires a number of eastern, midwestern, and southeastern States
and the District of Columbia to submit SIPs that address the regional
transport of ground-level ozone through reductions in NO_X.
States may meet the requirements of the rule by participating in an
EPA-administered trading program. To participate in the program, the
States must submit rules sufficiently similar to a model trading rule
promulgated by the Agency (40 CFR part 96). More information on this
program is available in:
(1) The preamble and rule in the Federal Register at 63 FR 57356
(October 1998),
(2) The NO_X compliance guide, available at http://www.epa.gov/acidrain/modlrule/main.html#126,
(3) Fact sheets for the rule, available at
http://www.epa.gov/ttn/rto/sip/related.html#prop,
(4) Additional information available on EPA's Web site, at
http://www.epa.gov/acidrain/modlrule/main.html.
5. A third program that provides a good example of trading programs
is the Ozone Transport Commission (OTC) NO_X budget program.
The OTC NO_X budget program was created to reduce summertime
NO_X emissions in the northeast United States. The program
caps NO_X emissions for the affected States at less than half
of the 1990 baseline emission level of 490,000 tons, and uses trading
to achieve cost-effective compliance. For more information on the
trading provisions of the program, see:
(1) Memorandum of Understanding (MOU), available at
http://www.sso.org/otc/att2.HTM,
(2) Fact sheets available at
http://www.epa.gov/airmarkets/otc/,
(3) Additional information, available at
http://www.epa.gov/acidrain/otc/otcmain.html.
6. We are including in the docket for this rulemaking a detailed
presentation that has been used by EPA's Clean Air Markets Division to
explain the provisions of NO_X trading programs with State
and local officials. This presentation provides considerable
information on EPA's views on sound trading programs.
7. We recognize that it is desirable to minimize administrative
burdens for sources that may be subject to the provisions of several
different emission trading programs. We believe that it is desirable
for any emission trading program for BART to use existing tracking
systems to the extent possible. We believe that any trading program
established by States for BART should be fully consistent with the
recently proposed NO_X/SO_X Transport rule. Should
the transport rule not be in effect for the same time period or in the
same States as any BART trading program, we recommend that States and/
or regional planning organizations should conduct additional technical
analyses to determine whether the time periods for tracking of
allowances under other existing programs (i.e., annual allowances for
SO₂ for the acid rain program, and allowances for the ozone
season for NO_X) are appropriate for purposes of
demonstrating greater reasonable regional progress vis a vis BART.
Further, we recommend that you conduct any such analysis in conjunction
with the timelines for development of SIPs for regional haze.
7. How Would a Regional Haze Trading Program Interface With the
Requirements for ``Reasonably Attributable'' BART Under Sec. 51.302 of
the Regional Haze Rule?
1. If a State elects to impose case-by-case BART emission
limitations according to 40 CFR 51.308(e)(1) of the regional haze rule,
then there should be no difficulties arising from the implementation of
requirement for ``reasonably attributable'' BART under 40 CFR 51.302.
However, if a State chooses an alternative measure, such as an
emissions trading program, in lieu of requiring BART emissions
limitation on specific sources, then the requirement for BART is not
satisfied until alternative measures reduce emissions sufficient to
make ``more reasonable progress than BART.'' Thus, in that period
between implementation of an emissions trading program and the
satisfaction of the overall BART requirement, an individual source
could be required to install BART for reasonably attributable
impairment under 40 CFR 51.302. Because such an overlay of the
requirements under 40 CFR 51.302 on a trading program under 40 CFR
51.308 might affect the economic and other considerations that were
used in developing the emissions trading program, the regional haze
rule allows for a ``geographic enhancement'' under 40 CFR 51.308. This
provision addresses the interface between a regional trading program
and the requirement under 40 CFR 51.302 regarding BART for reasonably
attributable visibility impairment. (See 40 CFR 51.308(e)(2)(v)).
2. We recognize the desirability of addressing any such issues at
the outset of developing an emissions trading program to address
regional haze. We note that the WRAP, the planning organization for the
nine western States considering a trading program under 40 CFR 51.309
(which contains a similar geographic enhancement provision), has
adopted policies which target use of the 51.302 provisions by the
Federal Land Managers (FLMs). In this case, for the nine WRAP States,
the FLMs have agreed that they will certify reasonable attributable
impairment only under certain specific conditions. Under this approach,
the FLMs would certify under 40 CFR 51.302 only if the regional trading
program is not decreasing sulfate concentrations in a Class I area
within the region. Moreover, the FLMs will certify impairment under 40
CFR 51.302 only where: (1) BART-eligible sources are located ``near''
that class I area and (2) those sources have not implemented BART
controls. In addition, the WRAP is investigating other procedures for
States to follow in responding to a certification of ``reasonably
attributable'' impairment if an emissions trading approach is adopted
to address the BART requirement based on the sources' impact on
regional haze.
3. The specific pollutants and the magnitude of impacts under the
regional haze rule and at specific Class I areas may vary in different
regions of the country. We expect that each State through its
associated regional planning organization will evaluate the need for
geographic enhancement procedures within any adopted regional emissions
trading program.

[FR Doc. 04-9863 Filed 5-4-04; 8:45 am]
BILLING CODE 6560-50-P

Notices For
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994

Regional Haze Regulations and Guidelines for Best Available Retrofit Technology (BART) Determinations

Local Navigation